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Human activities in the karst Ozark Plateaus can impact water quality of springs where surface water is rapidly transferred to subsurface conduits. Bennett Spring, in southern Missouri, is the fourth largest spring in the state and supports local tourism activities. Questions regarding poorly functioning on-site wastewater systems (OWS) have raised concerns over the long-term water quality of the spring. This study reports the results of a surface water quality monitoring program in the recharge area where monthly samples were collected at base flow to identify potential pollution sources to the spring. Base flow hydrology of the recharge area was highly variable over the study period, which was drier than normal, causing an incomplete sampling record due to no flow conditions at some sites. For most of the year, nutrient levels were less than the eutrophic threshold (ET) of 0.075 mg/l total phosphorus (TP) and 1.5 mg/l total nitrogen (TN). Sites that consistently displayed concentrations of TP and TN higher than the ET were influenced by wastewater treatment plants (WTP) or OWS. Sites with nutrient concentrations above the ET were likely influenced by the re-release of nonpoint source related TP and TN delivered to streams during storm events. Water quality and discharge at the spring outlet remained consistent over the sampling period suggesting diffuse recharge from a deep aquifer source is able to dilute shallow ground water sources carrying nonpoint pollutants at base flow. Historical and regional data comparisons show these trends have been consistent over at least the last two decades.

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Greater London, among many large cities, was subject to bombing by the German military in both the World Wars and was the target of many air raids during the Second World War (WW2). This was particularly the case during the Blitz, September 1940-May 1941, when over 28,000 high explosive bombs and parachute mines were dropped on London. Post war research conducted in 1949 estimated that approximately 12,750t of bombs, including V1 and V2 rockets, were dropped on London. The night of 16 th-17 th April 1941 was one of the worst bombing raids, when 446t of bombs were dropped on London and over 58t did not detonate. Unexploded bombs remain buried underground today, as they were unidentified at the time or abandoned owing to difficulties in recovering them. Uncharted bombs continue to pose a potentially significant hazard for developments around London. This paper considers the probability of discovering unexploded ordnance (UXO), particularly WW2 ordnance, during intrusive groundworks in London. The prevalence of unexploded ordnance has been assessed using data obtained from governmental organisations to estimate the likelihood of discovery in London.