PlainRecordsCAMBRIDGE WATER DEPARTMENT
A community water system serving CAMBRIDGE, Massachusetts: 118,214 people (EPA's count), surface water. PWS ID MA3049000. EPA's file dated Oct. 23, 2026.
ZIP codes in its service area: 02141, 02142, 02140, 02139, 02138 (99%). The percentage is this system's share of the ZIP's people on a public water system, from EPA's service area map.
Health-based violations on EPA's record since Oct. 23, 2023: none listed (EPA file Oct. 23, 2026).
Lead and copper: EPA's sample results
Lead, 90th percentile of the samples in the sampling period Jan. 1, 2021 to Dec. 31, 2023, first reported Dec. 19, 2023: 8 ppb (.008 mg/L), not above EPA's action level of 15 ppb.
Exceedances of these action levels are not violations, but trigger other requirements to limit exposure to lead and copper in drinking water. The 90th percentile is the value that 90% of the sampled taps were at or below; EPA lists a result under its whole sampling period, which can end after the day the result was first reported; the action level is not a health standard. Values as EPA reports them (mg/L), shown in ppb for lead; a value marked "not plausible" (below zero, or above 1 mg/L lead or 100 mg/L copper) is listed as EPA has it but is probably a unit or entry error in EPA's file, and is not compared with an action level.| Sampling period ended | Lead (90th pct.) | Copper (90th pct.) |
|---|---|---|
| Dec. 31, 2023from Jan. 1, 2021 | 8 ppb first reported Dec. 19, 2023 | – |
| Dec. 31, 2020from Jan. 1, 2018 | 4 ppb first reported Dec. 16, 2020 | – |
| Dec. 31, 2017from Jan. 1, 2015 | 7 ppb first reported Dec. 19, 2017 | – |
| Dec. 31, 2014from Jan. 1, 2012 | 5 ppb first reported June 12, 2015 | – |
| Dec. 31, 2011from Jan. 1, 2011 | 5 ppb first reported Sept. 15, 2011 | – |
| Dec. 31, 2008from Jan. 1, 2008 | 9 ppb first reported Dec. 18, 2008 | – |
Source: EPA ECHO, SDWA lead and copper sample results (the newest 6 periods per contaminant). Lead in tap water across the U.S.
PFAS (“forever chemicals”): EPA's tests, 2023–2024
PFOA up to 4.8 ppt (Dec. 5, 2023). EPA's limit for each is 4.0 ppt, which systems must meet from 2029.
One-time EPA testing, not a compliance test: a result at or above a limit is not a violation.How EPA tested
UCMR 5 is EPA's one-time testing of 29 PFAS and lithium, to learn where they occur; it is not a compliance test. A result at or above a limit is not a violation: under the 2024 rule a system is judged on the running annual average at each entry point from 2029 (EPA proposed in May 2026 to let systems ask for two more years, to 2031, for PFOA and PFOS; not final). Labs report a result only at or above EPA's minimum reporting level (4.0 ppt for PFOA and PFOS); a lower amount is reported as not found.| Found | Found in | Highest result | EPA limit |
|---|---|---|---|
| PFOAperfluorooctanoic acid | 1 of 4 tests | 4.8 ppt (0.0048 µg/L)Dec. 5, 2023 | 4.0 ppt |
| PFPeA | 2 of 4 tests | 3.6 ppt (0.0036 µg/L)Dec. 5, 2023 | no EPA limit |
| PFHxA | 2 of 4 tests | 3.1 ppt (0.0031 µg/L)Dec. 5, 2023 | no EPA limit |
PFOA: Limit set by EPA in April 2024; water systems must meet it from April 26, 2029 (EPA proposed in May 2026 to allow until 2031).
