State Moving Forward with Modified Grand Lake St. Marys Alum Treatment Plan

The State of Ohio is moving forward with plans to treat Grand Lake St. Marys this spring with aluminum sulfate and a buffering solution of sodium aluminate in an effort to prevent harmful algae blooms and to improve water quality within the lake.

Heavy, prolonged rainfalls in late winter and early spring are contributing to high levels of nutrients and algae in Grand Lake St. Marys, resulting in revisions to the state’s initial plan for a whole lake alum treatment.

An expedited bid process is underway to avoid delays in the alum application. The goal is to begin applying the alum no later than the first week of June.

Instead of treating the entire lake with a low dose of aluminum sulfate, a more concentrated treatment will focus on 4,900 acres in the central lake area where phosphorous levels are highest. This concentrated treatment will help to inactivate phosphorus that contributes to the harmful algal blooms in the lake.

The adjusted alum treatment is one step in a multi-faceted, multi-year approach to improve water quality at the lake.

Dredging and rough fish removal efforts, along with installation of a treatment train and other water quality initiatives continue – action steps the state and the lake community consider integral to helping improve the water quality of the 13,000-acre recreational lake in western Ohio.

“While we are disappointed that we cannot complete the entire alum treatment as originally designed, Grand Lake St. Marys Restoration Commission members are encouraged by the adjusted alum application being implemented yet this spring,” said Grand Lake St. Marys Restoration Commission facilitator, Tom Knapke. “Our community cares about a successful outcome and will pursue new innovations and opportunities to improve our local economies surrounding the lake. By working together, environmental renewal is possible, and the benefits of regional growth – economically and recreationally – will be our reward.”