Coalbed Methane Produced Water In The Western Us

well or shallow drip systems); and disposal into impoundment facilities (pits or reservoirs) (DiRienzo, 2008). Wyoming has established an interagency working group29 to address issues related to CBM produced water management, including monitoring and protocols.

Generally groundwater appropriation permits for CBM produced water are granted from the State Engineer's Office if a beneficial use is demonstrated (Table 3.1) and if the State Engineer determines that the proposed means of diversion and construction are adequate. An application can be denied if the State Engineer determines that the activity is not in the public interest. The State Engineer's Office considers CBM production different than conventional natural gas production "due to the necessity for production of water for the production of the gas resource" and has designated CBM as a beneficial use of water on this basis. Permits are thus required for appropriation of groundwater (Wyoming SEO, 2004). Groundwater protection with respect to surface discharges into impoundments is monitored under the DEQGroundwater Pollution Control program (Fischer, 2009),30 which has had standards and practices in place for groundwater monitoring, reporting, and monitoring well plugging and abandonment.

Unlined surface impoundments require permits in Wyoming by the State Engineer's Office (for reservoirs—"on-channel"31) or the Oil and Gas Conservation Commission (for pits—"off-channel"32). In addition, the BLM authorizes impoundments on federal lands and issues federal leases for water disposal to such impoundments. Discharge permits to impoundments are required by the Wyoming DEQunder WYPDES; the permits required vary by drainage basin. In some cases, groundwater protection permits are required under the Wyoming Groundwater Pollution Control (GPC) Program. These permits are also issued by the Wyoming DEQ. Monitoring requirements under the GPC program depend on depth to groundwater and water quality beneath the impoundment and the degree of hydrologic connection to surface water. 33

In April 2010, Wyoming DEQreleased a new set of specific guidelines for compliance monitoring and siting requirements for unlined impoundments (on- and off-channel) containing CBM produced water (Wyoming DEQ, 2010). These guidelines supersede

29See www.wy.blm.gov/prbgroup/ (accessed May 19, 2010).

30See also deq.state.wy.us/wqd/groundwater/index.asp (accessed March 4, 2010).

31An "on-channel" (or "in-channel") impoundment that receives CBM produced water is sited within a designated water feature or within the floodplain or alluvium of a water feature. These features include intermittent perennial and ephemeral streams, dry washes, and lakes. Engineering modifications are made to the channel to enhance capacity for temporary or long-term storage of water. An "off-channel" impoundment is not sited within such a designated water feature and is constructed in areas outside of the natural flow path and not directly connected to any direct surface flow paths to pre-existing ephemeral or perennial channels.

32An "off-channel" impoundment is not sited within such a designated water feature and is constructed in areas outside of the natural flow path and not directly connected to any direct surface flow paths to pre-existing ephemeral or perennial channels.

33D. Fischer, Wyoming DEQ, Personal communication, July 14, 2009.

requirements in previous guidance documents and were revised as a result of a comprehensive review of groundwater compliance monitoring data that the Wyoming DEQhad received since the inception of the monitoring requirements in August 2004. Groundwater monitoring is required because water infiltrating from unlined CBM impoundments has the potential to dissolve in situ minerals and affect the state's groundwater resources. The revised guidelines implemented changes to the existing compliance monitoring program and maintained the siting and subsurface groundwater compliance monitoring requirements prior to new impoundment construction and subsequent to discharge of CBM produced water into the impoundment.

Under WYPDES, the state has established a policy specifically for discharges of CBM produced water to surface waters of the Powder River mainstem to provide assurance that both Wyoming narrative standards and Montana numerical standards for TDS and sodium are met. A key foundation to the policy is management of the "assimilative capacity"34 of the Powder River. Of the chemical constituents in CBM produced water, TDS and sodium were the only ones identified with sufficient potential to exceed Montana water quality standards at the state line, and the Wyoming DEQhas therefore instituted a greater level of permitting oversight for these two constituents. Wyoming has no numerical standards in place for sodium and Wyoming's existing numerical standards for TDS are not applicable to the protection of irrigation uses of water. Wyoming state officials use the Montana numerical standards for TDS (as a proxy for EC) and SAR (see above) to ensure that discharges into the Powder River do not exceed the assimilative capacity and do not degrade designated uses of surface waters (Wyoming DEQ 2006).

Utah

Under Utah law, administration of the appropriation and distribution of the state's water resources rests with the Utah Division of Water Rights (DWRi), led by the state engineer within the Utah Department of Natural Resources (DNR).35 The Utah DEQs Division of Water Quality and the Board of Water Quality oversee water quality issues associated with surface water and groundwater of the state36 and have jurisdiction over the UIC program for Class I, III, IV, and V wells. Specific jurisdiction over CBM development and produced water management rests under the DNR with the Division of Oil, Gas, and

34"Assimilative capacity" refers to the capacity of a natural body of water to receive wastewaters or toxic materials without deleterious effects and without damage to aquatic life or humans who consume the water. See www.epa.gov/OCEPAterms/ aterms.html (accessed March 4, 2010).

35See nrwrt1.nr.state.ut.us/ (accessed March 4, 2010).

36See www.waterquality.utah.gov/DWQ_info.htm (accessed March 4, 2010).

0 0

Post a comment