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HomeMy WebLinkAboutSEPA EPIC-ND-2 - LINCOLN PROPERTIES - DEVELOPMENTLINCOLN PROPERTIES EPIGND -2 Frank Todd, Mayor 6230 SOUTHCENTER BLVD. TUKWIL.A, WASHINGTON 98067 PLANNING DEPARTMENT Mr. Tom Sconzo, Architect 1411 Fourth Avenue Building Seattle, Washington 98101 Dear Mr. Sconzo: 29 March 1974 The Environmental Assessment. Summary, together with two addendums entitled Air Quality Assessment and Water Quality Assessment, has been reviewed in accordance with the State Environmental Policy Act and City of Tukwila Ordinance #759 for the proposed Lincoln Properties development. This corresponsense will serve to inform you of the satisfactory completion of the SEPA requirements. Should you have any questions regarding this matter, please contact me. Sincerely, Gary Crutchfi6-1d Planning Technician GC /lt cc: Dir Pub Wks Bldg. Dir • • Frank Todd, Mayor CITY o F T U KW I LA 6230 SOUTHCENTER BLVD. TUKWI LA, WASHINGTON 98067 PLANNING DEPARTMENT DECLARATION OF NO SIGNIFICANT ADVERSE .ENVIRONMENTAL.EFFECT LINCOLN PROPERTIES DEVELOPMENT I. Location and Description of Project The project is proposed to be located on 23+ acres located at the northeast corner of the intersection of South 180th Street and Southcenter Parkway. The project will include four industrial buildings, a ware- house /retail furniture outlet and a restaurant. The entire site, and surrounding vicinity, has been zoned for light industrial and commercial uses for more than fifteen years. II. Existing Conditions Much of the site has been surcharged to elevations ranging from 22' to 30' M.S.L. No significant botanical or biological species exist on the site. A small creek flows northerly from under South 180th Street to the general center of the site where the creek tends to pond. Utilities must be provided in conjuction with implemen- tation. III. Environmental Impact of Proposed Action No significant adverse environmental effect will be realized as a result of implementation of the proposed action. While no major botanical species exist, existing biological species will be displaced. However, the relatively close proximity of a comparatively natural area is considered adequate to absorb some degree of this displacement, thereby further reducing the insignificant degree of that impact. Air quality, as well as water quality, will receive measurable impacts although both are considered to be minimal. Traffic will be unaltered although measurable Lincoln Properties Development Page 2 increase in vehicle numbers is expected. No change is expected in the social patterns of Tukwila, although a noticeable increase in the City's tax base is certain. IV. Alternatives A do- nothing alternative is not feasible. Although it would eliminate displacement of the existing botanical and biological species. The economics associated with such an alternative preclude it from being employed. V. Long -Term Productivity and Irreversible Resource Committments The allocation of the 23 acres of land is the major resource committment, and it's relative long -term productivity will be enhanced in terms of economics. Gary rutchfiel Pla ping Technic Please refer to Environmental Assessment studies enclosed for basis of this summary. •ank Todd, Mayor ITV op T K ,;:,.ILA 6230 SOUTHCENTER BLVD. TUKWILA, WASHINGTON 98067 PLANNING DEPARTMENT MEMORANDUM TO: Building Official FROM: Planning Department SUBJECT: Lincoln Properties Development 8 Said development has not completed the Environmental Assessment requirements of Tukwila Ordinance #759; thus, it is expressly requested that no permits be granted until that requirement has been satisfactorily met. GC /lt LL `'% z_�_X`c Gary Crutchfield. \; Planning Technician • Frank Todd, Mayor CITY of TUKWILA 14475 - 59TH AVENUE SOUTH TUKWILA, WASHINGTON 98067 Febnuany 7, 1974 Steve Hall Acting P!ann.i.ng Dixec ton City ob Tukw..L a Re: The negative .impact .statement ob Southcenten Parkway g 180th Dean Steve: ECEIVE FEB 11 1974 CITY OF TUKWILA 4 L.incotn Pnopeeittes, I am conce' ned about the C.c ty4' position t%on .in accepting the negative impact .statement ob LLncotn Pnopenti.es on South 180th. Did the .statement, in view o6 the tame .incneas a in pa/thing negwvicements and Land u4 e, adequately address the Ottow.Lng items. 1. Adds tionat nun 46 and water pottutLon. 2. A.Z/i. quality. 3. Social aspects, such as added ponce pnotec ti.on, cic e pnatec tLo n and wti it y s env.Lce nequitements. I ask these questions because I have an uneasy £eeting that they did not do 40 in the negative statement and A.6 not, I feet we 4hou2d take immediate action to connect any oven sights we might have made and could be chattenged on. Very tnu2y young, CITY OF TUKWILA Frank Todd Mti yon FET /dc 1912Y #4.7- 15 ,2eFta, Tr)- IS CONS utpN6 F=1t2M Fort fiiu s 1 S I QU p VrQ le • Frank Todd, Mayor CITY OF TUK \1L 14475 - 59TH AVENUE SOUTH TUKWILA, WASHINGTON 98067 5 December 1973 • Mr . •_;Tom. ,Sconz.o, ..;Architect • Suite 1403 1411 - 4th Avenue Building. Seattle, Washington ,98101 Dear Mr. Sconzo: PLANNING DEPARTMENT This office has reviewed the Environmental Assessment Summary for the proposed Lincoln. Properties Development Project. While the Assessment Summary is basically sound, with the exception of air quality assessment, several gross errors were noted and are listed herein. Page #1: Under Summary of the Proposed Action, item #2 refers to Exhibit #1 -1973. This Exhibit is not included in the document. Page #3: Item #5, Historical Background, is extremely detailed in relation to other matters discussed throughout the document. This item should be condensed somewhat to appear balanced with the rest of the document. Page #5: Item #1 -b, Topography, is rather mis- leading in regard to this specific site and describes the Green River Valley in general. This section should•be aimed at describing the topographical characteristics of the 23 -acre project site. Item #1 -d, Biological and Botanical Elements, refers to a Table 2 which does not exist within the document. Page #7: Item #1 -a:(2) is, again, grossly in error and should be corrected. Mr. Tom Sconzo. Page 2 Item #1 -a(3) of the same page is confusing. We have no idea what you are speaking of. Page #8: Item b is extremely brief and completely uninformative. This section should relate, any incapabilities of the soil to support the pro- posed project, at least. Item c of the same page does not discuss the impact on the Green River from discharge of surface run -off and the extent of the added volume of said run -off. Page 9: As you are already aware, Item d must be expanded to meet criteria outlined in the Environmental Protection Agency's Transportation Control Plan, Parking Management Section. Item #2 -a of the same page is erroroneous if speaking of biological life changes resulting from the project. 'There should be a Section a for biological and Section b for botanical included under Section 2, Resultant Life Changes. This would alleviate any possible confusion. In addition to the above, a discussion of alternatives to the known storm sewer problem should be included. Generally, inclusion of the suggestions contained herein will satisfy this department's requirement of an assessment of the environmental impacts resulting from implementation of the proposed project. However, a decision as to whether or not a detailed statement will be required cannot be made until such time as an adequate assessment summary has been reviewed by this office. Sincerely, n1 Steven M. Hall Acting Planning Director GC /lt cc: Mayor Todd 1974 CI i i1O TUKWILA WATER QUALITY ANALYSIS FOR ENVIRONMENTAL ASSESSMENT FOR LINCOLN PROPERTY COMPANY TUKWILA DEVELOPMENT PROJECT PREPARED BY WILSEY & HAM, INC. MARCH 1974 MANSON BENNETT & ASSOCIATES The 1411 Fourth Ave. S:lil;!ng Seattle, Wash.. 98101 WATER QUALITY CONTENTS I. INTRODUCTION 1I. EXISTING CONDITIONS A. Water Quality in the Green /Duwamish River. B. Sampling Results and Comparison to Standards for the Tukwila City Pond at Andover Park. III. IMPACT A. Projections of Water Quality Impact As A Result Of Development Of the Subject Site. 1) Methods 2) Results IV. APPENDIX - Water Quantities I. INTRODUCTION The historical drainage pattern of the Green River Valley has been altered by the industrialization of the valley. Within the vicinity of the sub- ject site, drainage patterns have been altered by the construction of river levees and by the implementation of the City of Tukwila Master Drainage Plan. Specifically, when development of the subject site is completed, drainage will be routed to the P -17 drainage ditch (a component of the Tukwila drainage system) which flows into the city retention pond located off Minkler Boulevard. When water in the retention pond reaches a mean elevation of 16 to 20 feet, it is pumped into the river. There are 695 acres within the P -17 drainage basin and most of this acreage has been or is being developed for commercial and industrial park uses. Parts of both the Southcenter complex and the Andover Industrial Park as well as another industrial area and the subject site are located within the P -17 drainage area. The proposed action, which has been described elsewhere, will result inthe development of 25.4 acres in close proximity to the Green River for retail, commercial and warehouse buildings. Thus, the resulting land use will be similar to the adjacent Andover Industrial Park and the Southcenter complex. Typically such facilities result in building coverage of 45 -50% of the land in addition to 35-40% paved surfaces or a maximum total of 90% impervious surfaces. The question addressed in this discussion is the water quality impact of developing the subject site for commercial and industrial park type purposes. First the water quality in the Green River and the effect of the city retention pond as an effluent is discussed in general terms. For this purpose water quality samples were taken in the P -17 ditch, in the pond itself and in the pond outfall as it enters the river. Then the impact: of developing the subject site in terms of impact on water quality is projected. In general, the samples taken are more of an indication of short -term impact of development in the P -17 drainage area because construction work was taking place on several large sites at the time the samples were taken. As a result, the samples are high in silt, B.O.D., etc. The projections of water quality impact more closely approximate the long -range water quality implications of the development of the subject site in relation- ship to the development of the remainder of the P -17 drainage area. II. EXISTING CONDITIONS A. Water quality in the Green - Duwamish River The Duwamish River estuary is an important industrial waterway and has been receiving industrial, municipal, and storm water wastes since the early 1900's. In the 1940's fisheries - resource agencies and commercial interests became concerned about the impact of degraded water quality on the rich aquatic life of the estuary. In 1958, in response to growing water quality problems through -out the Seattle metropolitan area, Seattle area residents voted to form the Municipality of Metropolitan Seattle (METRO). METRO is a federa- tion of cities united to deal with waste water disposal and transporta- tion service. The METRO Comprehensive Sewerage Plan includes an extensive network of sewer trunklines and several sewage treatment plants. The Renton treatment plant is located approximately three - quarters of a mile downstream from the site and discharges treated effluent at that point. Thus, for most water quality parameters, except coliform counts, the Renton treatment plant overshadows the effluent from the retention pond (see Tables A and B). Since June 1965, the Renton Treatment Plant (RTP) has been discharging increasing amounts of treated effluent to the Duwamish River as new trunklines have been constructed and the treatment plant's service area has been enlarged. The design capacity of the present Renton secondary treatment process is 36 million gallons per day, although the actual volume of effluent varies. By way of comparison, the water is discharged from the Tukwila retention pond is a relatively small volume. The existing pump has a maximum capacity of 60 -85 c.f.s. and is running less than 5 % of the time. In recent years, a number of studies have been performed to determine the water quality effects of the various effluents into the river. From these, a brief overview of the river can be obtained. From 1963 to 1967 METRO and the U. S. Geological Survey conducted a cooperative study of water quality in the Lower Duwamish River in order to determine the chemical, physical, and ecological changes that take place in the estuary when raw or partially- treated wastes are replaced by treated effluent from the Renton Treatment Plant. This study was primarily concerned with the hydraulics of the estuary, the physical and chemical characteristics of the water (temperature, dissolved oxygen, and bio- chemical oxygen demand), and certain aspects of the ecology relating to the plankton communities. The findings of this early study have been substantiated by later studies performed by Dr. Eugene Welch at the University of Washington in 1967 and 1969, and by the RIBCO (the River Basin Coordinating Committee, a technical advisory committee to METRO) Water Quality Management Study Interim Report of October 1973. Conclusions regarding the interpretation of past trends and data, as well as specific estimates of possible future impacts affecting the Duwamish estuary and Green River will be available' in the near future as RIBCO completes its estuary studies. Just upstream of the subject site, conditions of low dissolved oxygen have often been recorded in the late summer. The Green - Duwamish River • still experiences such low dissolved conditions during the summer months. Although the most recent METRO six -month report analyzing data from March 1973 through October .1973 indicates an improving trend in dissolved oxygen, the RIBCO analysis indicates low dissolved oxygen levels are still a problem. Low dissolved oxygen in the Duwamish Estuary is attributable to oxygen consumption by benthos (bottom organisms) and algae as well as high temperatures due to shallow depths, low flows, • and inadequate shading. However, it appears to be highly unlikely that the present anadromous fish runs or annual aquatic ecosystem of the Duwamish will be affected by dissolved oxygen depressions, according to RIBCO. biologists. By way of a general note, dissolved oxygen is a key parameter in the, Green - Duwamish River and in similar streams that have commercially and, recreationally important fish populations. The respiratory processes of fish, shellfish, benthos, etc. are affected by changes in dissolved oxygen content. The dissolved oxygen is depleted by the oxidation (degradation) of natural as well as man -made materials and is replaced naturally by aeration at the air -water surface or by mixing with water having greater dissolved oxygen and /or by photosynthesis of aquatic plants. Since the degradation of the more common wastes requires their oxidation, the variation in dissolved oxygen is a significant indicator of the general amount'and persistence of pollutants. .The capacity of water to retain dissolved oxygen is also reduced with increasing temperatures. Upstream from the subject site and the retention pond, the river may be loaded slightly beyond its natural` B.O.D. (Biological Oxygen Demand) as indicated by the fact that °both the average dissolved oxygen values and average B.O.D. values at the Renton Treatment Plant monitoring station ( #351) are generally lower than at the monitoring station up- stream of the subject site ( #312). The high B.O.D. in the river adjacent.to the site is probably due to the cumulative effect of-numerous point sources of effluent, one of which is the discharge from the Tukwila pond. However, the pond is a relatively minor source as noted above. Thus, it is possible that effluent from the pond has only a small direct effect on dissolved oxygen concentrations in the lower river and estuary. Temperatures for the river from the monitoring station 315 at Kent to just downstream of the subject site are lower than those which would indicate thermal pollution levels. The river responds to inputs of warmer water from the Renton Treatment Plant as shown by several stations downstream. At station 3077, a small decrease occurs as a result of the Ranier Vista Treatment Plant effluent, then the influence of Elliott Bay seawater is registered. If the retention pond effluent is a source of thermal pollution, its effect is certainly overshadowed by the Renton Treatment Plant. Ammonia and phosphate concentrations.in the Green /Duwamish River are relatively low adjacent to the subject site but have significantly' • increased downstream from the Renton Treatment. Plant outfall since the introduction of the effluent in .tune 1965. The Renton Treatment Plant is only 16% efficient for ammonia and 3% efficient for phosphates:' The concentrations of these nutrients are at least doubled as a result of the present input of treated effluent from the plant. According to METRO data, the Renton Treatment Plant is a quite significant source of nitrites and nitrates. The impact on aquatic life in the estuary attri- butable to this input of nutrients is, however, unknown'at this time. Maximum concentrations of all nutrients in the Duwamish Estuary occur at low tide, partly because at this time there is a minimum of seawater dilution of fresh water nutrient sources. High levels of nutrients are also recorded in the fall and winter, however, when light conditions are minimal, a severe algal bloom cannot be sustained. Nuisance blooms and eutrophication are well known problems that develop from increases in phytoplankton production frequently caused by nutrients in domestic waste water. However, the USGS Study indicates that in the case of the Duwamish River, nutrient concentrations do not control the occurrence of the blooms inasmuch as nitrogen and phosphorous com- pounds always are present in sufficient quantities for a bloom to exist. For example, previous data indicates that a bloom occurred prior to the installation of the Renton Treatment Plant. The chief factors "controlling whether or not a phytoplankton bloom will occur are favor- \, able hydrological and climatic conditions. Nutrients from such sources as the county -city pond may increase the biomass produced by the phyto- plankton blooms, once the other favorable conditions are established. The dissolved oxygen of surface waters is increased by the photo- synthetic process of the bloom, but the dissolved oxygen of the sub- surface waters is decreased as the plants die and oxygen is consumed in decomposition processes. Coliform concentrations in the Duwamish River exceed the median count established by the water quality standards, according to the last six -.. month METRO report. Although a good relationship between total and fecal coliform is not evident, the same general trend of increasing' contamination in downstream locations is apparent in the fecal .col iform count as well. At present, as a result of construction activities which are taking place within the P -17 drainage basin, the retention pond is high in coliforms. However, due to the relatively low volume of discharge from this source, only a slight impact is observable from the river: water quality data Soluble trace metal concentrations for copper and lead (Table C). are fractions of a part per billion in the estuary water. This data was obtained from the trace metal laboratory, University of Washington,,' Department of Oceanography, core sampling within the estuary. The fate of metals borne by the river is transferral to the sediments. The concentrations of lead and zinc at the surface of the cores and one meter deep in the cores (Table B) are extremely high and demon-" strate how effectively the transfer proceeds. The cores were obtained in June, 1973, and were analyzed by the Region Ten Environmental Protection Agency Laboratory. Since nearshore ocean sediments contain an average of 60,000 ppb lead and 150,000 ppb zinc, it appears that the Duwamish Estuary sediments have been greatly enriched by inputs from the river and from industrial sites around the estuary. There- fore any contamination from the proposed site such as auto exhaust borne lead, which is introduced into the river, would be transferred downstream to the surface sediments and would comprise an undetectable, increase in the already heavily loaded sediments. CHART A WATER QUALITY - KENT TO ELLIOTT BAY JUNE 1973 Coliform Counts (100m1) Metro Total Fecal - Ammonia/ Phosphate Silica Dissolved Conductivity Temperature Station Coliform Coliform Nitrate (mg /1) (mg /1) (mg /1) Oxygen umhos /cm °C (mg /1) 306 6,400 120 .48 .50 .24 - 16.3 307 9,400 50 .11 .26 .09 - - 12.8 3077(1) 3,400 20 21.25 1.28 4.80 - - 17.0 3106 1,400 42 .70 .50 .35 - - - 17.1 3107 1,200 20 .38 .49 .26 '17.2 351(2) 110 20 .02 5.20 8.0 151 18.8 3108 700 50 .18 .49 .20 - - 17.2 311 (3) 1,400 67 .12 .46 .17 - - - - 17.3 312(4) 660 20 .10 .42 .42 .21 - - 17.9 315 510 20 .15 .40 .14 - - 17..4 - - No Data (1) Ranier Vista effluent . (2) Renton Treatment Plant (3) Immediately downstream of subject site (Renton Junction) (4) Immediately upst4eam of subject site CHART. B WATER QUALITY - KENT TO.ELLIOTT BAY, DECEMBER 1973 Metro Station 306 307 3077(1) 3106 3107 351 (2 ) 3108 311(3) 312 (4) 315 - No Data Coliform Total Coliform Counts (100 Fecal Coliform ml) Ammonia/ Phosphate Silica Dissolved Conductilty Temperature Nitrate (mg /1) (mg /1) (mg /1) Oxygen umhos /cm °C 1,900 130 .18 .43 .16 - 8.4 7,600 980 .21 .45 .13 8.3 520 24 4.13 1.29 4.48 - - - - 14.o 400 20 .17 .40 .12 7.0 380 20 .05 .39 .09 - - 6.5 20 0 .14.80 .13 3.24 - - 15.0 180 20 .04 .40 .09 6.3 720 20 .04 .42 .09 11.67 68 6.5 420 170 .05 .34 .09 - - - - 6.5 180 20 .05 .40 .10 - - 6.2 Ranier Vista effluent Renton Treatment Plant Immediately downstream of subject site (Renton Junction) Immediately upstream of subject site TABLE C METALS CONCENTRATIONS IN DUWAMISH: ESTUARY (parts per billion) Soluble Metals Depth Date Location (Meters) Cu Pb 9/13/72 West Waterway 0 0.15 0.16 15 0.15 0.40 6/01/71 West Waterway 8 0.4 17 0.4 9/13/72 East Waterway 0 0.4 0.44 15 0.07 0.13 '6/01/72 East Waterway 3 0.4 8 1.9 13 0.5 Sediments (Total Acid Soluble) Depth Core No. Location (Meters) Pb Zn 12 Duwamish Mouth 0 71,000 130,000 11 Duwamish Mouth 0 194,000 25,000 -1 152,000 20,000 10 Duwamish Mouth 0 195,000 400,000 -1 18,000 69,000 16 East Waterway 0 346,000 600,000 -1 61,000 140,000 B. Sampling Result and Comparisons to Standards for the Tukwila City Pond at Andover Park Water quality of the Tukwila retention pond was sampled on March 13, 1974. Three locations were choosen in order to gain a dynamic perspec- tive of water quality conditions as water inters and leaves the retention pond. Samples were takers at the following three locations: Station I: Water samples were taken directly west of the retention pond in the P -17 drainage ditch where the ditch enters the pored. Station II: A sample was taken at the point in the pond where the discharge pump is located. Stationlll: A sample was taken from the high velocity discharge pipe as effluent was being pumped into the Green /Duwamish River. 