Tests on Bowen Island water supply produce surprising results

Nestled in picturesque Howe Sound, Bowen Island provides an idyllic place to live, play, and raise a family. But questions about water quality from the island’s primary drinking water source have long simmered. So when one of the island’s residents – Dr. Peter Ross, an international expert on pollution and director of Raincoast’s Healthy Waters program – collected and analysed water from Grafton Lake for an independent evaluation of water quality, a surprising narrative emerged.

Documented in a new report (‘A water quality snapshot of Grafton Lake on Nex̱wlélex̱wm (Bowen Island)‘) released on June 9, Ross’s findings reveal that cocaine, the diabetes medication metformin, and the artificial sweetener, sucralose, are entering the lake. These pharmaceuticals and personal care products are considered ‘tracers’ that indicate that human waste is entering the lake. This could be the result of leaking or failing septic systems nearby, and/or recreational swimmers using the lake.

In addition to pharmaceuticals and personal care products, the report reveals traces of pesticides and industrial PCBs. The report concludes that these may be driven by the deposition of air pollution onto the lake’s surface. 

Grafton Lake is small (14.7 km²) and relatively shallow (average depth 8.8 m). This means it is vulnerable to contamination by activities within the lake’s watershed, and by air pollutants that travel from sources outside the area. Homes, businesses, and nearby roads contribute to the release of a complex mixture of pollutants into the lake and its tributaries, directly or onto adjacent lands that impact the lake. Current and new developments have the potential to further degrade water quality in Grafton Lake.

The report notes that while there were no exceedances of Drinking Water Quality Guidelines or Environmental Quality Guidelines – providing a measure of reassurance – there are no guidelines available to determine the safety of the majority of pollutants found. This, however, does not dampen Ross’ enthusiasm for knowledge and action:

“In detecting as many as 125 pollutants in this important body of water, we created a powerful profile that identifies the primary threats to Grafton Lake. This has the potential to establish priorities and implement targeted solutions, allowing us all to step up to protect the lake for people – and wildlife. This is where bad news has strong potential to contribute to good news.”

Ross is encouraged by the long-awaited launch of a new drinking water treatment plant for Grafton Lake water to reduce the levels of E. coli, pathogens, turbidity, manganese, cancer-causing trihalomethanes (THMs) and cysts before distribution of this drinking water.

But treatment is only one part of the solution. The report highlights the importance of protecting Grafton Lake water from the unintended effects of activities within the watershed. Treatment will not eliminate all pollutants in drinking water, and fish and wildlife downstream depend on clean water from Grafton Lake. 

Ross said, “Our findings provide a poignant reminder that we all have a role to play in protecting waterways. The silver lining in our report lies in that message.”