Increases in population often coincide with increases in housing units that can increase impervious surface cover in the form of new roads, parking lots, and residential rooftops. During rainfall, these areas generate runoff quicker than undeveloped surfaces and can transport nonpoint source pollutants into the nearest waterbody. Increases in nonpoint source pollutants pose a threat to both aquatic as well as terrestrial ecosystems. Therefore, in this study housing units were analyzed to evaluate water quality status and trends in the Raritan.
Housing units trends are increasing but slowing, which, given the increase in population, could indicate a move to higher density housing or that much of the area is already built out. Increases in housing units is associated with an increase in impervious surfaces that can transport non-point source pollutants into surface waterbodies and degrade water quality. This has a negative impact on water quality.