DDW Issues Order for PFAS Monitoring – Sept 2020

In July 2019, California Assembly Bill (AB) 756 was signed into law.  AB 756 gave the State Water Resources Control Board (SWRCB) authority to require public water systems conduct monitoring for PFAS and included specific requirements for public notification.  Under AB 756, if a public water system is required to monitor for PFAS and has a “confirmed detection” the utility “….shall report that detection in the water system’s annual consumer confidence report.”

Under authority of AB 756 this month the Division of Drinking Water (DDW) sent orders to public water systems throughout California requiring monitoring for PFAS.  DDW posted a copy of the cover letter, General Order and exhibits at: https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/pfas_ddw_general_order/

Copies of all documents are presented here: (pfas_go_cover_letter pfas_go_2020_0003_ddwgo_exhibit_a_section1go_exhibit_a_section2go_exhibit_a_section3go_exhibit_a_section4go_exhibit_a_section5go_exhibit_bgo_exhibit_c)

Quarterly monitoring is to begin in the fourth quarter of 2020 and according to the cover letter shall continue “…until further notice.”  The enclosed General Order states if four consecutive quarters of testing results are below the CCRDL [Consumer Confidence Report Detection Level – described below] “…the public water system may submit a request to their DDW District Engineer for a modification or reduction in monitoring.”

Exhibit a was posted in five sections and contains the list of public water systems and specific wells required to monitor.

Exhibit b presents the list of 18 PFAS compounds to be monitored using EPA Method 537.1.  The list of 18 PFAS compounds includes the CCRDL for each compound.  DDW describes the CCRDL as follows:

“The CCRDL is based on a review of the reporting levels reported for monitoring conducted between August and December 2019. Specifically, the SWB calculated the CCRDL as the reporting level that was achievable in 90 percent of all negative result reported during that period. Results were rounded to the nearest whole number.”

“For HFPO-DA, the rounded CCRDL is lower than the 90th percentile of conveyed reporting levels based on consultation with the laboratory reporting the highest volume of results, and their statement that a reporting level of 4 ng/L (4 ppt) could readily be achieved.”

The General Order contains language to clarify what constitutes a “confirmed detection.”