Contact your local household hazardous waste facility for disposal instructions
Store the bad gasoline in an approved, sealed fuel container
Label the container clearly as bad gasoline
Keep the container away from heat, sparks, flames, and direct sunlight
Do not pour gasoline down drains, into soil, or into storm sewers
Do not mix gasoline with other chemicals or waste
Take it to a hazardous waste drop-off site or collection event
Ask a licensed automotive shop or fuel recycler if they accept old gasoline
If the gasoline is only slightly degraded, ask a mechanic whether it can be diluted and used safely in equipment designed for it
Follow all local, state, and federal disposal regulations