Well water in Islip, New York
1in17
Testing recommended
tested well samples in Islip exceeded the EPA limit for nitrate (10 mg/L), based on public data from USGS Water Quality Portal.
The strongest signal is PFOA: 100% of 11 local samples were above the limit, too few samples to carry the headline but first on the test list below.
16,213 test results across 15 contaminants from at least 275 wells, 1932 to 2023; iron has the most at 3,918. Data refreshed September 3, 2026.
Compiled by Nick at Well Water Nerd from public records. How these pages are built
What individual samples found
Each row summarizes every public sample for that contaminant inside Islip. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.
| Contaminant | Above limit | Samples | Detected | Median | Highest | Limit |
|---|---|---|---|---|---|---|
| PFOA 2018 to 2021 | 11 | 100% | 9.1 | 17 | 4 ng/L EPA limit | |
| PFOS 2018 to 2021 | 11 | 64% | 18 | 41 | 4 ng/L EPA limit | |
| E. coli 2007 to 2019 | 10 | 10% | 0 | 2 | 0 MPN/100mL EPA limit | |
| Nitrate 1973 to 2021 | 294 | 65% | 0.05 | 22.7 | 10 mg/L EPA limit | |
| Arsenic 1971 to 2016 | 304 | 30% | 0 | 29 | 10 ug/L EPA limit | |
| Copper 1967 to 2018 | 1,307 | 60% | 0.02 | 8.4 | 1.3 mg/L EPA limit | |
| Fluoride 1964 to 2023 | 759 | 35% | 0 | 8.12 | 4 mg/L EPA limit | |
| Lead 1971 to 2016 | 383 | 26% | 0 | 0.36 | 15 ug/L EPA limit | |
| Uranium 2006 to 2016 | 12 | 25% | 0 | 0.008 | 30 ug/L EPA limit | |
| Radium (226 + 228) 2012 to 2016 | 10 | 50% | 0.011 | 0.7 | 5 pCi/L EPA limit | |
| Iron 1932 to 2023 | no limit | 3,918 | 69% | 0.47 | 170,000 | 300 ug/L nuisance level |
| Manganese 1959 to 2023 | no limit | 3,562 | 59% | 0 | 29,000 | 300 ug/L health guideline |
| Chloride 1932 to 2023 | no limit | 3,409 | 100% | 8 | 18,000 | 250 mg/L nuisance level |
| Sodium 1961 to 2023 | no limit | 2,218 | 100% | 6.5 | 9,500 | 20 mg/L health guideline |
Sampled fewer than 10 times, too few to summarize: Radon (5).
Over time
Share of samples above the limit by period. A cell needs ten samples to show; a comparison needs twenty in each period. Later periods sample fewer wells, and often the ones already known to have a problem.
| Contaminant | before 2000 | 2000s | 2010s | 2020s |
|---|---|---|---|---|
| Copper | 1%1,282 samples | n/a | 0%18 samples | n/a |
| Fluoride | 0%733 samples | n/a | 0%17 samples | n/a |
| Nitrate | 7%187 samples | 0%41 samples | 6%63 samples | n/a |
Nitrate above the limit in Islip rose from 0% of 41 samples in the 2000s to 6% of 63 in the 2010s.
Closer than the town
See the sampled wells near your address
The same records, drawn around one point: which wells within a few miles were sampled and what they found, how deep the wells next to you were drilled, and any leaking tank or cleanup site within a mile.
Check my addressWhat this means
The contaminants most often above their limit here are pfoa (100% of 11 samples), pfos (64% of 11 samples), and e. coli (10% of 10 samples). A well next door can differ sharply from yours because bedrock fractures, well depth and plumbing all matter, so these rates describe the area, not your tap.
Iron, Manganese, and Chloride are widespread in local groundwater. They are mainly a staining and taste problem, but high manganese also carries a health advisory for infants.
What to test for in Islip
- 1PFOA100% of 11 local samples were above the limit.
- 2PFOS64% of 11 local samples were above the limit.
- 3E. coli10% of 10 local samples were above the limit.
- 4Nitrate6% of 294 local samples were above the limit.
- 5Arsenic1% of 304 local samples were above the limit.
- 6Copper<1% of 1,307 local samples were above the limit.
- 7Fluoride<1% of 759 local samples were above the limit.
- 8Volatile organic compounds (VOCs)48 hazardous waste sites on record locally.
- 9Metals panel48 hazardous waste sites on record locally.
Test your Islip well for PFOA, PFOS and E. coli
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
Just want bacteria checked first? Tap Score coliform and E. coli test, $99. Coliform and E. coli are the tests every well needs every year.
Want a quick look before paying for a lab? Home well water test strips on Amazon check hardness, iron, pH and nitrate in minutes. They are a screen, not a result: arsenic, bacteria, uranium and PFAS need a certified lab.
Affiliate links: the merchant pays us a commission and the price is the same for you. It does not change what the data above says. As an Amazon Associate we earn from qualifying purchases.
