Urgent Notice - Golden Mussels Found in Arvin-Edison System
Dear Water Users:
During our recent 2025 Winter Maintenance activities, District Staff found presence of Golden Mussels throughout the District’s Distribution System (see pictures below). At the December 9 Board meeting, Staff reported the findings of such, and subsequently, the Board directed Staff to take immediate actions to surround the topic and eradicate the invasive species as soon as possible.
It shall be noted that our 2024 Winter Maintenance activities indicated no presence of Golden Mussels. This rapid infestation is a troubling sight. Golden Mussels were first detected October 2024 in the San Joaquin-Sacramento Delta and have subsequently spread throughout the California Aqueduct and Delta Mendota Canal. Consequently, Golden Mussels unknowingly entered the District’s facilities from the Cross Valley Canal (CVC) and the District’s Aqueduct Turnout. Friant Water Authority is reviewing their system, but it appears they are not present currently in Millerton Lake nor the upper reaches of the Friant-Kern Canal (however, the lower reaches in Kern County are implicated due to reverse flow deliveries from the CVC).
The Golden Mussels attach to pipes/structures and can build upon each other, which greatly reduce pipeline capacity, starve pumps, clog trash racks including traveling water screens, with the most vulnerable being small diameter pipelines.
Taking control of this issue is a top priority and Staff has begun investigating treatment options including contacting State and Federal officials, engaging with expert scientists, consultants, and working with companies to chemically remove the Golden Mussels (copper sulphate, chlorine and even biological solutions like zequanox, which are safe for crops).
Initial plans may include aggressive treatment to eliminate the established Golden Mussels followed by periodic treatments at surface water import locations at headworks facilities to limit and/or prevent growth. Assistance from Water Users may be necessary to move treated water into the most downstream facilities to reach all parts of the system.
Staff will continue to update Water Users frequently on this issue.