NSTAR GAS COMPANY

Incident Narrative

REPORT FILED ON BY HALF OF NSTAR GAS COMPANY D/B/A EVERSOURCE ENERGY. BASED UPON THE INITIAL NARRATIVE PROVIDED BY THE MAYNARD FIRE DEPARTMENT TO EVERSOURCE, ON SEPTEMBER 2, 2021 AT 16:14, THE MAYNARD FIRE DEPARTMENT DISPATCH RESOURCES TO 27 PARK ST MAYNARD, MA DUE TO AN ODOR CALL. THE MAYNARD FIRE DEPARTMENT ARRIVED ON SITE AT 16:17 TO A STRUCTURE FIRE. EVERSOURCE RECEIVED A CALL FROM THE MAYNARD FIRE DEPARTMENT AT 16:33 NOTIFYING EVERSOURCE OF THE SUBJECT STRUCTURE FIRE. EVERSOURCE COORDINATED WITH THE MAYNARD FIRE DEPARTMENT, MASSACHUSETTS STATE FIRE MARSHALL, AND STATE REGULATORY AGENCY ON SITE. THE SITUATION WAS MADE SAFE THROUGH A MAINLINE REPAIR ON SEPTEMBER 3, 2021. A SECTION OF THE MAIN WITH A COUPLING WAS SECURED AND DELIVERED TO THE MASSACHUSETTS MATERIAL RESEARCH FACILITY FOR 3RD PARTY ANALYSIS. NEITHER THE MAYNARD FIRE DEPARTMENT NOR THE STATE FIRE MARSHALL REPORTS HAVE BEEN RELEASED AT THIS TIME. PLEASE NOTE THE FOLLOWING AS IT RELATES TO THIS REPORT: PART A.4, A.12 THIS WAS THE TIME THE COMPANY COMMENCED A LEAK INVESTIGATION DURING WHICH GAS READINGS WERE DETECTED. THE FINAL FAILURE AND CAUSE OF THE INCIDENT IS STILL PENDING THE INVESTIGATION. PART A.21 THE COMPANY RESPONDED YES BASED UPON THE INITIAL NARRATIVE PROVIDED BY THE MAYNARD FIRE DEPARTMENT AND GAS READINGS FOUND IN NEAR PROXIMITY TO THE STRUCTURE FIRE. NEITHER THE FIRE DEPARTMENT NOR THE STATE FIRE MARSHAL HAVE ISSUED THEIR FINDINGS AS TO WHETHER RELEASED GAS CAUGHT FIRE. PART A.21.A THE TIME THE MAYNARD FIRE DEPARTMENT ARRIVED ON SITE TO A STRUCTURE FIRE. PART A.21.D PER ""SECTION III. CONCLUSION"" OF THE MASSACHUSETTS FIRE DISTRICT FOURTEEN'S REGIONAL FIRE INVESTIGATION TEAM FIRE ORIGIN AND CAUSE INVESTIGATION REPORT, ISSUED TO EVERSOURCE ON OCTOBER 13, 2021, ""THE MOST PLAUSIBLE HYPOTHESIS IS THAT OF FUEL GAS EXPLOSION. IT IS BELIEVED TO BE AN ACCIDENTAL LOW ORDER FUEL GAS EXPLOSION CAUSED [THE] FIRE."" PART A.7,A.21.C, D2.F VALUES DEFAULTED TO 1 AND 0. THE AMOUNT OF GAS RELEASE IS UNKNOWN AT THIS TIME. PART D.2.A THE PUBLIC AND NON-OPERATOR PRIVATE PROPERTY DAMAGE IS CURRENTLY BASED ON A PROPERTY ASSESSMENT PROVIDED BY THE FIRE DEPARTMENT AS WELL AS COSTS ASSOCIATED WITH LANDSCAPING, PAVING AND CONCRETE. PART D.2.B THE REPAIR COST INCLUDES THE REPAIR COSTS AS WELL AS THE FOLLOW UP LEAK SURVEY COSTS PART E.2 AN AVERAGE OPERATING PRESSURE WAS OBTAINED PRIOR TO THE INCIDENT. PART E.3.B THE MAIN WAS INSTALLED IN 1968 PRE-CODE. THE DATE FOR MAOP WAS DEFAULTED TO 7/1/1970 AS THAT WAS WHEN 192.619(C) WAS ESTABLISHED. PART E.5 THE DRIP REFERENCED IS A DRIP ODORIZER - Z9000 PART E.6 THE COMPANY TOOK MULTIPLE READINGS NONE OF WHICH REACHED OR EXCEEDED 0.15%. THE READING PROVIDED WAS THE FIRST READILY DETECTABLE LEVEL RECORDED AT 0.07. THIS REPORT FUNCTIONALITY ROUNDED THE NUMBER UP TO 0.1.