Is Cambridge, MA tap water safe?
Supplied by Cambridge Water Department · serves 118,214 people (15,001 connections) · Surface water · EPA ID MA3049000
Data: U.S. EPA · How we read the data · How we check it
Buys water from Massachusetts Water Resources Authority (MWRA). Treated water bought from another system can carry that system's contaminants.
Summary
No federal limits exceeded in EPA data.
- PFAS
- Detected, below limit3 of 29 PFAS found at least once. All averages below the federal limits.
- Lead
- Below action level8 ppb (parts per billion) at the 90th percentile: 9 in 10 homes sampled were at or below it. Action level 15 ppb, falling to 10 ppb in Nov 2027. Monitoring period ending Dec 2023. Your home's pipes can make yours higher.
- Violations
- None health-basedNo health-based violations since 2016.
- Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Want to reduce what was found? Filters for these results.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Cambridge Water Department's annual water quality report (Consumer Confidence Report). It lists every regulated contaminant tested and is usually on the utility's website or mailed with your bill, and you can also request it at (617) 349-4770. EPA: how to find it.
PFAS (“forever chemicals”)
EPA UCMR 5: 1 entry point tested Sep 2023 to Jun 2024. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA One sample above limit Limit 4 ppt | 1.2 ppt 30% of the limit |
| PFOS Not detected Limit 4 ppt | – |
| PFHxS Not detected Limit 10 ppt | – |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Not detected Limit 1 | – |
| PFBS Not detected Guideline 2,000 ppt | – |
| PFBA Not detected Guideline 6,000 ppt | – |
| PFHxA Detected, below limit Guideline 3,000 ppt | 1.53 ppt |
| PFPeA Detected, no limit | 1.78 ppt |
29 PFAS tested, 3 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Not detected in 4 samples (reporting limit 9 ppb). About lithium.
Lead and copper
Latest 90th percentile: 8 ppb lead (Jan 2021 – Dec 2023). Below action level
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2021 – Dec 2023 | 8 ppb |
| Jan 2018 – Dec 2020 | 4 ppb |
| Jan 2015 – Dec 2017 | 7 ppb |
Earlier results (9)
| Jan 2012 – Dec 2014 | 5 ppb |
| Jan 2011 – Dec 2011 | 5 ppb |
| Jan 2008 – Dec 2008 | 9 ppb |
| Jan 2003 – Dec 2005 | 7 ppb |
| Jan 2002 – Dec 2002 | 9 ppb |
| Jan 2001 – Dec 2001 | 9 ppb |
| Jan 1998 – Dec 1998 | 5 ppb |
| Jan 1997 – Dec 1997 | 5 ppb |
| Jan 1996 – Dec 1996 | 5 ppb |
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Earlier EPA testing (2013–2020)
| Contaminant | Highest | Guideline |
|---|---|---|
| Manganese | 12.6 ppb | 300 ppb |
| Strontium | 0.18 ppm | 1.5 ppm |
| Chromium-6 | 0.074 ppb | – |
| Chlorate | 300 ppb | 210 ppb |
Where it serves
Cambridge
ZIP codes the system reported serving: 02138, 02139, 02140, 02141, 02142
Nearby utilities
- Somerville Water Dept. (MWRA) Somerville · 1 mi
- Medford Water Dept. (MWRA) Medford · 3 mi
- Brookline Water and Sewer Division Brookline · 4 mi
- Malden Water Division (MWRA) Malden · 5 mi
- Newton Water Dept. (MWRA) Newton · 5 mi
- Boston Water and Sewer Commission (MWRA) Boston · 6 mi
Questions
Is Cambridge tap water safe to drink?
Most of Cambridge gets its water from Cambridge Water Department. Cambridge Water Department has no health-based violations since 2016. EPA testing found no PFAS above the federal limits. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does Cambridge water have PFAS?
Yes. EPA's 2023–2025 testing of Cambridge Water Department found 3 PFAS at least once. None of the averages were above the federal limits.
What is the lead level in Cambridge water?
The most recent 90th-percentile lead result for Cambridge Water Department is 8 ppb, for the period ending Dec 2023. The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for MA3049000: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID MA3049000).
- EPA SDWIS download: the lead results, population and violation records we use.
- The utility's annual water quality report (Consumer Confidence Report): ask Cambridge Water Department at (617) 349-4770, or see EPA's guide to finding it.
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.