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Five alternative feedlot runoff control systems were previously modeled to predict and compare performance at six Iowa locations for the years 1951-2000. Mean runoff control in these systems, which used a truncated pumping regimen, varied from 72% to 87% across the six locations. In this report, both managerial and structural modifications to those truncated systems are explored in an attempt to increase performance to near total control of runoff. Among the modifications explored are 1)pumping the containment beyond the designated months; 2)pumping at a 2.5X greater rate in the month of November; 3)adding extra capacity to the containment structure; and 4)commencing pumping in October rather than November in those systems with a fall pump period. Among all systems and their modifications, the best runoff control was achieved with a spring and fall pumpout that used October instead of November in the fall pump period. With this system, mean runoff control across six locations was 92.5%. Simply increasing the size of the containment structure was not an effective means of achieving total containment of runoff.