Water and Sewer Infrastructure in Cold Region Communities Compiled by Ken Johnson, RPP, P.Eng. Planner, and Engineer
NOTES TABLE OF CONTENTS
1.0
HISTORY OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
2.0
EXISTING WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
3.0
DEVELOPMENT TIMELINE OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
4.0
COST OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
5.0
ENGINEERING ASPECTS OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
6.0
LAND USE PLANNING ASPECTS OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
7.0
CAPITAL PLANNING ASPECTS OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
8.0
REGULATORY ASPECTS OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
9.0
OPERATION AND MAINTENANCE ASPECTS OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
10.0
COMMUNITY PARTICIPATION IN WATER AND SEWER INFRASTRUCTURE FOR COLD REGION COMMUNITIES
11.0
EXAMPLES OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
12.0
FUTURE POSSIBILITIES OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
FOR MORE INFORMATION PLEASE CONTACT: KEN JOHNSON, M.A.Sc., RPP, P.ENG. 780 984 9085 ken.johnson@cryofront.com
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 1.0
HISTORY OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
Prior to World War II, the Northern Territories of Canada, were, for the most part, an unknown frontier of aboriginals, fur traders, miners, and adventurers. Perceptions of the north were based upon the Klondike Gold Rush of 45 years before, or the stories written by explorers of the 1800s. The common perception of the entire region was of a land of ice and snow, occupied by subsistence hunters and gatherers. This perception was in fact true for the majority of this vast area that occupies almost 40 percent of Canada’s land mass. The trading posts of the Hudson’s Bay Company were the most prominent modern feature at the main gathering centers. Nearby were Catholic and Protestant missions, Royal Canadian Mounted Police Stations, and Department of National Health and Welfare Buildings. In the western Northwest Territories, there were church-operated hospitals and residential schools at Aklavik, Fort Simpson, and Fort Providence and church-operated hospitals at Rae, Fort Resolution and Fort Smith. With the onset of World War II, there began a gradual and significant change to the north, first with the American Army construction of a chain of airports northward from Edmonton to Norman Wells, and northwest from Edmonton to Fairbanks. Along with these airports came the construction of the Alaska Highway and the Canol Pipeline was also a significant construction project of the time between Norman Wells and Whitehorse. In 1950, Prime Minister John Diefenbaker made a historic visit to the Arctic, where he found a need for a greater government presence in the North. He was dismayed when he found that residents of Old Crow, Yukon Territory, received mail by way of Alaska. He also noted the state of health services available to the aboriginal population throughout the North, and his positive response was reflected in his position paper, Vision of the North. As a result of the Diefenbaker visit, more schools and nursing stations were built at remote settlements. Inuvik, was planned and constructed as a major administrative and education center for the Mackenzie Delta region, and the community was serviced with piped water and sewer. Many other towns were also built where there were formerly small settlements. To plan and design the water supplies, sewers, and waste treatment and disposal for some of these communities, the Department of Indian and Northern Affairs retained various engineering resources. These engineering resources began the process of technological innovation which has evolved to the cold region municipal engineering expertise which is applied today in communities across northern Canada, and in many cases around the world.
Reference:
The Changing North. Jack Grainge, 1999
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 2.0
EXISTING WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
Characteristic Water System
Trucked Water and Sewer Supply to water tank in building. Delivery vehicles typically 2,500 to 10,000 litres. Fire suppression limited to the use of delivery vehicles.
Piped Water and Sewer Piped water service connection to building. Fire suppression may incorporate hydrants, large mains, storage and pumping capacity.
Sewage System
Collection to wastewater tank in building. Collection vehicles typically 2,500 to 10,000 litres.
Piped wastewater service connection to building. System may use gravity, low pressure or vacuum technology.
System Considerations
Requires year round vehicle access to buildings, and allweather roads for large vehicles.
Requires freeze protection considerations (heating, insulation and recirculation) and design for frozen ground installation.
Building Systems
Pressurized water system and associated tanks in building. Partial to full building plumbing.
Pressurized water service from main system, and freeze protection. Full building plumbing.
Technology
Relatively simple technology. Usually reliable and easily repaired.
Relatively complex technology. Usually reliable, but repairs in winter may be difficult.
