Three Valleys advances $1.2M chemical feed upgrade to combat Golden Mussels

Three Valleys advances $1.2M chemical feed upgrade to combat Golden MusselsThe California district is retrofitting operational infrastructure to deploy copper-based algaecides, aiming to protect treatment assets and groundwater recharge basins from invasive species.

TVMWD is designing a $1.2 million replacement of its acid feed system to inject EarthTec algaecide.

The project aims to mitigate invasive Golden Mussels, which are currently complicating groundwater recharge operations.

$200,000 is budgeted for design in the current fiscal year, with construction funds to follow in the next cycle.

The system will include a remote injection site at the plant's headworks to protect downstream assets.

Three Valleys Municipal Water District (TVMWD) is proceeding with the design of a $1.2 million replacement for its acid feed system, which is being adapted to serve as a primary defense against invasive Golden Mussels. During the January 21, 2026, board meeting, staff provided an update on the project, which involves replacing aging poly tanks and injection pumps with a new system capable of injecting "EarthTec," a copper-based algaecide. The project was originally intended solely to replace a sun-damaged sulfuric acid injection system but has been strategically repurposed. A staff member identified as Kevin noted that the district identified a secondary purpose for the capital improvement: locating a remote injection site near the PM21 meter to inject the chemical at the head of the plant. This upstream injection is intended to protect all assets within the plant from the invasive mussels. Staff explained that EarthTec contains a soluble version of copper that is NSF 61 approved for drinking water. It was noted that the solution is effective because Golden Mussels and their veligers (larvae) cannot survive the treatment; trials have demonstrated that the chemical can achieve 100% mortality in adult mussels within 24 days at concentrations of 500 parts per billion. While efficacy can vary based on water chemistry parameters such as pH, the treatment remains a viable method for controlling infestation. The new design will likely switch from polyethylene tanks to Fiberglass Reinforced Plastic (FRP) tanks to better withstand UV exposure and extend the asset lifespan. The total project cost is estimated at $1.2 million. The district has budgeted $200,000 in the current fiscal year for design and construction documents, with construction costs to be included in the next budget cycle. The infrastructure upgrade aligns with broader regional concerns regarding the invasive species. General Manager Matthew Litchfield reported that the district is coordinating with the Six Basins Watermaster and Stetson Engineering regarding challenges the Golden Mussel poses to recharge operations in the Main San Gabriel Basin. The district plans to present updates on these mitigation measures to the Six Basins Board in the coming week.