Safe Drinking Water Act Overview

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Since passage of the Safe Drinking Water Act (SDWA) in 1974, localities struggle to meet federal mandates that do not make sense in all drinking water systems. The U.S. Environmental Protection Agency (EPA) has based many of its rules on weak science, leading to needlessly onerous federal standards. As a result, localities are forced to spend limited resources on misguided federal priorities. Small systems are particularly hard hit, paying for standards that provide no verifiable benefits while diverting resources from legitimate needs (e.g., infrastructure upgrades and repairs, expansion of the water supply system). Unfortunately, 1996 amendments to the law failed to fix these fundamental flaws. Congress should focus on ways to give states and localities more power in setting priorities. After all, each locality has a better grasp of its particular needs and can better express preferences about how the community wants to expend limited resources.

The SDWA regulates about 54,000 existing public and private “public water systems.” These systems provide piped drinking water for 60 or more days a year to at least 25 individuals or to at least 15 service connections. Approximately 15 million Americans draw water from unregulated “nonpublic water systems,” such as private wells.

The EPA regulates more than 80 drinking water contaminants that might be found in the water of public water systems. For each regulated contaminant, the EPA usually specifies a maximum contaminant level goal (MCLG), which represents the level of a contaminant that the EPA ideally wants to allow in drinking water. The EPA uses the MCLG as a guide in setting the enforceable standard, the maximum contaminant level (MCL). The MCL represents the amount of that contaminant that systems may legally allow in tap water. For example, the EPA allows systems to provide only drinking water that contains no more than 0.005 milligrams of benzene per liter of water. When the EPA determines that it is technically or economically infeasible to monitor for a contaminant, it is directed by Congress to promulgate mandatory “treatment techniques,” such as mandatory installation of filtration devices.