The United States Environmental Protection Agency, on March 14, announced new proposed limits for six different per- and polyfluoroalkyl substances (PFAS) in drinking water. The proposed limits target six different PFAS – PFOS, PFOA, PFBS, GenX, PFHxS and PFNA.
The EPA has proposed maximum contaminant levels (MCLs) for two of the most notorious PFAS – PFOA and PFAS. MCLs are the maximum amount of contaminants the EPA allows in drinking water. The EPA considers feasibility, the cost of water treatment, and health into consideration when proposing MCLS.
The EPA proposed enforceable MCLs of 4 parts per trillion (ppt) for PFOA and PFOS. This is the current detection limit for each chemical.
The EPA also proposed that PFBS, GenX, PFHxS and PFNA be limited in drinking water using an approach known as a hazard index. This approach would determine if combined levels of these PFAS in drinking water pose a risk.
The EPA is requesting comments from the public regarding the proposed limits. The EPA is anticipating that the rule will be finalized by 2023’s end.
What Is A Hazard Index?
A hazard index evaluates the health-related risks of exposure to several related chemicals which are mixed together.
The EPA is proposing that PFBS, GenX, PHFxS and PFNA be limited in drinking water using the hazard index approach because:
- They have known toxic effects
- They have additive toxic effects
- They occur in drinking water
- They likely co-occur in drinking water
The EPA proposes an enforceable hazard index limit of 1.0 for these PFAS and any mixture that contains one or more of these PFAS, as this represents a level where no anticipated or known adverse health effects are expected to happen, and a level which provides an adequate safety margin.
Water systems, in order to measure the hazard index of these PFAS, would monitor the amount of these PFAS in their drinking water, comparing it to the level where no effects on health are expected regarding that PFAS. Comparison values for these PFAS would be added together by water systems. If the value for all of the PFAS in a mixture exceeds 1.0, it would exceed the hazard index limit proposed by the EPA.
The EPA’s intention is to provide water systems with forms that are web-based and will automatically calculate hazard indexes.
What Else Is The EPA Proposing?
The EPA has also proposed the following:
- PFAS monitoring: The EPA proposed monitoring requirements regarding PFOS, PFOA, PFBS, GenX, PFHxS and PFNA in drinking water. These requirement build upon the agency’s previous monitoring frameworks. The frequency of monitoring depends on prior results under these frameworks. The EPA has also proposed flexibilities which allow water systems to utilize data which has been collected previously to satisfy initial requirements regarding monitoring.
- Notification of the public: The EPA proposed requiring public water systems to notify the public when levels of PFAS exceeding the new proposed limits are detected by monitoring.
- Water treatment: The EPA proposed requiring public water systems to take steps to reduce PFAS levels in drinking water when levels exceed the proposed limits. This may include removing PFAS through treatment. This may also include switching to a different water supply that complies with the limits.
Why Is The EPA Proposing These Limits?
The EPA is proposing these limits because exposure to these PFAS may cause negative effects on human health, especially when exposure happens over a long period of time, during pregnancy, as well as in babies who are developing.
PFAS are manufactured chemicals. They have seen use in consumer products and industry for over 70 years. Their characteristics mean they are useful in many products, such as waterproof clothing, nonstick cookware and firefighting foam.
Human exposure to PFAS can happen in numerous ways. Many people see a significant part of their exposure to PFAS come from drinking water when that water has PFAS contamination.
There are many sources of PFAS which enter the environment. PFAS usually break down extremely slowly in the environment. Because of this, PFAS often end up in water sources which are used for drinking water. Reducing the amount of PFAS in drinking water reduces the health risks associated with PFAS.
Because PFAS break down very slowly, they can accumulate in the environment, as well as in people and animals. Being exposed to the PFAS which the EPA is proposing drinking water limits for can increase one’s risk of experiencing numerous effects on health, including:
- An increased risk of cancer, including an increased risk of testicular and kidney cancers
- Damage to the liver
- An increase in levels of cholesterol
- Interference with human hormones, such as thyroid hormones
- A reduction in the body’s ability to fight infection via the immune system
- A reduction in the effectiveness of vaccines
- Developmental delays or effects in kids, including behavioral changes, bone variations and low birth weight
- Reproductive effects like increased blood pressure in those who are pregnant
How Can People Be Exposed To PFAS?
Many people are exposed to PFAS through drinking water. Environmental Working Group has estimated that 110 million Americans’ drinking water is contaminated with PFAS.
Sources of PFAS contamination include:
- Military bases
- Manufacturing plants
- Wastewater treatment plants
Drinking water in communities near these places can be contaminated by PFAS because PFAS can end up in drinking water a long distance from their source since they break down so slowly.
Many communities near manufacturing plants which manufacture products containing PFAS have seen their drinking water contaminated by PFAS. Many communities near military bases have also seen their drinking water contaminated by PFAS.
Military bases are a common source of PFAS contamination because of the use of AFFF firefighting foam on military bases. AFFF firefighting foam contains PFAS, including PFOS and PFOA.
Firefighters and military personnel can also be exposed to AFFF firefighting foam directly during the course of their job. This is a source of PFAS exposure which is in addition to exposure through drinking water.
AFFF firefighting foam is also commonly used at airports, so communities near airports may see their drinking water contaminated with PFAS.
Additional sources of PFAS exposure include:
- Products like nonstick cookware, stain-resistant carpeting and water-repellant clothing
- Food which is packaged in material that contains PFAS
- Accidentally swallowing soil or dust that contains PFAS
- Eating fish sourced from water contaminated with PFAS
- Stain-resistant fabrics such as upholstery
- Varnishes, sealants and paints
- Personal care products like eye makeup, nail polish, dental floss and shampoo
- Cleaning products