Gas Leak Maps

The Maps

Every year, Massachusetts gas distribution utilities are required to report the location of gas leaks and leaks that were repaired in their territories to the Department of Public Utilities. HEET uses the reports to create the maps and information below. Use these maps to zoom in on your home, school, or business to find local gas leaks. Remember:

  • The maps are snapshots in time as of the last day covered by the report, December 31 of each year
  • Any one leak could have been repaired since or new ones developed
  • Independent researchers typically find 1.5 to 3 times as many leaks as utilities report
  • Google Maps places map pins on buildings – the leaks are on public streets, not inside buildings
  • You can learn more about HEET’s mapping process here
Jump to Utility Maps
Jump to Town Maps

Leak Grades

Gas leak grading indicates how potentially hazardous a leak is, ranging from Grade 1 to Grade 3. Leak grades are now indicated on the maps as numbers in the leak map pins, for example,is a Grade 3 unrepaired leak. Grades are defined as follows:

  • Grade 1 leaks are hazardous 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 non-hazardous, but could be 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 SEI are grade 3 leaks larger than 2000 square feet in rectangular extent – these are leaks of significant environmental impact, or SEI’s. They are approximately the largest 7% yet contribute approximately 50% of all leak emissions. They are required to be repaired in 1-3 years. HEET is working to improve utility adoption of the leak extent method to better identify SEIs in the field.

Emissions Estimates

Estimated methane emissions from gas leaks are now calculated and included in the tables below.

Due to the LAUF (Lost And Unaccounted For) gas regulations enacted in 2019, utilities were required to submit standardized estimates of their annual statewide methane emissions from leaks to the DPU. We used the same data and methods from utilities’ estimations, but with municipality-specific data (from the geocoded leaks dataset) substituted for statewide data where applicable.

These are underestimates due to only including reported leaks, and that the state is using an older conservative method of estimating the rates at which methane emits from leaking pipes. More information on the LAUF data and emissions estimates can be found on the LAUF Calculator page.

Data Sharing

We share our geocoded leaks data under a Creative Commons license. Please contact us directly if you would like a copy.

Emissions unit:

Leak Maps by Utility

Click on a utility to open its map.

By Utility
Unrepaired Leaks 2020
Repaired Leaks 2020
Utilities
Totals146409907
Berkshire Gas110200Berkshire Gas
Eversource Gas of MA18601847Eversource Gas of MA
Eversource Energy22771178Eversource Energy
Fitchburg Gas0172Unitil
Liberty Utilities352339Liberty Utilities
National Grid - Boston Gas91255606National Grid - Boston Gas
National Grid - Colonial Gas916565National Grid - Colonial Gas

Leak Maps by Town

Click on a town to open its map.

