Community Water System · PWS NH1141010
Hillsborough Water Works
Operator location Hillsborough, New Hampshire - 48% of 737 violations are health-based (upper-third health share (> 23%)); surface water source; 2,000 served per SDWIS.
- 2,000
- People served (this PWS) Middle third of systems
- 737
- EPA violations (this PWS) Upper third of systems
- 354
- Health-based (this PWS) Upper third by health-based share
- Untested
- UCMR5 (this PWS) No UCMR5 result
Hillsborough Water Works standing, high SDWIS violation third
48% of 737 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 48% is upper-third health share (> 23%). Population rank #13,610 of 29,740 among systems serving 500+.
The verdict
Hillsborough Water Works sits in the upper third of the sitemap cohort by violation count (737), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 2,000 (mid served population (≤ 3,309)). Health-based share is 48% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- #13,610 of 29,740
- Population · /systems
- #65 of 284
- Population · NH
- 737
- Total EPA violations on record
- 48%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
Based on EPA SDWIS violation history and UCMR5 PFAS testing only, not water taste, odor, infrastructure age, or contaminants outside the federally tracked set.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 907
- County
- Hillsborough
- School/Daycare
- No
- MCL Violations
- 353
- Monitoring Violations
- 376
- Treatment Tech Violations
- 1
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| TTHM | MCL | 187 | 2014 |
| Total Haloacetic Acids (HAA5) | MCL | 144 | 2014 |
| Coliform (TCR) | MCL | 22 | 2008 |
| Nitrate | MR | 8 | 1994 |
| Coliform (TCR) | MR | 7 | 2005 |
| cis-1,2-Dichloroethylene | MR | 7 | 1996 |
| Xylenes, Total | MR | 7 | 1996 |
| Chromium | MR | 7 | 1996 |
| CYANIDE | MR | 7 | 1996 |
| o-Dichlorobenzene | MR | 7 | 1996 |
| Fluoride | MR | 7 | 1996 |
| p-Dichlorobenzene | MR | 7 | 1996 |
| Mercury | MR | 7 | 1996 |
| Vinyl chloride | MR | 7 | 1996 |
| 1,1-Dichloroethylene | MR | 7 | 1996 |
| Selenium | MR | 7 | 1996 |
| trans-1,2-Dichloroethylene | MR | 7 | 1996 |
| 1,1,1-Trichloroethane | MR | 7 | 1996 |
| Carbon tetrachloride | MR | 7 | 1996 |
| 1,2-Dichloropropane | MR | 7 | 1996 |
| Trichloroethylene | MR | 7 | 1996 |
| 1,1,2-Trichloroethane | MR | 7 | 1996 |
| CHLOROBENZENE | MR | 7 | 1996 |
| Toluene | MR | 7 | 1996 |
| Ethylbenzene | MR | 7 | 1996 |
| Styrene | MR | 7 | 1996 |
| Arsenic | MR | 7 | 1996 |
| 1,2,4-Trichlorobenzene | MR | 7 | 1996 |
| Barium | MR | 7 | 1996 |
| Thallium, Total | MR | 7 | 1996 |
Violation Count vs. the National Corpus
Hillsborough Water Works has 737 recorded EPA violations, 98% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 2% carry more. 48% of this system's own violations are health-based (354 of 737), and it ranks #13,610 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
737 Higher than most more violations than 98% 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
How many violations vs. how serious, among peer systems
Hillsborough Water Works plotted against 29 peer public water systems (500+ people served), by total violation count (x) and the share of those violations that are health-based (y). The crosshair sits at this sample's own median on each axis. A high violation count does not automatically mean a serious record: most monitoring and reporting violations are minor, not health-based.
Violation volume vs. health-based share
Health-based violations on Hillsborough Water Works
354 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for NH1141010.
Sources: EPA SDWIS
Nationwide peers
737 violations · 2,000 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Hillsborough Water Works
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.
Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.