WATER AUDIT OF CONRAD

GREBEL COLLEGE

Author: Helen Godschalk

Course Instructor: Professor Jim Robinson

Course: ERS 285

Date: Spring 1994

TABLE OF CONTENTS

1.0 INTRODUCTION ............................................................................................... 1

2.0 CONRAD GREBEL COLLEGE ........................................................................... 1

2.1 Academic Functions ........................................................................................... 1

2.2 History of Water Consumption ........................................................................ 1

2.3 Past Water Conservation Initiatives ............................................................... 4

3.0 PURPOSE .............................................................................................................. 4

4.0 OBJECTIVES ......................................................................................................... 5

5.0 PROJECT BOUNDARIES .................................................................................. 5

6.0 DESCRIPTION OF THE WATER SUPPLY SYSTEM .................................... 5

6.1 Biophysical Component .................................................................................... 5

6.2 Administrative Component ............................................................................. 10

7.0 METHODOLOGY ................................................................................................ 11

7.1 Definition of the Water System ........................................................................ 11

7.2 Description of Water Use Processes ................................................................. 11

7.3 Calculation of the Water Balance ..................................................................... 13

7.4 Evaluative Criteria ............................................................................................. 13

8.0 RESULTS .............................................................................................................. 14

8.1 Description of Water-Using Equipment ......................................................... 14

8.1.1 Dishwasher ........................................................................................................... 14

8.1.2 Urinals ................................................................................................................... 14

8.1.3 Toilets .................................................................................................................... 16

8.1.4 Humidifiers .......................................................................................................... 16

8.1.5 Washing Machines ............................................................................................. 17

8.1.6 Walk-in Freezer and Walk-in Refrigerator ................................................... 17

8.1.7 General Water Use in the Kitchen ................................................................... 17

8.1.8 Outdoor Water Use ............................................................................................ 18

8.2 Water Balance ...................................................................................................... 18

9.0 EVALUATION OF CONSERVATION MEASURES ................................... 22

9.1 Replacement of the Compressor in the Freezer and Refrigerator ............ 22

9.2 Replacement of the Toilets in the Quad Wing ............................................. 24

9.3 Replacement of the Taps with Motion-sensored Faucets ........................... 25

10.0 RECOMMENDATIONS .................................................................................... 26

11.0 REFERENCES ...................................................................................................... 28

APPENDIX A: THE TALE OF KING WATERMORE AND KING WATERLESS

LIST OF FIGURES

Figure 1: Annual water consumption at Conrad Grebel College (1983-1993) .... 2

Figure 2: Annual cost of water at Conrad Grebel College (1983-1993) ................. 3

Figure 3: Water supply system at Conrad Grebel College ...................................... 7

Figure 4: Hierarchical scales of water consumption ................................................ 9

Figure 5: Percentage distribution of water consumption by actors groups for an

average week in the Fall 1993 term ............................................................ 23

LIST OF TABLES

Table 1: Size of the actor groups at Conrad Grebel College .................................. 8

Table 2: Ways in which the Conrad Grebel College actor groups utilize

water ................................................................................................................ 9

Table 3: List of water-using equipment at Conrad Grebel College ..................... 15

Table 4: Estimated flow rates of commonly used water equipment at

Conrad Grebel College ................................................................................. 19

Table 5: Frequency and length of use of commonly used water equipment ... 20

Table 6: Water use during an average week in the Fall 1993 term .................. 21

1.0 INTRODUCTION

Water is used for a multitude of purposes. From an anthropocentric point of view, its most important use is as drinking water, since it is essential for human survival. Water is also necessary for sanitary purposes - for washing clothes and dishes, taking showers and baths, and flushing toilets. However, the utilization of water for maintaining lawns and gardens, cleaning cars and filling swimming pools is less vital to the survival of humans.

In urban areas, water resources are usually supplied by the municipal government. As an urban area grows, an increased water supply is often required. An alternative method of meeting the need for water is demand management, which focuses on reducing water consumption. A water audit is a technique or method which helps to identify ways of conserving water by determining any inefficiencies.

