Is Sudbury Water District water safe to drink?

Sudbury Water District (PWS ID: MA3288000) has 284 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 6 PFAS compounds found. EPA SDWIS lists this system's service population as 18,416 people using Groundwater sources.

How many people does Sudbury Water District serve?

EPA SDWIS reports that Sudbury Water District serves 18,416 people (this public water system's service population, not the municipal population of Sudbury or any other city). It is a Local-owned system using Groundwater water sources with 6,288 service connections. The operator address is listed in Sudbury, Massachusetts.

What type of violations does Sudbury Water District have?

Sudbury Water District has 284 total violations: 31 health-based violations (MCL exceedances or treatment failures), 247 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.

Has PFAS been detected in Sudbury Water District water?

Yes. UCMR5 testing detected 6 PFAS compounds in Sudbury Water District's water supply: PFPeA, PFHxA, PFOA, PFBS, PFBA, and others. PFAS are persistent "forever chemicals" that do not break down in the environment.

What water source does Sudbury Water District use?

Sudbury Water District uses Groundwater 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 Sudbury Water District sit among U.S. public water systems?

According to EPA SDWIS population_served among sitemap-advertised systems (serving 500+), Sudbury Water District ranks #2,914 of 29,740 by people served, and #125 of 418 in Massachusetts. Ordinals use population_served DESC among systems serving 500+ (the sitemap cohort). See /methodology#corpus-placement.

How does Sudbury Water District's violation count compare nationally?

Sudbury Water District has 284 recorded EPA SDWIS violations, fewer than 10% of the 29,740 public water systems serving 500 or more people nationwide (the same sitemap cohort used for the corpus-placement ranking above). 90% of that cohort has fewer violations than Sudbury Water District. 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 MA3288000

Sudbury Water District

Operator location Sudbury, Massachusetts - UCMR5 detected 6 PFAS compounds (upper-third PFAS panel (> 4 compounds)) on this PWS; SDWIS lists 284 violations and 18,416 people served.

Compiled by PlainWater · May 15, 2026

18,416
People served (this PWS) Larger third of systems: 284
EPA violations (this PWS) Upper third of systems: 31
Health-based (this PWS) Middle third by health-based share: 6 PFAS
UCMR5 (this PWS) Upper third of PFAS-detected systems

Follow published updates (RSS)

Sudbury Water District standing, high SDWIS violation third

UCMR5 detected 6 PFAS compounds - upper-third PFAS panel (> 4 compounds). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 11% is middle-third health share (≤ 23%). UCMR5: upper-third PFAS panel (> 4 compounds). Population rank #2,914 of 29,740 among systems serving 500+.

The verdict

Sudbury Water District sits in the upper third of the sitemap cohort by violation count (284), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (18,416; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 11% (middle-third health share (≤ 23%)). UCMR5 detected 6 PFAS compounds (upper-third PFAS panel (> 4 compounds)).

#2,914 of 29,740
Population · /systems: #125 of 418
Population · MA: 284
Total EPA violations on record: 11%
Health-based (MCL / treatment failure)

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

PFAS Detected

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

Water Safety Score

16/100

Sudbury Water District

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 F

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

Monitoring & reporting violations F

253

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

PFAS contamination D

0.0090 µg/L

Highest PFAS compound level detected in UCMR5 testing

System Details

System Type: Community
Owner Type: Local
Connections: 6,288
County: Middlesex
School/Daycare: No
MCL Violations: 31
Monitoring Violations: 247
Treatment Tech Violations: 0

Violation History

Contaminant violations recorded by EPA.

Contaminant	Category	Count	Latest
Coliform (TCR)	MCL	31	1997
Lead and Copper Rule	MR	9	2022
Coliform (TCR)	MR	7	2014
BHC-GAMMA	MR	5	2001
Methoxychlor	MR	5	2001
Toxaphene	MR	5	2001
Endothall	MR	5	2001
Glyphosate	MR	5	2001
Di(2-ethylhexyl) phthalate	MR	5	2001
Picloram	MR	5	2001
Dinoseb	MR	5	2001
Hexachlorocyclopentadiene	MR	5	2001
Carbofuran	MR	5	2001
Aldicarb	MR	5	2001
Atrazine	MR	5	2001
LASSO	MR	5	2001
2,3,7,8-TCDD	MR	5	2001
2,4-D	MR	5	2001
Pentachlorophenol	MR	5	2001
Total Polychlorinated Biphenyls (PCB)	MR	5	2001
1,2-DIBROMO-3-CHLOROPROPANE	MR	5	2001
ETHYLENE DIBROMIDE	MR	5	2001
Endrin	MR	5	2001
Diquat	MR	5	2001
Di(2-ethylhexyl) adipate	MR	5	2001
OXAMYL	MR	5	2001
Simazine	MR	5	2001
Aldicarb sulfone	MR	5	2001
Heptachlor	MR	5	2001
2,4,5-TP	MR	5	2001

