Appendix B
Case Studies
Note: The facilities marked with an asterisk were part of
a water audit study completed by Proctor and Redfern Limited between
December 1991 and April 1992, on behalf of the Interdepartmental
Advisory Group on Water Conservation at Federal Facilities. Due to time
limitations, the study examined only portions of the water supply system
for a two-week period, so projected savings and costs are preliminary in
nature. Nevertheless, the study concluded that excellent opportunities
exist to achieve significant water reduction at the ten audited sites.
All cost estimates reflect expenditures necessary to
procure and install only the recommended devices, and exclude any
incidental engineering and construction costs that may in fact be
necessary to achieve the stated water reduction at those facilities.
All payback periods are based on these preliminary cost
estimates and on current water charges.
Animal Research Centre (AgrC)*
Abstract
1. Background
Under the auspices of the Interdepartmental Advisory Group on Water
Conservation at Federal Facilities, member agencies pledged to conduct
water audits at selected sites. Agriculture Canada chose the Animal
Research Centre as its nominee to demonstrate water
conservation/efficiency opportunities with short payback period
characteristics.
The Centre is a collection of buildings housing various domestic
animals and support materials scattered around the site. Water from a
regional main is supplied to 11 animal and maintenance groups. In
addition to the predominant water consumption by animals, water is used by
laboratories, laundry facilities, cooling, and staff showers, as well as
for drain flushing, boiler make-up water and feed preparation process.
The objectives for this study were twofold, to
- identify and quantify uses of water for each building group and for
the entire facility
- identify and recommend options, based on cost-benefit analysis, for
reducing the overall water requirement.
The cost of the study was $27 000.
2. Water audit
To test the integrity of the extensive underground water distribution
network, a leak detection survey was undertaken. No leakage was found. Due
to the diversity of uses on site, several new water meters were installed.
For a 3 week period in January these and the existing meters were
read twice a day. The water balance, completed for the main meter and for
all individually metered buildings, indicated a 9% loss in the system. The
extensive flow monitoring and on-site water use survey indicated that the
average estimated water demand for the Centre was 310,000 L/d. During
the summer months this demand is expected to increase because of cooling
water used in air conditioners.
An estimated 20 000-130 00 L/d of water is used at many
barns for 4-5 days in the spring and fall to wash out the manure that
has collected over the previous season. In one building over 40% of the
total water used by the whole site runs continuously 24 h/d; most of
it is used by a drain flushing system, which accounts for an estimated
129 000 L/d. This is a far higher volume than would normally be
expected. At the processing plant, an estimated 34 000 L/d is
used for walk-in coolers.
3. Water management program
Immediate water reductions can be achieved by replacing the
self-flushing urinals with flush valves. The cost of the modifications is
$1 500, and with savings of $4 550, a payback period is
4 months. Major water reduction would result from the elimination of
once-through cooling at a number of buildings with a payback period of
1.5 years, from the net $23 900 saving and $35 000
modification cost. Pending the outcome of further investigations, there is
a potential for savings of up to $35 000/year for the continuously
flushing drain lines.
The recommended program includes a range of measures, including routine
monitoring of all meters, installations of low-flow devices, replacement
of once-through with closed-loop cooling systems, and reduction of flow
rate to floor drains. The overall cost of the program, which has 56%
volume savings potential, is estimated at $36 600 with a 5-month
payback period.
Sir F.G. Banting Building (HWC)*
Abstract
1. Background
Under the auspices of the Interdepartmental Advisory Group on Water
Conservation at Federal Facilities, member agencies pledged to conduct
water audits at selected sites. Health and Welfare Canada chose the Sir
F.G. Banting Building as its nominee to demonstrate water
conservation/efficiency opportunities with short payback period
characteristics. This institution is a multi-discipline research facility
with laboratories and offices in two wings and a large animal wing. Water
is supplied from the regional network and, beyond a main meter, the system
branches into the three distinct wings of the building. The recirculated
hot water system is arranged similarly and serves the animal handling
wings for cage washing and hydrobrushing. There is a "shower in" and
"shower out" requirement for personnel entering the area. Cold water is
used for cooling, the cafeteria, the washrooms, and laboratory use. A
distilled water unit fulfills requirements for the research areas of all
wings. Since the facility had only one meter and was a high consumer of
both cold and hot water, it was decided to submeter both systems for all
three wings. The main objectives of this study were to identify and
quantify uses of both hot and cold water for each wing and for the entire
facility. The study was to identify and recommend options, based on a
cost-benefit analysis, for reducing the overall water requirement. The
cost of the study was $20 000.
