1. Chapter 5
Water Quality
Prof. Dr. Ali El-Naqa
Hashemite University
June 2013

2. Chapter Headings
 Water Pollution
 Basic Parameters of Water
 Inorganic Chemicals
 Organic Chemicals
 Waterborne Diseases
 Water Quality Management

3. Water Pollution Water pollution can affect
 Surface waters
 Ground waters
 Can occur naturally but is usually due to man’s activities
 US waters have improved significantly since the Clean
Water Act Amendments were passed in 1972
 But many waters still don’t meet standards

5. Point Source Pollution
 Contamination
discharged through a
pipe or other discrete,
identifiable location
 Relatively easy to
quantify and evaluate
impact
 Historically, the focus of
regulation
Water. 1993. National Geographic Special Edition

6. Point Sources
 Factories and sewage treatment plants
 Landfills
 Abandoned mines
 Underground and above-ground storage tanks

7. Nonpoint Source Pollution
 Contamination from a
diffuse source
 Difficult to measure
 Focus of recent
regulatory efforts
Soil erosion from a farm field
Gary Hawkins, UGA

8. Nonpoint Sources
 Lawns, gardens, and golf courses
 Agricultural and forestry practices
 Street refuse
 Construction activities
 Stormwater runoff

9. Chapter Headings
 Water Pollution
 Basic Parameters of Water
 Inorganic Chemicals
 Organic Chemicals
 Waterborne Diseases
 Water Quality Management

10. Basic Parameters of Water
 Temperature
 Dissolved oxygen (DO)
 pH
 Turbidity

11. Temperature
 Temperature affects physical, chemical, and biological
processes in water
 Chemical example: DO decreases as temperature
increases
 Biological example: fish seek thermal refuges
 Temperature affected by depth
 Causes lake turnover
 Loss of streamside shade trees causes temperature to
increase

12. Dissolved Oxygen Atmosphere consists of 21% O2
 Water consists of <1% O2
 When water and atmosphere come into intimate
contact, O2 tends to diffuse into water
 Occurs as water passes over riffles, rapids, and falls and
to a lesser extent in still water
 Aquatic plants also pump O2 into water
 During daytime when they are undergoing
photosynthesis

13. Dissolved Oxygen
 Fish depend on DO in
water
 O2 diffuses from water
to blood in gills
 When DO
concentrations in water
drop below 5 milligrams
per liter (mg/L) most
fish have trouble
www.fishdoc.co.uk

14. pH

15. pH
 pH = power of 10 for the H ion concentration (drop the
minus sign)
 Pure distilled water has a pH of 7 (neutral)
 1 x 10-7 = 0.0000001 moles H+ per liter
 Most rivers and lakes have a pH of 4 to 9
 Fish have a narrow range that varies by species
 pH outside the range can cause damage to gills, eyes,
skin, etc.

16. Turbidity
 Clarity of water
 Measured as light
penetration in
nephelometric turbidity
units (NTU)
 Also measured with a
Secchi disk
 Record the depth at
which you can no longer
see the banded colors
on the disk

17. Secchi disk depth comparison from clear (left) to murky (right)
http://earthobservatory.nasa.gov/Study/WaterQuality/water_quality2.html

18. Chapter Headings
 Water Pollution
 Basic Parameters of Water
 Inorganic Chemicals
 Organic Chemicals
 Waterborne Diseases
 Water Quality Management

19. Inorganic Chemicals
 Compounds that do not contain carbon (C)
 Originally defined as compounds that do not originate
in plants or animals
 Metals, minerals, and nutrients1
1book lists nutrients under organic compounds but most
nutrients are in the inorganic form

20. Metals Lead
 Used in electrical conductors, pipes (soldering), paints,
and a by-product of mining
 Lead poisoning causes toxic reactions, brain damage,
death
 Especially harmful to brain development in children
 Arsenic
 Found naturally in some rocks, in banned pesticides,
wood preservatives, and as an industrial by-product
 Causes neurological damage and cancers
 Drinking water standard used to be < 50 ppb
 Starting Jan 2006 it is < 10 ppb

21. Notice in Shanghai store says Barbie dolls are out of stock
Financial Post Canada.com

22. Arsenic in Bangladesh Wells
 For past 30 years, Bangladesh had a program to drill
wells for cleaner drinking water
 Traditional drinking water source was surface waters
contaminated with cholera, fecal bacteria, etc.
 5 million wells drilled
 83% of wells have toxic levels
 Arsenic occurs naturally in rock
www.uswaternews.com/archives/arcglobal/tarspoi4.html

23. Minerals
 All surface and groundwaters contain minerals
 At high concentrations they can cause adverse
effects
 Salt: sodium chloride (NaCl)
 Salinity: the presence of excess salts in water or in soil
 Saline water is undrinkable
 Saline soils make water uptake difficult for plants and
microbes
 Aquatic plants and animals sensitive to salinity (oysters
in Apalachicola Bay)

25. Colorado River and Salt
 U.S. irrigation and water withdrawals cause Colorado
River salinity to be very high by the time it reaches
Mexico
 1974 law requires average annual salt concentration be
<115 ppm at border
 Battery of wells at border
 13-mile long 5-mile wide area
 Pump low salinity groundwater into river to dilute salt
concentrations

26. Nutrients
 Major minerals important in animal and plant
nutrition:
 Nitrogen, phosphorus, potassium, calcium
 Trace elements also required in
 Iron, zinc, manganese, etc.
 At high concentrations in streams and lakes they can
cause problems

27. Nutrients: Nitrogen
 Nitrogen (N) an important plant nutrient
 Takes several forms in nature
 Nitrogen gas (N2)
 Nitrate (NO3
-)
 Ammonia gas (NH3)
 Ammonium (NH4
+)
 Organic forms

29. Nutrients: Nitrogen
 Nitrate in drinking water is a pollutant
 When ingested by babies in milk formula
 Causes methemoglobinemia or blue baby syndrome
 Converts to nitrite (NO2
-) which interferes with oxygen
transport in the blood
 Baby suffocates
 Drinking water standard is <10 ppm nitrate
 Very mobile in soil and leaches easily to
groundwater
 Sources: manures, fertilizers, sewage

30. Nutrients: Phosphorus Phosphorus (P) an important plant and animal
nutrient
 Can cause excessive algal growth in lakes
 A little bit of algal growth is good
 Source of food for fish
 Too much is bad
 Microbes that decompose dead algae use oxygen and lower
DO
 Low DO stresses fish, forcing them to the surface, selecting
against species such as trout, and even causing fish kills

31. Nutrients: Phosphorus Over time, lakes lose depth and naturally evolve
from low nutrient to high nutrient status
 Oligotrophic => mesoptrophic => eutrophic =>
hypereutrophic
 Happens over 100’s of years
 Excessive inputs of P speed up the process
 Call this accelerated eutrophication
 Happens over 10’s of years
 Concentrations as low as 0.01 ppm stimulate algae

32. Lake Aging
Natural Process Accelerated by land use

33. Nutrients: Phosphorus Lake in Manitoba Province
of Canada
 Divided by plastic curtain
 For 8 years
 N and C added each year to
one side
 N, C, and P added to other
side
 Every year there was an
algal bloom in response to
adding P
 www.umanitoba.ca/institu
tes/fisheries/eutro.html

34. Nutrients: Phosphorus Disinfection byproducts
• Occur when lake with algal bloom is a source of public
drinking water
 Chlorine used to disinfect water
 Chlorine combines with organic carbon to produce
carcinogens
 Taste and odor events
 Certain types of algae produce organic compounds that
give drinking water a “dirty taste” and foul odor

35. Nutrients: Phosphorus
Atlanta Journal
Constitution
17 Sep 2007

36. Nutrients: Phosphorus
 Sources: manures, fertilizers, sewage, detergents
 Not very mobile in soils
 Usually doesn’t leach to groundwater
 Instead it runs off into streams
 Dissolved in runoff or
 Attached to eroded sediment particles
 Not harmful to humans directly
 P was banned from detergents in 1990’s

37. Phosphorus concentrations in the Chattahoochee below Atlanta

38. Nutrients and Marine Waters
 Algal growth in marine waters is controlled primarily
by N
 P can be important at certain times of the year
 Estuaries (which are intermediate between fresh and
marine waters in terms of salinity) are affected by both
N and P

39. Gulf of Mexico Hypoxia
 Nitrogen from the
Mississippi River
watershed is causing
algal blooms and low
DO (hypoxia) in the Gulf
of Mexico each summer
 Dead zone at lower
depths kills aquatic
species including shrimp

40. Chapter Headings
 Water Pollution
 Basic Parameters of Water
 Inorganic Chemicals
 Organic Chemicals
 Waterborne Diseases
 Water Quality Management

41. Organic Chemicals
 Compounds that do contain carbon (C)
 Often large complex molecules
 May be natural or man-made (synthetic)
 Synthetic compounds may last for a long time in the
environment
 Natural decomposing processes are unable to break
down these complex molecules

42. Organic Chemicals
 Many synthetic organic chemicals are carcinogens:
 Benzene (C6H6), commercial solvent
 Carbon tetrachloride (CCl4), in fire extinguishers,
solvents, and cleaning agents
 Polychorinated Biphenyls (PCBs), used as a coolant in
electrical transformers
 Pesticides are synthetic organic chemicals used to
kill unwanted pests
 Can be harmful to humans and wildlife

