Well water in North Hempstead, New York
In North Hempstead, 4% of 255 tested well samples exceeded the EPA limit for nitrate (10 mg/L), based on public data from USGS Water Quality Portal.
The strongest signal is PFOA: 63% of 27 local samples were above the limit, too few samples to carry the headline but first on the test list below.
16,131 test results across 15 contaminants from at least 420 wells, 1935 to 2024; chloride has the most at 4,155. 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 North Hempstead. 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 2022 | 27 | 81% | 12 | 31 | 4 ng/L EPA limit | |
| PFOS 2018 to 2022 | 27 | 67% | 4.1 | 36 | 4 ng/L EPA limit | |
| Nitrate 1973 to 2018 | 255 | 83% | 1.3 | 21 | 10 mg/L EPA limit | |
| Lead 1971 to 2016 | 381 | 25% | 0 | 700 | 15 ug/L EPA limit | |
| Copper 1957 to 2018 | 733 | 75% | 0.02 | 1.92 | 1.3 mg/L EPA limit | |
| Fluoride 1935 to 2024 | 1,080 | 63% | 0 | 2.6 | 4 mg/L EPA limit | |
| Arsenic 1971 to 2016 | 149 | 10% | 0 | 9 | 10 ug/L EPA limit | |
| Chloride 1935 to 2024 | no limit | 4,155 | 99% | 9 | 20,400 | 250 mg/L nuisance level |
| Iron 1935 to 2024 | no limit | 3,625 | 82% | 40 | 869,000 | 300 ug/L nuisance level |
| Manganese 1949 to 2024 | no limit | 3,424 | 66% | 0 | 7,460 | 300 ug/L health guideline |
| Sodium 1935 to 2024 | no limit | 2,263 | 99% | 8.1 | 50,800 | 20 mg/L health guideline |
Sampled fewer than 10 times, too few to summarize: Uranium (5), Radium (226 + 228) (4), E. coli (1), Radon (2).
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 |
|---|---|---|---|---|
| Fluoride | 0%1,055 samples | n/a | 0%14 samples | n/a |
| Copper | <1%718 samples | n/a | 0%12 samples | n/a |
| Nitrate | 4%223 samples | 0%18 samples | 0%14 samples | n/a |
| PFOA | n/a | n/a | 91%11 samples | 44%16 samples |
| PFOS | n/a | n/a | 82%11 samples | 31%16 samples |
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 (63% of 27 samples), pfos (52% of 27 samples), and nitrate (4% of 255 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.
Chloride, Iron, and Manganese 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 North Hempstead
- 1PFOA63% of 27 local samples were above the limit.
- 2PFOS52% of 27 local samples were above the limit.
- 3Nitrate4% of 255 local samples were above the limit.
- 4Lead3% of 381 local samples were above the limit.
- 5Copper<1% of 733 local samples were above the limit.
- 6Coliform bacteriaRecommended for every private well, every year.
- 7RadonMedian local reading is 73 pCi/L.
- 8Volatile organic compounds (VOCs)68 hazardous waste sites on record locally.
- 9Metals panel68 hazardous waste sites on record locally.
Test your North Hempstead well for PFOA, PFOS and nitrate
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 North Hempstead numbers, $29. Every line explained, ranked by what matters, with the fix for each.
The rock under North Hempstead
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 North Hempstead
NYSDEC remediation sites records 68 hazardous waste sites in North Hempstead, among 93 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.
- 68
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 25
- 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
Nitrate
Point-of-use reverse osmosis; Anion exchange; Distillation
Lead
Point-of-use reverse osmosis; Certified lead-removal carbon filter; Neutralizing filter to raise pH and stop leaching
Copper
Neutralizing filter to raise pH; Point-of-use reverse osmosis
Systems we would look at first
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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 lead
Acid neutralizing filter
whole-house, at the point of entry, about $1,200
Raises pH so plumbing stops leaching lead and copper.
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Common questions
Is there arsenic in well water in North Hempstead?
Arsenic was detected in 10% of 149 public well samples in North Hempstead, and 0% 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 North Hempstead?
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 North Hempstead
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: 16,131 samples in North Hempstead. 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 remediation sites: 93 regulated sites located in North Hempstead. 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.