HomeMy WebLinkAboutUtilities 2012-05-30 Item 2B - Contract Supplement #2 - Water and Sewer Comprehensive Plans with Carollo EngineersCity of Tukwila
Jim Haggerton, Mayor
INFORMATIONAL MEMORANDUM
TO: Mayor Haggerton
Utilities Committee
FROM: Bob Giberson, Public Works Director 10
BY: Mike Cusick, Senior Engineer
DATE: May 25, 2012
SUBJECT: Water and Sewer Comprehensive Plans
Project No. 91040101, Contract No. 10 -055
Supplement No. 2
ISSUE
Approve Supplement No. 2 to Contract No. 10 -055 with Carollo Engineers for the Water /Sewer Comprehensive Plan.
BACKGROUND
The Departments of Health and Ecology require the City of Tukwila to update the Water and Sewer Comprehensive Plans every
six years. In 2010, the City contracted with Carollo Engineers to update the Water and Sewer Comprehensive Plans.
DISCUSSION
Carollo Engineers completed the work draft of Chapter Two, "Demographic Analysis and Demand Projections," for the
Comprehensive Plan in October 2010 using current population data. In November 2010, DCD requested that the Public Works
department rerun the population study model with 4,800 new housing units and 15,500 net new jobs by the year 2031.
In the 2005 water model, most areas of the City had more than adequate fire flows in excess of 4,500 gpm. In May 2011, the
Tukwila Fire Marshal requested that the fire flows in the Commercial Business District (CBD) be increased from 6,000 gpm to
8,000 gpm. The increased fire flows resulted in most of the CBD not having adequate fire flows and would require costly upgrades
to existing water lines. In April 2012, the Fire Marshal revised the required fire flows in all areas of the CBD except north of
Strander Blvd to 6,000 gpm.
The Consultants scope of work was to prepare a sewer system map book for the Public Works field crews to carry in their vehicles.
The task went over budget due to City staff finding multiple discrepancies in the existing sewer pipe maps.
FINANCIAL IMPACT
Supplement No. 2 will increase the Consultant's scope of work for Task 300 Planning Considerations for $5,721.50, Task 700
Distribution System Analysis and Task 900 Capital Improvement Program for $10,000, and Task 060 Hydraulic Model and
Mapping for $6,000, for a total Supplement of $21,721.50. Funding for the additional work will come from the Interurban Water
Reuse Project, page 86, 2012 CIP.
EXPENDITURES
Fundina BudcLet
Original contract
$291,000.00
Water Comp Plan
160,000.00
Supplement No. 1
12,662.00
Sewer Comp Plan
143,000.00
Supplement No. 2
21,721.50
Interurban Water Reuse
25.000.00
Total
$325,383.50
$328,000.00
RECOMMENDATION
Council is being asked to approve Supplemental Agreement No. 2 to Contract No. 10 -055 with Carollo Engineers in the amount of
$21,721.50 and consider this item at the June 11, 2012 Committee of the Whole meeting and subsequent June 18, 2012 Regular
Council meeting.
Attachment: Supplemental Agreement No. 2
W:\PW Eng \PROJECTSW- WT Projects \Water Comprehensive Plan -Water (91040101) \InfoMemo -Water Comp Plan Sup #2 052512- sb.doc
SUPPLEMENTAL AGREEMENT NUMBER 2
to
CONSULTANT AGREEMENT NUMBER 10 -055
THIS SUPPLEMENTAL AGREEMENT is entered into between the Citv of Tukwila.
Washington, herein -after referred to as "the City and Carollo Engineers hereinafter referred to
as "the Consultant in consideration of the mutual benefits, terms, and conditions hereinafter
specified.
The City desires to supplement the agreement entered into with the Consultant and executed on,
May 19, 2010, and identified as Agreement No. 10 -055. All provisions in the basic agreement
remain in effect except as expressly modified by this supplement.
The changes to the agreement are described as follows:
1. Scope of Services, for Supplemental Agreement 42 to the Comprehensive Sewer and
Water Plans (Plans) for the City of Tukwila. The purpose of this supplement is to add:
a. $5,721.50 for Task 300 Planning Considerations Section 304 Population. The
Consultant to rerun population growth model using revised data from the PSRC for
the year 2010.
b. $10,000.00 for Task 700 Distribution System Analysis and Task 900 Capital
Improvement Plan. The Consultant to reanalyze the water system in the CBD south of
Strander Boulevard for a reduced fire flow of 6,000 gpm and required Capital
Improvement Program.
c. $6,000.00 for Task 060 Hydraulic Modeling and Mapping of the Sanitary Sewer
System. The Consultant is to reconcile the existing pipe data with current piping
inventory.
2. Deliverables
a. Revised Chapter Two of the Comprehensive Plan with increased population
numbers based on November 2010 PSRC data.
b. Revised Chapter Six of the Comprehensive Plan "Distribution System Analysis" for
the CBD south of Strander Boulevard.
c. Revised Chapter Eight of the Comprehensive Plan "Capital Improvement Plan" for
the CBD south of Strander Boulevard.
d. Revise sanitary sewer map books.
3. Time for Performance, is amended to change the number of calendar days for
completion of the work to read an additional 90 days for a total of 980 days.
4. Payment, shall be amended as follows:
4
Payment for the work provided by the Consultant as part of this supplement shall be
made for an additional $21,721.50. The total amount for the Consultant for this contact
shall not exceed $325,383.50 without express written modification of the Agreement
sided by the City.
DATED this day of 2012.
CITY OF TUKWILA
Jim Haggerton, Mayor
CONSULTANT
By:
Printed Name:
Title:
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