Vulnerability
Systems are independent and designed for periodic service. Systems are vulnerable to prolonged service interruption.
Systems are dependent upon major fixed infrastructure facilities and designed for continuous service. Systems are vulnerable to any service interruptions of any significant duration.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
2.0 CONTINUED
NOTES
Characteristic Level of Service
Trucked Water and Sewer Piped Water and Sewer Level of service can match Level of service high. individual building needs Flexible response to changes and quantity of demand. in service demand. Limited response on unexpected service demand.
Physical Flexibility
Responds well to physical changes in community.
Potentially unresponsive to physical changes in community because of fixed facilities.
Relative Economics
Low capital costs and high operating costs. The key economic factor is quantity of water used.
High capital costs and low operating costs. The key economic factors are building density and community layout.
Human Resources
Continuous requirement for semi-skilled workers (drivers) and skilled workers (vehicle mechanics).
Continuous requirement for skilled workers to construct, operate, and maintain system.
System Self-Reliance
Potential for local technical, financial, and administrative responsibility and control and user finance. High levels of water use may require financial assistance.
Often requires technical assistance for design, construction and operation, and financial assistance for capital funding.
Reference:
Cold Regions Utilities Monograph, Third Edition. American Society for Civil Engineers. 1996.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 3.0
DEVELOPMENT TIMELINE OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
The scheduling of a project is an important aspect of water and sewer infrastructure in cold region communities. A realistic timeframe for many projects may be a four to five year period. The first year of a project schedule is utilized for project planning. This is a necessary, but often time consuming and expensive step to establish the necessary lines of communication between the various groups involved in the project, and to refine the project needs, and project resources. The time and expenses are due to the isolation of project site, and the cultural differences of the project users. A simple visit to a project site may take several days of travel each way and may cost thousands of dollars. The second year of a project schedule is utilized for preliminary engineering and detailed design. These technical stages of the project may be characterized by the various technical activities with typical "southern" engineering. However, the design criteria include careful consideration of cold temperatures, ice and snow, and how these are influenced by wind, darkness, and isolation. The third and potentially fourth year of a project is utilized for project construction. Construction of roads, pipelines, reservoirs, and lagoons is limited to a window between June and October. Construction before or after this period is certainly possible, but the cold temperatures often create problems which may jeopardize the integrity of the project. Projects in the coastal communities are faced with the problem that material and equipment supply cannot occur until late July, at the earliest. This is due to the fact that arctic waters are not free of ice until the mid summer to allow the annual sealift to occur. Airlifting of materials and equipment is a last resort because it is extremely expensive. Other projects, particularly in the western arctic, may have access to all-weather roads, or winter roads for material and equipment delivery. This allows for delivery during the winter months and for construction to begin as soon as temperatures permit. The final year of the project schedule is post construction and warranty. This period of a project is not without its own particular problems, which may result from the ability of the contractor to complete deficiencies once his forces are demobilized, and the general "bugs" which may have to be worked out of a newly completed project.
Reference:
Municipal Engineering “North of 60". Ken Johnson. PEGG Magazine, 1996.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 4.0
COST OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
Cost estimating in the north may at times be considered more of an art than a science. Even the project cost estimate founded upon the best possible historical information may end up being significantly lower than the price tendered by the contractor. Factors such as competitiveness, contractor experience and confidence, and transportation which play a major role in northern construction may at times only be judged with a crystal ball, which most engineers do not have at their disposal. The specifics of costs for municipal engineering North of 60 are often mind boggling. A good example is the construction of a municipal sewer system in the City of lqaluit. Insulated small diameter sanitary sewer mains in lqaluit are more than $400 per metre. This cost does not include the supply and installation of simple Access Vaults, which are more than $40,000 each. In communities of the Northern Territories, the cost to provide trucked services to houses is generally less than piped services for small communities. Large communities generally have more high-density housing, more non-residential customers, and are generally not as spread out, therefore, pipe services are generally less expensive.
System Component
Capital $ (%)
Operation and Maintenance $ (%)
Total (%)
Piped System Water and Sewer Connections Water and Sewer Mains Water and Sewer Facilities Total
15 35 20 70
10 10 10 30
25 45 30 100
Trucked System Tanks in Homes Garages for Trucks Trucks Drivers Water and Sewer Facilities Total
15 3 10 10 38
2 2 15 33 10 62
17 5 25 33 20 100
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 4.0 CONTINUED The service life for facilities and equipment in cold regions is usually shorter than that in southern climates. This is especially true for equipment that operates outside in the cold winter temperature. Actual service life depends in large part on the appropriate design and the quality of operation and maintenance.
