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Lewisboro Commons

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
168 people
Connections
5
Water source
Groundwater influenced by surface water
Based in
Lewisboro (T), NY
County
Westchester
Owner
Private

The short answer

1 result is above the health goal. The worst: Uranium, above the health goal. No health-based violations on file since 2016.

What handles it

What was found

Uranium, total trihalomethanes (TTHM), nitrate, haloacetic acids (HAA5) and arsenic: New York’s yearly summaries per water system, 2022 to 2024.

Above the health goal1

Uranium

Comes from the source

Above the health goal

0.87ppb

Highest yearly average, 2022 to 2023

Averaged by year, the highest was 0.87 ppb, in 2023: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 1.4 ppb. That was also the latest year on file.

What handles it

Below EPA’s limits3

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

11.8ppb

Highest yearly average, 2022 to 2024

2024 average: 9.8 ppb

Averaged by year, the highest was 11.8 ppb, in 2023, below EPA’s legal limit of 80 ppb. Its highest single sample was 14.9 ppb. In 2024, the latest year on file, it averaged 9.8 ppb.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Nitrate

Comes from the source

Below EPA’s limits

1.1ppm

Highest sample; found in 6 of 6

2024 average: 0.21 ppm

The highest sample, in 2023, was 1.1 ppm, below EPA’s legal limit of 10 ppm. In 2024, the latest year on file, it averaged 0.21 ppm.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

3.0ppb

Highest yearly average, 2022 to 2024

2024 average: 2.0 ppb

Averaged by year, the highest was 3.0 ppb, in 2023, below EPA’s legal limit of 60 ppb. Its highest single sample was 4.7 ppb. In 2024, the latest year on file, it averaged 2.0 ppb.

What handles it

No certification claim covers this compound yet.

2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Lead

What handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

At the tap, or for the whole house?

These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. How whole-house systems compare.

Filters with those claims on a certifier’s listing

None of the filters TapBuff has checked so far carry these claims. Search the certifier listings for the claim above.

Compare five-year costs

Violations since 2016

No health-based violations on file with EPA since 2016.

What this report can’t tell you

  • Everything else. Uranium, total trihalomethanes (TTHM), nitrate, haloacetic acids (HAA5) and arsenic results here are New York’s own yearly summaries from 2022 on, with EPA’s national file for 2012 to 2019. Lewisboro Commons’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 2022 to 2024.

Testing your own tap

Lewisboro Commons’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab New York certifies.

No lab New York certifies is within 75 miles of the area Lewisboro Commons serves on the state’s list. Some take samples by mail; the state’s page lists them all.

All 161 certified labs for New York

Sources

PWSID NY5930083. Rebuilt from EPA data on Oct. 18, 2026.

Also in Westchester County

All New York utilities

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