PSMS Lessons Learned - May 2026

The conditions most directly compromised during this event related to two primary elements of API RP 1173, Operational Controls and Documentation and Record Keeping. The pre-job walkthrough did not translate into a positive, field-based verification of all services (an operational control/hold point), and the organization’s reliance on a service transfer log and maps without confirming documentation allowed missing or inaccurate records to be treated as proof that no service existed (normalization of risk). Strengthening these elements means requiring independent verification when records are incomplete and ensuring field discoveries are promptly captured in updated service tapes/maps.

Description of event:

During a main retirement project, gas service to a residential building was inadvertently interrupted. The service tape for this address was not included in the engineering job package and was not identified during the pre-retirement walkthrough, as the service was not shown on existing maps.

The affected service consisted of a two-inch plastic line inserted into a three-inch retired steel service. Because this configuration was not mapped or documented, the service was overlooked during planning and execution. As a result, an unplanned outage impacted 56 residential apartments.

Key Causal Factors and Root Causes:

Primary Causal Factor:

• The residential building was not captured in the job package prepared by Engineering.
  • Work Direction - Preparation – Work Package/Permit Needs Improvement (NI)
• The service to the residential building was not mapped.
  • Management System – SPAC NI – Drawings/Prints NI
• A pre-retirement walkdown was conducted; however, the service to the residential building was not verified.
  • Work Direction – Preparation – Walk Thru NI
  • Communication – No Communication

Key Corrective Actions:

• Ensure the day of the pre-retirement email includes sign-off from all required parties, with all relevant departments providing documented comments via SharePoint.
• When a main retirement includes housing complexes, verify that all buildings are positively identified as either in-scope or out of scope prior to work.
• Require job packages for main retirements involving housing complexes to include service tapes for all addresses within the complex.
• Update service tapes to accurately reflect field conditions, including inserted or legacy services.
• Contractor to communicate internal corrective actions to Contractor Oversight so lessons learned can be shared with other contractors.
• Contractor to conduct a safety stand-down with all crews to review incident, expectations, and applicable policies.
• Contract Oversight to conduct a safety stand-down with inspectors to reinforce lessons learned from the incident and relevant procedures.

Key Lessons Learned:

• Reinforce the importance of situational awareness during pre-retirement walkthroughs, including active discussion of any nearby or adjacent services that may fall outside the defined job scope.
• Housing complexes require enhanced diligence to ensure all buildings and services are accounted for and verified.
• Be cautious of risk normalization related to reliance on the service transfer log; absence of documentation does not confirm absence of service.

Where safety puzzle was potentially impacted (pipeline, process, and personal)

• Pipeline safety: unmapped/undocumented inserted service, missed active service during retirement, and reliance on records as proof of “no service,” leading to the unplanned outage.
• Process safety: work package/service tape missing, maps/records inaccurate, pre-retirement walkdown not achieving positive verification (missing hold point), and a communication/coordination gap.
• Personal safety: increased potential for unexpected live-gas interaction for crews and public exposure associated with the unplanned outage and response activities.