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SEPA EPIC-1-MISC - PRELIMINARY ENVIRONMENTAL NEPA (1982)
PRELIMINARY ENVIRONMENTAL NEPA Southcenter Blvd EPIC- I -VIISC •7906 City of Tukwila 6200 Southcenter Boulevard Tukwila Washington 98188 Gary L. VanDusen, Mayor 29 :September 1982 Entranco Engineers. 1515 116th Ave. W.E. Bellevue, WA 98004 Attn: Ed Bersch.i.nski. Subject: Preliminary E.A. - Southcenter Boulevard As requested at our meeting of 21 September 1982, I have reviewed the Draft Environmental Assessment for the improvement of Southcenter Boulevard: I) Weed for the project - Discussion of modal interrelationship segment referencing Metro ve is too vague. The urgency of improving Southcenter Blvd. in particular, rather than general system -wide improvements, should be emphasized. (Pg. 5, 5th paragraph). - Environmental impact mitigation value of the project is included ,,,/'only by implication; a more concrete description of the project's favorable environmental consequences should be included. (_E.A. outline - line 175.) II) Description of proposed project ,Under permits needed (Page 9, last paragraph), delete Coast V Guard Bridge Permit and add FEMA Flood Plain Management Permit. Treatment of related actions (Page 11, 1st paragraph) too vague; % describe how the project has been "coordinated" with the other projects: (funding, environmental assessmennt_;' tirming ;. etc.). III) Impacts of the proposed action Air - We disagree with the assertion that no quantitative data pertinent Page -2- Entranco Engineers 29. September 1982 to project area air quality is available on the local level. The recently circulated DEIS for "Tukwila Hotel" contains an excerpt from the PSAPCA Air Quality Data Summary and the Quarterly Air Monitoring Data Summary published by D.O.E. which:. includes. .readings of ollutant product levels found at selected sub - regional monitoring ,la in the project vicinity from which at least some conclusions can be drawn. Suspended particulates and CO levels as project - related incremental increases to existing conditions: should be quanitified in the E.A. Water - Suggested editorial change to last sentence, Page 16, paragraph 1: t/4-..and includes the future maximum P -1 channel pumping capacity, at such time as this facility is placed in service. Land Use - We suggest that the project be analyzed for consistency with the transportation policy section of the City's Comprehensive Plan and ✓the Six -Year Street Plan, and that a generalized statement of compliance be included in the E.A. Risk of Upset - The existing conditions narrative should be expanded to reflect awareness of the I -405 corridor's status as a principal travelway for hazardous material shipments and the project's implications, if any, ,/ for expanding the volume of hazardous material traffic present in the community. Mitigating measures should include description of any hazardous incident control equipment or design features incorporated in the project such as fire standpipes, drain -grate covers, rescue access corridors or the like. Population Please indicate in the first line of the first paragraph on Page 28 that the 1980 census count is approximate. Transporation /Circulation - Table 1 (Page 32) indicates 6 property damage accidents during the reporting*periods but 10 injury incidents during the same time. It seems possible but not likely that there can be injuries without some damage to vehicles or surroundings. Please check if these figures are reversed. Energy - Exceptionally well- done: Page -3- Entranco Engineers 2R September 1982 . Utilities /Economic Impacts - Are utility relocation costs a part of project.funding, or are such costs to be borne by the respective agencies? Human Health - We disagree with the conclusion that this section is N /A. Following completion of WSDOT's air quality analysis described on Page 14, the affects of air- pollution products on human health, especially long -term exposure to nearby residents, as a function of the benefits or liabilities of the project, should be included in the E.A. both under "Air Quality" and "Human Health." Economic Impacts . required in the environmental assessment procedure outline ( Page 12, line 641), the effects of.the project on adjacent property values, especially the adjoining homesites; should be addressed. TV) Comments and coordination - Due to the critical interrelationship of alignment between Grady Way bridge and its associated approaches, and Southcenter Blvd. under alternative design #4, please emphasize verbal and written coordina- tion efforts with the City of Renton. We hope that these comments will be of value to your continuing work on the NEPA clearance process. We would of course appreciate the opportunity to comment on the supplemental studies on archaeology and air quality, as well as the completed draft E.A. Tukwil nning Department • M k Caughey ssociate Planner MC /blk xc: Senior Engineer Planning Director INTRODQCTICN 3 This outlin6 is intended as a guide to assist the preparers and 7 reviewers of Environmental Impact Statements and Environmental 8 Assessments to ensure that the documents prepared are complete and in 9 ccmpliance with the regulations of both NEPA and SEPA. 10 The purpose of this outline is to identify all possible subjects and 12 headings that may require evaluation of potential environmental 13 impacts during the preparation or review of environmental documents. 14 R. E. Bockstruck, P.E. Project Development Engineer Washingtcn State Department of Transportation APRIL a 1982 17 18 19 20 23 Federal Highway Administration 64 Region 10 65 e TITLE OF PROPOSED ACTION 68 CITY OR COUNTY OF ACTION. 70 ENVIRONMENTAL ASSESSMENT 72 (AND 4(f) EVALUATION 74 . PURSUANT TO P.L. 91 -190 76 U. S. DEPARTMENT CF TFANSPCRTATION FEDERAL HIGHWAY ADMINISTRATION and WASHINGTON STATE DEPARTMENT CF TRANSPORTATION and (LOCAL AGENCY) 78 79 81 83 85 87 90 DATE APPBCVED: 91 92 DATE DATE City cr County Engineer 94 APPBCVED: 95 R. E. Eockstrnck, F.E. 96 Project Developmert Engineer 97 Washington State Department 98 of Transrortation 99 101 APPBCVED: 102 Federal Highway Administration 103 Official 104 (Title Sheet for Local Agency Prcjects) 107 INDEX 110 I. Title Page 1 113 II. Table of Contents 2 115 III. Description cf Proposed Action .2 117 IV. Impacts cf the Proposed Action 3 119 A. Earth 3 .121 B. Air 3 122 C. Water 4 123 D. Flora 4. 124 E. Fauna 5 125 F. Noise 5 126 G. Light and Glare 5 127 H. Land Use 5 128 I. Natural Resources 6 129 J. Risk cf Upset 6 130 R. Population 6 131 L. Housing 6 132 1. Transportation /Circulation 7 133 N. Public Services 7 134. 0. Energy 7 135 P. Utilities 8 . 136 Q. Human Health 8 137 R. Aesthetics 8 138 S. Recreation 9 139 T. Archaeological /Historical 9 140 U. Economic Impacts o.. 9 141 V. Alternatives Considered . 10 143 VI. Comments and Coordination 11 145 ENVIRONMENTAL ASSESSMENT 152 I. TITLE PAGE - See example attached. 155 II. TABLE OF CONTENTS - Include all sections, illustrations and figures. 157 158 NEED FOR THE ACTION — Describe problem which proposal will 160 address, clearly dem.onstra.t.e-- that_a__need exists. Discussion .162 will form the basis for the “no action" discussicn in alternative section. Discussion should include, where 164 appropriate, the following needs, and should stress the need for 165 the project independent of projected traffic or use increases. 166 A. Transportation demand needs. B. Safety needs. C. Social service demands or economic development needs. D. Environmental impact mitigaticn needs. 168 170 173 175 E. nodal interrelationship needs (needs for transit service, 177 etc. 178 X F. System linkage needs - to complete a gap in transportation 181 system, etc. X G. Need to improve structural condition of existing facility. 184 X H. Legislative direction or inclusion in applicable transportation plans. 186 187 III. DESCRIPTION OF PROPOSED ACTION 190 A. One cr two paragraph histcry of development of the Eroposed .193 action. B. Describe length, termini, and logic of termini. 196 C. Describe proposed improvements, including number of lanes or tracks, access control, interchange and structure locations, bicycle and pedestrian facilities, if any. 198 199 200 D. Identify schedule of proposed construction and completion 202 of action. 203 E. Identify permits needed. 205 F. Identify future additions, expansions, or related actions. 208 G. Identity the cost of the proposed action. 210 Iv. IMPACTS CF THE PROPOSED ACTION - In discussing impacts, describe 213 the physical setting of the proposal and include any other 214 information needed to give an accurate understanding of the 216 environmental setting cf the proposal including existing traffic .217 flow and vehicle circulation patterns. All environmental 219 factors mentioned in the SEPA Checklist or the Department's EIS 220 outline must be addressed, unless it is clear without explanation that there are no impacts involved. Otherwise, 222 include an explanation of who no impacts result. Where 223 possible, quantify impacts identified. A. Earth 226 1. Describe the existing terrain and soils in the project 229 area. 2. Evaluate possible impacts caused by project such as: 233 a. Unstable earth conditions. 235 b. Changes in topography - landslides, settling, 238 etc. c. Excavation, embankment, or overcovering of soil. 240 Consider pit sites, etc. Quantify excess excavation 242 and identify if waste sites are State cr Contractor 243 provided. d. Increase in wind or water erosion. 245 e. Deposition or erosion of beach sands, river beds, 247 bays, etc. 248 f. Changes in siltation. 250 3. Identify mitigation measures proposed. - 252 B. Air ; c .CS --1------e x-1--C\ S-L 7-. - I , 255 1. Describe the existing air quality. 257 2. Evaluate possible impacts caused by the project such 261 as: a. Air emissions or deterioration of ambient air quality - consider impacts of both construction and operation. b. Creation of objectionable odors. c. Alteration of air movement, moisture, temperature, or climate. 263 264 266 268 269 3. Identify mitigation measures proposed. 271 -6- C. Water 274 1. Describe the existing water quality in the area. 277 2. Evaluate possible impacts caused by the project such 281 as: a a. Changes in currents or the course and direction 283 of water movement. 284 b. .Changes in abscrpticn rates, drainage, patterns, 286 or the rate and amount of surface water runoff. 287 c. Alterations to the course or flow of flood 290 waters. d. Change in the amount of surface water in any 292 water Cody. 293 e. Discharge into surface water or alteration of 295 surface eater guality resulting from erosion, 296 sedimentation, spillage from trucks, deicing and weed 297 control sprays, etc. f. Alteration of the direction or rate of flow of 299 ground waters. 300 g. Change in the quantity cf ground waters. 302 h. Deterioration in ground water quality. 304 i. Reduction in the amount of water otherwise 306 available for public water supplies. 307 j. Flood plain impacts. 309 3. Identify mitigation measures proposed. 311 D. Flora 314 1. Describe the existing flora in the area. 316 2. Evaluate possible impacts caused by the project, such 320 as: a. Change in the diversity cf species. 322 b. Reduction in the numbers of unique, rare or 324 endangered species. 325 c. Introduction of new species. 327 d. Reduction in critical habitat of unique, rare, or endangered species or the acreage of any agricultural crop. 329 330 3. Identify mitigation measures proposed. 332 E. Fauna 335 1. Describe the existing fauna in the area. 337 �. Evaluate possible impacts caused by the project, such 341 as: a. Changes in the diversity of species. 343 b. Reduction in the critical habitat of or numbers 345 of, any unique, rare or endangered species. 346 c. Introduction of new species. 348 d. Deterioration of existing fish or wildlife 350 habitat. 351 3. Identify mitigation measures proposed. 353 F. Noise 356 1. Describe the existing noise levels in the area. 359 2. Evaluate the possible impacts caused by the project 362 due to noise increases. Identify residences and buildings 364 affected. Include impacts of both construction and 365 operation. 3. Identify mitigation measures proposed. 367 G. Light and Glare 370 1. Describe the existing light and glare in the area. 373 2. Evaluate the possible impacts of the ,project. 377 3. Identify mitigation measures proposed. 379 H. Land Use 382 1. Describe the existing land use in the area. 385 2. Evaluate the possible impacts to land use resulting 388 from the project. Include impacts on minorities, lower 390 income residents, and their neighborhoods. 391 a. Taking of land for right -of -way. 393 -8- b. Increased accessibiltiy. c. Induced secondary development in region. d. Consistency with state and local plans. 3. Identify mitigation measures proposed. 395 397 399 401 I. Natural Resources .404 F 1. Describe the existing natural resources in the area. 407 2. Evaluate possible impacts caused by the project, such 411 as: a. Increase in the rate of use of any natural 413 resources. 414 b. Depletion of any non- renewable natural resources. 417 c. Taking of resources for right -of -way and 419 construction materials - quantify amounts. 420 3. Identify mitigation measures proposed. 422 J. Fisk cf Upset 425 1. Describe the existing risk of upset (explosion or 427 release cf hazardous substances) in the .project area. 428 2. Evaluate possible impacts cf the proposal relative to 432 increasing cr decreasing the risk of upset. 3. Identify mitigation measures proposed. 434 K. Population 437 1. Describe the existing population make -up density, and 439 growth rate in the area. 440 2. Evaluate the possible impacts tc these population 443 factors caused by the project. 444 3. Identify mitigation measures proposed. 446 L. Rousing 449 1. Describe the existing housing in the area. 452 2. Evaluate the effect the proposal will have on existing 455 housing and the tendency cf the proposal to create demand 456 for additional housing. Consider housing taken for right- 458 of -way. Consider impacts on minorities and low income 1159 groups. If homes and occupants are displaced by this 460 -9- acticn, a discussion of the 206 Housing Program together with a commitment tc ,provide that housing should be included. If homes and occupants are displaced by thiE action, a discussion of the 206 Housing Program together with a commitment to provide that housing should be included. 461 462 464 466 3. Identify mitigation measures proposed. 468 F M. Transporta_tionLCirculation 471 1. Describe the relationship of the proposal to existing 473 transportation facilities in the area. 474 2. Evaluate the possible impacts caused by the project 477 such as: 478 / a. 'Generation of additional vehicular movement; 480 impact on efficiency of existing transportation 481 facilities and need for maintenance. 482 b. Effects cn existing parking facilities or demand 484 for new parking. 485 c. ✓Impact upon existing transportation systems and accessibility of project area. d. Alteration to present patterns of circulation or movement of people and/or goods. e. Alterations to waterborne, rail or air traffic. f. Increase in safety hazards to motcr vehicles, bicyclists or pedestrians. 3. Identify mitigation measures proposed. 487 488 490 491 494 496 497 499 N. Public Services 502 1. Describe the existing public services in the area. 505 2. Evaluate the possible impacts caused by the project, 508 such as: 509 a. Fire and police protection. b. Religious and social institutions. c. Schools. d. Social services. e. Other governmental services. -10- 511 513 515 517 519 3. Identify mitigation measures proposed. 521 O. Energy 524 1. Description of existing energy use in the area. 527 2. Evaluate the possible impacts on energy use caused by 530 the Eroject, such as: 531 a. Energy needed for construction. Identify period 534 of operation time needed to Fay back this amount of 535 energy. b. Energy consumed on the completed facility. c. Energy consumed in the region. Effect of the project on vehicle miles traveled. 537 540 d. Eemand upon existing sources of energy, or 542 requirement of development of new sources of energy. 543 3. .Identify mitigation measures propcsed. 545 P. Utilities 548 1. Describe the existing utilities in the area. 551 2. Evaluate the impacts of the Froject cn (or possible 554 generation cf the need for new systems or alterations to 555 existing) utilities such as: 556 a. Power or natural gas. 558 b. Communications systems. 560 c. Water. 562 d.. Sewer or septic tanks. 564 e. Storm water drainage. 566 f. Solid waste and disposal. 568 3. Identify mitigation measure proposed. 570 Q. Human Health 573 1. Description of existing human health in the area if 5.76 applicable. 2. Evaluate the Fossible impacts the project may cause 579 relative to the creation of any health hazard. 580 3. Identify mitigation measures proposed. 582. R. Aesthetics 585 1. Describe the existing aesthetic values in the area. 588 2. Evaluate the possible impacts caused by the project 591 relative tc: 592 a. Obstruction of any scenic vista or open _view. 595 b. Creation of an aesthetically offensive site open 597 to the public view. 598 3. Identify mitigation measures proposed. 600 S. Recreation 603 1. Describe the existing parks and recreation facilities 605 in the area. 606 2. Evaluate the possible impacts on the quality or quantity of existing recreational opportunities. 3. Identify mitigation measures proposed. 609 610 612 T. ArchaeologicalzHistorical 615 1. Identify archaeological or historical resources in the 618 area. 2. Evaluate possible impacts cf the proposal on 621 archaeological or historical sites, structures, objects, or 622 buildings. 3. Identify mitigation measures proposed. 624 U. Economic Impacts 627 1. Describe the existing economic conditions in the area 629 - employment, property values, taxes, and overall output of 630 goods and services. 2. Evaluate the possible impacts caused by the project 633 such as: 634 a. Effect on employment. 636 b. Effect on businesses by access control or 638 displacement. 639 c. Effect on property values. 641 d. Effect on tax revenues. 643 e. Effect of project expenditures and investment on 645 the public and private development cf the project area 646 and its overall output cf goods and services. 647 V. ALTERNATIVES CONSIDERED - Discuss any alternatives to the proposed action which were considered and why they are not proposed fcr action. 649 650. A. The No Action Alternative 653 �. Description of alternative. 655 2. • Impacts of alternative. Describe, where relevant, the 659 impacts of this alternative upon each cf the impact areas 660 listed above. If, and only if, it is clear without • 661 discussion that there are no impacts in certain areas, the 662 EA should include a statement that only those impact areas 663 with impacts are discussed. In such case, a "no impact" 664 one liner is not needed in the impact areas where there are 665 no impacts. 3. Conclusion - A conclusionary statement relative to the 667 alternative considered should include the following type of 668 language, !Due to the followirg environmental impacts 669 associated with not constructing the proposed facility the 670 no action alternative is not felt to be a reasonable 671 alternative: "(1) ; j2) . ; (3) 672 , etc. B. Corridor B.z_Corridor Ct etc. 675 1. Description of alternative improvement - design 677 configuration etc. 678 2. Impacts of alternatives as appropriate - see above. 682 3. Conclusion - see above. 684 C. Desicn Options A. B. etc. etc. (where relevant) 687 1. Description of alternative improvement. 2. Impact of alternative as appropriate - see above. 3. Conclusion - see above. 689 693 695 D. Improve Existing Facility 698 1. Description of alternative improvment - design etc. 701 2. Impacts of alternative as appropriate. See above. 705 3. Conclusion - see above. 7C7 -13- VI. COMMENTS PND COCRDINA ION - Describe all early ccm ;eats and 710 coordination efforts, all comments received from gcvernment 711 agencies and the public, and all agencies and persons consulted. 712 D 0 T nevi's o°, °,7a DATE: FROM: Phone: To: January 6, 1981 R. S. Nielsen /J. B r ti DEPARTMENT OF TRANSPORTATION INTRA- DEPARTMENTAL COMMUNICATION SUBJECT: FHWA /UMTA Environmental Impact and Related Procedures v, D. Zirkle /T..R. Burke D. P. Swanson /D. W. O'Brien A. R. Morrell /R. C. Cook R. L. Carroll /G. L. Edwards R. C. Schuster /W. I. Hordan W. R. Horning /E. W. Ferguson Attached for your information is a copy of the FHWA and UMTA Final Rule on 'Environmental Impact and Related Procedures and an abstract of its significant changes and provisions. This Rule was previously sent to your respective Environmental Coordinators for their information and use on upcoming projects. Although this rule was effective on December 29, 1980 the Appendices to it, which includes the format and content requirements for the various environmental documents, will be published at a later date. This information will be sent to you as soon as it is available. If you have any questions concerning these provisions, please feel free to contact this office for further discussion. RSN:F21 / 103 JB Attachment cc: A. D. Andreas K. M. Eggen R. E. Bockstruck - FEDERAL HIGHWAY ADMINISTRATION AND URBAN MASS TRANSPORTATION ADMINISTRATION ENVIRONMENTAL IMPACT AND RELATED PROCEDURES SUMMARY Section 771.109 Applicability and Responsibility Final EIS's accepted by the Administration (FHWA or UMTA) prior to July 30, 1981 whose Drafts were filed with the EPA prior to July 30, 1979 (for FHWA Novmber 30, 1979) may be developed in accordance with the regulations in effect at the time this Draft document was filed. All Final EIS's accepted by the Administration after July 30, 1981, whose Drafts were filed with EPA prior to July 30, 1979 (for FHWA November 30, 1979) will be developed in accordance with these regulations except that a Record of Decision will not be required. It will be the responsibility of the applicant to implement those mitigation measures stated as commitments in the environmental documents. Section 771.111 Early. Coordination and Project Development No EIS or EA is required at the systems planning - stage; however, the information developed at this stage should be used to identify the probable classification of the proposed action. Section 771.113 Timing of Administration The design work needed to make the necessary engineering and environmental - decisions to complete a Finding of No Significant Impact (FONSI) or an EIS will be completed. Other design work, property acquisition (other than hardship or protective buying) or construction shall not proceed until the project has been classified as a Categorical Exclusion; or a FONSI has been adopted; or a Final EIS has been adopted and circulated and a Record of Decision has been prepared and signed; and the FHWA Division Administrator has received and accepted the required public hearing transcripts, etc. Section 771.115 Classes of Actions There are three classes of actions which are similar to past ,adtian classifications, but are now referenced as follows: • :)•-c Class I - An action that my significantly affect the environment and require the preparation of an EIS. Class II - Actions that do not individually or collectively have a significant effect on the environment. These actions will not • require the preparation of an EIS or an EA. These actions are Categorical Exclusions (CE). Class III - Actions in which the significance of the impacts on the environment are not clearly established. All actions in this class require the preparation of an Environmental Assess- ment (EA). Section.771.117 Categorical Exclusions The CE listing is a national list of projects which are not normally anticipated to result in a significant impact on the environment. Proposals meeting the criteria will not require environmental documentation other than the Interdisciplinary Environmental Evaluation and Classification Summary. Section 771.117 Environmental Assessments (EA) During the development of the EA, early consultation with interested agencies and individuals is stressed. This early coordination will be accomplished through the Action Plan process (community involvement) or through a scoping process. The EA need not be circulated for review and comment. But must be made available for public inspection. A Notice of Availability of the EA must be submitted to the state and areawide clearinghouses. When a public hearing is required, the EA must be prepared prior to the hearing. The Hearing Notice will include the Notice of Availability of the EA. • When a public hearing is not planned, a Notice similar to the Public Hearing Notice must be published in the local newspapers identifying the proposal, the availability of the EA and inviting comments on the action. A 30 day comment period (from the date of Notice publication) shall be provided. Section 771.121 Findings of No Significant Impact (FONSI) The FONSI is a separate written "finding" by the Administration that the project will not result in significant impacts to the environment. A Notice of Availability must be sent to the State and areawide clearinghouses by the applicant. • If a FONSI has been made by another Federal agency, the Administration can evaluate the information and if it is determined that the proposed action is adequately considered the Administration will issue its own .FL3NSI incorporating the other agency's FONSI. 1 _,•4 I 2 Section 771.123 Draft Environmental Impact Statements When the decision has been made that the project will cause a significant ,impact on the environment and an EIS will be required a Notice of Intent to prepare an EIS will be prepared and published in the Federal Register. We are "encouraged" to announce the intent to prepare an EIS, by appropriate means, at the local level. After publication of the Notice of Intent the applicant will begin the Scoping Process. For FHWA projects "scoping" is normally achieved through the Action Plan process. For UMTA projects a scoping meeting will normally be held. If scoping meetings are planned, it will be announced in the Federal Register and local area Notice. The Draft EIS shall discuss all reasonable alternatives to the proposed action, summarize the studies, reviews, coordination and consultation with other agencies. For projects in urbanized areas, the EIS must reflect the involvement of the Metropolitan Planning Organization (MPO). Alternatives to be considered shall be developed in consultation with the MPO. UMTA requires that a public hearing be held during the Draft EIS circulation period. The FHWA . public hearing requirements are contained in the Action Plan provisions. If a public hearing is held, the Draft EIS shall be made available 30 days in advance of the public hearing. The availability of the Draft EIS shall be included in any Public Hearing Notice. If a public hearing is not held, a Notice of Availability of the Draft EIS must be published in a similar manner as a hearing notice. The Draft EIS shall be furnished to State and Federal land management entitites which may be significantly affected by the proposal or its alternatives. Section 771.125 Final Environmental Impact Statements The Final EIS shall identify the preferred alternative, discuss substantive comments received on the Draft EIS and all reasonable alternatives considered, summarize citizen involvement and include a description of measures which will be followed to assure that all environmental mitigation measures are implemented. The views of the MPO regarding the preferred alternative shall be included. If significant issues or differences with interagency policies or evaluations remain, the Final EIS must identify this fact and the measures which were taken to resolve them. t A preliminary Record of Decision shall accompany the proposed Final EIS, during the internal review process. . Final EIS's prepared for the following type projects must receive prior concurrence from the Administration Office in Washington, D.C. before the Regional Administrator (FHWA) will sign the Document Title Sheet: 3 1) Any highway project on a new location in an urbanized area of over 100,000 population, or bypassing such an area. 2) Any new controlled access freeway. j 3) • New construction or extension of a fixed guideway transit system. 4) Any major transportation related development whose construction requires the preparation of an EIS (see % 771.115(a)(4)) if the proposed Administration grant assistance exceeds $5 million or if the proposed total cost of publicly and privately funded consruction is expected to exceed $50 million. 5) Any action to which a Federal, State or local government has indicated opposition on environmental grounds (which has not been resolved to the written satisfaction of the objecting agency). 6) Any action for which the Administration or the Office of the Secretary of Transportation requests that the FEIS be reviewed at the Washington Headquarters office. At the time the FEIS is distributed and filed with EPA, the applicant is responsible for making the FEIS available through state and areawide clearinghouses, publication of a notice of availability in local newspapers, and for furnishing the document to any person(s), organizations, or agencies that made substantive comments on the DEIS or requested a copy. 'At this time the FEIS shall be available for public review at the applicant's offices and at appropriate Administration offices. A copy should also be made available for public review at public institutions such as local government offices, public libraries, and schools, as appropriate. Section 771.127 Record of Decision (ROD) A Record of Decision shall be prepared and signed no sooner than 30 days after publication of the Final EIS Notice in the Federal Register. The ROD will summarize the factors considered in making the decision on the project. If at some future time the Administration wishes to take an action that was not identified as the proposed action in the Final EIS, or makes a substantial change to the mitigation measures or findings discussed in the ROD, a revised preliminary ROD shall be processed: Section 771.129 Reevaluation Prior to proceeding with the next major project approvals or authorizations we must assure the Administration that there has been no significant Change in the project proposal or the environmental conclusions as expressed in the Final EIS. If there has been a significant change in either the project scope, the proposed environmental impacts or the proposed mitigation measures, a supplemental Draft and Final EIS must be prepared. 