From Harford County government:
Harford County residents can safely dispose of their household hazardous waste products on Saturday, May 14, free of charge at the Harford County Waste Disposal Center’s Mulch and Compost Facility. Items such as oil-based paints, cleaning products, bleach, pool chemicals, herbicides, pesticides, and mercury thermometers will be accepted from 8:00 a.m. – 12:00 p.m. at the facility located in Street at 3135 Scarboro Road.
The collection event is open to Harford County residents only. Business, industrial or commercial farm waste will not be accepted and proof of residency will be required.
For more information about what will be accepted at this waste collection event, please visit http://www.harfordcountymd.gov/276/Household-Hazardous-Waste or contact the Harford Waste Disposal Center Office of Recycling at 410-638-3417.