Test treatment of Grand Lake St. Marys yields no quick fix for algae
As control of the Ohio EPA and the state Department of Natural Resources shifts from outgoing Gov. Ted Strickland’s administration to that of Gov.-elect John Kasich, officials should set the pressing issue of toxic algae at Grand Lake St. Marys and other Ohio lakes as one of their top priorities.
Addressing the problem, which last summer sickened people and pets and devastated recreation businesses at Grand Lake St. Marys, requires short-term and long-term solutions: a way to immediately reduce algae concentrations likely to form this summer and farming regulations to reduce the manure and fertilizers that cause the problem.
So far, neither agency has commented extensively on an EPA report, released Dec. 30 that showed disappointing results from an attempt in the fall to reduce the poisonous, blue-green algae by spraying it with aluminum sulfate.
The idea is that the compound, also called alum, bonds with phosphorus – the algae’s main food supply – causing it to sink to the bottom of the lake, thus starving the algae. But, after alum was sprayed on several test sites in the lake, phosphorus levels were reduced by only 50 to 60 percent at two locations and not at all at a third.
A Seattle-based consultant who reported on the testing said the results should have been better, and suggested that the phosphorus concentration in the lake in September, when the testing was done, might still have been so high as to overwhelm the alum.
That argues in favor of taking some action early in the season this year, before algae have started to grow. Consultant Harry Gibbons of Tetra Tech Inc. recommends a new round of tests as soon as the lake ice melts in the spring.
That will be a decision for the new EPA and ODNR directors to make. Last year’s round of testing cost $61,500; treating the full lake could cost between $5 million and $10 million. Giving the method another trial run under better conditions, before committing to a full treatment, makes sense.
For the longer term, officials will have to grapple with the lake’s underlying problem: the vast stretches of agricultural land that surround it, and from which phosphorus-laden manure and fertilizers migrate into the lake. With an average depth of 5 to 7 feet over 13,000 acres, Grand Lake St. Marys is essentially a petri dish, ideal for growing algae. It has no defense against its agricultural surroundings.
New state officials should weigh a plan proposed last summer and aired before lawmakers in December to declare Grand Lake St. Marys a "watershed in distress" and impose restrictions on how farmers in the lake’s drainage area can use manure. The rules would require farmers to test soil to determine how much manure is needed in the soil and would ban spreading manure on frozen fields, which allows greater runoff.
In line with farmers’ concerns, the state should establish clear criteria for naming any body of water a "watershed in distress."
But if any lake qualifies, surely it would be one where people have to be warned not to touch the water, let alone drink or fish in it, for fear of nerve toxins generated by pollution-fed poison algae.