2. Water audit
Over the 3 week monitoring period the average cold and hot water
demands of 188 000 L/d and 41 000 L/d, respectively,
were measured. The Laboratory wing was the largest user of cold water at
144 000 L/d, of which two-thirds was used for cooling, and an
estimated 33 800 L/d consumed by various laboratory uses. A
further 39 000 L/d of cold water was used by the air handling
units in the Laboratory wing. In the Animal wing total cold water use was
estimated at 35 500 L/d, of which the air handling units used
27 500 L/d. The coolant for storage rooms was the major user of
cold water (12 600 L/d) in the Communal wing. The greatest
volume of hot water (24 000 L/d) was utilized by cage and bottle
washers in the Animal wing. A further 9 600 L/d was estimated
for use in experiments, cleaning, and washing equipment in the Laboratory
wing. Most of the hot water (3 000 L/d) in the Communal wing was
used by the kitchen dishwasher.
3. Water management program
Due to the sensitive nature of processes dealing with the animals
drinking water supply, cleaning, etc., water reductions in these areas
have not been included. Replacing all the fittings in the washrooms and
showers with low-flow devices would save $5 000/year in water and
energy costs. The $7 650 for the work would give a payback period of
1.5 years. Installation of low-flow valves in washrooms would save
$1 430. The installation cost would be $250, and the payback period
0.2 years. Converting water-cooled refrigeration equipment to
closed-loop systems would result in yearly savings of $14 000. The
modification costs of $30 000 would give a payback period of
2.1 years. A sewer charge rebate could be negotiated with the region
to take into account the over $5 600/year in sewer charges currently
charged for water that does not discharge to the sewer. Cooling water
should be reused for process purposes such as humidification. While hot
water use for showers and washrooms would be reduced by the same
proportion as cold water, water savings would also contribute to energy
cost savings. The overall cost, which has 41% volume savings potential, is
estimated at $39 900 with a 10-month payback period.
Chemical Radioactive Ores Building (EMR)*
Abstract
1. Background
Under the auspices of the Interdepartmental Advisory Group On Water
Conservation at Federal Facilities, member agencies pledged to conduct
water audits at selected sites. Energy, Mines and Resources Canada
selected the Chemical Radioactive Ores Building (555 Booth Street) as
one of its two nominees to demonstrate water conservation/efficiency
opportunities with short payback period characteristics.
The building, constructed in the early 1960s, has three wings
accommodating laboratories and administrative offices. All water supplied
to the building from a regional water main passes through a meter before
being distributed by a riser system in a continuous common loop. All air
handling units, drinking water chillers, the domestic hot water system and
the hot water perimeter heating system are located in the basement. All
special water use equipment (a water distillation unit, a de-ionizer/water
purifier, and a cooling tower) are located in the west wing. There are
water-cooled AC units throughout the laboratory wings.
Identification of the uses of water at the building and recommendation
of options for reducing the overall requirement for water, as well as a
cost-benefit analysis for each option were requested of the consultant.
The cost of the study was $11 000.
2. Water audit
A 4-week period of flow monitoring indicated that half of the estimated
136 000 L/d average weekday water demand for 555 Booth
Street was used by air handling units. Primarily during the winter, these
units use approximately 70 000 L/d for air wash and
humidification. In the summer months, the air handling demand is replaced
by 44 000 L/d needed to cooling water requirements in air
conditioner units. Continuously operating flush tank urinals use
15 000 L/d, whereas compressor after-cooling and pump
lubrication/cooling account for another 13 000 L/d and
11 000 L/d respectively.
3. Water management program
The installation of low-flow valves on the self-flushing urinal tanks
at 555 Booth Street would save $3 450, with a payback of
0.5 years for the $1 750 installation cost. Many water-cooled
air conditioning units should be replaced by air-cooled units or converted
to a closed-loop cooling system. The latter would cost $20 000 with a
4-year payback period, from the net annual saving of $5 000. A number
of cooling loads in the basement, which include drinking fountain
chillers, air compressor cooling, and tenant equipment, should be
converted to a closed-loop cooling system. The savings of $12 000 and
modification cost of $10 000 will give a 10-month payback period. A
sewer charge rebate could also be negotiated with the municipality to take
into account over $6 000 in sewer charges currently charged for water
that does not discharge to the sewer. When water must be used for cooling,
it should be reutilised for process purposes such as humidification. The
overall cost of the program, which has 42% volume savings potential, is
estimated at $32 250 with a 12-month payback period.
