Risk Analysis of Aquifer Contamination by Brine

Abstract

Underground disposal of liquid wastes poses a danger of groundwater contamination. The prediction of their impacts is subject to many uncertainties. This paper develops and applies a risk analysis model that addresses several of these uncertainties. The model inputs are hydrogeologic parameters, the reliability of waste disposal, and demographic information. The outputs of the model are probability distributions of the number of rural home wells or municipal groundwater well fields that may be contaminated. Contamination is defined as occurring when the concentration for any disposed chemical exceeds its water quality standard. The model is used to analyze the risks posed by annular disposal of oil and gas brines in Ohio. It is found that the economic costs associated with those risks are an order of magnitude smaller than the benefits of the practice.