State Water Board fines Stockton East Water District after investigation into foul-smelling drinking water

STOCKTON – Following an investigation into widespread complaints about foul-smelling and bad-tasting drinking water, the State Water Resources Control Board has issued a $51,500 penalty against Stockton East Water District after finding it used an unauthorized water source on over 100 days.

The investigation by the State Water Board's Division of Drinking Water was prompted by complaints from Stockton residents in May about unusual taste and odor problems in their drinking water. Staff discovered that the district used water from Salt Spring Valley Reservoir, delivered through Rock Creek – a source not approved for drinking water – on at least 103 days since 2022. Records show that water from the reservoir accounted for as much as 40% of the raw water supply on one day in May, the month when customer complaints peaked.

The district supplies treated drinking water to California Water Service–Stockton and the city of Stockton, which serve a combined 375,000 people. Both CWS – Stockton and the city blend treated surface water from the district with groundwater and treated surface water from their water systems.

In addition to the penalty, the board’s Nov. 5 enforcement order directs the district to comply with its existing permit and prohibits further use of the unapproved source for drinking water.

“When parents fill a glass of water for their children, they trust that it’s safe,” said Tricia Wathen, a supervising water resource control engineer with the board’s division of drinking water. “We took residents’ complaints seriously, investigated their concerns and held the district accountable for violating that trust.”

The district purchased the water from the reservoir and mixed it with water from an approved source in a shared conveyance system before reaching the drinking water treatment plant. Water from the unapproved drinking water source underwent conventional treatment at the district's facility.

California law requires public water systems to obtain an amended permit before adding or changing drinking water sources. The requirement allows the board to evaluate water quality and treatment needs before a new source is introduced.

The State Water Resources Control Board works to preserve, enhance and restore the quality of California's water resources and drinking water for the protection of the environment, public health and all beneficial uses, and to ensure proper water resource allocation and efficient use.