The Rural Voice, 1989-02, Page 21chemical fertilizer as well as manure.
And according to Dr. Beauchamp, this
is probably happening in Ontario.
Some farmers seem to disregard
the nitrogen in manure, and add more
fertilizer, he says. Year in and year
out, this can lead to nitrate problems
in the water table.
Nitrates and phosphates from
manure can also run off the land
surface into lakes and streams. In
Ontario, Dr. Beauchamp says, there
are some seepage problems associated
with clay soils. Clay is not as perme-
able to liquids as other soils; there are
cases where liquid manure has shown
up in drainage tiles and then found its
way into streams.
Some farmers seem to
disregard the nitrogen in
manure, and add more
fertilizer. Year in and year
out, this can lead to nitrate
problems in the water table.
Low soil permeability is also
associated with the seasons. Runoff
increases because frozen winter soils
absorb less moisture. So the timing of
manure application is critical. If the
manure is applied on top of ice and
snow, the likelihood of a pollution
problem is increased.
Happily for farmers, the recom-
mended times for manure application
coincide with the times that minimize
the risk from pollution.
Jack Westlake at the Grey County
office of the Ontario Ministry of
Agriculture and Food notes that to
make the best use of the nutrients in
the manure it is best to apply it in the
spring, just before seeding. But since
spring is a busy time, many farmers
apply manure in the fall, incorporating
it into the soil.
And while spreading manure
is not recommended in the winter
because this is the worst time for
nutrient loss (the manure sits on top
of the soil and nitrogen is lost to the
air), some farmers do apply manure
in the winter, again because of time
constraints.
ACUTE POLLUTION
The most devastating type of
pollution associated with manure is
caused by accidental spills of con-
centrated liquid manure. The large
numbers of bacteria in the liquid
manure rapidly consume oxygen in
water, and if enough bacteria are
introduced at one time they can elim-
inate oxygen in the water, suffocating
fish.
Because liquid manure is highly
mobile and is usually handled in large
volumes, the potential for disaster
exists at all stages of handling. This
June, for example, The Rural Voice
reported an incident of liquid manure
escaping through a broken tank
coupling. The manure flowed into a
drainage tile and then into a municipal
drain that led into a Huron County
creek, causing a substantial fish kill.
The greatest danger lies with the
storage tanks designed to hold up to
200 days worth of manure. This vol-
ume could have catastrophic effects.
In Britain, the Water Authorities
Association has documented one such
instance, the worst ever encountered
by officials at Trent -Severn Water.
An above -ground, glass -lined steel
tank ruptured, sending 50,000 gallons
of liquid pig manure into a nearby
river. The result killed 10,000 brown
trout and 100,000 smaller fish. The
cause of the accident was a structural
failure — corrosion caused by damage
to the glass lining 10 years earlier.
The farmer was fined £1,650 (approx-
imately $3,300 Can.).
The British report on the case
(1985) shows a significant increase
in farm -related pollution incidents in
Britain.* Incidents involving manure
jumped from 656 in 1984 to 881 in
1985, while those involving silage
effluent jumped to 1,006 from the 573
incidents reported in 1984.
The severity of the pollution is
indicated by the prosecution rate:
while responsible for a sixth of the
total number of reported incidents,
farms were involved in more than half
the prosecutions. The authors of the
report say the risk associated with
modern manure handling systems is
aggravated by poor management.
Storage spills have not been a
problem in Canada. Dr. Beauchamp
has no information on bursting storage
tanks, but he has heard of tall silos
bursting and of one case 10 years ago
where a river was affected.
Brian Jaffray of the Ontario
Ministry of the Environment in Owen
Sound agrees. He says that most of
the reported problems in this region
are caused by spills from liquid
manure spray tanks.
Spreading and storage are not the
only situations that can lead to manure
pollution. A feedlot, where large
numbers of animals live in a small
area, is an obvious example of pollu-
tion potential.
In 1975, D. Richard Coote wrote a
report for Agriculture Canada exam-
ining the amount and quality of runoff
In Europe we see how far
things can go: in some places
fields are saturated with
manure and there is talk of
banning animal production
from some river systems.
from four different types of animal
operations.* Although the data were
not absolutely conclusive, it appeared
that water quality on unpaved lots was
worse than on paved ones. The report
concluded that pollution Loads from all
sites were severe and represented an
environmental hazard should the
runoff reach streams or lakes.
In the 13 years since that warning,
much has changed. Dr. Beauchamp
says that runoff from feedlots has all
but stopped because OMAF has set up
grants designed to improve feedlot
systems and avoid runoff. If OMAF
does find a feedlot with high runoff,
Dr. Beauchamp says, it pulls the plug
on the operator and gets the system
cleaned up.
Besides handling manure properly
during storage and spreading, the only
other way to reduce the potential for
pollution is to treat the manure to
reduce its toxicity.
Dr. Beauchamp cites several
attempts in Ontario to treat manure
prior to application. In one instance,
the owner of a feedlot separated the
liquid from the solids, drying and
FEBRUARY 1989 19