Connecticut Department of Energy & Environmental Protection

Underground Storage Tank Release Prevention

An Environmental Program Fact Sheet

Underground Storage Tank Release Prevention

Approximately 45,000 commercial underground storage tanks (USTs) are currently registered in Connecticut, of which approximately 8,000 are still in use. Underground storage tank systems pose a pervasive environmental threat to Connecticut and Long Island Sound without the protection provided by continuous upgrading or replacement. The underground storage tank regulations and the Connecticut underground storage tank enforcement program have been in effect since November 1985. The regulations were adopted at both the State and federal levels for preventing pollution and to clean up any petroleum or chemical leakages emanating from usts. Since 1985, as a result of this regulatory program, over 33,000 USTs were removed because their ages exceeded established average life expectancy criteria, and the systems therefore constituted potential hazards to the environment and to public health and safety. Connecticut now boasts one of the nation's lowest ratio of releases to total number of commercial USTs in use. Federal and State rules require certain UST underground storage tank systems installed before December 22, 1988 to have pollution prevention modifications including protection from spills, overfills, and corrosion.

Owners and/or operators of USTs must choose one of the following actions for existing systems:

  • addition of spill, overfill and corrosion protection before December 22, 1998;
  • approved closure of the existing UST by December 22, 1998; or
  • approved replacement of closed UST systems with new USTs replacement of and UST components (e.g. integral piping) with components which fully meet new installation standards.
1998 Requirements

If your UST and integral piping are neither fiberglass-reinforced plastic with a manufacturer warranty that has yet to expire or steel with a manufacturer-applied anti-corrosive coating and cathodic protection, consistently monitored either annually, or monthly, then by December 22, 1988, you were required to:  

  1. upgrade the UST by adding spill, overfill, and corrosion protection, or
  2. replace it with a new UST than has spill, overfill, and corrosion protection, or
  3. properly close the old UST, including soil sampling and site remediation, as necessary.
Spill Protection

You must have spill protection by installing a "spill bucket" (a catchment basin sealed around the fill pipe). If you and your delivery driver follow standard fuel delivery practices, nearly all spills and overfills can be prevented.

Overfill Protection

Overfill equipment is designed to restrict or stop the flow of fuel during delivery before the tank reaches full capacity. Your UST needs:

  1. an automatic shutoff device, or
  2. an overfill alarm, or
  3. a ball float valve.
Corrosion Protection

Some existing USTs already meet the corrosion protection requirements if they are made of noncorrodible materials (such as fiberglass) or their exteriors are heavily coated with noncorrodible material (such as ACT-100 7 tanks). Also, steel tanks that have a corrosion-resistant coating and cathodic protection (such as sti-P3 7 tanks) meet the corrosion protection requirements.

In Connecticut, UST systems must have corrosion-resistant components and cathodic protection.

If your tank and integral piping is not one of these types already protected from corrosion, your UST system is illegal and must be properly closed, including soil sampling and site remediation, if necessary.  

If your UST system is in compliance and is cathodically protected, (sacrificial anodes or impressed current system), that cathodic protection must be tested annually (sacrificial anode) or monthly (impressed current).

Replacing USTs

All new USTs must meet leak detection requirements, and effective October 1, 2003, all new USTs for commercial use (or for residential heating oil supplying four or more residential units) must be double-walled with double-walled piping. All new double-walled UST systems must have a continuous 360° interstitial space, which is continuously monitored using inert gas or liquid, vacuum monitoring, electronic monitoring or mechanical monitoring.

Closing USTs

You need to notify the regulatory authority that you intend to close your UST. Then make sure only trained professionals safely and correctly close your UST.

For further information please contact the Storage Tank Enforcement Unit at (860) 424-3374 or write to:

Department of Energy and Environmental Protection
Bureau of Materials Management and Compliance Assurance
Emergency Response and Spill Prevention Division
Storage Tank and PCB Enforcement Unit  
79 Elm Street
Hartford, CT 06106-5127

Source: Excerpt taken from U.S. EPA 510-1 June 1995 Don't Wait Until 1998 Brief Facts

Content Last Updated January 8, 2020