The Safe Drinking Water Act (SDWA) sets the parameters for determining which contaminants need to be monitored. Under the SDWA, the U.S. Environmental Protection Agency (EPA) regulates more than 90 contaminants that have been assigned either an action level or a treatment technique.
Unregulated contaminants are not held to the same rigorous monitoring requirements. When one of these contaminants is detected, the amount of guidance available to municipal water systems and the public varies immensely.
PFCs in the Water Supply
Most recently, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), both perfluorinated chemicals (PFCs), were detected in drinking water in New York, New Jersey, Alabama and Colorado. These chemicals are unregulated contaminants. Research shows continued exposure to low levels of PFOA and PFOS in drinking water may result in adverse health effects, including developmental impacts to fetuses or breast-fed infants, and effects on the immune system and thyroid.
PFOA and PFOS are manmade. In the past, they were used in various applications such as waterproof materials, paper packaging, fabrics, grease- and stain-resistant products, and firefighting foam. By 2002, PFOS was voluntarily phased out in the U.S., and in 2008, multiple companies agreed to phase out their production of PFOA. However, these chemicals are still lingering in the environment. EPA and the Agency for Toxic Substances and Disease Register have found PFOA and PFOS in human blood samples nationwide, indicating exposure is widespread.
One method of exposure to PFOA or PFOS is through contaminated water supplies. The source of contamination often can be tracked to a local facility—for example, a factory that utilized these chemicals in a manufacturing process or an airport that used foam-based fire suppressants to practice emergency response procedures. EPA now has taken steps to provide guidance on these chemicals.
Lifetime Health Advisory
Health advisories offer information on contaminants EPA has found to cause human health effects and may appear in drinking water. This is a way the agency can provide guidance on contaminants not otherwise regulated. EPA advisories are non-enforceable and non-regulatory; instead they offer technical support for state agencies and public health officials on potential health effects, detection methods and treatment options. The information is gathered from peer-reviewed studies, and health advisory levels are calculated to offer protection against health effects to sensitive populations.
EPA’s first health advisory for PFOA and PFOS was published in 2009. Upon further research, in May 2016, the agency established a lifetime health advisory and supporting documents for these contaminants. The lifetime health advisory level was set at 0.07 ppb. EPA’s fact sheet on the new health advisory also outlines recommended actions for drinking water systems if PFOA and PFOS are detected above a combined total of 0.07 ppb.
Collecting Occurrence Data
Under the Unregulated Contamination Monitoring Rule (UCMR), EPA is able to collect data on unregulated contaminants. Once every five years, the agency is required to develop a list of no more than 30 unregulated contaminants for selected public water systems to monitor. This supplies occurrence data and exposure information that can be used to decide if further regulations on specific contaminants are needed. The last UCMR program collected results from 2013 to 2015 and consisted of two viruses and 28 chemicals, including PFOA and PFOS.
The information gathered through this program contributes to research and helps protect the environment and public health. The reported data on the identified contaminants enable EPA and other interested parties to map occurrence and examine estimated levels of exposure. This influences future water treatment decisions and potential regulations at the local and federal levels.
Product Certification
Once a water contamination public notice is released, regulators and consumers may wonder what treatment options are available. In 2008, the Minnesota Department of Health worked with the Water Quality Assn. on a case study that looked at treatment options for PFOA and PFOS. Testing was done with point-of-use water treatment devices and demonstrated that activated carbon and reverse osmosis were effective at reducing both chemicals.
The water treatment industry continues to evolve with new research and it is passionate about providing technologies to address contaminants. Now, NSF/ANSI Standard 401 offers a recognized standard for emerging compounds and incidental contaminants. This includes filters designed to address pharmaceuticals, personal care products and endocrine-disrupting compounds. This is a prime example of the industry addressing unregulated contaminants and investing in the improvement of water quality.