In order to clarify the regulatory requirements that may vary depending on the operational status of a pipeline, the Pipeline and Hazardous Materials Safety Administration (PHMSA) issued Advisory Bulletin (ADB)-2016-0075 to all operators of Hazardous Liquid and Carbon Dioxide pipelines. ADB-2016-0075 advises operators who wish to defer certain activities for purged pipelines to coordinate the deferral in advance with regulatory agencies, such as CAL FIRE - Office of the State Fire Marshal (OSFM) for intrastate pipelines. According to the bulletin, purged pipelines present different risks, and different regulatory treatments may be appropriate. The OSFM will consider each deferral request and approve deferral activities that are deemed impractical for purged pipelines.

It is important to note that PHMSA is currently in the process of rulemaking to establish a defined operational status called "idled" for pipelines that are temporarily taken out of service. This rulemaking also aims to set forth operations and maintenance requirements for idled pipelines and establish inspection requirements for idled pipelines that are subsequently returned to service. The ongoing rulemaking process, with a Regulatory Identification Number (RIN) of 2137-AF52, indicates PHMSA's commitment to addressing the regulatory framework for idled pipelines. Meanwhile, the OSFM follows the guidelines provided in ADB-2016-0075 when reviewing deferred maintenance requests for purged pipelines submitted by operators.


Step 1: Deferral Request 

The operator is required to submit a deferral request to the Assistant Deputy Director of the Pipeline Safety Division at the OSFM. The request should be sent via email to the Pipeline Notification address:

The deferral request must provide the following information about the pipeline:

  • OSFM Pipeline Identification Number.
  • Commodity contained in the pipeline at the time of the application.
  • Length of the purged pipeline segment, along with a map showing the beginning and end locations of the purged pipeline.
  • Procedure for purging the hazardous liquid from the pipeline.
  • Activities for which the operator is requesting a deferral, including specific regulatory sections.
  • Supporting documents demonstrating how the line is isolated from the active pipeline system (e.g., pictures with GPS locations for both ends of the subject pipelines).
  • Explanation of why each deferred activity is impractical for the subject pipeline.

Step 2: Field Inspection(s) and/or Records Review 

Upon receiving the deferral request, the OSFM may request the operator to provide a schedule of any field activities related to the subject pipeline. The OSFM may also conduct field inspections to verify that the pipeline has been purged and cleaned in accordance with the provided procedure.

At the conclusion of the field activities, the operator must submit the following supporting documents to the OSFM:

  • Records demonstrating that the subject pipeline has been purged.
  • Pictures and GPS locations of each isolation point.

Step 3: Acknowledgment 

Each deferral request is evaluated based on the criteria outlined in PHMSA-2016-0075:

  • Proper purging of the hazardous liquid from the pipeline.

The OSFM will send a letter acknowledging each deferral request upon review.