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Assessing the Spatial and Temporal Distribution of MTBE and BTEX Compounds in Lake Lewisville, Texas February 1999 - February 2000

Description: The spatial and temporal distribution of Methyl Tertiary-Butyl Ether (MTBE) and BTEX (Benzene, Toluene, Ethylbenzene, Xylenes) compounds were assessed in a multipurpose reservoir, Lake Lewisville, Texas between February 1999 and February 2000. Concentrations of MTBE ranged from 0.0 - 16.7 mg/L. Levels of MTBE in the lake were related to watercraft. BTEX concentrations were never detected above 2.0 mg/L during the sampling period. Finished drinking water from Denton and the Upper Trinity Regional Water District (UTRWD) Treatment Plants were also tested for MTBE and BTEX. MTBE and BTEX were not detected in UTRWD water samples. Denton's finished water samples never exceeded 2.2 mg/L for MTBE and BTEX was not detected except for one replicate of 1.1 mg/L toluene.
Date: August 2000
Creator: Lee, Anne W.
Partner: UNT Libraries

Evaluation of the Chlorophyll/Fluorescence Sensor of the YSI Multiprobe: Comparison to an Acetone Extraction Procedure

Description: The purpose of this study was to examine the suitability of the YSI model 6600 Environmental Monitoring System (multiprobe) for long term deployment at a site in Lewisville Lake, Texas. Specifically, agreement between a laboratory extraction procedure and the multiprobe chlorophyll/fluorescence readings was examined. Preliminary studies involved determining the best method for disrupting algal cells prior to analysis and examining the precision and linearity of the acetone extraction procedure. Cell disruption by mortar and pestle grinding was preferable to bath sonication. Comparison of the chlorophyll/fluorescence readings from the multiprobe and the extraction procedure indicated that they were significantly correlated but temperature dependent.
Date: May 2001
Creator: Lambert, Patricia
Partner: UNT Libraries

Primary Productivity and Nutrient Relationships in Garza-Little Elm Reservoir

Description: A large, multi-basin, reservoir (Garza-Little Elm Reservoir) in north central Texas was studied to determine the relative effects of various parameters on primary productivity. The basins were impounded several years apart,thus allowing the influence of age on water chemistry and biota to be considered. Another principal influence on water quality was secondary sewage effluent that entered one basin from a nearby source.
Date: May 1973
Creator: Smith, Jerry Allen
Partner: UNT Libraries

Primary productivity and nutrient relationships in Garza-Little Elm reservoir

Description: A large, multi-basin reservoir (Garza-Little Elm Reservoir) in north central Texas was studied to determine the relative effects of various parameters on primary productivity. The basins were impounded several years apart, thus allowing the influence of age on water chemistry and biota to be considered. Another principal influence on water quality was secondary sewage effluent that entered one basin from a nearby source.
Date: May 1973
Creator: Smith, Jerry Allen
Partner: UNT Libraries

Comparison of Bare Root vs. Potted Plants, Species Selection, and Caging Types for Restoration of a Prairie Wetland, and Quantitative Analysis and Descriptive Survey of Plant Communities and Associations at Lewisville Lake Environmental Learning Area (LLELA), Lewisville, TX

Description: Lewisville Lake Environmental Learning Area (LLELA) is an 809-hectare property in Denton County, TX. A study of the vegetation community identified 466 species in 104 families, with 25% of the species from only two families, Asteraceae and Poaceae. The property demonstrates the characteristics of an early successional community, dominated by weedy species. Prairie communities are dominated by Johnson grass and ragweed, with climax tall grass prairie communities only in areas that have been planted with native grass seed. Forest communities are similarly in an early successional stage, dominated by the hackberry-elm-ash alliance, with small remnants of native Cross Timbers found in isolated patches. Species richness and diversity were highest in the forests and lowest in the wetlands; evenness, though not different across ecosystems, demonstrated a strong seasonal component. The species list was compared with previously reported lists for Denton County, and 256 species identified had not been previously reported for the county. A wetland restoration study was conducted to determine if there was a difference in survival and growth between potted transplants with intact root systems and bare-root transplants. Two different mesh sizes were used for protection, and the success of the different caging was evaluated. Of eight species, only four survived through the second growing season. There was no significant difference in the success of the propagule types for Sagittaria latifolia. The treatments planted with intact root systems showed significantly higher growth and reproduction than the bare-root treatments for Eleocharis quadrangulata, Heteranthera dubia, and Vallisneria americana. There was no survival recorded in the coarse mesh cages, likely due to the presence of crayfish that are able to get through the coarser mesh and feed on the transplants.
Date: May 2007
Creator: Buckallew, Robin R.
Partner: UNT Libraries

