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Grand Isle Water System

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
278 people
Connections
111
Water source
Groundwater
Based in
Grand Isle, ME
County
Aroostook
Owner
Local government
The ZIP code it serves

04746

The short answer

2 results are above the health goal. The worst: Lead, 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 2009 to 2024.

Total trihalomethanes (TTHM), arsenic, haloacetic acids (HAA5) and nitrate: Maine’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, chromium (total) and fluoride: EPA’s compliance monitoring file, samples taken from Dec. 29, 2014 to March 28, 2017. Newer results are in the utility’s annual water quality report.

Above the health goal2

Lead

Comes from pipes, often your own

Above the health goal

2.1ppb

90th percentile, 2022 to 2024

In the latest period, 9 in 10 homes sampled were at or below 2.1 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

Uranium

Comes from the source

Above the health goal

1.3ppb

Highest yearly average, 2015 to 2017

2017, one sample: 1.2 ppb

Averaged by year, the highest was 1.3 ppb, in 2015: below EPA’s legal limit of 30 ppb, but above its health goal of zero. In 2017, the latest year on file, its one sample was 1.2 ppb.

What handles it

Below EPA’s limits3

Chromium (total)

Comes from the source

Below EPA’s limits

3.1ppb

Highest yearly average, 2014 to 2017

2017, one sample: 0.81 ppb

Averaged by year, the highest was 3.1 ppb, in 2014, below EPA’s legal limit of 100 ppb. In 2017, the latest year on file, its one sample was 0.81 ppb.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

2.1ppb

Highest yearly average, 2022

Averaged by year, the highest was 2.1 ppb, in 2022, below EPA’s legal limit of 80 ppb. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.5 ppb, in 2013.

What handles it

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

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.1ppm

Highest yearly average, 2014 to 2017

2017, one sample: 0.1 ppm

Averaged by year, the highest was 0.1 ppm, in 2014, below EPA’s legal limit of 4.0 ppm. In 2017, the latest year on file, its one sample was 0.1 ppm.

What handles it

3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Haloacetic acids (HAA5)
  • Nitrate

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 5 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM), arsenic, haloacetic acids (HAA5) and nitrate results here are Maine’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Uranium, chromium (total) and fluoride come from EPA’s file alone, which ends in 2019. Grand Isle Water System’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 Maine cover 2020 to 2023; EPA’s compliance samples are from Dec. 29, 2014 to March 28, 2017.

Testing your own tap

Grand Isle Water System’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 Maine certifies.

The lab Maine certifies closest to the area Grand Isle Water System serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

Maine Health and Environmental Testing Laboratory: Well water test kits ordered online, from a bacteria-only test to full panels for new wells and home sales. The lab must receive the sample within 30 hours of collection. The basic safety test is $42, bacteria alone $27, first-draw lead $32, and the fuller well tests $127 to $147. Maine Private Well and Radiological Water and Air Test.

All 53 certified labs for Maine

Sources

PWSID ME0092285. Rebuilt from EPA data on Oct. 18, 2026.

Also in Aroostook County

All Maine utilities

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