Welcome!
Please pass back the
permission slip and
read the board!
Field work next week – Water quality testing
Mon
Tues
Wed
Th
Fri
Assign test,
practice
Practice test
In field to run
test
In field to run
test
Analyze
results
Have you ever been in a place
where you can’t drink the water?
CLEAN WATER
Pollutant of the Day!
Pathogens
World Health Organization Statistics:
Concerns:
Improvements:
 2.6 billion people do
 84% of the population
not have adequately
clean water
 rural habitants are 5
times less likely to use
improved drinking
water than those in
urban centers.
in developing regions
are using an improved
source;
 in 2000, 1 billion more
people used such a
source than in 1990.
 One out of four urban dwellers
UN-Water
Decade
Programme on
Advocacy and
Communication
does not have access to improved
sanitation facilities.
 90% of all waste water in
developing countries is
discharged untreated, polluting
rivers, lakes and seas.
 Every day, 2 million tons of
sewage and other effluents drain
into the world's waters
Bacterial pathogens
 Typhoid – diarrhea, severe vomiting, inflamed
intestines
 Cholera – diarrhea, severe vomiting
 Dysentery – diarrhea, usually only fatal in infants
Giardia protezoan – diarrhea, cramps,
fatigue
Schistosomiasis – parasitic worm
Guinea worm – burns as it leaves the human body
'Fiery serpent' ... A guinea worm emerges from the leg of a south Sudanese girl.
(Reuters: Skye Wheeler, file photo)
How are all of these passed on?
Global water initiatives
The Life Straw
LifeStraw
Swiss-based Vestergaard
Frandsen for tourists and people
living in developing nations.
There are several models of the
product: LifeStraw Personal
filters a minimum of 700 litres of
water, enough for one person
and one year. LifeStraw Family
filters a minimum of 18,000 litres
of water, providing safe drinking
water for a family for more than
two years. It removes 99.9999%
of waterborne bacteria, 99.99%
of viruses, and 99.9% of
parasites. LifeStraw Personal
kills 99.9999% of waterborne
bacteria and 98.5% of viruses.
OK, so what happens to water
in the US?
Septic Tanks – out in the country
trap greases & large solids & discharge the
remaining wastes over drainage field
Fig. 12–26
© Brooks/Cole Publishing Company / ITP
OK, so what happens to MY
water?
Primary Treatment
involves screens & settling tanks to remove
solids from sewage
Fig. 12–27
© Brooks/Cole Publishing Company / ITP
Secondary Treatment
uses biological processes to break down
biodegradable, oxygen–demanding wastes
Fig. 12–27
© Brooks/Cole Publishing Company / ITP
Advanced Treatment
uses one or more processes to remove specific pollutants
Fig. 12–28
© Brooks/Cole Publishing Company / ITP
Sewage treatment facilities are SOURCES of
pathogens IF
 Volume is too great, causing material to move
through too quickly.
 Leaks in the system or other technical damage
 In northern US, storm drains and sewage treatment
plants are often combined systems. Big storms can
cause overflow.
Wichita Falls, Texas 2014
*Heavy duty
filtration
*2
decontamination
stages
*lots of testing
*water cleaner
than reservoir
Constructed wetlands for sewage treatment
 Slow water = time to
settle solids
 Plants absorb nitrates
and phosphates
 Organic material has
time to decompose
Constructed wetlands for sewage treatment
*Primary, Secondary
treatment
*Eight wetland cells with a
variety of broad- and narrowleaved emergent plants, and
six of the cells were planted
with three species of woody
plants.
*Capacity of the system
13,800 gallons per day.
Check for understanding
 Name one bacterial pathogen
 Name one parasitic worm
 How do human pathogens get into our water supply?
 How will you remember that primary sewage




treatment is physical?
Name one action that primary treatment involves.
Why is oxygen bubbled through sewage during
secondary treatment?
Why is tertiary treatment rare?
What ecosystem naturally mimics sewage treatment?
Compare Contrast
Water
treatment
plant
Sewage
treatment
plant