4 A supplemental EIS will not be necessary if the Administration decides to fund an alternative adequately covered in the Final EIS but not identified as . the proposed action. The decision to prepare a supplemental EIS will not require a withdrawal of pr vious approvals. When a supplemental EIS is prepared, it is not necessary to initiate the scoping process again. A supplemental EIS will be prepared in the same manner as . a normal Draft and Final EIS. A Draft EIS is considered valid for three years. If an acceptable Final EIS is not prepared within this period, a written evaluation of the Draft EIS must be prepared prior to submitting the Final EIS. If major steps to advance the project have not been taken within three years of the approval of the Final EIS, a written evaluation of the EIS must be prepared. If, in either case (Draft or Final EIS) there has been significant changes in the proposed action, the affected environment, the anticipated impacts, or proposed mitigation measures, a new or supplemental EIS must be prepared and circulated. If major steps to advance the project have not taken place within five years of the approval of the Final EIS, the written evaluation required must be forwarded for review to the same offices which took approval action on the original EIS. Section 771.131 Emergency Action Procedures Deviations from these procedures due to emergency situations must be granted by the Administration's Washington, D.C. offices. Section .771.135 Section 4(f) of the DOT Act No action will use land from a significant publicly owned park, recreation area, or wildlife and waterfowl refuge or any significant historic site unless a determination is made that: 1) There is no feasible and prudent alternative to the use of land from the property; and 2) The proposed action includes all possible planning to minimize harm to the property resulting from such use. • ''g' Supporting information must demonstrate that there are unique problems or unusual factors involved in the use of alternatives and that the cost, environmental impacts, or community disruption resulting from such alternatives reaches extraordinary magnitudes. 5 Consideration under section 4(f) is not required when the Federal, State, or local official having jurisdiction over a park, recreation area, or refuge determines that "it" is not significant. The "it" in this case relates to the total park or recreation area. Fog purposes of section 4(f), a historic site is significant only if it is on or/ eligible for the, National Register, unless the Administration determines that • the application of section 4(f) is otherwise appropriate. Relating to other Federal lands, Section 4(f) applies only to portions of such lands that are being used or are designated for use . as being for park, recreation, wildlife or waterfowl refuge or historic purposes. Section 4(f) applies to all archeological sites on or eligible for inclusion on the National Register, including those discovered during construction, unless the Administration, after consultation with the State Historic Preservation Officer and the Advisory Council on Historic Preservation determines that the archeological resource is important chiefly for the information it contains and has minimal value for preservation in place. For sites discovered during construction, where preservation of the resource in place is warranted, the section 4(f) process will be expedited. In such cases, the evaluation of feasible and prudent alternatives will take account of the level of investment already made and the review process, including the consultation with other agencies, will be shortened as. appropriate. An action may proceed without consideration under Section 4(f) if the property interest in the Section 4(f) type lands was acquired for transportation purposes prior to its designation. The Section 4(f) evaluation shall be provided for coordination and comment to the official having jurisdiction over the section 4(f) property and to the Department of the Interior and, as appropriate, to the Department of Agriculture and the Department of Housing and Urban Development. A time limit of 45 days shall be established for receipt of comments. 2 /EP 1 • Categorical Exclusion (a) • PRESENT ENVIRONMENTAL PROCESS 'State Improvement Program] 1Proposed FHWA Action I Environmental Assessment i Public Hearing Opportunity, When Required Finding of No Significant Impact (a) NEPA process completed (b) State Action Plan requirements can be used to satisfy this step. 1 (a) i Decision to Prepare EIS 1 Notice of Intent in Federal Register • (b) Scoping Process I Draft EIS Public Hearing Opportunity, When Required 1 Final EIS Record of Decision 1 • LETTER OF TRANSMITTAL To Gii of 7 pert ENTRANCO Engineers ENVIRONMENTAL AND TRANSPORTATION CONSULTANTS Office: Attention' Re„."- k Cot-‘) Date* / 0 —1 2 - 1B - Job Title: � -�� es2_..�, 4-CAC �,� e.�-�e.+r'dL Job No' gap Location: Subjects . �Se.�S r►� fit" We are sending herewith via* We are sending under separate cover via: r No. of No. of No. of No. of Description Originals Sepias Prints (Other) 1.)(-0.1-4 u; tAgce--- -cS t ,AF-4 4 C A S , C 0 PAS D,r ,P 4-e 1 / ❑ For Approval ❑ For Your Information ❑ As Per Your Request ❑ Approved as Noted Remarks' c < nc_2� S , . pr- e., (} ,---‘; r\- r +- o--rc...4-■ ik S24- 4- u,-k.-- cal P(e -wSe✓ ci-e,....4._ . p f •i- 1 -, re , u.-.sL 4-O C.< < < 6.11s , z .44\4 6%--- 70 U' 1 ( ft-i'VCA 1'‘'•''-3 j : g-e -4 _ rte./ f' -e--er r o e-� e- -,- ----o____„j_, .r— e & . BELLEVUE, WASHINGTON By Cam/ 1515 - 116th AVE. N.E.. 98004 (206) 454 -0683 ❑ Returned for Corrections as noted n Please Re- submit >r� A -02.2 revised 12/80 N,,,ILA , • 4 City of Tukwila 0 .1908 6200 Southcenter Boulevard Tukwila Washington 98188 Gary L VanDusen, Mayor WSDOT -State and Office District State Aid Engineer . 6431 Corson Ave. So. Seattle, WA 98108 Attn: Don Hoffman, P.E. SUBJECT: Southcenter Blvd. Environmental Assessment - M- 1147(5) Enclosed are two (2) prelminary drafts of the E.A. for the above referenced project. Please note that special studies will be conducted for the air, noise, and archaeological /historical sections of this assessment; the necessary paperwork to contract these studies is presently being processed.. We request that your agency review .. this document for compliance with the approved format and also note your comments relative to content for completed sections. We will incorporate later the information made available by the special studies and revise those sections of the document accordingly. We feel that this early review will allow us to save processing time later by simply revising the air, noise, and archaelogical /historical sections according to the special studies prior to issuing the complete draft document. Also enclosed is a draft list of recipients of the draft E.A.; please suggest additions or deletions to this list. Thank you for your continued cooperation and prompt attention to this request. 'MC /blk xc: Entranco Engineers Ping. Dir. Senior Engr. TUKWILA 9'C NNING DEPT. Mar )(Caughey Associate Planner • • CITY OF TUKWILA Suggested Distribution List - Draft Environmental Assessment Federal 1) Environmental Protection Agency 2) US Army Corps._. of Engineers - Seattle District Office 3) Dept. of Agriculture, Soil Conservation Service 4) Dept. of Commerce U.S. Coast Guard State 1) Dept. of Transportation (Forward to WSDOT Envir. & FHWA Envir.) 2) Dept. of Game 3) Dept. of Fisheries 4) Office of Archaeology & Historic Preservation 5) Dept. of Ecology Regional 1) Metro - Transit & Water Quality Division 2) Puget Sound Air Pollution Control Agency 3) Puget Sound Council of Governments Local 1) City of Tukwila 2) City of Renton 3) City of Kent 4) City of Seattle 5) King County - Planning and Community Development 6) King County - Public Works Surface Water Mgmt. Division Utility /Services 1) South Central School District #406 2) Puget Sound Power and Light 3) Washington Natural Gas Co. Private Organizations 1) Tukwila Chamber of Commerce 2) Rainier Audubon Society • • DRAFT October 6, 1982 WSDOT - State Aid Office District State Aid Engineer 6431 Corson Avenue So. Seattle, WA 98108 Attn: Don Hoffman Re: Southcenter Boulevard; Environmental Assessment — M- 1147(5) Gentlemen: Enclosed are two (2) preliminary drafts of the E.A. for the above referenced project. Please note that special studies will be conducted for air, noise, and archaeological and historical sections of this assessment; the necessary paperwork to contract these studies is presently being processed. At this time, we wish to have this document reviewed for compliance with the approved format and also receive your comments relative to content for com- pleted sections. We will later incorporate the information made available by the special studies and revise those sections of the document accordingly. We feel that this early review will allow us to save processing time later by simply revising the air, noise, and archaeological and historical sections, and issuing the draft document. Also, enclosed is a draft list of recipients of the draft E.A. Please provide input for additions or deletions to this list. Thank you for your continued cooperation and prompt attention to this request. Sincerely, CITY OF TUKWILA CC, ✓o..c� E�.� n_c.erC • SOUTHCENTER BOULEVARD DRAFT ENVIRONMENTAL ASSESSMENT RECIPIENTS City of Tukwila Department of Planning 6200 Southcenter Blvd. Tukwila, WA 98188 WSDOT - State Aid Office (forward to WSDOT Environmental) District State Aid Engineer (forward to FHWA Environmental) 6431 Corson Ave. So. Seattle, WA 98108 WSDOT - District 1 District Administrator 6431 Corson Ave. So. Seattle, WA 98108 Washington State Dept. of Game 600 No. Capitol Way Olympia, WA 98504 Washington State Dept. of Fisheries 115 General Administration Bldg. Olympia, WA 98504 Puget Sound Air Pollution Control Agency 410 W. Harrison Seattle, WA 98119 Municipality of Metropolitan Seattle Transit Planning Exchange Bldg. - 821 Second Ave. Seattle, WA 98104 City of Renton 211 Mill Ave. So. Renton, WA 98055 King County Planning and Community Development W. 217 King County Courthouse Seattle, WA 98104 • Department of Array Seattle District Corps of Engineers P.O. Box C -3755 Seattle, WA 98124 PSCOG - King Subregional Council 655 - 120th N.E. Bellevue, WA 98005 pOE • • • • • •- • • • rRELL..l�A2Y- SUBJECT TO REVISLOI4 Federal Highway Administration Region 10 SOUTHCENTER BOULEVARD IMPROVEMENTS 62ND AVENUE SOUTH TO GRADY WAY CITY OF TUKWILA ENVIRONMENTAL ASSESSMENT PURSUANT TO P.L. 91 -190 U.S. DEPARTMENT OF TRANSPORTATION FEDERAL HIGHWAY ADMINISTRATION and WASHINGTON STATE DEPARTMENT OF TRANSPORTATION and CITY OF TUKWILA Date Approved: Date City of Tukwila Approved: R.E. Bockstruck, P.E. Project Development Engineer Washington State Department of Transportation • Date Approved: Federal Highway Administration Official • • • • • TABLE OF CONTENTS PAGE TABLE OF CONTENTS i LIST OF FIGURES LIST OF TABLES NEED FOR THE PROJECT 1 DESCRIPTION OF PROPOSED ACTION 7 IMPACTS OF THE PROPOSED ACTION 12 A. Earth 12 B. Air 14 C. Water 16 D. Flora 20 E. Fauna 22 F. Noise 23 G. Light and Glare 26 H. Land Use 27 I. Natural Resources 28 J. Risk of Upset 29 K. Population 30 L. Housing 30 M. Transportation /Circulation 31 N. Public Services 43 0. Energy 46 P. Utilities 47 Q. Human Health 48 R. Aesthetics 48 S. Recreation 50 T. Archaeological /Historical 50 U. Economic Impact 50 ALTERNATIVES CONSIDERED 52 COMMENTS AND COORDINATION 57 APPENDIX A • • • • • • ' • • LIST OF FIGURES FIGURE NUMBER PAGE 1 Project Vicinity 2 2 Project Location 3 3 Existing Alignment 7 4 Recommended System 10 5 1981 Average Weekday Traffic 31 6 1990 No Build Average Weekday Traffic 35 1990 Recommended Alternative Average Weekday Traffic 36 8 Proposed Alternatives 51 • • • • • • • • LIST OF TABLES TABLE NUMBER. PAGE 1 1979 -1981 Accidents 32 2 1990 Level of Service 37 3 1990 Accidents 39 • NEED FOR THE PROJECT • Southcenter Boulevard is an important east /west roadway that serves as an alternative route to a heavily congested section of I -405 for trips between Renton and Tukwila. The portion of Southcenter Boulevard scheduled • for improvement lies between 62nd Avenue S. and Interurban Avenue. It is currently a narrow, curving two -lane road with unpaved shoulders and open drainage. West of 62nd Avenue S., the street widens to five lanes with curb and gutter, sidewalk, and closed drainage. East of the project, Grady Way is being widened to five lanes with curb, gutter, and sidewalk. • Southcenter Boulevard curves north along the west side of the Green River, • • • - • intersecting Interurban Avenue approximately 600 feet north of the intersection of Grady Way and Interurban Avenue. The resulting offset between Southcenter Boulevard and Grady Way requires that east /west traffic make a weaving movement between the two intersections. There is limited left -turn storage on Interurban Avenue, which frequently overflows into the through lanes during peak hours. Traffic signals are currently located just west of the project at the intersection of 61st Avenue S. and Southcenter Boulevard, at the Interurban Avenue /Southcenter Boulevard intersection, and at the Interurban Avenue /Grady Way intersection. The speed limit is 35 mph. The 1981 average weekday traffic count is.8,800 vehicles per day. Southcenter Boulevard /Grady Way has a functional classification of "minor arterial" from I -5 into Renton. Interurban Avenue (SR -181) has a functional classification of "principal arterial." Geometry along the existing roadway is poor, with a series of short radius, horizontal reverse curves connected by short, straight segments. Sight distance is limited due to the adjacent topography and the roadway profile. The Green River and the I- 405 /SR -181 interchange ramps are major obstacles to improving the alignment for this section of Southcenter Boulevard. The present alignment and narrow roadway increase travel time and congestion in the corridor, which reduces the effectiveness of Southcenter Boulevard /Grady Way as an alternative east /west route to I -405. • Mountlake Terrace ® Brier Kenmore BoIhtll''r- ) Ind,anole lj. c_ Poul:bo kn II L,:, i`� :Tr; r' .i Suquamish ;I ' Agaf. lb N,f ♦1,., . ` L ,s T. ratt KerPM 1 11.;7c,,,%4 I � Ilod •. -.t 101$ J8 • 1- 1.1 P nr r l..? • Rollin£ Bar f .ti 'To•oselAeCl BANBRIDGI m .. r B r- Porte , 1 red ik ': 11----) ' 1'Un` % :..JIQJt. ' pr. ., .i:: ' :ISLAND_ '_ `.. 'r..naf Pl 1 . I r : Trj �- : '1 _ 'Winslow l. (-';.1:1 \l\l!i��� / . r Par (Chico `' ?! .' -Y. Draws -rche II „tr Li Ilro._ "- •- -1= O Port Bakely .� i= . -c, J Pt y_Pr .'..t - � ra..' ' .•Du.em � • C^' .P ® I l .''T'• • Wan" ' Repar•wn,.' He al, !' `; \i�,• YBftRI! 0 � - � r ' 1r^r,` / e : •Be.ru�Pr WI! ftP% '''I' Pogo iki __ ^� ,r ' : ,U,chudR ,^..60 m:,r� n% 2 Bmwn,o ,'s iJ1^ '.111Q1Manchester Nnaeu,i II I I , v, Port I • %, r _: `o\Cokhester t•�, -" r�N OrehMd era�1 'Ir �, ) ' dote I - neat: 6. / rw Colby 1 / Fong / Wdlrnu r•'Va. on� ••- /S m. Bra i Soullworth • 3 yashon Heights A �- _ __ • ,I �rsloLwK� ... ^r !_ _ _- -. eo 3 =-/ / a % Do;an,n Pr i Redmond •• yam Beale - Alb.. ..1-*.1 .1 yI Pe,a, Dela° ••-' JA.... h _ \�-p;( IC19 Harbor ♦ ,..11.--- � ahleawn 0e ie..r .rc ea+o �• � .q — 0..n 'I' ply - •_`.1 ,I�, - 1 1,.141,,,, Tacomaa •\ '7'1. 0" • ftdefll • Way -- N�. tan, sr ti EMRANCO Engineers City Of Tukwila SOUTHCENTER BOULEVARD . 62nd Avenue South To Grady Way Figure 1 PROJECT VICINITY ♦ FT. DENT PARK unnun111n ENTRANCO Engineers City Of Tukwila SOUTHCENTER BOULEVARD 62nd Avenue South To Grady Way Figure 2 PROJECT LOCATION J • • • • • • The existing street system within the study area, particularly along SR -181, exhibits considerable operational problems. Through traffic from Grady Way to Southcenter Boulevard must turn right onto SR -181 and then left at the next intersection onto Southcenter Boulevard. Existing data indicate that this, as well as the reverse trip, is a high- volume movement, particularly during the p.m. peak hour. Although level of service calculations would indicate that this section of SR -181 would operate reasonably well, the high volume of left turns onto Grady Way causes considerable congestion. Left -turn storage is not adequate to handle the volume and cannot be lengthened due to the proximity of the two inter- sections. Vehicles back onto the through lanes, restricting traffic. Since these intersections are quite close together, the backups can actually extend into the preceding intersection, blocking traffic there as well. The operation of the section more closely resembles the level of service at the worst intersection, that being level D -E. The Department of Transportation counted traffic on I -405 and the access ramps in 1981 in conjunction with its high occupancy vehicle (HOV) study. These counts showed that freeway lanes through Tukwila are now operating at or near capacity during peak hours. Even with the additional HOV lanes proposed for I -405, the freeway lanes will be operating at capacity during peak hours. Traffic volume between 1981 and 1990 is expected to increase considerably in the Tukwila area. The Tukwila Micro -Model Study, completed by Entranco Engineers in 1981, forecast a growth of 33 to 46 percent in vehicle trip ends over the ten -year period between 1980 and 1990 for the commercial - industrial area. The Southcenter Boulevard /Grady Way system is the only parallel arterial serving the I -405 corridor. It presently does not function adequately as an alternative route to I -405 for local traffic, partially due to the alignment shift at Interurban Avenue. The comprehensive street plans for the city of Tukwila and the city of Renton, as well as regional • • • • • • • goals of the Puget Sound Council of Governments, include an improved east /west arterial in this corridor. The roadway section proposed by this project is the final link in the route. Sixty -three accidents have been reported along this section of roadway over the last three years, resulting in 19 injuries. There have been two major types of accidents: intersection accidents involving turning or stopped vehicles, and accidents along the narrow curving roadway between 68th Avenue S. and SR -181 and between the Grady Way Bridge and SR -181, usually caused by a driver losing control of his vehicle. With increasing traffic volumes, the number of accidents is expected to increase. At the intersections, the level of congestion will increase and with it the accident rate. With the completed project, future accident rates are predicted to be below existing levels. Metro Transit's adopted 1990 plan includes a package of major service improvements in Tukwila aimed at creating a Regional Transit Center in the Southcenter /Andover Park area. This Regional Transit Center will be a transit focal point, and will coordinate transfers between local routes and through routes going to the Seattle CBD and to other activity centers. Current transit service focuses on downtown Seattle and on peak hour service. Future plans are to expand service to all day on existing routes and provide new service to areas that are currently without adequate transit service. The timely movement of buses on the street system is critical for the implementation of Metro's plan. Metro has requested that turn lanes and radii, signalization, and channelization improvements be made throughout the route system, and has specifically noted the need for these.improve- ments on Interurban Avenue and Southcenter Boulevard as being essential to facilitate the movement of transit vehicles (see Metro memorandum of January 28, 1982, "Comments and Coordination" section). • • • • • The Tukwila Park Department's plan for sidewalks and trails includes the junction of two major routes within the limits of the proposed Southcenter Boulevard improvements. An east /west sidewalk /bikeway connecting Tukwila and Renton is recommended for this corridor and is currently either completed or under construction outward from each terminus of this proposed project. The Christensen Greenbelt Trail extends from S. 180th Street to Tukwila Parkway. The proposed project would extend it to Fort Dent Park. There is currently no sidewalk in the project corridor. The Puget Sound Council of Governments has given a high regional priority to the Southcenter Boulevard improvements because of the major corridor it serves, the existing congestion in the corridor, and the project's significance as the final link in the route with improvement projects completed or under way on both ends. In summary, the proposed project will help reduce the existing environmental problems: 1. Traffic congestion and high accident rates. 2. Poor pedestrian access and safety along the corridor. 3: Restricted transit operations. 4. Limited function as an east -west arterial. To Fort Dent Park T co co SOUTHCENTER BOULEVARD PARKWAY NORTH City Of Tukwila SOUTHCENTER BOULEVARD Figure 3 EXISTING ALIGNMENT neers • • • • DESCRIPTION OF THE PROPOSED ACTION The Environmental Assessment coincides with a preliminary engineering study that addresses proposed improvements to Southcenter Boulevard. The proposed project will provide an improved connection between Renton and Tukwila along Southcenter Boulevard /Grady Way. The proposed project is located in the city of Tukwila adjacent to the north side of Interstate 405. Tukwila and its vicinity are shown in Figure 1. Figure 2 shows the project location. The project limits are 62nd Avenue S. on the west and Grady Way on the east, and include intersections with Interurban Avenue (SR -181), the southbound on /off ramps of I -405, 68th Avenue S. (Christensen Road), 65th Avenue S., and 62nd Avenue S. West of 62nd Avenue S., Southcenter Boulevard is a five -lane facility up to its connection with I -5. Grady Way improvements, which extend from the eastern terminus of this project, will soon be constructed, making Grady Way a five -lane facility. Upon completion of the Grady Way improvements, this project segment will exist as the remaining unimproved link in this vital east /west arterial. The existing roadway alignment is shown in Figure 3. In October 1981, the Tukwila City Council authorized Entranco Engineers to perform a preliminary engineering study to determine the nature of the design required to complete the unimproved segment of Southcenter Boulevard (Southcenter Boulevard, 62nd Avenue S. to Grady Way, September 1982). That study and this document have been prepared under the auspices of the Tukwila Department of Public Works and the Washington State Department of Transportation, State Aid Division. Funding for this project was made available through the Federal -Aid Urban Systems (FAUS) program. ,1 To Fort Dent Park T Connection Point Of Proposed Trail With Existing Sidewalk 4, To Fort Dent Park • • • • ® TER L_A 4p 5 m G 4 NORTH ENTRANCO Engineers ....P..", ••••, •rC'o h nr•r.M CMS.1•••15 TUKWILA PARKWAY Realignment Of Existing Roadway ' ' New Bridge Structure -+T► Widen Existing Roadway Close Existing Roadway • • • Proposed Trail System Sidewalk /Bikeway 111111111011 cc w 0 O w � Y z a City Of Tukwila SOUTHCENTER BOULEVARD 62nd Avenue South To Grady Way Connection Point Of Proposed Trail With Existing Christensen Greenbelt Park I Figure 4 RECOMMENDED SYSTEM J • Four basic• alternatives were developed and evaluated for this project. • The four alternatives are: (1) a "no- build" alternative that evaluated the effects of not improving the route; (2) widening the road to five lanes on the existing alignment; (3) constructing a high -level bridge between 68th Avenue S. and Grady Way spanning the Green River, the I -405 ramps, and • Interurban Avenue; and (4) realignment of the roadway between 68th Avenue S. and Grady Way, creating an at -grade intersection with Interurban Avenue. Alternative 4, realignment at grade, is recommended as the alternative that best meets the objectives of the project. Consistent with City policy, access to Southcenter Boulevard from Old Macadam Road right -of -way will not be allowed in any of the alternatives. • • • The recommended improvements are shown in Figure 4. The recommended roadway section for Southcenter Boulevard consists of two 12 -foot wide through lanes in each direction, with a 12 -foot wide two -way left -turn lane the full length of the project (approximately 3,500 feet). Curb and gutter with closed drainage are provided on both sides of the roadway, with an 8 -foot wide sidewalk /bikeway on the north side only. A new traffic signal will be installed at the Southcenter Boulevard /Grady Way /Interurban Avenue intersection, and at the Southcenter Boulevard /68th Avenue S. intersection, with minor revisions to the existing signal at the Fort Dent Park/ Interurban Avenue intersection. A continuous illumination system will be installed on Southcenter Boulevard and on the realigned I -405 ramps. Three new bridges are required for the recommended alignment, including one on Southcenter Boulevard spanning the Green River and two on the realigned I -405 ramps: one crossing the realigned Southcenter Boulevard and one crossing the Green River. The two proposed river crossings will be a three -span design having superstructures of prestressed concrete girders • with cast -in -place concrete deck slab. The Southcenter Boulevard Bridge and I -405 southbound ramp bridge over the Green River will have minimum vertical clearances to the 100 -year flood elevation of approximately 6 feet, as recommended by King County. The I -405 southbound ramps over • • Southcenter Boulevard will be two prestressed concrete box girder • superstructures having a minimum vertical clearance of 16' 6" to Southcenter Boulevard. • The proposed trail system element (see Figure 4) will begin at the intersection of Tukwila Parkway and Christensen Road /Christensen Greenbelt Park and progress northward along the Green River. It will pass under I -405 and realigned Southcenter Boulevard, then follow the old Southcenter Boulevard alignment from a connection with the proposed sidewalk /bikeway on the south to Fort Dent Park on the north. No designated park land will be affected by the implementation of this project. A small amount of right -of -way (0.06 acre) will be required for the recommended design at some street and driveway intersections and for rock wall construction in areas of steep cut slopes. Temporary easements will be required for cut slopes and property restoration during construction, and access control is proposed at the new ramp intersection with Interurban • Avenue. • • Depending upon foundation restrictions, environmental approvals, and permit limitations, the project could be under construction in the spring of 1984 and completed in the fall of 1986. Permits and approvals required for this project include: City of Tukwila Shoreline Management Substantial Development Permit State Flood Control Zone Permit State Department of Game and Fisheries Hydraulics Approval FEMA Floodplain Management Permit U.S. Army Corps of Engineers 404 Permit State of Washington Department of Transportation Design Approval Extensive coordination between this project and the I -405 NOV construction has been accomplished through numerous interstaff meetings. The WSDOT I -405 NOV design team has been kept up -to -date on the Southcenter Boulevard preliminary design to avoid conflicts and /or duplication of • effort on the separate projects. Coordination of this project is also being accomplished with WSDOT in conjunction with the proposed expansion/ relocation of the Christensen Road (T -line) Bridge. The design of the Christensen Greenbelt Trail has been coordinated with • WSDOT and the City of Tukwila Department of Parks and Recreation. The landscape architects who designed other portions of the trail, are members of the Southcenter Boulevard project team and work closely with the City Parks Department staff to assure. continuity. • • • Plans for the Grady Way Bridge Replacement were received from the City of Renton's consultant. The design of Southcenter Boulevard has been integrated into plans for the Grady Way Bridge. Coordination between the Cities of Renton and Tukwila will continue as further work on these two projects proceeds. The total estimated construction cost for the proposed alternative is $6,813,000 in 1982 dollars; estimated right -of -way costs are $40,000. Total project cost is $6,853,000. IMPACTS OF THE PROPOSED ACTION • A. Earth Existing Conditions • According to the U.S. Soil Conservation Service soil survey of the King County area, a small area of Newberg silt loam, an alluvial soil, is present near the existing intersection of Interurban Avenue and Southcenter • Boulevard. With this exception, soils in the rest of the project area are classified as "urban." This classification is interpreted to mean that there has been so much excavation, filling, and other general soil movement in the project vicinity that the soils in the area cannot be accurately • 12 • • • • • • • • • • identified as any particular soils series or complex. The survey notes that the Green River Valley fill generally ranges from 3 to 12 feet deep and ranges in composition from gravelly sandy loam to gravelly loam. The topography of the project area varies greatly. At its intersection with 62nd Avenue S., Southcenter Boulevard has an elevation of approxi- mately 60 feet above sea level. Eastward, the roadway slopes down gradually to about 30 feet above sea level at its intersection with 65th Avenue S. before rising to about 44 feet above sea level just west of the Green River, where the existing northward curve. begins. Following the bend of the river to the northeast, Southcenter Boulevard varies slightly in elevation before dropping to a level of about 35 feet above sea level at its intersection with Interurban Avenue. Just north of the roadway, between 62nd Avenue S. and the Green River, a steep bluff rises to a height of about 90 feet. South of the roadway, the land slopes down sharply to I -405, which has elevations ranging from about 25 to 30 feet in this area. East of the Green River, I -405 (with embankment elevations of 44 to 50 feet) is higher than the adjacent land, which lies approximately 24 to 28 feet above sea level. Environmental Impacts In constructing the project, soils will be disrupted and displaced. Road widening and storm drain installation along Southcenter Boulevard between 62nd Avenue S. and the Green River will require excavation, compaction, and overcovering of the soil. Fill will be needed for approaches to the two bridges over the Green River, for the realigned Southcenter Boulevard east of the river, and for the planned northward extension of the existing I -405 southbound on /off ramps. Embankments will be as high as 30 feet, altering the local topography. Some localized deep borings may be necessary for pier supports to elevate the I -405 ramps above the realigned Southcenter Boulevard. 