We believe in the wisdom of nature's design. We know that
soil, water, plants, and wild creatures depend upon each other and are
vital to human life. We recognize that each living thing links to many
others in the chain of nature. We believe that persistent research into
the intricate patterns of outdoor life will help to assure the wise use
of earth's abundance. So we will be vigilant to protect wilderness areas,
refuges, and parks and to encourage good use of nature's storehouse of
resources.
-statement of Audubon philosophy from "Corkscrew
Swamp Sanctuary, a Self-guided Tour of the Boardwalk," 1960.
The world is a vast repository of unappreciated or unknown
biological strategies that have immense importance for humans if we can
develop a science of integrating the stories embedded in nature in the
basic systems that sustain us. The survival of civilization may well require
that we enter into the natural world and use its teachings to reshape and
redefine our tools and technologies.
--John Todd, March 1990
BACKGROUND
The Corkscrew Swamp is an incredibly magnificent
natural attraction. With its cathedral-like old growth cypress forest and
abundant resident wildlife, it offers some of the best wildlife and nature
viewing and photographic experiences in the world. But when it was established
in 1954, it was a remote wilderness, attracting fewer than 10,000 visitors
annually in its early years.
Forty years later, however, attendance
surpassed 100,000 visitors a year and the increase in visitors overwhelmed
the sanctuary facilities. Accommodations were made in most areas and eventually
improvements came: a new boardwalk was finished in 1996 and ground was
broken in October, 1998, for an adjacent new visitor/education center.
But the inability to handle waste water from the rest room facilities was
an immediate, intolerable, and illegal problem. At the 100,000 visitor
level, Florida law required the Sanctuary to build a sewage system.
CONVENTIONAL SYSTEMS
Conventional wisdom recommended two small
"package" plants working in tandem, both running full speed during
the tourist season and only one during the off-season. The problem with
this traditional solution involved questionable efficiency and reliability.
Maintenance, chemical additives, the ultimate quality of the effluent,
and the large amount of space needed (several acres) were also major concerns.
A BETTER IDEA
Enter John Todd of Ocean Arks International.
He designed waste water treatment systems - called Living Machines - that
used sunlight, bacteria, green plants, and animals to restore water to
pure conditions.
Dr. Todd proposed a Living Machine for
Corkscrew Swamp Sanctuary that would occupy an area of only 70x70 feet,
purify wastes without additives, and recycle 90 percent of the purified
water back into the restrooms for reuse in the toilets. This innovative
system also cost substantially less than the conventional technology.
During the fall of 1993, National Audubon
Society worked with Dr. Todd to design a treatment system unique to Corkscrew
Swamp. Permits were submitted to the Florida Department of Environmental
Protection and required nearly six months for processing. The system was
considered experimental by the DEP and required more extensive monitoring
than less efficient treatment plants that served entire towns.
Construction began in May, 1994, and was
completed in October, 1994. Corkscrew now has the first Living Machine
treatment system permitted in Florida.
HOW IT WORKS -- PRINCIPLE
The Living Machine mimics nature because
it is a natural water restoration system instead of an artificial water
treatment plant. Its innovative aquatic treatment system restores waste
water to near-drinkable quality using native, nutrient-absorbing wetland
plants and animals. The water that passes through the system is typically
more pure than water that comes from municipal water treatment plants.
The key to accomplishing this is combining
living organisms chosen specifically to perform certain functions and placing
them in a contained enviromnent -- a Living Machine, or what Dr. Todd refers
to as "half engineered artifact and half wild nature."
HOW IT WORKS -- AT CORKSCREW
Waste is first pumped to two below-ground
10,000-gallon fiberglass tanks for initial anaerobic digestion.
Then it goes to two parallel series of
five 2,500-gallon tanks, each of which is furiously aerated and copiously
supplied with bacteria, green plants from algae to trees, snails, shrimp,
insects, and fish. Here ammonia and organic nitrogen are converted to nitrates.
Each one of the five tank-series is capable of handling 75% of the maximum
daily flow. Water then flows into a sixth tank where the water is pumped
out of the top to the next step, and any remaining sediment is pumped from
the bottom back to the anaerobic tanks. There, the sediment begins the
cycle again to be eliminated.
The process then continues in two 30'x30'
plastic-lined, artificial marshes filled with crushed limestone. The marshes
are planted with typical wetland species from Corkscrew Swamp including
alligator flag, arrowhead, pickerel weed, blue flag iris, and swamp lily
that remove the last vestiges of nitrogen through the root systems and
convert them to harmless nitrogen gas.
When the effluent exits these marshes,
it is clean. But to satisfy state regulators, it is disinfected with chlorine,
pumped to a holding tank, and then pumped to a chamber to dechlorinate
the water with sodium sulfite. The water is recycled into the restrooms
for flushing.
A separate line brings potable water from
the drinking water system for hand-washing sinks and drinking fountains.
BONUSES
A unique feature of the Corkscrew Living
Machine was the total coverage by an aluminum screen enclosure. This allowed
control of insect populations and the creation of a protected butterfly
aviary within the Living Machine in addition to the native plant butterfly
garden just outside.
The Living Machine is also an educational
opportunity. The entire facility is open to the public and interpreted
with signs and displays. "We've already booked tours that have come
specifically to see the system in action," said Ed Carlson, Sanctuary
and South Florida Audubon manager. "We feel this attractive yet functional
waste water treatment plant is the ideal setting to teach water chemistry,
purification, and recycling lessons."
