PORTLAND — Natural gas provider Unitil has started to replace about 75 miles of cast iron and steel pipelines in Portland and Westbrook.

Whether that work will be finished in 12 years or up to 20 years – and its effect on gas rates – will be the subject of a public hearing at Portland City Hall on Wednesday night, June 9, at 6 p.m.

The project is pitting the Maine Public Utilities Commission against Unitil and other appointed and elected state officials.

The PUC is advocating for a more aggressive, 12-year schedule to complete the project, while Unitil would like 15 to 20 years to complete the upgrade.

The two plans have prompted the office of Maine’s public advocate, which represents consumer interests in matters before the PUC, and three of the city’s state representatives to call on residents to oppose the PUC plan.

“Adding the burden of a quick replacement program will likely require deficit spending and further automatic rate increases,” Rep. Herb Adams, D-Portland, said in a press release. “Gas rate increases hit both homeowners and renters. Both are captives of the system with few other affordable options.”

The PUC contends that a more aggressive timetable will not substantially increase the project cost, which will be absorbed through rate increases to residents and businesses that use natural gas.

The cost increase to an average residential customer would be between $5 and $20 a year, or about 1 percent to 2 percent, the PUC said in a press release.

The public advocate, meanwhile, says the PUC plan, estimated to cost $64 million, adds $16 million in unnecessary construction costs.

“This is not the time to be unnecessarily increasing natural gas delivery rates to thousands of struggling Maine families and businesses dealing with the worst economic conditions in more than 70 years,” Public Advocate Richard Davis said in a press release.

PUC spokeswoman Evelyn deFrees said the goal is to balance public safety needs with the impact on ratepayers.

The original gas pipe system was installed in the late 1800s to carry manufactured coal gas, according to the PUC. Most of the remaining iron pipes are 70 years old and would be replaced with state-of-the-art polyethylene plastic pipes.

The spokeswoman declined to comment on why the PUC plan was safer than Unitil’s.

“We, in general, don’t speak beyond the written documents because this is a litigation process,” deFrees said.

Portland’s legislative delegation, which intervened to require the public hearing on the PUC plan, said in a joint statement the timing is not right for an aggressive timetable. The lawmakers said Unitil is already planning to ask for a 37 percent rate increase, without the pipeline project.

Rep. John Hinck, D-Portland, said customers need to be protected from “rate shock.”

“People’s budgets are stretched as it is,” Hinck said. “Outdated gas pipes can be replaced without compromising on safety and without causing a punishing rise in gas bills.”

Opponents also claim the aggressive schedule will also negatively impact Unitil’s financial health – a view the PUC staff doesn’t share.

Wednesday’s hearing is in City Council chambers at Portland City Hall.

Randy Billings can be reached at 781-3661 ext. 100 or rbillings@theforecaster.net