1) Sample Methods Sample methods and analysis were performed according to methods specified in Standard Methods for the Examination of Water and Waste Water, 13th edition. Nutrients were analyzed by a technican* Auto Analyzer II. Turbidity was measured on a HACH* Model 2100A Turbidimeter. Coliforms, both total and fetal, were tested and analyzed by methods specificed in Standard Methods for the Examination of Water and Wastewater 1 th edition. 2) Results A pH value of 7.0 was obtained for Station I, 7.2 for Station II, and 7.2 for Station III. All these stations are well within the limits set for surface water criteria for public waters, which states the pH must lie between 6.0 and 8.5. Dissolved Oxygen Dissolved oxygen (D.0.) was measured at 9.5 milligrams per liter (mg /1) at Station 1, 10.1 mg /1 at Station II, and 9.6 mg /1 at Station III. These values are within the Washington State Water Quality Standards for AA Water. However, it must be pointed out that all parameters must be within the AA Water Quality Standards to be classified AA waters. In such a system as this holding pond one or two parameters might be included in AA waters but the remainder of the parameters will far exceed the parameters. Alkalinity Alkalinity (as CaCO3) was measured as 80 mg /1 at Station 1, 55 mg /1 at Station II and 44 mg /1 at Station III. Alkalinity is a buffer system in natural water and usually occurs between 30 -500 mg /1. Specific Conductance Specific Conductance was measured at 268 mho /cm2 at Station I, 170 mho /cm2 at Station 11 and 175 mho /cm2 at Station III, these high values are most likely due to the nature of the holding ponds water- shed. Specific conductance will be raised as a result of run -off from sites on which construction activities are taking place. Dissolved Solids Dissolved solids were measured at 168 mg /1 Station 1, 104 mg /1 at Station II and 110 mg /1 at Station III. Turbidity Turbidities of 11 J.C.U. were measured at Station I, 26 J.C.U. at Station II and 20 J.C.U. at Station III. These high values are most likely due to the construction work in the area. When high turbidity values occur, particulate matter (or road film) is reducing light penetration into the water. As the particulate matter settles out, it forms a coating around objects and may cause platform buildup in the stream channel. In addition, bottom dwelling organisms and /or fish eggs covered by settled particulate matter risk suffocation. An increased load of suspended matter also interferes with filter- feeding organisms or organisms which locate their food by sight. The values obtained at Stations 1, 11, 111 far exceed AA Water Quality Standards. Total Coliforms Station 1 had 4,600 total coliforns, Station 11 had 46,000 total coliforms, and Station 111 had 24,000 total coliforms. These values far exceed Class AA Water Quality Standards which state that total fecal organisms shall not exceed median values of 50 for fresh water. Fecal Coliforms Fecal coliforms were measured at 1,500 at Station 1, 430 at Station 11, and 930 at Station 111. Biological Oxygen Demand (B.O.D.) Biological oxygen demand (B.O.D.) was determined at, 1.5 mg /1 02 at Station 1, 2.1 mg /1 at Station 11 and 2.0 mg /1 02 at Station 111. CHART D WATER QUALITY SAMPLING RESULTS STATION I STATION II STATION III Temperature °C 10 °C 10 °C 10 °C pH 7.00 7.2 7.2 D.O. mg /1 9.5 mg /l 10.1 mg /I 10.4 mg /1 Alkalnity 80 mg /1 55 mg /1 44 mg /i (as CaCO 3 ) SpecfiE Conductance mho /cm Total Disolved Solids Turbidity Jackson Turbidity Units B.O.D. Ammonia (NH3 -N) Total : Organ i c= Nitrogen (NO 3 + NO2 -N) Phosphate (Ortho -PO4) Total Colforms M.P.N. Fecal Colforms. M.P.N. 268 mho /cm2 170 mho /cm2 175 mho /cm2 168 mg /1 104 mg /1 110 mg /1 11 JCU 26 JCU 20 JCU 1.5 mg /1 2.1 mg /l 2.0 mg /1 .111 mg /1 .089 mg /1 .070 mg /1 .937 mg /1 .635 mg /i .562 mg /1 43 mg /1 31.5 mg /1 27.7 mg /1 4,600/100/ml 46,000/100/m1 24,000/100 ml 1,500/100 ml 420 /100 /m1 930/100/m1 ANDOVER POND MARCH 13, 1974 III ENVIRONMENTAL IMPACT RESULTING FROM THE PROPOSED ACTION A. Projections of Water Quality Impact 1) Methods In the previous section, the studies undertaken by the River Basin Coordination Committee ( RIBCO) were mentioned. Part of the RIBCO studies involved a model whereby the water quality impact of the runoff from different types of land uses can be projected. Varying amounts of pollutants were found to build up during dry periods on a typical acre depending on the land use classification. Then, according to the intensity and duration of rainfall, a percentage of these pollutants will wash off. In the case of the subject site, the runoff carrying these pollutants eventually finds its way into the P -17 drainage ditch and then to the City of Tukwila retention pond until it is pumped into the Green River. Thus, using the RIBCO model, the concentration of pollutants in an average liter of runoff from the site reaching the river during different weather conditions can be calculated. The projections of pollutant concentrations can be performed for innumerable weather situations, however for the purposes of this analysis, the following four weather situations were chosen on the basis of weather information obtained from the National Weather Service. In December of 1973, there were 7 days in which 0.5 inches or more of rain fell. In an extreme case during December there might be 4.5 days of no rain during which time pollutants build up on the land and then are washed off in a rainfall in which 0.50 inches rain falls within one hour. This situation corresponds to the first column of Chart E. In June of 1973 there was only one day in which 0.5 inches or more of rain fell. In an extreme case in the summer there might: be a 30 day period of no rain during which time pollutants build up on the land and then are washed off in a rainfall in which 0.5 inches rain falls in one hour (see the second column of Chart E). Rainfalls of 0.1 inches or more are considerably more frequent in both the winter and summer. In December there were 25 days in which 0.10 inches or more rain fell and in June there were 9 days in which 0.10 or more inches fell. So, for the purposes of this analysis, a typical case might be one in which there is a relatively short interval of no rain followed by 0.10 inches falling within one hour for both winter and summer (see the third and fourth columns of Chart E). According to The Seattle Rain Gage Program and Rainstorm Data, by H.W. Duff and G.C.C. Hsieh (Oct 1969), a rainfall of O. inches in an hour might occur in a 10 year storm and 0.1 inches rainfall will occur several times in a year. According to the RIBCO analysis, a rainfall of 0.5 inches in an hour will wash off 90% of the pollutants built up in the preceeding dry period. By the same manner, a rainfall of 0.10 inches in an hour will wash off 37% of the pollutants. Thus, the following formula was used in the water quality projections: Acres x Number of Dry Days x Washoff Factor (above) x RIBCO waste load factor liters of runoff Weather Winter 4.5 days no rain followed by 0.5 inches rain in 1 hour. Chart E Projections of Water Quality Impact 25.4 Acres (Commercial - Light Industrial) Summer 30 days no rain followed by 0.5 inches rain in 1 hour. % Impervious Surface 90% BOD (mg /liter) imp.* 18.23 per. 11 sub. .02 90% 12.18 .001 Conductivity (mhos /liter) imp. .00035 .054 per. 11 11 sub. .035 5.4 Total Coliform ( #/ 100 ml) imp. 788,040 5,253,580 per. 11 �1 sub. 35,000 2,300 Fecal Coliform ( #/ 100 ml) imp. 7,880 52,535 per. 11 ,1 sub. 350 23 Organic Nitrogen (mg /liter) imp. .40 2.6 per. sub. Ammonia (mg /liter) imp. 18.26 per. 11 sub. 9.1 36.53 18.26 (mg /liter) imp. .08 .53 per. .99 6.62 sub. 13.90 92.67 Phosphate (mg /liter) imp. 1.58 per. 0.16 sub. 7.94 10.59 1.06 92.67 Winter 1.24 days no rain followed by 0.10 inches rain in 1 hour. 90% 10.34 .001 .0002 .02 446,300 11 19,840 4,460 11 200 .22 11 11 4.49 " 2.25 .045 .56 7.87 .044 .004 7.87 Summer 3.33 days no rain followed by 0.10 inches rain in 1 hour. 90% 27.76 • 11 .0003 .0005 11 .05 n 12.08 6.04 .12 1.51 21.14 2.41 .24 12.08 *impervious pervious subsurface, • 2) Results The previous data indicates that the subject site will constitute a source of pollution of coliforms, nutrients and will create additional biological oxygen demand in the Green River which will eventually receive the runoff. The samples taken in the City of Tukwila retention pond provide a relative indication of the short term water quality impact which can be expected when construction occurs on the site. When these samples were taken, there had been several days of light rainfall, and much construction was underway within the drainage basin. Consequently siltation, biological oxygen demand and coliforms were high, but due to the amount of rainfall which had occurred, the sampling data yielded values somewhat lower than those projected for the site upon complete development. Upon full development, the highest pollutant concentrations can be expected to occur in runoff from the site after a rainfall following a long dry period. Thus, the factor most influencing pollutant concentrations in this case, is the length of time between rainfalls. The highest pollution concentrations will probably occur in summer runoff. The subject site represents a little less than 4% of the total P -17 drainage basin. If the land were in open space, impervious areas might be less than 5% and pollutant concentrations in the runoff might be as low as a tenth of the values projected for most water quality parameters. These relationships dramatically show the small but cumulative impact on water quality of development of increments of the Green River Valley. The subject site is not a major contributor to water quality problems and indeed, the site alone would create an imperceptible change in the total water quality of the Green River. However, the overall development of the Green River Valley has resulted in deleterious effects on the river. • 0 Pt City of Tukwila DRAFT ENVIRONMENTAL IMPACT STATEMENT for Lincoln Properties Inc. Development Project Tukwila, King County, Washington Pursuant to: Washington State Environmental Policy Act of 1971 -- Chapter 43.21 C. RCW City of Tukwila, Washington Ordinance No. 759 Frank Todd Mayor by Delbert F. Moss Planning Coordinator • The nature of this report is a Draft Environmental Impact Statement with the City of Tukwila. Planning Department Sponsor: Delbert F. Moss, Planning Coordinator Attention: City of Tukwila Planning Department 6230 Southcenter Boulevard Tukwila, Washington 98067 Type of Proposed Action: Administration decision by the City of Tukwila, review of proposals, and permit approval for the property described in Exhibit A, B and C Legal Description, and site plan Exhibit "1 ", - 1973 by private interests. Permits to be granted: 1. Building permit. 2. Sewer and Water permit. 3. Permits to power, natural gas, and telephone utility companies for use of city right -of -way in providing service to the subject area. Other Official Action = Review 1. Review of State Department of Ecology Flood Zone permit by Public Works Director. 