February 7, 2001

Mr. Paul Beels
Buffalo Field Office
BUREAU OF LAND MANAGEMENT
1425 Fort Street
Buffalo, Wyoming 82836

Re: Wyodak Drainage Coal Bed Methane Environmental Assessment
      (WY-070-01-034)

Dear Mr. Beels:

The Petroleum Association of Wyoming (PAW) would like to thank BLM for the opportunity to comment on the referenced document. PAW is Wyoming's largest and oldest oil and gas trade organization, the members of which account for over ninety percent of the natural gas and over seventy percent of the crude oil produced in the State. The Wyodak Drainage Coal Bed Methane Environmental Assessment (EA) will directly affect members of PAW.

PAW has the following comments regarding the Proposed Action (PA) for the above referenced EA:

1. Page 1-2, Paragraph 2: "This Wyodak Drainage Environmental Assessment (Drainage EA) considers federal PDS, which is an extension of the existing analysis contained in the Wyodak EIS. Therefore, the Drainage EA is tiered to the Wyodak EIS."

PAW agrees with BLM's assessment that the PA to develop 2,500 additional protective CBM wells on lands where mineral rights are owned and controlled by the federal government is appropriate and that the PA is not a major federal action significantly affecting the human environment. PAW agrees with BLM's preliminary Finding of No Significant Impact (FONSI) decision.

2. Page 3-10, Paragraph 6: "Flows within the Wyodak project area and outflows of surface waters from the project area are reduced by losses due to evapotranspiration to the atmosphere and leakage (infiltration) into underlying alluvium and geologic substrate…However, recent observations by BLM and others indicate this previously assumed rate of one percent per mile used in the Wyodak EIS is much less than the actual observed rate of loss…A specific infiltration study has been initiated as part of the ongoing Powder River Basin Oil and Gas EIS to further quantify the stream/drainage losses within the larger Powder River Basin EIS analysis area."

PAW agrees with this analysis. For BLM's consideration, PAW has attached, and incorporated by reference to this comment letter, supporting data provided by Arthur O'Hayre, Ph.D. with Applied Hydrology Associates, Inc. from Denver, Colorado.

3. Page 3-15 Paragraph 1: "Although CBM produced water may not be suitable for irrigation of crops, the quality of the CBM water in the area is generally suitable for livestock consumption."

This paragraph could lead the reader to believe that ALL CBM water is unsuitable for irrigation of crops. PAW suggests that BLM clarify this statement by stating "Although some CBM produced water may not be suitable for irrigation of crops, the quality of CBM water in the area is generally suitable for livestock consumption". Suitability for irrigation is dependent upon interaction of soil types, SAR values, salinity values and crops grown. Indeed, in many instances CBM water can and has been used to irrigate.

4. Page 4-1, Paragraph 2: "Those impacts addressed in the Wyodak EIS and approved in the Wyodak ROD for the approved action (Alternative 1) have been considered in this EA as threshold criteria for the determination of significant impacts. The analysis has shown that potential impacts to resources are either less than those impacts assessed in the Wyodak EIS or are not significant."

Significant development has now been conducted in the Wyodak project area and PAW agrees that the projected impacts analyzed in the Wyodak EIS and approved in the Wyodak ROD were higher than impacts that actually occurred. The data accumulated through existing development supports the FONSI decision for the PA because thresholds established in the EIS have been analyzed for and have not been reached. The trends show that even with the development of an additional 2,500 protective wells, the existing thresholds will not be reached.

5. Page 4-1, Paragraph 5: "Assuming this actual rate of disturbance remains constant through implementation of the PA, the cumulative drilling of 12,501 wells (includes Wyodak EIS wells, the PA's 2,500 wells, and projected state and fee wells) would affect 17,251 acres. This figure is well below the total aerial extent of disturbance projected in the Wyodak EIS (26,448 acres) for these facilities. Thus, disturbance associated with the PA in addition to those associated with the 1999 Wyodak project do not exceed the level of effect disclosed in the Wyodak EIS and ROD."

