How contaminants in drinking water are regulated by the EPA and states

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How contaminants in drinking water are regulated by the EPA and states

Everyone should have clean drinking water. But millions of Americans are exposed to harmful contaminants in their tap water.

Despite decades of federal regulations, much work remains to be done to protect public health. Just because a contaminant is considered “legal” by federal standards doesn’t mean it’s as safe for drinking as it should be.

EWG has crafted health-based standards that focus solely on what’s safe for public health in light of the most recent science. In contrast, federal standards must consider cost and feasibility and are rarely updated. For over 20 years, EWG’s no-compromise approach has worked to protect families from exposure to harmful substances in water and to hold polluters accountable.

The Environmental Protection Agency has fallen behind in ensuring safe drinking water for all Americans. EWG steps into the gap by advocating for safe, clean water guided by standards that put public health first.

Gaps in federal regulation

The Safe Drinking Water Act, enacted in 1974 and weakened by amendments in 1996, regulates drinking water supplies. Its intent is to protect the public health of all Americans. But the EPA currently regulates only about 90 contaminants out of the 324 substances detected in U.S. tap water.

Further, many of the regulations that the EPA has issued under the law are outdated, with some last updated in the 1990s. Millions of Americans are left vulnerable to unsafe levels of chemicals in their drinking water.

Most community water systems meet the EPA’s legal standards. But these standards do not guarantee safety, as health harms can occur even at those levels. This disparity is particularly problematic when it comes to emerging contaminants, some of which have been linked to serious health issues, such as cancer, brain and nervous system damage, fertility problems and hormone disruption.

The EPA approach to guidelines

Regulating contaminants in drinking water begins with identifying chemicals, heavy metals and microbes that may pose health risks.

The EPA keeps a Contaminant Candidate List of substances that may need regulation. Experts review it then determine whether a contaminant poses enough of a public health risk to warrant legal limits. If so, the EPA can set a maximum contaminant level, or MCL, which is the highest allowable concentration of a contaminant in drinking water.

But this process has often been very slow and reactive.

In particular, the agency dragged its feet on regulating the toxic “forever chemicals” known as PFAS, which have contaminated drinking water for hundreds of millions of Americans and are linked to serious health risks. The EPA took over 20 years to finalize MCLs for six PFAS compounds. To date, these are the only chemicals for which the EPA has set new limits through the process outlined in the 1996 amendments to the Safe Drinking Water Act.

When the EPA finally did set MCLs, it set them at very low levels, making them among the most health-protective drinking water standards for PFAS in the world.

But these limits are now under threat. The chemical industry and water utilities have filed lawsuits to weaken or delay these regulations. They argue that the costs of implementation are too high – but this ignores the full health benefits of the limits, including reducing cancer and cardiovascular diseases.

What are maximum contaminant levels?

The process of establishing MCLs is essential but slow. The EPA has only set one new MCL for hazardous chemicals in the last 25 years.

But even when regulations exist, there are limitations.

In many cases, the EPA doesn’t update the rules to keep up with emerging science or the realities of public health risks. The agency must conduct a cost-benefit analysis before finalizing regulations, and it is much easier to calculate costs than public health benefits. The cost of implementing and complying with these regulations can also pose a significant burden, particularly for smaller water systems. These financial concerns can influence regulatory decisions, at the expense of public health.

What is the Unregulated Contaminant Monitoring Rule?

One key tool the EPA uses to monitor contaminants is the Unregulated Contaminant Monitoring Rule, or UCMR. This program helps the agency identify and track emerging contaminants, which haven’t yet been regulated. The program is crucial for tracking...