Two field trials were constructed to investigate the effect on water quality of tire chip fills placed above the groundwater table. Control wells were used to distinguish the substances naturally present in groundwater from those that leached from tire chips. There was no evidence that tire chips increased the level of substances that have a primary drinking water standard. In addition, there was no evidence that tire chips increased the levels of aluminum, zinc, chloride or sulfate which have secondary (aesthetic) drinking water standards. Under some conditions iron levels may exceed their secondary standard. It is likely that manganese levels will exceed their secondary standard, however, manganese is naturally present in groundwater in many areas. Two sets of samples were tested for organics. Results were below the method detection limit for all compounds.