City water profile

Water hardness in Colchester

Find official utility reports, understand hardness, and check the water system serving your home in Colchester, Connecticut.

Utility-reported hardness

Not yet available

Check your provider and source →

State comparison: Unavailable
Evidence comparison rank: —
Matched utilities: 8
Active health records: 2

Your tap water

What does the utility report?

Match the utility name to your water bill. These results describe the utility’s water, not a test at your home. A ZIP can include several water systems.

Utility hardness unavailable in this index

Nearby river or groundwater samples cannot tell us the hardness coming out of your tap. Ask your water provider for total hardness as CaCO₃, or test it at home.

Find an official utility report →

Convert a hardness result →Test your tap →

Match the name on your water bill

Your utility’s measurements and compliance records

These are possible serving systems. A record for one system does not apply to every home in this ZIP. Confirm your provider before interpreting a measurement or notice. Federal records can lag current utility notices.

EPA snapshot: 2026Q2. Historical window begins Jan 1, 2021.

Colchester Sewer & Water Commission

CT0280011 · Groundwater · 4,020 people served system-wide

The system names this served city; Census place overlap links the city to this ZCTA.

No active health-based record in this imported snapshot

Find this utility’s official report →

Measurements (1)

An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.

Lead (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Below action level

Reported level: 0 mg/L
Action level: 0.015 mg/L

0% of the listed benchmark

Monitoring period: Jan 1, 2025 to Dec 31, 2025

Violation history (13)

Imported violation history for Colchester Sewer & Water Commission
Rule	Status	Period
E. COLI	Archived	Mar 1, 2026 to Mar 31, 2026
Consumer Confidence Rule	Resolved	Aug 10, 2025 to Aug 29, 2025
Consumer Confidence Rule	Resolved	Jul 1, 2025 to Jul 25, 2025
Public Notice	Resolved	Jun 15, 2025 to Aug 29, 2025
Public Notice	Resolved	Jun 15, 2025 to Aug 29, 2025
Public Notice	Resolved	May 25, 2024 to Aug 29, 2025
E. COLI	Resolved	Mar 1, 2024 to Mar 31, 2024
E. COLI	Resolved	Jan 1, 2024 to Jan 31, 2024
Total Haloacetic Acids (HAA5)	Resolved	Jan 1, 2024 to Dec 31, 2024
TTHM	Resolved	Jan 1, 2024 to Dec 31, 2024
Consumer Confidence Rule	Resolved	Jul 1, 2023 to Jul 17, 2023
Chlorine	Resolved	Oct 1, 2022 to Nov 30, 2022
Consumer Confidence Rule	Resolved	Jul 1, 2021 to Jul 2, 2021

Ctwc - Amston Lake Division

CT0670331 · Groundwater · 910 people served system-wide

The system names this served city; Census place overlap links the city to this ZCTA.

No active health-based record in this imported snapshot

Find this utility’s official report →

Measurements (1)

An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.

Lead (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Below action level

Reported level: 0.0015 mg/L
Action level: 0.015 mg/L

10% of the listed benchmark

Monitoring period: Jan 1, 2025 to Dec 31, 2025

Violation history (0)

No record returned in this imported window. This is not a guarantee of tap-water safety.

Colchester Estates

CT0280041 · Groundwater · 276 people served system-wide

The system names this served city; Census place overlap links the city to this ZCTA.

1 reported active health-based record(s) for this system

Find this utility’s official report →

Measurements (1)

An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.

Lead (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Below action level

Reported level: 0 mg/L
Action level: 0.015 mg/L

0% of the listed benchmark

Monitoring period: Jan 1, 2025 to Dec 31, 2025

Violation history (32)

Imported violation history for Colchester Estates
Rule	Status	Period
Lead and Copper Rule	Resolved	Dec 30, 2024 to Dec 31, 2024
LEAD AND COPPER RULE REVISIONSHealth-based	Unaddressed	Oct 17, 2024
LEAD AND COPPER RULE REVISIONS	Unaddressed	Oct 17, 2024
Nitrate	Resolved	Jan 1, 2023 to Dec 31, 2023
Nitrite	Resolved	Jan 1, 2023 to Dec 31, 2023
Consumer Confidence Rule	Resolved	Aug 10, 2022 to Oct 12, 2022
Public Notice	Resolved	Dec 29, 2021 to Mar 11, 2022
Consumer Confidence Rule	Resolved	Aug 10, 2021 to Aug 16, 2021
Combined Radium (-226 and -228)	Resolved	Jan 1, 2021 to Dec 31, 2023
Gross Alpha, Excl. Radon and U	Resolved	Jan 1, 2021 to Dec 31, 2023
1,2,4-Trichlorobenzene	Archived	Jan 1, 2021 to Dec 31, 2023
cis-1,2-Dichloroethylene	Archived	Jan 1, 2021 to Dec 31, 2023
o-Dichlorobenzene	Archived	Jan 1, 2021 to Dec 31, 2023
p-Dichlorobenzene	Archived	Jan 1, 2021 to Dec 31, 2023
trans-1,2-Dichloroethylene	Archived	Jan 1, 2021 to Dec 31, 2023
1,2-Dichloroethane	Archived	Jan 1, 2021 to Dec 31, 2023
1,1,1-Trichloroethane	Archived	Jan 1, 2021 to Dec 31, 2023
Carbon tetrachloride	Archived	Jan 1, 2021 to Dec 31, 2023
1,2-Dichloropropane	Archived	Jan 1, 2021 to Dec 31, 2023
Trichloroethylene	Archived	Jan 1, 2021 to Dec 31, 2023
CHLOROBENZENE	Archived	Jan 1, 2021 to Dec 31, 2023
Toluene	Archived	Jan 1, 2021 to Dec 31, 2023
Styrene	Archived	Jan 1, 2021 to Dec 31, 2023
1,1,2-Trichloroethane	Archived	Jan 1, 2021 to Dec 31, 2023
Combined Uranium	Resolved	Jan 1, 2021 to Dec 31, 2023
Ethylbenzene	Archived	Jan 1, 2021 to Dec 31, 2023
DICHLOROMETHANE	Archived	Jan 1, 2021 to Dec 31, 2023
1,1-Dichloroethylene	Archived	Jan 1, 2021 to Dec 31, 2023
Benzene	Archived	Jan 1, 2021 to Dec 31, 2023
Tetrachloroethylene	Archived	Jan 1, 2021 to Dec 31, 2023
Vinyl chloride	Archived	Jan 1, 2021 to Dec 31, 2023
Consumer Confidence Rule	Unaddressed	Jul 1, 2017

Ctwc - Westchester Village

CT0282001 · Groundwater · 252 people served system-wide

The system names this served city; Census place overlap links the city to this ZCTA.

No active health-based record in this imported snapshot

Find this utility’s official report →

Measurements (1)

An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.

Lead (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Below action level

Reported level: 0 mg/L
Action level: 0.015 mg/L

0% of the listed benchmark

Monitoring period: Jan 1, 2025 to Dec 31, 2025

Violation history (0)

No record returned in this imported window. This is not a guarantee of tap-water safety.

Westchester Hills Condominium Assn.

CT0280031 · Groundwater · 225 people served system-wide

The system names this served city; Census place overlap links the city to this ZCTA.

No active health-based record in this imported snapshot

Find this utility’s official report →

Measurements (1)

An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.

Lead (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Below action level

Reported level: 0 mg/L
Action level: 0.015 mg/L

0% of the listed benchmark

Monitoring period: Jul 1, 2025 to Dec 31, 2025

Violation history (3)

Imported violation history for Westchester Hills Condominium Assn.
Rule	Status	Period
Consumer Confidence Rule	Resolved	Jul 1, 2024 to Jul 2, 2024
Consumer Confidence Rule	Resolved	Jul 1, 2022 to Oct 3, 2022
Lead and Copper Rule	Resolved	Apr 1, 2021 to Sep 20, 2021

Colchester Commons

CT0286011 · Groundwater · 224 people served system-wide

The system names this served city; Census place overlap links the city to this ZCTA.

1 reported active health-based record(s) for this system

Find this utility’s official report →

Measurements (1)

An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.

Lead (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Below action level

Reported level: 0 mg/L
Action level: 0.015 mg/L

0% of the listed benchmark

Monitoring period: Jan 1, 2025 to Dec 31, 2025

Violation history (4)

Imported violation history for Colchester Commons
Rule	Status	Period
Lead and Copper Rule	Resolved	Dec 30, 2024 to Dec 31, 2024
LEAD AND COPPER RULE REVISIONS	Unaddressed	Oct 17, 2024
LEAD AND COPPER RULE REVISIONSHealth-based	Unaddressed	Oct 17, 2024
Revised Total Coliform RuleHealth-based	Resolved	Oct 1, 2022 to Oct 31, 2022

Knob Hill Condominiums

CT0280051 · Groundwater · 84 people served system-wide

The system names this served city; Census place overlap links the city to this ZCTA.

No active health-based record in this imported snapshot

Find this utility’s official report →

Measurements (1)

An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.

Lead (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Below action level

Reported level: 0 mg/L
Action level: 0.015 mg/L

0% of the listed benchmark

Monitoring period: Jul 1, 2025 to Dec 31, 2025

Violation history (14)

Imported violation history for Knob Hill Condominiums
Rule	Status	Period
Consumer Confidence Rule	Resolved	Jul 1, 2022 to Oct 3, 2022
Arsenic	Resolved	Jan 1, 2022 to Dec 31, 2024
Chromium	Resolved	Jan 1, 2022 to Dec 31, 2024
CYANIDE	Resolved	Jan 1, 2022 to Dec 31, 2024
Mercury	Resolved	Jan 1, 2022 to Dec 31, 2024
Selenium	Resolved	Jan 1, 2022 to Dec 31, 2024
Cadmium	Resolved	Jan 1, 2022 to Dec 31, 2024
Nickel	Resolved	Jan 1, 2022 to Dec 31, 2024
Fluoride	Resolved	Jan 1, 2022 to Dec 31, 2024
Beryllium, Total	Resolved	Jan 1, 2022 to Dec 31, 2024
Antimony, Total	Resolved	Jan 1, 2022 to Dec 31, 2024
Barium	Resolved	Jan 1, 2022 to Dec 31, 2024
Thallium, Total	Resolved	Jan 1, 2022 to Dec 31, 2024
Revised Total Coliform Rule	Resolved	Aug 20, 2021 to Feb 7, 2022

Ctwc - Ponemah Village

CT0280071 · Groundwater · 60 people served system-wide

The system names this served city; Census place overlap links the city to this ZCTA.

No active health-based record in this imported snapshot

Find this utility’s official report →

Measurements (1)

An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.

Lead (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Below action level

Reported level: 0.0047 mg/L
Action level: 0.015 mg/L

31% of the listed benchmark

Monitoring period: Jan 1, 2022 to Dec 31, 2024

Violation history (0)

No record returned in this imported window. This is not a guarantee of tap-water safety.

City summary

What the indexed records say

Colchester has 1 published ZIP profile across New London County. The regional-evidence median is 71 PPM. The city does not meet the stricter comparison standard.

Because only one ZIP is represented, the city median and range are the same local estimate. It should not be read as multiple independent samples across the community.

Hardness distribution

How local ZIP estimates compare

Soft0 ZIPs

Moderately hard1 ZIP

Hard0 ZIPs

Very hard0 ZIPs

1 of 1 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance: 11.9 miles
Profiles with evidence: 1/1

Confidence labels

High: 0Moderate: 1Low: 0

Observation window: May 17, 2016 to Nov 21, 2025.

ZIP directory

Water reports in Colchester

Open a ZIP for site-level provenance and measurements.

ZIP code

06415

Moderately Hard

71.2 PPM

Nearest site: 11.9 mi
Confidence: Moderate

View full ZIP evidence →

Practical next steps

Move from index to evidence

1. Open your ZIP. Check distance, dates, confidence, and the associated utility.
2. Read the current CCR. Confirm source water, detections, limits, ranges, and notices.
3. Use a measured hardness result. Confirm health concerns or treatment sizing with the right method.

Continue comparing

Other Connecticut communities

New London

New London County

23 PPM median

Norwich

New London County

25 PPM median

Stonington

New London County

16 PPM median

Waterford

New London County

23 PPM median

Norfolk

Litchfield County

72 PPM median

Bristol

Hartford County

69 PPM median

Search all 52 Connecticut cities →

Questions people ask

About water in Colchester

Is the water hard?

Check the utility-reported result above when available. Nearby environmental samples cannot establish tap-water hardness. Ask your provider or test your tap.

Is the tap water safe?

Compliance history is utility-wide and cannot guarantee conditions at every tap. Check current notices and test when address-specific evidence is needed.

Do I need treatment?

Choose treatment only after confirming the problem at the property. A softener targets hardness; contaminant treatment requires a matching, verified performance claim.