I found my way into this page for 2014: https://www.epa.gov/air-emissions-inventories/2014-national-emissions-inventory-nei-data
Which has a lot of point source and other data in Excel .xlsx.xlsx files, which I imagine we might add to the growing list of layers in Leaflet Environmental Layers, but I'd like to know more about how good or incomplete the data is, and also if it's already reflected in Frac Tracker data:
Do folks know about the NEI and if it's useful data?
For what it's worth, it lists many sources and types, including:
Agriculture Dust Fires Fuel Combustion Industrial Processes Miscellaneous Mobile Solvent Industrial Surface Coating Other Sector