A Chemical, Physical, and Biological Investigation of the Total Suspended and Dissolved Substances in Lake Dallas with Emphasis on Sanitation

Description: The purpose of this investigation is to determine the suspended organic matter and the total phosphorus in the waters of Lake Dallas and to evaluate these findings. Since organic matter floating in lakes is largely composed of minute plants, animals, and detritus derived from animals and plants, the fertilizing effect of phosphorus must be considered as an integral part of this problem.
Date: 1942
Creator: Eads, Ewin A.
Partner: UNT Libraries

Life History Allocation of Energy to Growth and Reproduction in Gizzard Shad, Dorosoma cepedianum, in North Central Texas

Description: Life history allocation of energy to growth and reproduction was determined for female gizzard shad. Absolute caloric energy allocated to eggs increased with age. The relative amount of production energy directed to reproduction increased with age up to 5 years and then decreased. Seasonal variation in lipids was studied. Quantitative changes occurred in ovarian lipids during the reproductive cycle. Carcass lipids varied seasonally. Age of sexual maturity was 3 years. Delayed maturity is attributed to high allocation of energy to growth enabling shad to outgrow intense competition and predation in pre-reproductive ages; there is little competition and predation in reproductive shad. Growth rates and condition factors indicated constant availability of food seasonally.
Date: December 1976
Creator: Fagan, Joseph A.
Partner: UNT Libraries

Surface Water and Groundwater Hydrology of Borrow-Pit Wetlands and Surrounding Areas of the Lewisville Lake Environmental Learning Area, Lewisville, Texas

Description: The focus of this study was to characterize the surface water and groundwater hydrology of borrow-pit wetlands located within the borders of the Lewisville Lake Environmental Learning Area (LLELA), east of the Elm Fork of the Trinity River. The wetlands were excavated into alluvial deposits downstream of the Lewisville Lake Dam. Both surface water and groundwater contribute to the hydro-period of the borrow-pit wetlands. Nearby marshes exhibit characteristics of groundwater discharge. Salinity in groundwater-fed wetlands could affect establishment of vegetation, as suggested from plant surveys. Surface water input from storm events dilutes salinity levels. Management of LLELA wetlands should include long-term evaluation of hydrology and plantings to enhance habitat. Plans for additional wetlands should consider both surface water and groundwater inputs.
Date: August 2004
Creator: Dodd-Williams, Lynde L.
Partner: UNT Libraries

[News Clip: Water Projects]

Description: Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story. This story aired at 5:00 P.M.
Date: August 6, 1979
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

[News Clip: Boat Race]

Description: Video footage from the WBAP-TV station in Fort Worth, Texas to accompany a story about the second annual North Texas Water Safari.
Date: June 13, 1964
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

[News Script: Drownings]

Description: Script from the WBAP-TV/NBC station in Fort Worth, Texas, covering a news story about several drownings that happened in Dallas, Texas.
Date: May 13, 1962
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

[News Script: Drowning]

Description: Script from the WBAP-TV/NBC station in Fort Worth, Texas, covering a news story about a local teenage boy drowning at the Garza-Little Elm reservoir near Lewisville, Texas.
Date: June 5, 1963
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Location Info:
Partner: UNT Libraries Special Collections

[News Clip: Search]

Description: Video footage from the WBAP-TV station in Fort Worth, Texas to accompany a story about a search near Lewisville, Texas for the body of Captain Richard Carroll of Wichita Falls whose body was sucked from the compartment of a B-52 bomber.
Date: June 23, 1964
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

[News Clip: Missing Family]

Description: Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, covering a news story. This story aired at 5pm.
Date: June 7, 1993, 5:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

[News Clip: New bridge]

Description: Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: August 3, 1979, 5:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Location Info:
Partner: UNT Libraries Special Collections

[News Clip: Lewisville]

Description: Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, covering a news story. This story aired at 5pm.
Date: June 8, 1993, 5:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

[News Script: Drowning]

Description: Script from the WBAP-TV/NBC station in Fort Worth, Texas, covering a news story about a man that drowned at the Garza-Little Elm Reservoir in Denton, Texas.
Date: May 26, 1962
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections