Fragile karst worries neighbors of proposed wind turbines 

YORK TOWNSHIP – To call Bellevue and its surrounding area Ohio’s sinkhole capitol is not too much of stretch.

Sinkholes, disappearing streams, caves and springs are some of karst terrain’s signature features, and these geologic hazards can be found throughout eastern Sandusky and Seneca counties.

So what will happen if these karst formations collide with proposed wind energy development in the region?

APEX Clean Energy says it will take great pains to build its proposed Republic Wind Farm around sensitive karst areas. The plan includes 47 turbines that could reach as high as 602 feet.

Sandusky County residents Deb and Casey Didion aren’t convinced.

Every three or four years, water bubbles up from a Riddle Road karst area near the Didions’ Bellevue home.

It forms a temporary lake on each side of elevated railroad tracks and floods the road.

Migratory birds find their way there and it’s become a popular eBird hotspot on the Bellevue Birding Drive, a driving loop for birders that spans four counties.

Two of 47 proposed Republic Wind Farm industrial wind turbines are slated to go in a neighbor’s corn field between the Didions’ property and that karst area.

When earth is moved and concrete poured to build those turbine foundations, the Didions fear there will be catastrophic environmental impacts on well water systems, a massive redirection of the region’s underground water flow and possible flooding if karst seams are fractured or filled.

“It’s just fragile. You don’t want to open them up. You don’t want to plug them,” Casey Didion said Monday, as he, his wife and Seneca Anti-Wind Union leader Deb Hay voiced their concerns about the turbines, karst and regional wind energy development in general.

Geotechnical process explained

The Republic Wind Farm project, as well as other proposed wind projects in Seneca, Sandusky, Erie and Huron counties, has generated fierce opposition from hundreds of landowners like the Didions.

APEX Clean Energy Spokesman Natasha Montague told the News-Messenger her company plans to start construction on the Republic project in 2020.

Ohio’s Power and Siting Board still has not voted on whether to approve the Republic Wind field and there will likely be future public hearings locally and in Columbus this year on the project.

In an email, Montague laid out a series of steps she said the company takes to detect karst and avoid groundwater sources.

Apex is developing projects in areas of Oklahoma and Texas that have karst features, she noted.

Montague said Apex’s geotechnical investigation process begins with preconstruction engineering, during which a third-party engineer conducts boring tests at turbine locations.

These tests help flag for the potential existence of karst.

If a turbine location is determined to be in a potential karst area, additional testing is conducted (such as electrical resistivity imaging or shear wave testing) to search for karst features.

Should the third-party engineer determine a location is unsuitable for turbine placement, a different turbine location will be activated, Montague said.

“Again, the geotechnical investigation begins long before preconstruction engineering. The groundwater hydrogeological and geotechnical report, which is included in our project application, is reviewed by the Ohio Power Siting Board prior to when we will begin borings,” Montague said.

Montague said the typical and expected foundation of the turbine models under consideration in Apex’s northern Ohio wind projects extend to a maximum depth of approximately 10 feet, which she described as not significant enough to impact groundwater.

She said turbines are intentionally sited away from wells and other water sources.

An OPSB staff report on the Republic project recommended that the agency’s board authorize construction of the proposed wind farm, subject to 57 conditions.

The report noted that 27 of Apex’s 47 proposed Republic turbines are situated in areas exhibiting karst features, according to the company.

Hay and the anti-wind union responded to the OPSB report and pointed out the 57 conditions identified by the state agency include: lack of appropriate siting for multiple turbines, interference with navigable airspace including air ambulance, interference with operations of the Seneca and Sandusky County airports, avoidance and mitigation of all existing microwave paths/licensed communication systems, multiple impacts to native wildlife, and concerns related to nighttime sound levels.

Her Seneca County home near Township Road 178 includes a karst area.

Hay showed the drop off in elevation as she stepped into vegetation that obscured her front yard sinkhole.

“If they change the flow of the water, I could have a lake in my front yard,” Hay said.

Hay disputes Apex’s assertions about turbine foundation construction and its impacts on groundwater.

She said wind companies will drive piles deep into the ground until they reach bedrock, disturbing multiple layers of black shale and limestone in the Bellevue karst region.

“And if they run into karst, they’re just going to grout it. They’re just going to fill it with rocks and stones,” Hay said.

Karst identified in Bellevue area

The Ohio Department of Natural Resources mapped nearly 1,000 karst areas in the Bellevue Quadrangle and parts of the Clyde and Castalia quadrangles in 2012 and 2013, with state geologist Douglas Aden producing a report on regional data he collected.

That includes the area near the Didions, who live on County Line Road.

The report’s introduction includes the line, “different types of karst features may pose infrastructure complications, roads, utilities, houses and other facilities built in karst areas are at risk of subsidence, collapse and other damage.”

