HomeMy WebLinkAboutEarth Tech Stormwater Managmetn Planning Contract # 3@ EarthTech
A tgCU International Ltd. Company
July 3, 2008
Mr. David Patek
Department of Public Works
215 Church Avenue
P.O. Box 1130
Oshkosh; WI 54903 -1130
1210 Fourier Drive
Suite 100
Madison, WI 53717
Kall
VIN ZNJIN VIA,
J L 10 2008
P 608.836.9800
F 608.836.9767
www.earthtech.com
Subject: Amendment #3 Request to Stormwater Management Planning Contract
City of Oshkosh PO #: 101458
Earth Tech Project No. 84350
Dear Mr. Patek:
This letter is requesting an amendment to the scope and budget for the above referenced
project. The scope items detailed below have been reviewed by city staff. The scope change is
to conduct two tasks:
1) Re -model (using WinSLAMM v 9.2.5) the city using updated street sweeping conditions; and
2) Assist city staff with review of guidance documents for the erosion control and stormwater
management ordinances.
Task 1: Re -Model City with Updated Street Sweeping Information
1. Background
After the last review of the Stormwater Management Plan (June 20, 2008) comments were
received regarding the street sweeping parking controls assumptions (Table 4 -2 of the draft
plan). The conditions specified in the table were based on information provided and reviewed by
the city. This information does not correctly describe the current conditions, and the changes to
the conditions may result in an improvement of the existing street cleaning practices of
approximately 25 tons of sediment per year. It was determined that updating the pollution
modeling to incorporate the correct parking controls information is worth the effort because of the
improved pollution control results.
2. Scope of work
Conducting the modeling re- analysis and updating the results will require the following steps:
1) Update Existing Management Standard Land Use (WinSLAMM) files
2) Update the Proposed Management Standard Land Use (WinSLAMM) files
3) Re -run the loading calculations for Existing and Proposed Management conditions
4) Update Access database and re- calculate sub -basin sediment, phosphorus and copper
loads
5) Update Stormwater Plan tables: ES -1, 4 -2, 4 -3, 4 -4, 5 -2A, 5 -2B, 5 -6, 5 -7, 7 -2, 7 -3,
Appendix C, and Appendix D
@) EarthTech
A tgCO International Ltd. Company
Mr. David Patek
Stormwater Plan Change Order Request #3
July 3, 2008
Page 2
6) Update Stormwater Plan text in chapters ES, 4, and 5
7) Update figures 4 -1, 4 -2, 4 -3, and 4 -4.
8) Review impacts on project schedule and possibly modify text.
9) Allow for two additional meetings with city staff (this task does not include meetings with
the city's Stormwater Utility Committee)
Task 2: Assist With Review of Ordinance Guidance Documents
The City is requesting Earth Tech assistance with the development of Guidance Documents for
the revised Construction Erosion Control, and Post - Construction Stormwater Management
Ordinances. The current Stormwater Management Plan agreement includes scope items for the
development of draft language for both of these ordinances — which has been done — however
development of a Guidance Document is not in the current agreement. The budget below allows
for 16 hours of Jim Bachhuber's time and 2 hours of Word Processing time to conduct the review
and comment.
Contract Amendment Budget
Task 1 WinSLAMM re-analysis
$12,500.00
Task 2: Ordinance Guidance Document
$2,500.00
Assistance
Total Amendment:
$15,000.00
All other conditions of the original contract will remain unchanged.
If everything is in order, please have both copies of this letter signed and return one fully signed
copy to me. Thank you for you consideration of this request and please do not hesitate to
contact me with any questions.
Sincerely,
J f ery . Hanson PE
Vice - President
x
James A. Bachhuber
Department Manager
cc: James Rabe; City of Oshkosh
� Ear thTech
A'tgCO International Ltd. Company
Mr. David Patek
Stormwater Plan Change Order Request #3
July 3, 2008
Page 3
Peggy t` ` o, Finance Director
hereby certify that the necessary provisions
Have been made to pay the liability which will
Accrue under this contract.
Signed for and in behalf of the City of Oshkosh