Hazardous wastes should not be disposed of with ordinary trash, dumped on the ground or in the toilet or sink.  Discarded chemicals can leach through landfill liners or get washed into storm drains, polluting ground, creek and lake water.  Dallas residents can dispose of many hazardous chemicals at no charge during Household Chemical Collection Day.  Residents who show a picture I.D. and a utility bill (water) as proof of residence can drop off the following household chemicals: