City water profile
Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Derry, New Hampshire.
Median indexed hardness
57PPM
2 indexed ZIPs
Range 56–58.8 PPM
City summary
Derry has 2 published ZIP profiles across Rockingham County. The indexed median is 57 PPM, compared with 58 PPM across New Hampshire.
Among the 74 New Hampshirecities with an indexed median, Derry ranks #39from highest to lowest. Across all 90 state ZIP profiles, available estimates run from 16to 102 PPM.
The 56–58.8 PPM range shows how much the available ZIP estimates vary within the city label.
Hardness distribution
2 of 2 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.
Evidence quality
Confidence labels
Observation window: Jan 4, 2016 to Jun 8, 2026.
ZIP directory
Open a ZIP for site-level provenance and measurements.
Public water systems
PWSID NH0611010
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID NH0612150
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID NH0612020
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID NH0612010
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID NH0612070
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID NH0612170
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID NH0612230
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID NH0612140
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID NH0613060
The system names this served city; Census place overlap links the city to this ZCTA.
PWSID NH0613010
The system names this served city; Census place overlap links the city to this ZCTA.
Compliance history
No active health-based violation appears among the associated systems in the represented EPA reporting quarter. This does not mean every contaminant was tested at every tap.
| Record | System | Period | Status |
|---|---|---|---|
| Arsenic | NH0613010 | Oct 1, 2023 | Resolved |
| Nitrate | NH0613060 | Jul 1, 2023 | Resolved · health-based |
| E. COLI | NH0613010 | Jan 11, 2023 | Resolved |
| Revised Total Coliform Rule | NH0613010 | May 10, 2022 | Resolved |
| Lead and Copper Rule | NH0613010 | Apr 1, 2022 | Resolved |
| Revised Total Coliform Rule | NH0613010 | Apr 1, 2022 | Resolved |
| Revised Total Coliform Rule | NH0613010 | Apr 1, 2021 | Resolved |
| Revised Total Coliform Rule | NH0613010 | Apr 1, 2021 | Resolved |
Practical next steps
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Questions people ask
The indexed city median is 57 PPM. Open the ZIP report to verify the distance and confidence behind that estimate.
Compliance history is utility-wide and cannot guarantee conditions at every tap. Check current notices and test when address-specific evidence is needed.
Choose treatment only after confirming the problem at the property. A softener targets hardness; contaminant treatment requires a matching, verified performance claim.