13 • Approximately 14,000 cubic yards of soils will be excavated, and about • 34,000 cubic yards of fill will be required. Roadway widening and realignment and I -405 ramp extensions will add approximately 3.5 acres of impervious surfacing to the area. • During site preparation and construction activities, the presence of uncovered soils and stockpiled fill will increase the potential for erosion. • • Mitigating Measures The placement of embankments and other construction activities that have a potential for increasing erosion can be scheduled to avoid the rainy season. A number of methods and devices can be employed to control erosion during construction. These measures include the use of desiltation ponds, • construction staging to limit the amount of soils exposed in the project area at any one time, and covering or revegetation of exposed soils and stockpiled fill. • B. Air Existing Conditions National ambient air quality standards have been established to protect the public from air pollutants discharged from various sources (i.e., factories, autos). Of significance to the present and future usage of Southcenter Boulevard project are motor vehicle emissions that contribute • carbon monoxide (CO), oxides of nitrogen (N0x) and hydrocarbons (HC) to the atmosphere. These pollutants may concentrate under stagnant weather conditions and exceed health standards. They may also chemically react under the influence of sunlight to form photochemical oxidants (smog) that • can be harmful to human health, vegetation, and property. Also of • • significance to this project, especially during construction, is the generation of particulates (microscopic particles) which suspend in the atmosphere and impose visibility and health problems. Air quality in Tukwila falls under the jurisdiction of the Puget Sound • Air Pollution Control Agency (PSAPCA). By law, the standards set by any subfederal jurisdiction cannot be less stringent than the national standards. The standards adopted by the PSAPCA are identical to the national standards, with the exception that additional standards have been • promulgated for sulfur dioxides. PSAPCA records indicate that particulate levels in the Tukwila area have been increasing since 1975 and occasionally exceed:State standards. • • • • • • • Carbon monoxide is the only air pollutant that can be accurately quantified and predicted on a small -scale basis with existing technology and modeling programs. There was no CO monitoring data available from any federal, state, local, or private agency that was pertinent to the project area; therefore, current air quality conditions relative to CO standards are unknown. Existing air quality in the project area is affected largely by general urbanization and vehicular travel in the Tukwila region. The proposed site is shown on maps from the State Implementation Plan as being within the boundaries of nonattainment areas for carbon monoxide and photochemical oxidants. Environmental Impacts Construction activities will generate dust and other suspended particulates, which may result in short -term violations of air quality standards. Emissions from construction equipment and paving operations may also result in short -term air quality and odor impacts. • Some air quality impacts from increased traffic usage of the new facility can be expected. It is believed that the improved traffic flow • and reduced congestion resulting from construction of the new facility will be beneficial for air quality on a long -term basis. Most air quality degradation in the project area will continue to be related to vehicles using I -405, SR -181, and other nearby roadways and parking facilities. However, an air impact analysis using projected traffic counts and physical characteristics of the new facility will be undertaken for the City by the Washington State Department of Transportation in order to substantiate the • assumption of nonsignificant impact. This document will be appropriately amended when the results of the air analysis are made available. • • • • • • • Mitigating Measures Watering haul roads and cleaning streets should help reduce construction - related dust. Proper maintenance of construction equipment and minimum idling time will help minimize construction vehicle emissions. No operational plan to mitigate long -term vehicular emission impacts is proposed other than reliance on the State vehicle inspection and maintenance program and the gradual replacement of older vehicles with newer models with better emission controls. C. Water Existing Conditions The Green River is the major water body in the project vicinity and receives all drainage from the project area. According to the State of Washington Water Quality Standards, this portion of the Green River falls into the Class A (excellent) designation. Water quality of this class shall meet or exceed the requirements for all or substantially all uses, including water supply, wildlife habitat, recreation, commerce, and fish production. There are established water quality criteria for Class A waters which should not be violated. • • • • • • • • • • • The Municipality of Metropolitan Seattle (Metro) regularly samples the water quality of the Green River at different locations along the water course within Metro's jurisdictional boundaries. Data collected at the Interurban Avenue crossing of the Green River was reviewed in an effort to evaluate the existing water quality conditions and compare the existing values to State standards. From the 50 sampling dates over the 1980 -81 period, the following determinations were made: 1. In the project area, the Green River exceeds the standards for fecal coliform organisms. 2. On one occasion during that two -year period, the river exceeded the desirable limit of 18° C for temperature. The dissolved oxygen level dropped below the standard of 8.0 mg on this same occasion. 3. Turbidity standards are occasionally exceeded. High turbidity tends to coincide with periods of high suspended solids. Other parameters, including nutrients and heavy metals, for which the Green River is tested often exceed the recommended limits considered beneficial for freshwater aquatic life. A U.S. Geological Survey flow recording station is also located on the Green River in the vicinity of the project area. The latest year of record is 1979. During that year, the maximum flow recorded was 6,490 cfs, with a minimum flow of 250 cfs and mean of 1,193 cfs. The maximum flow ever recorded was 13,200 cfs in November of 1959. According to the King County Surface Water Management Division, the 100 -year flood discharge is estimated to be 12,000 cfs. The 12,000 cfs . river flow is controlled by discharge of the Howard Hanson Dam and includes the future maximum P -1 channel pumping capacity, at such time as this facility is placed in service. 17 • Environmental Impacts • The recommended alternative will result in the formation of approximately 3.5 acres of additional impervious surface area. During the 100 -year frequency storm, this surface area would result in an additional • runoff volume of 2.5 cfs. This volume was calculated by using the formula Q = CiA = 0.90 (0.80)(3.5) = 2.5 cfs, • • where: Q = runoff volume (cfs) C = runoff coefficient (0.90) i = intensity in inches /hour (0.80 for 100 -year storm, 1 hour duration) A = area in acres (3.50) The modified Southcenter Boulevard alignment, new bridges, and new ramps will require some changes in the existing drainage structures, but • drainage patterns will remain basically the same. The total additional 2.5 cfs for the above described storm event will enter the river as fractionated flow from various discharge points, but all will enter near the new Southcenter Boulevard crossing. Since the river has an estimated discharge of 12,000 cfs at this location during the 100 -year occurrence, the small amount of additional runoff does not merit concern. • When major storms occur in the region, the Green River flow is allowed to increase by the manual control of outflow through the Howard Hanson Dam. Stormwater discharge to the river must occur prior to the time that rise in • water level reaches the Tukwila area or gravity discharge into the river will not take place, backing up stormwater into drains, surface drainage channels, and streets. Therefore, in the project area east of Christensen Road, no stormwater detention presently exists nor is any proposed to • • • minimize the time required for runoff to enter the Green River. Storm • runoff west of this area will continue to be discharged into the existing detention basin, where some physical treatment occurs. • • • • • • • The new impervious surface area will collect some additional atmospheric and automobile - generated pollutants that will be washed into the river during storm events. Again, considering the volume . of . additional runoff and the river volume during rainstorms, the pollutant contributions are not considered to have any significant water quality impacts. Fill necessary to construct the new bridge embankments will be placed in the Green River floodplain. Although the project will result in the loss of 0.25 acre of the floodplain fringe area, no construction will take place in the floodway and no impact on the flow of floodwaters is expected. During construction, the fill required to construct new embankments as well as spoils piles from excavation will be subject to erosion. If not controlled, eroded soil will enter the waterway and add to the turbidity and suspended solids problems that now occur during many rainstorms. Oil, hydraulic fluids, fresh concrete, and other materials may also enter the river during construction activities. No groundwater impacts are anticipated. Mitigation Measures All established practices for controlling erosion and for preventing construction equipment pollutants from entering the Green River will be specified in the contract documents. A good street cleaning and maintenance program can help reduce the potential for water quality impacts. 19 • • D. Flora Existing Conditions The project corridor can be divided into two distinct segments, each of • which are represented by different vegetation habitats. The western half of the project corridor consists of Southcenter Boulevard between 62nd Avenue S. and 68th Avenue S. (Christensen Road). This portion of the corridor has plant life that can be considered "roadside" habitat. A • portion of the flora on the north side of the roadway in this area is composed of lawn and landscaping plants, some of which are poorly maintained. Trees found on the north side of the roadway include Big Leaf Maple, Oregon Ash, Red Alder, Pacific Willow, Black Cottonwood, Mountain • Ash, Hawthorne, Western Holly, and Black Locust, with understory vegetation consisting primarily of trailing blackberry, horsetail fern, and various species of grasses. •- • • • • • Most of the vegetation on the south side of Southcenter Boulevard along the western section of the roadway consists of Big Leaf Maple, Oregon Ash, and Red Alder trees. These trees border the right -of -way and persist on the steep hillside that slopes downhill toward I -405. The understory vegetation is much the same as along the north roadway border. These trees are periodically trimmed to prevent them from becoming an obstruction to vehicles traveling east on Southcenter Boulevard. The eastern portion of the project area is represented by typical Northwest riparian vegetation. Trees covering the left bank of the river include Big Leaf Maple, Red Alder, Pacific Willow, and Black Cottonwood. The right bank is mostly covered by blackberry vines and thick grasses but also has scattered groupings of trees of the same species as previously described for the left bank. A large section of grassy floodplain lies adjacent to the right bank of the river. It is bordered on the other two sides by roadway -- Interurban Avenue on one side and I -405 on the other. This area is presently an unmaintained grass field scattered with a variety • • • • • • • of trees and shrubs. Some of the plants are not native to the Northwest and were likely introduced by farmers who settled the area. Introduced species observed in this area include Horse Chestnut, Rybergs Cottonwood, and Red Maple. Other trees include some very old growth Big Leaf Maple and Black Cottonwood, as well as Black Locust, Oregon Ash, and False Arborvitae. Although the area is a floodplain, it does not support wetland vegetation. Its dryness is reflected by the remnants of an irrigation system in the field described above. However, a small patch of cattails was observed in a depression at the end of one drainage culvert. The slopes of the existing I -405 southbound on /off ramps are planted with Scotch Broom. The highway right -of -way east of Interurban Avenue is a grassy area bordered by Poplar, Cottonwood, and Silver Maple trees. Environmental Impacts A total area of approximately 4.5 vegetated acres will be cleared and grubbed to build the preferred alternative. Most of the land cleared of vegetation will be paved or covered with overburden to establish the new alignment for Southcenter Boulevard, change the I -405 ramps, and create the widened portion of the existing roadway. Some will be cleared temporarily to facilitate the movement and storage of construction materials and equipment, but will be revegetated upon completion of the project. Trees and plantings along the existing two -lane roadway west of 68th Avenue S. will be removed from both the north and south side of the street, but the change will be more physically evident on the north side. Because of the installation of drainage structures and retaining walls to construct a sidewalk, vegetation removal will be more of a permanent change on the north side. Even where clearing is required on the south side, a strip of vegetation will still separate the new roadway from the I -405 right -of -way. ai • The major vegetation loss will be the trees and plants which will be • removed along the river banks and in the floodplain in order to construct the bridges for the new Southcenter Boulevard alignment and I -405 ramps. This includes some old growth plants and some exotics that cannot be readily replaced. • • • • • • • • • No land currently used for agricultural purposes will be utilized for this project. With the exception of an approximately five - square -foot drainage area that supports a group of cattails, no established wetland will be affected by this project. No rare or threatened plant species are known to exist in the project area. Mitigating Measures All exposed soil areas will be revegetated with rapid - growing plants upon completion of construction. A landscape plan has been developed for the street and trail sections utilizing both indigenous and introduced species of plants that will not only provide protection against erosion but also attract wildlife and add beauty to the area upon maturity. E. Fauna Existing Conditions Both the existing roadside habitat and riparian habitat described in the flora section of this document are capable of supporting a variety of birds, small mammals, and reptiles. A complete list of mammals and birds sighted in the Lower Green River Watershed is provided in Appendix A. Because of the present developed nature of the project area, only those organisms that can readily adjust to human encroachment can be expected to utilize the existing habitat. For example, members of the rodent family, oppossum, and raccoon may be found in the region, but it is unlikely that mink, bobcat, or fox would be sighted. Most birdlife in the project area is likely to consist of songbirds or those species that require the unique elements of the river habitat for survival (i.e., bank swallows). • Fish species in the Green River are also listed in Appendix A. Sixteen types of fish are known to inhabit the river, including several anadromous species. Impacts • As described in the "Flora" section, approximately 4.5 acres of vegetation will be lost by implementation of the preferred alternative. The removal of this plantlife will result in the displacement and /or destruction of many of the animals that utilize this flora for their • habitat. Mature trees that provide nesting, perching, and food sources for birds will be lost. Placement and compaction of fill material will eliminate food sources and burrows of many small mammals and reptiles. • • • • • • • During construction, when earth from excavation and fill placement is unstable, erosion during rainstorms could result in a reduction in water quality that might be harmful to fish and other aquatic organisms. The loss of riparian vegetation reduces food sources and natural shade to the river. No rare or endangered species will be affected by this project.. Mitigating Measures Revegetation of exposed areas and permanent landscaping will provide some compensation for lost habitat. Mitigation measures discussed in the "Earth" and "Water Quality" sections will help prevent erosion and reduce impacts to fish species. F. Noise Existing Conditions The project area is near the I -405 corridor. Approximately 125 horizontal feet and a grade level difference of about 40 feet separate the • • • closest lane of I -405 from Southcenter Boulevard at its intersection with 62nd Avenue S. About 900 horizontal feet and a grade level separation of approximately 22 feet separate the closest lane of I -405 from Southcenter Boulevard at its intersection with Interurban Avenue. Traffic volumes on I -405 are the principal noise source in the project area. On December 8, 1981, the State Department of Transportation (WSDOT) took noise readings during the afternoon peak hour (4:15 p.m.) at two locations approximately 3/4 of a mile east of the intersection of • Interurban Avenue and Southcenter Boulevard. One location was approximately 100 feet from the nearest I -405 lane, and the second was about 225 feet from the nearest I -405 lane and about 50 feet from S.W. 16th Street, the access road to Longacres racetrack. • • • • Estimated traffic volumes on I -405 during the afternoon peak hour of December 8, 1981 were 3,312 for the northbound (nearer) lanes and 2,988 for the southbound lanes. Heavy trucks composed approximately 2 percent of the combined volumes. At the first location, closer to I -405, a maximum level of 88 dBA and an Leq of 74 were registered. The second location had a maximum level of 78 and an Leq of 67. Based on proximity, these readings are considered to be of the same general magnitude as those that currently exist along Southcenter Boulevard, as influenced by I -405. Environmental Impacts The nearest structure to the area where construction would take place is a commercial building located approximately 30 feet from the existing • Southcenter Boulevard roadway. Several other businesses and homes are located at higher elevations and significantly greater distances from the roadway. • • • • • According to the list contained in "Noise from Construction Equipment and Operations, Building Equipment, and Home Appliances," issued by the U.S. EPA, most construction equipment likely to be used on the project produces noise levels ranging from 79 to 91 dBA when recorded 50 feet from the source. Pile drivers are one of the noisier types of equipment, with sound levels at about 101 dBA when measured from a distance of 50 feet. Temporary noise impacts to the commercial property close to Southcenter Boulevard would arise primarily from equipment used to widen the roadway. • Because of the proximity of the building, intermittent noise levels received by this property during the widening phase of project construction could sometimes be in the range of 91 dBA. • • • Supports for the new bridges over the Green River will be pile'driven. However, greater distances (at least 200 feet) would separate developed properties from pile driver operations. The noise impact expected at the commercial building'from this particular source would be reduced to approximately the level of impact from other project equipment. During construction of the Southcenter Boulevard bridge over the Green River, bicyclists and pedestrians near the existing northern terminus of the Christensen Greenbelt Trail would be subject to elevated noise levels arising from the use of a pile driver and, other equipment. As a result, the attractiveness of this part of the trail may be temporarily reduced for its users. No significant adverse noise impacts are expected as a result of this project once construction, has been completed. However, a noise impact analysis that assesses the noise levels to adjacent properties as a result of this project is being conducted by the State of Washington Department of Transportation. Although the analysis is not yet complete, traffic volumes on I -405 are the dominant noise source in the area and will likely remain so. With the project, the Southcenter Boulevard alignment east of the • river will be closer to I -405 and farther from developed properties. • These determinations will be modified as necessary when the Department of Transportation analysis is complete. • Mitigating Measures -A. number of measures can-be taken to reduce potential project noise; mpactsy: during construction, including: 1.- Limit the use of equipment that generates high noise levels to normal working hours (8:00 a.m. to 5:00 p.m.). - 2. Use modern equipment that is designed or properly muffled to reduce noise. 3. Construct temporary noise barriers around pneumatic equipment or other high noise generators. No permanent noise protection is planned for installation as an element of thi s' project. G. Light and Glare Existing Conditions Street lighting is currently provided only where Southcenter Boulevard intersects other streets: 62nd Avenue S., 65th Avenue S., 68th Avenue S., and Interurban Avenue. The luminaires provide lighting for pedestrians at the existing intersections. Some light from luminaires along I -405 may contribute minimally to the existing lighting level along Southcenter Boulevard. Headlights on vehicles traveling on Southcenter Boulevard provide the majority of available lighting during the evening and nighttime hours. �c, • • • • • • • • • Impacts Additional traffic expected to use the new roadway will increase the amount of light and glare from headlights during the evening and nighttime. The continuous illumination system along Southcenter Boulevard required by development of a full length left-turn pocket will .•provide a minimum design light level of 0.9 foot candles.. ,: The ><< new;. system will :;uti l ize venergy1: efficient high pressure sodium vapor lamps. Mitigating Measures • The new illumination system will direct light where needed on the roadway surface and the proposed sidewalk by use of reflectors and refractors. Post - construction landscaping will also help prevent light from luminaires and vehicles from being transmitted to other areas. H. Land Use Existing Conditions Land use to the north of Southcenter Boulevard is a mixture of single - family residences, multifamily residences, and commercial offices. Most of the hillside north of Southcenter Boulevard between 68th Avenue S. and Interurban Avenue is undeveloped. A large portion of that is designated park land (Tukwila Park). The area between Southcenter Boulevard south to Tukwila Parkway is owned by the State as part of the I -405 right -of -way. The existing comprehensive land use plan designates the area just north of Southcenter Boulevard for office development. The State -owned property is undesignated. The project is consistent with the transportation objectives and policies of Tukwila's Comprehensive Land Use Policy plan and the 1983 -1988 Six -Year Transportation Improvement Program. • Impacts • The proposed project will improve access and increase the capacity of the roadway system. This may accelerate the development of currently undeveloped land or the redevelopment-of currently underutilized land. A • total of approximately 2,600,square feet of land designated for. office use' - will ; _be; acquired`; for . road ri gh't =of- way:. • • • • • Mitigating Measures None. I. Natural Resources Existing Conditions Natural resources in the project area are limited. There are no energy sources, mineral deposits, marketable timber, or other major resources that have been identified in the project area. The Green River is considered the most valuable natural resource in the project corridor. Impacts Materials and fuels used for construction of the new facilities will add to the depletion of natural resources. Materials include cement . concrete, asphalt concrete, reinforcing steel, gravel, and other general construction materials. The estimated fuel and material consumption has been converted to equal 112,000 million BTU's of energy. No impacts to the resource value of the Green River are anticipated. Mitigating Measures See "Energy." • J. Risk of Upset • Existing Conditions • I -405 is the principal travelway in the project corridor. Therefore, trucks carrying shipments of hazardous materials would likely use I -405 rather than Southcenter Boulevard. Other than normal traffic hazards, there is no known source of explosion or hazardous substance release related to the present use of this • facility. Impacts • • • The new roadway width, improved alignment, illumination,: and signals should increase safety and reduce the risk of upset. No special design features are being incorporated into the project to contend with hazardous substance release. During construction, the risk of upset may be increased due to equipment fueling or other operations that pose a certain risk not normally associated with regular roadway use. Mitigating Measures The contractor should follow the necessary safety precautions when • handling hazardous or flammable materials. The Tukwila Fire Department has a hazardous materials response team that reacts quickly to contain accidentally released materials, including • acids, radioactive materials, and petroleum product spills. The Tukwila Fire Department is also playing a leading role in forming a cooperative hazardous materials response team with other South King County communities. • • • • • • • • • • • K. Population Existing Conditions The approximate population of the city of Tukwila was 3,600 in 1980 according to the 1980 U.S. census of population and housing. This is a.2 percent increase in population since 1970. During the -same time period, King County population has grown 9.5 percent. Projections made by the Puget Sound Council of Governments for the Tukwila area indicate an increase of 12 percent, to just over 4,000 in 1990. Impacts The improved access to employment and residential areas may attract a minimal number of people who would otherwise locate elsewhere. Mitigating. Measures None are proposed. L. Housing Existing Conditions The 1980 housing count for the city of Tukwila indicated a total of 1,940 dwelling units. This is a 16 percent increase over the 1970 housing total. During the same time period, the number of dwelling units in King County grew by 24 percent. Projections for 1990 made by PSCOG indicate a growth of 29 percent over 1980 totals for the city of Tukwila. This would result in 2,500 dwelling units in 1990. • • Impacts A minimal increase in housing demand may result from construction of this project due to a minimal increase in population. Mitigating Measures • None are proposed. • M. Transportation /Circulation Existing Conditions • • • • • • • Southcenter Boulevard is an important east /west roadway that serves as an alternative to a heavily congested section of I -405 for trips between Renton and Tukwila. It is currently a narrow, curving two -lane road with unpaved shoulders and open drainage. West of 62nd Avenue S., the street widens to five lanes with curb and gutter, sidewalk, and closed drainage. East of the project, Grady Way is being widened to five lanes with curb, gutter, and sidewalk. Southcenter Boulevard curves north along the west side of the Green River, intersecting Interurban Avenue approximately 600 feet north of the intersection of Grady Way and Interurban Avenue. The resulting offset between Southcenter Boulevard and Grady Way requires that east /west traffic make a weaving movement between the two intersections. There is limited left -turn storage on Interurban Avenue, which frequently overflows into the through lanes during peak hours. Traffic signals are currently located at the intersection of 61st Avenue S. and Southcenter Boulevard, just west of the project at the Interurban Avenue /Southcenter Boulevard intersection and at the Interurban Avenue /Grady Way intersection. Geometry along the existing roadway is poor, with a series of short radius, horizontal reverse curves connected by short, straight segments. Sight distance is limited due to the adjacent topography and the roadway alignment. The Green River and the I- 405 /SR -181 interchange ramps are • • • major obstacles to improving the alignment for this section of Southcenter Boulevard. The present alignment and narrow roadway increase travel time and congestion in the corridor, which reduces the effectiveness of Southcenter Boulevard /Grady Way as an alternative east /west route to I -405. Average daily traffic volumes were counted in the project vicinity in 1979, 1980, and 1981, then factored to- a',common. year-and balanced -for the entire system using both computer and manual methods. The estimated 1981 average weekday traffic volumes are shown in Figure 5. The number of accidents in the Southcenter Boulevard corridor has been remarkably low considering the geometric configuration and high traffic volume. Property damage accidents are predominately rear-end type - accidents generally caused by driver inattention. Injury accidents result from a driver losing control of his vehicle, usually on the narrow, winding section of roadway between Interurban Avenue and 68th Avenue S. The total number of accidents within the project limits for the three preceding years (1979 -1981) is 63. Table 1 summarizes the accidents by type and severity for those years. According to current traffic counts along I -405 between Tukwila and Renton, that segment of freeway is operating at level of service E during peak hours. Travel speed drops to less than 30 mph, with long delays for traffic attempting to enter the traffic stream from entrance ramps. The only alternative route through the corridor is Southcenter Boulevard /Grady Way. The poor alignment and narrow roadway on that route prevent it from providing efficient relief to I -405. The existing street system within the study area, particularly along • SR -181, exhibits considerable operational problems. Through traffic from Grady Way to Southcenter Boulevard must turn right onto SR -181 and then left at the next intersection onto Southcenter Boulevard. Existing data indicate that this, as well as the reverse trip, is a high - volume movement, particularly during the p.m. peak hour. These large turn volumes cause • • 16,540 To Fort Dent Park 19,01.0 15,860 22,750 TER 88,570 SOUTHCENTER BOULEVARD 17,310 4NORTH ENTRANCO Engineers (.VaC....,.... ..0 .,..eCr..O. coy tatA R{ 15,400 City Of Tukwila SOUTHCENTER BOULEVARD 62nd Avenue South To Grady Way Figure 5 ;1981 AVERAGE WEEKDAY TRAFFIC 1 • • • • • • • • • • TABLE 1 ACCIDENT HISTORY SOUTHCENTER BOULEVARD From 62nd Avenue S. to Interurban Avenue and Grady Way 1979 -1981 _ ACCIDENTS- Property • Damage Only Injury -- Total* COLLISION TYPE 1979 -1981 1979 -1981 1979 -1981 Rear -end 15 1 16 Right -angle 1 0 1 Left -turn 7 4 11 Right -turn 5 3 8 Side -swipe 9 0 9 Head -on 1 0 1 Pedestrian 0 1 1 Out of control 6 10 16 Total 44 19 63 * There were no fatalities for these three years. 