About Cattaraugus County, NY — Private Well Facts and Water Quality Data
Cattaraugus County covers more than 1,300 square miles of the Southern Tier of New York State, making it the third-largest county in New York by land area. With a total population of approximately 76,000 residents (U.S. Census Bureau, 2020), it is one of the most rural counties in Western New York. Small cities like Olean and Salamanca serve as regional centers, but the vast majority of the county is made up of small towns, hamlets, farmland, and forest — much of it outside the reach of any municipal water system.
Private well water is not the exception in Cattaraugus County. It is the rule.
Population and Private Well Ownership
According to U.S. Census Bureau American Community Survey data, an estimated 35 to 42 percent of occupied housing units in Cattaraugus County rely on private wells — one of the highest private well dependency rates in all of New York State. That represents approximately 13,000 to 16,000 households drawing their drinking water, bathing water, and household supply entirely from privately drilled and maintained groundwater systems.
The concentration of well-dependent homes is highest in the central and southern parts of the county — in towns like Franklinville, Ellicottville, Great Valley, Humphrey, Otto, Lyndon, and Farmersville — where terrain and low population density have historically made public water infrastructure impractical. Even in areas closer to Olean or Salamanca, many rural parcels sit just beyond municipal service lines and rely on private wells.
New York State requires all private wells to be drilled by a licensed contractor and registered with the county health department. Cattaraugus County Department of Health maintains local well permit records and sets construction standards for new installations.
Geology of Cattaraugus County
Cattaraugus County sits squarely on the Allegheny Plateau, a deeply dissected upland underlain almost entirely by Devonian-age sedimentary bedrock — primarily dark organic shales, siltstones, and fine-grained sandstones deposited in ancient marine and deltaic environments between 360 and 420 million years ago. The plateau surface here reaches elevations of 1,500 to over 2,000 feet in some areas, making it significantly higher and more rugged than the terrain to the north in Chautauqua County or Erie County, PA.
Glacial activity shaped the surface landscape — filling valleys with drift, smoothing ridgetops, and depositing till across much of the upland — but the glacial overburden in Cattaraugus County is generally thinner than in Erie County. In most areas, drillers encounter bedrock within the first 30 to 80 feet. After that, progress depends entirely on the fractured shale and sandstone formation beneath.
Water in Cattaraugus County wells comes almost exclusively from fractured bedrock aquifers — specifically from the network of joints, fractures, and bedding plane partings that develop in shale and sandstone over geologic time. There are no large sand and gravel aquifers equivalent to those found in Erie County’s northern lake plain. This means yields are more variable, depth requirements are generally greater, and the character of the water is shaped largely by the chemistry of the shale and sandstone it moves through.
McCandless uses cable tool drilling in Cattaraugus County’s bedrock formations — a method well-suited to the fractured shale geology, allowing drillers to read the formation carefully and identify productive water-bearing zones as they go.
Common Water Quality Issues in Erie County
The chemistry of Cattaraugus County’s Devonian shale bedrock directly shapes what comes out of local well water. Here is what homeowners and property owners most commonly encounter:
Iron and Manganese
Iron is the dominant water quality problem across Cattaraugus County’s private well population. The organic-rich Devonian shales contain significant iron-bearing minerals, and as groundwater moves through fractures in these formations, it picks up dissolved iron and often manganese as well. Iron concentrations exceeding the EPA secondary standard of 0.3 mg/L are routine — in some wells, particularly those tapping deeper, more reducing zones in the shale, levels can run much higher. Red-brown staining on sinks, tubs, and laundry is a near-universal experience for Cattaraugus County well owners who have not installed treatment. A whole-home iron filtration system is the most practical long-term solution.
Hardness
While Cattaraugus County water is generally somewhat less hard than water from Erie County’s carbonate-influenced glacial aquifers, moderate hardness is still common — particularly in wells drawing from sandstone layers interbedded with the shale sequence. Hardness levels of 80–150 mg/L are typical. Scale buildup in water heaters and fixtures and reduced soap efficiency are the most common complaints. A water softener sized appropriately for household usage resolves hardness for most residential systems.
