Read the full article by Atascadero News (The Atascadero News)

“Levels fo PFAS are below the California State Board Response Level

In December 2019, Atascadero Mutual Water Company (AMWC) was directed by the California State Water Board (Water Board) to sample five of its main production wells for perfluoroalkyl substances (PFAS) under the Water Board’s Monitoring Order.  PFAS are a group of man-made compounds that have been manufactured and used in a variety of industries around the globe, including in the United States, since the 1940s.  PFAS are very persistent in the environment.  

Two PFAS compounds were detected in the five wells sampled by AMWC under the Water Board’s order – perfluorooctanoic acid (PFOA) and perflourooctanesulfonic acid (PFOS).  The sampling results showed PFOA levels ranging from 3.5–19 parts per trillion (ppt) and PFOS levels ranging from 8.7–39 ppt.  At the time, none of these wells had combined levels of PFOA and PFOS that exceeded the Water Board’s Response Level of 70 ppt.  

Response Levels are established by the Water Board for contaminants that may be considered candidates for establishment of maximum contaminant levels (MCL) but have not yet undergone or completed the regulatory, standard-setting process.  Response Levels are not drinking water standards; they are levels at which the Water Board recommends the water purveyor take additional steps to reduce public exposure to the contaminant.

In February 2020, the Water Board adopted new, lower Response Levels for PFOA and PFOS of 10 ppt and 40 ppt, respectively.  Four of wells previously sampled under the Water Board’s order now had had PFOA levels above this newly adopted Response Level of 10 ppt.  AMWC immediately took these wells out of service.  They will remain out of service until AMWC can treat the water to reduce PFOA levels.  AMWC’s ability to meet peak summer water demands may be hindered with these four wells out of service…”