By Elisabeth Pernicone
Dec. 16, 2009
Due to its many health threats, mercury is regulated in foods, pesticides and industry. But some coal-fired power plants in the Great Lakes region discharge mercury into water at levels hundreds of times greater than deemed safe for wildlife and up to 25 times greater than deemed safe for humans.
It’s all legal, and even when it’s not, most violators are never fined.
Now the U.S. Environmental Protection Agency is preparing to step up its regulations of mercury and other contaminants in coal-fired power plant wastewater. While mercury discharge into the Great Lakes has been regulated for years, the agency only focused on suspended solids and pH in other water bodies.
Confused? Here’s why.
In 1995, the Environmental Protection Agency and the eight Great Lakes states agreed to reduce mercury released into waters. This Great Lakes Initiative limited mercury discharged into the Great Lakes to an average of 1.3 nanograms per liter each month (ng/L).
That’s about one drop of mercury in 20 Olympic-sized swimming pools over an entire month.
The standard was developed to ensure wildlife safety. But mercury also poses a risk to humans. Because of mercury, fish consumption advisories have been in place in the Great Lakes since 1971.
Mercury occurs naturally in the environment, but is transformed into a more dangerous form by bacteria and plants in the water. This new form, called methylmercury, builds up in fish.
Consuming contaminated fish can cause heart, kidney, and lung damage. Pregnant women are advised to limit their consumption of fish, since mercury can damage the brain of the fetus.
More than 300,000 infants born every year may face learning disabilities from mercury exposure in the womb, according to the EPA.
Many power plants have difficulty meeting mercury discharge limits because of the costs. In addition, some water bodies already have high mercury levels. So the power plants that dump into them are disadvantaged from the start.
States can approve new discharge limits for plants that cannot meet current standards.
And, here’s where it gets confusing.
If a plant is not releasing wastewater into one of the Great Lakes, it does not have to follow the 1.3 ng/L standard. Each state sets its own limits — with EPA approval – for the average amount of mercury that can be discharged into non-Great Lakes water.
The EPA had intended to regulate mercury discharge in these eight states, but never implemented a standard.
“The EPA drafted a strategy, [but] it was never issued because the agency perceived a general lack of public interest, and agency resources were directed towards other Great Lakes Initiative activities,” according to a report by the Government Accountability Office.
A whopping 63 percent of power plants in Great Lakes states are not required to monitor for mercury, according to the EPA database.
For plants that do, wide variations exist for mercury discharges exist by water body, month and even facility.
Michigan officials adopted the 1.3 ng/L limit for surface water in the state. Other states, such as Indiana, have less stringent mercury discharge limits on water that doesn’t flow into the Great Lakes. Indiana’s limit is 12 ng/L — nearly 10 times the Great Lakes limit – for water bodies in the southern part of the state.
Indiana officials did not implement the 1.3 ng/L for inland water bodies because they believed their current standard was satisfactory, said Amber Finkelstein, spokeswoman for the Indiana Department of Environmental Management. Also, many recreational activities, such as swimming and fishing, are limited outside Lake Michigan.
A review of the EPA data from 2006 to 2009 gives a sense of the disparity of limits and discharges throughout the region:
- In Pennsylvania- PPL Montour power plant, in Washingtonville, has a permit to discharge about 10 times more mercury than EME Homer City Generation power plant, 170 miles to the west. Neither plant discharges into the Great Lakes.
Discharges can even vary for power plants discharging into the same Great Lake, even though the standard is set at 1.3 ng/L.
- In Lake Erie in May 2009- Ceco JR Whiting power plant in Michigan and Dunkirk Generating Station in New York discharged about twice as much mercury as Cleveland Electric Illuminating Co. in Ohio.
- Discharges from the same plant can even vary by month. In Michigan- Ceco JR Whiting power plant in Luna Pier discharged a wide range of mercury from one of its pipes. In 2007, the plant released 80 ng/L from pipe 1. A year later the mercury discharge dropped to about 21 ng/L.
Here’s why limits and discharges may vary from one power plant to another:
1) Power plants take in water from rivers and lakes for their cooling towers. But not all water starts out clean. If water already has mercury in it from prior pollution, it may be allowed to have a higher discharge limit, according to Dawn Roush, a biologist in the Water Quality Division of the Michigan Department of Environmental Quality.
2) Power plant owners may not have the finances to meet the current limit, Roush said.
3) Mercury levels in coal vary. Not all power plants use the same type of coal, said Finkelstein, who works for Indiana’s environmental agency.
Here’s why variances may occur at the same power plant:
1) The sampling tools are more accurate at detecting large amounts of mercury. Low levels, such as 1.3 ng/L, are hard to detect and the accuracy of detecting mercury decreases with low levels present, said Tarek Buckmaster, an environmental quality analyst for Michigan’s Department of Environmental Quality.
2) Other industrial plants upstream may affect a coal plant’s monthly mercury sample. An automobile plant upstream may discharge a high amount of mercury while a power plant samples its waste water. The coal plant would therefore intake water with more mercury (which would make the level of mercury in its discharge increase), said Buckmaster.
Pennsylvania power plants among worst offenders
Since many factors and limits vary by state, it is hard to point fingers at the worst state in the region for mercury pollution. But Pennsylvania utilities stick out.
The state had the two worst power plants for water quality violations out of all the power plants analyzed in the Great Lakes states.
Reliant Energy’s Conemaugh Generating Station, in New Florence, Penn., violated water quality standards 232 times in the past three years, according to the EPA database. Almost all of the violations were for metals such as aluminum, manganese, mercury and iron.
Just five miles upstream, Reliant Energy’s Seward Power Plant violated water quality standards 84 times since 2006 for metals such as aluminum, iron and manganese. Both power plants discharge into the Conemaugh River.
Neither was fined under the Clean Water Act.
Pennsylvania also has the highest mercury discharge limits in the region.
Forty percent of its plants that monitor for mercury have limits that are thousands of times greater than the Great Lakes standard, according to the EPA database; although most have not discharged anywhere near this level.
Why some plants don’t monitor for mercury
EPA data shows that more than 63 percent of power plants in Great Lakes states don’t even monitor for mercury.
This is because smaller facilities may have demonstrated that discharging mercury in amounts greater than 1.3 ng/L is not a concern, said Buckmaster, who works for Michigan’s Department of Environmental Quality. In this case states may only require mercury testing every few years to ensure the levels remain below the limit.
The future of mercury discharge
While a lot of the mercury present in the water is from power plant air emissions, discharge into waters accounts for some of the pollution, Roush said.
Some power plants have air pollution devices called scrubbers, which clean air emissions by spraying water to absorb pollutants. This process takes the contaminants out of the air, but merely transfers them to wastewater and since many states have passed legislation to reduce mercury air emissions, mercury in the wastewater may soon become an even bigger issue.
Michigan recently passed legislation to reduce mercury air emissions by 90 percent by 2015. It’s not alone. Wisconsin, Pennsylvania, Ohio, Illinois, Minnesota, and Indiana all have passed similar legislation, or have proposed laws. Illinois plans to have this reduction by 2012.
With more power plants installing scrubbers, “we are doing a better job of controlling air pollution, but as a result the water often times suffers,” said James Clift, policy director of the Michigan Environmental Council.
“We need to watch to make sure that mercury isn’t reintroduced into our waters,” he said.
NOTE: This post was updated for accuracy 12/17/2009 at 16:18