Waste stabilization pond (WSP) is globally one of the most popular wastewater treatment options because
of its high efficiency and low cost. However, no rigorous assessment of WSPs that account for cost in
addition to hydrodynamics and treatment efficiency has been performed. A study was conducted that
utilized Computational Fluid Dynamics (CFD) coupled with an optimization program to optimize the
selection of the best WSP configuration based on cost and treatment efficiency. Several designs generated
by the CFD/optimization model showed that both shorter and longer baffles, alternative depths, and reactor
length to width ratios could improve the hydraulic efficiency of the ponds at a reduced overall construction
cost. In addition, a study was conducted on the optimized WSP which consisted of an anaerobic,
facultative, and a maturation stage whose baffle orientation, length to width ratio, was specified by a CFD
model prediction and was compared with a three stage WSP designed according to literature suggested
reactor geometric configurations. Experimental tests were performed on a pilot scale version of the threestage
WSP where the removal performance was based on a number of parameters (Faecal coliform, pH,
TDS, and Conductivity). Results showed that the significantly lower cost design based on the optimized
CFD simulations displayed slightly better removal performance compared to the standard WSP design
developed from literature data. The results of this study clearly showed that unit treatment process designs
based on rigorous numerical optimization can aid in producing cost effective designs that make it more
possible for developing nations to incorporate adequate and effective sanitation