Every result found, as EPA reports it (5)
- Dec. 5, 2023PFHxA: 0.0031 µg/LWalter J Sullivan WTP · Entry Point to Dist. System · sample M3K0309-01
- Dec. 5, 2023PFOA: 0.0048 µg/LWalter J Sullivan WTP · Entry Point to Dist. System · sample M3K0309-01
- Dec. 5, 2023PFPeA: 0.0036 µg/LWalter J Sullivan WTP · Entry Point to Dist. System · sample M3K0309-01
- Sept. 13, 2023PFHxA: 0.0030 µg/LWalter J Sullivan WTP · Entry Point to Dist. System · sample M3H1111-01
- Sept. 13, 2023PFPeA: 0.0035 µg/LWalter J Sullivan WTP · Entry Point to Dist. System · sample M3H1111-01
Source: EPA, UCMR 5 occurrence data, tests from Sept. 13, 2023 to June 12, 2024. PFAS in tap water across the U.S.
Tests and paperwork
Monitoring and reporting violations (a required test not done or not reported on time), EPA's flag: No. Quarters with a violation of any kind in the last 3 years: 0 of 12.
EPA's summary fields for this system, under EPA's labels
- Quarters with violation (3 years)
- 0
- Health-based violation now (EPA's current flag)
- No
- Enforcement priority
- No
- Quarters as an enforcement priority (3 years)
- 0
- Monitoring and reporting violations
- No
- Public notice violations
- No
- Other violations
- No
- Has new violations (draft)
- No
- Rules in violation (3 years)
- 0
- Rules being violated
- 0
- Lead action level exceedances (5 years)
- – (not in EPA's file)
- Copper action level exceedances (5 years)
- – (not in EPA's file)
- Complete sanitary surveys (5 years)
- 1
- Date of last complete sanitary survey
- June 7, 2023
- Site visits (5 years)
- 3
- Inspections (5 years)
- 0
- Date of last formal enforcement action
- Dec. 20, 2019
Health-based violations: Violations of maximum contaminant levels (MCLs) or maximum residual disinfectant levels (MRDLs), which specify the highest concentrations of contaminants or disinfectants, respectively, allowed in drinking water; or of treatment technique (TT) rules, which specify required processes intended to reduce the amounts of contaminants in drinking water. MCLs, MRDLs, and treatment technique rules are all health-based drinking water standards.
Monitoring and reporting violations: Failure to conduct regular monitoring of drinking water quality, as required by SDWA, or to submit monitoring results in a timely fashion to the primacy agency.
Public notice violations: Violations of the public notification requirements of SDWA, which require systems to immediately alert consumers if there is a serious problem with their drinking water that may pose a risk to public health.
Other violations: Violations of other requirements of SDWA, such as issuing annual consumer confidence reports or maintaining required records.
Enforcement priority: 'Yes' indicates a public water system with unresolved serious, multiple, and/or continuing violations that is designated as a priority candidate for formal enforcement, as directed by EPA's Drinking Water Enforcement Response Policy.
Lead and copper action levels: Exceedances of these action levels are not violations, but trigger other requirements to limit exposure to lead and copper in drinking water.
Has new violations: Violations that have been reported to SDWA since end of the last official quarter. These violations are considered draft and do not reflect the official compliance status for the facility.
Sanitary survey: A sanitary survey is an on-site review of a system's water source, treatment, distribution system, storage, pumps, monitoring and reporting, management and operation, and operator compliance, intended to point out sanitary deficiencies and assess the system's capability to supply safe drinking water.
Enforcement actions: Formal enforcement actions compel a PWS to take specific actions by specific dates to return to compliance. Informal enforcement actions do not specify actions and deadlines for returning to compliance.
About this system
- PWS ID
- MA3049000
- State
- Massachusetts
- Cities served
- CAMBRIDGE
- Counties served
- Middlesex
- ZIP codes served
- 02138
- Population served
- 118,214
- Primary source
- Surface water
- Owner type
- Local government
- Service area
- Residential Area
From EPA's Safe Drinking Water Information System (SDWIS), through EPA ECHO's drinking water system download. Health-based violations from EPA Envirofacts, downloaded Nov. 2, 2026. EPA's file dated Oct. 23, 2026. EPA: “All compliance and enforcement data displayed on ECHO are current as of the last official quarterly refresh of the source data system, SDWIS, which may lag by three to six months.” These are records of violations, not a test of your tap water today: your water system's annual Consumer Confidence Report has its test results. Names and values are shown as EPA writes them. EPA ECHO drinking water search. How to read this record.