Largest ultrafiltration plant in North America under construction

The expansion and upgrade of the Lakeview water treatment plant addresses multiple challenges for the region’s drinking water supply – regulations, consumer demands for improved tap water aesthetic quality, and increased production.

Andrew Farr, Ken Mains, Jesus Garcia-Aleman

The Canadian Region of Peel, currently serving over one million consumers in Greater Toronto, Ontario, is constructing a 363-million-liter-per-day (ML/d)) expansion of the Lakeview Water Treatment Plant. The plant is set to commence operation in the summer of 2007 and will supply high quality drinking water to more than 600,000 consumers in the region and a neighboring municipality through a long-term water supply agreement.

The Lakeview expansion project is a key component of the Region’s Master Servicing Plan for Water and Wastewater, which includes the expansion and upgrade of treatment capacity in multiple plants and the construction of additional water distribution pipelines, pump stations and storage reservoirs. The plan is intended to proactively address multiple challenges regarding the region’s drinking water supply, including: more stringent water quality regulations; consumer demand for improved tap water aesthetic quality (i.e, taste, odor and color); and increased production due to rapid growth. As a first step in the Plan, the Region revisited the treatment objectives in all of its facilities. The result was a commitment to enhance treatment objectives to not only meet but to in many cases, exceed the requirements of the Ontario Safe Drinking Water Act.

CH2M Hill Canada worked with the Region and all stakeholders to engineer a large-scale, large-capacity treatment facility that addresses multiple objectives that will provide a high level of regulatory, public and governmental acceptance.

Highest quality finished water. The treatment process will provide year-round aesthetically-pleasing drinking water that surpasses current regulatory requirements and addresses future water quality concerns, including pathogen removal (Cryptosporidium and Giardia), removal of taste- and odor-causing compounds, disinfection-by-products, and emerging trace contaminants (e.g., endocrine disruptors, personal care products).

Reliability. Processes are in place to optimally leverage plant staff and maximize automated plant control through a comprehensive water quality monitoring system interconnected with the plant PLC and SCADA system. Multiple treatment barriers are in place to address each of the water quality objectives set forth by the Region.

Environmental impact and sustainability. Aprimary goal of the Region was to select treatment processes that minimized both energy and chemical use, which resulted in a facility having reduced noise, chemical deliveries, truck traffic and waste (residuals) production. The plant was designed using advanced three-dimensional software which maximized the preservation of green spaces around the plant by reducing the overall plant footprint, allowing the continued use of Region property at the site for public recreational purposes during and after construction.

The Lakeview water treatment plant will be the largest drinking water plant in North America using ultrafiltration membrane technology.

Cost-effectiveness. An environmental assessment and subsequent six-month pilot study were conducted in 2003 and 2004 to first select and test the optimum treatment alternative in order to maximize the above objectives while minimizing capital and operating costs. The facility will set cost benchmarks for both membrane equipment and construction costs.

Flexibility. The treatment expansion will be integrated into the existing conventional Lakeview water treatment plant while maintaining the latter in operation. The original expansion capacity was increased from 262 ML/d to 363 ML/d to support the future plant upgrades in line with the master plan without compromising the Region’s ability to provide a high quality water of adequate capacity to its consumers.

Water supply for the plant expansion is from the northern shore of Lake Ontario, characterized as moderately hard and generally low in turbidity, organics and disinfection-byproducts precursors. The source water challenges are derived from the heavy use of the lake as a waterway and a recreational area, the proximity of the Lakeview power generation facility and wastewater treatment plants, and seasonal events of elevated turbidity and taste- and odor-causing compounds. The integrated treatment process combines membrane ultrafiltration with other advanced treatment processes, including ozonation and biological carbon filtration, in a synergistic manner that not only addresses the above source water challenges, but provides the highest quality finished water in a cost-effective and environmentally sustainable manner.

Simultaneous projects at this site include regulator-mandated upgrades in the existing conventional plant (560 ML/d), the construction of a new 25 ML/d finished water reservoir, the construction of a new 760 ML/d high lift pumping station feeding two separate pressure zones, and the addition of low lift pumping capacity (560 ML/d) to replace and expand existing capacity.

When completed, the Lakeview water treatment plant will be the largest drinking water plant in North America using ultrafiltration membrane technology. An additional plant expansion is planned as well as retrofit of the existing conventional plant, which will result in an ultimate projected finished water capacity of at least 1,150 ML/d treated with ozone, biological filtration and membranes.

CH2M Hill Canada is providing engineering services and construction management for the initial and subsequent expansion. Design, construction and startup will be completed in less than 36 months.

Authors’ Note

Andrew Farr is the manager of Capital Works for the Region of Peel. Ken Mains is chief engineer for CH2M Hill Canada. Jesus Garcia-Aleman is a membrane project engineer for CH2M Hill Canada.