U.S. Department of the Interior 

Bureau of Land Management

Wyoming State Office 

Rawlins Field Office August 2004

ENVIRONMENTAL ASSESSMENT for the Scotty Lake 

Coalbed Natural Gas Pilot Project, Sweetwater County, 

Wyoming
MISSION STATEMENT 

It is the mission of the Bureau of Land Management to sustain the health, 

diversity, and productivity of the public lands for the use and enjoyment of 

present and future generations. 

BLM/WY/PL-04/031 + 1310 

WY-030-04-EA-359
United States Department of the Interior

BUREAU OF LAND MANAGEMENT 

Rawlins Field Office 

 P.O. Box 2407 (1300 North Third Street) In Reply Refer To:

 Rawlins, Wyoming 82301-2407 1790

 August 6, 2004 

Re: Environmental Assessment for the 

Scotty Lake Coalbed Natural Gas 

Pilot Project 

Dear Reader: 

This is to inform you of the availability of the Scotty Lake Coalbed Natural 

Gas Pilot Project Environmental Assessment (EA) at the Wyoming Bureau of Land 

Management’s (BLM) website: 

www.wy.blm.gov/rfo/nepa.htm

The Scotty Lake pilot project is an exploratory coalbed natural gas (CBNG) 

project located in Sweetwater County, Wyoming, approximately 45 miles 

northwest of Wamsutter, Wyoming. The project is within the existing Scotty 

Lake CBNG Exploratory Unit and lies primarily within the jurisdictional 

boundaries of the Rawlins Field Office with a small portion lying within the 

Lander Field Office boundaries. In order to satisfy the requirements of the 

National Environmental Policy Act, this EA was prepared to analyze impacts 

associated with the exploratory drilling of coal formations in the project 

area.

It is expected that this EA can be viewed at our website beginning August 6, 

2004. This will begin the 30-day public review/comment period for the 

document. We will review all comments and will address substantive comments 

in the Decision Record. A substantive comment is one that would alter 

conclusions drawn from the analysis based on: 1) new information, 2) why or 

how the analysis is flawed, 3) evidence of flawed assumptions, 4) evidence of 

error in data presented, and 5) requests for clarification that bear on 

conclusions presented in the analysis. 

Your comments should be as specific as possible. Comments on the 

alternatives presented and on the adequacy of the impact analysis will be 

accepted by the BLM until September 7, 2004. 

Comments may be submitted via regular mail to: 

John Ahlbrandt, Project Manager 

Bureau of Land Management 

Rawlins Field Office 

P.0. Box 2407 

Rawlins, Wyoming 82301 
2

or may be submitted electronically at the address shown below (please refer 

to the Scotty Lake Pilot Project): 

e-mail: rawlins_wymail@blm.gov 

Please note that comments, including names, e-mail addresses, and street 

addresses of respondents, will be available for public review and disclosure 

at the above address during regular business hours (7:45 a.m. to 4:30 p.m.), 

Monday through Friday, except holidays. Individual respondents may request 

confidentiality. If you wish to withhold your name, e-mail address, or 

street address from public review or from disclosure under the Freedom of 

Information Act, you must state this plainly at the beginning of your written 

comment. Such requests will be honored to the extent allowed by law. All 

submissions from organizations or businesses, and from individuals 

identifying themselves as representatives or officials of organizations or 

businesses, will be made available for public inspection in their entirety. 

The EA may also be reviewed at the following locations: 

Bureau of Land Management Bureau of Land Management 

Wyoming State Office Rawlins Field Office 

5353 Yellowstone Road 1300 N. Third Street 

Cheyenne, Wyoming 82009 Rawlins, Wyoming 82301 

If you require additional information regarding this project, please contact 

John Ahlbrandt, Project Manager, at the Rawlins address or phone 

(307) 328-4223. 

 Sincerely, 

 Field Manager 
ENVIRONMENTAL ASSESSMENT FOR THE 

SCOTTY LAKE COALBED NATURAL GAS PILOT PROJECT, 

SWEETWATER COUNTY, WYOMING 

Prepared for 

Bureau of Land Management 

Rawlins Field Office 

Rawlins, Wyoming 

This Environmental Assessment was prepared by Anderson Environmental Consulting, an 

independent environmental consulting firm, with the guidance, participation, and independent 

evaluation of the Bureau of Land Management (BLM). The BLM, in accordance with Federal 

Regulation 40 CFR 1506.5 (a) and (b), is in agreement with the findings of the analysis and 

approves and takes responsibility for the scope and content of this document. 

August 2004 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

TABLE OF CONTENTS 

Document Section Page

1.0 PURPOSE OF AND NEED FOR ACTION 1 

 1.1 Introduction 1 

1.2 Purpose and Need for the Proposed Action 3 

1.3 Conformance with Existing Land Management Plans 3 

1.4 Authorizing Actions and Relationship to Statutes and Regulations, or 

Other Plans 5 

1.5 Land and Resource Management Issues and Concerns 5 

2.0 PROPOSED ACTION AND ALTERNATIVES 7 

 2.1 Introduction 7 

2.2 Proposed Action 9 

2.2.1 Well Pad Construction 9 

2.2.2 Access Roads 9 

2.2.3 Drilling Operations 12 

2.2.3.1 Drilling Fluids System 13 

2.2.3.2 Casing & Cementing Operations 13 

2.2.4 Completion and Evaluation Operations 13 

2.2.5 Production Operations 15 

2.2.6 Pipeline Gathering System 15 

2.2.6.1 Gas Gathering System 16 

2.2.6.2 Water Discharge Lines 17 

2.2.7 Ancillary Facilities 17 

2.2.8 Transportation and Workforce Requirements 17 

2.2.9 Water Production and Disposal 18 

2.2.10 Hazardous Materials 19 

 2.2.11 Abandonment 19 

 2.2.12 Reclamation 19 

2.2.12.1 Producing Well Location 20 

2.2.12.2 Access Roads 20 

2.2.12.3 Pipelines 21 

2.2.12.4 Abandoned Well Location 21 

2.3 Applicant-Committed Environmental Protection Measures 21 

2.3.1 Preconstruction Planning and Design Measures 21 

2.3.2 Air Quality 22 

2.3.3 Cultural Resources 22 

2.3.4 Geology and Minerals 23 

 2.3.5 Hydrology 23 

 2.3.6 Noise 23 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

TABLE OF CONTENTS - Continued

Document Section Page

2.3.7 Range Management 24 

 2.3.8 Soils 24 

 2.3.9 Transportation 25 

 2.3.10 Wildlife 25 

2.4 No Action Alternative 26 

2.5 Alternatives Considered But Not Analyzed in Detail 27 

2.5.1 Re-Injection of Produced Water 28 

2.5.2 Directional Drilling 28 

3.0 AFFECTED ENVIRONMENT 30 

 3.1 Introduction 30 

3.1.1 Environmental Elements Not Considered in Detail 30 

3.2 General Setting and Climate 31 

3.3 Air Quality 32 

3.4 Cultural Resources 33 

3.5 Geology and Minerals 34 

 3.5.1 Geology 34 

 3.3.2 Minerals 35 

 3.6 Hydrology 36 

3.6.1 Surface Hydrology 36 

3.6.2 Sub-Surface Hydrology 37 

3.7 Range Management 38 

 3.8 Soils 39 

3.9 Visual Resources 40 

3.10 Wildlife and Special Status Species 40 

3.10.1 Big Game Species 41 

3.10.2 Greater Sage Grouse 42 

3.10.3 Raptor Species 43 

3.10.4 Threatened and Endangered Species 43 

3.10.5 Special Status Species 45 

3.10.6 Migratory and Non-Migratory Birds 45 

3.11 Wild Horse Management 46 

4.0 ENVIRONMENTAL IMPACTS 49 

 4.1 Introduction 49 

4.2 Air Quality 49 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

TABLE OF CONTENTS - Continued

Document Section Page

4.2.1 Proposed Action 49 

4.2.2 The No Action Alternative 50 

4.2.3 Mitigation and Monitoring 50 

4.3 Cultural Resources 50 

4.3.1 Proposed Action 51 

4.3.2 The No Action Alternative 51 

4.3.3 Mitigation and Monitoring 52 

4.4 Geology and Minerals 52 

4.4.1 Proposed Action 52 

4.4.2 The No Action Alternative 52 

4.4.3 Mitigation and Monitoring 52 

 4.5 Hydrology 52 

4.5.1 Proposed Action 52 

4.5.1.1 Erosion and Sedimentation 53 

4.5.1.2 Surface Water Discharge 53 

4.5.1.3 Sub-Surface Hydrology 54 

4.5.2 The No Action Alternative 54 

4.5.3 Mitigation and Monitoring 54 

4.6 Range Management 55 

4.6.1 Proposed Action 55 

4.6.2 The No Action Alternative 56 

4.6.3 Mitigation and Monitoring 56 

 4.7 Soils 56 

4.7.1 Proposed Action 56 

4.7.2 The No Action Alternative 57 

4.7.3 Mitigation and Monitoring 57 

4.8 Visual Resources 57 

4.8.1 Proposed Action 58 

4.8.2 The No Action Alternative 59 

4.8.3 Mitigation and Monitoring 59 

4.9 Wildlife and Special Status Species 59 

4.9.1 Proposed Action 60 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

TABLE OF CONTENTS - Continued

Document Section Page

4.9.1.1 Habitat Loss and Displacement 60 

4.9.1.2 Big Game Species 61 

4.9.1.3 Greater Sage Grouse 61 

4.9.1.4 Raptor Species 61 

4.9.1.5 Threatened and Endangered Species 62 

4.9.1.6 Special Status Species 63 

4.9.1.7 Migratory and Non-Migratory Birds 64 

4.9.2 The No Action Alternative 64 

4.9.3 Mitigation and Monitoring 64 

4.10 Wild Horse Management 65 

4.10.1 Proposed Action 65 

4.10.2 The No Action Alternative 66 

4.10.3 Mitigation and Monitoring 66 

4.11 Cumulative Impacts 66 

4.11.1 Air Quality 68 

4.11.2 Cultural Resources 70 

4.11.3 Geology and Minerals 70 

 4.11.4 Hydrology 70 

4.11.4.1 Surface Hydrology 70 

4.11.4.2 Sub-Surface Hydrology 71 

4.11.5 Range Management 71 

 4.11.6 Soils 72 

4.11.7 Visual Resources 72 

4.11.8 Wildlife and Special Status Species 72 

4.11.8.1 Big Game Species 73 

4.11.8.2 Greater Sage Grouse 74 

4.11.8.3 Raptor Species 74 

4.11.8.4 Migratory and Non-Migratory Birds 74 

4.11.9 Wild Horse Management 75 

4.12 Short-Term Use of the Environment Versus Long-Term Productivity 75 

4.13 Irreversible and Irretrievable Commitment of Resources 75 

4.13.1 Air Quality 75 

4.13.2 Cultural Resources 76 

4.13.3 Geology and Minerals 76 

 4.13.4 Hydrology 76 

4.13.5 Range Management 76 

 4.13.6 Soils 76 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

TABLE OF CONTENTS - Continued

Document Section Page

4.13.7 Visual Resources 77 

4.13.8 Wildlife and Special Status Species 77 

4.13.9 Wild Horse Management 77 

4.13 Residual Impacts 77 

5.0 CONSULTATION AND COORDINATION 79 

 5.1 Background 79 

5.2 Public Participation 79 

5.3 List of Preparers 79 

6.0 REFERENCES 81 

7.0 ABBREVIATIONS AND ACRONYMS 87 

APPENDIX A : Permits, Approvals and Authorizing Actions Applicable to 

Additional Exploration in the Scotty Lake CBNG Pilot Project 

Area

APPENDIX B : Issues Identified in Conjunction with Project Scoping that were 

Determined Not to be Significant Issues Related to the Proposed 

Action

APPENDIX C : Scotty Lake CBNG Pilot Project Plan of Development and Master 

Field Permit

APPENDIX D : Scotty Lake CBNG Pilot Project Water Management Plan 

LIST OF TABLES 

 Table Number Description Page

Table 2.1 Wells Proposed in Conjunction with the SLPP 7 

Table 3.1 Critical Elements of the Human Environment, Scotty Lake CBNG 

Pilot Project, Sweetwater County, Wyoming 30 

Table 3.2 Background Air Quality Concentrations, Ambient Standards and 

PSD Increments (μg/m3

) 33 

Table 3.3 Wells Previously Drilled in and/or Adjacent to the SLPA 36 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

vi

LIST OF TABLES - Continued

 Table Number Description Page

Table 3.4 Grazing Allotments in the SLPA 38 

Table 3.5 Population Objectives, 2002 Post-Hunt Population Objectives and 

 Population Trends in Antelope, Elk and Mule Deer Populations 

 in the SLPA 42 

Table 3.6 Raptor Nesting Activity in or Adjacent to the SLPA 43 

Table 3.7 List of Partners in Flight (PIF) Priority Bird Species Potentially 

 Found within the SLPA 47 

Table 4.1 Area of Influence for Each Specific Resource Component 67 

Table 4.2 Summary of Existing Surface Disturbance in the Area of 

 Influence by Watershed 69 

Table 4.3 Summary of Total Surface Disturbance Anticipated in the SLPP 

 Area of Influence by Watershed 69 

Table 4.4 Areas of Influence for Analysis of Cumulative Impacts 

 To Wildlife and Special Status Species 72 

Table 5.1 Interdisciplinary Reviewers from the Bureau of Land Management 80 

Table 5.2 Principal Interdisciplinary Team 80 

LIST OF FIGURES 

 Figure Number Description Page

Figure 1.1 General Vicinity Map 2 

Figure 1.2 Small Scale Map Showing the Proposed Scotty Lake CBNG 

Pilot Project Area 4 

Figure 2.1 Map Showing the Proposed Scotty Lake Coalbed Natural Gas 

Pilot Project Area 8 

Figure 2.2 Typical Location Layout 11 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

1.0 PURPOSE OF AND NEED FOR ACTION

1.1 INTRODUCTION

Hudson Group, LLC (Hudson) has notified the Rawlins Field Office (RFO), Bureau of Land 

Management (BLM) of their proposal for a coalbed natural gas (CBNG) pilot project within the 

proposed Scotty Lake CBNG Exploratory Unit located within the administrative boundaries of both 

the Rawlins and Lander Field Offices, BLM. The proposed pilot project would encompass

approximately 2,880 acres of federal surface and mineral estate within the Scotty Lake CBNG 

Exploratory Unit in Sweetwater County, Wyoming (see Figure #1.1) and would involve the drilling 

of up to eighteen CBNG wells in three phases over a period of three years. 

These wells would be drilled to test the potential of coals within the Fort Union Formation for

commercial natural gas production at depths of up to 5,000 feet. Information gathered from the 

drilling of these pilot wells would ultimately be used to determine if additional CBNG exploration 

and development is warranted within the Scotty Lake CBNG Exploratory Unit. National mineral

leasing policies and the regulations by which they are enforced recognize the statutory right of lease 

holders to explore for and develop federal mineral resources in order to meet continuing national 

needs and economic demands as long as undue and unnecessary environmental degradation is not 

incurred.

There are currently three producing CBNG wells in the project area consisting of previously 

abandoned well bores which were re-entered by Hudson in 2002 and successfully completed in the 

Fort Union Formation. Additional exploration proposed in conjunction with the Scotty Lake CBNG 

Pilot Project would generally consist of the following component activities: 

x construction of up to 18 additional well locations within the Scotty Lake CBNG Exploratory 

Unit;

x construction of approximately 26,579 feet (5.03 miles) of access road necessary to provide 

access to the pilot well locations proposed by Hudson; 

x installation of approximately 43,342 feet (8.21 miles) of buried natural gas and 22,597 feet (4.27 

miles) of buried produced water pipelines for the gathering and transportation of gas and water 

produced from wells within the project area to sales (gas) and disposal (water) facilities;

x installation of processing and production facilities, and the routine operation/maintenance of 

commercially productive wells within the field; 

x expansion of existing water disposal facilities to facilitate the surface discharge of water 

produced from the pilot wells under pre-existing National Pollutant Discharge Elimination

System (NPDES) permits issued by the Wyoming Department of Environmental Quality 

(WDEQ); and

1

Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

x abandonment and reclamation of individual well locations and associated facilities as wells are 

determined to be commercially non-productive. 

These activities are hereafter referred to as the Proposed Action. Those lands potentially affected by 

implementation of the proposed action are defined as the “project area” and the boundaries of this 

project area are shown on Figure 1.2. 

Through interdisciplinary analysis and review, consideration of reasonable alternatives, and public 

participation, this EA will serve as a vehicle for: 

x determining the significance of environmental impacts associated with the Proposed Action and 

alternatives;

x assisting in the decision-making process; 

x deciding whether an Environmental Impact Statement (EIS) is necessary; and, 

x identifying and developing appropriate mitigation measures to minimize the environmental

impacts of the Proposed Action and alternatives. 

1.2 PURPOSE AND NEED FOR THE PROPOSED ACTION

The development of federal oil and gas leases is an integral part of the BLM oil and gas leasing 

program under the authority of the Mineral Leasing Act (MLA) of 1920 as amended (30 U.S.C. 181, 

et seq), the Federal Land Policy and Management Act (FLPMA) of 1976 (P.L. 94-579), the Federal

Onshore Oil and Gas Royalty Management Act (FOOGRMA) of 1982 (30 U.S.C. 1701, et seq), and 

the Federal Onshore Oil and Gas Leasing Reform Act (FOOGLRA) of 1987 (43 CFR Part 3100). 

The BLM’s oil and gas leasing program is intended to encourage the development of domestic oil 

and gas reserves, thereby reducing national dependence upon foreign energy supplies. Furthermore,

exploration and production of natural gas, including methane gas from coal-bearing formations, is in 

accordance with the President’s National Energy Policy as outlined in Executive Order (EO) 13212. 

1.3 CONFORMANCE WITH EXISTING LAND MANAGEMENT PLANS 

The Scotty Lake Coalbed Natural Gas Pilot Project (SLPP), as proposed by Hudson, would be 

consistent with management direction contained in: 

x the Record of Decision (ROD) for BLM’s Great Divide Resource Area Resource Management

Plan dated November 8, 1990 (BLM 1990); and

x the Record of Decision (ROD) for BLM’s Lander Resource Area Resource Management Plan

dated June 6, 1987 (BLM 1987). 

3

Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Furthermore, all operations proposed by Hudson would be conducted in full compliance with the 

terms and conditions of the federal leases involved in the Proposed Action or project alternatives, 

applicable Onshore Oil and Gas Orders, 43 CFR Part 2800 regarding right-of-way grants, and also 

with oil and gas leasing regulations as contained in 43 CFR Part 3100, specifically with subpart 

3162 concerning Requirements for Operating Rights, Owners and Operators. 

1.4 AUTHORIZING ACTIONS AND RELATIONSHIP TO STATUTES AND 

REGULATIONS, OR OTHER PLANS

The proposed project is in conformance with the State of Wyoming Land Use Plan (Wyoming State 

Land Commission 1979) and would comply with all relevant federal, state, and local laws and 

regulations. Please refer to Appendix A for a discussion of primary federal, state, and local 

permitting requirements.

The development of this project would not affect the achievement of the Wyoming Standards for 

Healthy Rangelands (August 1997). 

1.5 LAND AND RESOURCE MANAGEMENT ISSSUES AND CONCERNS 

In accordance with NEPA and the CEQ regulations contained in 40 CFR 1501.7, an open process 

has been employed for the determination and scope of issues to be addressed in this environmental

document. In compliance with this procedural requirement, the RFO released a scoping notice on 

March 17, 2004 in order to identify the significant issues related to the SLCBNGPP proposal. Ten 

comment letters were received in response to project scoping which led to the identification of the 

following land and resource management issues and concerns potentially associated with the 

Proposed Action: 

x Acquisition of appropriate permits

x Conformance with LUP 

x Control of invasive, non-native species (weeds) 

x Cumulative impacts

x Effects of erosion and sedimentation

x Geologic Hazards (earthquakes) 

x Habitat fragmentation

x Impacts to air quality 

x Impacts to aquifer being produced including water quality and recharge of aquifer

x Impacts of fences and roads on migratory antelope herd 

x Impacts to greater sage grouse 

x Impacts to livestock grazing operations 

x Impacts to migratory birds and compliance with the Migratory Bird Treaty Act 

x Impacts of noise 

x Impacts to social/economic values 

x Impacts to soils from construction of roads, well pads and buried pipelines 

x Impacts of surface discharge on soils and surface water quality 

x Impacts on wetlands and riparian areas 

5
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

6

x Potential for impacts to biological soil crusts 

x Potential for depletion of Colorado and/or Platte River water 

x Potential effects on small and big game species 

x Potential for migration of methane 

x Potential for underground (coal seam) fires 

x Protection of special status wildlife and plant species including endangered, threatened, 

candidate, proposed and BLM sensitive species 

x Reclamation 

x Risk from earthquakes 

x Risk to ground water from hydraulic fracturing 

x Use of alternative technologies, including directional drilling 

x Use of hazardous/toxic materials in drilling/completion operations 

Certain issues identified in conjunction with project scoping were determined not to be “significant 

issues related to the Proposed Action” (40 CFR 1501.7) because they are not potentially affected or 

impacted by the proposal. Those issues brought forth during public scoping that are not considered 

in depth in this document and the reasons for eliminating that particular issue from consideration in 

this analysis are enumerated in Appendix B. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

2.0 PROPOSED ACTION AND ALTERNATIVES

2.1 INTRODUCTION 

Hudson Group, LLC (the Operator) has proposed a coalbed natural gas pilot project within the Scotty 

Lake CBNG Exploratory Unit consisting of the drilling, completion, and testing of up to 18 CBNG 

wells within the 2,880 acre pilot project area (see Figure 2.1). These wells would be drilled in three 

phases over a period of three years. A review of Figure 2.1 will reveal wells proposed in conjunction 

with the proposed pilot project as follows: Phase I - 4 potential new well locations; Phase II - 6 potential 

new well locations; and Phase III - 8 potential new well locations. 

Although 21 well locations are depicted on Figure 2.1, only 18 total wells will be drilled in conjunction 

with the SLPP. The ultimate selection of those wells to be drilled during Phase III of the pilot project 

will be based upon the results of initial drilling and testing operations on wells previously drilled in 

Phases I and II with consideration given to contractual obligations for operations on leases within the 

Phase III project area boundary. Table 2.1 lists the wells proposed in conjunction with the SLPP. 

Table 2.1

Wells Proposed in Conjunction with the SLPP 

Well Name Legal Location of Well Federal Project BLM Field 

and Number Quarter Section Township Range Lease Number Phase Office

 Scotty Lake Unit # 9 SE1⁄4NW1⁄4 24 26 North 97 West WYW-14104A I Rawlins

 Scotty Lake Unit #10 SE1⁄4NE1⁄4 24 26 North 97 West WYW-14104A I Rawlins

 Scotty Lake Unit #11 SE1⁄4SE1⁄4 24 26 North 97 West WYW-14104A I Rawlins

 Scotty Lake Unit #12 SE1⁄4SW1⁄4 24 26 North 97 West WYW-14104A I Rawlins

 Scotty Lake Unit # 7 NE1⁄4NE1⁄4 19 26 North 96 West WYW-52013 II Rawlins

 Scotty Lake Unit #22 C SE1⁄4 18 26 North 96 West WYW-52012 II Lander

 Scotty Lake Unit #23 NW1⁄4NW1⁄4 20 26 North 96 West WYW-131839 II Rawlins

 Scotty Lake Unit #24 C SW1⁄4 17 26 North 96 West WYW-152174 II Lander

 Scotty Lake Unit #25 NE1⁄4NE1⁄4 19 26 North 96 West WYW-5201 II Lander

 Scotty Lake Unit # 8 NE1⁄4NW1⁄4 23 26 North 97 West WYW-147468 III Rawlins

 Scotty Lake Unit #13 NW1⁄4SW1⁄4 14 26 North 97 West WYW-147467 III Rawlins

 Scotty Lake Unit #14 NE1⁄4NW1⁄4 23 26 North 97 West WYW-147468 III Rawlins

 Scotty Lake Unit #15 C SW1⁄4 23 26 North 97 West WYW-147468 III Rawlins

 Scotty Lake Unit #19 SE1⁄4SE1⁄4 22 26 North 97 West WYW-147467 III Rawlins

 Scotty Lake Unit #20 C NE1⁄4 22 26 North 97 West WYW-147467 III Rawlins

 Scotty Lake Unit #26 C NE1⁄4 23 26 North 97 West WYW-147468 III Rawlins

 Scotty Lake Unit #27 C SE1⁄4 14 26 North 97 West WYW-147467 III Rawlins

 Scotty Lake Unit #28 SE1⁄4SE1⁄4 23 26 North 97 West WYW-147468 III Rawlins

 Scotty Lake Unit #16 1 NE1⁄4NW1⁄4 26 26 North 97 West WYW-158426 III Rawlins

 Scotty Lake Unit #17 1 NW1⁄4NW1⁄4 26 26 North 97 West WYW-158426 III Rawlins

 Scotty Lake Unit #18 1 C NE1⁄4 26 26 North 97 West WYW-158426 III Rawlins

1

 Optional wells

7
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

8
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

This environmental assessment (EA) addresses both the Proposed Action and the No Action alternative. 

Directional drilling operations were considered for wells proposed in conjunction with the SLPP but this 

alternative was not analyzed in detail (please refer to Section 2.5.2 for additional information in this 

regard).

x Proposed Action. This alternative would allow the Operator to construct 18 additional well 

locations and install related production (ancillary) facilities within the Scotty Lake Coalbed Natural 

Gas Pilot Project Area (SLPA). Approximately 106.05 (+/-) acres of initial (short-term) surface 

disturbance would occur in conjunction with the project proposal. 

x No Action Alternative. This alternative implies that both ongoing and previously approved natural 

gas exploration, development, and production activities would be allowed to continue by the BLM 

in the overall project area, but additional activity would not be allowed. Future Applications for 

Permit to Drill (APD’s) and Right-of-Way (ROW) applications would be evaluated by the BLM on 

a case-by-case basis through site specific environmental analyses in accordance with management

direction contained in both the Great Divide and Lander Resource Area approved RMP’s (BLM 

1990, BLM 1987). 

2.2 PROPOSED ACTION

The proposed action entails the initiation of a pilot project in the Scotty Lake CBNG Exploratory Unit 

designed to test the productive potential of coals in the Fort Union Formation for commercial CBNG 

production. Surface disturbing activities associated with Phase I of the proposed pilot project would 

commence in late summer of 2004 and would continue over a period of approximately 3 years, with 

Phases II and III of the proposed pilot project initiated in the summer of each successive year following 

2004. Should commercial CBNG production be established in conjunction with this pilot project, the 

productive life of these wells is estimated to be somewhere between 15 and 25 years. 

The statewide spacing pattern established by the Wyoming Oil and Gas Conservation Commission

(WOGCC) for oil and natural gas wells in this area of Wyoming is 40 acres or 16 wells per 640-acre 

section. However, the operator is currently proposing to drill those wells proposed in conjunction with 

the SLPP on a 160-acre spacing pattern or 4 wells per section, with a fifth well drilled in (or close to) the 

center of selected sections (which equates approximately 120 acres/well). 

Specific components of the proposed pilot project are contained in both the SLPP Plan of Development

and Master Field Permit (see Appendix C) and the Water Management Plan (see Appendix D) and 

which are summarized below. Additional site-specific environmental analyses and resource information

would be contained in each individual Application for Permit to Drill (APD) and/or Right-of-Way

(ROW) application subsequently submitted to the BLM. 

2.2.1 Well Pad Construction 

As indicated in Section 1.1, the 18 wells proposed in conjunction with the SLPP are all situated on 

surface and mineral estate owned by the United States of America (USA) and administered by the BLM.

A typical location layout for CBNG wells as proposed by the Operator is shown on Figure 2.2. Major 

components of each individual well pad would include: 

9
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

x a leveled area suitable for placement/support of the drilling rig and related equipment; and 

x an earthen reserve pit designed to contain drilling fluids, drilled cuttings, and fluids produced during 

the drilling operation. 

The entire well pad area would be cleared of all vegetation and graded to the required specifications 

prior to moving in the drilling rig and subsequent commencement of actual drilling operations. 

Sufficient topsoil to facilitate revegetation would be segregated from subsoil material during 

construction operations and stockpiled for future reclamation of the disturbed area. The salvaged topsoil 

would be evenly distributed over those disturbed surfaces subject to reclamation upon termination of 

drilling and completion operations as part of the reclamation and revegetation program. Topsoil 

stockpiles would be stabilized with vegetation until used for reclamation purposes. 

After the topsoil has been removed, the well pad would be graded to produce a level working platform

around the drill hole for support of the rig substructure. The excavated soil material (subsoil) would be 

utilized in overall pad construction, with the finished well pad graded to allow for positive drainage of 

natural water (e.g., rain and/or snow melt) away from the drill site. 

Generally, each individual well location would be designed so that the amount of soil material excavated 

(less the stockpiled topsoil) should “balance”, thereby eliminating the need to store excess subsoil 

material(s) in large stockpiles adjacent to the well location until site reclamation. Balancing of the 

excavated soil material would apply to the leveled area of the pad and would not include any materials

excavated from the reserve pit below the finished pad grade. Subsoil excavated from the reserve pit 

would be stockpiled directly adjacent to the reserve pit and would be utilized to backfill the pit once 

operations were completed and the pit was reclaimed.

The leveled area required for initial drilling and completion operations for each individual well would 

equal approximately 1.16 acres in size (including the reserve pit). Likewise, the area(s) required for 

cut/fill slopes and topsoil/subsoil stockpiles associated with the proposed pad design would average 

approximately 0.67 acres per well pad (based upon a 25-foot buffer zone surrounding the entire well pad 

to accommodate cut/fill slopes and topsoil/subsoil stockpiles). Overall surface disturbance associated 

with the construction of individual well pads would average approximately 1.83 acres per well location. 

Erosion control would be maintained through prompt revegetation and by constructing surface water 

drainage controls such as berms and diversion ditches as necessary at each individual well location. 

2.2.2 Access Roads 

Exploration and development activities to date within and/or directly adjacent to the SLPA have resulted 

in the construction of approximately 26,579 feet (5.03 miles) of new access road therein. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Generally speaking, previous exploration activities within the SLPA have resulted in the construction of 

a road system that should be more than adequate to serve the needs of the Operator for arterial traffic 

into and within the overall project area. 

New road construction associated with additional exploration and development in the project area would 

generally average approximately 1,477 feet (0.28 miles) of resource road per well location and would 

utilize existing two-track trails in the project area to the extent possible or feasible. Considering a total 

disturbed right-of-way (ROW) width which did not exceed forty (40) feet, this new road construction 

would result in additional surface disturbance equal to approximately 24.41 acres (or approximately 1.36 

acres per well location). Whenever possible, access roads would be designed and constructed to 

disturb less than the 40 foot ROW width referenced above, as long as traffic and safety concerns 

could be satisfied. The existing access roads would be maintained as necessary to accommodate

appropriate year-round traffic and prevent unnecessary erosion. These access roads would be

constructed in accordance with roading guidelines established for oil & gas exploration and 

development activities as referenced in the joint BLM/USFS publication: Surface Operating Standards 

for Oil and Gas Exploration and Development, Third Edition and/or BLM Manual Section 9113 

concerning road construction standards on federal lands (BLM 1985, 1991). Please refer to the SLPP 

Plan of Development and Master Field Permit (Appendix C) for additional information in this regard. 

2.2.3 Drilling Operations 

To facilitate the drilling of these proposed wells, the Operator would utilize a single rotary drilling rig 

rated for drilling operations to depths of approximately 5,000 feet. Rig transport and on-site assembly

would be completed in approximately 4 days, involve approximately 15 people per well location, and 

require approximately 60 round trips per well location. Generally speaking, drilling operations would 

be expected to occur on a seasonal basis during the summer and early fall periods when weather 

conditions are generally more favorable for field operations in this area of Wyoming.

Drilling operations would require approximately 7 days per well location from the time the drilling rig is 

moved onto the location (move in-rig up) until such time as drilling operations have been completed and 

the rig is moved off of the location (rig down-move out). 

After completion of the drilling phase of operations and prior to rig release, the well would be logged 

and production casing would be set to total depth and cemented into place. Setting and cementing the 

production casing string would serve to maintain hole integrity while isolating those formations

downhole which could potentially contain either fresh water or hydrocarbons. Proper cementing of the 

production casing string would reduce or eliminate the possibility for fluid communication between 

hydrocarbon bearing zones and/or near surface fresh water aquifers. 

