OAK HAMMOCK MARSH, Man. – The Oak Hammock Marsh area is filled with
ponds and marshes that provide homes to thousands of ducks, geese and
other waterfowl. It’s a pleasant, inviting home for migratory birds
that spend their summers here before flying south through the gauntlet
of raised shotguns held by the hunters who paid for this marsh to be
built.
This is not a natural marsh. At one time there was a large marsh here,
but the land was drained and flattened by farmers. That created more
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farmland, but removed a key nesting area for birds. So more than 20
years ago, Manitoba’s environment department and Ducks Unlimited, which
is funded by hunters, bought the land and started reversing the
drainage work. They built new marshland out of the cropland, and today
it’s hard to believe tractors ever plowed this soil.
The uneasy relationship between wetlands, wetland birds and farmers has
caused many fights.
Farmers see ducks and geese ravaging their crops, and drainage bans
limiting their ability to farm potentially productive land. Hunters see
farmers destroying the continent’s best nesting land for the sake of
more grain.
But lying in some of the artificial ponds here, and in some artificial
ponds in Manitoba’s Interlake region, may be something that could make
wetlands and farmland more complementary, and less antithetical.
“This is really low-tech,” said one visitor in a clearly admiring
manner.
What he was talking about was a regular-looking pond that didn’t smell
much. Near it were two other ponds, one bursting with cattails.
It was hard to believe that thousands of litres of human feces and
urine had been pumped into the pond earlier this summer.
This is the Oak Hammock Marsh visitor centre’s sewage system.
Human waste is collected, pumped into the first pond, allowed to sit
for a few weeks, and then flowed into the next pond, where it sits
again. Then it is directed into the third pond – the one with cattails
– where it sits again.
Then it is simply allowed to flow into the waterfowl marshes.
Ducks Unlimited officials say the water is not dangerous to the birds
and other marsh denizens, and the sewage water is actually cleaner than
the marsh water it joins.
The success of this system doesn’t surprise Pat McGarry of the Prairie
Farm Rehabilitation Administration. He’s helped build two similar
systems in the Interlake, which take feedlot manure and break it down
in pond systems.
“It’s often said that wetlands are the kidneys of the landscape,”
McGarry said.
“They’ve been here since the last ice age. We’re just harnessing
nature’s power.”
In 1996 and 1997 the PFRA built two pond systems beside feedlots to see
whether wetlands could be used to filter feedlot waste. Since then, the
systems have proven to work well and require little maintenance.
“We built it thinking it was proven technology, but you have to show
people,” said McGarry.
He admitted that building the wetlands isn’t cheap.
“The initial costs are fairly steep, but we think we can get those
down.”
The operating costs are only about $1.30 per head, McGarry said,
depending on animal density and other site-specific conditions.
Both PFRA systems were built on three to four acres of pasture.
The water can be used for irrigation, or it can be released into
wetlands.
Pond feedlot waste treatment systems have good potential, McGarry said,
but probably won’t catch on until more restrictions are placed on
feedlot runoff. If regulators begin forcing feedlot operators to
minimize fecal runoff, then a system like this will become attractive.
“Its time will come,” he said.
“It’s just a matter of getting the economics in line and there has to
be a push somewhere to increase people’s awareness of the need to do
something about feedlot runoff.”
When that push comes and feedlot operators begin looking for a solution
to their runoff problems, McGarry wants to be there with a proven
system.
The PFRA is now writing its final report on the two systems it built,
information that producers will be able to use.
“They’re proven effective.”
