Improving water quality in rural Mount Pleasant

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water pressure filter system
Delivery of the pressure filter system used to remove iron and manganese residuals.

By Allan Choi, Zoran Filinov and Marvin Fehrman

Mount Pleasant, Ontario, located in the County of Brant, is a predominantly rural-agricultural community. The County is responsible for servicing approximately 500 residences and 20 commercial accounts. Water is sourced from two existing non-GUDI (not under the direct influence of surface water) wells in individual well houses.

Iron and manganese levels occasionally exceed the Ministry of the Environment’s (MOE) aesthetic objectives. This results in brown/black sediment deposits in the reservoir and watermains, as well as taste and colour complaints from customers.

In past years, the County has dealt with iron and manganese by implementing a rigorous and regular flushing program for the distribution system. This regular maintenance not only wasted water and energy, it was also not fully effective.

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In 2008, the County received a $4.3 million combination grant and loan from the Municipal Green Fund, to improve water aesthetics, water quality, and reduce water and energy waste. The total project value was approximately $8 million. This amount was divided among several smaller projects for the Mount Pleasant water supply system, namely building a new reservoir, assessing the watermains and upgrading the water facility. The new reservoir was commissioned in 2010, and the watermain assessment was completed in 2012.

A Class Environmental Assessment was initiated for the Mount Pleasant water facility in 2010 to identify a solution for elevated iron and manganese levels. It needed to be environmentally friendly, affordable, reliable, simple to operate, and meet both the short and long-term needs for the facility. Specific evaluation criteria included: water usage of the new treatment process, geotechnical conditions of the existing site, potential impacts to the natural environment during construction and operation, and life cycle cost.

water pressure filter system
Delivery of the pressure filter system used to remove iron and manganese residuals.

The preferred process involved the addition of pressure filtration and residue management processes. This consisted of a backwash equalization tank and a lagoon for iron and manganese residuals, in addition to high-lift pumping and chemical systems upgrades.

In early 2011, a local resident filed a Part II Order request with the MOE, raising concerns over the lagoon’s possible adverse environmental effects. The MOE ultimately ruled that the solution proposed is an established and approved method for municipal water treatment under the Clean Water Act. Furthermore, the MOE was satisfied that the County of Brant and R.V. Anderson Associates Ltd. developed the project in accordance with the Class EA provisions, and that a range of alternative solutions had been considered.

The design for the facility upgrades began in early 2012 and used 3D modelling/drafting to improve the County staff’s understanding of the project’s early stages. These models allowed operators to be involved during the design stage and to minimize coordination issues by providing realistic visual representations of the new equipment and building layout. This approach reduced changes and additions to the contract during construction, which frequently occurs on upgrades of existing facilities for which there is limited information.

Originally, the Mount Pleasant water facility was comprised of two ground water wells, two in-ground reservoirs, four high-lift pumps, and a sodium hypochlorite chemical dosing system for disinfection. A portable diesel generator provided standby power.

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