On July 20, 2023, the State Water Resources Control Board (SWRCB) published the Notice of Proposed Rulemaking (NPRM) for the proposed Direct Potable Reuse (DPR) regulations.
Copies of the NPRM, proposed DPR regulations and the SWRCB’s Initial Statement of Reasons (ISOR) are below.
Notice of Proposed Rulemaking
NPRM_Proposed DRP Regulations
Proposed DPR Regulations
DPR Proposed Regulations
DPR Initial Statement of Reasons
DPR Initial Statement of Reasons
The SWRCB will hold a public hearing at 9:30 am, on September 7, 2023. The deadline to submit written comments is September 8, 2023. A link to watch the public hearing and information on presenting oral comments is provided in the NPRM.
In July 2021, the California Office of Environmental Health Hazard Assessment (OEHHA) published, for review and comment, draft Public Health Goals (PHGs) for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS).
Last week, OEHHA released a second draft of the proposed PHGs. The proposed PHGs just released are the same as published in 2021, and are presented below:
PFOA – 0.007 parts per trillion (ppt)
PFOS – 1 ppt
The deadline to submit public comments is August 14, 2023.
The proposed PHGs are based on the one in a million cancer risk estimates. According to information posted by OEHHA, the PFOA proposed PHG is based on kidney cancer in humans, and the PFOS proposed PHG is based on liver and pancreatic cancer in animal studies.
OEHHA’s announcement (https://wqts.com/wp-content/uploads/2023/08/PFAS-PHGs-OEHHA-Announcement.pdf ).
OEHHA’s second draft Technical Support document for the proposed PHGs can be found at the following link:
Information to register for EPA’s August 8th meeting with the National Drinking Water Advisory Council (NDWAC) has been posted at the following site:
During week of July 10, 2023 the State Water Resources Control Board (SWRCB) released an advanced copy of the proposed Direct Potable Reuse (DPR) regulations (Advanced Copy Proposed DPR Regulations). SWRCB expects the formal Notice of Proposed Rulemaking to be published this week (July 21, 2023) for a 45 day public comment period. An advanced copy of the supporting document Initial Statement of Reasons has not yet been posted.
AB 574, signed into law in October 2017, required that the State Water Resources Control Board (SWRCB) adopt uniform criteria for Direct Potable Reuse (DPR) by December 31, 2023. “Direct potable reuse is the planned introduction of recycled water either directly into a public water system or into a raw water supply immediately upstream of a water treatment plant.” The bill required that before adopting the criteria, the SWRCB submit the criteria to an Expert Panel for review.
In June 2021 the SWRCB and the National Water Research Institute (NWRI) convened an expert review panel as required by Section 13561.2 of the Water Code to review DDW’s proposed DPR criteria. The charge of the expert panel was to review the proposed criteria (regulations) for DPR and make a finding as to whether, in its expert opinion, the proposed criteria would adequately protect public health. The Expert Panel held public meetings on August 24 and 25, 2021, December 1, 2021; January 28, 2022; and February 28, 2022. In March 2022 the DPR Expert Panel released a draft memorandum presenting their review and recommendations of the draft DPR criteria. DDW staff prepared and posted a response to the Expert Panel’s draft memo. In July 2022 the SWRCB posted the Memorandum of Findings: Expert Panel Preliminary Findings and Recommendations on Draft DPR Criteria. “The Panel’s Preliminary….Finding is that the Early Draft of Anticipated Criteria for Direct Potable Reuse dated August 17, 2021, adequately protects public health.”
Additional Information Can Be Found Here:
Link to the SWRCB’s DPR website:
On August 8, 2023, from 10:30 am to 5 pm (ET) EPA will hold a public (virtual) meeting with the National Drinking Water Advisory Council (NDWAC or Council). The stated purpose of the meeting is to “…update the Council on Safe Drinking Water Act programs and to consult with the NDWAC as required by the SDWA on a final National Primary Drinking Water Regulation (NPDWR) for per- and polyfluoroalkyl substances (PFAS).” Link to copy of Federal Register notice (Fed Reg EPA to Brief NDWAC on Proposed PFAS MCLs ). Information on how to register to join the public meeting will be posted at the following location:
(Registration information has not yet been posted)
Background on Proposed MCLs for PFAS
On March 29, 2023 EPA published for public review and comment, proposed MCLs of 4 parts per trillion (ppt) for PFOA and 4 ppt for PFOS. EPA also proposed “….to use a Hazard Index (HI) approach to protecting public health from mixtures of PFHxS, HFPO-DA and its ammonium salt, PFNA, and PFBS because of their known and additive toxic effects and occurrence and likely co-occurrence in drinking water.”
