Contaminants discharging from on-site wastewater treatment systems (OSWTSs) can impact groundwater quality, threatening human health and surface water ecosystems. Risk of negative impacts becomes elevated in areas of extreme vulnerability with high water tables, where thin unsaturated intervals limit vadose zone attenuation. A combined geophysical/hydrogeological investigation into the effects of an OSWTS, located over a poorly productive aquifer (PPA) with thin subsoil cover, aimed to characterise effluent impacts on groundwater. Groundwater, sampled from piezometers down-gradient of the OSWTS percolation area displayed spatially erratic, yet temporally consistent, contaminant distributions. Electrical resistivity tomography identified an area of gross groundwater contamination close to the percolation area and, when combined with seismic refraction and water quality data, indicated that infiltrating effluent reaching the water table discharged to a deeper more permeable zone of weathered shale resting on more competent bedrock. Subsurface structure, defined by geophysics, indicated that elevated chemical and microbiological contaminant levels encountered in groundwater samples collected from piezometers, down-gradient of sampling points with lower contaminant levels, corresponded to those locations where piezometers were screened close to the weathered shale/competent rock interface; those immediately up-gradient were too shallow to intercept this interval, and thus the more impacted zone of the contaminant plume. Intermittent occurrence of faecal indicator bacteria more than 100m down gradient of the percolation area suggested relatively short travel times. Study findings highlight the utility of geophysics as part of multidisciplinary investigations for OSWTS contaminant plume characterisation, while also demonstrating the capacity of effluent discharging to PPAs to impact groundwater quality at distance. Comparable geophysical responses observed in similar settings across Ireland suggest the phenomena observed in this study are more widespread than previously suspected.

No abstract

No abstract

R r me, a lowly prison scribe, to try to transpose the timely aphorism uttered by one of Canada's leading scholars (recently deceased) may seem a little pretentious, if not totally antithetical. But I know in my mind that Marshall McLuhan, who was routinely called a media guru and the oracle of the electric age, would have welcomed contrary insight from anyone with the temerity to tinker with his favorite toys-words. McLuhan's brash statement that "the medium is the message" turned the world of communications on its head, as did many of his theories-a term he disliked. From what I understand, he preferred to call his concepts a "probe" into the collective consciousness surrounding the art and science of communication: a probe designed to stir controversy and stimulate dialogue, a process that inevitably leads to the development of character and mental powers, which is how the dictionary defines education.Herbert Marshall McLuhan was born in Edmonton, Alberta, on July 21, 1911. Several years later his family moved to Wmnipeg, Manitoba, where he grew up while receiving a modest grade school education. He enrolled at the University of Manitoba with the intent of becoming an engineer, but quickly switched to English literature. He was awarded his B.A. degree at Manitoba in 1933, and his M.A. degree in 1934. He studied overseas at Trinity Hall in Cambridge University, taking another B.A. degree in 1936, another M.A. in 1940, and his Ph.D. in 1942, in the respective fields of medieval education, Renaissance literature, and Elizabethan rhetoric. Upon his return to North America, he taught at the

No abstract