In 1938, the Board of Supervisors of Prince William County, Virginia, appropriated sufficient money to the State Department of Health to provide the county with a full-time health service. This department included the services of a medical health officer, a public health nurse, and a public health engineer. Inasmuch as the inclusion of the services of a graduate engineer in rural health departments in the State was a recent innovation, supplanting that of the field-trained sanitarian, the standardized sanitation program was insufficient. Very shortly, however, it was observed that the improvement of school sanitation would, in addition to the public health value discussed later, involve sufficient engineering problems to show the advantages to be gained by the new resident engineering service. A comprehensive program of this kind would also involve problems of economics and politics, which could be surmounted only by careful technical design and judicious application of the funds available. There is little doubt that the ultimate possibilities have not been revealed, but the completion of the program serves to disclose some of those possibilities. The degree of perfection attained in this specific program may be determined by the reader; but for the purpose of this thesis, it is of little moment, since the conclusions drawn are justified by the facts. A review of literature preceding the main portion of the thesis includes sections on soil and ground-water pollution, water supply, and sewage disposal. Descriptions of the county, the school system, and the health department follow, in an effort to present the implements or factors contributing to the performance of the program. In reviewing the program each project is described and discussed separately so that technical points may best be considered. A report of the conditions existing before the beginning of the work is included, as well as a review and discussion of the results. Suitable conclusions of an economic, political, and technical nature are noted, and the plans and specifications of one project are appended. / Master of Science