EPA considers waste and materials that are donated/reused, recycled, and composted as diverted.
The EPA National Measurement Workgroup defined diversion as:
“activities surrounding the handling of recovered resources such that they are not disposed of in landfills, waste piles, surface impoundments, land application units on a permanent or long-term temporary basis; and are not incinerated or converted to fuel energy, or base chemicals through combustion, pyrolysis, gasification, or other conversion technologies. Diversion can be attributed to several processes where materials are systematically redirected from disposal: Recycling, Reuse, Beneficial Use, and Composting."
This is consistent with how other organizations define diversion as well, including the State of California and the US Green Building Council.
Diversion from being buried in a landfill or burned in an incinerator extends a material’s useful life. Recycling transforms waste materials into new products, thereby conserving natural resources. Composting returns nutrients from organic wastes to the land as a valuable soil amendment.
You can track your Waste to Energy separately, and run a report with the tons distinguished between landfill and waste to energy. For example, if you have a 100 tons of trash each month and specify that 75% is going to landfill and 25% to Waste to Energy, over the course of a year 1200 tons was disposed, 900 was disposed in a landfill, and 300 tons was disposed at a waste to energy facility.