Skip to content

UST System Closures

Temporary Closure/Extended-Out-Of-Use (EOU)

Temporary Closure is an option that tank owners may choose when they decide not to use the tanks for a period of time. Proper temporary closure is referred to as Extended-Out-Of-Use (EOU). In order for a facility to remain in compliance while out-of-use, the following requirements must be met:

  • The tanks should be pumped out to less than one inch of product. If the tanks are not pumped out, monthly release detection must continue.
  • If a cathodic protection system exists, it must be maintained. Three-year tests must be performed on time.
  • Registration fees are due every year
  • Financial Responsibility must be maintained
  • After 3 months of out-of-use status, all lines, pumps, manways and ancillary equipment should be capped and secured
  • Vent lines should remain open and functioning
  • Release reporting, investigation, response, and corrective action of any confirmed release is still required

When an UST system is temporarily closed for more than 12 months, the tank system must be permanently closed if it does not meet the cathodic protection requirements found in R.61-92, Part 280.20 and 280.21 (pdf).

Permanent Closure

There are two acceptable methods for permanent closure, removal from the ground (recommended) and fill-in-place with an approved inert solid substance.

At least 30 days prior to beginning closure activities, an accurately filled out Tank and Sludge Disposal Form (pdf) must be submitted to the Division.

Points to consider:

Once all information is received and deemed acceptable, an approval letter will be mailed out to the tank owner as well as the closure contractor (if applicable). The tank owner must then give 48-hours notice prior to the actual closure (removal or fill-in-place) event so that a Division representative may be present.

Soil sampling is required at all permanent closures. Information about sampling requirements can be found in the Underground Storage Tank Assessment Guidelines as well as the Analytical Methodology for Groundwater and Soil Assessment Guidelines. A Closure Report must be submitted to the Division within 60 days of the closure event. Please contact the Division with any questions regarding closure or sampling specifics, including variances.

Soil sampling is required at all permanent closures. Information about sampling requirements can be found in the Underground Storage Tank Assessment Guidelines (pdf) as well as the Analytical Methodology for Groundwater and Soil Assessment Guidelines (pdf). A Closure Report must be submitted to the Division within 60 days of the closure event. Please contact the Division with any questions regarding closure or sampling specifics, including variances.