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.
Sediment basin
A sediment trap is a temporary settling basin installed on a construction site to capture eroded or disturbed soil that is washed off during rain storms, and protect the water quality of a nearby stream, river, lake, or bay. The trap is basically an embankment built along a waterway or low-lying area on the site. They are typically installed at the perimeter of a site and above storm drain inlets, to keep sediment from entering the drainage system. Sediment traps are commonly used on small construction sites, where a sediment basin is not practical. Sediment basins are typically used on construction sites of or more, where there is sufficient room.