West Vancouver, British Columbia
The Quayside Village Co-Housing Ltd. building is a 20-unit apartment building in which renovated grey water will be reused for toilet flushing. The demonstration wastewater renovation and reuse system has been installed, and will be monitored, with the financial assistance of Canada Housing and Mortgage Corporation (CMHC). The building is located in an area where municipal water and wastewater services are available. Design water demand is about 20,000 L/day.
This project is intended to:
- provide a showcase for residential wastewater reuse technology,
- demonstrate grey water reuse in a multi-unit residential building, and
- apply and adapt technology developed in CMHC's Toronto Healthy House project to a multi-unit residential building.
Description of Technology
The current demonstration will focus on reuse of light and dark grey water from all fixtures except toilets for reuse in toilets only. Quayside Village is double-plumbed throughout to permit recycling to showers if advisable in the future.
The wastewater renovation system, based on that developed for the Healthy House (which recycles all wastewater for all non-potable uses), includes a settling tank, filtration tank, biofilter, pre-ozonation, multi-stage sand filtration, and ozonation.
Wastewater from toilets that is not renovated, and excess from the treatment system, discharge to the municipal sewer. A connection to the municipal water system, protected by backflow prevention devices, provides a back-up supply if the reuse system malfunctions or water use exceeds the renovated water supply.
Operation, maintenance, and on-line monitoring will be the responsibility of the developer. An independent engineering firm will perform inspections, monitoring, sampling, testing and reporting related to performance evaluation.
Capital cost of the equipment was approximately $115,000. Estimated maintenance cost is $100 per month.
Benefits expected to be demonstrated by this project are:
- availability of an alternative approach to water supply and wastewater servicing for multi-unit residential buildings, which may have applications in situations where conventional services are unavailable, expensive, or raise environmental concerns, and specifically
- reduction of water demand, and associated water supply costs, of about 40%, and reduction in wastewater flows of about 40%, with associated reductions in the size and cost of an on-site wastewater treatment and disposal system.