The State Water Project – one of ACWD’s key suppliers -- is experiencing an algae bloom, likely due to the high temperatures in the past several weeks. Algae are microscopic plants that thrive at certain times of the year in rivers and reservoirs. The algae is removed from the water in the treatment process, but tiny amounts of compounds can remain behind and cause odors described as “earthy” or “musty.”
There is no health hazard presented by this phenomenon. The water remains safe to drink, cook with and for all other uses.
ACWD is taking immediate steps to address this issue and we expect the problem to clear up in a few days. We are adjusting our water treatment and production processes, including increased ozone treatment. We believe this ozonation process will minimize the unusual tastes and odors some customers have noticed.
Although we don't know how long the conditions in the Sacramento-San Joaquin Delta may persist, we are working with the California Department of Water Resources, the which operates the State Water Project, as well as neighboring water agencies to monitor and manage this source water issue.