ACWD tested drinking water supplies for PFOA and PFOS compounds in 2014, as required by the United States Environmental Protection Agency under the third Unregulated Contaminant Monitoring Rule. ACWD did not detect PFOA or PFOS in the drinking water in 2014.
Since 2014, advances in testing technologies since 2014 have allowed us to detect substances at increasingly low levels. Therefore, ACWD, once again, in June 2020, voluntarily sampled several water supply sources ahead of any regulatory requirement. This proactive monitoring allows ACWD to ensure the best water quality is available to our customers and take measures to treat our source supplies.
Our voluntary testing identified low levels of PFOA in our groundwater sources between non-detect and 6.4 ppt, with some sources above the customer notification level of 5.1 ppt. However, all treated water delivered to customers had no detections of PFOA.
PFOS was detected in most groundwater sources at low levels, between non-detect and 15 ppt, with some sources above the customer notification level of 6.5 ppt set by the State Board. However, all treated water delivered to customers was below the notification level or non-detectable.
PFBS was detected in some groundwater sources at low levels, between non-detect and 7.4 ppt, with all sources below the customer notification level of 500 ppt. All treated water delivered to customers had no detections of PFBS.
PFHxS was detected in most groundwater sources, between non-detect and 14 ppt, with most of the sources above the customer notification level of 3 ppt. Since the establishment of the notification level, ACWD has optimized operations to ensure all treated water delivered to customers remain below notification levels.
Results from this same monitoring program did not detect PFOA, PFOS, or PFBS in surface water supplies which account for almost two-thirds of ACWD’s total water delivered to our customers.