Proposed Definition of Hazard Index: “Hazard index (HI) is the sum of component hazard quotients (HQs), which are calculated by dividing the measured regulated PFAS component contaminant concentration in water (e.g., expressed as ppt) by the associated Health-Based Water Concentration (e.g., HBWC expressed as ppt). For PFAS, a mixture HI greater than 1.0 is an exceedance of the MCL.” [emphasis added]
How To Calculate the Hazard Index: Steps to calculate the HI: “….a ratio called a hazard quotient (HQ) is calculated for each of the four PFAS (PFHxS, HFPO-DA and its ammonium salt (also known as GenX chemicals), PFNA, and PFBS) by dividing….the measured level of each of the four PFAS in drinking water, by a health reference value for that particular PFAS. For health reference values, in this proposal, EPA is using Health Based Water Concentration (HBWCs) as follows: 9.0 ppt for PFHxS, 10.0 ppt for HFPO-DA; 10.0 ppt for PFNA; and 2000 ppt for PFBS. The individual PFAS ratios (HQs) are then summed….to yield the HI. If the resulting HI is greater than one (1.0), then the exposure metric is greater than the health metric and potential risk is indicated
The public comment period for the proposed PFAS MCLs closed May 30, 2023.
The August issue of the journal “Environment International” posted an article by the US Geological Survey (USGS) titled
“Per- and polyfluoroalkyl substances (PFAS) in United States tapwater: Comparison of underserved private-well and public-supply exposures and associated health implications.” Link to copy of the article (USGS Article PFAS in Drinking Water ).
Link to USGS website announcement:
Text copied from the USGS website announcement:
“The study tested for 32 individual PFAS compounds using a method developed by the USGS National Water Quality Laboratory. The most frequently detected compounds in this study were PFBS, PFHxS and PFOA. The interim health advisories [HA] released by the EPA in 2022 for PFOS and PFOA were exceeded in every sample in which they were detected in this study.” [PFOA HA = 0.004 parts per trillion, PFOS HA = 0.02 ppt]
“Scientists collected tap water samples from 716 locations representing a range of low, medium and high human-impacted areas. The low category includes protected lands; medium includes residential and rural areas with no known PFAS sources; and high includes urban areas and locations with reported PFAS sources such as industry or waste sites.”
“Most of the exposure was observed near urban areas and potential PFAS sources. This included the Great Plains, Great Lakes, Eastern Seaboard, and Central/Southern California regions. The study’s results are in line with previous research concluding that people in urban areas have a higher likelihood of PFAS exposure. USGS scientists estimate that the probability of PFAS not being observed in tap water is about 75% in rural areas and around 25% in urban areas.”
The USGS study is getting a lot of media coverage and the focus appears to be primarily on the modeling done by USGS and on statements like the following statement from the abstract: “We estimate that at least one PFAS could be detected in about 45% of US drinking-water samples.”
Link to CNN article:
Link to CBS News
Link to AP News:
Some items in the news regarding PFAS that may be of interest:
Link to Washington Post article: “How do you know if your water is safe from forever chemicals?”:
Link to AP News Article “3M reaches $10.3 billion settlement over contamination of water systems with ‘forever chemicals.’:
Link to PBS NewsHour story earlier this month on a separate legal settlement (with DuPont de Nemours Inc., Chemours Co. and Corteva Inc.) for PFAS cleanup: “$1.18 billion deal reached over drinking water contamination by ‘forever chemicals.’:
On Wednesday, June 28th, from 2:00 pm to 3:30 pm (EDT) EPA will hold a webinar titled “Supporting Private Lead Service Line Replacement (LSLR) with the Drinking Water State Revolving Fund (DWSRF).”
Link to Register: https://attendee.gotowebinar.com/register/3235276012326084960
Topics will include:
• Bipartisan Infrastructure Law (BIL) LSLR provisions and funding options from the DWSRF
• Examples of how state DWSRF programs support private LSLR
• Examples of how public water systems conduct LSLR
On June 16, 2023, the Division of Drinking Water (DDW) posted the enclosed Notice of Proposed Rulemaking (NPRM) proposing a Maximum Contaminant Level (MCL) of 10 µg/L for hexavalent chromium (CrVI). There will be a 45-day public comment period. CrVI Notice of Proposed Rulemaking
DDW will hold a public hearing on August 2, 2023 at 1:00 pm. The deadline to submit public comments is August 4, 2023.
Also enclosed, please find a copy of DDW’s Initial Statement of Reasons (Proposed CrVI MCL ISOR ), and the Initial Statement of Reasons (ISOR) Attachment 1 (cost tables). (ISOR Attachment 1 Cost Tables )
Additional attachments for the ISOR can be found at the following website (scroll down to the heading “Rulemaking Documentation”):