Chloride in Groundwater and Surface Water in Areas Underlain by the Glacial Aquifer System, Northern United States

Abstract

The U.S. Geological Survey (USGS) is committed to providing the Nation with credible scientific information that helps to enhance and protect the overall quality of life and that facilitates effective management of water, biological, energy, and mineral resources (http://www.usgs.gov/). Information on the Nation's water resources is critical to ensuring long-term availability of water that is safe for drinking and recreation and is suitable for industry, irrigation, and fish and wildlife. Population growth and increasing demands for water make the availability of that water, now measured in terms of quantity and quality, even more essential to the long-term sustainability of our communities and ecosystems. The USGS implemented the National Water-Quality Assessment (NAWQA) Program in 1991 to support national, regional, State, and local information needs and decisions related to water-quality management and policy (http://water.usgs.gov/nawqa). The NAWQA Program is designed to answer: What is the condition of our Nation's streams and groundwater? How are conditions changing over time? How do natural features and human activities affect the quality of streams and groundwater, and where are those effects most pronounced? By combining information on water chemistry, physical characteristics, stream habitat, and aquatic life, the NAWQA Program aims to provide science-based insights for current and emerging water issues and priorities. From 1991-2001, the NAWQA Program completed interdisciplinary assessments and established a baseline understanding of water-quality conditions in 51 of the Nation's river basins and aquifers, referred to as Study Units (http://water.usgs.gov/nawqa/studyu.html). In the second decade of the Program (2001-2012), a major focus is on regional assessments of waterquality conditions and trends. These regional assessments are based on major river basins and principal aquifers, which encompass larger regions of the country than the Study Units. Regional assessments extend the findings in the Study Units by filling critical gaps in characterizing the quality of surface water and groundwater, and by determining status and trends at sites that have been consistently monitored for more than a decade. In addition, the regional assessments continue to build an understanding of how natural features and human activities affect water quality. Many of the regional assessments employ modeling and other scientific tools, developed on the basis of data collected at individual sites, to help extend knowledge of water quality to unmonitored, yet comparable areas within the regions. The models thereby enhance the value of our existing data and our understanding of the hydrologic system. In addition, the models are useful in evaluating various resource-management scenarios and in predicting how our actions, such as reducing or managing nonpoint and point sources of contamination, land conversion, and altering flow and (or) pumping regimes, are likely to affect water conditions within a region. Other activities pla...

Road Salt Stress Induces Novel Food Web Structure and Interactions

“…We chose to expose developing larvae to elevated chloride upon reaching Gosner stage 25 (Gosner 1960), the point in larval development where tadpoles begin to serve as consumers in the pond food web, which was the focus of this study. Chloride concentrations in urban ponds are not constant but occur in pulses throughout the year (Jackson and Jobbagy 2005;Howard and Maier 2007;Kelly et al 2008;Mullaney et al 2009), therefore frog embryos are likely to develop under fluctuating chloride conditions depending on road salt application rates, proximity to roads, timing of snow melt, groundwater recharge, or evaporative concentration as ponds dry during the spring and summer months.…”

“…While the timing of road deicer application, application rates, and chemical make-up vary by jurisdiction (Transportation Research Board 2004;Mullaney et al 2009), freshwater salinization is becoming a year-round phenomenon due to long-term storage and transport of the dissociated salt ions in groundwater and soils (Jackson and Jobbagy 2005;Howard and Maier 2007;Kelly et al 2008;Mullaney et al 2009). Therefore, freshwater food webs are experiencing increasing exposure to deicing salts.…”

Environmental change in Lake Champlain revealed by long-term monitoring

“…Increasing chloride concentrations have been found in lakes (Chapra et al, 2009;Novotny and Stefan, 2009), rivers (Robinson et al, 2003;Kauschal et al, 2005), and groundwater (Mullaney et al, 2009;Eyles and Meriano, 2010) across the northern hemisphere, particularly as a result of the application of deicing salts for winter road maintenance (Chapra et al, 2009;Daley et al, 2009;Trowbridge et al, 2010). Road salt application rates in Vermont state highway districts within the Lake Champlain Basin increased during the 1990s but then declined in more recent years (Fig.…”

Salinization alters ecosystem structure in urban stormwater detention ponds

“…Extensive research documents the negative impact of these chemicals on freshwater life (e.g., Whitton 1970;Forstner and Prosi 1979;Munn et al 2006;Vonesh and Kraus 2009), yet more recently road salt deicers have been identified as a rising source of salinization to freshwaters in the United States (Kaushal et al 2005). Freshwater salinization is becoming a year-round phenomenon due to long-term storage and transport of dissociated salt ions (e.g., chloride, sodium, magnesium) in groundwater and soils (Jackson and Jobbagy 2005;Howard and Maier 2007;Kelly et al 2008;Mullaney et al 2009). Concerns of toxicity are closely associated with the chloride ion (Marsalek 2003;Kaushal et al 2005) and a positive relationship has been identified between percent impervious surface cover within a watershed and freshwater chloride concentration (Kaushal et al 2005;Morgan et al 2007).…”