Once they are harvested, a new crop can be planted. Some materials, however, like the fossil fuels used to produce energy, are not renewable. The Earth contains a fixed amount. The technology we developed made it possible for industry to use raw materials at a much greater rate than ever before, frequently faster than even the renewable resources could be replaced. Technological progress and population growth have contributed to the production of hazardous waste that pollutes the land, air, and water.
Hazardous waste comes from a wide variety of sources, and from both present and past activities.
It most often is a by-product of manufacturing processes. Some of it comes from our homes as well, when we do not dispose of hazardous substances properly. Years ago, before we understood the dangers of hazardous waste, there were no laws controlling waste disposal. Eventually, thousands of uncontrolled or abandoned hazardous waste sites were created at manufacturing facilities, harbors, processing plants, landfills, and many other kinds of places. Congress created the Superfund Program to investigate and clean up hazardous waste sites nationwide.