Sources and Source Pathways

Emerging contaminants can originate from a variety of animal- and human-waste sources. Pathways to the environment range from rapid and direct discharges of effluent into a water body to the slow leaching of stored waste through soils. Photo Credit: Kent Becker, USGS.

Sample bottels like these filled with leachate were analyzed for contaminants of emerging concern (CECs) including pharmaceuticals, industrial chemicals, household chemicals, steroid hormones, and plant/animal sterols. Photo Credit: Dana W. Kolpin, USGS

To effectively minimize environmental contamination it is necessary to understand potential contaminant origins and pathways to the environment.

A myriad of sources of emerging contaminants and pathways to enter the environment exist throughout the world. Sources and Source Pathway research activities address: 1) identification and quantification of the contaminants or groups of contaminants associated with major sources and 2) processes that govern how these contaminants enter the environment (pathways). Research on sources and source pathways includes:

Emerging Chemical Contaminants

• Source characterization study
• Wastewater treatment plants
• Land Application of Municipal Biosolids
• Onsite Wastewater Systems
• Landfill leachate
• Animal feeding operations
• Aquaculture

Emerging Microbial Contaminants

• Source characterization study

Related Science Features

• Landfill Leachate Released to Wastewater Treatment Plants and other Environmental Pathways Contains a Mixture of Contaminants including Pharmaceuticals
• Potential Exposure to Bacteria and Viruses Weeks after Swine Manure Spill
• Personal Care Products, Pharmaceuticals, and Hormones Move from Septic Systems to Local Groundwater
• Endocrine Disrupting Chemicals Persist Downstream from the Source
• Chemicals Found in Treated Wastewater are Transported from Streams to Groundwater
• Pharmaceuticals and Other Chemicals Common in Landfill Waste
• Antibiotics in Groundwater Affect Natural Bacteria
• Endocrine Disrupting Chemicals in the Slick Scum that Covers Stones in Streams
• Do Combined Sewer Overflows Increase or Decrease Wastewater-Related Chemicals in Receiving Waters?
• Pharmaceuticals Found in Soil Irrigated with Reclaimed Water
• Veterinary Medicines in the Environment

More Information

• Emerging Contaminants Sources and Source Pathways Bibliography