共查询到20条相似文献，搜索用时 31 毫秒
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W. Brian Hughes 《Ground Water Monitoring & Remediation》1991,11(1):97-102
Continuous high-frequency marine seismic profiling was used to define the extent of geologic units in the offshore areas of J-Field, Aberdeen Proving Ground, Maryland, during March and April of 1988. J-Field is an area that was used by the U.S. Army for disposal of chemical warfare agents, munitions, and organic solvents from the 1950s through the 1970s. A major concern at this site is the subsurface migration of hazardous wastes into offshore areas and eventually into the Chesapeake Bay. A 150-foot (45.7 meter) deep paleochannel containing Pleistocene age fluvial and estuarine sediments was identified from boreholes constructed onshore. The paleochannel sediments consist of three lithic units. From bottom to top these units consist of gravel and sand, massive silty and sandy clay, and interbedded sand and clay. The seismic profiles were used to identify the extent of these units and map them in offshore areas. An accurate knowledge of the distribution of the geologic units in onshore and offshore areas is important to the investigation because the coarse-grained paleochannel sediments may provide a preferential flow path for contaminated ground water and the fine-grained sediments may impede the movement of contaminants into deeper aquifers. 相似文献
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Peter M. Kearl Nic E. Korte Mike Stites Joe Baker 《Ground Water Monitoring & Remediation》1994,14(4):183-190
Micropurge sampling of ground water wells has been suggested as a possible replacement to traditional purge and sample methods. To compare methods, duplicate ground water samples were collected at two field sites using iraditional and micropurge methods. Samples were analyzed for selected organic and inorganic constituents, and the results were compared statistically. Analysis of the data using the nonparametric sign test indicates that within a 95 percent confidence interval, there was no significant difference between the two methods for the site contaminants and the majority of analytes. These analytical results were supported by visual observations with the colloidal borescope, which demonstrated impacts on the flow system in the well when using traditional sampling methods. Under selected circumstances, the results suggest replacing traditional sampling with micropurging based on reliability, cost, and waste minimization. 相似文献
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