The Environmentally Responsible Construction and Renovation Handbook
Chapter 6 - Water Conservation
6.1 Introduction
Canada is in the envious situation of having one-fifth of the world's fresh water supply. Canadian water usage per capita is the second highest in the world at approximately 326 litres per day. To put this in perspective, this is double the per capita usage of France and Germany. This level of water consumption places an ever-increasing strain on our fresh water resources and requires energy and monetary expenditures to provide clean water for our everyday use. A 10% improvement in water efficiency would reduce our consumption to about 350 litres per person per day. With a population of 30 million and an average water rate of $1.03 per cubic metre, this improvement would save Canadians over $1.25 million per day or $460 million per year. Already, many large metropolitan centres are experiencing problems because their water treatment facilities cannot keep up with the demands placed on them.
The quality, quantity and economic considerations associated with the use of our water supply are complicated but we are able to minimize impacts by the way that we manage water or practise water conservation which simply means doing the same with less. Using water more efficiently reduces pollution and health risks, lowers water costs and extends the useful life of existing supply and waste treatment facilities. The terms water efficiency and water conservation are often used interchangeably, but in fact, they mean different things. Water conservation proposes using less water and reducing waste. It can also imply a lifestyle change or technological intervention. Water efficiency is implemented through the application of appliances, practices and processes that provide the same level of service while using less water. Water efficiency reduces our demand for water. This has multiple environmental and economic benefits. Because less water is being used, the energy required for water treatment and the pollution caused by water treatment processes are also reduced. The cost of providing primary services for the community is lower and our individual water bills can decrease.
The following section provides an overview of the environmental impacts associated with water use and explores initiatives that can be taken to reduce water consumption.
6.2 The Hydrologic Cycle
Through the process of evaporation water travels into the air, becomes part of a cloud and then returns to the earth as precipitation. This process repeats itself over and over again, in a process referred to as the hydrologic cycle.
Text description of The Hydrologic Cycle is available on a separate page.
Precipitation creates run-off that travels over the ground surface and helps fill lakes and rivers. It also percolates or moves downward through openings in the soil to replenish aquifers under the ground. Water dissolves minerals, chemicals and other substances from the ground. Some places receive more precipitation than others due to their proximity to large bodies of water, which allows more water to evaporate and form clouds. As clouds move up and over higher landmasses such as mountains, the water vapour condenses to form precipitation.
6.3 Water Quality
Water quality is a problem in many Canadian cities. The decline in water quality is associated with the way that we use water. All wastewater is contaminated to some degree. Once contaminated water enters the sewer system, it is treated in a sewage treatment plant. However, this process is never 100% effective, which translates into water quality deterioration.
Text description of Water Quality is available on a separate page.
Poor water quality can also be caused by agricultural run-off containing residual pesticides and fertilizers, industrial pollution, chemical leaching from landfills and improperly treated sewage from both municipal facilities and private septic systems. The improper handling of wastewater can have a strong impact on water quality. In Canada, only 57% of the population is serviced by waste treatment facilities compared with 74% of Americans, 86.5% of Germans and 99% of Swedes.
Groundwater can be contaminated by agricultural activities, underground storage tanks, leachate from landfill and other forms of human intervention. Contaminated groundwater eventually finds its way into our water supply, either from wells or municipal water sources.
In Canada, the government has implemented various guidelines and objectives to protect water quality. Water quality guidelines are scientifically determined and establish allowable chemical or substance concentrations for a particular purpose such as drinking, swimming or livestock husbandry. These national guidelines provide targets for environmental protection.
Water quality objectives specify the concentrations of chemicals or substances allowable for all intended water uses at a specific location on a body of water. The objectives are based on the water quality guidelines for intended uses at the location, public input and socio-economic considerations. Water quality guidelines and objectives not only protect water users and the environment, they also encourage sustainable water management procedures.
6.4 Water Conservation is a Sound Business Practice
Water conservation not only benefits the environment but also is a sound business practice. In many cases, application of even simple, common sense conservation techniques can yield payback periods of one year or less.
