Septic tank
In the United States, the 2007 American Housing Survey indicated that about 20 percent of all households rely on septic tanks, and that the overwhelming majority of systems are located in rural (50%) and suburban (47%) areas. Indianapolis is one example of a large city where many of the city's neighborhoods still rely on separate septic systems. In Europe, septic systems are generally limited to rural areas.
Emerald Lake Hills, California
Emerald Hills used septic tanks until the early 1980s, a factor that limited building: In 1982, the year the sewer system was installed, the neighborhood had 900 homes. A building moratorium from the late 1970s to 1986 forestalled the boom—but by 1992, the count had boomed to 1,400, eliminating most of the vacant lots. Many of the new homes were large and expensive. Among the new residents were several Forty-Niners, including Joe Montana, as the team was then training in Redwood City. Today, only a few lots remain open, and though building of homes continues, most of them are on the sites of former cabins and vacation homes.