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Existing Reservoir and Pump House
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TIMELINE:
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1847
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the city studies the possibility to pump
water into a reservoir located on the mountain.
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1852
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the city hires an engineer,
Mr. Thomas C. Keefer, to produce a report
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1853-1856
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construction of the mctavish
reservoir:
- oval shape
- uses natural rock to hold the water
whenever possible
- low side held by masonry
- 24’ deep
- capacity 13,5 million gallons
- masonry wall divides the reservoir
- small gate house is built to store
excess water
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1859
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1862
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reservoir is enlarged to 16
million gallons
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1869
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1872
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1875
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first steam pump
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1877
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reservoir has a capacity of
37 million gallons
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1907
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1928-1932
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construction of the present
pump house, containing 6 pumps
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1946
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- addition to the pump house
allows for a greater pumping capacity, with 6 more pumps.
- major restoration work is done on the reservoir, subdividing it into
6 tanks to facilitate maintenance and covering it.
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1957
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1957 the reservoir has been
covered and the old pump house as well as the new one coexist.
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2002
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no major changes have been
made to the reservoir since 1950. the pump house is now fully automated
and the original pumping station has been demolished.
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PHOTOS:
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PUMP HOUSE:
Originally the McTavish reservoir was supplied by a gatehouse, which
had a water driven pump. the first pump house was constructed in 1875 and
was located on the southwestern tip of the site. It was designed in the
French Renaissance style and would house the first steam pump to serve
the reservoir. It’s original capacity was one half million gallons per
day. By 1913 a centrifugal pump with a capacity of 12 million gallons per
day was in place.
The pump house, in it’s present location, was constructed between 1928
and 1932. Designed by the engineer Charles J. Desbaillets, it drew
its inspiration from medieval castles from his native Switzerland.
The structure was made of steel and was clad with cut stone. The treatment
of the windows is irregular and asymmetric. The whole composition was meant
to be romantic and picturesque, with the chateau-style pump house casting
its reflection into the reservoir, which was encircled by a wrought-iron
fence.
The original pump room contained 6 pumps, 3 with a capacity of 12 million
gallons per day and 3 with a capacity of 15 million gallons per day. In
1947 an auxiliary pump house was added to the building, also designed by
Desbaillets. It was in the same style, however, it lacked the characteristic
corbelled brackets of the original structure. The addition would house 6
more pumps, bringing the station’s capacity to 157.5 million gallons per
day.
The overall dimensions of the building are 365 feet in length and 60
feet in depth. Its height is 115 feet, to the top of the central tower,
which is at 85 feet above Doctor Penfield Avenue. Today the pump house is
fully automated and is controlled remotely from the Atwater filtration plant.
The offices in the main tower are now abandoned. The reservoir itself is
now outpaced by most of the newer reservoirs, in terms of capacity.
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RESERVOIR:
In considering the structural system for any new buildings on the site,
one must understand the existing condition of the reservoir itself. According
to the available information, the first step in the covering of the
reservoir was the pouring of a 7” thick slab on the existing bedrock. The
original wall, bisecting the reservoir was removed. The reservoir
was then divided into six cells, made of 2-foot thick walls, 25 feet 9 inches
in height. The water level, in the tanks, is 24 feet. Each tank is separated
from the next by a 28-inch space and water can travel between the tanks
through 6X10- foot openings. The roof slab is 217 000 sq. ft in area and
is supported by 456 columns, 22 inches in diametre, spaced 20 feet apart.
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WATER NETWORK:
The treatment steps of water filtration required to enhance the quality
of the water are:
1. Rough screening: rough screening of raw
water to intercept material or objects which might damage the low lift
pumps.
2. Filtration: filtration on a siliceous sand-supported
bacterial bed, which eliminates some floating matter and bacteria.
3. Ozonization: this process, which added
to the water tretment at the Charles-J. Des Baillets plant, involves the
injection of ozone into the filtered wate. This substance is an oxidizing
agent and a powerful disinfectant.
4. Chlorination: chlorination to ensure the
water’s disinfection and maintain its quality until it reaches the consumer.
To achieve this, the amount of chlorine is modulated according to a predetermined
value of the residual chorine.
