Regulating toxicity in drilling mud: An innovative approach using pollution prevention.

摘要

Both in terms of volume and toxic pollutants, drilling muds and drill cuttings are the most significant waste streams from exploratory and development activities in the oil and gas industry. Under the Clean Water Act, the US Environmental Protection Agency (EPA) regulates discharges of all contaminants, including drilling muds, into the waterways and offshore areas of the United States. EPA employs technology-based effluent standards in issuing discharge permits to both onshore and offshore operators. This paper examines the regulatory approaches used by EPA to limit toxicity in drilling muds at offshore drilling platforms and discusses other measures EPA has adopted to reduce toxicity of drilling muds discharged offshore. This effort focuses on an innovative approach that emphasizes pollution prevention used by EPA Region X for offshore Alaska, which is contrasted with a more traditional command and control regulatory approach used by other EPA regional offices. The Region X approach includes collection of influent and effluent data, development of a comprehensive data base of technical information, and prescription of specific mud formulas. This influent-effluent approach reduces uncertainty and guesswork, enhances use of innovative technology, and lowers toxic discharges compared to the standard EPA command and control approach. The influent-effluent approach provides a model for future efforts to incorporate pollution prevention into regulatory development and implementation. While this investigation found no evidence that toxicity limitations promulgated by EPA were having a deleterious impact on offshore developments, it identified major improvements in technology application, process management, and selection of raw materials which reduce toxicity of spent muds.