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Safe Drinking Water Act (SDWA) – Drinking Water Regulations

safe drinking water act
Written by Warner Levit

In 1974, the US Congress enacted the first Safe Drinking Water Act (SDWA). The responsibility to set the national health standards for drinking water was given to the United States Environmental Protection Agency (EPA).

The US government strived to improve the SDWA through revisits and amendments in 1986 and 1996. In the sections that follow, we will be discussing the important points of the SDWA 1996 amendment and its effects on the quality of America’s drinking water supply:

Safe Drinking Water Act (SDWA) Standards and Regulations

SDWA Standards and Regulations

1. National Primary Drinking Water Regulations

The National Primary Drinking Water Regulations (NPDWR) establishes the regulations that public water systems must follow. This regulation contains specific information on harmful contaminants found in water, their sources, acceptable levels, and the desired levels.

EPA defines contaminants as any physical, chemical, biological or radiological substance or matter in water. They conduct thorough studies to determine how much of these substances and contaminants can be present in the water without it causing health problems.

The Maximum Contaminant Level (MCL) defines the legally acceptable limit of substances allowed in the public water system. Any establishment whose contaminants in the drinking water supply exceed the MCL shall be answerable to the law.

Then, there are the desired levels, or technically termed as Maximum Contaminant Level Goals (MCLG). These are ideal standards of contaminant levels in the water. These are legally unenforceable limits but MCL strives to measure its standards as close to that of MCLG as possible.

2. National Secondary Drinking Water Regulations

The National Secondary Drinking Water Regulations (NSDWR) are additional sets of standards to assist the public water system in managing water problems such as:

  • Aesthetic effect – Different color, smell, and/ or taste of water
  • Cosmetic effect – Ingestion of contaminants that can cause skin discoloration
  • Technical effect – Staining of fixtures due to corrosion, scaling, and sedimentation of pipes.

Although federal regulations do not make it mandatory, public water systems and state health agencies still monitor and treat their water supply from unwanted contaminants. Some of the conventional water treatment techniques used are coagulation and water filtration, aeration, and ozonation.

Expensive and non-conventional treatments include reverse osmosis, distillation, and electrodialysis which are used for removing chloride.

3. Unregulated Contaminants

Unregulated Contaminants are chemicals and substances present in water but are not yet included in the health-based standard set in the SDWA.

The EPA conducts a five-year periodical review of contaminants from the Contaminant Candidate List (CCL). The CCL is a list of contaminants that already are or can potentially be present in the drinking water. To ensure uninterrupted access to safe drinking water, the EPA continuously gathers data and carries out further research to determine the potential health effects that contaminants may pose to humans and their occurrence in the drinking water.

To do this, the EPA uses the Unregulated Contaminant Monitoring Rule (UCMR). The UCMR4 requires monitoring of 30 contaminants between 2018 and 2020 to include pesticides, alcohol, semi-volatiles, cyanotoxins, halo-acetic acid groups, and disinfectant by-products.

4. Bottled Water Regulations

Bottled water refers to water that is sealed in a container with the intent to be sold for human consumption. The Federal Food, Drug, and Cosmetic Act (FD & C Act) of the U.S. Food and Drug Administration (FDA) governs the standard and quality of bottled water, specifically providing the following regulations:

  • Standard of identity – define the different types of bottled water based on its origin.
  • Standard of quality – sets the maximum levels of contaminants.
  • Current good manufacturing practices – require that bottled water be manufactured in safe and sanitary conditions.

FDA follows the standards that EPA sets on contaminants. They adopt these standards only when they find it applicable to drinking water. The FD & C Act ensures that the quality standards for bottled water are aligned with the standards on tap water set by EPA.

Note that beverages that are labeled “sparkling water”, “soda water”, “tonic water”, etc. are not considered bottled water, instead, are classified as soft drinks.

5. Consumer Confidence Reports

Consumer Confidence Reports (CCR) contain information on the quality of the local drinking water provided to consumers. This annual report is provided by public water systems every July 1 as mandated by EPA.

The report must contain data on the risk of exposure to certain contaminants, regulated contaminants found in the local drinking water, contaminants violating the EPA standard and its effects on health, actions taken to restore safe drinking water quality, contact details of local water systems. Although these reports contain information specific to each state, it must also reflect outline information on federal requirements.

More Information

1. Commercially Bottled Water

As consumers, we must know the sources of our drinking water. Refer to the labels of the water bottles for the information on the water treatment used and its manufacturer’s contact details.

