

Water Quality
Water quality affects the health and well-being of communities across the United States.
The Environmental Protection Agency (EPA) regulates over 90 contaminants in drinking water via legal thresholds called Maximum Contaminant Levels (MCLs) as well as through monitoring and reporting requirements. Under the Safe Drinking Water Act, the EPA and states establish and enforce drinking water standards. Public water systems routinely test their water to ensure compliance with these regulations. However, contaminant levels in some cases exceed EPA limits, posing health risks to people and communities. Even within those limits, lower levels are necessary to truly protect public health. Additionally, the EPA doesn’t regulate all chemicals found in drinking water with health risks: A recent analysis by ProPublica found that over the past decade, 61 million people were exposed to dozens of unregulated contaminants in their drinking water at potentially harmful levels. Protection from EPA by the Safe Water Drinking Act does not apply to people who get their water from private wells, which is around 15% of the U.S. population: The responsibility falls on the building or homeowner to protect occupants from health contaminants.
While bacterial and microbiological contaminants are well-known to cause health issues, chemical contaminants like lead, PFAS, and arsenic pose significant risks, and more should be done to protect residents. Whether you are an occupant, a building manager/owner, a builder, or a developer, finding out what chemicals are present in your tap or well water and the health risks they pose is critical to protecting occupant health.
How to find what contaminants are in your tap water
This database allows you to enter your zip code and see which contaminants exceed the legal limit. Note: This data is from 2021. However, it’s a useful tool to use as a starting place.
The EPA requires water providers to publish an annual drinking water quality report. This resource helps you find your report based on your location.
Getting your tap or well water tested by a laboratory is the most effective way to learn what chemicals are in your water.
Learn about different contaminants in water, how they affect health, and the legal and ideal limits.
EWG shares their “no compromise” contaminant limits for public health, which are more stringent than EPA’s list.
This step-by-step guide from NRDC explains how to check if your home has lead service lines.
This guide by NSF/ANSI helps you find water filters that meet the reduction claims for several different contaminants.
Lead contamination in drinking water
Lead-contaminated drinking water remains a significant issue in many communities, mainly due to the legacy of lead service lines that were widely used in plumbing before they were outlawed in 1986. The EPA estimates that 9.2 million lead service lines deliver water to properties and communities in the United States. Homes built before 1986 and urban areas with aging infrastructure are more likely to have lead pipes. Lead can also be present in internal plumbing, faucets, and fixtures, and as with lead pipes, they can corrode and deposit lead into water, rendering the water supply dangerous to human health.
There is no safe amount of lead to consume. Lead is a toxic metal that harms the brain and nervous system and is especially harmful during pregnancy and infancy when it can decrease the developing child’s IQs, diminish academic abilities, and increase attention deficits and problem behaviors. Even the lowest blood lead levels can affect the developing brain and central nervous system. In adults, lead can cause increased blood pressure, heart disease, decreased kidney function, and cancer. Communities of color and lower-income communities often bear a disproportionate brunt of the hazards of lead water contamination. Eliminating lead exposure in our water systems can not only keep communities safe and healthy but also create family-sustaining jobs and boost local economies across the country, particularly if members of the impacted communities themselves are unionized and hired to do this work.
Checking and testing for lead in water
Residential building owners and developers can protect residents from lead in drinking water by taking the necessary steps to determine whether a building has LSR or lead plumbing components. Visually inspect whether a service line is made of lead by locating the service line and applying the scratch test or a magnet test (magnets don’t stick to lead pipes). If your pipes are copper, it’s also possible that they have lead solders. Brass faucets and valves are likely to contain lead as well. The EPA states that testing your water for lead is the only way to be 100% certain that your water does not contain lead.
If there’s lead
If there is lead in a building’s water supply, residential building owners should provide immediate protection by supplying water filtration devices certified to remove lead while plans are made to replace lead plumbing. Educating residents about the risks of lead and providing them with resources for minimizing exposure and maintaining their water filters is essential. Additionally, staying informed about and compliant with regulations ensures ongoing safety and legal adherence. Taking these proactive steps helps to ensure a safer living environment for all residents.
Lead-free plumbing components
It is possible that faucet fixtures may contain lead, both newer and old. When outfitting or replacing faucet fixtures, select products that are certified to NSF/ANSI 61, ensuring that they are truly lead-free.
Other Contaminants
PFAS
Per- and polyfluoroalkyl substances (PFAS) are a group of chemicals used in various industrial and consumer products for their water and oil-resistant properties. PFAS exposure is linked to a range of health issues, including cancer, liver damage, immune system disruption, and developmental problems in children. A recent study by the U.S. Geological Survey found 45% of the nation’s tap water is estimated to have one or more types of PFAS.
