Estimating Domestic Self-Supply Water Use for the Delaware River Basin, 1990 U.S. Census Blocks

According to the U.S. Geological Survey, an estimated 258 million people nationwide,
or 86% of the U.S. population, relied on public water supplies for their household use
in 2005 (USGS, 2013). The remaining population obtains their water from different
sources, such as a domestic self-supply well. However, the spatial distribution of
water supply systems has not been compiled. Mapping where these people are
located can be done within a GIS (Geographic Information System). The approach
used takes into account a number of different attributes gathered from the United
States Census Bureau for the block group and block shapes within the Delaware
River Basin.