Secondary Containment

DEEP has made revisions to Connecticut’s Underground Storage Tank (“UST”) regulations section 22a-449(d)-101 to 113, inclusive of the Regulations of Connecticut State Agencies, effective December 1, 2021.  These revisions are in response to the U.S. Environmental Protection Agency’s (“USEPA”) rule change to the federal underground storage tank regulations, published on July 15, 2015.  The amendment included Secondary Containment requirements per RCSA 22a-449(d)-102.  Highlights of these requirements are as follows:
  • New UST systems must include:
    • liquid tight under-dispenser containment sumps with sensors, and
    • liquid tight piping containment sumps with sensors.
  • The requirements for new under-dispenser containment must be met when:
    • replacing more than fifty (50) percent of the dispensers at a facility, the requirements for new under-dispenser containment sumps must be met for all dispensers at the facility or
    • replacing a dispenser and more than fifty (50) percent of the flex-joint or flexible piping that is directly beneath the dispenser.
  • Upon installation and prior to operating any newly installed double-walled UST system:
    • testing must be performed which demonstrates that liquids which accumulate in any part of the UST system (including sumps) will not be released to the environment, and
    • re-tests will be required every three (3) years thereafter, although this requirement does not apply to certain secondary containment systems that are hydrostatically or vacuum monitored continuously.
  • Under-dispenser containment sumps and piping containment sumps that require repairs must be tested to demonstrate that the repaired sump meets the requirements of a new under-dispenser containment sump or new piping containment sump.
  • Integrity testing is required once every three (3) years, revised from every five (5) years, for UST Systems, including but not limited to, testing of secondary containment and spill prevention systems, under dispenser containment sumps (“UDCs”), piping containment sumps (“STPs”), spill buckets and piping transition sumps. This requirement does not apply to UST systems that automatically monitors the integrity of both primary and secondary containment which are continuously monitored by being brine-filled or under constant vacuum. For UST Systems installed before August 8, 2012, the testing required does not need to include a piping containment sump or under dispenser containment sump unless such sumps meet the requirements of a new piping containment sump or a new under-dispenser containment sump. If testing has not been conducted previously for a UST System installed prior to August 8, 2012, the required testing must be conducted no later than December 1, 2022. [RCSA sec. 22a-449-102(a)(15) & RCSA sec. 22a-449-103(a)(4)].
Secondary containment questions may be directed to the Storage Tank and PCB Enforcement Program at 860-424-3374 or

Content last updated April 2022