A report released by Tetra Tech, a firm enlisted jointly by the Ohio EPA and US EPA, recommends several actions for cleaning the water in Grand Lake St. Marys and preventing future contamination.
Methodologies, estimated costs, anticipated effectiveness, and more information on each of these proposed solutions can be found in the full report.
The stated goals of the report were to propose actions that would:
- Improve Grand Lake St. Marys from its present hypereutrophic and unhealthy state (200 μg/L of phosphorus) to a eutrophic state (between 25 μg/L and 50 μg/L phosphorus).
- Greatly reduce harmful algae blooms by inactivating internal nutrients.
- Restore and maintain water quality to ensure safe human recreation.
- Greatly reduce fish kills caused by insufficient dissolved oxygen levels.
- Reduce external nutrient and sediment loads into Grand Lake St. Mary’s.
- Improve local land use management to protect Grand Lake St. Mary’s.
The multi-year plan calls for sevearl concepts to be tested for effectiveness before being deployed lakewide, and some of the proposed potential solutions include:
Aeration or Water Column Circulation at site-specific areas to reduce cyanobacteria (blue-green algae) by neutralizing its buoyancy
Dredging in srategic locations to remove phosphorus-rich sediment, which fuels algal blooms
Alum Treatment to neutralize phosphorus by bonding aluminun sulfate to it. Proper dosing is expected to be effective for approximately 10 years
Hydrogen Peroxide Treatment to neutralize phosphorus
Tributary Alum Treatment to reduce phosphorus entering Grand Lake
Deploying Large-Scale Tributary Treatment Systems to clean water before it enters Grand Lake
Shoreline Maintenance to idenify and correct problem areas with grassed waterways and filter strips
Development of Nutrient Management Plans to reduce overall nutrient load in the watershed
Proper Manure Handling and Storage Plans for producers in the watershed
Cover Crops for more efficient nutrient use
Conservation Tillage to control erosion and runoff
Filter Strips and Filter Areas to reduce erosion, trap pollutants, clean water and provide habitat
Controlled Drainage to divert runoff and remove infiltration and pollutants before releasing it into the watershed
Constructed Wetlands to treat animal waste
Restoration of Riparian Buffers and Channels
Conservation Planning
State officials will now review the proposals to determine what steps to take to help restore Grand Lake St. Marys. Methodologies, estimated costs, anticipated effectiveness, and more information on each of these proposed solutions can be found in the full report.