Recent study indicating nitrate and perchlorate are the primary inorganic constituents of interest here, coming from human activities such as agriculture.
Links to maps of New Jersey showing nitrate levels, pesticides, Total Volatile Organic Compounds (VOCs), and radium in wells and land use of the 1970s.
Study of pesticides in shallow groundwater and surface water to help decision makers evaluate and manage pesticide application practices to protect drinking water resources, especially deeper, potable groundwater as well as aquatic species.
Field manual (also available in PDF and paper formats) with instructions on techniques to collect and process water samples and to perform measurements of temperature, oxygen content, conductance, pH, turbidity, and fecal contaminants.
Cooperative national project with the Federal Highway Administration (FHWA) to evaluate FHWA's guidelines for highway-runoff quality. Links to searchable online bibliography of related publications by the USGS, EPA, FHWA, and state agencies.
Data warehouse for national water quality program with links to chemical, biological, and physical data for water, sediment and animal tissues, nutrient, pesticide, and VOC levels, streamflow, and ground water levels from national study units.
Distribution and characteristics of natural oil and gas seeps in California, including processes of formation and effects on the environment; with discussion of tar pits and asphaltum.
Despite public sector efforts to reduce nonpoint-source nutrients in streams and rivers, concentrations have remained the same or increased, continuing to pose risks to aquatic life and human health.
Results (*.pdf) of a 1998 targeted reconnaissance survey on the sources of radium, polonium, and lead radionuclides, data collection and laboratory methods, existing occurrences in drinking water, risk assessments, and compliance monitoring.