Local Watercourses Research Articles

How can stakeholder participation improve European watershed management: the Water Framework Directive, watercourse groups and Swedish contributions to Baltic Sea eutrophication

Nutrient losses from agricultural land constitute an important part of the total flow of nutrients to lakes and seas in Sweden and the Baltic region. With the Water Framework Directive, to be implemented shortly throughout Europe, emphasis is increasing on the role of stakeholder participation and decentralisation of various responsibilities from authorities to groups in the civil society. This paper investigates a Swedish case where local watercourse groups (WCGs) have formed in order to be involved more actively in the efforts to reduce nutrient losses from agricultural lands. This paper presents a qualitative analysis of the institutional landscape surrounding WCGs, goals, goal formulation and space of action.

Soil salinisation: a local life cycle assessment impact category

Salinity is an increasing environmental problem in agricultural ecosystems and is not adequately represented in conventional life cycle assessment (LCA) impact categories. It is often not the total quantity of salts emitted or the proportion of salt accumulated in the soil profile that is the primary mechanism for deteriorating soil conditions for irrigated salinity, rather the ratio of major cations in the soil matrix and the potential for colloid dispersion and reduced permeability. A soil salinisation potential (SP) is proposed as an indicator for irrigated salinity and potential soil degradation from poor irrigation practices. The indicator uses the threshold electrolyte concentration concept that predicts the adjusted sodium adsorption ratio (SAR)/ Electrical conductivity (EC) ratio that soil will no longer flocculate, but potentially disperse. The SAR is converted to a threshold EC and compared to the measured EC in order to develop a site-specific irrigation equivalence factor (EF). This site/region/process specific EF is then used to weight the sodium load to soil and repeated for each stage throughout the entire life cycle to determine the overall Salinisation Potential (SP). The data required for calculating the SP is generally readily available either on site or from the water chemistry of the local watercourses. Preliminary calculations simply require the volume, pH, electrical conductivity (EC), alkalinity and the concentrations of Na, Ca, and Mg of the irrigation water. The site/process/region specific nature of the indicator ensures a quantitative measure to enable comparisons between different systems and is useful for identifying stages in the life cycle of a product (particularly food products), where the potential for soil salinisation and soil degradation is most severe.

Optimal Combination of Flocculating Filtration and Ultra Filtration for Advanced Effluent Treatment in the Netherlands

With changing policies to solve local environmental and dehydration problems and with increasing interest in differentiation of water qualities by industrial and domestic users, a growing need exists to improve the effluent quality of wastewater treatment plants (wwtp) in the Netherlands. The change of policy to retain water in its original environment as much as possible leads to an increasing interest in discharging wwtp effluent into polders and local water courses instead of large surface waters. Besides, a new element is the interest in the production of household and industry water by the Dutch drinking water companies. At several Dutch wwtp's research on (the combination of) fluocculating filtration and ultra filtration is done to develop the possibilities of (re)using effluent in the Netherlands. The results of the research have shown that flocculating filtration and/or ultra filtration are technically and economically applicable for the production of household and industry water.

Optimal combination of flocculating filtration and ultra filtration for advanced effluent treatment in The Netherlands

With changing policies to solve local environmental and dehydration problems and with increasing interest in differentiation of water qualities by industrial and domestic users, a growing need exists to improve the effluent quality of wastewater treatment plants (wwtp) in the Netherlands. The change of policy to retain water in its original environment as much as possible leads to an increasing interest in discharging wwtp effluent into polders and local water courses instead of large surface waters. Besides, a new element is the interest in the production of household and industry water by the Dutch drinking water companies.At several Dutch wwtp's research on (the combination of) flocculating filtration and ultra filtration is done to develop the possibilities of (re)using effluent in the Netherlands. The results of the research have shown that flocculating filtration and/or ultra filtration are technically and economically applicable for the production of household and industry water.

Reconstruction of discharges and environmental doses from a former tritium facility at BNFL Capenhurst

The Capenhurst site was established in the early 1950s to enrich uranium, initially for defence purposes. A tritium facility was also operated from 1965 to 1987. When operations ceased the tritium plant was kept under care and maintenance until 1993, since when decommissioning and dismantling of the plant have been undertaken. This is now in its final stages. The operation of this plant has been subject to security classification. Its existence has now been declassified, allowing BNFL to publish information on radioactive discharges. The existence of the plant was made known to the Capenhurst District Liaison Committee in May 1997. An extensive review of original documents has been undertaken, from first commissioning of the plant in 1963, and full operation in 1965, to current discharges arising from decommissioning. While the documents still contain classified information, a full summary is presented here of those records relating to discharges from this facility. Doses to members of the public have been reconstructed. Peak estimated annual doses from routine atmospheric discharges were around 25 - 30 to infants in 1973 - 76 and again in 1985. These coincide with higher releases of tritium as tritiated water. More generally, early doses were around 10 - 15 to all age classes, declining to 1 or 2 over recent years. A number of short-term releases also occurred, primarily in the mid to late 1960s. Specific dose estimates for these events are made. Including routine releases, the maximum annual dose, which occurred in 1966, may have been up to to an infant or to an adult. The next highest annual dose, combining short-term and routine releases, was to an infant or to an adult. The dose limit throughout most of this period was . Recently, a limit of 1000 has applied. For comparison, the average annual dose to the UK population from natural radioactivity is about 2200 . Maximum collective doses from atmospheric releases occurred in the period 1965 - 76, with a projected UK exposure of around 3 to 4 manSv for each year of operation. The total projected collective dose from all aerial releases, 1963 - 96, is 40 manSv to the UK and 51 manSv to the world. Because of the relatively short half-life of tritium, most of this dose is delivered in the first 50 years or so. For comparison, the collective dose to the UK population from natural sources of radioactivity is 130 000 manSv per year, and to the world is 13 000 000 manSv. Liquid discharges of tritium resulted in much lower doses. At the limit of detection applicable throughout the 1960s and 1970s a dose of could apply to children playing in a local watercourse. At the lower limits of detection applicable from 1979, the estimated dose reduces by a factor of 10 to 100. The UK collective dose exposure from liquid discharges, 1963 - 96, is about . The corresponding world dose is 0.035 manSv. These are considered to be negligible.

