Twin Ridge Sanitary Sewer Extension and Lagoon Abandonment Project - Acceptance of Public Improvement Construction ContractCity of Dubuque
City Council
CONSENT ITEMS # 11.
Copyrighted
November 17, 2025
ITEM TITLE: Twin Ridge Sanitary Sewer Extension and Lagoon
Abandonment Project - Acceptance of Public Improvement
Construction Contract
SUMMARY: City Manager recommending City Council adopt the attached
resolution accepting the public improvement, establishing the
final contract amount at $615,775.64, and authorize the
payment of the final contract retainage amount of $30,788.78
to Tschiggfrie Excavating Co. for the Twin Ridge Sanitary
Sewer Extension and Lagoon Abandonment Project.
RESOLUTION Accepting The Twin Ridge Sanitary Sewer
Extension And Lagoon Abandonment Project
SUGGUESTED Receive and File; Adopt Resolution(s)
DISPOSITION:
ATTACHMENTS:
1. MVM Memo
2. Twin Ridge Sanitary Sewer Ext Project - Acceptance MEMO
3. Twin Ridge Sanitary Sewer Ext Project - Acceptance RESOLUTION
4. Twin Ridge Sanitary Sewer Ext Project - ENGINEERS CERTIFICATE
Page 184 of 750
Dubuque
THE CITY OF
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TO: The Honorable Mayor and City Council Members
FROM: Michael C. Van Milligen, City Manager
SUBJECT: Twin Ridge Sanitary Sewer Extension and Lagoon Abandonment Project
Acceptance of Public Improvement Construction Contract
Project No. 5581500024
DATE: November 13, 2025
Assistant City Engineer Robert Schiesl is recommending City Council adopt the
attached resolution accepting the public improvement, establishing the final contract
amount at $615,775.64, and authorize the payment of the final contract retainage
amount of $30,788.78 to Tschiggfrie Excavating Co. for the Twin Ridge Sanitary Sewer
Extension and Lagoon Abandonment Project.
The remaining balance of the SRF loan funding allocated for the Twin Ridge Sanitary
Sewer Extension and Lagoon Abandonment Project, in the amount of $285,783.43, will
be reallocated to 5581500009 to support the Granger Creek Lift Station Capacity
Improvements project. The final SRF loan amount will be established upon the
acceptance of the Granger Creek Lift Station Capacity Improvements project.
I concur with the recommendation and respectfully request Mayor and City Council
approval.
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Mic ael C. Van Milligen
MCVM:sv
Attachment
cc: Crenna Brumwell, City Attorney
Cori Burbach, Assistant City Manager
Gus Psihoyos, City Engineer
Robert Schiesl, PE Assistant City Engineer
Todd Irwin, Water Resource Project Supervisor
Jenny Larson, Chief Financial Officer
Max O'Brien, PE Civil Engineer
Page 185 of 750
Dubuque
THE CITY OF
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TO: Michael C. Van Milligen, City Manager
FROM: Robert Schiesl, Assistant City Engineer
SUBJECT: Twin Ridge Sanitary Sewer Extension and Lagoon Abandonment Project
Acceptance of Public Improvement Construction Contract
Project No. 5581500024
DATE: November 12, 2025
INTRODUCTION
The enclosed resolution provides for establishing the final contract amount, and
acceptance of the public improvement construction contract for the Twin Ridge Sanitary
Sewer Extension and Lagoon Abandonment Project.
BACKGROUND
In 1998 the City began to extend sanitary sewer along Granger Creek, for the Dubuque
Technology Park development. The Granger Creek Interceptor Sewer (GCIS)
extension consisted of the Granger Creek Pump Station and approximately 17,600 LF
of both 20 inch and 18" diameter pipe. In 2015, the City extended the interceptor sewer,
continuing along Granger Creek and U.S. Highway 151/61, to the Dubuque Regional
Airport. The GCIS extension increased the sanitary Sewer Shed 4 to approximately
6,300 acres.
Since the GCIS and the extension to the Dubuque Regional Airport has been
completed, several adjacent areas, in or near Key West, have connected to the City's
sewer system such as; Table Mound Mobile Home Park, Kerrigan Heights Subdivision,
Truck Country, a portion of Twin Ridge Subdivision, and Silver Oaks Subdivision.
Tamarack Business Park and the City's Crossroads Industrial Park, along with other
adjacent parcels, are also able to be served by GCIS.
The City of Dubuque submitted a facility plan, based on the results of an intensive
evaluation of the existing interceptor collection and pumping systems that convey
sewage to the Water Resource Recovery Center (WRRC), to Iowa Department of
Natural Resources (IDNR), in September of 2021. The facility plan identified three
improvement projects related to the Granger Creek Interceptor Sewer System: Granger
Creek Lift Station Capacity Improvements, Twin Ridge Sanitary Sewer Extension and
lagoon abandonment and the Tamarack Sanitary Sewer Extension.
The Twin Ridge Sanitary Sewer Extension and Lagoon Abandonment Project extended
the sanitary sewer gravity system and connected into the existing Twin Ridge
Subdivision gravity sewer system, along with abandoning the existing lagoon system.
Page 186 of 750
With the completion of this project, the City will no longer need to permit, operate and
maintain the lagoon system. The parcel will still need to be maintained, by the City, until
redevelopment occurs.
