Lake Champlain | When blue algae deprive cities of water

The presence of blue-green algae in Lake Champlain was so severe this summer that municipalities were without drinking water for weeks. A frozen vegetable company had to bring in tankers of water to rinse its produce. Concerned, four mayors in the area have passed resolutions urging the government to take action.

(Bedford) The high presence of blue algae in Lake Champlain, as well as certain failures at the local filtration plant, deprived the citizens of Bedford of drinking water for six weeks this summer.

Mayor of the municipality, Claude Dubois explains that the drinking water supply problem in his municipality was triggered in particular by the significant presence of cyanobacteria in Lake Champlain. “This was unprecedented this summer. Our water source is in the lake,” he says.

In a notice issued to its population on 1^er August, the mayor of Bedford wrote that “this episode of cyanobacteria with such virulence is a first for our water intake at Lake Champlain.” He mentioned that “a new product had to be added to the water treatment since carbon was not effective in removing the toxins from the cyanobacteria.” But this product was not effective. A second product also had to be tried. To do this, a special authorization for “urgent activity” had to be obtained from the Ministry of the Environment.

All around Lake Champlain, signs were installed this summer to warn of the presence of blue-green algae. “This water could contain blue-green algae […] “Do not swim in this water,” some posters read.

Met on the dock in Venise-en-Québec in early September, Émile Tardif had just caught a bass in Lake Champlain. “Look at the water. It’s beautiful today. But this summer, there were days when it was as green as the trees,” he said.

This large presence of blue-green algae in Lake Champlain forced the town of Bedford to issue a boil water advisory on July 9. This advisory was extended until August 12. And even after that date, the water continued to be brownish and to give off such a strong odor that the municipality installed a water tank where citizens could go to get their water.

“The smell was so strong that my daughter didn’t want to take her bath,” laments Cynthia Lemieux, a resident of Bedford.

Elizabeth Nellis has lived in Bedford for 25 years. She notes that boil water advisories sometimes occur during the summer. “But never this long this summer,” she says.

Located on Kemp Street in Bedford, Nortera’s huge plant produces frozen vegetables. Deprived of drinking water, the company had to bring in water tankers to wash its vegetables this summer, confirms company spokesperson André Fortin. “It goes without saying that a vegetable processing plant of our size needs water to operate properly. We were able to guarantee a supply of drinking water, which allowed us to keep the production line running.” […] “We are pleased to have found a solution to avoid the shutdown of our operations,” he said by email.

Pressure on the government

Concerned about the impacts of this lack of water on citizens, merchants and businesses, the mayors of four municipalities in the sector adopted a resolution in August to ask the government for rapid action to improve the quality of the water in Lake Champlain and investments to improve drinking water infrastructure.

In their resolution, the mayors of the municipalities of Clarenceville, Venise-en-Québec, Bedford and Saint-Armand emphasize that while the Quebec government had committed, notably in an agreement with Vermont, to reduce the quantity of phosphorus (responsible for blue algae) in Lake Champlain to 0.025 mg/L, this threshold is now rather 0.040 mg/L.

A consultant to the Missisquoi Bay Watershed Organization, agronomist Louis Robert mentions that the “eutrophication threshold”* of a lake is set at 0.03 mg/L. “We have really exceeded this threshold in Missisquoi Bay,” he says.

Saint-Armand Mayor Caroline Rosetti says blue-green algae have been present in Lake Champlain for at least 35 years. “But the lack of drinking water this summer was a new alarm,” she says. M^me Rosetti says Lake Champlain has “among the highest phosphorus levels in Quebec.” According to the Missisquoi Bay Watershed Organization, nearly 80 percent of the phosphorus in Lake Champlain comes from agricultural crops. The lake also borders the United States, which is responsible for about 62 percent of the phosphorus production in the water.

Far from wanting to cast stones at farmers who “really make an effort”, M^me Rosetti and the region’s mayors believe the government could do more to limit phosphorus input into the lake.

In their resolutions, they write that “despite the observation of the continued deterioration of water quality in the Missisquoi Bay watershed, the Ministry of the Environment still issues, each year, certificates of authorization for livestock increases without assessing the environmental impact.” At the beginning of the summer, the Ministry of the Environment authorized a breeder in the region to add 5,000 chickens to his farm.

The mayors are asking in particular for “a moratorium on any increase in livestock numbers”, because the phosphorus present in particular in the feed, then in the manure, of the animals contributes to increasing what ends up in the watershed area, explains Louis Robert.

In their resolution, the mayors also emphasize that “the recommendations for phosphate fertilizers for corn cultivation recommended in Quebec exceed by at least 40% […] the needs of crops established by Quebec research work”.

Agronomist and consultant, Louis Robert believes that “we have been recommending too much phosphorus for decades [dans les sols] in Quebec.” “If we want to reduce phosphorus, we have to reduce its application,” he says […] We have been talking about it for 30 years, but we do nothing.”

The Ministry of Agriculture explains that soil phosphorus standards are established by regulation. It emphasizes that on each agricultural land, “it is up to the agronomist to establish the dose he recommends according to the context and his professional judgment, in compliance with the rules of the art and his code of ethics.” As for the fact that the authorized standards are higher in Quebec than elsewhere, the Ministry believes that comparisons should be avoided, because other territories “are likely to enjoy a warmer climate and a longer growing period than Quebec.”

“We have to do something. Because right now we are trying to clean the bath, but the tap is dirty,” says M.^me Rossetti.

* Eutrophication is defined by the Ministry of the Environment as the “process of gradual enrichment of a lake with nutrients”. This enrichment accelerates the growth of algae.