The Saint Laurent pumping station provides the intake of water to the drinking water treatment plant for the City of Quebec. Tetra Tech CSO performed a preliminary bench test that showed that optimization of the command rules can generate energy cost savings of up to $22,000/year for a pumping capacity of 3000m3/h.
The City commissioned Tetra Tech CSO to proceed with major renovations and the expansion of the Saint Laurent pumping station in order to augment capacity, bring the building up to code, and automate equipment. Detailed works involved:
- Modifications at the existing pumping station to increase the actual pumping capacity from 4,000 m³/h to 7,000 m³/h, through the installation of six new variable speed heavy duty pumps;
- Expansion of the current pumping station and renovation of the external shell and interior of the existing building. Bring the building up to code for noise emissions and re-do the exterior landscaping;
- Verification of certain equipment that was to be preserved, both their operational state and overhaul of their condition, if required, such as the anti-hammer tank;
- Development of a plan that enables work to be performed without interrupting pumping for a period of more than one day at a time, in order to ensure the protection of untreated wells against overflows;
- New electrical line of 25 kV and replacement of the 2400 V distribution by 600 V;
- Installation of two prime power type electrogenisis groups of 2000 kVA each, including the connected fuel and cooling systems;
- Reconstruction of existing equipment: two screen rakes, four sluice gates, and two grit chambers;
- Automation of equipment ventilation and cooling systems using water from the St. Lawrence River during the winter and glycol during the summer;
- Integration of controls associated with water intake from the river, which consists of circulating heated brine through the screen in order to impede the forming of frazil ice during the winter;
- Addition of instruments for analysis of untreated water;
- Development of software for command and supervision processes;
- Programming of control software, including automation and graphic interfaces;
- Integration of SCADA into the central water treatment plant;
- Telecommunication link using cellular technology instead of a dedicated hard-line.