HomeMy WebLinkAboutA019 - Lime Sludge Disposal ContractITEM #:20
DATE:08-26-25
DEPT:W&PC
SUBJECT:WATER TREATMENT PLANT LIME SLUDGE DISPOSAL CONTRACT
COUNCIL ACTION FORM
BACKGROUND:
The City's Water Treatment Plant (WTP) is a conventional lime-softening facility that
generates lime sludge as a by-product of the lime softening process. The lime sludge consists
primarily of calcium carbonate and magnesium hydroxide, which is dewatered and stored in
lagoons prior to being beneficially applied on agricultural ground as a soil conditioner. To
continue to have adequate storage for the lime sludge, the material must be removed from the
lagoons annually.
On April 25, 2023, City Council awarded a contract to Wulfekuhle Injection and Pumping, Inc.
of Peosta, Iowa for the removal and disposal of lime sludge. The contract calls for the removal
of 26,000 wet tons of lime at a unit cost of $14.89 per wet ton, plus mobilization charges of
$5,000, for a total contract price of $392,140. The contract is renewable annually for a total of
five years, dependent on successful performance by the contractor each year. The contract
unit prices are fixed for the entire five-year agreement.
Work performed under Year Two of the agreement has been completed. There was a single
change order approved by Council to carry over a portion of the Year One quantities that were
delayed due to a warm winter and wet spring. Wulfekuhle disposed of 33,576.38 wet tons of
the maximum 36,000 wet tons authorized, for a total contract price of $504,952.30. The work
is completed and is ready for Council acceptance.
The City Council is also being asked to award the third year of the agreement to
Wulfekuhle Injection and Pumping Inc. in an amount not to exceed $392,140 for FY
2025/26 (contract period July 1, 2025 – June 30, 2026). Funding for this contract is outlined
in the table below:
FY 2025/26 Contract
Expenses Funding Source
Mobilization $5,000
Lime Sludge
Disposal, 26,000
wet tons
$387,140
FY 2025/26 Water
Treatment
Operating Budget
$392,140
TOTAL $392,140 $392,140
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Award for future renewal years will be brought to Council annually and will be subject to the
contractor's acceptable ongoing performance, the proposed cost increase, and the annual
allocation of sufficient funds.
ALTERNATIVES:
1. The City Council can:
a. Accept completion of the Year Two contract (FY 2024/25) for lime sludge disposal
with Wulfekuhle Injection and Pumping of Peosta, IA in the final amount of
$504,952.30.
b. Award a contract to Wulfekuhle Injection and Pumping Inc. of Peosta, IA for FY
2025/26 (Year Three) lime sludge disposal service in the amount of $392,140.
2. Reject bids and direct staff to solicit new bids for lime sludge disposal.
3. Reject bids and direct staff to pursue landfilling of the lime sludge in lieu of land
application.
CITY MANAGER'S RECOMMENDED ACTION:
Wulfekuhle Injection and Pumping, Inc. has completed the FY 2024/25 lime sludge disposal
contract, and an Engineer's Statement of Completion has been received (attached).
The original bid included the option to extend the agreement for up to five years, on a year-to-
year basis. Staff is satisfied with the performance of the contractor to date and is
recommending that a third year be awarded at the same unit cost as FY 2024/25. Therefore, it
is the recommendation of the City Manager that the City Council adopt Alternative No. 1 a. and
b. as stated above.
ATTACHMENT(S):
Engineer's Statement of Completion.pdf
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515.239.5150 main
515.239.5496 fax
1800 E. 13th Street
Ames, IA 50010
www.CityofAmes.org
Water & Pollution Control Department
Smart Choice
ENGINEER’S STATEMENT OF COMPLETION
WATER TREATMENT PLANT
LIME SLUDGE DISPOSAL CONTRACT – Year Two (FY 2024/25)
Contract No. 2023-098
Certifying Engineer: Ames Water and Pollution Control Department
Contractor: Wulfekuhle Injection and Pumping Inc.
I hereby certify that the Lime Sludge Disposal Contract – Year Two (FY 2024/25) Project, by a contract awarded
by the Ames City Council on July 9, 2024, has been satisfactorily completed in general compliance with the
terms, conditions, and stipulations of said contract.
The work was completed on or about May 31, 2025. One change order was executed to carry over 10,000 wet
tons from the FY 2023/24 contract into the FY 2024/25 contract. The total quantity of lime sludge disposed of
was 33,576.38 wet tons.
I further state that the amount due to the contractor for the fulfillment of said contract is $5,000 for
mobilization and $499,952.30 for lime sludge disposal, for a total contract amount due of $504,952.30.
_______________________________ Date: August 14, 2025
John R. Dunn, PE #14826 EXP: 12-31-2026
Director, Water & Pollution Control
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