Human waste generated at well locations would be collected in standard portable chemical toilets or 

service trailers and regularly transported off-site to a state-approved wastewater treatment site. Each 

well location would be provided with one or more such facilities during drilling and completion

operations. A septic system would not be required. Non-human waste would be collected in enclosed 

containers and disposed of at a state-approved solid waste disposal facility.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

2.2.3.1 Drilling Fluids System 

The actual drilling operation would utilize a water-based mud system with additives for lost circulation, 

hole stabilization, and/or conditioning prior to logging and/or running casing. Basically, this system

involves drilling with water and utilizing non-hazardous additives to minimize downhole problems. On 

the average, the Operator would utilize approximately 1.5 barrels of water (42 gallons/barrel) per foot of 

hole drilled. Fresh water for use in drilling operations would be obtained either from the Pickett 

Lake Unit #1 producing CBNG well located in the NW1⁄4SE1⁄4 of Section 24, Township 26 North, 

Range 97 West or from an existing storage reservoir constructed by the Operator in the NW1⁄4SE1⁄4

of Section 24, Township 26 North, Range 97 West (see Appendix C). No water would be used from

either the North Platte River or the Colorado River or their tributaries for use in construction, drilling, 

cementing, or completion operations within the SLPA. 

Water to be utilized in drilling operations would be contained in a “reserve pit” constructed on each 

location (refer to Figure 2.2) and would serve as the base medium for the drilling mud system. The 

reserve pit would be fenced on the three non-working sides during drilling, with the fourth side of the pit 

fenced immediately following removal of the drilling rig in order to protect wildlife and livestock. 

Fencing would be installed in accordance with guidelines contained in the joint BLM/USFS publication: 

Surface Operating Standards for Oil and Gas Exploration and Development, Third Edition and would 

be maintained until the reserve pit has been backfilled (see Appendix C). 

Fluids that accumulate in the reserve pit during drilling and completion operations would be contained 

therein and would be allowed to evaporate prior to the reclamation of said pit. Once free of liquids, the 

reserve pit would be reclaimed by backfilling the pit with the sub-soil (spoil) material removed

therefrom during construction. Once the pit has been backfilled, a portion of the stockpiled topsoil 

would be evenly distributed (spread) over the reclaimed area and reseeded in accordance with the 

specifications of the BLM (see Appendix C). 

2.2.3.2 Casing & Cementing Operations 

Surface casing would typically be set to a minimum depth of 450 feet and cemented back to the surface 

on each proposed well (see Appendix C). This would serve to isolate all near surface fresh water 

aquifers which could occur in the project area. Upon reaching total depth, production casing would be 

run and cement circulated to a minimum of 200 feet above the top of the shallowest coal in the Fort 

Union Formation, effectively isolating all geologic formations encountered down hole in compliance

with Onshore Oil and Gas Order Number 2. This procedure would eliminate any possibility for fluid

communication between potential hydrocarbon bearing zones and any near-surface fresh water aquifers 

which may be encountered downhole. 

2.2.4 Completion and Evaluation Operations

Once the well has been drilled and cased, a completion (work-over) unit is moved onto the well location 

and completion operations are commenced. These completion operations generally require an average 

of 3 to 5 days per well location, consist of cleaning out the well bore with fresh water, pressure testing, 

and perforating the potentially productive formations downhole.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

After the casing has been perforated, production tubing is run and dewatering operations commence. In 

certain instances, it may be necessary to hydraulically fracture the coals within the Fort Union 

Formation using fresh (produced) water. Should the initial hydraulic “frac” prove to be unsuccessful, a 

second “frac” would be performed utilizing a mixture of approximately 1,500 barrels of fresh water and 

100,000 to 150,000 pounds of sand which would be pumped down the casing under extreme pressure 

and forced through the perforations into the formation. As the formation is fractured, the resultant 

fissures (fractures) are filled with sand which props them open and facilitates the flow of gas/water into 

the well bore and subsequently to the surface. Upon completion of the frac job, the well would be 

flowed back to the surface in an attempt to recover as much of the frac fluid as possible and to clean 

excess sand out of the perforations prior to setting production equipment on location and placing the 

well on line. All fluids utilized in the completion procedure are captured either in the reserve pit or in 

test tanks on the well location and ultimately disposed of in strict accordance with Wyoming

Department of Environmental Quality (WDEQ) rules and regulations. 

Once each well has been completed, a submersible/progressive cavity pump would be set and the 

evaluation (dewatering) phase of the project would commence. The operator would obtain approval of 

an Application for Permit to Appropriate Ground Water (form #UW-5) from the Wyoming State 

Engineer’s office (WSEO) prior to beginning the dewatering process. In this regard, we would expect 

the continuous operations of these wells for a period ranging from approximately 6 months to 2 years in 

order to obtain a proper evaluation of the Fort Union Formation and subsequently determine the 

commercial feasibility of CBNG production therefrom. During this initial evaluation phase of 

operations, these wells could be expected to be on pump continuously twenty-four (24) hours a day. 

Each “producing” well would be monitored on a daily basis by a single contract pumper to ensure that 

the wells were functioning properly and that no leaks had occurred in the gas/water gathering system.

Generally speaking, natural gas within the coal is held in place by pressure from water contained in 

fractures within the coal seam. Mechanical pumping removes this water, lowering the formation

pressure, and thus allowing the gas to “desorb” from the coal facies. An evaluation of the actual 

volume(s) of water removed prior to commencement of desorption, coupled with the resultant 

desorption rates will be extrapolated to calculate the commercial feasibility of additional exploration 

and/or development activity within the Scotty Lake CBNG Exploratory Unit and will also be used to 

refine a prediction of potential well densities required to accomplish economic recovery of the CBNG 

resource.

As the coal is depressured, desorption will occur and CBNG will commence flowing to the surface.

Typically, there is an inverse relationship between water and gas production, with water volumes

tending to decrease over time as the water pressure in the coal is lowered, while gas volumes tend to 

increase as the water is removed from the formation. Eventually, an equilibrium will be reached at 

which point maximum gas desorption will occur in association with diminished water production. 

However, this equilibrium can only be maintained as long as the well remains on pump. Should the well 

be “shut-in” for any period of time, the coal(s) could recharge with water, resulting in a loss of gas 

production as pressures rebuild. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

2.2.5 Production Operations

Production equipment required at each individual well location would typically include the following 

equipment:

x a small christmas tree at the well head (a series of valves designed to control pressures and regulate 

flows from the well) with a submersible/progressive cavity pump;

x 50 horsepower (hp) generator powered by natural gas which would power the 

submersible/progressive cavity pump used to dewater the coal seam;

x a 50 hp screw compressor powered by natural gas; and 

x a meter run for measurement of gas volumes produced into the pipeline. 

All above ground production facilities installed at each producing well location would be painted a 

standard environmental color that blends with the surrounding landscape (see Appendix C). 

The presence of very small quantities of liquid hydrocarbons (condensate) within the Fort Union 

Formation may necessitate the installation of tanks at selected well locations where condensate 

production is encountered. These tanks would be used to contain fluids produced from the well bore, 

allowing separation of the liquids prior to discharge. The collected condensate would either be 

introduced into the gas sales pipeline for capture downstream or be trucked to sales upon collection of a 

sufficient quantity to justify trucking. At this point, liquid hydrocarbon production from the three 

existing CBNG wells is nominal.

Pipelines would be installed for the transportation of natural gas and water produced from the well bore. 

Gas would be transported via buried pipeline to a connection with the closest existing line within the 

project area while the produced water would be transported to a discharge point for surface disposal. 

No hydrogen sulfide (H2S) is known to occur within the Fort Union Formation and none is expected to 

be encountered during project operations. 

Water produced in association with the gas stream is expected to average approximately 700 barrels of 

water per day (bwpd) per well. 

2.2.6 Pipeline Gathering System 

Two types of pipelines would be installed as part of the proposed pilot project: 

1) gas-gathering pipeline systems consisting of low pressure lines that would collect gas produced at 

the well head and transport said gas downstream to an existing central production facility 

(compressor site located in the SW1⁄4NE1⁄4SE1⁄4 of Section 23 in Township 26 North, Range 97 

West); and

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

2) produced water disposal lines. 

In those cases where the gas and water lines are traveling in the same direction, both lines would 

typically be installed (buried) in a common trench. In most cases, however, produced water will be 

discharged to the surface in relatively close proximity to the well location and may involve a separate 

pipeline ROW that is divergent from the gas gathering system pipeline ROW.

2.2.6.1 Gas Gathering System 

An existing gas gathering system within the project area would be augmented as necessary to transport 

CBNG produced from wells drilled in association with the SLPP to a pre-existing, compressor facility 

located approximately in the SW1⁄4NE1⁄4SE1⁄4 of Section 23, Township 26 North, Range 97 West. These 

pipelines would follow existing and proposed roads within the SLPA to the greatest extent possible. 

Pipelines installed directly adjacent to existing/proposed access roads within the SLPA would typically 

require a slightly smaller overall right-of-way (ROW) width of 25 feet as the Operator would be able to 

utilize the existing access road running surface as a staging area for pipe assembly and installation, as 

opposed to cross-country lines which would require a ROW width of approximately 50 feet. Industry 

standard pipeline equipment, materials, techniques, and procedures conforming with all applicable 

regulatory requirements would be employed during construction, testing, operation, and maintenance of 

gathering system pipelines in order to ensure the safety and efficiency of all pipelines installed in the 

SLPA.

As indicated above, pipeline ROWs would generally be located adjacent to existing/proposed roads to 

the greatest extent possible in order to minimize surface disturbance and maximize construction and gas 

transport efficiency. Where major excavation is required, sufficient topsoil to facilitate reclamation

would be removed from the pipeline ROWs before construction, as determined by the Authorized 

Officer. Where individual ROWs do not require major excavation, vegetation would be removed to 

ground level by mechanical treatments including either “brush-beating” or scalping, both of which leave 

the topsoil intact minimizing disturbance to plant root systems, thereby facilitating vegetative reestablishment. Brush beating or scalping would typically be limited to an area approximately 15 feet in 

width along the pipeline ROW. All pipeline ROW reclamation would be initiated as soon as practical 

following disturbance, but would be completed within a maximum of 1 year following completion of 

pipe installation. 

All CBNG pipelines would be tested with either natural gas or water to ensure the integrity of newly 

constructed lines. This testing would consist of filling pipeline segments with the testing medium and 

pressurizing the segments to levels exceeding expected operating pressures. If leaks or ruptures occur, 

they would be repaired and testing would be repeated until successful. Natural gas used for testing 

would either be returned to the gathering system for sales or would be vented (released) to the surface in 

accordance with NTL-4A and/or WOGCC Rule 340. Water used in hydrostatic testing would be 

discharged to the surface in accordance with Wyoming Department of Environmental Quality rules and 

regulations governing surface water discharges. 

Approximately 23,353 feet (4.42 miles) of 2 inch gas pipeline would be required to connect the 18 wells 

proposed in conjunction with the SLPP to an existing/proposed gas gathering system for transportation 

to the compressor site located in Section 23. Approximately 4,382 feet of the 2 inch line would be 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

installed in “cross-country” right-of-ways with the remaining 18,971 feet of pipeline installed directly 

adjacent to existing/proposed access roads within the SLPA. An additional 19,989 feet (3.79 miles) of 8 

inch line would be installed as a gathering system to transport gas collected from individual wells in 

Phases II and III of the SLPA, with approximately 7,396 feet of the 8 inch line installed in “crosscountry” right-of-ways and the remaining 12,592 feet of pipeline installed directly adjacent to 

existing/proposed access roads within the SLPA. These pipelines would be buried to a depth of 

approximately 6 feet within the ROW. Reclamation of pipeline right-of-ways (ROWs) would occur as 

soon as practical following pipe installation. Installation of 43,342 feet of buried pipeline to transport 

gas produced from the individual wells within the SLPA to the compressor site in Section 23 would 

result in short-term surface disturbance equal to approximately 31.63 acres (which includes 31,564 feet 

of pipeline in a 25 foot ROW and 11,778 feet of pipeline in a 50 foot ROW).

Gas delivered to the central compressor facility referenced above would be introduced into an existing 

gas transmission for transportation to market via a pre-existing connection therewith. 

2.2.6.2 Water Discharge Lines 

Water produced from each CBNG well would be transported via buried pipeline to a surface discharge 

point typically located in close proximity to the producing well. These produced water pipelines would 

generally consist of 3 inch polyethylene pipe buried at a maximum depth of 6 feet. In most cases these 

pipelines would be installed “cross-country” in order to achieve the most direct route from the well to 

the discharge point and minimize the amount of surface disturbance associated with pipe installation, as 

well as minimize the potential for freeze-up during the winter months.

The 22,597 feet (4.28 miles) of water discharge line would typically be installed with a small trencher 

(ditch witch or backhoe) resulting in a minimum of surface disturbance within the pipeline ROW. As a 

result, it is anticipated that no ROW preparation (i.e., topsoil salvage or blading) would be required prior 

to the commencement of actual trenching activities, pipe installation, and subsequent backfilling of the 

trench. Consequently, surface disturbance associated with the installation of these buried water 

discharge lines would be primarily limited to the actual trench itself (approximately six inches in width) 

and the travelway along the ROW route used for trenching activities and pipe staging. Considering a 

travelway width of 10 feet, short-term surface disturbance associated with the installation of these water 

discharge lines would result in approximately 5.19 acres of short-term disturbance. 

2.2.7 Ancillary Facilities 

The Proposed Action would utilize the existing ancillary facility infrastructure within the SLPA to the 

greatest extent possible for access to proposed well locations, gas gathering, and water disposal. 

2.2.8 Transportation and Workforce Requirements

Estimated transportation and workforce requirements for drilling, completion, and evaluation operations 

on similar CBNG projects have been analyzed for numerous, similarly-sized CBNG projects

throughout southwestern Wyoming in recent years. Consequently, the reader is directed to one or 

more of these documents for additional information in this regard: 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

x Decision Record, Finding of No Significant Impact and Environmental Assessment for Lower 

Bush Creek Coal Bed Methane Exploratory Pilot Project. Rock Springs Field Office, Bureau of 

Land Management. August 2003. 

x Environmental Assessment for the Atlantic Rim Interim Drilling Project, Doty Mountain POD, 

Carbon County, Wyoming. Rawlins Field Office, Bureau of Land Management. October 2003. 

x Environmental Assessment for the Atlantic Rim Coalbed Methane Project, Brown Cow POD, 

Carbon County, Wyoming. Rawlins Field Office, Bureau of Land Management. December

2003.

2.2.9 Water Production and Disposal 

The operator has previously obtained approval of a National Pollutant Discharge Elimination System

(NPDES) permit (permit #WY0049662) from the Wyoming Department of Environmental Quality 

(WDEQ) which allows for the surface discharge of water produced from both pre-existing wells as well 

as those wells proposed in conjunction with the SLPP within the approved parameters of said permit.

NPDES Permit #WY0049662 currently allows the operator to discharge 0.81 million gallons of water 

per day (mgwpd) into Red Creek and ephemeral tributaries thereof. No produced water will be 

discharged into the West Alkali Creek drainage basin. The operator estimates that water production 

from wells drilled in conjunction with the SLPP would average approximately 550 barrels of water per 

day (bwpd) per well, for total water production from all 18 wells equivalent to 9,900 bwpd or 415,800 

gallons per day (gpd), which is approximately one-half of the discharge currently approved under 

NPDES Permit #WY0049662 as amended.

Surface disposal methods that would be utilized in conjunction with the proposed SLPP would include 

the following or various combinations thereof: 

1) Direct discharge of produced water to the surface via a “bubbler” or gravel envelope; 

2) discharge into an unlined water retention pit with an overflow outlet; or 

3) discharge into an unlined retention pit without an overflow outlet. 

The appropriate disposal method would be selected at the time of the on-site inspection for each 

individual well location and would be included in the approval of each individual Application for Permit

to Drill (APD) by BLM as a condition of approval. Please refer to the SLPP Water Management Plan 

(WMP)(Appendix D) for a full description of these discharge methods and diagrams depicting same.

Surface disturbances associated with direct surface discharge under discharge alternative 1 (above) 

would typically be minimal as compared to the construction of the water retention pits referenced under 

discharge alternatives 2 and 3. Water retention pits designed to contain the water produced from

individual CBNG wells would typically be approximately 165’ X 100’ X 12’ in size and would result in 

the long-term (LOP) disturbance of approximately 0.66 acres/pit including a 20’ buffer around the 

perimeter of the retention pit. Installation of these pits would typically be limited to those particular 

instances where a suitable surface discharge point (ephemeral tributary to Red Creek) was not available 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

in close proximity to the discharge source. A suitable surface discharge point would be a location 

approved by the WDEQ that has both a suitable gradient and channel characteristics to allow for 

discharge to occur without excessive erosion and/or channel form changes such as vertical or lateral 

movement.

For the purposes of this environmental analysis, calculations of surface disturbance will assume that a 

water retention pit will be constructed at each of the 18 proposed well locations, which will overstate the 

surface disturbance associated with this aspect of the SLPP, yet will allow for a simplification of the 

impact analysis in Chapter 4, while including potential disturbances resulting from installation of 

bubblers or gravel envelopes under discharge alternative 1. On-site inspections conducted on the wells 

proposed in conjunction with Phase I of the SLPP did not identify the need for any water retention pits; 

consequently, the likelihood that numerous retention pits will be required in conjunction with Phases II 

and III is considered to be unlikely at best. 

2.2.10 Hazardous Materials 

Hudson Group, LLC has reviewed the EPA’s Consolidated List of Chemicals Subject to Reporting 

Under Title III of the Superfund Amendments and Reauthorization Act (SARA) of 1986 (as amended) to 

identify any hazardous substances proposed for production, use, storage, transport, or disposal by this 

project, as well as the EPA’s List of Extremely Hazardous Substances as defined in 40 CFR 355 (as 

amended) and has determined that none of the materials listed as hazardous and/or extremely hazardous 

would be used or generated by this project. 

2.2.11 Abandonment

In the event that wells within the SLPA become commercially non-productive, the Operator would 

obtain the necessary authorization(s) from the appropriate regulatory agencies to abandon the nonproductive well(s). All above ground facilities would be removed, the well bore would be physically 

plugged with cement as directed, and both the abandoned road and well location reclaimed according to 

BLM recommendations.

2.2.12 Reclamation 

All disturbed surfaces would be reclaimed as soon as possible following the initial disturbance. This 

reclamation would consist primarily of backfilling the reserve pit, leveling and recontouring of disturbed 

areas, redistribution of stockpiled topsoil over the disturbed areas, installation of erosion control 

measures as appropriate, and reseeding as recommended by the BLM. 

Reclamation of the reserve pit would be accomplished when the pit is no longer required for completion

and/or testing operations. Free standing water in the pit would be allowed to evaporate through natural 

means to the greatest extent possible prior to the commencement of backfilling; however, in some

instances the pit contents may be mixed with suitable solid materials and the pit backfilled, as approved 

by the BLM. Prior to the mixing of reserve pit contents with approved stabilizing materials, the contents 

of the reserve pit would be tested for total petroleum hydrocarbons (TPH) and toxicity characteristics 

leaching procedure (TCLP) constituents, and appropriate closure permits would be obtained from the 

WOGCC and/or WDEQ. If necessary, reserve pit contents would be removed and disposed of at an 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

approved disposal facility in a manner commensurate with all relevant county, state, and federal 

regulations and stipulations pertaining thereto. 

Reclamation of the well location would be accomplished within a maximum of 2 years following the 

termination of drilling and completion operations (in the case of productive wells) or well abandonment

(in the case of newly drilled dry holes). 

2.2.12.1 Producing Well Location

During the production/testing phase of operations, the unneeded (non-working) area(s) of the well pad 

would be reclaimed as soon as possible after conclusion of drilling and completion operations, weather 

permitting. Reclamation would consist of backfilling the reserve pit, reducing the cut/fill slopes by 

pushing the fill material back up into the cut, redistributing the stockpiled topsoil over these reclaimed

areas, installing erosion control measures as appropriate, and reseeding the reclaimed areas as 

recommended by the BLM. Restoration of these previously disturbed areas would result in the 

reclamation of approximately 60% of each individual well pad, or 1.10 acres/well location. As indicated 

above, this reclamation would be performed within 2 years of well completion and would reduce the 

long-term or life of project (LOP) disturbance resulting from well pad construction under this proposal 

to 13.14 acres. 

2.2.12.2 Access Roads

A minimum of 6 inches of topsoil would be stripped from the access road corridor (new construction 

portions only) prior to the commencement of construction activities and would be redistributed on the 

“outslope” areas of the borrow ditch after completion of road construction activities. These borrow 

ditch areas would then be reseeded as soon as practical thereafter. Likewise, any surface disturbances 

on/along the “outslope” areas of existing roads within the project area resulting from implementation of 

the Proposed Action would be reseeded as well. 

Restoration of those areas disturbed in conjunction with right-of-way clearing, topsoil salvage, and 

subsequent road construction would typically result in the reclamation of approximately 30% of the 

disturbed road ROW (for a road having a 16-foot unsurfaced running surface), not including any 

provision for the revegetation of the outslope portion of the borrow ditch. As indicated above, this 

reclamation would be performed within 2 years of well completion and would reduce the long-term or 

LOP disturbance resulting from access road construction under this proposal to approximately 17.09 

acres.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

2.2.12.3 Pipelines

A minimum of 6 inches of topsoil would be stripped from the gas pipeline ROWs prior to the 

commencement of construction activities. Once trenching and pipe installation operations have been 

completed, the trench would be backfilled with the subsoil materials previously removed therefrom, the 

trench will be compacted to avoid settling, and the stockpiled topsoil redistributed over the disturbed 

ROW. The gas pipeline ROW would then be reseeded as soon as practical thereafter. 

Considering the negligible amount of surface disturbance associated with the installation of water 

discharge lines, wholesale reclamation would not be required unless blading and shaping of the ROW

(on steep slopes) were required resulting in surface disturbance comparable to disturbances associated 

with gas line installation. In these instances, these water discharge ROWs would be reclaimed and 

reseeded as above. 

Considering that all disturbances associated with pipeline construction would be reclaimed and reseeded 

as soon as practical following pipe installation, these disturbance are considered as short-term and are 

not included in the LOP cumulative disturbance totals. 

2.2.12.4 Abandoned Well Location 

Upon final abandonment, all existing surface facilities would be removed from the well location as 

stated in Section 2.2.9. The access road and remaining “work” areas of the well location would be 

scarified and recontoured, erosion control measures would be installed as necessary, and all recontoured 

(disturbed) areas would be reseeded as recommended by the BLM. 

2.3 APPLICANT-COMMITTED ENVIRONMENTAL PROTECTION MEASURES

The following applicant-committed practices, design features, and procedures would be implemented by 

the Operator in order to minimize impacts to the environment. Each applicant-committed practice is 

listed only once, under the first resource where it applies; however, many practices apply to several 

resources and would reduce impacts to each. These practices, design features, and/or procedures may be 

waived when deemed inappropriate by the BLM if a thorough analysis determines that the resource(s) 

for which the measure was developed would not be impacted. Additional site-specific mitigation

measures would be identified during the APD and ROW application review processes. 

2.3.1 Preconstruction Planning and Design Measures 

1. The Operator and BLM would conduct on-site inspections of each proposed disturbance site (e.g., 

well sites, roads, pipelines, etc.) to develop site-specific recommendations and mitigation measures.

2. Roads required for the proposed project would be constructed in accordance with BLM Manual 

9113 standards (BLM 1985, 1991). 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

3. The Operator would prepare and submit individual drill site design plans to the BLM for approval 

prior to initiation of construction. These plans would show the layout of the well location over the 

existing topography, dimensions of the well pad, volumes and cross-sections of proposed cuts 

and/or fills, location and dimensions of reserve and flare pits, and access road design. 

4. Prior to construction, the Operator would submit an addendum to the Plan of Development and 

Master Field Permit (Appendix C) which contains site-specific information concerning each 

proposed well site, pipeline segment, and access road project. These site-specific addendums

would enumerate the measures and techniques to be used for erosion control, revegetation, and 

restoration, and would provide specific detail on project administration, time frames, responsible 

parties, objectives, characteristics of site predisturbance conditions, topsoil removal, storage and 

handling, runoff and erosion control, seed bed preparation, recommended seed mixtures, seed 

application, fertilization, mulching, site protection, weed and livestock or other herbivore control, 

and monitoring and maintenance.

5. The Operator would slope-stake construction activities on steep and/or unstable slopes when 

required by the BLM, and would receive approval by the BLM prior to initiating construction. 

6. The Operator would identify aggregate and other road material sources for use in drill site and road 

construction. The appropriate surface management agency would approve these sources, including 

timing for extraction, prior to use. 

2.3.2 Air Quality 

1. The Operator would adhere to all applicable Wyoming Ambient Air Quality Standards (WAAQS)

and Regulations including those for fugitive dust suppression presented in Wyoming Air Quality 

Regulations on Fugitive Dust Suppression Section 14(F) (WDEQ 2003a). If a fugitive dust 

problem is identified by the BLM as a result of this project, immediate abatement measures (e.g., 

applications of water or chemical dust suppressants to disturbed surfaces) would be initiated in 

consultation with the BLM and WDEQ to avoid exceeding ambient air quality standards. 

2. The Operator would not allow open burning of garbage or refuse at well locations or other facilities

in the SLPA. Any other open burning would be conducted under the permitting provisions of 

Section 13 of the Wyoming Air Quality Standards and Regulations (WDEQ 2003a). 

2.3.3 Cultural Resources 

1. The Operator would follow the Section 106 compliance process prior to any surface disturbing 

activity.

2. The Operator would halt construction activities if previously undetected cultural resource materials

are discovered during construction. The BLM would be immediately notified, and consultation 

with the SHPO and Advisory Council would be initiated, as appropriate, to determine proper 

mitigation measures pursuant to 36 CFR 800.11. Construction would not resume until a Notice to 

Proceed is issued by the BLM.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

2.3.4 Geology and Minerals 

1. BLM/WOGCC casing and cementing criteria would be followed to protect all subsurface mineral

and water-bearing zones. 

2.3.5 Hydrology 

 1. Construction at drainage crossings would be limited to periods of low or no-flow. 

2. The Operator would follow all practical alternatives and designs to limit disturbance within 

drainage channels, including ephemeral and intermittent draws. 

3. A 100 foot wide buffer area of undisturbed land would be left between construction sites and 

ephemeral and intermittent channels, except for those construction activities designed to reduce 

erosion in conjunction with surface discharge locations. 

4. Channel crossings by pipelines would be constructed so that the pipe is buried at least 4 feet below 

the channel bottom.

 5. Channel crossings by roads and pipelines would be constructed perpendicular to flow. 

 6. Disturbed channel beds would be reshaped to their approximate original configuration. 

7. All reserve pits would be constructed with a minimum of one-half (1/2) the total depth of the pit 

below the original ground surface on the lowest point within the pit. 

 8. All reserve pits would be designed with a minimum of 2 feet of freeboard. 

9. The discharge of all water (storm water, produced water, etc.) would be done in conformance with 

applicable WDEQ, BLM and WOGCC rules and regulations. 

10. An isotopic analysis will be conducted on a water sample to be taken from one CBNG well within 

the Scotty Lake Unit before production begins from Phase I of the SLPP. 

2.3.6 Noise 

1. All motorized equipment will be muffled and maintained in accordance with the manufacturer’s

specifications.

2. All areas of operations (drill sites, etc.) where noise levels may exceed federal OSHA safe limits,

the operator will provide and require the use of proper personal protective equipment by workers. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

2.3.7 Range Management 

1. Removal or disturbance of vegetation would be kept to a minimum through construction site 

management (e.g., by utilizing previously disturbed areas, using existing ROWs, designating 

limited equipment/material storage yards and staging areas, scalping, etc.). 

2. The Operator would seed and stabilize disturbed areas in accordance with management direction 

from the Authorized Officer, BLM. 

3. The Operator would monitor for noxious and invasive weed species and would apply BLMapproved weed control techniques (e.g., soil sterilants, biological controls, etc.) as necessary to 

control infestations with the prior approval of the Authorized Officer, BLM. 

4. The Operator would fence water retention pits as deemed necessary by and in accordance with 

management direction received from the Authorized Officer, BLM. 

2.3.8 Soils 

1. Prior to commencement of construction activities, all available topsoil (up to a maximum of 12 

inches) would be stripped from areas of cut, fill, and subsoil storage, and stockpiled for future

reclamation operations. 

2. The Operator would keep the area of disturbance to the minimum necessary for drilling and 

subsequent production activities, while providing for worker safety on site. 

 3. The Operator would restrict off-road vehicle activity by employees and contract workers. 

4. The Operator would restrict project-related travel and reclamation activities during periods when 

soils are saturated and excessive rutting could occur. 

5. Where feasible, the Operator would locate pipelines immediately adjacent to roads or other 

pipelines to avoid creating separate areas of disturbance. 

6. The Operator would minimize construction activities in areas of steep slopes and apply special 

slope stabilizing structures and techniques (e.g., mulch, matting, etc.) if construction cannot be 

avoided in these areas. 

 7. The Operator would not conduct construction and/or reclamation activities using frozen or saturated 

soils, unless an adequate plan is submitted and approved by the BLM that demonstrates potential 

impacts would be mitigated.

8. Runoff and erosion control measures such as water bars, berms, and interceptor ditches would be 

installed as necessary. 

9. All drainage crossing structures would be designed to carry at least a 10 year storm event, pursuant 

to guidelines contained in BLM Manual, Section 9113 (BLM 1985, 1991). 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

10. Upon completion of drilling operations and/or production facility installation, the Operator would 

restore those areas disturbed in conjunction therewith to the approximate original contours. 

11. The Operator would replace topsoil or suitable growth materials over all disturbed surfaces prior to 

reseeding.

12. The Operator would reseed all disturbed sites as soon as practical following initial disturbance. 

2.3.9 Transportation

1. Existing roads and trails would be utilized to the greatest extent possible and upgraded as necessary 

to comply with BLM road construction specifications. 

2. All roads not required for routine operation and maintenance of producing wells or ancillary 

facilities would be reclaimed as directed by the BLM. These roads would be permanently blocked, 

recontoured, reclaimed, and revegetated by the Operator, as would disturbed areas associated with 

permanently plugged and abandoned wells. 

3. The Operator would comply with existing federal, state, and county requirements and restrictions to 

protect road networks and the traveling public. 

4. Special arrangements would be made with the WDOT to transport oversize loads to the project 

area. Otherwise, load limits would be observed at all times to prevent damage to existing road 

surfaces.

5. All development activities along approved ROWs would be restricted to areas authorized in the 

approved ROW.

6. The Operator would be responsible for maintenance of roads in the project area and for closure of 

roads following production activities. 

7. Where proposed roads would follow existing roads, those portions of existing roads not included in 

the new ROW would be reclaimed and revegetated by the Operator. 

2.3.10 Wildlife

1. Reserve, workover, and production pits potentially hazardous to wildlife would be adequately 

protected (e.g., fencing, netting) to prohibit wildlife access as directed by the BLM, to ensure 

protection of migratory birds and other wildlife. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

2. USFWS and WGFD consultation and coordination would be conducted for all mitigation activities 

relating to raptors, and T&E species and their habitats and all permits required for movement,

removal, and/or establishment of raptor nests would be obtained. 

2.4 NO ACTION ALTERNATIVE

The National Environmental Policy Act of 1969 (NEPA) requires that the “No Action” alternative be 

considered in all environmental documents. Under the No Action Alternative, the BLM would deny 

further CBNG exploration activities on federal lands within the SLPA as currently proposed by the 

Operator, while allowing other land and resource uses to continue without the impacts which would be 

associated with the pilot project proposal. Denial of this specific pilot proposal is not, however, a denial 

of all future CBNG exploration and development in the area. Under the No Action Alternative, 

development of lands in the Scotty Lake CBNG Exploratory Unit and adjoining areas could occur at 

levels similar to those which have occurred on the area in the past and could occur as authorized by 

existing management directives contained in the Great Divide and Lander RMP’s, which includes the 

requirement for site-specific NEPA analysis on all proposals. 

