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SCWA, North Stonington Division (Nst)

What EPA’s and CDC’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
1,860 people
Connections
255
Water source
Groundwater
Based in
North Stonington, CT
County
New London
Owner
Local government
The ZIP code it serves

06359

The short answer

1 result is above the health goal. The worst: Lead, above the health goal. 1 health-based violation since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2009 to 2026.

Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 3.1 ppm, for the period ending Dec. 31, 1993. None since is on file, so it is not counted as a current finding.

Nitrate, arsenic and uranium: Connecticut’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2020 to 2023, with EPA’s 2012 to 2019 file for earlier years.

Chromium (total) and fluoride: EPA’s compliance monitoring file, samples taken from Feb. 7, 2012 to Nov. 14, 2018. Newer results are in the utility’s annual water quality report.

Above the health goal1

Lead

Comes from pipes, often your own

Above the health goal

1.1ppb

90th percentile, 2026

In the latest period, 9 in 10 homes sampled were at or below 1.1 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits1

Nitrate

Comes from the source

Below EPA’s limits

0.63ppm

Highest yearly average, 2020 to 2023

2023 average: 0.63 ppm

Averaged by year, the highest was 0.63 ppm, in 2022, below EPA’s legal limit of 10 ppm. In 2023, the latest year on file, it averaged 0.63 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.64 ppm, in 2015.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Chromium (total)
  • Fluoride
  • Uranium

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?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. How whole-house systems compare.

Filters with those claims on a certifier’s listing

Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

Compare five-year costs

The best water filters for lead, ranked

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Revised Total Coliform RuleE. coli was confirmed in the water system.EPA: Maximum Contaminant Level Violation, E. coli (RTCR)July 1, 2017 to July 31, 2017—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 3 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Nitrate, arsenic and uranium results here are Connecticut’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Chromium (total) and fluoride come from EPA’s file alone, which ends in 2019. SCWA, North Stonington Division (Nst)’s own annual report, which it must send you every year, has newer results for those and 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; CDC’s yearly averages for Connecticut cover 2020 to 2023; EPA’s compliance samples are from Feb. 7, 2012 to Nov. 14, 2018.

Testing your own tap

SCWA, North Stonington Division (Nst)’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 Connecticut certifies.

The 3 labs Connecticut certifies closest to the area SCWA, North Stonington Division (Nst) serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Eurofins Rhode Island

    North Kingstown, RI · about 23 miles

    Certified for nitrate, metals, minerals and other inorganics

    (413) 340-3947

  • New England Testing Laboratory, Inc.

    West Warwick, RI · about 23 miles

    Certified for bacteria, nitrate, metals, minerals and other inorganics, organic chemicals, disinfection byproducts

    (401) 353-3420

  • Microbac Laboratories, INC. - Dayville

    Dayville, CT · about 26 miles

    Certified for bacteria, nitrate, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, radioactivity

    (860) 774-6814

All 86 certified labs for Connecticut

Sources

PWSID CT1020021. Rebuilt from EPA data on Oct. 18, 2026.

Also in New London County

All Connecticut utilities

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