3 `i • • • • • • • • • • considerable congestion. The SR -181 /Grady Way intersection currently operates at level of service D -E. The Fort Dent Park /SR -181 intersection is at level of service B, and the I -405 northbound ramp /SR -181 intersection is at level of service C. Although level of service calculations would indicate that this section of SR -181 would operate reasonably well, the high volume of left turns onto Grady Way causes considerable congestion. Left -turn storage is not adequate to handle the volume and cannot be lengthened due to the proximity of the two - intersections. Vehicles back onto the through lanes, restricting traffic. Since these intersections are quite close together, the backups can actually extend into the preceding intersection, blocking traffic there as well. The operation of the section more closely resembles the level of service at the worst intersection, that being level D -E. Metro Transit currently operates 14 routes that serve Tukwila, totaling approximately 320 trips per day, all of which either traverse or intersect Southcenter Boulevard.: Most of the routes operate peak hour only and only four routes operate on weekends. They connect Tukwila with the major activity areas in the region: the Seattle central business district, Bellevue, Renton, Kent, and the Duwamish Valley. There are two major.trail /sidewalk routes within the Southcenter Boulevard project: an east -west sidewalk /bikeway connecting Renton and Tukwila; and a north -south extension of the Christensen Greenbelt Trail. Impacts Traffic volume between 1981 and 1990 is expected to increase considerably in the Tukwila area. The Tukwila Micro -Model Study, completed by Entranco Engineers in 1981, forecast a growth of 33 to 46 percent in vehicle trip ends over the ten -year period between 1980 and 1990 for the commercial- industrial area. The results of that modeling effort (which included a number of land use and roadway alternatives) and the existing traffic counts were used to evaluate the various alternatives for Southcenter Boulevard using 1990 as a design year. • • • • • • • • • • Significant differences are expected to occur if Southcenter Boulevard is improved. Figures 6 and 7 show 1990 average daily traffic for the no -build alternative and the proposed project. Major increases in traffic are expected to occur on Southcenter Boulevard with the realignment alternative attracting 3,000 to 7,000 more vehicles than the no -build alternative. Corresponding decreases in traffic volumes are expected on I -405. Volumes on Grady Way would increase by about 2,000, with volume on 68th Avenue S. increasing by 4,700. Other changes in traffic should be of much lesser significance. The 1990 approach volumes and existing turning movement counts were used to generate 1990 p.m. peak hour turning movements. These were then used to calculate level of service for the three intersections - -Fort Dent Park/ SR -181, Grady Way /SR -181, and I -405 northbound ramp /SR -181. Table 2 shows the anticipated 1990 level of service for the various alternatives. Only alternatives 3B and 4 provide level of service D or better at the Fort Dent Park /SR -181 intersection; only alternatives 3A and 4 provide level of service D or better at the Grady Way /SR -181 inter- section, while none of the alternatives provide better than level of service E at the I -405 northbound ramp /SR -181 intersection ( "Alternatives Considered," for a description of Alternatives 3A and 3B). The latter intersection needs a separate right -turn lane for southbound traffic on SR -181 to improve access to I -405 northbound. Construction of this lane is outside the scope of this project, and was therefore not considered in 'any of the alternatives. As previously stated, current storage length for left turns from SR -181 southbound onto Grady Way eastbound is not adequate to handle the p.m. peak hour demand. On some signal cycles, left turning traffic backs up onto the through lanes, blocking that movement. In some cases, it may backup through the present Southcenter Boulevard /Fort Dent Park /Interurban Avenue intersection, severely restricting traffic flow. The increase in traffic volumes expected by 1990 will exacerbate the situation. Only alternatives 3A and 4 offer any relief: 3a because it will eliminate the Grady Way /SR -181 intersection, and 4 by converting the left -turn movement from Southcenter Boulevard to a through movement due to the realignment. 36 19,040 •To Fort Dent Park T 17,450 35,410 14,350 MONSTER 3,240 87,630 SOUTHCENTER BOULEVARD 28,710 18,230. 30,800 13,300 18;480 T UKWILA PARKWAY 32,430 City Of Tukwila Figure 6 SOUTHCENTER BOULEVARD 1990 AVERAGE, DAILY TRAFFIC ALTERNATIVE I NO BUILD ENTRANCO Engineers ... ,•..Y.., .o /+ •s.rn .on, casuus 19,040 To Fort Dent Park T 28,100 36,910 OT ER 19,320 8,490 4,740 23,250 93,500 83,930 9,210 6,130 SOUTHCENTER BOULEVARD 30,850 31,080 TUKWILA 32,430 City Of .Tukwila SOUTHCENTER BOULEVARD Figure 7 1990 AVERAGE DAILY TRAFFIC ALTERNATIVE 4 REALIGNMENT AT GRADE • • • Alternative 1. No Build 2. Widen Existing 3A. High Level Bridge, Southcenter Boulevard Ramp • 3B. High Level Bridge, Grady Way Ramp • • • • • • 4. New Alignment, At -Grade Intersection° TABLE 2 1990 LEVEL OF SERVICE I -405 Northbound Fort Dent Park Grady Way/ Ramp at at SR -181 at SR -181 SR -181 * - F F E -F E D E -F B E F D - D E * This intersection is outside the limits of this project. In order to achieve an acceptable level of service, a right -turn lane should be added on the north approach. Recommended alternative. 39 • • • • With increasing traffic volumes, the number of accidents is expected to increase. At the intersections, the level of congestion will increase and with it the accident rate. One method of comparing safety factors for the improvement alternatives is to compare expected accidents in the design year. Table 3 shows a comparison between the alternatives. The referenced traffic volumes are for Southcenter Boulevard west of SR -181. Alternatives 3A, 3B, and 4 provide the greatest benefit in terms .. of accident reduction. Accidents per million vehicle miles would be reduced from 11.0 for the no -build alternative to 3.3 for the proposed project. This is due to the removal of the existing curves and elimination of weaving movements. The proposed trail system is approximately 0.3 mile in length and will extend the Christensen Greenbelt Trail from the intersection of Tukwila Parkway and Christensen Road/ Christensen Greenbelt Park northward along the Green River. It will pass under I -405 and Southcenter Boulevard, then follow the old Southcenter Boulevard alignment from a connection with the proposed sidewalk /bikeway on the south to Fort Dent Park on the north. The development of this trail will provide a valuable link in the City of Tukwila's trail system, as well as providing an excellent recreation resource for the people living within the greater Green River Valley. The trail will connect with the sidewalk system adjacent to Southcenter • Boulevard, with the existing Christensen Greenbelt Trail and the pedestrian circulation system within Fort Dent Park. It will provide a broad range of recreational opportunities and a safe transportation system for pedestrians and bicyclists that does not exist at the present time. • • • • The proposed project also includes an eight -foot sidewalk /bikeway on the north side. It will provide a continuous facility for pedestrians and bicyclists between Renton and Tukwila. The project will incorporate features such as turn channelization, signalization,.si•dwalks, and illumination that will facilitate movement of Metro Transit buses and loading and unloading of passengers. yO • • TABLE 3 ANTICIPATED ACCIDENT RATES - 1990 Alternatives° Existing 1 2 3A 3B 4 Estimated Accidents /Year* 21 37 31 17 14 16. Average Daily Traffic (ADT) 8,800 14,300 16,700 18,400 20,800 20,800 Million Vehicle Miles (MVM) of Travel /Year 2.1 3.4 4.0 4.4 4.9 4.9 • Accidents /MVM 10.0 11.0 7.6 3.8 2.8 3.3 • • • • • • * Based on method for estimating future accidents in the Transportation and Traffic Engineering Handbook, ITE. 1965. pp. 394 -399. 0 All figures are for the 1990 design year. Alternative 4 is the recommended alternative. yl • • • • There will be no effect on existing parking facilities nor will a demand for new parking be created. There will be no effect on waterborne, rail, or air traffic. Mitigating Measures A new signal with advanced capabilities will be installed at the intersection of Grady Way and Interurban Avenue. The existing State -owned traffic signal at the Interurban Avenue /Fort Dent Park intersection will require only minor revisions. Another signal will be installed at the . intersection of Southcenter Boulevard and 68th Avenue S. to improve traffic flow and provide safe pedestrian movement. Reference was made earlier to completion of the Grady Way Bridge • replacement located at the east terminus of the Southcenter Boulevard project. It will provide a five -lane section from Interurban Avenue into Renton. The programmed completion date for the bridge replacement is 1983 -84, which should help mitigate traffic impacts of this project. • • • • • • An additional planned project in the vicinity is construction of high occupancy vehicle (HOV) lanes on I -405. The first phase of the project calls for construction from I -5 in Tukwila to the Renton "S" curves. Programmed for construction in late 1983, the project will provide exclusive lanes for transit, carpools, and vanpools. Although they will provide significant time savings for HOV's during peak hours, they will probably not significantly improve the overall level of service. In conjunction with that project, WSDOT has agreed to participate in replacement of the T -line bridge (68th Avenue S. bridge) with a new four -lane structure. The widened roadway will greatly improve access for the Tukwila commercial- industrial area and adjacent portions of the community. A study of possible alternative alignments is currently under way, with completion anticipated in the fall of 1982. • • • • The extension of the Christensen Greenbelt Trail will provide a continuous Class II (separate right -of -way) bicycle facility between S. 180th Street and Fort Dent Park. The proposed sidewalk /bikeway on the north side of Southcenter Boulevard will complete the pedestrian link between Renton and Tukwila. Metro's adopted 1990 plan includes a package of major service improvements in Tukwila aimed at creating a Regional Transit Center in the Southcenter Shopping Center vicinity. This Regional Transit Center will be a transit focal point, and will coordinate transfers between local routes and through routes going to the Seattle CBD and to other activity centers. Increased transit service and revision of existing routes are proposed as part of the 1990 transit plan. The proposed transit improvements are aimed at accommodating a projected 10 percent peak hour mode split by 1990. N. Public Services (1) Fire Service • Existing Conditions Fire protection in the area is provided by the Tukwila Fire Department. • Two fire stations are located in the immediate vicinity, one at 444 Andover Park East and the other at S. 147th Street and 59th Avenue S. They provide pumpers, aerial ladder trucks, aid car, and support vehicles on a full -time basis. • • • • Impacts Completion of the project will decrease response time by decreasing congestion and minimizing the potential for vehicle blockage. During construction, some temporary increase in response time may occur. y3 • • • • • • Mitigating Measures Emergency vehicle pre - emption sensors will be installed at all signalized intersections. (2) Police Protection Existing Conditions Police protection in the area is provided by the City of Tukwila Police Department. The police station is located in City Hall at 6200 Southcenter Boulevard. The force is currently composed of 27 commissioned officers. Impacts Response time will be decreased by completion of the project by decreasing congestion and minimizing the potential for vehicle blockage. During construction, a temporary increase in response time may occur. Mitigating Measures None. • (3) Schools Existing Conditions • • • • Tukwila is in South Central School District 406. There are three elementary schools, one junior high school, and one high school in the district. Impacts Travel time will be decreased for school buses routed along Southcenter Boulevard. Pedestrian safety will be improved along the corridor. �1 y • • • • • f • • • • • • Mitigating Measures An eight -foot sidewalk /bikeway will be provided along the north side of Southcenter Boulevard which will improve safety for school children. (4) Parks and Recreation Existing Conditions There are several recreational facilities in the vicinity of Southcenter Boulevard. Tukwila Park, on 65th Avenue S. just north of Southcenter Boulevard, is Tukwila's oldest park. There are four tennis courts, a play court, restrooms, picnic tables, trails, playground apparatus, a gazebo, fire pits, and open grass areas nestled among the large fir trees and rhododendrons. Bicentennial Park is a small neighborhood park located at the intersection of Strander Boulevard and Christensen Road. It contains a log cabin, picnic tables, restrooms, and playground apparatus and provides the main parking areas for it and the Christensen Greenbelt Park. The Christensen Greenbelt Park stretches two miles, from S. 180th Street to Tukwila Parkway along the west bank of the Green River. It is a narrow park, often referred to as the Christensen Trail, consisting of an eight -foot wide hard surface bycycle path and a six -foot wide cinder jogging path. Also found along the trail are a fitness course, duck pond, bicycle racks, and four picnic areas. Fort Dent Park is a part of the King County Parks system. Located just north of Southcenter Boulevard and just east of the Green River, the park is accessed from Interurban Avenue at Southcenter Boulevard. The 50 -acre park has soccer and softball fields, tennis courts, a running track, and picnic areas. The soccer and softball fields are used extensively by King County Parks Department recreation leagues. Major privately owned recreational facilities include Longacres racetrack, located just east of the project site, and Foster Golf Course, located on Interurban Avenue near I -5. Longacres is open from spring until • • fall, generally on Wednesday- through- Sunday schedule. Foster Golf Course is an 18 -hole golf course open year- round. Impacts The project includes an extension of the Christensen Trail from its • current northern terminus near Tukwila Parkway to Fort Dent Park. -Picnic tables, rest areas, and landscaping will be provided. Some increased maintenance can be expected. • • • • • • • • Mitigating Measures Extension of the Christensen Trail will improve access to area parks for all residents as well as providing increased park acreage. 0. Energy Existing Conditions The major source of energy consumption is from automobiles consuming gasoline as they traverse the existing roadway. Smaller amounts of diesel fuel are consumed by trucks and buses. Minor amounts of electricity are used by the existing traffic signals and illumination. Impacts During the construction phase, 112,000 million BTU's of energy will be consumed by construction equipment and materials. Completion of the project will result in 6,200 fewer vehicle miles of travel per day and an average speed two miles per hour greater than the no -build situation. This will result in a savings of 735 gallons of gasoline per weekday, or 91.9 million BTU's per weekday. It will take approximately five years to pay back the energy used in construction. No new energy sources will be required. • • • • • • • • • • Mitigating Measures Construction of the project will reduce energy consumption due to decreases in congestion and vehicle miles of travel and increases in travel speed. High pressure sodium vapor lamps will be used in all luminaires. These lamps have a very high efficacy (lumens per watt of power consumed), which results in considerable energy savings. Metro Transit currently operates 14 routes in the project vicinity. Metro's 1990 Transit Plan recommends improved service in the corridor consisting of new routes and increased service on existing routes. The proposed service improvements are aimed at accommodating a projected 10 percent peak hour mode split. Turn lanes and radii, signalization, and channelization improvements will be designed to facilitate the movement of transit vehicles. Metro will benefit by reduced travel time and reduced fuel costs. P. Utilities Existing Conditions Power and telephone lines run parallel to and occasionally cross Southcenter Boulevard. Poles supporting these lines are within the existing street right -of -way. Most of the power poles are located on the south side of the street. Natural gas mains are buried within the Southcenter Boulevard roadbed. A waterline and sanitary sewer line is located under the pavement of the present roadway. Two storm sewers pass under the roadway and carry drainage toward I -405. • • • • • • • Impacts Power and telephone lines will be placed underground throughout the project limts. This work will be completed by the respective utility companies at their own expense. Any necessary adjustments to gas mains would be completed by the gas company. Stormwater runoff from Southcenter Boulevard between 62nd Avenue S. and 68th Avenue S. will be collected in new storm drains and continue to be discharged into the existing detention basin to the south through a proposed closed retention /oil separation system. Other utility work will be limited to relocation and adjustment of existing facilities. Domestic water system improvements include relocation of fire hydrants and adjustment of valves and valve chambers. Sanitary sewer improvements include adjustment of manholes to the new street grade. Mitigation Measures Planning and coordination will take place with the respective utility representatives during design and construction to avoid interruption of service to customers and prevent unnecessary project delays. Human Health At this time, no impacts to human health are anticipated as a direct result of this project. A complete analysis of air and noise impacts may result in a future revision of this determination. R. Aesthetics Existing Conditions • The existing roadway is a two -lane roadway that parallels I -405 from 62nd Avenue S. to 68th Avenue S. and then turns north along the Green • • • • • • • • • • • River. Trees border it along the south and east sides. A steep hillside runs along the roadway to the north and west. Views of the Green River are obscured by the border of trees and the elevation difference between the river and the roadway. The area between I -405 and the Green River is an open field with some trees. Other potential views are generally obscured by the I -405 bridge structures, elevation differences, or trees. Impacts Construction of the project will convert a portion of the open area between I- 405 and the Green River to a five -lane roadway. Views from the new roadway will be opened up to the north, particularly from the relocated I -405 southbound ramps. No existing views will be blocked. Mitigating Measures Extension of. the Christensen Trail will provide views of the Green River, Longacres racetrack, Renton, and Fort Dent Park for pedestrians and bicyclists. Landscaping will be provided in all areas requiring vegetative restoration due to the proposed street and trail construction and its effects on existing vegetation. A concerted effort will be made to utilize indigenous: plant materials that will attract birds and other forms of wildlife adjacent to the Green River environs. Also, the selection of plant materials will include the considerations of seasonal color and drought - tolerant plant varieties. The landscape development adjacent to the natural vegetation areas will be confined to the planting of clover and wildflowers. This landscape treatment will assist in restoring the existing vegetation that will be scarred as a result of trail construction. The total landscape of the trail and roadway would accomplish two things: (1) establish a park /trail atmosphere, and (2) create a compatible environment with adjacent land uses. • S. Recreation See "Public Services." • T. Archaeological /Historical • • • • • Existing Conditions The State of Washington Office of Archaeology and Historic Preservation has reviewed available records and noted that the project area has a high potential for occurrence of previously unidentified cultural resources. Based on this review, it is recommended that a professional archaeological survey of the project area be conducted prior to further action. A professional survey team from the University of Washington Office of Public Archaeology will be contracted to do this survey. U. Economic Impacts Existing Conditions As of December 1980, the city of Tuwila contains 1,006 businesses employing 19,174 people. The Southcenter Boulevard project is located on the border between the Tukwila /Interurban and the Southcenter /Andover areas, as definded by the 1980 City of Tukwila Employment Survey. The Tukwila /Interurban area had employment of 1,257 people, while the Southcenter /Andover area had employment of 15,056 people, or 78.5 percent of total employment. Gross floor area of leasable space for 1980 totaled approximately 10,668,000 square feet, with the majority of that (6.9 million square feet) devoted to light industrial uses and warehousing. There were approximately • 2 million square feet of retail space and 1.8 million square feet of office space. • •' • Impacts By 1990,. total gross floor area of leasable space is expected to grow to 12.5 million square feet, or 17 percent more than in 1980. Major • increases are expected in office space with an additional 1.8 million square feet to be provided. Employment is expected to increase by 40 percent, to about 26,000 people in 1990. Access improvements provided by this project are necessary to achieve that projected growth. • • • • The proposed project will cost $6.8 million to construct. Federal funding sources are expected to provide 80 percent of the funds, with local sources, general sales tax, and motor vehicle fund taxes providing 20 percent of the funds. Construction of the project will improve the local economy by providing jobs for area contractors and sales of materials for local suppliers. Current land use designations along Southcenter Boulevard are for office use. Property is developed consistent with this designation except for five single - family residences on the hillside south of Tukwila Park (across Southcenter Boulevard from the T -line bridge). Since access to the adjacent property will be improved by construction of this project, property values along this corridor may be expected to rise. Mitigating Measures • Construction of the project will improve access to the Tukwila industrial - commercial district. Without improved access to the area, projected growth in employment and gross floor area may be slowed or may not occur due to traffic congestion and poor accessibility. • Reductions in gasoline consumption due to increased average travel speeds and decreased vehicle miles of travel will result in a savings of 191,000 gallons of gasoline per year, equaling approximately $250,000. • Reductions in accidents due to improved geometrics and lighting will result in a yearly savings of about $50,000. • • • ALTERNATIVES CONSIDERED This section discusses four roadway alternatives to the proposed project: (1) the no -build alternative; (2) improve the existing facility; (3A) build a high -level bridge with access to Interurban Avenue at Fort • Dent Park; and (3B) build a high -level bridge with access to Interurban Avenue at Monster Road. Figure 8 shows the alternatives. Alternative 4 shown in that figure is the proposed project. • Alternative 1 - No -Build Description • The no -build alternative is a consideration of the effects of not improving the route. If the proposed project is not built, the section of Southcenter Boulevard east of 62nd will remain as a two - lane .. facility without sidewalks. The portion of Grady Way west of the bridge will be • widened to five lanes as part of the Grady Way Bridge project, with no improvement in the alignment. No further improvements would be made to the route. Impacts Less traffic would use Southcenter Boulevard than with the proposed project. I -405 would have higher traffic volumes, and congestion would be • greater on both routes as well as on Interurban Avenue. Emissions and fuel consumption would be higher due to the greater congestion. Travel time through the corridor would be higher. Anticipated development in the Tukwila commercial - industrial district (CID) may not occur because of poor • access. Traffic hazards would increase. Response time for emergency vehicles would be increased. The Christensen Greenbelt Trail would not be extended, and pedestrian access to Renton would not be improved. A savings of $6.9 million would occur, as opposed to the proposed project; however, this would be offset • T• fewl Dom •... •ATTKWAY f. ALTERNATIVE 1 No Build • Widen To 5 Travel Lanes s • foe Taal Own. ••• • • / • / != •MTPITTAY rm. ALTERNATIVE 2 Improve Existing System T• I 0••• Popo 777-77! = New Alignment 6- . New E3ridge 1111111111111111 Roadway To Be Closed T. foot 0-.4 r7.7-717,1..-, New Alignment ;- New Bridge % 1111111111111111 Roadway To Be Closed NORTH ALTERNATIVE 3A High Level Bridge ENTRANCO Engineers •NOTII•NY.0.11,1,01% CONSUL,•MIS Fi ALTERNATIVE 3B High Level Bridge New Alignment New Midge 1111111111111111 Roadway To Be Closed T. 7.0 Don rat. 11. dA111111.. "OW City Of Tukwila SOUTHCENTER BOULEVARD 62nd Avenue South To Grady Way 8 a PARKWAY ALTERNATIVE 4 At-Grade Intersection Figure 8 PROPOSED SOUTHCENTER BOULEVARD ALTERNATIVES • • somewhat by higher costs associated with maintenance, fuel consumption, and accidents. • • • • • • • • Conclusion The no- action alternative is not a reasonable alternative for -the following reasons: (1) increased congestion; '(2) increased traffic hazards; (3) increased auto emissions; (4) increased fuel consumption; (5) reduced pedestrian and auto access; and -(6) decreased pedestrian safety. No action will also limit potential growth in the area due to the problems stated above. Alternative 2 - Improve Existing Facility Description This alternative would maintain the existing alignment but would widen the roadway section to provide five travel lanes on Southcenter Boulevard west of Interurban Avenue and five travel lanes on Grady Way from Interurban Avenue (SR -181) to the Grady Way Bridge. Sidewalks would be provided and some intersection channelization installed. A signal would be installed at the intersection of Southcenter Boulevard and 68th Avenue S. The Christensen Greenbelt Trail would be extended as an eight -foot sidewalk /bikeway adjacent to the travel lanes. Impacts Traffic volumes would be slightly lower on Southcenter Boulevard than for the proposed project, while they would be slightly higher on 1-405. The level of congestion would be greater on both routes as well as on Interurban Avenue. Emissions, fuel consumption, travel time, and the number of accidents would be greater than with the proposed project, but less than with a no- action alternative. • • Some anticipated development in the Tukwila CID may not occur due to the access constrictions. The Christensen Greenbelt Trail would be extended to Fort Dent Park as an eight -foot sidewalk /bikeway adjacent to the travel lanes. Pedestrian and bicyclist safety would be lower than with • the proposed project. Retaining walls may be required between 68th Avenue. S. and Interurban Avenue on the northwest side of.:Southcenter Boulevard. The narrow right -of -way in that area may require _ acquisition -of additional right -of -way to avoid severe impacts on the Green River. The cost in 1982 • dollars would be $1.9 million. This is a savings of $5.0 million as compared to the proposed project. This savings would be slightly offset by higher fuel consumption, an increase in accidents, and increased travel time delay. Conclusion • • • • The "improve existing facility" alternative is not believed to be a reasonable alternative for the following reasons: (1) increased traffic congestion; (2) increased fuel consumption; (3) increased auto emissions; (4) increased impacts on the Green River; and (5) decreased pedestrian safety.. The traffic weave and storage problems associated with the intersection at SR -181 will remain. Alternative 3A - High -Level Bridge with Access to Interurban Avenue at Fort Dent Park Description This alternative would consist of construction of a high -level bridge west from Grady Way to 68th Avenue S. crossing over SR -181, the I -405 southbound on /off ramps, and the Green River. Connection to Interurban Avenue would be made via the existing section of Southcenter Boulevard between 68th Avenue S. and Interurban Avenue. The Grady Way access to Monster Road and Interurban Avenue would be closed. The high -level bridge would consist of four lanes. The existing section of Southcenter Boulevard • • • • • west of 68th Avenus S. would be widened to five travel lanes, while the section east of 68th Avenue S. would be maintained as a two -lane facility. A traffic signal would be installed at the intersection of Southcenter. Boulevard and 68th Avenue S. The Christensen Greenbelt. Trail would be extended north under the I -405 bridge and Southcenter Boulevard bridges on an independent alignment. Along 68th Avenue S. it would consist of an eight -foot sidewalk /bikeway adjacent to the existing travel lanes. Impacts The impacts associated with this alternative are similar to the proposed project. The capacity of the roadway would be slightly higher; however, the level of congestion would also be higher due to the indirect access to I -405. The improved access to the Tukwila CID would allow the anticipated growth to occur. Accidents would be slightly higher than for the proposed project. Pedestrian and bicycle safety would be somewhat lower due to the Christensen Greenbelt Trail being adjacent to the travel lanes between 68th Avenue S. and Interurban Avenue. The cost of construction would be $10.6 million in 1982 dollars; this is $3.7 million more than for the proposed project. Fuel consumption and accident costs would be similar to the proposed project. Conclusion Alternative 3A is not believed to be a reasonable alternative because • of high cost and decreased pedestrian safety. • Alternative 3B - High -Level Bridge with Access to Interurban Avenue at Monster Road Description This alternative is similar to alternative 3A. A high -level bridge • would be constructed west from Grady Way to 68th Avenue S., crossing over SR -181, the I -405 southbound on /off ramps, and the Green River. Connection • • • • • • • • to Interurban Avenue would be made via the existing section of Grady Way between Monster Road and Interurban Avenue. The existing section of Southcenter Boulevard between 68th Avenue S. and Interurban Avenue would be closed. The section of Southcenter Boulevard west of 68th Avenue S. would be widened to five travel lanes. The high -level bridge would consist of four travel lanes. Traffic signals would :. be installed at the - intersections of Southcenter Boulevard and 68th Avenue S. and Grady Way and the Interurban Avenue connector. The Christensen. Greenbelt Trail would be extended north on an independent alignment, as shown for the proposed project. Impacts The impacts of this alternative are similar to both the proposed project and Alternative 3A. Congestion would be slightly greater than with the proposed alternative, while capacity would be similar. The number of accidents would be slightly lower and pedestrian /bicycle safety would be similar. The cost of construction in 1982 dollars would be $10.7 million. This is $3.8 million more than for the proposed project. Fuel consumption and accident costs would be similar to the proposed project. Conclusion Alternative 3B is not believed to be a reasonable alternative because of its high cost. COMMENTS AND COORDINATION This action has been under study since October of 1981. The study included traffic analysis and modeling, numerous engineering considerations, review of compatibility with other facilities and plans, and preparation of the appropriate environmental documents. • • • • • • • Coordination to date has included both written and verbal communication with the appropriate officials representing the City of Tukwila, King County, the Puget Sound Council of Governments, the Municipality of Metropolitan Seattle, the State of Washington Department : of - :.Transportation, the Federal Highway Administration, and other state and .