hydrological function, stream channel geomorphology, macroinvertebrates, nutrient loading, and fisheries, should be conducted and the results used as input to review and enhance, as needed, CBM produced water management, treatment, and disposal requirements.
The requirements associated with leasing and permitting CBM operations on federal and tribal lands through BLM and protecting water resources on federal, state, tribal, or private lands through the CWA and SDWA under EPA’s jurisdiction are relatively broad, but clear. Specific provisions under the NPDES permitting process apply to disposal of produced waters to the surface, and the UIC program, under the SDWA, applies if subsurface reinjection of produced water for disposal is used. Federal agencies work in concert with state and tribal authorities to enforce the federal standards and regulations, and EPA has delegated primacy for some of these permitting and regulatory functions to relevant state and tribal authorities in the six western states examined in this study.
Regulations regarding treatment and management of CBM produced water differ among the states examined in this study, as do the degree to which the states have been delegated primacy by federal agencies for permitting and regulation of CBM produced water management. Recognizing the jurisdiction of Indian tribes in regulating CBM development and managing CBM produced water is also important. Although different approaches have been taken by states and tribes, the various governing authorities generally appear to try to work in concert in their efforts to negotiate the complexities of these interleaved regulations for the protection and preservation of clean and safe surface water and groundwater resources and environmental protection.
At present, a challenge to effective management of produced water is inconsistency in the definition and consideration of CBM produced water as either a waste or a “beneficial use” in the six western states. Identifiable beneficial opportunities for use of CBM water include irrigation, rangeland habitat improvement, livestock watering, alluvial aquifer recharge, aquifer storage, wildlife habitat enhancement, reclamation of well pads, industry applications, and potentially municipal use or consumption. CBM produced water volumes change over time and eventually decrease to near zero as development of CBM fields mature, making sustainability or long-term dependability of this water supply an issue in consideration of these beneficial use opportunities.
The committee concludes that management of CBM produced water is presently driven by regulations and economics of disposal and treatment costs relative to revenues generated from the sale of methane rather than consideration of the potential for beneficial use. Additionally, efforts to direct produced water management based on uncalibrated models need to be avoided.