client: Regional Municipality of Hamilton-Wentworth
location: Hamilton, Ontario
project description:
The Region, under the Federal/Provincial/Municipal Infrastructure Programme, retained R.V. Anderson Associates Limited to design a 75,000 m³ underground CSO tank for the containment of combined sewage flows. This project was completed as part of the Region's "pollution control plan" to protect Hamilton Harbour from municipal sewage overflows. Special features of this structure incorporated:

• computer modelling for cut/fill balancing for on-site storage
• soil management strategy to deal with on-site contaminated soil
• property constraints (excavating next to buried high voltage hydro cables)
• tunnel boring technology in extending sewers beneath Highway #403
• diverting flows into tank sewer extension by means of SCADA operated controlled gates at manhole chambers
• "tipping bucket" method for flushing the tank floor after each storm event

project status:
The project was completed at a construction cost of $22,000,000.