Canada Centre for Inland Waters (EC)
Abstract
1. Background
The CCIW research/laboratory establishment, built around 1967 in
Hamilton, occupies 47 700 m2 of mixed
use floor area in seven wings of a single structure. The facility has, in
the past, taken a number of water conserving and cost saving actions.
Since 1985, uncontaminated water has been diverted through a storm sewer
outlet to Hamilton harbour. This resulted in decreased flows to the
Hamilton Wastewater Treatment Plant, and as a consequence, credit
continues to be received on sewer surcharges from the local water
authority. Further actions included
- replacement of manual flush units with automatic ones in urinals
- installation of water meters to monitor water use and to allocate
costs
- use of harbour water for lawn watering
- reduction in flush/refill frequency in tanks and flumes by cutting
back the algae growth rate
All these actions have resulted in an annual water and sewerage bill of
about $160 000 after rebates. To further enhance water conservation
at the facility, a consultant was retained to complete a water efficiency
audit. The cost of the study was $35 000.
2. Water audit
A 3-week period of flow monitoring and an on-site water use survey
indicated that the average estimated water demand for the institution was
23 800 m3/month. Over the recording
period, the base load of water use was about 70% continuous flow. Water
use tended to concentrate in two main areas:
- fisheries laboratory (183 m3/d
average, of which 174 m3/d is discharged)
- administration and laboratory wing (299 m3/d average, of which 200 m3/d is used for once-through cooling and
subsequently discharged)
Water use was split into four categories represented by a percentage of
the city water intake: cooling (50%), process (36%), domestic (7%), and
laboratory (7%). Water intake totalled 717 m3/d including 7% unaccounted-for water flow. The
estimated per capita domestic use in the facility is 65 L/d.
3. Water management program
The main recommendation concerns the curtailment of cooling water
demands. Due to CCIW's fortunate location, all cooling water may be drawn
directly from the harbour. The cost of intake development to replace ca
327 m3/d of city water was estimated at
$101,000. The estimated savings at current water costs are
$53 000/year for a payback period of under 2 years.
At 36%, the fisheries laboratories' tanks use the second largest volume
of city water. The cost of reusing some of the once-through cooling water
for process applications ($23 350) would result in annual savings of
$22 600, for a 1.03-year payback.
With water-saving devices already in place, only user habit changes
could produce small savings. It was also proposed to
- move certain operations at the laboratories to periods when lower
volumes of water are used
- reactivate the existing pressure-reduced cold water network to
achieve water use reductions
- more thoroughly use existing/new water meters to monitor use and
ensure that reductions maintained in the future
Curve Lake First Nation School (INAC)*
Abstract
1. Background
Under the auspices of the Interdepartmental Advisory Group on Water
Conservation at Federal Facilities, member agencies pledged to conduct
water audits at selected sites. Indian and Northern Affairs selected the
Curve Lake First Nation School as one of its two nominees to demonstrate
water conservation/efficiency opportunities with short payback period
characteristics.
It is primarily an elementary school but offers some adult education
programs, operating 194 days per year with a current enrollment of
53 students and 8 staff members. Adult education classes, with
7 students and one instructor, are conducted 335 days/year in a
portable classroom located on the elementary school site. Generally, both
elementary and adult students occupy the school weekdays between 0845 and
1600 hours. The domestic cold water supply at the elementary school and
the portable classroom is pumped from a well (no permanent flow meter)
located on the school site.
The objective for this study was the identification of present water
uses at the school site. A cost-benefit analysis of the recommended
measures for reducing the overall requirement for water was also included.
The cost of the study was $6 000.
2. Water audit
As stated previously, there was no existing water meter at the facility
and a pump supplied water to the school on demand. To document water
consumption by the facility, a clip-on meter was used to record pump
operation.
A week of flow monitoring indicated that the average estimated water
demand for the institution was 3 500 L/d, which was reasonable
for a small facility. The domestic portion of the water,
2 500 L/d, is used in the washrooms. This includes a system loss
of 270 L/d, attributed to a leaking toilet in the boys' washroom.
Process water, 1 060 L/d in total, was estimated for general use
(including cleaning) in the classrooms and daily flushing of the pipes at
the drinking fountain.
Commencing with the summer of 1992, a lawn watering program will be
implemented; however, its effects were not considered in the audit.
3. Water management program
The only water reduction alternative is in the domestic uses.
Retrofitting the plumbing fixtures with low-flow devices would give an
annual saving of $850. The observed leak in the boys' washroom could cost
as much as $400/year. At an estimated cost of under $50 to fix it, this
would pay back in about one month.