By Municipality
Unrepaired Leaks 2020
Repaired Leaks 2020Utilities
Abington4323National Grid - Boston Gas
Acton20933National Grid - Boston Gas
Acushnet165Eversource Energy
Adams915Berkshire Gas
Agawam5670Eversource Gas of MA
Amesbury1612National Grid - Boston Gas
Amherst52Berkshire Gas
Andover4350Eversource Gas of MA
Arlington269154National Grid - Boston Gas
Ashland1620Eversource Energy
Attleboro5538Eversource Gas of MA
Auburn125Eversource Energy
Avon416Eversource Gas of MA
Ayer2711National Grid - Boston Gas
Barnstable3136National Grid - Colonial Gas
Bedford7933National Grid - Boston Gas
Bellingham1010Eversource Gas of MA
Belmont11271National Grid - Boston Gas
Beverly13954National Grid - Boston Gas
Billerica10544National Grid - Colonial Gas
195162National Grid - Boston Gas
13891151National Grid - Boston Gas,Eversource Energy
Bourne2019National Grid - Colonial Gas
Boxboro51National Grid - Boston Gas
Boxford514National Grid - Boston Gas
Boylston00Eversource Energy
Braintree15148National Grid - Boston Gas
Bridgewater159Eversource Gas of MA
Brighton9272National Grid - Boston Gas
Brockton263131Eversource Gas of MA
Brookfield275National Grid - Boston Gas
Brookline219173National Grid - Boston Gas
Burlington7736National Grid - Boston Gas
Buzzards Bay00National Grid - Colonial Gas
Cambridge18783National Grid - Boston Gas,Eversource Energy
Canton5431Eversource Gas of MA
Carlisle213National Grid - Boston Gas
Carver40Eversource Energy
Centerville00National Grid - Colonial Gas
Charlestown3040National Grid - Boston Gas
Chatham2221National Grid - Colonial Gas
Chelmsford13525National Grid - Colonial Gas
Chelsea24110National Grid - Boston Gas
Cheshire03Berkshire Gas
Chicopee4647Eversource Gas of MA
Clinton1114National Grid - Boston Gas
Cohasset7728National Grid - Boston Gas
Concord15140National Grid - Boston Gas
Cotuit33National Grid - Colonial Gas
Dalton710Berkshire Gas
Danvers11050National Grid - Boston Gas
Dartmouth6831Eversource Energy
Dedham19558Eversource Energy
Deerfield02Berkshire Gas
Dennis1521National Grid - Colonial Gas
Dighton76Eversource Gas of MA
Dorchester316304National Grid - Boston Gas
Dover00Eversource Gas of MA
Dracut8018National Grid - Colonial Gas
Dudley4011National Grid - Boston Gas
Duxbury2111Eversource Gas of MA
East Boston4787National Grid - Boston Gas
East Bridgewater1414Eversource Gas of MA
East Brookfield164National Grid - Boston Gas
East Longmeadow3735Eversource Gas of MA
Easthampton1326Eversource Gas of MA
Easton4024Eversource Gas of MA
Essex55National Grid - Boston Gas
Everett5376National Grid - Boston Gas
Fairhaven14831Eversource Energy
Fall River220167Liberty Utilities
Falmouth2951National Grid - Colonial Gas
Fitchburg0130Unitil
Florence52Eversource Gas of MA
Foxboro2213Eversource Gas of MA
Framingham9560Eversource Energy
Franklin3833Eversource Gas of MA
Gardner021Unitil
Georgetown176National Grid - Boston Gas
Gloucester6354National Grid - Boston Gas
Grafton2715Eversource Energy
Granby00Eversource Gas of MA
Great Barrington63Berkshire Gas
Greenfield614Berkshire Gas
Groton3212National Grid - Boston Gas
Groveland158National Grid - Boston Gas
Hadley02Berkshire Gas
Halifax03Eversource Gas of MA
Hamilton (area)62National Grid - Boston Gas
Hampden23Eversource Gas of MA
Hanover1915Eversource Gas of MA
Hanson78Eversource Gas of MA
Harvard172National Grid - Boston Gas
Harwich2127National Grid - Colonial Gas
Hatfield02Berkshire Gas
Haverhill179111National Grid - Boston Gas
Hingham9444National Grid - Boston Gas
Holbrook168Eversource Gas of MA
Holden74Eversource Energy
Holliston2310Eversource Energy
Hopedale22Eversource Energy
Hopkinton4612Eversource Energy
Hudson2421Eversource Energy
Hull4365National Grid - Boston Gas
Hyannis2535National Grid - Colonial Gas
Hyde Park13246Eversource Energy
Indian Orchard611Eversource Gas of MA
Ipswich1512National Grid - Boston Gas
Jamaica Plain7766National Grid - Boston Gas
Kingston243Eversource Energy
Lakeville32Eversource Gas of MA
Lanesborough11Berkshire Gas
Lawrence93280Eversource Gas of MA
Lee83Berkshire Gas
Leeds00Eversource Gas of MA
Leicester102National Grid - Boston Gas
Lenox85Berkshire Gas
Lenox Dale00Berkshire Gas
Leominster10288National Grid - Boston Gas
Lexington14551National Grid - Boston Gas
Lincoln656National Grid - Boston Gas
Littleton519National Grid - Boston Gas
Longmeadow4649Eversource Gas of MA
Lowell17585National Grid - Colonial Gas
Ludlow1113Eversource Gas of MA
Lunenburg22National Grid - Boston Gas
Lynn221371National Grid - Boston Gas
Lynnfield12920National Grid - Boston Gas
