Aquatic herbicides cause tension in Greely – News – By Emma Jackson Manotick Local Community News

Aquatic herbicides cause tension in Greely

Posted May 3, 2012By Emma Jackson

Click to Enlarge
 The private man-made lake at Lakeland Estates in Greely has been treated with algaecides and herbicides since 2008.

Emma Jackson, Metroland
The private man-made lake at Lakeland Estates in Greely has been treated with algaecides and herbicides since 2008.

EMC news – Several Greely residents are raising the alarm after the Ministry of Environment issued a permit to apply aquatic herbicides on their private man-made lakes last month.

The application from the Lakeland Estates Lot-owners Association (LELA) was approved to apply 450 litres of Polydex, a copper sulphide chemical used to control algae blooms, in the community's main quarry lake as well as a smaller pond nearby. The algaecide was applied to the water on April 16.

Home owner Chris Leblanc wasn't there to see it, she left her home that weekend to stay in a hotel until Tuesday night, because she said the chemicals can cause her nausea, headaches and dizziness.

Leblanc said she strongly disagrees with LELA's continued use of algaecides and herbicides, which has increased in volume and number of applications since the association began treating the lake in 2008. Leblanc has lobbied the ministry to stop approving the permits.

But the ministry sides with the association, of which the vast majority of its 41 members support pesticide use, on the grounds that the lakes are privately owned and do not affect other water bodies.

"The algaecide used in the ponds has been approved by Health Canada for this use and is classified by the Ministry of the Environment for use in Ontario./This is private property and the majority of lot owners are supportive of this use," said ministry official Ruth Orwin, supervisor of the air, pesticides and environmental planning section of the ministry's Kingston office, in an email.

LELA first applied herbicides on the subdivision's lakes in July 2008, when it used the chemical diquat to control an invasive and lake-strangling weed called Eurasian milfoil.

Six weeks later both water bodies experienced a massive and toxic blue-green algae bloom that the ministry found was producing a rare toxin well above Health Canada's prescribed safe levels. Ottawa Public Health issued an advisory warning residents not to use the lake. The toxic bloom returned the following spring.

Algaecide permits were approved alongside diquat in 2010 and the association now applies copper sulphate algaecide every April and June along with the weed-killing diquat in June.

This April, the usual 250 litres of chemical was upped to 450 litres. Leblanc said this is an irresponsible way to manage the lake, and that pesticide use is not meant to be a long-term management plan.

"(The Ministry of Environment) said pesticides are a short-term solution, (but) we're now going into five years and we're using more and twice a year," Leblanc said. She said she wants to use non-chemical methods to control the weeds, such as lakeshore buffer zones to reduce fertilizer run-off, a septic emptying program and harvesting programs to keep the weeds down.

"With all the money we've spent (on pesticides) we could have bought a harvester," she said. "I'd like to see the fish come back. They used to be very plentiful and you don't see those two- or three-pound bass anymore."

LELA president Anne-Marie Simard disagrees with Leblanc's position, calling her "extremely green." She said the association spent years trying alternate methods of weed control, including a number of summers harvesting the weeds and has looked into aeration to keep the water moving.

Nothing worked, she said.


The problem is that algae and weeds thrive when nutrients are plentiful. Those nutrient levels can be significantly bolstered by the surrounding home owners' use of fertilizers and septic systems and from things like geese populations on the water.

While the association has ruled that homeowners can't apply fertilizer within 30 metres of the shoreline, Leblanc said fertilizer still ends up in the lake because there is no shoreline buffer strategy in place to reduce run-off.

Simard said the association uses "the honour code" to encourage homeowners to monitor septic systems on a regular basis for leaks. Simard said the association also undertakes E.coli testing in several locations throughout the spring and summer.

However, nutrient input can also be caused by killing a large amount of plant life and letting it decay on the lakebed, according to biologist Fred Schueler, who directly correlates the community's past algae blooms to killing the milfoil.

"When all the nutrients go into the water you get an algae bloom," he said. "This has been a textbook demonstration of how these plants work in water bodies."

That's why Leblanc so strongly supports harvesting: she said it gets the weeds out of the water so their decaying nutrients don't cause another bloom – negating the need for algaecide.

However, Simard said harvesting the milfoil failed to keep the lake free of the clogging weeds.

"We worked very hard to try harvesting and see if it would work. The result was that we were in a huge problem because the density of the invasive species was increasing at such a rate that we could not keep up with them by harvesting," she said.

They tried harvesting in a variety of capacities in the early 2000s until 2007, including hiring professionals and hiring students to help cut down the weeds throughout the season. She said it was especially expensive to hire professionals enough times to keep up with demand.

Simard said it costs the association about $20,000 to apply pesticides each season and that in the early 2000s it cost about $15,000 each season to hire students to help with harvesting. She said those labour costs will have risen since 2007, and the association would also have to replace its boat motors in order to start up again.


Orwin said the ministry "continues to encourage LELA to explore non-pesticide options to reduce the weed growth in their ponds," but ultimately the ministry will not rule on the issue.

"As this is private property, it is a matter between LELA and its members to effect a long term change in the management of the ponds. This decision lies with the lot owners, not with the ministry," Orwin wrote in an email.

All the ministry will do is issue permits, when warranted, for algaecides and other pesticides on a short term basis, Orwin said. She said each permit is decided "on an individual basis."

Greely has a number of developments built around man-made lakes and ponds, including Woodstream, Sunset Lakes, Cedar Lakes, South Village and Water's Edge. Lake management is an issue homeowner associations deal with here and across the province.

So far in 2012, Lakeland Estates is the only private community in eastern Ontario to receive a permit for algaecide. Orwin said between five and seven algaecide permits are given out to private landowners in eastern Ontario each season.

Osgoode Coun. Doug Thompson said he can't get involved because it's private property, but he hopes the residents can find a compromise.

"The issue with lakes like this is people want to use them as part of their home to have a nice pristine lake," he said. "The advice I give is try to work with the ministry and hopefully the homeowners can have a consensus."

via Aquatic herbicides cause tension in Greely – News – By Emma Jackson Manotick Local Community News.