In Clinton County and along the NE “coast” of Iowa, we fall into what is known as the Driftless Region, untouched by glaciers 10,000 years ago. The result is an environmentally significant area; home to rare and protected species, having the largest number of freshwater surface streams in the WORLD and underlain by karst topography. Karst features a triple permeability including fissures, fractures and conduits. The continual water flow through these underground passages constantly dissolves surrounding rock and could increase the dimensions of voids. Our nation’s 20% Karst provides 40% of its fresh, clean drinking water.
Our neighbors in both proximity and topography in SW Wisconsin are also being targeted for industrial wind turbines. The Environmental Assessment prepared for the potential Badger Hollow Wind project states: “if karst features such as voids or fractures are encountered during excavation, appropriate mitigation techniques such as engineered fill or GROUTING would be used to ensure structural integrity and minimize pathways for surface pollutants to reach groundwater.” This is ignoring the fact that the grouting materials themselves are made of suspensions that may be toxic, neurotoxic or carcinogenic. There is a real RISK that these hazardous materials will leach into the fragile, but effective natural water purification system. Additionally, grouting is injected under high pressure. This could open additional cracks or expand existing voids. How predictable is the effect of these injected materials? Though structures can be tested in one area, is their effect in surrounding areas considered? Has enough study been done relating to this?
Are you aware of how much material is required for the base of a 600′ turbine? One 5MW turbine requires an 80′ diameter reinforced concrete foundation for support. This requires 850-900 cubic yards of concrete. Topped by a 77 ton turbine, this equates to 250,000 tons. Considering the risks to our groundwater AND this is only after heavy equipment (and possibly blasting) excavations, concussion from pressure hammers, etc. affect the subterranean karst. What about the ongoing vibrations from the turbines themselves?
The scariest thing to consider is the fresh drinking water necessary for you and me as well as thousands of people, animals, livestock and habitats downstream.
If you are being invited/asked/poached to consider industrial wind or even solar on your ground, you need to weigh the risks. To install 600’ plus tall, environmentally damaging turbines atop this fragile terrain will have an irrevocable effect. Are we certain we are aware of the extent and potential negative side effects of these installations? It would be an utter shame to sacrifice our clean water and environmentally significant region for these installations which enrich corporations with our tax dollars, but not necessarily the taxpayers they propose to benefit.
Roberta Jennings-Barham and Jenn Kutsch
Blanchardville, WI/Delmar, IA
