Canadians are among the highest users of water in the world. As you know, the demand for fresh water is on the rise. Population growth, accelerated urbanization and industrialization. At this growing pace, shortages will increase and the reliability of drinking water will decrease. Many have turned to reuse & recycle water.
DIRECT POTABLE REUSE IS DEFINED AS “THE INCORPORATION OF RECLAIMED WATER DIRECTLY INTO A POTABLE WATER SUPPLY SYSTEM” (METCALF & EDDY, 2003).
To my knowledge, this level of reuse is not presently found in Canada nor is it common worldwide. Though, it is gaining attention as population rises, technology advances, and fresh water sources become limited and/or less reliable. In the US, some states like Arizona and California are looking at enacting regulations for direct potable reuse.
The Windhoek (Namibia) Plant has been credited worldwide as the first municipality to supplement their drinking water with reclaimed wastewater and can provide up to 50 % of the community’s water demand during severe drought conditions. It has been in practice since 1968.
In North America, Big Spring, Texas, implemented in 2013 the first example of direct potable reuse. It now provides 15 % of the city’s water.
As for indirect potable reuse, for about 50 years now LA County Sanitation District and Orange County Water District have been using purified reclaimed water for supplemental groundwater injection. Since 1985 for El Paso. As for the Upper Occoquan Service Authority, they have been practicing surface water augmentation outside Washington, D.C. since 1978.
REUSE OF EFFLUENT FROM WASTEWATER TREATMENT PLANTS
To my knowledge, in Canada, the only document on the subject was issued by Health Canada in 2010 (http://bit.ly/2oqo288). They recommended the reuse of treated domestic wastewater to supply flush toilets and urinals. However, the recommendations only apply to domestic wastewater and not to municipal wastewater.
British Columbia adopted a norm on reused of treated water for various applications. It defines the quality criteria required in two categories for the public with restricted or unrestricted access to water (http://bit.ly/2nYAQGd).
It also describes the conditions:
- The requirements for treatment systems;
- The various possible uses for the reclaimed water; and,
- Other restrictions.
British Columbia's guidelines not only apply to water reuse for toilets and urinals but also irrigation, indirect potable reuse, ponds, fountains, vehicle washing, snow and ice production, dust abatement, wetland restoration, etc.
As for the Prairies, the reuse of treated water is regulated by provincial regulations. The three provinces authorize the use of reclaimed water for irrigations purposes.
I’m not familiar with Yukon’s regulations.
I think DPR will be coming to Canada. Nevertheless, DPR legislation and regulations are not currently in place in Canada. Carrying out the necessary testing and developing suitable legislation may take considerable time.
From an operating point a view, I think to ensure proper management of the plants due to their complexity it will necessitate an advanced certification program for operators.