Underground Storage Tanks

An Underground Storage Tank system (UST) is a tank (or a combination of tanks) and connected piping having at least 10 percent of their combined volume underground. The tank system includes the tank, underground connected piping, underground ancillary equipment and any containment system. Over time, USTs may corrode, leaking their contents into the surrounding soil and, eventually, groundwater. For this reason, USTs with a 110-gallon or greater capacity for storing petroleum products are regulated under the Municipal Code of Chicago by DOE.

Anyone wishing to install, upgrade, repair, remove, abandon, install a Stage II vapor recovery system on, or put an interior lining in a UST must first obtain a permit from DOE (to download permit application forms, see UST Permits).

Owners and operators of USTs are responsible for ensuring their USTs do not leak. To assist them, DOE has developed the UST Operation and Maintenance Manual for Owners and Operators. A copy of this manual is attached as a PDF file.

Anyone who suspects that a UST is leaking should call the Illinois Emergency Management Agency (IEMA) at (800) 782-7860 within 24 hours of the suspected leak.

NOTIFICATION FOR UST ACTIVITY. Notice of UST activity must be submitted in writing by the contractor to the Fire Department and Department of Environment. Notice of removal of an UST shall be given to the office at least 30 days prior thereto, unless such action is in response to a known or suspected release, which has been assigned an incident number by Illinois Emergency Management Agency. In the event of a known or suspected release, the Department of Environment may waive the 30-day waiting period. However, a permit is still required. No UST activity or portion thereof is to be performed without an UST inspector from the City of Chicago Department of Environment and Fire Department.

TEMPORARY CLOSURE. USTs may be temporarily closed for up to 5 years. During this period, the UST must continue to be monitored for leaks and corrosion. If a release is detected, it must be quickly abated and reported to the Illinois Emergency Management Agency within 24 hours.

If the UST is temporarily closed for longer than three months, all lines, pumps, manways, and ancillary equipment must be capped and secured except for vent lines, which may remain open. After 5 years, the UST system must be removed.

PERMANENT CLOSURE. You can either remove the UST from the ground or fill it with inert solid material. In both cases, the tank must be emptied and cleaned by removing all liquids, dangerous vapor levels, and accumulated sludge.

TANK INSTALLATION. The proper design and installation of underground storage tank is necessary to insure that normal operational loads will not cause the tank to deform and rupture. The most common cause of structural failure is improper installation. The environment surrounding an underground tank must be adequately characterized before a tank is installed. Environmental factors that can affect sitting and installation decisions include: bedding and backfill characteristics; high water level, requiring a tank to be anchored; location and magnitude of soil loads over a tank. Information on proper tank installation procedures is given in the City of Chicago Department of Environment's required checklist for underground storage tank installation.

TANK REMOVAL. All personnel involved in this recommended practice should be familiar with the potential hazards, and be knowledgeable in the appropriate health and safety measures needed to ensure a safe working environment. USTs should be handled with extreme care during removal and disposal off-site. Information on proper tank removal procedures is given in the City of Chicago Department of Environment's required checklist for underground storage tank removal.

TANK ABANDONMENT IN PLACE. Tank abandonment in place is granted due to loss of adjacent or subjacent support of nearby structures, railroad tracks, street, other USTs or in unusual situations where removal is infeasible. Contractors seeking a waiver shall provide all documentation including four copies of a completed permit application, statement of need and site plans. Information on proper tank abandonment in place procedures is given in the City of Chicago Department of Environment's required checklist for underground storage tank abandonment in place.