It is not enough that bottled water manufacturers treat their water. Best safety practices on bottle sealing, shipping, and storing must be observed to ensure that the product is free of harmful contaminants.  Ingesting contaminated water may cause serious health problems. Contact your local public health agency if you suspect your bottled water is causing illness.

2. Importance of Water Quality and Testing

The SDWA does not only provide the standard on drinking water quality, it also imposes water-testing schedules and methods that water systems must follow. Even when your water supply is aesthetically clean, contamination is still possible. Possible sources of contamination can come from sewage releases, chemical run-offs, and improperly maintained water pipes, etc.

When authorities find a concerning issue with the water supply, they release a water advisory to inform and protect the consumers. The specifics on reports on waterborne disease outbreaks are posted in the Morbidity and Mortality Weekly Report (MMWR).

3. Drinking Water Regulations

Regulations on drinking water ultimately aim to protect human health by keeping the water relatively clean. Presently, EPA has set legal limits on over 90 drinking water contaminants.

The data collection process on the chemicals and microbes present in water is conducted by EPA’s contracted laboratories. These laboratories need to meet EPA’s requirements on equipment, laboratory performance, and data reporting. To maintain approval, they are required to stick with the quality assurance and control procedures and criteria

4. Drinking Water Rule Quick Reference Guides

Here are quick links to help make searching for the data you need easier:

5. Human Health and Contaminated Water

Before the SDWA, rules on water sanitation and safety standards varied from State to State. In the 1960s, several waterborne disease outbreaks were recorded. Most of them were associated with the use of untreated water sources (wells and springs).

The creation of SDWA has significantly decreased incidences of outbreaks relating to waterborne diseases. America has one of the safest drinking water in the world. However, public water systems need to regularly monitor their water quality because of the possible presence of certain microbes that are resistant to conventional disinfection like the Cryptosporidium.

In healthy individuals, the presenting signs and symptoms can be mild, but for immunocompromised people, the effects can be life-threatening.

6. Source Water Protection

In the 1996 amendment, the Source Water Protection Program was created to protect all identified sources of drinking water (both for surface and groundwater). Source Water Protection Areas are watersheds or groundwater sources that need to be safeguarded to minimize pollutants that contaminate drinking water.

There are two types of protection areas:

  • Watershed Protection Area – a part of the watershed (rivers, streams, reservoirs) that is protected to prevent contamination of surface water.
  • Wellhead Protection Area – refers to the area surrounding a drinking water well or well field that needs protection to lessen the chances of drinking water contamination.

Preventing contaminants from getting into water sources is the best and cheapest guarantee for safe drinking water. However, the use of land for such purposes is a state issue.

7. Safe Drinking Water Act: Consumer Confidence Reports

If you were not furnished with a copy of the latest CCR, you may search it online using the EPA’s CCR search tool. Just type in the name of your state or to narrow the search further, you may include the name of your county. Note, however, that not all states have an available CCR.

For those whose water source comes from a non-community system (i.e. a hospital with its own water system), please contact the building manager.

Simply, the CCR should contain information on the water source and what’s in it. Anything that is not a water molecule will be marked as a contaminant. For example, chlorine may be marked as a contaminant even if its main function is to clean the water. The ones you need to keep an eye out for are those remarked with “violated”. Knowing what is in your drinking water will help you determine the next steps you need to take to protect your health.

8. Water Quality Information (U.S. Geological Survey)

The SDWA was enacted to ensure that we get quality drinking water. But how do we define “water quality”?

We can tell the water quality is good through a number of its properties:

  • Alkalinity and Acid Neutralizing Capacity

This is the capacity of water to stabilize acids and bases and maintain a safe pH. Water ecosystems in bodies of water that have high alkalinity fair better through phenomena such as acid rains and chemical/ oil spills. A sudden change in pH can be harmful to the organisms living in the water.

  • Biological Oxygen Demand and Water

Streams and lakes contain dissolved oxygen. Although the amount of oxygen is small, it is crucial in maintaining aquatic life and the aesthetic effects of water bodies. Occurrences such as hot summer temperatures and fertilizer run-off to bodies of water can affect its amount of oxygen and cause stress to the local aquatic organisms.

  • Water Color

Water does not have a clear color, but a slight blue, instead. Often, the water’s color is affected by the sediments and organic matters present in it. The color of the water is affected by suspended materials and sediments. Too much of these can block sunlight and have an undesirable effect on the local aquatic life form. In local residences, colored water can stain clothes and fixtures and cause permanent damage.

