Cyanide violations in Connecticut
21 active public water systems in Connecticut had a Cyanide violation in the past three years. What Cyanide is and why it matters.
Systems with a Cyanide violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Aquarion-Eastern Fairfield County Beacon Falls, Bridgeport, Darien and 17 more · Fairfield County |
351,756 | 2 | 0 | |
|
Aquarion-New Milford Regional Brookfield, New Milford · Fairfield County |
13,331 | 4 | 0 | |
|
Bethel Water Dept Bethel, Danbury · Fairfield County |
9,507 | 6 | 0 | |
|
ST Lukes School Athletic Center New Canaan · Fairfield County |
500 | 5 | 0 | |
|
Sherman Elementary School Sherman · Fairfield County |
430 | 5 | 1 | |
|
Cornwall Consolidated School Cornwall · Litchfield County |
202 | 4 | 0 | |
|
Emmanuel Episcopal Church Weston · Fairfield County |
113 | 6 | 1 | |
|
Atlas Commons Old Saybrook · Middlesex County |
100 | 8 | 1 | |
|
Woods Edge Apartments Mansfield · Tolland County |
96 | 5 | 2 | |
|
Knob Hill Condominiums Colchester · New London County |
84 | 2 | 0 | |
|
School Hill Association, Inc. East Windsor · Hartford County |
77 | 5 | 1 | |
|
Round Hill LLC Well# 1&2 Lisbon · New London County |
72 | 9 | 3 | |
|
Granby Congregational Church Granby · Hartford County |
65 | 6 | 1 | |
|
Weston Shopping Center Associates, LLC Weston · Fairfield County |
65 | 5 | 1 | |
|
Nod Hill Brewery Ridgefield · Fairfield County |
60 | 7 | 2 | |
|
125 Commerce Drive Brookfield · Fairfield County |
37 | 4 | 0 | |
|
Tashua Village Association, Inc. Trumbull · Fairfield County |
35 | 6 | 0 | |
|
Keeler Ridgefield B Ridgefield · Fairfield County |
30 | 8 | 3 | |
|
Windsorville Water Association East Windsor · Hartford County |
29 | 8 | 1 | |
|
144 Oxford Road, LLC Oxford · New Haven County |
25 | 4 | 1 | |
|
Southford Retail Center Southbury · New Haven County |
25 | 4 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Cyanide, including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Cyanide alone.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Connecticut records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.