PFAS in Drinking Water
In every part of the world, people depend on clean water to survive. Residents often take it for granted that they can use water from the faucet for drinking or cooking without further treatment. However, water contamination is a severe concern for municipal water systems. Extended boil water orders and stories of lead contamination raise worries about the safety of the supply.
The EPA has established safe levels of many common contaminants in drinking water. These standards provide water treatment centers with measures of their effectiveness. However, there is a class of chemicals for which there is no such guidance. Polyfluoroalkyl substances are ubiquitous chemicals that pose health concerns.
What are PFAS?
PFAS are a type of chemical that has been in production since the 1940s. As a chemical family, they resist substances such as oil, water, and grease. These compounds are often resistant to heat as well. Because of these properties, consumers can find PFAS in nonstick cookware, stain-resistant fabrics, and household paints. Airports and petroleum industry sites also use PFAS-based fire-extinguishing foams.
The stability that makes PFAS effective is also problematic. The carbon-fluoride chemical bond is powerful, so these compounds do not break down under normal conditions. They can accumulate in the soil, water, air, and the human body. Scientists refer to them as “forever chemicals.”
The Origins of PFAS Water Contamination
PFAS water testing reveals that these compounds are a common contaminant. Because of their stability, PFAS released during industrial processes tend to make their way into the water supply. When an airbase sprays foam to put out a fire, the ground absorbs the chemicals. From there, they can leach into nearby water sources.
The Risks of PFAS Chemicals in Water
When people consume PFAS in drinking water, the chemicals accumulate in different parts of the body. At high enough levels, these compounds have been linked to several medical disorders.
The body handles toxins in two major ways. The liver breaks troubling chemicals into simpler compounds that the body can dispose of as waste. However, the stable nature of PFAS makes them difficult to process. In sufficient amounts, they can cause liver damage.
Fat deposits throughout the body store unprocessed toxins. This storage may be responsible for the link between PFAS and several different types of cancer and immune system issues.
Effective PFAS Water Testing and Removal
The federal government has become more aware of the danger of PFAS water contamination. Both the EPA and FDA have offered guidance to limit their use and exposure in the general population. However, water testing has shown that PFAS are present in the majority of municipal water systems. While there are efforts to reduce the amount of the compounds going into the water supply, water treatment plants must look at ways to remove the chemicals already present.
In reverse osmosis, a water stream travels under pressure through one or more membranes. Tiny pores allow pure water to pass while diverting impurities like PFAS. The water treatment plant can then send the concentrated reject stream to a facility to break down the compounds.
Reverse osmosis is a powerful tool in purifying the water supply. However, it is also an energy-draining and expensive process. Pressurizing water to force it through the membrane takes a great deal of power.
Activated Charcoal Filters
Charcoal filters are a standard solution to PFAS contaminants. The charcoal serves as an adsorptive surface that captures impurities, drawing them out of the water. The filters require careful monitoring and periodic replacement because they have a limited useable life.
Using SCADA Technology to Address PFAS Chemicals in Water
SCADA technology will increase the efficiency and functionality of wastewater treatment. Water quality sensors can take measurements before and after treatment to monitor the efficacy of the intervention. Empowered by real-time data, the treatment plant can receive alerts when it is time to change a PFAS-removing membrane or filter, maintaining consistent water quality.