23. Sewer in the News This scattergraph is a hydraulic mother lode showing three distinct hydraulic events. This flow monitor was installed in a 15-in sewer located just upstream from four consecutive 90-degree turning manholes. The head loss due to this routing causes a capacity loss of 0.5 MGD. A […]
Daily Archives: November 12, 2018
22. Hydraulic Hysteresis This scattergraph displays data from a flow monitor installed in a 21-in trunk sewer. During wet weather, backwater and surcharge conditions are observed in a distinct manner referred to as hydraulic hysteresis. During the intial response to this rain event, downstream storage is available within the system, […]
21. Knife Gate Valve A satellite collection system discharges wastewater to another agency through a 27′ sewer for subsequent conveyance and treatment. The observed minimum and maximum dry weather flow rates are 0.6 MGD and 1.8 MGD. Greater flows were observed during wet weather, creating problems for the recieving agency. […]
20. Inverted Siphon This flow monitor is installed in a sewer just upstream from an inverted siphon comprised of two 8-inch barrels. The incoming sewer has a design capacity of 2.7 MGD. The scattergraph shown here indicates that the first barrel has a capacity of 1.3 MGD. Additional flow is […]
19. Pump Station When operating in backwater conditions caused by a pump station wet well, flow monitoring data follow and iso-Q equal to the pumping capacity. This monitor is located upstream from a pump station that alternates between two lead pumps, each with a rated capacity of 9 MGD. The […]
18. CSO Side Weir This scattergraph displays data from a flow monitor installed in a 120-in sewer located just upstream from a CSO regulator. Dry weather flows are funneled into a 54-in sewer and continue to the WWTP. However, once the flow depth exceeds 28 inches, additional flow is carried […]