ALBERT

Notes: Article 14 of the Water Framework Directive requires member states to demonstrate that they are enabling increased public participation in water governance issues at the river basin level. Yet little research has been conducted to understand in what regard water governance bodies are held by the public. In particular, few studies have concentrated on which water resource management issues concern consumers at the catchment and sub-catchment scale within England and Wales. A household study was conducted in 2003 along the River Nene catchment in the east of England to understand in more detail the range of these consumer perceptions and attitudes at different spatial scales, focusing on water resource management issues such as flooding, sector performance and policy making. The results of the survey demonstrate that formulating policy at the catchment scale does not always capture the diversity of opinion or the range of legitimacy issues which concern consumers at the sub-catchment level. The paper concludes that public participation initiatives may be improved by paying closer attention to the various legitimacy concerns at the catchment and sub-catchment scales.

Notes: The effect of controlling the pre-coagulation regime on downstream ultrafiltration of raw upland waters has been investigated. It has been shown that zeta potential can be used to detect changes in the coagulation process and hence to determine appropriate dosage levels. This is important, as incomplete coagulation has a detrimental effect on ultrafiltration membrane performance, particularly in terms of fouling caused by excess iron. Submerged hollow-fibre membrane units yield superior performance with pre-coagulation and sufficient slow mixing of coagulant guarantees high permeate flow recovery after backwashing. Fouling by natural organic matter can be remedied by conventional cleaning techniques. However, fouling due to excess iron can only be removed by heating the cleaning solution. The associated costs are thus two-fold; that of excess coagulant and that of cleaning.

Notes: Llangefni WwTW receives discharge from the rural town of Llangefni and the local industrial estate and to date this is the first and only BNR plant in Wales. The consents from March 2003 included a reduction in ammonia (NH4_N) to 1.5 mg/l, suspended solids to 20 mg/l (SS) and Biological Oxygen Demand (BOD) to 7 mg/l and included a new Phosphate (PO4_P) standard of 2 mg/l. The process selected to meet the new consents was Biological Nutrient Removal (BNR) and was unusual as it was for a small, rural wastewater treatment plant that receives about 26% of its flow from an industrial estate.During commissioning, the plant produced an average phosphate concentration of 1.0 mg/l and an ammonia concentration of 0.7 mg/l. It was confirmed that to achieve consistent phosphate removal a BOD:P ratio greater than 20:1 is required along with a high VFA (Volatile Fatty Acids) concentration of 200–300 mg/l.

Notes: Book Review in this ArticlesBlue patches and clear water, by Brian RofeBiology of Wastewater Treatment (second edition), by N. F GraySweet and wholesome water, by Ted Flaxman and Ted Jackson. E. W. Flaxman

Notes: The existence of fresh groundwater overlaying saline water in groundwater systems is widespread in many inland aquifers and most coastal aquifers. The Jericho district suffers from the phenomenon of saline upconing. The Pleistocene aquifer, which is the main source of water supply for irrigation in the Jericho district, comprises a layer of salt water covered with lenses of fresh water. It appears that drought and heavy exploitation from Jericho wells are the main reasons for the saline upconing problem in the Pleistocene aquifer. The objectives of this research were to (a) investigate the saline upconing phenomena and (b) provide recommendations for control of the fresh and salt-water mixing in the Jericho aquifer underneath a skimming well. A model, which coupled density-dependent flow and solute transport, was used to simulate movement of the salt water under different hydrogeological and operational conditions. Results from the simulations showed that location of the screen has a strong impact on salt-water movement in the well. Reasonable control of saline upconing was observed when the screen was placed against the gravel layers.

Notes: A computer model was developed to evaluate the impact of various technologies for water conservation in domestic households, in terms of the Impact on the operation of downstream infrastructure. These technologies, which include (a) low-flush toilets, (b) greywater re-use, and (c) re-use of rainwater from roof runoff for toilet flushing, were compared using indicators of sustainability to measure water consumption, sewerage-system operational performance and process treatment efficiency. The results demonstrated that rainwater re-use is potentially the most sustainable strategy in terms of the benefits associated with water conservation and reduction in sewage discharges from combined-sewer overflows (CSOs). The benefits were observed without the problems associated with increased sedimentation in sewers during dry weather, associated with other water-conservation strategies such as reduced-flush toilets, greywater re-use and the resultant increase in pollutants from CSOs during wet weather.

Notes: The east and south-east of England has the lowest rainfall in the UK, water resources are limited and under pressure through increased demand and population growth. In the late 1990’s AW Innovation (the AW R&D group) developed a process that could produce high purity water from sewage effluent using membrane technology. In late 1999 Texas Utilities (TXU) signed a contract with Alpheus Environmental for the supply of high purity water for Peterborough Power Station. The novel treatment plant was built in 1999 - 2000 and opened in July 2000 by the Mayor of Peterborough. This paper is a review of the plant design, the technology used for the treatment process and a summary of the first four years of operation.Changing from potable water to high purity water produced from sewage effluent has brought significant benefits for the power station resulting in higher purity steam generation while reducing chemical, power and effluent discharge costs. In addition Anglian Water is now saving 1,000 m3/day of potable water.

Notes: This paper considers recent developments in the understanding of diffuse pollution, its generation, transport and impacts. The relative importance of diffuse sources to total pollutant loading must be identified in order to develop appropriate strategies for management.Research has indicated that individual diffuse pollutants respond differently to changing flow conditions and that there is a widespread misconception that higher flows are associated with lower pollutant concentrations. Evidence is presented to highlight this discrepancy and a rationale for load assessment is presented. The implications of this for monitoring within the context of the EU Water Framework Directive are discussed as are the implications for the mitigation of diffuse pollution.

Notes: Some landfill site operators use wastewater treatment plants for the discharge of complex leachate waste. However, for the water company involved in managing the wastewater plant, leachates can pose a problem to the quality of the effluent, due to the high levels of Chemical Oxygen Demand (COD), ammonia and inorganic metal constituents. Electrochemical oxidation of landfill leachate has been successfully used by researchers(1,2,3,4) with current densities of 5 to 100 mA/cm2. A new laboratory system has been developed which utilises a low current density of 2.42 mA/cm2 and the performance has been evaluated with synthetic and ’real’ landfill leachates from 2 wastewater sites.This system reduces COD of synthetic mixtures by 58%, with complete removal of ammonia. For real leachates, 5 out of 8 samples resulted in ammonia reduction, with 2 samples experiencing approximately. 60% COD reduction. Power costs for treatment have been determined and the potential for a full-scale installation considered.

Notes: The implementation of the EU Landfill Directive in the UK demands high rates of recycling by local councils and regional waste authorities. Currently recycling is either carried out at cost intensive materials recycling facilities (MRF) or through separate collection services. Collection of separate materials is undertaken in inner-city boroughs of London mainly through bring-banks, which are often severely contaminated, and by kerbside collections from street properties. However, the provision of door-to-door collections in inner-city estates has not been widely used yet, because of the lack of data to assess the potential and costs of such recycling services. In this paper a detailed assessment of a pilot door-to-door recycling service is presented. This pilot was carried out for a year by a local not-for-profit company in two inner-city estates in the London Borough of Tower Hamlets (LBTH).

Notes: The Environment Agency have proposed that daily flow volume discharged from small wastewater treatment works should be capable of being measured to an accuracy of ±8%, where the daily totalised flow volume is estimated to be greater than 5m3. It is estimated that every water company in the UK has several hundred small wastewater treatment works that will be required to be equipped with the capability of measuring the released daily totalised flow volume for specified periods. This paper investigates the feasibility of modifying existing dosing syphons, which are present within many of these works, to operate as flow measuring devices. Laboratory testing of a full-scale syphon demonstrated that by the addition of two water level detectors and a data logger to monitor the filling part of the syphon cycle, it is possible to accurately calculate the daily totalised flow volume within the Environment Agency’s proposed performance criteria.

