Water Quality Report · Updated October 07, 2026
PENNICHUCK WATER WORKS
PENNICHUCK WATER WORKS delivers tap water graded B (78/100) by TapWaterSafety.org. The utility serves approximately 89,073 residents in NASHUA, New Hampshire using surface water. The most significant water quality concerns are: PFAS contamination; Perfluorohexane sulfonate (PFHXS) significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline; Perfluorooctanoic acid (PFOA) significantly above health guideline.
Is NASHUA tap water safe to drink?
PENNICHUCK WATER WORKS delivers tap water that earns a grade of B (78/100) from TapWaterSafety.org — a good rating, with only minor concerns relative to health-based guidelines.
The utility serves 89,073 residents in NASHUA, drawing from surface water.
Public testing data identifies 5 contaminants in this water above EWG's health-based guidelines, including: Perfluorooctanoic acid (PFOA), Perfluorohexane sulfonate (PFHXS), Haloacetic acids (HAA9), Perfluorooctane sulfonate (PFOS), Chromium (hexavalent). For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
EPA compliance record
Official U.S. EPA records for PENNICHUCK WATER WORKS (system ID NH1621010) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Quick actions for NASHUA residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for PENNICHUCK WATER WORKS.
PFAS contamination
Severe concernPerfluorooctane sulfonate (PFOS), Perfluorooctanoic acid (PFOA) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Perfluorohexane sulfonate (PFHXS) significantly above health guideline
Moderate concernPerfluorohexane sulfonate (PFHXS) detected at 1.19 ppt, 1186x above the EWG health guideline of 0.001 ppt.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 17.8 ppb, 296x above the EWG health guideline of 0.06 ppb.
Perfluorooctanoic acid (PFOA) significantly above health guideline
Moderate concernPerfluorooctanoic acid (PFOA) detected at 9.92 ppt, 110x above the EWG health guideline of 0.09 ppt.
Contact PENNICHUCK WATER WORKS
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for NASHUA
Filters matched to the specific contaminants in this water supply.
Filter certified for PFOA/PFOS (NSF/ANSI 53 or 58)
$180-$750Reverse osmosis and some carbon block filters reduce PFAS. Look for certification to NSF/ANSI 53 or 58 for PFOA/PFOS.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 78/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Perfluorooctanoic acid (PFOA) PFAS |
9.92 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | EPA violation |
| Perfluorohexane sulfonate (PFHXS) PFAS |
1.19 ppt | 0.001 | 10.0 | — | — | — | — | 1186× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
17.8 ppb | 0.06 | — | — | — | — | — | 296× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
2.63 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 8.8× over |
| Chromium (hexavalent) Heavy metal |
0.0488 ppb | 0.02 | — | — | — | — | — | 2.4× over |
| Chlorate Disinfection byproduct |
117.1 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
6.37 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
2.17 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
1.79 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
1.27 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluoroheptanoic acid (PFHPA) PFAS |
0.933 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
1.01 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.0711 ppb | 1500.0 | — | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
PENNICHUCK WATER WORKS service area
This water system serves 1 community in Hillsborough County, New Hampshire. Click any city for its dedicated tap water quality page.
Find the right filter for NASHUA water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.