Both the Isle of Palms City Council and the Sullivan’s Island Town Council have received a letter from Charleston Water System (CWS) outlining the financial impacts of new federal regulations to limit PFAS, or “forever chemicals,” in water systems. The U.S. Environmental Protection Agency (EPA) has introduced stricter standards for PFAS levels in drinking water, which will significantly increase water rates for CWS customers and others nationwide.
Per- and polyfluoroalkyl substances (PFAS) are a class of more than 14,000 chemical compounds that persist in the human body and are associated with adverse health effects, making them a global health concern.
As of November 2024, Charleston Water System reports concentrations of two common PFAS subtypes, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), at 4.1 and 6.5 parts per trillion (ppt), respectively. While these levels indicate minimal PFAS presence in its water system, they slightly exceed the EPA’s newly established standard of 4 ppt for both PFOA and PFOS. To comply with the regulations, CWS anticipates $155 million in infrastructure upgrades as part of its 2027 capital improvement plan, along with $24 million annually for operation and maintenance costs. These expenses will ultimately be passed on to customers, including Sullivan’s Island and Isle of Palms residents, through higher water rates.
The EPA’s new 4 ppt regulation for PFOA and PFOS in drinking water is among the world’s strictest. By comparison, the European Union’s primary drinking water law limits 20 PFAS types to a combined 100 ppt, while individual countries such as Denmark (2 ppt), Sweden (4 ppt), Germany (20 ppt by 2028), and the UK (100 ppt) have adopted varying limits.
Thanks to contractual agreements, Sullivan’s Island is in a relatively favorable position compared to other municipalities served by CWS. Under these agreements, the town is only responsible for capital improvements directly benefiting its residents. Currently, Sullivan’s Island accounts for approximately 0.07% of CWS capacity, limiting its share of the projected $155 million in upgrades.
“We’re in a better position than a lot of other municipalities because we have that language in our agreement,” said Justin Novak, Sullivan’s Island mayor pro tempore. “We would be at most responsible for 0.07% of that infrastructure improvement.”
CWS projects four consecutive years of 12.25% rate increases starting in 2026, resulting in a cumulative 59% increase by 2029. Of this, 33% is tied to compliance with the PFAS regulations, translating to an additional $14.46 per month for the average residential customer by 2029.
“This could be the most expensive drinking water regulation ever implemented by the EPA,” said Mark Cline, CEO of Charleston Water System. “[The PFAS rule] will lead to unprecedented rate hikes.”
While Cline acknowledged the importance of protecting public health, he noted that drinking water is only one of many PFAS exposure sources. He cited a 2022 Yale School of Public Health study that found PFAS levels in household dust at 300,000 ppt—75,000 times higher than the new EPA drinking water standard.
Cline also cautioned that the $155 million estimate might be conservative, given inflation and the high demand for engineering and construction resources required to address PFAS contamination nationwide.
Public water systems have until 2027 to complete initial compliance monitoring and must meet the new maximum contaminant levels (MCLs) by 2029. The EPA estimates that 6% to 10% of the nation’s 66,000 water systems will need to take action to comply with the stricter standards.
The incoming Trump administration may consider pausing or modifying the PFAS regulations. However, until any changes are formalized, CWS and other utilities must proceed with compliance planning.