Sewage Treatment Plant

There are a number of instances of duplication, with the same material being given in more than one chapter. In one place the reader is referred to Section 15 when apparently it should have been Section 14. Unfortunately NBS Handbook 69 (June, 1959) was not available as a reference source at the time the manuscript was prepared. No mention is made of examination for cataract as part of the medical control program.

For those who can afford it. this handbook should find its place alongside the familiar handbooks of chemistry and physics as a useful standard reference work.

This practical manual summarizes current practices in the design of sewage treatment plants and offers guidance in processes, equipment, layout. and anticipated
results of treatment. It contains the composite views of plant superintendents and consulting engineers but offers no approvals or disapprovals of various methods or mechanisms. Its value lies in the selected inclusion of processes which have been used in the sewage works field during the two decades, 1935-1955. The committees representing
the two technical societies offer the warning that omission of any newer methods or treatment does not indicate that they are not effective: the manual subjects were chosen by the practicing engineers who constituted the committee.

Twenty-one chapters cover the basic processes of sewage treatment. with references to industrial wastes limited to their effect on process loading and design criteria. Each chapter provides

interpretation of the purposes of the phase of treatment; and information on selection of types of units and auxiliary facilities, bases of design, experiences and results in actual plant installations. and references to technical literature. In addition to coverage of treatment processes, the manual contains a thorough discussion of sewage characteristics
and contributing populations and industries which affect design. Guidance is provided on general plant layout, design of pumping stations, and materials of construction. Safety provisions in design are stressed. This book will be a valuable addition to the library of every designer and supervisor of sewage works facilities.

Traditionally, statistics has been regarded as dealing with methods for the collection, analysis. and interpretation of data. Since World War II. Some mathematical statisticians have examined statistical methodology from a different point of view, that of its contribution to the making of decisions involving elements of uncertainty. This development. stimulated by two books-Von Neumann and Morgenstern's "Theory of Games and Economic Behavior" (1944). And Wald's "Statistical Decision Functions"
(1950)-has become one of the major areas of research in theoretical statistics. Roughly speaking. decision theory deals with problems in which one of a number of possible courses of action is to be chosen. The consequences of each action can be measured on some common scale, e.g.. in terms of monetary profit or loss or of utility. However, these consequences are known imperfectly because they depend on certain unknown characteristics of the situation.