Is Cambridge Water Department water safe to drink?

Cambridge Water Department (PWS ID: MA3049000) has 70 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 3 PFAS compounds found. EPA SDWIS lists this system's service population as 118,214 people using Surface Water sources.

How many people does Cambridge Water Department serve?

EPA SDWIS reports that Cambridge Water Department serves 118,214 people (this public water system's service population, not the municipal population of Cambridge or any other city). It is a Local-owned system using Surface Water water sources with 15,063 service connections. The operator address is listed in Cambridge, Massachusetts.

What type of violations does Cambridge Water Department have?

Cambridge Water Department has 70 total violations: 2 health-based violations (MCL exceedances or treatment failures), 63 monitoring/reporting violations, and 1 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.

Has PFAS been detected in Cambridge Water Department water?

Yes. UCMR5 testing detected 3 PFAS compounds in Cambridge Water Department's water supply: PFHxA, PFPeA, PFOA. PFAS are persistent "forever chemicals" that do not break down in the environment.

What water source does Cambridge Water Department use?

Cambridge Water Department uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.

Where does this data come from?

All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.

Where does Cambridge Water Department sit among U.S. public water systems?

According to EPA SDWIS population_served among sitemap-advertised systems (serving 500+), Cambridge Water Department ranks #388 of 29,740 by people served, and #5 of 418 in Massachusetts. Ordinals use population_served DESC among systems serving 500+ (the sitemap cohort). See /methodology#corpus-placement.

How does Cambridge Water Department's violation count compare nationally?

Cambridge Water Department has 70 recorded EPA SDWIS violations, fewer than 35% of the 29,740 public water systems serving 500 or more people nationwide (the same sitemap cohort used for the corpus-placement ranking above). 65% of that cohort has fewer violations than Cambridge Water Department. A system can have zero recorded violations and still be actively monitored, and a high violation count often reflects a system that reports thoroughly, not necessarily one with worse water.

States → Massachusetts

Community Water System · PWS MA3049000

Cambridge Water Department

Operator location Cambridge, Massachusetts - larger served population (> 3,309) at 118,214 people served; 70 SDWIS violations on record from surface water sources.

Compiled by PlainWater · May 15, 2026

118,214
People served (this PWS) Larger third of systems: 70
EPA violations (this PWS) Middle third of systems: 2
Health-based (this PWS) Middle third by health-based share: 3 PFAS
UCMR5 (this PWS) Middle third of PFAS-detected systems

Follow published updates (RSS)

Cambridge Water Department standing, mid SDWIS violation third

118,214 people served (SDWIS) - larger served population (> 3,309). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 3% is middle-third health share (≤ 23%). UCMR5: middle-third PFAS panel (≤ 4 compounds). Population rank #388 of 29,740 among systems serving 500+.

The verdict

Cambridge Water Department lands in the middle third by violation volume (70), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is large (118,214; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 3% (middle-third health share (≤ 23%)). UCMR5 detected 3 PFAS compounds (middle-third PFAS panel (≤ 4 compounds)).

#388 of 29,740
Population · /systems: #5 of 418
Population · MA: 70
Total EPA violations on record: 3%
Health-based (MCL / treatment failure)

Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.

PFAS Detected

3 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

C-

Water Safety Score

53/100

Cambridge Water Department

Based on EPA SDWIS violation history and UCMR5 PFAS testing only, not water taste, odor, infrastructure age, or contaminants outside the federally tracked set.

Health-based violations C-

EPA SDWIS health-based violations on record (MCL, MRDL, treatment technique)

Monitoring & reporting violations F

Non-health SDWIS violations (monitoring, reporting, and other compliance)

PFAS contamination A-

0.0048 µg/L

Highest PFAS compound level detected in UCMR5 testing

System Details

System Type: Community
Owner Type: Local
Connections: 15,063
County: Middlesex
School/Daycare: No
MCL Violations: 1
Monitoring Violations: 63
Treatment Tech Violations: 1

Violation History

Contaminant violations recorded by EPA.

Contaminant	Category	Count	Latest
Heptachlor	MR	2	2019
Pentachlorophenol	MR	2	2019
Toxaphene	MR	2	2019
2,4,5-TP	MR	2	2019
BHC-GAMMA	MR	2	2019
Total Polychlorinated Biphenyls (PCB)	MR	2	2019
1,2-DIBROMO-3-CHLOROPROPANE	MR	2	2019
Dalapon	MR	2	2019
Dinoseb	MR	2	2019
Glyphosate	MR	2	2019
HEXACHLOROBENZENE	MR	2	2019
Hexachlorocyclopentadiene	MR	2	2019
OXAMYL	MR	2	2019
Picloram	MR	2	2019
Carbofuran	MR	2	2019
Chlordane	MR	2	2019
2,4-D	MR	2	2019
ETHYLENE DIBROMIDE	MR	2	2019
Methoxychlor	MR	2	2019
Di(2-ethylhexyl) adipate	MR	2	2019
Simazine	MR	2	2019
Atrazine	MR	2	2019
Heptachlor epoxide	MR	2	2019
Benzo(a)pyrene	MR	2	2019
Di(2-ethylhexyl) phthalate	MR	2	2019
Consumer Confidence Rule	Other	2	2017
Endrin	MR	2	2019
2,3,7,8-TCDD	MR	2	2019
Endothall	MR	2	2019
Diquat	MR	2	2019

