Canada-U.S. group studies phosphorus run-off issues

A new phosphorus-loss program in Ontario hopes to focus attention on heading off phosphorus runoff before it gets to waterways.

Charles Lalonde, co-ordinator for the Thames River Phosphorus Reduction Collaborative, said the biggest problem is trying to sort out the various groups and phosphorus reduction projects already underway.

“They all have the same thing at heart, they want to do their piece for the environment,” he said.

The collaborative began in 2016 as a partnership between the Ontario Federation of Agriculture and the Great Lakes and St. Lawrence Cities Initiative to treat phosphorus loss in runoff between farm fields and main watercourses.

The GlSCI is an association comprising about 125 municipalities in Canada and the United States.


The Dauphin municipal drain, which empties into Jeannette’s Creek in Chatham-Kent, Ont., is included in a project that monitors farm fields for the loss of phosphorus and other nutrients. | Mary Baxter photos

Since then, the organization’s steering committee has grown to 27 municipalities, industry groups such as Grain Farmers of Ontario and the Drainage Superintendents Association of Ontario and government ministries.

The collaborative was an-nounced during a June 27 tour of phosphorus reduction activities in the Jeannette’s Creek sub-watershed near Tilbury, Ont. The creek is part of the Thames River system, which covers a large portion of southwestern Ontario.

Researchers have linked phosphorus loss from farm fields, primarily from the Maumee River watershed in Ohio, to a greater frequency of toxic algal blooms in Lake Erie.

Recent research has implicated to a lesser degree the Thames River watershed even though the river empties into nearby Lake St. Clair.

Tributaries that travel through Leamington in Essex County, home to much of the province’s greenhouse industry, are also watercourses of concern. Lake St. Clair connects with Lake Erie through the Detroit River.

In 2013, Canada and the U.S. signed an update of the Great Lakes Water Quality Agreement pledging, among other things, to tackle the phosphorus issue in Lake Erie.


The authority has attached automatic samplers and flow metres to discharge pipes at pump houses used to manage municipal drain flow. | Mary Baxter photos

In 2015, the two governments announced the goal of reducing phosphorus loading in Lake Erie by 40 percent of its 2008 levels by 2025 in the lake’s western and central basins, the areas of greatest concern.

“There isn’t one sector to blame, or one industry or one group of people to blame for the phosphorus issue we face,” said Trevor Thompson, a Chatham-Kent councillor.

“It’s a collaborative effort that we’re all going to have to tackle of phosphorus in the Great Lake Erie basin and all throughout the municipalities we call home.”

Agricultural groups are doing good work on improving best practices for fertilizer applications, said consultant Nicola Crawhall, one of the project team members.

Nevertheless, factors beyond farmers’ control can result in the escape of nutrients from fields.


Water quality specialist Austin Pratt shows an automatic water sampler used to monitor phosphorus and nutrient levels. | Mary Baxter photos

During one of the tour stops, Colin Little, Lower Thames Valley Conservation Authority agricultural program co-ordinator, recalled one such instance in the Jeannette’s Creek area in early March when a windstorm arriving on the heels of an unseasonably warm winter and several dry days scooped up soil from fields.

“You could see the plume as far as Chatham” about 20 kilometres away, he said.

The conservation authority also saw the impact in terms of nutrient loss from the nearby fields in its monitoring system along the Jeannette’s Creek watershed. That came with the next big rain following the windstorm, when one of the municipal drains emptying into the watercourse showed a huge spike in phosphorus and nitrogen levels.

“We saw the largest concentrations we’ve ever seen out here from sampling,” Little said.

The conservation authority is also monitoring nutrient losses from plots in two farm operations within the sub-watershed. One farm uses conservation practices, such as cover crops and no-till; the other employs conventional practices.

It’s too early to draw conclusions, but the ability to compare results from the sites with those from the overall creek watershed should yield useful data about the effectiveness of different farming practices, Little said.

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