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Castle Reach

What EPA’s and CDC’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals, plus violations since 2016, with the certification that handles each result.

Serves
110 people
Connections
44
Water source
Groundwater
Based in
Windham, NH
County
Rockingham
Owner
Private
The ZIP code it serves

03087

The short answer

2 results are above the health goal. The worst: Arsenic, above the health goal. 2 health-based violations since 2016.

What handles it

What was found

Arsenic, uranium, total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate: New Hampshire’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2020 to 2023.

Above the health goal2

Arsenic

Comes from the source

Above the health goal

1.7ppb

Highest yearly average, 2021

Averaged by year, the highest was 1.7 ppb, in 2021: below EPA’s legal limit of 10 ppb, but above its health goal of zero. That is the only year on file.

What handles it

  • NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
  • NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”

Uranium

Comes from the source

Above the health goal

2.0ppb

Highest yearly average, 2021

Averaged by year, the highest was 2.0 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.

What handles it

Below EPA’s limits2

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

43ppb

Highest yearly average, 2020 to 2023

2023 average: 25 ppb

Averaged by year, the highest was 43 ppb, in 2020, below EPA’s legal limit of 80 ppb. In 2023, the latest year on file, it averaged 25 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

12ppb

Highest yearly average, 2020 to 2023

Averaged by year, the highest was 12 ppb, in 2023, below EPA’s legal limit of 60 ppb. That was also the latest year on file.

What handles it

No certification claim covers this compound yet.

One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • 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.”

  • NSF/ANSI 53

    Claim: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

    Other certifiers’ wording: Arsenic (III) (50 ppb influent level)

  • NSF/ANSI 58

    Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Uranium

    For: Arsenic, Uranium

    Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)

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

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 reverse osmosis systems, 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)Sept. 1, 2021 to Oct. 1, 2021—Resolved
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 11, 2018 to Jan. 10, 20190.018 MG/LResolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record.

What this report can’t tell you

  • Everything else. Arsenic, uranium, total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate results here are New Hampshire’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Castle Reach’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; CDC’s yearly averages for New Hampshire cover 2020 to 2023.

Testing your own tap

Castle Reach’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 Castle Reach serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Eurofins Derry

    Derry, NH · about 5 miles

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

    (603) 432-3044

  • Nelson Analytical LLC

    Manchester, NH · about 12 miles

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

    (603) 622-0200

  • Pace Analytical Services LLC - MA

    Woburn, MA · about 24 miles

    Certified for asbestos

    (781) 935-3212

All 63 certified labs for New Hampshire

Sources

PWSID NH2542140. Rebuilt from EPA data on Oct. 18, 2026.

Also in Rockingham County

All New Hampshire utilities

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