Component
Service Life (years)
Wells Storage Tanks Water Distribution Piping Sewage Collection Piping Service Connections Building Tanks Lift Station Structure Pumps and Controls Boilers and Furnaces Meters Valves Septic Tanks Drainfields Haul Vehicles Buildings Utility Truck Heavy Equipment (backhoe, loader, grader, bulldozer)
References:
25 to 35 20 to 40 20 to 40 20 to 40 10 to 30 10 to 20 20 to 30 5 to 15 5 to 15 5 to 15 10 to 20 20 to 30 10 to 20 5 to 10 10 to 30 5 to 10 10 to 15
Municipal Engineering "North of 60". Ken Johnson. PEGG Magazine, 1996. Cold Regions Utilities Monograph, Third Edition. American Society for Civil Engineers. 1996.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 5.0
ENGINEERING ASPECTS OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
The engineering aspects of water and sewer infrastructure in cold region communities are unique in comparison to those in the south because these conditions are often pushed to the extreme. Frost penetration, where there is not permafrost, may extend 3.5 to 4.0 metres into the ground. Material supply and delivery is very often controlled by the opportunity window of either an ice road, or sealift, depending upon the location of the project. Construction is also controlled by the very short opportunity window called summer (June through September). A basic design principle used over and over again is that water will freeze. The design criteria for water and sewer systems may include preventing the pipes from freezing, and also allowing access to thaw the pipes when they do freeze using systems referred to as Access Vaults. A reasonably safe assumption is that at some point in the future the pipes will freeze. Consideration of pipe insulation, water temperature, and minimum flow to prevent freezing are standard in any northern water or sewer system. The isolation of projects and short construction season present a constant challenge to the northern contractors who undertake the work and the engineers who monitor the work. Mobilization and demobilization become significant portions of the project cost, if a contractor is not based in a community. The engineering activities for water and sewer infrastructure in a cold region community may be generally described in terms of project planning and project management. Project planning is a process of taking the Capital Planning information (see Section 7.0) through to a viable construction project. The activities within project planning generally include preliminary engineering, detailed design, and tendering. Project management may overlap project planning and involve the management activities through the design process, the tendering of a design, and the project construction. The tendering process includes issuing the necessary documents (plans and specifications); reviewing the tenders received; presenting a recommended contractor for adoption by the Community Council; and, processing the documentation for the successful contractor. 'The construction management is completed by conducting site inspections, and issuing progress claims to the contractor for the work completed. The detailed activity to the construction management includes dispute resolution, construction documentation, and issuing completion certificates.
Reference:
Municipal Engineering “North of 60�. Ken Johnson. 1996.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 6.0
LAND USE PLANNING ASPECTS OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
Water and sewer infrastructure in cold region communities should be included as part of any land use planning activities because the location of, and distance to the water and sewer facilities is important for public health, public safety, and community capital and operation costs. Sewage treatment infrastructure has setback requirements of the General Sanitation Regulations of the NWT and Nunavut Health Acts. The impact of these setbacks is twofold. The first impact is objective, and may be quantified in the capital cost of constructing a road and power supply around a setback envelope to a new residential development; the cost of operating and maintaining the road; and the cost of operating water, sewer, fuel and waste management vehicles over this road. The second impact is subjective in the separation distance between neighbourhoods. This separation limits access to amenities, and the social structure of the community, both of which are very important to aboriginal communities. The NWT and Nunavut Planning Acts enable the preparation and adoption of General Plan and Zoning Bylaws as the tool for communities to organize and guide development. Once a General Plan Bylaw is adopted, a Zoning Bylaw must be enacted to include those areas of land affected by the General Plan. For many communities this approach may be desirable, but inappropriate to the community’s needs and resources. Many northern communities are just too small in regard to their community growth, and administration size to need the development tools enabled in General Plan and Zoning Bylaws. The Land Use Plan format was created outside the Planning Acts as a non-statutory means of addressing the small community’s desire to organize, and guide development. A Land Use Plan has no definition in the existing Planning legislation, and is more of a guideline for a community to use when approving development. The phrase "Land Use Plan" was adopted as a distinguishable name from the phrase "Community Plan" used in the Planning Acts to identify a General Plan. In the production of Land Use plans, the availability in recent years of large format colour map plotters has provided the opportunity to create vivid Land Use Plans at a reasonable cost. These colour maps provide another useful tool to community planning consultation, and implementation in the cross cultural settings of the north. The creation of a Land Use Plan does not restrict a community from at any time from expanding the existing documents to create the more comprehensive documents that are adopted under the Planning Act. Many communities can be expected to pursue a Community Plan in the future as their community growth requires the tools for development or redevelopment enabled by a Community Plan. References: The Northern Land Use Plan: Origin of the Species. Ken Johnson, 2001. Residential Land Use Related to Landfill Site in Cold Region Communities. Ken Johnson, 2001.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 7.0
