A year-long Inflow/Infiltration (I/I) Study is currently being undertaken by RJN Group Inc., for the city of Davenport, Iowa on their Duck Creek Middle Basin. Sanitary sewer mapping, flow monitoring and modeling, as well as a master plan for its sanitary sewer collection system was completed prior to the start of the I/I study.
The previous flow monitoring indicated extensive inflow during rain events. In addition, areas of the basin have experienced basement backups. There are several creeks in the basin, and most of the main sewer lines in this basin run along these creeks.
RJN will install, maintain and monitor 12 flow meters and two rain gauges for 60 days. Field technicians from RJN will also perform surface manhole inspections, structure locates, smoke testing of up to 58,000 linear ft, as well as TV inspection (in PACP format) on up to 11,000 linear ft of sewer. RJN’s modeling specialists will create a skeletal model of the basin in order to estimate peak storm flows for 1-, 5-, and 50-year 60-minute storms.
From identified sources and model analysis, RJN will provide recommendations to the city on rehabilitation to be done to remove I/I sources. The I/I study began in May of this year and is scheduled for completion by the end of March 2013.
Source: RJN Group
