Mesa is urging residents to stop flushing pharmaceuticals down the toilet or pouring them down the drain to prevent chemicals from polluting groundwater.
Because wastewater treatments plants do not treat for pharmaceuticals, the chemicals eventually pollute rivers.
Mesa asks that residents take prescription and over-the-counter drugs to hazardous waste collection events. The next one is scheduled for Oct. 2 at the East Mesa Service Center, 6935 E. Decatur St.
The event is free. For information about what is accepted, visit www.mesaaz.gov/waste/hhw.aspx.