You may have recently seen news coverage of a family of man-made chemicals that are showing up in groundwater in Southern California. These are known as perfluoroalkyl and polyfluoroalkyl substances, or PFAS for short. There are over 4700 related chemicals in this family, and they have been around since the 1940s. PFAS chemicals are widely used to repel water, oil, grease, and stains. They are also used in firefighting foam, food wrappers, cosmetics, carpet and upholstery fabrics, and water-resistant clothing.
Why are PFAS a concern, and why are we hearing about them now?
PFAS are a concern because they are likely a carcinogen at some levels and do not break down naturally, this is why PFAS are sometimes referred to as “forever chemicals.” PFAS are in the news now because recent developments in detection technology allow identification of PFAS at levels of fewer than five parts per Trillion. A part per trillion is equivalent to a grain of sand in an Olympic size swimming pool. We know that, at some level, PFAS chemicals are bad for us, and now we are learning how widespread the family of chemicals is in the environment.
Testing for PFAS chemicals is very complex now that we have the technology to detect such minute levels. The person taking the samples must be very careful and cannot wear new clothing, not to protect them from the sample, but so that they do not contaminate the sample. The equipment used in the sample collection must be sterile and maintained as sterile while the collection is made and the sample transported to the laboratory. The analysis of the sample must be done in a specialized laboratory with strict clean room measures in place.
Where are PFAS chemicals found?
PFAS chemicals are concentrated near places where they are manufactured, where firefighting foam is regularly used, like airports and military bases, and where they are used in manufacturing processes. Because PFAS chemicals are used in so many common products, they can be found in almost every American household and in the bodies of almost every American.
PFAS chemicals have made their way into the underground aquifers in many areas and are commonly found in sewage effluent and, therefore, in the treated wastewater coming from sewage treatment plants. In Southern California, much of the treated wastewater is used to replenish local aquifers; this means PFAS may be in the water pumped to supply our domestic water needs. Stormwater runoff may also contain PFAS chemicals and is used to replenish aquifers from which domestic water supplies are pumped.
How do PFAS chemicals get into our bodies?
PFAS chemicals may be absorbed by both plant and animal life, so they are often in our food. They may be in liquids we drink (including water). We can absorb PFAS chemicals through our skin from clothes, carpet, upholstery, nonstick cookware, food wrappers, and cosmetics. Because PFAS are all around us, most have at least some in our bodies.
What is being done to remove PFAS from the environment?
PFAS Chemicals can be removed from water using a variety of technologies, including reverse osmosis, activated charcoal filters, and ion exchange filters. In each case, the technology concentrates PFAS chemicals in the filter medium, and that must then be treated or safely disposed of. Work on ways to break down PFAS chemicals is underway. High heat is one way we know of now.
The Federal EPA is looking at regulations to control the maximum level of PFAS chemicals in drinking water and will adopt regulations soon. The Federal Government is also looking at regulations to control the importation and use of PFAS chemicals and to develop alternative means to achieve the benefits of PFAS chemicals.
In California, the Division of Drinking Water has set reporting requirements for the presence of the most common PFAS chemicals. The levels are 5.1 parts per trillion for perfluorooctanoic acid (PFOA) and 6.5 parts per trillion for perfluorooctanesulfonic acid (PFOS). Local agencies like a city or county must be notified if regularly required testing detects these contamination levels. As of 2020, water agencies like Riverside Public Utilities and Western Municipal Water District are expected to remediate levels of PFOA at ten parts per Trillion and PFOS at 40 parts per Trillion. This can be accomplished by no longer using the source that exceeds the limits, by treating to remove the contaminants, or by blending with other water to lower the level to below the threshold.
Our local water providers (RPU and Western Water) regularly monitor the level of PFAS chemicals and other contaminants and take appropriate steps to ensure the water served to customers meets all regulatory requirements. Every water utility in California publishes an annual report on the quality of the water they serve. These are mailed to customers and are available on each provider’s website.
Looking to the future, federal and state regulators are developing revised standards for drinking water, and local water providers are working on ways to remove PFAS chemicals from both treated wastewater and water pumped for domestic use.
Cleanup is expensive, and I anticipate cooperation among water providers to develop regional solutions that will avoid duplication of effort and save the customers of each provider unnecessary expense. In Riverside, Western Water and RPU meet regularly to work on mutually beneficial projects and technologies. The two utilities have multiple interconnections and can provide water to each other when needed.