Background
In April 2019, the State Water Board issued specific orders to airports, landfills and adjacent water systems, identified as potential PFAS source locations. Data from more than 600 water system sites adjacent to nearly 250 airports with fire training areas and municipal solid waste landfills within California have been received by the State Water Board in response to these specific orders. The assessment of this data obtained by these actions is a prolonged undertaking and additional analysis will be conducted in the coming years. Selection of the location of public water supply (PWS) wells sampled was based on the following criteria:
- Within 2 miles of a commercial airport* and/or within 1 mile of a municipal solid waste landfill that received Investigative Orders on March 20, 2019
- Resampling of PWS wells sampled during the 2013-2015 US EPA’s Third Unregulated Contaminant Monitoring Rule (UCMR 3)
- Within 1 mile of UCMR 3 sampled PWS wells that had detections of PFOA and PFOS
*Certified by Federal Aviation Administration per Title 14 Code of Federal Regulations Part 139
The Division of Drinking Water required the Public Water Systems to sample the PWS wells quarterly for four consecutive quarters.
In August 2020, the Division of Drinking Water issued a General Order to expand the PFAS testing of Public Water Systems based on the 2019 PFAS sampling results. In February 2021, the Division of Drinking Water issued a General Order for PFAS testing of Public Water Systems located in or within the vicinity of the Department of Defense sites in California.
Public Water Supply Well Results
The State Water Board is providing charts of the 2019/2020 results on this webpage. The 2019/2020 and future public water system results are found on the PFAS GeoTracker Mapping Tool.
The 2019/2020 dataset of PFAS results for the PWS wells sampled during the 1st, 2nd, 3rd, and 4th Quarter is available for download in this file: (pfas_monitoring_Q1Q2Q3Q4)
In this dataset and on the following charts, if a water system sampled a well more than once in a quarter, the concentration equals to the average concentration for that analyte. Additionally, PFOA or PFOS concentrations reported at less than the reporting limit are shown as zero.
Charts for 2019/2020 Data
Charts #1 and #2
- A series of two charts are shown. Each chart shows the frequency of detections for PFOA and PFOS, respectively for all results less than 70 ppt for PFOA or PFOS. The first column along the X-axis is equal to the NL for PFOA (5.1 ppt) or PFOS (6.5 ppt). Each column within each concentration range represents a quarter of data.
Charts #3 and #4
- A series of two charts are shown. Each chart shows the frequency of detections for PFOA and PFOS, respectively for all results for PFOA or PFOS. Each column within each concentration range represents a quarter of data.
Chart #5 – Detections by All PFAS Chemicals
- This chart displays the frequency of detections versus each of the PFAS chemicals analyzed. Each column within each concentration range represents a quarter of data.
Chart #6 – Detections by All PFAS Chemical Classes
- This chart displays the frequency of detections versus PFAS class. The PFAS classes used are:
- PFCAs = PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFDoA, PFTrDA, PFTA;
- PFSAs = PFBS, PFHxS, PFOS;
- FOSAs = NMeFOSAA, NEtFOSAA;
- PFECAs = HFPO-DA, ADONA;
- Cl-PFESAs = 11Cl-PF3OUdS, 9Cl-PF3ONS
Perfluoroalkyl acids (PFAAs) include PFCAs and PFSAs. Each column within each chemical class represents a quarter of data.
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