Use of GIS to Identify and Delineate Areas of Fluoride, Sulfate, Chloride, and Nitrate Levels in the Woodbine Aquifer, North Central Texas, in the 1950s, 1960s, 1970s, 1980s, and 1990s

Use of GIS to Identify and Delineate Areas of Fluoride, Sulfate, Chloride, and Nitrate Levels in the Woodbine Aquifer, North Central Texas, in the 1950s, 1960s, 1970s, 1980s, and 1990s

Date: August 2001
Creator: Sanmanee, Sirichai
Description: ArcView and ArcInfo were used to identify and delineate areas contaminated by fluoride, sulfate, chloride, and nitrate in the Woodbine Aquifer. Water analysis data were obtained from the TWDB from the 1950s to 1990s covering 9 counties. 1990s land use data were obtained to determine the relationship with each contaminant. Spearman's rank correlation coefficients and Kruskal-Wallis tests were used to calculate relationships between variables. Land uses had little effect on distributions of contaminants. Sulfate and fluoride levels were most problematic in the aquifer. Depth and lithology controlled the distributions of each contaminant. Nitrate patterns were controlled mainly by land use rather than geology, but were below the maximum contaminant level. In general, contaminant concentrations have decreased since the 1950s.
Contributing Partner: UNT Libraries
Distribution and Probable Sources of Nitrate in the Seymour Aquifer, North Central Texas, USA

Distribution and Probable Sources of Nitrate in the Seymour Aquifer, North Central Texas, USA

Access: Use of this item is restricted to the UNT Community.
Date: May 2001
Creator: Hillin, Clifford K.
Description: This study utilized GIS and statistical methods to map the spatial variability of nitrate and related groundwater constituents in 30 counties above the Seymour Aquifer, analyze temporal patterns of nitrate pollution, identify probable sources of pollution, and recommend water development strategies to minimize exposure to nitrate and reduce future aquifer contamination. Nitrate concentrations in excess of 44 mg/L (US EPA limit) were commonly observed in the Seymour Aquifer region, especially in the central agricultural belt. Data indicated that this is an ongoing problem in the Seymour Aquifer and that agricultural activity and rural septic systems are the likely sources of the nitrate. Inconclusive results emphasized the need for a more comprehensive spatial and temporal water quality monitoring.
Contributing Partner: UNT Libraries
Nitrate, Arsenic and Selenium Concentrations in The Pecos Valley Aquifer, West Texas, USA

Nitrate, Arsenic and Selenium Concentrations in The Pecos Valley Aquifer, West Texas, USA

Date: 2010
Creator: Hudak, Paul F.
Description: This article discusses nitrate, arsenic, and selenium concentrations in the Pecos Valley Aquifer in west Texas in the context of local geology and land use.
Contributing Partner: UNT College of Arts and Sciences
Nitrate and Chloride Concentrations in Groundwater beneath a Portion ofn the Trinity Group Outcrop Zone, Texas

Nitrate and Chloride Concentrations in Groundwater beneath a Portion ofn the Trinity Group Outcrop Zone, Texas

Date: 2012
Creator: Hudak, Paul F.
Description: This article discusses a study in which the authors evaluated spatial distributions of nitrate and chloride concentrations in groundwater in an area of north-central Texas with agricultural activity, in addition to oil and natural gas exploration and activity.
Contributing Partner: UNT College of Arts and Sciences