Chapter 14 Water Pollution

Chesapeake Bay Largest Estuary in the US. Fresh water mixing with saltwater (brackish water) Water shed that include urban, suburban and agricultural areas. Pollution: nitrogen, phosphorus from sewage plants, concentrated animal feeding operations, agricultural and lawn runoff (fertilizers). Sediment Anthropogenic Chemicals: pesticides, hormones, pharmaceutical drugs Recovery of the Blue Crab: Started in 2000 -> 2010 60% increase.

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. Example: Nonpoint sources- diffuse areas such as an entire farming region that pollutes a waterway.

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. Normal range less than 5 mg of oxygen Polluted water 150+ mg of oxygen

Eutrophication Eutrophication is an abundance of fertility to a body of water. Eutrophication is caused by an increase in nutrients, such as fertilizers (nitrogen and phosphorus). Eutrophication can cause a rapid growth of algae which eventually dies, causing the microbes to increase the BOD. Bacteria breakdown the dead algae using up all the oxygen Can lead to fish die offs and “dead zones” Dead Zones- areas of water with little oxygen and life (example: Gulf Coast/Mississippi drainage)

Common Diseases from Human Wastewater Human wastewater can contain dangerous pathogens (disease producing). Estimated 1.1 billion people do not have access to safe drinking water Estimated 42% of the world does not have proper sanitation. 3.1 million death per year attributed to unsafe drinking water and disease.

Common Diseases from Human Wastewater Water is tested using an “indicator species”. Fecal coliform bacteria like E. coli (Escherichia coli). Also entercocci. Fecal Coliform Testing – 500 to 10,000 colonies per 100 ml of water. Water sample, vacuum/siphon through filter paper (.45 micrometers), culture for 24 hours.

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 Septic systems- Scum layer – float to the top. Middle layer is septage ( bacteria and nutrients) Sludge Layer sink to the bottom. Septage leaves the tank through tube to the leach field where they are naturally broken down or used Advantage : require no electricity Disadvantage: must be pump 5-10 years and sludge disposed to a treatment plant.

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. Primary Treatment – removes solid wastes and settles out solid waste into sludge Removed to landfill, burned or used as fertilizer

Treatments for Human and Animal Wastewater Secondary Treatment – Aeration for bacteria to breakdown organic matter. More sludge produced. Remaining water is disinfected with chlorine, ozone or UV light and released. Tertiary Treatment – Used to remove nitrogen and phosphorus.

Sewage Dumping Raw sewage can make its way into our waterways - (on going fecal coliform testing) Older Treatment plants High Rain/Flood overwhelm drainage systems

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. Drawbacks – liner tears/leaks and being close adjacent waterways

Heavy Metals and Other Substances that can threaten human Health and the Environment Lead – old plumbing (pipes). Brain, nervous and kidney damage. Arsenic –naturally occurring. Human activity: mining and wood preservatives. Can be removed through filters and reverse osmosis. Mostly in west and midwest. Causes skin, lung, kidney and bladder cancer. Can take 10 years to develop Fight over acceptable levels?

Heavy Metals and Other Substances that can threaten human Health and the Environment Mercury - naturally occurring as well as from burning coal (2/3 of produced mercury). Burning garbage (medical supplies) Manufacturing of cement Mining Results in: Biomagnification or bioaccumulation Methylmercury produced from bacteria. (eating shellfish)

Heavy Metals and Other Substances that can threaten human Health and the Environment Acids – from burning coal releasing sulfur dioxide and nitrogen dioxide. Wet Acid Deposition – From rain and snow Dry Acid Deposition – From gasses and particles Low pH can react with other compounds and elements like pyrite ( breakdown to iron and H+) Cause zinc, copper, aluminum and manganese to be soluble. Coal Scrubbers have limestone to remove acidic gasses.

Heavy Metals and Other Substances that can threaten human Health and the Environment Synthetic compounds: Pesticides: DDT Round up (inert ingredients) – break down waxy layer of plants and affect amphibians and fish. Pharmaceuticals and Hormones: USGS Testing for various contaminants. Perchlorates from rocket fuel (thyroid issues) Industrial: PCB’s (polychorinated biphenyls) - from plastics and electrical transformer (carcinogenic) PBDE (polybrominated diphenyl ethers) – flame retardant materials (causes brain damage) Breast Milk: NYT vs CDC

CO2 and Acidification Increase in global CO2 level are increasing dissolved CO2 levels in the ocean The increase in the dissolved CO2 level in the ocean is leading to ocean acidification. What does acidification affect?

Oil Pollution

Oil Pollution Review: US Oil Disasters? Effects still seem 20+ years later? 60% from “oil seeps” in North America

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 Underwater Oil Plumes: Harder to contain? High pressure Hot Water for Clean up?

Other Water Pollutants Solid waste pollution (garbage) North Pacific Gyre – Great Pacific Garbage Patch (plastics) Coal Ash and Coal Slag Beaches – Animals – Medical Wastes

Other Water Pollutants Sediment pollution (sand, silt and clay) How? 30 % ____________ and 70% _______________ What does if affect? Thermal pollution – hot and cold Thermal Shock – kill fish Warm Water contain less oxygen Solution: Cooling towers Noise pollution – sonar from ships affecting whales and dolphins. US Navy Exempt?

Water Laws Clean Water Act- (1972) supports the “protection and propagation of fish, shellfish, and wildlife and recreation in and on the water”. Does not Include groundwater 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.

Water Laws Developing versus Developed Countries