PAW agrees with this statement and therefore the scope of analysis for surface disturbance has already been conducted in the Wyodak EIS and approved in the ROD. The surface disturbance figure will be less than anticipated due to the use of existing roads and facilities and well within the established thresholds.

6. Page 4-1; Paragraph 6: "Based on the BLM's and WOGCC's current projections for increased numbers of wells and their compilation of water production data for existing wells, total water production for 1,425 new producing protective federal wells will be approximately 98,172 acre feet over the 15-month period or about 82,900 acre feet for the 12-month period ending February 28, 2002."

PAW suggests adding the following language after the above quoted sentence; "The water production values reported to the WOGCC provide an upper bound estimate of past or current water production. The water production values reported to the WOGCC have typically been instantaneous well production measurements. These values overestimate production because they do not include shutdown time and they usually include some produced gas in the flow measurement. Furthermore, the WOGCC well water production values do not account for rate declines with time."

7. Page 4-4; Paragraph 1: "There is potential for increased frequency and magnitude of localized flooding where channels or basin capacity is insufficient to handle the increase flows."

This statement leaves the reader considering how big and how often localized flooding could occur. Although PAW recognizes the difficulty in predicting such occurrences, BLM should add information to the EA that provides the reader with a reference as to what should be expected for channel capacities in Northeast Wyoming in terms of handling certain storm events (i.e. a 25 year event) and the relation of CBM discharges to those capacities. For instance, BLM could take a representative basin(s) and compare the channel capacity at the mouth to anticipated CBM flows emanating from the basin that would reach the mouth. As an alternative, BLM could describe on a percentage basis, the increase that CBM water could add to a 25-year storm event occurring at the mouth of or gauging station on a representative drainage(s). This information is readily available for drainages such as the Belle Fourche or Caballo Creek.

8. Page 4-10, Last Paragraph: "The anticipated acreage of habitat disturbance from the PA's drilling of the 2,500 wells, construction of facilities, and field operations is 3,450 acres, based on the 1.38-acres per well disturbance factor defined in Chapter 2."

PAW believes that this surface disturbance figure is based on a worse case scenario and that there will be less surface disturbance than anticipated due to the use of existing roads, production facilities, pipeline, etc. Due to the lack of manpower within BLM offices, it is optimistic to believe that all 2,500 APD's will be approved and drilled in a 15-month timeframe; however, should this scenario occur, only 0.15 percent of the entire Wyodak project area will be affected by this additional development and the total surface disturbance is well below the established threshold already analyzed for and approved in the Wyodak EIS and ROD. Existing mitigation measures will adequately address the protection of new surface disturbance.

9. Appendix D, Biological Assessment: "Wyoming Coal Bed Methane Drainage Project"

BLM has incorporated a Biological Assessment (BA) that was conducted in December of 2000 to determine "if the action 'may affect' any federal listed threatened, endangered, or proposed species." The US Fish and Wildlife Service identified four species that may be present in the project area: Bald Eagle, Black-Footed Ferret, Mountain Plover, and the Ute Ladies'-Tresses Orchid. In all cases, it was determined that "implementation of the proposed action as described above may affect, but is not likely to adversely affect," the above listed species or their habitat. Existing protection measures implemented through the Wyodak EIS and the Buffalo Resource Management Plan, Conditions of Approval, lease stipulations, and site-specific analysis were considered adequate and that development could occur without adversely affecting these species and their habitat.

10. Page 4-27, Paragraph 4: "Socioeconomics: The impact to the local economy, and to federal, state, and county governments from taxes and royalties would total approximately $551.2 million."

PAW believes that the implementation of this PA would significantly benefit the above listed governments and is a benefit to the residents of Wyoming.

In conclusion, PAW believes that it is necessary for BLM to develop federal drainage protective wells to prevent the loss of methane gas resources and loss of revenues to the federal government; therefore, PAW supports the Proposed Action.