-local . agencies. Evidence of coordination with some of the officials representing these agencies is attached. • December 18, 1981 Paul A. Treman, P.E. Entranco Engineers 1515 - 116th Ave. N.E. Suite 200 • Bellevue, WA. 98004 EN-1 Akt, V O EN Re: Southcenter Boulevard Extension, Job No. 82028 -20 Dear Mr. Treman: The following comments are in response to questions from your December 14 letter as numbered: King County State of Washington Randy Revelle, County Executive Department of Public Worts James W. Guenther, Director 900 King County Administration Building 500 Fourth Avenue Seattle, Washington 98104 (206) 344 -2517 0 Mar v-F 1) The 100 -year flood elevations are noted on the enclosed map. They are noted in blue figures as M.S.L.Datum. • 2) The ordinary high water elevation (9000 cfs) and (12000 cfs) flood elevation which included the P- Channel pumping are noted in black figures on the enclosed photo -copy of HUD map, 2 of 2, City of Tukwila. 3) Enclosed photo- copies of area from City of Tukwila Floodway and Flood Insurance Rate Maps. 4) Vertical clearance of 6 feet above the 100 -year water surface is re- commended as stated in King County Code 20.50 (Ord, 2281, Surface Water Runoff Drainage Policy 1.10). The City of Tukwila, U.S. Army Corps of Engineers and the State Department of Fisheries should also be addressed for vertical clearances. A State Flood Control Zone Permit shall be required. Also check with the U.S. Coast Guard for • their navigation on safety recommendations. 5) I spoke with John Bordon, King County Bridge Engineer, about the two existing bridges. They are not county bridges and we have no vertical datum on these structures. 6) Enclosed application for a State Flood Control Zone Permit. • 7). The State Flood Control Zone Permit would be the only review by our Department.: Further questions should be directed to Doug Grochow or Meredith Mamanakis of my staff at 344 -3874. Sincerely, G.E. WANNAMAKER, P.E. Development Review Section Surface Water Management Division GEW:DG:dk VSE L .4 (tow( SLFV, Foee I L, ovo c FJ , Nor 100 Y r? F (.3 k=3 EL(/ - OF.0 NE,(3 u (. ,ass -qoPb) rz-zz -9/ I�Ar • • Encl: As noted •, rsPE CU LIMIT 15 5i Sincerely,., John E. Mikesell Chief, Bridge Section By direction of the District Conunarxier • • • • •• • • • NPSEN -PL -ER DEPARTMENT OF THE ARMY SEATTLE DISTRICT. CORPS OF .ENGINEERS P.O. BOX C -3755 SEATTLE. WASHINGTON 98124 Brad. Collins, Director Tukwila Planning Department 6200 Southcenter Boulevard Tukwila, Washington 98188 Dear Mr. Collins: 28 APR 1982 We have reviewed the Proposed Declaration of Non - Significance and the ac- companying Environmental Checklist for the proposed realignment of South - center Boulevard within the City of Tukwila, Washington, with respect to the U.S Army Corps of Engineers' areas of responsibility for flood con- trol, navigation, and regulatory functions. We have the following comments: a. It is not clear from the Environmental Checklist whether the lo- cation of fill will remove significant areas of wetland and /or riparian habitat. This issue is not adequately addressed and should be clarified. It may be pertinent to the final decision on the significance of -the proj- ect. As you know, wetlands are ecologically significant areas which help maintain the quality of the human environment in a number of important ways. Seattle District encourages you to consider the use of alternatives which minimize impacts to wetlands. b. It is noted that interior drainage will be altered, thereby in- creasing runoff into the Green River which is already a severe problem in the Green River basin. Drainage patterns resulting from road relocation should be addressed. c. Water quality in the Duwamish River is a key environmental issue. Mitigation of construction - induced pollution should be addressed as well as a long -term means of reducing oils and other surface water contaminants. d. The bridge should be designed to withstand a 100 -year frequency flood. The design should also include free board water surface for drift clearance. e. The enlarged arterial would affect the proposed greenbelt trail. The impacts, such as noise and safety, should be discussed. • • • • • • • • NPSEN -PL -ER Brad Collins, Director We appreciate the opportunity to review this checklist and regret that our response was delayed. If you have any questions, please feel free to con- tact Dr. Steven F. Dice, telephone (206) 764 -3624, of my staff. Sincerely, czt,,c7-‘04,..A/ R.P. SELLEVOLO, P.E. Chid, Engloosting Division JOHN SPELLMAN Governor • • • • • • • • • STATE OF WASHINGTON OFFICE OF ARCHAEOLOGY: AND HISTORIC PRESERVATION 111 West Twenty-First Avenue, KL -11 • Olympia, Washington 98504 • (206) 753 -4011 July 30, 1982 Mr. Ed Berschinski Entranco Engineers 1515 - 116th Ave. N.E., Suite 200 Bellevue, WA 98004 Log Reference: 332- C -KI -02 IACOB THOMAS Director Re: Southcenter Boulevard 62nd Ave. S. to Grady Way Project ()82028 -20 Dear Mr. Berschinski: We have reviewed the materials forwarded to us for the above referenced project. A _search of our records, including the National and State Registers of Historic Places and the Washington State Archaeological and Historic Sites Inventories, indicates surveys have been conducted in the general vicinity of the project area. Known site distributions, ethno- historic sources, and /or consultation with others indicates that the project area has high potential for the occurrence of previously uniden- tified cultural resources. Based on the results of our records searches, consultations, and the materials provided for out review, we recommend professional archaeological surveys of the project area be conducted prior to further action. The above comments are based on the information available at the time of this review. Should additional information become available, our as- sessment may be revised. In the event that cultural materials are inadvertently discovered during construction, work in the immediate vicinity should be discontinued and this office notified. Please in- dicate the log reference number noted above in further communications concerning this project. A copy of these comments should be included in subsequent environmental documents. dj Sincerely, Robert G. Whitlam, Ph.D. Archaeologist • • TO: FROM: • DATE: • City of Tukwila 6200 Southcenter Boulevard Tukwila Washington 98188 Frank Todd, Mayor Mark Caughey Don Williams January 18, 1982 MEMORANDUM SUBJECT: Widening of Southcenter Blvd. - E.C.F. Response) ,, • The Department of Parks and Recreation is very interested in the continued development of Southcenter Blvd., specifically the . sidewalk's width and location. We look at the sidewalk "sections as additional links in an interconnecting pedestrian/bicycling system within the community. Any provision for a sidewalk will be a step forward from what we have, or rather, do not have now. I would encourage the wide development of the new sidewalk to match the present sidewalk, narrowing to not less than eight feet. Also, all curb ramps for the handicapped and bicyclists surd be included. I am most concerned on how the new roadway/sidewalk(s) will connect into • Christensen Greenbelt Park (Trail) and into any future sidewalks along Interurban Ave. The goal of our department has been to interconnect the residential area,'Fort Dent Park, Christensen Trail and the . commercial area, including the ability of a citizen or shopper to use a sidewalk to reach any of the four areas via a safe route. What will cloud my ability to evaluate any specific road design is the lack of final design for Phase III of Christensen Trail. We have discussed, a number of times, with the State's D.O.T. the route of our trail, either going under their 405 bridge that crosses the Green River . or widening, with a sidewalk, their Christensen Road bridge (T -Line Bridge). D.O.T. prefers we widen the Christensen Road Bridge. No final route has been selected, thus it will be difficult to evaluate what may be designed for the Southcenter Blvd. extension. Perhaps the road redevelopment will provide the City with the platform to finalize the trail design. I would encourage all parties involved in this project to keep this trail extension in mind. • • • Please keep me informed about this project. DW/blk cc: Phil Fraser, Acting Public Works Director Mayor Frank Todd RECEIVED CITY OF TUKWILA JAN 2 PUBLIC 1'VS,Sne CE ?T. • • • o ciTipe Municipality li of Metropolitan Seattle Exchange Bldg. • 821 Second Ave., Seattle,Washington 98104 January 28, 1982 MEMORANDUM TO: Tukwila Technical Advisory Committee 'FROM: Bob White, Supervisor of Capital Development SUBJECT: Transit Improvements for Southcenter Attached is a conceptual description of the service and capital improvements package which would provide Metro with the ability to serve a Tukwila Regional Transit Center. Metro believes that this package, when fully implemented, would result in a ten percent or better mode split for the area. If combined with higher employment /trip densities in 1990 or beyond, this concept could accomplish even more. It should be noted that the transit center locations shown on • the map are generalized and considerable flexibility exists in the location and design. Metro looks forward to the oppor- tunity to continue to work with you in the implementation of improved transit, appropriate to and supportive of your land use and development plans. • • • BW:kc Attachment ' W :�i.. c••> ua'F 'i-. c.�..i77"�- v} fR'. 4 .Y`n 1 .Yr..i .. ?'•z,���.i �'iijti'?r!`i1:G•:,,�'C 4:� �•X.;gSd'n.,.w .!. �Jr a ya � >A, ^' . [: � M - • • • • • Regional Transit Centers Regional Transit Centers will serve as "gateways" to the regional transit system and to their surrounding communities. These centers shall be located in.existing or emerging regional activity centers with convenient pedestrian access . to nearby activities. The purpose of Regional. Transit Centers will be multifold: 1) to : serve. as transit..focal= points. for the respective areas.which function .as regorial.destinations themselves; 2). to facilitate transfers between buses going to the Seattle CBD or to other activity.centers;:;..3) to serve as transit system information and customer service centers for greater public convenience; and 4) to provide connections between the transit system and those public and privately • operated vanpool services oriented'to employment areas which cannot be as efficiently served by regular or subscription bus services. Local service to and from these Regional: Transit Centers will be provided during the off -peak periods in a "timed- transfer" manner. Timed - transfer means that buses would be scheduled to arrive at a center at almost the same time to allow convenient, "no wait" transfers. In this way, most of the' perceived negative aspects of having to transfer can be reduced or eliminated. Similar operations have been found . to be an efficient and effective way to provide greater mobility and service coverage to lower density urban and suburban areas. Southcenter has a logical potential to be a transit focal point by virtue of its location and the vitality of growth in the Southcenter /Andover Park area. The large Southcenter shopping mall is an attractive midday destination for many southend residents, while the Andover Park area is a growing center of employment. A well integrated transit center /timed- transfer bus service would provide Metro a way in which both peak and off -peak transit needs could be enhanced. 1/28/82 • • • 4. Is LEVUE gerse a Ilo• . . ...„ • • ..-.-!!. A....,- N, ce +1 I tilt r 4 !ill i ii a ii a ••,'! ri.■,-.. 1 v.i• ---4 . sti a • - .4t4, I rig a -•:1,$:* ..-,1!, 6111 V g',1 g T.; Iran" Rente _. ..1. -4, ....4.01/ Isipit as ar a # ina-mr-- ..%, aq ' \ C %.1.1 II g r . z 0 0 a 1 • a . 0_ r s Lori N. ... II 1 its* ii 31 nvi mum al w al .11••■., • W.4 A METRO SERVICE ORIENTATION TRANSIT 1990 PLAN E3 METROPOLITAN CENTER SECONDARY URBAN AREA ® 'REGIONAL TRANSIT CENTER Eg COMMUNITY TRANSIT CENTER A TRANSIT COLLECTICN'EXCHANGE RADIAL SERVICE TO SEATTLE CB.D Nagano SERVICE TO OTHER CENTERS oak PARATR.ANSIT ROVING VAN SERVICE 'VAN POOLS • ao • Service Concept - Southcenter Regional Transit Center. Existing service to Southcenter area consists of: - Five routes operate all day to the area from Seattle, Burien, Auburn /Kent, Renton and Bellevue /Eastside. (Routes 123, 150, 155, 240, 340.) This service is augmented by limited paratransit service. - Most peak hour service has been scheduled to serve • core hours at Southcenter with some express service provided. Limited peak hour service scheduled specifically for Boeing complexes. • - No direct service from the Federal Way area exists at this time. - Many of our existing routes serve only the Southcenter Mall with little penetration South of that area. Initial concepts for service to the Regional Transit Center • include: • • • - Revised routing to serve both the Southcenter Mall as well as industrial /office parks via a "transit corridor" on Andover Park West. - Continued operation of direct service to the area from Auburn /Kent, Renton, Burien, Bellevue /Eastside, and downtown Seattle. - Initiate new,peak hour service from areas that do not presently have direct service. Federal Way /Southcenter Kent East Hill /Southcenter West Seattle /Southcenter (Limited midday service from these areas may also be added.) - Possible shuttle service to be provided by the Southcenter merchants and /or major employers in the area. 'Operating to /from the transit center. JH:ct 1/27/82 • • • • TRANSIT IMPROVEMENTS FOR THE SOUTHCENTER AREA The following numbers are keyed to the Daily Traffic Assignment map: . . OInterurban Avenue and Southcenter Boulevard Improve turn radii and signalization /channelization. Tukwila Parkway and Andover Park West Improve turn radii and. signalization /channelization. OStrander Boulevard and Andover Park West Signaliza.tion /channelization. Minkler Boulevard and Andover Park West Signalization /channelization. OSouth 180th Street and West Valley Highway • Signalization; provide preferential transit turning lanes; provide space and improvements for bus zones at this intersection to allow transfers. OSouth 18.0th Street and Andover Park West • Improve turn radii and signalization; widen South 180th Street between Southcenter Parkway and West Valley High- way and incorporate preferential transit turning lanes at this intersection. South 180th Street and Southcenter Parkway Signalization /channelization. South 188th Street and I -5 South Provide a new southbound ramp for new connecting arterial • between South 188th Street /I -5 and Southcenter Parkway. OAndover Park West between Tukwila Parkway and South 180th Street. Construct a transit -only lane in each direction on Andover • Park West to ensure efficient transit operations. Incor- proate with items 2 -5. • • 10 Tukwila Parkway between Southcenter Parkway access and Christensen Road Construct a transit -only lane in each direction. along Tukwila Parkway to minimize transit delays due to congestion. (ID Mid -Block Pedestrian Access Construct pedestrian walkways at mid -block between inter - sections of superblocks east and west from Andover Park West as indicated by arrows to improve pedestrian access • to the proposed transit corridor. • Transit Center Facilities Construct one facility near the shopping mall and a second facility further south along Andover Park West to allow all • routes arriving from north and south to serve both the shopping area and the office /industrial park area. Routes arriving from the north would turn around at the south facility, while routes arriving from the south would turn around at the north facility. • • • • • HOV Projects Neither Programmed nor Budgeted by WSDOT • I -5 South: Southcenter Ramp Improvements Provide HOV lanes from I -5 to Southcenter. Approximate cost: $9,200,000,1983 -1987. • I -405 South: Southcenter Transit Access Provide HOV lanes from I -405 to Southcenter. Approximate cost: $6,000,000, 1983 -1987. JL:ct 1/28/82 J*4 r w rA.AtrT nV /I�� •t.rs�ur o. .• M T.... ■•••■■ t. • 1•■••■• ' "ten• 0•P OS , f 7 O KT v TYaw.L. ac...[ e..a.r[ss 1OV4.4 4HT CA •• Orr.M• 1 h7 • ,...11111111.C131 • AIN MAP NO. 6 Number of Additional Lanes Needed to Maintain Level of Service D ••••••• One Additional Lane 1111111111 Two Additional Lanes lual Three Additional Lanes DAILY TRAFFIC ASSIGNMENT WITH 1990 PROBABLE GROWTH TRANSIT / CARPOOL WITH 10% MODE SPLIT, 1.40 ACO /M • /b 4 NI A /M 4M• 41.0 AV,. suL Revised & Printed October 1978 TRI -LAND CORPORATION • • • APPENDIX A • • • • • • • • • • • • • APPENDIX A VEGETATION FOUND ALONG THE PROJECT CORRIDOR COMMON NAME Trees Black Cottonwood Black Locust Big -Leaf Maple Common Horse Chestnut False Arborvitae Hawthorne Madrona Oregon Ash Red Maple Silver Maple Shrubs English Holly Himalayan Blackberry Pacific Willow Scotch Broom Herbaceous Plants Bluegrass var. Clover var. Common Tansy Common Dandelion English Ivy Fescue -grass var. Foxtail Barley Goldenrod Horsetail Sweetpea Source: Entranco Engineers SCIENTIFIC NAME Populus trichocarpa Robina pseudoacacia Acer macrophyllum Aesculus hippocastanum Thujopsis databrata Crataegus laevigata Arbutus menziesii Faxinus latifolia Acer rubrum Acer saccharinum Ilex aquifolium Rubus discolor Salix lasiandra Cytisus scoparius Poa sp. Trifolium spp. Tanacetum vulgare Teraxacum officinale Hedera helix Festuca sp. Hordeum murinum Solidago sp. Equisetum sp. Lathyrus sp. • • • • • • • • MAMMALS OF THE LOWER GREEN RIVER WATERSHED COMMON NAME American Oppossum Cinerous Shrew Vagrant Shrew Dusky Shrew Water Shrew Marsh Shrew Trowbridge's Shrew Shrew -mole Townsend's Mole Coast Mole Various Bats Eastern Cottontail Snowshoe Hare Mountain Beaver Townsend's Chipmunk Eastern Gray Squirrel Fox Squirrel Douglas' Squirrel Northern Flying Squirrel Beaver Common Deer Mouse Mountain Deer Mouse Bushy - tailed Wood Rat Gapper's Red - Backed Mouse Townsend's Meadow Mouse Long - tailed Meadow Mouse Oregon Meadow Mouse Muskrat Norway Rat Black Rat House Mouse Pacific Jumping Mouse Porcupine Nutria Coyote SCIENTIFIC NAME Didelphis marsupialis Sorex cinereus Sorex vagrans Sorex obscurus Sorex palustris Sorex bendirei Sorex trowbrdigei Neurotrichus gibbsi Scapanus townsendi Scapanus orarius Chiroptera Sylvilagus floridanus Lepus americanus Aplodontia rufa Eutamias townsendi Sciurus carol.inensis Sciurus niger Tamiasciurus douglasi Glaucomys sabrinus Castor fiber Peromyscus maniculatus Peromyscus oreas Neotoma cinerea C1ethrionomys. gapperi Microtus townsendi. Microtus longicaudus Microtus oregoni Ondatra zibethicus Rattus norvegicus Rattus rattus Mus musculus• Zapus tr.inotatus Erethizon dorsatum Myocastor coypus Canis latrans • • • • • • • • • • • MAMMALS OF THE LOWER.GREEN RIVER WATERSHED COMMON NAME Red Fox Black Bear Raccoon Short - Tailed Weasel Long - Tailed Weasel Mink Spotted Skunk Striped Skunk River Otter Bobcot Black- Tailed Deer SCIENTIFIC NAME Vulpes vulpes fulva Ursus americanus Procyon lotor Mustela erminea Mustela frenata Lutreola lutreola Spilogale putorius Mephitis mephitis Lutra canadensis Lynx rufus Odocoileus hemionus Source: Eastside Green River Watershed DEIS, U.S. Soil Conservation Service, November 1978 as adapted from Tukwila Hotel EIS. • • • • • • • • • Fish Soec i es of the '?r en ? i •i, =r Cc: mon '!arse Prickly Sculpin Threespine,Stickleback Brown Bullhead Large -mouth Black bass Chum Salmon Coho Salmon Chinook Salmon Yellow Perch Mountain whitefish Long - !lose Dace .Speckled Dace Cutthroat Trout Steelhead Trout Rainbow Trout Dolly Virden Trout Starry Flounder Scientific Name Cottus asper Gasterosteus aculeatus Ictalurus nebulosus Micropterus salrnoides Oncorhynchus keta Oncorhynchus kisutch Oncorhynchus tshawtscha Percy flavescens Prosopium williamsoni Rhinichtays cateractac Rhinichtays oculus Salmo clarki Sa l mo ga i r-d ner i Sa l rno oa i rdner i Salvelinus malma Prosopium stellatus Source: East Side Green River iate rshed DEIS, SCS, November, 1973. as adopted from Tukwila Hotel EIS. • • • • • • • • Swa i nscn' s Thrush Mountain 5luebira :!estern Iuebird Golden- Crowned Kinglet Ruby - Crowned Kinglet 11-ater P i p i t Cedar ':•; axw i.ng Northern Shrike Starling Solitary Vireo Red -eyed Vireo Warbling Vireo Orange-Crowned Warbler Hermit Warbler Yellow Warbler Townsend' s Warbler Black- Throated Gray Warbler Yellowthroat ',!i Ison's Warbler House Sparrow Western Meadow 1 arkk Red - !'dinged Blackbird Bullock's Oriole Brewer's Blackbird Brown- Headed Cowbird Western Tanner Black- Headed Grosbeak Pine Grosbeak Purple Finch House Finch Pine Siskin American Goldfinch White-Winged Crossb i 1 1 Rufous -Sided Towhee Slate - colored Junco Savanna Sparrow Chipping Sparrow White-Crowned Sparrow Golden- Crowned Sparrow White- throated Sparrow Fox Sparrow Lincoln's Sparrow Song Sparrow �'y locichla ustule a Siu.Iia currucoides Siilia mexicanna Regulus satrzpa Regulus calendula Anthus spinoletta Sobycilla cedrorum Lanius excubitcr Sturnus vulaaris Vireo solitarius Vireo olivaceus Vireo gilvus Vermivora celata Dendroica occidentatis Cendroica petechia Dendroica townsendi Dendroica nigrescens Geothlypis tichas !Wilsonia pusill Passer domesticus Sturnella neglecta Euphagus-cyancephalus Icterus bullockii Euphagus cyancophalus Molothrus ater Piranga 1udovici -ana llesperiphona vespertine Pinicola enucleator Carpodaccus purpureus Carpodacus mexicanus Spinus pinus Spinus tristis Loxia Ieucoptera Pipilo erythrophthalmus Junco hyemalis Passercu I us sand:r i chens i s Spizella passerine Zonotrichia leucophrys Zonotrichia artricpi1la Zonotrichia albicollis Passerella iliaca !1elospiza lincolnii ''elospiza melodia Source: East Side Green River 'Watershed DEIS, SCS, November, 197C. as adopted from Tukwila Hotel EIS. • • • • • • • American Coot Killdeer Common Snipe SpottedSandpiper Greater Yellowlegs ,Lessor Yellowlegs Pectoral Sandpiper Least Sandpiper Dunlin Long - billed Dowitcher !Western Sandpiper Wilson's Phalarope Glaucous- winged Gull Western Gu I I California Gull Ring - billed Gull i 'ew Gull Bonapar.te's Gull Band- Tailed Pigeon Rock Dove !burning dove Barn Owl Snowy Ow Spotted Owl Short -Eared Owl Common Nighthawk Slack Swift Vaux's Swift Anna's Hum ingbirdd Rufous Hummingbird Belted Kingfisher Red- Shafted Flicker Hairy l loodpecker Trail's Flycatcher Western Flycatcher Western Wood Pee Wee Olive -Sided Flycatcher Horned Lark Violet -Green Swallow Tree Swallow Bank Swallow Rough- Winged Swallow Barn .Swallow Cliff Swallow Purple i•lart i n Steller's Jay Common Crow Clack- Capped Chickadee Chestnut - Backed Chickadee Common Dushtit Winter —en Beer i ck' s ;Wren Long - Billed ,arsh ! r,.n Robin Varied Thrush Fulica americana Chcradr i pus voc i f erus Capella gallinaco Actitis macularia Totanus melanoleucus Totanus flavipes Erolia melanotos Erolia minutilia Erolia alpina Limnodromus scolopaceus Ereunetes mauri Steganopus tricolor Larus glaucescens Larus occidentalis Larus californicus Larus delawarensis Larus canus Larus philadelphia Columba fasciata columba livia Zenaidura macroura Tyto alba Hyctea scandiaca Strix occidentalis Asio flammeus Chordeiles minor Cypseloides niger Chaetura vauxi Calypte anna Selasphorus rufus P?enaceryle alcyon Culaptes cafer Dendrocopos Pubescens Empidonax traillii Empidonax difficilis Contopus sordidulus N'uttallornis borealis Fremophila alpestris Tachyccineta thalassina lridoprocne bicolor Riparia riparia Stelgidopteeryx ruficollis liirundo rustica Petrochelidon pyrrhonota Progne subis Cyanocitta stelleri Corvus brachyrhynchos Parus atricapillus Parus rufescens Psaltriperus minimus Troglodytes 'troglodytes Thryomanes b:;cr! i ck i i Telmatodytes palustris Turdus migratorius Ixoreus Maevius • • • Birds oi the Lower Green River Watershed Common Name Common Loon Horned Grebe • Western Grebe Pied - Billed Grebe • Double- Crested Cormorant.: Great Bluo Heron Green Heron -. . American Bittern Whistling Swan Canada Goose White- Fronted Goose Snow Goose Mallard Gadwall Pintail Green-Winged Teal Blue - tinged Teal Cinnamon Teal .European..Wigeon American l'!igeon or Baldpate Shoveler Wood Duck Redhead Ring - Necked Duck Canvasback • Greater Scaup Lesser Scaup Common Go 1 deneye Bufflehead Harlequin Duck White- winged Scoter Surf Scoter Common Scoter Ruddy Duck Hooded Merganser Common Merganser Red - Breasted Merganser Goshawk Sharp - shinned Hawk Red- Tailed Hawk Bald Eaale Marsh Hawk Osprey Gyrfalcon Peregrine Falcon Macon Hawk Sparrow Hawk Ruffed Grouse California Quail Ring - Necked Pheasant Virginia Rail Scientific Nara. Gavla irnmer . Pcdiceps auritus Aechmophorus occi- dentalis :Pod i I ymb us podi ceps Phalacrocoraxauritus Ardee.herodias l3utorides.virescens Botaurus lentiginosus Olor columbianus Branta canadensis Anser albifrons Chen hperborea Anas platyrhynchos Anas strepera Anas acuta Anas carolinensis Anas discors Anas cyanoptera Maraca penelope Maraca americana Spatula clypeata Aix sponsa Aythya americana Aythya collaris Aythya valisineria Aythya marila Aythya Affinis Sucephala clangula Sucephala albeola Histrionicus histrionicus Melanitta deglandi Melanitta perspeicillata 01demia nigra Oxyura jamaicensis Lophodytes cucullctus I•'ergus merganser tergus serrator Accipiter genti1is Accipiter cooperii. Buteo jamaicensis Haliaeetus leucocephalus Circus cyaneous Panion haliaetus Falco rusticolus Falco peregrinus Falco columbarius Falco sparverius Bonasa umbellus Lophcrtyx californicus Phasianus colchicus Ral lus I ir,iicola • • • • • • •, • n vironmental ssessment: prepared for CITY OF TU KW I LA, WA. SOUTHCENTER BOULEVARD 62nd Avenue. South To Grady Way September 1982 • • • • • • • • Federal Highway Administration Region 10 FOR REVIEW NLY SOUTHCENTER BOULEVARD IMPROVEMENTS 62ND AVENUE SOUTH TO GRADY WAY CITY OF TUKWILA ENVIRONMENTAL ASSESSMENT PURSUANT TO P.L. 91 -190 U.S. DEPARTMENT OF TRANSPORTATION FEDERAL HIGHWAY ADMINISTRATION and WASHINGTON STATE DEPARTMENT OF TRANSPORTATION and CITY OF TUKWILA Date Approved: City of Tukwila Date Approved: R.E. Bockstruck, P.E. Project Development Engineer Washington State Department of Transportation • Date Approved: Federal Highway Administration Official • • • • • • • • • • TABLE OF CONTENTS PAGE' r TABLE OF CONTENTS i LIST OF FIGURES ii LIST OF TABLES iii NEED FOR THE PROJECT 1 DESCRIPTION OF PROPOSED ACTION 6 IMPACTS OF THE PROPOSED ACTION 11 A. Earth 11 B. Air Art17, C. Water 13 -it D. Flora 18 E. Fauna 21 F. Noise 22 G. Light and Glare 25 H. Land Use 26 I. Natural Resources. 26 J. Risk of Upset 27 K. Population 28 L. Housing 28 M. Transportation /Circulation 29 N. Public Services 41 0. Energy 44 P. Utilities 45 Q. Human Health 46 R. Aesthetics 46 S. Recreation 48 T. Archaeological /Historical 48 U. Economic Impact . 48 ALTERNATIVES CONSIDERED 5� COMMENTS AND COORDINATION 55 APPENDIX A i • • • • • • • • • LIST OF FIGURES FIGURE NUMBER PAGE 1 Project Vicinity 2 2 Project Location 3 3 Existing Alignment 7 4 Recommended System 10 5 1981 Average Weekday Traffic 31 6 1990 No Build Average Weekday Traffic a3' 7 1990 Recommended Alternative Average Weekday Traffic 36 8 Proposed Alternatives _59'_5' ii • LIST OF TABLES • TABLE NUMBER PAGE 1 + 1979 -1981 Accidents 32 • 2 1990 Level of Service 37 3 1990 Accidents 39 • • • • • iii • • • • • • • • • • • NEED FOR THE PROJECT Southcenter Boulevard is an important east /west roadway that serves as an alternative route to a heavily congested section of I -405 for trips between Renton and Tukwila. The portion of Southcenter Boulevard scheduled for improvement lies between 62nd Avenue S. and Interurban Avenue. It is currently a narrow, curving two -lane road with unpaved shoulders and open drainage. West of 62nd Avenue S., the street widens to five lanes with curb and gutter, sidewalk, and closed drainage. East of the project, Grady Way is being widened to five lanes with curb, gutter, and sidewalk. Southcenter Boulevard curves north along the west side of the Green River, intersecting Interurban Avenue approximately 600 feet north of the intersection of Grady Way and Interurban Avenue. The resulting offset between Southcenter Boulevard and Grady Way requires that east /west traffic make a weaving movement between the two intersections. There is limited left -turn storage on Interurban Avenue, which frequently overflows into the through lanes during peak hours. Traffic signals are currently located just west of the project at the intersection of 61st Avenue S. and Southcenter Boulevard, at the Interurban Avenue /Southcenter Boulevard intersection, and at the Interurban Avenue /Grady Way intersection. The speed limit is 35 mph. The 1981 average weekday traffic count is 8,800 vehicles per day. Southcenter Boulevard /Grady Way has a functional classification of "minor arterial" from I -5 into Renton. Interurban Avenue (SR -181) has a functional classification of "principal arterial." Geometry along the existing roadway is poor, with a series of short radius, horizontal reverse curves connected by short, straight segments. Sight distance is limited due to the adjacent topography and the roadway profile. The Green River and the I- 405 /SR -181 interchange ramps are major obstacles to improving the alignment for this section of Southcenter Boulevard. The present alignment and narrow roadway increase travel time and congestion in the corridor, which reduces the effectiveness of Southcenter Boulevard /Grady Way as an alternative east /west route to I -405. 1 • • • • • • • • • 4 "..yslon Edmonds F'.ba ry mt • I Woodway. • �r rte, Indianolau. Poutsbo 1 I - ° �•''� ~• . • Supwmith "Lime PO" Y Pa. h.1h ' • mules , M,•aGov ; :i( I ql r. ri r r ■ rr , • Rolling Ray �- - -: w «I r u ,• G Poi:. \• , -lll -1y Y•.,rnalt Pt 1 Winslow wn,T Pant 144,4• ]Oa^ Port Rukely i ye.naa ' /a4n4r'•.:7 1L��NWhin- : •• .. 144.4 Re.wration, aIMA��i- ,' ,e .tea - „Urcnard P ••^ � 60 ml Wesouma Manchester Port 1 • •G, tt< Orchard�..�(tr,l ' ” -- pkokhesler e Colby mink l•ri4.nd� s Kkkland Alki Point Medina® --s Groat ft: o,..y�r rkanr , ' Veu.onv " rsmm B"q\ : -. SoutAwortn •at- Vashon Relines ' - -. .oy-% / Cb nP Point W.Ilrrru 4A ���q�hP V t.y / .tryj WIT' yt 4\e, _ -i Peter Saobn.' .II �ti.Jl.._\:11, 1 of _ ' 1tm1 Beau .i �. • •m ...