Pollution

For learning purposes we shall split the pollution from geothermal energy into air and water pollution...

Air

The most airborne pollution from geothermal energy is in the form of hydrogen sulfide and carbon dioxide that come from geothermal brine. Luckily in the eighties they started using crystal clarifying technology which captures the hydrogen sulfides and carbon dioxide and puts it back into the geothermal reservoirs. This is a method of cleaning the little pollution there is from geothermal energy. Overall, Geothermal energy prevents 22 tons of carbon dioxide, 200,000 tons of sulfur dioxide, 80,000 tons of nitrogen oxides, and 110,000 tons of particulate matter from getting into the air. Carbon dioxide and nitrogen oxides are huge contributors to the problem of global warming, so this resource is one of the best for our environment. 

Water

Bioaccumulation can happen when the steam extracted from the geothermal reservoirs contain high amounts of boron, arsenic, mercury and lead. If the water is dumped into streams, these elements when eaten by fish, and then bigger fish, and then us, get into our system, and can have drastic health consquences. The USA has regulations that say the geothermal water must be re-injected and reused as opposed to being dumped into streams, therefore eliminating this as a threat.

Thermal pollution occurs when hot water gets into creeks and streams and it can't carry as much dissolved oxygen to the fish. These fish suffocate and die without the oxygen they need to breathe. Once again, we have regulations that require geothermal power plants to return this warm water back into the geothermal reservoirs. This not only keeps water clean, but it makes Geothermal energy one of the most sustainable sources of energy there is!