Illegal tire dumping is a growing problem in Manteca.Used tires are being tossed in alleys, left in commercial parking lots, and dumped in the countryside.To combat the problem, the City of Manteca is offering a free tire collection on Saturday, March 19, from 8 a.m. until noon at the Solid Waste Division yard at 210 East Wetmore Street off of South Main Street.There is a limit of nine tires per visit. Tires from passenger cars or light trucks are only being accepted. Tires on rims are also being accepted.