Focussed Engineering Study

case study: Southwest Chatham sanitary trunk sewer study

The Corporation of the Municipality of Chatham-Kent is located in Southwestern Ontario. The Municipality has a population of 108,000 in a mix of urban and rural communities.

Following the successful completion of our combined sewer investigations in 2019, Andrews.engineer (A.E) subsequently bid and won the project to develop and carry out focussed sanitary sewer investigations for the sanitary trunk sewers along Park Avenue which experience surcharging conditions during storm events.

The activities performed by A.E include:

• Flushing, CCTV inspections and maintenance hole (MH) inspections for an 8 km stretch of sanitary trunk sewers and 86 MHs within the study area
  
• Create as-constructed drawings for all MHs
• Perform flow monitoring, data management and maintenance of the flow monitors at 16 locations over a five month period
• Hydraulic model establishment and calibration for the study area 
• Targeted overflow investigation and remediation strategy modelling

Following the data collection and analysis, the project team concluded that the system experiences significant surcharging along Park Avenue in large part due to a system backup near the treatment plant. The team also identified three system hydraulic restrictions that are limiting the overall performance of the trunk sewer. Through monitoring and hydraulic analysis, the team identified two areas with significantly higher than expected flows during storm events. These areas are further studied for I&I during events.

A.E performed additional hydraulic modelling and analysis to evaluate various system improvement measures, including the addition of a temporary pumping system to alleviate system surcharge issues in the near term. The modelling also included an option for a permanent pumping station establishment.