Class 1 Facility out of service and decommissioning

In July 2023, we amended WAC 173-180 to require Class 1 facilities with out of service oil storage tank or transfer pipeline to take certain actions. We define “out of service” as a tank or pipeline where no oil has been added, removed, or transferred in one year or more.

Read our implementation guide.


Facilities must either:

  • Monitor, inspect, maintain, and repair the storage tank or transfer pipeline as if it were in service, or  
  • Decommission the storage tank or pipeline, as described in WAC 173-180-910.  

Facilities choosing to monitor, inspect, maintain, and repair storage tanks and pipelines must also continue to meet the requirements of the facility’s operations manual and prevention plan, conduct API standard inspections, conduct testing, and continue to maintain corrosion and cathodic protection systems.

To decommission a storage tank or transfer pipeline, the storage tank and transfer pipeline must be completely oil-free, certified as gas-free.  Transfer pipelines must be blanked at both ends. Storage tanks must be disconnected from all associated piping and instrumentation and control lines; all piping, instrumentation, and control lines to the storage tank must be blanked. All piping to the storage tank must be air gapped.  All electrical devices connected to either storage tank or transfer pipeline must be de-energized.

Any marine transfer hoses must be completely oil-free, certified as gas-free, and physically removed from the dock.

Storage tanks and transfer pipelines that have been placed in caretaker status as defined in 33 C.F.R. Part 154 or that have been permanently closed as defined in 40 C.F.R. Part 112, will be considered decommissioned.  

The owner or operator of a facility must submit electronic notification to ecology 30 days prior to decommissioning and returning to service.