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Clark Shores Water Corporation

What EPA’s and Massachusetts’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
350 people
Connections
50
Water source
Groundwater
Based in
Lakeville, MA
County
Plymouth
Owner
Private
Hardness
Moderately hard
The ZIP code it serves

02347

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), haloacetic acids (HAA5), nitrate, fluoride, arsenic and chromium (total): Massachusetts’s own results, samples taken from March 2, 2020 to Sept. 9, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal1

Uranium

Comes from the source

Above the health goal

5.5ppb

Highest yearly average, 2020

Averaged by year, the highest was 5.5 ppb, in 2020: 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

Below EPA’s limits4

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

10.9ppb

Highest yearly average, 2020 to 2026

2026, one sample: 4.5 ppb

Averaged by year, the highest was 10.9 ppb, in 2022, below EPA’s legal limit of 80 ppb. In 2026, the latest year on file, its one sample was 4.5 ppb.

What handles it

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

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

5.0ppb

Highest yearly average, 2020 to 2026

2026: not found

Averaged by year, the highest was 5.0 ppb, in 2023, below EPA’s legal limit of 60 ppb. In 2026, the latest year on file, it wasn’t found in its one sample.

What handles it

No certification claim covers this compound yet.

Nitrate

Comes from the source

Below EPA’s limits

0.74ppm

Highest sample; found in 4 of 4

2025, one sample: 0.74 ppm

The highest sample, in 2025, was 0.74 ppm, below EPA’s legal limit of 10 ppm. That was also the latest year on file, and its one sample was 0.74 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 9.7 ppm, in 2017.

What handles it

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

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.13ppm

Highest yearly average, 2025

Averaged by year, the highest was 0.13 ppm, in 2025, below EPA’s legal limit of 4.0 ppm. That is the only year on file.

What handles it

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

Hardness

Moderately hard, 119 mg/L (7 grains per gallon), at its one sampling point, in 2020.

Hardness is calcium and magnesium. EPA sets no limit for it: it shows up as scale on fixtures and in water heaters, and as soap that won’t lather. USGS calls water above 60 mg/L moderately hard, above 120 hard and above 180 very hard.

Softeners compared at 7 grains per gallon, salt includedSoftener or salt-free conditioner?Massachusetts water hardness, utility by utility

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), haloacetic acids (HAA5), nitrate, fluoride, arsenic and chromium (total) results here are Massachusetts’s own from 2020 on, with EPA’s national file for 2012 to 2019. Clark Shores Water Corporation’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; Massachusetts’s results run from March 2, 2020 to Sept. 9, 2026.

Testing your own tap

Clark Shores Water Corporation’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 Massachusetts certifies.

The 3 labs Massachusetts certifies closest to the area Clark Shores Water Corporation serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Eurofins Providence (AB)

    Middleborough, MA · about 5 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics

    (508) 946-2225

  • New Bedford Health Department Lab

    New Bedford, MA · about 16 miles

    Certified for bacteria

    (508) 991-6199

  • Pace Analytical LLC-Mansfield-320 Forbes

    Mansfield, MA · about 18 miles

    Certified for lead and copper, metals, PFAS

    (508) 822-9300

All 81 certified labs for Massachusetts

Sources

PWSID MA4146006. Rebuilt from EPA data on Oct. 18, 2026.

Also in Plymouth County

All Massachusetts utilities

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