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 that diverts dry weather flow to the wastewater treatment plant (WWTP) through a 15-in sewer.  Once the flow depth exceeds the weir height, additional flow is carried over the weir and is discharged to the receiving water.  This CSO lasted for almost 22 hours and discharged 428,000 gallons of untreated wastewater to the receiving water.