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.
Body
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 approve the Award and Agreement 10069 with GSE Construction Company, Inc. for emergency cleaning of the aerobic digester at the Union Mine Wastewater Treatment Facility. Upon approval by County Counsel and Risk Management, the Procurement and Contracts division will forward two originals of the Agreement, along with the required bonds and the approved Contract Routing Sheet, to the Chair for signature. Once the agreement has been fully executed, Environmental Management will issue the Notice to Proceed and commence the project.
ALTERNATIVES
The Board may choose to deny approval of this construction project. This would prevent Environmental Management from accepting residential septic and commercial portable toilet waste at the Union Mine Waste Water Treatment Plant.
PRIOR BOARD ACTION
See discussion/background.
CAO RECOMMENDATION/COMMENTS
Award bid and authorize the Chair to sign once the agreement is approved by County Counsel and Risk Management.
FINANCIAL IMPACT
There is no change to Net County Costs associated with this item. The Fiscal Year 2025-26 Adopted Budget includes sufficient funding for this project.
CLERK OF THE BOARD FOLLOW-UP ACTIONS
Clerk of the Board will obtain the Chair's signature on two (2) originals of the Agreement, and forward signed Agreements to the Chief Administrative Office, Contracts and Procurement Unit, for further processing.
STRATEGIC PLAN COMPONENT
Public Infrastructure
CONTACT
Jeffrey Warren, REHS
Director of Environmental Management