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Tap water quality report

Colchester Sewer & Water Commission

EPA monitoring tested this supplier for 110 contaminants and detected 25. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

110
contaminants tested
25
detected
4,020
people served
0
health-based violations
Connecticut rankingsLead in ConnecticutPFAS in Connecticut
Water source
Ground water
Ownership
Local government
Counties served
New London

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.

0
health-based violations
159
violations on file
0
still open
ViolationTypeStatusPeriod
MR Monitoring Archived 2026-03-01 → 2026-03-31
Other Monitoring Resolved 2025-08-10
Other Monitoring Resolved 2025-07-01
Other Monitoring Resolved 2025-06-15
Other Monitoring Resolved 2025-06-15
Other Monitoring Resolved 2024-05-25
Other Monitoring Resolved 2024-05-25
MR Monitoring Resolved 2024-03-01 → 2024-03-31
MR Monitoring Resolved 2024-03-01 → 2024-03-31
MR Monitoring Resolved 2024-03-01 → 2024-03-31

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).
ContaminantMaxDetection ratePeriod
PFHXS 0.0036 µg/L 4/8 2023
PFOS 0.0090 µg/L 4/8 2023

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
Copper
171.8 µg/L 13%
of the EPA limit 1300 µg/L
worst single sample: 362 µg/L
63/63 SYR4 2014–2019
Bromodichloromethane
7.185 µg/L
No EPA limit set
worst single sample: 8 µg/L
24/59 SYR4 2012–2019
Chloroform
18.85 µg/L
No EPA limit set
worst single sample: 19 µg/L
24/59 SYR4 2012–2019
Nitrate
2070 µg/L 21%
of the EPA limit 10000 µg/L
worst single sample: 2100 µg/L
24/34 SYR4 2012–2019
Dibromochloromethane
4.095 µg/L
No EPA limit set
worst single sample: 4.3 µg/L
22/59 SYR4 2012–2019
Dichloroacetic Acid
6.98 µg/L
No EPA limit set
worst single sample: 8 µg/L
18/18 SYR4 2012–2019
TTHM
29.355 µg/L 37%
of the EPA limit 80 µg/L
worst single sample: 30.8 µg/L
18/19 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
12.3 µg/L 21%
of the EPA limit 60 µg/L
worst single sample: 14 µg/L
18/18 SYR4 2012–2019
Trichloroacetic Acid
3.905 µg/L
No EPA limit set
worst single sample: 4.5 µg/L
18/18 SYR4 2012–2019
Dibromoacetic Acid
1.83 µg/L
No EPA limit set
worst single sample: 1.9 µg/L
15/18 SYR4 2012–2019
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 13/13 LCR 2025
Nitrate-Nitrite
1990 µg/L 20%
of the EPA limit 10000 µg/L
worst single sample: 2100 µg/L
12/17 SYR4 2012–2019
Lead
14.2 µg/L 95%
of the EPA limit 15 µg/L
worst single sample: 15 µg/L
9/63 SYR4 2014–2019
Bromoform
0.7000 µg/L
No EPA limit set
 7/59 SYR4 2012–2019
Barium
25.5 µg/L 1.3%
of the EPA limit 2000 µg/L
worst single sample: 26 µg/L
6/6 SYR4 2012–2018
Tetrachloroethylene
0.7640 µg/L 15%
of the EPA limit 5 µg/L
worst single sample: 0.7800 µg/L
5/41 SYR4 2012–2019
Combined Radium (-226 And -228)
1.086 pCi/L 22%
of the EPA limit 5 pCi/L
worst single sample: 1.09 pCi/L
2/6 SYR4 2013–2018
Gross Alpha, Excl. Radon And U
6.971 pCi/L 46%
of the EPA limit 15 pCi/L
worst single sample: 6.98 pCi/L
2/6 SYR4 2013–2018
Monobromoacetic Acid
1 µg/L
No EPA limit set
 2/18 SYR4 2012–2019
Monochloroacetic Acid
1 µg/L
No EPA limit set
 2/18 SYR4 2012–2019
Fluoride
60 µg/L 1.5%
of the EPA limit 4000 µg/L
 1/6 SYR4 2012–2018
Selenium
6 µg/L 12%
of the EPA limit 50 µg/L
 1/6 SYR4 2012–2018
Simazine
0.0500 µg/L 1.3%
of the EPA limit 4 µg/L
 1/12 SYR4 2013–2019
85 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, TotalArsenicAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumCombined UraniumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDinosebDiquatEthylene DibromideEndrinEthylbenzeneGlyphosateHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaNitriteOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPfmbaPfmpaPFNAPFOAPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramStyreneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
LEONE, JOSEPH D.
Phone
860-537-7288
Email
[email protected]

Frequently asked questions about Colchester Sewer & Water Commission

Is Colchester Sewer & Water Commission tap water safe to drink?

EPA monitoring detected 25 contaminants in Colchester Sewer & Water Commission'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 Colchester Sewer & Water Commission's water?

EPA monitoring detected Copper, Bromodichloromethane, Chloroform, Nitrate, Dibromochloromethane, and others. The full list with the level and data source for each is above.

How many people does Colchester Sewer & Water Commission serve?

Colchester Sewer & Water Commission reports serving 4,020 people in Connecticut, per its EPA record.

Has Colchester Sewer & Water Commission had any water quality violations?

The EPA has 159 violations on file for Colchester Sewer & Water Commission, of which 0 are health-based (a contaminant limit or required treatment was breached) and 0 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.