In this WATGREEN project, a water audit will be conducted of both the academic and residence buildings of Conrad Grebel College (CGC). The water audit will be based primarily on the methodology developed by Collins et al. (1992) in a previous WATGREEN project. Possible methods of reducing water consumption will be identified and their feasibility for implementation will be evaluated.

2.0 CONRAD GREBEL COLLEGE

2.1 Academic Functions

Conrad Grebel College (CGC) is one of four church colleges affiliated with the University of Waterloo (UW). Day and night courses are offered in a number of different subject areas, including history, music, peace and conflict studies, philosophy, sociology, religious studies, and graduate theological studies (Conrad Grebel College, [1993]). A maximum of 113 students can be accommodated in its residence facilities (Smith, pers. comm.). A small library and several research programs, including the Institute of Peace and Conflict Studies and the Institute of Anabaptist-Mennonite Studies, are located at CGC.

2.2 History of Water Consumption

The annual water consumption of CGC (1983-1993) is shown in Figure 1 and the annual water cost (1983-1993) in unadjusted dollars is shown in Figure 2. Between

Figure 1

Figure 2

1983 and 1993, the maximum annual water consumption was 14,094 m3 (1985) and the maximum annual water cost (in unadjusted dollars) was $14,417.50 (1991). Since 1985, the annual water consumption has decreased, except for slight increases in 1990 and 1991. The annual water consumption in 1993 (9745 m3) was less than that for 1983 (11,098 m3). The annual water costs, however, increased between 1983 and 1991, despite the observed reduction in water consumption (Conrad Grebel College, n.d.). If water prices continue to increase, water conservation initiatives may be an important method of reducing the operating costs of CGC.

2.3 Past Water Conservation Initiatives

The decrease in water consumption at CGC since 1985 can likely be attributed to the water conservation measures which were implemented in the late 1980s and early 1990s. As older models of shower heads deteriorated, they were replaced with water-efficient models. A valve to control the rate of flushing of the urinals was also installed. This valve detects changes in water pressure, resulting from other uses in the water system. When water pressure is variable, the urinals flush more frequently. At night, when there is less water consumption and therefore less variation in water pressure, the flushing occurs less often (Penner, pers. comm.).

A couple of years ago, a group of students at CGC produced a video which addressed a number of conservation issues, including water use. I watched this video once during my first year (1991-1992) and once during my second year (1992-1993) while a resident at CGC. As far as I know, this video has not been viewed by residents in recent years.

Presently, some of the washroom sinks are being removed. Instead of having four sinks in the washrooms, there will only be three. The amount of maintenance required (i.e. cleaning of sinks) and the volume of water wasted through leakage will be reduced (Penner, pers. comm.).

3.0 PURPOSE

The purpose of this project is to conduct a water audit at Conrad Grebel College (CGC), and thereby be able to identify ways in which CGC can reduce water consumption. I hope to be able to give Paul Penner, the business manager of CGC, a better understanding of water consumption at CGC. As well, I hope to be able to provide the administration with a few alternative ways of reducing water consumption that are feasible for implementation, based on the results of the water audit.

4.0 OBJECTIVES

The objectives of this project are as follows:

* To identify all water using operations and their users at Conrad Grebel College (CGC)

* To quantify the amount of flow and the frequency of use of each of the major water-using operations

* To calculate a water balance

* To identify strategies for conserving water

* To determine the feasibility of these initiatives from an administrative perspective

5.0 PROJECT BOUNDARIES

Strategies for conserving water can encompass technical changes in water appliances and behavioural changes of those using the water supply system. The installation of water efficient toilets is a permanent alteration. However, permanently changing the water consumption habits of the members of the Conrad Grebel College (CGC) community is more difficult to accomplish. Since new students move into the residence every term, education would need to be ongoing. In this project, I plan to focus on technological methods of reducing water consumption.

6.0 DESCRIPTION OF THE WATER SUPPLY SYSTEM

6.1 Biophysical Component

Water consumption at Conrad Grebel College (CGC) is a subsystem of the urban water cycle, which consists of both water supply and wastewater treatment. The Regional Municipality of Waterloo acquires its water supply from the Grand River and from groundwater. This water is distributed to CGC by the City of Waterloo. The resulting wastewater is treated at the Waterloo Wastewater Treatment Plant prior to discharge into the Grand River (ERS 375I, 1994).

The water supply system at CGC is separate from that of the main campus of UW. As shown in Figure 3, after the water enters the college's water supply system, a portion of the water is heated through natural gas. Hot water is used in faucets, showers, and washing machines. Cold water is used in faucets, showers, washing machines, toilets, urinals, and in kitchen appliances.

A water softening system, which reduces the hardness of the water, treats the water that is utilized by the dishwasher and the steamer. A significant portion of the water supply of the Regional Municipality of Waterloo is groundwater, which contains mineral ions, such as magnesium and calcium, that cause hardness. Hard water causes water stains on glasses and build up of minerals in equipment such as steamers. A water softening system removes many of these ions, and replaces them with sodium ions.

The wastewater from the water-using operations leaves the CGC system through sanitary sewers.

As mentioned in section 2.1, CGC serves a number of diverse functions. The consumers of water at CGC are the residents, the students taking courses at CGC, faculty, janitorial staff, administrative staff, kitchen staff, and visitors. The sizes of these different actor groups (see Table 1) and their water consumption patterns (see Table 2) are varied.

Water consumption at CGC is a part of a larger water consumption system as shown in Figure 4. The academic and residence buildings at CGC are representative of many buildings on the UW campus which serve as either places of residence or places of study.

The main sources of water supply at the Regional level are groundwater and the Grand River (Associated Engineering, n.d.). Therefore, by consuming less water, more groundwater will remain for future use. Leaving resources for future generations to utilize is an important component of sustainability.

Water conservation also results in less water being abstracted from the Grand River, thus reducing the impacts on downstream ecosystems. Natural fluctuations of water levels occur in river ecosystems. During the spring, the water levels are

Figure 3

Table 1

Table 2 and Figure 4

higher due to the melting of the snow. In the summer, water levels are usually low, thus encouraging the decomposition of organic material along the edges of water bodies. (Smith, 1992). In municipal water management, the peak demands for water occur in the summer, when the water levels in the river are already fairly low. Thus, by decreasing water consumption, the water levels of the Grand River will be allowed to maintain their seasonal fluctuations and an overall natural homeostasis.

Presently, the Regional Municipality of Waterloo is considering a number of water supply alternatives for the future, some of which involve piping water from one of the Great Lakes into the Region (Associated Engineering, n.d.). Thus, water consumption at a local level could ultimately have an impact on the larger Great Lakes - St. Lawrence ecosystem.

Water consumption is not an isolated system, but rather interacts with other systems at CGC and the Region. A reduction in hot water use decreases the amount of natural gas required to heat water. A reduction in water consumption also reduces the magnitude of the water and natural gas bills, thus decreasing the operating costs of CGC. At the municipal level, a decrease in water use will reduce the amount of wastewater that is treated, thus delaying the construction or expansion of wastewater treatment facilities.

6.2 Administrative Component

Paul Penner, the business manager of Conrad Grebel College, is responsible for overseeing the general maintenance of the academic and residence buildings. The feasibility of projects that require large expenditures is decided upon by a budget committee. Paul Penner stated that the largest constraint to implementing environmentally friendly technology is the amount of capital that must initially be spent on the purchase and installation of new equipment. An associated risk is, that in the long term, the measures may not save enough money to break even.

Aside from financial considerations, the water conservation initiatives must be compatible with the structure of the buildings as well as the structure of the water-using appliances and other equipment. Furthermore, the measures should not significantly interfere with the activities nor compromise the productivity of the faculty, staff, and students.

The recommendations made in this project will, therefore, be given from this administrative perspective. If the recommendations are feasible from an administrative perspective, then they are more likely to be implemented.

7.0 METHODOLOGY

Collins et al., in Understanding and Reducing Water Use: A Case Study of the University of Waterloo, developed a methodology for conducting water audits (Collins et al., 1992). The following methodology is based primarily on their work, with a few modifications by myself to reflect the specific context of Conrad Grebel College (CGC).

The main steps of a water audit are as follows:

* Definition of the water system

* Description of water use processes

* Calculation of water balance

Further descriptions of these steps are given in the following sections.

