The City of Guelph provides municipal utility services to nearly 136,000 residents. By 2051, to meet provincial growth targets, the number of residents using municipal services is expected to climb by almost 50% to over 200,000. To accommodate the future service demand and to maintain the reliability of its infrastructure, the City has invested considerably in its drinking water system, including the Paisley Pumping Station. The City retained CIMA+ to complete the preliminary and detailed design and provide contract administration and site inspection services for the full upgrade of the station and reservoir.
Maximizing the benefits of the improvements
The Paisley pumping station transfers water from Pressure Zone 1, where most of Guelph’s groundwater supply wells are located, to Pressure Zone 2 in the northwest corner of the city, where significant development is projected. Upgrades to the Paisley station are an important part of the City’s long-term water-supply plan and achieve a range of objectives:
- Help the city achieve its 2051 development targets by increasing the station’s firm capacity from 265 L/s to 480 L/s
- Improve the reliability of the Zone 2 water supply through replacement of infrastructure and equipment at the station that is at the end of its service life
- Increase the operational flexibility of the station to draw water from Zone 1 through the installation of a second inlet connection
- Allow for the connection of a future Zone 2 watermain through the construction of a second outlet from the station
A complete station overhaul without any loss of service
The Paisley pumping station plays a critical role in the city’s water supply system. As a result, shutdowns of the station and reservoir had to be minimized to maintain redundancy in the system. To safeguard the Zone 2 supply, the upgrades were completed with maintenance of the station’s operation at all times, apart from a single 17-hour shutdown to replace the station discharge header. During this shutdown, water was supplied by reserves in the system.
Completion of the extensive upgrades at the facility while it continued to operate and within a tight complex of pumps and piping entailed engineering and construction challenges that are not present in an equivalent greenfield project or even a typical pumping station upgrade. By the end of construction, and working entirely within the constraints of the existing building footprint, all of the station’s pumping and chemical systems and mechanical and electrical equipment had been replaced, rooms had been completely reconfigured and re-purposed, and new station inlets and outlets had been installed through the reservoir walls to provide enhanced supply redundancy.