Waste disposal is dated back from ancient times, and sanitary sewers have been found in the ruins of Crete and the ancient Assyrian cities. Although the primary function of storm-water sewers was drainage, the Roman practice of dumping waste in the streets caused mass quantities of organic matter to be carried along with the rainwater runoff. Toward the end of the Middle Ages, underground privy vaults and cesspools were developed. When these containers became full, sanitation workers removed the deposit; waste was used as fertilizer farms or dumped into watercourses or onto vacant land.
A few centuries later, there was renewed innovation of storm sewers, mostly as open channels or street gutters. Disposing waste in these sewers was forbidden, but by the 19th century it was recognized that community health could be improved by discharging human waste into the storm sewers. Development of municipal water-supply systems and household plumbing brought about flush toilets and the start of modern sewer systems. By 1910, there were about 25,000 miles of sewer lines in the United States.
At the start of the 20th century, cities and industries recognized that sewage caused health problems, and resulted in the construction of sewage-treatment facilities. Relatively the same time, the septic tank was introduced as a means of treating sewage from households in suburban and rural areas. Because of the abundance of diluting water and social / economic problems, only a few municipalities and industries provided waste-water treatment.
During the 1950s and 60s, the U.S. government provided funds for municipal waste-treatment plants, water-pollution research, and technical training and assistance. New treatments were developed for sewage, waste-water analysis, and studies on environmental effects of pollution. Due to the growing population, industries, and economy, the National Environmental Policy Act (NEPA) was signed in January 1970. In December 1970, the Environmental Protection Agency (EPA) was created to unite all pollution-control programs related to air, water, and solid wastes. In 1972, the Water Pollution Control Act Amendments significantly increased federal funding for waste-treatment works. Congress initiated regulatory mechanisms and established uniform effluent standards.