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In March 2005, Okotoks' wastewater plant was operating and almost at full capacity with discharge limits nearing regulatory caps. The the town partnered with EPCOR to provide the necessary upgrades to their existing wastewater treatment plant, and manage the ongoing operations and maintenance of their water and sewage utilities for the next 20 years.

In the fall of 2006, the 10 million litre per day (ML/d) tertiary wastewater treatment plant was completed. It uses the latest standards and technology including a bioreactor that doubles flow capacity, ultraviolet (UV) light disinfection, a biological nutrient removal process and composting of the biosolids sludge.

In order to complete the $11.2 million expansion at less than half of the initial estimated costs, EPCOR utilized existing facilities and buildings to save on cost and land requirements.

Our solution saved Okotoks more than $13 million based on initial estimates.

Town Council continues to set annual utility rates, approve annual utility budgets and bill customers.

Services

  • Water treatment
  • Water distribution
  • Wastewater treatment
  • Wastewater collection

Model

  • Design-Build-Operate (20 year term)
  • Operations & Maintenance

Population served

  • 28,016 (2015 Municipal Census)

​About the System Infrastructure

Water System

Water treatment

  • 13 shallow wells
  • Three booster stations
  • 10 pressure reducing vaults

Water treatment plant

  • Capacity: 21.5 ML/d (peak production); average daily production: 7.5 ML/d
  • Treated water storage capacity: 19 ML (million litres) in three reservoirs

Process

Acti-Flo pre-treatment clarifiers were added in 2011 to handle fluctuations in raw water (tubidity) quality most often associated with large storm events.

  1. Okotoks receives its raw water from 12 groundwater wells that are affected by surface water (e.g., river, rain, and runoff).
  2. Clarifiers settle out most of the dirt and other particles (turbidity).
  3. A coagulant chemical is added that sticks to the remaining dirt particles. This makes the "floc" heavy enough to sink to the bottom of the clarifier. Meanwhile the clear water at the surface of the clarifier moves to the filters.
  4. Water flows through three gravity filters made of anthracite coal, sand and gravel. They remove even smaller particles.
  5. Water from the filters receives fluoride and chlorine to disinfect bacteria and other micro-organisms.
  6. UV light is an additional disinfection step to remove any remaining micro-organisms (e.g., Cryptosporidium).
  7. From here the water goes to reservoirs and the disinfectants are allowed further time to work.
  8. From the reservoirs, the water is pumped to both the North and South Okotoks water distribution systems.
Wastewater System

Collection system

  • Six sanitary lift stations
  • 128 km of gravity sewer mains

Wastewater treatment plant

  • Capacity: 10 ML/d
  • Plant rated as Level lV
  • Treatment Process: Biological nutrient removal (BNR) combined with disk filtration
  • Biosolids are composted
  • Technologies Used: UV light disinfection

Process

  1. Raw sewage enters system.
  2. Screw pumps move sewage from collection system into plant.
  3. Fine screens (6 mm diameter) removes large debris. Debris is taken to regional landfill.
  4. Pebbles and sand are removed and landfilled in the grit chamber.
  5. Large organic solids settle to the bottom of the primary clarifier. The resulting sludge, after being blended with secondary sludge, is taken to a composting facility.
  6. In the bioreactor, active bacteria consume harmful nutrients that might otherwise end up in the Sheep River. The sludge is composted.
  7. Active bacteria settle to the bottom of the secondary clarifier. Any remaining sludge is returned to the bioreactor and composted.
  8. Fine particles are trapped in the filter and removed.
  9. Filtered water is disinfected with UV light, which neutralizes harmful bacterial.
  10. Treated effluent returns to Sheep River.

Environmental considerations

Water system source

  • Water source: Sheep River Aquifer
  • Effluent discharge: Sheep River, South Saskatchewan River Basin

We work in cooperation with local, provincial and federal environmental agencies to ensure all regulatory and environmental requirements are met or exceeded.

The Town has targeted a reduction in water consumption from 404 litres/customer/day (lcd) to 275 lcd by 2017. In 2013 the Town achieved 273 lcd.

Awards

On November 14, 2014, the Federation of Canadian Municipalities (FCM) announced the winners of its 2015 Sustainable Communities Awards, recognizing innovation and excellence in municipal sustainable development in six categories: brownfields, energy, neighborhood development, transportation, waste and water. That year's winning initiatives all share a focus on partnerships and community engagement to ensure environmental, economic and social benefits.

The Town of Okotoks has been honored as an award winner within the water category, for its Water Conservation, Efficiency and Productivity Programs and formally accepted the award in London, Ontario on February 11. EPCOR was recognized for our assistance and involvement in these efforts.

The Town of Okotoks also received a Provincial Ministers' Award of Excellence for achieving the community's Water Management Plan goals. EPCOR was recognized for our assistance and involvement in these efforts.