Permanent Closures - Underground Storage Tank (UST) removals are hazardous undertakings involving flammable and combustible liquids, excavations and confined space. Worker and public safety is vital. Out-of-service UST systems can also cause harm to the environment and must be properly closed. For these reasons, closure activity must be conducted by an Iowa licensed remover and a closure assessment must be conducted or supervised by a Certified Groundwater Professional according to 567—134.28 Iowa Administrative Code (IAC). The UST system owner is responsible for contacting the qualified individuals to complete UST closure. A list of Certified Groundwater Professionals and licensed removers is provided on the Iowa Licensed UST Professionals webpage.
The Iowa licensed remover must notify the Department of Natural Resources (DNR) UST Section at least 30 days before removal, fill-in-place or change-in-service by completing the Notification of Closure form. An Iowa licensed remover must be on site for all regulated UST system closures.
After receiving the completed Notification of Closure form, the UST Section will send a letter to the owner and remover acknowledging the closure date. Removers must notify the DNR Field Office in the region where the closure is taking place (see closure guidance) at least one working day prior to closure. Make sure the local fire department is notified for permitting and other requirements before implementing any closure activity.
Workers must not enter a tank pit excavation to obtain samples unless the proper shoring or sloping is in place. Evidence of contamination must be reported within 24 hours or 6 hours if a hazardous condition exists.
The Iowa Licensed Remover is responsible for submitting the UST closure report form within 45 days of closure.
Temporary Closure - Owners/operators of UST systems must submit notification for temporary closure. If you decide temporary closure is appropriate for your tanks, the following requirements must be met:
- The underground storage tank may be filled with a non-corrosive, non-hazardous liquid if there are concerns about hydraulic pressure exerted on the tank.
- Except for required venting, all fill and access locations and piping must be sealed using locking caps or concrete plugs.
- Power service must be disconnected from all pumps associated with the use of the UST, unless the power services some other equipment which is not being closed.
- Compliance inspections must be completed to ensure temporary closure requirements continue to be met.
- Pollution liability insurance must be maintained. If insurance cannot be maintained, a site check is required of the facility before the owner's eligibility to file a claim expires.
At the end of the 12-month temporary closure period, the UST must be returned to service, permanently closed or an extension of temporary closure filed. All compliance and testing requirements will be enforced prior to completion of temporary closure.
Abandonment In-Place - The last option for decommissioning is abandonment in-place. This is relatively rare and allowed when the removal of the tank may cause damage to existing structures. Please contact the Iowa licensed remover for questions regarding tank or piping abandonment. When considering abandonment in-place, keep in mind that when the property is sold, the owner will still have a buried UST or solid waste underground. Property is easier to sell when the UST system is removed and everything is documented.
Sampling & Reporting - Part of the requirements for closure of a UST is that the owner must demonstrate to the satisfaction of DNR that no release has occurred. This is based on soil and groundwater sample analyses. This analysis must be performed during or immediately after closure activities. Following sampling, a tank closure report must be submitted to DNR.