7.1 Definition of the Water System

Identify all water use processes

As far as I know, a list of water-using equipment at CGC does not exist. Therefore, a list was compiled by walking through CGC and noting the locations of the water use processes. Assistance was requested from the janitorial and kitchen staff to locate water-using equipment that was not readily identifiable.

Identify inputs/outputs of each process

In this step, the inputs and outputs of each water use process were identified. For example, a water softening system is utilized at CGC; however, this softened water is only used in a few water use processes. In a similar manner, not all appliances are connected to the hot water supply. The input and output data were determined by visual inspection and by contacting Paul Penner, the business manager of CGC.

7.2 Description of Water Use Processes

Determine how water is used in the process

In this step, the manner in which water is used in each water operation was determined. In most processes, the water is only used once before being discharged

into the sanitary sewers. This information was primarily determined by visual inspection.

Determine the actor groups which use the process

For each piece of equipment, the main actor groups which utilize it were identified. For example, some of the washrooms in the residence building are mainly utilized by the students in residence whereas other washrooms are used by staff and visitors.

Amount of water flow for each process

Water flow is the amount of water that flows through a piece of equipment (e.g. showers, faucets) per unit time or the amount of water that is used per cycle (e.g. dishwasher, toilets). This data is needed in order to calculate the total amount of water that is used in a particular process.

The following methods can be used to quantify water flows:

* The standard flows of equipment, such as dishwashers and humidifiers, may be found in the model brochure.

* Through testing, the flow of water can be estimated. The flow rate equals the amount of water discharged into a bucket of water divided by the time taken to fill the bucket.

* Operators of the equipment may be able to provide an estimate of the flow rate.

* If the model number of the appliance is known, the manufacturer or distributor of the equipment can be contacted for information regarding the flow rate.

In this study, the latter three methods were used to estimate the flow rate.

Frequency of use

Frequency of use is the other component required to calculate the volume of water used in a particular process. The following methods can be used to quantify frequency of use:

* Ask the users how often they use a particular piece of equipment

* Utilize estimates developed by other researchers. This method assumes that the water use habits of individuals at CGC are similar to those individuals observed by the researcher.

* Determine frequency of use through direct observation.

In this study, frequency of use was most often established by direct observation.

7.3 Calculation of the Water Balance

The purpose of calculating a water balance is to compare the metered water use of the CGC water system (from the water bill) with the estimated water consumption of the CGC actor groups (from the water audit). A large discrepancy between the metered water use and the estimated water consumption would indicate either a leakage in the water supply system, errors in the estimates, or an unaccounted use of water.

A water balance can be calculated either by user or by water appliance as shown in the equations below:

Water Use At CGC = Water used by: Faculty + Kitchen Staff + Janitorial Staff + Administrative Staff + Residents + Students Taking Courses + Visitors

Water Use At CGC = Water used in: Faucets + Showers + Toilets + Urinals + Washing Machines + Water Fountains + Dishwasher + Humidifiers + . . . + Outdoor Water Connections

In this project, a combination of these two methods was often utilized.

7.4 Evaluative Criteria

During the course of conducting the water audit, suggestions for water conservation measures were given by Sylvan Martin, janitor of the residence building, and Jeff Faessler, a plumber from W.M. Roberts Ltd., who services the plumbing at Conrad Grebel College.

The feasibility of each of these alternatives was examined. Paul Penner stated that the payback period of a water conservation initiative was of particular importance to him. The payback period of a conservation measure is "the length of time required for an investment to pay for itself in terms of . . . savings" (Allen, 1990). The data required to calculate the payback period are as follows:

* Estimate the amount of water reduction

* Calculate the amount of money saved through the water reduction

* Determine the capital costs of implementing and installing the water conservation measure as well as the ongoing operation and maintenance costs

The payback period is equal to the total cost of the conservation measure divided by the annual water savings.

Paul Penner stated that he would want a payback period of approximately two years. It is difficult for him to obtain extra funds from the CGC budget, especially when other programs require funds to maintain their activities.

