Cornerstone Place
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
- 25 people
- Connections
- 14
- Water source
- Groundwater
- Based in
- Deerfield, NH
- County
- Rockingham
- Owner
- Private
The ZIP code it serves
The short answer
1 result is above EPA’s legal limit. The worst: Uranium, above the legal limit. 2 health-based violations since 2016.
What handles itWhat was found
Uranium, nitrate, arsenic and total trihalomethanes (TTHM): New Hampshire’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2022 to 2023, with EPA’s 2012 to 2019 file for earlier years.
Fluoride and chromium (total): EPA’s compliance monitoring file, samples taken from Sept. 9, 2014 to July 10, 2017. Newer results are in the utility’s annual water quality report.
Above the legal limit1
Uranium
Comes from the source
12.6ppb
Highest yearly average, 2022 to 2023
Averaged by year, the highest was 12.6 ppb, in 2023: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That was also the latest year on file. EPA judges this limit at each sampling point, and recorded a violation for uranium at this utility in 2025. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 4.5 ppb, in 2018. One result, 207 ppb on Sept. 9, 2014 in EPA’s file, is left out as a likely entry error: the typical result there is 2.4 ppb.
What handles it
- NSF/ANSI 58 look for “Uranium”
Below EPA’s limits2
Fluoride
Forms or is added in treatment
0.21ppm
Highest yearly average, 2014 to 2017
2017: not found
Averaged by year, the highest was 0.21 ppm, in 2014, below EPA’s legal limit of 4.0 ppm. In 2017, the latest year on file, it wasn’t found in its one sample.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Nitrate
Comes from the source
0.26ppm
Highest yearly average, 2022 to 2023
2023 average: 0.22 ppm
Averaged by year, the highest was 0.26 ppm, in 2022, below EPA’s legal limit of 10 ppm. In 2023, the latest year on file, it averaged 0.22 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 1.9 ppm, in 2014.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Total trihalomethanes (TTHM)
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 58
Claim: Uranium
For: Uranium
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 costsViolations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Combined Uranium | The running average was above the legal limit.EPA: Maximum Contaminant Level Violation, Average | July 1, 2025 to Sept. 30, 2025 | 49 UG/L | Archived |
| Groundwater Rule | A significant problem found in a state inspection was not fixed on time.EPA: Failure To Address Deficiency | Jan. 10, 2016 | — | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 3 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Uranium, nitrate, arsenic and total trihalomethanes (TTHM) results here are New Hampshire’s yearly averages as CDC publishes them, from 2022 on, with EPA’s national file for 2012 to 2019. Fluoride and chromium (total) come from EPA’s file alone, which ends in 2019. Cornerstone Place’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 2022 to 2023; EPA’s compliance samples are from Sept. 9, 2014 to July 10, 2017.
Testing your own tap
The 3 labs New Hampshire certifies closest to the area Cornerstone Place serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Nelson Analytical LLC
Manchester, NH · about 14 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts
Seacoast Analytical Services LLC
Lee, NH · about 17 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics
Eurofins Concord
Concord, NH · about 17 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- CDC Environmental Public Health Tracking Network, yearly averages New Hampshire supplied to CDC, 2020 to 2023, read Oct. 8, 2026. TapBuff’s comparisons with EPA’s limits are its own, not CDC’s or New Hampshire’s.
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: New Hampshire ELAP, drinking water labs, as listed in TNI LAMS, read Oct. 13, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID NH0594010. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on UraniumWhat each one does to health, where it comes from, and the certification claim that addresses it.About Uranium
- Get the utility’s own reportCornerstone Place must send you a water quality report every year. It covers contaminants this page does not show, and has newer results than EPA’s national file for the ones here that come from it.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Compare certified filtersWhat the filters certified for these results cost over five years, cartridges included.Compare five-year costs