  • Dissolve Water Oxygen and Water

The quality of water in a lake or stream can be measured through the amount of dissolved oxygen. Oxygen is introduced into the water through the atmosphere and in areas discharge groundwater into streams. An increase in bacterial activity because of organic matter decays can affect the level of oxygen in a body of water. This can lead to an oxygen-deficient phenomenon also known as eutrophic conditions.

Since oxygen level in water is inversely proportional to its water temperature, summer seasons usually experience eutrophication.

  • Conductivity (Electrical Conductance) and Water

Water conducts electricity. The presence of ions in water makes a very good conductor.

The higher the ion concentration the better the conduction. This can be true about the sea. The sea has very high saltwater levels that if lightning should strike while you are swimming in seawater, the electricity will follow the path of the ions present in the water and ignore the human body.

Although, it is said that pure water is the best insulator. The thing is, all bodies of water are ionized though you may have to look for the best water ionizer in some cases. Even distilled water has small amounts of ions in it.

  • Hardness of Water

Water sourced from groundwater usually are hard because of the naturally-occurring minerals carried from soil and rock to the groundwater supply. The amount of dissolved minerals, mostly, calcium and manganese determine the hardness of the water. Water softeners are used to remove the hardness from water.

This can sometimes be the cause of cloudy dishes and glassware even after thoroughly washing them. When hard water is heated, it can form solid deposits of calcium carbonate. This can decrease the efficiency of water heaters and clog pipes.

However, this can also bring some benefits to human health. The World Health Organization (WHO) says that people who have low calcium and magnesium levels in their body can benefit from, drinking hard water.

  • Nitrogen and Phosphorus in Water

Adequate levels of Nitrogen and Phosphorus are essential to plant and animal nourishment. That is why nitrogen is widely used in agriculture. Although it occurs naturally in the environment, excessive amounts of nitrogen can be introduced by sewage and fertilizers mostly to surface water.  The introduction of too much nitrogen into bodies of water can cause overstimulation of the growth of aquatic plants and algae. One of the worst effects of excessive nitrogen in the water is algal bloom which can lead to “fish kill”.

  • pH and Water

pH is the measure of the alkalinity (high amounts of hydroxyl ions) or acidity (high amounts of free hydrogen ions) of water. The pH range is from 0 to 14. pH level 7 is considered neutral. Readings lower than 7 are considered acidic and can corrode metals. Higher pH readings are basic and can cause bitter water taste and deposit crusts in pipes and other water-using appliances. The pH of most drinking water is from 6.5 – 8.5.

  • Turbidity and Water

Turbidity makes the water cloudy or opaque. The ideal drinking water must have very low turbidity for health benefits. An increase in drinking water turbidity can cause health concerns. It can promote the growth of pathogens and lead to waterborne disease outbreaks. Microbes can attach themselves to particulates which aid in their survival. The good news is that conventional water treatment effectively removes water turbidity.


Water is the source of life. The first cellular life form came from water and the creatures that evolved from it need water to survive. The water that gives life can also take it away and there is no one else to blame but us. The increase in our human population and our commercial activities have poisoned our waters — the water we drink and give to our families. It is good that cognizant men and women were able to curb the deadly situation that faced our children and posterity by passing the Safe Drinking Water Act (SDWA).

This law extends beyond protecting the various sources of drinking water. It has also equipped the American people with adequate knowledge and involved them in safeguarding their rights to safe and clean drinking water. From a macro perspective, the SDWA has changed millions of American lives and continues to do so. This is a huge step towards a good quality of life, especially, for those who have little to help them go by.

The impacts of SDWA must not be limited to America. Laws that promote good health, and therefore, a better quality of life, need to be recognized outside American borders. Developing countries who strive for socio-economic advancement must first invest in their people’s health, for it is only when its citizens are safe and healthy can a country move forward towards true progress.

About the author

Warner Levit

Water Filtration Expert

As a trained chemist and an independent researcher I started working on a portable water filter project as part of my business plan. While carrying out my research, I got involved with FaucetsReviewed. My fields of expertise include environmental science, biochemistry and water purification chemistry. Apart from contributing to this website, I’m currently working on my book “Water Filtration Science”. It will be published soon. I grew up in California, and completed my postgraduate degree from the University of California-Berkeley. I also work as a private counselor on the household water management system.

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