Currently, there are no federal regulations (i.e. Maximum Contaminant Levels (MCLs)) for PFAS in drinking water. However, in 2016 the U.S. Environmental Protection Agency (EPA) issued a Health Advisory Level (HAL) of 70 parts per trillion (ppt) for the sum of PFOA and PFOS concentrations in drinking water. While not an enforceable regulatory standard, the EPA HAL does provide drinking water customers, even the most sensitive populations, with a margin of protection from lifetime exposure to PFOA and PFOS in drinking water.
In 2020, MDE started sampling 129 public water treatment systems for PFAS. The highest measured levels of PFOA and PFOS (i.e. those greater than EPA’s HAL of 70 ppt) were found in water treatment systems serving the City of Westminster and the Town of Hampstead. When initial sample results from these systems measured levels greater than EPA’s health advisory level, MDE worked with both water systems to take actions including: immediately taking the affected water treatment plants offline while needed confirmation samples were collected; collecting additional groundwater and finished water samples; and issuing public notices. The systems have continued to keep the affected plants or wells off-line until a proper treatment plan is in place.
That initial phase of drinking water sampling was completed and a report was issued in July 2021. For the second phase of sampling, drinking water systems were selected based on: consumer potential for long term exposure to PFAS, if present; source water vulnerabilities; interest by MDE in determining whether groundwater from confined aquifers are less likely to be impacted by PFAS; and proximity to potential PFAS sources. The report on that second phase describes the results of sampling of 65 public water systems across the state. Results for these two phases of sampling can be found in the "Additional Information" section at the end of this webpage.
Sampling for the third phase of MDE efforts to sample public water systems for PFAS began in August 2021 and is expected to continue through late spring 2022. MDE will address any elevated PFAS levels that are detected and produce a report on these results as well.
In June 2022, the EPA announced new drinking water health advisories for PFAS chemicals and that it is inviting states and territories to apply for $1 billion – the first of $5 billion in Bipartisan Infrastructure Law grant funding – to address PFAS and other emerging contaminants in drinking water, specifically in small or disadvantaged communities.
In recent years, as the risk posed by exposure to PFAS has emerged and evolved as a national concern, the Maryland Department of the Environment has placed a priority on understanding, reducing and communicating that risk. The department has done this through sampling and assessment, applying updated science and working in partnership with other agencies and local governments. This includes sampling at more than 450 community water systems, serving nearly 90% of Maryland’s population. Where high concentrations of PFAS have been found, MDE has worked with systems to find alternate sources of water. MDE is prepared to use the PFAS-specific funding under the Bipartisan Infrastructure Law to reduce the risk of exposure. MDE is also examining the best course for Maryland to take in the future regulation of these chemicals, including the possibility of proceeding ahead of the EPA in establishing an enforceable Maximum Contaminant Level for PFAS in drinking water. All of this positions Maryland well for continued progress in protecting our citizens and communities. The interim health advisory announced by EPA, which for PFOA and PFOS are below detectable limits, raises technical challenges that we hope will be resolved with upcoming regulations that will account for feasibility, costs and benefits. MDE will work with the water supply system operators in Maryland to provide guidance in making the best use of this interim health advisory.
In addition to conducting additional drinking water sampling, MDE continues to carefully monitor the EPA’s work with regard to PFAS in drinking water. As additional information is published, such as MCLs and toxicity assessments, MDE will take additional actions to reduce unacceptable human health risks with respect to PFAS. The Maryland Department of Health, out of an abundance of caution, has issued a
health advisory for a specific PFAS, Perfluorohexane Sulfonic Acid (PFHxS), in drinking water in concentrations at or above 140 parts per trillion.
MDE also has information for local health officers and Marylanders who rely on private wells, including
general information on PFAS in private drinking water supplies, a
capable of testing PFAS in drinking water and
guidance on interpreting PFAS test results.