Toxic Substances Hydrology Program

Featured Science Activities

Our science activities are summarized in a series of feature articles that highlight recent U.S. Geological Survey (USGS) environmental health science activities. They are short summaries of peer-reviewed journal articles and USGS reports co-authored by our specialized teams of scientists.
Older featured science activities are on our old Web site.

Filter Total Items: 90
Date published: February 24, 2017
Status: Completed

Examining Shifts in Stream Microbial Communities Exposed to Oil and Gas Wastewaters

Shifts in the overall microbial community structure were present in stream sediments that contained chemicals associated with unconventional oil and gas wastewaters. This work is part of a long-term study designed to understand persistence of chemicals from oil and gas wastewaters in sediments and water and how those factors might be related to exposures and adverse health effects, if any, on...

Date published: February 23, 2017
Status: Completed

Nitrate Addition Enhances Arsenic Immobilization in Groundwater

The addition of nitrate in a low oxygen groundwater resulted in the immobilization of naturally occurring dissolved arsenic and the conversion of nitrate to innocuous nitrogen gas.

Date published: January 11, 2017
Status: Completed

Understanding Pathways of Unconventional Oil and Gas Produced Water Spills in the Environment

A new study measures the transport of chemicals associated with unconventional oil and gas (UOG) produced waters downstream from a pipeline leak in North Dakota. This work is part of a long-term study designed to understand chemical persistence in sediments and water and how those factors might be related to contaminant exposures and associated with adverse health effects, if any, on organisms...

Date published: November 21, 2016
Status: Completed

New Study Measures Crop Bactericide, Nitrapyrin, in Iowa Streams

First-ever reconnaissance study documents the off-field transport of nitrapyrin — a nitrification inhibitor applied with fertilizers as a bactericide to kill natural soil bacteria for the purpose of increasing crop yields — to adjacent streams. This study is the first step in understanding the transport, occurrence, and potential effects of nitrapyrin or similar compounds on nitrogen...

Contacts: Emily Woodward
Date published: October 25, 2016
Status: Completed

Gestodene Affects Fish Reproductive Behavior in Laboratory Exposure Study

Short-term laboratory exposure of adult fathead minnows to the human contraceptive progestin, gestodene (GES), at environmentally relevant concentrations induced rapid and negative effects on reproductive health and suggests that wild fish may be similarly affected.

Date published: September 1, 2016
Status: Completed

Swine Manure Application as a Source of Hepatitis E Virus and other Livestock-Related Pathogens

The presence of indicator bacteria, hepatitis E virus (HEV), and numerous bacterial pathogen genes increased following precipitation-induced runoff events in streams draining adjacent land surfaces in Iowa where swine manure was recently applied.

Contacts: Carrie Givens
Date published: August 30, 2016
Status: Completed

Recovery of Stream and Adjacent Groundwater After Wastewater Treatment Facility Closure

The hydrology and chemistry of a wastewater-impacted stream and adjacent groundwater responded rapidly (had fewer chemicals at lower concentrations) following wastewater treatment facility shutdown. However, the adjacent shallow groundwater remained a continuing source of some wastewater-derived contaminants to the stream at least 1 year post-shutdown.

Date published: August 29, 2016
Status: Completed

Study Reveals Processes that Control Uranium Bioavailability in a Freshwater Snail—Relevance to Aquatic Biota in the Grand Canyon Area

Scientists refined an existing speciation model to identify key biogeochemical processes controlling dissolved uranium bioavailability to a freshwater snail. This information is important to advance current understanding and prediction of the ecological risk posed by uranium mining to freshwater ecosystems, including federally managed lands such as in the Grand Canyon area.

Date published: July 20, 2016
Status: Completed

Nutrients in Dust from the Sahara Desert cause Microbial Blooms on the East Coast of the United States

Saharan dust nutrients, particularly iron, deposited episodically in tropical marine waters stimulate marine microbial bloom growth and change microbial community structure.

Contacts: Dale Griffin
Date published: June 24, 2016
Status: Completed

DOI Distinguished Service Award Given to Two Program Scientists

Two U.S. Geological Survey (USGS) Toxic Substances Hydrology Program (TSHP) scientists, Denis R. LeBlanc and Dr. Michael T. Meyer, received the Department of Interior's (DOI) highest honor—the Distinguished Service Award. The award is given to recognize outstanding contribution to science, outstanding skill or ability in the performance of duty, outstanding contribution made during an eminent...

Contacts: Mike Focazio
Date published: June 21, 2016
Status: Completed

USGS Scientists Measure New Bacterial Nitrogen Removal Process in Groundwater

For the first time, U.S. Geological Survey (USGS), Virginia Institute of Marine Science, and the University of Connecticut scientists have detected active anammox bacteria in groundwater.

Date published: June 20, 2016
Status: Completed

Bacterial Pathogen Genes in Streams related to Animal Type and Hydrologic Conditions

A U.S. Geological Survey (USGS) study elucidates the influence of animal type and environmental variables on bacterial pathogen occurrence in streams under typical watershed conditions.