DISCUSSION
The Twin Ridge Sanitary Sewer Extension and Lagoon Abandonment Project has been
completed by Tschiggfrie Excavating Co., of Dubuque, Iowa in the final contract amount
of $615,775.64. This is a 1.5% decrease from the original contract amount of
$624,975.70.
BUDGETIMPACT
The Twin Ridge Sanitary Sewer Extension and Lagoon Abandonment Project is one of
three projects included in a single State Revolving Fund (SRF) loan being utilized to
fund the projects. The Tamarack Sanitary Sewer Extension Project and the Granger
Creek Lift Station Capacity Improvements Project will be presented under separate
memos.
The table below details the final total project cost for the Twin Ridge Sanitary Sewer
Extension and Lagoon Abandonment Project:
Description
Award
Final
Planning & Design
$ 67,000.00
$ 67,000.00
Construction
624,975.70
615,775.64
Contract Admin / Construction Engineering
66,000.00
60,430.44
Contingency
70,338.95
0.00
City Staff & Legal
12,413.79
12,279.32
0.5% SRF Loan Origination Fees
5,031.17
5,031.17
Total Project Cost
$ 845,759.61
$ 760,516.57
The SRF loan, for all three projects, is being funded through multiple Fiscal Year
appropriations. The funding summary of the loan amount allocated to the Twin Ridge
Sanitary Sewer Extension and Lagoon Abandonment Project is detailed below:
Project No.
Fund Description
Fund Amount
FY23
5581500024
Twin Ridge Lift Station Abandonment
$ 120,000.00
FY24
5581500024
Twin Ridge Lift Station Abandonment
926,300.00
Total SRF Project Funding
$ 1,046,300.00
The remaining balance of the SRF loan funding allocated for the Twin Ridge Sanitary
Sewer Extension and Lagoon Abandonment Project, in the amount of $285,783.43, will
be reallocated to 5581500009 to support the Granger Creek Lift Station Capacity
Improvements project. The final SRF loan amount will be established upon the
acceptance of the Granger Creek Lift Station Capacity Improvements project.
2
Page 187 of 750
RECOMMENDATION
I recommend that the City Council accept the public improvement, establishing the final
contract amount at $615,775.64, and authorize the payment of the final contract
retainage amount of $30,788.78 to Tschiggfrie Excavating Co. for the Twin Ridge
Sanitary Sewer Extension and Lagoon Abandonment Project.
I further recommend that the SRF loan funding balance ($285,783.43) be reallocated to
5581500009 to support the Granger Creek Lift Station Capacity Improvements project.
ACTION TO BE TAKEN
The City Council is requested to adopt the attached resolution accepting the public
improvement, establishing the final contract amount at $615,775.64, and authorize the
payment of the final contract retainage amount of $30,788.78 to Tschiggfrie Excavating
Co. for the Twin Ridge Sanitary Sewer Extension and Lagoon Abandonment Project.
Prepared by Todd Irwin, Water Resource Project Supervisor
cc: Jenny Larson, Chief Financial Officer
Bob Schiesl, PE, Assistant City Engineer
Max O'Brien, PE Civil Engineer
3
Page 188 of 750
Prepared by: Kerry Bradley City of Dubuque Engineering50 W. 13`h Street Dubuque IA 52001 (563)589-4270
Return to: Adrienne N. Breitfelder, City Clerk, 50W 131h Street, Dubuque, IA 52001 (563)589-4100
RESOLUTION NO. 366-25
ACCEPTING THE TWIN RIDGE SANITARY SEWER EXTENSION AND LAGOON
ABANDONMENT PROJECT
WHEREAS, the public improvement contract for the Twin Ridge Sanitary Sewer
Extension and Lagoon Abandonment Project (the Project) has been completed by the
Contractor, Tschiggfrie Excavating Co., of Dubuque, Iowa, (Contractor), and the City
Engineer has examined the work and recommends that the Project be accepted; and
WHEREAS, the final contract amount for the Project is $615,775.64-1 and
WHEREAS, the Contractor has previously been paid $584,986.86, leaving a
retainage balance of $30,788.78-1 and
WHEREAS, the City Council finds that the recommendation of the City Engineer
should be accepted.
NOW, THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF
DUBUQUE, IOWA:
SECTION 1. The recommendation of the City Engineer is approved, and the
Project is hereby accepted.
SECTION 2. The Finance Director is hereby directed to pay to the Contractor the
balance of the retainage of $30,788.78 as provided in Iowa Code chapter 573, and to pay
such retainage in accordance with the provisions of Iowa Code chapter 573 or Iowa Code
chapter 26.13.
Passed, approved and adopted this 17t" day of November 2025.
Brad Mayor
Attest:
�' /I? i / 11/,�l.� ,4'� I ' Al,C�. '
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Adrienne N. Breitfelder, City Clerk
CITY ENGINEER'S CERTIFICATE OF FINAL COMPLETION OF TWIN RIDGE
SANITARY SEWER EXTENSION AND LAGOON ABANDONMENT PROJECT
The undersigned City Engineer of the City of Dubuque, Iowa, hereby certifies that
the Twin Ridge Sanitary Sewer Ext. and Lagoon Abandonment Project has been
inspected, completed and performed in compliance with the terms of the Public
Improvement Contract, and that the total cost of the completed work is $760,516.57.
Dated this 12th day of November 2025.
Gus Psihoyos, City Engineer
Filed in the office of the City Clerk on the 12th day of
November 2025.
Adrienne N. Breitfelder, City Clerk
Page 190 of 750