The state Department of Natural Resources, Ameren Missouri, the Sierra Club and 6th District County Councilman Steve Stenger, D-Affton, all agree that Ameren must monitor the groundwater around its Oakville coal-fired power plant — when and how it will happen, however, is still in question.

No one disputes that the plant is, by far, the largest polluter in St. Louis County, county Department of Health Director Dr. Delores Gunn told the County Council at a Committee of the Whole meeting last week.

That pollution can come through toxic chemicals released into the air and, potentially, the groundwater. One of the key pollutants released into the air from a coal-fired power plant is sulfur dioxide, which is a byproduct of burning coal and can cause damage to the respiratory system if inhaled.

Ameren’s Meramec Energy Center opened in 1953 at the intersection of the Mississippi and Meramec rivers.

The Department of Health can use readings from Ameren’s own monitors on its stacks to know how many tons of pollution the plant emits into the air at any given time. Those readings show that Ameren’s allowed air pollution levels are “quite a bit higher than we will actually emit, and at a level that’s protective of public health,” said Mike Meaney of Ameren Missouri.

The air-quality readings that the state relies on may not be the most reliable indicators of true pollution levels, however.

After the meeting, Stenger told the Call he was shocked to learn that the quality of air in St. Louis County is monitored only by air monitors in surrounding counties, not any within the county itself.

“I would think with a county of a million people, we would have some (sulfur-dioxide) monitors,” he said. “Frankly, it’s hard to believe … and it is concerning. A great place to start would be to have some monitoring within the county limits.”

The closest sulfur-dioxide air monitor around St. Louis County is in Herculaneum in Jefferson County, Missouri Sierra Club Director John Hickey told council members during a period for public comment at the meeting.

Groundwater monitoring has not been conducted around the plant for decades, which means the county does not know where it stands with coal-ash pollution in the groundwater at all, Gunn said.

“Groundwater testing hasn’t been done in 20 or 30 years?” Stenger said. “That’s astonishing. I can’t believe that … Frankly, I’m outraged. I can’t believe that’s the case … How can we have a baseline whatsoever?”

Ameren plans to start tests of the groundwater around the coal-ash ponds, Meaney said, but it is currently studying where to test and what to test. He did not give a time line or prediction of when the study would be completed or when monitoring could begin.

Illinois requires its coal plants to monitor ground water, noted several speakers. The Illinois Environmental Protection Agency has found unsafe levels of several toxic metals, including arsenic, at four of Ameren’s five coal-fired plants in Illinois.

In early August, Stenger wrote a letter to the Missouri DNR requesting groundwater monitoring of the coal-ash ponds at Ameren’s Meramec Energy Center. The letter came after lobbying by the Beyond Coal campaign of the Sierra Club, which has put pressure on Ameren to monitor the groundwater at its Missouri plants the way it is required to at its plants in Illinois.

“We fully intend to do that. We will be doing that,” Meaney said of groundwater monitoring, also noting that the Oakville coal-ash ponds Ameren currently uses will probably be closed down within the next decade due to new federal regulations.

The groundwater near Ameren’s ash ponds, which are both lined and unlined, would not be used by any residents, Meaney noted.

“There’s no one that would get exposed to this,” he said. “So there really is no exposure here — there’s no danger to public health in any way, shape or form.”

A few residents of Oakville have addressed the council and noted cases of asthma in their family, but Meaney disputed that these would be caused by the Oakville coal plant, noting that asthma rates have increased nationwide, as Ameren’s pollution levels have decreased by two-thirds.

In an Aug. 14 response to Stenger, Sara Parker Pauley, head of the Missouri Department of Natural Resources, told him that as part of future pollution permit renewals, Ameren will be required to install groundwater monitors at its plant.

That effort hinges on a detailed site study of the site’s geology and hydrology, she told Stenger. Once the study is in hand, investigations of the groundwater will include drilling, water monitoring and sampling, she added.