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Notes: The described methodology for the assessment of the reliable outputs of groundwater sources was developed during a recent contract for UK Water Industry Research. It is relatively simple and flexible so that it can be applied to the wide range of groundwater source types and aquifers encountered in the UK. It can be used for all water level conditions, including that of drought, and for various demand conditions. There are two approaches, one based upon operational data and the second upon the analysis and extrapolation of pumping test data. The operational approach has several options of increasing refinement – the choice of option depending on data availability and user requirements. The application of the methodology to real groundwater sources is described using three examples.

Notes: A Series of: comprehensive studies have been carried out to identify potential water abstraction sources to meet future demands throughout the Grampian area, in Scotland. In the Moray and Banff coastal areas a new supply is to be developed to meet future increases in demand which have been predicted to be about 9 MVd by the year 2001, increasing to about 18.5 Ml/d by the year 2011.Grampian Regional Council has engaged Sir M. MacDonald & Partners, consulting engineers, to examine various options within the area and the consultant has concluded that the development of the alluvial gravels on the west bank of the river Spey immediately upstream of Fochabers would provide the Council with the best solution.The paper describes the various investigations undertaken. The main conclusions and results of the studies are briefly outlined in the following paragraphs.The alluvium was shown to have good water-transmitting properties. The seismic refraction and borehole investigations confirmed the superficial deposits to be about 10 to 15 m. Test pumping of wells with associated piezometers proved the transmissivity values and storage coefficients of the aquifer and hence a suitable wellfield.The wellfield so identified extends some 2.8 km upstream on the west bank from the bridge across the river Spey at Fochabers, with an estimated reliable yield of 20 MVd. The water abstracted from the test wells was shown to be about 80 per cent river water which had been drawn into the aquifer. The contribution from the landward side could result in a reduction of the watertable affecting the yield of deep rooted crops (cereals and grass) over about one-half the area one year in three.Examination of the water drawn from the wells confirmed it to be low in colour, iron, and manganese. The results were consistent and were of drinking quality. The mechanism causing the dramatic change in the water from river to well was thoroughly explored and found to be a biological process so ensuring that water qualities would be sustained.In conclusion, the various studies undertaken have shown that a consistent high quality water can be produced from the alluvial gravels of the river Spey near Fochabers in sufficient quantity to meet the needs of the lower Moray and Banff coastal areas of Grampian Region to the year 2011.