It’s not hard to spot what Casey Didion called “karst tubes” in farm fields throughout the region, or trees and lower areas surrounded by vegetation that stick out like sore thumbs in fields otherwise filled with rows and rows of maturing corn stalks.

He pulled up to a friend’s County Road 29 property in Seneca County and hiked back to show off a massive karst area.

“Some of these are as small as six to seven inches around and some of them get quite large, as some of these you can see,” Didion said. “Seneca Caverns is a good example of one that goes down a long way.”

Groundwater flows north through Bellevue’s karst region.

Didion said the groundwater eventually makes its way to Lake Erie, going through the Blue Hole area in Castalia.

Previous flooding in Bellevue

Aden’s 2013 ODNR report noted karst-related flooding that occurred in Bellevue in 2008.

ODNR’s divisions of ground water and geological survey released an investigative report in 2009 that examined the unusual Bellevue flooding causes of the previous year.

On March 18, 2008, Bellevue-area groundwater levels rose to 40-year highs, with sinkholes acting as springs.

Kenn Rospert, a Bellevue resident who lives on Ohio 269, could have three proposed wind turbines from the Emerson Creek Wind project erected directly behind his property.

Rospert lives in Erie County. If he takes a walk across the street, he crosses over into Sandusky County.

Ohio 269 in front of Rospert’s house remained closed for three months following the 2008 Bellevue floods.

When there’s an obstruction in the karst, the water just goes in all directions, Rospert said.

The ODNR investigative report recommended best management practices, such as sinkhole structures and grassed buffer strips and waterways, should be put in around sinkholes to minimize ground water contamination and to keep sinkholes open to prevent surface karst-related flooding.

Property owners like Rospert, the Didions and Hay rely on wells for water.

Jeannie Gore, a Bellevue business owner along U.S. 20, said well water contamination is one of her biggest fears with the proposed project.

“If wells get contaminated, we can’t sell and move somewhere else. This is our home,” Gore said.

In his backyard, Rospert’s well also serves as an ODNR monitor site that records ground water levels.

Karst-generated pressure pushed Rospert’s basement floor up during the 2008 flood

Rospert wonders what will happen to his well when wind companies start building turbine footers filled with 750 yards of concrete and 100 tons of steel.

“Once you start interrupting this water flow, residents are concerned they’re going to lose their wells,” Rospert said.

Montague said a stormwater permit is required by the National Pollutant Discharge Elimination System (NPDES) for the Republic Wind project.

She said this permit, administered by the Ohio Department of Natural Resources, ensures that proper stormwater controls are in place so construction can proceed in a way that protects a community’s clean water and the surrounding environment.

Lori Riedy, owner of Russell’s Flowers, Garden Center and Gifts on Ohio 269, operates her longtime family business a few blocks north of Rospert’s home.

Her business depends on access to clean well water, as she has eight greenhouses of plants she waters on a regular basis.

When the 2008 flooding closed Ohio 269, Riedy was entering the busiest season of the year for her greenhouse.

“I’ve got greenhouses full of plants and nobody coming in to buy them,” Riedy said.

Russell’s Flowers closed for several days and Riedy helped sandbag other people’s homes as she waited for floodwaters to recede in Bellevue.

ODNR’s 2009 report noted that flooding due to upwelling ground water in the area in close proximity to Bellevue had happened only six times since 1800.

The last two occurrences prior to 2008 were in 1969 and 1937. All three of these occasions were in response to heavy precipitation events.

Riedy doesn’t want wind turbine construction to result in plugged sinkholes and trigger a repeat of 2008’s disaster.

“It’s going to have an effect in our drainage and wells,” she said.

Future of Republic Wind project

Apex will prepare a wind turbine assembly area by grading and removing vegetation

within a maximum radius of 300 feet around each turbine location, according to the OPSB staff report.

The most likely type of turbine foundation would be a spread footing foundation. An alternative that could be used is a rock anchored pile-supported foundation, the company reported to the state agency.

The company projects the largest turbines in its Emerson Creek Wind project to produce pressure of approximately 1,050 pounds of pressure per square foot on surrounding earth and bedrock existing below the surface of turbine foundations.

In OPSB’s staff report, the agency reported Apex’s project area is comprised of

roughly 19,000 acres of leased private lands involving approximately 440 properties.

OPSB has not yet scheduled its next public hearing on the Republic project

Sandusky County commissioners voted July 25 to rescind the county’s Alternative Energy Zone (AEZ), a move applauded by the anti-wind union and the Didions.

As the family waits to see how OPSB will rule on the Republic Wind project, Deb Didion said she and Casey have lived at their Sandusky County home for 33 years.

She understands why some area landowners signed leases with Apex, but didn’t think the turbines were worth it to sign a similar lease.

“You can gain all the money you want, but if it impacts your quality of life and lifestyle, it’s not worth it,” Didion said.

The proposed turbines prompted three of her nearby County Line Road neighbors to sell their homes and move away, Didion said.