The decision to select the No Action Alternative for additional exploration within the SLPA is available 

to the BLM through denial of individual APD’s; however, the right to drill and develop somewhere

within the leasehold cannot be denied by the Secretary of the Interior. Consequently, the BLM’s 

authority to implement the No Action Alternative is somewhat limited. This limitation is based upon the 

fact that valid leases have been issued which specifically grant the lessee (or his designated operator) the 

“right to drill for, ...extract, remove and dispose of all oil and gas deposits” in the leased lands subject 

to the terms and conditions of the respective leases. Because the Secretary of the Interior has the 

authority and responsibility to protect the environment within federal oil and gas leases, restrictions can 

be imposed on the lease terms (see Cooper Valley Machinery Works, Inc. vs. Andrus, 474 F. Supp. 189, 

191; D.D.C. 1973; 653 F. 2nd 595; D.D.C. 1981; Natural Resources Defense Council vs. Berland, 458 

F. Supp. 925, 937; D.D.C. 1978), but the secretary can not deny development of the lease. 

The Tenth Circuit Court of Appeals in Sierra Club vs. Peterson (717 F. 2nd 1409, 1983) found that “on

land leased without a No Surface Occupancy stipulation, the Department cannot deny the permit to 

drill...once the land is leased the Department no longer has the authority to preclude surface disturbing 

activity even if the environmental impact of such activity is significant. The Department can only 

impose mitigation measures upon a lessee who pursues surface disturbing exploration and/or drilling 

activities”. The court goes on to say “...notwithstanding the assurance that a later site-specific 

environmental analysis will be made, in issuing these leases the Department has made an irrevocable 

commitment to allow some surface disturbing activities, including drilling and road building”.

This was clarified somewhat in Instruction Memorandum 92-67 issued by the Director, Bureau of Land 

Management on December 3, 1992 which states that “...Because all oil and gas activities are subject to 

FLPMA, mitigation required to protect public lands from unnecessary and undue degradation is 

consistent with the lease rights granted. The caveat, however, is that...unnecessary and undue 

degradation implies that there is also necessary and due degradation”. As a matter of policy, any 

mitigation measures “...which would render a proposed operation uneconomic or technically unfeasible 

is not considered to be consistent with a lessee’s rights and cannot be required absent a lease 

stipulation, unless it is determined that such mitigation is required to prevent unnecessary and undue 

degradation of public lands or resources...”. To deny all activity would thus constitute a “taking” of the 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Operators right to conduct exploration activities on the subject federal leases. As the court held in 

Union Oil Company of California vs. Morton, “Congress itself can order leases forfeited, subject to 

payment of compensations. But without Congressional authorization, the Secretary of the executive 

branch in general has no intrinsic power of condemnation”.

Based upon the above, selection of the No Action Alternative would deny the proposal as submitted, but 

would allow BLM to consider additional exploration and development of the federal mineral estate on a 

case by case basis through individual APD’s and site specific environmental analysis. Off-lease access 

to drill sites and/or the transportation of natural gas products would also be considered on a case by case 

basis by BLM. 

Many leases in the SLPA contain various stipulations addressing surface disturbance, steep slopes, 

wildlife, and other matters of concern. These stipulations would allow the BLM to preclude 

development in certain areas (e.g., where slopes exceed 25%) or at certain times of the year (e.g., to 

protect big game crucial winter habitat) if operations cannot be acceptably mitigated. However, there is 

no stipulation, such as a NSO, that would allow the BLM to preclude drilling operations everywhere on 

a lease at all times of the year. If any one of the stipulations cannot be acceptably implemented and 

impacts mitigated, then an exception would not be granted. A decision, therefore, of No Action, as 

authorized by the leases, would only be considered, given one of the following conditions: 

x If there were no acceptable means of mitigating significant adverse impacts to stipulated surface 

resource values, then this would trigger denial of the APD and require consideration and analysis of 

another alternative(s). Effectively, exception(s) to one or more of the lease stipulations would not be 

approved.

x If the USFWS concluded that the Proposed Action and alternatives would likely jeopardize the 

continued existence of threatened or protected plant and animal species, then the APD and lease 

development may be denied in whole or in part. 

This EA will help to determine whether the proposed project meets any of these conditions. 

2.5 ALTERNATIVES CONSIDERED BUT NOT ANALYZED IN DETAIL 

The BLM requires the development of alternatives when there are unresolved conflicts involving 

alternative uses of available resources. Based upon scoping comments received for the Scotty Lake 

Coalbed Natural Gas Pilot Project, two questions were raised regarding both the disposal of water 

produced from wells proposed in conjunction with the SLPP, as well as the issue of directional drilling 

to minimize surface impacts within the overall analysis area. These two alternatives will be discussed 

separately below. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

2.5.1 Re-Injection of Produced Water 

As indicated in Section 2.2.9, the operator has previously obtained approval from the WDEQ for the 

surface discharge of water produced from CBNG wells in the SLPA to Red Creek and ephemeral

tributaries thereof. This NPDES permit presently allows for the discharge of up to 0.81 MGWPD so 

long as the water quality standards as set forth in the approved permit are maintained. Furthermore,

information contained in Chapter 3.0 (Affected Environment) will disclose that the Great Divide Basin 

is a closed basin with no outside drainage; consequently, water produced in conjunction with the SLPP 

and subsequently discharged to the surface will not flow outside of said basin. Considering that the 

water being produced from the Fort Union Formation is of relatively good quality (see Appendix D), 

discharge of this water to the surface or containment in water retention pits represents a beneficial use to 

both livestock and wildlife within the overall analysis area as surface water sources within the area are 

limited at best. 

Furthermore, as the project name implies, this is solely a pilot project designed to determine the 

economic feasibility of additional exploration and development of the CBNG resource within the Scotty 

Lake CBNG Exploratory Unit. At the present time, it is unknown if there is a sub-surface geologic 

formation below the Fort Union Formation that would be suitable for the disposal of water produced in 

conjunction with the SLPP. In the event that the pilot project proves to be successful, additional 

environmental analyses would be required before any additional activities would be allowed within the 

Scotty Lake CBNG Exploratory Unit. Geological investigations to determine the feasibility of reinjection may be implemented at that time as appropriate. 

2.5.2 Directional Drilling 

The proposed action includes the drilling of up to 18 exploratory wells within the SLPA on a 160-acre 

spacing pattern in order to evaluate the potential productivity of coals within the Fort Union Formation

for commercial natural gas production. As indicated in Sections 1.1 and 2.1, these wells would be 

drilled to depths of up to 5,000 feet. Comments received in conjunction with the public scoping process 

have suggested that directional drilling operations could be utilized in conjunction with the proposed 

SLPP in order to reduce the environmental impacts of the project by reducing surface disturbing 

activities associated with well pad, access road, and pipeline construction. Directional drilling 

techniques are typically utilized to gain access to portions of an oil/gas lease that are not directly below 

the surface well location and where surface locations are expensive or prohibitive for a variety of 

reasons. Directional drilling techniques have been used extensively and successively, particularly in the 

development of off-shore oil/gas leases where reservoirs are typically extensive and the cost of installing 

submersible or semi-submersible drilling platforms represents a substantial investment. However, even 

in offshore exploration activities, the initial well is typically drilled vertically and directional drilling 

activities are not employed until a discovery has been made and development of the reservoir ensues. 

The purpose of any pilot project, such as the on currently proposed by Hudson Group, LLC, is to gather 

the data necessary to determine the economic feasibility of a potentially larger exploration and 

development program. At this particular juncture, the operator has not gathered a sufficient amount of 

data to adequately assess the commercial feasibility of CBNG production from the Scotty Lake coal 

member of the Fort Union Formation. The SLPP is being proposed to collect additional data on the 

physical characteristics of the Scotty Lake coals including reservoir characteristics, coal thicknesses, gas 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

29

content, gas chemistry, recovery efficiency, coal permeability, and water quantities. This data would 

then be combined with economic factors such as drilling, completion and evaluation (production) costs 

to determine if additional exploration and/or development is warranted. This data must be collected 

before a reasonable assessment of commercial feasibility may be properly evaluated. To date, 

directional drilling methods have not been successful in low-pressure, shallow CBNG wells (such as the 

Scotty Lake coals) and particularly so in wells where some form of rod-pumping is required in 

conjunction with the depressurization of said coals. Furthermore, topography and/or other physical 

resource concerns (such as steep or unstable slopes, critical habitats, or other sensitive resources), which 

might suggest the need for directional drilling operations in order to fully evaluate the project, are not 

present in the SLPA. Due to these factors, mandating the use of directional drilling operations in 

conjunction with the SLPP was found to be unreasonable and will not be further evaluated herein.
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

3.0 AFFECTED ENVIRONMENT 

3.1 INTRODUCTION 

This chapter describes the affected environment in the vicinity of the Proposed Action (the project 

area) as it exists today. This description is organized by resource with descriptive information taken 

from a wide range of sources including the BLM and various other federal and state agencies and 

has been guided by management issues identified by BLM’s RFO, public scoping, and by 

interdisciplinary field analyses of the project area. The critical elements of the human environment

and any potential affects arising from implementation of the Proposed Action are listed in Table 3.1. 

Table 3.1 

Critical Elements of the Human Environment, Scotty Lake CBNG 

Pilot Project, Sweetwater County, Wyoming 1

Element Status in 

Project Area 

Addressed

In EA 

 Air Quality Potentially Affected Yes

 Areas of Critical Environmental Concern None Present No

 Cultural Resources Potentially Affected Yes

 Environmental Justice Concerns Not Affected Yes

 Prime or Unique Farmlands Not Affected No

 Floodplains Not Affected No

 Native American Religious Concerns Not Affected No

 Threatened and Endangered Species Not Affected Yes

 Hazardous or Solid Wastes Not Affected No

 Water Quality Potentially Affected Yes

 Wetlands/Riparian Habitat Not Affected No

 Wild and Scenic Rivers Not Affected No

 Wilderness Concerns Not Affected No

1 As listed in BLM’s National Environmental Policy Act Handbook H-1790-1 (BLM 1988) and

Subsequent Executive Orders 

In addition to the critical elements listed above, this EA also discusses the potential effects of the 

Proposed Action on geology/minerals, range resources, soils, visual resources, wildlife (including 

special status species), and wild horses. 

3.1.1 Environmental Elements Not Considered in Detail 

The following resources would not be adversely affected by implementation of the Proposed Action. 

Consequently, these resources will not be addressed in this chapter or in Chapter 4.0 (Environmental

Consequences) to follow.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

x Recreation - the project area consists entirely of federal lands in the northeastern corner of

Sweetwater County. Access to this relatively remote area is provided by a series of existing 

BLM roads which traverse the area and provide access thereto from communities such as Jeffrey 

City and Wamsutter. Considering that there are no special recreation management areas or 

developed recreational sites within the project area, combined with the generally large expanse 

of adjacent federal lands, implementation of the proposed SLPP would not adversely affect 

recreational opportunities or patterns in the area. 

x Vegetation - considering that there are no T/E, candidate, or sensitive plant species known to 

occur within the SLPA, the long-term disturbance of 42.11 acres (1.46% of the total surface 

acreage) over the LOP would not represent an impact to T/E, candidate, or sensitive plant 

communities within the SLPA. Vegetation and the impacts thereto are considered in other 

elements within the document including Range Resources and Soils. 

x Environmental Justice - neither the Proposed Action nor the No Action Alternative would 

disproportionately affect minority or low income people, and is not discussed further in this EA. 

The proposed project would provide some additional employment opportunities for a small

number of workers in Sweetwater County, Wyoming and would add to the local economy.

3.2 GENERAL SETTING AND CLIMATE 

The project area is generally situated on the extreme northeastern periphery of the Great Divide 

Basin, a closed intermountain basin which is located within both the Middle Rocky Mountain 

Division of the Northern Rocky Mountain Physiographic Province and the Great Plains Division of 

the Great Plains Physiographic Province (Peterson et al 1987, Curtis and Grimes 2004). More 

specifically, the SLPA is situated in an upland area of northeastern Sweetwater County locally 

known as Cyclone Rim that is located generally north of Red Creek, south of West Alkali Creek, 

west of the Stratton Lakes, east/southeast of Scotty Lake, and north/northeast of Bastard Butte. This 

area is classified as a High Plains Steppe (cold desert) and is characterized by gently to moderately

undulated uplands dissected by numerous, ephemeral tributary drainages of Red Creek to the south 

and West Alkali Creek to the north. Elevations in the project area generally range from a low of 

6,960 feet along an ephemeral drainage at a point located in the SW1⁄4SW1⁄4SE1⁄4 of Section 26 in 

Township 26 North, Range 97 West (Phase III) to a high of 7,280 feet at a point located in the 

SE1⁄4NE1⁄4SW1⁄4 of Section 17 in Township 26 North, Range 96 West (Phase II). 

The local climate is characterized by a lack of moisture (where evaporation exceeds precipitation), 

which leads to warm summer days, cool summer nights and cold winters characteristic of a 

continental arid, cold-temperate-boreal climate (Trewartha 1968). Generally speaking, Wyoming

has a relatively cool climate with an annual average temperature of 45.6° F, with temperatures above 

6,000 feet rarely exceeding 100° F. The average number of frost-free days in northeastern 

Sweetwater County ranges from 81 to 100 days (Curtis and Grimes 2004). Air masses enter the 

region from the Pacific and mountains to the west act as effective moisture barriers. The majority of 

the precipitation occurs as a result of late spring and summer thunderstorms, which coincide with the 

growing season. The remainder of the precipitation comes in the form of snowfall, primarily from

November through April, with heaviest snowfall in the spring (Martner 1986). Annual precipitation 

at Jeffrey City, Wyoming (closest NOAA weather station) averaged 7.50 inches in 2002 and 10.64 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

inches in 2003, with peak average precipitation occurring in the months of May and June (NCDC 

2002, 2003). Most precipitation occurs as rain due to frontal systems and thunderstorms. Complete

precipitation data for the NOAA weather station in Wamsutter, Wyoming was not available for the 

2002 or 2003 reporting periods. 

Monthly mean temperatures in Jeffrey City during 2003 ranged from a February low of 20qF to a 

monthly mean high of 71qF in July, with average daily low and high temperatures ranging from 8qF

to 31qF in February, and 51qF to 90qF in July (NCDC 2003). However, as is characteristic of dry 

continental climates, temperature extremes are pronounced with a low temperature of -24qF

recorded on February 24, 2003 and a high temperature of 97qF recorded on July 25, 2003. The 

average number of days per year with a maximum temperature below 32qF is 66 days and the 

average number of days per year with a maximum temperature above 90qF is 28 days (NCDC 2003). 

Mean annual evaporation ranges from 45 inches (lake) to 70 inches (pan); therefore the potential 

evaporation is 21 to 23 inches, compared to the mean annual precipitation of 6 to 10 inches (Martner 

1986, Curtis and Grimes 2004). This gives an average annual deficit of nearly 14 inches, creating a 

predominantly dry climate where evaporation exceeds precipitation. 

Prevailing winds are from the west and southwest. These winds are relatively constant and have an 

average speed of 12 to 14 miles per hour. The uniformly high wind speeds enhance dispersion, 

prompting lower pollutant concentrations than would occur in the absence of steady, high wind 

speeds. Strong, sustained winds occur quite often, and observations indicate winds of 70 to 80 mph

(with gusts to 100 mph) can occur throughout Wyoming.

3.3 AIR QUALITY 

Current and complete monitoring data for ambient air quality are not available for the SLPA; 

however, based on data collected in similar locations and reviewed by the State of Wyoming,

Department of Environmental Quality, Air Quality Division (WDEQ/AQD), air quality levels are 

assumed to be in attainment for all Wyoming Ambient Air Quality Standards (WAAQS) and 

National Ambient Air Quality Standards (NAAQS). 

Estimation of background air pollutant concentrations (reported in micrograms per cubic meter, or 

μg/m3

) is necessary in order to compare potential total air quality impacts from the Proposed Action 

and Alternatives with applicable air quality standards. Thus, for comparison against an applicable 

standard, total impacts are the sum of the background concentration plus direct modeled impacts. It 

is important that individual background concentration values, model predictions, and applicable air 

quality standards are for the same averaging time period for each pollutant. Background air 

pollutant concentration data were provided by WDEQ/AQD (WDEQ 2003b). Background 

concentrations of carbon monoxide (CO) are taken from representative data collected by 

WDEQ/AQD and commercial operators at Ryckman Creek for an 8-month period and summarized

in the Riley Ridge EIS (BLM 1983). Sulfur dioxide (SO2) gaseous air pollutant data were gathered 

at the Lost Cabin Gas Plant site in Fremont County (1986-87). Nitrogen dioxide (NO2) and ozone 

data were collected at the Thunder Basin National Grasslands (2001-2002).

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Particulate matter less than 10 microns in diameter (PM10) and particulate matter less than 2.5 

microns in diameter (PM2.5) were collected in an urban area at the Cheyenne State Office Building 

(2002). Background air pollutant concentrations and applicable air quality standards are 

summarized in Table 3.2, which illustrates that regional background concentrations are well below 

established standards (WDEQ 2003b). These regional monitoring results indicate that air quality 

within the SLPA exceeds all applicable state and federal air quality standards. 

Table 3.2

Background Air Quality Concentrations, Ambient Standards 

and PSD Increments (μg/m3

)

Airborne Averaging Background Air Quality Standards PSD Increments 

Pollutant Time 1 Concentration WAAQS NAAQS Class I Class II 

Carbon Monoxide 1-hour 3,336 40,000 40,000 None None

(CO) 8-hour 1,381 10,000 10,000 None None

Nitrogen Dioxide (NO2) Annual 5.0 100 100 2.5 25

1 –hour 162 235 235 None None Ozone (O3) 8 –hour 150 157 157 None None

3-hour 93 1,300 1,300 25.0 512

Sulfur Dioxide (SO2) 24-hour 32 260 365 5.0 91

Annual 4 60 80 2.0 20

24-hour 47 150 150 8.0 30 PM10 Annual 16 50 50 4.0 17

24-hour 15 65 65 None None PM2.5 Annual 5 15 15 None None

Source: WDEQ 2003b. 

1 Short-term concentrations reflect the maximum measured values during the entire period of record, except for 

ozone, which reflect the average of available 2001 and 2002 second high data (1-hour) and fourth-high data

(8-hour). Short-term (1-hour, 3-hour, etc.) ambient standards allow not more than one expected exceedance 

per year. Long-term (annual) standards are not to be exceeded. 

3.4 CULTURAL RESOURCES 

Approximately 330 acres have been inventoried for cultural resources within the SLPA (Albanese 

2004), which represents 11.5% of the overall land area included within the project area. An 

additional 247 acres that lie directly adjacent to the proposed project area have also been inventoried 

for cultural resources (Albanese 2004). These inventories were conducted in compliance with 

Section 106 of the National Historic Preservation Act (NHPA).

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Cultural resource inventories have identified 2 cultural sites within the project area, one of which is 

considered as eligible for nomination to the National Register of Historic Places (NRHP). Based on 

an overview of the known cultural resource data and geomorphological data for the SLPA, it can be 

said that there is a moderate potential for locating intact buried cultural deposits. Most significant

cultural resources are found along major ephemeral drainages and along the lower benches of 

escarpments found commonly throughout the project area. Certain topographic settings have higher 

archaeological sensitivity such as aeolian deposits (e.g., sand dunes, sand shadows, and sand sheets), 

alluvial deposits along major drainages, and colluvial deposits along lower slopes of ridges. 

3.5 GEOLOGY AND MINERALS

Geologic units within the SLPA include the Wasatch, Fort Union, Lance, Lewis and Mesaverde 

Formations. The Wasatch Formation occurs at the surface throughout the SLPA and generally 

extends to the top of the Fort Union Formation (Fm). The Wasatch Fm occurs at the surface 

throughout the SLPA and generally extends to the top of the Fort Union Fm. Both the Wasatch and 

Fort Union Fms were deposited (formed) in the Paleocene epoch of the Tertiary Period (Cenozoic 

Era), while the Lance, Lewis and Mesaverde Fms were deposited (formed) in the Late Cretaceous 

Period of the Mesozoic Era. The primary geologic units that are targeted for CBNG exploration 

within the SLPA are the Scotty Lake coals which are interbedded in the Fort Union Fm at depths 

generally ranging between 2,000 feet and 5,000 feet. 

3.5.1 Geology 

The Scotty Lake (SL) coals are unique in that they are a geologically isolated deposit that pinches 

out to the west, east, and south and are bounded to the north by both the Wind River Thrust Fault 

and the Continental Fault. Based upon subsurface mapping (see Section 3.5.2), the SL coal appears 

to be limited to an area 6 miles wide and 9 miles long (or approximately 54 square miles) in 

northeastern Sweetwater County. The northern boundary of the SL coal is approximately one-half 

mile south of the Fremont County line which corresponds to the Wind River Thrust Fault. Rocks on 

the north side of the thrust fault have been uplifted relative to the south side of the fault and the SL 

coal interval does not exist to the north of the fault (Babb 2004a). The SL coals occur as three 

mappable sequences within the Fort Union Fm (upper, middle, and lower coals), each consisting of 

multiple coal beds with individual beds ranging in thickness for 2 to 50 feet. The top of the SL coal 

in the Picket Lake Unit #2 is at a depth of 2,121 feet, with the base of the coal at a depth of 4,250 

feet. Total SL coal thickness in the Picket Lake Unit #4 is 477 feet. Numerous shale sequences in 

the lower Wasatch Fm occur above the top of the SL coal, thereby providing an impermeable barrier 

between the top of the SL coal and shallower fresh water aquifers which may occur in the upper 

portions of the Wasatch Fm. It should be noted that the Osborne Spring Unit #31-24 recently drilled 

by Cabot Oil and Gas Corporation (SE1⁄4SW1⁄4 of Section 32 in Township 26 North, Range 97 West)

reportedly did not encounter the SL coal interval (Hudson 2004). 

The Big Red (BR) coal is also present within the SLPA, occurring at depths approximately 3,000 

feet below the base of the SL coals. The BR coal is more regional in extent than the SL coals, 

underlying most of the Great Divide Basin (3,895 mi2

), outcropping on the Rock Springs uplift 

approximately 38 miles southwest of the SLPA and pinching out to the north as it approaches the 

faulting and thrusting associated with the Wind River mountain range. The BR coal is part of a 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

regional hydrologic system, with water contained therein subjected to higher pressures, 

temperatures, and residence times resulting in higher mineralization and lower water quality as 

compared to the SL coal. This has been demonstrated by recent exploration activity within the BR 

coal to the west/southwest (Kennedy Oil Lower Bush Creek Project), which recorded total dissolved 

solids (TDS) of 21,771 parts per million (ppm) from water produced by the Kennedy State #1-36 

well located in the NE1⁄4NE1⁄4 of Section 36 in Township 23 North, Range 97 West (BLM 2003a). 

The presence of numerous shale and siltstone facies between the base of the SL coal and the top of

the BR coal effectively isolates these two coal-bearing units (Hudson 2004). 

3.5.2 Minerals 

In 1978, Davis Oil Company (Davis) formed the Picket Lake Unit (PLU) which encompassed

approximately 14,458 acres including the acreage now proposed for CBNG exploration within the 

SLPA. The PLU was primarily formed to test the productive potential of the Mesaverde Fm at 

depths of up to 14,000 feet. Subsequent to the approval of the PLU by the U.S. Geological Survey 

(USGS) on July 25, 1978, Davis proceeded to drilled five wells in the newly-formed exploratory 

unit between July 27, 1978 and October 19, 1979 (see Table 3.3). Of these five initial unit wells, 

four were completed in the Lewis formation as producing gas wells and one well was drilled and 

subsequently abandoned. Davis also drilled a sixth well directly adjacent to the PLU named the 

Zephyr Federal #1. Presidio Exploration, Inc. subsequently drilled a seventh unit well in 1995, 

which was also completed in the Lewis formation as a producing gas well. Of the five unit wells 

successfully completed in the Lewis Fm, two were subsequently plugged and abandoned as noncommercial wells in the mid 1980’s. The two remaining wells continue to produce from the Lewis 

Fm and are currently owned and operated by Hudson Group, LLC. Geologic information obtained 

from the drilling of these wells, coupled with regional geologic data gathered from other 

conventional oil/gas wells drilled in the northern end of the Great Divide Basin, have been compiled

by Hudson Group, LLC and were subsequently utilized to identify a general CBNG project proposal. 

In this regard, it should be noted that the concept of CBNG production from the Scotty Lake coals 

has been tested on a very limited basis through the re-entry of the PLU #1, PLU #2 and PLU #4 

abandoned well bores by the operator in 2002. These existing well bores were re-entered and 

completion operations undertaken in selected intervals within the Scotty Lake coals. Preliminary

gas/water production information obtained from these three re-entries has resulted in the current 

pilot project proposal to further define the nature of the Scotty Lake coals and the potential for 

commercial CBNG production therefrom.

Of the eight wells that have been drilled in the overall project area since the formation of the PLU, 

total reclamation has been achieved on those wells which have subsequently been plugged and 

abandoned except as noted below. It should be noted that the WOGCC has no record for any wells

drilled in the SLPA prior to the approval of the Picket Lake Unit by the USGS in 1978. Likewise, the

non-working areas of the 2 producing Lewis wells have also been successfully reclaimed. Re-entry 

and re-completion operations on the PLU #1, PLU #2 and PLU #4 resulted in additional short-term

surface disturbance on these previously abandoned and reclaimed locations. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Table 3.3

Wells Previously Drilled in and/or Adjacent to the SLPA 

Well Name Legal Location of Well Target/Producing Spud Well

and Number Quarter Section Township Range Formation Date Status

Zephyr Federal #1 NW1⁄4SW1⁄4 17 26 North 96 West Mesaverde 07/28/1979 P & A 

Picket Lake Unit #3 1 NW1⁄4SW1⁄4 18 26 North 96 West Lewis 02/28/1979 Producing

Picket Lake Unit #2 2 SW1⁄4NW1⁄4 19 26 North 96 West Lewis 05/25/1979 P & A 

Picket Lake Unit #5 SW1⁄4NE1⁄4 13 26 North 97 West Lewis 08/04/1979 P & A 

Picket Lake Unit #40-13 1 C SE1⁄4 13 26 North 97 West Lewis 04/10/1995 Producing

Picket Lake Unit #4 2 NW1⁄4SE1⁄4 23 26 North 97 West Lewis 05/11/1979 P & A 

Picket Lake Unit #1 2 NW1⁄4SE1⁄4 24 26 North 97 West Lewis 07/27/1978 P & A 

Picket Lake Unit #6 SW1⁄4NE1⁄4 25 26 North 97 West Mesaverde 10/19/1979 D & A 

1

 The producing wells referenced above are owned/operated by Hudson Group, LLC 2

 Abandoned well bores re-entered by Hudson Group, LLC and completed in the Fort Union Formation

Source: Wyoming Oil and Gas Conservation Commission Well Files and Computerized Database (WOGCC 2004) 

Based upon field examination, the five active wells within the project area currently represent 

approximately 13.15 acres of surface disturbance within the overall project area. Considering the 

overall age of the existing road/pipeline infrastructure within the PLU/SLPA, we will assume that 

short-term reclamation of non-working areas of these linear ROWs has been achieved and that any 

remaining long-term surface disturbance within the project area is limited to the existing access road 

network. Initial construction of the approximately 50,748 feet (9.61 miles) of access road within the 

project area resulted in total surface disturbance equal to 46.60 acres (assuming a total disturbed 

ROW width of 40 feet). The subsequent reclamation of approximately 30% of these existing access 

road ROWs (including cut/fill slopes and outslope areas of the borrow ditch) has resulted in longterm or LOP disturbance equal to approximately 27.96 acres. 

3.6 HYDROLOGY 

3.6.1 Surface Hydrology 

The SLPA encompasses portions of two separate watersheds as follows: 

1) Red Creek, containing approximately 13,184 acres (20.6 mi2

), which makes up 90% of the 

overall SLPA. For the purposes of this environmental analysis, the Red Creek watershed is 

defined as those ephemeral tributaries of Red Creek either directly or indirectly affected by 

surface water discharges as indicated in the Water Management Plan contained in Appendix D 

(Babb 2004b); and 

2) West Alkali Creek, containing approximately 37,760 acres (59.0 mi2

), which makes up 10% of 

the overall SLPA.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

The hydrologic divide between these two watersheds is Cyclone Rim, which generally represents the 

jurisdictional boundary between BLM’s Lander and Rawlins Field Offices. The West Alkali Creek 

watershed lies to the north of Cyclone Rim while the Red Creek watershed lies to the south. Hudson 

Group, LLC is currently discharging water produced from the Picket Lake Unit #2 to an ephemeral

tributary of Red Creek at the rate of approximately 550 barrels of water per day (bwpd). Water

being produced from the Picket Lake Unit #1 and Picket Lake Unit #4 wells is being contained in 

water retention pits located directly adjacent to each respective well. 

The bulk of the SLPA (2,586 acres) falls within the overall Red Creek watershed, which 

encompasses approximately 76,160 acres (119 square miles) within the Great Divide Basin and 

which ultimately flows into Hay Reservoir (Babb 2004b). The West Alkali Creek watershed 

encompasses approximately 37,760 acres (59 square miles) and merges with East Alkali Creek in 

Section 24 of Township 28 North, Range 96 West (Babb 2004a). As their names imply, these 

watersheds are drained by ephemeral tributaries of Red Creek and West Alkali Creek respectively. 

These ephemeral drainages are intermittent in nature and normally flow only during periods of

spring runoff and/or localized periods of heavy rainfall. As indicated above, runoff generated in the 

Red Creek watershed would flow west/southwest to Hay Reservoir, which has no outlet. Runoff 

generated in the West Alkali Creek watershed would generally flow to north into the Sweetwater 

River via Alkali Creek. 

Other than the two water retention pits mentioned above, there are no other surface impoundments

(stock reservoirs) within the SLPA. 

A fairly comprehensive look at surface hydrology within the area is presented in the Scotty Lake 

CBNG Pilot Project Water Management Plan (WMP) contained in Appendix D. 

3.6.2 Sub-Surface Hydrology 

The primary, near-surface, fresh water aquifer within the SLPA is the Eocene Wasatch Fm which 

overlies the Tipton shale member of the Green River Fm (Babb 2004b). In the Picket lake Unit #1, 

the Wasatch Fm extends from the surface to a depth of approximately 2,681 feet (Babb 2004a). A 

review of existing ground water rights within the SLPA issued by the Office of the Wyoming State 

Engineer indicates that two water supply wells have been drilled and completed within the project 

area as follows: 

x Picket Lake #40-13 Water Well: NE1⁄4SE1⁄4 of Section 13, Township 26 North, Range 97 West.

Permit #P145371W issued to Hudson Group, LLC and the Bureau of Land Management, Priority 

Date 06/03/2002. Well drilled to a total depth of 600 feet, yield 25 gpm.

x Picket Lake #1 Water Well: NW1⁄4SE1⁄4 of Section 24, Township 26 North, Range 97 West.

Permit #P135633 issued to Hudson Group, LLC and the Bureau of Land Management, Priority 

Date 06/06/2001. Well drilled to a total depth of 500 feet, yield 20 gpm.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Both of the above wells were permitted and drilled by Davis Oil Company in 1978 in conjunction 

with initial (conventional) oil/gas exploration activities in the Picket Lake Unit and subsequently repermitted by Hudson Group, LLC for their operations therein. 

A fairly comprehensive look at sub-surface hydrology within the area is presented in the Scotty Lake 

CBNG Pilot Project Water Management Plan (WMP) contained in Appendix D. 

3.7 RANGE MANAGEMENT 

The 2,880 acres of public land included within the SLPA encompass portions of two separate 

grazing allotments including Cyclone Rim and Green Mountain Common, which are administered

by the Rawlins and Lander Field Offices, respectively. Table 3.4 provides general information

concerning each grazing allotment within the SLPA including allotment name and number,

managing office, total acres of public land and total Animal Unit Months (AUMs) in each respective 

allotment.

Table 3.4 

Grazing Allotments in the SLPA

Allotment BLM Allotment Acres of Total

Name Office Number Public Land AUM’S

 Cyclone Rim Rawlins 10103 291,954 40,661

 Green Mountain Common Lander 32001 468,379 47,729

Grazing management on the Cyclone Rim Allotment (CRA) was evaluated by the RFO in 2002 and 

the SLPA area passed all standards for rangeland health and trend. Overall, the CRA passed all 

standards except Riparian/Wetland Health due primarily to excessive use by wild horses during the 

growing season, which has been complicated in some cases by livestock grazing. The Standards and 

Guides Report for the Great Divide Basin (BLM 2003b) states that these areas would likely show 

heavy use even with proper grazing management and proper management of the wild horse 

population due to the unique and rare characteristics for these areas and the relatively higher 

palatability of the associated plants. 

Current livestock grazing management for portions of the Green Mountain Common Allotment

(GMCA) has been evaluated by the LFO as unsatisfactory. The overall trend in condition is 

declining on the riparian areas within the GMCA based upon standards assessments which were 

performed by LFO in July, 1999. These standards assessments found that approximately 15,000 to 

25,000 acres (3 to 5 percent) of the public lands primarily near or associated with riparian areas 

within the GMCA were not in compliance with Wyoming BLM standards for Rangeland Health 

(BLM 1998). As a result, initial changes in livestock management practices were implemented in 

2000 and have been ongoing for the last 4 years. The current grazing management plan is being 

revised. It is projected that plan implementation will be fully completed within the next 5 years.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Generally speaking, Cyclone Rim represents the unfenced boundary between the Cyclone Rim and 

the Green Mountain Common Allotments, with the CRA to the south and the GMCA to the north. 

In the past there has been minimal north/south livestock drift over the rim due to the general lack of 

developed or natural surface water in the vicinity thereof. 

There are no known rangeland improvements within the proposed SLPA that would be affected by 

surface disturbing activities associated therewith. 

A survey of the proposed SLPA was conducted in July 2004 to identify infestations of noxious or 

invasive non-native weed species within the overall project area. No noxious weeds, as designated 

by Wyoming Statute (W.S.) 11-5-102(a)(xi) (WSWT 2003), were located within the project area. 

Two invasive non-native weed species were located on existing disturbed areas within the SLPA and 

included both halogeton (Halogeton glomeratus) and Russian thistle (Salsola iberica). An 

infestation of Russian knapweed (Acroptilon repens) was located approximately five miles south of 

the SLPA, which represents the nearest known noxious weed infestation. Likewise, an infestation 

of halogeton was identified approximately three road miles south of the SLPA. Both weed 

infestations were observed along existing BLM Road #3219. 

It is possible that Canada thistle (Cirsium arvense), musk thistle (Carduus nutans), and leafy spurge 

may occur on or adjacent to previously disturbed areas within the overall area. These particular 

species have been designated as noxious weeds by the State of Wyoming [Wyoming Statute (W.S.)

11-5-102(a)(xi)] (WSWT 2003). 

3.8 SOILS 

Soils information for northern Sweetwater County is primarily limited to a Fourth Order Soils 

Inventory which describes soils within the project in very general terms only. Based upon this 

Fourth Order Inventory, the predominate soil encountered within the SLPA consists of Typic 

Torriorthents complex. This soil complex consists of ridges and steep hillsides at elevations ranging 

between 6,600 and 7,400 feet and on slopes of 6 to 40 percent and is composed primarily of shallow 

Typic Torriorthents occupying rounded ridges and steep hillsides. Included in this complex are 

areas of rock outcrop which consists of thin, very gravelly soils and steep drainages. The Typic 

Torriorthents have a loam to gravelly loam profile extending down to soft bedrock at depths of 10 to 

20 inches and exhibit moderate permeability, low available water capacity, and are used primarily

for range and wildlife habitat. 

Soils in the S1⁄2NW1⁄4 of Section 26 in Township 26 North, Range 97 West (Phase III) are included 

within the Typic Torriorthents association, rolling, which occur on gently sloping to sloping alluvial 

fans and on rolling upland hillsides at elevations ranging from 6,700 to 7,000 feet and on slopes of 3 

to 15 percent. The areas consist of approximately 45% deep Typic Torriorthents on alluvial fans and 

approximately 35% moderately deep Typic Torriorthents on rolling hillsides. Included in these 

areas are loam or channery loam and sandy loam soils with soft bedrock at 10 to 20 inches. These 

Typic Torriorthent soils have a loam surface layer 2 to 3 inches thick with loam underlying layers to 

approximately 40 inches. These soils exhibit moderate permeability and moderate to high available 

water capacity. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

As indicated in Section 3.7, a survey of the proposed SLPA was conducted in July 2004 to review 

soil types within the SLPA. Based upon this survey, soils over the area fall in the Typic 

Torriorthents association as described above, but range from sandy loam to clay loam soils that are 

very shallow to shallow on average for those sites to be disturbed. 

3.9 VISUAL RESOURCES 

As indicated in Section 1.1, the SLPA encompasses federal lands that are included within both the 

Lander (LFO) and Rawlins (RFO) Field Offices. Those portions of the project area that fall within 

the jurisdiction of the LFO have been designated as Visual Resource Management (VRM) Class IV 

(modification of the landscape character) in the Lander Resource Management Plan Final 

Environmental Impact Statement (BLM 1986). Under this VRM class, changes may subordinate the 

original composition and character of the landscape; however, they should reflect what could be a 

natural occurrence within the characteristic landscape. 

Those portions of the project area that fall within the jurisdiction of the RFO have been designated 

as VRM Class III (partial retention of the landscape character) in the Great Divide Resource Area 

Record of Decision and Approved Resource Management Plan (BLM 1990). Under this VRM class, 

changes in the basic elements (form, line, color, or texture) caused by a management activity may be 

evident in the characteristic landscape. However, the changes should remain subordinate to the 

visual strength of the existing (land) character. 

Cultural modifications to the existing landscape within the SLPA have resulted from construction 

activities primarily associated with previous oil/gas exploration activity within the area as outlined 

in Table 3.3. Previous road construction activities within the overall project area (BLM roads 3216 

and 3219) not associated with oil/gas exploration activity has also resulted in cultural modifications

to the existing landscape. 

3.10 WILDLIFE AND SPECIAL STATUS SPECIES 

The dramatic differences in altitude encountered in Wyoming have resulted in a varied climate

which has produced differing floral and faunal communities, referred to by Cary (1917) as life 

zones. Of the five life zones he described for Wyoming, only the Upper Sonoran can be found in the 

Great Divide Basin and covers a broad expanse of the relatively low altitude country in the arid Red 

Desert.

Vegetation typically includes different species of saltbush, greasewood (Sarcobatus vermiculatus),

different species of rabbitbrush, sagebrush, including spiny sagebrush (Artemisia spinescens), Plains 

yucca (Yucca glauca), and different species of prickly pear cactus, with skunk bush (Schmaltzia

trilobata) and different species of juniper on the bluffs (SCS 1974). Specific vegetation observed 

within the project area which is characteristic of this life zone and the soils identified therein include 

greasewood, rabbitbrush, sagebrush, prickly-pear cactus, Indian ricegrass, western wheatgrass, and 

prairie junegrass. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

The Upper Sonoran zone within the SLPA is somewhat weak in nature in that it exhibits a relatively 

small number of the characteristic life zone species of mammals and birds. Mammalian species 

which exemplify this zone within the Great Divide Basin, and which would be expected to occur 

within the specific project area include the Pronghorn antelope (Antilocapra americana), Colorado 

chipmunk (Eutamias quadrivittatus), Northern grasshopper mouse (Onchomys leucogaster articeps),

kangaroo rat (Dipodomys ordii luteolus), and spotted skunk (Spilogale putoris).

3.10.1 Big Game Species 

These big game species occur within the overall project area and include Pronghorn antelope 

(Antilocapra americana), Mule deer (Odocoileus hemionus), and Rocky Mountain elk (Cervus

elaphus) and are discussed in greater detail below. 

Pronghorn Antelope 

Antelope populations residing within the overall project area are classified within the Red Desert 

Herd Unit, which includes antelope hunt areas 60, 61, and 64. The herd objective for antelope in the 

Red Desert Herd Unit is 15,000 post hunt animals (WGFD 2003a). Generally speaking, antelope 

numbers in the Red Desert Herd Unit are near, but slightly below the desired herd objective, with the 

2003 population estimated at 14,950 animals (see Table 3.5). Recruitment (fawn production) in this 

herd unit has been below management goals for 10 of the last 11 years, with an estimated 48 fawns 

per 100 does in 2002. Likewise, buck/doe ratios are also below the stated management goal of 60 

bucks per 100 does, with an observed buck/doe ration of 49 bucks per 100 does in 2002. The low 

buck/doe ratios combined with a population that is nearing objective will result in the issuance of 

additional doe/fawn licenses and a concomitant decrease in buck licenses in an attempt to achieve a 

buck/doe ratio of 60 bucks per 100 does, while maintaining the population at or near the stated 

population objective (WGFD 2003a). There is no crucial antelope winter range within the SLPA. 

Mule Deer 

Mule deer populations residing in that portion of the project area located on the south side of BLM 

Road #3216 (Cyclone Ridge Road) are classified within the Steamboat Herd Unit, which comprises

deer hunt area 131. Populations of mule deer on the north side of the Cyclone Ridge Road are 

classified within the South Wind River Herd Unit, which includes deer hunt areas 91-95 and 160. 

Herd objectives for mule deer in the Steamboat and South Wind River Herd Units are 4,000 and 

13,000 post hunt animals, respectively (WGFD 2003a). Herd objectives for mule deer in both herd 

units are below objective by 22.5% and 43% respectively (WGFD 2003a) due primarily to the 

effects of the ongoing drought on population recruitment - particularly in those portions of both herd 

units within the Great Divide Basin as a direct result of water availability (see Table 3.5). The 

inability of these deer populations to rebound from the sustained drought has resulted in license 

reductions and a concomitant reduction in hunter opportunity in both herd units (WGFD 2003a). 

There is no crucial mule deer winter range within the SLPA. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Rocky Mountain Elk 

Elk populations residing within the overall project area are classified within the Steamboat Herd 

Unit, which comprises elk hunt area 100. The herd objective for the Steamboat Herd Unit is 

currently 1,200 post hunt animals with a 2002 post-hunt population estimate of 1,530 animals (see 

Table 3.5). It should be noted that the herd unit objective was increased by 240% in 2002 from 500 

post-hunt animals to the current herd objective of 1,200 animals (WGFD 2003a). As the numbers

imply, elk populations in the Steamboat Herd Unit have expanded well beyond the initial herd unit 

objective of 500 post hunt animals and are thriving within hunt area 100. 

Table 3.5 

Population Objectives, 2002 Post-Hunt Population Estimates and 

and Population Trends in Antelope Elk and Mule Deer Populations in the SLPA 

Herd Elk Antelope Mule Deer

Unit Objective Actual Trend Objective Actual Trend Objective Actual Trend

Red Desert 15,000 14,950 0.33% 

Steamboat 1,200 1,530 127.5% 4,000 3,000 25% 

S. Wind River 13,000 7,385 43% 

Source: WGFD Annual Big Game Herd Unit Job Completion Reports (JCRs) for the Lander and Green River Regions

(WGFD 2003a) 

The increased elk population has resulted in increased hunting opportunity as permits for both bull 

and cow elk have been increased in an effort to decrease the population below 1,600 animals and 

move towards the current herd objective. 

3.10.2 Greater Sage Grouse 

The greater sage grouse (Centrocercus urophasianus) is an important upland game bird in Wyoming

and the project area does contain limited amounts of suitable nesting habitat; however, there are no 

known leks within a 2 mile radius of the proposed SLPA. The closest known leks to the project 

area are located as follows: 

x Bastard Butte Lek: NE1⁄4SE1⁄4 of Section 10, T25N, R97W - lek active in 2003; 

x Scotty Lake Lek: SE1⁄4NW1⁄4 of Section 17, T26N, R97W - lek active in 2003; 

x Red Creek Lek: NE1⁄4NE1⁄4 of Section 10, T26N, R98W - lek active in 2003; 

x Red Creek Well Lek: SW1⁄4SW1⁄4 of Section 30, T25N, R95W - lek active in 2003. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Sage grouse populations throughout Wyoming remain well below both historic and WGFD desired 

levels due to low recruitment resulting from poor nesting conditions attributable to the ongoing 

drought as well as other poorly understood factors such as predation and habitat loss. Declining 

populations of sage grouse in Grouse Management Area 9 have resulted in action designed to reduce 

harvest including shortening the hunting season from 30 days in 1993 to 9 days in 2002 and a 

concomitant reduction in bag limits from 3 birds per day with 9 in possession in 1993 to 2 birds per 

day with 4 birds in possession in 2002. These population declines are clearly defined in extant 

harvest data which recorded a harvest of 6,876 birds by 2,441 hunters in 1993 versus 1,728 birds 

harvested by 788 hunters in 2002 (WGFD 2003b). There are no population data estimates for sage 

grouse within the SLPA. 

3.10.3 Raptor Species

Several birds-of-prey species may occur within the SLPA including ferruginous hawk (Buteo

regalis), northern harrier (Circus cyaneus), golden eagle (Aquila cyrysaetos), and prairie falcon 

(Falco mexicanus). Table 3.6 provides information on the five (5) ferruginous hawk nests which 

have been documented in or adjacent to the SLPA. 

Table 3.6 

Raptor Nesting Activity In or Adjacent to the SLPA 

Raptor Nest 2003 Nest Legal Location of Nest Structure 2004

Species Type Condition Quarter-Quarter Section Township Range Status

FH Stick Fair SE1⁄4SE1⁄4 15 26 North 97 West Inactive

FH Stick Poor Center NE1⁄4 22 26 North 97 West Inactive

FH Stick Good SE1⁄4NE1⁄4 23 26 North 97 West Inactive

FH Stick Good SE1⁄4NW1⁄4 25 26 North 97 West Inactive

FH Stick Good SE1⁄4SE1⁄4 26 26 North 97 West Inactive

3.10.4 Threatened and Endangered Species 

Threatened and/or endangered (T/E) species include those species which are in danger of extinction 

due to drastic population declines and which have subsequently been listed as threatened or 

endangered pursuant to the Endangered Species Act (ESA) of 1973 (as amended). Those T/E 

species identified by the U.S. Fish and Wildlife Service (USFWS) which may potentially occur 

within the project area include: 

x Bald eagle (Haliaeetus leucocephalus) - Status: Threatened. 

Migrant through the area during the fall and spring migrational periods, seasonal resident during 

the winter months along major river systems throughout the state.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Historic habitat for bald eagles migrating through or wintering in west central Wyoming would 

include riparian area(s) along the North Platte River in Carbon and Natrona Counties; the Big 

and Little Wind Rivers in Fremont County; the Green River in Lincoln, Sweetwater and Sublette 

Counties; and the Little Snake River in Carbon County which provide roosting and perching 

areas for eagles foraging along the river courses and their adjacent uplands. There are no known 

bald eagle roosting areas in northeastern Sweetwater or southern Fremont County (south of the 

Shoshone National Forest boundary)(BLM 2004a). 

Open rangelands throughout west-central Wyoming are probably being used opportunistically by 

bald eagles for foraging; however, no bald eagles have been observed in the area in conjunction 

with BLM or BLM-approved inventories within the project area (BLM 2004a). 

x Black-footed ferret (Mustela nigripes) - Status: Endangered. 

Potential resident in prairie dog (Cynomys sp.) colonies. 

As there are no known prairie dog towns within the SLPA, impacts to black-footed ferrets are 

not expected to occur. 

x Ute ladies’-tresses (Spiranthes diluvialis) - Status: Threatened. 

Potential resident in seasonally moist soils and wet meadows below 7,000 feet. Locally found in 

the North Platte River drainage below Alcova Reservoir and in the drainages of the Cheyenne 

and Niobrara Rivers in southeastern Wyoming.

As indicated above, there are no perennial or intermittent streams with associated riparian 

habitats within the SLPA. Furthermore, as the SLPA does not occur in the drainages of the 

North Platte, Cheyenne, or Niobrara Rivers, the expected area(s) of occurrence, impacts to Ute 

ladies’-tresses are not expected to occur. 

x Water Depletions to the North Platte and Colorado River Systems

In their response to project scoping, the U.S. Fish and Wildlife Service also identified four T/E 

fish species which could potentially be affected by water depletions to the Colorado River 

system (including the Colorado, Green and Yampa rivers) including the endangered bonytail 

chub (Gila elegans), Colorado pikeminnow (Ptychochelius lucius), humpback chub (Gila

cypha), and razorback sucker (Xyrauchen texanus). In this regard, the Great Divide Basin is a 

hydrographically closed basin from both a surface and subsurface standpoint (BLM 2003a). The 

proposed SLPP has no potential to affect or impact the Colorado River System or the T/E species 

residing therein; consequently, these species will not be given further consideration in this 

document.

Although not specifically identified by the USFWS in their response to project scoping, water 

depletions to the North Platte River system could also potentially affect five T/E species 

including the endangered interior least tern (Sterna antillarum), pallid sturgeon (Scaphirhynchus

albus), and Eskimo curlew (Numenius borealis) as well as the threatened piping plover 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

(Charadrium melodus) and western prairie fringed orchid (Platanthera praeclara). Considering 

that no North Platte River depletions would result from the proposed action, the SLPP has no 

potential to affect or impact the North Platte River System or the T/E species residing therein; 

consequently, these species will not be given further consideration in this document.

3.10.5 Special Status Species 

Special status species would include those plants/animals that do not currently warrant protection 

under the Endangered Species Act of 1973 (as amended), yet are considered by the Bureau of Land 

Management as sensitive species. Special status species that may be expected to occur within the 

SLPA include: 

x Mountain plover (Charadrius montanus)

The mountain plover is generally considered an associate of the shortgrass prairie, which is 

dominated by blue grama (Bouteloua gracilis) and buffalo grass (Buchloe dactyloides)(Graul

1975). The species breeds across the western Great Plains and at isolated locales in western 

Colorado, Wyoming and New Mexico (Leachman and Osmundson 1990). Between 1966 and 

1991, continental populations of the mountain plover declined by 63% (Knopf 1994), with the 

Pawnee National Grassland in Weld County, Colorado being both the historic and current 

breeding stronghold of this aridland member of the family Charadriidae (Graul and Webster

1976). A second major breeding population of mountain plovers is currently located on the 

Charles M. Russell National Wildlife Refuge in Phillips, Montana (Knopf and Miller 1994). 

In April of 2004 a search was made of the Wyoming Natural Diversity Database (WYNDDB)

records to determine if any sightings of mountain plover had been recorded within Township 26 

North, Ranges 96 and 97 West. One mountain plover sighting was recorded in the 

NE1⁄4NE1⁄4SW1⁄4 of Section 17 in Township 26 North, Range 97 West on May 2, 1993. No 

additional sightings are documented in the WYNDDB (WYNDDB 2004). 

3.10.6 Migratory and Non-Migratory Birds 

Habitats in the SLPA and immediate vicinity are primarily sagebrush-dominated uplands (shrubsteppe) with interspersed shortgrass prairie (WYNDDB 2004). Wyoming Partners in Flight 

(PIF) priority species potentially occurring in the shrub-steppe (SS) and shortgrass prairie (SGP) 

habitat types are listed in Table 3.8 (Nicholoff 2003). 

In this regard, the SLPA lies within an area directly north of latitude 42°11’25” N and directly 

west of longitude 108°17’50” W. Species distribution as reported in The Atlas of Birds, 

Mammals, Reptiles and Amphibians in Wyoming (WGFD 1999) includes a compilation of 

observations mapped by latitude and longitude, with the State of Wyoming divided into 28 

different regions, where these observations are reported within a specific region of the state. 

These regions are based upon a one degree separation of both latitude and longitude. As a 

consequence, the SLPA falls with Wyoming Distribution Area (latilongs) 17 as defined by 

WGFD (1999). Avian distribution data contained in The Atlas of Birds, Mammals, Reptiles and 

Amphibians in Wyoming (WGFD 1999) for the PIF priority species potentially occurring within 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

the SLPA is included in Table 3.7. Only those birds that have been classified by WGFD (1999) 

as confirmed breeders (nest and/or young observed), with circumstantial evidence of breeding 

(nest and/or young not located), or that have been observed at any time (season) within the 

general area (but without any evidence of breeding) are included in the list. Breeding Bird 

Survey (BBS) data for survey routes within Wyoming were included in this database (WGFD

1999). Definitions for those symbols used in Table 3.7 to report Wyoming distribution are as 

follows:

x B: Nest or young dependent upon parent birds observed. 

x b: Circumstantial evidence of breeding. 

x O: The species has been observed, but there was no evidence of nesting. 

x N: The species has not been observed in the area. 

Most of the birds listed in Table 3.7 typically nest either on the ground or in shrubs; thus 

activities associated with the Proposed Action may have the potential to destroy individual nests, 

eggs, and/or young of some of these species. Projected losses are indeterminate as there are no 

Breeding Bird Survey (BBS) routes located within the immediate vicinity of the SLPA which 

could provide information on breeding bird densities within the shrub-steppe and shortgrass 

prairie habitats encountered within the SLPA. 

Concerns regarding the decline of both migratory and non-migratory bird populations both 

locally and on a continental scale have resulted in a nationwide bird conservation planning 

effort. Management goals and objectives for bird conservation are found in the following 

documents:

1) Land Bird Strategic Plan; 

2) Presidential Executive Order (EO) 13186 dated January 17, 2001; and 

3) Proposed Memorandum of Understanding associated with the above Presidential EO. 

Bird Conservation Plans prepared at the state and regional levels also include objectives for bird 

conservation. As evidenced by EO 13186, there has been national direction to implement actions 

that incorporate these goals. 

3.11 WILD HORSE MANAGEMENT 

The proposed SLPA falls in the extreme southwest corner of the Antelope Hills Horse Management

Area (HMA) which is administered by BLM’s Lander Field Office (LFO). This HMA encompasses

approximately 110,000 acres of both federal and non-federal lands in Fremont and Sweetwater 

Counties.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Table 3.7 

List of Partners In Flight (PIF) Priority Bird Species 

Potentially Found Within the SLPA 

Common Scientific Name Habitat Distribution

Name Name Type Area 17

Level I Species (Conservation Action)

 Ferruginous Hawk Buteo regalis SS/SGP B

 Mountain Plover Charadrius montanus SS/SGP B

 Upland Sandpiper Bartramia longicauda SGP N

 Long-billed Curlew Numenius Americana SGP/M B

 Burrowing Owl Athene cunnicularia SGP B

 Short-eared Owl Asio flammeus SGP/M O

 Brewer’s Sparrow Spizella breweri SS/MFS B

 Sage Sparrow Amphispiza belli SS/MFS b

 McCown’s Longspur Calcarius mccownii SS/SGP O

Level II Species (Monitoring)

 Loggerhead Shrike Lanius ludovicianus SS b

 Sage Thrasher Oreoscoptes montanus SS B

 Vesper Sparrow Pooecetes gramineus SS B

 Lark Sparrow Chondestes grammacus SS B

 Lark Bunting Calamospiza melanocorys SGP O

 Grasshopper Sparrow Ammodramus savannarum SGP N

 Chestnut-collared Longspur Calcarius omatus SGP N

 Dickcissel Spiza Americana SGP O

 Bobolink Dolichonyx oryzivorus SGP/M B

Level III Species (Local Interest) 

 Common Poorwill Phalaenoptilus nuttallii SS/MFS b

 Say’s Phoebe Sayornis saya SS O

Source: Wyoming Bird Conservation Plan, Version 2.0 (Nicholoff 2003)

The population objective or “appropriate management level” (AML) for this particular HMA is 60 to 

82 adult horses with a population currently estimated at 166 horses. Two other HMAs occur directly 

adjacent to the SLPA as follows: 

x Lost Creek HMA which is managed by BLMs Rawlins Field Office (RFO); and 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

48

x Great Divide Basin HMA which is managed by BLMs Rock Springs Field Office. 

The Lost Creek HMA encompasses approximately 250,000 acres, lies completely within the Great 

Divide Basin, and adjoins the Antelope Hills HMA directly to the south of the SLPA. The AML for 

the Lost Creek HMA is 140 to 165 adult horses, with the population currently estimated at 143 

horses. Through genetic testing, the Lost Creek wild horse herd has been shown to carry a very high 

percentage of genetic markers identified with the Spanish Mustang breed, which means that these 

horses are genetically more like the Spanish Mustang and other New World Iberian breeds than 

other breeds such as American Quarter Horse or Morgan. The Spanish Mustang breed was 

introduced to the Americas by the Spanish explorers and conquistadors in the 1500s. As a 

consequence, this characteristic makes these horses unique among the wild horse herds tested in 

Wyoming to date. 

The Great Divide Basin HMA encompasses approximately 778,915 acres and adjoins the Antelope 

Hills HMA approximately 8 miles to the west of the SLPA boundary. The AML for the Great 

Divide Basin HMA is 415 to 600 adult horses, with the population currently estimated at 812 horses. 

Horses in the Antelope Hills and Great Divide Basin HMAs have not been genetically tested to 

determine if they share genetic markers with the Spanish Mustang breed; however, horses in all 

three herds are considered as one single meta-population that has been subdivided into separate 

herds for management purposes. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

4.0 ENVIRONMENTAL IMPACTS 

4.1 Introduction 

The potential environmental consequences of construction, drilling, completion, and evaluation 

activities associated with both the Proposed Action and No Action Alternative are discussed for each 

potentially affected resource. An environmental impact is defined as a change in the quality or 

quantity of a given resource due to a modification in the existing environment resulting from

project-related activities. Impacts can be beneficial or adverse; a primary (direct) result or a 

secondary (indirect) result of an action; long-term (more than five years) or short-term (less than five 

years); and can vary in degree from a slightly discernable change to a total change in the 

environment. In accordance with CEQ regulation 40 CFR 1502.16, this chapter includes a 

discussion of the potential impacts of the Proposed Action and the No Action Alternative. Possible 

conflicts between the Proposed Action and No Action Alternative and the objectives of the Great 

Divide and Lander RMPs as well as state and local land use plans and policies are identified if such 

conflicts exist. 

Potential impacts are quantified when possible; however, when impacts are not quantifiable 

appropriate adjectives are used to best describe the level of impact. Impact assessment assumes that 

all applicant-committed practices will be successfully implemented. If such measures are not 

implemented, additional adverse impacts may occur. Additional mitigation measures are suggested 

if such measures are appropriate, and BLM will decide whether to include such additional measures

in the Decision Record. The Decision Record will be the decision document for this proposed 

project.

The air quality analysis found in this document tiers to and incorporates by reference the Desolation 

Flats Natural Gas Field Development Project (BLM 2004b). 

4.2 AIR QUALITY

4.2.1 Proposed Action

BLM has recently released the Final Environmental Impact Statement for the Desolation Flats 

Natural Gas Field Development Project (BLM 2004b). The northern boundary of the Desolation 

Flats Project (DFP) Area is located approximately 60 air miles south of the SLPA. Detailed air 

quality modeling was conducted for Alternative A of the Desolation Flats NEPA analysis and 

included the drilling of 592 gas wells, and both the successful completion and subsequent production 

of 385 gas wells. The results of the modeling studies for Desolation Flats indicate that no adverse 

impacts to sub-grid or near-field air quality would result from the proposed project and the DFP 

would comply with all state and national ambient air quality standards. The air quality modeling

conducted for the DFP suggested the possibility of some contribution to far-field visibility reduction 

within the Class I airsheds when combined with all other human development in the analysis area. 

The scope of the Scotty Lake project differs considerably from Desolation Flats in well numbers (18 

versus 592), well-site equipment (conventional gas production versus coalbed natural gas), and 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

compression horsepower requirements (32,000 hp versus 50 hp/well), which will result in a dramatic

reduction in overall emissions associated with the proposed SLPP as compared to the DFP. 

Construction emissions associated with the Proposed Action would include PM10, SO2, NOx, CO, 

and VOCs. These emissions would result primarily from construction, drilling and completion

activities, would be temporary in nature and would occur in isolation at each individual well 

location. Considering that construction, drilling and operations within the SLPA would be 

conducted one well, the relatively small number of exploratory wells and facilities proposed in 

conjunction with the SLPP would generate a near-undetectable level of emissions that would be 

limited to the near-field with no impact in the far-field.

The use of Best Available Technology in the small engines to be utilized to power the generators 

and screw compressors at each individual well location would ensure the operator complies with 

applicable state and national ambient air quality standards. As indicated in Section 2.3.2, the 

Operator would take appropriate measures to minimize impacts to air quality. Non-particulate 

emissions would be minimized by ensuring that vehicles, rig engines, and generator, and screw 

compressors are maintained in proper operating condition. Watering of access roads (or the use of 

chemical dust suppressants ) within the SLPA during periods of heavy vehicle traffic vehicle would 

also serve to reduce fugitive dust (PM10) by 50% or more (BLM 2003a). 

4.2.2 The No Action Alternative 

Under the No Action Alternative, there would be no additional impacts to ambient air quality. 

4.2.3 Mitigation and Monitoring 

Please refer to Section 2.3.2 for Applicant-Committed Practices designed to reduce impacts to air 

quality within the overall analysis area. No additional mitigation is recommended.

4.3 CULTURAL RESOURCES 

Cultural resources, including archaeological and historic sites, on lands subject to federal authority 

are protected by various laws and regulations commencing with the Antiquities Act of 1906. 

Specific directives concerning Cultural Resource Management can be found in Archaeology and

Historic Preservation: Secretary of the Interior’s Standards and Guidelines (Federal Register 1983) 

and BLM Manual Section 8100. Prior to the initiation of any federal action, cultural resources must

be inventoried and evaluated to determine their eligibility for inclusion in the NRHP. NRHP criteria 

(36 CFR 60.4) for determining eligibility define four (4) criteria of significance based upon “...the 

quality of significance in American history, architecture, archaeology, and culture present in 

districts, sites, buildings, structures, and objects of state and local importance that possess integrity 

of location, design, setting, materials, workmanship, feeling, and association; and that: 

x are associated with events that have made a significant contribution to the broad patterns of our 

society; or 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

x are associated with the lives of persons significant in our past; or 

x embody the distinctive characteristics of a type, period, or method of construction, or that 

represent the work of a master, or that possess high artistic values, or that represent a significant 

and distinguishable entity whose components may lack individual distinction; or 

x have yielded, or may be likely to yield, information important in prehistory or history”. 

Cultural properties are generally not eligible for inclusion in the NRHP if they lack diagnostic 

artifacts, subsurface remains, or structural features. Furthermore, sites that cannot be placed in a 

temporal context or shown to be related to other sites are usually not eligible and therefore are 

discharged from management.

4.3.1 Proposed Action

As indicated in Section 3.4, the records of the Wyoming State Historic Preservation Office (SHPO) 

indicate that approximately 578 acres have been inventoried for cultural resources within or directly 

adjacent to the SLPA. Six cultural sites were identified in conjunction with these inventories 

including 1 site which was considered as eligible for nomination to the NRHP (Albanese 2004). 

From these numbers, we may predict a site density of one cultural site per 96 acres and one 

potentially eligible cultural site per 578 acres. Predictions of site density within the SLPA are drawn 

from environmental factors within the study area including depositional environments, as well as 

past studies of cultural resources in the area. Certain environments are more likely to yield intact, 

buried cultural deposits than others. Most significant cultural resources are found along major

ephemeral drainages and along the lower benches of escarpments found commonly throughout 

southern Wyoming. Certain topographic settings have higher archaeological sensitivity such as 

aeolian deposits (e.g., sand dunes, sand shadows and sand sheets), alluvial deposits along major

drainages, and colluvial deposits along lower sloes of ridges. 

Prior to initiation of any ground disturbing activity associated with exploration operations within the 

SLPA, a Class III cultural resource inventory would be completed on all areas that would be 

disturbed and any NRHP-eligible cultural resources identified would either be avoided or mitigated

according to standard procedures. Likewise, any unanticipated discoveries of cultural resources 

made during construction activities would be mitigated according to standard procedures and project 

personnel would be prohibited from collecting any artifacts or disturbing any significant cultural 

resources in the area. As a consequence, impacts to cultural resources would likely be negligible to 

nonexistent.

4.3.2 The No Action Alternative 

Under the No Action Alternative, there would be no project-related surface disturbances beyond 

those levels previously approved and impacts to cultural resources would remain at current levels. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

4.3.3 Mitigation and Monitoring 

Please refer to Section 2.3.3 for Applicant-Committed Practices designed to reduce impacts to 

cultural resources within the overall analysis area. No additional mitigation is recommended.

4.4 GEOLOGY AND MINERALS

4.4.1 Proposed Action 

Potential oil/gas exploration activities within the SLPA would not have an adverse impact upon 

other mineral resources and would be consistent with management direction for the area as 

prescribed in the LFO and RFO RMPs. Conflicts which could interfere with the recovery of other 

mineral resources within the immediate project area, such as mining for gravel or uranium, would be 

subject to prior existing rights, thereby lessening the potential for future conflict. At this time, there 

are no other known mineral resources within the project area which are considered to be 

economically recoverable. 

Minimum engineering standards established by Onshore Oil and Gas Order Number 2 for oil/gas 

drilling and completion operations would ensure hole integrity and should preclude the possibility of 

downhole fluid migration between formations.

4.4.2 No Action Alternative 

No additional impacts would result to the geology and mineral resources within the SLPP under this 

action alternative. 

4.4.3 Mitigation and Monitoring

Please refer to Section 2.3.4 for Applicant Committed Practices and the Typical Drilling Prognosis 

contained in Appendix C for those measures designed to reduce impacts to geologic and mineral

resources within the overall analysis area. No additional mitigation is recommended.

4.5 HYDROLOGY 

A comprehensive Water Management Plan (WMP) has been prepared in conjunction with the 

proposed Scotty Lake Coalbed Natural Gas Pilot Project (Appendix D). The subject WMP not only 

discusses alternative methods for water disposal, but discloses the current hydrologic situation 

within the SLPA and discusses the impacts of the produced water discharge upon both the surface 

and subsurface hydrology of the area. Information contained in the WMP will be summarized

below.

