Ever look at satellite images of coastal cities, such as LA or the greater NYC region? Turn off all map and road labels so it’s just a view of land use and cities just look like a giant concrete mass sprawling hundreds of miles. Now view over Nevada or other major flatland, desolate regions. 2x2 miles of landfill wouldn’t even be visible from the same altitude view. I believe ground water and aquifers are near non-existent in many western areas too so we wouldn’t have to fret about ground water contamination.