Use of the payback method for assessing the feasibility of upgrading water efficiency does not always tell the whole story. It often underestimates the benefits of water efficiency over the lifetime of a measure, particularly when taking into account potential energy cost reductions and reduced maintenance costs from not having to heat as much water for certain applications. Lower wear and tear due to water efficiency may also extend the life of equipment such as boilers, heat exchangers and pumps.
The economic benefit of efficient water use is apparent when a lifecycle costing (LCC) exercise is carried out. LCC allows a potential renovator to estimate the net benefits of an efficiency investment, over the lifetime of the measure or product. It includes the costs of initial equipment purchase, operating and maintenance costs, fuel costs, the costs of inflation and disposal, and the cost of money over time.
The integration of water efficiency into renovation projects takes into account the 'true costs' of water. The true cost of water refers to all the costs that go into producing the clean water we use. It includes the capital and operational costs of potable water treatment plants, sewage treatment plants and the entire infrastructure required for delivery and disposal of water and its waste products. It excludes government funding and subsidies.
Up front costs are often seen as a barrier to implementing water efficiency improvements. What some managers fail to realize is that often the additional cost of upgrading to a water efficient fixture is not significant (often less than 30%) when savings in operating costs are considered. Applying water efficiency measures can quickly offset costs that seem to be prohibitive.
6.5 Regulations
All construction and renovation projects should be in compliance with applicable regulations at the municipal, provincial and federal levels. The following regulations can affect water reduction decisions during a project:
- national building codes
- Provincial building codes
- plumbing codes
- the Canadian Environmental Protection Act [CEPA].
6.6 The Interdepartmental Advisory Group on Water Conservation at Federal Facilities
The Interdepartmental Advisory Group on Water Conservation at Federal Facilities (WCFF) was formed in 1990 to help implement the water conservation aspects of the Green Plan and the Code of Environmental Stewardship. The WCFF has approximately 30 members that represent sixteen departments and agencies and is chaired by Environment Canada.
In 1994, the Canadian Council of Ministers of the Environment endorsed a National Action Plan to Encourage Municipal Water Use Efficiency. This action plan calls for federal and provincial levels of government to demonstrate leadership by reducing water use in their facilities and to adopt polices, regulations and codes concerning water efficiency.
The Guide to Greening Government Operations was signed by all federal Ministers, committing federal government departments to lower the environmental impacts of their operations, policies and programs. The Commissioner of the Environment and Sustainable Development will audit the departmental performance. The guide provides the framework for the greening of operations and one of the specific areas referenced is water usage. The document also promotes environmental management systems (EMS) as a procedure for ensuring those environmental objectives are properly considered and implemented.
The WCFF helps federal government departments meet objectives and obligations relating to these initiatives. The Advisory Group has been responsible for the development of the Water Conservation Plan for Federal Government Facilities and the accompanying Manual for Conducting Water Audits and Developing Water Efficiency Programs for Federal Facilities. The WCFF serves as a forum for sharing experiences and developing joint tools. The WCFF uses a mail list server as a quick, electronic way of asking each other questions and sharing information and ideas.
6.7 The Federal Buildings Initiative
The Federal Building Initiative (FBI) is a comprehensive program created by Natural Resources Canada to provide federal facility managers with an opportunity to realize the benefits of improved energy efficiency. The program also assists in the incorporation of water saving initiatives when considered in conjunction with energy refits.
6.8 Reducing Water Use
Changes in staffing arrangements often require renovations to existing buildings, or sometimes even the construction of a new facility. Most renovations and new construction projects can provide opportunities to reduce water consumption. For example:
- if the planned renovations include washroom facilities, this is an opportunity to upgrade plumbing fixtures to water efficient faucets, urinals, showerheads and toilets Refer to NMS. The plumbing fixtures and trim section of the NMS has been "greened" and now recommends using the ultra low water conserving options.;
- if occupant densities increase in a particular facility, changes to system capacities are probably required. This could be an opportunity for water efficiency improvements such as connecting water-cooled refrigeration of air conditioning equipment to a closed loop system;
- in some facilities, designers can incorporate the use of ground water or surface water for heating or cooling requirements.