4.5.1 Proposed Action 

Because there are no perennial streams, springs, or other sources of permanent surface water (stock 

water reservoirs) known to exist within the project area, the potential for degradation of existing 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

surface water quality in or adjacent to the SLPA resulting from implementation of the proposed 

action is considered to be remote.

4.5.1.1 Erosion and Sedimentation 

The 106 acres of short-term surface disturbance within the SLPA would occur in the two watersheds 

defined in Section 3.6.1. Of this total, 76.49 acres (72 percent) of the surface disturbance would 

occur in the Red Creek watershed, with the remaining 29.55 acres (28 percent) occurring in the West

Alkali Creek watershed, which would represent less than one percent (0.6 and 0.08) percent of each 

respective watershed. 

The potential for off-site erosion and sedimentation throughout the SLPA would be reduced through 

the implementation of Best Management Practices (BMP) in the construction and subsequent 

reclamation of surface disturbances as referenced in the Master Field Permit (Appendix C). These 

reclamation techniques would be augmented on an as-needed basis through the incorporation of site 

specific reclamation requirements directly into the conditions of approval for those actions within 

the SLPA requiring federal authorization. Typically, these reclamation requirements would be 

developed during the permit review process (on-site inspection) and would be based upon sitespecific concerns identified during the course thereof. Consequently, the potential for increased 

erosion and sedimentation within or directly adjacent to the SLPA is considered to be negligible 

when one considers the following: 

x the total amount of surface disturbance which would result over the LOP from additional oil/gas 

exploration and development activity within the SLPA (106 acres of short-term disturbance) 

represents only 3.7 percent of the total land area within the SLPA; 

x successful reclamation of disturbed areas not required for on-going production operations (57 

acres) would result in an approximate 53% overall reduction in long-term or LOP surface 

disturbance, thereby further reducing the potential for erosion and off-site sedimentation (LOP 

disturbance for the SLPP = 49 acres); and 

x the implementation of site specific “Best Management” reclamation practices designed to 

stabilize disturbed areas as quickly as possible, would result in a 94% overall reduction in 

erosion after the first year and a 95% reduction in erosion after five years (refer to Section 4.8.1). 

4.5.1.2 Surface Water Discharge 

Water produced in conjunction with the proposed SLPP is of good quality as indicated in Table 2a 

of the referenced WMP and will be discharged to the surface via one of three methods as discussed 

in Section 2.2.9 under an existing NPDES permit issued to Hudson Group, LLC by the WDEQ.

Based upon analyses contained in the WMP, this water is expected to dissipate quite rapidly, 

irrespective of the discharge method. The WMP predicts that water discharged to one of three 

primary ephemeral drainages (drainage basins A, B and C) of Red Creek will dissipate within a 

maximum of 4.8 miles (drainage basin C) downstream of the discharge point due to conveyance loss 

(Babb 2004a). Flow rates for the discharged water would be less than two feet per second, with 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

most flows being less than one foot per second - which is below erosion thresholds (Babb 2004a). 

No water will be discharged into the West Alkali Creek drainage on the north side of Cyclone Rim.

4.5.3.2 Sub-Surface Hydrology 

Chemical analyses contained in the WMP indicate that water produced from the Scotty Lake coals 

(Fort Union Fm) is geologically isolated from the fresh water aquifers in the shallower Wasatch Fm

and also from the degraded Big Red aquifer within the Fort Union Fm below the Scotty Lake coals 

(Babb 2004a). These analyses confirm that there is no significant communication between the 

geologic horizons above or below the Scotty Lake coals and that said coals represent a confined 

aquifer within the Fort Union Fm (Babb 2004a). 

In this regard, concern has been expressed regarding potential aquifer depletion and potential crosscontamination between aquifers. As indicated in Section 2.2.4, water is removed from the coal in 

order to depressure said coal and facilitate the desorption of gas from the coal facies. It is a popular 

misconception that the aquifer must be or is completely dewatered in conjunction with CBNG 

production - which leads to fears of subsidence and underground coal fires. Studies conducted in 

conjunction with CBNG production in Wyoming’s Powder River Basin have shown that up to 

twenty percent of the entrained water must be removed from the aquifer in order to depressure the 

coal sufficiently to facilitate gas desorption (Babb 2004a). Once a pressure equilibrium has been 

reached and gas begins to flow into the well bore, water production falls off dramatically and, in 

many cases, ceases altogether. As a consequence, the concerns expressed regarding the potential 

dewatering of the aquifer are unfounded. Likewise, concerns regarding subsequent subsidence and 

underground coal fires are also unfounded as the Scotty Lake coals will not be dewatered, but only 

depressured to the extent that gas will desorb and flow to the well bore. Concerns regarding 

subsidence, underground coals fires and hydraulic fracturing have been addressed in Appendix B. 

Drilling and completion techniques to be utilized by Hudson Group, LLC will ensure that no 

communication occurs between aquifers in the shallower Wasatch Fm and the Fort Union Fm which 

contains the Scotty Lake coals. As indicated in Section 2.2.3.2 and Appendix C, surface casing 

would be set to an approximate depth of 450 feet and cemented back to surface, with production 

casing set to total depth (TD) with cement circulated from TD back to a point located approximately

200 feet above the shallowest coal in the Fort Union Fm. Cement bond logs would be run to ensure 

that full cement coverage was obtained. 

4.5.4 The No Action Alternative 

Under the No Action Alternative, there would be no additional impacts to either the surface or subsurface hydrology of the overall project area. 

4.5.5 Mitigation and Monitoring

Please refer to Section 2.3.5 for Applicant-Committed Practices designed to reduce impacts to 

surface and sub-surface hydrologic resources within the overall analysis area. No additional 

mitigation is recommended.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

4.6 RANGE MANAGEMENT

Actual construction of the individual well pads, access roads, pipelines, etc. would result in an 

overall reduction in livestock and wildlife forage and a subsequent reduction in the available animal

unit months (AUMs) in each affected grazing allotment. For the purpose of assessing impacts to 

range resources, acres of disturbance were converted to a reduction in AUMs based upon an average 

of 7.2 acres/AUM for the overall project area (based upon the average AUMs in the Cyclone Rim

allotment).

4.6.1 Proposed Action

The primary impact to range resources within the SLPA would be the initial loss of vegetation and 

vegetative (forage) production resulting from additional oil/gas exploration activity. As indicated in 

Section 2.2, routine activities associated with oil/gas exploration and development in the SLPA 

would result in approximate surface disturbances as follows: 

x 32.94 acres associated with the construction of 18 well locations; 

x 24.41 acres associated with access road construction and reconstruction; 

x 36.82 acres associated with installation of the gas/water gathering system; and 

x 11.88 acres associated with the installation of water retention pits at each individual well 

location.

Under these assumptions, the initial loss of approximately 106.05 (106) acres of vegetation would 

result in the short-term loss of 14.7 AUMs, which represents approximately 3.7% of the 400 average 

total AUMs (2,800 acres ÷ 7.2 average AUMs) available on surface lands within the SLPA. 

Reclamation of those areas not required for ongoing production and operations would place 

approximately 57.28 acres back into forage production within 1 to 2 years following the initial 

disturbance. Reclamation of these areas would result in a long term loss of 6.8 AUMs, which 

represents less than one percent of the total average AUMs available on surface lands within the 

SLPA. It should be noted that selection of a water discharge option other than the construction of 18 

water evaporation (retention) would reduce the long-term (LOP) disturbance by approximately 11.88 

acres, which would result in a concomitant decrease in the long-term AUMs lost from 6.8 to 5.1 as a 

result of project-related activities. 

Selection of surface water disposal methods 2 or 3 (discharge into an unlined water retention pit with

or without an overflow outlet) as defined in Section 2.2.9 could attract additional cattle to these 

discharge sites. Depending on the amount, duration, and specific location of the discharge, an 

estimated 100 to 200 head of cattle could drift from the GMCA south into the CRA across the 

unfenced boundary. This estimate is based on documented cattle observations at the two existing 

water retention pits (one fenced and one unfenced) within the SLPA during the 2003 and 2004 

grazing seasons. Should the water retention pit option be selected for discharge, it is likely that 

additional cattle would be initially attracted to these sites. However, if these pits were properly 

fenced, the cattle would quickly learn that water at these sites was not available and would thus be 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

less likely to return. All three discharge options are likely to increase the number of cattle that 

would cross into the CRA from the GMCA; however, option #3 could exacerbate the current 

situation and create a long term range management problem that would require additional livestock 

control measures.

Additional impacts to the range resource within the SLPA would result from the invasion of newly 

disturbed areas by invasive non-native and/or noxious weed species. As indicated in Section 3.7, 

several species of invasive non-native weeds have become established on disturbed sites within the 

SLPA including halogeton (Halogeton glomeratus) and Russian thistle (Salsola iberica), with a 

possibility of invasion of disturbed areas within the SLPA by other non-native and noxious weed 

species. However, surface disturbances associated with the proposed SLPP would affect less than 

four percent of the combined surface acreage within the overall SLPA. As indicated above, 

selection of a water discharge option other than the installation of 18 water retention pits would 

reduce overall long-term (LOP) surface disturbance within the SLPA by approximately 11.2 percent, 

which would lessen the areas potentially subject to invasion by non-native and noxious weed 

species. Nonetheless, Hudson Group, Inc. intends to implement an aggressive weed management

policy as indicated in Section 2.3.7 and Appendix C. 

4.6.2 The No Action Alternative 

Under the No Action Alternative there would be no further loss of vegetation with a concomitant

reduction in available AUMs. Likewise, the invasion of disturbed areas by non-native species would 

be restricted to areas previously disturbed in conjunction with prior approvals. 

4.6.3 Mitigation and Monitoring 

Please refer to Section 2.3.7 for Applicant-Committed Practices designed to reduce impacts to the 

range resource within the overall analysis area. No additional mitigation is recommended.

4.7 SOILS

4.7.1 Proposed Action

Removal of native vegetation and disturbance of the underlying soil material as a result of surface 

disturbing activities associated with the Proposed Action would increase the potential for loss of the 

existing soil resource through erosion. This potential would increase proportionately as degree of 

slope increases. Overall, soils within the overall project area generally have an adequate amount of 

topsoil available to ensure satisfactory reclamation, assuming the use of proper techniques designed 

to control erosion and ensure revegetation of the reclaimed areas are utilized in the reclamation

process and slopes throughout the project area are relatively gentle. Additional oil/gas exploration 

activity within the SLPA would result in the overall disturbance of approximately 106 acres of the 

soil resource, or less than four percent of the total surface estate included within the proposed project 

area.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Analyses conducted in conjunction with the Cave Gulch-Bullfrog-Waltman Natural Gas 

Development Project (BLM 1997) determined that implementation of BMP for reclamation and 

erosion control would result in a substantial reduction in erosion rates for surface disturbances 

associated with project activities (Grah 1997). While this was a project-specific analysis based upon 

information gathered in conjunction therewith, these calculations suggest that soil erosion resulting 

from additional CBNG exploration activity in the SLPA could be reduced to negligible levels with 

the application of BMP for reclamation and stabilization of disturbed soils as outlined in Section 2.3 

and Appendix C. Site specific reclamation, erosion control, and revegetation recommendations

would be developed on a site-specific basis in conjunction with the on-site inspections to be 

conducted on each individual well location (including access road and pipeline ROWs). These 

recommendations would be incorporated in the Conditions of Approval (COAs) appended to each 

APD. Subsequent construction and reclamation activities would be monitored and remedial action 

taken as necessary to ensure that all surface disturbances are properly reclaimed, erosion is 

minimized, and the disturbed areas revegetated. 

4.7.2 The No Action Alternative 

Under the No Action Alternative there would be no project-related disturbance of soils and soils 

would remain in their current state. 

4.7.3 Mitigation and Monitoring 

Please refer to Section 2.3.8, Applicant-Committed Practices, for measures designed to reduce 

impacts to soil resources within the overall analysis area. No additional mitigation is recommended.

4.8 VISUAL RESOURCES 

Short-term visual impacts associated with implementation of the Proposed Action would include 

visual contrasts between the industrial character of the construction and drilling equipment and the 

somewhat natural surrounding landscape. In addition, potentially heavy volumes of sporadic truck 

traffic and the fugitive dust created as a result thereof, could produce negative visual impacts beyond 

the immediate project area. In this regard, both short-term and long-term impacts to the visual 

resource would be possible where patterns of line, form, color and texture in the existing 

characteristic landscape would be visually contrasted by drilling equipment and/or construction 

related disturbances to the existing topography or other readily visible site features. The severity of 

this impact would be dependent upon a number of factors including: 

x the visual absorption capability of the surrounding landscape, 

x distance from the most sensitive viewing area, 

x reclamation potential of the landscape to be disturbed, and/or 

x the level of disturbance to the visual resource to be created by the Proposed Action. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

The duration of the impact would be a function of both the time required to complete the action and 

the time required for the disturbed site to return to a pre-disturbance condition. In general, the visual 

impact would be greatest on those sites where mitigation would be difficult and/or where the visual 

contrast would be highly visible to a potentially large number of viewers. 

As indicated in Section 3.9, that portion of the project area north of Cyclone Rim falls under the 

jurisdiction of the Lander Field Office and is included in VRM Class IV. Under this VRM Class, 

changes may subordinate the original composition and character, but must reflect what could be a 

natural occurrence within the characteristic landscape. The majority of the project area south of 

Cyclone Rim falls within the jurisdiction of the Rawlins Field Office and is included in VRM Class 

III. Under this VRM class, changes in the basic environmental (topographic) elements caused by 

additional oil/gas exploration and development may be evident in the characteristic landscape; 

however, the changes should remain subordinate to the visual strength of the existing (land) 

character.

The following analysis of visual impacts will focus on a discussion of the visual landscape in terms

of viewer proximity to intrusions related to additional oil/gas exploration and development from a 

foreground, middleground, and/or background perspective. For the purposes of this document, the 

terms foreground, middleground and background are defined as follows: 

Foreground - Generally the area that lies within one-half mile of the viewer. 

Middleground - The area between the foreground and background in a landscape. The area 

located from one-half mile to five miles from the viewer. 

Background - The distant part of a landscape located from five miles to infinity from the 

viewer.

4.8.1 Proposed Action

The SLPA is located in a remote area of northeastern Sweetwater County far from established 

recreational areas, historic sites or other areas that would routinely attract visitors thereto. The 

distances from paved access to the SLPA are such that travel to/from the area would generally be 

restricted to periods of good weather by hardy individuals possessing vehicles suited to extended 

travel over dirt/gravel roads such as sport utility or other four-wheel drive (4WD) vehicles. The 

primary access route into the area would be via the Red Creek Road (BLM Road #3219). The 

westernmost boundary of the proposed pilot project is approximately one mile east of the Red Creek 

Road at its closest point thereto. Consequently, additional CBNG exploration activities within the 

SLPA would not affect the foreground perspective of viewers traveling along said road. 

Depending upon the direction of travel on the Red Creek Road, surface disturbance and projectrelated facilities within the SLPA would primarily be visible from both a middleground and 

background perspective. Viewers traveling south on the Red Creek Road would view the SLPA 

primarily from a middleground perspective for a short time as they come over Cyclone Rim and 

were directly west of the project area. However, the viewer perspective traveling south from

Cyclone Rim would be dominated in the background by a panoramic vista of the Great Divide Basin 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

including Bastard Butte. Viewers traveling north on the Red Creek Road would view the SLPA 

from both a background and middleground perspective depending upon their position on the road - 

with the perspective transitioning from background to middleground as the viewer moves closer to 

the SLPA area along the Red Creek Road. Again, the viewer perspective traveling north from

Bastard Butte would be dominated by Cyclone Rim and the panoramic vistas associated therewith. 

Short-term disturbances (construction, drilling and completion activities) associated with the 

proposed pilot project may well dominate the viewshed in the short-term. Removal of 

drilling/completion rigs and successful reclamation of the disturbed areas within the SLPA would 

reduce the long-term visual impact(s) of existing wells and would reduce the visual contrast (form

and texture of the landscape) to a level that is subordinate to the visual strength of the existing, 

natural landscape. Moreover, mitigation measures recommended below would further minimize the 

visual impacts of oil/gas exploration activity to viewers from both the middleground and background 

perspective. As a consequence, the proposed Scotty Lake CBNG Pilot Project would not violate 

existing visual resource management direction for the area or produce contrasts beyond the degree 

allowed for in the stated VRM guidelines from either a foreground, middleground, or background 

perspective.

4.8.2 The No Action Alternative 

Under the No Action Alternative there would be no project-related degradation of the viewshed 

resulting from the proposed action and visual contrasts in the area would remain as they are today. 

4.8.3 Mitigation and Monitoring 

While visual intrusions which would result from project activities are not inconsistent with the stated 

VRM management goals, the following mitigation measures are suggested in order to minimize the 

overall visual impact associated with additional CBNG exploration activity within the SLPA. 

1. All permanent (on-site for six months or longer) above-ground structures constructed or installed 

on the individual well locations (including pumping units, tank batteries, etc.) should be painted 

a flat, non-reflective, earthtone color to match one of the standard environmental colors as 

determined by the Five State Rocky Mountain Interagency Committee.

Those facilities required to comply with Occupational Health and Safety Act (OSHA) rules and 

regulations would be excluded from this painting requirement.

4.9 WILDLIFE AND SPECIAL STATUS SPECIES

The overall project area provides habitat for many species of both game and non-game vertebrates, 

including antelope, elk mule deer, raptors, upland game birds, predators and furbearers. The 

principal impacts likely to be associated with additional CBNG exploration activity within the SLPA 

would include potential displacement of some wildlife species from preferred habitat and the 

potential loss of wildlife habitat as a result of project activities

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Crucial habitat(s) for either big game or game bird species are not known to exist with the SLPA. 

4.9.1 Proposed Action

Impacts on local wildlife populations would result from direct removal or alteration of habitat, 

increased human presence associated with additional CBNG exploration activity, and direct 

wildlife/human interaction. Activities associated with additional exploration and/or development

activity within the SLPA would temporarily eliminate approximately 106 acres of wildlife habitat, 

consisting mostly of shrubs, grasses and forbs, until project reclamation occurs. This would result in 

a proportionate reduction in the amount of herbaceous and browse forage available to herbivorous 

species such as antelope and mule deer, as well as a reduction in nesting, feeding and security 

habitat for game birds (e.g., sage grouse) and those smaller vertebrate species that may inhabit the 

affected areas. These habitat losses can generally be classified as being either short-term or longterm in duration, with these terms defined below. 

1. Short-term loss refers to disturbances that would be reclaimed immediately after exploration 

activities are completed.

Loss or alteration of habitats in grass-shrub meadows and/or on grassy slopes would be 

considered short-term and are expected to occur in conjunction with lease development.

2. Long-term loss would occur in areas that could not be returned to their original vegetative state 

within a reasonable period of time (3 to 5 years), such as producing well sites and access roads. 

4.9.1.1 Habitat Loss and Displacement

Disturbances resulting from well pad, access road, and pipeline construction activity within the 

SLPA would result in the loss of smaller, less mobile species of wildlife, such as small mammals

and reptiles until such time as reclamation has been accomplished. However, considering the 

relatively small geographic area of disturbance, the actual magnitude of this loss and any potential 

displacement of these species would be considered as minimal.

Rather than direct habitat loss, the greatest impact on wildlife populations would be from

displacement of economically important wildlife species such as antelope, elk and mule deer from

preferred habitats as a result of increased level(s) of human activity (including vehicular traffic) and 

associated noise. The extent of this displacement is difficult to predict when one considers that 

response to noise and human presence varies from species to species as well as among individuals of 

the same species. In some cases, wildlife species may habituate to noise and human presence after 

initial exposure, and begin to re-invade areas that were formerly avoided. It is commonly assumed

that these effects are detrimental to individual species and numerous studies have examined the 

effects of human presence on big game species (Klein 1974; Irwin and Peek 1979; Ward and Cupal 

1979; MacArthur et al 1982; Brekke 1985). 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

In addition to the avoidance response, an increased human presence intensifies the potential for 

wildlife-human interactions ranging from the harassment of wildlife to poaching and increased legal 

harvest. Likewise, increased traffic levels on existing access roads could increase the potential for 

wildlife-vehicle collisions. These collisions are most frequent where roads traverse areas commonly

frequented by game species. Considering the relatively minimal road network to be constructed in 

association with additional CBNG exploration activity within the SLPA, the generally short duration 

of intensive field activities (i.e., construction, drilling, and completion operations), combined with 

the inconsequential amount of daily/weekly production traffic expected within the field, the potential 

for adverse wildlife-human interaction is considered to be minimal.

4.9.1.2 Big Game Species

The project area includes year-round habitat for several economically important game species 

including pronghorn antelope (Antilocapra americana), elk (Cervus elaphus), and mule deer 

(Odocoileus hemionus). While the project area includes year-round habitat for the above species, 

crucial habitat(s) for these species are not known to occur within the SLPA. Considering that no 

crucial wildlife habitat(s) will be affected by implementation of the Proposed Action, the potential 

for long-term displacement and/or individual losses (mortality) attributable to human activities 

within the SLPA are considered to be minimal. Since population numbers for both antelope and 

mule deer in their respective herd units (Red Desert, Steamboat and S. Wind River) are currently 

below objective levels as indicated in Table 3.6, implementation of the proposed SLPP should not 

cause a substantial increase in the current downward trend of these specific herds. 

4.9.1.3 Greater Sage Grouse

As indicated in Section 3.10.2 there are no known leks within a two mile radius of the SLPA. The 

closest known leks to the project area would be the Bastard Butte lek located in Section 10, T25N, 

R97W (3.25 miles southwest of the southern project are boundary) and the Scotty Lake lek located 

in Section 17 (3.25 miles west/northwest of the western project area boundary). Both leks were 

active in 2003 (WGFD 2003b). Considering the distance of these leks from the exterior boundaries 

of the project area, it is questionable whether nesting is occurring within the SLPA, particularly 

considering that suitable patches of sagebrush with the appropriate height and density to support 

sage grouse nesting are rather discontinuous in nature throughout the overall project area. The 

relatively small percentage of total surface disturbance proposed within the 2,880 acre SLPA would 

suggest that the potential effects of the proposed pilot project upon sage grouse nesting will be 

minimal at best. 

4.9.1.4 Raptor Species

As indicated in Section 3.10.3, five historic raptor nests are known to exist within or directly 

adjacent to the SLPA, with two of these five historic nests located within the 2,880 acre project area. 

These historic raptor nests were not active in either 2003 or 2004 (AEC 2004). It should be noted 

that the ferruginous hawk nest located in the NE1⁄4 of Section 22 (FH26972201) is in close proximity

to (within several hundred feet of) the proposed Scotty Lake #20 CBNG well. The subject nest was 

observed to be in very poor condition on June 23, 2004 (AEC 2004). 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Raptors may utilize presently unoccupied nesting territories within the SLPA in future years. The 

implementation of seasonal timing restrictions (within a “buffer zone” around active nests) to avoid 

surface disturbing activities (including construction, drilling and completion operations) within a 

“buffer zone” around active nests should reduce impacts the nesting raptors within the overall 

project area (see Section 4.9.5). Currently, the BLM also attempts to relocate well pad facilities if 

they fall within a 1200’ distance of a ferruginous hawk nest and 825’ of any other raptor. The 

installation of additional infrastructure in conjunction with the proposed SLPP and the concomitant

human activity associated therewith may prevent some raptors from utilizing potential nesting 

habitat during the life of the project. 

4.9.1.5 Threatened and Endangered Species

x Bald eagle (Haliaeetus leucocephalus) - Status: Threatened. 

The SLPA does not contain suitable roosting/perching habitat, concentrated feeding areas 

(perennial streams), or other special (nesting) habitats which might result in increased eagle 

activity therein. While the general area may be opportunistically used by bald eagles in 

conjunction with wide-ranging foraging activities, these foraging activities would likely occur 

during times of the year when human activity within the project area is at seasonally low levels, 

which would minimize the potential impacts to eagles foraging in the area. Consequently, we 

would not expect any potentially significant impacts to occur to bald eagle populations as a 

result of activities associated with the proposed pilot project. 

Determination: May affect, but not likely to adversely affect. 

x Black-footed ferret (Mustela nigripes) - Status: Endangered. 

It is well documented that black-footed ferrets depend primarily upon prairie dogs (Cynomys

ssp.) for food and upon prairie dog burrows for shelter (Hillman and Clark 1980, Fagerstone 

1987). Inventories within the SLPA conducted by AEC during the spring/summer of 2004 failed 

to identify any prairie dog colonies within the analysis area (AEC 2004). Considering the lack 

of both an available food source and suitable habitat for black-footed ferrets within the SLPA, 

impacts to this species are not anticipated. 

Determination: No effect. 

x Preble’s meadow jumping mouse (Zapus hudsonius preblei) - Status: Threatened. 

The SLPA is well outside of the limits of known habitat for the Preble’s Meadow jumping

mouse. Considering that there are there are no perennial or intermittent streams with associated 

riparian habitats within the SLPA and the project area is not within the area of expected 

occurrence thereof, we do not expect any impacts to this species. 

Determination: No effect. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

x Ute ladies’-tresses (Spiranthes diluvialis) - Status: Threatened. 

As indicated in Section 3.10.3.1, the SLPA is outside of the expected area of occurrence for Ute 

ladies’-tresses. Considering the general lack of suitable habitat within the overall project area 

(seasonally moist soils and wet meadows associated with riparian habitats), we do not expect any 

impacts to this species. 

Determination: No effect. 

x Colorado River Species 

As indicated in Section 2.2.3.1, fresh water to be used in drilling operations would be obtained 

from existing water wells/produced water facilities within the SLPA which produce water from

aquifers not connected to the Colorado, Green or Yampa River systems. As there will be no 

depletions to the Colorado River or it’s tributaries, impacts to the above-named species will not 

occur (see Section 3.10.4). 

Determination: No effect. 

x Black-tailed prairie dog (Cynomys ludovicianus) - Status: Proposed for Listing. 

As indicated above, there are no known prairie dog towns within the SLPA and the proposed 

project area is outside of the known range of the black-tailed prairie dog. Consequently, we do 

not anticipate any impacts to black-tailed prairie dogs as a result of project-related activities. 

Determination: No effect. 

4.9.1.6 Special Status Species

Mountain plover (Charadrius montanus) are considered to be a sensitive species and management

decisions should consider impacts thereto. A review of the records maintained by the Wyoming

Natural Diversity Database in April 2004 identified one recorded mountain plover sighting in 

Township 26 North, Ranges 97 and 98 West. Please refer to Section 3.10.4 for additional 

information in this regard. 

There are areas within the SLPA which meet the habitat requirements for mountain plover 

breeding/nesting from a slope, aspect, vegetative height and density standpoint; however, patch size 

within the area is generally less than optimum and generally does not meet the 26-54 hectare 

polygon size believed to be the minimum requirement for brood rearing (Knopf 2004). Small

patches of habitat may support nesting plovers if larger patches of suitable habitat are nearby; but, in 

general, the large contiguous habitats (open grasslands) preferred by mountain plover are lacking in 

the project area. Considering the relatively small amount of long-term surface disturbance within 

the SLPA, and the fact that existing plover habitat within the overall project area is relatively 

marginal, the potential impact to breeding/nesting mountain plovers would be slight. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

4.9.1.7 Migratory and Non-Migratory Birds

Three of the species identified in Table 3.9 including ferruginous hawk, greater sage grouse, and 

mountain plover have been discussed elsewhere in Section 4.10 and will not be discussed further 

herein.

Surface disturbing activities associated with the Proposed Action would result in the initial 

disturbance of approximately 106 acres of shrub-steppe and shortgrass prairie habitat which 

would provide a source of food, security cover and nesting habitat for many of the species listed 

in Table 3.9. Approximately 54% of this disturbance would be reclaimed within five years of 

initial disturbance resulting in a long-term (LOP) loss of approximately 49 acres of habitat. 

Considering the relatively small percentage of total surface disturbance proposed within the 2,880 

acre project area, the actual magnitude of direct habitat loss and subsequent displacement would be 

minimal. The displacement of bird species to adjacent, undisturbed habitats, while difficult to 

predict, would be relatively short-term in nature given the overall duration of additional 

development activities associated with the Proposed Action. 

4.9.2 The No Action Alternative 

Under the No Action Alternative impacts to wildlife, raptor, and special status species populations in 

the area would continue at existing levels. 

4.9.3 Mitigation and Monitoring

Please refer to Section 2.3.10 for a listing of Applicant-Committed Practices designed to minimize

impacts to wildlife, raptor, and special status species populations within the SLPA. Additional 

mitigation is recommended as follows to minimize impacts to wildlife within the SLPA. 

1. To protect important raptor nesting habitat, drilling and/or surface use will not be allowed within 

one-half (0.50) mile of occupied raptor nests during the period from February 1 to July 31. 

2. If unusual maintenance is proposed within one-half (0.50) mile of an occupied nest between 

March 1 and June 15, the operator must contact the BLM Authorized Officer for prior approval 

of operations or maintenance which would be “unusual”. “Unusual” means extensive or 

significant operations, such as workover operations or other operations, which include loud noise 

or night-time activity. Emergency (safety) situations would not be restricted. 

3. Casual use activities away from existing roads and facilities that are scheduled to occur between 

March 1 and mid-June should be coordinated with the BLM in order to minimize or avoid 

potential impacts to nesting raptors in the area. Casual uses include, but are not limited to, 

ground activities such as: (1) preliminary scouting of routes or sites, (2) land surveying and 

staking, and (3) cultural and wildlife surveys. Because casual use is generally not treated as a 

managed or permitted activity, there is a potential for causing impacts to nesting raptors. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

4. The Operator would implement policies designed to control poaching and littering and would 

notify all employees (contract and company) that conviction of a major game violation could 

result in disciplinary action. Contractors would be informed that any intentional poaching or 

littering within the SLPA could result in dismissal.

Implementation of the following Best Management Practices (BMP) developed by Wyoming PIF 

(Nicholoff 2003) would reduce the impacts of surface disturbing activities within the SLPA on 

migratory and non-migratory bird species. 

1. Relocate surface disturbing activities to avoid large sagebrush stands to the greatest extent 

possible in order to prevent habitat fragmentation within the shrub-steppe habitat type. 

2. Where possible, restore or rehabilitate degraded and disturbed sites to native plant communities.

3. Maintain remaining biological soil crust communities by minimizing sources of soil disturbance 

such as off-road vehicle use. 

4. In large disturbed areas, sagebrush and perennial grasses may need to be reseeded to shorten the 

recovery time and prevent dominance by non-native grasses and forbs. 

4.10 WILD HORSE MANAGEMENT

As indicated in Section 3.11, the proposed SLPA falls within the Antelope Hills Horse Management

Area (HMA) and is directly adjacent to both the Lost Creek and Great Divide Basin HMAs, which 

constitute a wild horse meta-population in this area of Wyoming. Horse populations in both the 

Antelope Hills and Great Divide Basin HMAs exceed the appropriate management level (AML) 

established for these areas, while populations within the Lost Creek HMA are within the established 

AML. The Lost Creek herd has been determined to carry a high percentage of genetic markers

identified with the Spanish Mustang breed, while those horses in the Antelope Hills and Great 

Divide Basin HMAs have not been genetically tested as of this date. 

4.10.1 Proposed Action

As discussed in Section 4.6.1, implementation of the Proposed Action would result in the loss of 

approximately 106 acres of short-term and 49 acres of long-term forage production which would 

affect grazing opportunities within the SLPA. However, considering the fact that the Antelope Hills 

HMA encompasses approximately 110,000 acres, the loss of 49 acres of long-term forage production 

is negligible by comparison. As indicated above, the wild horse population within the Antelope 

Hills HMA exceeds the upper end of the AML by a factor of two. 

There has been some concern expressed about the possible commingling of horses from the three 

different HMAs, particularly considering that the Lost Creek horses are apparently descended from

the horses (mustangs) originally brought to the new world by the Spanish Conquistadores. In this 

regard, fresh water discharged to the surface may represent an attractant to these horses which could, 

in turn, result in interbreeding between individual horses in these three herds. While horses in the 

Antelope Hills and Great Divide Basin herds have not been genetically tested, there is no reason to 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

believe that these horses are genetically different from the Lost Creek herd and that interbreeding 

has already occurred between these herds at some point or points in the past - particularly 

considering that there are no absolute physical barriers separating the horses in these three herds. 

These horses are considered by BLM to be a single meta-population, but have been divided into 

three sub-populations or HMAs solely for management purposes. So, while the discharged water 

may represent an attractant to horses in an otherwise dry landscape, this does not mean that 

interbreeding would occur where none has taken place in the past or that said interbreeding, if it did 

occur, would dilute the genetics of the Lost Creek herd. In this regard, it is worth noting that 

Osborne Spring is approximately four miles southwest of the SLPA and represents an unfenced 

natural source of perennial water that may already act as an attractant for horses in all three herds - 

particularly in drought years and in cases where an expanding population forces individuals to 

occupy new or non-traditional areas within the management area. Likewise, Picket Lake is 

approximately six miles northwest of the SLPA and also represents an unfenced perennial source of 

water in the area. There is seven miles of separation between Osborne Spring and Picket Lake and it 

is unreasonable to assume that horses would use one source of water to the exclusion of the other. 

