Two federal lawmakers representing a city where a natural gas explosion at a chocolate factory killed seven employees are calling for removal of Aldyl A piping, the trademarked name of a polyethylene pipe product manufactured by DuPont and installed mostly in the late 1960s to early 1980s.
Democratic Congresswoman Chrissy Houlahan and Republican Congressman Dan Meuser, who both represent Berks County, Pa., proposed a bill that would require utilities to replace Aldyl A pipes within five years.
The bill, HR-5638, is in response to the deadly R.M. Palmer Co. explosion in West Reading, Pa., on March 24, 2023. The blast destroyed one building and damaged another, killing seven people, injuring 11, displacing residents of nearby apartments and prompting an evacuation of the area.
The National Transportation Safety Board is investigating. The agency pinpointed the plastics-related cause in the first sentence of its last update on July 18, 2023.
"Natural gas was leaking from a DuPont Aldyl A service tee that was installed in 1982," NTSB reported.
The gas utility provider, King of Prussia, Pa.-based UGI Corp., had retired the service line connected to the tee during a meter relocation project in 2021, when a new service tee and new service line were installed.
However, the 1982 service tee remained connected to the natural gas system at full pressure, and it was less than 2 feet from subsurface infrastructure, including a cracked and corroded steam line, a condensate line and several heated chocolate pipelines, the NTSB investigative update says.
The service tee had consisted of an outer shell and a DuPont Delrin-brand insert that each had fractured, according to NTSB.
DuPont PE service tees with Delrin acetal inserts were installed in the late 1960s to early 1980s. In 2007, the products had been put on a list of pipe materials with "poor performance histories relative to brittle-like cracking" by the Pipeline and Hazardous Materials Safety Administration (PHMSA), the NTSB update notes.
In addition to poor performance, the DuPont service tees had a history of deadly failures, including leaks that caused explosions that killed three people in Maryland in 1973, one in Arizona in 1978, one in Texas in 1983, six in Iowa in 1994, and 33 in San Juan, Puerto Rico, in 1996.
While the 2007 PHMSA advisory warned of premature cracking in Aldyl A pipes and urged utilities to frequently survey the lines for leaks, pipeline safety administrators never required the pipe to be dug up and replaced.
After leaky plastic gas pipes sparked a fire at a Cupertino, Calif., condominium complex and then set a street on fire in Roseville, Calif., in back-to-back unrelated incidents in 2011, officials with Oakland, Calif.-based Pacific Gas & Electric Co. (PG&E) took it upon themselves to replace some 1,230 miles of aging Aldyl A pipeline.
A year later, Avista Corp. announced a 25-year program to remove and replace select portions of the DuPont Aldyl A medium density polyethylene pipe in its natural gas distribution system in Washington, Oregon and Idaho.
"In 2012, we had 737 miles of Aldyl A pipe throughout our service territory. We have replaced 427 miles of Aldyl A Pipe, investing approximately $239 million to date," Avista spokesman David Vowels said in an email. "Forecasting the remaining costs related to the project is challenging given many factors. Avista invests hundreds of millions of dollars in our system every year to provide safe, reliable service for our customers now and into the future."
Twelve years after Avista, federal action began.