When does building an MBR make sense? How variations of local construction and operating cost parameters impact overall project economics

This study details the expansion of a tool used to compare the capital and operating cost of membrane bioreactor (MBR) and conventional activated sludge (CAS) processes for a greenfield 5 MGD facility based on identical influent loading conditions for varying levels of effluent treatment objectives. Results from the original study (Young et al, 2012) are further developed to evaluate the impact of modifying key design assumptions and changing economic input variables such as the cost of labor, materials, equipment, land, and electricity. The sensitivity and scenario analyses presented in this study provide insight into which conditions tend to be most favorable for CAS or MBR facilities.