8.0 RESULTS

8.1 Description of Water-Using Equipment

A list of water-using equipment was tabulated (see Table 3). As can be expected, the residence building, which contains the residence facilities and the cafeteria, has considerably more water-using equipment than the academic building. A description of some of the more commonly used equipment is given below.

8.1.1 Dishwasher

The dishwasher at CGC is a commercial model. A dishwasher cycle consists of a wash cycle and a rinse cycle. The bottom of the dishwasher contains a reservoir which stores the hot water utilized in previous rinse cycles. A heating element in this reservoir maintains the temperature of the water. An employee from Hobart Canada stated that approximately two gallons of clean water are used per rinse cycle.

Softened water is used in the dishwasher to prevent water stains from appearing on the glasses. As well, the dish detergent works better with softened water (Penner, pers. comm.).

8.1.2 Urinals

The urinals in the residence building contain special valves which automatically control the rate of flushing. When the water pressure in the system is low, indicative of water use, flushing occurs more frequently. Observed times between flushing cycles ranged from 2 minutes, when an individual was taking a shower, to 17 minutes. The urinals in the academic building are flushed by the user.

Table 3

8.1.3 Toilets

Most of the toilets at Conrad Grebel College are flush valve Tech II toilets. Flush valve toilets do not have tanks. Rather, when the handle is tripped, the valve opens for a certain length of time, allowing the flow of water into the toilet bowl. The length of the flush depends on the make of the valve and the model of the toilet bowl. At the University of Waterloo, the length of flow is checked every year as part of a preventative program. Eleven to thirteen seconds is the ideal length of flow for Tech II toilets. This length of flush corresponds to a flush volume of approximately 1.5 imperial gallons (Dietrich, pers. comm.).

At Conrad Grebel College, a modified flush valve is used that has a weight attached to it. In such a system, the length of flush depends on how long the user applies pressure to the tripping mechanism (Faessler, pers. comm.). The average flow times of the toilets at CGC ranged from 8 to 12 seconds. The flow volume, however, could not be established.

One bathroom, located in the Quad wing of the residence building, contains tank toilets. These toilets utilize approximately 18.2 litres per flush (Faessler, pers. comm.). It could not be established whether leakage occurs in these toilets; the washroom was inaccessible due to the presence of conference groups.

8.1.4 Humidifiers

Two humidifiers are utilized in the academic building. The purpose of these humidifiers is to put moisture into the air, especially during winter months when the air is dry. The humidifier for the archives of the Conrad Grebel Library is in operation from October to April. Last year, the humidifier that services the academic building was not utilized at all (Penner, pers. comm.).

In a humidifier, electrical probes are immersed in a canister of water. The water is turned into steam and forced into the air duct, where some of the moisture immediately condenses and is drained. When water is turned into steam, the mineral content of the hard water remains. In order to prevent conductivity and arcing, the canister is periodically flushed with clean water to remove the mineral build-up (Faessler, pers. comm.). The amount of water utilized by the humidifiers could not be determined because the equipment brochure could not be found.

8.1.5 Laundry Machines

CGC has an agreement with Coinamatic, a laundry and appliance specialist, whereby Coinamatic provides the coin-operated laundry machines (and dryers) and CGC provides the water and electrical resources. The money collected is divided between the two parties according to a pre-determined ratio. The frequency of use of the laundry machines was calculated from the 1993 invoice received by CGC from Coinamatic.

A salesperson at Harco Co. Ltd., Ontario's commercial Maytag distributor, stated that the laundry machines used at CGC (Model No. A23CS) use between 34 and 37 U.S. gallons per cycle, depending upon the load setting. The latest Maytag model (Model No. MAT 10 CS) utilizes 34 U.S. gallons per cycle. The water setting in this model can be lowered by adjusting the wire that controls the timing of water flow. The salesperson, however, did not recommend the adjustment since the clothes are not cleaned as well at this lower setting.

8.1.6 Walk-in Freezer and Walk-in Refrigerator

The temperature of the walk-in freezer and walk-in refrigerator is maintained by flow-through cooling. After flowing through the compressor, the cooling water is drained into the sewage system. The water pipe that drains this water is located in the boiler room of the residence building. The flow rate was estimated to be 3.9 litres per minute. The testing was conducted in the early afternoon on a week day. In a subsequent conversation with Paul Penner, he suggested that another flow rate be measured in the middle of the night or early in the morning to determine whether the flow rate varied with the amount of kitchen use. A second flow rate was estimated to be 2.9 litres per minute. It was measured around eight o'clock on a Sunday morning. The freezer and refrigerator had not been utilized since around midnight the evening before (Massey, pers. comm.).

