pipeline Accident Report

Rupture of Piney Point Oil Pipeline and Release of Fuel Oil

Chalk Point, Maryland
April 7, 2000

NTSB Number PAR-02/01
NTIS Number PB2002-916501
Adopted on July 23, 2002

Executive Summary

On the morning of April 7, 2000, the Piney Point Oil Pipeline system, which was owned by the Potomac Electric Power Company, experienced a pipe failure at the Chalk Point Generating Station in southeastern Prince George’s County, Maryland. The release was not discovered and addressed by the contract operating company, Support Terminal Services, Inc., until the late afternoon. Approximately 140,400 gallons of fuel oil were released into the surrounding wetlands and Swanson Creek and, subsequently, the Patuxent River as a result of the accident. No injuries were caused by the accident, which cost approximately $71 million for environmental response and clean-up operations.

Probable Cause

The National Transportation Safety Board determines that the probable cause of the April 7, 2000, Piney Point Oil Pipeline accident at the Potomac Electric Power Company’s Chalk Point, Maryland, generating station was a fracture in a buckle in the pipe that was undiscovered because the data from an in-line inspection tool were interpreted inaccurately as representing a T-piece. Contributing to the magnitude of the fuel oil release were inadequate operating procedures and practices for monitoring the flow of fuel oil through the pipeline to ensure timely leak detection.

This report discusses the following major safety issues:

  • The sufficiency of the evaluation procedures for pipe wrinkles;
  • The efficiency of the leak notification procedures; and,
  • The effectiveness of the incident command.

In addition to these issues, the Safety Board’s investigation addressed the leak detection procedures used on the Piney Point Oil Pipeline and the analysis of the pipeline in-line inspection results.

As a result of its investigation of this accident, the Safety Board makes safety recommendations to the Research and Special Programs Administration and the Environmental Protection Agency.