According to the Environmental Protection Agency (EPA), 44% of assessed stream miles, 64% of lakes and 30% of bay and estuarine areas are not clean enough for fishing and swimming.It can happen when a factory or power plant that is using water to cool its operations ends up discharging hot water.This makes the water hold less oxygen, which can kill fish and wildlife.Much of it is classified as non-hazardous, such as construction material (wood, concrete, bricks, glass, etc.) and medical waste (bandages, surgical gloves, surgical instruments, discarded needles, etc.).Hazardous waste is any liquid, solid or sludge waste that contain properties that are dangerous of potentially harmful to human health or the environment.Another common type of air pollution is dangerous gases, such as sulfur dioxide, carbon monoxide, nitrogen oxides and chemical vapors.These can take part in further chemical reactions once they are in the atmosphere, creating acid rain and smog.A common type of air pollution happens when people release particles into the air from burning fuels.This pollution looks like soot, containing millions of tiny particles, floating in the air."In nearly all cases, 90% of this water is returned to its source, where it can raise the water temperature in an area immediately surrounding the water discharge pipe.Depending on water flow, the water temperature quickly returns to ambient temperatures that do not harm fish." Donn Dears, former president of TSAugust, a not for profit corporation organization focused on energy issues, told Live Science.