Underground Storage Tanks

Connecticut's registered tank records come from the Underground Storage Tank (UST) program of the Department of Energy and Environmental Protection (DEEP). DEEP says its UST Regulations, RCSA sections 22a-449(d)-1 and 22a-449(d)-101 to 22a-449(d)-114, set the performance standards for owners and operators of state regulated and federally regulated UST systems.

In a Phase I ESA

UST registrations are the Connecticut form of the state registered storage tank records that ASTM E1527-21 lists as a standard source. The general reading of a registered tank listing is on the UST / AST page. A registration says a tank system exists or existed. Releases are a separate record, the UST Clean-Up page.

Three Connecticut details shape the search.

• Filing is electronic. DEEP's page says notifications are filed through its ezFile portal, and that Public Act 15-1 requires all communication with DEEP to be electronic unless DEEP grants an exception on a hardship request. For returning users the page gives August 1 to October 10 as the window to submit a notification and fee payment.
• Closure leaves two notices. DEEP's page says notice is required 30 days before a tank is removed, and that notification through ezFile is still required no later than 30 days after removal is complete. A closure file can therefore hold both.
• Small residential heating oil tanks are outside the program. DEEP's UST Clean-Up page says the installation and use of residential home heating oil tanks serving four or fewer units are not regulated by DEEP. Do not expect a registration for one.

What a tank file can hold

DEEP's list of UST forms does not say which forms are sent to DEEP, but it shows the paper a regulated tank can generate: a pre-notification of scheduled permanent closure, a sump and spill bucket removal report, a weekly inventory report, monthly and annual inspection reports, a suspected release reporting form and a notice of completion of UST closure. DEEP's Records Center page says its UST files include inspection reports, notification forms and variance requests, with the earliest stored files dated 1986.

Where to look a site up

• The Records Center page links a dataset of Registered Underground Storage Tanks on Connecticut's open data platform. DEEP says these datasets give only data from its databases, not electronic documents, and can be used to find a case number or an address before searching the document portal.
• The same page lists an Underground Storage Tank Registration List among the documents available in the file review area without staff assistance.
• For questions, DEEP gives its Licensing and Enforcement Unit at 860-424-3374 and DEEP.USTEnforcement@ct.gov.

Getting the file

The listing tells you a tank is registered. The notifications, inspection reports and closure documents are in the file. DEEP's Records Center holds UST program files and takes appointments, as the Environmental Quality Records Center page describes. Under its Registered Underground Storage Tanks and Leaking Underground Storage Tanks datasets, the Records Center page prints the note "Some documents are available via the DEEP Online Search Portal." It does not say which documents, so ask the Records Center.

Sources

Department of Energy and Environmental Protection pages, read October 8, 2026:

• Underground Storage Tanks, no modified date shown; the page's footer reads "Content last updated December 2025".
• UST Registration, Compliance & Release Prevention, no modified date shown; the page's footer reads "Content last updated May 2026".
• UST Clean-Up, no modified date shown; the page's footer reads "Content last updated March 2026".
• Environmental Quality Records Records Center File Room, no modified date shown; the page's footer reads "Content Last Updated July 2024".