Violation Count vs. the National Corpus

Cambridge Water Department has 70 recorded EPA violations, 65% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 35% carry more. 3% of this system's own violations are health-based (2 of 70), and it ranks #388 of 29,740 by population served among that same cohort.

EPA violations vs. the national water-system corpus

Public water systems serving 500+ people (EPA SDWIS)

70 Around the middle fewer violations than 35% of 29,740 water systems

the national water-system corpus, bucketed by value

Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source EPA SDWIS · 2026-05-15

How many violations vs. how serious, among peer systems

Cambridge Water Department plotted against 29 peer public water systems (500+ people served), by total violation count (x) and the share of those violations that are health-based (y). The crosshair sits at this sample's own median on each axis. A high violation count does not automatically mean a serious record: most monitoring and reporting violations are minor, not health-based.

30 public water systems (500+ people served), EPA SDWIS current release.

How to read this

Each dot is one public water system; the highlighted dot is Cambridge Water Department. A system to the right has more recorded violations; a system higher up has a larger share of those violations classified health-based rather than monitoring or reporting.

Rare but serious: few violations, but most of them are health-based.
Frequent, mostly paperwork: many violations, but mostly monitoring or reporting, not health-based.
Clean record: below-median on both counts, the tinted corner.

View all 30 systems as a list

City of Ballinger: 372 violations, 85% health-based
Nooksack Valley Water Association: 16 violations, 31% health-based
Montgomery Co RWD 12: 7 violations, 29% health-based
Irvin Water District #6: 11 violations, 27% health-based
Ticonderoga WD: 47 violations, 26% health-based
Pine Valley Plantation: 37 violations, 24% health-based
McLouth, City Of: 29 violations, 17% health-based
Kipling Oaks 1: 25 violations, 16% health-based
South Deerfield Water Supply District: 96 violations, 16% health-based
Sunset Ridge Water District: 82 violations, 15% health-based
Orange Water Dept: 136 violations, 14% health-based
Mount Pleasant Water Sys #1: 167 violations, 11% health-based
Cambridge Water Department: 70 violations, 3% health-based (this system)
Lake Gibson Estates: 42 violations, 2% health-based
Benson Culinary Improvement District: 212 violations, 1% health-based
Conemaugh Twp Muni Auth: 567 violations, 1% health-based
Miccosukee Service Plaza: 0 violations, 0% health-based
Brazoria - Fort Bend Counties MUD 3: 0 violations, 0% health-based
Tanglewilde Thompson Place 600: 2 violations, 0% health-based
Center Water Co: 5 violations, 0% health-based
Spring Mills Elem School/Hvs: 9 violations, 0% health-based
Great Bend Industrial Park: 14 violations, 0% health-based
Glen Park Village: 19 violations, 0% health-based
Camp Is-Sho-Da: 22 violations, 0% health-based
Hamilton: 33 violations, 0% health-based
Town of Welaka: 54 violations, 0% health-based
Township of Blairstown Dpw: 61 violations, 0% health-based
McIntosh Water & Fire Pro Authority: 71 violations, 0% health-based
Clarkdale Municipal Water System: 114 violations, 0% health-based
Eureka Water Association: 273 violations, 0% health-based

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 5 of 116 samples detected PFAS.