CAPITAL PLANNING ASPECTS OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
The initial aspect of the capital planning process for water and sewer infrastructure in cold regions involves the completion of the appropriate engineering studies in support of infrastructure improvement projects. Several planning horizons may then be applied for projects with a technical need, and an associated preliminary cost. A 5 year horizon is the most critical for the 5 year "Capital Planning" cycle, and subordinate to the 5 year horizon are 10 years and 20 year horizons, which are identified as "Capital Needs". In support of a 5 year Capital Plan are "Briefing Notes", which serve as a succinct presentation of the capital funding requirements, and the technical basis for a project (usually less than a page in length). The Briefing Note is the most critical item in support of the Capital Planning process because it provides the documentation upon which a Senior Government makes its capital funding allocations. The capital funding allocation process is very competitive because of the many projects vying for very limited funds. Since the expression of the capital funding requirements may rest solely with the Briefing Note, this document must by well organized, concise, and strongly supported by a technical need. The engineering studies in support of capital planning includes several objectives and analyses. Reliability of water and sewage service is a planning and design objective for systems and facilities. The essential infrastructure services normally include: (i) (ii) (iii) (iv) (v) (vi)
uninterrupted water supply and sewage collections for pipe serviced buildings; scheduled water delivery and sewage collection for truck serviced buildings; water supply requirements for fire protection; minimizing public health risks through the system operations; minimizing any risk to the integrity of water and sewage facilities. and appropriate technology to the site conditions.
Backup measures shall be incorporated where necessary to provide reliable essential service. The planning and design of water and sewage infrastructure must try to minimize the total present value of all associated capital and operation and maintenance costs net of any subsidies or grants. The present value shaft be calculated over a 20 year planning horizon discounted at an annual rate of interest of 8% net of inflation.
Reference:
Water and Sewage Facilities Capital Program: Standards and Criteria. MACA, GNWT. 1993.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 8.0
REGULATORY ASPECTS OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
The general objectives of the various Territorial water boards are to provide for the conservation, development and utilization of the water resources. The guidelines applied for the discharge of treated municipal wastewater serve those objectives, and as well seek to protect public health. The guidelines are based on the following precepts: • • • • • • • • •
Water is a renewable resource to beconserved and protected; Municipal wastewaters may pollute receiving waters by depletion of oxygen, deposition of solids, eutrophication, toxicity, release of pathogenic organisms, release of mutagens and carcinogens and aesthetic nuisance; The discharge of raw wastewater should be eliminated due to the special relationship between northern residents and northern inland waters; The discharge of treated municipal wastewater needs to be regulated through a licensing and monitoring process; Care should be considered on a site-specific basis because the range of environmental conditions found in the north are so broad; Receiving water quality objectives need not be satisfied in a defined initial mixing zone immediately around an effluent discharge point; The onus is on the water license applicant to obtain all the information necessary to design an adequate treatment and disposal system, and to demonstrate that the proposed system will meet these guidelines after implementation; More stringent or less stringent limits in water licenses may be applied whenever it is deemed appropriate to do so in light of site specific circumstances; and Full public consultation is undertaken prior to making any licensing decision;
Compliance with the objectives and the specific information in a water license does not absolve the owner or operator of any wastewater collection, treatment or disposal system from the responsibility to comply with any other applicable Federal, Territorial or Municipal legislation. For example, the Fisheries Act prohibits the deposit of a deleterious substance of any type into waters frequented by fish. Deleterious is generally accepted as acutely lethal, whereby undiluted effluent kills more than 50% of the trout or daphnids in their respective bioassay tests. This end-of-pipe requirement may or may not be more stringent than the mixing zone approach incorporated within guidelines.
