The California State Water Resources Control Board (Water Board) has issued Order WQ 2020-0015-DWQ, requiring Publicly Owned Treatment Works (POTWs) with dry weather design flows greater than 1 mdg to test for per- and polyfluoroalkyl substances (PFAS) in influent, effluent, biosolids, and, in some cases, groundwater. POTWs with existing groundwater monitoring programs may be required to submit initial documentation for compliance as early as August.
The order covers 31 PFAS analytes (see table provided here), as well as 11 additional analytes listed for “optional analysis.” All treatment sampling and analysis and groundwater monitoring proposals and analysis must be uploaded to the Water Board’s GeoTracker system, and will be incorporated into the Board’s ongoing PFAS mapping project.
Treatment System and Groundwater Sampling
Starting in October, POTWs must sample and analyze influent, effluent, and reverse osmosis concentrate/retentate for the listed PFAS quarterly for one year. Biosolids must be sampled for PFAS and moisture content quarterly by POTWs with dry weather design flows greater than 5 mgd, and just once by smaller POTWs.
POTWs with existing groundwater monitoring and reporting programs must also monitor groundwater for PFAS, and must submit a groundwater monitoring proposal at least 60 days before the next groundwater monitoring period that includes the following:
- A figure of the groundwater monitoring well network and groundwater flow direction that indicates a minimum of three monitoring wells proposed to be sampled.
- Rationale for the selection of groundwater monitoring wells for representative sampling.
Following approval of the proposed sampling locations, a one-time monitoring event must commence during the next groundwater monitoring period, but no sooner than October.
Ongoing Non-Drinking Water PFAS Investigation.
POTW PFAS testing requirements are designed to support “preliminary investigation of the mass loading of PFAS into the POTW and then leaving the POTW in different media (treated wastewater, brine, biosolids).” PFAS testing at POTWs was included the third phase of a three-phase investigation plan announced in 2019. The Water Board issued its first non-drinking water investigatory orders to airports and landfills in March 2019, and issued testing orders to chrome plating facilities in October 2019. Refineries, bulk terminals, and non-airport fire training areas have also been identified as sites where testing may be required.
Detection of PFAS exceeding reporting limits may result in requirements for reduction of PFAS levels in discharges and/or remediation of affected surface and groundwater, particularly as ongoing PFAS-related legislative and regulatory initiatives proceed. California has already adopted notification levels for drinking water for PFOS and PFOA to 6.5 ppt and 5.1 ppt, and response levels of 40 ppt for PFOA and PFOS. Limits for additional substances are expected. Given the attention PFAS have garnered, publicly posted and mapped data reported through the GeoTracker system will be scrutinized by private plaintiffs as well as regulators seeking to understand the sources and scope of PFAS releases. Failure to comply with the order can result in civil penalties up to $10,000 per day of noncompliance.