SPRINGFIELD — A fatal natural gas explosion at the Ozark Empire Fairgrounds could lead to a costly “comprehensive plastic pipe replacement program” by City Utilities of Springfield.The staff of the Missouri Public Service Commission in Jefferson City believes CU should replace many gas lines that are similar to the one that leaked and led to the explosion. The staff also believes CU should do additional training for employees who repair and replace gas lines.

The PSC staff issued a 19-page report on Wednesday in a probe of CU’s natural gas main and service lines that followed the explosion on June 18, 2003, that killed Brad Murphy.The fairgrounds maintenance worker died when a building exploded while he was in its basement, which was used to store fairgrounds equipment.Investigators found that natural gas seeped into the basement after moving underground from a plastic pipe with a hole in it.The building had no natural gas service.Rock that was around a section of the pipe caused the hole but CU said it could not determine how the rock got there.The company’s policy is to put sand around plastic natural gas pipes.

The report begins by highlighting a special investigative report by the National Transportation Safety Board in April 1998.That report describes how plastic piping used for natural gas lines across the country from the 1960s through the early ’80s “may be vulnerable to brittle-like cracking resulting in gas leakage and potential hazards to the public and property.”The report points to 93 plastic pipe failures on CU’s system as a result of rock impingement since 1991 — 25 in the last year alone.

Ernest DeCamp, a CU spokesman, said Wednesday night that the company had not had a chance to examine the report.He said, however, that the PSC staff and CU staff have been working together closely.

“We’ve been working with them and we know because all the information came from us,” said DeCamp.”So we know what information we provided and we’ve been having dialogue as we’ve gone through this.”

The report says CU has 275 miles of plastic pipeline installed prior to 1982.That’s a critical year because the Office of Pipeline Safety ofthe U.S. Department of Transportation says plastic pipes installed before that year should be a special concern to all natural gas distribution companies.The PSC staff thinks all pipe olderthan 1982 should be replaced, as well as entire lengths of pipes that have ever been repaired between a gas main and a gas meter.That would be an extremely expensive endeavor.

CU is already using several other recommendations in the report, such as using sand with no rocks when it’s putting down pipeline in the trenches of plastic pipeline.

On Thursday, CU General Manager John Twitty met with reporters and said CU will continue to work closely with the PSC staff “to continue to provide a safe and reliable source of natural gas.”Twitty said he does not believe that the PSC will require CU to immediately replace all pipe installed before 1982.CU has 60 days to formally respond to the report.