The overall cost of the program, which has 39% volume savings
potential, is estimated at $3 300 with a 32-month payback period.
Douglas Border Crossing (RC-CE)*
Abstract
1. Background
Under the auspices of the Interdepartmental Advisory Group on Water
Conservation at Federal Facilities, member agencies pledged to conduct
water audits at selected sites. Revenue Canada, Customs and Excise,
selected the Douglas, B.C., border crossing station as one of its two
nominees to demonstrate water conservation/efficiency opportunities with
short payback period characteristics. It is a smaller than average
facility with the Customs and Immigration departments contained in a
common block processing primarily noncommercial border traffic. In 1990,
there were about 5.3 million cross-border travellers processed by
this facility. At one time, domestic cold water was supplied to the
facility from the United States, but in the past few years the water main
was replaced, and water is now purchased from Canadian sources. Two
existing meters are located in hand holes at the municipally operated
water main, making the water supply to the Immigration and Customs areas
entirely separate. The water supply is generally limited to drinking
fountains, washrooms, and make-up water for the domestic hot water heater
and the hot water heating system.
The water audit study was to identify and quantify uses of water for
the entire facility as well as to identify and recommend options for
reducing the overall requirement for water and to carry out a cost-benefit
analysis for each option. The cost of the study was $10 000.
2. Water audit
Flowmeter reading for the Immigration building was intended to continue
for a 3-week period, but seasonal rains flooded the meter chamber so that
the meter could not be read. No flooding problems arose in the meter
chamber for the Customs building, and the meter was monitored over a
5-week period. Separate individual balances for the Immigration and
Customs building totalled 18 100 L/d and 3 800 L/d
respectively. Most of the water, 17 900 L/d, in the Immigration
building is consumed for domestic purposes in the public washrooms and
drinking fountains. Process water is used in the kitchen at an estimated
190 L/d and the lawns are watered in the summer. The domestic water
use at the Customs building is estimated to be 3 020 L/d. During
the busier summer months the above figures will increase significantly.
The process water uses are in the kitchen and at the alcohol disposal tank
with 780 L/d. An exterior sprinkler system waters the lawns in the
summer.
3. Water management program
If all the lavatories were fitted with aerators and/or flow
restrictors, and all the water closets and urinals were fitted with
low-flow flush valves, the total domestic water consumption would be
reduced by an estimated 4 700 L/d. This would amount to savings
of $450/year. The cost of the proposed renovations would be approximately
$3 150 for an estimated payback period of 7 year. Since summer
time will bring more people and more domestic water use, a significantly
shorter payback period can be expected. Reducing the present flush rate by
throttling back the valve to the flush tank in the men's public washroom
would produce an immediate savings of approximately 7 000 L/d.
Water and cost savings would amount to 2 555 000 L/yr or
$670.
The overall cost of the program, which has 39% volume savings
potential, is estimated at $3 150 with an 34-month payback
period.
Fuel Research Laboratory Building (EMR)*
Abstract
1. Background
Under the auspices of the Interdepartmental Advisory Group on Water
Conservation at Federal Facilities, member agencies pledged to conduct
water audits at selected sites. Energy, Mines and Resources Canada chose
the Fuel Research Laboratory Building (562 Booth Street) as one of
its two nominees to demonstrate water conservation/efficiency
opportunities with short payback period characteristics.
The Laboratory, constructed about 1930, is a three-storey building and
was selected for water audit because its historical water use was high for
its building size. The building has a floor area of 2 758 m2 and a staff of 18. The domestic cold water is
supplied to the facility by city water mains operated by the Regional
Municipality of Ottawa-Carleton. Beyond the water meter, the domestic cold
water branches into three lines to serve the south, north, and centre of
the building. At one time, the south branch was used to supply air
conditioning units and laboratory sinks; however, most of the air
conditioning units and sinks have been disconnected. The centre branch
supplies make-up water to the domestic hot water system. The north branch
supplies the remainder of the building, including washrooms, laboratories,
one large walk-in refrigeration unit, and one small unit. Identification
of the uses of water at the building and recommendation of options for
reducing the overall requirement for water, as well as a cost-benefit
analysis for each option, were requested of the consultant. The cost of
the study was $7 000.
2. Water audit
Meter readings for the two 2-week periods produced an average estimated
water demand of 8 500 L/d. As a note of interest, a video camera
was used to take hourly readings for two days due to the lack of personnel
available.The completed water balance indicated that domestic water was
used by the 18 staff in the washrooms at an estimated 600 L/d.
