At 42 years old, the pipeline could take no more.
Colonial Pipeline has identified a break in a previously repaired segment of pipe as the cause of a 272,580-gallon gasoline spill in Huntersville in August. Details of the accident were made public in a 30-day report filed with the Pipeline and Hazardous Materials Safety Administration.
The leak source originated from beneath a portion of pipe repaired in 2004 as part of an integrity assessment. The pipe had been installed 3 feet below ground.
The pipeline, one of two owned by Colonial transporting petroleum products from Texas to New Jersey, is 40 inches in diameter, with walls three-tenths of an inch thick, coated with coal tar and made by Bethlehem Steel in 1978.
At the time of the spill, the pressure inside the pipeline was 183 pounds per square inch, far below the maximum of 673.
Colonial estimated it will incur costs of at least $10 million, including $2.6 million to clean up and monitor the contaminated groundwater and soil, plus $351,000 in lost gasoline.
Although a remote supervisory control and data acquisition system — SCADA — was operating at the time of the accident, it did not detect or confirm any drop in pressure, the report said. The leak was discovered by two teenagers riding ATVs in the Oehler Nature Preserve, who saw liquid bubbling at the surface of the ground.
Because of the age of the pipeline, there was no computational pipeline monitoring system — CPM — in place that could have detected the leak earlier. Federal law exempts pipelines built before Oct. 1, 2019 from installing CPMs until Oct. 1, 2024.
Policy Watch reported yesterday that Colonial had increased the estimated size of the spill by more than four times — from 63,000 gallons to more than 272,000 gallons, one of the largest gasoline spills in North Carolina history. About half of the product has been recovered. The groundwater and soil have been contaminated, but the size of the underground plume of gasoline has yet to be determined.
The neighborhoods around the spill are on private well water. Although no petroleum products have been detected in residential wells, Colonial has offered to cap some of them and connect the homes to a public water system, plus pay the owners $1,000 for future water bills.
However, landowners have stated publicly that they feel pressured by Colonial to sign the agreements. The contracts, Policy Watch reported, exclude important protections for the landowners.