Title
Environmental Management Department recommending the Board consider the following pertaining to the Union Mine Wastewater Treatment Plant Cleaning of Digester #1:
1) Award Bid 2025-0163 to the lowest responsive and qualified bidder, GSE Construction Company Inc., to supply all personnel, parts, equipment, vehicles, and supplies to remove and dewater all material from inside the open-top five hundred thousand (500,000) gallon aerobic Digester Number 1; and
2) Authorize the Chair to sign Public Works Agreement 10069 for $373,700 on work to be completed within 180 calendar days commencing from the date shown on the Contractor Notice to Proceed, subject to review and approval by County Counsel and Risk Management.
FUNDING: Non-General Fund / CSA 10 Liquid Waste Funds.
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DISCUSSION / BACKGROUND
El Dorado County owns, operates, and maintains the Union Mine Wastewater Treatment Facility located at 5700 Union Mine Road, El Dorado, CA. The facility, operational since 1996, processes leachate from the on-site landfill, as well as residential septic tank waste and portable toilet waste generated on the County’s West Slope.
On December 3, 2025, County staff discovered a severe blockage in the centrifuge feed line caused by compacted grit and sludge. This obstruction led to equipment failure and a complete system shutdown. Despite multiple attempts to clear the line, the issue remained unresolved, requiring immediate cleaning of the aerobic digester. The Board approved the bid documents and sample agreement for Bid No. 2025-0163 on December 9, 2025, Legistar file 25,2060.
Due to the shutdown, the facility has been closed to liquid waste haulers since December 13, 2025, and will remain closed until Digester #1 is repaired and processing resumes.
Bid No. 2025-0163 produced six (6) bids, and a Notice of Intent to Award has been issued to GSE Construction Company, Inc., the lowest qualified bidder, with a total project cost of $373,700.
Staff recommends the Board app...
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