The largest flow, 3 000 L/d, is at two flush tanks in the men's
washrooms. The once-through cooling for the building has been reduced in
recent years. Two large walk-in refrigerator/freezers have been removed,
and the use of room air conditioning units in the summer months has been
significantly reduced. The remaining walk-in refrigerator/freezers use an
estimated total of 3 000 L/d. An estimated 1 900 L/d
is used in the laboratories and support rooms in the building. The
historical water records for 562 Booth Street indicated a ten times
greater flow into the building than was recorded during the audit. The
facility staff have been alerted to this discrepancy and will investigate
the matter.
3. Water management program
The installation of new flush valves on 2 self-flushing urinals in
the washrooms will save $1 300/year, with a 0.3-year payback period,
for a modification cost of $375. A closed-loop cooling system could be
installed for the water-cooled refrigeration systems for a savings of
$900/year. The modifications cost would be $5 000 and the resulting
payback period 5-6 years. The water-cooled air conditioning units should
continue to be removed or replaced with air-cooled units. The ten times
discrepancy in flowmeter reading has the potential for a reduction in the
water bill of $33 600/year.
The overall cost of the program, which has 97% volume savings
potential, is estimated at $5 375 with a 2-month payback period.
Lacolle Border Crossing (RC-CE)*
Abstract
1. Background
Under the auspices of the Interdepartmental Advisory Group on Water
Conservation at Federal Facilities, member agencies pledged to conduct
water audits at selected sites. Revenue Canada, Customs and Excise,
selected the Lacolle, P.Q., border crossing station as one of its two
nominees to demonstrate water conservation/efficiency opportunities with
short payback period characteristics. The crossing, regulating both
commercial and noncommercial cross border traffic, comprises several
buildings for Immigration and Customs operations. It processed
approximately 2.7 million travellers in 1990. Domestic cold water for
the site is supplied by a well and reservoir system. Some treatment of the
water is undertaken at the reservoir before its discharge to the site
distribution system. The main meter is located immediately after the
domestic cold water pumps, and a sub-meter is in the Duty Free Shop. All
water used on the site passes through the main meter except during periods
of high flow, at summer weekend evening hours. On these occasions when the
domestic cold water system pressure drops, the fire pumps operate to
increase the water supply. Most water is used in the washrooms and some
air conditioning units; a small amount of make-up water is needed for the
hot water heating system. Water use by the sewage treatment plant is
minimal and infrequent. The water audit was to identify and quantify uses
of water as well as to identify and recommend options for reducing the
facility's overall water requirements and to carry out a cost-benefit
analysis. The cost of the study was $11 000.
2. Water audit
A 2-week period of flow monitoring indicated that the average estimated
water demand for the facility is 22 900 L/d. Because of the
nature of operations, the busier summer months will increase this demand
significantly. As the station has an extensive underground network, about
3 000 m, there is potential for leakage. Routine detection
survey indicated no leaks. The main areas of water use at the station are
in the public washrooms, with an estimated 8 400 L/d used. The
staff washrooms, lunchrooms, and locker rooms use an estimated
4 100 L/d; the Duty Free Shop uses 3 700 L/d of water
in the washrooms; and an air conditioning unit uses an estimated
10 000 L/d. Summer cooling water demand will increase with the
use of two additional air conditioners.
3. Water management program
If all the lavatories were fitted with flow restrictors and all
washroom fixtures were fitted with low-flow flush valves, the total
domestic water consumption would be reduced by an estimated
3,600 L/d. For the estimated $8,650 retrofit cost, a 1.6-yr payback
period would result. A closed-loop cooling system for the air conditioning
units could be installed for approximately $10,000. This system would save
7 300 000 L/yr. The estimated annual cost savings would be
the water saved, less the cost of electrical energy required to run the
pump and fans on the closed-loop cooler. The estimated water savings are
$30 150/year; when the operating cost of $1 300 is taken into
account, the net savings are $28 850. The resulting payback period is
0.4 years. An additional benefit would be the elimination of seasonal
demands, thereby reducing the need for the fire pump to operate in summer
months to maintain system pressure. The overall cost of the program, which
has 69% volume savings potential, is estimated at $18 650 with a
7-month payback period.
