The Water Quality Control Division will host our kickoff meeting on Thursday, Aug. 22, 2024, from 1 to 2:30 p.m to discuss the statewide adoption of the EPA’s PFAS National Primary Drinking Water Regulation under the Water Quality Control Commission’s Regulation No. 11.
We invite all interested individuals to participate in the process but strongly encourage community and non-transient, non-community public water systems to attend.
- Sign up through the PFAS drinking water rule engagement form if you would like to continue to receive email correspondence regarding this process.
PFAS Questions
What just happened with the PFAS rule?
On April 10, 2024 the Environmental Protection Agency (EPA) set maximum contaminant levels (MCLs) for five individual PFAS: PFOA, PFOS, PFNA, PFHxS, and HFPO-DA (known as GenX). The EPA is also setting a Hazard Index level for two or more of four PFAS as a mixture: PFNA, PFHxS, HFPO-DA, and PFBS.
Table 1. New federal PFAS Regulatory Levels
Definitions
Maximum Contaminant Level Goal (MCLG): The level of a contaminant in drinking water below which there is no known or expected risk to health and allows for an adequate margin of safety. MCLGs are non-enforceable public health goals.
Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. MCLs are enforceable standards.
Parts per trillion (ppt): A ppt is a measurement of the quantity of a substance in the air, water or soil. A concentration of one part per trillion means that there is one part of that substance for every one trillion parts of either air, water or soil in which it is contained. One part per trillion is equivalent to one nanogram per kilogram ng/L.
Hazard Index (HI): The Hazard Index is a long-established approach that EPA regularly uses to understand health risk from chemical mixture. The HI is made up of a sum of fractions. Each fraction compares the level of each PFAS measured in the water to the highest level determined not to have risk of health.
What is a Hazard Index?
Research shows that mixtures of PFAS can have additive health effects. This means that low levels of multiple PFAS that individually would not likely result in adverse health effects may pose health concerns when combined in a mixture. EPA’s Hazard Index MCL is set at 1 and applies to any mixture containing two or more of PFNA, PFHxS, PFBS, and GenX. The Hazard Index is made up of a sum of fractions. Each fraction compares the level of each PFAS measured in the water to the highest level below which there is no risk of health effects.
Is this going to impact my water system?
Community Water Systems and Non-Transient Non-Community Water Systems must comply with the PFAS drinking water MCLs. Consecutive community systems and NTNC systems must comply with the MCLs as well but the requirements are less extensive.
When will I see this on my Monitoring Schedule? When do I need to start sampling? Am I going to need to install treatment?
By the end of 2026:
- Systems must conduct initial monitoring or obtain approval to use previously collected monitoring data
- States must adopt PFAS rule into state regs
Starting in 2027:
- Systems must start their ongoing compliance monitoring
- There are opportunities for reduced monitoring depending on the system’s initial monitoring results
- Systems must include results of their monitoring for the regulated PFAS in their Consumer Confidence Reports
- Systems must start issuing public notification for any monitoring and testing procedure violations
By the end of 2028:
- Systems that detect PFAS above the new standards must implement solutions that reduce PFAS in their drinking water to below the MCLs to remain in compliance with the rule
Starting in 2029:
- Systems must comply with all regulated PFAS MCLs
- Systems must provide public notification for violations of the PFAS MCLs
What treatment methods will remove PFAS?
- Granular activated carbon (GAC), ion exchange and reverse osmosis are the most common methods of removing PFAS from drinking water.
- Most conventional drinking water treatment methods will not remove PFAS.
- Powdered activated carbon (PAC) may remove some PFAS but testing is required to confirm.
- PFAS is not removed by boiling.
How do I deal with PFAS treatment residuals?
The EPA released an interim disposal guidance for PFAS media, backwash water, and RO concentrate. Their current recommended methods are:
- Underground injection
- Landfill
- Thermal treatment/incineration - this is the best option but isn’t widely available yet. Note that exhausted GAC media can be thermally regenerated for non potable use.
- Interim storage for high PFAS content materials.
Are there labs to do this testing? Is it expensive?
- Testing costs vary from lab to lab and typically range from about $300 to $600 per sample. Systems must use an approved test method (EPA 533 or EPA 537.1) Be aware that there are lower cost PFAS tests available and while these may be good for applications like testing a private well, they may not be acceptable for compliance purposes.
- Systems can sign up for CDPHE’s grant program for initial PFAS monitoring or reach out to cdphe_wqcd_pfas_grant@state.co.us.
- All labs on the EPA’s list of labs certified for PFAS testing are acceptable for compliance purposes.
Where can I find more information?
- CDPHE's Water Quality PFAS website
- EPA’s Water Quality PFAS Website
- CDPHE's PFAS testing results in public water systems in Colorado
➽ Chelsea Cotton, Lead Drinking Water Engineer