Notes: In this paper, the tritium levels in the leachates and methane gas condensates which have occurred at 13 sanitary landfills of municipal solid wastes (MSW) are investigated and reported. During the 6 months investigation period, the mean tritium concentrations of the raw leachates were distributed from 17 to 1,196 TU. They corresponded to several scores or hundreds higher tritium levels than that of the normal environmental level except for two cases. High tritium levels were also detected in the effluents of the leachate treatment facilities. Generally, the tritium existed in the dissolving fraction of the leachate but for some cases about 10% of the total tritium content was present as colloidal particles of over 0.45 μm in size. In general, the relationship between the tritium and other contaminants in the raw leachate was low, but it was relatively high between the tritium and TOC. Thus, it is predicted that the dissolving state of the tritium in the leachates would be affected by the tritium sources of the tipped wastes in a MSW.

Notes: The number of river restoration projects undertaken in the UK has increased rapidly over the last five years. However, schemes are still largely undertaken on an ad-hoc basis rather than part of a co-ordinated, strategic, catchment restoration strategy. Additionally, project level restoration is rarely initiated through a systematic approach that involves all stages from baseline studies through to design, installation, monitoring and post-project appraisals. The need for both strategic and project levels to be undertaken effectively is necessary if the requirements of the Water Framework Directive (WFD) are to be met. This directive has the potential to significantly increase the number of schemes, as restoration of surface water bodies has become a key duty of member states. There exists, therefore, a need for a holistic catchment scale approach to restoration to be adopted to maximise benefit to the fluvial systems and ensure compliance. This paper outlines key components of strategic and project level protocols for river restoration from a UK perspective.

Notes: The Tlimore Brook, In Hampshire, typifies the Impact of new housing development that has taken place In phases over the past 20 years or so, on a river corridor. However, the issue is not one of flooding, because the channel itself had been straightened and deepened in historical times and had been adjusted further by down-cutting; thereby forming an over-large channel sufficient to contain flood flows. Perhaps rarely for lowland Britain, the key problem was that of erosion, threatening adjacent properties. This paper describes the nature of the erosion problem and the subsequent geomorphological design to mitigate it. A key unique feature of this project was the extent of backfilling required, over the entire length, to raise the over-deep channel bed. The project was constructed in 2003.

Notes: This paper analyses the Issue of water and sewerage service charge affordability in Great Britain, focusing exclusively on the domestic or household sector. It discusses the meaning of affordability, outlining ways in which it might be measured, before presenting empirical data to calibrate the phenomenon. A discussion of affordability benchmarking for household water and sewerage services is followed by a brief critique of the various financial support mechanisms currently available to low Income households.

Notes: Pollutants build up on highways and are washed off during a rainfall event; and are usually discharged via an outfall to a watercourse. CIRIA report 142 (1994) guidance for evaluating wafer quality downstream of a highway outfall considers only copper and zinc in the water quality assessment of highway outfalls; determinands thought to occur in significant concentrations in highway runoff. This guidance has since been adopted in the Design Manual for Roads and Bridges environmental assessment. However, recent investigations suggest that other determinands may occur in unacceptably high concentrations. This paper demonstrates that additional determinands should be considered in the water quality assessment downstream of a highway outfall.

Notes: There is currently limited guidance available in the UK for predicting the significance of the impacts of developments on the water environment. This may be partly due to the disparate nature of the components of the water environment, which are covered by a range of scientific and engineering disciplines. This paper reviews the current status of Environmental Impact Assessment for the water environment in the UK and identifies key methodologies and guidance. Proposals are made for a more detailed approach to determining the significance of impacts on rivers, stillwaters (lakes and ponds), groundwater and floodplains, building on methodologies previously developed for highways schemes. Account is taken of the Environment Agency’s ongoing work to classify water features to meet the requirements of the Water Framework Directive.

Notes: Over the course of history, development in and around London has encroached significantly into the River Thames floodplain. As a result, approximately 116 km2 of heavily urbanised land between Teddington Weir and Dartford Creek is at risk of tidal flooding. This area is currently protected from overtopping for levels in excess of the 1:1000-year flood event by an integrated system of static and moveable defences. However, the residual risk due to the probability of defence failure (through breaching) and the resulting consequences of such a failure remains high.To effectively manage this risk the Environment Agency needs to be able to prioritise investment in the defence system, predict probable flood extents as a result of a breach event, issue timely warnings and ensure that the response to an event is an appropriate one. Currently, this is not possible due to a distinct lack of information regarding the propagation of floodwaters through the complex urban topography in and around London.This paper details a 2D floodplain modelling project, currently underway within the Environment Agency, which was initiated to address these issues. The paper highlights the constraints and problems associated with urban flood modelling, suggests potential solutions and outlines how this type of modelling system could be used to inform future flood risk management tools.

Notes: The remarkable progress made in the early 20th century in improving the microbiological quality of municipal drinking water supplies is undoubtedly one of the most important factors contributing to the improved health and life expectancy of the developed world during that century. The paper highlights perceived milestones in the 19th and early 20th centuries in the scientific and technological developments in municipal water treatment practice, particularly in relation to the improvements in the chemical and biological quality of drinking water supplies. The paper concludes by summarizing key developments in the methods of measuring water quality and in the improvements in drinking water quality standards during that period.

Notes: A floating reed bed was Installed on a lowland eutrophic reservoir, replacing ferrous chloride dosing as a method of phosphate reduction. Since the study was undertaken on an active water supply reservoir, this technique was further supported by the use of submerged barley straw applications on the downstream reservoir to limit algal growth. The study examined algal, chlorophyll a, phosphate and nitrate levels in both the source water and the treated through-How to measure the effectiveness of phosphate reduction and algal control during the maturation phase of the bed. The results show that although not as effective as chemical dosing, total phosphate levels were reduced across the reservoir body and algal numbers were typically restricted to levels suitable for treatment at the receiving water treatment works. It Is concluded that although the study did not coincide with Ideal climatic conditions for prolific algal growth, the adopted techniques demonstrated significant potential as components of a holistic management approach for eutrophic waters.

Notes: The performance of a novel industrial membrane bioreactor (MBR) comprising denitrification, nitrification and ultrafiltration for the secondary treatment of primary treated animal rendering wastewater has been compared with an experimental, low-cost and novel vertical-flow constructed wetland planted with Typha latifolia L. (Reedmace or Broad-leaved Cattail). The process wastewater followed pre-treatment by dissolved air flotation (DAF). The mean DAF effluent gave highly variable chemical oxygen demand (COD) and ammonia concentrations of 5816 (standard deviation (SD): 3005.0) and 614 (SD: 268.7) mg/l, respectively. The mean MBR effluent for COD and ammonia was 37 and 86 mg/l, respectively. The mean treatment performance of the constructed wetland for COD, ammonia and suspended solids was 205, 67 and 57 mg/l, respectively.

Notes: Regulations Introduced in 1999 obliged water companies In England and Wales to conduct risk assessments of their treatment works to establish whether there was a significant risk from Cryptosporidium oocysts in the water supplied. More than 330 treatment works were identified as being at risk, just over half of which were plants treating groundwater. This paper provides an overview of what water companies themselves identified as the most at-risk settings for their groundwater-based works in terms of aquifer and type of supply. Evaluation of results from the subsequent continuous monitoring regulatory regime that came into force on many of these supplies could validate the primarily qualitative nature of the initial assessments of at-risk settings. There would also be public health benefits from confirmation of whether currently-employed risk assessment methods are well-founded because similar procedures could then be applied with confidence to the many small private supplies In Britain.

Notes: Hong Kong is an Asian city with nearly 7 million people. Because of the lack of natural resources, the local water supply is not adequate to meet the demand. Fresh water supply in Hong Kong relies on the cross border import of water from the East River (Dongjiang) in China. To conserve fresh water, seawater has been used for toilet flushing since the 1950s. In this paper, the current status of seawater for toilet flushing in Hong Kong is reviewed, and the future strategy toward sustainable toilet flushing water supply, including other alternatives, is discussed.

