Though a danger advisory was issued for Castaic Lake by the California Department of Water Resources (DWR) on Sept. 26, drinking water for all SCV Water customers remains safe and meets high standards for quality. DWR issued an advisory to refrain from recreational activities in the lake due to the presence of blue-green algae at Castaic Lake, which in addition to health concerns can give off a distinctive odor described as fishy or earthy smelling.

“It is important to note that DWR recommends avoiding contact with water in the lake, as well as drinking, cooking or washing dishes with untreated surface water,” said Matt Stone, SCV Water general manager. “SCV Water thoroughly treats water drawn from Castaic Lake to ensure it meets high standards of quality set by the U.S. Environmental Protection Agency.”

About half of the water supply in the Santa Clarita Valley is imported from the State Water Project, which delivers water to Castaic Lake from Lake Oroville, northeast of Sacramento. Water withdrawn from Castaic Lake then flows via large underground pipelines to be treated through two state-of-the-art water treatment plants, the Earl Schmidt Filtration Plant in Castaic and the Rio Vista Water Treatment Plant in Saugus.

Multibarrier treatment processes employed by SCV Water are effective at managing cyanobacteria (blue-green algae) and related toxins. Chloramine is also used during the treatment process to protect against disease-causing microorganisms. Treated water is then
distributed to customers.

“There are no impacts to our treatment plant operations from this advisory at this time,” said Mike Alvord, SCV Water director of operations and maintenance. “However, if DWR decides to treat the algal bloom with copper sulfate (bluestone), the algae will die off and turbidity, or cloudiness, levels will more than likely increase. Minor adjustments will need to be made, such as lowering the ozone dose during treatment, but that would have much less of an impact on operations than we saw during the heavy rains earlier in 2023.”

Typically, DWR notifies SCV Water a week in advance of any dosing. As of now, no notice has been received.

For any water quality concerns about SCV Water, please contact the Water Quality hotline at (661) 388-4980.