Mercury rules vex towns on Lake Superior
Aug 20, 2017 09:22AM
By Pam Louwagie Star Tribune AUGUST 19, 2017 — 5:39PM
GRAND MARAIS, MINN. – Leaders in this scenic North Shore tourist town pride themselves on trying to run things green and clean. Earlier this year, they passed a resolution to come up with a plan to study everything from the town’s greenhouse gas emissions to ways it can reduce waste and improve energy efficiency.
So it’s a bit awkward now that they find themselves fighting state and federal mercury regulations.
Like dozens of communities that put treated wastewater into Lake Superior or its tributaries, Grand Marais is under a costly mandate to reduce the amount of mercury in its effluent. While city leaders agree it’s a noble goal, they say it’s highly impractical and could force taxpayers to spend millions of dollars to hold back about a thermometer’s worth of mercury per year — an amount they argue is negligible compared to the mercury entering the lake from rain and the air.
In a town of only 1,300 residents that already puts less mercury into the lake than it takes out, leaders believe the money would be better spent on other environmental projects. For now, they are asking the state for a variance allowing them to maintain the status quo for at least the next five years.
“It’s a bit of a confusing ecological situation,” said Mayor Jay Arrowsmith-DeCoux. “We need to take another look at this standard to make sure that this is the best thing we can do and that it’s actually being effective.”
More than a dozen Minnesota communities that discharge effluent into Lake Superior or nearby waters have become subject to the mercury standards in recent years. A couple of small towns are embarking on water treatment plant upgrades that they estimate will cost from $7 million to nearly $9 million. Others have finished revamping their wastewater plants to comply.
Most is present in the air
Mercury, found naturally in the environment, is released into the air through emissions from coal-fired power plants and other industrial sources. But when it accumulates in lakes, rivers and other surface water, bacteria transform it into methylmercury, which is absorbed by fish.
The U.S. Food and Drug Administration (FDA) advises children and women who are pregnant or may become pregnant against eating too much of certain types of fish because it can lead to the accumulation of methylmercury in the body. In a pregnant woman, that methylmercury can get passed onto the fetus, potentially harming the growing brain and nervous system.
A 2011 state health department study found that 10 percent of newborns near the North Shore had risky levels of mercury. Officials have been trying to reduce that through an educational campaign about the amounts and types of fish women should eat.
Officials in Grand Marais want a clean lake — a big part of their economy relies on tourists drawn to Lake Superior’s rocky shore, and local restaurants are stocked with fish from its water. They just aren’t sure a revamped wastewater treatment plant will make any difference in the lake’s condition.
“There’s no evidence to suggest it will help in alleviating the problem whatsoever,” said attorney Daniel Marx, who is representing the city in the matter.
Ninety-nine percent of mercury found in Minnesota lakes and streams comes from the air, said Bruce Monson, a research scientist at the Minnesota Pollution Control Agency (MPCA). A study of mercury in the Great Lakes categorized sources differently and found that 59 percent of mercury in Lake Superior comes from precipitation, 28 percent from the watershed and 13 percent from industry, Monson said.
Standards for the Lake Superior Basin in Minnesota mirror those of other Great Lakes states and federal EPA standards for Great Lakes areas.
Mercury concentration in effluent needs to be below 1.3 nanograms per liter, explained Steve Weiss, who supervises the MPCA’s effluent limits unit. Mercury standards for surface water in the rest of the state aren’t as stringent, and most towns have no problem meeting limits, Weiss said.
The timeline for communities to meet the Lake Superior basin limits vary, depending on when their five-year wastewater permit is up for renewal.
Tests are sensitive
Mercury is “biologically active at very low quantities,” Weiss said, and economics aren’t always the primary goal. “If it’s expensive to meet the limit, it doesn’t mean the standard is inherently wrong.”
But he said his agency takes economics into account when considering variances, adding that one of the criteria is widespread socioeconomic harm.
Down the shore from Grand Marais, the city of Two Harbors spent $4 million to upgrade its wastewater treatment plant by adding filters to catch more mercury. About half that expense was covered by a government grant; the rest is showing up on residents’ bills. Maintaining the plant and periodically testing the mercury output is adding about $35,000 to the city’s annual costs, said Luke Heikkila, wastewater treatment plant superintendent.
The mercury tests are so sensitive, Heikkila explained, that those testing the wastewater have been instructed not to breathe when pouring a sample into a test bottle. The water accumulates mercury as it is poured through the air and that is taken into account, he said. But something as simple as a mercury filling in a tooth could skew the results.
“The silver lining in all of this is … the water going out into Lake Superior is absolutely beautiful,” Heikkila said, adding that the new system filters out other pollutants, too.
In Hoyt Lakes, city officials are proceeding with plans to build an addition to their wastewater treatment facility to meet the standard but will continue only if they win a state grant to cover 80 percent of its anticipated $7 million price tag, said Floyd Nelson, public works director. If not, they will apply for a variance.
“There’s no way we could pay for it,” Nelson said. “We’ve got 2,000 people.”
Like Grand Marais, the city is already releasing less mercury than it takes in.
“Our plant already removes, on average, about 85 percent of what’s in there,” Nelson said. “I don’t disagree with cleaning up things, but our $7 million could do a lot of other good … on other pollution issues, way more than this tiny little bit of mercury.”
Upgrades are costly
The Minnesota basin’s largest wastewater contributor, the Western Lake Superior Sanitary District in Duluth, has won awards for working with dental and medical companies and schools to make sure less mercury gets into the system. The district meets the mercury limit some months, but officials haven’t been able to figure out the source of occasional spikes, said Executive Director Marianne Bohren.
A membrane filtration system would have cost more than $150 million to install and didn’t promise to be effective. It would also have increased operating costs by half and required twice the amount of electricity, which would have meant more mercury emissions, Bohren explained. The project was not considered economically feasible for the district’s 130,000 residents.
The district, which handles wastewater for 18 communities and four major industries, got a variance but is working on finding other solutions to meet the limit, Bohren said.
In the town of Gilbert, city leaders considered seeking a variance but decided the $10,000 cost wasn’t worth the risk, said city clerk Deb Sakrison.
“There’s no guarantee of getting one and you’re still probably going to have to meet the standards,” she said. So they’re going ahead with an anticipated $8.9 million upgrade, part of which should be covered by a state grant, she said. “It’s going to be a huge impact to our citizens.”
The Pollution Control Agency may not appear empathetic, but Weiss said the agency is willing to work with communities to find solutions.
“We get it,” he said. “We get that some of these costs to meet the optimal would be exorbitant. We also understand there’s ways we can work and achieve some benefit without bankrupting communities.”
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