Testing the water

Back in 2016, California Water Service Co. took two of its groundwater wells in Chico out of service after tests showed they were contaminated with toxic flourinated chemicals known as PFAS—or per- and polyfluoralkyl substances—that have been linked to cancer and other adverse health effects.

The move was done quietly. Under questioning by the Butte County Water Commission earlier this month, Loni Lind, water quality manager for Cal Water, told the board the public was not notified at the time.

“We took them offline the second we had results,” Lind told the board. “So, it wasn’t like there was a period of time when we were running it knowingly with these results in hand.”

The removal of the wells from Chico’s water supply came after a round of testing mandated for large public water systems by the U.S. Environmental Protection Agency (EPA). More examinations were ordered statewide by the California Water Resources Control Board earlier this year, finding hundreds of wells and other water sources containing traces of PFAS. State and federal water officials continue to explore regulation, mitigation and notification requirements for the substances.

PFAS are a group of man-made substances—sometimes referred to as “forever chemicals”—that are resistant to heat, water and oil, according to the state water board. They can be found in a variety of sources, such as nonstick cookware, fast-food wrappers and firefighting foam, and can accumulate in the body over time.

Two common PFAS substances—PFOS and PFOA—are no longer manufactured or imported into the U.S., though traces of PFAS have been found in nearly every person tested in several national surveys, according to the state.

Elaine McSpadden, Butte County’s environmental health director, said the health effects of PFAS are not yet fully understood, but she added that the county is working in conjunction with state and federal agencies as regulations are being developed. The ultimate goal, she said, is the implementation of legislation that would require public water systems to monitor for the chemicals, provide proper notification and develop treatments.

George Barber, district manager for Cal Water’s Chico and Oroville branches, told the CN&R that regulation for PFAS has taken a different path than other contaminants. Essentially, he said, water systems are mitigating a chemical while state and federal requirements—known as maximum contaminant levels—are still being developed.

When Cal Water found that the two wells in Chico had tested positive for PFOS in 2016—one at 76 parts per trillion (ppt), and the other around 58 ppt—it took action immediately to ensure it wasn’t delivering unsafe water, Barber said. As for keeping the public in the dark at the time, he said Cal Water follows the rules and makes notifications when required.

“We didn’t know what the [maximum contaminant] levels would be at that point, [and] whether it was going to need treatment or not,” he said. “So, we notify when we are required to. I don’t want that to sound harsh, but we don’t want to concern people. It’s not like we’re hiding anything.”

Nevertheless, the district manager said it’s likely Cal Water will be more proactive in notifying the pubic about water supply decisions in the future, even when it’s not required, “to try and help our customers understand the reality of our certain districts.”

Last month, the state released results for PFAS testing mandated for nearly 600 drinking water supply wells. More than 300 wells and other sources throughout the state tested positive for the chemicals. In Chico, Cal Water was required to test fewer than half of its wells, but the utility decided to test all 56 of them, Barber said. Eleven were found to have traces of PFAS above the state’s notification level of 6.5 ppt for PFOS or 5.1 ppt for PFOA, though none reached the response level of 70 ppt—the point at which officials recommend removing a well from service. A notification level requires further monitoring and notification to local governments.

The state water board says the notification level has been set “conservatively” as it further assesses health effects. However, the Environmental Working Group, a nonprofit environmental health organization, has developed a health guideline of 1 ppt for PFAS in drinking water.

The two wells previously taken out of service remain offline. Barber didn’t disclose where they are located. He noted, however, that close proximity to a certain well doesn’t necessarily mean a customer is receiving water from it.

“The water is safe,” he said. “The water in Chico is safe.”

In Oroville, where Cal Water tested all four of its wells, one was found over the response level for PFAS. The water supplier worked with the state to remove that well from service.

Almost all drinking water in Oroville comes from surface water, not groundwater, Barber said, and tests did not detect the chemicals in surface water there.

Regular testing remains ongoing, he said, and treatment options—such as granular activated carbon and ion exchange—are being explored. Treatment can range from $1 million to $2 million per site.

In January, new legislation will require water systems to either remove from service drinking water sources that exceed the response level or provide public notice.

As the state continues to develop regulations for PFAS, Barber said Cal Water’s message is: Don’t be concerned.

“We’re on it,” he said. “We’re testing. … We’re taking actions as appropriate.”