Is ethanol tapping too much water?

With a flood of ethanol plants headed toward Minnesota, there's growing concern about whether there will be enough groundwater to satisfy the booming industry's thirst.

The issue was brought into focus last year in Granite Falls, where an ethanol plant in its first year of operations depleted the groundwater so much that it had to begin pumping water from the Minnesota River.

It takes between four and five gallons of water to produce a gallon of ethanol at a biofuel plant, and with 17 ethanol plants now operating in the state, six under construction and 10 more proposed or in the planning stages, the threat of more drains on underground water are rising.

This week, the Minnesota Environmental Quality Board will convene an interagency group as the first step toward looking more closely at ethanol and groundwater availability. The board accepted a request two weeks ago from the Minnesota Pollution Control Agency, which regulates ethanol plants.

The MPCA Citizens' Board wants more information about total groundwater supplies in the state, as well as whether current and future ethanol plants could consume it faster than it can be replenished.

The industry is consuming about 2 billion gallons of groundwater per year, according to state estimates.

That amount could quadruple by 2011 if the state's ethanol production more than doubles, as expected.

"I would characterize it as a concern about where we're going to allocate groundwater over the next 10 years relative to what are the needs going to be in 20 or 30 years, and whether we're doing a good job in thinking ahead," said MPCA Commissioner Brad Moore.

In many cases, there's considerable uncertainty about how much water is available underground.

And even when ethanol plant developers test aquifers--the underlying layers of porous rock and sand that store water --the results can be misleading. The Granite Falls plant had been given a temporary three-year groundwater permit from the Minnesota Department of Natural Resources, but had to switch to the river after little over a year.

The ethanol industry is developing new technology that will reduce the amount of water needed to produce ethanol, said Matt Hartwig, spokesman for the Renewable Fuels Association, a national trade group. "Industry is very aware of its use of natural resources like water and we're taking steps to improve that," he said.

Fear for future resources

The exponential growth of ethanol plants and burgeoning need for groundwater worry Jeff Broberg, a licensed geologist and president of the Minnesota Trout Association. Broberg said that groundwater is an "unseen environment" and that ethanol plants will deplete what's used for drinking and for sustaining the headwaters of many trout streams, especially in southeastern Minnesota.

"There's public interest in protecting these resources not only now, but also in the future," Broberg said. "We're dealing with groundwater that's probably 5,000 years old, and we don't get it back, and our state agencies have no idea of what's sustainable in terms of water use."

Individual ethanol plants must receive water appropriation permits from the Minnesota Department of Natural Resources, which requires owners of proposed plants to drill wells and conduct tests to determine how high-volume pumping will affect groundwater supplies.

Jim Sehl, the DNR's groundwater specialist in southern Minnesota, said that once given permits, companies are also required to monitor various wells constantly and to report their findings. "If we see groundwater starting to drop, it's a warning shot across the bow," Sehl said. Companies can be told to cut back production, shut down temporarily, or shift to a different source of water if there is trouble, he said.

Is there enough for us all?

Dale Setterholm, associate director of the Minnesota Geological Survey, said the DNR's approach is reasonable, given the general lack of knowledge about groundwater supplies in the state. "I don't think you can deny somebody water just because there's a potential for a problem in the future," Setterholm said. "It makes sense to give a tentative go-ahead to companies and monitor the effects of it."

The only way to truly know how much water can be tapped on a long-term basis, said Setterholm, is know the location, size and number of aquifers in an area, how they are related to surface lakes and rivers, and how they are recharged. "A lot of that work has not ever been done," he said.

The Environmental Quality Board (EQB), consisting of citizens and commissioners from various agencies that deal with the environment, will take up that question in the coming weeks. Its staff published a report last year that indicated some Twin Cities metro counties are facing limits on how much groundwater will be available for future use. Ramsey County is already using more groundwater than is considered renewable, according to the report, and Washington, Hennepin and Dakota counties could reach their limits by 2030.

John Wells, EQB strategic planning director, said that it's time for the state to look more comprehensively at how current and future demands from ethanol, population growth and other needs will match up with available groundwater supplies.

"It's not a crisis, but it's a lot different than saying we've got all the water we need and we'll never need to worry about it," Wells said. "We're not there anymore."

Tom Meersman • 612-673-7388