A private well is its own water system. Its safety cannot be inferred from a town name, a neighbor's test, or a calculated pet cutoff.
● Key Takeaways
Use area records to learn what may be plausible, then obtain a certified sample from the tap or well that supplies the bowl. CheckYourTap leads with source-backed EWG/OEHHA human household guidance, displays EPA legal values separately, and does not relabel either as a dog threshold.
What the Dog Aging Project Study Established
The 2025 pilot received 178 private-well samples from participating dog households; 114 had at least one analyte above an EPA MCL or guidance comparator. That makes private-well testing a meaningful research and household-health question.
The comparators were human regulatory or guidance values. The study did not establish that an exceedance caused disease in a dog, did not create a canine safe concentration, and did not describe municipal tap water. Participation and returned samples also do not form a random national well survey.
Build the Panel Around the Property
Bedrock can contribute arsenic, uranium, manganese, radon, hardness, or other minerals. Agriculture and septic systems can influence nitrate and microbes. Industrial or pesticide history may change the panel. Premise plumbing can add lead or copper after the well water enters the building.
Confirm units and chemical basis. Nitrate as nitrogen and nitrate as nitrate are not interchangeable without conversion. Gross-alpha activity cannot identify a specific radionuclide. A detection is not automatically an exceedance, and a nondetect is bounded by the laboratory reporting limit.
Why the Former Dog Table Was Removed
The prior article compared well results with numeric dog levels derived from human screening doses, legal values, assumed intake, and a generic life-stage factor. Those calculations were not validated veterinary drinking-water standards. The historical table remains in version control and the research changelog, but it no longer drives live claims.
What to Do With a Confirmed Result
Use the verified EWG/OEHHA human health guideline as whole-household context and EPA values as separate regulatory context. If a result is concerning, use a safe alternative source while confirming it, involve a veterinarian where an animal may be affected, and select treatment against the exact contaminant and water chemistry. Verify treatment with a post-installation sample.
Keep Reading
Sources: Sexton CL et al., Testing for heavy metals in drinking water collected from Dog Aging Project participants, PLOS Water, 2025; U.S. EPA private-well and regulatory context; EWG/OEHHA human health guidance; state and USGS groundwater sources retained in the project evidence corpus. Consult a veterinarian for animal-specific advice.
