June 24, 2011

FEATURE | Sewer and Watermain/Water & Wastewater

Bennett Contracting works on reservoir, pumping station expansion in Mississauga, Ontario

DAN O’REILLY

correspondent

The 40-year-old Streetsville Reservoir and Pumping Station in Mississauga is receiving a major overhaul to meet increasing population growth in the north half of that city and neighbouring Brampton, Ontario.

A $16-million first-phase expansion has been underway since November and a second phase will start some time in 2012, says Peel Region project manager Heather Jefferson.

One of a series of facilities that transfer water north from the Lorne Park Water Treatment Plant on the shores of Lake Ontario, the plant is being upgraded to meet projected population growth in 2031.

Millgrove, Ontario-based Bennett Contracting is the general contractor in charge of the current phase, with the largest component being the construction of a 24-megalitre reservoir.

That has been a logistical challenge as the reservoir is being built immediately adjacent to the existing one.

The excavation area is also close to a forested park and tennis court to the west and is less than 50 metres from a residential area to the north, says Jefferson.

More than 40,000 cubic metres of excavated earth has been removed by a steady stream of trucks into the station, located on the heavily used Erin Mills Parkway. To facilitate safe entry and exit access, the curb lane of the highway is closed during the day, although the barriers are removed in the evening, says Jefferson.

Limited on-site space has certainly slowed the process, especially the movement of Caterpillar 385 and 330 excavators used for the earth and rock excavation, says Bennett project manager Brian Abele.

Even so, the reservoir is now about 60 per cent complete. He attributes that accomplishment to the pre-construction planning and design, plus ongoing consultations with the region, the consultants and residents.

The contractor’s initial focus was the construction of the reservoir and the valve chamber that houses twin 1650-mm pipes and a single 2100-mm pipe. The installation of yard piping and electrical and mechanical connections is currently in progress, says Abele.

Apart from the logistical hurdles for the contractor, the combination of the truck traffic, the noise and dust has resulted in some impact and inconvenience to the nearby residents.

If that wasn’t enough, the region-owned section of a leash-free dog walk will remain closed during the duration of the project.

However, solid board fence was erected around the site and a series of public-relations initiatives including pre-construction surveys and a planned community barbecue seem to be paying off, says Jefferson. “We’ve had few complaints.”

The excavation is now complete, the walls are being installed and, in early June, the contractor started pouring the concrete slab. The reservoir will be covered with a precast roof.

Other components of the project include the construction of an overflow/stormwater management pond and the valve chamber plus the building of a new electrical substation, the installation of yard piping and a 75-mm sanitary sewer forcemain along a nearby street.

It will conclude with a comprehensive landscaping and restoration program including planting native trees and shrubs at the north end of the site to create a visual barrier for the neighbouring homeowners, says Jefferson.

As that work is wrapping up, the second phase should be starting. Over the anticipated 21-month schedule, the pumping station will be doubled in size — although initially it will be equipped with only three of a potential maximum of eight pumps. The original reservoir will also be drained so that needed rehabilitation of its concrete columns and other structural elements can be carried out.

Other Phase 2 work includes the building of a new access house to the original reservoir and the completion of landscaping at the south end of the plant, says Jefferson.

AECOM is the consultant.

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