Farming and Your Tap Water
For millions of Americans in farm country, tap water comes with an unwanted dose of toxic contaminants – pesticides, fertilizers, animal wastes and other substances that are associated with health hazards, including some types of cancer, birth defects and communicable diseases. Utilities try to eliminate or reduce the presence of these chemicals, but as EWG’s Tap Water Database shows, in rural America tainted drinking water remains a daily reality.
Just under half of the land in the U.S. is farmed in one way or another. Every year, manure from 90 million cows, 66 million pigs and 1.9 billion chickens – plus 44 billion pounds of fertilizer and 925 million pounds of pesticides – goes on American farmland. It takes very careful management of how crops and livestock are produced to keep those contaminants out of our water. Unfortunately, most farm fields aren’t that carefully managed.
Water that runs off farm fields treated with manure and chemical fertilizers is laced with nitrate. Our database shows that more than 7 million people are drinking water with unsafe levels of nitrate. Multiple studies by the National Cancer Institute have found that nitrate increases the risk of colon, kidney, ovarian and bladder cancers. Nitrate-contaminated water has also been linked to adverse reproductive effects and changes in thyroid function.
Manure and fertilizer that drain into lakes and streams also lead to explosive blooms of algae. Chemicals such as chlorine, which drinking water utilities use to disinfect tap water, react with algae to form carcinogenic disinfection byproducts. Over 11 million people are drinking water contaminated with these byproducts at levels that are just below the legal limit but far above what scientists think is safe.
Worse yet, some types of algae produce toxins that can be deadly to pets, livestock, wildlife and people. These toxins can harm the nervous system, kidneys and liver, and cause digestive problems. Even brief exposures can trigger allergies, skin rashes, eye irritation and breathing issues. In 2014, residents of Toledo, Ohio, had to go without water for several days when these toxins got into their drinking water supply. Beyond the health effects, algae can make water smell bad and taste even worse.
Utilities do a good job of removing pesticides, but some still end up in tap water. Almost 8.4 million people are drinking water contaminated with unsafe levels of atrazine, a widely used herbicide that can cause hormonal changes in laboratory animals, and possibly infertility, reproductive problems and fetal abnormalities in people.
Increasingly, water utilities in all parts of the nation face contamination problems they can’t fix. The more polluted the source water, the more often contaminants will exceed safe limits in the resulting tap water. We’re counting too much on treatment and doing too little to keep farm pollution out of source water in the first place.
Often the people paying the highest price live in farm country. Just ask anyone from a small town whose water utility has had to build a new water treatment plant or drill a deeper well. And because the supplies of small water utilities and water in private wells aren’t routinely tested for contaminants, the problem may be worse than the numbers in our database show.
It doesn’t have to be this way.
Farmers can do simple things to keep water clean while producing crops and livestock. Planting strips of grass to filter water running off fields, protecting stream banks from grazing animals and fertilizing more carefully would make a big difference in improving source water quality. Some farmers are doing these things and more – but not nearly enough.