Researchers have located thousands of methane gas leaks throughout the Boston area. An article by Ashlee Fairey published in last week’s Courant describes the leaks and sheds some light on the threat posed by neglecting this problem. In addition to creating a serious safety hazard the leaks are killing trees along the Commonwealth Avenue Mall.
According to the article, there are approximately 4,000 gas leaks throughout 90% of the city. Bob Ackley, president of Gas safety Incorporated, is conducting research with Nathan Phillips, director of the Center for energy and environmental studies at Boston University, and estimates between 30 and 50 leaks along Commonwealth Avenue between Massachusetts Avenue and Arlington Street. The citywide average is approximately 5 leaks per road mile.
National Grid, Boston’s sole natural gas provider, classifies leaks as grade 1,2 or 3 depending on the severity. Grade 1 indicates danger of explosion and will be addressed immediately. Grade two leaks are responded to as soon as construction allows and grade 3 leaks are checked only once a year. National grid representatives say that leaks classified as grade 3 do not present a danger of any kind to the safety of the public, Phillips disagrees.
“Peer-reviewed literature suggests that the values we read in Boston are well above the levels of methane that would have health impacts on humans,” Phillips said. Methane can be harmful at 2.2 parts per million and measurements taken by Phillips show levels up to 30 parts per million in Boston.
State Representative Marty Walz considers this to be matter of public safety “since these small leaks can easily turn into dangerous ones…Beyond that,” Walz says, “these leaks are damaging and sometimes killing trees, and they add to the harmful effects of climate change.”
How Gas Leaks are killing trees
Methane causes the oxygen and moisture in the soil to become displaced killing the tree roots. All of the trees along the inbound side of the Mall between Fairfield and Exeter streets are beginning to show symptoms of methane related ailments.
National Grid has agreed to cover the replanting costs for several of the trees and will continue to do so on a case-by-case basis but has not formally acknowledged a relationship between the gas leaks and the dying trees. A two-year infrastructure upgrade planned for the inbound side of Commonwealth Avenue starting next year would replace 3,000 feet of gas main. Sate representative Lori Ehrlich of Marblehead has proposed four bills aimed at establishing timelines for gas leak repairs and inspections of trees suffering from methane. A house hearing is scheduled for Tuesday, October 25.