By Scott Taylor,Staff Writer

State officials will meet with natural gas provider Northern Utilities this week to determine if the utility needs to replace Maine’s network of cast iron pipes more quickly.

The Maine Office of the Public Advocate wants the utility to replace its statewide 122-mile-long cast iron network within the next 10 years, according filings with the Public Utilities Commission.

The company has been replacing cast iron pipe sections, like the one blamed for a January 2004 explosion on Main Street, Lewiston, at a rate of about three miles per year since 1985. At that rate, the utility would replace all existing cast iron within the next 43 years.

The matter goes to the Public Utilities Commission later this month if the utility cannot strike a deal with state.

“It’s quite common to settle something like this,” said Carol MacLennan, staff attorney with the PUC. “There has been a lot information traded back and forth, and you can find common ground sometimes or develop a compromise.”

If the state and the utility cannot agree, they’ll present formal arguments to the PUC at a March 22 meeting. Commissioners would return a decision in mid-April.

Representatives from Northern Utilities declined to comment Friday.

Faster replacement could be more expensive for natural gas customers through 2014, according to PUC filings. The PUC filings estimate costs would increase by about 5 percent to pay for the work for the next 10 years. On the other hand, cost should go down by the same amount after 2014.

A leaking cast-iron pipe led to an explosion on Jan. 12, 2004, on Main Street in Lewiston, according to the PUC. The blast and a subsequent fire demolished Lewiston Radiator Works and the former Hotel Holly. Five people were injured.

That leak was caused by gradual “graphitization,” according to PUC reports. That’s a chemical process where the iron in the older pipes leaches out, leaving behind a much weaker graphite and iron oxide pipe. Tests on a 6-foot section of pipe removed from the scene of the Jan. 12 explosion revealed at least a dozen pinhole leaks due to graphitization, according to the PUC.