Although most public health and environmental engineers are aware of the importance of microbial activity, many civil engineers do not appreciate the part microbiological process play in, for example, biodeterioration of concrete and other construction materials, alteration of soil and rock properties, clogging of boreholes, distribution and irrigation systems, and biofouling in embankment dams. There is a need for greater interaction between scientists and engineers in this respect. Recent advances in applied microbiology and biochemistry could usefully be extrapolated to fields of civil engineering. Indeed an understanding of microbiological activity in what is often thought of as purely physical and/or chemical processes and an awareness of what to look for is becoming increasingly important for civil engineers in their design of a variety of systems and structures. This book forms the Proceedings of the International Conference held at Cranfield Institute of Technology, UK, in September 1990.