Water-Quality Effects of Tire Shreds Placed Above the Water Table: Five-Year Field Study

A field trial was constructed beneath a secondary state highway in North Yarmouth, Maine, to investigate the water-quality effects of tire shred fills placed above the groundwater table. Samples were collected in three 3-m² geomembrane-lined basins located beneath the shoulder of the road. Two of the basins are overlaid by 0.61 m of tire shreds with a 75-mm maximum size topped by 0.72 to 1.37 m of granular soil. The third basin serves as a control and is overlaid by only 0.72 m of granular soil. Quarterly samples for inorganic constituents were taken from January 1994 through June 1999. In addition, samples were taken for volatile and semivolatile organic compounds on three dates. Filtered and unfiltered samples were analyzed for the following substances, which have a primary drinking water standard: barium, cadmium, chromium, lead, and selenium. There was no evidence that the presence of tire shreds altered the concentrations of these substances from their naturally occurring background levels. In addition, there was no evidence that tire shreds increased the levels of aluminum, zinc, chloride, and sulfate, which have secondary (aesthetic) drinking water standards. In a few samples, iron levels exceed their secondary standard. Manganese levels consistently exceeded their secondary standard; however, this is an aesthetic-based standard. Three sets of samples were tested for organics. Negligible levels of organics were found.