Triple Bottom Line Impacts
MacDonald Island is located immediately north of Fort McMurray, Alberta, Canada at the junction of the Snye, Athabasca and Clearwater Rivers. It is currently home to a sports complex that contains three ice arenas, twelve curling rinks, a fitness center, a golf course, and an Olympic size swimming pool. Wastewater was conveyed via gravity sewer across the Snye River to downtown Fort McMurray where it was transported via a lift station and force main to an existing centralized treatment plant located on the west bank of the Athabasca. The MacDonald Island golf course received its irrigation water from the Snye and Clearwater Rivers and uses an average of 20 million gallons (75,708 m3) through the season from May to September. The sports complex was recently expanded to include an additional football, soccer, and baseball stadium with the capacity for 8,000 spectators along with a proposed 200-unit hotel. Wastewater demands for this recreational development exceeded the capacity of the existing centralized collection system and would have required costly infrastructure construction beneath the Snye River.
Natural Systems Utilities (NSU) constructed and commissioned a water reclamation and heat recovery facility on MacDonald Island. The system provides 60,000 gpd (227m3/d) of treatment and reuse capacity with flow equalization and storage for major events.This project represents the first integration of direct water reuse with a District Energy Sharing System (DESS). Services include detailed design, permitting, fabrication, delivery, installation and commissioning. This project reduced capital expense by $3 million as compared to the conventional wastewater approach, while also allowing for energy recovery opportunities, thereby providing significant economic, energy, and environmental benefits.
This distributed water treatment and recycling system with heat recovery for MacDonald Island reduces total indoor potable water use by approximately 30% (50% for the proposed hotel) and reduces wastewater flow to the centralized facilities by nearly 100%. In addition, diversion from the Snye and Clearwater Rivers for golf course irrigation will also be reduced by up to 100% by utilizing reclaimed water. This will increase stream flow within the Snye River which is reported to have environmental concerns with decreasing flow. Energy will be recovered from the treated water before reuse and will be used to heat the indoor pool facilities. The peak energy recovery from the treated water heat system is estimated to be 240kW. The integrated ice plant refrigeration heat recovery is estimated to peak at 263kW, displacing a total of 2,570 MWh and resulting in a reduction of 605 tCO2e greenhouse gas emissions for RMWB.
This project provides the lowest impact design and construction while supporting the areas intent for low energy and low emissions, to demonstrate world leading sustainable operations in the region. Additional goals include minimizing the Life Cycle Cost for combined water-energy district energy and direct water reuse systems. MacDonald Island will serve as the pilot for a Neighborhood Energy Concept which RMWB is evaluating.< back to case studies