Dec. 9—With the removal last month of a final piece of cast iron pipe installed in 1927, a $178 million, 14-year gas distribution replacement project in Portland and Westbrook came to an end.
Swapping out 126 miles of cast iron and unprotected steel pipes with high-density plastic pipe and making other upgrades were among Unitil Corp.’s “largest and most aggressive capital improvement initiatives,” said the natural gas utility that owns and maintains the system. Some of the pipes were more than 100 years old.
The work also included upgrades to 8,862 service lines and 16,945 meters. In all, the project serves about 9,000 “end points,” or metered residential and business customers, more than one-fourth of its 33,000 Maine customers.
Fewer gas leaks and a drop in methane emissions are among the project’s benefits. In addition, the system has more control points, where flow and pressure are regulated; improved regulator stations; and overall, it provides a more reliable gas supply and better gas quality, the company said.
With the new pipelines, Maine now “has one of the tightest systems,” Unitil spokesman Alec O’Meara said.
The project goes back a while, with the initial filing before the state Public Utilities Commission in March 2008. Following much discussion with the utility, the Office of the Public Advocate and others, the PUC acknowledged in July 2010 that replacing aging pipes was the best way to address leaks and other safety concerns, said Carol MacLennan, senior staff attorney at the agency.
Gas lines had been in the ground for 46 to 110 years, according to the PUC. Northern Utilities, which was acquired by Unitil in 2008, experienced at least 89 broken cast iron mains between 1998 and 2002, regulators said.
Between nine and 27 pipeline breaks occurred annually during those four years.
A corroded and cracked cast iron pipe in Lewiston exploded in January 2004, injuring five people and damaging property. The PUC approved a plan to replace cast iron and bare steel in Lewiston and Auburn over four years. It then directed Northern to come up with a proposal to do the same in Portland and Westbrook.
Public safety was a key reason that Public Advocate William Harwood said he supported the project. “It called into question if they continued to use cast iron pipes if they were meeting the requirement of safe, reasonable and adequate service,” he said.
Two dozen states have eliminated cast or wrought iron natural gas distribution lines, according to the U.S. Department of Transportation. The pipelines are among the oldest in the U.S., and many were installed more than 60 years ago, the agency said. Degrading iron alloys and pipeline age have increased the risk of continued use, the DOT said.
The Department of Transportation announced in October $196 million in grants, funded by the Bipartisan Infrastructure Law, to repair and replace aging natural gas pipes. The round of funding will support 60 modernization projects for natural gas pipelines across 20 states, the agency said.
Harwood and environmentalists supported state legislation this year seeking to scale back natural gas expansion by changing how it’s financed. That was not an issue with the Unitil project, which does not expand the network of pipelines, but replaces it.
“We’re OK with the program,” Harwood said.
The project’s cost paid by ratepayers has been phased in over most of the 14-year project to prevent “rate shock,” MacLennan said. The utility was required to submit an annual plan that was used to compare with the following year’s plan, she said.
Harwood said Unitil filed cost details each year separately from the PUC’s ratemaking procedures and was “put on a separate tracking system” to allow regulators and the Public Advocate to “see exactly what they were spending and make sure they recovered just what they were allowed and no more.”
The project’s cost has ballooned over the years. Northern Utilities said in March 2008 it expected that replacing all cast iron in Portland and Westbrook would cost between $21 million and $52 million, with the range likely between $40 million and $52 million.
O’Meara said the scope of the project expanded since 2011. In 2014, it was broadened to include replacing certain uncovered steel pipes and safety valves. The pipe replacement project was required by the PUC in 2008 before Unitil’s acquisition of Northern, he said.
In addition, “prices change in unforeseen ways over time, especially on long-term construction projects, ” O’Meara said. “That’s exactly what occurred here.”
Copy the Story Link