Where to get a well tested in New York: certified labs, state programs and prices.
Already have results back? Get your lab report read against the Islip numbers, $29. Every line explained, ranked by what matters, with the fix for each.
Wells in Islip
47 domestic wells in Islip are on record with the state. the typical well is 66 feet deep (one in ten goes past 105 feet).
Find your own well's report
The state keeps the driller's report for most wells drilled since 1984. It tells you how deep your well is, where bedrock starts, and how much water it makes, which decides what treatment can work.
- Open NYSDEC water well completion reports and choose Water Well.
- The report lists depth, depth to bedrock, cased depth, yield and the driller.
Drillers have filed reports with the state since April 2000; a well drilled before then usually has no record.
The rock under Islip
Northern Atlantic Coastal Plain aquifer system
Semiconsolidated sand. Coastal plain sands like these give steady yields at moderate depth. Salt water and sodium are the usual issues near the coast, and nitrate where the water table is shallow; arsenic and radon from bedrock are less common.
Classification from the USGS Principal Aquifers of the United States (national map, 2003 edition, GIS release 2015), read at the town centroid. A single well can sit in a different unit, especially near a boundary.
Official help in New York
Two places to start that are not selling anything: the state program that answers private well questions, and its list of labs certified to run drinking water tests. A certified lab is the difference between a result you can act on and a number.
- Private Wells, NYSDOH
- Environmental Laboratory Approval Program, NYSDOH
Contamination sources on record in Islip
NYSDEC remediation sites records 48 hazardous waste sites in Islip, among 64 regulated sites in total. Groundwater does not follow property lines, so a well within a few hundred feet of one of these is worth testing for what that site could release.
- 48
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 16
- other remediation projects
Treatment that fits the local profile
PFOA
Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
PFOS
Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
E. coli
Shock chlorination and fix the well cap or casing; UV disinfection whole-house; Chlorination system
Nitrate
Point-of-use reverse osmosis; Anion exchange; Distillation
Arsenic
Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange
Systems we would look at first
Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
For PFOA
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For PFOA
Whole-house PFAS carbon system
whole-house, at the point of entry, about $3,000
Granular activated carbon certified to NSF/ANSI 53 for PFOA and PFOS; replace media on schedule.
For PFOA
Aquasana SmartFlow reverse osmosis
under-sink or countertop, about $225
Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.
For PFOS
Aquasana Claryum 3-Stage under-sink filter
under-sink or countertop, about $175
Certified to NSF/ANSI 53 to reduce 99% of lead and 99.7% of PFOA and PFOS at the tap. Not a fix for arsenic, nitrate or bacteria.
For PFOS
Aquasana HealthShield whole-house filter
whole-house, at the point of entry, about $2,099
Whole-house carbon system the maker certifies to reduce PFAS (PFOA and PFOS) and VOCs at every tap; a UV option adds bacteria protection.
For E. coli
UV disinfection system
whole-house, at the point of entry, about $900
Fix the well cap and casing first; UV keeps bacteria from returning.
For E. coli
Aquasana Rhino Well Water with UV
whole-house, at the point of entry, about $2,871
Whole-house system built for wells: sediment pre-filter, KDF and carbon, and a UV lamp rated to kill 99.99% of bacteria and viruses. It does not remove arsenic, nitrate, uranium or radon.
Free, no obligation
Get on the list for a free in-home water test in Islip
No water treatment company serves Islip through Well Water Nerd yet. We are signing licensed companies on county by county: they test at your tap for free, walk you through the numbers, and quote treatment only if something needs fixing. Leave your details and you are first in line. Nothing is shared until a company joins for Islip, and you get an email naming it first.
Common questions
How deep are wells in Islip?
The typical domestic well in Islip is 66 feet deep, based on 47 wells reported to the state. One in ten is deeper than 105 feet.
Is there arsenic in well water in Islip?
Arsenic was detected in 30% of 304 public well samples in Islip, and 1% were above the EPA limit of 10 ug/L. Arsenic has no taste or smell; a lab test is the only way to know your level.
How often should I test a private well in Islip?
Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.
Towns near Islip
Closest first. Groundwater does not stop at a line on a map, so the next town over is a fair second opinion.
Want the numbers themselves? Download the New York dataset as CSV, every county and town, with the sources named.
Sources
- USGS Water Quality Portal: 16,213 samples in Islip. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
- NYSDEC water well completion reports: 567 well records in Islip, 47 domestic. Water well completion reports filed with the New York State Department of Environmental Conservation Water Well Contractor Program since 2000. Only aggregates are shown; owner names and addresses are never stored. Retrieved September 16, 2026.
- NYSDEC remediation sites: 64 regulated sites located in Islip. State Superfund, brownfield, voluntary cleanup, RCRA and spill remediation sites from the New York State Department of Environmental Conservation Environmental Remediation Sites database. Retrieved September 16, 2026.
Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.