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TransAlta currently operates two water treatment plants on Lake Wabamun. Both plants are located on the south shore of Lake Wabamun, near the Sundance Plant. The first plant was brought into service in 1997. The second plant was brought into service in 2002. Both plants were constructed as a result of stakeholder input as it related to TransAlta's impacts on Lake Wabamun. Together, the two plants produce 20 million m3 of water every year, under a commitment to the Environmental Appeal Board. That equals almost 8,300 imperial gallons per minute.
Click her to go to TransAlta's Web Site to view monthly production rates as it relates to the water treatment plants.
The water that is pumped into Lake Wabamun meets the guidelines that have been established by Alberta Environment in their permit to operate the plants. The process of treating the water is different for each of the two plants. The first plant (1997) uses a settling process (or clarifier process) that takes up to two hours for the water to clear, prior to it being treated with ozone. The ozone is used to kill any bacteria or micro-organisms that may be present in the water. The second plant (2002) incorporates a different technology, where the settling process (ballasted flocculation) typically takes less than 15 minutes. The water is still treated with ozone to control bacteria.
Located beyond the water treatment plant are several cooling towers. These towers are used to control the temperature of the water that is being discharged to Lake Wabamun. Alberta Environment requires that the water temperature be within 3°C (plus or minus) of the ambient lake temperature at the time of discharge. If the discharge water does not meet this criterion, it will automatically divert to the cooling ponds. The 3°C window is required to meet fisheries requirements.
In February 2002, the Energy and Utilities Board as a result of an appeal presented by Lake Wabamun Enhancement and Protection Association (LWEPA) amended the requirement of TransAlta to repay its historic debt to the Lake. The water treatment plants will now be required to increase their output by 10%. For the period January 1, 2003 to December 31, 2006 the production of treated water will increase from 80 million cubic metres to 88 million cubic metres. Should increased natural precipitation result in the water level over-topping the weir then TransAlta's debt would be met and only ongoing operations and impacts would have to be paid back to the Lake. With the planned shutdown of the Wabamun Power Plant and assuming TransAlta has paid back their debt, the water treatment plant that was constructed in 2002 would be decommissioned as their ongoing debt can be easily managed by a single facility, that being the one constructed in 1997.
Update
The Lake Wabamun Watch Executive toured the two water treatment
plants in July 2002. The difference between the 1997 and 2002
plants is significant and we encourage you to organize a group
(up to ten people) to take a tour to appreciate the magnitude
of the facilities. The volume of water being treated and discharged
to the Lake is encouraging. During the month of July 2002, the
two plants pumped on average, greater than 8,000 imperial gallons
per minute into Lake Wabamun. Despite these volumes of water,
the warm weather and strong winds that we had resulted in still
lower water levels on the lake.
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