SALEM, OREGON—
If you think
that making a silk purse out of a sow's ear sounds difficult, consider
the task that lies before the staff of Willow Lake Wastewater Treatment
Plant in Salem, Oregon. Over one hundred million gallons of sewage and
agricultural waste water pour into the plant every day, and before it
leaves, it must be clean enough to release into the Willamette River.
Supervisors
Dave Robben and John Magee, two of the professional water alchemists at
Willow Lake, walked us through the steps of filtering, digesting and chemical
treatment. Once the incoming water has been through the "barscreen,"
which snags big debris, it goes to a primary clarifier where heavier solids
are removed. The solids are recycled as "Biogro," which is used
in agriculture. The next step for the water is a filter that mimics the
natural cleaning action of a river. The water trickles over rocks, and
green "zoogleal slime" further cleans the water through microbial
action.
More microbes
work on the water in the "reactor," where the temperature is
just right for "activated sludge organisms" to feast sumptuously.
After the protozoans have finished with it, the water heads for the secondary
clarifier (pictured above). By this time, you'd have a hard time distinguishing
the water from what what you'd find in a lake, but the cleaning process
is not quite complete. Just to make sure that nothing unhealthful will
be released into the river, the water passes though a contact basin where
it is tested and disinfected with chlorine.
John showed
us a sample of treated water. "Would you drink it?" we asked.
"I'd drink it in a pinch," said Dave. "It's purer than
most water in most rivers." We decided against the ultimate test,
but marveled at the clarity of the water which only seventeen days before
had been raw sewage. "You really are magicians," we said.
Willow Lake
has other wonders. One is the "Enginator," a machine that turns
the methane gas generated by the water treatment process into enough electricity
to supply about 30% of the needs of the entire plant. Another is a stupendous
rose garden that just won seven ribbons in the Salem Rose Show. The top
wonder, however, is the staff of water wizards. These scientists and technicians
are true unsung heroes.
If
you're in the Salem area and would like to visit Willow Lake,
call (503) 588-6380 or write Willow Lake Wastewater Treatment
Plant, 5915 Windsor Island Road North, Salem, OR 97303.
Water
Wizards
