By Claire Corcoran
The Friends of the Public Garden has been working with a group of organizations known as the Gas Leak Allies advocating for policy changes that would speed up the rate of repair of an estimated 3,500 gas leaks under Boston's streets. We joined this effort because of our mission to care for the trees on the Commonwealth Avenue Mall, which have been seriously impacted by gas leaks. The trees in the Common and Public Garden are further away from the gas mains, but a recent survey found 25 trees along the Commonwealth Avenue Mall that are being impacted by leaking methane gas.
The infrastructure that brings methane gas to homes and businesses in Boston dates back to the days of gas street lamps during the Victorian era. Back in those days, when our historic downtown neighborhoods were constructed, the pipes laid to deliver methane to the street lamps (and later adapted for homes and businesses) were 12 foot lengths of cast iron pipe. Junctions of the pipe at intersections or along streets were "sealed" by stuffing the cracks with burlap bags, and painting creosote over the outside. In the ensuing hundred-plus years, cycles of freeze/thaw and movement of groundwater, combined with rusting and decay of the pipes, have opened up many of these seams and junctions, leaking the methane gas into the surrounding soil. The roots of trees require oxygen to survive, and when methane gas displaces the oxygen, the trees literally begin to suffocate. These gas leaks have caused the deaths of many of our city's trees, and in fact it is possible in many locations to measure the gas that is being emitted from the exposed xylem of the stumps of removed trees.
There are many other reasons why gas leaks should be repaired as quickly as possible. It is wasteful - and the unaccounted-for gas is included in the calculation of our rates, meaning that we consumers are paying for the leaked gas. It contributes significantly to climate change - methane gas is actually 80 times worse over the first 20 years for our climate disruption than other fossil fuels when it is released into the atmosphere without being combusted. The leaked methane is bad for respiratory health, contributes to ground level ozone which causes asthma, and contains unknown toxins as residue from the fracking process which produces 60% of our gas supply. Also, it is important to note that the gas companies are reimbursed for the repairs that they make to our infrastructure. But the foremost reason that the Friends of the Public Garden is advocating on this issue is that gas leaks kill and damage trees along our treasured Commonwealth Avenue Mall, and we will continue to advocate for their speedy repair and for the reimbursement of the cost of the damaged trees.