Transcript No Slide Title

When you pull the drain plug, wash clothes,
or flush the toilet the magic of wastewater
begins......
The clean water that comes into your
house by one set of pipes, must leave
your house by another
set of pipes.
When you live in the City the wastewater
that leaves your home is carried by a pipe
to the City’s sewer pipes that are buried
underground. Usually when you see
streets dug up for work on a pipe line, it is
either the sewer pipes or the pipes that
bring drinking water to your home.
When you live in the country, wastewater
goes into large underground tanks called
septic tanks.
The sewer pipes empty into
larger pipes, called trunk
lines. The City of Pueblo has
six major trunk lines that
merge to bring all the
wastewater to plant for
treatment.
The first thing we do to start cleaning the
wastewater is to run it through big
screens. These screens catch the rags,
diapers, rocks, pieces of wood and other
large items. A rake pulls the trash off the
screen and dumps it on a moving belt
that carries the trash to the truck that
takes it to the dump.
Gravel, seeds, and other heavy
particles are then removed from the
wastewater by a grit chamber that
spins the water in circles, allowing the
heavy particles to fall to the bottom.
The wastewater then
enters into the Primary
Clarifiers, which are
large tanks where the
water sits quietly. The
heavy solids that are
remaining settle to the
bottom and the lighter
things like grease float
to the top.
The heavy solids and the grease are taken to the digester to be
treated. We will talk about them more later. The water
coming off in between these layers is still dirty because it
contains stuff dissolved in the water.
It is ready to go onto the next process to be cleaned more.
At this point we have done
what we can to clean the
water and now we have to get
help. The wastewater is
carried to the top of many
layers of thin plastic webs in a
tank called a trickling filter.
As the water flows through
these webs, the webs get
covered with a slime of
bacteria, protozoa and fungi,
just like the slick rocks you
walk on in a stream. The
bacteria and fungi use the
dissolved organics, in the
wastewater for food and the
protozoa feed on the bacteria.
Pipes then carry the wastewater to the Aeration
Basin. This is a large tank with a lot of bacteria
and protozoa in it.
These bugs need to have oxygen bubbled into
the water to grow quickly. By eating the
dissolved materials as their food the bacteria
grow and increase in number until they can be
separated from the wastewater.
The wastewater is piped to other tanks called Secondary
Clarifiers that let the bacteria settle to the bottom, and
they are taken to the digester also. The nearly clean water
that comes off the top is piped to the next step.
Chlorine is used to kill any bacteria that are left
in the water before it goes back into the river.
Since chlorine can kill the fish, we have to
remove the chlorine with another chemical
called sulfur dioxide after the bacteria are
dead.
Now the water is clean and can be put into the river. In some
areas the water needs to be cleaner to keep the unwanted plants
and algae from growing so much that there isn’t any oxygen
left for the fish. If this is a problem then the wastewater plant
would also be required to remove nitrogen and phosphorus
before taking it back
to the river. These
nutrients are good in
small amounts since
they are the same as
the fertilizer you put
on your grass, but too
much can cause
problems.
Now are we done?
The river is getting
clean water
and…….
Oops…. what about the heavy stuff
from the bottom of all of the tanks?
This is called sludge. The sludge is
piped to a large tank called a digester
where it is heated to almost 100
degrees. The solids in the tank are
turned into gas and harmless sludge by
a different type of bacteria. The gas is
burned in a boiler to provide heat for
all the buildings at the Water
Reclamation Facility. After the sludge
has been in the digesters about 30 days
it is dried. The treated sludge, now
called Biosolids, looks almost like dirt.
The Biosolids can be put into a landfill
or used as a fertilizer to improve the
soil.
As you can see, our job is really to
just make the bacteria happy so
that they will do most of the work
to clean the wastewater for us.
We have to keep all the equipment working
to give them what they need and to move
the wastewater and sludge to the next step.
Wastewater treatment goes on every day
and every night. It is very important to
the quality of the water in our rivers, but
everything will stop getting clean if the
bacteria die. Dirty water can carry many
diseases that can cause illnesses that we do
not typically see in the United States
because of how we clean the water.
That is why it is
important not to
put any chemicals
down the drain in
your home. We
do not want to
kill the bacteria
and let dirty
water get into our
river.
Remember the water we have now
is all the water we've ever had, and
all the water we will ever have.
ONLY YOU CAN PREVENT
WATER POLLUTION
We have a responsibility to clean up our
wastewater to protect the river for everyone.
Remember:
We all live
downstream!