You should contact your municipality (city hall) for advice on this. Both latex and oil based paints need proper disposal and should not be dumped into septic tanks or city sewer systems.
Many landfill / garbage disposals have special facilities to receive these products. Whatever you do, don't pour down the drain! Pour latex paint into a larger container, such as a 5 gallon bucket and add kitty litter. The kitty litter should absorb the paint and it can then be disposed of with your regular garbage pick-up.