North Castle Water District #1
What EPA’s and New York’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.
- Serves
- 2,500 people
- Connections
- 696
- Water source
- Surface water bought from another system
- Based in
- North Castle (T), NY
- County
- Westchester
- Owner
- Local government
The ZIP code it serves
The short answer
Nothing in EPA’s and New York’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.
What was found
Haloacetic acids (HAA5), total trihalomethanes (TTHM), nitrate and arsenic: New York’s yearly summaries per water system, 2020 to 2024, with EPA’s 2012 to 2019 file for earlier years.
Below EPA’s limits3
Haloacetic acids (HAA5)
Forms or is added in treatment
47ppb
Highest yearly average, 2020 to 2024
Averaged by year, the highest was 47 ppb, in 2024, below EPA’s legal limit of 60 ppb. Its highest single sample was 71 ppb. That was also the latest year on file. EPA recorded no violation for haloacetic acids (HAA5) at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 39.8 ppb, in 2018.
What handles it
No certification claim covers this compound yet.
Total trihalomethanes (TTHM)
Forms or is added in treatment
41.3ppb
Highest yearly average, 2020 to 2024
Averaged by year, the highest was 41.3 ppb, in 2024, below EPA’s legal limit of 80 ppb. Its highest single sample was 49.1 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 38.4 ppb, in 2018.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Nitrate
Comes from the source
0.17ppm
Highest sample; found in 4 of 5
2024 average: 0.15 ppm
The highest sample, in 2022, was 0.17 ppm, below EPA’s legal limit of 10 ppm. In 2024, the latest year on file, it averaged 0.15 ppm.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Lead
Violations since 2016
No health-based violations on file with EPA since 2016. There are 4 monitoring or reporting violations: a sample missed, late or not reported.
What this report can’t tell you
Everything else. Haloacetic acids (HAA5), total trihalomethanes (TTHM), nitrate and arsenic results here are New York’s own yearly summaries from 2020 on, with EPA’s national file for 2012 to 2019. North Castle Water District #1’s own annual report, which it must send you every year, has the contaminants this page does not show.
Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.
What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.
Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; New York’s yearly summaries cover 2020 to 2024.
Testing your own tap
The 3 labs New York certifies closest to the area North Castle Water District #1 serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
EAS Inc. - Eastern Analytical Services Inc.
Elmsford, NY · about 2 miles
Certified for lead and copper, asbestos
Rtca-Radon Testing Corporation of America, Inc.
Elmsford, NY · about 2 miles
Westchester Co Labs and Research
Valhalla, NY · about 2 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, PFAS
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- New York State Department of Health, Environmental Public Health Tracker, results from Jan. 1, 2020 to Dec. 31, 2024, read Oct. 8, 2026
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: NYS Environmental Laboratory Approval Program (ELAP), drinking water labs, as listed in TNI LAMS, read Oct. 11, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID NY5903445. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and New York’s records for this utility. They don’t cover everything, which is why the next step matters.Every contaminant TapBuff tracks
- Get the utility’s own reportNorth Castle Water District #1 must send you a water quality report every year. It covers contaminants this page does not show.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Decide if you want a filter at allA filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.NSF/ANSI standards, decoded