43. Chapter Headings
 Water Pollution
 Basic Parameters of Water
 Inorganic Chemicals
 Organic Chemicals
 Waterborne Diseases
 Water Quality Management

44. Waterborne Diseases
 Early concerns regarding water quality caused by
waterborne diseases
 Plagues in the Middle Ages
 Cholera epidemic in 1848-1849 caused 53,000 deaths in
London
 Connection between disease and water was unknown
until shown by Dr. John Snow
 1854 Broad Street Pump study

45. Dr. John Snow
 Found that cholera causes
were clustered around a
community water pump at
Broad Street in London
 Water company that
supplied pump took it
from Thames River
downstream of London
 Advised that the pump
handle be removed

46. Replica of Broad Street
pump with handle
removed outside the
John Snow pub
www.ph.ucla.edu/epi/snow

47. Waterborne Diseases
 Microorganisms include
 Viruses – bits of DNA or RNA
 Bacteria – single cell organisms
 Other – protozoa, worms, blue-green algae
 Examples of microorganisms that are pathogens
(disease-causing organisms)
 Escherichia coli (E. coli) – bacterium
 Giardia – protozoa
 Cryptosporidium – protozoa

48. E. Coli E. coli are a common bacteria in the human
intestines
 Aid digestion, harmless
 Used as an indicator organism
 One strain of E. coli (0157:H7) is lethal, however
 In a town in Ontario in 2000, 2,300 people became ill
and 7 died when the water supply became contaminated
with 0157:H7
 Attributed to contamination from cattle manure

49. Spinach E. Coli Outbreak 2006
205 illnesses
3 deaths

50. Indicator Organisms
 Too costly and dangerous to test water for individual
pathogens
 Instead we test for indicator organisms
 Harmless but indicate fecal origin
 Common indicator organism
 Total coliform bacteria – seldom used today
 Fecal coliform bacteria – most common today

51. Indicator Organisms
 Standard for drinking water in Georgia is <1 fecal
coliform per 100 mL
 Standard for streams and lakes is <200 fecal coliforms
per 100 mL

52. Fecal coliforms in the Chattahoochee below Atlanta

53. Chapter Headings
 Water Pollution
 Basic Parameters of Water
 Inorganic Chemicals
 Organic Chemicals
 Waterborne Diseases
 Water Quality Management

54. Water Quality Management We try to manage water quality so that waters don’t
become contaminated (pollution prevention)
 Costly and risky to rely only on treatment of drinking
water (cryptosporidum oocysts unaffected)
 Reduce impact on wildlife
 Book calls this Fate and Transport
 The movement and ultimate disposition of pollutants
 Water quality management programs focus on
ground water and surface water

55. Groundwater Management Pollutants usually move horizontally in a plume away
from the source in groundwater
 Concentration decreases as pollutant gets farther away
from source
 Pollutant may break down with time
 Mixing with uncontaminated groundwater causes
dilution
 Pollutants may be more or less mobile
 Depends on adsorption to soil and rock

57. Groundwater Management
 U.S. EPA Superfund Program established in 1980
 Purpose to clean up highly contaminated point-
sources of pollution
 Currently there are more than 1,200 sites in the U.S.
 80% involve groundwater contamination

58. Groundwater Management
 Example site is Nebraska Ordnance Plant near
Mead, OK
 During WWII and Korean War, bombs were made
at the plant
 Solvent (TCE) and explosive compound (RDX)
were washed from the assembly buildings into
ditches and ponds
 Estimated that 22.5 billion gals of groundwater is
contaminated
 Extraction wells are being used to treat water and
restrict plume migration

60. Surface Water Management
 Water sampling is important part of surface water
quality management
 Only way to know if a river or lake meets the water
quality standard
 Also used to determine if clean up plan is working
 Federal and state agencies take samples
 Also volunteer groups (Adopt-a-Stream)

61. Surface Water Management
 Example of local volunteer group is Upper Oconee
Watershed Network (UOWN)
 http://www.uown.org/
 Quarterly monitoring of Upper Oconee River
 Annual River Rendezvous
 Maintain a database

62. Chapter Summary
 Pollutants come in many forms (inorganic, organic,
nutrients, microorganisms)
 Point and nonpoint sources of pollution
 Pollutants usually come from human activity
 Water quality management programs focus on
preventing pollution before it happens

63. Quiz
 Indicate whether the sources of pollution below are point
or nonpoint sources:
 golf course
 waste water treatment plant
 farm field
 Landfill
 underground storage tank
 construction activity
 Why is dissolved oxygen a water quality issue?
 Who was Dr. John Snow?
 What is an example of an inorganic water quality
pollutant?