Walking the Line: Developing Control Strategies to Implement New Technologies and Meet Permit and Process Demands

摘要

The implementation of more restrictive regulations for disinfection byproducts (DBPs) forsurface water discharges in California has resulted in numerous municipalities converting fromchlorination to an ultraviolet (UV) disinfection. Although chlorination does generate DBPs, it isbeneficial for recycled water (RW) as it provides a chlorine residual, which helps maintain andprevent bacteria and algae growth in RW systems. In addition, changes in the demand fordifferent process waters varies throughout the day, which means that storage and/or equalizationis often required to meet these demands. The separation and storage of effluent within awastewater treatment plant (WWTP) to meet these demands requires significant forethought andcareful integration into the plant’s control strategy. Balancing DBP formation in effluent beingdischarged while maintaining a RW distribution system is a fine line that plant operators mustwalk. Two case studies – the City of Roseville, California, Pleasant Grove (PG) WWTP and theCalifornia Men’s Colony (CMC) WWTP – are presented in this paper are that explore thedevelopment and tuning of control strategies to incorporate new technologies while meetingvarious permit requirements and plant demands.