Pesticides usage disposal
Before applying a single dose of pesticide, Gardners' should always read and carefully follow the manufacturers instructions printed on the container/label. Pesticides should be stored carefully in a secured location such as a locked garage or shed or somewhere kids can't get a hold of them.
These and other poisonous chemicals should be kept in their original containers to eliminate confusion, poisoning someone or contamination. Pets can also be harmed by pesticides and should be kept away from treated areas (Areas you've applied pesticide).
Lakes, creeks, and rivers can also be contaminated by pesticides if used incorrectly. Never use pesticides near these water sources or get it on neighboring properties, garden areas growing edible crops, especially during harvest seasons.
Pesticides should be disposed according to the label's instructions. Never discard a container that still has pesticide remaining in it. Store left over pesticide for later use when necessary in a safe location or take remaining content to a household hazardous waste collection site. Improper disposal such as burning containers or loitering may contaminate water supplies/sources.
Local state agencies
This article courtesy of www.hydroponicsearch.com