Class Notes (923,128)
CA (543,101)
UTSC (32,996)
Geography (721)
GGRA03H3 (139)
Lecture 8

Lecture Eight

5 Pages
80 Views

Department
Geography
Course Code
GGRA03H3
Professor
Andre Sorensen

This preview shows pages 1-2. Sign up to view the full 5 pages of the document.
Lecture 8
Urban Ecosystems, Pollution
Urban Ecosystem Analysis
During the last 15 years new understandings of cities as complex ecosystems
Cities are now seen as complex organisms with their own metabolic processes
They have huge inputs and outputs that are structured by metabolic processes of
production, delivery, consumption and waste emission
Inputs and outputs can be measured and where necessary can be influenced by public
policy
It is critical to the understand the nature of inputs and outputs
To be able to reduce waste u need to know what is going on in a city- u cannot influence
until u know what is happening. Need to understand nature of inputs and outputs
Water inputs and outputs
Water is one of the most important urban inputs
Ensuring quality water supply is important for health
Polluted water is one of the main urban outputs
One of the key achievements of 19 century sanitary revolution was the development of
public water supply and waste water removal infrastructure
Initially just pipes to dump water downstream, later primary treatment secondary
treatment, tertiary treatment systems were added
Polluted water dumped somewhere else which is fine if u dump downstream and u r near
a lake, the problem is downstream people will get sick
Primary waste treatment was streams, let water and small particulates keep flowing,
secondary system= settling ponds , putting bacteria and aerating the water, bacteria
metabolized most of the organic matter and the other junk was filtered out ( rubber, paper
clips, that doesnt dissolve) so water is actually quite clean. Tertiary systems= take out not
just organic stuff but actually toxic material, example heavy metals that goes into sewer
systems, organic solvents. Now people are developing ways of cleaning toxic waste out of the
www.notesolution.com
system. There has been a progression of figuring out how to deal with more complicated
stuff thats in the waste water stream
Current Water Challenges
Arise partly from dominant sewer technology
Combined sanitary and storm water sewer systems used one set of pipes for all waste water
in cities
Works well in dry weather, but heavy rain events routinely overloaded the system and water
released into streams, rivers, lakes
Billions of gallons of untreated waste into water bodies
Gradually cities were rebuilding systems to separate sanitary and storm sewers
Storage for storm water surges
Problem of combined sewer system is that it only works when it is not raining. The problem
is when u have rain, almost all combined sewer systems ever built cannot handle storm
water surges so they dump untreated billions of gallons in nearby river and lake. One of the
solutions is separating the systems, trying to divert he storm water so it s=doesnt go into
the sewerage plan, building double sets of pipes. Storm water retention ponds. In new
suburbs the requirement in Ontario is that if u build a subdivision u have to keep storm
water on site, the parks are low lying areas. If u have huge heavy rain, there is an incentive
system to take water from roof and take it into garden so it will leak into the ground.
Enormous tunnel underground which holds certain cubic meters if water is for storm water
retention. When u have a surge of water it gets diverted fills up the tunnel and next day
after rain has stopped they start pumping it back out,
Current water challenges-2
Point source and non point source
Point sources are those where there is a clear point of discharge e.g. factories, sewers etc
with a pipe that discharges liquid wastes
These are relatively easy to monitor, and considerable progress in cleanup
Non point source pollution is everything else including pesticides and fertilizers on lawns,
dog feces and pollution on roads (anti freeze, gasoline, and tire rubber)
Things that dont have a single location. In a lot of cities dog shit is a big source. Non point
source is target for tertiary treatment system. Chemicals on the surface of the roads are
www.notesolution.com

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Description
Lecture 8 Urban Ecosystems, Pollution Urban Ecosystem Analysis During the last 15 years new understandings of cities as complex ecosystems Cities are now seen as complex organisms with their own metabolic processes They have huge inputs and outputs that are structured by metabolic processes of production, delivery, consumption and waste emission Inputs and outputs can be measured and where necessary can be influenced by public policy It is critical to the understand the nature of inputs and outputs To be able to reduce waste u need to know what is going on in a city- u cannot influence until u know what is happening. Need to understand nature of inputs and outputs Water inputs and outputs Water is one of the most important urban inputs Ensuring quality water supply is important for health Polluted water is one of the main urban outputs One of the key achievements of 19 century sanitary revolution was the development of public water supply and waste water removal infrastructure Initially just pipes to dump water downstream, later primary treatment secondary treatment, tertiary treatment systems were added Polluted water dumped somewhere else which is fine if u dump downstream and u r near a lake, the problem is downstream people will get sick Primary waste treatment was streams, let water and small particulates keep flowing, secondary system= settling ponds , putting bacteria and aerating the water, bacteria metabolized most of the organic matter and the other junk was filtered out ( rubber, paper clips, that doesnt dissolve) so water is actually quite clean. Tertiary systems= take out not just organic stuff but actually toxic material, example heavy metals that goes into sewer systems, organic solvents. Now people are developing ways of cleaning toxic waste out of the www.notesolution.com
More Less
Unlock Document


Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit