Geography 2011A/B Lecture Notes - Lecture 2: Polycyclic Aromatic Hydrocarbon, Point Source Pollution, Biomagnification
7 May 2018
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MODULE TWO
State of the Great Lakes: Water Quality and Quantity
Goals and Objectives:
This module is designed to provide an overview of the state of the environment in the Great Lakes (and in Ontario to
a lesser extent). You will learn about types and sources of water pollution, and gain an understanding of how pollution
has impacted the Great Lakes over the last 50 years. You will develop an appreciation of the complexity of Great
Lakes water levels and learn about the demand for fresh water that puts pressure on the lakes.
At the end of the module you should be able to:
• List and describe the major types of water pollution and their sources
• Understand the concerns and difficulties associated with each of the types and sources
• Have an appreciation of the historical and current state of the environment in the Great Lakes (and Ontario
to a lesser extent)
• Be aware of issues related to water levels and pressures for diversion of water from the lakes.
Readings:
The Great Lakes: An Environmental Atlas and Resource Book, Jointly produced by the Government of Canada
and United States Environmental Protection Agency, Third Edition,
1995 http://nepis.epa.gov/Exe/ZyNET.exe/P1004ICU.TXT?ZyActionD=ZyDocument&Client=EPA&Index=1995+Thru+
1999&Docs=&Query=&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear
=&QFieldMonth=&QFieldDay=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5Czyfiles%5CIndex%20D
ata%5C95thru99%5CTxt%5C00000023%5CP1004ICU.txt&User=ANONYMOUS&Password=anonymous&SortMetho
d=h%7C-
&MaximumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=p%7Cf&DefSeek
Page=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=1&Se
ekPage=x&ZyPURL
• Chapter Two – Natural Processes in the Great Lakes(just the following subsections)
Surface Runoff
Wetlands
Groundwater
Lake Levels
Lake Processes
Living Resources
• Chapter 4 – The Great Lakes Today – Concerns (the entire chapter)
Water Level Fact Sheet, from Environment Canada. (Posted at the bottom of this page)
“Why the Great Lakes are Slowly Getting Less Great” by Kim Mackrael from The Globe and Mail, August 25,
2012. (Posted at the bottom of this page)
"A Balanced Diet for Lake Erie: Reducing Phosphorus Loadings and Harmful Algal Blooms"
February, 2014. Pages 1 - 6 only. (Posted at the bottom of this page).
Types of Water Pollution
There are two primary types of water pollution: NON-PERSISTENT and PERSISTENT
It is important to understand the difference between them because they have different impacts over time, and very
different strategies must be used to manage them.
Non-Persistent Pollutants:
• Non-persistent pollutants are degradable over time
• This means that environmental damage can be reversible
• Can be broken down by chemical reactions or by natural bacteria into simple, non-polluting substances
Examples:
Domestic sewage
Fertilizer
Some industrial wastes
find more resources at oneclass.com
find more resources at oneclass.com
Non-persistent pollutants can be very damaging in the short term. Sewage and agricultural runoff can contain
harmful pathogens that can cause disease or death.
· Humans at risk of contracting bacterial, viral and parasitic diseases
· Can get ill from drinking contaminated water (i.e. Walkerton Water Crisis – e-coli in a local well)
· Also risks from direct body contact with contaminated water (i.e. beach closings in Toronto due to high bacteria
counts after heavy rains)
· in many developing countries, 80% of diseases are water-related
This link will take you to several clips about the history of pollution in the Great Lakes. It is an excellent archive worth
exploring to get the whole picture of pollution in the lakes:
http://www.cbc.ca/archives/topic/troubled-waters-pollution-in-the-great-lakes
And now, in the 21st Century, the Great Lakes is facing chemicals of emerging concern. These include:
• pharmaceuticals
• endocrine disrupters
• flame retardants
• microbeads
Check out these links for more information:
http://globalnews.ca/video/1586647/environmental-concerns-over-microbeads-draining-into-great-lakes
http://www.cbc.ca/news/canada/5-chemical-threats-to-the-great-lakes-1.1055139
Non-persistent Pollution – Lake Erie Case Study
Lake Erie provides us with a very good case study to see the impact and cleaning up of non-persistent pollution. We
can track the changes in the lake over the last 50 years.
Lake Erie underwent a period of intense “eutrophication” which resulted in a huge growth in algae and a massive die-
off of fish. This reached a peak in the late 1960s and early 1970s. Much effort and regulation was put into place to
solve the problem, and in many ways it was successful. However, problems have begun to re-emerge in Lake Erie.
There is a good summary of the historical situation in your reading (Chapter 4 of the Great Lakes Atlas). The “Late
Great Lake” article brings you up to date on the state of Lake Erie.
Eutrophication and Oxygen Depletion
• Each lake has a natural level of biological productivity = the amount of living material supported within a
lake
Lakes that are the least productive = Oligotrophic
Lakes that have intermediate productivity = Mesotrophic
Lakes that are most productive = Eutrophic
• Eutrophication ...... is to become more productive
Biological productivity of any lake is determined by:
• temperature
• light
• depth
• volume
• nutrients
Lake Erie (and the other Great Lakes) naturally not very productive = oligotrophic
However, the natural conditions have been impacted by human activity:
• Temperatures of tributaries increased. How?
Forest cleared by the water so there is more sunlight
Water returned to lakes and rivers after use may be warmer
• Amount of nutrients increased – more phosphorous, nitrogen and potassium
• Sources? -- phosphate detergents, fertilizers
Eutrophication (lake is becoming more productive)
• increase in nutrients = growth of plants
• plants die, settle, and decompose
• this decomposition uses dissolved oxygen
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
State of the great lakes: water quality and quantity. This module is designed to provide an overview of the state of the environment in the great lakes (and in ontario to a lesser extent). You will learn about types and sources of water pollution, and gain an understanding of how pollution has impacted the great lakes over the last 50 years. You will develop an appreciation of the complexity of great. Lakes water levels and learn about the demand for fresh water that puts pressure on the lakes. At the end of the module you should be able to: The great lakes: an environmental atlas and resource book, jointly produced by the government of canada and united states environmental protection agency, third edition, Page=x&searchback=zyactionl&back=zyactions&backdesc=results%20page&maximumpages=1&zyentry=1&se ekpage=x&zypurl: chapter two natural processes in the great lakes(just the following subsections) Living resources: chapter 4 the great lakes today concerns (the entire chapter)
