Massachusetts Gas Leaks Map
At the end of every year, Massachusetts gas distribution utilities are required to file annual service quality reports to the Department of Public Utilities (DPU). HEET extracts and maps the reported leak locations from these reports. Use the map to zoom in on your home, school, or business to find local gas leaks, noting the following:
- The map is a snapshot in time as of the last day covered by the reports, December 31 of each year.
- A leak could have been repaired or new ones developed since the reports were published.
- Locations of leaks are reported using addresses. However, leaks are on mains or service lines under streets, not inside buildings.
- Independent researchers typically find 1.5 to 3 times as many leaks as utilities report.
- The estimated equivalent cost of leaked gas is based on the EIA‘s average price of natural gas delivered to residential Massachusetts customers for the year being mapped.
About the Leaks
Leaks are graded by the utilities to indicate how potentially hazardous they are, ranging from Grade 1 to Grade 3 SEI, 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 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 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.
Leaks are reported with a specific status :
- Repaired indicates repair work was performed on the leak.
- Pending or open indicates the leak is not yet repaired.
- Eliminated by replacement indicates the leak was repaired under the Gas System Enhancement Program (GSEP).
- Eliminated by ‘otherwise’ indicates the leak was removed for a variety of other reasons. Examples include : a routine survey did not detect gas at the leak, the leak was reported at a wrong address, or the grade of the leak was changed.
A leak’s grade and status are indicated on the map as a number in a colored bubble.
Using the Map
The map includes the following layers of information:
- Open leaks reported by each utility, by town and Boston neighborhood
- Repaired leaks reported by each utility, by town and Boston neighborhood
- Estimated emissions and equivalencies, by both town and Boston neighborhood
- GSEP plans (more information about GSEP can be found here)
Controls
The map application provides controls for navigating and exploring.
Layers
The map provides various layers of information which can be selected with the Layer List button. In the example below, National Grid Boston Gas repaired and open leaks layers are enabled, together with Boston neighborhood and MA town boundaries.
Interacting With the Map
To see detailed information about a leak, click on it. Use the Maximize button to expand it.
If multiple layers of information are available, use the Next feature and Previous feature buttons to scroll them. In this example, we scroll between the leak details, and the leak summary and emissions estimates for the town which the leak is in.
You can use the search bar to search for leaks and addresses across all layers, and then constrain to specific layers. In the example above, Highland Rd, Brookline is searched for, and then results are limited to just National Grid Boston Gas layers.
Data in layers can be selectively chosen using filter expressions using the Attribute Tables button. The example below reveals just the open Grade 3 SEI leaks in the selected region. A layer is selected and then filtered by selecting leaks where the ‘Grade for mapping’ attribute is ‘G3SEI’. Filters persist until removed.
Estimated emissions information is included in pop-ups for towns and colored emissions layers for both towns and Boston neighborhoods are available.
Using the Basemap Gallery, you can choose a different base map if you prefer.