Notes: This paper reviews methods of estimating recharge for a wide variety of aquifers in Britain. A soil moisture balance technique is used with direct representation of relevant soil and crop properties. Recharge contributions due to rainfall, runoff from impervious areas and leaking water mains and sewers are considered. In many field situations low permeability strata, which overlie the main aquifer, modify the timing and magnitude of the actual recharge. Runoff from less permeable strata can become runoff-recharge at the aquifer outcrop. Reference is made to several case studies.

Notes: Nitrogen removal from wastewater is rapidly becoming an essential but expensive upgrade for many small wastewater treatment works in the UK. Using a pilot-scale waste stabilization pond effluent, this paper highlights a low-cost upgrading unit, capable of removing BOD, SS, ammonia and faecal colliforms. Results are given for 12 months of operation and it is suggested that these units could be used by the water companies when ammonia removal is necessary to meet with current legislative demands and prevent eutrophication of receiving watercourses.

Notes: Ultrasound treatment, which involves the introduction of high-intensity sound waves into a sludge medium, is one of several technologies which promote hydrolysis during sludge treatment. It has become well-established with numerous full-scale plants in Europe operating for several years. The basic principle involves the release of extra-cellular material which then catalyses biological reactions and improves bacterial kinetics, resulting in lower sludge quantities and (in the case of anaerobic digestion) increased biogas production. Its use is most suited to plants containing large quantities of refractory material and/or cellular matter, such as waste activated sludge. This paper uses the data from several full-scale part-stream ultrasound plants and discusses the influence of the technology on numerous operating conditions, especially with respect to improved digestion and enhanced biogas production.

Notes: Groundwater residence-time survey results on 21 public water supplies in the chalk aquifer in southern England are compared with a previous Cryptosporidium risk assessment which was carried out on the same supplies for regulatory-compliance purposes in 1999. The results indicate that residence-time indicators could provide useful corroborative evidence for rapid recharge hazard - not only in those settings already identified by microbiological surveillance, but also in the more difficult-to-identify situation where potential rapid pathways have been identified but the bacteriological indicators are negative or ambiguous. However, groundwater-mixing processes under pumping conditions are complex, especially in the chalk, and will always require interpretation informed by an understanding of the local hydrogeological and operational setting.

Notes: Bulk age determinations, based upon chlorofluorocarbons and sulphur hexafluoride measurements of samples from twenty-one chalk groundwater supplies in southern England, Indicate that waters of relatively recent age predominate In both unconfined and partially confined situations. Water from pumping stations located on chalk below Palaeogene cover can be distinguished hydrochemically, and a likely interpretation is that these supplies are receiving a small proportion of recharge via induced via induced leakage. Whilst water which is abstracted from the chalk always involves mixing processes, for a sub-set of confined supplies, ‘piston’ flow could be inferred as a dominant mechanism - resulting in bulk groundwater ages of a few decades. Other supplies are the product of complex mixing. Although low-level chlorofluorocarbon enrichment was encountered for half the catchments sampled, they and sulphur hexafluoride appear to provide independent corroboration to microbiological indicators of the presence of rapid recharge.

Notes: Traditionally, Wales has relied on surface water, with only 8% of the total public supply currently derived from groundwater sources. There are various significant aquifers in Wales, including the Carboniferous Limestone in South and North-East Wales and the Triassic aquifer in the Vale of Clwyd, as well as superficial granular deposits that are of particular importance in West Wales. Groundwater quality is generally good and minimal treatment is required. Hydrogeological data in the public domain for Wales are scarce: the Carboniferous Limestone, for example, is particularly poorly documented. Despite this lack of information there are some notable groundwater schemes, but current legislative aspects now require a better overall understanding of the hydrogeology of Wales. A key recommendation is the preparation of public domain data-sets and a comprehensive report on the hydrogeology of Wales.

Notes: Spatial variations in hydraulic conductivity (K) can significantly affect the transport of contaminants in ground water. Conventional field methods, however, rarely provide a description of these variations at the level of detail necessary for reliable transport predictions and effective remediation designs. A direct-push (DP) method, hydrostrati-graphic profiling, has been developed to characterize the spatial variability of both electrical conductivity (EC) and hydraulic conductivity in unconsolidated formations in a cost-effective manner. This method couples a dual-rod approach for performing slug tests in DP equipment with high-resolution EC logging. The method was evaluated at an extensively studied site in the Kansas River floodplain. A series of profiles was performed on a surface grid, resulting in a detailed depiction of the three-dimensional distribution of EC and K. Good agreement was found between K estimates obtained from this approach and those obtained using other methods. The results of the field evaluation indicate that DP hydrostratigraphic profiling is a promising method for obtaining detailed information about spatial variations in subsurface properties without the need for permanent wells.

Notes: According to common understanding, the advective velocity of a conservative solute equals the average linear pore-water velocity. Yet direct monitoring indicates that the two velocities may be different in heterogeneous media. For example, at the Camp Dodge, Iowa, site the advective velocity of discrete Cl− plumes was less than one tenth of the average pore-water velocity calculated from Darcy's law using the measured hydraulic gradient, effective porosity, and hydraulic conductivity (K) from large-scale three-dimensional (3D) techniques, e.g., pumping tests. Possibly, this difference reflects the influence of different pore systems, if the K relevant to transient solute flux is influenced more by lower-K heterogeneity than a steady or quasi-steady water flux.To test this idea, tracer tests were conducted under controlled laboratory conditions. Under one-dimensional flow conditions, the advective velocity of discrete conservative solutes equaled the average pore-water velocity determined from volumetric flow rates and Darcy's law. In a larger 3D flow system, however, the same solutes migrated at ∼65% of the average pore-water velocity. These results, coupled with direct observation of dye tracers and their velocities as they migrated through both homogeneous and heterogeneous sections of the same model, demonstrate that heterogeneity can slow the advective velocity of discrete solute plumes relative to the average pore-water velocity within heterogeneous 3D flow sytems.

Notes: Naturally occurring long-term mean annual recharge to ground water in Nebraska was estimated by a novel water-balance approach. This approach uses geographic information systems (GIS) layers of land cover, elevation of land and ground water surfaces, base recharge, and the recharge potential in combination with monthly climatic data. Long-term mean recharge 〉 140 mm per year was estimated in eastern Nebraska, having the highest annual precipitation rates within the state, along the Elkhorn, Platte, Missouri, and Big Nemaha River valleys where ground water is very close to the surface. Similarly high recharge values were obtained for the Sand Hills sections of the North and Middle Loup, as well as Cedar River and Beaver Creek valleys due to high infiltration rates of the sandy soil in the area. The westernmost and southwesternmost parts of the state were estimated to typically receive 〈 30 mm of recharge a year.

Notes: Proper management of ground water resources requires knowledge of the rates and spatial distribution of recharge to aquifers. This information is needed at scales ranging from that of individual communities to regional. This paper presents a methodology to calculate recharge from readily available ground surface information without long-term monitoring. The method is viewed as providing a reasonable, but conservative, first approximation of recharge, which can then be fine-tuned with other methods as time permits.Stream baseflow was measured as a surrogate for recharge in small watersheds in southeastern Wisconsin. It is equated to recharge (R) and then normalized to observed annual precipitation (P). Regression analysis was constrained by requiring that the independent and dependent variables be dimensionally consistent. It shows that R/P is controlled by three dimensionless ratios: (1) infiltrating to overland water flux, (2) vertical to lateral distance water must travel, and (3) percentage of land cover in the natural state. The individual watershed properties that comprise these ratios are now commonly available in GIS data bases.The empirical relationship for predicting R/P developed for the study watersheds is shown to be statistically viable and is then tested outside the study area and against other methods of calculating recharge. The method produces values that agree with baseflow separation from streamflow hydrographs (to within 15% to 20%), ground water budget analysis (4%), well hydrograph analysis (12%), and a distributed-parameter watershed model calibrated to total streamflow (18%). It has also reproduced the temporal variation over 5 yr observed at a well site with an average error 〈 12%.

