Thermal pollution occurs when a large amount of hot water is discharged into a lake or slow-moving stream. The water comes from sources such as manufacturing, nuclear and electric power plants. Large amounts of hot water kills or harms aquatic life and has a serious impact on the environment. Many laws and standards have been put in place to stop or slow the damage that is being done.
Use Less Electricity
Generation of electric power uses the largest percentage of cooling water, thus reducing the amount of electricity that is used will reduce thermal pollution. Although there is an increasing number of power-generating plants, the amount of thermal pollution has not increased at the same rate because of improved efficiency of power plants and the increased use of hydropower. An increase in the use of nuclear power won’t reduce the need for cooling waters since they also use cooling water.
Reduce Temperature and Volume of Discharge
Heated water can be cooled before releasing it, and less can be released to cause less damage. Unfortunately, the cheapest and easiest way to get cooling water is to withdraw it from a nearby body of water and then release it back into the body of water heated. The warmer temperature water lowers the oxygen content of the water, which increases the respiratory rates of aquatic organisms and weakens them so that they are more vulnerable to disease and death. Releasing the heated water near the shoreline doesn’t lessen the problem since this may disrupt spawning and kill fish.
Store and Reuse Heated Water
It would reduce thermal pollution if those using cooling water were to empty the heated water into shallow ponds or canals, wait for it to cool and then reuse the water; land availability is a hindrance to this method, but this is the idea behind using cooling towers. A cooling tower is an efficient way to reduce thermal pollution because it transfers the heat from the water into the atmosphere. Cooling towers are wet or dry. The rejection of heat into a dry tower is evaporative and raises the relative humidity. According to the Cooling Technology Institute, the cooling potential of a wet surface is much better because there is less evaporative heat transferred into the atmosphere.
Discharge in Less Vulnerable Zones
Discharging in less vulnerable zones is not the best way to reduce thermal pollution. In the past scientists have called it thermal enrichment to release heated water, most scientist don’t consider it enrichment at all and feel that addition to any zone causes thermal pollution. Certainly, however, there would be fewer fish and aquatic organisms killed by thermal shock if there were fewer fish and organisms in the area where the water is discharged.