Finally, it should be noted that the HMA boundaries are somewhat artificial and the horses may or 

may not respect these artificial boundaries. These populations are dynamic and it is likely that 

genetic testing of the Antelope Hills and Great Divide Basin herds will ultimately determine that all 

of these horse herds are inter-related as no physical obstacles occur within the overall area to 

preclude interbreeding. As a consequence, we do not anticipate any adverse impacts to wild horse 

populations in the area in general or a dilution of the unique genetic characteristics of the Lost Creek 

herd as a result of the Proposed Action.. 

4.10.2 The No Action Alternative 

Under the No Action Alternative impacts to wild horse populations in the area would continue at 

existing levels. 

4.10.3 Mitigation and Monitoring

No mitigation or monitoring is recommended.

4.11 CUMULATIVE IMPACTS 

Pursuant to NEPA, the BLM must consider the cumulative impacts of the Proposed Action in 

conjunction with other ongoing oil/gas exploration and development activities within the general 

area. In addition, unrelated activities within the overall project area which might have an adverse 

impact upon existing natural resources in the area and, consequently, which would further contribute 

to the overall degradation of the human environment must be considered in the analysis of 

cumulative impacts as well. In this regard, the primary activity within the general area consists of

past and present oil/gas exploration activity within the Picket Lake Unit as discussed in Section 

3.5.2. Additional oil/gas exploration activity within the general area includes the following: 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

x Cabot Oil & Gas Corporation Osborne Spring Unit #32-14: SE1⁄4SW1⁄4 of Section 32, Township 

26 North, Range 97 West. Drilled to 13,745 feet and completed in the Ericson Formation. Well

is currently being placed on production. 

x Davis Petroleum Corporation Picket Lake Federal #1-14: NW1⁄4SW1⁄4 of Section 14, Township 

26 North, Range 87 West. Well proposed to 14,700 feet to test the productive potential of the 

Lewis Formation. The well was originally permitted in early 2001, was not drilled, and has been 

subsequently been renewed on an annual basis since initial permit approval. 

There are no other oil/gas exploration and/or development activities existing or proposed within a 

six mile radius of the SLPA. 

Considering that the approving agencies (the WOGCC and BLM’s Lander and Rawlins Field 

Offices) have not received any proposals for additional resource development or major surface 

disturbing activity (e.g., mines, highways, and/or industrial sites) in or adjacent to the SLPA other 

than those referenced above, the Proposed Action represents the only reasonably foreseeable 

resource development in the overall project area. 

For the purposes of this Environmental Assessment, an Area of Influence (AOI) has been defined for 

those resource components potentially affected by additional oil/gas exploration and development

within the SLPA with the AOI adjusted for each specific resource. Table 4.1 provides a listing of 

each specific resource component discussed herein and the AOI as defined for each. Generally 

speaking, the AOI defined for most resource components consists of the project area as cumulative

impacts to those resources would typically be confined to the area of impact. Certain notable 

exceptions exist for those resource components where impacts resulting from the proposed SLPP 

may migrate off-site or affect population dynamics in the case of wildlife. 

Table 4.1 

Area of Influence for Each Specific Resource Component 

Resource Component Area of influence 

 Air Quality Great Divide Basin

 Cultural Resources Project Area 

 Geology and Minerals Project Area + Buffer Including Above Wells

 Hydrology - Surface Watersheds

 Hydrology - Subsurface Scotty Lake Aquifer 

 Range Management Grazing Allotments

 Soils Watersheds

 Wildlife Varies by Species - See Section 4.11.8 

 Wild Horses Horse Management Area(s) 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

As indicated in Table 4.1, the AOI for Surface Hydrology and Soils has been defined by watersheds 

as discussed in Section 3.6.1 and in the Scotty Lake CBNG Pilot Project Water Management Plan 

(WMP). However, it should be noted that the WMP does not consider impacts to the West Alkali 

Creek watershed as no produced water will be discharged north of Cyclone Rim. Primary surface

disturbance within the Red Creek watershed AOI includes the existing wells within the SLPA as 

discussed in Section 3.5.2, both the existing Cabot and proposed Davis wells discussed above, and 

the existing BLM roads in the area (including BLM Road numbers 3214, 3216, and 3219). 

Disturbances associated with these three BLM roads will vary somewhat throughout the overall 

AOI. However, for the purposes of this document, we will assume that the long-term disturbance 

associated with each BLM road right-of-way is equal to forty feet. While this is an overstatement of 

currently existing disturbance for BLM roads 3214 and 3216, it is fairly accurate for BLM Road 

3219. Routine maintenance of these roads and the frequency thereof will dictate long-term surface 

disturbance associated therewith as will use of BLM Road #3216 for access to the well proposed by 

Davis Petroleum Corporation. Consequently, we must assume that the road ROWs either have 

recently been bladed or will be bladed in the near future, which will result in a continuing level of 

disturbance to soils and subsequent plant growth thereon. Existing two-track trails within the CIAA 

are not being considered in this analysis as field inspections conducted on April 14 and again on 

June 23, 2004 indicated that area two-track trails are both stable and well vegetated. As these trails 

are not contributing to potential erosion and/or sedimentation and represent only a minor reduction 

in forage production within the CIAA they will not be considered herein. 

Existing/proposed surface disturbance within the watershed AOI is quantified in Table 4.2 by 

disturbance type in each respective watershed. It should be noted that BLM Road #3216 follows 

Cyclone Rim, which generally represents the hydrologic boundary between Red Creek and West

Alkali Creek and also represents the administrative boundary between the Lander and Rawlins Field 

Offices as mentioned previously. In this regard, both map and field inspections of existing surface 

disturbance within the SLPA suggests that most of the existing surface disturbance is situated on the 

south side of the hydrologic divide. For the purposes of this document, existing disturbance 

associated with BLM Road #3216 east/southeast of the Picket Lake Unit #3 will be allocated to the 

West Alkali Creek Drainage as well as surface disturbance associated with the existing Picket Lake 

Unit #3 well location and access road route. 

Table 4.3 provides a summary of total surface disturbance by watershed including existing/proposed 

disturbance quantified in Table 4.2 and including additional surface disturbance associated with the 

Proposed Action. 

4.11.2 Air Quality

The cumulative impact of emissions resulting from the implementation of the proposed 18 well 

Scotty Lake pilot project would be much the same as those discussed for similar oil and gas projects 

such as the Seminoe Road Coalbed Methane Pilot Project (BLM 2001), Lower Bush Creek Coal Bed 

Methane Exploratory Pilot Project (BLM 2003a), and Wind Dancer Natural Gas Development

Project (BLM 2004c). 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Table 4.2

Summary of Existing Surface Disturbance in the

Area of Influence by Watershed

Name of Facilities 1 BLM Roads 2 Collector Roads 3 Resource Roads 4 TOTAL

Watershed (acres) (acres) (acres) (acres) (acres)

 Red Creek 21.55 60.63 21.82 12.75 116.75

 West Alkali Creek 1.00 6.89 00.00 0.45 8.34 

Totals 22.55 67.52 21.82 13.20 125.09

1 Includes well pads (19.83 acres), existing compressor site (0.62 acres), and water retention pits (2.10 acres). 

2 73,525’ of road with a 40’ total disturbed ROW width (66,025’ in Red Creek and 7,500’ in West Alkali Creek).

3 23,760’ of road with a 40’ total disturbed ROW width.

4 9,530’ of road with a 40’ total disturbed ROW width and 6,924’ of road with a total disturbed ROW width of 28’. 

Table 4.3

Summary of Total Surface Disturbance Anticipated in the

SLPP Area of Influence by Watershed

Name of Facilities BLM Roads Access Roads 1 Pipelines 2 TOTAL

Watershed (acres) (acres) (acres) (acres) (acres)

 Red Creek 53.92 60.63 54.02 24.67 193.24

 West Alkali Creek 13.45 6.89 5.41 12.15 37.90 

Totals 67.37 67.52 59.43 36.82 231.14

1 Includes existing collector and resource roads shown in Table 4.2 and proposed resource roads to be constructed in

conjunction with the Proposed Action.

2 Includes both gas and water pipelines to be constructed in conjunction with the Proposed Action.

In depth air quality analyses have been conducted on three large-scale oil and gas exploration and 

development projects in southwest Wyoming including the Continental Divide/Wamsutter II Natural 

Gas Project EIS (BLM 1999a), Desolation Flats Natural Gas Field Development Project Final EIS 

(BLM 2004b), and the Pinedale Anticline Oil and Gas Exploration and Development Project EIS 

(BLM 1999b). Analyses contained in the Continental Divide/Wamsutter II air quality study found 

that both short and long term predicted pollutant concentrations would comply with applicable air 

quality standards (i.e., WAAQS and NAAQS) resulting from direct, indirect, and cumulative project 

emissions (including construction and operation). Likewise, analyses presented in the Pinedale 

Anticline air quality study found no significant impacts to near-field air quality standards at a 

predicted 40 acre well density (16 wells per section). Air quality analyses conducted in conjunction 

with the Desolation Flats EIS found no significant adverse impacts to air quality resulting from

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

either the Proposed Action (385 wells drilled with a 65% success rate) or from Alternative A (592 

wells drilled with a 65% success rate). Clearly, the emissions from the 18 well pilot project would 

be inconsequential when compared to the level of development proposed in the Continental Divide, 

Desolation Flats and Pinedale Anticline projects and consequently would not violate applicable 

WAAQS and NAAQS air quality standards. 

4.11.2 Cultural Resources

Both the surface and sub-surface mineral estate included within the AOI is in federal ownership. In 

this regard, the Class III cultural resource inventories that have been/would be conducted in 

conjunction with proposed surface disturbing activities therein would not only add to our knowledge 

of the distribution of such resources within the area but would serve to minimize if not prevent 

impacts to potentially eligible cultural sites. Because all known cultural resources would either be 

avoided or potential impacts thereto mitigated in accordance with BLM/SHPO recommendations, no 

adverse cumulative impacts would occur to cultural resources within the AOI. 

4.11.3 Geology and Minerals

Existing, proposed and reasonably foreseeable future actions within the AIO would not add 

appreciably to the level of impact to geological and mineral resources therein. Development of oil 

and gas resources within the AIO would result in minor alterations to the existing topography with 

the bulk of these alterations occurring on surface/mineral estate owned by the United States of 

America and subject to BLM approval. Application of site-specific Conditions of Approval (COAs) 

at the time of permit approval would effectively mitigate these minor levels of topographic 

disturbance. Likewise, use of industry standard drilling procedures and application of BMPs would 

minimize potential impacts to the sub-surface mineral resources penetrated in conjunction with 

oil/gas exploration activity within the AOI. 

4.11.4 Hydrology 

4.11.4.1 Surface Hydrology 

Additional oil/gas exploration and development activity within the SLPA would result in negligible 

impacts to surface waters and their applicable watersheds within the AOI. In this regard, Table 4.3 

presents a summary of the cumulative surface disturbance which would be expected within each 

individual watershed and would include the surface disturbance associated with the construction and 

subsequent drilling of the 18 wells proposed in conjunction with the SLPP. Implementation of the 

Proposed Action would increase the cumulative surface disturbance in the Red Creek watershed by 

approximately 61 percent from 119.75 acres to 193.24 acres, with the cumulative surface 

disturbance equal to approximately 1.47 percent of the Red Creek watershed. Likewise, 

implementation of the Proposed Action would also increase the surface disturbance in the West

Alkali Creek watershed by approximately 354 percent from 8.34 acres to 37.9 acres, with the 

cumulative surface disturbance equal to less than 1 percent (0.10%) of the West Alkali Creek 

watershed.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Surface disturbing activities associated with the Proposed Action would increase total surface 

disturbance in the 50,944 acre AOI by approximately 0.20 percent from 0.25 percent to 0.45 percent.

An increase of less than 1 percent in overall surface disturbance within the AOI would be considered 

as a negligible impact upon the affected watersheds. 

As there are no permanent sources of surface water within the SLPA or the AOI, we do not 

anticipate any cumulative impacts to surface waters or the surface hydrology of the AOI resulting 

from surface disturbing activities associated with the Proposed Action. 

4.11.4.2 Sub-Surface Hydrology 

Implementation of the Proposed Action would result in the removal of fresh water from the Fort 

Union Fm (Scotty Lake coals) at the rate of approximately 9,900 barrels of water per day (bwpd). 

As there are no known water wells within the AOI which are permitted to the Fort Union Fm (Scotty 

Lake coals) other than the existing CBNG wells referenced in Section 3.5.2, cumulative impacts to 

the sub-surface hydrology of the AOI will not occur. There are no other activities (either currently 

ongoing or proposed) within the AOI which would result in a cumulative impact to the ground water 

resources thereof. 

4.11.5 Range Management 

As indicated in Table 4.1, the Area of Influence (AOI) for the Range Management resource would 

consist of both the Cyclone Rim and Green Mountain Common grazing allotments. An analysis of 

cumulative impacts was conducted in conjunction with the Wind Dancer Natural Gas Development

Project (BLM 2004c) which analyzed the cumulative impacts of oil/gas exploration and 

development activity within the Cyclone Rim grazing allotment. This analysis included the 

proposed Scotty Lake CBNG Pilot Project in the cumulative impact analysis and estimated that 

approximately 103 AUMs would be lost due to existing and reasonably foreseeable development

therein, which amounted to 0.3 percent of the 40,661 total AUMs therein. This estimate is slightly 

inflated as approximately 30 acres of surface disturbance included within the proposed SLPP 

actually occurs within the Green Mountain Common allotment; however, this small error would only 

serve to reduce the impacts within the Cyclone Rim allotment proportionately and would be minor in 

comparison with the overall size of the Cyclone Rim allotment.

The Green Mountain Common allotment contains approximately 468,379 acres of public lands with 

a total of 47,729 AUMs. The cumulative disturbance of 37.90 acres in the reasonably foreseeable 

future would amount to a short-term loss of approximately 5.26 AUMs within the Green Mountain 

Common grazing allotment, or substantially less than one percent (0.01%) of the total AUMs 

available in said allotment.

Because non-native invasive and noxious plant species would be controlled by the Operator, it is 

unlikely that the Proposed Action would have any adverse cumulative impacts. However, any 

area(s) within the SLPA subjected to new surface disturbance would represent an opportunity for the 

establishment of these invasive non-native species. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

4.11.6 Soils 

As indicated in Section 4.6.1, surface disturbances associated with the Proposed Action would result 

in the short-term disturbance of approximately 106 acres of the soil resource within the SLPA, or 

approximately 3.7% of the overall project area. The addition of 125.09 acres of existing/proposed 

surface disturbance within the AOI would result in cumulative, short-term disturbance of 231.14 

acres or less than one percent (0.45%) of the AOI as defined in Table 4.1. 

Considering that oil/gas exploration activities within the SLPA, and directly under the control of 

Hudson Group, LLC, represents the primary surface disturbing activity within the overall AOI, 

quantification of these existing and proposed impacts will present a fairly accurate view of impacts

to the soil resource within the Area of Influence. Addition of the 106.05 acres of surface disturbance 

attributable to the Proposed Action would increase the overall, short-term surface disturbance within 

the AOI by approximately 85 percent. However, implementation of BMP for reclamation and 

erosion control within the AOI would result in a commensurate reduction in overall erosion rates as 

discussed in Section 4.7.1. The successful reclamation of surface disturbance within the AOI 

combined with routine monitoring of reclamation success and implementation of remedial measures

as necessary to correct any identified deficiencies would reduce the cumulative impacts to the soil 

resource to negligible levels. 

4.11.7 Visual Resources 

While implementation of the Proposed Action would increase the overall number of facilities within 

the viewshed, the cumulative impact of these facilities upon the landscape would remain consistent 

with the stated VRM designations for the overall project area. 

4.11.8 Wildlife and Special Status Species 

As indicated in Table 4.1, the Area of Influence (AOI) for wildlife will vary by species. Table 4.4 

defines the AOI for those species to be discussed below, with these definitions based on previous 

analyses including the Wind Dancer Natural Gas Development Project EA (BLM 2004c). 

Table 4.4 

Areas of Influence for Analysis of Cumulative Impacts to Wildlife and Special Status Species 

Species Area of Influence Rationale

 Big Game (antelope, elk, and mule deer) WGFD Herd Unit Potential range of herd

 Raptors Project Area + 1 Mile Buffer Current Nesting Stipulations

 Sage Grouse Project Area + 2 Mile Buffer Current Lek Stipulations

 Other Migratory Birds Project Area + 1 Mile Buffer Based on Raptor Stipulation

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Surface disturbing activities within the AOI for the SLPP have already accounted for approximately

125.09 acres of short-term habitat loss (see Table 4.2). Implementation of the SLPP proposal and 

subsequent drilling of all 18 wells proposed in conjunction therewith would add an additional 106.05 

acres of short-term habitat loss, resulting in a cumulative habitat loss of 231.14 acres of habitat as 

shown in Table 4.3. This total includes short-term disturbance associated with oil/gas exploration 

activity which has previously occurred within the overall project area (or is proposed to occur as in 

the case of the Davis well). These disturbed areas will be subjected to an indeterminate amount of 

reclamation in the near term resulting in an overall reduction in the amount of surface disturbance 

remaining over the long term (post reclamation disturbance) for the LOP. However, for the purposes 

of this analysis we will assume that this 231.14 acres of surface disturbance represents post 

reclamation (or long-term) disturbance. 

4.11.8.1 Big Game Species

An analysis of cumulative impacts to big game species in the Great Divide Basin was conducted in 

conjunction with the Wind Dancer Natural Gas Development Project (BLM 2004c) which analyzed 

the cumulative impacts of oil/gas exploration and development activity within the Red Desert 

(antelope) and Steamboat (elk and mule deer) Herd Units. This analysis included the proposed 

Scotty Lake CBNG Pilot Project in the cumulative impact analysis and estimated that approximately

13,150 acres of wildlife habitat would be/have been lost to both existing and reasonably foreseeable 

oil/gas exploration and development activity within the Red Desert antelope herd unit (2.16 million

acres). Likewise, approximately 11,150 acres of wildlife habitat would be/have been lost to both 

existing and reasonably foreseeable oil/gas exploration and development activity within the 

Steamboat elk and mule deer herd units (2.5 million acres) (BLM 2004c). Surface disturbances 

resulting from approval of the Proposed Action would affect less than one-tenth of one percent of 

the total acreage included in both herd units and would represent slightly less than one percent of the 

total surface disturbance predicted in the respective herd units. 

While direct impacts resulting from the implementation of the SLPP would affect less than one 

percent of the total area included within the Red Desert and Steamboat Herd Units, the increase in 

human activity associated with both existing and proposed oil/gas exploration activity within the 

AOI has the potential to add a larger human “footprint” to an otherwise remote area, thereby 

increasing the indirect impact of human intrusion and associated disturbance to wildlife populations. 

Animals within the affected areas will be displaced into surrounding habitats, with this displacement

occurring over an indeterminate area and for an indeterminate period of time. However, considering 

that there are no crucial habitats within the proposed SLPA, the cumulative impact of this additional 

human presence within these herd units is considered to be minimal.

As stated in Section 3.10.1, that portion of the SLPA lying north of BLM road #3216 is included in 

the South Wind River Herd Unit for mule deer. An additional 29.56 acres of habitat on the extreme

southern edge of the South Wind River Mule Deer Herd Unit would be affected by activities 

associated with the Proposed Action, which represents substantially less than one percent (0.002%) 

of the total acreage included within the subject herd unit (1,229,793 acres). As indicated in Section 

3.10.1, there are no crucial mule deer habitats known to exist within the overall SLPA. Large 

portions of the Wind River Herd Unit including hunt areas 91, 93, 94 and 95 have no existing or 

ongoing oil/gas activity therein, with limited activity occurring in hunt areas 92 and 160 consisting 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

mainly of old, existing fields. Considering the extremely small amount of additional disturbance 

proposed within the South Wind River Herd Unit to result from project related activities, no 

additional analyses will be undertaken as the cumulative impact of the Proposed Action on mule

deer within said herd unit will inconsequential, both from a direct (surface disturbance) and indirect 

(displacement) standpoint. 

4.11.8.2 Greater Sage Grouse

There are no known leks within a two mile radius of the proposed SLPA. The closest leks to the 

actual SLPA boundary include both the Bastard Butte and Scotty Lake leks (see Section 3.10.2), 

which are approximately 3.25 miles southwest and 3.25 miles west/northwest respectively of the 

project area boundary. The AOI for sage grouse would encompass a two mile buffer zone 

surrounding the SLPA. Surface disturbance within the buffer zone surrounding the project area 

would be limited to pre-existing disturbance including the existing road network and reasonably 

foreseeable activity including the proposed Davis well - activities associated with the Proposed 

Action would not contribute to cumulative impacts to sage grouse nesting habitat within the AOI as 

defined in Table 4.4. 

4.11.8.3 Raptors 

Although historic raptor nests are known to occur within the AOI for the SLPP, inventories 

conducted in both 2003 and 2004 failed to identify any active raptor nesting within the project area. 

Mitigation measures suggested in Section 4.9.5, would serve to eliminate the cumulative impacts of 

additional CBNG exploration activity within the SLPA to these nesting territories by restricting 

surface disturbing activities within 0.5 miles of active nests during the period between February 1 

and July 31 in any given year should an active nest be discovered. As stated in Section 4.9.1.4, 

BLM also attempts to relocate well pad facilities if they should fall within 1200 feet of a ferruginous 

hawk nest and 825 feet of any other raptor nest. 

4.11.8.4 Migratory and Non-Migratory Birds 

Direct impacts to migratory and non-migratory birds within the SLPA would include the cumulative

loss of approximately 231.14 acres of habitat. Indirect losses would primarily involve the 

fragmentation of existing habitat within the 2,880 acre SLPA. As there are no reliable population 

data for migratory and/or non-migratory birds within the area, and considering that both direct and 

indirect impacts upon these bird populations are poorly understood, it would be difficult to 

accurately predict the cumulative impacts of the project thereon. The 106.05 acres of additional 

surface disturbance which would result from project implementation would increase cumulative

surface disturbance within the SLPA by approximately 3.68 percent from 4.34 percent to 8.03 

percent of the 2,880 acre project area. The impact of this 3.68 percent increase in cumulative

surface disturbance to the migratory and non-migratory bird species identified in Table 3.9 would be 

negligible.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

4.11.9 Wild Horse Management 

The AOI for wild horses would be the Antelope Hills HMA, which encompasses approximately

110,000 acres in Fremont and Sweetwater counties. Cumulative impacts resulting from the loss of 

an additional 231.14 acres of forage production within the 110,000 acre HMA would account for 

less than one percent (0.21%) of available forage within the overall HMA, which is negligible in 

comparison to the total amount of forage available elsewhere within the HMA. 

4.12 SHORT-TERM USE OF THE ENVIRONMENT VERSUS LONG-TERM 

PRODUCTIVITY

Short-term use of the environment during the life of the project would not detract from long-term

productivity of the area. Even during the life of the project, only the small areas from which 

vegetation is removed would be unavailable for grazing and wildlife habitat. Once the project is 

completed and disturbed areas are reclaimed the same resources that were available prior to the 

project would be available once again, with the exception of the hydrocarbons that were extracted 

from the subsurface. While it may ultimately take up to 25 years to regenerate a mature, climax

stand of shrubs (e.g., sagebrush) comparable to shrub populations present prior to project initiation, 

successful and ongoing reclamation of surface disturbance within the overall project area would 

introduce vegetative communities which would support wildlife and livestock grazing. 

4.13 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENT OF RESOURCES

The term “Irreversible Commitment of Resources” refers to the loss of future options which would 

result from additional exploration and development of those lands included within the SLPA and 

primarily applies to the resultant impacts upon: 

x non-renewable resources such as minerals or cultural resources; or to 

x processes or factors that are renewable only over long periods of time (e.g., soil productivity). 

Likewise, the term “Irretrievable Commitment of Resources” refers to the loss of production, 

harvest, or use of natural resources. For example, some or all of the forage production from an area 

is irretrievably lost while the area serves as an oil/gas well pad. Although this forage production 

loss is irretrievable, the action is not irreversible and, if the land use changes though subsequent 

abandonment and reclamation of these facilities, forage production would resume.

4.13.1 Air Quality

No irreversible or irretrievable commitment of resources would occur to air quality. Short-term

impacts to air quality resulting from additional CBNG exploration activity within the SLPA would 

be reversible. Similarly, these impacts would not be irretrievable since air quality is a transient 

characteristic subject to improvement through natural meteorological movements within the 

atmosphere.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

4.13.2 Cultural Resources

Should cultural resource inventories fail to identify or inventory all sites and/or artifacts within the 

proposed area(s) of disturbance, there is a possibility that the cultural resource could be damaged or 

destroyed during subsequent construction activities. Such an impact would be both an irreversible 

and irretrievable commitment of the affected cultural resource. Likewise, the loss of contextual 

information that could have been retrieved from the undamaged cultural site would also be an 

irretrievable commitment of the cultural resource. 

The loss of cultural properties as a result of vandalism or artifact collection would be both an 

irreversible and irretrievable commitment of the cultural resource as well. 

4.13.3 Geology and Minerals

The removal natural gas from the Fort Union Fm would be both an irreversible and irretrievable 

commitment of resources. Once the hydrocarbons have been removed from the formation and put to 

other uses, the natural gas resource has been irreversibly and irretrievably lost. 

4.13.4 Hydrology 

No irreversible and only a minimal irretrievable commitment of resources would occur to the 

hydrologic environment of the project area. Water withdrawn from the Fort Union Fm in 

conjunction with CBNG operations in the SLPA would discharged to the surface and would be 

irretrievably lost to the parent aquifer; however, the aquifer would be expected to naturally recharge 

over time so the loss to the aquifer would not be irreversible. Likewise, the water withdrawn from

the Fort Union Fm would be potentially withheld from other uses (such as agricultural uses) and 

would be irretrievably lost to those uses that are not able to take advantage of the discharged water. 

4.13.5 Range Management

The only potentially irreversible commitment of range resources would result from the direct 

mortality of individual plants resulting from surface disturbances associated with additional CBNG 

exploration activities, which would translate into a direct reduction of available forage for livestock, 

wild horse, and wildlife use. However, plants (both as populations and as communities) have the 

reproductive potential to renew themselves. Consequently, this loss of individual plants would be 

reversible in the long term as disturbed areas were reclaimed. Likewise, the interim loss of 

vegetative cover types and associated resources (AUMs) would represent a minor irretrievable 

commitment of resources. As above, this irretrievable commitment of resources (loss of forage) 

would persist until such time as the disturbed area(s) had been reclaimed and their original 

productivity restored. 

4.13.6 Soils

Any loss of topsoil associated with surface disturbance resulting from additional CBNG exploration 

activities within the SLPA and the subsequent loss or reduction in soil productivity resulting there 

from would be considered as an irreversible commitment of the soil resource. However, this 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

commitment is expected to be quite small when one considers the relatively small amount of soil 

disturbance that would result from the Proposed Action. A minimal irretrievable commitment of the 

soil resource would result from the disturbance of previously productive soils in conjunction with 

surface disturbing activities such as road and well pad construction. This commitment of resources 

would last until final project abandonment and reclamation.

Soil disturbances associated with additional CBNG exploration activity within the SLPA could 

result in erosion and the subsequent discharge of sediments into ephemeral tributaries of both Red 

Creek and West Alkali Creek which would both an irreversible and irretrievable commitment of

resources.

4.13.7 Visual Resources

Visual intrusions resulting from alterations to the natural landscape would represent an irretrievable 

commitment of resources. However, these visual intrusions on the landscape are not irreversible and 

would be eliminated upon final abandonment of project related facilities within the SLPA and 

subsequent reclamation of disturbed areas associated therewith. 

4.13.8 Wildlife and Special Status Species

The only irreversible commitment of resources that could occur to wildlife populations within the 

SLPA would be the direct mortality of individual animals. Wildlife species have the reproductive 

capacity to renew themselves and thereby maintain their populations, given the overall availability 

of quality habitat within the general vicinity of the potential impact. Considering both the 

availability and diversity of wildlife habitat existing throughout the overall project area, no 

irreversible commitment of resources would be expected to wildlife populations in the affected area. 

The loss of habitat use associated with project related activities resulting from displacement

(alteration of behavioral patterns) due to human intrusion would be an irretrievable commitment of 

wildlife resources. However, with proper timing constraints in critical habitats, the magnitude of 

such a commitment would be small and the commitment would be reversible upon final project 

termination and reclamation.

4.13.9 Wild Horses

The irreversible and irretrievable commitment of resources that are defined above for Wildlife and 

Special Status Species (Section 4.13.8) would apply to wild horses as well. 

4.14 RESIDUAL IMPACTS

The term “residual impacts” refers to those impacts remaining after all reasonable mitigation has 

been applied. The disturbance of approximately 106 acres of soil and related wildlife habitat 

resulting from construction associated with additional CBNG exploration activity within the SLPA 

would constitute a short-term impact, considering that approximately 54% of this initial disturbance 

(49 acres) would be reclaimed within two years following initial disturbance. The remaining 57 

acres of initial surface disturbance would not be reclaimed until termination of the project and 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

78

would, therefore, represent a long-term (or residual) impact to the affected resources. This longterm impact to both the soil and related resources would also represent a residual loss of both 

domestic livestock, wild horse and wildlife forage, as well as associated wildlife habitat for a 

comparable period of time. 

Construction of roads and drill pads, in conjunction with the installation of permanent production 

facilities on each individual well location would result in a long-term (or residual) impact to the 

visual resource of the area. Final abandonment of the project, plugging of each individual well, 

reclamation and revegetation of the remaining 57 acres of disturbed surface area and cessation of 

project related human intrusions into the area would effectively eliminate all of the above-referenced 

residual impacts associated with this project. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

5.0 CONSULTATION AND COORDINATION

5.1 BACKGROUND

The Scotty Lake Coalbed Natural Gas Pilot Project (SLPP) Environmental Assessment was prepared 

by an independent environmental consulting firm, with the guidance, participation, and independent 

evaluation of the Bureau of Land Management. A list of the personnel responsible for document

preparation, and their individual responsibilities are provided in Section 5.3. 

5.2 PUBLIC PARTICIPATION

As indicated in Section 1.5, an open process has been employed for the determination and scope of 

the issues addressed in this environmental document. In compliance with the procedural 

requirements of the Council on Environmental Quality for the implementation of NEPA (40 CFR 

15001.7, the RFO released a scoping notice on March 17, 2004 in order to identify the significant 

issues related to the SLPP proposal. The scoping notice was sent to all individuals, agencies, 

companies, and organizations listed on the BLM’s NEPA mailing list. The thirty day public 

comment period ended on April 19, 2004, Comments were received from the following individuals, 

agencies, or organizations: 

x Natural Resources Conservation Service 

x Petroleum Association of Wyoming

x Southern Ute Indian Tribe 

x U.S. Fish and Wildlife Service 

x Wyoming Department of Agriculture 

x Wyoming Department of Environmental Quality 

x Wyoming Game and Fish Department

x Wyoming Office of State Lands and Investments

x Wyoming Outdoor Council - Biodiversity Conservation Alliance 

x Wyoming State Engineer’s Office 

5.3 LIST OF PREPARERS

The following tables identify those BLM and consulting individuals that played a key role in the 

preparation of this Environmental Assessment.

