HR: 0800h
AN: H21F-1082    [Abstracts]
TI: Factors Affecting the Sustainability of Groundwater-Source Cooling
AU: * Ferguson, G A
EM: gferguso@stfx.ca
AF: St. Francis Xavier University, Department of Earth Sciences, Antigonish, NS B2G 2V5 Canada
AU: Woodbury, A D
EM: woodbur@cc.umanitoba.ca
AF: University of Manitoba, Department of Civil Engineering 246C Engineering Building 15 Gillson Street, Winnipeg, MB R3T 5V6 Canada
AB: The use of groundwater in thermal applications has grown in popularity due to increases in environmental awareness and rising energy costs. While this source of energy is generally seen as beneficial to the environment, changes in subsurface temperatures resulting from thermal development and other factors may make this practice unsustainable. An example of such changes in subsurface temperatures has been observed in Winnipeg, Manitoba, where groundwater is extensively used for cooling applications. Temperatures in a regional aquifer beneath the city were found to be as much as ten degrees Celsius greater than those measured in surrounding rural areas. Numerical modeling indicates increases in temperature of up to 5 degrees Celsius can be attributed to downward heat flow originating in buildings in many cases. Areas where increases in temperature were found to be greater corresponded to areas where water is being injected into the aquifer. This water is being produced in the process of using groundwater for cooling applications, such as air conditioning and industrial cooling, and is being injected back into the aquifer to maintain hydraulic head and reduce the demand on Winnipeg's sewer system. In most cases, the heat introduced by injecting this water is significantly affecting temperatures at the production well of the same system and numerical modeling indicates that this is inevitable with the current method of development. The combination of heat loss from buildings and injection of heated water is largely responsible for a reduction in the efficiency of groundwater as a coolant and may eventually make the use of groundwater in cooling applications unsustainable.
DE: 1803 Anthropogenic effects
DE: 1829 Groundwater hydrology
DE: 1878 Water/energy interactions
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting