The Dugan & Meyers Construction Team on the Hite Creek Water Quality Treatment Center Expansion Project placed a 950 CY base mat for the new Biological Nutrient Removal (BNR) tank structure. The 14,000 SF slab is broken up by six interior walls which create three BNR Tanks, Two Aeration Basins and a Pump Station. Getting this slab placed was a big milestone for this project as it has been delayed for two months due to unexpected geotechnical conditions. The unexpected karst subsurface conditions lead to additional onsite geotechnical investigation and nearly two months of coordination between D&M, Louisville MSD and the Project Design team. In the end D&M had to over excavate nearly 6’ and replace with nearly 2,000 CY’s of compacted stone infill. As a result of the excavation delays D&M worked with the structural engineer to turn what was a four section slab placement plan into a single base mat placement plan.