Hydrogen Sulfide (Rotten Egg Odor)
Cattaraugus County has a higher prevalence of hydrogen sulfide odor in well water than almost
anywhere else in McCandless’s service area. The county’s thick, organic-rich black shales —
including formations within the Genesee and Java Groups — release hydrogen sulfide gas as organic
matter breaks down under anaerobic conditions deep in the bedrock. Many homeowners report the
odor as a defining characteristic of their water, especially when it is first drawn. Aeration
treatment or oxidizing filtration eliminates the problem reliably.
Coliform Bacteria
Bacteria testing is recommended annually for all private well owners, and Cattaraugus County is no exception. Older wells, wells near agricultural operations, and wells with aging or deteriorating casing seals are most at risk for total coliform or E. coli contamination. The Cattaraugus County Department of Health provides a list of certified testing labs for residents. McCandless handles water testing as part of every new well installation and offers standalone testing for existing wells. UV purification systems are a cost-effective ongoing protection option for wells with any bacteria history.
Methane (Naturally Occurring)
In portions of Cattaraugus County — particularly in areas overlying or adjacent to the Devonian shale sequence that also hosts natural gas deposits — trace amounts of naturally occurring methane have been detected in private well water. This is distinct from contamination related to oil and gas drilling. At low concentrations, methane in well water is typically not a health hazard, but it can create flammability risks near enclosed spaces and should be assessed if detected. New York State DEC has documented naturally occurring methane in well water across parts of the Southern Tier.
Turbidity After Heavy Rain
In shallower wells or wells with older surface seals, turbidity (cloudy water) following heavy rainfall events is occasionally reported. This indicates that surface water is finding a pathway into the well — either through a deteriorating casing seal or through shallow fractures close to the surface. It is a condition that warrants immediate water testing and, if confirmed, well rehabilitation or seal repair.
Cattaraugus County Private Well Data at a Glance
| Data Point | Figure | Source |
|---|---|---|
| County population | ~76,000 | U.S. Census Bureau, 2020 |
| County land area | ~1,310 sq. miles | U.S. Census Bureau |
| Estimated private well households | 13,000–16,000 | ACS estimates, ~35–42% of housing units |
| Typical well depth | 150–400+ feet | Local drilling records, McCandless field data |
| Primary aquifer type | Fractured Devonian shale and sandstone | NY DEC / USGS |
| Most common water quality issue | Iron / hydrogen sulfide | McCandless field data, NY DEC |
| Recommended annual test | Bacteria (coliform + E. coli) | NYS DOH private well guidance |
| Private well regulation | NYS DOH / Cattaraugus County DOH | Permit required before drilling |
Sources: U.S. Census Bureau American Community Survey; New York State Department of Health; New York State DEC; USGS Appalachian Plateau groundwater studies; Cattaraugus County Department of Health; local well drilling records maintained by McCandless Well Drilling and Services, Inc.
Contact us today for professional well drilling services!
(716) 666-3708
Frequently Asked Questions
What is the average cost of drilling a water well in Cattaraugus County?
Well drilling costs vary based on depth, location, and geological conditions. On average, drilling a well in Cattaraugus County ranges from $5,000 to $15,000. Contact us for a personalized estimate.
What permits or regulations are required for drilling a water well in Cattaraugus County, NY?
Well drilling requires compliance with state and local health department regulations. Permits may be needed, and water quality testing is often required. We handle the permitting process to ensure full compliance.
Why is McCandless Well Drilling and Services, Inc. recognized as Cattaraugus County’s #1 Well Drilling Contractor?
With decades of experience, top-quality equipment, and a commitment to customer satisfaction, we provide reliable, efficient well drilling and maintenance. Our expertise ensures clean, dependable water for homes and businesses.
Are there any local resources or organizations in Cattaraugus County, NY that provide support or information about water wells?
Yes, the Cattaraugus County Health Department and the New York State Department of Environmental Conservation offer resources on well regulations, testing, and maintenance. We’re also happy to provide guidance.
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Contact us today for professional well drilling services!
(716) 666-3708