For the most part, land fills are not a problem so long as the trash that is being put there is bio-degradeable. The problem comes from the stuff that can be hazardous when it gets into the ground water. Stuff like old paint, oil, pesticides and etc. Some people disguise their garbage so that it will be collected and then dumped. The trash haulers try to watch out for the bad stuff but some of it gets through anyway. Old TV sets, old computers and monitors and the like contain some hazardous materials. The better way is to burn the bad stuff in special incinerators that convert it to a power source. Yes in some areas, such as NY City and other highly populated cities, it is a real problem. In areas where there are fewer people and wide open spaces, it is not a major problem. I think greater care has to be taken by everyone to make sure that they do not and poision to the trash. It takes some effort, but it is worth it.