The widespread PFAS contamination affects water supplies across the country. These chemicals are persistent in the environment and do not break down easily, leading to long-term contamination of water sources. The persistence and widespread use of PFAS, and the challenge of removing these chemicals from water supplies, contribute to ongoing contamination issues. There are many types of PFAS and all are not effectively removed by current standard municipal water treatment processes, making water filtration devices the first real line of defense for PFAS.
Protection from PFAS
On a broad scale, solving the PFAS problem requires comprehensive strategies, including stricter regulations, phasing out the use of PFAS in products, and investing in advanced water treatment technologies. In April 2024, the EPA imposed the first regulations creating a standard allowable level of PFAS across the U.S., marking a step towards progress federally. As for water filtration, a recent study has shown that reverse osmosis filters (under-sink and dual stage) showed near complete removal for all PFASs evaluated in the study, with activated carbon filters showing varied results. To ensure PFAS removal in drinking water, choose products with certifications for PFAS and PFOA reduction in NSF/ANSI 53- Health Effects or NSF/ANSI 58- Health Effects for Reverse Osmosis.
Arsenic
Arsenic- a tasteless, odorless, and colorless naturally occurring element is a toxic carcinogen to humans of any age and health status and is associated with bladder, kidney, liver, and skin cancers and impacts the cardiovascular, endocrine, immune, and nervous systems. The most common source of exposure is through drinking water. Arsenic can seep into groundwater through natural deposits or from agricultural and industrial practices and tends to be higher in wells than in municipal water systems. Higher concentrations of arsenic have been found in the drinking water of Hispanic/Latine populations as well as Native American and Alaskan Natives. Researchers have also found a link between the presence of arsenic in well water and the development of diabetes.
EPA limits the amount of arsenic in water to 10 parts per billion. New Hampshire and New Jersey have instituted more stringent standards than the national regulation, with their MCLs for arsenic set at 5 parts per billion. Buildings and homes on private wells need to take extra caution and test and filter for arsenic since well water does not get treated as municipal systems do. It is particularly an issue for those in rural communities in the Southwest, Midwest, and Northeast, and parts of Alaska where levels tend to be higher on average. The USGS estimates that 2.1 million people get their water from private wells with high amounts of arsenic. Source, NIEHS
To find out whether your drinking water contains arsenic, refer to the Natural Resources Defense Council (NRDC) website. NRDC has analyzed data compiled by the US Environmental Protection Agency (US EPA) in drinking water in 25 states over a period of 18 years. You can also get information on the presence of arsenic in your drinking water from your local Utility or state or by calling USEPA’s drinking water hotline (1-800-426-4791) for more information: https://wqa.org/wp-content/uploads/2022/09/2014_Arsenic.pdf
To protect against arsenic in drinking water, install effective filtration systems such as reverse osmosis, ion exchange, or distillation units, and regularly test water to monitor arsenic levels. Look for products certified to remove arsenic in NSF/ANSI 53- Health Effects or NSF/ANSI 58- Health Effects for Reverse Osmosis.
Agricultural Chemicals
Atrazine
A widely used herbicide, atrazine has been found in the water of many private wells in the Midwest. Drinking atrazine in your water may cause birth defects and liver, kidney, and heart damage. It is recommended to test for atrazine if you have well water and live near agricultural fields or in areas where pesticides are made, mixed, or stored. If you are in an agricultural area and want to learn whether your drinking water is impacted by pesticides, and how to test for it, refer to this guidance from Montana State University Water Quality Program.
Nitrates
Nitrate pollution in drinking water is a result of large amounts of inorganic fertilizer applied in agriculture. High nitrate levels are most commonly found in shallow private wells in agricultural areas. Water that contains more than 10 mg/L of nitrate is particularly dangerous for babies under one year old, who are susceptible to a condition called “blue baby syndrome”, or methemoglobinemia, in which the baby’s blood struggles to carry oxygen causing the baby’s skin and mouth to turn a blue-gray color, signaling the need for emergency medical attention. Nitrates have been studied for their links to birth defects, thyroid disease, and breast, colorectal, and bladder cancers. Hispanic/Latine people are more likely to be exposed through drinking water to elevated levels of nitrate, as are migrant worker populations, Alaska/Native villages, and those in other Tribal Lands.
Learn more about what to do if you suspect nitrate is in your water and how to protect yourself from its contamination and negative health effects. Reverse Osmosis systems certified by NSF/ANSI can reduce nitrate in water.