Coalbed Methane Produced Water In The Western Us

zone in the calculation of the discharge allowance; (3) the geographically limited extent of undiluted CBM produced water within a receiving stream once the produced water has entered the mixing zone; and (4) the relative mobility of fish and other aquatic organisms in perennial streams and rivers.

Few field assessments have investigated the effects of CBM produced water discharges on aquatic communities. Field assessments are difficult to conduct because of the lack of baseline information prior to CBM activity in the area; thus, observed changes to aquatic or riparian communities have been difficult to attribute directly to CBM related discharges. Studies of this nature are also complex to conduct and interpret because of the interactions and overlap between habitats, water quality, limited length of time to complete studies involving community transitions that might occur over extended periods of time, and species migration. A comprehensive assessment is currently being conducted by a consortium of state, federal, and nongovernmental organizations to establish current conditions for habitat and aquatic communities for the Powder River Basin. These data will be used to measure and monitor future changes. Another field study that examined differences in the number and composition of species in perennial streams and rivers across an entire watershed against numbers of CBM discharges in those streams and rivers noted difficulty in determining any direct effects of CBM discharges on fish assemblages. An instream toxicity study to assess potential toxic effects of CBM produced water on fish concluded that, despite elevated concentrations of ammonia and bicarbonate, acute toxic effects were mitigated by mixing of produced water with natural instream flows.

Various studies have proposed several primary adverse effects of CBM discharge to ephemeral drainages and their riparian systems. These potential effects include changes in the timing and amount of streamflow, bank erosion and instability, turbidity and increased sediment concentrations or deposition, and increased salinity of the soil, all of which may affect riparian plant communities. One study that directly examined the effects of CBM discharge waters on native and introduced vegetation in ephemeral drainages in Wyoming found greater percentages of nonnative plant species in channels receiving produced water than in those that did not receive CBM water. However, baseline data in ephemeral drainages are not widely available, so these potential and observed effects on riparian communities have not yet been substantiated with more rigorous studies.


Citizen complaints related to CBM activities are cataloged and investigated by several states with CBM production. In this section the general types of citizen complaints filed with state agencies are reviewed, using Colorado and Wyoming as examples. Also identified are instances of landowning citizens bringing complaints to court. In addition to the review of citizen complaint information in Colorado and Wyoming, the committee heard concerns from citizens and citizen groups about the effects of CBM production at its Denver meeting in March 2009.15

The COGCC maintains an electronic database of complaints on the Colorado Oil and Gas Information System (COGIS).16 Some level of investigation is completed on all claims. The database contains over 10,000 entries and allows searches for notices of alleged violations, complaints, and spills or releases. The database does not provide summaries of available information. Additionally, it is not possible to search specifically for complaints regarding impacts from CBM wells because the system aggregates all complaints pertaining to oil and gas wells. However, searches can be narrowed by qualifiers such as locality or company name, where wells are involved. A cursory review of the complaints indicated numerous complaints related to water quantity and water quality impacts to private domestic water supply wells. These problems were generally attributed by the complainant to poor practices by the operator (e.g., improperly cased wells). Other types of complaints included requests for baseline sampling before drilling began and dewatered well claims, as well as complaints related to produced water pits. Many of the complaints expressed concerns about methane gas contamination of wells. Most of the COGCC investigations of water quality concerns (including methane, sediment, and occasional salinity concerns) concluded that alleged well water impairments were not associated with CBM wells or CBM production activity. However, some occurrences of CBM contamination (methane gas contamination) of water wells have been confirmed as well as at least one instance where drilling fluid leaked from a pit, contaminating a nearby well.

Citizen complaints in Wyoming are processed by the Oil and Gas Conservation Commission (WOGCC), and complaints about both water quality and quantity have been received. The commission responds to all complaints, sends an inspector to the home or site associated with the complaint, interviews the complainant, and conducts a records check to determine if the water well has been permitted with the state, as required by state law. If the subject well is not permitted in Wyoming, the owner has no legal standing regarding potential impacts to the nonpermitted well water supply. The WOGCC requests assistance from the Wyoming DEQor the State Engineer's Office (SEO), as appropriate, to investigate serious claims. Complaints exist only as paper records and are not available electronically. In Wyoming, complaints are often settled directly with the CBM companies, based on advance legal agreements between both parties, thus obviating state involvement.17 The Wyoming SEO advises CBM companies to collect baseline water level data before drilling

15Papers submitted at the meeting are available through the National Academies Public Access Records Office. See Appendix C for the March 2009 meeting agenda.

16See (accessed April 7, 2010).

17J. Nelson, WOGCC, personal communication, April 2009.

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