- Install a separate "grey water" system to allow reuse
As with energy efficiency, the extent of the opportunities to incorporate water consumption initiatives depends on the scope of the project. Generally speaking, the greater the scope and the more complex the proposed project, the more opportunities there are for water reduction improvements.
The 'systems approach' to building design recognizes that the building and its occupants are a system with interconnected components. When changes are made to one component it will affect other aspects of the system, or have a synergistic effect. This concept applies to water use as well as energy consumption. Applying an integrated approach ensures that synergistic effects are anticipated and planned for accordingly. In addition, overall incremental costs can be reduced because of the potential for equipment downsizing. The principle behind an integrated approach (also known as whole building design) is to integrate the project's steps into a single comprehensive design. This approach recognizes that the project's stages are interactive as opposed to stand alone activities. It requires a team effort from all the experts involved in the project. The project team should remember to look at the long-term effects during project planning and when addressing issues that will affect water consumption.
Reduced Water Consumption
The specification and use of appliances that are rated as low water consumption reduces environmental impacts by reducing the necessity for water treatment. Water pollution combined with a rapid rate of water consumption can result in damage to hydrological systems. The treatment of wastewater requires the use of chemicals that impact ecosystems. Reducing the consumption rate of water diminishes the necessity for wastewater treatment. Appliances, fixtures and systems that have been specifically designed to fulfil their intended functions while providing reduced water flow rates compared to standard appliances, can claim to provide a lowered environmental impact.
Eco-labeling programs (EcoLogo website
) have established criteria that relate to the performance of specific products. The Canadian Standards Association (CSA) has developed specific tests that determine the flow rate of water consuming products. The CSA has also established flow rates for some products that define product specific low water consumption. This criterion is based upon the same principles as energy efficiency. It uses improved performance percentages against an established baseline for evaluation.
6.9 Water Management
It is estimated that the federal government's water costs for 1990 were $12 million for the National Capital area, and $100 million across Canada. Improved water management can have a significant financial impact on federal operations. Ongoing consultation with all members of the project team is an essential part of a renovation or construction plan. The sharing of experiences and ideas will ultimately result in a more co-ordinated and streamlined process. A water efficiency expert is a key resource.
Two elements are essential to the effective management of a project's water reducing components.
1. Assemble an In-House Team
Implementing water reduction measures is a complex process, entailing many activities. For a project to succeed, all levels of the organisation need to be involved. Senior management must support the program financially, and a commitment from other management levels will ensure the program works. A competent water management team (which can be part of the Green Office Building Plan team) is essential to the success of the project. The team should be assembled very early in the project process and should meet frequently to review progress. The team should include both technical and non-technical expertise and should reflect design management and operational perspectives.
2. Accessing the Experts
The range of technical expertise required is diverse and different capabilities may be required at various stages. Depending on the size and complexity of the project, the team may need to draw upon outside resources for assistance in the following areas:
- staff training;
- water auditing;
- costing and economic analysis;
- design;
- engineering;
- construction;
- commissioning, and
- maintenance and monitoring.
6.10 Integrating Water Management
The following information provides a framework for the activities that may be required for the implementation of water reduction measures. The sequence and scope of the phases may vary between projects. The documents developed by the WCFF, Water Conservation Plans for Federal Government Facilities and the accompanying Manual for Conducting Water Audits and Developing Water Efficiency Programs for Federal Facilities, will provide a more comprehensive guideline for this process.
Define the Scope of the Project
Understanding the project objectives, budget and timing will help determine whether the proposed improvements offer opportunities for water reduction improvements. As stated earlier, the larger the scope and more complex the project, the greater the likelihood that water reduction can be included as a project objective. Consulting with members of the project team will provide initial guidance.
Initial Evaluation
This stage requires a preliminary assessment of the financial benefits of including water reduction as an element of the overall project. To do so, the project team needs to know how much water can realistically be saved and at what cost. Taking an inventory of the present or anticipated water use and costs and calculating potential savings that will result from the improvements of an upgrade will provide a fair measure of the financial feasibility. Water use can be determined by conducting a water audit.
