Lake County, Illinois has been experiencing inflow/infiltration (I/I) in its sanitary sewer system during wet weather events. High rates of I/I can lead to sewerage backup and manhole overflows. RJN Group, Inc. (RJN) is currently working for the County to figure out which communities in the northwest region being served by the County are experiencing the worst I/I problems.
In order to do this, RJN is providing flow monitoring and smoke testing services to collect data that will be used for a complete I/I analysis.
Flow monitoring services are being conducted at nine (9) manhole locations, four (4) lift station locations, and two (2) rain gauge locations. Each location is maintained and calibrated by RJN to ensure that the data collected is accurate and consistent. Data is also analyzed and edited to minimize sensor fault influence and hydraulic instabilities. A total of 910,000 linear feet of pipeline is being monitored for this project.
Prior to beginning the flow monitoring in the northwest, RJN performed smoke testing services in the southeast region. Flow monitoring in the southeast region was previously completed by RJN in 2013. The smoke testing process effectively locates both public and private I/I source defects, including defective mainlines, service laterals and cleanouts, directly connected catch basins, downspouts, and outside drains, as well as indirect stormwater connections.
The flow monitoring and I/I analysis program is a one year project and is scheduled for completion by November 2014.