guelph residential greywater field test final report - City of Guelph

Both the 2007 Community Energy Initiative and the 2007 Council Strategic Plan set sustainability performance
goals of using “less water and energy per capita than any comparable Canadian city.” These goals continue to
guide the City’s current water conservation activities and bring greater emphasis to the relationship between
water supply, wastewater treatment, and energy demand.
To achieve these targets City staff initiated the Water Conservation and Efficiency Strategy (WCES) Update in
February of 2008. This award winning 10-year strategy was endorsed by Council in May 2009 and identifies
the preferred program, policy, and resource recommendations to achieve a further reduction of 8,773 m 3 /day
by 2019, as well as to achieve the aggressive reduction targets of the Water Supply Master Plan, Water and
Wastewater Master Servicing Study, Wastewater Treatment Master Plan, Community Energy Initiative, and
Council's Strategic Plan.
Through development of the WCES it was noted that many long standing local municipal water conservation
programs, such as toilet or clothes washers retrofit rebates, would reach saturation within the existing
housing sector by the end of the 10 year planning horizon of this strategy. Therefore, in meeting the longterm
targets of the City’s Water Supply Master Plan further capacity development was required in the
research and evaluation of new demand management alternatives. As part of public consultation completed
through development of the WCES strong public and political support for centralized demand substitution
approaches, including greywater reuse and rainwater harvesting, was expressed. With this in mind, pilot
programs for home-based greywater reuse and rainwater harvesting programs were approved by Guelph City
Council as part of the final strategy to further investigate these technology alternatives and build the
necessary technical and social capacity for future readiness of these alternatives.
Beyond the evaluation of centralized home-based greywater reuse systems as recommended through the
WCESU, the City’s 2006 Water Supply Master Plan, 2008 Water and Wastewater Servicing Master Plan, and
2009 Wastewater Treatment Master Plan also began exploring demand substitution from a communal
approach. Through these plans the introduction of a communal effluent reuse system is discussed
conceptually through the introduction of enhanced wastewater treatment and distribution of treated effluent
to customers within the City’s urban boundary. Although these Master Plans do anticipate a benefit
associated reducing water/wastewater demands and avoiding related capital/operation requirements, key
challenges facing implementation of a communal effluent reuse system include the absence of necessary
infrastructure design/legislative frameworks for such systems in Ontario, thresholds to the amount of effluent
which could be reused in maintaining the necessary assimilative capacity of Speed River (to which treated
wastewater is currently discharged), as well as defining the necessary customer base to support significant
capital investment and ongoing operation costs of such a utility. With reference to these ongoing
challenges, the City’s Wastewater Treatment Master Plan recommends completion of an Urban Reuse Study
within its initial 10-year forecast to further evaluate the technical feasibility and proposed viability of a
communal effluent reuse utility within Guelph.
City of Guelph Residential Greywater Field Test 8
Final Report