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Wetlands are common in montane and subalpine settings in the Rocky Mountains, Sierra Nevada, and other mountainous regions of the western U.S. Because they are efficient filters, many contain anomalous concentrations of uranium and other metals. Sorption by organic matter, complexing of the uranyl ion, (UO2) 2+, with humic and fulvic acids, and action by bacteria has produced geochemical enrichment factors greater than 10000 to 1 between peat and uranium-bearing waters. Sediments in 67 of 145 Colorado wetlands sampled by the U.S. Geological Survey contain moderate (20 ppm) or greater concentrations of uranium (some as high as 3 000 ppm) based on dry weight. The proposed maximum contaminant level (MCL) for uranium in drinking water is 20 μg/1 or 20 ppb. By comparison, sediments in many of these wetlands contain 3 to 5 orders of magnitude more uranium than the proposed MCL. Wetlands near the workings of old mines (widespread in Colorado and other areas) may be trapping any number of additional metals/elements including Cu, Pb, Zn, As and Ag. Anthropogenic disturbances and natural changes may release uranium and other loosely bound metals presently contained in wetland sediments. Draining of wetlands with resulting oxidation of organic-rich sediments, acidification, and other environmental and geochemical changes may free relatively high concentrations of metals that have accumulated for thousands of years in the organic-rich sediments. Destruction of wetlands eliminates the natural filtration function which serves to protect water quality.

Soil-gas radon concentrations are controlled seasonally by factors of climate and pedology. In a swelling soil of the semiarid Western United States, soil-gas radon concentrations at 100 cm depth increase in winter and spring due to increased emanation with higher soil moisture and the capping effect of surface water or ice. Increased soil moisture results from a combination of higher winter and spring precipitation and decreased insolation in fall and winter, lowering soil temperatures so that water infiltrates deeper and evaporates more slowly. Radon concentrations in soil drop markedly through the summer and fall. The increased insolation of spring and summer warms and dries the soil, limiting the amount of water that reaches 100 cm. As the soil dries, radon emanation decreases, and deep soil cracks develop. These cracks aid convective transport of soil gas, increase radon's flux into the atmosphere, and lower its concentration in soil gas. Probable controls on the distribution of uranium within the soil column include its downward leaching, its precipitation or adsorption onto B-horizon clays, concretions, or cement, and the uranium content and mineralogy of the soil's granitic and gneissic precursors.

During July of 1995 and June of 1996, thirteen oilfield production sites in the Big Sinking Creek and Schumaker Ridge areas of northern Lee County in eastern Kentucky were visited to determine if produced waters and produced water solids had impacted sites in this area. Salt-scarred areas at oilfield production sites in this area were found to be relatively restricted in size, not very deeply eroded compared to sites in the midwest and southwest, and to have revegetated fairly quickly, probably because of the high rainfall and rapid flushing of salts from the root zone of plants. Saline groundwater still remains in the shallow subsurface beneath small barren areas at some sites. Areas of barren or sparse vegetation at some sites were found to be underlain by oil-saturated soil at shallow depths suggesting that the oil inhibits plant growth. Seepage of brine at one site has raised stream conductivities about 35-45 percent higher than values just upstream. Five sites have slightly anomalous concentrations of copper, lead, and zinc in soils containing tank sludge. Two samples from one site have high levels of radium (1770-3390 pCi/g), copper (165-195 ppm), and lead (200-245 ppm). These two samples have high concentrations of barium and strontium and low concentrations of zirconium suggesting that they are composed mostly of solids from tank sludge and that barite is present in high concentrations. The lead levels in these two samples are below action levels used for Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and Resource Conservation and Recovery Act (RCRA) sites (400 ppm). Radiometric surveys and radiochemical analyses determined that 9 of 13 sites have high radioactivity and radium in equipment, soils, and wetland sediments. Moderate levels occur at 2 sites and low levels occur at 2 sites. Radium-rich tank sludge, soils, and sediments are widespread at one site at the northern end of Lake Zachariah. Sites with high radioactivity in equipment or high radium activity in soils would be Naturally Occurring Radioactive Material (NORM)-contaminant sites under the least conservative state regulations proposed or in place. The State of Kentucky does not presently have NORM regulations. Dispersion of radium is occurring in two ways: 1) by the movement of radium-bearing solids (mostly barite), and 2) movement of dissolved radium in water. Iron oxyhydroxide precipitates are forming in the seep zone in a small wetland downslope from a tank battery at one site. These precipitates are radioactive and the iron oxyhydroxides are probably adsorbing dissolved radium from the ground water. Elsewhere at this same site, radium-bearing barite is accumulating at the edge of and probably within the wetland at the toe of the slope below a large area of radiumenriched soils.

End_Page 294------------------------------A series of maps constructed from seismic data trace the late Pleistocene and Holocene development of Corpus Christi Bay. The seismic data consists of 320 km of older sparker data, 80 km of older Uniboom data, 160 km of recent ORE Geopulse data, plus some 3.5 kHz Datasonics data. Seismic facies and the principal sedimentary features are mapped. Main unconformities such as the Holocene/Pleistocene erosional unconformity and the thickness of Holocene fill are contoured. Vertically stacked channels indicate that the ancestral Nueces River meandered across the same geographic area during the late Quaternary. Seismic signatures suggest extensive distribution of sand as channel fill, bars and spits, and reworked older deposits. Numerous moundlike structures are interpreted to be ancient oyster banks, which occupy areas in the bay where no living oyster reefs exist today. Holocene evolution indicates progressive widening of the estuary and filling from both the Nueces River and the landward migrating barrier islands. End_of_Article - Last_Page 295