Notes: Performance assessments of repositories for the underground disposal of nuclear fuel and waste include models of ground water flow and transport in the host rocks. Estimates of hydraulic conductivity, K, based on field measurements may require adjustment (upscaling) for use in numerical models, but the choice of upscaling approach can be complicated by the use of nested modeling, large-scale fracture zones, and a high degree of heterogeneity. Four approaches to upscaling K are examined using a reference case based on exhaustive site data and an application of nested modeling to evaluate performance assessment of a waste repository. The upscaling approaches are evaluated for their effects on the flow balance between nested modeling domains and on simple measures of repository performance. Of the upscaling approaches examined in this study, the greatest consistency of boundary flows was achieved using the observed scale dependence for the rock domains, measured values from the large-scale interference test for the conductor domain, and a semivariogram regularization based on the Moye model for packer test interpretation. Making the assumption that large fracture zones are two-dimensional media results in the greatest changes to the median of travel time and improves the flow balance between the nested models. The uncertainty of upscaling methods apparently has a small impact on median performance measures, but a significant impact on the variances and earliest arrival times.

Notes: Degradation of dissolved chlorinated solvents using granular iron is an established in situ technology. This paper reports on investigations into mixing iron and bentonite with contaminated soil for in situ containment and degradation of dense nonaqueous phase liquid source zones. In the laboratory, hypovials containing soil, water, bentonite, iron, and free-phase trichloroethene (TCE) were assembled. Periodic measurement of TCE, chloride, and degradation products showed progressive degradation of TCE to nondetectable levels. Subsequently, a demonstration was conducted at Canadian Forces Base Borden near Alliston, Ontario, Canada, where, in 1991, a portion of the surficial aquifer was isolated and free-phase tetrachloroethene (PCE) was introduced. Using a drill rig equipped with large-diameter mixing blades, three mixed zones were prepared containing 0%, 5%, and 10% granular iron by volume. The bentonite was added to serve as a lubricant to facilitate injection of the iron and to isolate the contaminated zone. Analysis of core samples showed reasonably uniform distributions of iron through the mixed zones. Monitoring over a 13-month period following installation showed, relative to the control, a decline in PCE concentrations to virtually nondetectable values. Reaction rates in the laboratory tests were similar to those reported in the literature, while the rate in the field test was substantially lower. The lower rate may be a consequence of mass transfer limitations under the static conditions of the field test. Results indicate that mixing iron and bentonite into source zones may be an effective means of source-zone remediation, with the particular advantage of being relatively immune to effects of geologic heterogeneity.

Notes: Matrix diffusion can attenuate the rate of plume migration in fractured bedrock relative to the rate of ground water flow for both conservative and nonconservative solutes of interest. In a system of parallel, equally spaced constant aperture fractures subject to steady-state ground water flow and an infinite source width, the degree of plume attenuation increases with time and travel distance, eventually reaching an asymptotic level. The asymptotic degree of plume attenuation in the absence of degradation can be predicted by a plume attenuation factor, β, which is readily estimated as R′ (φm/φf), where R′ is the retardation factor in the matrix, φm is the matrix porosity, and φf, is the fracture porosity. This dual-porosity relationship can also be thought of as the ratio of primary to secondary porosity. β represents the rate of ground water flow in fractures relative to the rate of plume advance. For the conditions examined in this study, β increases with greater matrix porosity, greater matrix fraction organic carbon, larger fracture spacing, and smaller fracture aperture. These concepts are illustrated using a case study where dense nonaqueous phase liquid in fractured sandstone produced a dissolved-phase trichloroethylene (TCE) plume ∼300 m in length. Transport parameters such as matrix porosity, fracture porosity, hydraulic gradient, and the matrix retardation factor were characterized at the site through field investigations. In the fractured sandstone bedrock examined in this study, the asymptotic plume attenuation factors (β values) for conservative and nonconservative solutes (i.e., chloride and TCE) were predicted to be ∼800 and 12,210, respectively. Quantitative analyses demonstrate that a porous media (single-porosity) solute transport model is not appropriate for simulating contaminant transport in fractured sandstone where matrix diffusion occurs. Rather, simulations need to be conducted with either a discrete fracture model that explicitly incorporates matrix diffusion, or a dual-continuum model that accounts for mass transfer between mobile and immobile zones. Simulations also demonstrate that back diffusion from the matrix to fractures will likely be the time-limiting factor in reaching ground water cleanup goals in some fractured bedrock environments.

Notes: At three industrial sites in Ontario, New Hampshire, and Florida, tetrachloroethylene (PCE) and trichloroethylene (TCE), released decades ago as dense nonaqueous phase liquids (DNAPLs), now form persistent source zones for dissolved contaminant plumes. These zones are suspended below the water table and above the bottoms of their respective, moderately homogeneous, unconfined sandy aquifers. Exceptionally detailed, depth-discrete, ground water sampling was performed using a direct-push sampler along cross sections of the dissolved-phase plumes, immediately downgradient of these DNAPL source zones. The total plume PCE or TCE mass-discharge through each cross section ranged between 15 and 31 kg/year. Vertical ground water sample spacing as small as 15 cm and lateral spacing typically between 1 and 3 m revealed small zones where maximum concentrations were between 1% and 61% of solubility. These local maxima are surrounded by much lower concentration zones. A spacing no larger than 15 to 30 cm was needed at some locations to identify high concentration zones, and aqueous VOC concentrations varied as much as four orders of magnitude across 30 cm vertical intervals. High-resolution sampling at these sites showed that three-quarters of the mass-discharge occurs within 5% to 10% of the plume cross sectional areas. The extreme spatial variability of the mass-discharge occurs even though the sand aquifers are nearly hydraulically homogeneous. Depth-discrete field techniques such as those used in this study are essential for finding the small zones producing most of the mass-discharge, which is important for assessing natural attenuation and designing remedial options.

Notes: Three-dimensional grids representing a heterogeneous, ground water system are generated at 10 different resolutions in support of a site-scale flow and transport modeling effort. These grids represent hydrostratigraphy near Yucca Mountain, Nevada, consisting of 18 stratigraphic units with contrasting fluid flow and transport properties. The grid generation method allows the stratigraphy to be modeled by numerical grids of different resolution so that comparison studies can be performed to test for grid quality and determine the resolution required to resolve geologic structure and physical processes such as fluid flow and solute transport. The process of generating numerical grids with appropriate property distributions from geologic conceptual models is automated, thus making the entire process easy to implement with fewer user-induced errors. The series of grids of various resolutions are used to assess the level at which increasing resolution no longer influences the flow and solute transport results. Grid resolution is found to be a critical issue for ground water flow and solute transport. The resolution required in a particular instance is a function of the feature size of the model, the intrinsic properties of materials, the specific physics of the problem, and boundary conditions. The asymptotic nature of results related to flow and transport indicate that for a hydrologic model of the heterogeneous hydrostratigraphy under Yucca Mountain, a horizontal grid spacing of 600 m and vertical grid spacing of 40 m resolve the hydrostratigraphic model with sufficient precision to accurately model the hypothetical flow and solute transport to within 5% of the value that would be obtained with much higher resolution.

Notes: We incorporate a linear estimate of casing friction into the analytical slug test theory of Springer and Gelhar (1991) for high permeability aquifers. The modified theory elucidates the influence of inertia and casing friction on consistent, closed form equations for the free surface, pressure, and velocity fluctuations for overdamped and under-damped conditions. A consistent, but small, correction for kinetic energy is included as well. A characteristic velocity linearizes the turbulent casing shear stress so that an analytical solution for attenuated, phase shifted pressure fluctuations fits a single parameter (damping frequency) to transducer data from any depth in the casing. Underdamped slug tests of 0.3, 0.6, and 1 m amplitudes at five transducer depths in a 5.1 cm diameter PVC well 21 m deep in the Plymouth-Carver Aquifer yield a consistent hydraulic conductivity of 1.5 × 10−3 m/s. The Springer and Gelhar (1991) model underestimates the hydraulic conductivity for these tests by as muchas 25% by improperly ascribing smooth turbulent casing friction to the aquifer. The match point normalization of Butler (1998) agrees with our fitted hydraulic conductivity, however, when friction is included in the damping frequency. Zurbuchen et al. (2002) use a numerical model to establish a similar sensitivity of hydraulic conductivity to nonlinear casing friction.

Notes: This paper presents the design of the passive-discrete water sampler (PDWS) which has been developed to facilitate investigations of flow partitioning in fractured rocks. The PDWS continuously isolates seeping water into discrete samples while monitoring the seepage rate. The PDWS was used in a flow and transport experiment that investigated fracture-matrix interactions. During the experiment, a mix of conservative tracers with significantly different diffusion coefficients (lithium bromide [LiBr] and pentafluorobenzoic acid [PFBA]) was introduced along a fault located in fractured tuffs, and water seeping through the lower end of the fault was collected by the PDWS and analyzed for tracer concentrations. Preliminary results from this investigation show that samples of effluent captured by the PDWS effectively retained temporal changes in the chemical signature, while providing seepage rates.

Notes: Long-term reactivity and permeability are critical factors in the performance of granular iron permeable reactive barriers (PRBs). Thus it is a topic of great practical importance, as well as scientific interest. In this study, four types of source solutions (distilled H2O, 10 mg/L TCE, 300 mg/L CaCO3, and 10 mg/L TCE + 300 mg/L CaCO3) were supplied to four columns containing a commercial granular iron material. In all four columns, gases accumulated to ∼ 10% of the initial porosity and resulted in declines in permeability of ∼ 50% to 80%. In the columns receiving CaCO3, carbonate precipitates accumulated to ∼ 7% of the initial porosity, with no apparent decline in permeability. The data indicate that precipitates formed initially at the influent ends of the columns, reducing the reactivity of the iron in this region. As a consequence of the reduced reactivity, calcium and bicarbonate migrated further into the column, to precipitate in a region where the reactivity remained high. Thus precipitation occurred as a moving front through the columns. The results suggest improved methods for PRB design and rehabilitation, and also suggest improvements that are needed in the mathematical models developed for predicting long-term performance.

Notes: A collection of Visual Basic programs, entitled Function.xls, has been written for ground water spreadsheet calculations. This collection includes programs for calculating mathematical functions and for evaluating analytical solutions in ground water hydraulics and contaminant transport. Several spreadsheet examples are given to illustrate their use.

Notes: Sludge Reed beds have been used for dewatering (draining and evapotranspiration) and mineralisation of sludge in Denmark since 1988 when the first sludge processing system was introduced. Sludge from wastewater treatment plants (2,500-125,000 pe) is treated in sludge reed bed systems with 1–18 basins with loading rates of 25–2,200 tonnes dry solids/year for ten years. In 2002, approximately 95 systems were in operation. Dimensioning and design of reed bed systems depends on the sludge production rate, sludge type, quality and regional climate.The maximum sludge loading rate is approximately 50–60 kg DS/m2/year. Loading cycles are related to the sludge type and the age of the sludge reed systems. The sludge residue will, after approximately ten years of operation, reach an approximate height of 1.2–1.5 metres with dry solids content of 30–40%. Experience has shown that the quality of the final product with respect to heavy metals, hazardous organic compounds and pathogen removal after ten years of treatment make it possible to recycle the biosolids to agriculture as an enhanced treated product.

Notes: A lab-scale acid treatment system was developed to Investigate the effects of hydrochloric acid on the removal of calcium from field spent GAC (FSGAC). The effects of acid treatment on the subsequent regeneration process and regenerated GAC properties were also investigated using a lab-scale furnace. A linear relationship between calcium remaining on the GAC following acid treatment and GAC mass losses during regeneration was exhibited. FSGAC treated with 0.1 N hydrochloric acid resulted in 7.5% lower mass losses than non-acid treated GAC. An increase in total surface area of 7.2% and micropore volume of 3.1% was also noted following acid treatment and regeneration. This was due to a reduction in calcium-catalysed gasification of the GAC structure, which may have occurred in samples, which had not received acid treatment. Improvements in porosity, adsorption capacity and surface chemistry indicate that acid treatment is an effective process, which may be used to provide superior regenerated GAC product.

Notes: The zebra mussel, Dreissena polymorpha, is a major biofouling pest of water treatment works, irrigation systems and power stations in Europe and North America. This paper documents current problems associated with zebra mussels in English waterworks. Questionnaires and manual surveys conducted between 2001 and 2003 have revealed that over 30 water treatment works in England suffer problems associated with zebra mussels. Hundreds of tonnes of mussels are being removed each year from raw water intakes, pipelines and reservoirs. Problems have increased in. the last five years, due to a spread in the range of zebra mussels around England and the cessation of chemical treatment at the intakes of many treatment facilities during the 1990s. The importance of taking control of zebra mussels into account in planning new water supply schemes is highlighted.

Notes: With the rapid expansion of development in Jordan, more water resources are being consumed and, consequently, incremental quantities of wastewater and sewage sludge are being generated from wastewater treatment plants. These quantities will end up in streams, open ponds or one of the other environmental media, which can cause adverse impacts on human health and the environment. In the mean while, a country like Jordan faces a remarkable shortage of fresh water resources and poor soil. The best way to mitigate the adverse impacts and compensate the water budget and enrich the poor soil is through the proper utilization and management of treated wastewater and sewage sludge in the agricultural sector. One of the main obstacles to this is public rejection of this solution, largely due to lack of information.The purpose of this paper was to examine the acceptability to the Jordanian farmers of the utilization of reclaimed wastewater and treated sewage sludge in their irrigation activities. The scope of this study considered two potential areas at the northern part of the country, where a representative sample of local farmers were interviewed. The results were very encouraging and positive signs of acceptability were shown at all levels. These results were analyzed and documented and the recommendations are developed at the end of this paper.

Notes: flooding occurred in many locations in the united kingdom in the autumn/winter of 2000. One of the worst affected areas was Robertsbridge, in East Sussex, where over that winter, some properties were flooded up to eight times following those events, the environment agency targeted defences for this high-risk township as one of its high priority projects to‘fast-track’to implementation.studies started in January 2001, which recommended a stand-alone scheme that would project the township against the 1% probability flood. Project development progressed on a‘fast-track’basis to allow construction to start in September 2002 with completion planned in the summary of 2003.project development and implementation is always an obstacle course but the‘fast-track’approach magnifies the obstacle and introduces new ones. This paper describes experience from the Robertsbridge flood allevation scheme, with particular reference to some of the problems encountered, both technical and procedural

Notes: The remarkable progress made in the 19th and early 20th centuries in improving the qualify of municipal drinking water supplies is undoubtedly one of the most important factors contributing to the improved health and life expectancy of the developed world. Most of the conventional unit treatment processes currently used for mass-producing potable water had their origin during these years. This paper identifies key milestones in the understanding and development of water treatment technology during the 19th and early 20th centuries and considers their lasting importance.

Notes: Increasing water shortage and water pollution issues have attracted people to seek an integrated water management approach. This paper presents an integrated water management model at the industrial park level by employing a case of TEDA. Such a model is an overall management model for optimizing water resources within an industrial park, seeking potential water reuse among industries, incorporating the size and cost of reclaimed wastewater delivery systems. The main focus of this paper is to test how pricing strategy can influence water reuse scenarios by doing a cost sensitivity analysis. The results Indicate that when being set at the correct level, increased water charges could help reduce freshwater use and wastewater discharge, while covering administrative costs, financing environmental improvements (e.g. cleaner production), or subsidizing the operation of the wastewater treatment plant and the maintenance of freshwater infrastructure, therefore, providing water reuse incentives for water users within an industrial park.