Violation Count vs. the National Corpus

Sudbury Water District has 284 recorded EPA violations, 90% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 10% carry more. 11% of this system's own violations are health-based (31 of 284), and it ranks #2,914 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)

284 Higher than most more violations than 90% 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

Sudbury Water District 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 Sudbury Water District. 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
Sudbury Water District: 284 violations, 11% 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. 28 of 290 samples detected PFAS.

Contaminant	Date	Result	MRL	Status
PFPeA	6/6/2025	5.00 ppt	3.00 ppt	Detected
PFDoA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
PFHpA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
PFHxS	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
PFHxA	6/6/2025	5.00 ppt	3.00 ppt	Detected
PFBA	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected
PFMBA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
PFEESA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
NFDHA	6/6/2025	<20.00 ppt	20.00 ppt	Not Detected
PFTrDA	6/6/2025	<7.00 ppt	7.00 ppt	Not Detected
PFDA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
11Cl-PF3OUdS	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected
PFTA	6/6/2025	<8.00 ppt	8.00 ppt	Not Detected
PFOA	6/6/2025	8.00 ppt	4.00 ppt	Detected
PFOS	6/6/2025	<4.00 ppt	4.00 ppt	Not Detected
PFNA	6/6/2025	<4.00 ppt	4.00 ppt	Not Detected
PFBS	6/6/2025	4.00 ppt	3.00 ppt	Detected
HFPO-DA	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected
6:2 FTS	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected
9Cl-PF3ONS	6/6/2025	<2.00 ppt	2.00 ppt	Not Detected
PFUnA	6/6/2025	<2.00 ppt	2.00 ppt	Not Detected
PFHpS	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
PFPeS	6/6/2025	<4.00 ppt	4.00 ppt	Not Detected
PFMPA	6/6/2025	<4.00 ppt	4.00 ppt	Not Detected
8:2 FTS	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected
4:2 FTS	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
NMeFOSAA	6/6/2025	<6.00 ppt	6.00 ppt	Not Detected
ADONA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
NEtFOSAA	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected
PFTA	6/6/2025	<8.00 ppt	8.00 ppt	Not Detected
ADONA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
8:2 FTS	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected
PFEESA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
HFPO-DA	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected
PFMPA	6/6/2025	<4.00 ppt	4.00 ppt	Not Detected
9Cl-PF3ONS	6/6/2025	<2.00 ppt	2.00 ppt	Not Detected
NMeFOSAA	6/6/2025	<6.00 ppt	6.00 ppt	Not Detected
PFTrDA	6/6/2025	<7.00 ppt	7.00 ppt	Not Detected
PFBA	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected
NFDHA	6/6/2025	<20.00 ppt	20.00 ppt	Not Detected
NEtFOSAA	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected
PFOA	6/6/2025	<4.00 ppt	4.00 ppt	Not Detected
PFHpS	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
PFPeS	6/6/2025	<4.00 ppt	4.00 ppt	Not Detected
PFHxA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
PFMBA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
PFUnA	6/6/2025	<2.00 ppt	2.00 ppt	Not Detected
PFPeA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
PFDA	6/6/2025	<3.00 ppt	3.00 ppt	Not Detected
6:2 FTS	6/6/2025	<5.00 ppt	5.00 ppt	Not Detected

UCMR5 PFAS record for Sudbury Water District

Open EPA SDWIS federal reports for PWS MA3288000 to cross-check UCMR5 detections and violation codes; state primacy agencies enforce the Safe Drinking Water Act locally.

EPA SDWIS · PWS MA3288000 MA primacy agency

Sources: EPA SDWIS · MassDEP, Drinking Water Program

Nationwide peers

284 violations · 18,416 served: nearest cross-state SDWIS matches.

Cross-state systems with comparable violation load

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 Sudbury Water District

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.