SDG&E Distribution Mains &
Services Methane Emissions Map

Distribution Mains

SDG&E is providing customers with a consolidated, searchable map that displays Distribution Mains and Services methane emissions leak data collected since 2016. The data is collected through the company's various routine surveying practices and operational and maintenance practices of its distribution pipeline system. The data is updated on an annual basis to include the datasets of past years.

What is Methane?

Methane is a naturally occurring, colorless and odorless gas produced by the decay or digestion of organic material, such as plants. Its chemical formula is CH4 (one atom of carbon and four atoms of hydrogen). One of methane's important properties is that it produces more heat and light – while burning cleaner – than other hydrocarbon, or fossil fuels, such as coal and gasoline refined from oil.

Most people think of methane as being extracted as a natural gas from underground deposits, but there are many other naturally occurring and human-related sources, including:

  • Wetlands
  • Permafrost
  • Oceans and other bodies of water
  • Wildfires
  • Digestive processes of some insects and animals
  •  Agriculture and waste management activities

As a safety measure, SDG&E® odorizes* the natural gas in its pipeline system to allow for rapid detection in the event of a leak. Methane is the main component of natural gas.

* Some persons may not be able to smell the odor because they have a diminished sense of smell, olfactory fatigue (normal, temporary inability to distinguish an odor after prolonged exposure to it), a temporary loss of smell due to COVID-19, or because the odor is being masked or hidden by other odors that are present, such as cooking, damp, musty or chemical odors. In addition, certain pipeline and soil conditions can cause odor fade (the loss of odorant so that it is not detectable by smell).

SDG&E Efforts to Reduce Its Methane
Emissions of Distribution Mains and Services

SDG&E has a long-standing commitment to modernizing its system infrastructure to increase safety and reliability and reduce methane emissions. SDG&E continually employs best management to minimize and detect emissions such as accelerating leak surveys to make the system more resilient and robust.

Emissions Map

Enter your zip code below to see methane gas emissions in your area.

How to navigate the map

From the bar above the map:

  • Use the Year field to select a year.
  • Enter a ZIP Code or choose one from the drop-down list.
  • For an alternative view of the emissions, select the layer box at the top right corner of the map, and select "Methane Emissions Hatch."