2. Review of Storm drainage system. 3. Review of site plan and landscaping parking by City Planning Commission. 4. Review,of curb cut locations by Planning Commission. Summary of the Proposed Action 1. To undertake all official action necessary to allow completion of proposed project, in accordance with all city laws, policies, and plans. 2. Location: See attached exhibit 1 -1973 3. Size: Approximately 23 acres,. 4. Zone: C. M. - Industrial Park. The Environmental Impact for the development of this property in a C.M. Zone resulting from the proposed action will not have a significant environmental impact if sound architecture, engi- neering, hydraulic, and ecological principles are adhered to. 5.. Topographic /Geologic Impact: The earthwork operation required is but a continuation of work begun on all property north, west, and east, and would complete all properties up to South 180th Street. This earthwork program is being undertaken in a manner, consistent with sound soils engineering practice. 6. Biological Impact: This action will cover all remaining grass- lands; the major biological impact in this area occurred some- time ago when the area was established a Commercial Industrial Zone. 7. Atmospheric Impact: Noise level will increase with added automobile and trucking. An increase in concentration of air pollutants will result from automobile and construction work. 8. Surface Drainage /River System Impact: Surface runoff will contri- bute only a small part of the overall drainage problem associ- ated with the Green River System. 9. Change in Human Use: The continuation of commercial industrial development that will result from the proposed action represents no change in the human use other than to expand it onto land that has been dormant. • • • A. PROPOSED ACTION 1. Purpose It is the intention of the developer to construct retail, commer- cial and warehouse buildings. The buildings will be used by a varied type of user, similar to the other areas of Southcenter and Andover Park. The building designed will cover approximately 50% of land with parking per code, landscaping per code and ordinance. 2. Type of Action The City of Tukwila will perform administrative and legislative action in the review of proposals and the granting of permits, for the Lincoln Properties, Inc. commercial and industrial devel- opment which will hereinafter be referred to as the subject area. All review and permit procedures are prescribed by Tukwila City Ordinances and have been codified within the Tukwila Municipal code. This Environmental Impact Statement is intended to describe the anticipated effects upon environmental quality resulting from each incremental phase of development within the subject area until ultimate development is achieved as allowed by the appli- cable sections of the Tukwila Comprehensive Zoning Ordinance (ORD. 251 S1.1, 1957). 3. Justification for the Proposed Action The proposed action is the lawful implementation of previously determined City of Tukwila policies as embodied within official plans, ordinances and resolutions. 4. Location (Refer to Location Map, Exhibit 1 -1973. The subject area lies wholly within the Tukwila City limits, and is bounded by Southcenter Parkway on the west, Andover Park West on the East, 180th South on the south, and the North Access Road of Southcenter West Development. 5. ,Historical Background This area of the Green River Valley has been used primarily for dairying purposes ever since the white man settled in the area in the nineteenth century. Truck farming was also carried on but the high water table and poor drainage kept this use to a minimum. A large portion of the north end of the Green River Valley remained in marshes and sedges, and Cat Tails remained dominant plant types up to the time of rapid industrial growth in the early and mid 1960's. This industrial development resulted from a combination of factors. Geography sets severe constraints on where transportation routes • can be built in the Puget Sound region. • Seattle's response to Tacoma's predominance as the major rail- road terminus on Puget Sound led to the building of the Seattle and Spokane railroad lines, which later became part of the Chicago - Milwaukee, St. Paul and Pacific Railroad's main line up through the Duwamish and the lower Green and Maple Valleys. Eventually, other railroads, the Northern Pacific, Union Pacific and Great Northern followed nearly parallel routes from Seattle: to Tacoma. This . railroad building made the first and major changes in the location of the Green, Duwamish and Black River channels. The Black River has not been a major tributary since the Lake Washington Ship Canal was completed in 1914, lowering the lakes level by 15 feet. Prior to that time, both Lake Washington and the Cedar River were drained by the Black River into the Duwamish River. Except for the highway system under- taken in the first quarter of the century, little physical change occurred in the area until industrial development began in the 1960's. Early in the 1950's, the planners for the Port of Seattle real- ized that more area at dock side would be needed in order to handle large ships, and an ambitious plan to turn the Duwamish and Green River Valleys into a large industrial valley with a shipping canal was begun. The Port Authority has the right to impose it's zoning on the land if it can prove this to be the most valuable use. Suits by the residents'in the area began when they felt that they were not being treated fairly by the Port District. By incorpo- rating large areas into the City of Tukwila and imposing their own zoning on the land, the city was successful in preventing the Port District from imposing it's own zoning and, subsequent- ly, dredging a shipping canal through the Duwamish and Green River valleys. With industrial zoning placed on the land, and high increases in residential and commercial development on the adjacent hillside, the subsequent building of the freeway system, again to some extent dictated by geography and topographic fea- tures, started the present rush of industrial and commercial development that will not abate for several more years. Credits for Source of Information:- City of 'i'uKwila Planning Department. Draft: Draft: Environmental Impact Statement for the Strander Boule- vard extension and bridge. Values have .since changed, but events set in motion by the Port District's plans cannot be changed over a short time. The delay in developments have allowed for high quality standards to be imposed as a result of the changed attitudes toward the natural environment rather than only quantitative perimeters to be used. Location: The project is located on 180th South between South Center Parkway and Andover Park West and north approximately 1,400' - 0 ". 6. Financing The proposed method of financing is the owner, Lincoln Properties Inc. B. EXISTING CONDITIONS 1. Natural Setting a. Size The area involved and most directly affected by the develop- ment of this project is the 700 to 800 acres, more or less, contained in the Southcenter-Andover Park Industrial areas. b. Topography Topography is characterized by a flat alluvial plain, actu- ally part of the delta for the Green, Duwamish and Black Rivers. The river meanders widely throughout the whole length of the valley area and aerial photos indicate numer- ous abandoned river channels. In flood, the river is above some sections of the valley floor and is held back by ex- tensive levees, both natural and man -made. With the advent of industrial development, extensive pumping is required to remove excess water from the flatland and runoff from sur- rounding hills. c. Geology The geology of the area is characterized by layered gravel, and and clay materials, laid down as glacial till ridges, and, subsequently, uplifted and tilted by basaltic and bracial formations. This rock is exposed and extensively mined at several locations. The deposition of alluvial materials in the valley floor reflect the latest in geolo- gic sequential events, antidated by the most recent glacial retreat, which scoured the tectonically rippled hills and valleys in the characteristic north -south direction, common in the Puget Sound basin. d. Biological and Botanical Elements The existing dominant biological species in both the river and on the land of proposed action have been surveyed and listed in Tables 1 and 2. The natural setting at proposed site contains the mentioned botanical species with grasses (Gramineae) predominating. e. Lakes, Streams, Marine Water and Groundwater The Duwamish River flows through site of proposed action in a turn of its meanders. The land at this location is fairly 5 level, and the approximately 120 foot wide Duwamish River flows slowly, as it meanders. through our City of Tukwila. The natural course of the rive has been altered in various places near but not at the proposed site. The water table is high due to proximity of river, and during late winter and early spring, the water table may be within a few inches of the ground surface. 2. Human Use and Development a. Residential (8 square miles surrounding the area) (1) Single Family Dwelling 3,484 Average household size 2.3 (2) Two Family Dwellings 2 (3) Three or Four Family Dwellings 3 (4) Five to Eight Family Dwellings 0 (5) Nine or More Family Dwellings 59 (6) Hotels, Motels, and Tourist Homes 3 (7) Mobile Homes 0 b. Commercial (1) (2) Wholesale and Distributors Retail a. Southcenter b. c. Industrial 1. Shopping Population (daily) 2. Shopping Population (peak) 3. 1971 Total Shopping Population - 28,600 - 92,000 - 11,500,000 Other than Southcenter 34 108 10 (1) Mining 2 (2) Construction 2 (3) Manufacturing a. Southcenter 7 b. Other than Southcenter 24 d. Agricultural (1) (2) Dairy Farm (5) Acre Mixed Crops (7 Acre, 36 Acre, e. Recreational 3 Acre) 1 3 (1) Minor Parks (Less than 5 acres) 4 a. Picnic Tables b. 2 Tennis Courts (2) Golf Courses 1 (3) Tukwila Community Club 1 (4) Race Tracks (Longacres) 1 (5) Numerous Fishing Sites along the River 6 f. Transportation • (1) Railroads (BNSF Burlington Northern, Union Pacific, Milwaukee) • • g. a. Passenger b. Freight (2) Taxi Cab Services (3) 405 and I -5 Intersections a. Cars to Southcenter (daily average - 13,000) b. Cars to Southcenter (peak daily average - 40,000) (4) Truck Transportation - 2,500 daily a. Terminals b. Freeway Accesses (5) River Transportation (6) Helicopter service to Longacres (7) Employees (Southcenter) - 7,500 (8) Cars (Southcenter) - 5,013,600 yearly Education (1) Elementary 4 (2) Jr. High 1 (3) Sr. High 1 h.. Religion (1) Churches 10 NOTE: The area surveyed for a statistical baseline is proportionally larger, 8 square miles compared to the City's 4 square miles. However, nearly one - hundred percent of all new commercial/ industrial activity within Tukwila is of a regional nature. C. ENVIRONMENTAL IMPACT OF PROPOSED ACTION 1. Changes in Natural Characteristics a. Vegetation (1) Type Changed The following are plants that will be removed by proposed action: (See Table I) (2) Location of Change Approximately one -half mile upstream from the F.A.I. 405 Bridge over the Green River. (3) Density Changes Removal of approximately 10% A.C. of site. This action will cause a vegetation density change of at least 90% 7 • • • b. Soil and Rock Late forming alluminium and glacial silt from the late Pleistocene geological era. c. Rivers There will be no changes in bottom characteristics. TABLE I PLANTS DISPLACED BY PROPOSED ACTION BOTANICAL FAMILY GENUS AND SPECIES Aceraceae Acer circinatum Acer macrophyllum Compositae Anthemis cotula Cirsium arvense Hypochaeris radicata Matricaria matricarioides Sonchus asper Equisetaceae Equisetum hyemale Gramineae Agrastis tenuis Agropyron repens Hordeum leporinum 8 chemical properties, inflow - outflow and circulation. NOTE: The river at proposed location is approximately 120 feet across and flows at about midstream. d. Atmosphere The chemical properties of the atmosphere will be indirectly affected through the usage of proposed action by motor vehicles. Air circulation and weather processes will not be affected. There will be an increase in noise levels in the immediate surroundings due to automobiles and people.. 