Drinking water quality · 2024
What's in Cambridge, MA tap water
25 contaminants were measured in the Cambridge, MA water system's 2024 annual report. Each is shown below against its federal limit.
- Reporting year
- 2024
- Contaminants measured
- 25
- Over federal limit
- 0
- Approaching the limit
- 1
- Service area
- MA
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound above EPA limits in Cambridge, MA
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFOA (Perfluorooctanoic acid)
● Over EPA limit (1.2×)PFHxA
● Detected (no federal limit)PFPeA
● Detected (no federal limit)Where your water comes from · EPA SDWIS
Cambridge, MA's drinking water comes from surface water, drawn from 4 sources.
Source
- FRESH POND RES.
- HOBBS BROOK RES. LOW
- HOBBS BROOK RES. UPPER
- STONY BROOK RES.
Treatment
- WATER TREATMENT PLANT
Distribution
Also buys water from MWRA.
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Maximum contaminant level exceededHealth-based1 violation on record · most recent Aug 1994resolved
- Treatment technique violationHealth-based1 violation on record · most recent Jan 1992resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0–14 ug/LRangeSystem-wide | None set | Approaching the limit |
| CopperA metal that enters water from corroding household plumbing. | 0.003–0.042 mg/LRangeSystem-wide | 1.3 mg/LAction level | Within the limit |
| BariumA metal from erosion of natural deposits and industrial discharge. | 0.034 mg/LReported levelHighest Level Found | 2 mg/LMCL | Within the limit |
| CalciumA naturally occurring mineral that contributes to water hardness. | 18.1 mg/LAverageAverage Level Found | None set | Detected — no federal limit |
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 4 mg/LAverageAverage Level Found | None set | Detected — no federal limit |
| SodiumA naturally occurring salt component. | 88.1 mg/LAverageAverage Level Found | None set | Detected — no federal limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 0.78–3.05 mg/LRangeSystem-wide | 4 mg/LMCL | Within the limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 2.37–18.7 ug/LRangeSystem-wide | None set | Within the limit |
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 3.32–13.2 ug/LRangeSystem-wide | None set | Within the limit |
| BromodichloromethaneA trihalomethane disinfection byproduct. | 2.4 ug/LAverageSystem-wide | None set | Detected — no federal limit |
| BromoformA trihalomethane disinfection byproduct. | 0.95 ug/LAverageSystem-wide | None set | Detected — no federal limit |
| ChloroformA trihalomethane formed when chlorine reacts with organic matter in water. | 1.7 mg/LAverageAverage Level Found | None set | Detected — no federal limit |
| DibromochloromethaneA trihalomethane disinfection byproduct. | 2.7 ug/LAverageSystem-wide | None set | Detected — no federal limit |
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | 2.72 ng/LAverageSystem-wide | None set | Within the limit |
| Perfluorobutanesulfonic acidPerfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.' | 2.81 ng/LAverageSystem-wide | None set | Detected — no federal limit |
| PFAS | 6.93 ng/LReported levelHighest Level Found | None set | Detected — no federal limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.87 mg/LReported levelHighest Level Found | 4 mg/LMCL | Within the limit |
| NitriteA compound from fertilizer runoff, sewage, and erosion of natural deposits. | 0.13 mg/LReported levelHighest Level Found | 1 mg/LMCL | Within the limit |
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 0.41 mg/LReported levelHighest Level Found | 10 mg/LMCL | Within the limit |
| ChlorideA naturally occurring salt compound. | 142 mg/LAverageAverage Level Found | None set | Detected — no federal limit |
| SulfateA naturally occurring mineral from rock and soil. | 28.7 mg/LAverageAverage Level Found | None set | Detected — no federal limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.2 NTUReported levelHighest Level Found | None set | Within the limit |
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 300 mg/LAverageAverage Level Found | None set | Detected — no federal limit |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | 0.75 pCi/LReported levelHighest Level Found | 5 pCi/LMCL | Within the limit |
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | 1.03 pCi/LReported levelHighest Level Found | 15 pCi/LMCL | Within the limit |
People also ask about Cambridge, MA's water
+Is Cambridge, MA tap water safe to drink in 2024?
Every one of the 25 contaminants measured in Cambridge, MA's 2024 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in Cambridge, MA tap water?
25 contaminants were measured in Cambridge, MA's 2024 Consumer Confidence Report, spanning disinfection byproducts, metals, and inorganic chemicals. 8 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Are any contaminants in Cambridge, MA tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: Lead. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from Cambridge, MA's 2024 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Cambridge, MA's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2024 report; a new report will replace it once the utility publishes its next annual update.