Why were sanitary landfills developed in the mid-20th century?

Sanitary landfills were developed in the mid-20th century as a necessary response to the significant environmental and safety hazards posed by existing waste disposal practices. By that time, it had become clear that relying on open dumping and improper incineration was causing widespread pollution and directly jeopardizing public health.1

These facilities were designed to replace primitive open dumping methods by providing a controlled environment for the disposal of municipal solid waste. Unlike open dumps, sanitary landfills utilize specific engineering techniques—such as depositing waste in thin, compacted layers and covering them daily with soil—to minimize odors, prevent windblown debris, and protect the surrounding environment. This shift represented a broader movement toward more rigorous solid-waste management standards, which also included the development of separate regulations for hazardous and nonhazardous materials to further mitigate risks to society and the ecosystem.21