Connecticut’s Release-Based Cleanup Regulations (RBCRs) take effect on March 1, 2026, and the deadline is approaching quickly. Any releases discovered on or after this date must follow the new reporting and cleanup requirements. However, the RBCRs intentionally focus on newly discovered environmental releases, not information that already exists in historical files—commonly referred to as the “filing cabinet exemption.”
RBCRs and the Filing Cabinet Exemption
Under the RBCRs, “a release shall not be deemed discovered if the only evidence of such release is data available or generated before the date when the regulations are first adopted.”
A key clarification matters here. The original language tied the filing cabinet exemption to the adoption date of the regulations (May 16, 2025), rather than the effective date (March 1, 2026). This distinction would have limited the exemption to releases identified before May 16, 2025.
To resolve this inconsistency, the Connecticut legislature passed Public Act 25-54, which aligns the filing cabinet exemption with the RBCR effective date of March 1, 2026.
The most important element of the exemption remains the phrase “only evidence.” If historical data or reports created before March 1, 2026 represent the sole evidence of a release, the RBCRs do not consider that release newly discovered.
However, CTDEEP has clarified its position: a prior report alone does not constitute discovery under the RBCRs, but that same information may serve as one line of evidence. When combined with new observations or findings, it may support discovery and trigger RBCR reporting and response requirements.
How the Filing Cabinet Exemption Works in Practice
As the RBCRs take effect, real-world scenarios will further define how regulators apply the filing cabinet exemption. Property owners and environmental professionals should prepare now for how these rules may apply during routine due diligence.
For example, when a Licensed Environmental Professional (LEP) conducts a Phase I Environmental Site Assessment, they may observe site conditions that do not independently qualify as a release discovery. However, when those observations align with findings from a historical investigation report, the combined evidence may meet the RBCR definition of discovery and require follow-up reporting and investigation.
Making Smart Investigation Decisions Before March 1, 2026
As the RBCRs take effect, real-world scenarios will further define how regulators apply the filing cabinet exemption. Property owners and environmental professionals should prepare now for how these rules may apply during routine due diligence.
For example, when a Licensed Environmental Professional (LEP) conducts a Phase I Environmental Site Assessment, they may observe site conditions that do not independently qualify as a release discovery. However, when those observations align with findings from a historical investigation report, the combined evidence may meet the RBCR definition of discovery and require follow-up reporting and investigation.
Need Help Navigating the RBCRs and the Filing Cabinet Exemption?
Our team of Licensed Environmental Professionals helps property owners, buyers, and investors assess risk, plan investigations, and comply confidently with Connecticut’s new release-based cleanup system.
What are Connecticut’s Release-Based Cleanup Regulations (RBCRs)?
The RBCRs establish a new framework for reporting and addressing environmental releases in Connecticut. The regulations focus on timely reporting and investigation of newly discovered releases and take effect on March 1, 2026.
What is the “filing cabinet exemption” under the RBCRs?
The filing cabinet exemption clarifies that a release does not qualify as “discovered” if the only evidence comes from data or reports created before March 1, 2026. The RBCRs do not require reporting based solely on historical information found in existing files.
Does a prior environmental report trigger discovery under the RBCRs?
No. CTDEEP has stated that a prior report alone does not constitute discovery of a release under the RBCRs. However, that report may serve as one line of evidence if combined with new site observations or findings.
How can a Phase I Environmental Site Assessment affect discovery?
During a Phase I Environmental Site Assessment, an LEP may identify site conditions that do not independently qualify as discovery. When those observations align with historical reports or data, the combined evidence may meet the RBCR definition of discovery and trigger reporting and follow-up requirements.
Who should pay close attention to the filing cabinet exemption?
Property owners, buyers, sellers, lenders, and investors involved in Connecticut real estate transactions should understand how the exemption works—especially when conducting environmental due diligence before March 1, 2026.