Edmonton pool sets a standard

Canada’s first chemical-free public outdoor pool relies on rock filters and natural processes to purify its water in an award-winning design. Toronto-based architectural firm gh3* recently unveiled Borden Park Natural Swimming Pool in Edmonton.

The nearly 6,000-square-metre complex accommodates up to 400 swimmers and features a children’s swimming area in addition to the main pool. Visitors can also enjoy a sandy beach, picnic area and space for volleyball and other recreational activities. A large, modern structure houses universal changerooms, showers, restrooms and a staff area.

The pool’s design uses natural filtration processes, such as stone, gravel, sand and botanic filtering to keep water clean.

To make sure the chlorine-free concept aligned with Canada’s strict regulations for public swimming pools, experts were called in to establish a balanced ecosystem of plant materials, micro-organisms and nutrients that combine to create a filtering system involving no exposure to soil. For example, through the Neptune Filter, layers of granite rock strain out debris like leaves and larger materials, while a biofilm at the top removes small micro-organisms. The hydrobotanical beds — “constructed wetlands” — filter out phosphates, nitrogen, carbon dioxide and other contaminants from the water.

The sun’s intense ultraviolet rays also control bacteria levels before the water is reintroduced to the pool. All systems clean the water naturally through a long circulation process that is eco-friendly and safe for swimmers.

The pool that once occupied the site was built in the 1950s and had to be completely demolished to make way for the new pool’s infrastructure.