Jordan Lake’s Managers Authorize Lake-Stirring Trial To Prevent Algae Growth

Jul 11, 2014

State environment officials expect to install 36-solar powered water mixers into Jordan Lake by the end of the month, as part of a two-year trial to find out whether the mixers can prevent algae from growing in the lake, they said.  

The trial would start later than planned, potentially affecting the scope of information that can be gathered on the efficiency of the water mixers. The machines, called SolarBees, were expected to be installed by May, and would’ve been monitored for two full summers, Tom Reeder, the Department of Environment and Natural Resources’ water division director, told lawmakers in a public hearing this spring.

A SolarBee machine
A SolarBee machine
Credit Medora Corp.

The U.S. Army Corps of Engineers, which manages Jordan Lake, gave the state formal authorization to deploy the SolarBees this week. The corps is expected to give separate authorization by the end of the month to moor, or anchor, the machines at locations in Jordan Lake, a reservoir that covers 56 square kilometers west of Raleigh and south of Durham.

"We don't want these things just floating around the lake,” said Susan Massengale, an environment department spokesperson. “We need an easement in order to moor these on the lake bottom."

As the Durham Herald Sun reports, environmental groups have criticized the project because they say it does not remove nitrogen and phosphorous deposits from the impaired lake:

Environmental groups like the N.C. Sierra Club believe the state is wasting its time and money, as Medora’s “SolarBee” circulators don’t actually remove nitrogen and phosphorous from the water.

“It’s not really going to address pollution going into the lake,” said Cassie Gavin, the Sierra Club’s director of governmental relations, adding that the real problem is “too much nutrient” in the water.

The Corps of Engineers finding addressed only the limited question of whether the circulators themselves would do any harm. The question of whether they’ll do any good is, in essence, not in the corps’ jurisdiction, the finding said repeatedly.

But the U.S. Environmental Protection Agency, in commenting on the proposal, joined critics of the project in noting that it doesn’t address nutrient deposits. That means any good it does will be fleeting, disappearing the moment the two-year trial project ends.

EPA officials – charged with enforcing the federal Clean Water Act, the law driving the need for a clean-up of the lake – added that they see nutrient reduction efforts like the delayed rules package as the “long-term solutions” to Jordan’s water-quality problems.

The North Carolina General Assembly could extend the trial if there isn't enough information after two years. The project is expected to cost the state almost $1.3 million, according to a department invoice.