Diagnosis and treatment offered for blue-green algae in Lake Eugenia

The Friends of Lake Eugenia group told the council that introducing alum into the lake could have “dramatic” effects.

The nonprofit is concerned about water quality, particularly toxic blue-green algae blooms that have closed the beach in summers past.

The “Friends” group has conducted research and funded studies. A baseline study found an increase in lake temperature and phosphorus content linked to sediments from the dam.

Phosphorus release from the shorter ice season and warmer temperatures is linked to algae, a consultant hired by the group found.

The Council received the report but took no immediate action.

In her presentation, co-founder Morgan Anderson said there are two parts to remediation.

First, prevent future phosphorus loading. Methods include septic inspection, limiting direct drainage into the lake, and controlling drainage of vacant lots and lots.

Second, action must be taken on existing water quality – by applying alum to bind phosphorus in sediments. This has been described as a proven, non-toxic approach that delivers immediate results.

The “Friends” group speaks with a staff member from the Grey Sauble Conservation Authority.

The group raised $80,000 to fund the research. Scientists worked on the lake the weekend before the presentation, he said, and it appears the blue-green algae is migrating from the deeper part to other parts of the water.

Scientists have predicted a major algae bloom in the next two weeks because it is already forming, said Friends’ other co-founder, Doug Hill.

“The next step is we want to go to OPG because we now have information that we want to share with them,” he said. OPG owns the lake bed.

“It’s not bad news,” he said. “It’s very good news… We know what we can do to make this lake very enjoyable and very pleasant. And we’ve done that through our own research and our own funding.”

Councillor Tom Allwood asked a question about regulatory issues related to the use of alum. The response was that it is used in Pigeon Lake, Alberta and in the United States.

The OPG owns the lake bed and must be consulted. “No one really owns the water quality in the entire government structure,” he said. The MNR responds if there is a spill.

If the alum is not buffered, there can be fish kills, but when it is done properly, the results are “spectacular,” he said.

References to this approach can be found in a publication of the North American Lake Management Society. While noting that alum treats the effect and not the cause, the report endorses the controlled use of alum, as well as the adoption of a decisive approach.

After application, a solid precipitate called floc is formed, which absorbs the phosphates which fuel the proliferation of algae. It has no direct toxic effect on algae.

STORM WATER

Hill also said a Conservation Authority staff member told him they believed the rain events were also involved in the algae blooms.

The group would also like to see the water inlet to the Plantt’s Point culvert raised. The drainage culvert flows directly into the lake.

The culvert enters very close to the water’s edge, Hill said, which means there’s no room to build a retention area. There’s room to make changes close to the water to allow for settling and purification of the water before it enters the lake.

“The solution is relatively simple,” he said, and could be done by city staff.

The culvert could still protect the road from flooding and, with changes, it could also allow less direct water entry.

REQUEST FOR MUNICIPAL HELP

Morgan Anderson outlined four ways the council could help:

-implement regulations on septic tanks;

-control the direct supply of nutrients into road culverts;

-consider a policy on the use of fertilizers and regulations around the lake; And

– include the Friends of Lake Eugenia in the newly formed working group on lake management.

The group wants to work together to improve water quality. Hill said they are also working with the Lake Eugenia Property Owners Association.

He also talked about some of the approaches that are being taken in other lakes and rivers. Dredging is a huge problem, he said, because it destroys fish habitat. Oxygenation, which is used in Chesley, is good for fish habitat, but he said it would stir up the sediment, which would release phosphorus.

The group also carried out measurements of the “inflows” and “outflows” of Lake Eugenia. He acknowledged that there were some problems with the incoming flow. The water quality at the outlet is much worse than at the inlet, he said.

MT Fernandes, Local Journalism Initiative Reporter, The Flesherton Advance