Is Wellesley Water Division Tap Water Safe? Quality Report

Water source: SWP
Ownership: Local government
Counties served: Norfolk

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.

health-based violations

violations on file

still open

Violation	Type	Status	Period
MCL	Health-based	Resolved	2014-08-01 → 2014-08-31
MCL	Health-based	Resolved	2014-08-01 → 2014-08-31
MCL	Health-based	Resolved	2014-08-01 → 2014-08-31
MCL	Health-based	Resolved	2014-08-01 → 2014-08-31
MCL	Health-based	Archived	2002-08-01 → 2002-08-31
MCL	Health-based	Resolved	2000-12-01 → 2000-12-31
MCL	Health-based	Resolved	2000-12-01 → 2000-12-31
MCL	Health-based	Resolved	2000-12-01 → 2000-12-31
MCL	Health-based	Archived	1997-06-01 → 1997-06-30
TT	Health-based	Resolved	1997-01-01

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).

Contaminant	Max	Detection rate	Period
PFBS	0.0053 µg/L	4/10	2025
PFOA	0.0063 µg/L	4/10	2025
Pfpea	0.0043 µg/L	4/10	2025
Pfhxa	0.0039 µg/L	3/10	2025
PFOS	0.0066 µg/L	2/10	2025
Pfba	0.0052 µg/L	1/10	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.

Contaminant	Level vs EPA limit	Detection rate	Source	Period
TTHM	47.44 µg/L 59% of the EPA limit 80 µg/L worst single sample: 59.8 µg/L	132/132	SYR4	2012–2019
Total Haloacetic Acids (HAA5)	14.19 µg/L 24% of the EPA limit 60 µg/L worst single sample: 22 µg/L	132/132	SYR4	2012–2019
Bromodichloromethane	16.6 µg/L No EPA limit set worst single sample: 21.3 µg/L	120/120	SYR4	2012–2019
Chloroform	13.16 µg/L No EPA limit set worst single sample: 17.3 µg/L	120/120	SYR4	2012–2019
Dibromochloromethane	16.84 µg/L No EPA limit set worst single sample: 20.8 µg/L	120/120	SYR4	2012–2019
Dichloroacetic Acid	7.085 µg/L No EPA limit set worst single sample: 9.3 µg/L	116/120	SYR4	2012–2019
Bromoform	4.275 µg/L No EPA limit set worst single sample: 7.09 µg/L	111/120	SYR4	2012–2019
Dibromoacetic Acid	4.18 µg/L No EPA limit set worst single sample: 6.91 µg/L	107/120	SYR4	2012–2019
Trichloroacetic Acid	5.045 µg/L No EPA limit set worst single sample: 8.2 µg/L	106/120	SYR4	2012–2019
Monochloroacetic Acid	2.19 µg/L No EPA limit set worst single sample: 3.17 µg/L	41/120	SYR4	2012–2019
Nitrate	1447 µg/L 14% of the EPA limit 10000 µg/L worst single sample: 1600 µg/L	38/40	SYR4	2012–2019
Lead	0.0035 mg/L 23% of the EPA limit 0.0150 mg/L	25/25	LCR	2025
Barium	77.425 µg/L 3.9% of the EPA limit 2000 µg/L worst single sample: 77.9 µg/L	6/6	SYR4	2014–2017
Fluoride	972.5 µg/L 24% of the EPA limit 4000 µg/L worst single sample: 980 µg/L	6/6	SYR4	2014–2017
Monobromoacetic Acid	4.78 µg/L No EPA limit set worst single sample: 5.1 µg/L	5/120	SYR4	2012–2019
Copper	105 µg/L 8.1% of the EPA limit 1300 µg/L worst single sample: 110 µg/L	3/3	SYR4	2012
Antimony, Total	2.905 µg/L 48% of the EPA limit 6 µg/L worst single sample: 3 µg/L	2/6	SYR4	2014–2017

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-PF3ONSAdonaArsenicAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDinosebEthylene DibromideEndrinEthylbenzeneHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaNitriteOxamylPfdaPfdoaPfeesaPfhpaPfhpsPFHXSPfmbaPfmpaPFNAPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact: AARON J MILLER
Phone: 7812357600
Email: [email protected]

Frequently asked questions about Wellesley Water Division

Is Wellesley Water Division tap water safe to drink?

EPA monitoring detected 23 contaminants in Wellesley Water Division'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 Wellesley Water Division's water?

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

How many people does Wellesley Water Division serve?

Wellesley Water Division reports serving 29,550 people in Massachusetts, per its EPA record.

Has Wellesley Water Division had any water quality violations?

The EPA has 14 violations on file for Wellesley Water Division, of which 12 are health-based (a contaminant limit or required treatment was breached) and 1 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.