A survey found that pets drinking well water are exposed to above-recommended levels of arsenic, lead, and copper.
A recent study has found that two out of every three dogs tested are drinking water with heavy metal concentrations above recommended safety limits. The research, led by Audrey Ruple of Virginia Tech, in the open-access journal PLOS Water, examined households in 10 states that rely on well water. In 13 cases, the samples revealed arsenic, lead, or copper levels that surpassed guidelines set by the Environmental Protection Agency (EPA).
An estimated 15 million households across the United States depend on private wells for their drinking water. Unlike municipal systems, these wells are not covered by the EPA’s Safe Drinking Water Act, which enforces routine safety testing. As a result, both the families and the dogs living in these homes face greater risks of exposure to heavy metals that can seep into groundwater.
Study Design and Scope
In this study, the researchers analyzed drinking water samples from 178 dogs in homes not served by municipal water sources. All dogs are part of the Dog Aging Project, a long-term study of canine health and aging. Samples ranged across 10 states and tested for 28 heavy metals, about half of which are regulated by the EPA. Owners mailed drinking water samples to the researchers and completed detailed surveys about their dogs’ health and the home’s drinking water supply.
Across all 178 samples obtained, the researchers found detectable levels of all 28 metals tested. Two-thirds of the samples tested included at least one heavy metal over the EPA’s maximum contaminant level (MCL) or health guidance levels. In 13 instances, arsenic, lead, and copper tested above the EPA’s MCL guidance levels.
Correlations and Environmental Links
Correlations identified within the experiment include: nearby fracking sites are associated with more sodium and sulfur in the drinking water; railroad tracks are associated with increased levels of manganese; and dogs drinking from water treated with reverse osmosis or a sediment filter were less likely to have a non-chronic health condition.
The researchers emphasize that big-picture conclusions require further study, and expressed a desire to continue testing dogs’ drinking water composition juxtaposed to their long-term health. Ultimately, this information can help guide veterinary care decisions and improve the health of the dogs’ human companions.
The authors add: “Many households served by private wells are flying under the regulatory radar. Dogs living in these homes may be our first warning signs of environmental exposures in underserved rural areas.”
Reference: “Testing for heavy metals in drinking water collected from Dog Aging Project participants” by Courtney L. Sexton, Janice O’Brien, Justin Lytle, Sam Rodgers, Amber Keyser, Mandy Kauffman, Matthew D. Dunbar, Dog Aging Project Consortium,, Marc Edwards, Leigh Anne Krometis and Audrey Ruple, 6 August 2025, PLOS Water.
DOI: 10.1371/journal.pwat.0000296
This research is based on data collected by the Dog Aging Project, which is supported by U19 grant AG057377 from the National Institute on Aging (authors funded on this grant include: SR, AK, MK, MDD, and AR), a part of the National Institutes of Health. The publicly available data are housed on the Terra platform at the Broad Institute of MIT and Harvard.
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.
2 Comments
Well, if the dogs are drinking adulterated well water, then their people are also. Shouldn’t THAT have been the article focus?
AND people using drugs go wee-wee and there is a drug fragment sludge of every drug taken by humans in all water – that U are drinking. Uhh, and I wish to testify, people are getting slower and dumber. Need filters on every public water system – while we can still add two + two.