Sincerely,

Dru Bower
Vice President
Petroleum Association of Wyoming

cc: Dave True
Krista Mutch
Gene George
Curt Parsons
Bob Ugland
Joe Icenogle

Attachment

CURRENT CBM DISCHARGE CONTRIBUTIONS TO MAIN STEM STREAMS

POWDER RIVER BASIN, WYOMING

Prepared by

APPLIED HYDROLOGY ASSOCIATES, INC.
1200 S. Parker Rd.
Denver, Colorado 80231

1. Introduction

Conservative assumptions were made in the Wyodak EIS concerning the average well production rate and the rate of conveyance loss along stream channels. Based on these assumptions the estimated increase in flow in the main stem streams for the selected alternative were as follows:

These estimates used in the impact evaluation are sufficiently large to address the additional 2,500 wells included in the Wyodak Drainage CBM EA. The increased flow in the main stem streams were overestimated in the Wyodak EIS primarily because the volume of water that is lost to infiltration and evapotranspiration was under estimated.

Flow measurements from stream monitoring stations and recent instantaneous flow measurements along tributary channels downstream of CBM discharge locations show that very little of the produced water that is discharged reaches the Main Stem streams. These studies show that the Wyodak EIS underestimated the conveyance loss and over estimated the increase in flow in the main stem streams due to CBM discharges.

A study completed by Joe Meyer of the Bureau of Land Management in November 2000 analyzed CBM water production and streamflow data for Caballo Creek, and the Belle Fourche River. The scope of the data analysis was limited to the months of May, June, July, August and September. The study concluded that water production volumes are not as great as estimated, and streamflow conveyance losses have been significantly greater than predicted in the Wyodak EIS. During periods without significant precipitation, measured stream flow on Caballo Creek accounts for less than two percent of the total volume of water produced from CBM wells within the drainage above the gauging location. Often there was no flow at the stream gage. The results for the Upper Belle Fourche Drainage were very similar to Caballo Creek. During periods without significant precipitation, an average of less than three percent of produced water volumes were recorded at the stream gage. Similar trends have been observed in the Little Powder River Drainage, although the history of CBM development and data record is still limited in this drainage.

The second study was completed by Applied Hydrology Associates and Greystone Environmental Services for the on-going Powder River Basin Oil and Gas EIS. This study provided a detailed assessment of the amount of re-infiltration of CBM water discharges on representative basins within the PRB. Stream channel characteristics and cross sections, reservoir information and streamflow measurements were obtained for the following representative basins:

• Caballo Creek
  
• Pumpkin Creek
  
• Spotted Horse Creek, and
  
• Wildcat Creek

These drainage basins were selected based on the presence of current CBM production and water discharge in the basin, a wide geographic distribution about the basin with a range of channel conditions and, in the case of Caballo Creek, a long history of CBM discharge within the basin

The field studies to characterize representative stream channels and to measure CBM discharge conveyance loss in channels and reservoirs were initiated on October 16 and completed on October 28. It is thought that the measured reservoir and channel conveyance loss is predominantly re-infiltration as evapotranspiration rates are low at this time of the year. Measurements were taken along the main channel reach immediately above and below any reservoirs and immediately above and below each CBM discharge point or flowing tributary.

Caballo Creek Investigation

For Caballo Creek, a site reconnaissance was performed over much of the main stream channel from the headwaters above Highway 50 to the Belle Ayr Mine gaging station BA-6 located at near Highway 59. There was no flow at the Belle Ayr Mine gaging station BA-6 and no flow on Caballo Creek on its reach except for one location in Section 03, T47N, R73W. A flow of 0.034 cfs was measured at this location using a 2-inch flume. The measurement location was just downstream from the confluence of an unnamed tributary. Two reservoirs were located on the tributary just above its confluence with Caballo Creek. CBM discharge water was entering both reservoirs. Flow out of the lowest reservoir located just above the confluence with Caballo Creek was measured at 0.010 cfs using a 2" flume.

