Summary: On-Site Investigation and Analysis of the UB

An integral part of this project was to conduct an investigation of the full scale septic system that has been operating continuously at Modern Landfill since 2000. The design of this system was described in detail in Spagnoli et al., (2001) This system provides an ideal test bed to evaluate the long-term acceptability of tire derived aggregate (TDA) as an alternative to stone as the system’s absorption trenches have parallel lines of stone and TDA aggregate, which allows for side-by-side comparison. To evaluate TDA’s long-term potential in this system, several project objectives were formulated to answer common questions concerning the potential of TDA. These objectives were: Conduct a field survey and video inspection of stone and TDA absorption trench lines to evaluate sludge buildup, aggregate/absorption trench settlement, and overall absorption trench integrity; To evaluate the current hydraulic performance of stone and TDA absorption trenches. To evaluate the physical properties of the TDA including wire length and physical integrity; and To evaluate metals leaching from the TDA and stone into the soils surrounding the absorption trenches.