BONNYVILLE – During the Jan. 12 MD council meeting, Algae Control Canada representative Ray Menard and Dr. John Holz from HAB Aquatic Solutions outlined a pilot project to manage the chronic toxic blue-green algae blooms on Moose Lake.
Council heard that Moose Lake had been selected as a site for an Aluminum Sulfate (Alum) targeted treatment – a first in Canada – because of the lake’s high internal phosphorous load and because Moose Lake is one of the most studied and researched lakes in Alberta.
The delegation’s ultimate request from council was to write a letter to the Alberta Ministry of Environment and Parks, stating that as stakeholders in the health of Moose Lake, the MD of Bonnyville support the project and want to see it proceed.
Menard said that with a letter of support, it would hopefully help in securing between $13 - $15 million from the province to carry out the water treatment.
The Alum treatment is recommended by Algae Control Canada because the element permanently bonds to phosphorus and settles back into the sediment layer without remaining in the water column. This prevents phosphorus from being released during seasonal cycles and feeding algae blooms.
The use of Alum to treat excess phosphorus is commonly used in water treatment plants, dug outs and reservoirs in Alberta, as well as in hundreds of lakes south of the border to improve water clarity and control algae blooms
The community’s strong commitment and participation in the Moose Lake Watershed Society was also noted as a key factor as to why Algae Control Canada believes Moose Lake is the right choice to carry out the Canadian first project.
“This project, with the Alum controlling the internal loading, will also compliment and elevate the existing good work that is being done in the watershed already,” Holz said. “If we can knock that internal load down, it will make the watershed management work be more successful. Because if we take care of that 64 per cent of the phosphorus problem, our efforts that are aimed at the 31 per cent from the watershed (external nutrient loading) are just going to have more a dramatic impact.”
Dr. Holz told council that historic studies and core samples taken from the lake showed that water quality began to decline in 1920 to 1950. “So that's about how long the decline has been occurring, prior to that it was pretty pristine.”
More recent studies have shown exponential growth of phosphorus and algae have occurred in the lake within the last 10 years as well.
“The average phosphorus concentration in Moose Lake over the last 10 years is about 62 to 63 micrograms per liter. Prior to that it was about 44. So, you can see, not only are we seeing more phosphorus in the lake, but we're getting more extremes. This is indicating a lake that is a little bit out of balance,” Holz continued.
“(An) increase is also occurring with the amount of algae over the last 10 years. As a matter of fact, it's almost double what it was prior to that going back to 1983. We also see these level fluctuations from year to year, again indicating unstable conditions in bloom conditions for the algae.”
Holz went on to describe potential secondary benefits following treatment of the lake’s phosphorus levels, which includes improvement to fish habitat resulting from increased water clarity, reduced algae blooms and increased overall oxygen availability in the water for plant and aquatic life.
With increased water clarity and reduction in annual algae blooms, council heard that property value and tourism around Moose Lake would likely increase also.
Following the 15-minute delegation and after the presenters disconnected from the virtual meeting, council members decided they would postpone the decision of whether to support the project to a March committee meeting of the whole.
The general consensus of council seemed to be with so many benefits, and no apparent downsides, that the pilot project in essence seemed too good to be true. Council requested administration carry out an in-depth look at the use of Alum in lakes and present their findings in a future meeting.