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Aquarion - Cornwall

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
98 people
Connections
61
Water source
Groundwater
Based in
Cornwall, CT
County
Litchfield
Owner
Private
The ZIP code it serves

06753

The short answer

2 results are 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

Lead and copper: EPA SDWIS monitoring periods ending 2005 to 2026.

Total trihalomethanes (TTHM), nitrate and haloacetic acids (HAA5): 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.

Uranium, fluoride, arsenic and chromium (total): EPA’s compliance monitoring file, samples taken from Feb. 2, 2012 to May 15, 2019. Newer results are in the utility’s annual water quality report.

Above the health goal2

Uranium

Comes from the source

Above the health goal

4.2ppb

Highest yearly average, 2019

Averaged by year, the highest was 4.2 ppb, in 2019: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That is the only year on file.

What handles it

Lead

Comes from pipes, often your own

Above the health goal

1.2ppb

90th percentile, 2024 to 2026

In the latest period, 9 in 10 homes sampled were at or below 1.2 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 limits4

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

8.0ppb

Highest yearly average, 2020 to 2023

Averaged by year, the highest was 8.0 ppb, in 2023, below EPA’s legal limit of 80 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 8.0 ppb, in 2016.

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

0.61ppm

Highest yearly average, 2020 to 2023

2023 average: 0.5 ppm

Averaged by year, the highest was 0.61 ppm, in 2022, below EPA’s legal limit of 10 ppm. In 2023, the latest year on file, it averaged 0.5 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.77 ppm, in 2013.

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, 2020 to 2023

2023 average: 1.0 ppb

Averaged by year, the highest was 3.0 ppb, in 2022, below EPA’s legal limit of 60 ppb. In 2023, the latest year on file, it averaged 1.0 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.0 ppb, in 2012.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.08ppm

Highest yearly average, 2012 to 2019

2019, one sample: 0.07 ppm

Averaged by year, the highest was 0.08 ppm, in 2012, below EPA’s legal limit of 4.0 ppm. In 2019, the latest year on file, its one sample was 0.07 ppm.

What handles it

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

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

No health-based violations on file with EPA since 2016. There are 13 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM), nitrate and haloacetic acids (HAA5) results here are Connecticut’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Uranium, fluoride, arsenic and chromium (total) come from EPA’s file alone, which ends in 2019. Aquarion - Cornwall’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. 2, 2012 to May 15, 2019.

Testing your own tap

Aquarion - Cornwall’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.

No lab Connecticut certifies is within 75 miles of the area Aquarion - Cornwall serves on the state’s list. Some take samples by mail; the state’s page lists them all.

All 86 certified labs for Connecticut

Sources

PWSID CT0310011. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Litchfield County

All Connecticut utilities

What to do next