Chapter 18 Water Pollution

18.1 Water Pollution Water pollution is anything that degrades water quality Chemical Biological Particulate Matter Taste Esthetics Thermal

18.2 Types And Effects Of Water Pollutants Infectious agents remain an important threat to human health Bacteria are detected by measuring oxygen levels Coliform Bacteria Not Dangerous, but Indicate Fecal Contamination Nutrient enrichment leads to cultural eutrophication BOD = Biological Oxygen Demand Eutrophication can cause toxic tides and “dead zones”

18.2 Types And Effects Of Water Pollutants Inorganic pollutants include metals, salts, acids, and bases (alkalis) Organic pollutants include drugs, pesticides, and other industrial substances Sediment also degrades water quality Thermal pollution is dangerous for organisms

18.3 Water Quality Today The Clean Water Act protects our water The importance of a single word Water quality problems remain Other countries also have serious water pollution Groundwater is hard to monitor and clean There are few controls on ocean pollution London Dumping Convention 1990

18.4 Water Pollution Control Source reduction is often the cheapest and best way to reduce pollution Controlling nonpoint sources requires land management Human waste disposal occurs naturally when concentrations are low Water remediation may involve containment, extraction, or phytoremediation

18.5 Water Legislation The Clean Water Act of 1972 was ambitious, bipartisan, and largely successful “Fishable and Swimmable” What Can You Do? Steps You Can Take to Improve Water Quality Don’t Dump Pollutants (Lawn Fertilizer, Motor Oil, Pet Waste) Clean water reauthorization remains contentious Unfunded Mandates Other important legislation also protects water quality