Transcript Have you ever been in a watershed?

Waste Water
Treatment
• Water that we use around the house and
some that enters storm sewers is treated
through a wastewater treatment facility.
Here the dirty water goes through a series
of processes to clean that water and make
it healthy enough to enter a river or lake
ecosystem.
Stages of Treatment
• There are three stages of conventional wastewater
treatment.
– Primary treatment: a clarifying tank lets the solids, like
poop, settle to the bottom and leave the water.
– Secondary treatment: the water is next oxidized by
allowing movement of the water. The oxygen helps
bacteria live and they in turn eat some of the nutrients in
that water, also more solids are allowed to settle out of
the water.
– Tertiary treatment: This is the “advanced” step in water
treatment. Chlorination is done to remove any potential
pathogens in the water. Dechlorination is then done to
remove the chlorine.
– Water is then discharged into a close river or lake.
Alternative Methods
• Many alternative methods have been
approached to treat water in a more natural
way without the use of chemicals. This is
done with:
– Living machines ( www.livingmachines.com )
– Wetlands and marshes
( www.humboldt.edu/~ere_dept/marsh/flow1.html )