If the last sewage
technician you saw was Art Carney on the old "Honeymooners" show,
then Glen Lowe of Black Butte Ranch will take some getting used
to.
For one thing, Lowe, 37, works in a laboratory that's as spotless
as a medical clinic and has almost as much scientific equipment.
For another, Lowe is a profes-sional who is justifiably proud of
his job as the Ranch's utilities -- water and sewage -- operator.
On a 24-hour-per-day basis, Lowe is responsible for more than
$2 million dollars worth of sewer and water lines, pump and lift
stations, and the large Ranch sewage treat-ment plant. Most of
Lowe's time is spent at the treatment plant. In simple terms, his
job is to make sure that the sewage needs of a small city (The
Ranch has 328 sewer hookups) are met in an efficient and unobtrusive
manner.
On an average day, 90,000 gallons of raw sewage enters the Ranch's
12-mile gravity flow system. How to transport that sewage and treat
it so the water and solids can be returned to the Ranch's ecosystem
without odor or contamination is Lowe's main job.
How well does the system work?
Quite well, according to Lowe. “Century West Engineering,
which designed our system, tested the lakes and creeks on the Ranch
last summer," he explained. "They tested all the inlet
springs and then the main stream that drains our lakes and the
whole Ranch site. They found that the quality of the water leaving
the ranch was the same as that tested at the inlet spring," Lowe
says.
According to the Oregon Depart-ment of Environmental Quality, which
monitors the plant's perfor-mance, the Ranch has one of the best
facilities and operator around. Bob Shimek, the DEQ inspector who
visits the plant at least quarterly and generally more often than
that, says, "Glen has done a real good job for the Ranch.
He's kept the plant working well in circumstances that probably
would have washed other plants out. He's been very conscien-tious
about his job."
Lowe submits a monthly report to the DEQ. The report includes
records of Lowe's daily tests in the laboratory. The DEQ also conducts
its own testing of the facility.
"The sewage plant is like a brewery," Lowe says. "You've
got to really operate it full bore in order to reach maximum efficiency."
"We're reaching maximum capac-ity with the system but we may
be able to hold off expansion for another year," Lowe says.
Lowe has three years of operating experience at the plant and
has completed a one-year extension course in environmental technology
from Linn-Benton Community Col-lege. He holds a Grade III State
sewage plant operator certificate and attends numerous short courses
each year.
While it's not normal drawing room conversation, here's how the
Ranch sewage system works:
Sewage enters the 12-mile net-work of sewer pipe
from the 328 hookups. The sewage flows, because of gravity, through
8 and 10 inch pipes to the headworks lift station about 100 yards
from the treatment facility. Because most of the 328 hookups
are on fairly flat ground, however, the gravity system needs
a little help. As a result, there are 12 lift stations which
do just that; lift the sewage, which has been flowing toward
the treatment plant because of gravity, up to a new level so
that gravity can take over again.
Eventually the sewage reaches the headworks
lift station where it is pumped into the plant. The first stop
is the grit chamber where the speed of the sewage flow is reduced
enough to allow sand and grit to settle out so that it can
be removed mechanically. From the grit chamber, the waste enters
a "comminuter" where
large particles are shredded. From this point, the sewage flows
by gravity to the 52,845-gallon aeration basin, which is one of
three separate sections in a large, round, concrete, barrel-like
structure 13 feet deep. It is in this "aeration" basin
where the "activated sludge" process takes place.
Basically, the "activated sludge" process
utilizes aerobic bacteria to stabilize the waste. Since aerobic
bacteria require oxygen to live, larger blowers in the control
building push air through pipes to the bottom of the aeration
tank, where it creates bubbles in the sewage and keeps the
waste in contact with the bacteria. Surprisingly, there is no
odor detectable at this stage, even when you stand a few feet
from the aeration basin.
As the sewage "bubbles" or aerates in the aeration basin,
some of it overflows into another separate chamber called the "clarifier." There,
the solid sewage settles to the bottom of the tank. A rotating
mechanism moves along the bottom of the tank and moves the settled
solids into a trough where they are then pumped into a third chamber,
the "reaera-tion" basin where they are again mixed
and constantly exposed to the air.
As the solids settle, in the second stage,
the "clarifier," a
very clear liquid or "effluent" remains. This effluent
flows by gravity out of the treatment plant and into a chlorine
basin located underneath the treat-ment plant building. Here,
the effluent is chlorinated for an hour. It is then pumped to
the Ranch meadow area where it is sprinkler-irrigated on the
meadow grass. While not very tasty, this water is free of contamination
and could be drunk.
The solids, meanwhile, are then pumped into
another chamber, the "digester," where
they are allowed more time with aerobic bacteria. It is this process
that further stabilizes the waste before it is allowed to settle
and concentrate. It then flows by gravity to a drying basin.
After the sludge is exposed to open-air drying, the result is a
very stable, practically odorless sludge which is valuable as humus,
having a fairly high fertilizer value. The dried sludge, like the
treated water, is eventually spread on the meadow grass.
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