Reference:
Guidelines for the Discharge of Treated Municipal Wastewater in the Northwest Territories. NWT Water Board. 1992.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 9.0
OPERATION AND MAINTENANCE ASPECTS OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
The ultimate success of water and sewer infrastructure is dependent on the long term operation and maintenance of the systems. This responsibility may often rest with one operator. Their dedication and acceptance of responsibility, as well as the support of the community are usually direct indicators of a successful operation. Much of the difficulty of meeting water quality guidelines may be related to operation of the facilities, primarily time allotted, training and attitude of the operator and of the community. In small remote communities, it is critical that technical and management help are always available to the operator and community, especially to allow quick reactions to system failures. Many operators feel they have no one to turn to for advice other than the regulation board, and are rarely visited by knowledgeable support people to help them with small day to day issues. Adequate and ongoing training of the operator is critical, because it will give them the background to perform their job. It is important to consider the operation of the facility during design and selection of the system. Reliability of equipment and facilities is important in remote areas because it is expensive to replace or repair items if help or equipment must be flown in. Catastrophic failure of an entire system has been caused by the failure of an inexpensive control. The system should be designed with common parts that are easy to access and should be able to be repaired using local skill and equipment. Minimizing the types of equipment and variety of materials is easier for training and makes for less parts storage. In choosing components such as pumps, it is often better to use two or three smaller pumps than one large pump. With only one pump, failure of it shuts down the entire system, whereas if there is more than one pump, the system can continue to function if at a reduced capacity. The degree of automatic control should also be considered. Automation can be efficient and effective if the operator is not fully competent or available at all times. However, this system can be highly vulnerable when a failure occurs, because it has not been necessary for the operator to learn the system. Choosing systems and equipment that are easy to understand and service are more likely to be operated correctly and repaired with minimal disruption or damage.
Reference:
Community Issues in Design and Operation of Northern Water Supply Systems. Tracy Rhyason. 1996.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 10.0
COMMUNITY PARTICIPATION IN WATER AND SEWER INFRASTRUCTURE FOR COLD REGION COMMUNITIES
It is critical during design of a water and sewer infrastructure project to listen to the concerns of the community. Getting input into a project by a community is not always an easy task. In settlements, lack of control by aboriginal people over their lives and their community can produce a lack of interest and participation in planning. From the many citings of incidents where no one listened to the community's concerns, it can also be inferred that residents have concluded that it is not worth the effort since their advice will not be taken. They simply choose not to use the facility once constructed if they did not support the decision originally. Residents are usually initially interested in improving services, but are often confused and frustrated by the long planning process and detailed technical and economic evaluations that are conducted to rationalize the simple improvement they desire. Engineers often do not get the input they desire because they are not patient enough. Engineers often set up community meetings with a tight time schedule. Residents spend a great deal of time telling stories before getting down to business and the engineer leaves frustrated because little was accomplished. Listening to the community takes more time than what has been traditionally allotted. "Telling stories" is an important method for native people, particularly elders, to make comments and answer questions. The engineer must listen closely to these seemingly irrelevant stories, for often they will contain key opinions concerning the subject at hand. The planning process should inspire, guide and help residents become aware of problems and conditions in their community and how to plan and act to improve adverse conditions for the better. The technology and the planning process may be new to residents, so planning also has an educational role. The issues, data, analysis and technologies must be presented in ways and language which the residents understand. It is a challenge to integrate the knowledge of the engineers with the traditional knowledge and values of aboriginal residents. With the current shift to self-government, many communities are now taking on this planning and initiation of projects themselves. In the past, most decisions were made primarily by a senior government, so truly active participation in planning is a new process in many communities. Both the community and the engineer must recognize this, and face it as a learning experience, listening to one another and remaining flexible in the methods of execution.