Pumping and distribution of treated water:
Following disinfection, the water is fed from the Atwater and Charles-J
Des Baillets plants via the pumping stations to the different distribution
zones.
The territory is divided into six zones and a sub-zone created to accommodate
the different elevations.
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MASSING STRATEGIES:
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Strategy 1 - use of the existing column
grid to develop a 20 foot by 20 foot module for the buildings. They would
sit on this grid, but not on the walls of the tanks, avoiding the need
to drain multiple tanks for the construction of one building.
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Strategy 2 - use of the tank
walls in addition to the column grid. This may necessitate draining multiple
tanks at once during construction. The walls could, however, be excellent
anchorage points for the new buildings and would dictate their overall
shape.
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Strategy 3 - placement of
the buildings at the periphery of the reservoir and at the southwest corner
of the site. Buildings constructed at the periphery would need to incorporate
the service tunnel in any underground floors and could cantilever over
the reservoir. The southwest corner of the site has a dominant position
as well as being the site of the original pump house. There is also a steep
slope, which could serve as a design cue for the building.
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Structure 1 - structures keyed
into the column gird are relatively low, 2-3 storeys
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Structure 2 - when structures
do not rest only on the tank, building height may be increased.
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STRUCTURE:
According to one source, only 3 inches of earth were placed to cover
the roof of the reservoir. However, examinations on site have placed this
figure in doubt.
One possible strategy is to “key-in” to the existing column grid. However,
it must be determined if the columns need to be reinforced and if the walls
of the tank can also be used as load-bearing elements. The existing column
diametre and spacing, would suggest that it may be feasible to erect structures
above the reservoir. Another strategy would be to place buildings along
the periphery of the reservoir.
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ENERGY:
Geothermal system: is a heating and cooling
system which provides high level of comfort. It only requires relatively
small amount of electricity which can concentrate what nature provides and
than release high-quality heating or cooling inside a building. They
work on a different principle than an ordinary furnace/air conditioning
system.
To create heat, the earth’s natural heat is tapped by employing a series
of below-ground pipes, called a loop, installed in the soil or submersed
in a pond or lake. A fluid circulating in the loop absorbs the earth’s
heat in winter and carries it to the building where. Indoor geothermal
system then concentrates the heat and releases it at a higher temperature
inside the building. While in summer, the process is reversed, as
excess heat is drawn from the building, expelled to the loop, and absorbed
by the earth or water.
Geothermal system consumes less energy because the temperature of the groundwater
beneath the earth’s surface remains relatively constant throughout the year,
even though the outdoor air temperature may fluctuate greatly with the change
of seasons.
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Pond or Lake Closed Loop:
If the building or buildings are near a pond or lake, submersing
the loop beneath the surface of the water is often the most cost-effective
design. This type of loop configuration requires minimum piping and
excavation, but the pond or lake must be deep enough and have sufficient surface
area. The pipe may be coiled in a "slinky" shape to fit more of it
into a given amount of space. Fluid is pumped through the pipe, just
as it is in a closed-loop ground system. GeoExchange experts recommend using
a pond loop only if the water level never drops below six to eight feet at
its lowest level to assure sufficient heat-transfer capability. Pond
loops used in a closed system result in no adverse impacts on the aquatic
system.
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BIBLIOGRAPHY:
Asselin, Manon, Imaging the unseen, History and Theory Thesis, McGill University.
Héritage Montreal, Les stations de pompage de l’aqueduc.
Héritage Montreal, Montreal Waterworks, Government publication,
Service des travaux publics.
Lacoursière, Jacques, Chronologie de l’histoire de Montreal, Montreal,
1992, 129p.
Maffini, Guilio, The McTavish pumphouse, Student Paper, McGill University,
School of architecture, 1970
Manning, G. P., Reservoir and tanks, London, Butler and Tanner Ltd., 1967,
384p.
Geo-exchange:
www.ghpc.org/commercial/commercial.htm
Bibliothèque Nationale du Québec:
Album de rues E.-Z. Massicotte :
www.bnquebec.ca/massic/accueil.htm
Cartes et Plans
www.bnquebec.ca/cargeo/acceuil.htm
City of Montreal:
www.ville.montreal.qc.ca/tp/eaupot/ep.htm
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