8.1.7 General Water Use in the Kitchen

The kitchen staff were observed to rinse their hands approximately 3 times per hour per cook. Wash rags (to clean the surface of counters) were rinsed approximately 2.5 time per hour per cook.

Cooking pots and baking sheets are often soaked in a sink full of water. The sinks are filled approximately twice a day. The large cooking pot is used approximately once per week and is filled with water afterwards to clean it (Gingrich, pers. comm.). The amount of water used in the potato peeler, the steamer, and the ventilator system was not established.

8.1.8 Outdoor Water Use

The outdoor water use at CGC is relatively negligible. The lawns are not watered. The patio deck is kept clean by the rainfall, thus requiring virtually no washing by the janitorial staff (Martin, pers. comm.). In the spring term, residents occasionally fill up a small wading pool.

8.2 Water Balance

The estimated flow rates of common water-using activities is outlined in Table 4. The source of data is also indicated so that if in the future, the flow rate is determined by another method, the results of the two methods can be compared.

In Table 5, the estimates of frequency and length of use of the common water use processes are shown. When estimates could not be based on direct observation, a conservative estimate was given.

A weekly time period was chosen as opposed to daily time period because water use varies from week days to week ends. Staff and faculty generally do not work on the weekends and a portion of the student body leaves the residence on weekends to visit family or friends.

The observed average water use per week in the fall term (1993) was calculated to be approximately 230,000 litres. An estimate of weekly water use was calculated for the fall term using the data from the water audit (see Table 6).

The following estimates and assumptions were used in these calculations:

* Nineteen dishwasher sessions per week

* Twenty-five cooking shifts per week

* Seven hours of work per cooking shift

* Staff and faculty work 5 days per week

* Residents do not go elsewhere to reside

Table 3

Table 4

Table 5

* Visitors to Conrad Grebel College do not utilize any water

* The kitchen only serves food to the residents

* Fifty-eight female residents and fifty-seven male residents (seven of the male residents live in the Quad Wing)

Water consumption by the residents accounts for approximately 46% of total water use (see Figure 5). The next largest category was unaccounted water use (26%). Kitchen water use was also significant (20%).

Flow-through cooling accounted for 15% of weekly water use. Water use in toilets and urinals was approximately 30% of weekly water use.

The large percentage of unaccounted water use may be due to errors in the estimates of flow rate, frequency of use and length of use. Since the product of these values is the volume of water used in a particular process, a small error in each of the estimates may cause a large error in the product. For example, if the flow rate of the showers were 6.1 litres/minute, the frequency of use was 1.09 showers/day and the length of shower was 7.4 minutes, then the volume of water used in showers would increase by 25% even though the individual estimates had errors of less than 10%.

Other possible sources of error include water uses that are unaccounted for, unusual water uses, and leakage.

9.0 EVALUATION OF CONSERVATION MEASURES

The following three conservation measures were chosen for further evaluation:

* Replacement of the compressors in the walk-in freezer and walk-in cooler with compressors that do not utilize flow-through cooling

* Replacement of the toilets in the Quad Wing bathroom with 6 litre per flush toilets

* Replacement of the taps in the washrooms with motion-sensored faucets

9.1 Replacement of the Compressor in the Freezer and Refrigerator

As mentioned in Section 8.1.6, the flow rate of the flow-through cooling is 2.9 litres per minute during low kitchen use and 3.9 litres per minute during high kitchen.

Figure 5

The kitchen is generally in use for 12 hours per day (7 a.m. to 7 p.m.) and is open for at least 324 days per year.

