Underground Movement of Bacterial and Chemical Pollutants

Bacterial filtration rates in repacked and weathered soil columns

“…This demonstrates that development of preferential paths in soils exposed to weathering processes minimizes filtration processes and may facilitate the rapid transport of biotracers to great depths. Other researchers also argued that preferential flow may result in groundwater vulnerability even when it is at a considerable depth (Butler et al, 1954;Mosaddeghi et al, 2009;Pang et al, 2008;Smith et al, 1985).…”

Modeling microbial fate in the subsurface environment

“…They stated that this zone was the primary barrier to the subsurface migration of bacteria, and emphasized its importance to the proper functioning of the absorption field. Butler et al 67 also noted the importance of a mat in bacterial removal by soil. In addition to a surface mat, they described the formation of a second clogged zone deeper in the subsurface, usually 10 to 50 cm deep.…”

“…Butler et al 67 studied the movement of coliform bacteria in a variety of soils with effective grain sizes ranging from 0.0056 to 0.015 mm. They found that the removal was appreciably less in soils with large effective grain sizes than for finer-grained soils.…”

Relating Watershed Characteristics to Elevated Stream Escherichia coli Levels in Agriculturally Dominated Landscapes: An Iowa Case Study

“…As watershed size increases, so does the distance between land applied FIB sources and water monitoring points. This increased travel distance increases the opportunities for FIB losses due to sedimentation and entrapment of particle associated FIB, infiltration of runoff, and FIB decay [38][39][40][41]. A study conducted by Tian, et al [42] found that the delivery ratio of FIB to a stream increases as the distance decreases between the FIB source and the stream.…”