AUBURN – Northern Utilities should wrap up work replacing all of its cast iron natural gas lines in Auburn this Friday.

The company is on track to finish replacing all cast iron lines in both Lewiston and Auburn by November, capping a four-year project mandated by the state Public Utilities Commission.

“All we have left to do in Auburn is the South (Lown) Bridge, or just north of it,” said Northern Utilities project manager Perky Robichaud. “Everything else in the city is complete.”

Northern Utilities crews are scheduled to begin working in Lewiston again this week. Robichaud said crews will be replacing lines under Lincoln, Cedar and Oxford streets through November.

The PUC required the company to replace 57 miles of cast iron lines in the Twin Cities after a January 2004 explosion leveled the old Hotel Holly and the Lewiston Radiator Works, both on Lewiston’s Main Street.

Investigators blamed the explosion on a leak from one of Northern Utilities’ aging cast iron lines.

So far, the project has required the company to dig at 1,700 sites in Lewiston and nearly as many in Auburn. In all, the company is replacing or lining 28 miles of cast iron pipe in Lewiston and 29 in Auburn with plastic pipe.

Their final job, tentatively set for November, will be replacing the connections between the Lewiston and Auburn systems under the Longley and Lown bridges.

Robichaud said the work will quadruple the company’s capacity. He said the work has been good for business, as more homeowners have approached crews to talk about bringing natural gas service into their homes.

“We’ve had a lot more of that, especially as the price of heating oil has increased,” Robichaud said.