A change in the chemical, physical, biological, and radiological quality of water that is injurious to its existing, intended, or potential uses. (for example, boating, waterskiing, swimming, the consumption of fish, and the health of aquatic organisms and ecosystems). The term “water pollution” generally refers to human-induced (anthropogenic) changes to water quality. Thus, the discharge of toxic chemicals from a pipe or the release of livestock waste into a nearby water body is considered pollution. Conversely, nutrients that originate from animals in the wild (for example, a herd of elk) or toxins that originate from natural processes (for example, red tides) are not considered pollution.