Technical Series 98-127
Most Canadian municipalities face problems related to water and wastewater services. It has been estimated that Canada will need to spend approximately 4 billion dollars annually over the next 15 years simply to maintain water and wastewater systems. This estimate could increase to account for anticipated expansion requirements.
The scarcity of capital, as well as the site and soil conditions within specific regions, has compelled many of these municipalities to consider innovative water and wastewater technologies as a means of addressing current infrastructure problems.Three of the more promising solutions include: wastewater recycling and reuse; rainwater cistern systems (RWCS); and water conservation.
For several decades Canada Mortgage and Housing Corporation (CMHC) has led many of the initiatives in residential water and wastewater management.This report is intended to provide an information and discussion source about innovative technologies in this area, and their potential applications in Canadian communities.
The project involved an extensive review of the information in the Centre for Water Resources Studies (CWRS) database, in addition to the information supplied by CMHC. Further information was obtained from public and private agencies; suppliers and manufacturers; consultants; and researchers in Canada and abroad. All of the reference material was catalogued for future use.
Fresh water is a renewable, yet finite, resource. Despite a supply that seems abundant, clean water may be in limited supply or inaccessible in specific locations at specific times of the year.
In Canada, water scarcity and other water related problems may be attributed to several factors. In some regions, human activity (deforestation, over-grazing, over-farming, or urban development) often directly leads to water shortages. Pollution from numerous sources may contaminate the groundwater on which more than one-quarter of all Canadians rely for their water supply. Current national trends indicate an ongoing population shift from water rich areas in the East to water deficient areas in the West. Canadians also appear to be leaving metropolitan regions in favour of small town and rural living. These tendencies are imposing increased demands on the available water supplies in such expanding communities. Gradual changes in climate as a result of global warming may have the potential to alter rainfall patterns, sea levels, and irrigation demands across the country.
The majority of Canadas current water and wastewater infrastructure needs improvement or replacement to meet existing and expanding demands. Thus, many Canadian municipalities now face, or will encounter, serious problems related to water supply and wastewater management. A discussion of the problems identified in specific regions in each province and territory is covered in Section 2. Among these concerns are:
Each community could benefit from the implementation of one or more of the technologies addressed in this report.
The report considers three categories of innovative water and wastewater technologies that have been, or may be, used in single- or multi-unit residential buildings:
Rainwater cistern systems (RWCS) can provide an alternative or supplementary water source in situations where conventional sources are non-existent, inadequate, contaminated, or too expensive.
Water conservation can reduce demands on water sources or distribution systems. It can also reduce loads on wastewater collection, disposal and treatment systems.
Water reuse and recycling in residential, commercial, and industrial applications can reduce water demands and wastewater flows.
These technologies may be used alone or in combination to provide cost-effective alternatives to conventional services. In addition, they have the potential to address many of the water problems afflicting Canadian municipalities.These versatile solutions may be implemented at the level of individual buildings or entire municipal systems.
This section (Section 3) also introduces 17 case studies that illustrate applications of the three previously mentioned technologies in residential buildings.The majority of the case studies deal specifically with residential wastewater reuse and recycling.To reflect these solutions, detailed descriptions of 15 treatment components or systems are provided.These have been used, or have the potential for use, for wastewater recycling and reuse in residential systems. Each is described under the following headings:
Many Canadian municipalities have realized the potential of water conservation initiatives.These communities have been successful in reducing capital and operating costs of water and wastewater management. Section 4 presents examples of twelve communities that have invested significant effort in addressing specific water related problems.
A combination of several approaches was used to achieve many of the objectives outlined by each municipality. Among these initiatives were:
Although the solutions adopted by the 12 municipalities reflect circumstances unique to each community, the water efficiency initiatives employed may be extrapolated to regions with similar problems.
This section also explores examples of municipal wastewater recycling and reuse from around the world. These examples have been selected to illustrate reasons for the adoption of wastewater reuse, as well as to provide descriptions of how this wastewater has been used.
|Municipality||Objective of Water Conservation Initiatives|
|Barrie, ON||Reduce average water demands in order to defer the need for an increase in the capacity of its wastewater treatment plant, and to defer construction of a new water treatment plant.|
|Edmonton, AB||Reduce water demands resulting from population growth, in order to defer capital expenditures for water treatment plant expansion.|
|New Glasgow, NS||Defer capital costs of additional water treatment, and to avoid the need to develop a new water supply.|
|Yellowknife, NWT||Avoid or defer capital costs to reduce operating costs for water supply, to increase the capacity of an already overloaded wastewater lagoon, and to reduce effects of water main leakage on street pavements|
Section 5 draws on many recent references to review issues, obstacles and opportunities related to wastewater recycling and reuse. Successful implementation and use of the innovative technologies explored in this report will require the consideration of relevant concerns, in addition to careful planning. An outline of significant implications is given below:
This document is intended to serve as a resource for all individuals with an interest in the planning, design and management of water and wastewater systems.The examples provided in the report illustrate the need for innovative technologies in Canadian municipalities in order to prevent inevitable water shortages. Descriptions of the efforts undertaken by specific domestic and international communities may serve as guidelines for regions experiencing similar water related problems.The on-site systems and case studies introduced in this report may also provide viable solutions. Municipalities not currently experiencing difficulties with water and wastewater systems may also benefit from these technologies, as they have the potential to increase efficiency and reduce costs.
In any case, careful consideration of the issues and concerns related to each specific technology is required prior to the implementation of new programs.
Innovative Residential Water and Wastewater Management, 1998
D.H.Waller, J.D. Mooers,A. Samostie, B. Sahely Centre for Water Resources Studies, Dalhousie University in collaboration with totten simms hubicki associates, Blue Heron Environmental Technology, and Canadian Water and Wastewater Association.
The information in this publication represents the latest knowledge available to CMHC at the time of publication, and has been thoroughly reviewed by experts in the housing field. CMHC, however, assumes no liability for any damage, injury, expense or loss that may result from use of this information.
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