The Reliability of Groundwater Sources to Meet Increasing Demands

The groundwater resources of the Lee Valley Water Company have been examined in a joint study with the University of Birmingham. The Company is modifying its operating policy to make maximum use of the groundwater resources, which has involved the development of new methods of estimating the reliable output of the groundwater sources under differing conditions. The technology transfer involved in the project has enabled the Company to gain a greater understanding of the operation of its sources, and the University has modified existing techniques so that they are of greater practical use.     

Instrumentation, Control and Automation: the Grampian Way

The paper describes the experiences of Grampian Regional Council's Department of Water Services in designing, testing, and installing a regional telemetry system, together with the philosophy behind some of the decisions. The paper also describes the hardware involved and some of its capabilities.     

Laboratory Investigation into the Performance of an In-Sewer Vortex Flow Regulator

Aspects of the hydraulic performance of an in-sewer vortex regulator have been studied. These devices are increasingly used in stormwater management schemes, but their characteristics under a variety of prototypical situations have not been widely disseminated. The study used a full-size laboratory mockup of a section of sewer and associated manhole with facilities for measuring discharges of up to 60 1/s. The performance of a typical vortex flow regulator was investigated under both steady and unsteady flow conditions. The steady head-discharge relationship revealed the expected 'kick back'region (during rising head); however, this was less pronounced during falling head. Under unsteady conditions, vortex initiation was affected and a hysteresis effect was noted. The influence of downstream surcharge was significant at lower upstream heads. Theoretical comparison showed that to obtain equivalent performance, an orifice of 62% of the diameter of the vortex regulator would be required, and 25% savings in storage could be made.     

Digital Mapping for Watermains in Torbay

T he development of a digital mapping and database system for water supply and distribution is described. The procedures adopted in producing the User Requirement Specification and preparing the existing records for conversion to digital form are outlined, and the manual digitization methods used for data conversion are detailed.     

Water Quality of the North Sea: Concerns and Control Measures

The quality of the North Sea has become a topic high on the political agenda. Various claims have been made about quality deterioration but hard evidence has been less available. The paper reviews these concerns, summarizes the scientific evidence and considers the specific contaminants involved, together with estimates of inputs and the available controls. The new initiatives stemming from the Ministerial conferences and the evolving legislation should go a long way towards producing reassurance on the one hand and solutions to real problems on the other.     

The Disposal of Spoil from the Channel Tunnel Development

T his paper describes the nature of the spoil from the tunnelling activities, the plant requirements for its handling, and the investigation into possible disposal locations carried out in 1986 with a view to minimizing environmental impact. It further describes some of the steps currently being taken to minimize environmental impact at Shakespeare Cliff.     

A Methodology for Monitoring the Performance of Combined Sewer Overflows

The authors have been involved with the field monitoring of combined sewer overflows and screens over a number of years. During this period they have developed a monitoring methodology which ensures reliability, consistency and accuracy of results. The paper recommends appropriate equipment to be used for monitoring the qualitative and quantitative performance of combined sewer overflows and gives recommendations on location and installation thereof. Particular reference is made to methods for cross-correlating data amongst monitors and for proper interpretation of the results. The recommended methods have been proven in the field on a variety of working project.     

Ozone and the Formation of Bromate in Water Treatment

The ozonation of water is widely used within the drinking-water industry. The improvement of the performance of the Barcombe water-treatment works is envisaged. An ozonation stage and granular activated carbon filtration are being considered as an addition to the existing plant. As part of the investigation work, the influence of ozone on bromate formation was studied using a 3 m³/h pilot plant. The bromate production was found to depend upon (a) the applied ozone dose, (b) the contact period, and (c) the pH.
Using ozone in an appropriate way will be of benefit to the treatment process as well as meeting the new World Health Organization health guidelines for drinking water.     

Locating Outfalls on Meandering Channels to Optimise Transverse Mixing

Many sources of river pollution approximate steady-state conditions and, under such conditions, the rate of transverse mixing is critical in determining the impact of pollutants. Results are presented from transverse-mixing experiments which were carried out on a large-scale laboratory channel with meander planform geometry of natural cross-section, generated by flow over a mobile bed. Dye-tracer measurements below three point sources within one cross-section are presented and compared, together with hydrodynamic measurements. The results show the importance of locating outfalls to maximise mixing rates, hence minimising pollution impact (depending on the environmental need). A release on the outside of a bend is shown to result in a faster rate of transverse mixing than a release on the inside of a bend.     

WATER, SEWERAGE AND DRAINAGE INFRASTRUCTURE FOR PALESTINIAN REFUGEE CAMPS IN LEBANON

Many of the Palestinian refugee camps in Lebanon were originally established as tented encampments during the period 1948–1955. Half a century later, with high population densities and limited vehicular access, they remain largely separate from adjacent Lebanese communities, with infrastructure and welfare services mainly provided by the United Nations. Water supply, sewerage and stormwater-drainage systems have been developed on a piecemeal basis, are frequently in poor condition, and are inadequate to cops with expanding populations. A project for the design of new systems was commissioned to serve a total population of about 250 000 by the year 2020. The new facilities have had to take account of complex networks of narrow pedestrian alleyways that characterise many of the camps.
This paper provides an insight into (a) working within established refugee camps and other economically poor and densely populated communities, and (b) the problems which were experienced in developing feasible solutions for the improvement of infrastructure.