2. Resultant Life Changes a. Biological (1) The addition of landscaping and new trees will in- crease any displaced species by approximately 30 %. b. Community Patterns, Traditions and Functions (1) Patterns will largely be indirectly affected by pro- posed action. The new building will lead to more employment, increased tax base, and some increase in the City's population. (2) Traditions and functions will not be altered by pro - posed action but will be reinforced. In the past several years, Tukwila has become an industrial and business oriented city. c. Human Uses Residentially, agriculturally and recreationally, there shall be a minimal, if noticeable, life change with maximum fe change rtsulLLng in the commercial, industrial, and transportational areas. D. UNAVOIDABLE ADVERSE ENVIRONMENTAL EFFECTS The major adverse environmental effects would be the disruption of biological successional events. The proposed site was formerly a field and for several years has been unattended. This has given nature the opportunity to begin its course to increase the exising biological diversity. The disruption of this natural sequence is the unavoidable adverse envirotmental effect. The biological recovery of the displaced species is very unlikely due to usage and maintenance of proposed action and is not expected in the forseeable future. The reason for the unavoidabiiity is that a series of buildings will put in its place, including paving for access roads and parking. E. ALTERNATIVES TO THE PROPOSED ACTION The alternative would be to seek. other areas for development. 9 F. RELATIONSHIP BETWEEN LOCAL SHORT -TERM ENVIRONMEMTAL USES AND THE MAINTENANCE AND ENHANCEMENT OF LONG -TERM PRODUCTIVITY 1. Time Involved in Proposed Short -Term Uses Short -term uses for the building and the area served will con- stitute a transition time only in which all of the land within the subject area will be converted to commercial, industrial and business uses. 2. Potentials for Long -Term Productivity of Involved Resources Potentials for long -term productivity of involved resources non- renewable involve largely the land area itself. a. Choices of Use Available The project will preclude the land being used for agricul- tural purposes, except if market conditions determine that the need for land for industrial - commercial uses in this area is not critical. This may be the case farther south in the Green River Valley but not at this location. b. Potential Long -Term or Future Economic Productivity Future economic productivity will largely depend on the industrial growth trends in the Puget Sound Basin and what selection processes are used to protect environment while enhancing economic stability. Industry will continue to be largely distributive and service oriented rather than manu- facturing in nature. 3. Preclusion of Enhancement of Long -Term Potentials Because of its geographic location, that being the only major point south of the Seattle City Center, at which all major forms of land communications, utilities and transportation systems come together, in addition to air transportation, this area will continue to absorb the major overspill for industry in the metropolitan area. a. Optional Future Uses Precluded or Enhanced This process will only change if political and economic decisions reduce the market oriented growth dynamics of the area. Changes in technology could have other effects as yet un- known. b. Degree of Preclusion or Enhancement The present policy is one of enhancing the developments themselves and continuous study and revision of municipal and regional goals. 10 G. IRREVERSIBLE AND IRRETRIEVABLE RESOURCE COMMITMENTS WITH THE PROPOSED ACTION 1. Commitments Irreversible and irretrievable resource commitments with the proposed action include land use, construction materials (both for the project and the area served), cost, soil fertility and options for other potential uses. a. Nature and Relative Permanence of Commitments The commitment of the resource is long -term, probably tifty years or more. b. Stability of Resources Involved Resources, largely land area for industrial development, is in great abundance. Questions of availability ct basic raw materials tor products tlowing through the commercial area are far more critical than are alternative uses of few hundred acres of marginal farmland (which in Tukwila were largely swampland and wet pastures). c. Percentage of Resource to be Permanently Committed Nearly one- hundred percent ot the land served by the pro- posed project wilt be developed for commercial industrial uses. 2. Reason for Irreversibility and Irretrievability Transportation facilities and lack of land at competative prices in Seattle dictate commitments of land to the afore- mentioned uses. a. Potential for Diminishing Permanence of Commitments Potential for diminishing permanence of commitments rests with the regions commitment toward less economic growth in the future. b. Reasons for Not Employing Diminishing Measures It is not within the capability of citizens in Tukwila to determine region goals. They can only influence the quali- ty of the separate developments within their corporate limits. H. DEVELOPMENT OF THE PROPOSED ACTION 1.. Planning and Design of the Proposed Action a. Precipitating Event and Need to Initiate Planning Planning:; and design of the proposed action was initiated by private interest for private industry. l i. b. Period of Time Involved in Planning to Date At least six months planning including two months of inten- sive planning have gone into the project to date. c. Financial Commitments to Date The land is being purchased and preliminary plans and specifications are being prepared by the architect. 2. Public Expression and Participation Tukwila is unique for cities in the region in that a great many citizens attend nearly every public hearing where full advantage is taken to express views. In addition, newspaper coverage in both the Record Chronicle and Highline Times has been made. 3. Currency of Recommended Action a. Relationship with Local, Statewide and National Policies and Plans. The project complies fully with local, statewide and national policies and plans, particularly in the area of providing potential for employment. b. Relationship to Prevailing Economic Conditions Economic conditions, particularly in the South King County area, has been the most severly hit by the past recession. Unemployment reached more than twenty percent, locally, which itself provides a strong case for employment opportunities allowed by the project. This position has been reaffirmed by the State. c. Relationship to Current Technology The project is not only within the capability of current technology, but determined,and necessitated by it. d. Relationship to Existing Laws and Regulations Existing laws and regulations are being fully complied with including application of all required permits. 4. Pursuant Actions a. Plans for resolution in Areas of Conflicting Public Opinion or Agency Policy No areas exist where resolution of conflict have not been resolved. • i'4` 1i�14 ��'��jil b. Further Legislative, Financial, Administrative or Judicial Actions Necessary for Implementation. None required; all have been resolved. c. Further Study Planned or Contemplated for Resolution in Areas of Conflicting Resource Uses. No further study for resource uses will be required. d. Additional Time Anticipated for Full Implementation of the Proposed Action The project, including required permits, is presently on schedule with no additional time beyond current projection anticipated. EXHIBIT "A" September 11, 1973 File 73106 Sammamish Commercial Company, Inc. Legal Description of Parcel 1 of the 24 Acre Parcel That portion of the northwest quarter of the northeast quarter and the northeast quarter of the northwest quarter of Section 35, Township 23 North, Range 4 East, W.M. in King County, Washington - described as follows: beginning at the northwest corner of said northwest quarter of the northeast quarter; thence S 02° 24' 12" W along the west line of said northwest quarter of the northeast quarter a distance of 894.47 feet to the rorth line of the south 430 feet of said northeast quarter of the northwest quarter and the true point of beginning: thence N 87° 50' 57" W along said north line a distance of 177.29 feet to a line 36 feet easterly of the centerline of Southcenter Parkway (formerly 57th Avenue South); thence S 11° 59' 33" E along said line a distance of 322.74 feet; Sthence along a curve to the left having a radius of 107.24 feet, an arc distance of 141.96 feet through a central angle of 75° 50' 36" to a line 36 feet northerly of the centerline of South 180th Street; thence S 87° 50' 09" E along said line a distance of 576.70 feet to a line 740.70 feet west of the east line of said northwest quarter of the northeast quarter of said Section 35; thence N 01° 51' 39" E a distance of 603.89 feet to the southwest corner of the tract of land conveyed to Bruce E. McCann et al by deed recorded under Auditor's File No.. 7208 170 551; thence N 87° 55' 02" W a distance of 438.09 feet to a point 140.16 feet east of the west line of the northeast quarter of said Section 35; thence S 02° 24' 12" W a distance of 209.26 feet to the north line of the south 430 feet of said northwest quarter of the northeast quarter; thence N 87° 50' 09" W a distance of 140.16 feet to the true point of beginning. Subject to easements for rail and utility purposes. Situate in the City of Tukwila, County of King, State of Washington. EXHIBIT "B" September 11, 1973 File 73106 Sammamish Commercial Company, Inc. Legal Description of Parcel 2 of the 24 Acre Parcel. That portion of the northwest quarter.of the northeast quarter of Section'35, Township 23 North, Range 4 East, W.M. in King County, Washington described as follows: Beginning at the northeast corner of the northwest quarter of the northeast quarter of said Section 35; thence S 01° 51' 39" W along the east line of said northwest quarter of the northeast quarter a distance of 1003.74 feet; thence N 87° 55' 02" W a distance of 30.00 feet to the west margin of Andover Park ;lest and the true point of beginning: thence continuing N 87° 55' 02" W a distance of 270.00 feet; thence N 01° 51' 39" E a distance of 272.50 feet; thence N 87° 55' 02" W a distance of 440.70 feet; thence S 01° 51' 39" W a distance of 553.89 feet to a line 36 feet north of the centerline of South 180th Street; thence S 87° 50' 09" E along said line a distance of 685.17 feet; thence along a curve to the left, the center of which bears W 27° 26' 23 W having a radius of 50.00 feet, an arc distance of 52.97 feet through a central angle of 60° 41' 58" to the west margin of Andover Park West; thence N 01° 51' 39 E along said west margin a distance of 238.66 feet to the true point of beginning. Subject to easements for rail and utility purposes. Situate in the City of Tukwila, County of King, State of Washington. EXHIBIT "C" September 11, 1973 File 73106 Sammamish Commercial Company, Inc. Legal Description of Parcel 3 of the 24 Acre Site That portion of the southwest quarter of the southeast quarter of Section 26, Township 23 North, Range 4 East, Willamette Meridian, together with that portion of the northwest quarter of the northeast quarter of Section 35, Township 23 North, Range 4 East, Willamette Meridian, described as follows; Beginning at the southwest corner of the southeast quarter of said Section 26: thence S 87° 44' 08" E along the south line of said southeast quarter a distance of 140.16 feet to the true point of beginning: thence N 01° 12' 25" E parallel to the west line of said southeast quarter a distance of 137.06 feet; thence S 87° 55' 02" E a distance of 433.03 feet; thence S 01° 51' 03" W a distance of 822.00 feet; thence N 87° 55' 02" W a distance of 438.09 feet; thence N 02° 24' 12" E a distance of 684.96 feet to the true point of beginning. Together with a non - exclusive easement for ingress and egress over and across a strip of land 50 feet in width described as follows: Beginning at the southwest corner of that certain tract of land conveyed to 186 Corporation by deed recorded under Recording No. 711110 -0109; thence N 87° 55' 02" W a distance of 440.70 feet; thence S 01° 51' 39" W parallel to Andover Park West a distance of 50.00 feet; thence S 87° 55' 02" E a distance of 710.70 feet to the west margin of Andover Park West; thence N 01° 51' 39 E.along said west margin a distance of 50.00 feet to the southeast corner of said tract of land conveyed by Recording No. 711110 -0109; thence N 87° 55' 02" W along the south line of said tract of land a distance of 270.00 feet to the point of beginning. Exhibit C -Page 2 Ilk over and across a a strip for width described as followSi over and across a P Beginning at the northeast corner 3f ;the northwest quarter of the northeast quarter of said Section thence N 87° 44' 08" W along the north line of said section 35 a distance of 30.00 feet; thence N 01° 47' 29" E along the west margin of Andover Park West a distance of 115.66 feet tp the true point of beginning, thence N 87° 55' 02" W a distance of 710.70 feet; thence N 01° 51' 03" E a distance of 25.00 feet; thence S 87° 55' 02" E a distance of 710.67 feet to the west margin of Andover Park West; thence S 01° 47' 29" W along of sti�a og said beginning. Subject a distance of 25.00 feet to the true point Subject to easements for rail and utility purposes. Situate in the City of Tukwila, County of King, State of Washington. • northwest environmental technology laboratories, inc. 300 - 120th avenue n.e., bldg. 2 suite 108, bellevue, washington 98005, (206) 455 - 3570 NETL No. 50- 73-048 AN AIR QUALITY ASSESSMENT FOR LINCOLN CENTER SOUTH NO. 2 Prepared for: Manson Bennett Associates 1411 4th Avenue Seattle, Washington 98101 December 31, 1973 NETL No. 50 -73 -048 AN AIR QUALITY ASSESSMENT FOR LINCOLN CENTER SOUTH NO. 2 Prepared by Errol Nelso Air Quality Specialist Approved by: /r.■ h M. an anger, D ector nvironmental Servi es TABLE OF CONTENTS SUMMARY 1 1.0 INTRODUCTION 2 2.0 POLLUTION ASSESSMENT METHODOLOGY 2 2.1 General Background Concentrations 2 2.2 Line Source Concentrations 4 2.3 Concentrations from the Proposed Development 4 3.0 POLLUTION INVENTORY 5 3.1 Emissions from Background Sources 5 3.2 Emissions from Nearby Roadways 9 3.3 Emissions from the Proposed Development 9 4.0 METEOROLOGY 10 5.0 AIR MONITORING PROGRAM 10 5.1 Monitoring Instruments 11 5.2 Data Analysis 12 6.0 PREDICTED POLLUTANT CONCENTRATIONS 16 6.1 Specification of "Worst Case" Conditions 16 6.2 Background Concentration Predictions 17 6.3 Development Concentration Predictions 19 6.4 Comparison with Allowable Standards 19 7.0 REFERENCES 22 SUMMARY The impact of the proposed development on the local air quality is in relation to the contribution to the local air pollution burden from activity within the development itself, in comparison with the local background burden established by pollutant emissions from adjacent stationary source activity (residences and businesses), and by traffic on adjacent roadways. Under "worst case" meteorological and emission conditions (stable atmosphere and light northerly winds occurring with peak traffic loads on 1 -5, 1 -405 and in and around the Southcenter shopping mall), the eight -hour average carbon monoxide standard of 9 ppm is predicted to be approached, but not exceeded; the one -hour average standard of 35 ppm will not be approached. Pollution concentrations are expected to peak in 1975, and this study has shown that the 1975 predicted carbon monoxide concentrations due to background activity under "worst case" conditions are 8.9 ppm maximum one hour average concentration, and 6.2 ppm maximum eight hour average concentration. The development itself is predicted to add an additional 0.8 ppm one -hour average maximum, and 0.5 ppm eight -hour average maximum, to the background maxima. The total 9.7 and 6.7 ppm one- and eight -hour average concentrations, respectively, are well below applicable standards. Carbon monoxide concentrations obtained at the site under meteoro- logical and emission conditions similar to the specified "worst case" conditions indicated measured background concentrations of 8.5 ppm. and 4.7 ppm for the maximum one hour and eight hour averages, respectively. These data are in good agreement with the predicted 8.9 ppm and 6.2 ppm values. In conclusion, it is therefore expected that the proposed develop- ment will not create an additional traffic load great enough to prevent the attainment or maintenance of air quality standards in the vicinity of the proposed action. Relative to air quality, the proposed business and commercial development will have minimal impact on the surrounding environment. 1 AN AIR QUALITY ASSESSMENT FOR LINCOLN CENTER SOUTH NO. 2 1.0 INTRODUCTION Lincoln Center South No. 2 is a proposed business and commercial center of about 23.5 acres to be located on the north side of South 180th St. between Southcenter Parkway and Andover Park W. in Tukwila, Washington. The development will include the construction of approximately ten build- ings and parking for 675 automobiles and trucks. An assessment of air quality in the vicinity of the proposed devel- opment requires an evaluation of pollutant contributions from several sources. These are: the general background levels from nearby residences and, businesses; emission of pollutants from vehicles traveling on roads adjacent of the proposed development; emissions from vehicles; and heating within the boundaries of the proposed development. The maximum pollutant concentrations in the vicinity of the proposed action will be determined in appropriate mathematical diffusion models under local "worst case" meteorological conditions. The predicted con- centrations are compared with existing data and the national and state ambient air quality standards for 1975 and 1990. This report will evalu- ate in detail the concentrations of carbon monoxide because it is the pol- lution which is most likely to have an effect on the development and the applicable ambient air standards. Existing diffusion modeling techniques are insufficiently developed to effectively determine the concentrations of oxides of nitrogen and hydrocarbons (Federal Register, October 30, 1973). 2.0 POLLUTION ASSESSMENT METHODOLOGY 2.1 GENERAL BACKGROUND CONCENTRATIONS A 9 x 9 grid network consisting of segments one kilometer square was established with the proposed development in the center (Figure 1). Ap- propriate area source emissions were determined from the 1971 Puget Sound Air Pollution Control Agency emission inventory and assigned to area ele- 2 Grid Size = 1 Kilometer Figure 1 Area Surrounding Proposed Lincoln Center South No. 2 Showing Area Source Grids and Population for each Grid (1970). 3 1785 2753 1454 1000 387 670 704 1000 764 784 1794 1278 1011 244 33 206 > 522 1175 «.... 279 429 1264 ire 58 739 22 3 0 T. 486 461 Seattle- Tacoma. 374 1698 2216 338 0 18 - rz 18 163 1130: Airport I 0 1296 1922 521 Site 0 39 18 o 660 715 163 1911 1637 20 39 17 93 3° 50 191 454 1602 26 60 0 0 390 641 697 650 775 153 0 31 67 0 985 1292 'uget orth . 822 1281 112 44 50 51 562 501 520 Grid Size = 1 Kilometer Figure 1 Area Surrounding Proposed Lincoln Center South No. 2 Showing Area Source Grids and Population for each Grid (1970). 3 ments based on population. Added to the background emissions due to popu- lation are the emissions from the business and commercial activity in the area adjacent to the development. These emissions are not population de- pendent and must be added separately. The distribution of element area sources within the grid network, which are applied to the mathematical model, should be such that the source strength will vary less than one order of magnitude from one area element to the next (Hanna, 1971). The source strength within each ele- ment is assumed to be constant and uniform across the entire grid. A wind direction is then assumed which must be parallel to the grid orien- tation in any one of four possible directions. The orientation chosen should align with the wind direction which creates the highest likelihood of "worst case" meteorological conditions. The mathematical basis for the resultant computation involves the weighting of successive contributions from grid elements up -wind from a sensor location. The total composite concentration level is directly proportional to source strength and inversely proportional to wind speed (Hanna, 1971). The model used in this assessment is similar to the APRAC- lA prediction model methodology developed for the Environmental Protection Agency. 2.2 LINE SOURCE CONCENTRATIONS In the immediate vicinity of the proposed project, it is necessary to determine the pollutant concentrations from nearby roadways. A high- way line source model developed by the California Division of Highways (Beaton, et aZ., 1972) was utilized to determine these concentrations. The model employs an empirical approach in combination with the Gaussian plume equation for cross wind conditions, and considers as a special case the conditions of a wind parallel to the highway alignment. 2.3 CONCENTRATIONS FROM THE PROPOSED DEVELOPMENT The concentrations from the proposed development were treated as an area source emission. The development was assumed to be a 310 meter square, which conforms to the area of the project. The emissions generated by heating and vehicles moving within the project boundaries were used in the area source model (Hanna, 1971). The results estimate the increase in the ambient air concentrations and predict the impact of the project. 4 3.0 POLLUTION INVENTORY Pollutant concentrations in the vicinity of the proposed action come from several sources: 1) An ambient background concentration resulting from emissions due to residential and business activity in the surrounding area. 2) From emissions by vehicles utilizing roads adjacent to the project. 3) From emissions by space heating and vehicles moving about within the boundaries of the project. 