It looks like you're out in the sticks where there is little to no zoning regulations, let alone enforcement. The only way the township could shut it down is to declare the property a nuisance and say it violates one of their zoning regulations. The property owner has the right to sue the township if he disagrees with the nuisance order and doesn't want to shut down.
Any industrial facility where there is the potential for contaminants to be leaked onto neighboring properties is required to have an industrial NPDES permit on file with the Ohio EPA. This permit regulates contaminants from industrial operations and requires the owner to contain or treat any waste including surface water runoff that could contain oils or other fluids. I believe you can check the Ohio EPA website to see if this site has a permit. I'm not sure, but it may be too small of a site to require one of these permits. Or maybe, they can say that all the fluids are drained from those cars before they get to the site. Call the Ohio EPA department that deals with these permits. If the site is in violation of the permit, the Ohio EPA can shut it down. They usually give a few warnings first though.
You might want to have the soil tested where it is ruining your yard. The contaminants may not have made it to your well yet. If this soil is contaminated, it will help build your case against them. The dirt there might just be sediment from the gravel lot with little to know contaminants. Still, I believe that the EPA considers excessive sediment runoff from a constantly disturbed site to be a pollutant. The EPA may require them to build a sediment basin to capture that runoff. I once had to design 2 sediment basins and a new storm sewer for a concrete mixing company. Some of the fine cement from the mixing process had run off into a storm sewer on the road and over the years the cement accumulated in the pipe and clogged a 24" diameter pipe! The cement had hardened with the sediment and the whole run of 500' of pipe had to be replaced.
