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71.
J. GAY BSc MS CEng MICE R. WEBSTER BA MSc D. ROBERTS BA MSc M. TRETT BSc FLS 《Water and Environment Journal》1991,5(5):573-580
The environmental implications of implementing the requirement for treatment of coastal sewage prior to discharge, which were put forward in an EC draft Directive on municipal waste-water treatment, are examined. In order to establish the current situation, the results of a national survey of coastal and estuarine sewage discharges are presented. A review of the impact of sewage discharges on the marine environment is presented in conjunction with an assessment of the impact of sewage-treatment processes on the land and in the air. These aspects are integrated into overall conclusions about net environmental impact. Finally, a decision-tree approach to the assignment of priority to additional action required at individual locations is developed. 相似文献
72.
Richenda K Connell BSc DPhil Robert Willows BA PhD Jacquelyn Harman BSc MSc Stephen Merrett BA MPhil D.Lit 《Water and Environment Journal》2005,19(4):352-360
Climate risk management is a new and evolving area and many decisions are likely to be affected by climate risks over the long-term. This paper presents a decision-making framework designed for managing climate alongside nonclimate risk factors. The framework describes a process that should help identify and manage these risks. It can be used to help decision-makers answer questions about whether adaptation is required, and, if so, which measures should be implemented. Adaptive management is recommended as a useful approach for dealing with climate and other uncertainties. This paper describes an application of the framework to a water resources case study. Feedback from training workshops based on four different case studies suggests the framework provides at minimum a useful (post-hoc) decision analysis tool. Potential users, who include planners, consultants and policy-makers have been largely positive about the prospective utility of the framework. 相似文献
73.
P. L. YOUNGER BSc MS PhD FGS R. MACKAY BSc B. J. CONNORTON BSc MSc FGS C. Geol 《Water and Environment Journal》1993,7(6):577-585
Integrated fieldwork and modelling has been undertaken to assess the vulnerability of riverside wells to pollution when river water is contaminated. Results highlight the importance of streambed sediments as a barrier to groundwater pollution by river water. The bed of the River Thames is lined with brown and grey organic-rich silts of low hydraulic conductivity (about 0.002 m/d). A 3-D model for solute transport in stream-aquifer systems was developed and applied to two riverside sites in the middle Thames valley. Model results indicate that well-water quality would only breach EC limits if the river was heavily polluted for a week or even a month (clearly an unlikely scenario). Sensitivity analyses showed the models to be far more sensitive to streambed parameters than to aquifer parameters. Thus it would be more sensible to focus fieldwork on the measurement of streambed properties than on the more usually measured aquifer parameters. 相似文献
74.
F. A. Nicholson BSc MSc PhD B. J. Chambers BSc PhD A. Moore BSc PhD R. J. Nicholson BSc G. Hickman BSc 《Water and Environment Journal》2004,18(3):155-160
A review was undertaken of (a) the levels and prevalence of Salmonella spp., Campylobacter spp., Listeria monocytogenes, Escherichia coli 0157. Cryptosporidium parvum and Giardia intestinalis in livestock manure, and (b) factors which affect their survival during storage and following land application. Pathogens are commonly present in livestock manures and can survive in soil for several months or years after spreading or excretion onto land. Temperature was identified as being the most important factor influencing pathogen survival, although pH, UV light and drying were also important. Various practical measures to minimise the risk of pathogen transfer into the food chain were identified, including treatment, extended storage and no/harvest periods following land spreading. Guidelines are being developed on managing farm manures to minimise the risks of microbiological contamination of ready-to-eat crops. 相似文献
75.
S. Walker BSc PhD CEng FICE H. A. Smithers BSc MSc 《Water and Environment Journal》1998,12(4):273-279
As environmental regulator, the Environment Agency seeks the best balance between essential needs of water supply and the environment, whilst taking into account costs and benefits; nowhere is this balance more focused than in the management of droughts. The drought of 1995–96 was the most severe on record in the North West, and presented a major challenge to both the water company and the Environment Agency in safeguarding essential water supplies and minimizing the risks to the environment.
This paper describes the management of the drought from the Agency's perspective. 相似文献
This paper describes the management of the drought from the Agency's perspective. 相似文献
76.
P. K. Bishop BSc PhD CGeol FGS B. D. Misstear BA MSc CGeol FGS CEng MIEI M. White BSc CEng MICE N. J. Harding BSc 《Water and Environment Journal》1998,12(3):216-223
This paper summarizes the findings of a recent research project on groundwater contamination from leaking sewers, which was completed for the Construction Industry Research and Information Association. Fifty-four incidents were identified in England and Wales from a combined questionnaire survey and literature review. In addition to recorded incidents, the poor quality of many urban groundwaters suggests some effects from leaking sewers. Age is considered to be the most significant characteristic governing leakage from sewers; ground conditions (predominantly aquifer vulnerability) and usage (private versus public ownership) are also important factors relating to the likelihood of groundwater pollution from leaking sewers. Recommended strategies for reducing groundwater contamination include (a) modification of existing criteria for the service performance grading of existing sewers, (b) improved construction of new sewers in appropriate areas, (c) increased groundwater monitoring, and (d) risk assessments for new groundwater sources. 相似文献
77.
R. C. HARRIS MSc BSc CGeol FGS MIWM A. C. SKINNER PhD BSc CGeol FGS 《Water and Environment Journal》1992,6(6):569-574
The greatest threat of contamination to groundwater resources is posed by pollutants from diffuse sources, yet legislation in the UK has until recently been focused on point sources. The problem of widespread pollution from industrial sources is described and compared with that from agriculture. The legislative controls available under the Water Resources Act 1991 are outlined, and the approach adopted by the National Rivers Authority in its Groundwater Protection Policy is discussed with respect to the concept of groundwater vulnerability. 相似文献
78.
C. E. Round BSc MSc A. R. Young BSc MSc K. Fox BSc PhD 《Water and Environment Journal》1998,12(6):402-405
Measurements of flow velocity are often required for a broad range of issues surrounding water-resource management, and a velocity-estimation method is therefore desirable where extensive field data are unavailable. This paper presents the development of a model for estimating flow velocity using readily available catchment characteristics, and flow and channel geometry data. The velocity equations were calibrated using UK data, so that their application at any river site in the UK is attainable. The calibrated equation uses the mean flow and the dimensionless magnitude of the flow on the day in question to estimate the mean reach velocity for flows at any river site in the UK. 相似文献
79.
The paper reviews the regulation of water companies in England and Wales since 1989 by reference to the historical regulation of utilities in these countries. It considers how comparative competition, service standards and charging arrangements are developing. Particular mention is made of the debates over rates of return and household metering. The conclusion is that regulation, to be effective and appropriate, must be capable of evolution. 相似文献
80.
A novel peatland management strategy to utilise the high nutrient-retention potential of degenerated peatlands has been implemented in Northern Germany. The effect of raised water levels and extensive land-use management on hydraulic properties, water quality and vegetation characteristics of heavily vegetated and groundwater-fed open ditches, was investigated at the River Elder Valley - a nationally important wetland case study. A better understanding of the effect of vegetation on the temporal flow patterns and the hydraulic retention times is of high scientific interest, especially for improving nutrient standards in lowland rivers. Within-ditch vegetation and other hydraulic obstructions, including accumulated silt and organic debris, increase the hydraulic retention time and lead to an improvement of the water quality along the open ditch. Lower parts of the open ditches were flooded by the River Elder, due to the absence of a mowing scheme during late summer 相似文献