Per- and Polyfluoralkyl Substances (PFAS) Rule
As noted in my last Program Manager's Message, EPA is likely to begin developing a new rule in 2020 to address per- and polyfluoroalkyl substances (PFAS). PFAS, commonly used in firefighting foams, has contaminated several drinking water supplies in Colorado. Many manufacturers modified their processes to avoid using PFOS and PFOA several years ago, but hundreds or thousands of other PFAS chemicals have been used in commerce and may contaminate the environment and water supplies. National MCLs
In early 2020, EPA will make a regulatory determination about whether to establish Maximum Contaminant Levels (MCLs) for PFOA and PFOS (see EPA's PFAS Action Plan). The new rule’s structure will likely be similar to rules for other contaminants with MCLs. A PFAS rule would therefore include:
- The MCL values themselves, with a certain number of significant digits
- Sampling requirements including location, frequency and analytical methods
- Any opportunities for reduced monitoring or “grand-parenting” existing data
- How is compliance determined, e.g. running annual average?
- Public notice requirements for violations
- Health effects language that must be included in public notices
Colorado
Under Colorado Revised Statute (C.R.S.) Sections 25-1.5-202(3)-(4), the Water Quality Control Commission can set “minimum general sanitary standards” (MCLs) for contaminants or substances that are unregulated by the Safe Drinking Water Act, based on the division’s recommendation. Minimum general sanitary standards are Colorado’s equivalent to federal MCLs under the Safe Drinking Water Act.
To establish minimum general sanitary standards, the division must first “annually establish and revise a priority list of contaminants or substances for which standards may be considered and shall submit the list to the commission for review and approval.” In September 2019, the division submitted a priority list of contaminants to the commission for consideration (see Section D of our 2019 Annual Report to the commission), which included several PFAS compounds. The commission approved the priority list in October 2019.
The division believes that including PFAS chemicals on the priority list was warranted to support the department’s PFAS action plan.This does not set MCLs or minimum general sanitary standards for PFAS, and it does not necessarily mean that the division will pursue standards for these compounds in the near future. However, failing to establish a priority contaminant list that includes PFAS would unacceptably reduce the division’s flexibility for taking action to protect public health and address human exposure to PFAS. If the division should decide to move forward with setting state MCLs (minimum general sanitary standards) for PFAS, that process would start with considerable outreach and a stakeholder process to gain needed input.
Priorities
We prioritized the following compounds because of their confirmed presence in drinking water supplies and sources in Colorado, as described in the statute’s ranking process considerations:
- Perfluorooctanoic acid (PFOA) Chemical Abstract Service Number (CAS No.) 334-67-
- Perfluorooctane sulfonate (PFOS) CAS No. 1763-23-1.
- Perfluorohexane sulfonic acid (PFHxS) CAS No. 355-46-4.
- Perfluorononanoic acid (PFNA) CAS No. 375-95-1.
Ranking
The ranking process considerations, which are detailed in the report to the commission, included:
- Presence or threat of contamination
- Identified contamination pathway
- Analytical techniques
- Availability of information about health effects and treatment
- Magnitude of health risks
- National primary drinking water regulation
- Environmental fate and transport
- Populations and drinking water supplies at risk
- Level of effort to develop standard
Overall, this effort would likely involve numerous staff over many months prior to the actual rulemaking. If the commission adopted a rule, then the division would also need adequate resources for implementing and enforcing it and for providing compliance and technical assistance.
Please stay tuned as the department moves forward in implementing the PFAS action plan.
➽ Ron Falco, safe drinking water program manager