Annual Water Flow = (3.9 l/min * 60 min/hr *12 hr/day * 324 days/yr) +

(2.9 l/min * 60 min/hr * 12 hr/day * 324 days/yr) +

(2.9 l/min * 60 min/hr *24 hr/day * 41 days)

= 1,757,520 litres

= 1,757.5 m3

Therefore, the amount of water utilized in a year for flow-through cooling is approximately 1,757.5 m3. This represents 18% of total water consumption in 1993. The City of Waterloo charges $1.40 per cubic metre (1994 rate) of water. This charge includes the cost of water supply and wastewater treatment. CGC, therefore, spends approximately $2460 per year on flow-through cooling.

In the future, CGC will need to replace the compressors because they contain an old style of freon (Penner, pers. comm.). The College should consider replacing the compressors now rather than a few years in the future. The water savings would likely warrant such a replacement.

9.2 Replacement of the Toilets in the Quad Wing

The toilets located in the Quad Wing are the most inefficient toilets at CGC; they utilize approximately 18.2 litres per flush. The washroom in the Quad wing services only 7 residents; other washrooms located in the residence portion of the building service from 18 to 24 residents. The cost of replacing the 3 toilets located in this bathroom with 6 litre flush toilets would be approximately $750, including installation costs (Faessler, pers. comm.).

In recent years, seven residents have lived in the Quad wing in both the fall and winter terms. However, summer occupancy of the wing is dependent upon the number of conference groups that utilize the Quad wing. The following assumptions were made in calculating the water savings associated with this conservation measure:

* The washroom is only used in the fall and winter terms (219 days).

* The residents do not reside elsewhere at any time during the term.

* Each resident flushes the toilets 6.6 times per day

Annual Water Savings = 7 residents * 6.6 flushes/day * 219 days/year *

(18.2 litres/flush - 6 litres/flush)

= 123,437 litres

= 123.4 m3

The annual water savings associated with this measure would be 123.4 m3. Therefore, a conservative estimate of annual cost savings is $172 (water rate = $1.40/m3). The payback period (assuming a zero inflation rate and constant water charges) would be approximately 4.3 years. If two of the three toilets were to be replaced and the third stall locked up, the payback period would be 2.9 years.

9.3 Replacement of Taps with Motion-sensored Faucets

Sylvan Martin, the janitor for the residence building, expressed concern that residents waste water while brushing their teeth. As well, the taps are getting old and leaking taps are a problem.

A previous WATGREEN project (Dubanow et al., 1991) identified the following advantages of motion-sensored faucets:

* Easy to operate

* Savings of up to 85% on water and energy consumption

* No water leakage

The main purpose for the installation of automatic control faucets is "to prevent water from running at fixtures not being used" (Ploeser et al., 1992). A disadvantage of this system is that it is expensive. A resident, who had previously used automatic faucets mentioned that using the faucets can be frustrating if they do not readily detect the presence of toothbrushes.

The installation of motion-sensored faucets would require new faucets and sinks. A connection to the electrical system would also have to be installed. Jeff Faessler, a plumber with W.M. Roberts Ltd., estimated that it would cost approximately $1400 (this figure includes labour costs) to modify an entire washroom with automatic faucets.

The degree to which these faucets would save water could not be established, since this project did not focus on the long term water use habits of the residents. A more detailed water use study of the residents, quantifying the amount of water that is wasted by letting the faucets run unnecessarily, would need to be conducted to determine the feasibility of this project. If most of the residents turn off the tap while brushing their teeth or shaving, then this system would likely be unnecessary.

The replacement of conventional faucets just for the purpose of conserving water is usually not cost-effective (Ploeser et al, 1992). However, if the CGC need to be replaced due to deterioration, then motion-sensored faucets should be given further consideration.

10.0 RECOMMENDATIONS

The recommendations of this project are as follows:

For the administration of Conrad Grebel College:

* The flow rate of the flow-through cooling (of the walk-in freezer and walk-in refrigerator) should be measured again in the fall of 1994 to determine if the flow rate is dependent upon the outdoor temperature. If these flow rates still prove to be significant, Conrad Grebel College should replace the compressors of the walk-in freezer and walk-in refrigerator with compressors that do not utilize flow-through cooling.

* A toilet use study of the Quad Wing residents should be conducted to determine the toilet flush rate over a longer period of time (2 - 3 weeks). This would provide a more accurate estimate of the payback period for the replacement of the toilets with the 6 litre per flush toilets.

