Intentional Corruption of Land
I grew up in a town with an oil refinery. When it was built, the area wasn't densely populated at all, but as the jobs increased, the density grew. However the land under refinery is heavily contaminated with oil byproducts, heavy metals, and other toxins. Even if the oil company pulled up stakes, dismantled everything over the dozen acres or so, and left it an open plot, the land would be unfit for human habitation without substantial and sustained effort. In many ways the land value is negative at this point.
This got me to thinking, in Georgism what is to stop some land hoarders from poisoning their land if it doesn't interrupt their income stream if such poisoning reduces the value of land and therefore the LVT paid? Wouldn't that introduce an economic incentive to pollute/corrupt, especially if it's not obviously visible from outside the property, for example a lack of air pollution/smells?