Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Civil Engineering

First Advisor

James N. Dornbush


The planning and design of an engineering project can be viewed as a series of decisions. It follows , therefore , that a project is well engineered when good decisions are made in an efficient manner. This investigation seeks to examine engineering decision making for the general purpose of providing insights which may improve the engineering decision-making process. The study centers around a project constructed under the Clean Water Grant Program in California. There are two reasons for this 1) the Clean Water Grant Program is presently (1979) the largest public works program in the United States and is therefore, significant to the field o f civil engineering in general, and 2) the author has worked in the program for several years. Despite the choice of a Clean Water Grant project, the investigation is, in most respects, illustrative of engineering decision -making in general and applicable to other types of projects. The first part of the investigation is an overview of engineering decision-making . Utilizing the literature, as well as examples from other Clean Water Grant projects, various bases on which decisions are made are explored considering also, some psycho logical aspects and philosophical implications of engineering decision-making. Also, some special too ls and approaches current in the engineering field are discussed. The second part investigates, in detail, the planning and design of wastewater facilities for the City of Taft, California. Its purposes area 1) to survey all decisions made in ·the planning and design of the project; and 2) to identify and discuss the basis of the decisions. The Taft project was selected for study for several reasons: 1) the limited scope of its design allowed the design decisions to be identified without becoming unwieldy; 2) it is typical of Clean Water Grant projects in many respects; 3) the planning and design were exceptionally well done; and 4) there were interesting and uncommon features to the project, especially in the planning phase. In addition, the project engineer was willing to discuss candidly the basis of the decisions in this project. This is in contrast with engineers on other projects, who, when approached by the author, were very reticent to discuss the true basis of their decisions. Finally, the author's direct involvement in the project, by way of his duties working for the State Water Resources Control Board, greatly facilitated the investigation .

Library of Congress Subject Headings

Engineering -- Decision-making Sewage disposal plants -- California



Number of Pages



South Dakota State University