Major-General G.R. Pearkes Building (PWC)*
Abstract
1. Background
Under the auspices of the Interdepartmental Advisory Group on Water
Conservation at Federal Facilities, member agencies pledged to conduct
water audits at selected sites. Public Works Canada chose the
Major-General George R. Pearkes Building (101 Colonel By Drive)
as its nominee to demonstrate water conservation/efficiency opportunities
with short payback period characteristics. The complex is essentially an
office building comprised of two 20-storey towers and a central building
of 12 storeys. The domestic cold water supply system for the entire
complex is controlled from the North Tower, where city water enters at the
basement level mechanical room. The system consists of three components:
the city pressure system, a low rise pressure system, and a high rise
pressure system serving various heights of the complex. Domestic water is
used in the washroom facilities, for air conditioning units, and kitchen
refrigerators and freezers, as well as in cooling tower make-up during the
summer months. This water audit study was to identify and quantify uses of
water for the entire facility as well as to identify and recommend options
for reducing the overall requirement for water and to carry out a
cost-benefit analysis for each option. The cost of the study was
$10 000.
2. Water audit
The existing water meter was read twice daily for a 3-week period and
exhibited typical water use patterns for an office complex with an
estimated average of 429 000 L/d. Most of the 20 floors
have two women's and two men's washrooms, which use an estimated
117 500 L/d of water. In addition, continuously operating
self-flushing urinals in many of the washrooms account for an estimated
116 000 L/d. Cooling is accomplished by once-through city water,
a closed-loop cooling tower between the 11th and 20th floors, and chilled
water from the central plant. The city water air conditioning units
located throughout the building account for an estimated
129 800 L/d. A further estimated 17 300 L/d is used as
cooling tower make-up in the summer. Kitchen fridges and freezers and
serving hatches use an estimated 25 000 L/d of cooling water.
The kitchen dishwasher and pre-scrubbing machine is the largest process
water user at an estimated 13 000 L/d. In the summer, the
outside lawns are watered by an estimated 70 000 L/d a day.
3. Water management program
The installation of low-flow valves on up to 40 self-flushing urinal
tanks will save $40 000/year. For a modification cost of
$10 000, the payback period will be 3 months. The large number
of water-cooled air conditioning units should be converted to chilled
water or a closed-loop cooling system. A net savings of $20 000 would
result in a payback period of 2 year when the modification cost of
$40 000 is taken into account. Other water-cooled equipment,
including drinking fountain chillers and the cafeteria fridges and
freezers, should be converted to a chilled water or closed-loop cooling
system at a cost of $10 000. The savings of $4 500/year will
give a payback period of 2.2 years. At the soil table in the
cafeteria, control of water use could save up to $1 580/year. When
cooling water is unavoidable, it should be reused for process purposes
such as plant watering or floor drain priming. It was noted during the
audit that generally the larger pump operates continuously and the small
pump infrequently. There was no installed standby large pump, so
consideration should be given to improve the current standby provision.
The overall cost of the program, which has 54% volume savings potential,
is estimated at $60 000 with an 11-month payback period.
Ottawa International Airport (TC)
Abstract
1. Background
Under the sponsorship of the Interdepartmental Advisory Group on Water
Conservation at Federal Facilities, Transport Canada has selected the
Ottawa International Airport (OIA) as its test site to demonstrate water
conservation/efficiency opportunities. The OIA shares the airport complex
with NRC and DND areas of operations. The audit was restricted to only
those Transport Canada facilities where most of the water consumption was
assumed to occur, including the terminal and support/maintenance
buildings, hangars, and control tower. The airport complex receives
potable water from regional municipality sources via storage and treatment
on DND territory. It is pumped to all users with OIA being served by two
unmetered water mains.
The audit objectives included
- undertaking a system balance to account for water used throughout
the facility
- identifying and quantifying characteristic water uses for each
selected building
- identifying and recommending options, based on cost-benefit
analysis, for improving water efficiency and reducing the overall water
requirement
The cost of the study was $30 000.
2. Water audit
Temporary insertion meters and clamp-on meters, attached on supply
lines, and all existing meters were monitored for up to 2 week. The
average estimated water demand was found to be 672 m3/d, indicating that the audited buildings accounted
for almost 62% of the total demand. Over the recording period, the base
nighttime flow was 192 m3/d. Almost 50% of
all OIA consumption was concentrated in the main terminal building
(218 m3/d) where both the restaurant and
flight kitchen are located. Washrooms for the travelling public and staff
used 70 m3/d. Consumption demands, due to
air conditioning and lawn watering, will likely increase during the
summer. Several washrooms and a canteen contribute to the 27 m3/d used in the flight services hangar representing
approximately 10% of all OIA uses.
Leak detection survey indicated a tight system; therefore, buildings
not monitored account for the balance of water use. Further investigations
are necessary to determine whether any of these buildings consume
significant volumes of water.
3. Water management program
The main recommendation concerns the replacement of most existing flow
meters, which are oversized and underrate the flow, particularly those
used for billing purposes. A number of discrepancies between the
maintenance computer and the site meters were observed. Relays should be
checked to ensure that all communications with the computer are accurate.
