SCV Water looks at reservoirs due to winter, chemical concerns

The Rio Vista Water Treatment Plant at SCV Water. photo courtesy SCV Water.

A relatively dry winter and new state-set levels for the presence of a carcinogen in water  threatening the closure of groundwater wells have local water officials considering water from new sources and looking to use water they’ve already banked.

Santa Clarita Valley water users get their supply from two main sources via the SCV Water Agency — water imported from Northern California through the State Water Project and water from the ground under the SCV.

Both sources are expected to yield less this summer than officials had initially hoped.

“We are anticipating reduced supply from our two primary sources of water — the State Water Project, due to the dry year forecast by (the Department of Water Resources), and ground water as we take steps to address the presence of PFAS,” Dirk Marks, the agency’s director of water resources, said Tuesday.

With regards to imported water, in a memo to members of the agency’s Water Resources and Watershed Committee dated Jan. 30, Marks wrote: “Current uncertainty in the State Water Project watershed hydrology has resulted in a low 2020 SWP water allocation that may not meet imported water demands for SCV Water’s service area.”

To meet demands, the agency is expected to draw from water it’s been banking for drier days.

The committee meets Wednesday for a meeting open to the public, beginning at 6 p.m. in the Summit Circle Training Room at 26521 Summit Circle, off of Centre Pointe Parkway.

Marks has recommended the committee consider new water-management programs, such as buying water.

Banked water

Marks also suggested the agency may need to draw 22,500 acre-feet of water from water banked in existing programs.

An acre-foot of water is almost as much as a football field under a foot of water.

“The 22,500 acre-feet does anticipate both the shortfall in the SWP as well as potential short-term impacts due to PFAS until treatment can be put in place,” Marks said Tuesday.

“SCV Water has built a diverse water supply portfolio that provides resilience in exactly these circumstances,” he said. “We track supply and demand projections on a monthly basis and take actions such as this one to provide flexibility to draw on water banking, exchanges and purchases should conditions call for it.” 

Non-stick chemical

With respect to SCV groundwater, local officials were already building facilities near the William S. Hart Pony Baseball & Softball fields in an effort to remove tiny amounts of a non-stick chemical known as PFAS when they received word that state officials are expected to call for more stringent threshold levels for that carcinogen.

Construction workers drill into the soil to build a new water treatment facility next to the Wm. S. Hart Pony Baseball & Softball field in Santa Clara River wash Monday afternoon. Cory Rubin/The Signal

In the coming months, SCV Water is expected to voluntarily remove a number of its groundwater wells from service following the State Water Resources Control Board – Division of Drinking Water decision to lower its response level guidelines for two chemicals found in low concentrations in drinking water across the state.

On Thursday, the state lowered its response levels to 10 parts per trillion for perfluorooctanoic acid and 40 parts per trillion for perfluorooctanesulfonic acid, two chemicals in a family of per- and polyfluoroalkyl substances.

The state’s previous response level set a combined 70 ppt for PFOA and PFOS. 

These response levels are some of the most stringent guidelines in the nation, Matt Stone, SCV Water general manager, said in a news release issued Monday.

Stringent levels

For perspective, he pointed out, one part per trillion would be equal to four grains of sugar in an Olympic-size swimming pool.

As a result of earlier sampling, SCV Water voluntarily removed one groundwater well from service when it exceeded the prior response level in May 2019. All other wells tested well below that level.

“In August, we proactively sampled all wells in our system, so we have two quarters of data we can factor in now, giving us a head start in addressing the new guideline,” Stone was quoted as saying.

“We immediately removed one well from service last year when it exceeded the original response level, and we will take similar actions for additional wells that exceed the revised response level in the coming months,” he said.

Impacted wells

Under the new guidelines, as many as 18 of the 44 agency wells — close to half of them — could be impacted. 

SCV Water will tackle this challenge through a combination of new operating strategies and proven treatment options, Stone said.

The updated guidelines are part of the Division of Drinking Water’s effort to assess the scope of water supply contamination by PFOS and PFOA. 

In addition to revised response levels, DDW has indicated it will issue a new compliance sampling order in the near future. 

The revised response level guidelines are expected to be compared to a quarterly running annual average of sample results.

The first PFAS treatment facility has started construction and is expected to be in operation by June of this year, restoring three key wells to service, which represent a significant amount of the affected groundwater. 

The fast-tracked project is estimated to cost $6 million to build and $600,000 annually to operate.

“Today’s announcement is not about finding more PFAS in our water source, but rather implementing the revised state guideline to further protect public health,” Stone said.

“In response to DDW’s announcement today, we are taking immediate, proactive steps to ensure we remain in 100% compliance,” he said.

Health concerns

Studies indicate that both PFOA and PFOS can have reproductive, developmental, liver, kidney, thyroid and immunological effects in laboratory animals. Both sets of chemicals have caused tumors in animals.

With regards to humans, studies show increased cholesterol levels, liver enzymes and uric acid among exposed populations, with more limited findings related to:

  • Decreased infant birth weights.
  • Negative effects on the immune system, including decreased response to vaccinations.
  • Cancer, for PFOA chemicals.

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On Twitter: @jamesarthurholt

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