Reference:
Community Issues in Design and Operation of Northern Water Supply Systems. Tracy Rhyason. 1996.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 11.0
EXAMPLES OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
Small Sized Territorial Communities Carcross, YT Population
400
Tuktoyaktuk, NWT
Grise Fiord, NU
1000
200
Sewage Disposal
Evaporation/ exfiltration from a lagoon
Discharged once a year into the ocean
Discharged once a year into the ocean
Sewage Treatment
Engineered retention lagoon
Natural retention lake with engineered outlet
Engineered retention lagoon
Sewage Collection
Sewage holding tank emptied by vacuum truck
Sewage holding tank emptied by vacuum truck
Sewage holding tank emptied by vacuum truck
Water Delivery
Trucked water
Trucked water
Trucked water
Water Storage
Small tank in water truck garage continuously refilled
Large circular earth reservoir filled once a year
Two large steel tanks filled once a year
Water Treatment
Rapid sand filtration and microfiltration before chlorination
Chlorination and batch flouridation
Chlorination
Water Supply
Submerged inlet in Bennett Lake
Overland pipe with seasonal refill from Kudulak Lake
Overland pipe with season refill from glacial runoff
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 11.0 CONTINUED
Medium Sized Territorial Communities Haines Junction, YT Population
800
Fort Smith, NT
Rankin Inlet, NU
2500
2000
Sewage Disposal
Continuous lake discharge
Continuous river discharge
Continuous submerged ocean discharge
Sewage Treatment
Lagoon and wetland
Lagoon primary and secondary treatment
Mechanical primary treatment
Sewage Collection
Buried gravity system Buried gravity system
Water Delivery
Buried pressure system
Buried pressure system
Water Storage
Insulated, elevated tank
Insulated, elevated tank and concrete buried tank
Water Treatment
Chlorination
Mixed media filtration, chlorination and fluoridation
Chlorination and fluoridation
Water Supply
Surface water and well water
Surface water
Surface water
Reference:
75% shallow buried gravity system, and 25% sewage holding tank emptied by vacuum truck 75% shallow buried pressure system, and 25% trucked water Insulated, buried tank
Northern Communities, RWED/MACA, GNWT Compact Disk. 1998.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
NOTES 12.0
THE FUTURE OF WATER AND SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES
The climate, surficial bedrock, permafrost and soil conditions pose special problems for land development in the north. The use of conventional water and sewer servicing technology with freeze protection adds significantly to the cost of land development. Recent innovations in on-site wastewater treatment have extended the application of this technology into an urban setting, and into the specialized application of on-site wastewater recycling. Wastewater recycling may reuse approximately 55 percent of the wastewater stream for non-potable water uses such as toilets and laundry. The application of an on-site wastewater recycling system to a new development offers the opportunity to incorporate the plumbing requirements, space requirements, structural requirements, electrical requirements, and operation and maintenance requirements as an integral part of the building design for a single unit. The most critical part of the single unit is the plumbing, which must ensure a separation of the potable and non-potable water supply systems, and provide no opportunity for cross-connection between the systems. The most significant part of the incorporation of the system is the space requirement, which would be expected to be in the range of 10 square metres (4 metres by 2.5 metres) for a single unit within a household. Large scale and universal application of on-site wastewater recycling technology may not influence the typical subdivision design. However, without the need to consider the installation of a sewage collection system and a water distribution system, there is a greater potential for innovation in site planning and development phasing. New regulations will be required to implement on-site wastewater recycling. The practical responsibilities for on-site wastewater recycling should remain with the homeowner in regard to compliance with regulations, and with the Territorial Government for establishing and maintaining the regulations to compliment the Public Health legislation. Based upon preliminary cost estimates, an on-site wastewater recycling system may offer a significant cost saving in an application to a typical residential development in Yellowknife. A life cycle cost estimate (20 years - 4% net interest) suggests that the cost savings in comparison to a piped system may be approaching 40% ($47,000 versus $80,000 for a single unit); however, these numbers must be tempered with the fact that they reflect the potential production scale cost of the technology, and not the current experimental scale of the technology. Although the system may prove to be cost effective and technically appropriate, the implementation will require a marketing effort to gain public acceptance.
Reference: City of Yellowknife, On-Site Wastewater Recycling Study. 2000.
WATER & SEWER INFRASTRUCTURE IN COLD REGION COMMUNITIES