Introduction to Water Pollution Target: Describe sources of water pollution the effects of different pollutants in the water.

What are the major categories of water pollutants What are the major categories of water pollutants? Provide examples, major human sources, and harmful effects.

Infectious Agents Examples Components Examples Bacteria, viruses, protozoa, and parasitic worms Major Human Sources Human and animal waste Harmful Effects Disease

Oxygen-Demanding Wastes Components Examples Organic waste that can be decomposed by aerobic bacteria Major Human Sources Sewage, animal feedlots, paper mills, and food processing plants Harmful Effects Dramatic increase in BOD resulting in a crash in DO

Inorganic Chemicals Examples Major Human Sources Harmful Effects Components Examples Water-soluble acids; toxic chemicals such as lead, arsenic and selenium; salts and fluorides Major Human Sources Surface runoff, industrial effluences, and household cleaners Harmful Effects Unusable water for drinking and irrigation; fluoride can cause skin cancers and spinal/neck damage; lead and arsenic can damage nervous system, liver, and kidneys; harm aquatic life; lower crop yields; increase metal corrosion

Organic Chemicals Examples Components Examples Oil, gasoline, plastics, pesticides, cleaning solvents, detergents Major Human Sources Industrial effluents, household cleansers, surface runoff from farms and yards Harmful Effects Some pesticides can cause nervous system damage; some solvents can cause reproductive disorders and some cancers; fish and aquatic life

Plant Nutrients Examples Components Examples Water-soluble compounds containing nitrates, phosphates and ammonium ions Major Human Sources Sewage, manure and runoff of agricultural and urban fertilizers Harmful Effects Algae blooms – high BOD resulting in low DO; excessive levels of nitrates – blue baby syndrome

Sediment Examples Major Human Sources Harmful Effects Soil and silt Components Examples Soil and silt Major Human Sources Land erosion Harmful Effects Increase turbidity and decreases GPP; disrupt food webs, carry harmful substances such as pesticides and bacteria; destroy critical feeding and spawning grounds for fish; clog and fill lakes; artificial reservoirs, stream channels and harbors

Radioactive Materials Components Examples Radioactive isotopes of iodine, radon, uranium, cesium and thorium Major Human Sources Nuclear and coal-burning power plants, mining and processing of uranium and other ores, nuclear weapon production; natural sources Harmful Effects Genetic mutation, miscarriages, birth defects, and certain cancers

Heat- Thermal Pollution Components Examples Excessive heat Major Human Sources Water cooling of electric power plants and some industrial plants Harmful Effects Decreased DO levels – makes aquatic organisms more vulnerable to disease, parasites, and toxic chemicals; thermal shock

How do we measure water quality? WQI – Temperature pH DO BOD Turbidity Nitrates Phosphates Fecal coliform bacteria Macroinvertebrates

Healthy Ranges for Fecal Coliform and DO Drinking water: 0 colonies/ 100 mL Swimming: 200 colonies/ 100 mL Raw sewage: several million colonies/ 100 mL Good: 8-9 ppm at 20 degrees C Moderately polluted: 4.5-6.7 ppm at 20 degrees C Gravely polluted: below 4 ppm at 20 degrees C

What is the difference between point and nonpoint source pollution? Point: pollutants discharged at specific locations through drain pipes, ditches or sewer lines. Example: factories, sewage treatment plants, underground mines, and oil tankers Nonpoint: pollutants scattered and diffused which cannot be traced to any single site of discharge. Example: acid deposition and runoff from croplands, feedlots, logged forests, urban streets, lawns, golf courses, and parking lots.