From the site: "The conservation well layer identifies the permitted surface location of oil and gas conservation wells that have not been plugged. These include active, regulatory inactive, orphaned, and abandoned wells. A conservation well is any well which penetrates the Onondaga horizon, or in those areas in which the Onondaga horizon is nearer to the surface than thirty-eight hundred feet, any well which exceeds a depth of thirty-eight hundred feet beneath the surface."