Agricultural Impacts on Bacterial Water Quality in Karst Groundwater

Abstract

A 2‐yr study (1991–1992) was conducted in a karst region in southeast West Virginia to determine the impact of agriculture on groundwater quality. The primary agriculture is characterized by seasonal cattle grazing. Fecal coliform densities were measured weekly in the resurgences of three karst basins possessing different degrees of agricultural intensity (79, 51, and 16% land use in agriculture). Fecal coliforms were also measured in a creek at sites upstream and downstream of the known resurgences from the most agriculturally intensive (79%) basin. The fecal coliform densities in the resurgences peaked in the summer and declined in the fall, with a recovery in late winter before the introduction of new cattle. The timing of the recovery indicated that significant storage of fecal material had taken place, which was transported to the groundwater when soil water conditions permitted. For most of each year, soil water effects appeared to have a greater bearing on the fecal coliform densities than did the presence or absence of cattle. The data did not generally support a strong relationship with percent land use in agriculture. This was attributed to the high variability in the data and to low soil moisture during periods of recession that inhibited the transport of fecal material to the groundwater. The karst resurgence springs of the most intensively agricultural basin were contaminated with fecal bacteria. Fecal bacteria concentrations were observed to significantly increase, in the receiving surface stream, from a point upstream of the resurgence springs to a point downstream of the resurgence springs.

The occurrence of coliform bacteria in the cave waters of Slovak Karst, Slovakia

“…lowest densities and summer/early fall having the highest densities (data not shown). Pasquarell and Boyer (1995) reported four factors to explain the seasonal variation of faecal coliform densities: presence/absence of cattle, amount of soil water available to transport bacteria to ground water, storage of bacteria in the soil zone, and the rate of bacterial die-off in ground water. In karst aquifers, faecal bacteria can be transported over several kilometres (Green et al 1990).…”

Hydrogeochemical characteristics of karst groundwater in Tam Diep, Ninh Binh, Vietnam

“…The presence of E.coli is highly variable and exceeds the limit for drinking water, which state that coliform bacteria must be absent in a 100 mL water. The E.coli content at karst springs in the developed urban area (spring 17, 18 and 19) seems much creased urbanization, intensification of agriculture and human activities are impacts to bacterial water quality of karst groundwater (Pasquarell & Boyer 1995;Drew & Hötzl 1999). The bacterial contamination in Tam Diep karst water could be due to untreated domestic waste water, scattered waste and sewage disposal as well as cropping and livestock activities.…”

Factors Influencing the Bacteriological Water Quality in Mountainous Surface and Groundwaters

“…In mountainous regions, such bacteriological contamination is caused primarily by agricultural activity in the catchment area [1,2] and more especially by cattle grazing and manure spreading. Contamination by pathogens can result in severe outbreaks of waterborne infection [3Ϫ6].…”