© _t_;t �Tr--_ TUKWILA_ sw �,es_w 'SY ; Tree Point` N. Nathan Normandy '•• Pa vasnse :SI ANII PI Heyer ; �� ;�• : Elbsport ! pttPora`e 7 Des \ Moines )Robrnson /� R r" Zenith( DQk011 ,NAlikf ISUND ••• u Cm47.71 eh."oM • . _.1 Point Pin, o4I :_c • . -f N., a rt,) .. Ciq Harbor \ � ria'h Tahlequah • Onr. C' \ I aa ••r • A44,4. ° i ems 'me / Non `Ir,oa wns ......:,,,: \• \� BrPo.m A an' wton If ' jI_u_ \sIa ' 1L Redondo, a aocrh k Aer. "` Point '' 1 i 1,71 140 • nr ' • Arlen' • t'Tmtil- NORTFI Bay p View ENTRANCO Engineers s "'sTofa" '•- . • _;Tacoma - • City Of Tukwila • l Algona ,otuck SOUTHCENTER BOULEVARD 62nd Avenue South To Grady Way • 1 s.our� Figure 1 PROJECT VICINITY J • • • • • • • • • AFT. GENT PARK SOUTHCENTER nnnnlInhn Kieft 111,V.0 NORTH e City Of Tukwila SOUTHCENTER BOULEVARD 62nd Avenue South To Grady Way Figure 2 PROJECT LOCATION 1 • The existing street system within the study area, particularly along • SR -181, exhibits considerable operational problems. Through traffic from Grady Way to Southcenter Boulevard must turn right onto SR -181 and then left at the next intersection onto Southcenter Boulevard. Existing data indicate ghat this, as well as the reverse trip, is a high - volume movement, • particularly during the p.m. peak hour. Although level of service calculations would indicate that this section of SR -181 would operate reasonably well, the high volume of left turns onto Grady Way causes considerable congestion. Left -turn storage is not adequate to handle the volume and cannot be lengthened due to the proximity of the two inter- sections. Vehicles back onto the through lanes, restricting traffic. Since these intersections are quite close together, the backups can actually extend into the preceding intersection, blocking traffic there as • well. The operation of the section more closely resembles the level of service at the worst intersection, that being level D -E. The Department of Transportation counted traffic on I -405 and the access ramps in 1981 in conjunction with its high occupancy vehicle (HOV) study. These counts showed that freeway lanes through Tukwila are now operating at or near capacity . during peak hours. Even with the additional HOV lanes proposed for I -405, the freeway lanes will be operating at • capacity during peak hours. • • • Traffic volume between 1981 and 1990 is expected to increase considerably in the Tukwila area. The Tukwila Micro -Model Study, completed by Entranco Engineers in 1981, forecast a growth of 33 to 46 percent in vehicle trip ends over the ten -year period between 1980 and 1990 for the commercial - industrial area. The Southcenter Boulevard /Grady Way system is the only parallel arterial serving the I -405 corridor. It presently does not function adequately as an alternative route to I -405 for local traffic, partially due to the alignment shift at Interurban Avenue. The comprehensive street plans for the city of Tukwila and the city of Renton, as well as regional • goals of the Puget Sound Council of Governments, include an improved east /west arterial in this corridor. The roadway section proposed by this project is the final link in the route. • • • • • • • • Sixty;three accidents have been reported along this section of roadway over the last three years, resulting in 19 injuries. There have been two major types of accidents: intersection accidents involving turning or stopped vehicles, and accidents along the narrow curving roadway between 68th Avenue S. and SR -181 and between the Grady Way Bridge and SR -181, usually caused by a driverr losing control of his vehicle. With increasing traffic volumes, the number of accidents is expected to increase. At the intersections, the level of congestion will increase and with it the accident rate. Metro Transit's adopted 1990 plan includes a package of major service improvements in Tukwila aimed at creating a Regional Transit Center in the Southcenter /Andover Park area. This Regional Transit Center will be a transit focal point, and will coordinate transfers between local routes and through routes going to the Seattle CBD and to other activity centers. Current transit service focuses on downtown Seattle and on peak hour service. Future plans are to expand service to all day on existing routes and provide new service to areas that are currently without adequate transit service. The timely movement of buses on the street system is essential to the implementation of Metro's plan. Metro has requested that turn lanes and radii, signalization, and channelization improvements be made throughout the route system. Improvements to the Southcenter Boulevard corridor are essential to facilitate the movement of transit vehicles. The Tukwila Park Department's plan for sidewalks and trails includes the junction of two major routes within the limits of the proposed Southcenter Boulevard improvements. An east /west sidewalk /bikeway 5 • • -- • • • • • • • • • connecting Tukwila and Renton is recommended for this corridor and is currently either completed or under construction outward from each terminus of this proposed project. The Christensen Greenbelt Trail extends from S. 180th Street to Tukwila Parkway. The proposed project would extend it to Fort DentrPark. There is currently no sidewalk in the project corridor. The Puget Sound Council of Governments has given a high regional priority to the Southcenter Boulevard improvements because of the major corridor it serves, the existing congestion in the corridor, and the project's significance as the final link in the route with improvement projects completed or under way on both ends. DESCRIPTION OF THE PROPOSED ACTION The Environmental Assessment coincides with a preliminary engineering study that addresses proposed improvements to Southcenter Boulevard. The proposed project will provide an improved connection between Renton and Tukwila along Southcenter Boulevard /Grady Way. The proposed project is located in the city of Tukwila adjacent to the north side of Interstate 405. Tukwila and its vicinity are shown in Figure 1. Figure 2 shows the project location. The project limits are 62nd Avenue S. on the west and Grady Way on the east, and include intersections with Interurban Avenue (SR -181), the southbound on /off ramps of I -405, 68th Avenue S. (Christensen Road), 65th Avenue S., and 62nd Avenue S. West of 62nd Avenue S., Southcenter Boulevard is a five -lane facility up to its connection with I -5. Grady Way improvements, which extend from the eastern terminus of this project, will soon be constructed, making Grady Way a five -lane facility. Upon completion of the Grady Way improvements, this project segment will exist as the remaining unimproved link in this vital east /west arterial. The existing roadway alignment is shown in Figure 3. 6 410 To Fort Dent Park S9 ® t4S ER TUKWILA PARKWAY rTh CC W 0 W O 0 Y Z a ENTRANCO ErxNneers City Of Tukwila 1 SOUTHCENTER BOULEVARD 62nd Avenue South'To Grady Way 4111■1•■•11111■■••1111111•11111■1111■11< Figure 3 EXISTING ALIGNMENT • ;In October 1981, the Tukwila City Council authorized Entranco Engineers • to perform a preliminary engineering study to determine the nature of the design required to complete the unimproved segment of Southcenter Boulevard (Southcenter Boulevard, 62nd Avenue S. to Grady Way, September 1982). Tpat study and this document have been prepared under the auspices • of the Tukwila Department of Public Works and the Washington State Department of Transportation, State Aid Division. Funding for this project was made available through the Federal -Aid Urban Systems (FAUS) program. • • • • • • • • Four basic alternatives were developed and evaluated for this project. The four alternatives are: (1) a "no- build" alternative that evaluated the effects �f not improving the route; (2) widening the road to five lanes on the existing alignment; (3) constructing a high -level bridge between 68th Avenue S. and Grady Way spanning the Green River, the I -405 ramps, and Interurban Avenue; and (4) realignment of the roadway between 68th Avenue S. and Grady Way, creating an at -grade intersection with Interurban Avenue. Alternative 4, realignment at grade, is recommended as the alternative that best meets the objectives of the project. The recommended improvements are shown in Figure 4. The recommended roadway section for Southcenter Boulevard consists of two 12 -foot wide through lanes in each direction, with a 12 -foot wide two -way left -turn lane the full length of the project (3,500+ feet). Curb and gutter with closed drainage are provided on both sides of the roadway, with an 8 -foot wide sidewalk /bikeway on the north side only. A new traffic signal will be installed at the Southcenter Boulevard /Grady Way /Interurban Avenue intersection, and at the Southcenter Boulevard /68th Avenue S. intersection, with minor revisions to the existing signal at the Fort Dent Park/ Interurban Avenue intersection. A continuous illumination system will be installed on Southcenter Boulevard and on the realigned I -405 ramps. Three new bridges are required for the recommended alignment, including one on Southcenter Boulevard spanning the Green River and two on the realigned I -405 ramps: one crossing the realigned Southcenter Boulevard and one crossing the Green River. The two proposed river crossings will be 8 • • • • • • • • a three -span design having superstructures of prestressed concrete girders with cast -in -place concrete deck slab. The Southcenter Boulevard Bridge and I -405 southbound ramp bridge over the Green River will have minimum vertical clearances to the 100 -year flood elevation (12,000 cfs river flow) of approximately 4 feet and 6 feet, respectively. The I -405 southbound ramps over Southcenter Boulevard will be two prestressed concrete box girder superstructures having a minimum vertical clearance of 16' 6" to Southcenter Boulevard. The proposed trail system element (see Figure 4) will begin at the intersection of Tukwila Parkway and Christensen Road /Christensen Greenbelt Park and progress northward along the Green River. It will pass under I -405 and realigned Southcenter Boulevard, then follow the old Southcenter Boulevard alignment from a connection with the proposed sidewalk /bikeway on the south to Fort Dent Park on the north. No designated park land will be affected by the implementation of this project. A small amount of right -of -way (0.06 acre) will be required for the recommended design at some street and driveway intersections and for rock wall construction in areas of steep cut slopes. Temporary easements will be required for cut slopes and property restoration during construction, and access control is proposed at the new ramp intersection with Interurban Avenue. Depending upon foundation restrictions, environmental approvals, and permit limitations, the project could be under construction in the spring of 1984 and completed in the fall of 1986. Permits and approvals required for this project include: City of Tukwila Shoreline Management Substantial Development Permit State Flood Control Zone Permit State Department of Game and Fisheries Hydraulics Approval . U.S. Cost Guard Bridge Permit U.S. Army Corps of Engineers 404 Permit State of Washington Department of Transportation Design Approval 9 To Fort Dent Park T Connection Point Of Proposed Trail With Existing Sidewalk To Fort Dent Park 14Q cc 0 WILA a PARKWAY w CC ria 0 C z Connection Point Of Proposed Trail With Existing Christensen Greenbelt Park e 4 NORTH ENTRANCO Engineers Realignment Of Existing Roadway 1---1 New Bridge Structure --+r-• Widen Existing Roadway Close Existing Roadway • • • Proposed Trail System Sidewalk /Bikeway tuuutunt City Of Tukwila SOUTHCENTER BOULEVARD 62nd Avenue South To Grady Way Figure 4 RECOMMENDED SYSTEM • • This project has been coordinated with the replacement of the South Grady Way Bridge, the I -405 HOV considerations, and completion of the Christensen Greenbelt Trail. The tq.tal estimated construction cost for the proposed alternative is $6,813,000 in 1982 dollars; estimated right -of -way costs are $40,000. Total project cost is $6,853,000. IMPACTS OF THE PROPOSED ACTION • A. Earth Existing Conditions • • • • • • According to the U.S. Soil Conservation Service soil survey of the King County area, a small area of Newberg silt loam, an alluvial soil, is present near the existing intersection of Interurban Avenue and Southcenter Boulevard. With this exception, soils in the rest of the project area are classified as "urban." This classification is interpreted to mean that there has been so much excavation, filling, and other general soil movement in the project vicinity that the soils in the area cannot be accurately identified as any particular soils series or complex. The survey notes that the Green River Valley fill generally ranges from 3 to 12 feet deep and ranges in composition from gravelly sandy loam to gravelly loam. The topography of the project area varies greatly. At its intersection with 62nd Avenue S., Southcenter Boulevard has an elevation of approxi- mately 60 feet above sea level. Eastward, the roadway slopes down gradually to about 30 feet above sea level at its intersection with 65th Avenue S. before rising to about 44 feet above sea level just west of the Green River, where the existing northward curve begins. Following the bend of the river to the northeast, Southcenter Boulevard varies slightly in elevation before dropping to a level of about 35 feet above sea level at its intersection with Interurban Avenue. 11 • • • • • • • • • ;Just north of the roadway, between 62nd Avenue S. and the Green River, a steep bluff rises to a height of about 90 feet. South of the roadway, the land slopes down sharply to I -405, which has elevations ranging from about 25 to 30 feet in this area. East of the Green River, I -405 (with embankmeq elevations of 44 to 50 feet) is higher than the adjacent land, which lies approximately 24 to 28 feet above sea level. Environmental Impacts In constructing the project, soils will be disrupted and displaced. Road widening and storm drain installation along Southcenter Boulevard between 62nd Avenue S. and the Green River will require excavation, compaction, and overcovering of the soil. Fill will be needed for approaches to the two bridges over the Green River, for the realigned Southcenter Boulevard east of the river, and for the planned northward extension of the existing I -405 southbound on /off ramps. Embankments will be as high.as.30 feet, altering the local topography. Some localized deep borings may be necessary for pier supports to elevate the I -405 ramps above the realigned Southcenter Boulevard. Approximately 14,000 cubic yards of soils will be excavated, and about 34,000 cubic yards of fill will be required. Roadway widening and realignment and I -405 ramp extensions will add approximately 3.5 acres of impervious surfacing to the area. During site preparation and construction activities, the presence of uncovered soils and stockpiled fill will increase the potential for erosion. Mitigating Measures The placement of embankments and other construction activities that have a potential for increasing erosion can be scheduled to avoid the rainy season. 12 • • • • • • • • • • A number of methods and devices can be employed to control erosion during construction. These measures include the use of desiltation ponds, construction staging to limit the amount of soils exposed in the project area at any one time, and covering or revegetation of exposed soils and stockpile) fill. B. Air Existing Conditions National ambient air quality standards have been established to protect the public from air pollutants discharged from various sources (i.e., factories, autos). Of significance to the Southcenter Boulevard project are motor vehicle emissions that contribute carbon monoxide (CO), oxides of nitrogen (NOx) and hydrocarbons (HC) to the atmosphere. These pollutants may concentrate under stagnant weather conditions and exceed health standards. They may also chemically react under the influence of sunlight to form photochemical oxidants (smog) that can be harmful to human health, vegetation, and property. Air quality in Tukwila falls under the jurisdiction of the Puget Sound Air Pollution Control Agency ( PSAPCA). By law, the standards set by any subfederal jurisdiction cannot be less stringent than the national standards. The standards adopted by the PSAPCA are identical to the national standards, with the exception that additional standards have been promulgated for sulfur dioxides. Carbon monoxide is the only air pollutant that can be accurately quantified and predicted on a small -scale basis with existing technology and modeling programs. There was no CO monitoring data available from any federal, state, local, or private agency that was pertinent to the project area; therefore, current air quality conditions relative to CO standards are unknown. 13 • ;Existing air quality in the project area is affected largely by • vehicles traveling on I -405. The proposed site is shown on maps from the State Implementation Plan as being within the boundaries of nonattainment areas for carbon monoxide and photochemical oxidants. • • • • • • • • • r Environmental Impacts Construction activities will generate dust and other suspended particulates, which may result in short -term violations of air quality standards. Emissions from construction equipment and paving operations may also result in short -term air quality and odor impacts. Some air quality impacts from increased traffic usage of the new facility can be expected. It is believed that the improved traffic flow and reduced congestion resulting from construction of the new facility will be beneficial for air quality on a long -term basis. Most air quality degradation in the project area will continue to be related to vehicles using I -405, SR -181, and other nearby roadways. However, an air impact analysis using projected traffic counts and physical characteristics of the new facility will be undertaken for the City by the Washington State Department of Transportation in order to substantiate the assumption of nonsignificant impact. This document will be appropriately amended when the results of the air analysis are made available. Mitigating Measures Watering haul roads and cleaning streets should help reduce construction- related dust. Proper maintenance of construction equipment and minimum idling time will help minimize construction vehicle emissions. No operational plan to mitigate long -term vehicular emission impacts is proposed other than reliance on the State vehicle inspection and maintenance program and the gradual replacement of older vehicles with newer models with better emission controls. 14 • • • • • • • • • • C. Water Existing Conditions TheGAeen River is the major water body in the project vicinity and receives all drainage from the project area. According to the State of Washington Water Quality Standards, this portion of the Green River falls into the Class A (excellent) designation. Water quality of this class shall meet or exceed the requirements for all or substantially all uses, including water supply, wildlife habitat, recreation, commerce, and fish production. There are established water quality criteria for Class A waters which should not be violated. The Municipality of Metropolitan Seattle (Metro) regularly samples the water quality of the Green River at different locations along the water course within Metro's jurisdictional boundaries. Data collected at the Interurban Avenue crossing of the Green River was reviewed in an effort to evaluate the existing water quality conditions and compare the existing values to State standards. From the 50 sampling dates over the 1980 -81 period, the following determinations were made: 1. In the project area, the Green River exceeds the standards for fecal coliform organisms. 2. On one occasion during that two -year period, the river exceeded the desirable limit of 18° C for temperature. The dissolved oxygen level dropped below the standard of 8.0 mg on this same occasion. 3. Turbidity standards are occasionally exceeded. High turbidity tends to coincide with periods of high suspended solids.. Other parameters, including nutrients and heavy metals, for which the Green River is tested often exceed the recommended limits considered beneficial for freshwater aquatic life. 15 • • • • • • • • • • ;A U.S. Geological Survey flow recording station is also located on the - Green River in the vicinity of the project area. The latest year of record is 1979. During that year, the maximum .flow recorded was 6,490 cfs, with a minimum flow of 250 cfs and mean of 1,193 cfs. The maximum flow ever recorded was 13,200 cfs in November of 1959. According to the King County Surface Water Management Division, the 100 -year flood discharge is estimated to be 12,000 cfs. The 12,000 cfs river flow is controlled by discharge of the Howard Hanson Dam and includes the future maximum P -1 channel pumping. Environmental Impacts The recommended alternative will result in the formation of approximately 3.5 acres of additional impervious surface area. During the 100 -year frequency storm, this surface area would result in an additional runoff volume of 2.5 cfs. This volume was calculated by using the formula Q = CiA = 0.90 (0.80)(3.5) = 2.5 cfs, where: Q = runoff volume (cfs) C = runoff coefficient (0.90) i = intensity in inches /hour (0.80 for 100 -year storm, 1 hour duration) A = area in acres (3.50) The modified Southcenter Boulevard alignment, new bridges, and new ramps will require some changes in the existing drainage structures., but drainage patterns will remain basically the same. The total additional 2.5 cfs for the above described storm event will enter the river as fractionated flow from various discharge points, but all will enter near the new Southcenter Boulevard crossing. 16 • • • • • • • • • ;Since the river has an estimated discharge of 12,000 cfs at this location during the 100 -year occurrence, the small amount of additional runoff does not merit concern. When pajor storms occur in the region, the Green River flow is allowed to increase by the manual control of outflow through the Howard Hanson Dam. Stormwater discharge to the river must occur prior to the time that rise in water level reaches the Tukwila area or gravity discharge into the river will not take place, backing up stormwater into drains, surface drainage channels, and streets. Therefore, in the project area east of Christensen Road, no stormwater detention presently exists nor is any proposed to minimize the time required for runoff to enter the Green River. Storm runoff west of this area will continue to be discharged into the existing detention basin, where some physical treatment occurs. The new impervious surface area will collect some additional atmospheric and automobile - generated pollutants that will be washed into the river during storm events. Again, considering the volume of additional runoff and the river volume during rainstorms, the pollutant contributions are not considered to have any significant water quality impacts. Fill necessary to construct the new bridge embankments will be placed in the Green River floodplain. Although the project will result in the loss of 0.25 acre of the floodplain fringe area, no construction will take place in the floodway and no impact on the flow of floodwaters is expected. During construction, the fill required to construct new embankments as well as spoils piles from excavation will be subject to erosion. If not controlled, eroded soil will enter the waterway and add to the turbidity and suspended solids problems that now occur during many rainstorms. Oil, hydraulic fluids, fresh concrete, and other materials may also enter the river during construction activities. No groundwater impacts are anticipated. 17 • • • • • • • • ;Mitigation Measures All established practices for controlling erosion and for preventing construction equipment pollutants from entering the Green River will be specifiedoin the contract documents. A good street cleaning and maintenance program can help reduce the potential for water quality impacts. D. Flora Existing Conditions The project corridor can be divided into two distinct segments, each of which are represented by different vegetation habitats. The western half of the project corridor consists of Southcenter Boulevard between 62nd Avenue S. and 68th Avenue S. (Christensen Road). This portion of the corridor has plant life that can be considered "roadside" habitat. A portion of the flora on the north side of the roadway in this area is composed of lawn and landscaping plants, some of which are poorly maintained. Trees found on the north side of the roadway include Big Leaf Maple, Oregon Ash, Red Alder, Pacific Willow, Black Cottonwood, Mountain Ash, Hawthorne, Western Holly, and Black Locust, with understory vegetation consisting primarily of trailing blackberry, horsetail fern, and various species of grasses. Most of the vegetation on the south side of Southcenter Boulevard along the western section of the roadway consists of Big Leaf Maple, Oregon Ash, and Red Alder trees. These trees border the right -of -way and persist on the steep hillside that slopes downhill toward I -405. The understory vegetation is much the same as along the north roadway border. These trees are periodically trimmed to prevent them from becoming an obstruction to vehicles traveling east on Southcenter Boulevard. 18 • • • • The eastern portion of the project area is represented by typical Northwest riparian vegetation. Trees covering the left bank of the river include Big Leaf Maple, Red Alder, Pacific Willow, and Black Cottonwood. The right bank is mostly covered by blackberry vines and thick grasses: but also has scattered groupings of trees of the same species as previously described for the left bank. A large section of grassy floodplain lies adjacent to the right bank of the river. It is bordered on the other two sides by roadway -- Interurban Avenue on one side and I -405 on the other. This area is presently an unmaintained grass field scattered with a variety of trees and shrubs. Some of the plants are not native to the Northwest and were likely introduced by farmers who settled the area. Introduced species observed in this area include Horse. Chestnut, Rybergs Cottonwood, and Red Maple. Other trees include some very old growth Big Leaf Maple and Black Cottonwood, as well as Black Locust, Oregon Ash, and False Arborvitae. Although the area is a floodplain, it does not support wetland vegetation. Its dryness is reflected by the remnants of an irrigation • system in the field described above. However, a small patch of cattails was observed in a depression at the end of one drainage culvert. • • • The slopes of the existing I -405 southbound on /off ramps are planted with Scotch Broom. The highway right -of -way east of Interurban Avenue is a grassy area bordered by Poplar, Cottonwood, and Silver Maple trees. Environmental Impacts A total area of approximately 4.5 vegetated acres will be cleared and grubbed to build the preferred alternative. Most of the land cleared of vegetation will be paved or covered with overburden to establish the new alignment for Southcenter Boulevard, change the I -405 ramps, and create the widened portion of the existing roadway. Some will be cleared temporarily to facilitate the movement and storage of construction materials and equipment, but will be revegetated upon completion of the project. 19 • • • • • • • • • • Trees and plantings along the existing two -lane roadway west of 68th Avenue S. will be removed from both the north and south side of the street, but the change will be more physically evident on the north side. Because of the installation of drainage structures and retaining walls to construct a sidewalk, vegetation removal will be more of a permanent change on the north side. Even where clearing is required on the south side, a strip of vegetation will still separate the new roadway from the I -405 right -of -way. The major vegetation loss will be the trees and plants which will be removed along the river banks and in the floodplain in order to construct the bridges for the new Southcenter Boulevard alignment and I -405 ramps. This includes some old growth plants and some exotics that cannot be readily replaced. No land currently used for agricultural purposes will be utilized for this project. With the exception of an approximately five - square -foot drainage area that supports a group of cattails, no established wetland will be affected by this project. No rare or threatened plant species are known to exist in the project area. Mitigating Measures All exposed soil areas will be revegetated with rapid - growing plants upon completion of construction. A landscape plan has been developed for the street and trail sections utilizing both indigenous and introduced species of plants that will not only provide protection against erosion but also attract wildlife and add beauty to the area upon maturity. 20 • • • • • • E. Fauna Existing Conditions Both the existing roadside habitat and riparian habitat described in the flora section of.this'document are capable of supporting a variety of birds, small mammals, and reptiles. A complete list of mammals and birds sighted in the Lower Green River Watershed is provided in Appendix A. Because of the present developed nature of the project area, only those organisms that can readily adjust to human encroachment can be expected to utilize the existing habitat. For example, members of the rodent family, oppossum, and raccoon may be found in the region, but •.t is unlikely that mink, bobcat, or fox would be sighted. Most birdlife in the project area is likely to consist of songbirds or those species that require the unique elements of the river habitat for survival (i.e., bank swallows). Fish species in the Green River are also listed in Appendix A. Sixteen types of fish are known to inhabit the river, including several anadromous species. Impacts As described in the "Flora" section, approximately 4.5 acres of vegetation will be lost by implementation of the preferred alternative. The removal of this plantlife will result in the displacement and /or destruction of many of the animals that utilize this flora for their habitat. Mature trees that provide nesting, perching, and food sources for birds will be lost. Placement and compaction of fill material will eliminate food sources and burrows of many small mammals and reptiles. During construction, when earth from excavation and fill placement is unstable, erosion during rainstorms could result in a reduction in water quality that might be harmful to fish and other aquatic organisms. The loss of riparian vegetation reduces food sources and natural shade to the river. 