If you cannot use it up yourself, then consider giving the pesticide, in its original container, to another applicator to use according to label directions. See if your county and city health departments accept home and garden pesticide products for disposal. Safely store pesticides until an acceptable method for disposal is available. This may involve storage for extended times and safe storage is difficult. See if there are requirements for the proper cleaning of pesticide containers before disposal.
Directions are in the storage and disposal section of the label.
Most commonly, cleaning is accomplished by triple rinsing containers with water or shaking out paper or plastic bags. Rinse container thoroughly, pour rinse water into spray tank and drain for 30 seconds. Do this procedure three times. DO NOT pour pesticides down the drain or into water. DO NOT pour pesticides on the ground.