The Budd Inlet Treatment Plant uses both physical and biological processes to clean wastewater as it moves through the system. Disinfection with an ultraviolet light is the final treatment step. Parametrix worked with LOTT to design a new high efficiency UV disinfection system and associated facility modifications to replace the existing UV systems, electrical systems, and building systems at the plant. The new system allows for a peak flow of up to 75 mgd with an N+1 redundancy and incorporated 5 channels with 2 banks of 18 UV bulbs each. The design integrated multiple field controllers, a master control panel with an Allen Bradley CompactLogix PLC, and the existing Valmet max DNA DCS system.
The team developed custom process control strategies incorporating a tiered communication priority system that utilized hardwired and network communication. This allowed for operation in the event of multiple communication media and component failures. Construction change orders were 3 percent, 2 percent of these were attributed to unknown conditions. The project was completed on schedule.