Chapter 14 Water Pollution

Water Pollution Water pollution- the contamination of streams, rivers, lakes, oceans, or groundwater with substances produced through human activities and that negatively affect organisms. Point sources- distinct locations that pump waste into a waterway. Nonpoint sources- diffuse areas such as an entire farming region that pollutes a waterway.

Categories of Water Pollution Disease Causing Agents (Pathogens) - bacteria, viruses, protozoa, parasitic worms from sewage Oxygen Demanding Wastes - organic wastes that can be decomposed by aerobic bacteria which depletes oxygen, anything that encourages the growth of algae robs waterways of waste (Addition of Nitrates and Phosphorus) Eutrophication – Algae does not allow plants to photosynthesize, no oxygen, other species die –(Nitritates & Phosphates)

Waterborne diseases = chlorea, typhoid, polio, hepatitis Eutrophication Prevented by controlling runoff with buffers, timing applications of fertilizers, feedlots, denitrifying bacteria Phosphates Not Soluble but they adhere to soil – source from runoff Nitrates – water soluble

Biological Oxygen Demand (BOD) – direct measure of the oxygen available for organisms in the water, the colder the water the more oxygen Oxygen Demanding Organisms Mayfly, Stonefly, Caddisfly Larvae Heavy Metals – Methlymecury (Lead, Mecury, Nickel, cadmium) Poisoning called Minamata Disease-sources mining Mining – Use Cyanide to extract gold Calcium Ions – lessens soaps cleaning ability

Oil Pollution – covers birds feathers, reduces ability to stay warm, ability to forage and hide from predators, Ingested = kidney and liver damage, dehydration Oil floats on top = less sunlight, limiting photosynthesis, affecting food web Clean Up = chemical, sorbents, detergents (dissolve or clump(which sink)), controlled burning, skimming Air Pollutants – Mercury, Sulfur Dioxide, Ammonia

Organic chemicals - threatens animals and plants (oil, gas, plastics, pesticides, detergents, etc.) Sediments or Suspended Matter (largest class) - particles of soil/solid that stay suspended in water and made the water cloudy, reduces photosynthesis and disrupts food webs and clogs harbors, reservoirs, channels and artificial lakes SM – Ex = plastics – move up the food chain

Water-Soluble Radioactive Isotopes - tissues and organs and cause birth defects, cancer and genetic damages Thermal Pollution - rise in temp. because of heat absorbed in water to cool power plants Genetic Pollution - addition of nonnative species Iron and Sulfides – water pumped from mineral rich aquifers, rotten egg smell, Removed with carbon filters.

Pollution of Streams Oxygen Sag Curve - depends on stream’s volume, flow rate, temp., pH level and volume of incoming degradable wastes Extract drinking water downstream rather than upstream Ohio’s Cayahoga River Caught Fire in 1959 and 1969

Oxygen Sag Curve http://www.shodor.org/refdesk/Resources/Activities/DissolvedOxygen/Image1.gif

Human Wastewater Water produced by human activities such as human sewage from toilets and gray water from bathing and washing clothes or dishes.

Three reasons scientists are concerned about human wastewater: Oxygen-demanding wastes like bacteria that put a large demand for oxygen in the water Nutrients that are released from wastewater decomposition can make the water more fertile causing eutrophication Wastewater can carry a wide variety of disease- causing organisms.

Biochemical Oxygen Demand (BOD) BOD- the amount of oxygen a quantity of water uses over a period of time at a specific temperature. Lower BOD values indicate the water is less polluted and higher BOD values indicate it is more polluted by wastewater.

Eutrophication Eutrophication is an abundance of fertility to a body of water. Eutrophication is caused by an increase in nutrients, such as fertilizers. Eutrophication can cause a rapid growth of algae which eventually dies, causing the microbes to increase the BOD.

