1. Living in the Environment
Water Pollution
G. Tyler Miller’s
Living in the Environment
13th Edition
Chapter 19

2. What is water pollution?
Any chemical, biological, or physical change in water quality that has a harmful effect on living organisms or makes water unsuitable for desired uses.

3. Major Categories Infectious Agents Oxygen-Demanding Wastes
Inorganic Chemicals
Organic Chemicals
Plant Nutrients
Sediment
Radioactive Material
Heat (Thermal Pollution)
Review Table 19.1!!

4. Common Diseases Transmitted Through Contaminated Drinking Water
Type of Organism
Disease
Bacteria
Typhoid fever
Cholera
Bacterial Dysentery
Enteritis
Viruses
Infectious hepatitis
Parasitic Protozoa
Amoebic Dysentery
Giardiasis
Parasitic Worms
Shistosomiasis

5. Effects of Yuck Water
Premature death of 3.4 million people worldwide each year
Diarrhea alone kills 2.1 million people

6. How do we measure water quality?
Presence or Absence of Harmful Pollutants
Concentration of Harmful Pollutants
Drinking water
0 colonies per 100 ml
Swimming water
200 colonies per 100 ml
HUMAN CONSUMPTION
RECREATION
Fecal Coliform Test

7. How do we measure water quality?
Measuring the level of Dissolved Oxygen (DO)
Fig p. 485

8. How do we measure water quality?
Using DO + BOD measurements
Using chemical analysis
Presence/Absence and concentration
Using indicator species
macroinvertebrates

9. Sources of Water Pollution
Point Sources
Discharge of pollutants at specific locations through pipes, ditches, or sewers into bodies of surface water.
Easier to control
Non-Point Sources
pollutants cannot be traced to any single source of discharge, diffuse sources
Difficult to control

10. Point and Nonpoint Sources
Urban streets
Suburban development
Wastewater treatment plant
Rural homes
Cropland
Factory
Animal feedlot
POINT SOURCES
Fig. 19-4
p. 486

11. Pollution of Streams
DO + BOD Relationships
Fig p. 488

12. Oxygen Sag Curve

13. Pollution of Lakes Slow turnover Thermal stratification
Flushing and changing of water temp
Thermal stratification
Little vertical mixing
Biological Magnification
Increase in the concentration of chemicals in organisms at successively higher trophic levels of a food chain
Eutrophication
Natural nutrient enrichment of lakes

14. Biomagnification Water 0.000002 ppm Phytoplankton 0.0025 ppm
Herring gull
124 ppm
Phytoplankton
ppm
Herring gull eggs
124 ppm
Zooplankton
0.123 ppm
Lake trout
4.83 ppm
Rainbow smelt
1.04 ppm

15. 1. Eutrophication – enrichment of a body of water by inorganic plant and algal nutrients
Creates environmental problems as:
- excess nutrients enter water system
- increases photosynthetic productivity
- numbers of algae and cyanobacteria increase
- water become cloudy (turbid) from population increase
- populations die off and sink to bottom
- become food for decomposers
- decomposers  BOD but DO in waters
- fish die off
other species take root in nutrient rich sediments and begin to fill in waters
Lake said to be eutrophic!
Cultural or artificial eutrophication can occur as nutrient levels are increased from sewage or agricultural runoff into waterways!

16. Pollution of Lakes
Fig p. 491
Cultural Eutrophication

17. Oligotrophic Waters
Oligotrophic waters – have minimal levels of nutrients, unenriched, clear waters, small populations of aquatic organisms

19. Reducing Surface Water Pollution
Nonpoint Sources
Point Sources
Reduce runoff
Clean Water Act
Buffer zone vegetation
Water Quality Act
Reduce soil erosion

20. POLLUTION OF GROUNDWATER
It can take hundreds to thousand of years for contaminated groundwater to cleanse itself of degradable wastes.
Nondegradable wastes (toxic lead, arsenic, fluoride) are there permanently.
Slowly degradable wastes (such as DDT) are there for decades.

21. Groundwater Pollution: Sources
Hazardous waste injection well
Pesticides
Coal strip mine runoff
De-icing road salt
Buried gasoline and solvent tank
Pumping well
Cesspool septic tank
Gasoline station
Waste lagoon
Water pumping well
Sewer
Landfill
Leakage from faulty casing
Accidental spills
Discharge
Unconfined freshwater aquifer
Confined aquifer
Confined freshwater aquifer
Groundwater flow

22. Contaminant plume moves with the groundwater
Leaking
tank
Aquifer
Water
table
Bedrock
Figure 21.8
Natural capital degradation: groundwater contamination from a leaking gasoline tank. As the contaminated water spreads from its source in a widening plume, it can be extracted by wells used to provide water for drinking and irrigation.
Groundwater
flow
Free gasoline
dissolves in
groundwater
(dissolved
phase)
Gasoline
leakage plume
(liquid phase)
Migrating
vapor phase
Water well
Contaminant plume moves
with the groundwater
Fig. 21-8, p. 502

23. Groundwater Pollution Prevention
Monitoring aquifers
Leak detection systems
Strictly regulating hazardous waste disposal
Storing hazardous waste materials above ground

24. Water Break

25. Sewage Treatment
Septic tanks and various levels of sewage treatment can reduce point-source water pollution.

26. Sewage Treatment
Raw sewage reaching a municipal sewage treatment plant typically undergoes:
Primary sewage treatment: a physical process that uses screens and a grit tank to remove large floating objects and allows settling.
Secondary sewage treatment: a biological process in which aerobic bacteria remove as much as 90% of dissolved and biodegradable, oxygen demanding organic wastes.

27. Sewage Treatment
Primary and Secondary sewage treatment.

28. in landfill or ocean or applied to cropland,
Primary
Secondary
Chlorine
disinfection tank
Bar screen
Grit chamber
Settling tank
Aeration tank
Settling tank
To river, lake,
or ocean
Sludge
Raw sewage
from sewers
Activated sludge
(kills bacteria)
Air pump
Sludge digester
Figure 21.16
Solutions: primary and secondary sewage treatment.
Disposed of
in landfill or ocean or applied to cropland,
pasture, or rangeland
Sludge drying bed
Fig , p. 511

29. Primary Treatment
PRIMARY  removes suspended/floating particle screening and settling
Material removed called primary sludge

30. Secondary Treatment

31. Secondary Treatment
SECONDARY  microorganisms decompose suspended organic material
trickling filters = water flows through aerated rock beds with bacteria to degrade organic material
activated sludge process = aerated and circulated water with bacteria is allowed to settle out creating secondary sludge
NOW FREE OF SEWAGE!

32. Sewage Treatment Advanced or tertiary sewage treatment:
Uses series of chemical and physical processes to remove specific pollutants left (especially nitrates and phosphates).
Water is chlorinated to remove coloration and to kill disease-carrying bacteria and some viruses (disinfect).
TERTIARY  bio/chem/phy process that removes dissolved minerals (N & P), metals, viruses, organic cmpds

33. Sludge Disposal Options
Anaerobic digestion (need space and time)
Convert to Fertilizer (Town of Cary)
Incineration (Carbon dioxide emissions – ash disposal harmful)
Ocean Dumping – BAN in 1988/1991
Landfill Disposal

34. Advanced Sewage Treatment
Removes specific pollutants
Fig p. 505

35. DRINKING WATER QUALITY
Centralized water treatment plants and watershed protection
can provide safe drinking water for city dwellers in developed countries.
Simpler and cheaper ways can be used to purify drinking water for developing countries.
Exposing water to heat and the sun’s UV rays for 3 hours can kill infectious microbes.

36. 2 million plastic bottles, dumped every 5 minutes.
Is Bottled Water the Answer?
2 million plastic bottles, dumped every 5 minutes.

37. Is Bottled Water the Answer?
Some bottled water is not as pure as tap water and costs much more.
1.4 million metric tons of plastic bottles are thrown away.
Fossil fuels are used to make plastic bottles.
The oil used to produce plastic bottles in the U.S. each year would fuel 100,000 cars.

38. Safe Drinking Water Act (1974)
set uniform standards for drinking water across US
states had various standards prior to this date
EPA determined MCLs (maximum contaminant levels)
EPA oversees program
Amended 1986 & 1996
1996 Amendment required disclosure to citizens of contaminants in water

39. CLEAN WATER ACT (1977) Amended 1981 & 1987
formerly known as Water Pollution Control Act
TWO MAIN GOALS
eliminate discharge of pollutants
attain water quality for safe fishing and swimming
CWA effective at improving water quality at point sources
Point source discharges must obtain NPDES permits
(National Pollutant Discharge Elimination System) to release untreated wastewater into waterways
Nonpoint Source discharges very difficult to control
1987 NPDES permit needed for nonpoint source discharges
CWA not as effective at monitoring these discharges due to lack of cooperation/coordination between govt, citizens, and industry

40. CLEAN WATER ACT
CWA effective at improving water quality at point sources
Point source discharges must obtain NPDES permits
(National Pollutant Discharge Elimination System) to release untreated wastewater into waterways
Nonpoint Source discharges very difficult to control
1987 NPDES permit needed for nonpoint source discharges
CWA not as effective at monitoring these discharges due to lack of cooperation/coordination between govt, citizens, and industry

41. CLEAN WATER ACT
1987 NPDES permit needed for nonpoint source discharges
CWA not as effective at monitoring these discharges due to lack of cooperation/coordination between govt, citizens, and industry