As warm weather and nutrient pollution trigger algae blooms in Lake Champlain and other water bodies this summer, a new report says there’s a measure of progress in cleaning up Franklin County’s troubled Lake Carmi.
In recent years, the 1,400-acre lake has been plagued by blooms of cyanobacteria, also known as blue-green algae, fueled by phosphorus pollution.
No one is declaring Carmi healthy again. The blooms have hit the lake this summer as well. But the state report from the Department of Environmental Conservation says changes in farming and other land use practices have cut phosphorus to a level that is 41% of what's needed to meet clean-up goals.
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Oliver Pierson manages the Lakes and Ponds program for DEC, and he said the lake's water quality is improving.
“But we have a long way left to go, and so more work is needed," Pierson said. "And ongoing work needs to continue in the watershed to continue to reduce external loading or surface water runoff into Lake Carmi."
A note on the methodology: The state measures the improvements by calculating how much phosphorus runoff is expected to decrease due to certain changes in land use, such as cover crops. Researchers did not actually sample phosphorus levels going into the water, and then see if that has decreased over time.
"What we're doing up there is what we like to think is best management practices for reducing phosphorus loading into lakes. And these types of practices need to be implemented anywhere in any watershed of the lake where there's similar issues, including Champlain." — Oliver Pierson, Department of Environmental Conservation
“We implement agricultural best management practices on different pieces of land in the watershed, and those practices are assigned — based on the literature and actual field data collection and analysis — are assigned a phosphorus reduction co-efficient, if you will,” Pierson said. “The number of acres on which these ag BMPs are implemented at, multiplied by the phosphorus co-efficient, gives you a phosphorus reduction estimation.”
Pierson said some of the lessons learned from Lake Carmi — such as cover cropping and fixing manure storage — can be applied to other lake watersheds, including Lake Champlain.
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“What we're doing up there is what we like to think is best management practices for reducing phosphorus loading into lakes,” he said. “And these types of practices need to be implemented anywhere in any watershed of the lake where there's similar issues, including Champlain.”
Pierson noted that the big lake has other sources of phosphorus pollution besides agriculture, including stormwater runoff and sewage overflows.