Malden155123National Grid - Boston Gas
Manchester1110National Grid - Boston Gas
Mansfield1915Eversource Gas of MA
Marblehead14455National Grid - Boston Gas
Marion85Eversource Energy
Marlborough6139Eversource Energy
Marshfield3648Eversource Gas of MA
Marston Mills00National Grid - Colonial Gas
Mashpee1916National Grid - Colonial Gas
Mattapan8663National Grid - Boston Gas,Eversource Energy
Mattapoisset3611Eversource Energy
Maynard2311Eversource Energy
Medfield1510Eversource Gas of MA
Medford235167National Grid - Boston Gas
Medway1216Eversource Gas of MA
Melrose10074National Grid - Boston Gas
Merrimac118National Grid - Boston Gas
Methuen7489Eversource Gas of MA
Middleton85National Grid - Boston Gas
Milford3519Eversource Energy
Millbury336Eversource Energy
Millis52Eversource Gas of MA
Milton191135National Grid - Boston Gas
Monson30Eversource Gas of MA
Monument Beach00National Grid - Colonial Gas
Nahant3420National Grid - Boston Gas
Natick4040Eversource Energy
Needham10439Eversource Energy
New Bedford17479Eversource Energy
Newburyport4322National Grid - Boston Gas
Newton730349National Grid - Boston Gas
Norfolk12Eversource Gas of MA
North Adams821Berkshire Gas
North Andover3039Eversource Gas of MA
North Attleboro3316Liberty Utilities
Northampton3929Eversource Gas of MA
Northborough174Eversource Energy
Northbridge104Eversource Energy
Norton54Eversource Gas of MA
Norwell1110Eversource Gas of MA
Norwood11373National Grid - Boston Gas
623National Grid - Colonial Gas
Osterville00National Grid - Colonial Gas
Peabody15663National Grid - Boston Gas
Pembroke1511Eversource Gas of MA
Pepperell72National Grid - Colonial Gas
Pittsfield5092Berkshire Gas
Plainville45Liberty Utilities
Plymouth1814Eversource Energy
Pocasset00National Grid - Colonial Gas
Quincy339257National Grid - Boston Gas
Randolph8244Eversource Gas of MA
Raynham33Eversource Gas of MA
Reading12280
National Grid - Boston Gas,National Grid - Colonial Gas
Revere91113National Grid - Boston Gas
Rockland6556National Grid - Boston Gas
Roslindale9776National Grid - Boston Gas
Rowley154National Grid - Boston Gas
Roxbury5763National Grid - Boston Gas
Salem7173National Grid - Boston Gas
Salisbury1418National Grid - Boston Gas
Sandwich711National Grid - Colonial Gas
Saugus14442National Grid - Boston Gas
Scituate4737Eversource Gas of MA
Seekonk149Eversource Gas of MA
Sharon3021Eversource Gas of MA
Sherborn32Eversource Energy
Shrewsbury4018Eversource Energy
Somerset5383Liberty Utilities
Somerville161125National Grid - Boston Gas,Eversource Energy
South Boston4755National Grid - Boston Gas
South Hadley1512Eversource Gas of MA
Southborough66Eversource Energy
Southbridge5413National Grid - Boston Gas
Spencer83National Grid - Boston Gas
Springfield232313Eversource Gas of MA
Stockbridge01Berkshire Gas
Stoneham7640National Grid - Boston Gas
Stoughton7732Eversource Gas of MA
Stow33Eversource Energy
Sudbury14926National Grid - Boston Gas
Sutton85Eversource Energy
Swampscott10654National Grid - Boston Gas
Swansea2525Liberty Utilities
Taunton5940Eversource Gas of MA
Tewksbury6832National Grid - Colonial Gas
Topsfield155National Grid - Boston Gas
Townsend021Unitil
Turners Falls01Berkshire Gas
Tyngsborough165National Grid - Colonial Gas
Upton31Eversource Energy
Uxbridge53Eversource Energy
Wakefield93National Grid - Boston Gas
Walpole2420Eversource Gas of MA
Waltham212122National Grid - Boston Gas
Wareham1320National Grid - Colonial Gas
Warren166National Grid - Boston Gas
Watertown10865National Grid - Boston Gas
Wayland11431National Grid - Boston Gas
Webster5312National Grid - Boston Gas
Wellesley25070National Grid - Boston Gas
Wenham63National Grid - Boston Gas
West Boylston207Eversource Energy
West Bridgewater91Eversource Gas of MA
West Brookfield215National Grid - Boston Gas
West Roxbury19599National Grid - Boston Gas
West Springfield4060Eversource Gas of MA
Westborough2013Eversource Energy
Westford4522National Grid - Colonial Gas
Westminster00Unitil
Weston21244National Grid - Boston Gas
Westport1743Liberty Utilities
Westwood248Eversource Energy
Weymouth24097National Grid - Boston Gas
Whitman7923National Grid - Boston Gas
Wilbraham1221Eversource Gas of MA
Williamstown223Berkshire Gas
Wilmington2215National Grid - Colonial Gas
Winchester8678National Grid - Boston Gas
Winthrop3246National Grid - Boston Gas
Woburn10367National Grid - Boston Gas
Woods Hole21National Grid - Colonial Gas
Worcester433376Eversource Energy
Wrentham61Eversource Gas of MA
Yarmouth3725National Grid - Colonial Gas