Notes: The Ouse Washes is an area of Hood washland in Cambridgeshire. The site has been designated as an SPA and SAC, due to the presence of Spined Loach in the Old Bedford River and River Deiph and the invaluable over wintering and nesting habitats it offers for various nationally and internationally important species of birds. The site is currently thought to be in an unfavourable ecological condition, in terms of both the nutrient concentrations and the vegetation communities that populate the site. These factors affect the favourability of the site for both the Spined Loach and the bird populations. To restore favourable conditions to the Washes, a target vegetation community was defined for each discrete area of the site. Each of these communities had an ecohydrological prescription derived, which defined the required annual regime for mid-Held water table depth, flooding depth and duration and ditch nutrient concentration.A catchment-wide rainfall-runoff and nutrient transport model was used to derive flows and nutrient loads across the Washes under a range of catchment management scenarios. The model results for each discrete area of the Washes were analysed and the ecohydrological favourability under the different scenarios could then be quantified. By running various scenarios of different artificial influence and diffuse pollution conditions, the possible water and nutrient regime within the Washes was investigated and the suitability of different management options quantified relative to the target ecological requirements of the site. This allowed the Environment Agency to complete an Appropriate Assessment of the site, as required under the EU Habitats Directive.

Notes: 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

Notes: Development minister, Hilary Benn spoke at the Wilton Park conference on ‘Environment, Development and Sustainable Peace’ on 16–19 September 2004. His presentation follows.At the same conference, the head of the UN Environment Programme, Klaus Toepfer both described the programme’s work and launched a new UNEP report, ‘Understanding Environment, Conflict and Cooperation’ co-authored by many of the speakers at the conference. The UNEP report is available at

Notes: Book Review in this ArticlesSafe Drinking Water: Lessons from Recent Outbreaks in Affluent Nations, by S. E. Hrudey and E. J. Hrudey.Water Resources Management, by David Stephenson. Published by Balkema.Water, Sanitary and Waste Services for Buildings, by A. F. E. Wide and J. A. Swaffield.

Notes: Incineration has suffered from a sustained campaign of misinformation. Consequently it has been regarded as the least sustainable option for the treatment of wastes, including sewage sludge. By looking carefully at the issues surrounding the incineration of sewage sludge, as an example, it can be seen that reality does not support the commonly held view. Modern plants are an effective means of recovering the energy value of sludge and at the same time offer a continuous operation, which is independent of weather or land constraints.Of course incineration needs to be regulated and EU Directives and National Regulations set the emission standards. The technology is such that these standards can be met, and more than this, the systems are capable of upgrading as more stringent standards are imposed.Concerns over NOx, dioxins, metals and pathogens are highlighted. In addition the permitting process is discussed. None of these should present a barrier to the implementation of incineration projects. Indeed the paper goes further and demonstrates that there is likely to be an increasing role for incineration as landfill, recycling to agricultural land and other options become more restrictive.

Notes: This paper describes design and construction of two new sea outfalls discharging from Gullane Waste Water Treatment Works (WwTW) to Aberlady Bay, on the south side of the Forth estuary (Firth of Forth), 25km east of Edinburgh, Scotland. The outfalls were installed by float and lower, using the Flow-Lay® technique, believed to be a first for steel pipes. The paper also describes air transport, beach movement and soil liquefaction and their effect on pipe stability, material and profile.

Notes: 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.

Notes: Evaluation of drinking water quality for Jenln district in Palestine was carried out for the years 1997, 1998, and 1999, respectively. Only 53.1 %, 85.4% and 69.6% of the drinking water samples tested for free chlorine residual, total coliforms and faecal coliforms, respectively are within the limits of the Palestinian and International standards. The seasonal variation of bacteriological and chemical quality of drinking water was investigated. It was found out that the summer season has the best quality and the winter has the worst. There remains some ignorance in testing the drinking water in the villages and towns in Jenin district. Huge efforts are required to improve the drinking water quality in Jenin district, as well as other Palestinian districts, through public awareness, training of governmental Inspectors, in addition to a strict monitoring system for water quality.

Notes: Sustainable development and the Water Framework Directive demand stakeholder engagement and more specifically, public participation if they are to be successful. Indeed, signatories to the Aarhus Convention adopt a rights-based approach and guarantee rights of access to information, public participation in decision-making and access to Justice in environmental matters. This paper explores the justification and need to involve the public in the decision-making process. It discusses the issues involved, the approach and technologies that can support and facilitate the participation process and the benefits that can How from such involvement. It draws on practical experience gained from a long-term mapping and consultation project carried out for the Countryside Agency. Key points of interest and learning from the consultation process are discussed and recommendations are given for future public participation exercises.

Notes: A model was developed and tested to investigate the effects of various parameters on the processing costs of anaerobic digestion. The model was based on empirical data collected from full-scale plants which varied in size from 35,000 to 900,000 population equivalents. (Equivalent to loading rates of 0.5 to 2.7 kg VS/m3/d.) In spite of different operating regimes and conditions of the plants analysed, various relationships were discovered between: sludge quality and volatile solids destruction; sludge quality and biogas yield; and, effluent volatile solids and dewatering. Where correlations existed, these were used to make predictions on operating costs of the digestion and dewatering plant based on sensitivity analysis. The results of the model were used to make recommendations on how to optimise the operation of an anaerobic digestion plant.

Notes: The city of Aberdeen has a population of 265,000 people, which was previously served by a preliminary sewage treatment facility, Including screening and grit removal prior to discharge to the North Sea.The Nigg Waste Water Treatment Works (WwTW) was designed and built to treat the sewage from Aberdeen as part of a Private Finance Initiative (PFI) in order to achieve Urban Waste Water Treatment Directive (UWWTD) standards for BOD (25mg/l 95%ile) and COD (125mg/195%ile). A small footprint plant was required and involved lamella tube settlers for primary treatment followed by a Biological Aerated Flooded Filter (BAFF) plant for secondary treatment.The plant received loads above the design and chemical closing was applied to increase the capacity for treatment. Constant monitoring through the plant was put in place in order to optimise the performance. This paper gives details of the performance of the plant over the first year of operation.

Notes: Landfill liquor (leachate) is produced by complex microbial processes within a landfill site. The long retention period, typically in excess of many years, ensures that easily-biodegradable materials disappear rapidly, whereas intractable (hard) Chemical Oxygen Demand (COD) substances decay slowly. The resultant liquor is often difficult to treat biologically due to high concentrations of Ammoniacal N (amm.N) and low concentrations of nutrient Phosphorus (P) and Biochemical Oxygen Demand (BOD).The advanced treatment process adopted at the Stewartby landfill site has been based on extensive laboratory trials by WRG Ltd (formerly Shanks Ltd), with technical input from Birse Process Engineering Ltd. This has significantly reduced the risks involved in plant scale-up.The particular choice of treatment process reflects the stringent discharge consent and the wide variety of waste received at the site, in particular, the presence of hazardous waste producing a leachate which is especially difficult to treat.Treatment is based on the activated sludge process, assisted by Powdered Activated Carbon (PAC) dosing. The leachate is heated to improve oxidation of amm.N and the process stream also includes Dissolved Air Flotation (DAF) and Sand Filtration to remove suspended solids (SS) and P. Odour control is provided by a two-stage activated carbon unit.Results from the full-scale treatment plant have been excellent, averaging 70% COD removal and almost 100% amm.N removal and fully satisfying the sewer discharge consents imposed by Anglian Water and the Environment Agency.This paper describes the laboratory trials, process design and commissioning of the leachate treatment plant at the Stewartby landfill site.

Notes: An innovative technique has been used for flood estimation in a catchment study which was carried out for the Environment Agency. The River Don drains a large part of South Yorkshire. On its major tributaries (the Rivers Rother and Dearne), flow regulators and artificial washlands are used during extreme floods to delay and attenuate peak flows, allowing the peak on the Don to pass by first.The flood hydrology of the Don catchment is therefore unusual and cannot be adequately represented by conventional methods such as those in the Flood Estimation Handbook. Instead, a 1000 year series of hourly rainfall was generated using a stochastic rainfall model. This was converted to flow data using a set of probability distributed moisture rainfall-runoff models; therefore, inflows for a hydraulic model were created. This eliminated the need to make assumptions about a design flood event, leading to more robust flood estimates throughout the Don catchment. This approach could prove to be applicable to other UK or overseas studies, particularly on large or complex catchments, or in solving joint probability problems.

