The Safe Drinking Water Act Protects Public Health for 50 Years

The Environmental Protection Agency (EPA) administers the SDWA through science-based regulations, setting clear and strict standards for water utilities and systems with more than 25 customers or 15 service connections. The water sector continues to work diligently to carry out the SDWA mandate to keep America's water safe and reliable.

Here, we'll examine the SDWA's origins, key amendments, how the legislation drives standards, and the work professionals like water lab managers do to support it.

Safe Drinking Water Act Origins

Between 1961 and 1970, more than 46,000 cases of waterborne illnesses—like hepatitis, salmonellosis, and gastroenteritis—were documented in the United States. In a 1970 study, 90% of drinking water systems exceeded permissible microbial levels. Four years later, an Environmental Defense Fund report linked cancer deaths in New Orleans to contaminated drinking water from the Mississippi River. The leading causes of water quality issues were poor operating procedures, inadequate facilities, and inconsistent management.

Senator Warren Magnuson (D-WA) proposed the SDWA in January 1973 to achieve five goals:

1. Establish national drinking water standards for contaminants
2. Protect public water resources from contamination
3. Promote compliance with water system standards
4. Control the underground injection of fluids
5. Finance drinking water infrastructure projects

The SDWA focuses on all waters that are either designed for drinking use or have the potential to be, including surface and groundwater. The law gives EPA the authority to set national standards for naturally occurring and manmade contaminants in drinking water. The EPA also works with states, local authorities, and water suppliers to ensure compliance.

Primary standards address adverse health effects and consist of unenforceable maximum contaminant level goals (MCLGs), the maximum concentrations below which no adverse human health effects are known to exist. The enforceable maximum contaminant levels (MCLs) represent an upper limit on the allowed concentrations of regulated contaminants.

With smaller utilities in mind, the SDWA also required EPA to promulgate interim national primary drinking water standards that protect health but take cost into consideration. To attempt to limit the financial burden on municipal water systems, the SDWA has periodically made federal funds available for technology upgrades and infrastructure improvements.

Evolving Standards

Over the years, Congress has amended the SDWA several times to address various risks to delivering clean drinking water, from terrorist threats to lead in pipes:

• 1986: Congress amended the SDWA to protect underground sources of drinking water. The amendment also banned the use of lead pipes, lead solder, and flux in new potable water plumbing. The EPA was charged with regulating 83 contaminants in drinking water within three years.
• 2005: This amendment was aimed at potential terrorist threats and enhanced security measures to safeguard the nation's drinking water infrastructure.
• 2011: The Reduction of Lead in Drinking Water Act redefined "lead free" to lower the allowable maximum lead content in plumbing components.
• 2016: The Water Infrastructure Improvements for the Nation Act renewed the focus on reducing lead exposure through enhanced public notice and attention to lead in schools and childcare facilities, along with emphasizing funding for disadvantaged communities.
• 2018: America's Water Infrastructure Act of 2018 amended SDWA to require community water systems to assess and prepare response plans for both natural hazards and malevolent threats.

Next Steps

The EPA's standard setting started slowly but then accelerated—so much that by 1996, Congress had to slow the number of contaminants added to the books at the request of water suppliers and environmental groups. Since then, SDWA has kept up with changing times and evolving science as public water systems work to comply with existing standards. The EPA continues work to make water safer for consumers:

• On April 10, 2024, the EPA finalized a rule setting MCLs for certain forever chemicals—the per- and polyfluoroalkyl (PFAS) in drinking water—and will require water systems to monitor and comply with the limits.
• In May 2024, the EPA announced a final rule on Consumer Confidence Reports that upgrades the annual drinking water information provided and requires more frequent reporting for larger water systems.
• Following the Flint water crisis, the EPA revised the Lead and Copper Rule in 2021 and is considering further updates.

Every six years, the EPA evaluates existing national primary drinking water regulations and the need for new data, information, and technologies. As new contaminants are identified, the EPA will likely focus on developing standards for these emerging chemicals while addressing the need for funding to support compliance with stricter regulations.

The SDWA has helped ensure most Americans can turn on their drinking water taps without second-guessing its quality. This requires the help of water labs to test for contaminants and ensure state and local authorities and utilities comply with EPA standards.