21 • • • • • • • • • • No rare or endangered species will be affected by this project. Mitigating Measures Revegstation of exposed areas and permanent landscaping will provide some compensation for lost habitat. Mitigation measures discussed in the "Earth" and "Water Quality" sections will help prevent erosion and reduce impacts to fish species. F. Noise Existing Conditions The project area is near the I -405 corridor. Approximately 125 horizontal feet and a grade level difference of about 40 feet separate the closest lane of I -405 from Southcenter Boulevard at its intersection with 62nd Avenue S. About 900 horizontal feet and a grade level separation of approximately 22 feet separate the closest lane of I -405 from Southcenter Boulevard at its intersection with Interurban Avenue. Traffic volumes on I -405 are the . principal noise source in the project area. On December 8, 1981, the State Department of Transportation (WSDOT) • took noise readings during the afternoon peak hour (4:15 p.m.) at two locations approximately 3/4 of a mile east of the intersection of Interurban Avenue and Southcenter Boulevard. One location was approximately 100 feet from the nearest I -405 lane, and the second was about 225 feet from the nearest I -405 lane and about 50 feet from S.W. 16th Street, the access road to Longacres racetrack. Estimated traffic volumes on I -405 during the afternoon peak hour of December 8, 1981 were 3,312 for the northbound (nearer) lanes and 2,988 for the southbound lanes. Heavy trucks composed approximately 2 percent of the combined volumes. At the first location, closer to I -405, a maximum level of 88 dBA and an Leq of 74 were registered. The second location had a maximum level of 78 and an Leq of 67. 22 • • • • :Based on proximity, these readings are considered to be of the same general magnitude as those that currently exist along Southcenter Boulevard, as influenced by I -405. Envircanmental Impacts The nearest structure to the area where construction would take place is a commercial building located approximately 30 feet from the existing Southcenter Boulevard roadway. Several other businesses and homes are located at higher elevations and significantly greater distances from the roadway. According to the list contained in "Noise from Construction Equipment • and Operations, Building Equipment, and Home Appliances," issued by the U.S. EPA, most construction equipment likely to be used on the project produces noise levels ranging from 79 to 91 dBA when recorded 50 feet from the source. Pile drivers are one of the noisier types of equipment, with sound levels at about 101 dBA when measured from a distance of 50 feet. • • • • • • Temporary noise impacts to the commercial property close to Southcenter Boulevard would arise primarily from equipment used to widen the roadway. Because of the proximity of the building, intermittent noise levels received by this property during the widening phase of project construction could sometimes be in the range of 91 dBA. Supports for the new bridges over the Green River will be pile driven. However, greater distances (at least 200 feet) would separate developed properties from pile driver operations. The noise impact expected at the commercial building from this particular source would be reduced to approximately the level of impact from other project equipment. During construction of the Southcenter Boulevard bridge over the Green River, bicyclists and pedestrians near the existing northern terminus of the Christensen Greenbelt Trail would be subject to elevated noise levels 23 • • • • • • • • arising from the use of a pile driver and other equipment.• As a result, the attractiveness of this part of the trail may be temporarily reduced for its users. No significant adverse noise impacts are expected as a result of this project once construction has been completed. However, a noise impact analysis that assesses the noise levels to adjacent properties as a result of this project is being conducted by the State of Washington Department of Transportation. Although the analysis is not yet complete, traffic volumes on I -405 are the dominant noise source in the area and will likely remain so. With the project, the Southcenter Boulevard alignment east of the river will be closer to I -405 and farther from developed properties. These determinations will be modified as necessary when the Department of Transportation analysis is complete. Mitigating Measures A number of measures can be taken to reduce potential project noise impacts during construction, including: 1. Limit the use of equipment that generates high noise levels to normal working hours (8:00 a.m. to 5:00 p.m.). 2. Use modern equipment that is designed or properly muffled to reduce noise. 3. Construct temporary noise barriers around pneumatic equipment or other high noise generators. No permanent noise protection is planned for installation as an element of this project. 24 • • • • • • • • • • G. Light and Glare Existjng Conditions Street lighting is currently provided only where Southcenter Boulevard intersects other streets: 62nd Avenue S., 65th Avenue S., 68th Avenue S., and Interurban Avenue. The luminaires provide lighting for pedestrians at the existing intersections. Some light from luminaires along I -405 may contribute minimally to the existing lighting level along Southcenter Boulevard. Headlights on vehicles traveling on Southcenter Boulevard provide the majority of available lighting during the evening and nighttime hours. Impacts Additional traffic expected to use the new roadway will increase the amount of light and glare from headlights during the evening and nighttime. The continuous illumination system along Southcenter Boulevard required by development of a full length left -turn pocket will provide a minimum design light level of 0.9 foot candles. The new system will utilize energy efficient high pressure sodium vapor lamps. Mitigating Measures The new illumination system will direct light where needed on the roadway surface and the proposed sidewalk by use of reflectors and refractors. Post- construction landscaping will also help prevent light from luminaires and vehicles from being transmitted to other areas. 25 • • • • • H. Land Use Existing Conditions Land use to the north of Southcenter Boulevard is a mixture of single - family residences, multifamily residences, and commercial offices. Most of the hillside north of Southcenter Boulevard between 68th Avenue S. and Interurban Avenue is undeveloped. A large portion of that is designated park land (Tukwila Park). The area between Southcenter Boulevard south to Tukwila Parkway is owned by the State as part of the I -405 right -of -way. The existing comprehensive land use plan designates the area just north of Southcenter Boulevard for office development. The State -owned property is undesignated. Impacts The proposed project will improve access and increase the capacity of the roadway system. This may accelerate the development of currently undeveloped land or the redevelopment of currently underutilized land. A total of.0.06 acre of land designated for office use will be acquired for road right -of -way. Mitigating Measures None. • I. Natural Resources Existing Conditions • • • Natural resources in the project area are limited. There are no energy sources, mineral deposits, marketable timber, or other major resources that have been identified in the project area. The Green River is considered the most valuable natural resource in the project corridor. 26 • • • • • • Impacts Materials and fuels used for construction of the new facilities will add to the depletion of natural resources. Materials include cement . concrete,Aasphalt concrete, reinforcing steel, gravel, and other general construction materials. The estimated fuel and material consumption has been converted to equal 112,000 million BTU's of energy. No impacts to the resource value of the Green River are anticipated. Mitigating Measures See "Energy." J. Risk of Upset Existing Conditions Other than normal traffic hazards, there is no known source of explosion or hazardous substance release related to the present use of this facility. Impacts The new roadway width, improved alignment, illumination, and signals should increase safety and reduce the risk of upset. During construction, the risk of upset may be increased due to equipment fueling or other operations that pose a certain risk not normally associated with regular roadway use. Mitigating Measures The contractor should follow the necessary safety precautions when handling hazardous or flammable materials. 27 • • • • •.> • • • • • K. Population Existi,ig Conditions The population of the city of Tukwila was 3,600 in 1980 according to the 1980 U.S. census of population and housing. This is a 2 percent increase in population since 1970. During the same time period, King County population has grown 9.5 percent. Projections made by the Puget Sound Council of Governments for the Tukwila area indicate an increase of 12 percent, to just over 4,000 in 1990. Impacts The improved access to employment and residential areas may attract a minimal number of people who would otherwise locate elsewhere. Mitigating Measures None are proposed. L. Housing Existing Conditions The 1980 housing count for the city of Tukwila indicated a total of 1,940 dwelling units. This is a 16 percent increase over the 1970 housing total. During the same time period, the number of dwelling units in King County grew by 24 percent. Projections for 1990 made by PSCOG indicate a growth of 29 percent over 1980 totals for the city of Tukwila. This would result in 2,500 dwelling units in 1990. 28 • • • • • • • ;Impacts A minimal increase in housing demand may result from construction of this project due to a minimal increase in population. 0 Mitigating Measures None are proposed. M. Transportation /Circulation Existing Conditions Southcenter. Boulevard is an important east /west roadway that serves as an alternative to a heavily congested section of I -405 for trips between Renton and Tukwila. It is currently a narrow, curving two -lane road with unpaved shoulders and open drainage. West of.62nd Avenue S., the street widens to five lanes with curb and gutter, sidewalk, and closed drainage. East of the project, Grady Way is being widened to five lanes with curb, gutter, and sidewalk. Southcenter Boulevard curves north along the west side of the Green River, intersecting Interurban Avenue approximately 600 feet north of the intersection of Grady Way and Interurban Avenue. The resulting offset between Southcenter Boulevard and Grady Way requires that east /west traffic make a weaving movement between the two intersections. There is limited left -turn storage on Interurban Avenue, which frequently overflows into the through lanes during peak hours. Traffic signals are currently located at the intersection of 61st Avenue S. and Southcenter Boulevard, just west of the project at the Interurban Avenue /Southcenter Boulevard intersection and at the Interurban Avenue /Grady Way intersection. Geometry along the existing roadway is poor, with a series of short radius, horizontal reverse curves connected by short, straight segments. Sight distance is limited due to the adjacent topography and the roadway alignment. The Green River and the I- 405 /SR -181 interchange ramps are 29 • • • • • • • • • • • major obstacles to improving the alignment for this section of Southcenter Boulevard. The present alignment and narrow roadway increase travel time and congestion in the corridor, which reduces the effectiveness of Southcenter Boulevard /Grady Way as an alternative east /west route to.I -405. r Average daily traffic volumes were counted in the project vicinity in 1979, 1980, and 1981, then factored to a- common year and balanced for the entire system using both computer and manual methods. The estimated 1981 average weekday traffic volumes are shown in Figure 5. The number of accidents in the Southcenter Boulevard corridor has been remarkably low considering the geometric configuration and high traffic volume. Property damage accidents are predominately rear -end type accidents generally caused by driver inattention. Injury accidents result from a driver losing control of his vehicle, usually on the narrow, winding section of roadway between Interurban Avenue and 68th Avenue S. The total number of accidents within the project limits for the three preceding years (1979 -1981) is 63. Table 1 summarizes the accidents by type and severity for those years. According to current traffic counts along I -405 between Tukwila and Renton, that segment of freeway is operating at level of service E during peak hours. Travel speed drops to less than 30 mph, with long delays for traffic attempting to enter the traffic stream from entrance ramps. The only alternative route through the corridor is Southcenter Boulevard /Grady Way. The poor alignment and narrow roadway on that route prevent it from providing efficient relief to I -405. The existing street system within the study area, particularly along SR -181, exhibits considerable operational problems. Through traffic from Grady Way to Southcenter Boulevard must turn right onto SR -181 and then left at the next intersection onto Southcenter Boulevard. Existing data indicate that this, as well as the reverse trip, is a high - volume movement, particularly during the p.m. peak hour. These large turn volumes cause 30 • • • • • • • • 16,540 To Fort Dent Park 19,016 15,860 22,750 SOUTHCENTER BOULEVARD 88,020 15,400 TUK WILA PARKWAY • NORTH ENTRANCO Engineers iw�.cr.vrru� ••.o r....yrwono., co•sur•wTS /) City Of Tukwila SOUTHCENTER BOULEVARD Figure 5 62nd Avenue South To Grady Way 1981 AVERAGE WEEKDAY TRAFFIC • • • • • • • • • • • TABLE 1 ACCIDENT HISTORY SOUTHCENTER BOULEVARD From 62nd Avenue S. to Interurban Avenue and Grady Way 1979 -1981 ACCIDENTS Property Damage Injury Total* COLLISION TYPE 1979 -1981 1979 -1981 1979 -1981 Rear -end 15 1 16 Right -angle 1 0 1 Left -turn 7 4 11 Right -turn 5 3 8 Side -swipe 9 0 9 Head -on 1 0 1 Pedestrian 0 1 1 Out of control : 6 10 16 Total 44 19 63 * There were no fatalities for these three years. 32 • considerable congestion. The SR-181/Grady Way intersection currently • operates at level of service D -E. The Fort Dent Park /SR -181 intersection is at level of service B, and the I -405 northbound ramp /SR -181 intersection is at level of service C. Although level of service calculations would indicate ghat this section of SR -181 would operate reasonably well, the • high volume of left turns onto Grady Way causes considerable congestion. Left -turn storage is not adequate to handle the volume and cannot be lengthened due to the proximity of the two intersections. Vehicles back onto the through lanes, restricting traffic. Since these intersections are • quite close together, the backups can actually extend into the preceding intersection, blocking traffic there as well. The operation of the section more closely resembles the level of service at the worst intersection, that being level D -E. • • • • • • • Metro Transit currently operates 14 routes that serve Tukwila, totaling approximately 320 trips per day, all of which either traverse or intersect Southcenter Boulevard. Most of the routes operate peak hour only and only four routes operate on weekends. They connect Tukwila with the major activity areas in the region: the Seattle central business district, Bellevue, Renton, Kent, and the Duwamish Valley. There are two major trail /sidewalk routes within the Southcenter Boulevard project: an east -west sidewalk /bikeway connecting Renton and Tukwila; and a north -south extension of the Christensen Greenbelt Trail. Impacts Traffic volume between 1981 and 1990 is expected to increase considerably in the Tukwila area. The Tukwila Micro -Model Study, completed by Entranco Engineers in 1981, forecast a growth of 33 to 46 percent in vehicle trip ends over the ten -year period between 1980 and 1990 for the commercial - industrial area. The results of that modeling effort (which included a number of land use and roadway alternatives) and the existing traffic counts were used to evaluate the various alternatives for Southcenter Boulevard using 1990 as a design year. 33 • Significant differences are expected to occur if Southcenter Boulevard • is improved. Figures 6 and 7 show 1990 average daily traffic for the no -build alternative and the proposed project. Major increases in traffic are expected to occur on Southcenter Boulevard with the realignment alternative attracting 3,000 to 7,000 more vehicles than the no -build alternative. Corresponding decreases in traffic volumes are expected on I -405. Volumes on Grady Way would increase by about 2,000, with volume on 68th Avenue S. increasing by 4,700. Other changes in traffic should be of much lesser significance. • • • • • The 1990 approach volumes and existing turning movement counts were used to generate 1990 p.m. peak hour turning movements. These were then used to calculate level of service for the three intersections- -Fort Dent Park/ SR -181, Grady Way /SR -181, and I -405 northbound ramp /SR -181. Table 2 shows the anticipated 1990 level of service for the various alternatives. Only alternatives 3B and 4 provide level of service D or better at the Fort Dent Park /SR -181 intersection; only alternatives 3A and 4 provide level of service D or better at the Grady Way /SR -181 inter- section, while none of the alternatives provide better than level of service E at the I -405 northbound ramp /SR -181 intersection (see page 44, "Alternatives Considered," for a description of Alternatives 3A and 3B). The latter intersection needs a separate right -turn lane for southbound . traffic on SR -181 to improve access to I -405 northbound. Construction of this lane is outside the scope of this project, and was therefore not considered in any of the alternatives. As previously stated, current storage length for left turns from SR -181 southbound onto Grady Way eastbound is not adequate to handle the p.m. peak hour demand. On some signal cycles, left turning traffic backs up onto the through lanes, blocking that movement. In some cases, it may backup through the present Southcenter Boulevard /Fort Dent Park /Interurban Avenue intersection, severely restricting traffic flow. The increase in traffic volumes expected by 1990 will exacerbate the situation.. Only alternatives 3A and 4 offer any relief: 3a because it will eliminate the Grady Way /SR -181 intersection, and 4 by converting the left -turn movement from Southcenter Boulevard to a through movement due to the realignment. 34 • e 4NORTH ENTRANCO Engineers City Of Tukwila SOUTHCENT.ER BOULEVARD 62nd Avenue South To Grady Way Figure 6 1990 AVERAGE DAILY TRAFFIC ALTERNATIVE 1 NO BUILD • • 19,040 To Fort Dent Park NSTER 23,250 93,500 83;930 SOUTHCENTER BOULEVARD 93,570 31,080 15,900 1 15,600 PARK WA Y 4 NORTH ENTRANCO Engineers City Of Tukwila SOUTHCENTER BOULEVARD 62nd Avenue South'To Grady Way Figure 7 1990 AVERAGE DAILY TRAFFIC ALTERNATIVE 4 REALIGNMENT AT GRADE • • • • Alternative 1. No Build 2. Widen Existing 3A. High Level Bridge, Southcenter Boulevard Ramp • 3B. High Level Bridge, Grady Way Ramp • • • • • 4. New Alignment, At -Grade Intersection° TABLE 2 1990 LEVEL OF SERVICE I -405 Northbound Fort Dent Park Grady Way/ Ramp at at SR -181 at SR -181 SR -181* E F . F F F E -F E D E -F B E F D D E * This intersection is outside the limits of this project. In order to achieve an acceptable level of service, a right -turn lane should be added on the north approach. ° Recommended alternative. 37 • • • • • • • • • • • With increasing traffic volumes, the number of accidents is expected to increase. At the intersections, the level of congestion will increase and with it the accident rate. One method of comparing safety factors for the improvement alternatives is to compare expected accidents in the design year. Taple 3 shows a comparison between the alternatives. The referenced traffic volumes are for Southcenter Boulevard west of SR -181. Alternatives 3A, 3B, and 4 provide the greatest benefit in terms of accident reduction. Accidents per million vehicle miles would be reduced from 11.0 for the no -build alternative to 3.3 for the proposed project. This is due to the removal of the existing curves and elimination of weaving movements. The proposed trail system is approximately 0.3 mile in length and will extend the Christensen Greenbelt Trail from the intersection of Tukwila Parkway and Christensen Road/ Christensen Greenbelt Park northward along the Green River. It will pass under I -405 and Southcenter Boulevard, then follow the old Southcenter Boulevard alignment from a connection with the proposed sidewalk /bikeway on the south to Fort Dent Park on the north. The development of this trail will provide a valuable link in the City of Tukwila's trail system, as well as providing an excellent recreation resource for the people living within the greater Green River Valley. The trail will connect with the sidewalk system adjacent to Southcenter Boulevard, with the existing Christensen Greenbelt Trail and the pedestrian circulation system within Fort Dent Park. It will provide a broad range of recreational opportunities and a safe transportation system for pedestrians and bicyclists that does not exist at the present time. The proposed project also includes an eight -foot sidewalk /bikeway on the north side. It will provide a continuous facility for pedestrians and bicyclists between Renton and Tukwila. The project will incorporate features such as turn channelization, signalization, sidwalks, and illumination that will facilitate movement of Metro Transit buses and loading and unloading of passengers. 38 • • • Estimated Accidents /Year* Average Daily Traffic (ADT) Million Vehicle Miles (MVM) of Travel /Year TABLE 3 ANTICIPATED ACCIDENT RATES - 1990 A1 tern ati ves °. Existing 1 2 3A 3B 4 21 37 31 17 14 16 8,800 14,300 16,700 18,400 20,800 20,800 2.1 3.4 4.0 4.4 4.9 4.9 • Accidents /MVM 10.0 11.0 7.6 3.8 2.8 3.3 * Based on method for estimating future accidents in the Transportation • and Traffic Engineering Handbook, ITE. 1965. pp. 394 -399. ° All figures are for the 1990 design year. Alternative 4 is the recommended alternative. • • • • 39 • • • • • • There will be no effect on existing parking facilities nor will a demand for new parking be created. There will be no effect on waterborne, rail, or air traffic. Mitigating Measures A new signal with advanced capabilities will be installed at the intersection of Grady Way and Interurban Avenue. The existing State -owned traffic signal at the Interurban Avenue /Fort Dent Park intersection will require only minor revisions. Another signal will be installed at the intersection of Southcenter Boulevard and 68th Avenue S. to improve traffic flow and provide safe pedestrian movement. Reference was made earlier to completion of the Grady Way Bridge replacement located at the east terminus of the Southcenter Boulevard project. It will provide a five -lane section from Interurban Avenue into Renton. The programmed completion date for the bridge replacement is 1983 -84, which should help mitigate traffic impacts of this project. An additional planned project in the vicinity is construction of high occupancy vehicle (HOV) lanes on I -405. The first phase of the project • , calls for construction from I -5 in Tukwila to the Renton "S" curves. Programmed for construction in late 1983, the project will provide exclusive lanes for transit, carpools, and vanpools. Although they will provide significant time savings for HOV's during peak hours, they will probably not significantly improve the overall level of service. • • • In conjunction with that project, WSDOT has agreed to participate in replacement of the T -line bridge (68th Avenue S. bridge) with a new four -lane structure. The widened roadway will greatly improve access for the Tukwila commercial - industrial area and adjacent portions of the community. A study of possible alternative alignments is currently under way, with completion anticipated in the fall of 1982. 40 • The extension of the Christensen Greenbelt Trail will provide a • continuous Class II (separate right -of -way) bicycle facility between S. 180th Street and Fort Dent Park. The .proposed sidewalk /bikeway on the.. north side of Southcenter Boulevard will complete the pedestrian link between Rgnton and Tukwila. • • • Metro's adopted 1990 plan includes a package of major service improvements in Tukwila aimed at creating a Regional Transit Center in the Southcenter Shopping Center vicinity. This Regional Transit Center will be a transit focal point, and will coordinate transfers between local routes and through routes going to the Seattle CBD and to other activity centers. Increased transit_ service and revision of existing routes are proposed as part of the 1990 transit plan. The proposed transit improvements are aimed at accommodating a projected 10 percent peak hour mode split by 1990. . Public Services • (1) Fire Service Existing Conditions • • • • • Fire protection in the area is provided by the Tukwila Fire Department. Two fire stations are located in the immediate vicinity, one at 444 Andover Park East and the other at S. 147th Street and 59th Avenue S. They provide pumpers, aerial ladder trucks, aid car, and support vehicles on a full -time basis. Impacts Completion of the project will decrease response time by decreasing congestion and minimizing the potential for vehicle blockage. During construction, some temporary increase in response time may occur. 41 • • • • • • • • • • ;Mitigating Measures Emergency vehicle pre - emption sensors will be installed at all signalized intersections. 0 (2) Police Protection Existing Conditions Police protection in the area is provided by the City of Tukwila Police Department. The police station is located in City Hall at 6200 Southcenter Boulevard. The force is currently composed of 27 commissioned officers. Impacts Response time will be decreased by completion of the project by decreasing congestion and minimizing the potential for vehicle blockage. During construction, a temporary increase in response time may occur. Mitigating Measures None. (3) Schools Existing Conditions Tukwila is in South Central School District 406. There are three elementary schools, one junior high school, and one high school in the district. Impacts Travel time will be decreased for school buses routed along Southcenter Boulevard. Pedestrian safety will be improved along the corridor. 42 • • • • • • • • • • Mitigating Measures An eight -foot sidewalk /bikeway will be provided along the north side of Southcenter Boulevard which will improve safety for school children.. 0 (4) Parks and Recreation Existing Conditions There are several recreational facilities in the vicinity of Southcenter Boulevard. Tukwila Park, on 65th Avenue S. just north of Southcenter Boulevard, is Tukwila's oldest park. There are four tennis courts, a play court, restrooms, picnic tables, trails, playground apparatus, a gazebo, fire pits, and open grass areas nestled among the large fir trees and rhododendrons. Bicentennial Park is a small neighborhood park located at the intersection of Strander Boulevard and Christensen Road. It contains a log cabin, picnic tables, restrooms, and playground apparatus and provides the main parking areas for it and the Christensen Greenbelt Park. The Christensen Greenbelt Park stretches two miles, from S. 180th Street to Tukwila Parkway along the west bank of the Green River. It is a narrow park, often referred to as the Christensen Trail, consisting of an eight -foot wide hard surface bycycle path and a six -foot wide cinder jogging path. Also found along the trail are a fitness course, duck pond, bicycle racks, and four picnic areas. Fort Dent Park is a part of the King County Parks system. Located just north of Southcenter Boulevard and just east of the Green River, the park is accessed from Interurban Avenue at Southcenter Boulevard. The 50 -acre park has soccer and softball fields, tennis courts, a running track, and picnic areas. The soccer and softball fields are used extensively by King County Parks Department recreation leagues. Major privately owned recreational facilities include Longacres racetrack, located just east of the project site, and Foster Golf Course, located on Interurban Avenue near I -5. Longacres is open from spring until 43 • • • • • • • • • • fall, generally on Wednesday- through- Sunday schedule. Foster Golf Course is an 18 -hole golf course open year- round. Impacts e The project includes an extension of the Christensen Trail from its current northern terminus near Tukwila Parkway to Fort Dent Park. Picnic tables, rest areas, and landscaping will be provided. Some increased maintenance can be expected. Mitigating Measures Extension of the Christensen Trail will improve access to area parks for all residents as well as providing increased park acreage. 0. Energy Existing Conditions The major source of energy consumption is from automobiles consuming gasoline as they traverse the existing roadway. Smaller amounts of diesel fuel are consumed by trucks and buses. Minor amounts of electricity are used by the existing traffic signals and illumination. Impacts During the construction phase, 112,000 million BTU's of energy will be consumed by construction equipment and materials. Completion of the project will result in 6,200 fewer vehicle miles of travel per day and an average speed two miles per hour greater than the no -build situation. This will result in a savings of 735 gallons of gasoline per weekday, or 91.9 million BTU's per weekday. It will take approximately five years to pay back the energy used in construction. No new energy sources will be required. 44 • • • Mitigating Measures Construction of the project will reduce energy consumption due to decreases in congestion and vehicle miles of travel and increases in travel speed. High pressure sodium vapor lamps will be used in all luminaires. These lamps have a very high efficacy (lumens per watt of power consumed), which results in considerable energy savings. Metro Transit currently operates 14 routes in the project vicinity. Metro's 1990 Transit Plan recommends improved service in the corridor consisting of new routes and increased service on existing routes. The • proposed service improvements are aimed at accommodating a projected 10 percent peak hour mode split. Turn lanes and radii, signalization, and channelization improvements will be designed to facilitate the movement of transit vehicles. Metro will benefit by reduced travel time and reduced fuel costs. • • • • • • P. Utilities Existing Conditions Power and telephone lines run parallel to and occasionally cross Southcenter Boulevard. Poles supporting these lines are within the existing street right -of -way. Most of the power poles are located on the south side of the street. Natural gas mains are buried within the Southcenter Boulevard roadbed. A waterline and sanitary sewer line is located under the pavement of the present roadway. Two storm sewers pass under the roadway and carry drainage toward I -405. 