Worcester, MA – In this city still served by brittle cast iron natural gas mains from last century, firefighters respond to an average of three natural gas leak calls a week, according to dispatch records.
And gas leaks here that aren’t deemed an immediate danger often go unplugged for three or four years after they’re discovered, according to reports filed with state utility regulators.
In February, Worcester fire crews scrambled to evacuate businesses in the Webster Square area after a leaky cast iron pipe under Mill Street filled manholes with dangerous levels of explosive gas that then began to backflow into nearby buildings.
A Telegram & Gazette analysis of more than three years of Worcester Fire Department dispatch records show some cases of repeated gas leaks over time at particular addresses and in some neighborhoods.
Along four blocks of West Street, for example, city firefighters investigated a half dozen reports of natural gas leaks between September 2011 and September 2013, the records show. The city figures don’t include instances when residents who smelled natural gas notified NStar directly rather than first calling the fire department.
A man who works on West Street said he reported a strong odor of natural gas in the area to the utility in October. An NStar crew showed up and found the source of the leak quickly, he said, but didn’t return to dig up the street and fix the pipe until late December.
NStar reported 1,251 gas leaks, of which 349 were repaired, in Worcester last year, according to company figures provided by the state Department of Public Utilities. The state figures show NStar classified 203 of the leaks in Worcester last year as Grade 1, the most dangerous kind.
“If you think of it as any Grade 1 leak has the potential to explode, that’s a lot of Grade 1 leaks,” said Shanna Cleveland, a lawyer at the Boston-based Conservation Law Foundation, which has been seeking to raise public awareness about leaky, old gas mains.
NStar reported to state regulators that it has fixed all of the Grade 1 leaks reported in Worcester last year and early this year. State regulations require the gas companies to fix such leaks immediately or work on them continuously until the hazard is eliminated.
“When a gas leak or smell of gas is reported to us, we respond immediately. We have a good record of getting to most of them in under an hour,” NStar spokesman Michael Durand said.
While city officials agreed that the company’s crews respond quickly to reports of gas leaks, many leaks that aren’t considered immediately dangerous go unrepaired for years.
NStar reported to state regulators scrutinizing its now-completed merger with Northeast Utilities of Connecticut that, as of May 2011, the company was aware of 226 ongoing leaks in Worcester that dated back to 2008 and 182 that dated back to 2007.
State regulations don’t set any time requirements for repairing leaks not classified as dangerous, but gas companies are required to log and keep track of even minor leaks until they are repaired. Mr. Durand said NStar meets its obligations under the regulations.
“In terms of Worcester, it was among the first cities to have natural gas in the region,” Mr. Durand said. “As with other older cities in the area, there’s a higher concentration of cast iron pipes there, which is why we’re focused on replacing those existing pipes with new ones.”
The Boston-based company’s natural gas service area includes parts of Central Massachusetts, MetroWest and the South Coast.
Across that territory, NStar operates 423 miles of cast iron mains, installed between 1873 and 1957, and 332 miles of bare steel pipes put in between 1900 and 1960, according to company figures.
The cast iron and bare steel gas mains account for just under a quarter of the utility’s total inventory of about 3,200 miles of gas mains in Massachusetts, according to company figures.
While NStar doesn’t disclose figures on how many miles of old pipes it operates in particular communities, Director of Public Works and Parks Paul J. Moosey said that from what he’s seen over the years many miles of gas mains in Worcester are cast iron.
“Just like water and sewer, there are lots of old gas mains out there in the city. But in the last five years, I’d say, the gas company has accelerated the replacement of their mains,” Mr. Moosey said.
The city shares its street repaving plans with NStar regularly to give the utility the opportunity to replace old pipes without having to pay to fix the street after the work, Mr. Moosey said.
The Conservation Law Foundation’s Ms. Cleveland noted that, unlike other gas utilities in the state, NStar does not have a state-approved accelerated replacement program in place.
“They have been doing some replacement of mains, but it would certainly be a positive step for them to be moving faster in replacing that old cast iron,” she said. “It’s more susceptible to cracking when the ground freezes and thaws and moves that pipe up and down. There’s more opportunity for a leak to start and then just continue over time.”
A November 2012 gas explosion in downtown Springfield injured more than 20 people and caused extensive damage after a Columbia Gas employee accidently punctured a gas line while probing for a leak. Three months later, in February 2013, a gas leak in a Until Corp. pipe caused an explosion in Fitchburg that leveled an auto parts store after it had closed for the day.
NStar’s Mr. Durand said that while natural gas prices fluctuate based on factors beyond the utility’s control, the company hasn’t increased the rate it charges to distribute gas to its customers in more than two decades and recently agreed to freeze those rates until 2016 as part of its Northeast Utilities deal.
The company may seek state approval for an accelerated main replacement program when it next asks for a distribution rate increase, he said.
“Our system to deliver natural gas is extremely safe,” he said. “In Worcester alone, we have 45,000 customers that we deliver natural gas to every day, 24 hours a day.”