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80

Table 5.1

Interdisciplinary Reviewers from the Bureau of Land Management 

Name Title

Rawlins Field Office 

John Ahlbrandt Project Lead, Natural Resource Specialist 

Mike Calton Rangeland Management Specialist 

Bob Hartman Petroleum Engineer 

Krystal Clair Recreation/Visual

Bill Falvey Wildlife Biologist 

Susan Foley Soils/Invasive Weeds 

Pam Huter Archaeologist

Bob Lange Hydrologist, Water Quality 

Sandy Meyers Assistant Field Manager, Resources 

Clare Miller Assistant Field Manager, Minerals and Lands 

Mark Newman Geology 

Chuck Reed Wild Horses 

Mike Robinson Realty Specialist 

David Simons Environmental Planner 

Lander Field Office 

Greg Bautz Soil Scientist 

Chris Carusona Natural Resource Specialist 

Stuart Cerovski Petroleum Engineer 

John Likins Range Management 

Griff Morgan Wildlife Biologist 

Roy Packer Wild Horses 

Ruble Vigil Assistant Field Manager, Resources 

Ed Womack Assistant Field Manager, Minerals and Lands 

Table 5.2

Principal Interdisciplinary Team 

Name Affiliation Responsibility 

Robert M. Anderson Anderson Environmental Consulting Project Manager, Principal Author 

John Albanese Independent Archaeologist Cultural Resources 

Carleton S. Babb Independent Hydrogeologist Water Management Plan 

Susan J. Connell TRC Environmental Corporation Air Quality 

Chris Gardiner Uintah Engineering & Land Surveying, Inc. Cartography - Environmental Assessment 

Jeff Garrard Uintah Engineering & Land Surveying, Inc. Cartography - Environmental Assessment 

Arch Swank WyoCAD, LLC Cartography - Water Management Plan 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

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Group, LLC Scotty Lake Pilot Project Located in Township 26 North, Ranges 96 and 97 

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Anderson Environmental Consulting (AEC). 2004. Raptor nesting inventory of the Scotty Lake 

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Unpublished report prepared for Hudson Group, LLC and the Rawlins Field Office, Bureau 

of Land Management. Anderson Environmental Consulting. Casper, Wyoming. 6 pp + 

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Advanced Resources International, Inc. 2002. Powder River Basin Coalbed Methane Development

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

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Grah, Oliver J. 1997. Soils, water, and vegetation resources technical report. Report prepared for 

the Cave Gulch-Bullfrog-Waltman Natural Gas Development Project Environmental Impact

Statement. Prepared for the USDI-BLM, Casper District Office, Casper, Wyoming and 

Gary Holsan Environmental Planning, Thayne, Wyoming by ECOTONE Environmental

Consulting, Inc., Logan, Utah. 101 pp. 

Graul, W.D. 1975. Breeding biology of the mountain plover. Wilson Bulletin 87:6-31. 

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Graul, W.D. and L.E. Webster. 1976. Breeding status of the mountain plover. Condor 78:265-267. 

Hillman, C.N. and T.W. Clark. 1980. Mustela nigripes. Mammalian Species, Number 126. 3 pp. 

Hudson, Gene. 2004. Geologic report, proposed coalbed methane unit area, Sweetwater County, 

Wyoming. May 2004. Casper, Wyoming. Unpublished report. 2 pp. 

Irwin, L.L. and J.M. Peek. 1979. Relationship between road closures and elk behavior in northern 

Idaho. Pages 199-204. In: North American Elk: Ecology, Behavior and Management

edited by M.S. Boyce and L.D. Hayden-Wing. University of Wyoming. Laramie,

Wyoming.

Klein, D.R. 1974. The reaction of some northern mammals to aircraft disturbance. Pages 377-383. 

In: Eleventh International Congress of Game Biologists; September 3-7, 1973. Stockholm,

Sweden. Swedish Environmental Protection Board. Stockholm, Sweden. 

Knopf, F.L. 1994. Avian assemblages on altered grasslands. Studies in Avian Biology 15:247-257. 

_____. 2004. Personal communication. April 7, 2004. 

Knopf, F.L. and B.J. Miller. 1994. Charadrius montanus - montane, grassland, or bare-ground 

plover? The Auk 111(2):504-506. 

Leachman, B. and B. Osmundson. 1990. Status of the mountain plover: a literature review. U.S. 

Fish and Wildlife Service. Golden, Colorado. 83 pp. 

MacArthur, R.A., V. Geist and R.H. Johnson. 1982. Cardiac and behavioral responses of mountain

sheep to human disturbance. Journal of Wildlife Management 46:351-358. 

Martner, B. 1986. Wyoming Climate Atlas. Prepared in cooperation with the Wyoming Water

Research Center, University of Wyoming. University of Nebraska Press. Lincoln, 

Nebraska.

National Climatic Data Center (NCDC). 2002. Annual Climatological Summaries for Jeffrey City 

and Wamsutter, Wyoming. U.S. Department of Commerce, National Oceanic and 

Atmospheric Administration. Ashville, North Carolina. Online data retrieved from:

http://www1.ncdc.noaa.gov.

_____. 2003. Annual Climatological Summaries for Jeffrey City and Wamsutter, Wyoming. U.S. 

Department of Commerce, National Oceanic and Atmospheric Administration. Ashville, 

North Carolina. Online data retrieved from: http://www1.ncdc.noaa.gov.

Nicholoff, S.H., compiler. 2003. Wyoming Bird Conservation Plan, Version 2.0. Wyoming

Partners in Flight. Wyoming Game and Fish Department. Lander, Wyoming. 668 pp. 

84
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Peterson, D.A., K.L. Mora, M.E. Lowry, J.G. Rankl, J.F. Wilson, Jr., H.W. Lowham, and B.H. 

Ringen. 1987. Hydrology of Area 51, northern Great Plains and Rocky Mountain coal 

provinces, Wyoming and Montana. Water Resources Investigations, Open File Report 84-

734. U.S. Geological Survey. Cheyenne, Wyoming. 73 pp. 

Soil Conservation Service (SCS). 1974. Wyoming supplement for the Wind-Bighorn-Clarks Fork 

River Basin, Type IV Survey. USDA Water and Related Land Resources Report. Portland, 

Oregon.

Trewartha, G.T. 1968. An Introduction to Climate. McGraw-Hill Book Company. New York, 

New York. 

Ward, A.L. and J.J. Cupal. 1979. Telemetered heart rate of three elk as affected by activity and 

human disturbance. Pages 47-56. In: Proceedings of the Dispersed Recreation and Natural 

Resource Management Symposium. Utah State University. Logan, Utah. 

Water Resources Data System. 2004. Wyoming Earthquake Database cooperatively produced by 

the Wyoming State Geological Survey and Water Resources Data System. Electronic 

information available over the Internet at website: http://www.wrds.uwyo.edu/data.html.

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regulations. Wyoming Department of Environmental Quality. Cheyenne, Wyoming.

_____. 2003. Wyoming air quality standards and regulations, including revisions through 2003. 

Wyoming Department of Environmental Quality. Cheyenne, Wyoming.

Wyoming Department of Environmental Quality (WDEQ). 2003. Personal communications

between Susan Connell (TRC Environmental) and both Darla Potter and Cara Casten 

(WDEQ-AQD) regarding regional air pollutant background concentrations for central 

Wyoming. Wyoming Department of Environmental Quality, Air Quality Division. 

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Amphibians in Wyoming. Wyoming Game and Fish Department, Wildlife Division. 

Cheyenne, Wyoming. November 1999. 190 pp. + appendices. 

_____. 2003a. 2002 Annual Big Game Herd Unit JCRs. Lander and Green River Region Annual 

Big Game Herd Unit Reports 2002. Cheyenne, Wyoming. 288 pp and 349 pp, 

respectively.

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Lander Region. Cheyenne, Wyoming. 115 pp. 

85
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Wyoming Natural Diversity Database (WYNDDB). 2004. Data Compilation for Robert M. 

Anderson/Anderson Environmental Consulting. Completed on May 2, 2003. Unpublished 

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compiled and maintained by the Wyoming Oil and Gas Conservation Commission.

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by the Wyoming State Weed Team. June 2003. 12pp. Information acquired via the 

Internet at website: http://www.wyoweed.org.

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

7.0 ABBREVIATIONS AND ACRONYMS 

4WD Four Wheel Drive 

AEC Anderson Environmental Consulting

AML Appropriate Management Level

AOI Area of Influence 

APD Application for Permit to Drill 

AUM Animal Unit Month

BBS Breeding Bird Survey 

BLM Bureau of Land Management

BMP Best Management Practices

BR Big Red (coal)

bwpd Barrels of water per day

CBNG Coalbed Natural Gas 

CEQ Council on Environmental Quality 

CFR Code of Federal Regulations

CO Carbon monoxide

COA Condition of Approval

CRA Cyclone Rim Allotment

D & A Drilled and Abandoned 

DFP Desolation Flats Project

DR Decision Record 

EA Environmental Assessment

EIS Environmental Impact Statement

EO Executive Order

EPA Environmental Protection Agency

ESA Endangered Species Act

FLPMA Federal Land Policy and Management Act

Fm Formation

FOOGLRA Federal Onshore Oil and Gas Leasing Reform Act

FOOGRMA Federal Onshore Oil and Gas Royalty Management Act

gpd Gallons per day

GMCA Green Mountain Common Allotment

H2S Hydrogen sulfide (gas) 

HMA Horse Management Area

LFO Lander Field Office

LOP Life of Project

mi2 Square Mile

MLA Mineral Leasing Act of 1920 

mgwpd Million gallons of water per day

MSLE Modified Soil Loss Equation

NAAQS National Ambient Air Quality Standards

NCDC National Climatic Data Center

NEPA National Environmental Policy Act

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

NHPA National Historic Preservation Act

NO2 Nitrogen dioxide

NOAA National Oceanic and Atmospheric Administration

NPDES National Pollutant Discharge Elimination System

NRHP National Register of Historic Places 

O3 Ozone

OSHA Occupational Health and Safety Act

P & A Plugged and Abandoned 

PIF Partners in Flight

PL Public Law 

PLU Picket Lake Unit 

PM10 Particulate matter with an effective diameter less than 10 

microns

PM2.5 Particulate matter with an effective diameter less than 2.5 

microns

ppm Parts per Million

PSD Prevention of Significant Deterioration

RFO Rawlins Field Office 

RMP Resource Management Plan

ROD Record of Decision 

ROW Right-of-Way

SARA Superfund Amendments and Reauthorization Act

SCS Soil Conservation Service

SGP Shortgrass Prairie 

SHPO State Historic Preservation Officer 

SL Scotty Lake

SLPA Scotty Lake Project Area 

SLPP Scotty Lake Pilot Project

SO2 Sulfur dioxide

SS Shrub Steppe

TCLP Toxicity Constituent Leaching Process 

TD Total Depth

TDS Total Dissolved Solids

T/E Threatened and Endangered Species 

TPH Total Petroleum Hydrocarbons

t/ac/yr Tons per Acre per Year 

t/yr Tons per Year 

TRC TRC Environmental Corporation/TRC Mariah Associates Inc. 

USA United States of America

USC United States Code

USFWS U.S. Fish and Wildlife Service

USGS U.S. Geological Survey

UW University of Wyoming

VOC Volatile Organic Compound

VRM Visual Resource Management

WAAQS Wyoming Ambient Air Quality Standards

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Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

WDEQ Wyoming Department of Environmental Quality

 - AQD Air Quality Division

WGFD Wyoming Game and Fish Department

WMP Water Management Plan

WOGCC Wyoming Oil and Gas Conservation Commission

WSEO Wyoming State Engineer’s Office

WSWT Wyoming State Weed Team

WYNDDB Wyoming Natural Diversity Database

89
APPENDIX A 

FEDERAL PERMITS, APPROVALS AND AUTHORIZING ACTIONS APPLICABLE TO 

ADDITIONAL EXPLORATION IN THE SCOTTY LAKE CBNG PILOT PROJECT AREA 

A. DEPARTMENT OF THE INTERIOR

Agency Nature of Action 

1. Bureau of Land Management 

Approval of APD and Sundry Notices for actions on federal surface and/or mApproval to vent or flare gas during testing. Approval to dispose of produced water. Right-of-Way Grants for off-lease/unit facilities. Right-of-Way Grants to third party applicants for facilities both in and out of 

 a. Rawlins and Lander Field Offices 

Review cultural resource inventories, consult with SHPO and ACHP. 

 b. Wyoming Reservoir Management Group Approval of Unit Agreement and annual Unit Plan of Development. 

Review impacts to federally listed, or proposed for listing, threatened or enda

2. U.S. Fish & Wildlife Service wildlife and plants. 

Administers the Migratory Bird Treaty Act. 

B. DEPARTMENT OF THE ARMY

Agency Nature of Action 

1. U.S. Army Corps of Engineers Issue permits for the placement of dredged or fill material in or excavation of 

their adjacent wetlands pursuant to Section 404 of the Clean Water Act. 
STATE OF WYOMING PERMITS, APPROVALS AND AUTHORIZING ACTIONS APPLICABL

ADDITIONAL EXPLORATION IN THE SCOTTY LAKE CBNG PILOT PROJECT AREA 

Agency Nature of Action 

1. Department of Environmental Quality 

Approval to burn commercial garbage and/or any other open air burning. 

Permitting/approval for compression sites, flaring, and other natural gas pro

facilities. a. Air Quality Division 

Fugitive dust suppression. 

Approval of off-site solid waste disposal. b. Land Quality Division Approval of permits for aggregate material (e.g., sand and gravel) mining actiApproval of Storm Water Pollution Prevention Plan (SWPPP). 

 c. Water Quality Division Approval of surface discharge of produced water. 

Approval of waste water and sewage disposal. 

2. Department of Transportation 

The transport of oversize, overweight or overlength loads (particularly co

equipment) would require transport permits from the State of Wyoming (foand federal highway systems within the State). 

 Primary authority for drilling operations on state and privately owned m

secondary authority for drilling operations on federal lands. 

 Authority to allow or prohibit flaring or venting of gas on private or state ow Aquifer exemption permit.  Approval of directional drilling operations.  Rules and regulations governing drilling units. Underground Injection Control (UIC) permits. 

3. Oil & Gas Conservation Commission 

Approval of exceptions to well spacing patterns established under WOGCC Rorders approved by the commission. Underground Injection Control (UIC) pe

Issue permits for the appropriation of surface and ground water. 4. State Engineer’s Office Issue permits for the construction of water retention (evaporation) ponds. 

5. State Historic Preservation Office Section 106 consultation concerning inventory of, and impacts to, cultural and 
SWEETWATER COUNTY APPROVALS AND AUTHORIZING ACTIONS APPLICABLE T

ADDITIONAL EXPLORATION IN THE SCOTTY LAKE CBNG PILOT PROJECT AREA 

Agency Nature of Action 

1. Health Department Small wastewater (septic) system permits, where applicable. 

Administers zoning changes, where applicable. 

2. Planning Department Construction and conditional use permits for all new structures and non-m

(aggregate material) where appropriate. 

Driveway access permits where new roads intersect with existing county road

3. Road and Bridge Department Road use agreements and/or oversize trip permits when traffic on county roa

size/weight limitations or where the potential for excessive road damage exist
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix B 

1

NON-SIGNIFICANT ISSUES RAISED DURING THE PUBLIC SCOPING PROCESS 

As discussed in Section 1.5, certain issues identified in conjunction with project scoping were 

determined not to be “significant issues related to the Proposed Action” (40 CFR 1501.7) because 

they are not potentially affected or impacted by the proposal. Those issues brought forth during 

public scoping and reasons for eliminating that particular issue from consideration in this analysis 

are stated below. 

Conformance with LUP 

On April 15, 2003 the Interior Board of Land Appeals issued a decision (158 IBLA 384), Wyoming 

Outdoor Council, et al, in which they determined that the Great Divide Resource Management Plan 

(RMP) and subsequent documentation failed to identify any of the relevant areas of environmental 

concern associated with coalbed natural gas development, failed to discuss reasonable alternatives to 

the proposed action and did not satisfy BLM’s NEPA obligation. In the IBLA ruling they reversed 

the Acting Director’s decision and remanded the matter to BLM for further appropriate action. The 

Rawlins Field Office responded to the IBLA remand by preparing a new Documentation of Land 

Use Plan Conformance and NEPA Adequacy (DNA) to determine if exploration and development of 

methane gas from coal reservoirs is within the broad impacts predicted for oil and gas development 

described in the current land use plan. The DNA was transmitted to the BLM Wyoming State 

Office on July 29, 2003, and confirms that the exploration and development of methane gas from 

coal reservoirs is in conformance with the Great Divide RMP. 

Geologic Hazards (earthquakes) 

The Wyoming Earthquake Database lists four earthquakes having occurred in Sweetwater County 

since 1986 with a magnitude greater than 2.5. Two of these quakes occurred in northeastern 

Sweetwater County in May of 2000 just south of Bairoil, while the remaining two quakes occurred 

in the southwestern portion of the county in an area generally south of Little America in November 

of 1998 and January of 2000 respectively (WRDS 2004). 

According to Case (1999), 31 earthquakes have occurred in Sweetwater County between 1888 and 

1995, with these various quakes ranging in magnitude from 2.2 to 5.3 on the Richter scale. One of 

the most recent earthquakes occurred on February 3, 1995, with an epicenter located near Little 

America, Wyoming. The quake had a magnitude of 5.3, was felt throughout the state and as far 

away as Salt Lake City, Utah and was associated with the collapse of a shaft in an active trona mine. 

Fault zones in the geographic region have been recurrently active for the past 20 million years; 

however, their activity is poorly defined or nonexistent in recent times (Case et al 1995). Known or 

suspected active faults are located on the northern and southern boundaries of Sweetwater County 

(Case and Green 2000). 

Considering the relatively stable nature of the Great Divide/Green River Basin(s) and the fact that no 

devastating earthquakes have been recorded in Sweetwater County in over 115 years, the likelihood 

of a major earthquake occurring within the general area is unlikely, as is the probability of a quake 

that could/would cause extensive damage to any infrastructure constructed in conjunction with the 

Proposed Action. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix B 

2

Impacts of Noise 

The project area is located in a very-sparsely populated area which is subject to modest sound 

disturbances associated primarily with jet aircraft overflights, localized vehicular traffic on existing 

road networks within the area and, most notably, the wind. Local increases in noise may be 

expected as a result of exploration activities associated with the pilot project, but these impacts will 

typically be very short-term in nature and would occur primarily during active construction, drilling 

and completion operations. The EPA has established 55 decibels (dBA) as the maximum noise level 

that does not adversely affect public health and welfare. The State of Wyoming has not adopted any 

regulations concerning quantitative noise levels. 

Considering that the project area is located in a very sparsely populated area of Sweetwater County, 

any noise generated by activities associated with the Proposed Action during peak activity periods 

would be dispersed and short-term in nature and would likely be unnoticed by the relatively few 

visitors to the area. In this regard, noise impacts have been analyzed for numerous CBNG projects 

throughout southwestern Wyoming in recent years. Consequently, the reader is directed to one or 

more of these documents for additional information in this regard: 

• Decision Record, Finding of No Significant Impact and Environmental Assessment for Lower 

Bush Creek Coal Bed Methane Exploratory Pilot Project. Rock Springs Field Office, Bureau of 

Land Management. August 2003. 

• Environmental Assessment for the Atlantic Rim Interim Drilling Project, Doty Mountain POD, 

Carbon County, Wyoming. Rawlins Field Office, Bureau of Land Management. October 2003. 

• Environmental Assessment for the Atlantic Rim Coalbed Methane Project, Brown Cow POD, 

Carbon County, Wyoming. Rawlins Field Office, Bureau of Land Management. December 

2003. 

• Decision Record, Finding of No Significant Impact and Environmental Assessment for the 

Cooper Ridge Shallow Gas Exploration and Development Project. Rock Springs Field Office, 

Bureau of Land Management. December 2003. 

Impacts to Social/Economic Values 

Neither the economy of Sweetwater County nor the quality of life for the residents thereof will be 

adversely affected by the Proposed Action. As described in Chapter 2.0, additional oil/gas 

exploration and development activity in the SLPA would not result in an increase in the local 

workforce, with a concomitant burden on the resources of Sweetwater County and the infrastructure 

thereof. In point of fact, implementation of the Proposed Action would ultimately have a positive 

impact on the economy of Sweetwater County through increased revenues generated by additional 

hydrocarbon production from leases within the project area should commercial CBNG production be 

established from any/all of the proposed wells proposed in conjunction with this pilot project. 

As this is a pilot project, it would be difficult at best to predict the financial revenue to Sweetwater 

County, should commercial production result from any/all of the wells proposed in conjunction with 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix B 

3

said pilot project. Considering that no commercial production has been reported to date from the 

three initial wells completed by Hudson Group, LLC in the Scotty Lake coals, the task of predicting 

potential revenue (positive economic benefit) becomes highly speculative at best. 

Migration of Methane 

Coalbed natural gas production as proposed in the SLPP would occur from coal-bearing seams 

within the Fort Union Fm at depths ranging between 2,000 feet and 5,000 feet below the natural 

ground surface with an overburden consisting of sandstones, siltstones and shales. Considering that 

the Scotty Lake coal sequence represents a confined reservoir having a minimum of 2,000 feet of 

overburden, it is extremely unlikely that there would be any significant migration of methane to the 

surface resulting from the depressurization of the targeted coal-bearing seam in conjunction with this 

pilot project (see Appendix D). Furthermore, completion techniques to be utilized in conjunction 

with this pilot project would be designed and implemented in order to minimize the potential for 

communication with the surface (BLM 2003a). 

Potential for Depletion of Colorado River System Waters 

The sub-surface and surface water resources in the Great Divide Basin are hydrographically closed 

(see Section 3.5.1 and Appendix D). Consequently, the project proposal has no potential to impact 

these resources (BLM 2003a). 

Potential for Impacts to Biological Soil Crusts 

Biological soil crusts are common, but not widespread, in semiarid and arid environments. Crusts in 

southwest Wyoming appear to be confined to protected or inaccessible areas that probably have not 

been disturbed by heavy, sustained livestock use (both historic and contemporary), unlike the 

Colorado plateau where crusts are a prominent feature. While no crusts have been observed in the 

project area during past field reviews, this does not preclude their presence. However, the fact that 

these crusts may exist in the project area does not limit development or other surface disturbing 

activities, as they would be salvaged in conjunction with topsoil stripping associated with well pad, 

access road, and pipeline right-of-way construction. The salvaged topsoil would ultimately be 

placed back on the reclaimed portions of the disturbed area and re-seeded with native species as 

directed by the RFO, with these reclamation activities occurring as soon as practical following the 

initial surface disturbance in an attempt to maintain soil microbe viability and enhance reclamation 

success (BLM 2003a). 

While it is highly unlikely that construction activities associated with the Proposed Action would be 

located on contiguous or conterminous areas of biological soil crusts, efforts would be made to avoid 

the crusts should such an area be identified. 

Risk to Ground Water from Hydraulic Fracturing 

Fresh water aquifers utilized for water supplies within the overall project area are much nearer the 

surface than the Scotty lake coals and are separated by hundreds, if not thousands, of feet of 

sedimentary rock including layers of sandstone, siltstone, and shale. The hydraulic fracturing of the 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix B 

4

targeted coal-bearing seams will be conducted with the best technological methods designed to 

protect against risks to other aquifers. As indicated in Section 2.2.4, hydraulic fracturing conducted 

in conjunction with the SLPP would be conducted with fresh water and/or freshwater/sand and 

would not involve any chemical agents that could be considered as a contaminant. 

In this regard, the Environmental Protection Agency (EPA) has recently released a draft report 

addressing the potential for impacts to underground sources of drinking water by the hydraulic 

fracturing of coal bed natural gas reservoirs (EPA 816-D-02-006). Based upon information 

collected during the Phase I investigation, the EPA has preliminarily found that “the potential threats 

to public health posed by hydraulic fracturing of CBNG wells appear to be small and do not justify 

additional study” (BLM 2003a). Please refer to Section 2.2.4 of this document for additional 

information concerning hydraulic fracturing techniques. 

Subsidence 

Subsidence typically occurs when solid material is extracted (e.g., coal or trona). While it may be 

possible for subsidence to occur, the probability of subsidence occurring is extremely remote 

considering the depth of the targeted coals, the fact that no solid material is being removed from the 

coal-bearing seam, combined with the structural integrity of the overlying formations (sandstones 

and shales). Finally, the pilot project only affects a very small portion of the Scotty Lake coal, 

further reducing the potential for subsidence to occur. 

Underground Coal Fires 

Spontaneous combustion of the coal seam following depressurization (dewatering) is not likely 

considering the depth of the coal and the fact that the coal-bearing seam does not outcrop. As a 

consequence, sufficient oxygen is unavailable for spontaneous combustion. Furthermore, it should 

be noted that depressurization of the coal does not result in the removal of all entrained water 

therefrom. A sufficient quantity of water will be removed from the targeted coal-bearing seam to 

lower the hydrostatic pressure to the point where gas will desorb from the coal and flow to the 

surface via the well bore (see Section 2.2.4). Once this equilibrium has been reached, water 

production would decrease dramatically. Based upon studies conducted in conjunction with the 

Powder River Basin Oil and Gas EIS (ARI 2002, BLM 2003c), approximately 20% of the water in 

the coal aquifer is removed in order to facilitate desorption, leaving 80% of the entrained water in 

place. 

Use of hazardous/toxic materials in drilling/completion operations 

As indicated in Section 2.2.10, no hazardous or toxic materials will be utilized in drilling or 

completion operations. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

1

HUDSON GROUP, LLC 

Scotty Lake Coalbed Natural Gas Pilot Project 

Plan of Development and Master Field Permit 

Sweetwater County, Wyoming 

TYPICAL DRILLING PROGNOSIS 

 1. ESTIMATED TOPS OF IMPORTANT GEOLOGIC MARKERS 

The proposed Scotty Lake Coal Bed Natural Gas (CBNG) Pilot Project will test the productive 

potential of coals in the Fort Union Fm at varying depths across the project area. Please refer to 

each individual Application for Permit to Drill (APD) for site specific geologic information. 

 2. ESTIMATED DEPTHS OF ANTICIPATED WATER, OIL, GAS OR MINERAL 

FORMATIONS 

As indicated above, the Scotty Lake CBNG Pilot Project will test the productive potential of the 

Fort Union Fm at varying depths across the project area. No other potentially productive 

formations are anticipated between surface and total depth. Please refer to each individual 

Application for Permit to Drill (APD) for site specific geologic information. 

Any shallow water zones encountered will be adequately protected and reported. All potentially 

productive hydrocarbon zones will be cemented off. 

 3. PRESSURE CONTROL EQUIPMENT - Schematic Attached 

 A. Type: Double Gate Hydraulic Blow-Out Preventer (BOP) equipped as follows: 

 1. One (1) blind ram (above). 

 2. One (1) pipe ram (below). 

 3. Kill line (2-inch minimum). 

 4. One (1) kill line valve (2-inch minimum). 

 5. One (1) choke line valve. 

 6. Two (2) adjustable chokes (2-inch minimum). 

 7. Upper kelly cock valve with handle available. 

 8. Full opening internal blowout preventer or drill pipe safety valve able to fit all 

connections. 

 9. 2-inch (minimum) choke line. 

 10. Fill-up line above the uppermost preventer. 

B. Pressure Rating: 2,000 psi 

C. Testing Procedure: 

At a minimum, the BOP, choke manifold, and related equipment will be pressure tested to 

the approved working pressure of the BOP stack (if isolated from the surface casing by a 

test plug) or to 70% of the internal yield strength of the surface casing (if the BOP is not 

isolated from the casing by a test plug). Pressure will be maintained for a period of at least 

10 minutes or until the requirements of the test are met, whichever is longer. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

2

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Typical Drilling Prognosis 

Page 2 

 3. PRESSURE CONTROL EQUIPMENT

C. Testing Procedure: Continued 

At a minimum, the above pressure test will be performed: 

 1. When the BOP is initially installed; 

 2. Whenever any seal subject to test pressure is broken; 

 3. Following related repairs; and 

 4. At thirty (30) day intervals. 

In addition to the above, the pipe and blind rams will be activated each trip, but not more 

than once each day. All BOP drills and tests will be recorded in the IADC driller’s log. 

D. Choke Manifold Equipment: 

All choke lines will be straight lines unless turns use tee blocks or are targeted with running 

tees, and will be anchored to prevent whip and vibration. 

E. Accumulator: 

The accumulator will have sufficient capacity to close all BOP’s and retain 200 psi above 

precharge. Nitrogen bottles that meet the manufacturer’s specifications will be used as the 

backup to the required independent power source. The accumulator precharge pressure test 

will be conducted prior to connecting the closing unit to the BOP stack and at least once 

every six (6) months thereafter. The accumulator pressure will be corrected if the measured 

precharge pressure is found to be above or below the maximum or minimum limits specified 

in Onshore Oil and Gas Order Number 2. 

A manual locking device (i.e., hand wheels) or automatic locking device will be installed on 

all systems of 2M or greater. A valve will be installed in the closing line as close as 

possible to the annular preventer to act as a locking device. This valve will be maintained in 

the open position and will be closed only when the power source for the accumulator system 

is inoperative. 

F. Miscellaneous Information: 

The Blow-Out Preventer and related pressure control equipment will be installed, tested and 

maintained in compliance with the specifications in and requirements of Onshore Oil & Gas 

Order Number 2. 

 4. THE PROPOSED CASING AND CEMENTING PROGRAM 

Hudson Group, LLC proposes to test the potential of interbedded coals in the Fort Union Fm for 

natural gas production. Actual total depths will vary from well to well and will be reported in 

each individual Application for Permit to Drill. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

3

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Typical Drilling Prognosis 

Page 3 

 4. THE PROPOSED CASING AND CEMENTING PROGRAM - Continued

A. Casing Program: All New 

Hole Size Casing Size Wt./Ft. Grade Joint Depth Set 

12.000” 8.625” 20.0# J-55 ST&C 0 - 450’ 

7.875” 5.500” 15.5# J-55 LT&C 0 - Total Depth 

The surface casing will have centralizers on the bottom three (3) joints joint of casing, with 

a minimum of one (1) centralizer per joint starting with the shoe joint. 

Casing string(s) will be pressure tested to 0.22 psi/foot of casing string length or 1500 psi, 

whichever is greater (not to exceed 70% of the internal yield strength of the casing), after 

cementing and prior to drilling out from under the casing shoe. 

B. Cementing Program:

The surface casing will be cemented back to surface with approximately 160 sx of 

Halliburton “Lite” cement mixed at 12.4 ppg (yield = 1.97 ft3

/sx). The 5.500” production 

casing string will be cemented with Class “G” cement mixed at 14.5 ppg (yield = 1.15 

ft3/sx). Actual cement volumes may vary due to variations in the actual hole gauge and will 

be determined by running a caliper log on the drilled hole prior to cementing. Approximate 

cement volumes will be provided in each individual Application for Permit to Drill with 

cement circulated to a minimum of 200’ above the top of the shallowest coal in the Fort 

Union Fm. 

All waiting on cement (WOC) times will be adequate to achieve a minimum of 500 psi 

compressive strength at the casing shoe prior to drilling out. 

 5. MUD PROGRAM - Visual Monitoring 

Interval Mud Type Weight Viscosity Fluid Loss 

Surface to 3000’ Fresh Water/Gel 8.2 - 8.6 26 - 30 No Control 

3000’ to Total Depth LSND w/Polymer Sweeps 8.6 - 9.2 28 - 40 No Control 

Sufficient mud material(s) to maintain mud properties, control lost circulation and contain a 

blowout will be available at the well site during drilling operations. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

4

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Typical Drilling Prognosis 

Page 4 

 6. EVALUATION PROGRAM - Continued 

 Logs : DIL : from Total Depth to Surface. 

 FDC/GR/CAL-GR : from Total Depth to 2000’ *. 

 DST’s : Formation test(s) are possible in the Fort Union Fm. Additional tests will be run as 

warranted by logs and/or shows. 

 Cores : Cores are possible in the Fort Union Fm. Please refer to each individual Application 

for Permit to Drill for more specific information in this regard. 

* Pull Gamma Ray Log Back to Surface 

The evaluation program may change at the discretion of the well site geologist, with prior 

approval from the Authorized Officer, Rawlins Field Office, Bureau of Land Management. 

 Stimulation : No stimulation or frac treatment has been formulated for this test at this time. 

The drill site, as approved, will be of sufficient size to accommodate all 

completion activities. 

Whether each well is completed as a dry hole or as a producer, Well Completion and

Recompletion Report and Log (form #3160-4) will be submitted to the Rawlins Field Office not 

later than thirty (30) days after the completion of each individual well or after completion of 

operations being performed, in accordance with 43 CFR 3164. 

Two (2) copies of all logs, core descriptions, core analyses, well test data, geologic summaries, 

sample description, and all other surveys or data obtained and compiled during the drilling, 

workover, and/or completion operations, will be filed with form #3160-4. Samples (cuttings, 

fluids, and/or gases) will be submitted when requested by the Authorized Officer, Rawlins Field 

Office, Bureau of Land Management, P.O. Box 2407, Rawlins, Wyoming 82301-2407, 

Telephone: 307-328-4200. 

 7. ABNORMAL CONDITIONS 

No abnormal temperatures or pressures are anticipated. No H2S has been encountered in or 

known to exist from previous wells drilled to similar depths in the general area. 

