The State of Private Well Water in Western New York & Northwestern Pennsylvania: A 2026 Data Report

What federal, state, and academic data reveal about contamination risks, testing gaps, and what every well owner in our region should know.

Published by McCandless Well Drilling and Services, Inc. | Busti/Jamestown, NY

Introduction

We compiled data from the U.S. Geological Survey, the U.S. Environmental Protection Agency, the Centers for Disease Control and Prevention, the New York State Department of Health, and peer-reviewed academic research to answer a question that matters to every private well owner in our region: how safe is the water coming from your well in Western New York and Northwestern Pennsylvania?

Specifically, we examined 12 key data points covering contamination rates in private wells, the most common contaminants found in the glacial aquifer system beneath our region, PFAS “forever chemicals” risk for New York well owners, nitrate levels on rural farms in upstate New York, how often well owners actually test their water compared to what health experts recommend, and what the NYS Department of Health’s own risk maps show for Chautauqua, Cattaraugus, Erie, and Warren Counties.

Here are the results.

Key Findings

• According to USGS prediction models, up to 56% of New Yorkers who rely on private wells may have detectable PFAS “forever chemicals” in their water — yet New York does not require private well owners to test for them.
• Only about 9% of private well owners test their water annually, despite federal and state recommendations to test for bacteria every year.
• A USGS study of 2,100 private wells found that 1 in 5 (23%) contained at least one contaminant above a human-health benchmark for drinking water.
• Approximately 40% of private well households do not regularly test, treat, or filter their drinking water at all.
• The glacial aquifer system underlying Western New York has been flagged by the USGS for elevated risks of arsenic and manganese — contaminants linked to cancer and neurological harm — and supplies groundwater to 30 million people across 25 states.
• Testing a private well for PFAS costs $300 to $600 — roughly 3 to 6 times more than a standard bacteria and nitrate test — and no government program requires it for private wells.
• A study of 419 farm wells in rural upstate New York found that 15.7% exceeded the safe drinking water limit for nitrate, including 15% of wells on farms where infants lived.
• The NYS Department of Health’s Private Well Risk Mapper identifies areas across our region with elevated risk from flooding, agricultural runoff, naturally occurring arsenic, and porous carbonate bedrock.
• In Chautauqua County, the average well depth is approximately 115 feet and a new well and pump system typically costs $7,500 to $12,000 — 36% to 118% more than the national average.
• Only 56% of local health departments nationwide regulate, inspect, or license private wells — meaning nearly half of well owners have no local government oversight of their water source.
• From 1971 through 2008, the proportion of waterborne disease outbreaks linked to private water sources increased over time — even as public water safety improved.
• An estimated 4 million New Yorkers depend on private wells for drinking water, and the quality of that water is not regulated by any federal or state law.

Up to 56% of NY Well Owners May Have PFAS — and Nobody Has to Tell Them

Background: PFAS — per- and polyfluoroalkyl substances, commonly known as “forever chemicals” — have emerged as one of the most significant drinking water concerns in the United States. These man-made chemicals are found in everyday products from nonstick cookware to firefighting foam, and they don’t break down in the environment. Exposure through drinking water has been linked to elevated cholesterol, thyroid disease, reduced immune response, and increased risk of certain cancers. In 2024, the EPA finalized the first-ever national drinking water standards for six PFAS compounds.

Results: According to a USGS study that modeled the probability of PFAS occurrence in groundwater across the country, up to 56% of New Yorkers who source their drinking water from private wells are predicted to have detectable concentrations of PFAS. For New Yorkers on public groundwater systems, the predicted rate is even higher — up to 94%.

Context: New York State has responded aggressively to PFAS — at least for public water systems. The state set maximum contaminant levels of 10 parts per trillion for PFOA and PFOS, among the strictest standards in the nation. However, those standards apply only to regulated public water supplies. Private well owners are explicitly excluded. The state does not require private well owners to test for PFAS, and testing must be done through a certified laboratory at a cost that can run $300 to $600 per sample. For the thousands of families in Western NY and Northwestern PA who rely on private wells, this creates a significant gap: the government has acknowledged PFAS is dangerous enough to regulate in public water, but has left private well owners to discover and address the problem on their own. Reverse osmosis and granular activated carbon filtration systems can reduce PFAS in drinking water.

Only 9% of Well Owners Test Annually as Recommended

Background: The CDC, the EPA, and the NYS Department of Health all recommend that private well owners test their water for bacteria (total coliform and E. coli) at least once a year. New York State further recommends testing every three to five years for a broader set of contaminants including nitrate, iron, manganese, hardness, pH, sodium, chloride, sulfate, and dissolved solids. The logic is straightforward: groundwater quality changes over time due to seasonal variation, land use changes, aging well infrastructure, and climate events. A well that tested clean when it was drilled may not stay that way.

Results: A 2024 study published in Environmental Science & Technology surveyed more than 22,000 rural households with private wells in Iowa and found that only about 9% had tested their water in the past year. A separate Wisconsin-based study found similar patterns — only about 19% of well owners had tested within the prior 12 months, with nearly half not having tested in over a decade.

Context: These numbers are national and regional benchmarks, not specific measurements of WNY/NW PA behavior. However, there is little reason to believe our region is dramatically different. The factors that drive low testing rates elsewhere — lack of awareness, assumption that clear water is safe water, inconvenience, and cost — are all present here. The practical implication is significant: the vast majority of well owners in our region are likely drinking water that hasn’t been verified as safe in years, or ever. McCandless offers water testing services to help well owners in our service area stay on top of their water quality.

1 in 5 Private Wells Contain Contaminants Above Health Benchmarks

Background: Unlike public water systems, which are required by federal law to test regularly for dozens of contaminants and report the results, private wells have no mandatory testing requirements. The Safe Drinking Water Act does not apply to them. This means the only way to know whether a private well’s water is safe is for the homeowner to proactively have it tested.

Results: The USGS conducted a national study of approximately 2,100 private wells and found that water from about 23% — roughly 1 in 5 — contained one or more contaminants at concentrations exceeding human-health benchmarks. The contaminants most frequently found at elevated levels were inorganic chemicals with natural geologic sources: arsenic, manganese, radon, uranium, and nitrate. Man-made organic compounds such as pesticides and solvents were detected in about 60% of wells sampled, though they rarely exceeded health benchmarks (less than 1% of wells).

Context: If this national rate were applied to the estimated private well population in Chautauqua, Cattaraugus, Erie, and Warren Counties, it would suggest that thousands of wells in our region may have water quality concerns that their owners don’t know about. The specific contaminants most likely to affect our region — based on the glacial aquifer system beneath us — include arsenic, manganese, and iron, all of which are discussed in later sections of this report.

40% of Well Households Do Nothing to Check Their Water

Background: Testing is one way to protect yourself, but it’s not the only option. Water filtration systems, water softeners, and reverse osmosis units can all reduce or remove specific contaminants. Even choosing to use bottled water for drinking and cooking, while not ideal as a long-term solution, is a form of risk mitigation. The question is: how many well-owning households are taking any of these steps?

Results: According to the same Iowa State study of 22,000 households, approximately 40% of private well users do not regularly test their water, use any form of water treatment, or supplement their drinking water with an alternative source. In other words, they are doing nothing to verify or protect their water quality.

Context: This finding is particularly concerning when paired with the fact that many of the most dangerous well water contaminants — arsenic, nitrate, PFAS, bacteria — produce no change in how water looks, tastes, or smells. A household that does nothing to check or treat their water has no way of knowing whether a problem exists. For families with infants, young children, elderly members, or anyone with a compromised immune system, the stakes are even higher.

Western NY Sits on a Glacial Aquifer With Known Arsenic and Manganese Risks

Background: The geology beneath your property plays a major role in determining what’s in your well water. Western New York sits atop the glacial aquifer system — a vast network of sand, gravel, and glacial deposits left behind by retreating ice sheets thousands of years ago. This aquifer system spans 25 states across the northern United States and provides drinking water to approximately 30 million people.

Results: USGS researchers have developed 3-D prediction models that map where elevated concentrations of arsenic and manganese are most likely to occur within the glacial aquifer system. An estimated 5.7 million people nationally rely on glacial aquifer groundwater with high concentrations of one or more trace elements. Manganese is the most frequently elevated — in a study of 556 drinking-water wells in the glacial aquifer, about 10% exceeded the manganese Lifetime Health Advisory level. Arsenic concentrations exceeded the Maximum Contaminant Level of 10 µg/L in about 7% of drinking-water wells nationally, with the glacial aquifer specifically flagged as a concern area.

Context: For well owners in Western NY and Northwestern PA, this means the geology itself is a potential source of contamination — even on properties far from any industrial activity or agricultural operation. Arsenic exposure is linked to increased cancer risk (skin, bladder, kidney, liver) and other serious health effects. Manganese, while an essential nutrient in small amounts, can cause neurological harm in children when consumed at elevated levels in drinking water. Neither contaminant changes the taste, color, or smell of water. The only way to know your levels is to test your water.

PFAS Testing Costs $300–$600 — With No Requirement to Do It

Background: While the EPA finalized drinking water standards for PFAS in 2024 and New York has set some of the strictest state-level limits in the country, these rules apply exclusively to public water systems. For the roughly 4 million New Yorkers on private wells, PFAS testing is entirely voluntary — and entirely at the homeowner’s expense.

Results: The cost to have a private well tested for PFAS through a certified laboratory typically ranges from $300 to $600 per sample. By comparison, a standard bacteria and nitrate test — the most common type of well water testing — generally costs between $50 and $150. The PFAS test costs roughly 3 to 6 times more.

Context: The cost barrier is significant. For many rural households in our region, $300 to $600 is a meaningful expense — particularly for a test that may need to be repeated if contamination is found or if conditions change. The NYS Department of Health acknowledges this challenge and notes that some homeowners may choose to install a water filtration system (such as a reverse osmosis or granular activated carbon filter) rather than pay for testing, since effective filters can reduce PFAS regardless of whether you know your exact levels. Still, without testing, homeowners are making decisions about their family’s health without the data to inform them.

Nearly 16% of Rural NY Farm Wells Exceed Safe Nitrate Levels

Background: Nitrate is one of the most common contaminants in rural well water, primarily driven by agricultural activity — fertilizer runoff, animal waste, and septic system leachate. While nitrate is naturally present in soil at low levels, concentrations above 10 mg/L (the EPA’s maximum contaminant level) pose a health risk. Infants are especially vulnerable: high nitrate levels can interfere with the blood’s ability to carry oxygen, causing a condition known as methemoglobinemia, or “blue baby syndrome.”

Results: A study of 419 farm wells supplying drinking water in rural areas of upstate New York found that nitrates were detectable in 95% of wells tested. More concerning, 15.7% of wells had nitrate levels exceeding the 10 mg/L health standard. Among wells on farms where infants resided, 15% were also elevated above the safe limit.

Context: Chautauqua, Cattaraugus, and Warren Counties all have significant agricultural land use, making nitrate contamination a relevant concern for many well owners in McCandless’s service area. Shallow wells, dug wells, and springs were found to be more likely to have elevated nitrate — which is consistent with what our team sees in the field. Annual nitrate testing is recommended by both the EPA and NYS DOH and is one of the most affordable and accessible tests available to well owners.

What the NYS Risk Mapper Shows for Chautauqua, Cattaraugus, Erie, and Warren Counties

Background: In 2024, the New York State Department of Health launched the Private Well Risk Mapper — a free, interactive online tool that allows any New Yorker to type in their home address and view potential risks to their well water. The tool assesses four categories of risk: flooding, agricultural runoff, naturally occurring arsenic, and porous carbonate bedrock (which can create pathways for contamination to reach groundwater more easily).

Results: Across the counties served by McCandless — including Chautauqua, Cattaraugus, and Erie — the Risk Mapper identifies substantial areas flagged for one or more risk categories. Agricultural district designations are widespread in all three counties, indicating elevated potential for nitrate and pesticide contamination. Certain areas along waterways and in low-lying terrain are flagged for flood risk, which can introduce bacteria and surface contaminants into wells. Arsenic risk areas are also present, reflecting the underlying bedrock geology.

Context: The Risk Mapper is one of the most practical tools available to well owners in New York, and it’s completely free. Yet awareness of the tool appears to be low — it was only launched in 2024, and many homeowners have likely never heard of it. We encourage every well owner in our service area to visit health.ny.gov, search for “Private Well Risk Mapper,” and type in their address. The results can help you understand which contaminants you should prioritize when testing your water.

What It Costs to Drill a Well in Our Region vs. the National Average

Background: Understanding the full cost of well ownership is important context for any discussion of water quality. A well is a significant investment, and the costs vary substantially depending on geology, depth, and location.

Results: In Chautauqua County, the average well depth is approximately 115 feet. A complete new well and pump system typically costs between $7,500 and $12,000. Nationally, the average cost for a residential well system is roughly $5,500. That puts the cost of a new well in our region at 36% to 118% above the national average — a reflection of the local drilling conditions and geology.

Context: Given the investment involved, regular maintenance and water quality testing represent a relatively small additional cost to protect that asset. A standard annual bacteria and nitrate test can typically be done for $50 to $150 — a fraction of a percent of the total well system cost. A well that is properly maintained and monitored can provide safe, reliable water for 30 years or more. One that is neglected can develop problems that are far more expensive to fix than they would have been to prevent. If you’re experiencing issues, our well repair services can help.

44% of Well Owners Have No Local Health Department Oversight

Background: In many areas of the country, local health departments play a role in regulating, inspecting, or licensing private drinking water wells. This can include requiring inspections at the time of property transfers, setting minimum construction standards, or offering water quality testing programs. However, this role is not universal.

Results: According to the CDC, only 56% of local health departments in the United States regulate, inspect, or license private drinking water wells. That means 44% of well-owning households live in jurisdictions where no local government entity has any formal role in overseeing their water source.

Context: In New York, the DEC’s Water Well Contractor Program governs how wells are drilled and constructed, and some counties — including Erie County — require well inspections during property transfers. But the extent of local oversight varies county by county, and ongoing water quality monitoring is not required anywhere for private wells. The practical takeaway: well owners should not assume that any government agency is monitoring their water quality. That responsibility belongs to the homeowner.

Waterborne Disease Outbreaks From Private Sources Are Increasing

Background: The United States has made enormous progress in public water safety over the past century. Chlorination, filtration, and the regulatory framework of the Safe Drinking Water Act have made waterborne disease outbreaks from public systems relatively rare. Private water sources, however, have not benefited from these same protections.

Results: CDC surveillance data covering 1971 through 2008 shows that the proportion of waterborne disease outbreaks associated with private (non-public) water sources increased over that period. While public water systems became safer, private systems — primarily wells — accounted for a growing share of the problem.

Context: This trend is a reminder that well water safety is not improving on its own. Without the regulatory framework, mandatory testing, and professional treatment that public systems have, private well owners must be their own first line of defense. Regular testing, prompt response to any changes in water appearance or odor, and routine maintenance of the well structure and pump system are all essential.

4 Million New Yorkers Rely on Unregulated Private Wells

Background: New York State has one of the most extensive public water system networks in the country. The NYC water system alone serves over 9 million people, and in total, nearly 9,000 public water systems operate statewide. Approximately 95% of New Yorkers receive their water from a regulated public supply.

Results: That leaves roughly 4 million New Yorkers — about 5% of the state’s population — who source their drinking water from private wells. These wells are not covered by the federal Safe Drinking Water Act, not regulated by New York State, and in most cases, not monitored by any government agency after the initial construction.

Context: Four million people is a significant number — roughly the population of the entire state of Oregon. In rural regions like Western NY and Northwestern PA, the share of residents on private wells is substantially higher than the statewide average. For these communities, the data in this report is not abstract. It describes the water their families drink every day, the water they cook with, and the water they give their children. The purpose of this report is to make that data accessible — and to encourage every well owner in our region to take the simple steps needed to know what’s in their water.

What Should Well Owners in Western NY & NW PA Do?

Based on the data compiled in this report, here are the steps every private well owner in our region should consider:

Test your water annually for bacteria. The NYS Department of Health recommends testing for total coliform and E. coli at least once per year. This is the most basic and affordable test — typically $30 to $75 — and it can catch the most common acute health risks. Schedule a water test with McCandless.

Test every 3–5 years for a broader panel. NYS DOH recommends periodic testing for nitrate, nitrite, iron, manganese, hardness, pH, sodium, chloride, sulfate, and total dissolved solids. If you live in an area flagged for arsenic risk on the NYS Risk Mapper, add arsenic to your testing list.

Consider PFAS testing if you’re near a known or suspected source. If the EWG PFAS contamination map or the NYS DOH indicates potential PFAS sources near your property, a one-time PFAS test ($300–$600) can provide peace of mind or early warning. Alternatively, a reverse osmosis or granular activated carbon filtration system can reduce PFAS exposure without testing.

Check the NYS Private Well Risk Mapper. Visit the NYS DOH website and type in your address. It takes 30 seconds and provides a snapshot of your property’s risk from flooding, agricultural runoff, arsenic, and porous bedrock.

Inspect your well annually. Look for cracks in the casing, a missing or damaged well cap, standing water near the wellhead, or any changes in water appearance, taste, or odor. These can all indicate contamination pathways. If you find issues, contact us for a well inspection or repair.

Keep records. Document all maintenance, testing, and repairs. This protects you at resale time and helps you track changes in water quality over time.

Ask questions. If you’re unsure what to test for, how to interpret results, or when your well needs maintenance, a qualified local well service company can help. That’s what we’re here for. Get in touch with McCandless.

Conclusion

This report was compiled using data from the U.S. Geological Survey, the U.S. Environmental Protection Agency, the Centers for Disease Control and Prevention, the New York State Department of Health, and peer-reviewed research published in Environmental Science & Technology and other scientific journals. We are grateful for the work these organizations do to monitor and protect water quality, and we believe this data deserves to reach the homeowners, farmers, and businesses who rely on private wells every day.

We put this report together because we believe every well owner in Western New York and Northwestern Pennsylvania deserves to know what’s in their water. After nearly 50 years of drilling and servicing wells across this region, we’ve seen firsthand how much of a difference regular testing and maintenance can make.

Now we’d like to hear from you: When was the last time you had your well water tested? Let us know — or if it’s been a while, consider scheduling a test. Your water might look perfectly clear and still have something worth knowing about.

McCandless Well Drilling and Services, Inc. | 789 Busti Sugar Grove Rd, Jamestown, NY 14701 | (716) 338-3966 Serving Chautauqua, Cattaraugus, and Erie Counties in NY and Warren County in PA