The National Contingency Plan (40 CFR Part 300 ) requires that remedial strategies must, at minimum, protect human health and the environment and meet applicable and relevant or appropriate requirements (ARARs). Where groundwater is impacted, maximum contaminant levels (MCLs) and maximum contaminant level goals (MCLGs) set under the Safe Drinking Water Act are often used as ARARs, whether or not the aquifer is a reasonably anticipated future source of drinking water. The US Environmental Protection Agency now recognizes the difficulty of groundwater restoration at sites where dense nonaqueous phase liquids are present, particularly in certain complex hydrogeological settings (EPA 1993). However, demonstration of impracticability generally does not occur until active remediation (e.g., pump and treat) has been shown to be ineffective. A case study of a former manufactured gas plant (MGP) is used to demonstrate how physical and chemical properties of the aquifer and coal tar, the major waste product from MGP sites, influence the feasibility of active restoration. Field characterization investigations, laboratory studies, and groundwater modeling are integrated into a demonstration following EPA guidelines. Laboratory studies included microbiological characterization and natural biodegradation and suggest that intrinsic bioremediation is occurring at this site. This work will be useful as EPAmore » continues to develop presumptive remedies for cleanup under Superfund.« less
Exploiting microbial reactions to remediate chlorinated solvents and pesticide contamination appeared to be an attractive remedial alternative for a site located at the Dover Air Force Base in Dover, Delaware. To generate data to evaluate the feasibility of implementing enhanced in situ bioremediation as a remedial technique, a relatively inexpensive and rapid treatability study was designed. Batch microcosm studies were used to mimic in situ redox conditions (oxygenated and unoxygenated) and methanotrophic conditions. No evidence of target compound degradation existed under either the amended or unamended aerobic conditions; however, the activity observed in some samples under anaerobic conditions suggested transformation of chlorinated compounds and pesticides. Results showed that biodegradation may be inducible under certain conditions, but time lags and efficiencies could be expected to vary considerably. A remedial alternative analysis could not be expected to achieve the degree of accuracy and precision necessary without the data resulting from this study.
Since the advent of increased public awareness concerning hazardous waste and the enactment of statutes governing these wastes, hazardous waste has become an important component impacting the highway planning and property acquisition process. Hazardous waste impacts have been realized by the Delaware Department of Transportation (DelDOT) during the Final Design phase of a new, 46-mile highway facility, commonly referred to as the Relief Route Project. The principal thrust of this paper is to inform and promote sound engineering decisions concerning the methods which should be taken to minimize the impacts hazardous waste can have on a highway project.
This is a question that every nurse should consider as it could be a major factor in their nursing career. Indeed if training needs and education at all levels of the National Health Service are not reviewed and brought up to date, nursing could be heading for serious difficulties in the near future. Fortunately for nursing, the European Community has decided to bring manual lifting and handling to the forefront by issuing directives which they hope will 'harmonise health and safety standards throughout the European Community such that competitive advantage cannot be gained by lowering costs as a direct result of lowering standards'. The most important of these as far as nursing is concerned is Directive 90/269, especially articles three to four which state employers have 'an existing duty to prepare and revise as necessary and bring to the attention of their employees, a written Health and Safety Policy'. It also expects employers to provide equipment which will allow workers to avoid manual handling and to ensure that a full assessment of all manual lifting tasks is carried out prior to their commencement, whether there is a risk of injury or not to the employee.
