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

This 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.     

Thames Water Utilities'Emergency Response to the Bishopsgate Bomb in April 1993

ABSTRACT The paper describes Thames Water Utilities'response to the Bishopsgate bomb which exploded in the City of London in April 1993. Particular emphasis is placed on the procedures and control measures which were adopted to manage the activities associated with severe damage to water mains and sewers. The need for exceptional health and safety measures, whilst working in a potentially extremely dangerous environment, are highlighted.
Technical aspects of the repair work are discussed including the coordination with other utilities and the difficulties experienced in locating the position of underground apparatus which was subjected to bomb damage.     

Environmental Dredging on the Birmingham Canals: Water Quality and Sediment Treatment

Sediments in sections of the central Birmingham canals are heavily contaminated with heavy metals and mineral oils. The sediments promote high levels of metals within the water column, which suppress the establishment of aquatic vegetation and fisheries. Sediment disturbance by boat traffic results in the release of mineral oils which cause unsightly surface oil sheens.
Studies into a variety of treatment methods indicated that removal and ex-situ treatment of the contaminated sediments would significantly improve water quality and result in environmental benefits.
Funding from Birmingham City Council and British Waterways enabled the award of a contract with a value of approximately £800000 and commencement in February 1993 for the removal and processing of about 24 000 m³ of sediments by soil washing prior to off-site disposal. The nature of the sediments and water are reviewed, and the results of the soils washings are discussed. The impact of the dredging operations on water quality was monitored during the works and generally observed to be localized. An environmental management plan is now being implemented and the objectives for this are discussed.     

A REVIEW OF THE DANGEROUS SUBSTANCES AND EXPLOSIVE ATMOSPHERE REGULATIONS IN RELATION TO THE WATER INDUSTRY

This Technical Note presents the impact on the UK water industry of the Dangerous Substances and Explosive Atmosphere Regulations which became law in December 2002. These regulations introduce (into UK legislation) the requirements of a number of European Union Directives, including the Chemical Agents Directive and ATEX Directives dealing with potentially explosive and hazardous situations. The impact of the Dangerous Substances and Explosive Atmosphere Regulations on thermal-drying installations is relatively clear. However, there are potentially greater and far-reaching implications for the UK water industry.     

Design and Construction Quality Assurance

The paper describes the development, introduction and operation of quality assurance, with specific application to the design and construction industry and the consequential benefits which can be derived from the adoption of formalized quality assurance supported by third-party certification.
The main objectives of formalized third-party quality-assurance certification are in respect of: (i) quality-management systems of firms who provide a service to the industry and who meet the requirements of BS 5750¹, EN 29000², ISO 9000³; and (ii) product conformity to firms who show compliance with a national or other approved specification and who operate a BS5750 quality-management system.     

A Senegal Village Water Supply Project

T his P roject D escribes a rural water supply project in Senegal, West Africa, carried out in phases by Balfours, during the period 1983-88.
The first phase was a study, followed by detailed survey, construction works and borehole drilling.
The scheme was financed by a $6 million grant from the Overseas Development Administration (ODA). British equipment such as the vehicles, pumps, elevated sectional steel water towers, pipes and fittings, were purchased and shipped to Senegal by the Crown Aents.
Balfours designed, specified, and supervised the construction of water supply systems in 18 villages in Senegal comprising deep boreholes, pumping plant, elevated sectional steel water towers, and limited piped distribution systems. In order to ensure a full understanding of the project by the people it was to serve, and because major international contractors were unwilling to bid for a project which was scattered across a large area of Senegal, the work was carried out by direct labour, much of which was recruited in the villages in which the works were located. About 85000 people and 250000 cattle and sheep were provided with safe, reliable supplies of clean drinking water, as a result of the project.     

The Blashford Lakes Water Supply Scheme

Wessex Water has developed a new 35 Ml/d water supply source, using lakes formed from worked-out gravel pits, to meet increasing demands for water and to provide security for existing supplies.
Having identified the need for the scheme, an engineering feasibility study was carried out in conjunction with a full environmental assessment. This led to the successful promotion of the Stage I scheme in 1986. Design and construction took place immediately after, and the scheme was officially opened in 1989.
There are opportunities to expand the scheme as more lakes are formed by gravel working, and proposals for this are well advanced. This paper describes all the key elements in the promotion and development of the scheme.     

A Standardized Low-Cost Low-Flow Gauging Station

This paper describes the origins and development of a simple, low-cost, low-flow stream gauging station to meet the operational requirements of a major water resource management system. The utilitarian design uses standardized, prefabricated components in order to achieve maximum economy and ease of construction without sacrificing durability or hydrometric accuracy.     

Development of Biological Aerated Filters: A Review

Biological aerated filters are wastewater-treatment systems which contain support media for the development of a biofilm and provide oxygen at the base of the reactor for aerobic microbial processes. The origins of this type of filter date back to the early 1900s, and modern designs can provide a high level of treatment in small reactor 'footprints'.
This paper provides a review of the technology and development of biological aerated filters and submerged aerated filter systems.     

Performance of Fabric-Protected Slow Sand Filters Treating a Lowland Surface Water

The performance of slow sand nitration can be; substantially improved by the application of a non-woven synthetic fabric layer to the surface of the sand. By means of pilot-scale experiments, using the i River Thames as the source water and pretreatment by sludge blanket clarifiers, the comparative performance of fabric-protected slow sand filters has been evaluated over an eight-month period. Under conditions designed to simulate poorly-controlled pretreatment, a correctly-specified fabric type, configuration and thickness can extend filter run times by a factor of 3–5 compared to a conventional slow sand filter. Furthermore, this can be achieved, together with the avoidance of any significant change in the hydraulic behaviour of the underlying sand, thereby avoiding the need to remove and clean sand. Fabric washing is relatively simple and efficient.