Publications

In August 2006, the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, collected sediment?core samples from the bed of the Detroit River adjacent to Grassy Island. The goal of the sampling was to assess the distribution and concentration of chemical constituents in sediment adjacent to Grassy Island, which was operated from 1960 to 1982 as a confined disposal...

The U.S. Geological Survey, in cooperation with the Lenawee County Conservation District in Lenawee County, Mich., conducted a sampling effort over a single growing season (June to November 2007) to evaluate the microbiological water quality around a novel livestock reservoir wetland sub-irrigation system. Samples were collected and analyzed for fecal coliform bacteria, Escherichia coli...

Hydraulic tomography is a powerful technique for characterizing heterogeneous hydrogeologic parameters. An explicit trade-off between characterization based on measurement misfit and subjective characterization using prior information is presented. We apply a Bayesian geostatistical inverse approach that is well suited to accommodate a flexible model with the level of complexity driven...

Mercury contained in buried landfill waste may be released via upward emission to the atmosphere or downward leaching to groundwater. Data from the US Geological Survey’s Amargosa Desert Research Site (ADRS) in arid southwestern Nevada reveal another potential pathway of Hg release: long-distance (102 m) lateral migration of elemental Hg (Hg0) through the unsaturated zone. Gas collected...

Compliance with U.S. air quality regulatory standards for atmospheric fine particulate matter (PM2.5) is based on meeting average 24 hour (35 μ m−3) and yearly (15 μg m−3) mass‐per‐unit‐volume limits, regardless of PM2.5 composition. Whereas this presents a workable regulatory framework, information on particle composition is needed to assess the fate and transport of PM2.5 and determine...

This report depicts potentiometric surfaces and groundwater- level changes in three aquifers that underlie the seven-county Twin Cities Metropolitan Area. Approximately 350 groundwater levels were measured in wells from the three aquifers-the Prairie du Chien-Jordan, the Franconia-Ironton-Galesville, and the Mount Simon-Hinckley aquifers-in March and August of 2008. The report presents...

The Airport Cooperative Research Program (ACRP) has sponsored research on environmental characteristics of aircraft and pavement deicers and anti-icers focusing primarily on biochemical oxygen demand (BOD) and aquatic toxicity of formulated products and individual chemical components of formulations. This report presents a background of issues leading to this research, objectives of this...

The small watershed approach is well-suited but underutilized in mercury research. We applied the small watershed approach to investigate total mercury (THg) and methylmercury (MeHg) dynamics in streamwater at the five diverse forested headwater catchments of the US Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) program. At all sites, baseflow THg was generally less...

It is widely recognized that wetlands, especially those rich in organic matter and receiving appreciable atmospheric mercury (Hg) inputs, are important sites of methylmercury (MeHg) production. Extensive wetlands in the southeastern United States have many ecosystem attributes ideal for promoting high MeHg production rates; however, relatively few mercury cycling studies have been...

Atmospheric mercury (Hg) is delivered to ecosystems via rain, snow, cloud/fog, and dry deposition. The importance of snow, especially snow that has passed through the forest canopy (throughfall), in delivering Hg to terrestrial ecosystems has received little attention in the literature. The snowpack is a dynamic system that links atmospheric deposition and ecosystem cycling through...

Physical and biogeochemical characteristics of the aquatic environment that affect growth dynamics of phytoplankton and the zooplankton communities that depend on them may also affect uptake of methylmercury (MeHg) into the pelagic food web of oligotrophic reservoirs. We evaluated changes in the quality and quantity of suspended particulate material, zooplankton taxonomy, and MeHg...

Bioavailability of mercury (Hg) to Selenastrum capricornutum was assessed in bioassays containing field-collected freshwater of varying dissolved organic carbon (DOC) concentrations. Bioconcentration factor (BCF) was measured using stable isotopes of methylmercury (MeHg) and inorganic Hg(II). BCFs for MeHg in low-DOC lake water were significantly larger than those in mixtures of lake...