The Campaign for a Future WithOut Gas is relieved to learn that National Grid has repaired a Grade 1 (potentially explosive) gas leak on Walnut Street, near the site of the April 6, 2023 manhole explosion and fire.

Discovery of the dangerous leak was the result of BU scientist Nathan Phillips’ concern and determination. Phillips has been visiting Walnut Street daily since the manhole explosion with his leak detector (a CGI, combustible gas indicator) and has been finding and repeatedly calling National Grid about multiple leaks.

Nathan Phillips measures gas levels using a combustible gas indicator

He also wrote a letter to Newton Mayor Ruthanne Fuller, Department of Public Works Commissioner James McGonagle, and Chief Operating Officer Jonathan Yeo saying, “I am concerned for the safety of residents on Walnut Street and feel compelled to write you, because I will feel responsible if I don’t speak up and an explosion that harms people occurs.”

City Counselors Alison Leary, Susan Albright, and Deb Crossley also emailed the city officials to support Nathan’s call for action on the potentially explosive gas leaks. After being notified of the repair, Leary emailed Phillips to thank him for his “diligence and perseverance.”

Councilor Leary’s email to the mayor and city officials stated, “…Last week’s manhole explosion had the potential to be a much more serious event. I am concerned about the high methane gas readings recorded by Professor Phillips…This incident needs further review and the gas leak must be a priority repair.”

The other councilors also support an immediate assessment and full accounting of the cause of the manhole explosion and ongoing gas leaks. Although no one was hurt, the fact that there was an unrepaired high volume gas leak at that location, and many more leaks from the same network of pipes in the area, needs review and explanation.

Phillips said, “While it is an open question if that Grade 1 leak is related to the April 6 manhole explosion, it is evidence of a condition that could have contributed to the explosion.”

Two fresh patches in the newly paved Walnut Street show that National Grid repaired two other leaks on Walnut Street near Whole Foods. Though Phillips called to report those leaks over the weekend, as of Monday, April 17, there is still measurable gas at the site of those repairs.

After a high precision methane analyzer samples the air for natural gas (methane), it records the GPS location and the parts per million of atmospheric methane. The data is then mapped using Google Earth to help visualize the gas leaks on Walnut Street.

Newton Has a Serious Gas Leak Problem

National Grid’s latest data shows that Newton had to repair 166 Grade 1 potentially explosive leaks in 2022. There were 375 new leaks discovered. There are 143 Grade 2 leaks, 718 Grade 3 leaks and 83 high-volume unrepaired gas leaks (SEIs) like the one on Walnut Street near the site of the manhole explosion. Newton’s oldest unrepaired leak, at 52 Sewell Street, has leaked continuously since October 22, 1990.”

“To be safe, we need transparency about the condition of the whole leaky gas infrastructure. Until such time as National Grid is a full partner in our mission to prioritize the repair of the most dangerous gas leaks and responsibly retire our gas system, private citizens must remain vigilant and call in leaks to avert potential disasters,” said resident Cory Alperstein, an AFWOG member.

NGRID Gas Leak Hotline 24/7 – 1-800-233-5325

AFWOG urges Newton residents to report gas leaks. Any gas leak can become more significant at any time. And independent researchers typically find 1.5 to 3 times more leaks than are reported by the gas utilities.

Understanding Gas Leaks

When the utility company measures a leak, the state regulations requires it to assign a grade to indicate how potentially hazardous the leak is. Ranging from Grade 1 to Grade 3 SEI, they are defined as follows:

  •  Grade 1 leaks are high concentration potentially explosive leaks and must be repaired immediately. This includes leaks in or near a contained space, such as a building or manhole, where the gas could build up enough to potentially explode.
  • Grade 2 leaks are not immediately hazardous, but could become hazardous in the near future. They must be repaired within a year.
  • Grade 3 leaks are non-hazardous and are expected to remain non-hazardous. Grade 3 leaks initially designated on or after 1/1/2018 are required to be repaired or eliminated within 8 years.
  • Grade 3 SEIs are grade 3 but are leaking at such a high volume that the methane, a powerful greenhouse gas, has significant environmental impact. They are required to be repaired in 1-3 years.

In an email to Phillips and Newton officials reporting the repair of the Grade 1 Leak, Commissioner McGonagle included information on reporting a gas leak and the National Grid gas leak website.