In addition, permanent meters should be installed on both supply lines to
confirm billing from DND and to monitor consumption trends for possible
losses.
Throughout the audit some wastage were identified in the walk-in
coolers. Savings may be realized by changing to a closed-loop system but
payback periods would be high. The practice of supplanting automatic shut
off valves on washroom fixtures should continue. Low-flow nozzles should
be installed in the maintenance hangar to reduce equipment cleaning water
use. A method of billing customers for the water used in the Aircraft
Sewerage Disposal Building should be investigated.
Supplying lawn irrigation needs from local reactivated backup wells and
implementation of an annual leakage detection survey should be
investigated.
Parliament Hill, Centre Block (HofC)*
Abstract
1. Background
Under the auspices of the Interdepartmental Advisory Group on Water
Conservation at Federal Facilities, member agencies pledged to conduct
water audits at selected sites. House of Commons officials selected the
Centre Block to demonstrate water conservation/efficiency opportunities
with short payback period characteristics. Most of the internal piping and
appurtenances in the Centre Block date to the reconstruction of the early
1920s. The external domestic cold water supply is unique in that it
actually forms part of the internal system with entry to Centre Block from
the East and West Blocks. It is therefore possible for water to flow out
of Centre Block at either end of the building. There are no water meters
located on the internal watermain system in the building, and past water
usage rates have been assessed from meters recording water consumption for
all of Parliament Hill. City water pressure being insufficient, most of
the building is supplied from a pumped storage system. Water is pumped to
storage reservoirs located in the sixth floor towers. Domestic cold and
hot water supply systems are duplicated for the Commons and the Senate
sides. Special water use areas are the cafeteria and restaurant. During
the summer, offices located on the south side of Centre Block are supplied
with air conditioning units which operate with once-through cooling water.
The water audit was to identify the uses of water for the entire facility
as well as to recommend options for reducing the overall requirement for
water and to carry out a cost-benefit analysis for each option. The cost
of the study was $23 400.
2. Water audit
Due to the lack of installed flow meters and the unacceptability of
both insertion meters and clamp-on devices, the times of operation of the
domestic cold water pumps in Centre Block were measured indirectly, and
flow was calculated as 204 000 L/d for a 3-week period. For
future monitoring purposes, the most accurate water consumption data will
be generated by the installation of permanent flowmeters. Public washrooms
used an estimated 63,000 L/d, and private washrooms for MPs' offices
an estimated 6 000 L/d. In the summer an estimated
160 000 L/d is used by water-cooled room air conditioning units
and 45 000 L/d for other cooling purposes. A compressor
after-cooler accounted for an estimated 13 000 L/d. The main
volume in the process category was an unusually high estimated
33 000 L/d for heating system make-up. Two dishwashers at the
restaurant and cafeteria use a further 12 000 L/d. In the summer
the lawns are watered by an estimated 87,000 L/d, and a continuous
flow of 33 000 L/d is estimated to be used at the Centennial
Flame Fountain.
3. Water management program
All washrooms should be fitted with low-flow, or flow restrictive
devices. The cost of the modifications is $18 750, and the savings of
$6 275/year will give a payback period of 3.0 years.
Installation of low-flow valves on 8 self-flushing urinal tanks will
save $6 000 for a 4-month payback period on the modification cost of
$2 000. The water-cooled refrigeration equipment should be converted
to closed-loop systems. The modifications would result in a net saving of
$24 700/year, and with the cost of the works being $30 000, the
resulting payback period would be 1.2 years. Fixing an assumed leak
in the hot water heating system would save over $8 000/year in water
losses. The overall cost of the program, which has 34% volume savings
potential, is estimated at $51 250 with a 12-month payback
period.
Walpole Island First Nation School (INAC)*
Abstract
1. Background
Under the auspices of the Interdepartmental Advisory Group on Water
Conservation at Federal Facilities, member agencies pledged to conduct
water audits at selected sites. Indian and Northern Affairs selected the
Walpole Island First Nation School as one of its two nominees to
demonstrate water conservation/efficiency opportunities with short payback
period characteristics.
Walpole Island First Nation School, located on the Walpole Island
Reserve in southern Ontario, is an elementary school, from kindergarten to
grade 8, with some special amenities. It operates a normal school
year with 365 students and 30 teachers. Generally, the school is
occupied between 0830 and 1530 hours on weekdays. Occasionally,
extracurricular functions take place, including after-school sports events
and weekend craft shows. An existing flowmeter records the domestic cold
water supplied from the Reserve's water distribution system.
