Groundwater Rebound in the Leicestershire Coalfield

The Leicestershire coalfield has been mined for at least eight hundred years, the last deep mine closing in 1991. The earliest shallow mines on the exposed coalfield are not recorded on plan, but were later connected to the deeper workings in many seams. In order to protect the last deep mines, pumping was maintained from the abandoned mines to the north.
Water-table rebound was observed prior to closure, and is now affecting the surface. Increased emissions of poor-quality water into low-discharge surface water-courses are predicted. Renewed subsidence has implications for roads, services and property. Rising water levels will affect old opencast excavations and waste disposal sites.
Fieldwork and abandoned mine plan inspections have demonstrated renewed subsidence and evidence of increased emissions in those low-lying areas of the exposed coalfield which are believed to be most at risk.     

Development of a Friability Test for Granular Filter Media

ABSTRACT At present there is no generally accepted test available for characterizing the friability of granular filter media in the context of its ability to withstand handling and placing, as distinct from abrasion resistance during backwashing – which is the subject of other, existing, test methods. Most existing procedures tend to be grinding tests and have little meaning. The approach selected in this work was to adapt the ring shear test, in which a sample (large enough to be analysed by sieving) is subjected to shear under a known compression load and the change in the undersize fraction is assessed. A representative selection of dry media was submitted to the test and the results proved to be reproducible and capable of distinguishing (clearly) between friable and non-friable resistant types. The procedure is likely to become the basis of a standard test.     

Semi-reflecting roller blinds for windows: a performance simulation using real weather data for locations in England,Denmark and Switzerland

This paper assesses the performance, under European weather conditions, of windows fitted with semi-reflecting roller-blinds. The heat balance of a 1 m² window is calculated, using real hourly weather data, for windows facing North, South. East and West in three widely separated locations. Five types of window are considered: single. double and triple glazed, roller-blind permanently down and “managed” roller-blind.

By summing the net heat losses and gains over the local heating seasons. the total losses or gains are obtained for all cases. An attempt is also made to evaluate the summer overheating problem in each case. The managed roller-blind is found to have a performance comparable to that of triple glazing in the heating season and to give substantial reductions in overheating in summer. Maximum acceptable prices for the roller-blinds are estimated from the calculated energy savings and pay-back times assumed for domestic and commercial users.     

Land Disposal Practices in Europe and North America

This paper compares the land-based disposal of municipal and hazardous waste in Europe and North America, and the various disposal options are examined for each type of waste. It is concluded that landfill is still the most widely practised disposal method for most wastes in both continents. Other methods include composting, land farming, trenching/spraying, and deep underground disposal. More stringent controls on waste disposal are being introduced and a trend to seek greater uniformity of practice and standards is developing. However, local conditions, such as the nature of the wastes and the availability and nature of disposal sites, continue to work against this trend. There is no single method which is suitable for all wastes and for all conditions. The best environmental option for waste management will vary from place to place and waste to waste, therefore an imposed uniformity of practice is not in the best environmental interest.     

The Control and Monitoring of Discharges by Biological Techniques

Traditionally, the control of discharges to UK surface waters has been achieved using a chemical-specific approach. There are, however, benefits in also applying toxicity-based consents to effluents of complex composition.
This paper describes the approach to direct toxicity assessment of discharges being developed by the Water Research Centre for and with, the National Rivers Authority.