45 • • • • • • • Impacts Power and telephone lines will be placed underground throughout the project limts. This work will be completed by the respective utility companies; Any necessary adjustments to gas mains would be completed by the gas company. Stormwater runoff from Southcenter Boulevard between 62nd Avenue S. and 68th Avenue S. will be collected in new storm drains and continue to be discharged into the existing detention basin to the south through a proposed closed retention /oil separation system. Other utility work will be limited to relocation and adjustment of existing facilities. Domestic water system improvements include relocation of fire hydrants and adjustment of valves and valve chambers. Sanitary sewer improvements include adjustment of manholes to the new street grade. Mitigation Measures Planning and coordination will take place with the respective utility representatives during design and construction to avoid interruption of service to customers and prevent unnecessary project delays. Q. Human Health Not applicable. • R. Aesthetics Existing Conditions • • • The existing roadway is a two -lane roadway that parallels I -405 from 62nd Avenue S. to 68th Avenue S. and then turns north along the Green River. Trees border it along the south and east sides. A steep hillside 46 • • • • • • • • • • • runs along the roadway to the north and west. Views of the Green River are obscured by the border of trees and the elevation difference between the river and the roadway. The area between I -405 and the Green River is an open field with some trees.. Other potential views are generally obscured by the I -405 bridge structures, elevation differences, or trees. Impacts Construction of the project will convert a portion of the open area between I -405 and the Green River to a five -lane roadway. Views from the new roadway will be opened up to the north, particularly from the relocated I -405 southbound. ramps. No existing views will be blocked. Mitigating Measures Extension of the Christensen Trail will provide views of the Green River, Longacres racetrack, Renton, and Fort Dent Park for pedestrians and bicyclists. Landscaping will be provided in all areas requiring vegetative restoration due to the proposed street and trail construction and its effects on existing vegetation. A concerted effort will be made to utilize indigenous plant materials that will attract birds and other forms of wildlife adjacent to the Green River environs. Also, the selection of plant materials will include the considerations of seasonal color and drought - tolerant plant varieties. The landscape development adjacent to the natural vegetation areas will be confined to the planting of clover and wildflowers. This landscape treatment will assist in restoring the existing vegetation that will be scarred as a result of trail construction. The total landscape of the trail and roadway would accomplish two things: (1) establish a park /trail atmosphere, and (2) create a compatible environment with adjacent land uses. .47 • • • S. Recreation See "Public Services." T. Archaeological /Historical Existing Conditions The State of Washington Office of Archaeology and Historic Preservation • has reviewed available records and noted that the project area has a high potential for occurrence of previously unidentified cultural resources. Based on this review, it is recommended that a professional archaeological survey of the project area be conducted prior to further action. • • • • A professional survey team from the University of Washington Office of Public Archaeology will be contracted to do this survey. U. Economic Impacts Existing Conditions As of. December 1980, the city of Tuwila contains 1,006 businesses employing 19,174 people. The Southcenter Boulevard project is located on the border between the Tukwila /Interurban and the Southcenter /Andover areas, as definded by the 1980 City of Tukwila Employment Survey. The Tukwila /Interurban area had employment of 1,257 people, while the Southcenter /Andover area had employment of 15,056 people, or 78.5 percent of total employment. Gross floor area of leasable space for 1980 totaled approximately 10,668,000 square feet, with the majority of that (6.9 million square feet) devoted to light industrial uses and warehousing. There were approximately 2.million square feet of retail space and 1.8 million square feet of office space. 48 • • • • • • • • • • Impacts By 1990, total gross floor area of leasable space is expected to grow to 12.5 million square feet, or 17 percent more than in 1980. Major . increases0are expected in office space with an additional 1.8 million square feet to be provided. Employment is expected to increase by approximately 40 percent, to about 26,000 people in 1990. Access improvements provided by this project are necessary to achieve that projected growth. The proposed project will cost $6.8 million to construct. Federal funding sources are expected to provide 80 percent of the funds with local sources, general sales tax, and motor vehicle fund taxes providing 20 percent of the funds. Construction of the project will improve the local economy by providing jobs for area contractors and sales of materials for local: suppliers. Mitigating Measures Construction of the project will improve access to the Tukwila industrail- commercial district. Without improved access to the area, projected growth in employment and gross floor area may be slowed or may not occur due to traffic congestion and poor accessibility. Reductions in gasoline consumption due to increased average travel speeds and decreased vehicle miles of travel will result in a savings of 191,000 gallons of gasoline per year, equaling approximately $250,000. Reductions in accidents due to improved geometrics and lighting will result in a yearly savings of about $50,000. 49 • ALTERNATIVES CONSIDERED • This section discusses four roadway alternatives to the proposed project: (1) the no -build alternative; (2) improve the existing facility; (3A) build a high -level bridge with access to Interurban Avenue at Fort • Dent Park; and (3B) build a high -level bridge with access to Interurban Avenue at Monster Road. Figure 8 shows the alternatives. Alternative 4 shown in that figure is the proposed project. • Alternative 1 - No -Build Description • The no -build alternative is a consideration of the effects of not improving the route. If the proposed project is not built, the section of Southcenter Boulevard east of 62nd will remain as a two -lane facility without sidewalks. The portion of Grady Way west of the bridge will be • widened to five lanes as part of the Grady Way Bridge project, with no improvement in the alignment. No further improvements would be made to the route. • • • • • Impacts Less traffic would use Southcenter Boulevard than with the proposed project. I -405 would have higher traffic volumes, and congestion would be greater on both routes as well as on Interurban Avenue. Emissions and fuel consumption would be higher due to the greater congestion. Travel time through the corridor would be higher. Anticipated development in the Tukwila commercial - industrial district (CID) may not occur because of poor access. Traffic hazards would increase. Response time for emergency vehicles would be increased. . The Christensen Greenbelt Trail would not be extended, and pedestrian access to Renton would not be improved. A savings of $6.9 million would occur, as opposed to the proposed project; however, this would be offset 51) T. r>. o... P... ". Widen To 5 Travel Lanes BOUTRCERTER BOULEVARD . •ARKWAY ALTERNATIVE '1 No Build, (TT r__„.. T,,,M%A A •ARK W AY 1 ALTERNATIVE 2 Improve Existing System maw — -.. .. OR AOY 11 T. fart o•.+ P.• T. Fort O..4 •.. New Bridge IIIIIIIIIIIIIIII Roadway To Be Closed New Aigrnent _ New Bridge IIIIIIIIIIIIIIII Roadway To Be Closed New Bridge IIIIIIIIIIIIIIII Roadway To Be Closed PARKWAY ALTERNATIVE 3A High Level Bridge ALTERNATIVE. 3B High Level Bridge 4 NORTH ENTRANCO Engineers ..,,,...SMnT.,,Oh CO.s,X.•,« City Ot Tukwila SOUTHCENTER BOULEVARD 62nd Avenue South To Grady Way ALTERNATIVE 4 At -Grade Intersection Figure 8 PROPOSED SOUTHCENTER BOULEVARD ALTERNATIVES • • • • • • • • • • • somewhat by higher costs associated with maintenance, fuel consumption, and accidents. Conclusion • The no- action alternative is not a reasonable alternative for the following reasons: (1) increased congestion; (2) increased traffic hazards; (3) increased auto emissions; (4) increased fuel consumption; (5) reduced pedestrian and auto access; and (6) decreased pedestrian safety. No action will also limit potential growth in the area due to the problems stated above. Alternative 2 - Improve Existing Facility Description This alternative would maintain the existing alignment but would widen the roadway section to provide' five travel lanes on Southcenter Boulevard west of Interurban Avenue and five travel lanes on Grady Way from Interurban Avenue (SR -181) to the Grady Way Bridge. Sidewalks would be provided and some intersection channelization installed. A signal would be installed at the intersection of Southcenter Boulevard and 68th Avenue S. The Christensen Greenbelt Trail would be extended as an eight -foot sidewalk /bikeway adjacent to the travel lanes. Impacts • Traffic volumes would be slightly lower on Southcenter Boulevard than for the proposed project, while they would be slightly higher on I -405. The level of congestion would be greater on both routes as well as on Interurban Avenue. Emissions, fuel consumption, travel time, and the number of accidents would be greater than with the proposed project, but less than with a no- action alternative. 52 • • • • • Some anticipated development in the Tukwila CID may not occur due to the access constrictions. The Christensen Greenbelt Trail would be extended to Fort Dent Park as an eight -foot sidewalk /bikeway adjacent to the travel lanes. Pedestrian and bicyclist safety would be lower than with the proposed project. Retaining walls may be required between 68th Avenue S. and Interurban Avenue on the northwest side of Southcenter Boulevard. The narrow right -of -way in that area may require acquisition of additional right -of -way to avoid severe impacts on the Green River. The cost in 1982 dollars would be $1.9 million. This is a savings of $5.0 million as compared to the proposed project. This savings would be slightly offset by higher fuel consumption, an increase in accidents, and increased travel time delay. Conclusion The "improve existing facility" alternative is not believed to be a reasonable alternative for the following reasons: (1) increased traffic congestion; (2) increased fuel consumption; (3) increased auto emissions; i4) increased impacts on the Green River; and (5) decreased pedestrian safety. The traffic weave and storage problems associated with the intersection at SR -181 will remain. Alternative 3A - High -Level Bridge with Access to Interurban Avenue at Fort Dent Park Description This alternative would consist of construction of a high -level bridge west from Grady Way to 68th Avenue S. crossing over SR -181, the I -405 southbound on /off ramps, and the Green River. Connection to Interurban Avenue would be made via the existing section of Southcenter Boulevard between 68th Avenue S. and Interurban Avenue. The Grady Way access to Monster Road and Interurban Avenue would be closed. The high -level bridge would consist of four lanes. The existing section of Southcenter Boulevard 53 • west of 68th Avenus S. would be widened to five travel lanes, while the • section east of 68th Avenue S. would be maintained as a two -lane facility. • A traffic signal would be installed at the intersection of Southcenter Boulevard and 68th Avenue S. The Christensen Greenbelt Trail would be extended Borth under the I -405 bridge and Southcenter Boulevard bridges on • an independent alignment. Along 68th Avenue S. it would consist of an eight -foot sidewalk /bikeway adjacent to the existing travel lanes. • • • • • • • Impacts The impacts associated with this alternative are similar to the proposed. project. The capacity of the roadway would be slightly higher; however, the level of congestion would also be higher due to the indirect access to I -405. The improved access to the Tukwila CID would allow the anticipated growth to occur. Accidents would be slightly higher than for the proposed project. Pedestrian and bicycle safety would be somewhat lower due to the Christensen Greenbelt Trail being adjacent to the travel lanes between 68th Avenue S. and Interurban Avenue. The cost of construction would be $10.6 million in 1982 dollars; this is $3.7 million more than for the proposed project. Fuel consumption and accident costs would be similar to the proposed project. Conclusion Alternative 3A is not believed to be a reasonable alternative because of high cost and decreased pedestrian safety. Alternative 3B - High -Level Bridge with Access to Interurban Avenue at Monster Road Description . This alternative is similar to alternative 3A. A high -level bridge would be constructed west from Grady Way to 68th Avenue S., crossing over SR -181, the I -405 southbound on /off ramps, and the Green River. Connection 54 • to Interurban Avenue would be made via the existing section of Grady Way. between Monster Road and Interurban Avenue. The existing section of Southcenter Boulevard between 68th Avenue S. and Interurban Avenue would be closed. The section of Southcenter Boulevard west of 68th Avenue S. would be widened to five travel lanes. The high -level bridge would consist • of four travel lanes. Traffic signals would be installed at the intersections of Southcenter Boulevard and 68th Avenue S. and Grady Way and the Interurban Avenue connector. The Christensen Greenbelt Trail would be extended north on an independent alignment, as shown for the proposed • project. • • • • • • Impacts The impacts of this alternative are similar to both the proposed project and Alternative 3A. Congestion would be slightly greater than with the proposed alternative, while capacity would be similar. The number of accidents would be slightly lower and pedestrian /bicycle safety would be similar. The cost of construction in 1982 dollars would be $10.7 million. This is $3.8 million more than for the proposed project. Fuel consumption and accident costs would be similar to the proposed project. Conclusion Alternative 3B is not believed to be a,reasonable alternative because of its high cost. COMMENTS AND COORDINATION This action has been under study since October of 1981. The study included traffic analysis and modeling, numerous engineering considerations, review of compatibility with other facilities and plans, and preparation of the appropriate environmental documents. 55 • ;Coordination to date has included both written and verbal communication with the appropriate officials representing the City of Tukwila, King County, the Puget Sound Council of Governments, the Municipality of Metropolitan Seattle, the State of Washington Department of Transportation, the Federal Highway Administration, and other state and local agencies. • Evidence of coordination with some of the officials representing these agencies is attached. • • • • • • 56 • • • • • • December 18, 1981 0 Paul A. Treman, P.E. Entranco Engineers 1515 - 116th Ave. N.E. Suite 200 Bellevue, WA. 98004 Ei -0 NLC) ENC.I'' King County State of Washington Randy Revelle, County Executive Department of Public Works James W. Guenther, Director 900 King County Administration Building 500 Fourth Avenue Seattle, Washington 98104 (206) 344 -2517 Re: Southcenter Boulevard Extension, Job No. 82028 -20 Dear Mr. Treman: The following comments are in response to questions from your December 14 letter as numbered: D uar of c - 1) The 100 -year flood elevations are noted on the enclosed map. They are noted in blue figures as M.S.L.Datum. 2) The ordinary high water elevation (9000 cfs) and (12000 cfs) flood elevation which included the P- Channel pumping are noted in black figures on the enclosed photo -copy of HUD map, 2 of 2, City of Tukwila. 3) Enclosed photo- copies of area from City of Tukwila Floodway and Flood Insurance Rate Maps. 4) Vertical clearance of 6 feet above the 100 -year water surface is re- commended as stated in King County Code 20.50 (Ord, 2281, Surface Water Runoff Drainage Policy 1.10). The City of Tukwila, U.S. Army Corps of Engineers and the State Department of Fisheries should also be addressed for vertical clearances. A State Flood Control Zone Permit shall be required. Also check with the U.S. Coast Guard for their navigation on safety recommendations. 5) I spoke with John Bordon, King County Bridge Engineer, about the two • existing bridges. They are not county bridges and we have no vertical datum on these structures. 6) Enclosed application for a State Flood Control Zone Permit. 7) The State Flood Control Zone Permit would be the only review by our Department. • • Further questions should be directed to Doug.Grochow or Meredith Mamanakis of my staff at 344 -3874. Sincerely, G.E. WANNAMAKER, P.E. Development Review Section Surface Water Management Division • GEW:DG:dk # USE 4 co -c F_ (..r v, Foe ) L, ovo C (S go-T- /00 Y'2 r- 1.7•7d etfv - 6i OF ,C P Ft( Li /o ■NG ,4-55 -401(0 IL - LL -31 i�AT • • • • DEPARTMENT OF TRANSPORT TION UNITED STATES COAS RD City of l ukwila Planning Department ATR1: Mr. Brad Collins Director 6200 Southcenter Boulevard Tukwila, ?iA 98188 Gentlemen: MAILING AOORE•S COMMANDER (oan) THIRTEENTH COAST GUARD OISTRICI VIS SECOND AvE SEATTLE WA 94114 PHONE (206) 442 5864 16591 Serial 180 28 April 1982 Your letter of 29 March 1982 forwarded a proposed declaration of non- significance for the above- referenced project for our review and dent. It is noted that the project includes the construction of one or more bridges across the Green River. The Green River is a navigable water of the United States in the project area, therefore, Cbast Guard bridge permits will be required for the proposed bridges.' Reference is made to a new Grady Way Bridge which is presently under design. A bridge permit will also be required for that structure. In order. to provide timely input and avoid unnecessary delays in processing permit applications for the proposed structures, it is suggested that you make application for the necessary permits at your earliest opportunity. A copy of our Bridge :Permit Application Guide is enclosed for your information and • assistance. • •! S R C C U. LIMIT 11'. • law •• It is not clear from the information received whether, or not, any federal funds will be used for the project. It is requested that this information be furnished so that we may determine lead federal agency for environmental concerns. If you have any questions, please contact this office. Sincerely, Encl: As noted John E. Mikesell Chief, Bridge Section By direction of the District Commander • NPSEN -PL -ER DEPARTMENT OF THE ARMY SEATTLE DISTRICT: CORPS OF .ENGINEERS • P.O. BOX C -3755 SEATTLE. WASHINGTON 98124 Brad Collins, Director ' Tukwila Planning Department 6200 Southcenter Boulevard Tukwila, Washington 98188 Dear Mr. Collins: 28 APR 1982 We have reviewed the Proposed Declaration of Non- Significance and the ac- companying Environmental Checklist for the proposed realignment of South - center Boulevard within the City of Tukwila, Washington, with respect to the U.S. Army Corps of Engineers' areas of responsibility for flood con- trol, navigation, and regulatory functions. We have the following comments: a. It is not clear from the Environmental Checklist whether the lo- • cation of fill will remove significant areas of wetland and /or riparian habitat. This issue is not adequately addressed and should be clarified. It may be pertinent to the final decision on the significance of the proj- ect. As you know, wetlands are ecologically significant areas which help maintain the . quality of the human environment in a number of important ways. Seattle District encourages you to consider the use of alternatives which • mihimize impacts to wetlands. b. It is noted that interior drainage will be altered, thereby in- creasing runoff into the Green River which is already a severe problem in the Green River basin. Drainage patterns resulting from road relocation should be addressed. • c. Water quality in the Duwamish River is a key environmental issue. Mitigation of construction - induced pollution should be addressed as well as a long -term means of reducing oils and other surface water contaminants. d. The bridge should be designed to withstand a 100 -year frequency • flood. The design should also include free board water surface for drift clearance. e. The enlarged arterial would affect the proposed greenbelt trail. The impacts, such as noise and safety, should be discussed. • • • • • • •• • • • • NPSEN -PL -ER Brad Collins, Director We appreciate the opportunity to review this checklist and regret that our response was delayed. If you have any questions, please feel free to con- tact Dr. Steven F. Dice, telephone (206) 764 -3624, of my staff. • Sincerely, 2 7247' R.P. SElLEVOLD; P.E. Engineering • JOHN SPELLMAN Governor • • • • • • • STATE OF WASHINGTON OFFICE OF ARCHAEOLOGY AND HISTORIC PRESERVATION 111 West Twenty-First Avenue, KL -11 • Olympia, Washington 98504 • (206) 753 -4011 0 Mr. Ed Berschinski Entranco Engineers 1515 - 116th Ave. N.E., Suite 200 Bellevue, WA 98004 Dear Mr. Berschinski: July 30, 1982 Log Reference: 332- C- KI -02_ IACOB THOMAS Director Re: Southcenter Boulevard 62nd Ave. S. to Grady Way Project #82028 -20 We have reviewed the materials forwarded to us for the above referenced project. A search of our records, including the National and State Registers of Historic Places and the Washington State Archaeological and Historic Sites Inventories, indicates surveys have been conducted in the general vicinity of the project area. Known site distributions, ethno- historic sources, and /or consultation with others indicates that the project area has high potential for the occurrence of previously uniden- tified cultural resources. Based on the results of our records searches, consultations, and the materials provided for out review, we recommend professional archaeological surveys of the project area be conducted prior to further action. The above comments are based on the information available at the time of this review. Should additional information become available., our as- sessment may be revised. In the event that cultural materials are inadvertently discovered during construction, work in the immediate vicinity should be discontinued and this office notified. Please in- dicate the log reference number noted above in further communications concerning this project. A. copy of these comments should be included in subsequent environmental documents. dj Sincerely, Robert G. Whitlam, Ph.D. Archaeologist • • • APPENDIX A. • • • • • • • • APPENDIX A VEGETATION FOUND ALONG THE PROJECT CORRIDOR 0 COMMON NAME Trees Black Cottonwood Black Locust Big -Leaf Maple Common Horse Chestnut False Arborvitae Hawthorne Madrona Oregon Ash Red Maple Silver Maple Shrubs English Holly Himalayan Blackberry Pacific Willow Scotch Broom Herbaceous Plants Bluegrass var. Clover var. Common Tansy Common Dandelion English Ivy Fescue -grass var. Foxtail Barley Goldenrod Horsetail Sweetpea Source: Entranco Engineers SCIENTIFIC NAME Populus trichocarpa Robina pseudoacacia Acer macrophyllum Aesculus hippocastanum Thujopsis databrata Crataegus laevigata Arbutus menziesii Faxinus latifolia Acer rubrum Acer saccharinum Ilex aquifolium Rubus discolor Salix lasiandra Cytisus scoparius Poa sp. Trifolium spp. Tanacetum vulgare Teraxacum officinale Hedera helix Festuca sp. Hordeum murinum Solidago sp. Equisetum sp. Lathyrus sp. • • • • • MAMMALS OF THE LOWER GREEN RIVER WATERSHED COMMON NAME American Oppossum Cinerous Shrew Vagrant Shrew Dusky Shrew Water Shrew Marsh Shrew Trowbridge's Shrew Shrew -mole Townsend's Mole Coast Mole Various Bats Eastern Cottontail Snowshoe Hare Mountain Beaver Townsend's Chipmunk Eastern Gray Squirrel Fox Squirrel Douglas' Squirrel Northern Flying Squirrel Beaver Common Deer Mouse Mountain Deer Mouse Bushy - tailed Wood Rat Gapper's Red - Backed Mouse Townsend's Meadow Mouse Long - tailed Meadow Mouse Oregon Meadow Mouse Muskrat Norway Rat Black Rat House Mouse Pacific Jumping Mouse Porcupine Nutria Coyote SCIENTIFIC NAME Didelphis marsupialis Sorex cinereus Sorex vagrans Sorex obscurus Sorex palustris Sorex bendirei Sorex trowbrdigei Neurotrichus gibbsi Scapanus townsendi Scapanus orarius Chiroptera Sylvilagus floridanus Lepus americanus Aplodontia rufa Eutamias townsendi Sciurus carolinensis Sciurus niger Tamiasciurus douglasi Glaucomys sabrinus Castor fiber Peromyscus maniculatus Peromyscus oreas Neotoma cinerea C1ethrionomys gapperi Microtus townsendi Microtus longicaudus Microtus oregoni Ondatra zi bethi cus Rattus norvegicus Rattus rattus Mus musculus Zapus trinotatus Erethizon dorsatum Myocastor coypus Canis latrans • • • • • • • • • MAMMALS OF THE LOWER GREEN RIVER WATERSHED COMMON NAME Red ox Black Bear Raccoon Short - Tailed Weasel Long - Tailed Weasel Mink Spotted Skunk Striped Skunk River Otter Bobcot Black - Tailed Deer SCIENTIFIC NAME Vulpes vulpes fulva Ursus americanus Procyon lotor Mustela erminea Mustela frenata Lutreola lutreola Spilogale putorius Mephitis mephitis Lutra canadensis Lynx rufus Odocoileus hemionus Source: Eastside Green River Watershed DEIS, U.S. Soil Conservation Service, November 1978 as adapted from Tukwila Hotel EIS. • Birds of the Lower Green River Watershed • • • • • • • • Common !lame Common Loon Horned Grebe Western Grebe' Pied - Billed Grebe Double- Crested Cormorant Great Slue I -leron Green Heron American Bittern Whistling Swan • Canada Goose White - Fronted Goose Snow Goose Mallard Gadwall Pintail Green-Winged Teal Blue- tinged Teal Cinnamon Teal European t : igeon American Wipeon or Baldpate Shoveler Wood Duck Redhead Ring - Necked Duck Canvasback Greater Scaup Lesser Scaup Common Go I deneye Bufflehead • Harlequin Duck White- winged Scoter Surf Scoter Common Scoter Ruddy Duck Hooded Merganser Common Merganser Red- Breasted Merganser Goshawk Sharp - shinned Hawk Red - Tailed Hawk Bald Eagle Marsh Hawk Osprey Gyrfalcon Peregrine Falcon Pigeon Hawk Sparrow Hawk Ruffed Grouse California Quail Ring-Necked Pheasant Virginia Rail Scientific Name Gavia imrer Pcdiceps auritus Aechmophorus occidental is Podilymbus podiceps Phalacrocorax auritus Arden herodias Butorides virescens Botaurus lentiginosus Olor columbianus ^rants canadensis Anser albifrons Chen hperborea Anas platyrhynchos Anas strepera Anas acuta Anas carolinensis Anas discors Antis cyanoptera Mareca penelope Mareca americana Spatula clypeata Aix sponsa Aythya amer i cuna Aythya collaris Aythya valisineria Aythya marila Aythya Affinis Bucephala clangula Bucephala albeola Histri-onicus histrionicus Melenitta deglandi Melanitta:perspeicillata Oidemia nicra • Oxyura jamaiconsis Lophodytes cucullatus Mergus merganser Marcus serrator Accipiter gentilis Accipiter cooperii Buteo jamaicensis Haliaeetus leucocephalus Circus cyaneous Pinion haliactus Falco rusticolus Falco perecrinus Falco co l umbar i us Falco sparverius Bonasa urrbe I I us Lophcr yx californicus Phasianus ccichicus Ral lus l iiiicoia • • • • • American Coot Killdeer Common Snipe SpottedSandpiper Greater Yellowlegs Vessar Ye I I ow I eos Pectoral S,arrdp i per Least Sandpiper Dunlin Long- billed Dowitcher !Western Sandpiper Wilson's Phalarope Glaucous- winged Gull Western Gull California Gull Ring- billed Gull New Gu I I Bonaparte's Gull Band- Tailed Pigeon Rock Dove Mourning dove Barn Owl Snowy OW l_ Spotted Owl Short -Eared Owl Common Nighthawk Slack Swift Vaux's Swift Anna's Humn i ngb i rdd Rufous Hummingbird Belted Kingfisher Red- Shafted Flicker Hairy Woodpecker Trail's Flycatcher Western Flycatcher Western ;'food Pee Wee Olive -Sided Flycatcher Horned Lark Violet-Green Swa l I ow Tree Swallow Dank Swallow Rough-Winged Swallow Barn Swallow Cliff Swallow Purple Martin Steller's Jay Common Crow ^lack- Capped Chickadee Chestnut - Sacked Chickadee Common Cushtit Winter Wren Dewick's Wren Long-Billed Marsh Wren Robin Varied Thrush Fu l i ca amer i cana Charadrius vociferus Capella gallinaco Actitis rciacularia Totanus•melanoleucus Totanus flavipes Erolia melanotos Erolia ninutilla Erolia alpina Limnodromus scolopaceus Ereunetes mauri Steganopus tricolor Larus glaucescens Larus occidentalis Larus californicus Larus de I awarens i s Larus canus Larus philadelphia Columba fasciata Columba livia Zenaidura macroura Tyto alba liyctea scandiaca Strix occidentalis Asio flammeus Chordeiles minor Cypseloides niger Chaetura vauxi Calypte anna Selasphorus rufus i':egacery 1 e al cyon Culaptes cafer Dendrocopos Pubescens Empidonax traillii Empidonax difficilis Contopus sordidulus N'uttallornis borealis Fremophila alpestris Tachyccineta thalassina Iridoprocne bicolor Riparia riparia Stelgidopteeryx ruficollis Hirundo rustica Petrochelidon pyrrhonota Proane subis Cyanocitta stelleri Corvus brachyrhynchos Parus atricapillus Parus rufescens Psaltrip&rus ninirnus Troglodytes troglodytes Thryomanes becwickii Telmatodytes palustris Turdus migratorius Ixoreus.Naevius • • • • • • •. • • • Swainscn's Thrush Mountain Bluebird Western Bluebird Go l den - Crowned : i ng l et Ruby- Crowned ringlet !..liter Pipit Cedar !. axw i.ng Northern Shrike Starling Solitary Vireo Red -eyed Vireo Warbling Vireo Orange - Crowned Warbler Hermit Warbler Yellow Warbler Townsend's Warbler Black- Throated Cray Warbler Ye I I owthroat Wilson's Warbler House Sparrow Western Meadow 1 arkk Red - tinged Blackbird Bullock's Oriole Brewers Blackbird Brown- Headed Cowbird Western Tanaer Black- Headed Grosbeak Pine Grosbeak Purple Finch House Finch Pine Siskin American Goldfinch White-Winged Crossb i 1 1 Rufous -Sided Towhee Slate - colored Junco Savanna Sparrow Chipping Sparrow White-Crowned Sparrow Golden- Crowned Sparrow White- throated Sparrow Fox Sparrow Lincoln's Sparrow Song Sparrow 'ylocichla ustulata Sialia currucoides Sialia :.exicanna Regulus satrapa Regulus calendula Anthus spinoletta Bobyci1la cedrorum Lanius excubitcr Sturnus vuloaris Vireo solitarius Vireo olivaceus Vireo gilvus Vernivora celata Dendroica occidentalis Cendroica petechia Dendroica tow nsend i Dendroica nigrescens Geothlypis tichas !;ilsonia pusilla Passer donesticus Sturnella neglecta Euphagus cyancephalus Icterus bullockii Euphagus cyancophalus Nolothrus ater Piranga ludovici -ana tlesperiphona vespertina Pinicola enucleator Carpodaccus purpureus Carpodacus mexicanus Spinus pinus Spinus tristis Loxia Ieucoptera Pipilo erythrophthalmus Junco hyemalis Passercu1us sandw1chens1s Spizella passerine Zonotrichia leucophrys Zonotrichia artricpilla Zonotrichia albicollis Passerella iliaca "elospiza lincolnii elospiza melodic Source: East Side Green River Watershed DEIS, SCS, November, 1978. as adopted from Tukwila Hotel EIS. • • • • Fish Species she Troen Rivcr Common 'large Prickly Sculpin Threespine, Stickleback Brown Bullhead Large -mouth Black bass Chum Salmon Coho Salmon Chinook Salmon Yellow Perch "ountain whitefish Lonc- !Dose Dace Speckled Dace Cutthroat Trout Steelhead Trout Rainbow Trout Dolly Virden Trout Starry Flounder Scientific Name Cottus .osper Gasterosteus acu1eatus Ictalurus nebulosus Micropterus salnoides Oncorhynchus keta Oncorhynchus lkisutch Oncorhynchus tshawtscha Percy flcvescens Prosopium w i l 1 i arson i Rhinichtays cataractac Rhinichtays oculus Salmo clarki Salmo nairdneri Salvo cairdneri Saivelinus malma Prosopium stellatus Source: East Side Green River !„atershed DEIS, SOS, November, 1970. as adopted from Tukwila Hotel EIS.