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Tap water quality report

Sudbury Water District

EPA monitoring tested this supplier for 104 contaminants and detected 25. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

104
contaminants tested
25
detected
18,416
people served
32
health-based violations
Massachusetts rankingsLead in MassachusettsPFAS in Massachusetts
Water source
Ground water
Ownership
Local government
Counties served
Middlesex

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

32
health-based violations
279
violations on file
4
still open
ViolationTypeStatusPeriod
TT Health-based Addressed 2025-08-01
MCL Health-based Archived 1997-06-01 → 1997-06-30
MCL Health-based Archived 1997-06-01 → 1997-06-30
MCL Health-based Archived 1997-06-01 → 1997-06-30
MCL Health-based Archived 1997-02-01 → 1997-02-28
MCL Health-based Archived 1997-02-01 → 1997-02-28
MCL Health-based Archived 1997-02-01 → 1997-02-28
MCL Health-based Archived 1997-02-01 → 1997-02-28
MCL Health-based Archived 1997-01-01 → 1997-01-31
MCL Health-based Archived 1997-01-01 → 1997-01-31

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).
ContaminantMaxDetection ratePeriod
PFBS 0.0040 µg/L 6/10 2025
Pfhxa 0.0060 µg/L 6/10 2025
PFOA 0.0090 µg/L 6/10 2025
Pfpea 0.0050 µg/L 6/10 2025
Pfba 0.0050 µg/L 2/10 2025
Pfhpa 0.0030 µg/L 2/10 2025

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of this system's samples — over 100% is worth reading, but is not by itself a violation. Where a single sample came in higher than that percentile, it is noted under the bar. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Chloroform
48.05 µg/L
No EPA limit set
worst single sample: 82 µg/L
140/141 SYR4 2012–2019
TTHM
81.865 µg/L 102%
of the EPA limit, at the 95th percentile of samples — 80 µg/L
worst single sample: 138 µg/L
140/141 SYR4 2012–2019
Dibromochloromethane
12.1 µg/L
No EPA limit set
worst single sample: 16 µg/L
139/141 SYR4 2012–2019
Bromodichloromethane
27.2 µg/L
No EPA limit set
worst single sample: 44 µg/L
137/141 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
40.62 µg/L 68%
of the EPA limit 60 µg/L
worst single sample: 82.1 µg/L
137/140 SYR4 2012–2019
Dichloroacetic Acid
17.55 µg/L
No EPA limit set
worst single sample: 44 µg/L
130/140 SYR4 2012–2019
Trichloroacetic Acid
24 µg/L
No EPA limit set
worst single sample: 30 µg/L
128/140 SYR4 2012–2019
Nitrate
6210 µg/L 62%
of the EPA limit 10000 µg/L
worst single sample: 9900 µg/L
110/110 SYR4 2012–2019
Dibromoacetic Acid
4.63 µg/L
No EPA limit set
worst single sample: 7 µg/L
95/140 SYR4 2012–2019
Bromoform
2.17 µg/L
No EPA limit set
worst single sample: 3.1 µg/L
44/141 SYR4 2012–2019
Copper
89.68 µg/L 6.9%
of the EPA limit 1300 µg/L
worst single sample: 143 µg/L
37/58 SYR4 2013–2019
Lead
0.0035 mg/L 23%
of the EPA limit 0.0150 mg/L
 34/34 LCR 2025
Fluoride
1100 µg/L 28%
of the EPA limit 4000 µg/L
 17/34 SYR4 2012–2018
Monochloroacetic Acid
5.865 µg/L
No EPA limit set
worst single sample: 11 µg/L
14/140 SYR4 2012–2019
Barium
51.6 µg/L 2.6%
of the EPA limit 2000 µg/L
worst single sample: 54 µg/L
13/13 SYR4 2012–2018
Trichloroethylene
0.7470 µg/L 15%
of the EPA limit 5 µg/L
worst single sample: 0.8100 µg/L
7/149 SYR4 2012–2019
Monobromoacetic Acid
9.075 µg/L
No EPA limit set
worst single sample: 9.4 µg/L
6/140 SYR4 2012–2019
Arsenic
1.91 µg/L 19%
of the EPA limit 10 µg/L
worst single sample: 2 µg/L
3/13 SYR4 2012–2018
Cyanide
209.5 µg/L 105%
of the EPA limit, at the 95th percentile of samples — 200 µg/L
worst single sample: 220 µg/L
2/15 SYR4 2012–2019
79 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDinosebEthylene DibromideEndrinEthylbenzeneGlyphosateHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaNitriteOxamylPfdaPfdoaPfeesaPfhpsPFHXSPfmbaPfmpaPFNAPFOSPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneToxapheneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
VINCENT J ROY
Phone
9784436602
Email
[email protected]

Frequently asked questions about Sudbury Water District

Is Sudbury Water District tap water safe to drink?

EPA monitoring detected 25 contaminants in Sudbury Water District's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in Sudbury Water District's water?

EPA monitoring detected Chloroform, TTHM, Dibromochloromethane, Bromodichloromethane, Total Haloacetic Acids (HAA5), and others. The full list with the level and data source for each is above.

How many people does Sudbury Water District serve?

Sudbury Water District reports serving 18,416 people in Massachusetts, per its EPA record.

Has Sudbury Water District had any water quality violations?

The EPA has 279 violations on file for Sudbury Water District, of which 32 are health-based (a contaminant limit or required treatment was breached) and 4 remain open. The rest are monitoring or reporting failures.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.