As a nation we’re rapidly polluting our sources of fresh water. Here’s a release from the EPA:
A new EPA study shows concentrations of toxic chemicals in fish tissue from lakes and reservoirs in nearly all 50 U.S. states. For the first time, EPA is able to estimate the percentage of lakes and reservoirs nationwide that have fish containing potentially harmful levels of chemicals such as mercury and PCBs.
“These results reinforce Administrator Jackson’s strong call for revitalized protection of our nation’s waterways and long-overdue action to protect the American people,” said Peter S. Silva, assistant administrator for EPA’s Office of Water. “EPA is aggressively tackling the issues the report highlights. Before the results were even finalized, the agency initiated efforts to further reduce toxic mercury pollution and strengthen enforcement of the Clean Water Act – all part of a renewed effort to protect the nation’s health and environment.”
The data showed mercury concentrations in game fish exceeding EPA’s recommended levels at 49 percent of lakes and reservoirs nationwide, and polychlorinated biphenyls (PCBs) in game fish at levels of potential concern at 17 percent of lakes and reservoirs. These findings are based on a comprehensive national study using more data on levels of contamination in fish tissue than any previous study.
Burning fossil fuels, primarily coal, accounts for nearly half of mercury air emissions caused by human activity in the U.S., and those emissions are a significant contributor to mercury in water bodies. From 1990 through 2005, emissions of mercury into the air decreased by 58 percent. EPA is committed to developing a new rule to substantially reduce mercury emissions from power plants, and the Obama Administration is actively supporting a new international agreement that will reduce mercury emissions worldwide.
The study also confirms the widespread occurrence of PCBs and dioxins in fish, illustrating the need for federal, state and local government to continue efforts to reduce the presence of these harmful chemicals in our lakes and reservoirs and ensure that fish advisory information is readily available.
It is important that women of child-bearing age and children continue to follow the advice of EPA and the Food and Drug Administration on fish consumption as it relates to mercury. This study is also a strong message to state and local governments to redouble their efforts in looking for opportunities to reduce mercury discharges, as well as developing fish advisories, especially to reach those in sensitive and vulnerable populations.
Results from the four-year National Study of Chemical Residues in Lake Fish Tissue show that mercury and PCBs are widely distributed in U.S. lakes and reservoirs. Mercury and PCBs were detected in all of the fish samples collected from the nationally representative sample of 500 lakes and reservoirs in the study. Because these findings apply to fish caught in lakes and reservoirs, it is particularly important for recreational and subsistence fishers to follow their state and local fish advisories.
EPA is conducting other statistically based national aquatic surveys that include assessment of fish contamination, such as the National Rivers and Streams Assessment and the National Coastal Assessment. Sampling for the National Rivers and Streams Assessment is underway, and results from this two-year study are expected to be available in 2011. Collection of fish samples for the National Coastal Assessment will begin in 2010.
More information: http://www.epa.gov/waterscience/fishstudy
More information on local fish advisories: http://www.epa.gov/waterscience/fish/states.htm
More water pollution coverage here.
Energy policy — coal: Electrical generation water consumption
September 15, 2009
Here’s a report from last Wednesday’s meeting of the Arkansas Basin roundtable, from Chris Woodka writing for The Pueblo Chieftain. From the article:
“One of the trends we’re starting to see in the West and Colorado is a lot of ag-to-industry transfers,” Stacy Tellinghuisen of Western Resource Advocates told the Arkansas Basin Roundtable Wednesday. Tellinghuisen led a team that studied Arkansas Basin water needs for future power supplies in a project funded by the National Renewable Energy Lab. Western Resource Advocates is a 20-year-old group dedicated to preserving the environment in the West.
The group makes recommendations that it claims could reduce consumptive use for municipal water systems by up to 44,000 acre-feet per year and power generation up to 20,000 acre-feet per year by 2030. It specifically mentions the acquisition of one-half of the Amity Canal in Prowers County by the Tri-State Generation and Transmission Association and the power needs of the Southern Delivery System in the report. Western Resource Advocates represented Environment Colorado, which settled its lawsuit on Tri-State’s Water Court case involving the Amity shares in March, with Tri-State agreeing to a $1 million study of energy efficiency among its 44 cooperatives in four states…
[The Southern Delivery System], a $1 billion project by Colorado Springs, Security, Fountain and Pueblo West designed to provide water to meet future population growth, would require large amounts of power to move water uphill. “If these new energy demands are met with water-intensive forms of energy generation, like coal power, they will further increase water use in the basin,” Tellinghuisen said.
More coal coverage here.
USGS: Mercury in fish widespread
August 23, 2009
Here’s the abstract from the study:
Mercury (Hg) was examined in top-predator fish, bed sediment, and water from streams that spanned regional and national gradients of Hg source strength and other factors thought to influence methylmercury (MeHg) bioaccumulation. Sampled settings include stream basins that were agricultural, urbanized, undeveloped (forested, grassland, shrubland, and wetland land cover), and mined (for gold and Hg). Each site was sampled one time during seasonal low flow. Predator fish were targeted for collection, and composited samples of fish (primarily skin-off fillets) were analyzed for total Hg (THg), as most of the Hg found in fish tissue (95–99 percent) is MeHg. Samples of bed sediment and stream water were analyzed for THg, MeHg, and characteristics thought to affect Hg methylation, such as loss-on-ignition (LOI, a measure of organic matter content) and acid-volatile sulfide in bed sediment, and pH, dissolved organic carbon (DOC), and dissolved sulfate in water. Fish-Hg concentrations at 27 percent of sampled sites exceeded the U.S. Environmental Protection Agency human-health criterion of 0.3 micrograms per gram wet weight. Exceedances were geographically widespread, although the study design targeted specific sites and fish species and sizes, so results do not represent a true nationwide percentage of exceedances. The highest THg concentrations in fish were from blackwater coastal-plain streams draining forests or wetlands in the eastern and southeastern United States, as well as from streams draining gold- or Hg-mined basins in the western United States (1.80 and 1.95 micrograms THg per gram wet weight, respectively). For unmined basins, length-normalized Hg concentrations in largemouth bass were significantly higher in fish from predominantly undeveloped or mixed-land-use basins compared to urban basins. Hg concentrations in largemouth bass from unmined basins were correlated positively with basin percentages of evergreen forest and also woody wetland, especially with increasing proximity of these two land-cover types to the sampling site; this underscores the greater likelihood for Hg bioaccumulation to occur in these types of settings. Increasing concentrations of MeHg in unfiltered stream water, and of bed-sediment MeHg normalized by LOI, and decreasing pH and dissolved sulfate were also important in explaining increasing Hg concentrations in largemouth bass. MeHg concentrations in bed sediment correlated positively with THg, LOI, and acid-volatile sulfide. Concentrations of MeHg in water correlated positively with DOC, ultraviolet absorbance, and THg in water, the percentage of MeHg in bed sediment, and the percentage of wetland in the basin.
