Just put, the refinery is fine. It's the smelter that has problems, as they don't deconstruct buildings and smelters can lose lava. Sometimes, the humans build roads over lava, which is bad, as in some cases, you lose oil, others, tropical. Also, laws should also make humans automatically kill bears and snakes if they have killed any humans. Although, snakes should be farmable for the venom and eggs. Also, wells made with stone and wood that are discovered when you get the city hall. Would make metal and glass require water in their recipe. Wells can be made on any turf. And also mines, discovered with examining mountain, where humans go in with the mining intent, and return with ore, sand, rock, gold ore, or plutonium.