1. Chapter 14
Water Pollution

2. Pollution Sources
Water pollution is the contamination of water by substances produced by human activities and that negatively affect organisms
Point source pollution comes from a distinct location that can easily be traced (factory, pipe)
Nonpoint source pollution cannot easily be traced to the source (urban areas, farms). More difficult to control and more common

4. Nutrient pollution
Nutrient pollution comes from fertilizers, farms, sewage, lawns, golf courses, and leads to eutrophication
Fertilizers add phosphorus to water, which boosts algal and aquatic plant growth
Spreading algae cover the surface, decreasing sunlight
Bacteria eat dead algae, reducing dissolved oxygen
Fish and shellfish die
Solutions include:
Treating wastewater
Reducing fertilizer application
Using phosphate-free detergents/fertilizers
Planting vegetation to increase nutrient uptake

5. Human Wastewater
Human wastewater is water produced by human activities (sewage, laundry water). High in nutrients. Leads to 3 concerns
Oxygen demanding waste is organic matter that enters water and feeds the growth of microbes that are decomposers.
The more waste in the water, the more microbes. More microbes, the more they demand oxygen
Biological oxygen demand (BOD) is the amount of oxygen microbes use when breaking down waste
High BODs typically mean more wastewater. Eventually leads to dead zones because not enough oxygen to support life
When organic matter is decomposed, nutrients are released
Eutrophication – nutrients added to water which brings algae blooms. These die and bacteria increases and uses up oxygen
Cultural eutrophication is caused specifically by humans

6. Continued… 3.1 million deaths per year caused by unsafe drinking water
Wastewater can carry parasites and bacteria that can make humans ill. These are called pathogens
Cholera, typhoid fever, flu, diarrhea
3.1 million deaths per year caused by unsafe drinking water
We only test for certain bacteria in our water since there are so many different kinds

12. Treatment of Wastewater
Septic systems are sewage treatment systems found in rural areas. Has two major components
Septic tank takes wastewater in one end, and releases it out the other
Leach field are pipes where the septage (clear layer full of bacteria) moves out. Septage slowly leaks out of pipes into the ground
Sewage treatment plants are used for urban areas
Primary treatment lets solid stuff settle and become sludge. From there it can be taken to landfill, farms, etc
Secondary treatment uses bacteria to break down remaining organic matter. Also has a settling tank
Water gets released to nature, but contains high N and Ph levels
During times of heavy rain, treatment plants are overloaded and release raw sewage into nearby bodies of water

17. A typical wastewater treatment facility
Sludge = solid material resulting from treatment
Is decomposed microbially
Then landfilled, incinerated, or used as fertilizer on cropland
Methane-rich gas created by decomposition can be burned to generate electricity

18. Heavy Metals and Acid Deposition
Lead enters water through old lead pipes. Can damage brain, kidneys, and nervous system (especially babies)
Arsenic occurs naturally in rocks, but is increased by humans breaking up rocks. Leads to various cancers.
Mercury is natural and is also increased by human activities. Most human related mercury comes from burning fossil fuels.
Attacks central nervous system and fetuses. Often found in fish, mostly top consumers (bioaccumulation)
Acid deposition comes from burning ff. Leads to death of trees and aquatic ecosystems. Coals scrubbers and static help

21. Synthetic Organic compounds
SOC are man-made organic compounds
Pesticides help control pests, but lead to other problems
Don’t only kill pest they are designed to kill
Affect organisms down the food chain that eat these pests
Cancer, birth defects, bioaccumulation
Other common compounds found in water include military compounds, pharmaceutical drugs, and industrial compounds

22. Oil Spills
Toxic to many species, including algae which starts aquatic food webs
Surface oil is sucked up, skimmed up, chemicals are applied that break it up, bacteria is applied that eats it up, or coagulate it
No easy way to clean up underwater plumes

24. Not All Pollutants are Chemicals
Solid waste production
Plastic rings strangle animals
Medical waste hazardous to humans
Coal ash, which contains heavy metals
Sediment pollution comes from small particles carried in rivers
Occurs from land erosion (mostly in agricultural areas)
Reduce sunlight, this reducing photosynthesis
Clog gills
Thermal pollution is when human activity causes water temp to change (power plants)
Dissolved oxygen decreases as temperature increases
Noise pollution can affect animal communication (SONAR)

29. Pathogens and waterborne diseases
Enter water supplies through inadequately treated human waste and animal waste from feedlots
Fecal coliform bacteria indicate fecal contamination
They are not pathogenic organisms
But the water may also hold other disease-causing pathogens (e.g., giardiasis, typhoid, hepatitis A)
Bacterial pollution causes more human health problems than any other type of water pollution

31. Dissolved Oxygen (DO)
DO (measured in PPM) is necessary for aquatic life
Most comes from atmosphere
Rapidly moving water has higher DO levels
Stagnant water with high levels of organic matter can contain oxygen consuming bacteria that leads to eutrophication
As water temp increases, DO levels decrease, thus eutrophication is worse in summer

32. Laws Clean water act (1972) Safe drinking water act (1974, 1986, 1996)
Supports the protection and propagation of wildlife and recreation in and on the water
Defined standards of acceptable limits of various pollutants
Control how much discharge industries can put in water
Safe drinking water act (1974, 1986, 1996)
Established max contaminant level for 77 different elements or substances in surface and ground water

33. Problem:
In 2010, the South Anna River had a largemouth bass population of 25,000 individuals over a 10–mile stretch. In early 2011, a chemical spill occurred and the population of largemouth bass decreased to only 5000 individuals over the same area. Calculate the percent change in largemouth bass in the South Anna River.
To calculate percent change: divide the difference between the beginning and ending quantity by the original beginning quantity. Then, multiply the answer (the quotient) by 100 to find the percent change.