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  • Writer's pictureMahika Weerasekare

Following Safe Drinking Water and Clean Water Rules - A Balancing Act

Updated: Aug 20, 2021

Overview-While the Safe Drinking Water Act (SDWA)protects public health and source water, the Clean Water Act (CWA) ensures the nation’s navigable waters are fishable and swimmable.

Phosphate is one example when the two acts are in conflict. Public Water systems use Phosphate in corrosion control as a mean to minimize lead exposure as required by the SDWA. At the same time CWA categorizes phosphate as a nutrient pollutant that help toxic algal blooms.

1. Safe Drinking Water Act

History of Safe Drinking water standards-

The first standards for safe drinking water in the US were established by the Public Health Service (USPHS) in 1914 to prevent spread of E. coli through interstate commerce.(1,2) Although the law was applicable only to interstate carriers like trains, over time many public water utilities chose to follow the regulations as a common industry standard. The following five decades saw the addition of more than twenty contaminants to the list required to be tested and monitored by interstate water suppliers.(3)

Although the expanded list included several chemicals including radioactive material, it was only in the late 1960s that the American public became aware of the environmental harm and consequential health risks that came with untreated industrial waste and farm waste polluting water ways. Especially alarming were the toxic man-made chemicals that were released into water systems.

The response to this crisis led to several studies evaluating the nature of the public water systems. Findings were disturbing. One study found only 60% of the public water supplies surveyed complied with federal drinking water guidelines (USPHS, 1969). Another found 36 chemicals in treated water in Louisiana that sourced water from the lower Mississippi river (Environmental Protection Agency (EPA), 1972). An Environmental Defense Fund study reported later, in 1974, attributed consumption of lower Mississippi river water contaminated with industrial waste and sewage to cancer deaths in New Orleans.(4) The enactment of the Federal Safe Drinking Water law was a result of these studies.

Safe Drinking Water Act (SDWA)(5)

The Safe Drinking Water Act is a federal law enacted in 1974, with major amendments in 1986,1996 and 2016, that protects public water supplies from harmful contaminants. While the SDWA is administered by the EPA, implementation and enforcement of the law is left to State Authorities. (Private wells that serve fewer than 25 people are not regulated by this law, but the owners are encouraged to test their water for possible contaminants).

How EPA implements SDWA

1. Set National Standards for Drinking Water Quality-

i. Identify contaminants (both naturally occurring and man-made) found in drinking water that would adversely affect public health.

ii. Regulate by specifying a maximum contaminant level allowed, delivered to any consumer in a public water system or by specifying a treatment method.

2. Preventing pollution through source water protection (including regulation of underground injection of brine or other fluids), water system operator training, funding infrastructure improvements, annual consumer confidence reports, and public information.

2. Clean Water Act

Keeping America’s rivers, lakes, wetlands, and costal water free of pollutants

The first law to control water pollution was the Federal Water Pollution Act of 1948.(6) While this law provided local and State governments technical assistance and funding from the Federal government to tackle pollution problems, it did not allow federal enforcement.(7) By the mid-20th century, unchecked industrial waste discharge and ill-equipped waste treatment facilities had made two thirds of the America’s waterways unsuitable for swimming or fishing.(8)

Turning point-A river on fire (9,10,11)

The Cuyahoga River in Cleveland, OH was one such river. In the summer of 1969, a spark from a passing train ignited pollutants on the river surface setting the river on fire. At least 13 fires have erupted in the river before, the first recorded in 1868 with a 1952 fire causing more than $1 million worth of damages to riverfront property and boats going unnoticed by the rest of the country with no call for action. While the 1969 fire did not cause much damage, the Time magazine’s report of the fire that called the Cuyahoga River, a river that “oozes rather than flow” and in which if a person fell “would not drown but decay” with an accompanying list of other polluted rivers caught the public’s attention. Coming soon after an oil rig leak off the Santa Barbra coast that spilled millions of gallons of oil, the public outrage that followed the fire and the cry to regulate water pollutants propelled the Congress to pass the Clean Water Act (CWA) and spurred the creation of the EPA. (The Cuyahoga River fire is considered an important turning point for a budding Environmental movement and a teach-in moment at the first Earth Day, April 22, 1970)

Clean Water Act (CWA)(12)

Clean Water Act is a federal law enacted in 1972 with major amendments in 1977 and 1987 to protect the quality of the nations surface waters by regulating water pollutants and their points of origin. The EPA was given the authority to implement pollution control programs.

