Water Quality Report · Updated May 12, 2026
CAMBRIDGE WATER DEPARTMENT
CAMBRIDGE WATER DEPARTMENT delivers tap water graded F (50/100) by TapWaterSafety.org. The utility serves approximately 118,214 residents in CAMBRIDGE, Massachusetts 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; Total trihalomethanes (TTHMs) significantly above health guideline. For questions, the utility can be reached at 6173494770.
Is CAMBRIDGE tap water safe to drink?
CAMBRIDGE WATER DEPARTMENT delivers tap water that earns a grade of F (50/100) from TapWaterSafety.org — a poor rating, with significant contamination concerns and/or recent violations.
The utility serves 118,214 residents in CAMBRIDGE, drawing from surface water.
Public testing data identifies 19 contaminants in this water above EWG's health-based guidelines, including: Perfluorooctanoic acid (PFOA), Perfluorohexane sulfonate (PFHXS), Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Haloacetic acids (HAA5), Bromodichloromethane, Dibromoacetic acid, Dibromochloromethane, Dichloroacetic acid, Perfluorononanoic acid (PFNA), Chloroform, Perfluorooctane sulfonate (PFOS), Radium, combined (-226 and -228), Chromium (hexavalent), Nitrate, Bromoform, Bromate, Chlorate, Trichloroacetic acid. 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.
Quick actions for CAMBRIDGE residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for CAMBRIDGE WATER DEPARTMENT.
PFAS contamination
Severe concernPerfluorononanoic acid (PFNA), Perfluorooctane sulfonate (PFOS) 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 1.96 ppt, 1960x above the EWG health guideline of 0.001 ppt.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 13.7 ppb, 228x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 11.6 ppb, 77x above the EWG health guideline of 0.15 ppb.
Contact CAMBRIDGE WATER DEPARTMENT
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 CAMBRIDGE
Filters matched to the specific contaminants in this water supply.
Reverse Osmosis or NSF P473 certified carbon
$80-$750Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
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 50/100 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 |
5.96 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | EPA violation |
| Perfluorohexane sulfonate (PFHXS) PFAS |
1.96 ppt | 0.001 | 10.0 | — | — | — | — | 1960× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
13.7 ppb | 0.06 | — | — | — | — | — | 228× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
11.6 ppb | 0.15 | 80.0 | 100 | — | — | — | 77× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
6.54 ppb | 0.1 | 60.0 | 60 | — | — | — | 65× over |
| Bromodichloromethane Disinfection byproduct |
3.41 ppb | 0.06 | — | — | — | — | — | 57× over |
| Dibromoacetic acid Disinfection byproduct |
1.3 ppb | 0.03 | — | — | — | — | — | 43× over |
| Dibromochloromethane Disinfection byproduct |
3.24 ppb | 0.1 | — | — | — | — | — | 32× over |
| Dichloroacetic acid Disinfection byproduct |
5.07 ppb | 0.2 | — | — | — | — | — | 25× over |
| Perfluorononanoic acid (PFNA) PFAS |
0.11 ppt | 0.006 | 10.0 | — | — | — | — | 18× over |
| Chloroform Disinfection byproduct |
4.0 ppb | 0.4 | — | — | — | — | — | 10× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
2.18 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | 7.3× over |
| Radium, combined (-226 and -228) Radiological |
0.21 pCi/L | 0.05 | 5.0 | — | — | — | — | 4.1× over |
| Chromium (hexavalent) Heavy metal |
0.0563 ppb | 0.02 | — | — | — | — | — | 2.8× over |
| Nitrate Inorganic |
0.35 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 2.5× over |
| Bromoform Disinfection byproduct |
0.99 ppb | 0.5 | — | — | — | — | — | 2.0× over |
| Bromate Disinfection byproduct |
0.12 ppb | 0.1 | 10.0 | 10 | 10 | 0.1 | — | 1.2× over |
| Chlorate Disinfection byproduct |
231.3 ppb | 210.0 | — | — | — | — | — | 1.1× over |
| Trichloroacetic acid Disinfection byproduct |
0.105 ppb | 0.1 | — | — | — | — | — | 1.0× over |
| Aluminum Heavy metal |
31.8 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Barium Heavy metal |
36.7 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Manganese Heavy metal |
3.56 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
3.44 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluoroheptanoic acid (PFHPA) PFAS |
2.08 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
1.78 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
2.35 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
0.0542 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.00813 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.146 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Bromide Other |
71.9 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.7 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Nitrite Inorganic |
0.00326 ppm | — | 1.0 | — | — | — | — | 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.
CAMBRIDGE WATER DEPARTMENT service area
This water system serves 1 community in Middlesex County, Massachusetts. Click any city for its dedicated tap water quality page.
Find the right filter for CAMBRIDGE water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.