Notes: Rapid groundwater drawdown has become the biggest threat to social-economic sustainability in the Hebei Plain. To determine the cause of the groundwater decline and develop a practical plan for long-term groundwater use, water-table fluctuation data were collected over a period of 20 years. Adopting a simplified water balance model, the average infiltration coefficient of precipitation and specific yield in the Hebei Plain from 1985–1995 were simulated and the groundwater level decline by water-use sectors and crops was calculated. Analysis showed that agricultural water use was the main reason for groundwater drawdown. Winter wheat was the most water-consuming crop, causing a significant decline of the water table. It is suggested that planting strategies should be adjusted and water-saving agricultural practices be carried out, to achieve sustainable groundwater use in the Hebei Plain.

Notes: Published for World Water Day, 22 March 2005, WaterAid’s report ‘Getting to boiling point’ explores how the UK and other governments will fail to meet their water and sanitation promises to the world’s poor unless they improve their performance.Focusing on the financial waste and underinvestment which are currently trapping millions in poverty this report also gives national governments and the international community the routes forward which, if followed, could enable them to keep their promises to halve the proportion of people without safe water and sanitation by 2015 as set out in their Millennium Development Goals. With extensive data from 14 countries ‘Getting to boiling point’provides a baseline against which further progress on the world’s water and sanitation crisis can be measured. A summary of the report follows.

Notes: Groundwater is an important resource in the UK, with 45% of public water supplies in the Thames Water region derived from subterranean sources. In urban areas, groundwater has been affected by anthropogenic activities over a long period of time and from a multitude of sources. At present, groundwater quality is assessed using a range of chemical species to determine the extent of contamination. However, analysing a complex mixture of chemicals is time-consuming and expensive, whereas the use of an ecotoxicity test provides information on (a) the degree of pollution present in the groundwater and (b) the potential effect of that pollution. MicrotoxTM, EcloxTM and Daphnia magna microtests were used in conjunction with standard chemical protocols to assess the contamination of groundwaters from sites throughout the London Borough of Hounslow and nearby Heathrow Airport. Because of their precision, range of responses and ease of use, Daphnia magna and MicrotoxTM tests are the bioassays that appear to be most effective for assessing groundwater toxicity. However, neither test is ideal because it is also essential to monitor water hardness. EcloxTM does not appear to be suitable for use in groundwater-quality assessment in this area, because it is adversely affected by high total dissolved solids and electrical conductivity.

Notes: Effective implementation is crucial to the success of public policy. This paper focuses on the implementation of the EU Drinking Water Directive (80/778/EEC) in England and Wales and the Republic of Ireland. It demonstrates that the consumer can both positively and negatively affect implementation. It is concluded that, if water providers and regulators wish to improve their ability to shape and effectively implement water policy, they must engage with the consumer in a more informative and educational manner.

Notes: Results obtained from a linear programming ground-water management model are tested against those obtained using numerical and electrical analog ground-water models. The optimal distributions of pumping and head as predicted by the management model are verified.An improved optimal solution could be obtained by reformulating the management model using different constraints or a finer grid spacing.

Notes: DuPage County, one of the major counties of the Chicago metropolitan area, obtains all of its water supply from ground-water resources. In 1972, pumpage was 56.6 mgd, 18 percent more than the combined potential yield of shallow aquifers and the practical sustained yield of deep aquifers. Total pumpage from shallow aquifers almost equals the potential yield. In some areas, yields of shallow wells have declined drastically as a result of excessively heavy pumpage. Pumpage from deep aquifers is more than double the practical sustained yield. Demands for water are projected to increase more than 250 percent by the year 2020. Alternative methods of developing supplies to meet the anticipated demands include artificial recharge of shallow and/or deep aquifers, mining of deep aquifers, increased diversion of water from Lake Michigan, demineralizing Mt. Simon sandstone water, and importation of underdeveloped surface or ground-water resources in north central and northwestern Illinois. Increased coordination of development programs becomes of greater importance as locally available supplies lose the capability to meet growing demands.

Notes: The alluvial aquifer underlying and adjacent to the Mojave River near Barstow, California, has been subjected to degradation from percolation of industrial and municipal wastes for more than 60 years. Effluents discharged to the aquifer have contained high concentrations of both organic (detergents, oil and grease, phenols, humic compounds, and others) and inorganic (chromium, chloride, phosphates, and others) substances. The concentration of dissolved organic carbon (DOC), as determined by a wet combustion technique, has been shown to be a definitive parameter in identifying ground water affected by waste disposal. DOC concentrations ranged from 0.1 to 0.8 milligram per liter in the nondegraded ground water and exceeded 6 milligrams per liter in the ground water affected by the waste discharge.The general distribution of DOC in the degraded ground water has been defined both areally and vertically. The vertical distribution of DOC and other constituents indicates that two plumes of degraded water occur at different depths. A comparison of the areal distribution of DOC and detergents (as MBAS) suggests that some organic compounds may have been adsorbed by the aquifer sediments.

Notes: Analytical data for 161 sampling sites indicate orthophosphate concentrations in ground water ranging from 0 to 1.7 mg/1. Ground water in about 50 percent of the county contains concentrations of 0.1 mg/1 or greater. In two areas aggregating 115 square miles, orthophosphate concentrations exceed 0.5 mg/1. Principal sources of phosphate in ground water in Hall County include: indigenous soil phosphate, municipal sewage effluent, commercial fertilizer, and feedlot wastes.

Notes: In areas of crystalline and basaltic rocks in India dug wells of large diameter may offer the only opportunity to test for the hydrologic characteristics of the shallow aquifers. Analysis of aquifer tests in these wells is difficult, however, if the volume of water stored in the wells contributes significantly to their discharge during the tests. In most dug wells, the time rate and spatial distribution of drawdowns in the aquifer, and the rate of change of head in the dug well are not predictable by the Theis equation or its semilog modifications. High rates of pumping result in difficulties due to the insensitivity of head distributions to drawdowns in the well.A review of current methods of analysis of aquifer tests in large-diameter wells indicates that most have serious theoretical and practical deficiencies. It is concluded that the methods of Papadopulos and Cooper (1967) and Papadopulos (1967) are the best available approaches, providing measurements of well volume can be made with sufficient accuracy. A consideration of aquifer tests in fractured rocks suggests that these tests can probably best be handled by treating the aquifer as an anisotropic porous medium on a macroscopic scale and utilizing observation wells.

Notes: To aid in determining the direction of ground-water flow after the effluent from the Lake George Village sewage treatment plant is discharged onto natural delta sand beds, resistivity studies were made in the soil (sand) in the vicinity of the recharge beds. Ground water having high dissolved solids is identified as producing lower resistivity readings. The sewage effluent has a higher dissolved solids content than the existing ground water in the area. The path of the recharged sewage effluent, as identified by lower resistivity readings, appears to flow in a northerly direction from the sewage treatment plant along Gage Road toward West Brook. Due to interferences, the resistivity studies could not show whether the high conductivity ground water flows into or under West Brook.

Notes: Practically all of the toxic chemical land disposal sites now in operation are equipped with only minimal and generally ineffectual monitoring systems, which seldom are capable of detecting even excessive surface-water and ground-water pollution from such sites. From monitoring data normally obtained, it is practically impossible to quantitatively evaluate the total toxic chemical buildup in contiguous soil, plant, and water environments or the vertical and horizontal migration patterns of pollutants through underlying earth materials. Monitoring facilities and procedures described in this paper are designed to provide that data required to effectively evaluate all of these parameters. These evaluations in turn should be most helpful in selecting the safest possible sites for hazardous waste disposal, and in developing ways and means to design, operate, and monitor such facilities that will assure minimal danger to public health from this particular waste disposal practice in the future.