The Water Audit
A water audit is a systematic approach for gathering information about the water use of a facility. This includes both domestic uses by washroom fixtures, showers, kitchen areas and workshops and mechanical uses such as boilers, cooling towers and irrigation systems. It addresses all equipment types, usage and activity levels and provides answers to the following critical questions:
Who - the audit will determine which tenants or human activities of the facility consume the greatest amount of water;
When - the audit will determine a pattern for water use that will identify times or activities of highest consumption levels;
Where - the audit will gather data on the water consumption of specific activities or equipment;
What - the audit will identify areas that should be targeted to reduce water consumption.
A full technical description of a water audit can be found in the Manual for Conducting Water Audits developed by the WCFF. The following provides a brief synopsis of the elements of a water audit, and to the RPSB 5 Phase Water Audit and Workbook.
Source: PWGSC (1994)
Review Water Consumption Records
Looking at the building's history of water use over the course of twelve months gathered from meter reading data taken from utility bills and graphing and tabulating monthly water bills for at least two years will establish water use peaks. It is very simple to do as long as utility bills are accessible and water is metered.
Fluctuations in consumption and possible reasons should be noted during this process. Unexplained fluctuations should be noted and reviewed with the maintenance personnel to identify any unusual circumstances, such as mechanical failures or extensive maintenance work on boiler systems.
If metered readings are available for individual areas, these readings should be reviewed for the last twelve months and variances in consumption noted. The process should consist of a walk-through during which all areas of the facility that use water are noted and inventoried, including plumbing fixtures in washrooms, kitchens, workshops and other domestic uses. Mechanical systems, such as boilers, cooling towers and irrigation systems should also be inventoried. Such detail may also be acquired through the use of temporary water meters over a specified typical use cycle and extrapolated over a yearly basis.
Once the water use locations have been inventoried, the audit will then consist of the development of a building water balance. This calculation will identify the water consumption for each component of the building. The total of the water balance should equal the total water consumption of the building. A significant variance could indicate an area that has been overlooked or under-estimated during the audit. For new facilities, this information may be estimated through the use of engineering studies.
Define the Project's Water Reduction Plan
This stage defines the scope, costs and estimated benefits of the project's water reduction plans. This task should build on the results of the water audit and the record analysis. If it is decided that the proposed improvements will be part of a long-term project it is imperative that initial improvements ensure the possibility of later improvements.
Several factors will guide the development of the Water Reduction Plan.
- Interest in working with the FBI Program: If the project includes energy reducing measures, the option may exist to utilize the services of the Federal Building Initiative. If this option is available, any concerns that the project team might have about financial and management constraints can potentially be addressed through the FBI Program and the provision of water management services from ESCOs.
- Investment threshold: The department may have a specific financial threshold for this type of investment.
- Other needs and priorities: The water reduction investments need to be examined in light of other considerations such as project timelines.
- Realistic water reduction goals: The goals can be determined using information from the water audit and the record review.
Implement the Water Reduction Plan
During this stage, the water reduction plan is implemented. Execution takes place once the design is finalized and the budget is set and approved. Occupants of buildings should be inconvenienced as little as possible during this stage. Implementation includes a number of activities that will be co-ordinated with the overall renovation project. For example:
- prepare project specifications consistent with meeting the water reduction goals. Water efficient devices should be clearly specified and meet the project criteria. Reliability and ease of operation will ensure that devices will not be by-passed or removed after the project is complete;
- establish a realistic implementation schedule;
- recruit and brief the Water Management Team. These people are the key players in a water efficiency project and will be critical to its success. Team members should include facility personnel who represent technical operations, contracts and financial management;
- prepare the budget along with payback calculations. Make sure that you have considered all associated cost savings;
- assign specific responsibilities to the members of the Water Management Team. Provide them with reference material and expert advice, as required. The team should also monitor the ongoing renovation;
- initiate a tendering process. This should include a site visit and meeting with potential plumbing subcontractors to share project objectives and to communicate the mandatory requirements, and
- review the tenders and award contracts as required.
