U.S. Government Accountability Office. Web posted February 8, 2012.
Water is a significant byproduct associated with oil and gas exploration and production. This water, known as “produced water,” may contain a variety of contaminants. If produced water is not appropriately managed or treated, these contaminants may present a human health and environmental risk. GAO was asked to describe (1) what is known about the volume and quality of produced water from oil and gas production; (2) what practices are generally used to manage and treat produced water, and what factors are considered in the selection of each; (3) how produced water management is regulated at the federal level and in selected states; and (4) what federal research and development efforts have been undertaken during the last 10 years related to produced water.
http://gao.gov/assets/590/587522.pdf [PDF format, 56 pages].