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Groveton Water Sys

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
2,650 people
Connections
765
Water source
Groundwater
Based in
Northumberland, NH
County
Coos
Owner
Local government
The 2 ZIP codes it serves

03582, 03584

The short answer

1 result is above EPA’s legal limit, and 1 more is above the health goal. The worst: Lead, above the action level. No health-based violations on file since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 1993.

Uranium, nitrate, total trihalomethanes (TTHM), arsenic and haloacetic acids (HAA5): New Hampshire’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 July 29, 2014 to July 11, 2017. Newer results are in the utility’s annual water quality report.

Above the legal limit1

Lead

Comes from pipes, often your own

Above the action level

30ppb

90th percentile, 1993

In the latest period, 9 in 10 homes sampled were at or below 30 ppb, above EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027, and this result is at or above that. EPA’s health goal for lead is zero.

What handles it

Above the health goal1

Uranium

Comes from the source

Above the health goal

1.5ppb

Highest yearly average, 2021

Averaged by year, the highest was 1.5 ppb, in 2021: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.1 ppb, in 2015.

What handles it

Below EPA’s limits2

Nitrate

Comes from the source

Below EPA’s limits

1.7ppm

Highest yearly average, 2020 to 2023

2023 average: 1.3 ppm

Averaged by year, the highest was 1.7 ppm, in 2020, below EPA’s legal limit of 10 ppm. In 2023, the latest year on file, it averaged 1.3 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 1.9 ppm, in 2018.

What handles it

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

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

1.7ppb

Highest yearly average, 2020 to 2023

2023: not found

Averaged by year, the highest was 1.7 ppb, in 2021, below EPA’s legal limit of 80 ppb. In 2023, the latest year on file, it wasn’t found. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.3 ppb, in 2019.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Chromium (total)
  • Fluoride
  • Haloacetic acids (HAA5)

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.

What this report can’t tell you

  • Everything else. Uranium, nitrate, total trihalomethanes (TTHM), arsenic and haloacetic acids (HAA5) results here are New Hampshire’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. Groveton Water Sys’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 New Hampshire cover 2020 to 2023; EPA’s compliance samples are from July 29, 2014 to July 11, 2017.

Testing your own tap

Groveton Water Sys’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 Hampshire certifies.

The 3 labs New Hampshire certifies closest to the area Groveton Water Sys serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Gorham Wastewater Treatment Facility Laboratory

    Gorham, NH · about 23 miles

    Certified for bacteria

    (603) 466-3104

  • Laconia Water Works Laboratory

    Lakeport, NH · about 66 miles

    Certified for bacteria

    (603) 524-1096

  • Vermont Agriculture Environmental Laboratory

    Randolph, VT · about 68 miles

    Certified for bacteria, PFAS

    (802) 461-3363

All 63 certified labs for New Hampshire

Sources

PWSID NH1781010. Rebuilt from EPA data on Oct. 18, 2026.

Also in Coos County

All New Hampshire utilities

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