Community Water System · PWS NH1053020
Hemlock Haven
Operator location Portsmouth, New Hampshire - 49% of 49 violations are health-based (upper-third health share (> 23%)); groundwater source; 207 served per SDWIS.
- 207
- People served (this PWS)
- 49
- EPA violations (this PWS)
- 24
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Hemlock Haven standing, mid SDWIS violation third
49% of 49 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 49% is upper-third health share (> 23%).
The verdict
Hemlock Haven lands in the middle third by violation volume (49), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is smaller (207; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 49% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- 49
- Total EPA violations on record
- 49%
- Health-based (MCL / treatment failure)
- 207
- People served by this PWS (SDWIS)
- N/A
- PFAS compounds detected (UCMR5)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Private
- Connections
- 83
- County
- Rockingham
- School/Daycare
- No
- MCL Violations
- 24
- Monitoring Violations
- 21
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 20 | 1991 |
| Nitrate | MR | 10 | 1995 |
| Lead and Copper Rule | MR | 7 | 2021 |
| Coliform (TCR) | MR | 4 | 2005 |
| Revised Total Coliform Rule | MCL | 4 | 2023 |
Violation Count vs. the National Corpus
Hemlock Haven has 49 recorded EPA violations, 56% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 44% carry more. 49% of this system's own violations are health-based (24 of 49), and it ranks unranked by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
49 Around the middle fewer violations than 44% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
Health-based violations on Hemlock Haven
24 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for NH1053020.
Sources: EPA SDWIS
Nationwide peers
49 violations · 207 served: nearest cross-state SDWIS matches.
Cross-state systems near this violation count
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
What to do with Hemlock Haven
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in New Hampshire compares on the same EPA violation measures. New Hampshire systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.