17. CSO End Weir Flow monitoring data provide a means to determine the duration and volume of a combined sewer overflow (CSO). This scattergraph displays data from a flow monitor installed in a 30-in sewer located just upstream from a CSO structure. This structure is equipped with an end weir […]
Monthly Archives: November 2018
16. Reverse Flow Reverse flow in a sewer system is rare, but in this situation a 12-in sewer is overpowered by a much larger downstream interceptor. During a rain event, this sewer experiences backwater and surcharge conditions. However, note the sequence of events that occurs during surcharge conditions. The flow […]
15. SSO Overflow Pipe This 10-in sewer is equipped with an 8-in overflow pipe located in the downstream manhole. During a rain event, this sewer experiences backwater and surcharged conditions that limit flow to about 37% of the estimated full-pipe capacity. The SSO is activated once the flow depth reaches […]
14. SSO Downstream The scattergraph depicted here reveals backwater and surcharge conditions that result in a sanitary sewer overflow (SSO) downstream from this monitoring location.
13. SSO Upstream The scattergraph depicted here reveals backwater and surcharge conditions that result in a sanitary sewer overflow (SSO) upstream from this monitoring location. These conditions result in a capacity loss of 46% in this 54-inch pipe.
12. Continuous Backwater This scattergraph displays data obtained during dry weather from a flow monitor installed in a 27-in sewer just upstream from a 12-in Parshall flume. By design, the flume causes the upstream sewer to operate under continuous backwater conditions. This flume is no longer used for flow measurement. […]