Latex paint
is water based and generally not hazardous. Landfills and garbage haulers cannot accept latex paint in liquid form; it must be hardened. Place latex paint in the garbage after the liquid has hardened, and leave the lid off.
If you have a little paint left in the can, you can speed the drying process by mixing in an absorbent, such as concrete or cement mix, kitty litter, or thinly cut strips of newspaper.
If the paint can is too full to add an absorbent, line a cardboard box with a plastic bag, pour in paint and mix with an absorbent.
Oil-based paint
must be disposed of at either of the Hazardous Waste Facilities (Tacoma or Hidden Valley).