Contaminant	Date	Result	MRL	Status
PFOA	9/13/2023	<4.00 ppt	4.00 ppt	Not Detected
PFDoA	9/13/2023	<3.00 ppt	3.00 ppt	Not Detected
PFDA	9/13/2023	<3.00 ppt	3.00 ppt	Not Detected
PFTA	9/13/2023	<8.00 ppt	8.00 ppt	Not Detected
PFTrDA	9/13/2023	<7.00 ppt	7.00 ppt	Not Detected
NEtFOSAA	9/13/2023	<5.00 ppt	5.00 ppt	Not Detected
NMeFOSAA	9/13/2023	<6.00 ppt	6.00 ppt	Not Detected
PFOS	9/13/2023	<4.00 ppt	4.00 ppt	Not Detected
PFNA	9/13/2023	<4.00 ppt	4.00 ppt	Not Detected
PFHpA	9/13/2023	<3.00 ppt	3.00 ppt	Not Detected
PFBS	9/13/2023	<3.00 ppt	3.00 ppt	Not Detected
PFUnA	9/13/2023	<2.00 ppt	2.00 ppt	Not Detected
PFHxS	9/13/2023	<3.00 ppt	3.00 ppt	Not Detected
11Cl-PF3OUdS	9/13/2023	<5.00 ppt	5.00 ppt	Not Detected
PFPeS	9/13/2023	<4.00 ppt	4.00 ppt	Not Detected
PFHxA	9/13/2023	3.00 ppt	3.00 ppt	Detected
PFHpS	9/13/2023	<3.00 ppt	3.00 ppt	Not Detected
NFDHA	9/13/2023	<20.00 ppt	20.00 ppt	Not Detected
PFEESA	9/13/2023	<3.00 ppt	3.00 ppt	Not Detected
PFMBA	9/13/2023	<3.00 ppt	3.00 ppt	Not Detected
PFPeA	9/13/2023	3.50 ppt	3.00 ppt	Detected
PFMPA	9/13/2023	<4.00 ppt	4.00 ppt	Not Detected
4:2 FTS	9/13/2023	<3.00 ppt	3.00 ppt	Not Detected
6:2 FTS	9/13/2023	<5.00 ppt	5.00 ppt	Not Detected
PFBA	9/13/2023	<5.00 ppt	5.00 ppt	Not Detected
HFPO-DA	9/13/2023	<5.00 ppt	5.00 ppt	Not Detected
ADONA	9/13/2023	<3.00 ppt	3.00 ppt	Not Detected
9Cl-PF3ONS	9/13/2023	<2.00 ppt	2.00 ppt	Not Detected
8:2 FTS	9/13/2023	<5.00 ppt	5.00 ppt	Not Detected
PFBA	6/12/2024	<5.00 ppt	5.00 ppt	Not Detected
11Cl-PF3OUdS	6/12/2024	<5.00 ppt	5.00 ppt	Not Detected
PFOS	6/12/2024	<4.00 ppt	4.00 ppt	Not Detected
PFPeA	6/12/2024	<3.00 ppt	3.00 ppt	Not Detected
NMeFOSAA	6/12/2024	<6.00 ppt	6.00 ppt	Not Detected
NEtFOSAA	6/12/2024	<5.00 ppt	5.00 ppt	Not Detected
PFTrDA	6/12/2024	<7.00 ppt	7.00 ppt	Not Detected
PFTA	6/12/2024	<8.00 ppt	8.00 ppt	Not Detected
PFHxS	6/12/2024	<3.00 ppt	3.00 ppt	Not Detected
PFHpS	6/12/2024	<3.00 ppt	3.00 ppt	Not Detected
PFPeS	6/12/2024	<4.00 ppt	4.00 ppt	Not Detected
NFDHA	6/12/2024	<20.00 ppt	20.00 ppt	Not Detected
ADONA	6/12/2024	<3.00 ppt	3.00 ppt	Not Detected
PFMBA	6/12/2024	<3.00 ppt	3.00 ppt	Not Detected
PFUnA	6/12/2024	<2.00 ppt	2.00 ppt	Not Detected
PFMPA	6/12/2024	<4.00 ppt	4.00 ppt	Not Detected
8:2 FTS	6/12/2024	<5.00 ppt	5.00 ppt	Not Detected
4:2 FTS	6/12/2024	<3.00 ppt	3.00 ppt	Not Detected
6:2 FTS	6/12/2024	<5.00 ppt	5.00 ppt	Not Detected
HFPO-DA	6/12/2024	<5.00 ppt	5.00 ppt	Not Detected
PFNA	6/12/2024	<4.00 ppt	4.00 ppt	Not Detected

Population served record for Cambridge Water Department

EPA SDWIS lists 118,214 people served and 15,063 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.

EPA SDWIS · PWS MA3049000 MA primacy agency

Sources: EPA SDWIS · MassDEP, Drinking Water Program

Nationwide peers

70 violations · 118,214 served: nearest cross-state SDWIS matches.

Cross-state systems near this violation count

Nearest cross-state community systems (500+ served) by total SDWIS violations on record.

4 peers

Cross-state systems with similar served population

Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).

4 peers

What to do with Cambridge Water Department

Use this system's EPA-reported record as a starting filter, not a final verdict.

See how every tracked system in Massachusetts compares on the same EPA violation measures. Massachusetts systems
Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
Find and compare another public water system by name or PWSID. Search systems

EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater

Compiled by PlainWater, Drinking Water Quality Editorial Process · May 15, 2026

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.