3.1 EMISSIONS FROM BACKGROUND SOURCES Figure 1 shows the area which constitutes the background assessment for this report. Each square has the dimensions of one kilometer. Assigned to each grid segment is a population data point which represents an estimate of the number of people living in that one kilometer square in 1970 (Census Bureau, 1971). Estimates of future population by the Puget Sound Governmental Conference (PSGC, 1972) show that increases of approximately 1.5% and 25% are expected in that general area in 1975 and 1990, respectively. Emission rates associated with the population in the grid segments are derived from the Puget Sound Air Pollution Control Agency in 1971 emission inventory (PSAPCA, 1971a) and are shown in Table I. The determination of these emission rates requires a complex breakdown of the emission inventory and will not be discussed in detail in this report. The total emissions in each grid segment are a product of the segment's population and the corresponding pollutant emission rate. In addition to the pollutants generated from population oriented activity are the pollutants generated from commercial and industrial activity in the area. Adjacent to the site is the Southcenter shopping center and the Andover Industrial Park. The area has a high employment level and heavy traffic movement throughout the day, but a negligible population. The size of the area and activity will add substantially to the background concentrations due to the population oriented activity. Traffic and emission rate estimates given in Tables II, III and IV are utilized in the appropriate models described in Section 2 to provide an estimate of the predicted concentrations in the vicinity of the proposed project. 5 TABLE 1 EMISSIONS FROM AREA "BACKGROUND" SOURCES IN KING COUNTY grams /person /day Carbon Oxides of Particulate Oxides of Year Monoxide Hydrocarbons Nitrogen Matter Sulfur 1975 1046 180 115 8.2 1.9 1990 303 87 57 8.2 1.9 TABLE II PRESENT (1973) TRAFFIC COUNTS ADJACENT TO THE PROPOSED LINCOLN CENTER SOUTH NO. 2 FACILITY number of vehicles Peak Average ADT Hour Hour 1 -5 70,400 7,040 2,930 1 -405 57,200 5,720 2,380 S -180th 7,000 700 291 Strander 16,000 1,600 667 West Valley Highway 13,200 1,320 550 South Center Parkway 10,000 1,000 416 6 TABLE I11 MOBILE "LINE" SOURCE EMISSION FACTORS AT 30(45) MILES PER HOUR VEHICLE SPEED grams /vehicle mile Year Pollutant 1975 1990 Carbon Monoxide 34.0 (25.0) 9.5 (7.0) Hydrocarbons* 4.9 ( 3.7) 1.6 (1.2) Oxides of Nitrogen 5.5 ( 6.4) 2.5 (2.8) Particulate Matter 0.6 ( 0.6) 0.6 (0.6) Oxides of Sulfur 0.2 ( 0.2) 0.2 (0.2) Includes crankcase and evaporation emissions. Assumptions (EPA, 1973): 1. These values do not account for, the delay instituted by the EPA on the promulgated vehicle emission regulations (Federal Register, July 2, 1971). The effect will be to set back the full imple- mentation of the regulations by at least one year and the emis- sion reductions accordingly. 2. The emission factors assume a hypothetical composite vehicle consisting of both cars and trucks. 7 TABLE IV VEHICLE EMISSION FACTORS FOR THE PROPOSED LINCOLN CENTER SOUTH NO. 2 grams /vehicle mile* Carbon Oxides of Particulate Oxides of Year Monoxide Hydrocarbons Nitrogen Matter" Sulfur 1975 93.2 9.2 4.4 0.6 0.2 1990 26.0 2.8 2.0 0.6 0.2 * Emissions are based on the assumption that the average hypothetical composite vehicle travels on site at 10 mph, 300 meters (0.2 miles) under warm conditions and 300 meters under intermediate cold start conditions. As federal regulations are imposed on automobile exhaust the cold start emissions are assumed to decrease proportional to vehicle emission reductions. A cold start emission as defined by (Wendell, 1973) is an intermediate cold start, not a dead cold start. The total distance traveled by a vehicle on site is defined as an evolution. ** Emissions from vehicles also include lead (included under particulate matter) which is expected to be reduced significantly between the present and 1990. Regulations promulgated by the Environmental Pro - tection Agency (Federal Register, December 6, 1973) will reduce the levels of lead in gasoline (as tetraethyl lead) from the present average of 2.25 grams /gallon to an average of 0.5 grams /gallon by January 1, 1979. 8 Additionally, the Washington State Department of Ecology (DOE, 1973) has made baseline estimates of the background levels, including popula- tion oriented activity, in urban sections of the metropolitan Seattle area. The background levels around the Southcenter area are estimated to be between 4 and 5 parts per million of carbon monoxide. It is expected that these concentrations will be indicative of the background levels around the project also. 3.2 EMISSIONS FROM NEARBY ROADWAYS Traffic traveling on streets adjacent to the project will create a localized line pollutant source which contributes to the total level in the vicinity of the proposed project. The proposed development will cause a relatively slight increase in traffic surrounding the project. A traffic inventory and associated vehicular line source emission factors are shown in Tables II and III, respectively. The traffic in- ventory is based on actual counts taken by the City of Tukwila and the Washington State Department of Highways. The large volume of freeway traffic on 1 -5 and I -405 will also contribute to the pollutant concen- trations in the vicinity of the proposed action. 3.3 EMISSIONS FROM THE PROPOSED DEVELOPMENT The major impact of the proposed development on air quality is the movement of vehicles within the boundaries of the project. Emissions generated by the project will be determined by the behavior of the vehicles operating on the property. Table IV shows the expected emission rates and the assumptions necessary to determine the pollutant levels on the site. Estimates of 1975 traffic on the site (Private Communication, Manson Bennett, 1973) show that approximately 325 evolutions are expected daily throughout the eight -hour work day. This consists of 220 cars and trucks for the retail portion of the project and 105 cars and trucks for the commercial portion of the project. These traffic loads are expected to remain the same for 1990 also. Current plans by the developer are to heat the buildings in the project with electricity, subject to its availability at the time of construction. On this basis, it is expected that there will be no pollutant emissions due to space heating. 9 4.0 METEOROLOGY Weather conditions at the proposed site are similar to those at Seattle - Tacoma Airport, which is two miles west and 400 feet higher in elevation. Therefore, data for Sea -Tac is indicative of the site meteor- ology, with minor modifications due to topographic differences. It is expected that the north -south orientation of the Green River Valley will tend to channel the winds, especially the predominant south- west and north - northwest winds. Easterly winds at the project site will not be affected by topography, but westerly winds will strongly reflect the proximity of the west valley wall. Data from the Puget Sound Air Pollution Control Agency (PSAPCA, 1973b) shows the winds in the South - center area come predominantly from the north or south. During extended pollutant build -up periods (eight hours to several days) polluted air masses move up and down the valley under a channeled flow regime. Under these conditions, pollutant background concentrations can increase significantly, especially under a northerly flow which brings in air from urban Seattle.; Nocturnally, under calm conditions, drainage air will flow into the valley from surrounding high ground. Proximity of the project site to the west wall of the valley will assure that such air drainage will carry pollutants generated along .I -5 into the local area affected by the project. The conditions most conducive to "worst case" pollutant build-up are a two-mile per hour wind and F atmospheric stability for one hour, and a three -mile per hour wind and D atmospheric stability for eight or more hours during daylight hours. These conditions may be modified slightly in localized areas on the valley floor. The frequency of occurrence of "worst case" conditions will be greatest under the dominant northerly and southerly winds. "Worst case" conditions are defined in greater detail. in Section 6.0 5.0 AIR MONITORING PROGRAM Data were taken over a two -week period at a site on the property to be developed. The station was located 200 feet east of Southcenter Park- way and 25 feet north of S. 180th. Measurements of carbon monoxide, wind speed, wind direction, temperature and relative humidity were taken between December 7 and December 24, 1973. 10 5.1 MONITORING INSTRUMENTS Thermo- hygrographs The thermo - hygrographs were manufactured by C. F. Casella and Company of London, England. Temperature and relative humidity are recorded on a one -week moving drum chart in two colors. Temperature range is from 0° to +100 °F, with an accuracy of ±3 °F, relative humidity range is from 0 percent to 100 percent with an accuracy of ±3 percent of full scale. Wind Sensing Instruments The wind speed and direction monitoring equipment was manufactured by the R. M. Young Company of Traverse City, Michigan. Wind speed and direction were recorded continuously on a dual- channel strip chart recorder. The accuracy of the wind speed equipment is ±5 percent of signal resolution. The electronic accuracy of the wind direction indicator is ±1.8° azimuth. Carbon Monoxide Analyzer The Ecolyzer CO monitor was manufactured by Energetics Science, Inc. of New York City. The instrument range is from 0 to 100 ppm. Nominal accuracy of the equipment is ±1.0 percent of full scale or ±1.0 ppm CO. CO was monitored continuously on a strip chart recorder. Zero level calibrations of the instrument were conducted automa- tically at hourly intervals using a solid state calibration circuit. This modification to the standard Ecolyzer unit eliminates error caused by drift in the zero level thereby enabling the measurements below the nominal ±1.0 ppm manufacturers tolerance. Data is reduced to obtain averages over a minimum of one hour. One hour is defined as that period of time from the Oth through the 59th minute of each hour. For example, using a military 24 -hour clock, the data taken between 2 pm and 3 pm on a given day would be listed under 1400. Any data for which there was not a continuous record was not considered in the evaluation of the readings. 