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Platte River (platte + river)
Selected AbstractsPolycyclic aromatic hydrocarbons, aliphatic hydrocarbons, trace elements, and monooxygenase activity in birds nesting on the North Platte River, Casper, Wyoming, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2001Thomas W. Custer Abstract Tree swallow (Tachycineta bicolor) and house wren (Troglodytes aedon) eggs and chicks were collected near a refinery site on the North Platte River, Casper, Wyoming, USA and at a reference site 10 km upstream. Total polycyclic aromatic hydrocarbon (PAH) concentrations in swallow and wren chicks were higher at the refinery site than at the reference site. Polycyclic aromatic hydrocarbon concentrations in sediment and chick dietary samples were consistent with these findings. The general lack of methylated PAHs in sediment, diet, and bird carcasses suggested that the PAHs were derived from combustion and not from petroleum. The predominance of odd-numbered aliphatic hydrocarbons and the low ratios (,0.25) of pristane:n -C17 and phytane:n -C18 in chick and diet samples also suggested that swallow and wren chicks were not being chronically exposed to petroleum. Mean ethoxyresorufin- O -dealkylase and benzyloxyresorufin- O -dealkylase activities in tree swallow livers averaged nine times higher at the refinery site than at the reference site and were probably induced by exposure to PAHs. Trace element concentrations in eggs and livers of swallows and wrens were similar or greater at the reference site than at the refinery site. Selenium, strontium, and boron concentrations were elevated in eggs and livers of swallows and wrens at both the refinery and reference sites. [source] Application of Direct Push Methods to Investigate Uranium Distribution in an Alluvial AquiferGROUND WATER MONITORING & REMEDIATION, Issue 4 2009Wesley McCall The U.S. EPA 2000 Radionuclide Rule established a maximum contaminant level (MCL) for uranium of 30 µg/L. Many small community water supplies are struggling to comply with this new regulation. At one such community, direct push (DP) methods were applied to obtain hydraulic profiling tool (HPT) logs and install small diameter wells in a section of alluvial deposits located along the Platte River. This work was conducted to evaluate potential sources of elevated uranium in the Clarks, Nebraska drinking water supply. HPT logs were used to understand the hydrostratigraphy of a portion of the aquifer and guide placement of small diameter wells at selected depth intervals. Low-flow sampling of the wells provided water quality parameters and samples for analysis to study the distribution of uranium and variations in aquifer chemistry. Contrary to expectations, the aquifer chemistry revealed that uranium was being mobilized under anoxic and reducing conditions. Review of the test well and new public water supply well construction details revealed that filter packs extended significantly above the screened intervals of the wells. These filter packs were providing a conduit for the movement of groundwater with elevated concentrations of uranium into the supply wells and the community drinking water supply. The methods applied and lessons learned here may be useful for the assessment of unconsolidated aquifers for uranium, arsenic, and many other drinking water supply contaminants. [source] Stock characteristics of shovelnose sturgeon in the lower Platte River, NebraskaJOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2007D. A. Shuman Summary The objectives of this research were to evaluate the condition, size structure, and growth of shovelnose sturgeon (Scaphirhynchus platorynchus) in the lower Platte River, Nebraska. A total of 1338 shovelnose sturgeon was collected using drifted gill and trammel nets (n = 954), trot lines (n = 340), and benthic trawls (n = 44) in the spring, summer, and autumn from four reaches: (i) Two Rivers State Park, (ii) confluence of Platte and Elkhorn rivers (iii) Louisville, Nebraska, and (iv) confluence of Platte and Missouri rivers during the spring, summer, and autumn of 2000 through 2004. Structural and condition indices were compared among reaches and years. Incremental relative stock densities (RSD) for shovelnose sturgeon sampled throughout the entire lower Platte River were: stock-quality (1), quality-preferred (12), preferred-memorable (82), and memorable-trophy (5). Proportional stock values were >99 for all years. A significance was detected in RSD categories among reaches and years with larger length-categories observed in the upstream reaches. Mean relative weight (Wr) for all shovelnose sturgeon was 86.5, indicating a fit population. Mean Wr showed no significant differences among years, but significance was detected among reaches and RSD categories. Shovelnose sturgeon in the lower Platte River appear to be in good condition and exhibit different length-frequency distributions longitudinally. [source] EVALUATION OF A STREAM AQUIFER ANALYSIS TEST USING ANALYTICAL SOLUTIONS AND FIELD DATA,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2004Garey A. Fox ABSTRACT: Considerable advancements have been made in the development of analytical solutions for predicting the effects of pumping wells on adjacent streams and rivers. However, these solutions have not been sufficiently evaluated against field data. The objective of this research is to evaluate the predictive performance of recently proposed analytical solutions for unsteady stream depletion using field data collected during a stream/aquifer analysis test at the Tamarack State Wildlife Area in eastern Colorado. Two primary stream/aquifer interactions exist at the Tamarack site: (1) between the South Platte River and the alluvial aquifer and (2) between a backwater stream and the alluvial aquifer. A pumping test is performed next to the backwater stream channel. Drawdown measured in observation wells is matched to predictions by recently proposed analytical solutions to derive estimates of aquifer and streambed parameters. These estimates are compared to documented aquifer properties and field measured streambed conductivity. The analytical solutions are capable of estimating reasonable values of both aquifer and streambed parameters with one solution capable of simultaneously estimating delayed aquifer yield and stream flow recharge. However, for long term water management, it is reasonable to use simplified analytical solutions not concerned with early-time delayed yield effects. For this site, changes in the water level in the stream during the test and a varying water level profile at the beginning of the pumping test influence the application of the analytical solutions. [source] Agrichemicals in nebraska, USA, watersheds: Occurrence and endocrine effectsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2009Marlo K. Sellin Abstract The objective of the present study was to determine the occurrence and endocrine effects of agrichemicals in four Nebraska, USA, watersheds,the Elkhorn, Platte, Niobrara, and Dismal rivers. Land use in the Elkhorn River and Platte River watersheds is characterized by intense agriculture, including row crop and beef cattle production. In contrast, land within the Niobrara River and Dismal River watersheds consists primarily of grasslands. Polar organic chemical integrative samplers (POCIS) and caged fathead minnows were deployed at a site within each watershed for 7 d. The POCIS were analyzed for pesticides and hormones, while the caged minnows were analyzed for the expression of estrogen- and androgen-responsive genes. Amounts of pesticides recovered in POCIS extracts from the Elkhorn and Platte rivers were higher than those recovered from the Niobrara and Dismal rivers. Furthermore, female minnows deployed in the Elkhorn River experienced significant reductions in expression of two estrogen-responsive genes (vitellogenin and estrogen receptor ,) relative to females deployed at the other sites, indicating alterations in endocrine function. However, the defeminization of these females could not be definitely linked to any of the agrichemicals detected in the POCIS recovered from the Elkhorn River. [source] | ||||||||||