FIELD STUDY OF WATER QUALITY EFFECTS OF TIRE SHREDS PLACED BELOW THE WATER TABLE

A field trial was constructed to evaluate the water quality effects of tire shreds placed below the water table. The study consisted of three sites, each with 1.4 metric tons of tire shreds buried in a trench below the water table. The tire shreds were made from a mixture of steel and glass belted tires and had a maximum size of about 75 mm. The soil types at the sites were marine clay, glacial till, and peat. At each site, one water sampling well was located upgradient to obtain the background water quality, one well was located in the tire shred filled trench, and two to four wells were located 0.6 m to 3 m downgradient of the trench. Samples were taken over a four-year period and analyzed for a range of metals, volatile organics, and semivolatile organics. The results showed that tire shreds had a negligible effect on the concentration of metals with primary (health based) drinking water standards. For metals with secondary (aesthetic based) drinking water standards, samples from the tire shred filled trench had elevated levels of iron (Fe), manganese (Mn), and zinc (Zn). However, the concentrations of these metals decreased to near background levels for samples taken downgradient of the tire shred filled trench. Trace concentrations of a few organic compounds were found in the tire shred filled trenches, but concentrations were below method detection limits for virtually all the samples taken from the downgradient wells. Tire shreds placed below the water table appear to have a negligible off-site effect on water quality