CWA also allows “Citizen” enforcement of the rule, enabling individuals or groups to advocate for clean water in their communities.

How EPA implements CWA

1. Regulating industrial and municipal pollutant dischargers

i. Setting water quality standards for all contaminants in surface waters.

ii. Prohibiting the discharge of a pollutant from a point source into navigable waters unless a permit was obtained under the law’s provisions.

2. Providing federal financial assistance to construct municipal sewage treatment plants.

3. Amending the law in 1987 to address non-point source pollution (runoff from farmlands, forests, abandoned mines, construction sites, and urban areas), which is estimated to represent more than 50% of the remaining water pollution problems.

3. When the Safe Drinking Water Act and the Clean Water Act don’t agree- Corrosion Control and Nutrient pollution.

While the Safe Drinking Water Act calls for addition of phosphate as a corrosion control in lead service lines, Clean Water Act calls to limit phosphate release into waterways.

The EPA calls nutrient (Phosphorus and Nitrogen) pollution “one of America’s most widespread, costly, and challenging environmental problems”.(13) Overgrowth of toxic algae in our waterways is a result of nutrient pollution, affecting not only human and animal health but also the economy.(14) Adverse economic impact includes increasing cost of drinking water, commercial fishing and real estate losses as well as estimated $1 billion dollar losses in tourism industry.

Orthophosphate added to public water supplies as a corrosion control is identified as one such pollutant that threatens quality of surface water.

A solution from Denver Water Board (15)

In 2018, the Colorado Department of Public Health and Environment directed Denver Water to add orthophosphate to control lead corrosion to comply with the Safe Drinking Water Standards. At the same time toxic algae blooms had become a concern in the South Platt River, south of Denver.

Orthophosphate treatment is unpredictable and may still result in unexpected lead leaching, and once started orthophosphate treatment cannot be easily stopped.

Instead of adding Orthophosphate, Denver Water proposed full replacement of the lead service lines within 15 years. It would permanently remove the source of lead pollution while protecting surface waters from nutrient pollution. Until their service lines are replaced, Denver water will provide filters to reduce lead to those customers with known, suspected, or possible lead service lines. The plan was approved by the EPA in December 2019 and Denver Water started implementing the “Lead Reduction Program” in 2020.

As far back as 1991 when the EPA set limits to lead in drinking water, one of the remedial actions required utilities to replace 7% of the lead service lines each year or 14 years total for full service line replacement. But implementation has been slow, and some cities and utilities only replaced the portion of the lead pipe that runs from the water main to the property line of your house.(16)

Flint water crisis showed the only solution to lead contamination of drinking water is full replacement of lead service lines. More and more cities are now following Denver Water and are developing programs to replace both public and privately owned lead service lines and doing away with phosphate corrosion treatments, safeguarding both potable and surface water.

4. How You can help (17)

1. Apply lawn and garden chemicals sparingly.

2. Dispose of used oil, antifreeze, paints, and other household chemicals properly—not in storm sewers or drains.

3. Clean up spilled brake fluid, oil, grease, and antifreeze.

4. Purchase household detergents and cleaners that are low in phosphorous to reduce nutrient pollution of our surface waters.

5. Stop/reduce using salt for water softening. One teaspoon of salt can permanently pollute 5 gallons of water. (Roughly 65% of all salt passing through wastewater facilities, amounting to 136,000 tons of chloride annually, comes from residential and commercial water softening processes).(18)

About the Author

Dr. Mahika Weerasekare is a synthetic organic, and analytical chemist with over 20 years of work in research and development. Her experience ranges from small molecular drug development to biomaterial synthesis. Dr. Weerasekare became interested in water chemistry while developing synthetic biopolymers that mimic natural underwater glues for use as water-borne surgical adhesives.



1. The origin of federal drinking water quality standards Gurian and Tarr, Proceedings of the Institution of Civil Engineers ehh900009.3d 8/2/11 21:44:09

3. Unconventional Pollution Control Politics: The Reformation of the US Safe Drinking Water Act,2015, Zarkin, Michael, Electronic Green Journal, Issue 38, 2015, ISSN: 1076-7975

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