Injection of liquid wastes into subsurface strata is a concept in waste management which has found widespread use in industry only since 1960. This study is part of a nationwide effort by the U.S. Geological Survey to evaluate the environmental effects of subsurface waste injection. The specific objectives of this study were to: (1) Predict the reactions and interactions between certain organic wastes and aquifer components when organic wastes are placed in the subsurface environment and (2) define the effects that physical, chemical, and biological reactions have upon the distribution and movement of organic wastes in the subsurface.
In January 1971, the subsurface waste-injection system operated by Hercules Inc. near Wilmington, N.C., was selected for study. The site had several distinct advantages for this study: First, the industrial waste being injected into the subsurface contained high concentrations of several water-soluble organic com¬pounds which were liable to react and be transformed in the subsurface environment. Prior to this study, problems with an injection well pressure build-up after a period of waste injection indicated that the reactivity of the injected waste with the injection zone was an important aspect concerning the operation of this waste-injection system. Secondly, a network of 14 observation wells located at various distances from the injection wells, and drilled to different depths, enabled the monitoring of waste movement and the collection of waste samples in both horizontal and vertical directions from the points of waste injection. Third, the relatively shallow depth to the waste-injection zone (1,000 feet or 300 meters) facilitated chemical and microbiological experimentation under the simulated pressures of the injection zone without the use of very high pressure equipment. Last but not least, excellent cooperation and support was provided by the Company and various state and federal agencies.
By J.A. Leenheer, R.L. Malcolm, and W.R. White, 51 pages, 1976.