“Source: https://www.bostonglobe.com, November 15, 2018
By: Milton J. Valencia
Federal investigators Thursday singled out a Columbia Gas engineer with “limited knowledge” for errors in drafting work plans for a Lawrence construction site, setting in motion a chain of events that led to the Sept. 13 natural gas explosions that killed one man and left thousands without heat and hot water.
In the most detailed accounting to date of the catastrophe, the National Transportation Safety Board identified a series of missteps by the utility at the planning stages for a gas main replacement project in South Lawrence. The agency recommended “urgent” steps to increase oversight within the company and at the state level.
The NTSB investigators have focused on the replacement project and the failure of the engineer planning that job to account for a critical sensor in a line that was being replaced. Once the line was disconnected, the sensor detected a loss in gas pressure that caused the system to pump a huge amount of gas into live lines, leading to more than 120 fires and explosions across Lawrence, North Andover, and Andover, the report found.
“The Columbia Gas field engineer who developed the engineering plans told NTSB investigators that he developed them without reviewing engineering drawings that documented the regulator-sensing lines,” the NTSB said in its report.