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Currently Skimming:

Aquatic Research and Water Quality Trends in the United States
Pages 297-314

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From page 297...
... These~physical constraints are usually media-specific. Impact assessments of environmental and ecological resources are currently required by many state and federal agencies.
From page 298...
... Erosion is a major transport mechanism between terrestrial and aquatic communities. Most shallow groundwaters emerge as surface water through seeps, springs, and emergent water courses.
From page 299...
... There are two major pathways for carbon flow in the anaerobic sediments of warm-water lakes. The methanogenesis pathway involves an array of microbes that utilize electron acceptors (i.e., HCO3)
From page 300...
... The aquifer is contaminated with many thousands of kilograms of organic compounds, including benzene, dichloroethanes, toluene, and vinyl chloride. The parent company, Corn Products Corporation, has recommended an out-of-court settlement that involves monitoring, financial compensation for impairment of the resource, and air stripping through natural volatilization as the groundwater flows to the surface.
From page 301...
... Limitations such as the lack of an adequate electron acceptor, insufficient concentrations of the parent compound to support a healthy microbial community, or ecological interactions like predation or competition from other organisms, can restrict the expression of some idealized process of mineralization. Since natural microbial communities evolved to exploit a vast array of natural organic compounds under many environmental conditions, there is an enormous number of combinations of "compound x microbial community x ecosystem" that are important to understand.
From page 302...
... Many of the same physical characteristics of the contaminant molecules that influence transport in surface waters are also important in groundwater movement. Water solubility and the adsorption potential of a chemical are among the most significant.
From page 303...
... Total Phosphorus Inorganic Nitrogen Increasing Trend 35 72 Decreasing Trend 29 24 No Change 245 152 SOURCE: USGS Stream Quality Accounting Network, 1984 lllENDS IN WATER QUALITY IN THE UNITED STATES Nutrients 303 Nutrient loadings to surface waters were a major focus of the 1972 Federal Water Pollution Control Act. Phosphorus and nitrogen were the two elements associated with cultural eutrophication.
From page 304...
... in depth. The most likely sources of increasing inputs are animal production facilities, human septic fields, and mineral fertilizers.
From page 305...
... As a result of these developments, there is an everincreasing list of toxicants being detected in various environmental media. In 1983, the Great Lakes Water Quality Board reported finding over 1,000 anthropogenic chemical substances in surface waters.
From page 306...
... TABLE 2 Groundwater contamination (as percentages)
From page 307...
... production and use of these compounds. The majority of the inputs of PCBs into the surface waters of the Great Lakes are airborne materials emanating from municipal and industrial incinerators which are currently ret ycling through the ecosytem.
From page 308...
... Underground gasoline storage tanks and poorly designed landfills are dominant sources of organic contaminants. Uncovered storage of salt for ice removal in the winter months is a major inorganic source.
From page 309...
... 309 Contaminant LF DMP GUSI AGR CUSI AGT OIL PET SALT Benzene Xylenes Toluenes Ethylbenzenes Cadmium Chromium Copper Lead Nickel Zinc Cyanide Arsenic Phenols Dichloroethanes Trichloroethanes Trichloroethylene Tetrachloroethylene Naphthalenes Chloroform Hexachlorobenzene PCBs Phthalates Paint Residues Nitrate Pesticides Salt/Brine .
From page 310...
... of the volume of the examined lakes are currently mesotrophic, and these include most of the largest and deepest lakes in Poland (these data refer to lakes examined in the years 1973-1979~. Fifty-six percent of the lakes by number, and 41% of the surface waters by volume, are currently experiencing a serious level of water quality degradation.
From page 311...
... anaerobic conditions in the hypolimnion, and dense blooms of green and blue-green algae in surface waters. Although 45% of the lakes are considered highly susceptible to eutrophication (Bible 4)
From page 312...
... The annual total phosphorus loading is 0.066 g m~2y~i (Hillbricht-ILkowska, in press) , which is below the permissible level.
From page 313...
... 1987. Groundwater contamination from landfills, underground storage tanks, and septic systems.
From page 314...
... 1976. Advance in defining critical level for phosphorous in lake eutrophication.


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