* Motion-sensored faucets should not be implemented as a conservation measure unless the faucets need to replaced. Even then, a detailed water use survey would need to conducted to determine how much water, in fact, would be saved by such a system.

* The sink in the boiler room of the residence building is used for photo developing in the fall and winter terms. The disposal method of the chemicals should be established to determine whether hazardous materials are being poured down the drain.

For further water use studies at Conrad Grebel College:

* A survey of the residents at Conrad Grebel College should be conducted to ascertain, more specifically, their water use patterns (i.e. toilet use, shower use, water use for shaving and other hygienic purposes).

* A one day water audit should be conducted to establish more specifically how water is used at Conrad Grebel College.

For future water auditors:

* A water audit team should ideally include males and females so that male and female washrooms can be easily accessed.

For future ERS 285 students:

* Members of the ERS 285 class should remember to submit their final report to those individuals at UW who have assisted in the development of the project. In speaking to the maintenance manager at St. Paul's College, I found out that he has generally not received the final reports of projects (including WATGREEN ones) conducted at St. Paul's College.

11.0 REFERENCES

Allen, R.E., ed. 1990. The Concise Oxford Dictionary of Current English, eighth edition. Oxford: Clarendon Press.

Associated Engineering. [n.d.]. Regional Municipality of Waterloo Long Term Water Strategy: Phase 1 Report.

Behling, P.J., and Bartilucci, N.J. 1992. Potential Impact of Water-Efficient Plumbing Fixtures on Office Water Consumption. American Water Works Association Journal. 84 (10): 74-78.

Carbonneau, L. Employee at Coinamatic. Personal communication. June 28, 1994.

Collins, A., and Cratt, L. 1992. Understanding and Reducing Water Use: A Case Study of the University of Waterloo. [Waterloo]: Environment and Resource Studies ERS 390A.

Conrad Grebel College. [1993]. Conrad Grebel College: Undergraduate Calendar 1993-95.

Conrad Grebel College. n.d. Summary sheet of hydro and water bills.

Dietrich, K. Manager of Water Utilities, University of Waterloo, Waterloo, Ontario. Personal communication. July 11, 1994.

ERS 375I. [1994]. Draft Document on Integrated Resource Management. [Waterloo]: Department of Environment and Resource Studies, University of Waterloo.

Dubanow, T., Haghighi, T., Nauffts, S., Rupert, S., Van Ooteghem, T., and Wittig, J. 1991. Greening Campus Buildings: Guideline Document. [Waterloo]: Environment and Resource Studies 290/291.

Faessler, J. Plumber, W.M. Roberts Ltd. Personal communication. July 11, 1994.

Gingrich, S. Cook, Conrad Grebel College, Waterloo, Ontario. Personal communication. July 15, 1994.

Harco Co. Ltd, Ontario's Commercial and Maytag Distributor, Mississauga, Ontario. Personal communication with salesperson. July 20, 1994.

Hobart Canada, Hamilton, Ontario. Personal communication with salesperson. July 20, 1994.

Martin, S. Janitor of Residence Building, Conrad Grebel College, Waterloo, Ontario. Personal communication. July 11, 1994.

Massey, M. Student Cook, Conrad Grebel College, Waterloo, Ontario. Personal communication. July 24, 1994.

Penner, E.P. Business Manager, Conrad Grebel College, Waterloo, Ontario. Personal communication. July 4, 1994.

Ploeser, J.H., Pike, C.W., and Kobrick, J.D. 1992. Nonresidential Water Conservation: A Good Investment. American Water Works Association Journal. 84 (10): 65-73.

Smith, B. Dean of Students, Conrad Grebel College, Waterloo, Ontario. Personal communication. June 6, 1994.

Smith, R. L. 1992. Elements of Ecology (Third Edition). New York: Harper Collins Publishers.

Snider, A. Administrative Assistant, Conrad Grebel College, Waterloo, Ontario. Personal communication. July 11, 1994.

Swartzentruber, M.L. Receptionist and Administrative Assistant, Conrad Grebel College, Waterloo, Ontario. Personal communication. July 4, 1994.