Trinity River Basin Water Quality Management Plan: Evaluation of supplemental aeration for the Trinity River system.
The Trinity River System in the Dallas-Fort Worth area during low flow periods is completely dominated by secondary waste water effluents discharged from the major waste water treatment plants. The dissolved oxygen levels are suppressed severely during these periods and in many reaches of the River dissolved oxygen is non existent in the waterway. This situation presents a number of very serious problems including septic conditions, offensive odors, and the general creation of conditions detrimental to the aquatic communities existed along the River. This study defines the feasibility of using supplemental aeration as a viable alternative to correcting the problem of low dissolved oxygen levels. The study itself is divided into eight major chapters. Chapter I defines the nature of the dissolved oxygen problem and its causes. Chapter II explores the alternatives that are currently available for upgrading the dissolved oxygen levels in the system. The main discussion centers around alternate levels of advanced waste water treatment processes used in conjunction with a supplemental aeration system. The third chapter presents a critical review of those aeration systems which are capable of being used in a river or stream environment. Emphasis is placed on actual supplemental aeration studies and the results generated by a number of researchers. The fourth chapter deals with an analysis of dissolved water in the Trinity, the effects that various treatment methods will have on the system and an estimate of the required additional oxygen that must be supplied by a supplemental aeration system. In order to show that supplemental aeration is indeed a viable alternative, a case study applicable to the local conditions existing along the Trinity River System is developed in Chapter V. Chapters VI and VII analyze the results generated by the case study in terms of spacing, oxygen transfer site locations, site requirements, economics and operating period. Finally, a conclusion chapter, Chapter VIII, restates all those important conclusions developed in the previous chapters. The one important conclusion that has been developed by this study is the fact that supplemental aeration must be considered as a viable alternative for improving low dissolved oxygen levels in the Trinity River.