Long Term Boil Water Advisory Lifted through an Innovative Approach

The Village of Middle River is a small community of 12 homes, located in a remote site along the north shore of the Middle River outlet into the Trembleur Lake - about a two-hour drive from the closest city centre. Due to its direct proximity to the river, water is central to the Village culture and actives. The river supports the Village as the primary source of drinking water, fishing and water activities spot. Its perimeter ground also supports hunting, camping and other cultural activities. Upon arrival into the community, the boil water advisory (BWA) sign and the existing water treatment plant (WTP) are prominent.

Over the past 14 years, a series of water treatment methods were attempted in Middle River. However, each attempt succumbed to the challenges of a remote community and resulted in the on-going BWA. Adding to the challenges were the high organics, highly variable turbidity, and the community’s demand fluctuations. The community needed a simple, robust, and affordable treatment system that could endure the aforementioned operations challenges and provide longevity to the community.

Small and remote communities commonly face water treatment challenges do to limited financial and technical support. Taking an innovative approach to water treatment, WSP considered the available technologies, particularly ion exchange, to achieve the removal of organics.

In order to evaluate the operational performance of the ion exchange media using natural waters, WSP approached the University of British Columbia to conduct bench-scale research on ion exchange. Surprisingly, the results of the bench-scale tests did not follow the anticipated behaviour for ion exchange breakthrough patterns. It was found that the resin did not break through in terms of organics, as expected, but instead showed signs of biological growth. It was hypothesized that by running the ion exchange media without regeneration, biological communities were allowed to grow on the media, altering the organic removal mechanism from an ion exchange to a supplemental biological process – thereby coining the term biological ion exchange (BIEX).

BIEX appeared to have the required characteristics to be a successful treatment method in a small community.

As a result of the bench-scale success, BIEX was brought from a lab experiment to full-scale implementation in Middle River. A collaborative approach was used to apply the innovative treatment method, which included the government, university research and industrial partners who worked together to implement the world’s first BIEX treatment system.

With the operation of the new treatment system, the BWA was lifted in late 2018. The organics in the water were reduced by approximately 92%, as measured in terms of water colour. Through the reduction of organics, harmful by-products that formed when mixed with chlorine were no longer forming.

As operation of the first full-scale BIEX system is monitored, the potential benefits can be more widely realized. Read ‘The Future of Clean Drinking Water: A New Treatment Method’ to dive deeper into WSP’s exploration and implementation of the BIEX system.