Connecticut’s release-based cleanup rules: reporting, cleanup and the Transfer Act’s sunset
Connecticut’s Release-Based Cleanup Regulations, adopted by the Department of Energy and Environmental Protection (DEEP) on May 16, 2025, took effect March 1, 2026. They require new releases of oil, petroleum, chemical liquids or solids, or hazardous waste to the land and waters of the state, and existing releases once discovered, to be reported, investigated and cleaned up. New spills and newly discovered historical releases follow the same cleanup criteria and the same process. The regulations exclude many societal-type pollution sources and set lower bounds below which action is not required or is limited.
The regulations replace the Property Transfer Act for new transactions: no Transfer Act filings are required for transactions on or after March 1, 2026. Sites already in the Transfer Program continue their cleanup under the Transfer Act until it is verified, using the new cleanup standards as the endpoints; Public Act 25-54 lets them move to the new regulations’ process.
Investigation follows the owner’s own business decisions: reviewing historical records that show a past release is not, by itself, discovery of a release. Once a release is discovered, the regulations set reporting and cleanup requirements, with separate requirements for significant existing releases, those that pose an imminent risk to human health or the environment.
The regulations also add cleanup standards for multifamily properties, a permit-by-rule for managing polluted soil below buildings, concrete and pavement, and a permit-by-rule that avoids excavating lightly polluted soil on commercial and industrial properties. Releases from regulated underground storage tanks follow the tank rules, with these regulations supplying the cleanup criteria and alternate remedies; releases from residential tanks that heat fewer than four residential units are subject to these regulations.
The rules
- C.G.S. 22a-134pp to 22a-134yy; R.C.S.A. 22a-134tt-1 to -13Release-based cleanup program
Replaced the Transfer Act on March 1, 2026. Whoever creates or maintains a release of oil, petroleum or hazardous substances must report it to DEEP on a set clock, then investigate and clean it up.
- C.G.S. 22a-134 to 22a-134e; Public Acts 25-6 and 25-54Property Transfer Act, legacy sites only
The old rule that made property sales trigger cleanup. It no longer applies to new deals, but sites already in the program must still finish or switch to the release-based program.
- C.G.S. 22a-133k; R.C.S.A. 22a-134tt (was 22a-133k-1 to -3)Remediation standards for soil and groundwater
Sets the soil and groundwater cleanup numbers used in Connecticut cleanups, based on intended use. Since March 1, 2026 the standards sit in the release-based cleanup regulations.
Briefings
- HighConnecticut
Connecticut ends Transfer Act filings for sales from March 1, 2026; release-based cleanup applies
Since March 1, 2026 transactions no longer require Transfer Act filings, and cleanup duties arise when a release is discovered or occurs. A legislative study of brownfield problems under the new program is due January 1, 2027. Deal documents drafted around Transfer Act forms should be examined.