The objective for this study was the identification of present water
uses at the school site. A cost-benefit analysis of the recommended
measures for reducing the overall requirement for water was also included.
The cost of the study was $6 000.
2. Water audit
Most of the fixtures within the school (lavatories, water closets, and
laboratory sinks) represent no extraordinary water uses. Drinking
fountains within the facility have been turned off as a result of misuse
by the students. The student cafeteria serves breakfasts to students
during the winter season. The average daily flow for the entire 7-week
flowmeter monitoring period was 12,100 L/d. The main area of water
use is for domestic purposes in the washrooms at 10,100 L/d. Visible
leaks at six locations throughout the school account for a total of
1 460 L/d of water. The process water used in the laundry room
is estimated at 230 L/d. The kitchen dishwasher operates seasonally
and accounts for an estimated 100 L/d of water. Janitor's sinks and
the laboratories use a further 100 L/d each. A small amount of lawn
watering is performed in the summer.
3. Water management program
If all the lavatories were fitted with aerators and/or flow
restrictors, and all the water closets and urinals (excluding the
self-flushing ones) fitted with low-flow flush valves, the total domestic
water consumption would be reduced by 3 480 L/d. The cost of the
proposed renovations would be approximately $11 300 for an estimated
payback period of over 28 years, an unacceptably long period. The
major area for reduction of domestic water lies in the self-flushing
urinals. The installation of low-flow valves on the self-flushing urinal
tanks would save an estimated $300/year. A 1.7-year payback would result
from the $500 installation cost. The need for proper maintenance is also
very important. As observed during our site visit, several leaks were
detected and, unchecked, these leaks could cost as much as $300/year. The
estimated cost of $100 to repair these leaks would give a payback period
of 0.33 years.
The overall cost of the program, which has 35% volume savings
potential, is estimated at $600 with a 12-month payback period.
Warkworth Institution (CSC)
Abstract
1. Background
The Warkworth Institution is a medium security federally owned
correctional facility, located in Brighton Township, Ontario.The
penitentiary accomodates up to 590 inmates and 308 daytime staff
in over; 40 buildings on the site. Water is supplied to the
institution from its own filtration plant which draws water from the Trent
River. The collected sanitary sewage receives secondary treatment in
wastewater treatment plant on site.
The Institution currently undertakes a rejuvenation program of the
water supply and treatment and of sewage treatment facilities. Several
objectives were established for this study at the Institution: to identify
and quantify sources and uses of water (peak flow, time series of flows,
losses, etc.) for each building and for the entire facility as well as
amounts and types of wastewater; to identify and recommend options for
reducing the overall requirement for water {water saving devices, user
habit changes, etc.) and analyze their impacts; to carry out a
cost-benefit analysis for each option. The: cost of fhe study was
$56 000.
2. Water audit
A 4-week period of flow monitoring and an on-site water use survey
indicated that the average estimated water demand for the institution was
259 000 L/d. During the summer months this demand increases to
519 000 L/d, primarily attributed to cooling water used in air
conditioners. When the institution's facilities expand and if all uses
remain unchanged, the projected demand will increase by 9%. A
262 000 L/d difference is detected between measured water supply
rate and estimated demand, indicating losses in the system. Results from
sewage flow monitoring at the treatment plant do not exhibit these losses
resurfacing as infiltration. The calculated per capita water demand of
668 L/d is comparable to similar facilities; however, it is markedly
higher than values quoted in literature.
It was recommended to verify wastewater treatment plant flows by
additional flow monitoring.
3. Water management program
Reduction in water use and peak demand at the Institution is attainable
by altering components at various points in the supply system (toilets,
showers, air conditioners, etc.). Evaluation of cost effectiveness of
water reduction measures for toilets and handsinks indicates insignificant
gains, whereas the same for all other uses turn out to be acceptable.
Implementation of the recommended program would result in 115 ML/yr
water savings with a corresponding 40% drop in peak demand. Total cost of
the program is estimated at $38 000 with a 2-year payback period. The
cost excludes distribution system repair.
The recommended program includes measures from routine monitoring of
new meters and eliminating system leaks through installation of low-flow
showerheads and tap aerators, replacement of water with air cooled AC
units with or without auto timers, and reduction of flow rate to
compressors, to installation of auto shut-off outdoor spraying
devices.
To maintain the success of the program, staff education, daily flow
monitoring, routine inspection and repair of the supply system,
installation of water efficient devices, and periodical assessment and
update of this program is recommended.
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