Where can I bring old paint cans for proper disposal? Is there a cost to this?

You can buy stuff to speed up the drying process. Or you can mix absorbent material into the paint, such as: clay kitty litter, sawdust or concrete mix. Air drying paint can take a long time amd you run the risk of you or someone knocking it over and spilling it.

Clark County Recycling take them if they're dried up. You are asking Google users not Lowe's. If you want to talk to someone from Lowe's you need to contact the store.

Lowe's does not offer disposal of paint or other fluids. Oil-based paint is a hazardous waste and must be disposed at a proper facility. Clark County's sole hazardous waste facility is at 112 Industrial Way in Charlestown. Latex paint is "hazardous" until in a solid state. You may pass the paint on to someone who can use it, including the Habitat for Humanity ReStore. You may also open the can outdoors and let it evaporate into a solid state. Then it may be disposed of in regular trash. Empty paint cans should be recycled.