U.S. tap water should be safe. However, millions of Americans may face a higher risk of developing illnesses because of levels of contaminants in our drinking water that still get a pass from federal regulators.
The Environmental Protection Agency has set legal maximum levels in drinking water forabout 90 contaminants, using its authority under the Safe Drinking Water Act. But many of these rules are outdated and do not rely on the most current science or address ongoing public health concerns.
That’s why legal limits don’t always mean safe limits. Here’s what you should know about six of the most commonly detected contaminants in drinking water:
PFAS
PFAS are a group of fluorinated chemicals that are used in hundreds of products, from waterproof textiles and cosmetics to firefighting gear and firefighting foam. Known as “forever chemicals,” PFAS don’t break down in the environment and they can build up in our bodies.
PFAS can cause widespread harm, especially to the immune system, and they are also linked to cancer. The presence of PFAS in water sources, including rivers, lakes and groundwater, has in turn contaminated tap water across the U.S., compromising the safety of humans as well aswildlife. Filtering your water is one of the easiest ways to reduce your exposure to PFAS.
Disinfection byproducts
Drinking water must be disinfected so disease-causing microbes don’t make us sick. But when chlorine or chloramine is used to treat water, harmful disinfection byproducts can form.
Thesebyproducts are linked to an increased risk of cancer and harm during pregnancy. A simple carbon filter can effectively remove disinfection byproducts from water used for drinking and cooking.
Nitrate
Nitrate is one of the most common contaminants in tap water, and the most common in groundwater, since it does not degrade once it enters groundwater. It comes from fertilizer or livestock manure that has washed off farm fields into drinking water sources.
In more populous areas, nitrate from storm water runoff and wastewater treatment plant releases can also contaminate drinking water.
Studies show nitrate in tap water is linked to cancer and reproductive harm. Reverse osmosis filters are the most effective for reducing nitrate in tap water.
Heavy metals, including arsenic and hexavalent chromium
Heavy metals can especially be an issue when tap water comes from a groundwater well. For example,arsenic is a highly potent carcinogen, and ingesting even small amounts can increase the risk of cancer. It can contaminate water from naturally occurring minerals or from human activity such as mining and industrial uses.
Hexavalent chromium, orchromium-6, a carcinogen, is another metal that can contaminate groundwater from industrial pollution. California recently passed a limit on chromium-6 in drinking water, but the federal government has not, despite the metal’s widespread presence and link to cancer. It contaminates the drinking water of more than250 million Americans.
Radiological contaminants
Radiological contaminants like radium and uranium enter tap water from natural deposits, but can also be released by mining and drilling. Radiation in tap water can be dangerous and may cause harm during pregnancy. There are six radiological contaminants, but the most common are radium-226 and radium-228. The EPA’s drinking water limits for these contaminants are outdated, and even low levels of exposure can increase the risk of cancer.
Volatile organic compounds
Trichloroethylene, orTCE, is a type of volatile organic compound, orVOC, that has been used as a metal degreaser or dry cleaning agent. Industrial discharges of TCE have contaminated tap water. Like many VOCs, TCE is linked to increased risk of cancer and birth defects.
EWG's Guide to Safer Drinking Water
Reduce your exposures to common drinking water pollutants with EWG's handy tipsheet!
What you can do
You can take steps to reduce your exposure to many of these contaminants. The first step is finding out about your water:
Use EWG’sTap Water Database. Enter your ZIP code to find detailed reports on the contaminants found in your local water sources.
Invest in a home water filter. The right filter will increase your water quality and decrease your risk of long-term health concerns, like cancer, reproductive harm and harm to children’s health.
**Contact your local officials.**Tell them that the safety of your drinking water is an important issue to you.