Temporary Operating Procedures

Lessons from Tank Level Management

The February 2023 Process Safety Beacon has the title ‘People Are a Critical Part of Safe Operations’. Its message is that tank overflow was prevented by a non-documented action of an individual who was not directly involved in plant operations.

There are two direct lessons to be learned from this event. The first is to compliment the person who was monitoring tank levels, and to formalize this action into the operating procedures. The second lesson is that the High-High Level Alarms need to be set at a more realistic value.

There is, however, a third more-or-less hidden lesson to do with this potential incident. The bulletin states,

A temporary procedure was implemented to safety fill the tanks until new level devices could be installed at the proper level.

We are not told if the facility had a procedure for managing temporary operating procedures. If it does, then that procedure should consider the following questions.

• How is the word ‘temporary’ defined? Is there a specific time limit after which the new procedure is no longer valid?

• Has the new procedure for operating the tanks been incorporated into the Management of Change program?

• Are people trained in the use of the new procedure — including those who order the materials to fill the tanks?

• Is there a procedure for operations for the time when the temporary procedure is no longer in use?

• Are there any other operations whose safety depends on the actions on non-operations personnel? Is a root cause analysis called for?

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