Murgulet,D. and Tick,G.R.(2009): Assessing the extent and sources of nitrate contamination in the aquifer system of southern Baldwin County, Alabama. Environ. Geol., 58, 1051-1065.

『アラバマ州の南部Baldwin Countyの帯水層系における硝酸汚染の広がりと根源を評価すること』


Abstract
 A regional-scale groundwater study was conducted over a 2-year period to assess the extent of nitrate contamination and source identification for southern Baldwin County, AL. Groundwater wells were samples and analyzed for nitrate and a host of other geochemical parameters which revealed that extensive areas within aquifer zone A2 exhibited nitrate concentrations exceeding regulatory limits. Spatial iso-concentration maps of nitrate were constructed using ArcGIS software to determine the extent and severity of contamination for the aquifers underlying southern Baldwin County with the primary interest focused on the heavily utilized aquifer zone A2. Nitrate levels in the central and northeastern portion of the study area were most extensive with maximum concentrations of 63 mg/L likely resulting from agricultural inputs. several other small regions throughout the study area exhibited elevated levels of nitrate and chloride as high as 112 and 51.1 mg/L, respectively, and sources likely vary (i.e., residential septic systems, animal waste to agriculture). With the exception of a few groundwater samples, there was no obvious correlative relationship between chloride and nitrate concentration for data collected during the 2-year period. Collectively, a general inverse relationship between nitrate concentrations and well depth was observed for the aquifer system under investigation. The study provides an initial current data set of areas impacted or most vulnerable to nitrate contamination and initial assessment of likely sources of nitrate in the region.

Keywords: Nitrate; Groundwater contamination; GIS; Southern Baldwin County』

Introduction
Background
 Previous studies
Site description
 Location and extent of the study area
 Population and land-use/land-cover
 Stratigraphy and hydrogeology
Methodology
 Data collection
 Sample analysis
 Geographic information system (GIS)
Results
 Regional and local groundwater flow
 2006 Groundwater nitrate data
 2007 Groundwater nitrate data
Discussion
 Temporal changes
 Potential sources
Conclusions
Acknowledgements
References


ホーム