CBM discharges were observed on several named and un-named tributaries but, other than at the reservoir location previously mentioned, none of this flow reached the main channel of Caballo Creek. Based on water production data from the WOGCC, the total CBM water discharge in the Caballo Creek drainage basin above Highway 59 was 4380 gpm (9.76 CFS). We had difficulty finding measurable CBM flow anywhere except in close proximity to CBM discharge locations. Water was re-infiltrating on minor tributary channels and swales or surface water impoundments located downstream of the discharge point.

Pumpkin Creek Investigation

Pumpkin Creek was included in the investigation because it was a location where CBM water from Big George Coal wells were being discharged directly into the stream or into tributaries close to their confluence with Pumpkin Creek. Also, there were no reservoirs downstream of the CBM discharge points to attenuate flows.

A flow of 0.022 cfs (9.9 gpm) was measured on Pumpkin Creek in the NESE quarter-quarter of Section 36, T47N, R77W upstream of the first discharge point in Section 36. According to the water production data from the WOGCC, the total CBM water discharge to the Pumpkin Creek drainage basin upstream of Section 36 during September was 423 gpm. Thus, about 2.3% of the CBM discharges in the drainage basin above this point was appearing as streamflow. These results are consistent with the results obtained by BLM on Caballo Creek and the Belle Fourche River.

Five discharge points or tributaries with CBM discharge enter Pumpkin Creek in Section 36, T47N, R77W. From the measurements taken above and below these tributaries and discharge points it appears that the direct inflow to Pumpkin Creek of CBM discharges water in Section 36 is 0.78 cfs. About 3% of this water appears as streamflow at the last measurement point located approximately 9 miles downstream.

Wildcat Creek Investigation

The first flow monitoring site on Wildcat Creek was located upstream from the confluence with Jamison Prong of Wildcat Creek. The flow at this location was measured at 0.001 cfs using a 2 inch flume. This location was downstream of a CBM discharge point. There was also a significant quantity of CBM water flowing down Jamison Prong. A flow of 0.280 cfs was measured using a 4 inch flume on Jamison Prong immediately upstream from its confluence with Wildcat Creek.

A flow of at 0.006 cfs was measured on Wildcat Creek, approximately 1800 feet downstream from the confluence with Jamison Prong. The next measurement location on Wildcat Creek was approximately 2350 feet downstream from the previous location and downstream of CBM discharges. A flow of 0.264 cfs was measured at this site using a current meter. The last monitoring site on Wildcat Creek was located about 8500 feet downstream from the previous site. A flow of 0.130 cfs was measured at this location using a 4 inch flume.

From these measurements it appears that the direct inflow to Wildcat Creek in the study reach is about 0.54 cfs (242 gpm). About 24% of this water appears as streamflow at the last measurement point located or that 76 % of the CBM water has re-infiltrated through 2.8 mile reach of Wildcat Creek. Based on water production data from the WOGCC, the total CBM water discharge in the Wildcat Creek drainage basin above the last measurement point was 2,160 gpm (4.8 CFS). Most of this water was apparently re-infiltrating on minor tributary channels and swales or surface water impoundments located downstream of the discharge points. Based on the last flow measurement on Wildcat Creek less than 3% of the total CBM water production in the drainage basin was reaching this location.

Spotted Horse Creek Investigation

A flow of 1.07 cfs was measured using a current meter was measured on Spotted Horse Creek near its mouth at a location just upstream of the Powder River Road. Based on water production data from the WOGCC, the total CBM water discharge in the Spotted Horse Creek drainage basin above this measurement point was 1910 gpm (4.26 CFS). Much of this water was apparently re-infiltrating on minor tributary channels and swales or surface water impoundments located downstream of the discharge points. Based on the last flow measurement on Spotted Horse Creek approximately 25% of the total CBM water production in the drainage basin was reaching this location and 75% was removed by has re-infiltrated and evaporation.