The Toxic Substances Hydrology Program provides objective scientific information on environmental contamination to improve characterization and management of contaminated sites, to protect human and environmental health, and to reduce potential future contamination problems. Read more about the Toxics Program

Recent Headlines view all headlines				Research Projects view all research
Antibiotics in Groundwater Affect Natural Bacteria Endocrine Disrupting Chemicals in the Slick Scum that Covers Stones in Streams Chemical Geology Highlights Importance of Diel Processes in Rivers and Lakes Do Natural Processes Mitigate Contamination from Landfill Leachate? Understudied Fungicides Common in U.S. Streams Draining Agricultural Land Algal Blooms Consistently Produce Complex Mixtures of Cyanotoxins and Co-Occur with Taste-and-Odor Causing Compounds in 23 Midwestern Lakes Mixtures of Pesticides Detected in Crab Embryos				Subsurface Point-Source Contamination Projects: Petroleum (crude oil, gasoline, produced water) | Chlorinated Solvents | Mixed Wastes (landfills, wastewater) | Fractured-Rock Aquifers Watershed-and Regional Scale Contamination Projects: Hard-Rock Mining | Pesticides | Emerging Contaminants | Mercury | Amphibian Research | Priority Ecosystems Methods Development Topics: Microbial Geochemistry | Geochemistry | Hydrology | Contaminant Geophysics | Modeling
				Photo Gallery view gallery
				Plant foliage samples being placed in direct sunlight for water extraction by solar distillation. Water vapor released from the foliage condenses as liquid on the inside surface of the sample bag -- from the Detecting Tritium in Plants Photo Gallery
New Publications view all publications				Crosscutting Topics view all topics
Selected New Publications Evaluating remedial alternatives for an acid mine drainage stream--A model post audit: Runkel, R.L., Kimball, B.A., Walton-Day, K., Verplanck, P.L., and Broshears, R.E., Environmental Science and Technology, v. 46, no. 1, p. 340-347, doi:10.1021/es2038504 (IN PRESS). Tracking nonpoint source nitrogen pollution in human-impacted watersheds: Kaushal, S.S., Groffman, P.M., Band, L.E., Elliott, E.M., Shields, C.A., and Kendall, C., 2011, Environmental Science and Technology, v. 45, no. 19, p. 8225-8232, doi:10.1021/es200779e. Effects of the antimicrobial sulfamethoxazole on groundwater bacterial enrichment: Underwood, J.C., Harvey, R.W., Metge, D.W., Repert, D.A., Baumgartner, L.K., Smith, R.L., Roane, T.M., and Barber, L.B., 2011, Environmental Science and Technology, v. 45, no. 7, p. 3096-3101, doi:10.1021/es103605e. More > Upcoming Publications Simultaneous oxidation of arsenic and Antimony at low and circumneutral pH, with and without microbial catalysis: Asta, M.P., Kirk Nordstrom, D., and Blaine McCleskey, R., Applied Geochemistry, doi:10.1016/j.apgeochem.2011.09.002 (IN PRESS). Loss of volatile hydrocarbons from an LNAPL oil source: Baedecker, M.J., Eganhouse, R.P., Bekins, B.A., and Delin, G.N., Journal of Contaminant Hydrology, doi:10.1016/j.jconhyd.2011.06.006 (IN PRESS). Comparing the bioavailability of dissolved organic carbon in different aquifer systems: Chapelle, F.H., Bradley, P.M., McMahon, P.B., Kaiser, K., and Benner, R., Ground Water (IN PRESS). More >				Agricultural Chemicals Contaminant Occurrence Studies Contaminant Plume Geochemistry and Microbiology Geophysical Characterization Ground-Water Contaminant Transport Field Methods Laboratory Methods Models Natural Attenuation Nutrients Site Remediation Surface-Water Contaminant Transport Tracer Tests Unsaturated Zone
				Meetings view all meetings
				USGS cosponsors the special session Fate and Transport of Radionuclides in the Environment at the 2009 AGU Fall Meeting, San Francisco, California, December 14-18, 2009 USGS cosponsors the special session Nutrient Sources and Cycling in Aquatic Systems at the 2009 AGU Fall Meeting, San Francisco, California, December 14-18, 2009 USGS cosponsors the special session Fate and Behavior of Pharmaceuticals in Treated Wastewaters, Sludge and River Waters at the SETAC 30th Annual Meeting, New Orleans, Louisiana, November 19-23, 2009 The USGS sponsored the special session Endocrine Disrupting Chemicals--Analytical Methods and Environment Processes at the SETAC 30th Annual Meeting, New Orleans, Louisiana, November 19-23, 2009 USGS and Montana Tech of the University of Montana co-sponsor the Special Session Diurnal Biogeochemical Processes in Rivers, Lakes, and Shallow Groundwater at the 2009 GSA Annual Meeting, Portland, Oregon, October 18-21, 2009 USGS science featured at the AAAS symposium San Francisco Bay: Tracking and Understanding a Changing Estuary, San Francisco, California, August 17, 2009 USGS and Colorado State University co-sponsor EmCon2009-2nd International Conference on Occurrence, Fate, Effects, and Analysis of Emerging Contaminants in the Environment, Fort Collins, Colorado, August 4-7, 2009 USGS, University of Texas at El Paso, and the Mountain Studies Institute conducted a field trip on Acid Rock Drainage in the San Juans in Prospect Gulch, near Silverton, Colorado, on August 1, 2009.