11 5.2 DATA ANALYSIS During the two -week sampling period, 213 hourly values of all para- meters were obtained. Maximum temperature values ranged from 42 ° -54 °F while minimum ranged from 28 ° -46 °F. Relative humidities varied from 40 to 100% with the majority greater than 80 %. The average carbon monoxide reading over the sampling period was 1.2 parts per million. Wind speeds varied from calm (< 1 mph) to 10 miles per hour with the maximum frequency in the 2 to 6 mile per hour range. Wind directions were predominantly northerly or southerly. Figures 2 -4 show the hourly variation of wind direction and pollutant levels. During the sampling period there were several occasions when the average concentration of carbon monoxide exceeded 2 parts per million. The highest eight -hour average concentration occurred between 4 pm and midnight on December 21. The average concentration over the period was 4.7 ppm. An hourly maximum of 8.5 ppm was also observed during this period. Maximum hourly concentrations during this period were associated with a northerly wind direction and a wind speed of 2 miles per hour or less. Near the end of the eight -hour period, the wind shifted to southerly and the wind speed increased to 4 -5 miles per hour. Coincident with this shift, the carbon monoxide concentrations dropped to 1 -2 ppm. The noted high concentrations of carbon monoxide levels were due primarily to increased traffic in the Southcenter shopping center concomitant with peak traffic loads on 1 -5 and 1 -405 during the Friday before Christmas shopping rush. Carbon monoxide data was collected by the Air Pollution Agency (PSAPCA, 1973b) at McMicken Heights (South 176th and 42nd South) about two kilometers west of the project. Data taken from this site show that the highest one hour average was 6 ppm and the highest eight -hour average was 4 ppm during 1972. Data for 197.3 at the same location (Private Communication, PSAPCA, 1973) showed maximum one hour concentrations of 5 ppm and monthly averages of about 1 ppm. 12 1 1 l 1 0 5 10 15 20 25 30 Scale Occurrence. Figure 2 Wind Direction Frequency of Occurrence Lincoln Center South No. 2 December 7 -24, 1973 13 35 40 45 50 0 .5 1.0 1.5 2.0 2.5 3.0 Scale Carbon Monoxide PPm Figure 3 Carbon Monoxide Pollutant Rose Lincoln Center South No. 2 December 7 -24, 1973 14 Carbon Monoxide, PPm 2.540 2.0 IND 1.5 ow. 1.0 Figure 4 Average Daily Carbon Monoxide Concentrations Lincoln Center South No. 2 December 7 -24, 1973 1 1 1 1 1 1 1 1 $ .1 1 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 Hour of Day 6.0 PREDICTED POLLUTANT CONCENTRATIONS 6.1 SPECIFICATION OF "WORST CASE" CONDITIONS The spreading and dilution of pollutants throughout the atmosphere is caused by turbulence. The ability of the atmosphere to support turbulence, depends on how the atmosphere is structured with regard to temperature. Temperature inversions (temperature increasing with height) inhibit turbulence, whereas strong temperature lapse rates (temperature decreasing with height) enhance turbulence. An atmosphere exhibiting a temperature inversion is therefore termed "stable ", wheras that showing . a strong lapse rate is termed "unstable." By convention, the normal range of atmospheric stability is described in terms of six stability "categories," labeled A through F in ascending order, i.e., categories A and F describe the most unstable and the most stable atmospheric condi- tions, respectively. The "average" atmospheric state is described by category D, also termed the "neutral" stability condition. Because the efficiency of pollutant dispersion is related to stability, the stability category designations provide a convenient basis for the specification of "worst case" meteorological conditions relative to the degradation of local air quality. Cold air drainage down the Green River Valley (Section 4) gives rise to the development of pronounced temp- erature inversions within the valley, and therefore category F can be defined as the "worst case" stability condition likely to occur for one or two hours duration. This will be a wintertime, early morning and late evening condition (i.e., the beginning and end of the working day); solar heating during mid -day will likely modify the stability to category D. Given the specified "worst case" stability condition, the remaining factor which determines the local air quality is the strength and the direction of the mean wind. The lighter the wind, the poorer the disper- sion and the greater the pollution build -up. A wind direction directly from remote pollutant sources to the area in question assures the intro- duction of those pollutants to that area. With this last consideration, and with metropolitan Seattle lying to the north of the proposed develop- ment site, "worst case" wind conditions are defined as northerly winds as channeled by the Green /Duwamish River valley complex, at a speed of two miles per hour (Figure 2). 16 6.2 BACKGROUND CONCENTRATION PREDICTIONS With channeled northerly flow, the singular (i.e., in addition to the general residential area sources) pollutant sources which will contribute to the total "background" pollution level at the proposed development site are as marked by the hatched areas in Figure 5. These sources include the Southcenter Shopping area complex, the segment of 1 -5 from about the Foster to the Tukwila interchanges, and the segment of 1 -405 directly north of the site. Using the Hanna (1971) area source diffusion model for both the general residential and the Southcenter shopping complex concentration estimates, and the (Beaton, et.al., 1972) line source models for the estimates of the contributions 1 -5 and 1 -405, the total predicted "background" CO concentration budget is as given•in Table V. TABLE V 1975 BACKGROUND CARBON MONOXIDE CONCENTRATION BUDGET1 Contributing Source Residential Southcenter2 1 -53 I -4054 Southcenter Parkway TOTAL CO Concentration 0.4 ppm 0.6 ppm 6.4 ppm 1.0 ppm 0.3 PPm 8.4 ppm 1 One -hour "worst case" meteorological conditions 2 Peak vehicle evolution = 1000 VPH 3 Peak traffic load = 7040 VPH 4 Peak traffic load = 5720 VPH The "worst case" stability and wind conditions specified above, along with peak traffic and shopping center activity, fortuitously occurred during the data collection period between 5:00 pm and 6:00 pm, December 21. It was during this time period that the maximum CO con- centration value of 8.5 ppm was observed at the proposed site. This value is in remarkable agreement with the predicted value given in Table V. 17 Southcenter / Figure 5 Singular Contributors (hatched areas) to Background Concentrations at Lincoln Center South No. 2 (Green River Valley terrain contours are also shown) 18 For "worst case" eight hour stability and wind conditions the maximum carbon monoxide concentration is predicted to be 6.2 ppm. Data collected by the PSAPCA at McMicken Heights indicate a maximum observed eight hour average concentration of 4 ppm. Data collected on site is showed a maximum eight hour average concentration of 4.7 ppm. Table V shows that pollutant contributions from adjacent roadways will be minimal. Since worst case conditions occur under northerly winds, pollutants from vehicles on South 180th will have no impact on the development. 6.3 DEVELOPMENT CONCENTRATION PREDICTIONS The CO emissions from the proposed development will add to the predicted background CO concentrations. Representing the development as an area source 310 x 310 meters, and assuming 40 vehicle evolutions per hour (at the emission rates shown in Table IV) on the property throughout the working day in 1975, the predicted (Hanna's model) CO concentration contribution from the development to the background is about 0.8 ppm. This estimate is again for the one hour, "worst case" conditions, viz., F stability with a wind speed of 2 mph. The total one-hour "worst case" CO Concentration would thus be approximately 9 PPm• For D stability and three mile an hour wind speed the eight hour "worst case" carbon monoxide concentrations created by vehicles on the site is about 0.5 ppm in 1975. 6.4 COMPARISON WITH ALLOWABLE STANDARDS The ambient air quality standards for Washington State are given in Table VI. The predicted one -hour, "worst case" CO concentrations of 9.7 ppm (less than 10 percent of which will be attributable to the proposed development) is well below the allowable one-hour standard of 35 ppm. The one -hour predicted value is based on peak 1 -5 and 1 -405 traffic load. Assuming the peak hourly traffic volume is valid for two hours at the beginning and end of the working day, and reducing the 1 -5 and 1 -405 contributions to the CO background concentration budget (Table V) according to the ratio of the average -to -peak traffic loads for the remaining six hours, the eight -hour average, "worst case" CO concentration level is predicted at 6.7 ppm. Again, the 19 TABLE VI AMBIENT AIR QUALITY STANDARDS - WASHINGTON STATE ppm 1 STANDARDS2 (pg m -3) EMERGENCY EPISODE CRITERIA3 Alert Warning Emergency Suspended Particulate (6o) Annual geo.mean (150) 24-hr ay. (375) (625) (875) 24 -hr ay. 24 -hr ay. 24 -hr ay. Sulfur Dioxide 0.02 (60) 0.3 (800) 0.6 (1600) 0.8 (2100) Annual arith mean 24 -hr ay. 24 -hr ay. 24 -hr ay. 0.1 (260) 24 -hr ay. 0.4 (1060) 1 -hr ay. Carbon Monoxide 9 (10,000) 8 -hr ay. 35 (40,000) 1 -hr ay. 15 (17,000) 30 (34,000) 40 (46,000) 8 -hr ay. 8 -hr ay. 8 -hr ay. Hydrocarbons4 0.24 (160) (as Methane) 3-hr ay. 6 -9 a.m. alb MD Nitrogen Dioxide 0.05 (100) Annual arith mean 0.15 (282) 24 -hr ay. 0.6 (1130) 1 -hr ay. 0.3 (565) 24-hr ay. 1.2 (2260) 1 -hr ay. 0.4 (750) 24 -hr ay. 1.6 (3000) 1 -hr ay. Photochemical Oxidants 0.08 (160) 1 -hr ay. 0.2 (400) 0.4 (800) 0.6 (1200) 1-hr ay. 1 -hr ay. 1 -hr ay. 1 Volume to mass conversion factors at 25 °C and 760 mmHg are: One part per million equals ug m -3 Sulfur Dioxide 2,620 Carbon Monoxide 1,150 Hydrocarbons (Methane) 655 Nitrogen Dioxide 1,880 Oxidant 1,960 2 All standards which are averaged over 24 hours or less are not to exceed the average more than once per year.. 3 In order to activate the emergency episode plan, the value indicated must be exceeded and expected to remain that way for more than twelve hours. 4 The hydrocarbon "standard" is a guideline, not a. standard More needs to be done to establish the background concentrations of methane in the ambient air. There are no emergency episode standards for hydrocarbons. 20 predicted eight-hour concentration is well below the eight -hour standards. It can be anticipated, moreover, that with the imposition of federal emission standards for mobile sources, the predicted CO concentrations will be reduced by approximately 70 percent by the 1990 design year. 21 7.0 REFERENCES Beaton, J.L., J.B. Skog, E.C. Shirley, A.J. Ranzieri, "Mathematical' Approach to Estimating Highway Impact on Air Quality," State of Cali- fornia, Division of Highways, Publication No. CA- HWY -MR 6570825- 4- 72 -12, July, 1972. Census, Bureau of, "1970 Census of Housing -Block Statistics, Seattle - Everett, WA, Urbanized Area," Publication No. HC(3)-260, U.S. Department of Commerce, Washington, D.C., 1971. Ecology, Washington State Department of, "Information Memorandum - Base- line Carbon Monoxide Estimates, Seattle, Tacoma, Spokane," Division of Technical Services, Olympia, WA, November, 1973. Environmental Protection Agency, "Compilation of Air. Pollutant Emission Factors," Publication No. AP -42 (Revised), Research Triangle Park, N.C., 1973. Federal Register, "Exhaust Emission Standards and Test Procedures," 36, 12652, July 2, 1971. Federal Register, "Approval and Promulgation of State Implementation Plans - Review of Indirect Sources," 38, 29894, October 30, 1973. Federal Register, "Fuel Regulations - Control of Lead Additives in Gasoline," 38, 33734, December 6, 1973. Hanna, S.R., "A Simple Method of Calculating Dispersion from Urban Area Sources," Jour. Air Poll. Cont. Assn., 21, 774, 1971. Private Communication, Manson Bennett and Associates, Seattle, WA, December, 1973. Private Communication, Air Monitoring Division, Puget Sound Air Pollution Control Agency, Seattle, WA, December, 1973. Puget Sound Air Pollution Control Agency, "1972 Annual Report," Seattle, WA, 1973a. Puget Sound Air Pollution Control Agency, "Air Quality Data Summary - 1972," Air Monitoring Division, Seattle, WA, 1973. Puget Sound Governmental Conference, "Population and Employment Forecasts for the Central Puget Sound Region, 1975 - 1990 (1972 Revision)," Seattle, WA, 1972. Wendell, R.E., J.E. Norco, K.G. Croke, "Emission Prediction and Control Strategy: Evaluation of Pollution from Transportation Systems," Jour. Air Poll. Cont. Assn., 23, 91, 1973. 22