Collectively titled the 2023 Safe Drinking Water Act, N.C. Senate Bill 350 and House Bill 610 were filed on March 22 and April 13, respectively.
If passed, they would mandate that the North Carolina Commission for Public Health must establish maximum contaminant levels (MCLs) for chemicals in drinking water that are probable or known carcinogens or are otherwise toxic.
MCLs are enforceable standards that define the highest concentration of a contaminant allowed in drinking water so there is no known risk to public health. They are determined based on public health risks and cost-benefit analysis.
Some of the contaminants specifically targeted in the bills are per- and poly-fluoroalkyl substances (PFAS), chromium-6 and 1,4-dioxane.
PFAS, which include thousands of synthetic chemicals, are a byproduct of commercial and industrial manufacturing and processing. Known as "forever chemicals," they do not break down in water and remain in the environment. They contaminate soil and water, accumulating in fish and wildlife.
According to the Environmental Protection Agency, PFAS can cause reproductive harm, immune system damage and increased risk of several cancers.
Chromium-6 is considered a carcinogen and can cause allergic dermatitis with extended contact.
While trace amounts of chromium occur naturally in water sources, additional chromium has been released into the environment due to poor industrial waste disposal practices, according to the EPA.
Dioxane is also a synthetic industrial chemical that has been identified in groundwater sources. The EPA has classified dioxane as a likely human carcinogen. However, there is not much research available to support this point, said Jamie DeWitt, a professor of pharmacology and toxicology at East Carolina University.