LEEDS/BRADFORD AIRPORT: DISPOSAL OF AIRCRAFT DE-ICER FROM PARKING APRON.

Keywords LEEDS BRADFORD AIRPORT AIRPORTS, DISPOSAL, AIRCRAFT, DEICER, PARKING, APRONS, DRAINAGE, DISCHARGES, CHEMICALS, SURFACE, WATER, SYSTEMS, DRAINS, POLLUTION, CONTROL, DEICING, WATERCOURSES, FLOW, INSTRUMENTS, INSTRUMENTATION, SPECTROPHOTOMETERS LEEDS, BRADFORD, ENGLAND UK... Show All

Flood Frequency and Impacts at Khartoum since the Early Nineteenth Century

The nature and history of flooding problems at Khartoum since the early nineteenth century are examined using archival flow and river height records and historical documentary sources, putting the 1988 floods into historical perspective. Three genetically distinct types of flooding are identified: Nile floods; flooding of local ephemeral watercourses; and flooding of streets and houses by urban run off. The magnitude and frequency of Blue Nile floods has declined with the recent reduction in rainfall over Ethiopia. The 1988 Nile floods were minor in comparison to the 1946 flood and several in the late nineteenth century, when flooding was particularly frequent and severe. The 1988 floods mainly comprised overflows of local watercourses and widespread street flooding, both as a result of an exceptional 200-millimetre rainstorm over the Khartoum area. A recent decline in frequency of large rainstorms has been offset by a greater susceptibility to floods as a result of increased human occupation of flood-prone sites, inadequate urban drainage and increased run off coefficients. If the present dry conditions in the Sahel were to be replaced by the wetter climate of the late nineteenth century, Khartoum would face severe flooding problems.

Protecting Water Resources from the Effects of Landfill Sites: Foxhall Landfill Site

AbstractThis paper describes the work carried out to protect both ground and surface waters close to the Suffolk County Council Foxhall landfill sites. Monitoring of groundwater showed that a deterioration was occurring, likely to impact adversely on water quality in the adjacent stream. The National Rivers Authority expressed their concern, and measures have been introduced to eliminate this pollution risk. Contaminated groundwaters flowing towards a local watercourse are intercepted by a ‘Trammel’type geotextile cut‐off drain and flow to a central collection sump. Automatic monitoring of contaminant levels at this point controls the treatment and disposal options. Where quality is unacceptable for discharge to the local watercourse, the intercepted groundwaters are treated by irrigation onto the capped surface of a restored landfill. If quality remains unacceptable for discharge, further irrigation treatment or discharge to a percolation area utilizing aquifer attenuation properties is possible.

On‐Site Treatment of Leachates from Landfilled Wastes

ABSTRACTThe large accumulations of putrescible materials which comprise a modern landfill have potential to generate quantities of highly‐polluting leachate as they decompose anaerobically over many years. Operators must control and manage such leachates if severe environmental impacts are to be avoided.Progress has been made in the development of simple, automatic, robust and reliable treatment systems as full‐scale plants have been installed at UK landfills during the last decade, with the assistance of Department of the Environment funding to allow detailed monitoring of particular schemes.This paper describes the results from a site where such a plant was installed in 1985 to overcome a particularly difficult leachate problem, where high ammonia concentrations had posed a threat to local watercourses. More than two and a half years' results of detailed operational data are presented, and particular emphasis is given to the reduction of ammonia concentrations to low values.

EYE‐SORE: A Sewerage Agency Summary of Rehabilitation Experience

SYNOPSISPublic awareness of the importance of the sewerage network is inevitably highlighted when the system suffers malfunction. Associated with surface collapse or increased pollution to a local watercourse the effects are more widely felt, whilst even programmed work is not without significant environmental impact. With its history of deteriorating and failed sewers, the rehabilitation work already implemented and the introduction of a strategic sewerage policy, the paper outlines aspects of the City of Manchester's experience and effort to eradicate the consequential scars of its heritage whilst also looking to the future.