Common Diseases from Human Wastewater Cholera Typhoid fever Stomach flu Diarrhea Hepatitis

Treatments for Human and Animal Wastewater Septic systems- a large container that receives wastewater from the house.

Treatments for Human and Animal Wastewater Sewage Treatment Plants- centralized plants in areas with large populations that receive wastewater via a network of underground pipes.

Wastewater Treatment Preuse Water Treatment Filtered and Re-filtration – water is drawn through filters that have gravel and sand, at the end carbon filters remove smallest particles to improve taste Flocculation – Al Sulfate added to bind particles to be more easily filtered out Disinfection – chlorine, ozone, and UV light used to disinfect

Preuse Water Treatment Absorption – contaminants stick to surface of granular or powdered activated charcoal Ion Exchange – removes inorganic – excess fluoride nitrates, uranium

Sewage Treatment Primary Treatment – removes large particles through filtration, and then allows bacteria to partially digest carbon and nitrogen wastes in large settling tanks.(Filtration and Settling Process) (Physical) Secondary Treatment – holds waste at a longer time untill favorable for bacterial digestion of the carbon and nitrogen wastes. The carbon rich sludge settles and removed by anaerobic – methane producing bacteria (Biological)

Sewage Treatment Tertiary Treatment – removes nitrates, phosphates, and industrial pollutants (Chemical) Sand filtration, Wetlands, UV, Chlorine, Ozone Clorination #1 method in major cities

Removal of Toxic Waste Physical Method – air stripping (Exposing VOCs to air to evaporate), filtration, UV disinfecting, washing Chemical Methods – acid neutralization, oxidation, reduction, precipitation, (most act to bind particles to make larger to filter) Biological Methods – bioremediation, creating wetlands which act as a natural filter, use up nutrients that would otherwise cause a drop in oxygen, Duckweed lagoons, allowing bacteria to digest waste (Exxon Valdez)

Treatments for Human and Animal Wastewater Manure lagoons- large, human-made ponds line with rubber to prevent the manure from leaking into the groundwater. After the manure is broken down by bacteria, it is spread onto fields as fertilizers.

Heavy Metals and Other Substances that can threaten human Health and the Environment Lead Arsenic Mercury Acids Synthetic compounds (pesticides, pharmaceuticals, and hormones)

Oil Pollution

Ways to Remediate Oil Pollution Containment using booms to keep the floating oil from spreading. Chemicals that help break up the oil, making it disperse before it hits the shoreline. Bacteria that are genetically engineered to consume oil

Other Water Pollutants Solid waste pollution (garbage) Sediment pollution (sand, silt and clay) Thermal pollution Noise pollution

Case Studies Minamata Disease Exxon Valdez 1989 11- 30 gallons Prince William Sound 250,000 birds, 3,000 otters, 300 seals, 300 bald eagles, 22 whales, salmon and herring eggs, majority of plankton

Case Studies Gulf of Mexico Oil Spill (2010) April 2010 – Deepwater Horizon Fishing Tourism Industry & Habitat Destruction Cuyahoga River 1969 Cleveland River caught on Fire Lake Erie Shallowest & Warmest of Great Lakes 1960s Mass Eutrophication b/c of Phosphorus ,

Government/Regulations Clean Water Act 1972 – regulate discharge of pollutants into water, Govt gave EPA authority Safe Drinking Water Act 1974 Ocean Dumping Act 1988 Federal Water Pollution Control Act 1948 - eliminating/reducing the pollution of interstate water, improve sanitary conditions of surface & underground water Water Quality Act 1965 – Water purity standards

Water Laws Clean Water Act- (1972) supports the “protection and propagation of fish, shellfish, and wildlife and recreation in and on the water”. Issued water quality standards that defined acceptable limits of various pollutants in U.S. waterways.

Water Laws Safe Drinking Water Act- (1974, 1986, 1996) sets the national standards for safe drinking water. It is responsible for establishing maximum contaminant levels (MCL) for 77 different elements or substances in both surface water and groundwater.