SETS teamed with JJ & G on the City of Atlanta three high profile tunnels between 1998 and 2012: the Nancy Creek, South River, and Combined Sewer Overflow tunnels. These tunnel projects were installed by the City of Atlanta to contain the spill of existing sewer infrastructure now failing due to Atlanta Metro population explosion and consequent raw sewer dumping in area rivers and soil water. These federally mandated tunnels diverted sewer 150-200ft below river beds, one to nine miles long and 29 ft finished diameter.
SETS provided geological as well as Geo-technical services on the project. The magnitude of costs as well as construction related hazards calls for detailed and accurate analysis of underground rock conditions for the entire length of the projects. SETS contributed three engineering and mining geologists to the project. In addition to being responsible for the routine site and rock core management, SETS conducted point load tests, Parker tests and field mapping. The field mapping was essential to establishing the lineaments in the tunnel easement. The lineaments were essential in determining Mineralization, faulting, and other structural defects in the rock units. The point load tests were conducted to determine the crushing strength of both the weathered as well as the un-weathered rock. The Parker tests were conducted after each boring to determine the permeability of each interval. These projects were completed on time and under budget.