Backflow testing rules depend on the water utility—not just the town.

Aquarion publishes Connecticut cross-connection requirements and coordinates property-specific review, inspection, testing, and corrective action through its Cross Connections program.

Service area: Aquarion service areas across Connecticut

Bristol Water and Sewer administers the state backflow prevention program locally and publishes cross-connection requirements for irrigation and commercial facilities.

Service area: Bristol

Connecticut Water operates a cross-connection inspection and testing program in its service areas, including residential irrigation and other potential cross connections.

Service area: Connecticut Water service areas across 60 Connecticut towns

The DPH inventory identifies Danbury Water Department as a large community water system. Danbury publishes its Water Division contact and system information, but the reviewed city page does not publish a property-level backflow testing cadence or filing route.

Service area: Danbury municipal water service area

East Lyme publishes a cross-connection and backflow-preventer testing service and customer charges through its Water and Sewer Commission materials.

Service area: East Lyme municipal water service area

First District requires annual testing of backflow prevention devices by a certified tester and says District personnel perform its cross-connection testing and inspection services.

Service area: First Taxing District water service area in Norwalk

Groton Utilities runs an ongoing cross-connection and water-quality protection program that includes annual business plumbing inspections and device testing by certified utility personnel.

Service area: Groton

Ledyard’s 2026 rules require owners to install and maintain required backflow protection, and require reduced-pressure-principle devices to be tested and inspected at least annually.

Service area: Ledyard WPCA water service area

Manchester uses a two-step cross-connection program: inspection followed by annual testing of testable backflow prevention devices.

Service area: Manchester

Meriden maintains a dedicated cross-connection function that inspects and tests backflow devices, and its published fee schedule includes reduced-pressure-device testing charges.

Service area: Meriden

The MDC administers cross-connection control for its Hartford-area water system and requires owners to maintain approved protection where cross connections may introduce contaminants.

Service area: Greater Hartford and portions of nearby towns

Middletown requires an approved backflow preventer for secondary irrigation meters, annual inspection and testing by a licensed professional, and a passing report submitted to the Water and Sewer Department.

Service area: Middletown

New Britain publishes backflow prevention device guidance through its Water Department and Water & Utilities Management resources.

Service area: New Britain water service area

New London publishes a municipal-water application that requires a testable reduced-pressure backflow preventer when a live well remains on a property and places that property under cross-connection control.

Service area: New London municipal water service area

Norwich Public Utilities construction standards adopt Connecticut DPH cross-connection guidance and require approved testable backflow protection for commercial, industrial, fire-protection, irrigation, and other identified hazards.

Service area: Norwich

The Regional Water Authority inspects facilities and tests backflow preventers as part of its cross-connection control program.

Service area: New Haven and surrounding communities

Southington Water maintains a cross-connection program covering inspections and testing of backflow preventers, including residential irrigation systems.

Service area: Southington

Wallingford Water Division operates a cross-connection inspection and testing program and publishes irrigation backflow information and technical resources.

Service area: Wallingford

Waterbury operates the municipal water system and publishes a cross-connection test fee plus a penalty for failing to test or maintain a backflow device or permit a cross-connection inspection.

Service area: Waterbury, Watertown, Prospect, and Wolcott

Windham Water Works publishes annual cross-connection surveys and backflow-device testing, utility testing fees, approved installation requirements, and a 30-day repair window after a failed test.

Service area: Windham Water Works service area