Drinking water quality · 2024
· Verified
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 — 2 sit at or above that limit.
- Reporting year
- 2024
- Contaminants measured
- 25
- Over federal limit
- 2
- Approaching the limit
- 1
- Worst contaminant
- Sodium
- 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×)below national p90 (13.649999999999999 ng/L across detecting U.S. systems)
PFHxA
● Detected (no federal limit)below national p90 (12.190000000000003 ng/L across detecting U.S. systems)
PFPeA
● Detected (no federal limit)below national p90 (15.95999999999999 ng/L across detecting U.S. systems)
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.
Historical readings · EPA Six-Year Review (2012–2019)
1 contaminant historically over EPA limits in Cambridge, MA
Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.
| Contaminant | Worst detection | EPA limit | Years (2012–2019) |
|---|---|---|---|
HAA5 worst: 2019 | 0.0764 mg/L 1.3× | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
TTHM worst: 2018 | 0.032 mg/L within | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
FLUORIDE worst: 2013 | 1.06 mg/L within | 4 mg/L | '12'13'15'16'17'18 |
NITRITE worst: 2013 | 0.175 mg/L within | 1 mg/L | '12'13'14'15'16'17'18 |
NITRATE worst: 2013 | 0.771 mg/L within | 10 mg/L | '12'13'14'15'16'17'18'19 |
BARIUM worst: 2017 | 0.06 mg/L within below national p90 | 2 mg/L | '12'13'15'16'17'18 |
CHROMIUM worst: 2013 | 0.0013 mg/L within below national p90 | 0.1 mg/L | '13 |
COPPER worst: 2016 | 0.0013 mg/L below national p90 | — | '16 |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| SodiumA naturally occurring salt component. | 88.1 mg/LAverageAverage Level Found | 20 mg/LMCL | At or above the limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0–14 ug/LRangeSystem-wide | 15 ug/LAction level | Approaching 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 |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 300 mg/LAverageAverage Level Found | 500 mg/LMCL | Within the limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.2 NTUReported levelHighest 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. | 2.39 mg/LReported levelHighest Level Found | 4 mg/LMCL | Within the limit |
Inorganic chemicals
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PFAS | 0–6.93 ng/LRangeSystem-wide | 20 ng/LMCL | Within the limit |
| Perfluorobutanesulfonic acidPerfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.' | 2.81 ng/LAverageSystem-wide | None set | Detected — no federal limit |
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | 2.72 ng/LAverageSystem-wide | 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 |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChloroformA trihalomethane formed when chlorine reacts with organic matter in water. | 1.7 mg/LAverageAverage Level Found | 70 mg/LMCL | 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 |
| DibromochloromethaneA trihalomethane disinfection byproduct. | 2.7 ug/LAverageSystem-wide | None set | Detected — no federal limit |
People also ask about Cambridge, MA's water
+Is Cambridge, MA tap water safe to drink in 2024?
The 2024 Consumer Confidence Report for the Cambridge, MA water utility lists 2 contaminants at or above the federal limit: Sodium and Copper. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for 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. 17 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Which contaminants exceed federal limits in Cambridge, MA tap water?
2 contaminants in Cambridge, MA's 2024 report sit at or above the federal limit: Sodium (4.4× the limit); Copper (3.8× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.
+What is the worst contaminant in Cambridge, MA tap water?
The contaminant with the highest measured value relative to its federal limit in the 2024 report is Sodium, at 4.4× the federal threshold. It belongs to the metals family of contaminants.
+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.