If something is potable that means it's safe to drink. In developed countries, tap water is usually potable. Potable water is for drinking and domestic use (cooking, bathing, watering the lawn, etc. We get potable water from springs, wells, streams, rivers, lakes etc. This water still must be treated to kill bacteria. It must also be tested to be sure that toxins from polluting sources have not made it unsafe to drink. The average person uses many gallons of water each day. After we have used it, the water may be dirty and no longer fit to drink. So what happens to that water?

1. Potable Water
Part One
Kella Randolph
Copyright 2019

2. Vocabulary
• Potable water
• Wastewater treatment
• Aquifer depletion
• Conservation

3. Potable water
• If something is potable that means it's safe to
drink. In developed countries, tap water is
usually potable. Potable water is for drinking and
domestic use (cooking, bathing, watering the lawn,
etc. We get potable water from springs, wells,
streams, rivers, lakes etc. This water still must be
treated to kill bacteria. It must also be tested to
be sure that toxins from polluting sources have not
made it unsafe to drink.
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ds/science/drinking_water.png
https://elimufeynman.s3.amazonaws.com/media/uploads/science/water_cooking.jpg
https://elimufeynman.s3.amazonaws.com/
media/uploads/science/water_bathing.jpg

4. Wastewater
The average person uses gallons of water
each day. After we have used it, the water
may be dirty and no longer fit to drink. So
what happens to that water?
Water can be contaminated by all sorts of
things. We flush water down the toilet to
remove urine and feces from the home. Our
soapy, dirty bathwater goes down the drain,
too. The dishwasher cleans out plates but
the detergent used can be harsh chemicals,
especially chlorine. So, do we just let all of
that go untreated and down to the river to
be dumped? That is not how we treat
wastewater.
https://scioly.org/wiki/images/thumb/3/35/Wastewater_treatment.jpg/550px-Wastewater_treatment.jpg

5. Steps in Wastewater
Treatment
• Wastewater Treatment plants use a series of
steps to clean water, but this water after
cleaning is not considered to be potable
(drinkable by humans). After being treated in a
wastewater treatment plant, this water is
released into a body of water and then cleaned
again before returning to your faucet.
https://upload.wikimedia.org/wikipedia/commons/5/54/ESQUEMPEQUE-EN.jpg
https://redoubtnews.com/wp-content/uploads/2018/06/nampa-header.jpg

6. Step One
Large particles are filtered out using screens
and filters
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9oRLS4iQsa89GE7Ku4WhU_&Key-Pair-Id=APKAJ5Y6AV4GI7A555NA

7. Step Two
The remaining water is mixed
with bacteria that break down
any material that is remaining.
http://bytesizebio.net/wp-content/uploads/2010/03/gut-bacteria.jpg

8. Step Three
• A final treatment is done in which the water
is passed under UV light, or chlorine or ozone
are added to the water to further break down
material and kill any pathogens that remain in
the water.
• A pathogen is an organism that produces a
disease. ... Fecal contaminations of water can
introduce a variety of pathogens into
waterways, including bacteria, viruses,
protozoa and parasitic worms. Bacteria. A very
well-known pathogenic bacteria is Salmonella.
https://www.appropedia.org/images/c/c5/UV_spectrum_bacteria.jpg
https://upload.wikimedia.org/wikipedia/commons/thumb/1/13/UV-ontsmetting_laminaire-vloeikast.JPG/1200px-UV-
ontsmetting_laminaire-vloeikast.JPG
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a6/55/pathogens_preview_featured.jpg

9. Water for Agriculture
• About 80% of the surface
water and groundwater used
each year in the United States is
used by farmers to irrigate their
crops. Much of the farmer’s
water supply is pumped from an
aquifer below the surface of the
farmland.
• Remember, an aquifer is an
area below the surface which is
made of permeable rock layers,
gravel and sand that can hold
water or allow water to flow
through. Aquifers refill, or
recharge from precipitation that
infiltrates the soil and collects in
the aquifer.
https://c1.staticflickr.com/7/6232/6283083426_bb7e7d9c95_b.jpg

10. Aquifers
• Aquifers fill when there is
precipitation and water can be
removed from aquifers by
pumping. If the water coming
into the aquifer is about the
same amount as the water going
out, then there is balance. But,
if the farmer is pumping water
out faster than the aquifer can
recharge, eventually there will
be nothing left. This is called
aquifer depletion.
• The largest aquifer in the US is
the Ogallala Aquifer beneath the
Great Plains. This is the same
area that suffered the Dust bowl
in the 1930s.
https://modernfarmer.com/wp-
content/uploads/2015/07/ogallala_aquifer_usgs-1200x743.jpg

11. The Ogallala Aquifer
• The Ogallala Aquifer underlies
approximately 225,000 square
miles in the Great Plains region,
particularly in the High Plains of
Texas, New Mexico, Oklahoma,
Kansas, Colorado, and Nebraska.
• The Ogallala Aquifer is a
shallow water table aquifer
surrounded by sand, silt, clay, and
gravel located beneath the Great
Plains in the United States. One of
the world's largest aquifers, it
underlies an area of
approximately 174,000 sq mi in
portions of eight states. It was
named in 1898 by geologist .
Wikipedia
https://www.google.com/search?kgmid=/m/0_86g
&hl=enUS&kgs=ce7eecdf61ecbc28&q=Ogallala+Aqu
ifer&shndl=0&source=sh/x/kp&entrypoint=sh/x/kp
https://images.app.goo.gl/HVZyy43T45fCduTw6

12. The Ogallala Aquifer Depletion
The United States department of Agriculture ( USDA) has been working
to coordinate the various states that use this aquifer and establish a set
of rules to conserver the aquifer and prevent depletion.
By improving irrigating efficiency and implementing conservation
systems, producers benefit from using less water. Improved water
management reduces expenditures for energy, chemicals and labor,
while enhancing revenues through higher crop yields and improved crop
quality. Additionally these efforts help maintain the long-term viability
of the irrigated agricultural sector and offset the effect of rising water
costs and restricted water supplies on producer income.
By conserving water, the useful life of the aquifer may be extended, flow
is increased in rivers, benefiting wildlife like the least tern, whooping
crane, pallid sturgeon and piping plover.
https://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/national/programs/initiatives/?cid=stelprdb1048809
The Plains area now is covered with rich
crops of corn and other grains that are sold
as feed for cattle and other animals used for
food. But there is a problem.
The water in the Ogallala Aquifer is ancient.
It is called fossil water because the aquifer is
so old and deep. It recharges slowly because
that area does not receive much rain. To
make matters worse, the farmers are
pumping out water much faster than the
recharge can keep pace. So, estimates are
that within a number of years, aquifer
depletion will occur and a new Dust Bowl
could happen.
https://upload.wikimedia.org/wikipedia/commo
ns/thumb/4/47/Corn_production_in_Colorado.j
pg/1200px-Corn_production_in_Colorado.jpg