Do you know what is in your drinking water?

According to the US Geological Survey (USGS), 43 million Americans get their drinking water from domestic sources. Because these wells are on private property, it is the job of the property owner, not a government agency, to ensure the safety of that water.

If you live on a property serviced by a domestic well, do you know what’s in your water? According to experts we interviewed, if you haven’t had a certified lab to test your water in the last one to three years, the answer is no.

The potential health costs of ‘free’ water

For most rural Americans, having an on-site well is a necessary part of rural life. There are high upfront costs associated with installing the well when a house is built, but the homeowner never has to pay a water bill. However, according to Sydney Evans, senior scientific analyst at the Environmental Working Group (EWG), this “set it and forget it” mentality poses a real health risk.

“Because domestic water sources are not regulated in the same way as public utilities, less data is available,” Evans said, “but there may be radioactive contaminants such as radium or uranium, arsenic, nitrates and, depending on the age of the home, lead in the water.”

Perhaps the greatest risk is caused by microbial pathogens (harmful bacteria such as E. Coli), because well water is not treated. According to Bruce Lindsey, coordinator for National Water Quality at the USGS, tests conducted as part of the organization’s National Water Quality Assessment project found microbial contaminants at a much higher rate than other contaminants.

Both Lindsey and Evans emphasized that every home on a well should be tested annually for bacterial contamination. “Pathogens are of greatest concern because they can cause acute illness, rather than building up over time,” Evans said.

Water quality in rural areas varies greatly from place to place and is largely influenced by the geology of the area, the depth of the well and the environmental threats in the area.

In addition, risk factors can change over time. That was the case for Mike Tauber, a plumber from Hackensack, Minnesota. He and his wife built their home a few miles outside of town in 1995. In 2014, a large-scale agricultural company purchased the land next to their property. In 2018, Tauber had a test pit dug near the boundary of his property adjacent to the new farm, and in 2019 he began testing the water.

“We kind of knew it was coming, so we were prepared,” Tauber said. “It’s a good idea that if you apply chemicals to sandy soil and then irrigate water from it, you’re going to have problems with the water.” The laboratory results of his test confirmed this well.

From 2019 to 2021, the nitrate level in his test well was well below 1 mg/L. In 2022 it rose to 2.5 and then to 4.27 mg/l in the spring of 2023. In the fall of 2023, Tauber had the water tested twice to make sure the numbers he saw were accurate: 9.68 and 9.78 mg/l.

The only way to know is to test

In a written response to questions, the U.S. Environmental Protection Agency (EPA) stated: “The quality and safety of drinking water from private household sources are not regulated by the federal government under the Safe Drinking Water Act, nor by most state governments and laws. EPA recommends that well owners test their private well annually for total coliform bacteria, nitrates, total dissolved solids, and pH levels. Owners can also contact your local health department to find out what substances are commonly found in the area’s groundwater.

At the EWG, Evans agreed. “The first place I recommend people look is any kind of public document — from when you bought your house, anything from the company that did the well drilling or provincial documents,” she said. “It’s also a good idea to check nearby municipal water results from our database. The only real way to find out is to test your water.”

The cost of a certified lab test for a variety of contaminants can add up quickly, so we asked about cheaper at-home test kits. “Without looking at the individual tests and their claims and the science behind them, I can’t comment on their accuracy,” Evans said. “It’s best to go through a certified drinking water laboratory.”

Evans also emphasized that state and federal regulatory limits for certain pollutants are far higher than what is considered safe for human health. The EWG has created a page with recommended safe levels for some of the most common pollutants, with a link to a PDF with about 100 more.

Treatment options for contaminated water

So far, Tauber’s home hasn’t tested high for nitrate, but he and his family use a countertop water filter just to be sure. He used the EWG’s online water filter guide to choose the one that offered the best combination of protection against the specific contaminants in his area and long-term cost.

We asked Evans about the guide and treating contaminated water in general. She explained that there are three main types of filters: activated carbon, like most countertop varieties; ion exchange systems, such as water softeners, which are better against nitrate; and reverse osmosis, which removes most contaminants but is quite pricey. “They are each effective against different types of contaminants,” she said, “so the type and amount of contaminants in your water will determine which filter type is best.”

It is also important to think about ongoing costs. While a pitcher filter may be cheaper upfront, the cost of purchasing replacement filters, which wear out more quickly, means your annual costs can be a lot higher. “And it’s super important to follow the maintenance and filter replacement schedule according to the manufacturer’s instructions,” Evans said. After all, the whole reason to buy a filtration device is to remove contaminants, and a worn out filter won’t do that.

Resources for individuals in the field of domestic resources

For a good idea of ​​the quality of ground and domestic well water, the USGS web page on Domestic Water Supply Wells is an excellent resource.

For those who want to learn all about the basics, maintenance and quality of well water, check out this library of resources from the National Groundwater Association.

However, the experts we spoke with agreed that your best resource is your county’s Department of Health or Environmental Services. There you will learn what contaminants may be present in your area and whether your county has a well water testing program.

If financial constraints have prevented you from testing your water in the past, your district office should also know if there are free or subsidized testing and treatment programs available to you.

In Iowa, for example, free well water testing and financial assistance for treatment have been offered in participating counties since 1987. According to Erik Day, of the state’s Water Supply Engineering Section, more than 90% of counties are currently participating.

Other states offer free or subsidized water testing on a limited basis in the form of one-time or recurring grants. This clickable map, published by the EPA, contains links to resources for each state. Additionally, some counties and even nonprofits offer free water testing clinics for the most common contaminants in the area.

Even if free testing and treatment isn’t available in your area, it’s worth spending the money to ensure your water is safe. With the average American using 82 gallons of water every day, limiting exposure to potentially harmful chemicals is money well spent. The average household that uses municipal water pays about $1,000 a year in water bills, so why not spend a percentage of that amount on ensuring your drinking water is safe?