Groundwater is one of the most precious sources of drinking and irrigation water around the globe due to its usually good quality and easy accessibility. However, groundwater is susceptible to pollution and frequently, groundwater contamination occurs due to human activity such as intensive interference of natural land use. Groundwater contamination can be from both point and nonpoint sources. Point source pollution includes landfills, illegal dumping, accidental spills, leaks from gasoline storage tanks, and leaks from septic tanks, while nonpoint source pollution includes infiltration from pesticides and fertilizer applications (residential/commercial and agricultural lands). When groundwater gets contaminated, it is very expensive and difficult to purify, therefore, an analysis was conducted about known contaminated sites as well as known extent of groundwater contamination in the Raritan.
There are 1,723 known contaminated sites in the Raritan basin with over 20 percent of those in well-head protection areas. Limited data was available to better understand the relationship (if any) between known contaminated sites and groundwater contamination and no trends were determined. Further analysis is needed in this area.