Wednesday, June 14, 2023

A Guide to Recycling Water in Buildings. Saving Water, Saving Money.

At a recent Langley City Advisory Design Panel meeting, panel members discussed the viability of incorporating a non-potable water system into a building they reviewed. A non-potable (drinkable) water system captures rainwater, water used in A/C cooling towers, and greywater from laundry, dishwashing, bathing, and showering. The non-potable water is then lightly treated onsite for irrigation, toilets, A/C cooling towers, and laundry reuse.

The following diagram shows an example system.

Over 75% of the potable water goes to non-potable uses. There is a high cost to storing, treating and transporting clean drinking water throughout Metro Vancouver. As Metro Vancouver's population continues to increase, there will be further demand for potable water. We also know that we are seeing longer and drier summers. Growth and climate change mean that the Regional District and, therefore, we must collectively invest billions of dollars in expanding the water system.

By incorporating non-potable water systems into buildings, we can reduce the amount of potable water required, which could reduce our need to expand our water system and reduce the severity of water restrictions.

Because non-potable building water systems are uncommon in Metro Vancouver, the regional district has put together a guidebook for how to build these systems as well as a document called "Overcoming Barriers to Non-Potable Water Use in the Metro Vancouver Region."

To get more non-potable water systems built, we will need to:

  • Develop province-wide guidelines for use of non-potable water.
  • Clarify and expand non-potable water systems requirements in the BC Plumbing Code.
  • Continue to explore and identify a regulatory mechanism in BC to provide oversight for the safe and ongoing operation of non-potable water systems.
  • Develop and adopt regional policies that support non-potable water use.
  • Review and update municipal water policies that support non-potable water use.
  • Develop training materials and roll-out strategy to accompany province-wide guidelines and/or regulatory changes for industry and regulators.
  • Continue/expand regional data and research on non-potable water use.
  • Investigate options to develop a regional tracking mechanism for non-potable water systems.
  • Investigate mechanisms for monitoring and reporting of non-potable water systems in operation.
  • Establish a forum to host ongoing coordination across regulators, policy developers, and other key stakeholders.

Returning to the Advisory Design Panel meeting, the members did not recommend a non-potable water system for the building they reviewed because we needed more information. Hopefully, Metro Vancouver's guides will help raise awareness about and reduce the barriers to installing non-potable water systems.

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