Water pollution. Bioindicator, Sewage treatment, Industrial wastewater treatment, Agricultural wastewater treatment, Urban runoff, Clean Water Act, United States Environmental Protection Agency, Eutrophication, Hypoxia (environmental), Environmental monitoring, Freshwater environmental quality parameters, Marine pollution, Marine debris, Ocean acidification, Oil spill, Ship pollution, Surface runoff, Thermal pollution, Wastewater, Waterborne diseases, Water quality, Water stagnation, Nonpoint source pollution, Great Pacific Garbage Patch, Bacteriological water analysis