Notes: Aquifers may serve as storage reservoirs, as treatment mediums, as discharge conduits, or in some combination of the various uses. If an aquifer serves as a conduit, the Darcy equation gives an accurate and simple solution for discharge provided the conduit is uniform; if nonuniform, the accuracy may be very poor unless special care is taken.Differential equations based on Darcy's equation and the equation of continuity give the steady-flow discharge rate for confined aquifers in which the cross-sectional area and permeability vary from point to point. For the general case the derived discharge expression is theoretically exact, whereas, for specific cases an approximate form can be used depending on the boundary conditions. Integration of the approximate form for a given aquifer length yields simplified solutions for discharge where the variation in cross-sectional area and/or permeability with distance in the direction of flow can be described by some mathematical expression.

Notes: Contemporary use patterns of land and water resources create conflicts between natural and human environments. These conflicts are generally not discussed as part of a classical approach to geologic education. This paper addresses the need to increase non-earth science training simultaneous with traditional training. The benefits to be gained will be welcomed by both students and their potential employers. One approach to suggested interdisciplinary water-resource education is discussed.

Notes: Low-rate or irrigation-type systems for land application of sewage effluent or similar wastewater are often used in humid areas because they have a small impact on the underlying ground water. In arid areas, low-rate systems cannot be used to produce renovated water for ground-water recharge, because the renovated water will have a much higher salt content than the effluent. Renovated water of relatively low salt content can only be produced with high-rate systems. Such systems, which require permeable soil, can also be used in humid areas to reduce the land requirements. To minimize the impact of high-rate systems on ground-water quality, the system should be managed to remove as much of the pollutants (particularly nitrogen and phosphorus) as possible from the wastewater as it seeps through the soil, and to restrict the spread of renovated wastewater in the ground-water basin. Nitrogen removal can be maximized by stimulating denitrification in the soil. Certain soils can store large quantities of phosphate. The spread of renovated water in the ground water can be controlled by intercepting the flow of renovated water with wells or drains for reuse or discharge into surface water. Techniques for predicting the underground flow system are presented.

Notes: Bore hole sampling of loose saturated sands and gravels forms a very important part of water well investigations. The materials are often difficult to sample and the adoption of adequate equipment and techniques can sorely tax the ingenuity of the driller.In some situations, the standard exploration sampling procedures can provide satisfactory information, while in others, it is necessary to resort to more precise techniques.A great variety of samplers have been designed including types such as open drive, piston drive, jet and extension flap samplers. No single sampler can cover the very wide range of material conditions and operational requirements which may be met during the drilling of water wells.In extreme circumstances, particularly for uncemented or poorly cemented gravels, it may be found necessary to stabilize the strata prior to sampling.

Notes: When the Lake George sewage treatment plant was put into operation in 1939, it was described as a “complete treatment” plant. This was because the treated effluent is discharged onto natural delta sand seepage beds which are “at least 25 feet deep.”Studies were made to determine the removal efficiency in the sand beds of coliforms, BOD, chlorides, and the nitrogen and phosphorus compounds.It was found that when beds were dosed, they were no longer saturated with water at 15 feet. Ten feet of sand were found to remove coliforms by 99% and BOD by 96%. However, nitrates, phosphates, and chlorides remained in significant concentrations after filtration through 10 feet of sand. Phosphate removal in an infrequently used sand bed was greater than in a continuously used bed.

Notes: At the Savannah River Plant near Aiken, South Carolina, as at other locations where there are chemical separations plants for the processing of nuclear fuels, the high-level radioactive wastes are stored in concrete and steel tanks buried just beneath the surface of the ground. This waste is of such activity and longevity that it cannot be dispersed into the environment, but it must be contained for periods of time extending at least into hundreds and perhaps thousands of years. One concept for the terminal containment of this waste is to store it in excavated chambers within the bedrock, which is covered by about 1000 feet of Coastal Plain sediments at the plantsite. As part of the safety evaluation of this concept, the geology and hydrology of both the Coastal Plain sediments and the bedrock have been studied. However, intensive investigation of bedrock waste storage has now been deferred pending more detailed evaluation of alternative concepts of waste storage and management.In the studies completed, a buried Triassic basin that might have potential for waste storage was discovered beneath the southern third of the plantsite. Investigation into the characteristics of this basin was started in 1971. This was not an engineering or design study but was aimed at understanding the geohydrology of the Triassic basin to determine its compatibility with the safe storage of waste.Seismic surveys, gravity and magnetic surveys, and the drilling of several exploratory wells indicate that the Triassic basin is about 30 miles long, 6 or more miles wide, and perhaps 5300 feet thick. One well penetrated the Triassic border, a second was in the center of the basin, and a third investigated an inferred intrabasin fault. The rock is predominantly mudstone of very low permeability with a few lenses of poorly sorted gritty sand. The water yield of all the exploratory wells is extremely low, and water-transmitting fractures are virtually nonexistent.In two wells within the basin, heads above land surface have been measured that cannot be explained by connection with a recharge area. Ten possible explanations have been evaluated: aquifer head, fossil head, tectonic compression, rapid loading and compaction of sediments, water derived from igneous intrusions, infiltration of gas, precipitation of minerals, phase changes, temperature increase, and osmotic membrane phenomena. Systematic evaluation, particularly of the time for dissipation of an elevated head to the head of its surroundings, eliminates most of these explanations. Those that remain as possible explanations are: tectonic compression, temperature increase, and osmotic membrane phenomena. It is not known at present whether the high head is general over the entire basin or only in segments of it.

Notes: Many tube wells drilled for irrigation use fail prematurely because of poor well design, improper sized and placed gravel-pack material, and ineffective slotted-pipe screens. Well and gravel-pack design criteria and an improved slotted-pipe screen described in this paper offer promise of drastically reducing such failures. Properly designed tube wells equipped with this type of screen should have more than double the safe-yield and service-life capability of most irrigation tube wells now in use.In some countries large-diameter, low-capacity open wells always have been used to obtain irrigation water. Now, small-diameter, high-capacity tube wells are being constructed in the same aquifers. As extensive tube-well development occurs, the water table will drop, drying up many shallow open wells. In such instances, those who can afford the deeper, more expensive tube wells could gain almost exclusive use of the aquifer.Optimum development of surficial aquifers using both tube and open wells may have to be rigidly controlled to assure every farmer a fair share of available water. Such controls should be based on the potential safe yield capability of aquifers. A graphical procedure used in Illinois to obtain an estimate of this value for planning and initial development purposes is presented in this paper.

Notes: A mathematical model was developed and used to simulate the stream-aquifer system in the Arkansas River valley in southeastern Colorado, from Pueblo to the Colorado-Kansas State line. The model simulates the interrelations among ground water and surface water including reservoirs, losses, and transmountain diversions, utilizing various water-distribution rules. The model was used to analyze 24 water-management plans designed to reduce shortages in the irrigation supply. One management plan simulated salvage of water from phreatophyte evapotranspiration, different reservoir operation regulations, use of imported ground and surface water, a new reservoir, additional ground-water use, and application of excess streamflow. The resulting annual dependable supply was increased from 610,000 acre-feet to 870,000 acre-feet in relation to an annual demand of 1,100,000 acre-feet. The model can be used as a tool to analyze other water-management plans.

Notes: The technique for gridding of random data developed by Newton (1973) is useful in ground-water investigations. The method appears to have potential for both regional and local ground-water studies.The method as applied to the Wainwright area of Alberta shows that total dissolved solids content in glacial drift and at several depths in the bedrock is related to both the thickness and nature of the drift and to nature of the bedrock. Total dissolved solids in the ground water in areas of thick and coarse-grained drift are lower than in areas of thin and finer-grained drift. The dissolved solids content of the bedrock is lower where the bedrock is of nonmarine origin and where the overlying drift is thick. In areas where the bedrock is of marine origin and the glacial drift thin the total dissolved solids content of the ground water tends to rise.

Notes: The first three field reports were presented as part of a panel discussion entitled “Impact of Pollution Control Legislation on Ground-Water Management,” at the Ninth Biennial Conference on Ground Water, Francisco Torres Conference Center, Goleta, California, September 13-14, 1973.