Transcript Safe Water Notes - IHMC Public Cmaps (3)

Safe Water &
Treatment of
Drinking Water
Notes
• Water Treatment Process
– Sedimentation – the heavy particles settle to
the bottom and the clear water moves on.
– 1st Filtration – the water passes through a
layer of sand to remove large particles.
– Coagulation- removes dirt and other particles
suspended in water. Alum and other
chemicals are added to the water to form tiny
sticky particles to
• attract the dirt particles. The combined
weight of the particles becomes heavy
• EPA: Environmental
Protection Agency
(government agency) that
sets standards for safe, clean
drinking water
EPA was established in 1970,
a time when rivers actually caught fire!
Rail car accident set the oily Cuyahoga River on fire in 1969
Photo Credit: Cleveland State University Special Collections
Dead Fish in Grand Lake, CO
1972 epa.gov
• EPA standards are guidelines for
the protection of our natural water
sources and the quality of water
that reaches our homes
• Government agencies in states
and local communities enforce
laws based on the EPA
standards.
• Local water providers regularly test
water to make sure that it meets EPA
standards.
• If any concentration (amount of a
substance that is in another
substance) is higher than EPA
standards, the water must be treated.
• This is why the U.S. has one of the
safest, cleanest water supplies.
Substance
Common Source
Maximum Allowed, in
parts per million
Copper
Natural deposits; household
pipes
1.3
Cyanide
Various factories
0.2
Lead
Natural deposits; household
pipes
0.015
Mercury
Refineries, factories, landfills
0.002
Nitrite
Water running off fertilized
fields; sewage leaks
1
p. 51C in textbook
Treatment Process of Drinking Water
Treatment of Drinking Water
1. Water in a river or lake is piped to the
treatment plant.
2. Water flows through mixers where
clumping agents are added to make the
dirt and bacteria clump together
• 3. water flows through a clarifying pool, the
clumps sink to the bottom and water
becomes clearer
• 4. water flows through coal, sand, gravel
and is filtered
• 5. Chlorine is added to kill the last of the
bacteria
6. Treated water leaves the plant and can be
stored in water tanks so that there is
plenty of water available when people
need it.
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Coagulation
Sedimentation
1st filtration
2nd filtration
Disinfection
Storage