What is Once-Through Cooling?
The natural gas plants on the San Gabriel River use once-through cooling, tapping water from the San Gabriel River and discharging it through outflow stations which flow directly into the river. According to the Union of Concerned Scientists, once-through cooling can be described as follows (2012):
Once-through cooling can impact marine life through impingement (the trapping or damaging organisms against the screens during intake) and entrainment (the trapping or damaging of organisms inside the facility) when taking in water, and by discharging heated water back into the ecosystem (Hayat, 2012).
Once-through cooling can impact marine life through impingement (the trapping or damaging organisms against the screens during intake) and entrainment (the trapping or damaging of organisms inside the facility) when taking in water, and by discharging heated water back into the ecosystem (Hayat, 2012).
Once-through cooling is being phased out
Once-through cooling is a method which is being phased out in California. The Policy on the Use of Coastal and Estuarine Waters for Power Plant Cooling, adopted on May 4, 2010 by the State Water Board, "establishes technology-based standards to implement federal Clean Water Act section 316(b) and reduce the harmful effects associated with cooling water intake structures on marine and estuarine life" (CWA, 2014).
This change will affect the temperature of the water in the San Gabriel River estuary, which may affect the presence of the sea turtles in the river. Are you ready to see if you can spot the turtles surfacing in the river? |
|
Continue Exploring
Our next section for suggested reading covers how citizen scientists observe and record data without disturbing the sea turtles in their native habitat.
References
CWA. (2014, April 4). Ocean Standards - CWA §316(b) Regulation. Retrieved August 10, 2014.
Hayat, B. (2012, May 15). Power Plant Cooling and Associated Impacts. National Resources Defense Council. Retrieved August 10, 2014.
KQED News. (2012, June 12). The California Report: Power Needs Water. Retrieved August 14, 2014.
KQED News. (2012). Power Needs Water: How Many Gallons to Power That Microwave? Retrieved August 14, 2014.
Union of Concerned Scientists. (2013, July 15). How it Works: Water for Power Plant Cooling | UCSUSA. Retrieved August 12, 2014.
Hayat, B. (2012, May 15). Power Plant Cooling and Associated Impacts. National Resources Defense Council. Retrieved August 10, 2014.
KQED News. (2012, June 12). The California Report: Power Needs Water. Retrieved August 14, 2014.
KQED News. (2012). Power Needs Water: How Many Gallons to Power That Microwave? Retrieved August 14, 2014.
Union of Concerned Scientists. (2013, July 15). How it Works: Water for Power Plant Cooling | UCSUSA. Retrieved August 12, 2014.