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DRAINAGE
DIRECTORY
56 Promotional Supplement
DRAINAGE DIRECTORY
August 2016
Farmers and cities work together to
reduce phosphorus loss
By Nicola Crawhall
T
he Ontario Federation of Agriculture, representing
36,000 farmers, and the Great Lakes and St.
Lawrence Cities Initiative, a bi-national alliance of
125 mayors representing over 17 million people, have
forged a unique partnership to deal with phosphorus
entering our waterways by developing a Collaborative
Phosphorus Loss Reduction Strategy for the Thames
River Basin.
PHOSPHORUS IN LAKE ERIE
Since the mid 1990s, Lake Erie has seen a gradual
increase in phosphorus loadings, particularly dissolved
reactive phosphorus, which is more bio-available to feed
algae. This combined with warmer waters and more
intense rainfall as a result of climate change, and inva-
sive zebra and quagga mussels that filter the water to
allow sunshine to penetrate even deeper, have created
a perfect storm. The result – repeated years of algal
masses that cover up to 5,000 km 2 in the Western end
of Lake Erie. Known as ‘harmful algal blooms’ (HABs) or
by their more common name ‘blue green algae’, these
are not only unsightly, but also pose a threat to human
health. That is because HABs can contain a bacteria
called microcystin, a neurotoxin. A number of municipal
drinking water systems have had to close when micro-
cystin has been detected in Lake Erie, most dramati-
cally in Toledo Ohio in August 2014, when the drinking
water system was closed for three days, affecting over
400,000 people.
In response, the Governments of the United States
and Canada agreed to phosphorus reduction targets
of 40% based on 2008 levels. The states of Ohio and
Michigan and the Province of Ontario went one step
further by imposing an aggressive deadline of 2025 to
reach the target. Under the Great lakes Water Quality
Agreement, the two federal government are obligated
to release domestic action plans (DAPs) by 2018 to
reach the target, which will no doubt include measures