Commissioning and Training
Commissioning of the water reducing components of the project has two important objectives, both directed at achieving the targeted water savings. They are:
- to ensure that the specified equipment is installed and working properly, and
- to ensure that the targeted water reduction levels will be sustained throughout the lifetime of the specified measure.
Commissioning usually has both a technical and training component. The technical component involves testing the installed equipment and making adjustments as necessary. The training component focuses on producing operation manuals and on instructing staff and occupants on how the new equipment should be properly operated and maintained. Information sheets can make training easier. They provide brief, user-friendly and site-specific information about the equipment that has been installed and how to use it. They are particularly useful in cases where the manufacturers' manuals are complex.
After commissioning, all systems should be working properly and building staff and occupants should know how to use the new equipment. The commissioning should ensure that occupants get the service they expect with the new equipment.
Promote Water Awareness
Water dripping at the rate of one drop per second wastes 10,000 litres of water a year. The long-term success of any water efficiency program will depend on the way in which building occupants use water. They need to be educated on how to use water wisely. This will also encourage occupants to accept the water efficiency measures introduced during the project.
Use communications professionals to develop promotional materials, such as monthly water saving tips sheets. Showing occupants how to use water efficiently both at work and at home will demonstrate the cost implications of wasting water. Encourage occupants to identify water wasteage and to report it to building maintenance. Maintenance personnel should be instructed to respond to the report promptly and efficiently.
The Internet based Water Efficiency Experience Database is designed to encourage the exchange of information on both the successes and difficulties encountered in the rapidly growing field of water use efficiency. Currently there are over 125 experiences described on the site, from all levels of government, educational institutions and the private sector. Each case study provides a brief description of the water efficiency project, a contact person for more information, and, where available, details on costs and savings. You can make use of and contribute to the database regardless of the sector you represent at the Canadian Water and Wastewater Association (CWWA) site.
Develop ongoing water efficiency strategies for the building. Some suggestions are listed below:
- establish a policy for purchasing only water efficient fixtures for repair or replacement purposes;
- ensure that shut-off and isolation valves are appropriately located to facilitate repairs and to minimize system drain downs;
- maximize operational efficiencies through annual audits and reviews of water consumption and operational procedures,
- collect and reuse water wherever possible. Possibilities include collecting rainwater or using other wastewater "grey water" for irrigation purposes.
- WCFF has a washroom decal that is placed on the washroom mirror and along with a short efficiency message, asks users to "report leaks or other water problems at this or other locations promptly to…". The blank is filled in with the appropriate phone number.
Maintain the System
As with energy efficiency, scheduled preventative maintenance of new water efficient equipment and systems brings a number of benefits. It ensures that water savings are maintained, or increased, long after the renovation is completed. It prolongs the life of the equipment. It reduces disruptions from unscheduled equipment breakdowns and it reduces equipment replacement costs. Maintenance usually involves a number of tasks and the schedule should be developed based on the manufacturer's recommendations.
Monitoring the System
A monitoring program tracks water use and provides the information that allows management to determine if the anticipated water savings are on target. As with energy efficiency, the way in which buildings are metered can make monitoring a simple or complex activity. At the most basic level, monitoring means reviewing utility bills, but this provides only very general information. At the most complex level, monitoring involves sub-metering of parts of a building or of specific equipment. It is expensive to establish this process, but the information it produces is very specific and useful. Building monitoring can provide more information than a review of the utility bills, but it does not give a detailed picture of how the water is being used.
Typical monitoring activities include:
- set-up of a regular monitoring program. If meter readings are required, set-up a meter-log and specify who is responsible for the readings. Consider automating the metering if practical. Install water meters if they are not already in place. Meters play an important role in water conservation by providing the data on which to justify actions, measure progress and pay for water.;
- metering of high water usage operations. Specified operations will vary from facility to facility. They would normally include kitchens, laundries, cooling towers and boiler rooms;
- review the monitoring data on a regular basis. Compare results against the efficiency performance goals set for the facility. Use the data collected to develop seasonal averages and historical trends. Use this information to track and update efficiency goals;
- investigate any variances in consumption and correct problems immediately, and
- reconcile a building water balance on an annual basis.