Colliery Spoil Reclamation: An Appraisal of Two Sites in West Lothian

The work of this thesis is concerned with the effectiveness of the reclamation of two former colliery sites in West Lothian. Criteria for assessment were, the ability of the reclamation schemes to control pollution arising from the spoil material and the success of the spoil as a growth medium. The reclamation site at Foulshiels, on the periphery of the village of Stoneyburn, was also assessed with respect to the social benefits of the reclamation project, particularly in relation to visual benefit and amenity use. The environmental, social and economic importance of derelict and contaminated land are discussed in Chapter One. The problems of defining contaminated land are reviewed. Derelict and contaminated land arising from coal mining activities is discussed in relation to its particular physical and chemical characteristics. These characteristics can influence the potential of spoil as both a resource or a waste material. Possible solutions to the potential problems of colliery spoil are addressed in Chapter Two. Types of contaminated land treatment include physical, chemical and biological methods. Selection criteria for the different types of treatment are dependent on the concentrations of contaminants present, the proposed end use for the site and associated reclamation costs. Chapter Two concludes that, for colliery spoil heaps in rural areas, the most frequently chosen option for reclamation is to soft end use, where the site may provide amenity or recreational benefit in the area. Case study site histories are presented in Chapter Three. Foulshiels Colliery was reclaimed during the period 1972-1979. The proximity of the site to the village places emphasis on amenity value for the local community and this aspect was amongst the criteria taken into consideration in the reclamation design. Baads colliery, in comparison, is surrounded by farm land. The site was reclaimed in the mid 1970's. Spoil material at the site is high in iron pyrite (0.7-1.48% FeS2) which, on weathering, is responsible for acid production and acid mine discharge associated with spoil material. Assessment of the success of the spoil as a growth medium and pollution control were determined by laboratory and field studies. Chapters Four and Five review the suitability of the spoil as a growth medium with respect to pH and plant available copper, zinc, iron, manganese, calcium and magnesium. Comparison of analytical results with those obtained in 1976 indicate that ionic concentrations have declined with weathering and leaching, although the relationship between ionic concentrations and spoil pH has remained similar to those recorded during 1976. Analysis of water collected from Foulshiels Burn is also discussed in Chapter Four. The effect of reclamation on stream water quality was determined analytically by comparison of soluble aluminium, iron, manganese, lead, nickel, copper, zinc, cadmium and chromium content and pH with values obtained by previous workers prior to, and directly after reclamation. Although the stream is still contaminated by the site, results indicate that pollution has declined in association with improved site drainage. During the reclamation project a study was established to determine the effectiveness of different organic amendments on colliery spoil amelioration. Chicken manure, sewage sludge and Alginure, a commercial seaweed based amendment, were applied at different rates with varying applications of lime. The effectiveness of these treatments in ameliorating the problems associated with spoil as a growth medium are discussed in Chapter Five. Analysis of spoil from different trial plots shows that lime at the application rate at least of 50 t ha-1 is required for longterm counter-action of acidity, while organic amendments require regular application to be effective spoil conditioners. The social benefits of the reclamation at Foulshiels are considered in Chapter Six. A survey conducted in Stoneyburn indicated site user patterns and opinions to the suitability of the reclamation project. The site is regularly used by a cross section of the community for a variety of informal activities from walking to motorbike scrambling. Recommendations for the reclamation of former colliery sites to soft end uses and their subsequent management based on the findings of this work are given in Chapter Seven. Reclamation of colliery sites provide a valuable opportunity for wildlife habitat, natural history education, and informal recreation, while addressing the problems of environmental degradation arising from past mining activities