Sources and Occurrences of Nonpoint-Source Chemicals in Groundwater, Jackson Purchase Region, Kentucky: Data Report

Groundwater from the Jackson Purchase Region was sampled to investigate possible contamination by nonpoint-source chemicals. Conclusions drawn from the resulting data and methodology can be found in “Sources and Occurrences of Nonpoint-Source Chemicals in Groundwater, Jackson Purchase Region, Kentucky,” Kentucky Geological Survey Report of Investigations 22 (series 12), by R.S. Fisher and E.G. Beck

Shallow Groundwater Monitoring Associated with the Deep Saline Reservoir CO\u3csub\u3e2\u3c/sub\u3e Storage Test in Hancock County, Kentucky

A carbon dioxide injection test well was drilled in 2009 to a depth of 8,126 ft below ground surface in Hancock County, Kentucky. Six hundred ninety tons of CO2 was successfully injected into Knox Group saline aquifers. Two domestic wells (MB and GB) and two domestic springs (CA and RC) were sampled to monitor any potential changes in groundwater quality associated with possible migration of CO2 from deeper saline aquifers into shallow freshwater aquifers. The four sites were sampled for pH, bicarbonate, total dissolved solids, turbidity, anions, total dissolved metals, dissolved inorganic carbon, total CO2, and delta carbon-13 of the dissolved inorganic carbon (δ13CDIC). Values of pH for the four sites ranged between 4.58 and 7.82 and were consistent over time at all sites. Bicarbonate, total CO2, dissolved inorganic carbon, and TDS concentrations showed very little variation over time at all of the sites except at well MB. although water chemistry at well MB varied during the monitoring period, δ13CDIC values suggested that injectate had not migrated into the shallow aquifer at that site. All groundwater geochemical data clearly indicate that injectate CO2 had not migrated upward into the four monitored shallow aquifers before sampling was discontinued in August 2012

Sources and Occurrences of Nonpoint-Source Chemicals in Groundwater, Jackson Purchase Region, Kentucky

Nitrate concentrations that exceed U.S. Environmental Protection Agency drinking-water standards have been reported in Jackson Purchase Region groundwater since the 1960\u27s. More recently, other nonpoint-source chemicals such as pesticides and volatile organic compounds have also been found. The sources of these chemicals and the pathways by which they reach domestic groundwater supplies must be determined to protect human health and to design effective land-management practices. To investigate the occurrence of nonpoint-source chemicals in Jackson Purchase groundwater, 60 wells were selected on the basis of geographic location, hydrostratigraphic unit penetrated, and well type (bored or drilled); distances to row crops, known septic systems, and active and abandoned feedlots were recorded for each well. Groundwater was sampled in the spring and fall of 2005 for field measurements, water properties, major and minor solutes, nutrients, metals, pesticides, volatile organic compounds, caffeine, and bacteria. Nitrate concentrations exceeded EPA maximum contaminant levels in three wells, and exceeded half the MCL in three other wells. High nitrate concentrations were found mainly in samples from shallow wells in the Continental Gravel hydrostratigraphic unit near row crops. The combination of the permeable gravel and proximity to fertilizer applications makes these wells highly susceptible to nitrate contamination. Pesticides and caffeine were most commonly detected in Continental Gravel samples, but also in other units throughout the area. Total coliform bacteria were found throughout the region from all hydrostratigraphic units and all well types. High nitrate concentrations and detectable caffeine and pesticides are most often found in shallow wells regardless of whether the well was drilled or bored. Shallow wells, bored wells, and those near septic systems were most likely to produce water containing total coliform bacteria, however. The occurrence of high nitrate concentrations and detectable amounts of pesticides and caffeine shows that groundwater contamination is occurring in the Jackson Purchase. Land management practices that take into account the different hydrologic properties of hydrostratigraphic units and bored wells\u27 greater susceptibility to annular leakage are needed to protect groundwater quality from further degradation. The occurrence of total coliform bacteria in groundwater samples indicates contamination of either the well or water delivery system (or both) or the water-producing aquifer. More extensive testing is needed to determine exactly where the bacteria reside. This study was one of the first to consider well types and distances to potential sources of nonpoint groundwater contaminants with water-chemistry investigations. Future studies of nonpoint-source groundwater contamination must first establish that pollutants are not entering the well via local pathways such as leaky well casings or near-wellhead surface sources of chemicals, but rather that the local or regional groundwater system is affected. Second, future studies must carefully document distances from wells to potential sources of contaminants. In many cases this will require historical investigations to locate abandoned confined-animal feeding operations or on-site waste-disposal systems

Generalized Geologic Map for Land-Use Planning: Trigg County, Kentucky

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock

Generalized Geologic Map for Land-Use Planning: McCracken County, Kentucky

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock

Generalized Geologic Map for Land-Use Planning: Marshall County, Kentucky

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock

Generalized Geologic Map for Land-Use Planning: Caldwell County, Kentucky

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock

Generalized Geologic Map for Land-Use Planning: Lyon County, Kentucky

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock

Generalized Geologic Map for Land-Use Planning: Simpson County, Kentucky

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock