Connecticut

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Connecticut system directory

Find a community water system

Search every Connecticut community water system with a current nitrate result. Open a system to see its latest reading, reporting date, nitrate band and population served.

61

systems with a current result

2,302,273

people served by them

29

systems carrying a supplier result

1

system at or above 5 mg/L

How to read the directory: each system is placed in a band by its most recent reported result in the rolling three-year window. Purchased-water systems carry their supplier's result and are tagged. Bands describe how strongly human activity, read from nitrate, has marked a water source; they are not a safety verdict.

Showing 61 of 61 systems

A

Apple Rehabpurchased waterNatural background0.05 mg/L2025238 served Aquarion-Barnumpurchased waterNatural background0.22 mg/L2024120 served Aquarion-Berkshirepurchased waterNatural background0.22 mg/L202475 served Aquarion-DarienNatural background0.79 mg/L202518,737 served Aquarion-East Derbypurchased waterHuman impact clear3.82 mg/L20251,101 served Aquarion-Eastern Fairfield CountyHuman impact likely2.08 mg/L2024351,756 served Aquarion-GreenwichNatural background0.30 mg/L202453,297 served Aquarion-Hawkstonepurchased waterHuman impact clear3.82 mg/L2025120 served Aquarion-Hollandale Estatespurchased waterNatural background0.22 mg/L2024200 served Aquarion-Ken Oakspurchased waterNatural background0.22 mg/L2024152 served Aquarion-Litchfield Regionalpurchased waterNatural background0.03 mg/L20243,097 served Aquarion-Mckeonpurchased waterNatural background0.22 mg/L202467 served Aquarion-MysticNatural background0.26 mg/L202510,788 served Aquarion-New CanaanNatural background0.79 mg/L202510,097 served Aquarion-New Milford RegionalHuman impact clear3.01 mg/L202513,331 served Aquarion-Oxford Towne Centerpurchased waterNatural background0.19 mg/L2025449 served Aquarion-Pearce Manorpurchased waterNatural background0.22 mg/L2024133 served Aquarion-Plainville RegionalHuman impact likely2.28 mg/L202518,231 served Aquarion-Ridgefieldpurchased waterHuman impact likely2.08 mg/L20247,476 served Aquarion-Rolling Ridgepurchased waterNatural background0.22 mg/L2024115 served Aquarion-Simsbury RegionalHuman impact clear3.46 mg/L202514,691 served Aquarion-StamfordNatural background0.50 mg/L2024119,214 served Aquarion-ValleyHuman impact likely1.01 mg/L202513,080 served Avon Water CoHuman impact clear3.31 mg/L202411,590 served

B

Berlin Water Control Commissionpurchased waterNatural background0.03 mg/L20245,128 served Bethel Water DeptHuman impact likely2.13 mg/L20249,507 served Bristol Water DepartmentHuman impact likely1.05 mg/L202452,079 served

C

Cornell Hills Assoc, Incpurchased waterNatural background0.22 mg/L2024108 served Cromwell Fire District Water DepartmentHuman impact likely2.33 mg/L202514,316 served Ctwc - Chimney Hillpurchased waterNatural background0.05 mg/L2025227 served Ctwc - Naugatuck Region-Central SystemNatural background0.19 mg/L202522,735 served Ctwc - Northern Reg-Reservoir Heightspurchased waterHuman impact clear4.20 mg/L202462 served Ctwc - Northern Reg-Western SystemHuman impact clear4.47 mg/L2025101,313 served Ctwc - Shoreline Region-Guilford SystemHuman impact clear3.82 mg/L202533,975 served Ctwc - Shoreline Region-Masons Islandpurchased waterNatural background0.26 mg/L2025445 served Ctwc - Uconn Depot Div.purchased waterNatural background0.63 mg/L2025153 served Ctwc - Uconn Hunting Lodge Div.purchased waterNatural background0.63 mg/L2025234 served Ctwc - Uconn South Eagleville Div.purchased waterNatural background0.63 mg/L2025750 served Ctwc - Uconn Willowbrook Div.purchased waterNatural background0.63 mg/L2025134 served Ctwc - Unionville SystemHuman impact likely2.60 mg/L202314,693 served

D

Danbury Water DepartmentNatural background0.22 mg/L202462,055 served

H

Hazardville - Rye Hill Systempurchased waterHuman impact clear4.47 mg/L2025352 served Hazardville Water CompanyHealth-study range9.60 mg/L202518,544 served Heritage Water Companypurchased waterNatural background0.19 mg/L20257,300 served

K

Kensington Fire Districtpurchased waterNatural background0.03 mg/L20247,553 served

M

Manchester Water DepartmentHuman impact clear4.20 mg/L202451,198 served Meriden Water DivisionHuman impact clear4.61 mg/L202458,441 served Metropolitan District CommissionNatural background0.05 mg/L2025390,887 served

N

New Britain Water DepartmentNatural background0.03 mg/L202473,534 served Norwich Public UtilitiesNatural background0.21 mg/L202436,163 served

P

Portland Water Departmentpurchased waterNatural background0.05 mg/L20255,010 served

R

Regional Water AuthorityHuman impact clear3.82 mg/L2025418,900 served

S

Southington Water DepartmentHuman impact clear4.14 mg/L202443,069 served

T

Tolland Water Dept - Torry Roadpurchased waterHuman impact clear4.47 mg/L2025204 served Torrington Water CompanyNatural background0.03 mg/L202437,915 served

U

University of Connecticut - Main CampusNatural background0.63 mg/L202527,199 served

W

Wallingford Water DepartmentHuman impact likely2.30 mg/L202437,267 served Waterbury Water DepartmentNatural background0.03 mg/L2024107,271 served Watertown Water & Sewer AuthorityNatural background0.01 mg/L20249,972 served Wolcott Water Departmentpurchased waterNatural background0.03 mg/L20242,550 served Worthington Fire Districtpurchased waterNatural background0.03 mg/L20242,875 served

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NitrateSmart

Nitrate in community water systems, from the utilities’ own compliance reporting.

Results reaching back to July 2023 · current through August 9, 2026.

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