Includes bibliographical references (page 219).

Flooding and combined sewer overflow problem in urban metro areas / Vinton W. Bacon -- Metropolitan sanitary district of greater Chicago experiences and future plans for hard rock tunnels / Forrest Neil -- Role of storage in economics of sewage treatment plant design / William J. Bauer -- Impact of the deep tunnel plan on water resources in the Chicago area / Victor Koelzer -- Potential of pumped storage for hydro-electric generation in multi-level deep tunnel systems / Kenneth E. Sorenson -- European development and experience with mechanical moles in hard rock tunneling / Pieter Barendsen -- European development and experience with mechanical moles in hard rock tunneling / Ernst Weber -- Experience in Edmonton Canada with emphasis on pneumatic conveyance of muck / C.G. Chrysanthou -- Geologic exploration for Chicago land and other deep rock tunnels to be constructed by mechanical moles / George E. Heim, R.W. Mossman, Homer Lawrence -- Contractors viewpoint of the hard rock mechanical mole -- what's causing downtime? what do they want? / Victor L. Stevens -- Rapid excavation in hard rock: a state-of-the-art report / William E. Bruce, Roger Morrell. A symposia was held to discuss tunneling in hard rock, deep below ground surfaces. The goals were to: describe tunneling experiences in Chicago, western United States, Canada, and Europe; discuss some of the multiple-use aspects of deep tunnels; assess the future of rapid excavation in hard rock using mining machines; and encourage those facing combined sewer and flooding problems to assess the potential use of tunnels. The flooding and combined-sewer overflow problem is discussed, as are the investigations and plans of the Metropolitan Sanitary District of Greater Chicago for constructing a deep tunnel system to alleviate flooding and pollution from combined-sewer overflows. The potential of pumped-storage hydroelectric power generation and circulation of condenser water from underground nuclear generating plants, in conjunction with tunnel construction, is treated. Experiences with mechanical moles in the United States and other countries in boring through hard rock are described. Suggestions are given concerning pre-construction investigations, planning and design that can minimize field problems, expedite tunneling procedures, and reduce tunneling costs. Various viewpoints are presented.