SITUATION
The City of Fresno required a 90-day sewer bypass to allow repairs to the wastewater treatment plant headworks facilities. The project included a temporary bypass system capable of conveying up to 150 MGD (278 cfs) through approximately 1,300 linear feet of multiple 18-inch and 36-inch HDPE pipelines.
CHALLENGE
The project required replacing the wastewater treatment plant headworks while bypassing flows continuously for 90 days. In addition to maintaining flow, the team needed to determine effective methods for handling primary solids, grit, and plant communication throughout the duration of the bypass operation.
SOLVED
The team designed and installed grit-settling chambers along with cleaning processes that could be performed during live operation. Electronic flow monitoring and reporting systems were implemented to support plant operation and coordination. A serviceable screening system was designed and fabricated to facilitate primary solids removal, while crews monitored and maintained bypass flows 24 hours a day, seven days a week throughout the project.