Maximum anticipated bottom hole pressure in the Scotty Lake CBNG Pilot Project area equals 

approximately 2,300 psi (calculated at 0.50 psi/foot for the deepest well currently drilled or 

proposed) and maximum anticipated surface pressure equals approximately 1,288 psi (bottom 

hole pressure minus the pressure of a partially evacuated hole calculated at 0.22 psi/foot) for the 

deepest well currently drilled/proposed in the Scotty Lake CBNG Pilot Project area. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

5

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Typical Drilling Prognosis 

Page 5 

 8. ANTICIPATED STARTING DATES AND NOTIFICATION OF OPERATIONS 

A. Anticipated Starting Dates:

Anticipated Commencement Date : September 15, 2004 

Drilling Days : Approximately 14 Days per Well 

Completion Days : Approximately 14 Days per Well 

B. Notification of Operations:

Bureau of Land Management 

Rawlins Field Office 

P.O. Box 2407 

Rawlins, Wyoming 82301-2407 

Telephone: 307-328-4200 

Contacts for the Rawlins Field Office are: 

Contact Title Contact Name Work Phone Home Phone

Petroleum Engineer Bob Hartman 307-328-4254 307-321-3439 

Assistant Field Manager Clare Miller 307-328-4245 307-324-2372 

Petroleum Technician Cole Thomas 307-328-4249 307-328-1901 

Petroleum Technician Chuck Ross 307-328-4230 307-324-9123 

Petroleum Technician Bill Ashline 307-328-4263 307-324-6355 

Petroleum Technician Bryan Hurst 307-328-4277 307-324-5066 

Natural Resource Specialist John Ahlbrandt 307-328-4223 307-328-1808

Alternate Petroleum Engineer Contact if unable to reach Bob Hartman: 

Office Contact Name Work Phone Home Phone

Lander Field Office Stuart Cerovski 307-332-7822 307-332-2408 

C. General Conditions of Approval for Each Individual Well: 

 1. All lease and/or unit operations are to be conducted in such a manner to ensure full 

compliance with the applicable laws, regulations (43 CFR, Part 3160), Onshore 

Orders, Notices to Lessees, and the approved plan of operations. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

6

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Typical Drilling Prognosis 

Page 6 

 8. ANTICIPATED STARTING DATES AND NOTIFICATION OF OPERATIONS

C. General Conditions of Approval for Each Individual Well: Continued 

 2. The spud date will be reported orally to the Rawlins Field Office 24 HOURS PRIOR 

TO SPUDDING, unless otherwise required in the site specific conditions of approval. 

 3. All wells, whether drilling, producing, suspended or abandoned shall be identified in 

accordance with 43 CFR 3162.6. There shall be a sign or marker with the name of the 

operator, the lease serial number, the well number and the surveyed description of the 

well. 

 4. In accordance with Onshore Oil & Gas Order Number 1, this well will be reported on 

MMS form #3160-6, Monthly Report of Operations and Production, starting with the 

month in which operations commence and continuing each month until the well is 

physically plugged and abandoned. This report will be filed directly with the Royalty 

Management Program, Minerals Management Service, P.O. Box 17110, Denver, 

Colorado 80217. 

 5. All undesirable events (fires, accidents, blowouts, spills, discharges) as specified in 

NTL-3A will be reported to the Rawlins Field Office. Major events will be reported 

verbally within twenty-four (24) hours and will be followed with a written report 

within fifteen (15) days. Other than major events will be reported in writing within 

fifteen (15) days. Minor events will be reported on the Monthly Report of Operations 

and Production (form #3160-6) 

 6. No well abandonment operations will be commenced without the prior approval of the 

Authorized Officer. In the case of newly-drilled dry holes or failures, and in 

emergency situations, oral approval will be obtained from the Field Office Petroleum 

Engineer. A Notice of Intention to Abandon (form #3160-5) will be filed with the 

Authorized Officer within fifteen (15) days following the granting of oral approval to 

plug and abandon. 

 7. Upon completion of approved plugging, a regulation marker will be erected in 

accordance with 43 CFR 3162.6 The following information will be permanently 

placed on the marker with a plate, cap, or beaded-on with a welding torch: Company 

Name, Well Name and Number, Location by Quarter/Quarter, Section, Township, 

Range, and the Federal Lease Number. 

 8. A Subsequent Report of Abandonment (form #3160-5) will be submitted within thirty 

(30) days following the actual plugging of the well bore. This report will indicate 

where plugs were placed and the current status of surface restoration operations. If 

surface restoration has not been completed at that time, a follow-up report on form 

#3160-5 will be filed when all surface restoration work has been completed and the 

location is considered ready for final inspection. If the location is on private surface, a 

Landowner Acceptance of Reclamation letter will be attached to this “Sundry Notice”. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

7

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Typical Drilling Prognosis 

Page 7 

 8. ANTICIPATED STARTING DATES AND NOTIFICATION OF OPERATIONS

C. General Conditions of Approval for Each Individual Well: Continued 

 9. Pursuant to NTL-4A, lessees and operators are authorized to vent/flare gas during 

initial well evaluation tests, not exceeding a period of thirty (30) days or the 

production of fifty (50) MMCF of gas, whichever occurs first. An application must be 

filed with the Authorized Officer, and approval received, for any venting/flaring of gas 

beyond the initial thirty (30) day or otherwise authorized test period. 

10. Not later than the 5th business day after any well begins production on which royalty 

is due anywhere on a lease site or allocated to a lease site, or resumes production in the 

case of a well which has been off production for more than ninety (90) days, the 

operator shall notify the Authorized Officer by letter or sundry notice, of the date on 

which such production has begun or resumed. The notification shall provide at a 

minimum, the following informational items: 

a. Operator name, address, and telephone number 

b. Well name and number 

c. Well location “1⁄4, 1⁄4, Section, Township, Range, P.M.” 

d. Date well was placed in a producing status 

e. The nature of the wells production (i.e., crude oil, casing gas, or natural gas and 

entrained liquid hydrocarbons). 

f. The OCS, Federal or Indian lease prefix and number on which the well is located. 

Otherwise, the non-federal or non-Indian land category (i.e.: state or private). 

g. As appropriate, the communitization agreement number, the unit agreement name, 

number and participating area name. 

11. Within sixty (60) days following construction of a new tank battery, a site facility 

diagram of the battery showing actual conditions and piping must be submitted to the 

Authorized Officer. Facility diagrams shall be filed within sixty (60) days after 

existing facilities are modified. For complete information as to what is required on 

these diagrams, please refer to 43 CFR 3162.7-4(d). 

12. Pursuant to Onshore Oil & Gas Order Number 1, lessees and operators have the 

responsibility to see that their exploration, development, production, and construction 

operations are conducted in such a manner which conforms with applicable federal 

laws and regulations and with state and local laws and regulations to the extent that 

such state and local laws are applicable to operations on federal and Indian lands. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

8
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

9

HUDSON GROUP, LLC 

Scotty Lake Coalbed Natural Gas Pilot Project 

Plan of Development and Master Field Permit 

Sweetwater County, Wyoming 

TYPICAL MULTI-POINT SURFACE USE & OPERATIONS PLAN

 1. EXISTING ROADS - Refer to Maps “A” and “B” 

 A. Each proposed well site is staked and two (2) 200-foot reference stakes are present. 

 B. Specific information describing the proposed access to each individual well location from 

the community of Wamsutter, Wyoming will be contained in the Application for Permit to 

Drill (APD) submitted for each individual CBNG well included within the Scotty Lake 

CBNG Pilot Project Plan of Development. 

 C. Access roads - refer to Maps “A” and “B” in each individual APD. 

 D. Access roads within a one (1) mile radius - refer to Map “B”. 

 E. Existing roads will be maintained in the same or better condition as existed prior to the 

commencement of operations and said maintenance will continue until final abandonment 

and reclamation of wells drilled and completed in conjunction with the Scotty Lake CBNG 

Pilot Project Plan of Development. 

 2. PLANNED ACCESS ROADS

Each individual APD will contain site-specific information concerning the construction 

standard(s) proposed for implementation on each segment of the access road route required for 

access to the well location. Access roads constructed in the Scotty Lake CBNG Pilot Project 

area will be constructed in accordance with the road construction guidelines outlined below. 

 A. Width - fourteen (14) foot running surface with a sixteen (16) foot subgrade, crowned and 

ditched for both drilling and completion operations. 

 B. Construction standard - access roads will be constructed (or reconstructed as appropriate) 

in accordance with roading guidelines established for oil & gas exploration and 

development activities as referenced in the joint BLM/USFS publication: Surface 

Operating Standards for Oil and Gas Exploration and Development, Third Edition and/or 

BLM Manual Section 9113 concerning road construction standards on projects subject to 

federal jurisdiction. 

Access roads will be designed and constructed to meet the standards of the anticipated 

traffic flow and all-weather requirements. Construction will include ditching, draining, 

graveling, crowning, and capping the roadbed as necessary to provide a well constructed 

and safe roadway. A typical road design is presented in Attachment “A” which provides 

information concerning minimum standards for road construction associated with federally 

administered projects. 

Approximately six (6) inches of topsoil will be stripped from the new construction portion 

of each primary access road route prior to performing any further construction activities 

thereon. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

10

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 2 

 2. PLANNED ACCESS ROADS - Continued

 B. Construction standard - if soils along primary access road routes are dry during 

reconstruction, water will be applied to the road surface to facilitate soil compaction and 

minimize soil loss as a result of wind erosion. 

 C. Maximum grade - please refer to the individual APD’s for specific information concerning 

maximum grade(s) anticipated on/along each proposed access road route. 

 D. Turnouts - turnouts will be constructed along proposed access road routes as necessary or 

required to allow for the safe passage of traffic. These turnouts will be constructed in 

accordance with roading guidelines established for oil and gas exploration and 

development activities as referenced in the joint BLM/USFS publication: Surface 

Operating Standards for Oil and Gas Exploration and Development, Third Edition and/or 

BLM Manual Section 9113 concerning road construction standards on projects subject to 

federal jurisdiction. 

 E. Drainage design - primary access roads will be upgraded and maintained as necessary to 

prevent soil erosion and accommodate all-weather traffic. These roads will be crowned 

and ditched with water turnouts installed as necessary to provide for proper drainage along 

the access road route. 

 F. Culverts, cuts and fills - culverts will be installed on/along all access roads as necessary or 

required by the Authorized Officer. Please refer to each individual APD for specific 

information regarding the need for culverts on/along the proposed access road route. 

Any required culverts will be installed in accordance with roading guidelines contained in 

the joint BLM/USFS publication: Surface Operating Standards for Oil and Gas

Exploration and Development, Third Edition and/or BLM Manual Section 9113 concerning 

road construction standards on projects subject to federal jurisdiction. Attachment “B” 

presents a typical design for culvert installation on those road construction projects subject 

to federal jurisdiction 

Please refer to each individual APD for specific information regarding cuts and/or fills 

anticipated on/along the proposed access road route. 

 G. Surfacing material - access roads will be surfaced to an average minimum depth (after 

compaction) of four (4) inches with two (2) inch minus pit run gravel or crushed rock 

purchased from a local contractor having a permitted source of materials within the general 

area. These surfacing materials will be installed at the discretion/requirement of the 

Authorized Officer, Bureau of Land Management. 

 H. Gates, cattleguards or fence cuts - gates, cattleguards, and/or fence cuts will be installed 

on/along each proposed access road route as necessary to provide reasonable access to each 

individual well location. Where required, these cattleguards will be installed in accordance 

with roading guidelines contained in the joint BLM/USFS publication: Surface Operating

Standards for Oil and Gas Exploration and Development, Third Edition and/or BLM 

Manual Section 9113 concerning road construction standards on projects subject to federal 

jurisdiction. 

Please refer to each individual APD for specific information regarding the need for gates, 

cattleguards or fence cuts on/along the proposed access road routes. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

11

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 3 

 2. PLANNED ACCESS ROADS - Continued

 I. Road maintenance - access road surface(s) and shoulders will be kept in a safe and useable 

condition and will be maintained in accordance with the original construction standards. 

All drainage ditches and culverts will be kept clear and free-flowing, and will also be 

maintained in accordance with the original construction standards. 

Access road rights-of-way will be kept free of trash during all operations. 

 J. The proposed access road route to each individual well location will be centerline staked 

prior to conducting the individual on-site inspections. 

 3. LOCATION OF EXISTING WELLS WITHIN A ONE-MILE RADIUS OF THE 

SCOTTY LAKE CBNG PILOT PROJECT AREA

 A. Water wells - SW1⁄4SE1⁄4, Section 13, T26N, R97W. 

 NW1⁄4SE1⁄4, Section 24, T26N, R97W 

 see Item #3F (below) for existing CBNG wells. 

 B. Abandoned wells - NW1⁄4SW1⁄4, Section 17, T26N, R96W. 

 SW1⁄4SE1⁄4, Section 21, T26N, R96W. 

 SE1⁄4NW1⁄4, Section 28, T26N, R96W. 

 SW1⁄4NE1⁄4, Section 13, T26N, R97W. 

 SW1⁄4NE1⁄4, Section 25, T26N, R97W. 

 C. Temporarily abandoned wells - none known. 

 D. Disposal wells - none known. 

 E. Drilling wells - none known. 

 F. Producing wells - NW1⁄4SW1⁄4, Section 18, T26N, R96W. 1

 SW1⁄4NW1⁄4, Section 19, T26N, R96W. 1

 C SE1⁄4, Section 13, T26N, R97W. 1

 NW1⁄4SE1⁄4, Section 23, T26N, R97W. 1

 NW1⁄4SE1⁄4, Section 24, T26N, R97W. 1

 G. Shut-in wells - none known. 

 H. Injection wells - none known. 

 I. Monitoring wells - none known. 

1 - Coal bed natural gas wells previously drilled by Hudson Group, LLC. 

SOURCE: WOGCC computerized well files accessible via the Internet. 

 4. LOCATION OF EXISTING AND/OR PROPOSED FACILITIES OWNED BY HUDSON 

GROUP, LLC WITHIN A ONE (1) MILE RADIUS 

 A. Existing Facilities 

 1. Tank batteries - none known. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

12

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 4 

 4. LOCATION OF EXISTING AND/OR PROPOSED FACILITIES OWNED BY HUDSON 

GROUP, LLC WITHIN A ONE (1) MILE RADIUS 

 A. Existing Facilities - Continued

 2. Production facilities - NW1⁄4SW1⁄4, Section 18, T26N, R96W. 

 SW1⁄4NW1⁄4, Section 19, T26N, R96W. 

 C SE1⁄4, Section 13, T26N, R97W. 

 NW1⁄4SE1⁄4, Section 23, T26N, R97W. 

 NW1⁄4SE1⁄4, Section 24, T26N, R97W. 

 3. Oil gathering lines - none known. 

 4. Gas gathering lines - same as Item #4A2, above. 

 B. New Facilities Contemplated 

 1. All production facilities will be located on the disturbed portion of the well pad and at a 

minimum of fifteen (15) feet from the toe of the back slope. 

 2. Production facilities will require a working area approximately 150’ X 10’ in size. A 

diagram showing the proposed production facility layout will be submitted to the 

Authorized Officer via Sundry Notice (form #3160-5) for approval prior to 

commencement of installation operations. 

 3. Production facilities will be accommodated on the disturbed portion of the well pad. 

Construction materials needed for installation of the production facilities will be 

obtained from the site; any additional materials needed will be purchased from a local 

supplier having a permitted source of materials in the area. 

A dike will be constructed completely around those production facilities designed to 

hold fluids (i.e., production tanks, produced water tanks and/or separator). These dikes 

will be constructed of compacted subsoil, be impervious, hold 110% of the capacity of 

the largest tank, and be independent of the back cut. 

 4. Water Gathering and Discharge 

Free water produced from each well will be transported from the well head via flowline 

to a surface discharge point for disposal. A Permanent Water Management Plan has 

been prepared by Hudson Group, LLC and has submitted to the Rawlins Field Office 

under separate cover (see Appendix D). The outfall of each discharge will be lined with 

rock (rip-rap) or some other suitable material in order to prevent erosion. 

Water produced from wells in close proximity to each other will be routed to a common 

discharge point to the greatest extent possible in order to minimize the overall number of 

discharge points required for water disposal within the Scotty Lake CBNG Pilot Project 

area. Entrained water which is separated from the gas stream will generally be routed to 

the closest discharge point for disposal. The actual discharge point and method of 

disposal for each individual well will be determined by the BLM at the time of the onsite inspection. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

13

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 5 

 4. LOCATION OF EXISTING AND/OR PROPOSED FACILITIES OWNED BY HUDSON 

GROUP, LLC WITHIN A ONE (1) MILE RADIUS 

 B. New Facilities Contemplated - Continued

 5. Gas Gathering and Sales 

Gas produced from each well will be transported from the well head via buried flowline 

to an existing, processing/metering facility where any remaining (entrained) water will 

be separated from the gas stream via a gas/water separator. The gas will then be metered 

and introduced into a gas sales line for transportation to market. The gas and water 

gathering lines will be buried in a common trench directly adjacent to existing access 

roads to the greatest extent possible to minimize surface disturbances within the field. 

 6. Pipeline and Flowline Right-of-Ways 

Graders will be used whenever possible to construct or clear individual pipeline rightsof-way. Each right-of-way will not be more than twenty-five 12) feet wide [preferably 

ten (10) feet wide on the soil stockpile side and fifteen (15) feet wide on the working 

side of the trench] without prior approval from the Authorized Officer, Bureau of Land 

Management. Right-of-ways constructed for the installation of water discharge lines 

will be no more than ten (10) feet in total width. Bladed materials will be placed back 

into the cleared route once construction has been completed. Pipeline construction will 

not block or change the natural course of any drainage. 

 7. All permanent [on-site for six (6) months or longer] above-the-ground structures 

constructed or installed on the well location (including pumping units, tank batteries, 

etc.) will be painted Shale Green (Munsell standard color #5Y 4/2) or another of the 

standard environmental colors recommended by the Rocky Mountain Five-State 

Interagency Committee to be selected at the discretion of the Authorized Officer, BLM. 

The exception being that Occupational Safety and Health Act Rules and Regulations 

will be complied with where special safety colors are required. 

 C. We do not anticipate the need to construct a production (emergency) pit on any of the 

individual well locations. 

 D. During drilling and subsequent operations, all equipment and vehicles will be confined to 

the access road and any additional areas that may be specified in the approved Application 

for Permit to Drill. 

 E. Reclamation of disturbed areas no longer needed for operations will be accomplished by 

grading, leveling and seeding as recommended by the Authorized Officer, Bureau of Land 

Management as appropriate. 

 5. LOCATION AND TYPE OF WATER SUPPLY 

A. Fresh water for use in drilling operations will be obtained from the Picket Lake Unit #1 

producing CBNG well and water retention (evaporation) pond located in the NW1⁄4SE1⁄4 of 

Section 24, Township 26 North, Range 97 West. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

14

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 6 

 5. LOCATION AND TYPE OF WATER SUPPLY - Continued

 A. Should this source prove to be inadequate, additional water for use in drilling and 

completion operations would be obtained from existing commercial water wells within the 

Scotty Lake Unit as follows: 

 1) Picket Lake #40-13 water supply well located in the NE1⁄4SE1⁄4 of Section 13, Township 

26 North, Range 97 West, Permit #P145371W; or 

 2) Picket Lake #1 water supply well located in the NW1⁄4SE1⁄4 of Section 24, Township 26 

North, Range 97 West, Permit #P135633. 

Hudson Group, LLC will obtain all necessary permits for appropriation of surface and/or 

ground water from the office o the Wyoming State Engineer prior to diversion. 

 B. Water would be hauled over existing roads via tank truck from the Picket Lake Unit #1 

water retention (evaporation) pond to each proposed point of use. No new road construction 

would be required on/along the proposed water haul route(s). 

Should Hudson Group, LLC utilize either of the two existing water supply wells, water 

would then be transported via temporary surface pipeline from the source to each proposed 

point of use. These surface water lines will be laid in the borrow ditch directly adjacent to 

existing/proposed access road routes to the greatest extent possible. In the event that it is 

not practical to follow the existing road network, installation of “cross country” pipelines 

would be accomplished in such a manner as to minimize surface disturbances associated 

with the installation of said surface line(s). 

Access across any off-lease or off-unit federal lands on/along the proposed water haul or 

surface pipeline route(s) would be secured under a separate right-of-way (ROW) 

authorization to be issued by the Rawlins Field Office, Bureau of Land Management. Said 

ROW authorization would typically be issued concurrent with the approval of the individual 

Application for Permit to Drill for each individual well location proposed hereunder. 

 C. Hudson Group, LLC currently has no plans to drill any additional water supply wells in 

conjunction with the proposed Scotty Lake CBNG Pilot Project. 

 6. SOURCE OF CONSTRUCTION MATERIALS 

 A. Any construction materials (gravel) which may be required for surfacing of the individual 

drill pads and/or central processing/metering facility sites will be obtained from a private 

contractor having a previously approved source of materials within the general area. Please 

refer to Item #2G (page #3) for information regarding those construction materials which 

may be required for surfacing of the main access roads. 

 B. No construction materials will be taken from federal or Indian lands without prior approval 

from the appropriate Surface Management Agency. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

15

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 7 

 6. SOURCE OF CONSTRUCTION MATERIALS - Continued

 C. Any construction materials which may be required for surfacing of primary access roads 

and/or the installation of central processing/metering facilities will be purchased from a 

local supplier having a permitted source of materials within the general area. 

 D. No new access roads for transportation of these construction materials will be required. 

 7. METHODS OF HANDLING WASTE MATERIALS 

 A. Cuttings - the drilled cuttings will be deposited in the reserve pit. 

 B. Drilling fluids - including any salts and/or chemicals utilized in the mud system will be 

contained in the reserve pit. The reserve pit will be designed to prevent the collection of 

surface runoff and will be constructed entirely in cut on the uphill side of the well location. 

 C. Produced fluids - water produced from wells within the Scotty Lake CBNG Pilot Project 

area will be discharged to the surface as indicated in Item #4B3 (page #7) under existing 

National Pollutant Discharge Elimination System (NPDES) permits issued by the Wyoming 

Department of Environmental Quality (WDEQ). 

Any spills of oil, gas, salt water or any other potentially hazardous substance will be cleaned 

up and immediately removed to an approved disposal site. 

 D. Sewage - portable, self-contained chemical toilets will be provided on each individual well 

location for human waste disposal. Upon completion of operations, or as required, the toilet 

holding tanks will be pumped and the contents thereof disposed of in an approved sewage 

disposal facility. Sewage disposal will be in strict accordance with WDEQ rules and 

regulations regarding sewage treatment and disposal. 

 E. Garbage and other waste material - all garbage and non-flammable waste materials will be 

contained in a self contained, portable dumpster or trash cage to be located on each 

individual well location. Upon completion of operations (or as needed) the accumulated 

trash will be hauled off-site to a WDEQ approved sanitary landfill. 

No trash will be placed in the reserve pit. 

 F. Immediately after removal of the drilling rig, all debris and other waste materials not 

contained in the trash cage will be cleaned up and removed from each individual well 

location. No potentially adverse materials or substances will be left on these locations. 

Any open pits remaining upon conclusion of drilling operations will immediately be fenced 

with said fencing maintained until such time as the pits have been backfilled. 

G. Hazardous Materials - Hudson Group, LLC maintains a file, per 29 CFR 1910.1200 (g) 

containing current Material Safety Data Sheets (MSDS) for all chemicals, compounds, 

and/or substances which are used during the course of construction, drilling, completion, 

and production operations for this project. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

16

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 8 

 7. METHODS OF HANDLING WASTE MATERIALS - Continued

 G. Hazardous Materials - Hazardous materials which may be found at the site include drilling 

mud and cementing products which are primarily inhalation hazards, fuels (flammable 

and/or combustible), materials that may be necessary for well 

The opportunity for Superfund Amendments and Reauthorization Act (SARA) listed 

Extremely Hazardous Substances (EHS) at the site is generally limited to proprietary 

treating chemicals. All hazardous and Extremely Hazardous Substances and commercial 

preparation will be handled in an appropriate manner to minimize the potential for leaks or 

spills to the environment. 

 8. ANCILLARY FACILITIES 

None anticipated. 

 9. WELLSITE LAYOUT 

 A. Diagrams specific to each individual well location will be included in each respective 

Application for Permit to Drill and will include cross-sectional diagrams of the proposed 

well location as required under Onshore Oil and Gas Order Number 1. B. No permanent living facilities are planned on those individual well locations to be included 

in the Scotty Lake CBNG Pilot Project; however, there will be a maximum of three (3) 

trailers on location during drilling operations which will serve as offices and housing for the 

mud logger, geologist and toolpusher. 

 C. All equipment and vehicles will be confined to those areas subsequently approved 

(designated) in conjunction with each individual Application for Permit to Drill (e.g., access 

road, well pad, spoil and topsoil storage areas). 

 D. Diagrams showing the proposed production facility layout on each individual well location 

will be submitted to the Authorized Officer via Sundry Notice (form #3160-5) for approval 

prior to the commencement of installation operations. Please refer to Item #4B2 (page #3) 

for additional information in this regard. 

E. The reserve pit(s) will be lined with a plastic/vinyl liner in order to prevent drilling water 

loss through seepage. The liner will have a permeability less than or equal to 1 X 10 -7

cm/sec, will be chemically compatible with all substances which may be put into the pit and 

will be installed so that it will not leak. Liners made of any man-made synthetic material 

will be of sufficient strength and thickness to withstand normal installation and pit use. The 

liner will be installed with sufficient bedding (either straw or dirt) to cover any rocks, will 

overlap the pit walls, extend under the mud tanks, and be covered with dirt and/or rocks to 

hold it in place. 

No trash, scrap pipe, etc. that could puncture the liner will be disposed of in the reserve pit. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

17

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 9 

 9. WELLSITE LAYOUT - Continued

 F. Prior to the commencement of drilling operations, the reserve pit(s) will be fenced sheep 

tight on three (3) sides according to the following minimum standards:

 1. 32-inch net wire shall be used with two (2) strands of barbed wire on top of (above) the 

net wire. 

 2. The net wire shall be no more than four (4) inches above the ground. The first strand of 

barbed wire shall be ≈ three (3) inches above the net wire. Total height of the fence 

shall be at least forty-two (42) inches. 

 3. Corner posts shall be cemented and/or braced in such a manner to keep the fence tight at 

all times. 

 4. Standard steel, wood, or pipe posts shall be used between the corner braces. The 

maximum distance between any two (2) posts shall be no greater than sixteen (16) feet. 

 5. All wire shall be stretched, by using a stretching device, before it is attached to the 

corner posts. 

The fourth (4th) side of the reserve pit(s) will be fenced immediately upon removal of the 

drilling rig and the fencing will be maintained until the pit has been backfilled. 

 G. Any hydrocarbons on the pit will be removed as soon as possible after drilling operations 

are completed. 

10. PLANS FOR RECLAMATION OF THE SURFACE

 A. Rat and mouse holes (as appropriate) will be backfilled and compacted from bottom to top 

immediately upon release of the completion rig from the location. 

 B. If any oil is on the reserve pit and is not immediately removed after operations cease, the pit 

containing the oil or other adverse substance(s) will be flagged overhead or covered with 

wire mesh to protect migrating waterfowl. 

 C. Producing Operations: 

 1. Backfilling, leveling and re-contouring of each individual well location will be 

undertaken as soon as possible after cessation of drilling and completion operations. 

Waste and spoil materials will be disposed of immediately upon cessation of drilling and 

completion activities. 

 2. For production, the fill slopes will be reduced from a 1.5:1 slope to a minimum 3:1 slope 

and the cut slopes will be reduced from a 2:1 slope to a minimum 4:1 slope by pushing 

the fill material back up into the cut. Please refer to each individual Application for 

Permit to Drill for more specific information regarding slope reduction and timing of the 

reclamation activities. 

 3. Upon completion of backfilling, leveling and recontouring, all disturbed surfaces (access 

road and well pad areas) will be scarified to a depth of one (1) foot and the stockpiled 

topsoil will be evenly redistributed to a depth of six (6) inches over the reclaimed 

area(s). 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

18

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 10 

10. PLANS FOR RECLAMATION OF THE SURFACE

 C. Producing Operations: Continued 

 4. Prior to commencement of seeding operations, the seedbed will be prepared by disking 

on the contour to a depth of four (4) to six (6) inches, leaving no depressions that would 

trap water or form ponds. All disturbed surfaces (including the access road and well pad 

areas) will be reseeded using the seed mixture identified below (or a different mixture to 

be recommended by BLM’s Authorized Officer as appropriate). 

Species Pounds PLS/Acre 1

Western wheatgrass 5.0 

Needleandthread grass 3.0 

Indian ricegrass 3.0 

Bottlebrush squirreltail 3.0 

Gardner’s saltbush 2.0 

1

 Pounds of Pure Live Seed per Acre. 

 5. Seed will be drilled on the contour with a seed drill equipped with a depth regulator in 

order to ensure even depths of planting. Seed will be planted between one-quarter (1/4) 

to one-half (1/2) inches deep. Where drilling is not possible (too steep or rocky), hand 

broadcast the seed at double the rate indicated above and rake or chain the area to cover 

the broadcast seed. 

 6. Fall seeding will be completed after September 1st and prior to ground frost. If 

applicable, spring seeding will be completed after the frost has left the ground and prior 

to June 15th. The seeding will be repeated until a satisfactory stand, as determined by 

the Authorized Officer, is achieved. The first evaluation of growth will be made 

following the completion of the first growing season. 

 D. Pipeline and Flowline Right-of-Ways: 

 1. Pipeline/flowline trenches will be compacted during backfilling and said trenches will 

be maintained in order to correct settlement and erosion. 

 2. Prior to commencement of reseeding activities on/along the reclaimed pipeline/flowline 

right-of-ways, waterbars will be constructed at least one (1) foot deep, on the contour 

with approximately two (2) feet of drop per 100 feet of waterbar to ensure drainage, and 

extended into established vegetation. All waterbars will be constructed with the berm on 

the downhill side to prevent the soft material from silting in the trench. The initial 

waterbar should be constructed at the top of the backslope. Subsequent waterbars 

should follow the following general spacing guidelines provided below: 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

19

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 11 

10. PLANS FOR RECLAMATION OF THE SURFACE

 D. Pipeline and Flowline Right-of-Ways: Continued 

 2. Subsequent waterbars should follow the following general spacing guidelines provided 

below: 

% Slope Spacing Interval (feet) 

 2% or < 200’ 

 2% - 4% 100’ 

 4% - 5% 75’ 

 5% or > 50’ 

 3. All disturbed surfaces along pipeline/flowline right-of-ways will be reseeded as 

recommended in Item #10C3-6, above. 

 E. Abandoned Well Location: 

 1. Upon final abandonment of each well location and/or associated facilities, gravel will be 

removed from the access road surface and well location (as appropriate), water diversion 

installed as needed, and both the access road and well location will be restored to 

approximately the original ground contour(s) by pushing the fill material back into the 

cut and up over the backslope (as applicable). 

 2. No depressions will be left that would trap water or form ponds. All disturbed surfaces 

will be reseeded as recommended in Item #10C2-5, above. 

11. SURFACE OWNERSHIP 

All of the facilities included within the proposed Scotty Lake CBNG Pilot Project area are 

situated on surface estate which is owned by the United States of America. These public lands 

are administered in trust by: 

 Field Manager 

 Rawlins Field Office 

 Bureau of Land Management 

 P.O. Box 2407 

 Rawlins, Wyoming 82301-2407 

 Telephone: 307-328-4200 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

20

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 12 

12. OTHER INFORMATION 

 A. General Description of the Project Area: 

The Scotty Lake CBNG Pilot Project area is situated in an upland area of northeastern 

Sweetwater County locally known as Cyclone Rim. The overall area is located in the 

northern portion of the Great Divide Basin, a closed intermountain basin bounded by the 

Leucite Hills to the west, Delaney Rim to the south, the Wind River Mountains (and 

Beaver Rim) to the north, and the Sierra Madre Mountain range to the south. More 

specifically, the project area is located generally north of Red Creek, south of West Alkali 

Creek, west of the Stratton Lakes, east/southeast of Scotty Lake, and north/northeast of 

Bastard Butte. This area is classified as a High Plains Steppe (cold desert) and is 

characterized by gently to moderately undulated uplands dissected by numerous ephemeral 

drainages of Red Creek to the south and West Alkali Creek to the north. 

Local flora consists primarily of needleandthread grass, western wheatgrass, prairie 

junegrass, Indian ricegrass, threadleaf sedge, prickly pear cactus, sagebrush, and yucca. 

Local fauna consists primarily of mule deer, antelope, coyotes, badgers, skunks, rabbits, 

raptors, and various smaller vertebrate and invertebrate species. 

There are no known threatened or endangered species that would be affected by 

implementation of operations on any of the wells included within the proposed Scotty Lake 

CBNG Pilot Project. 

 B. Surface Use Activities:

Livestock grazing is the primary surface use within the area encompassed by the Scotty 

Lake CBNG Pilot Project. 

 C. Proximity of Water, Occupied Dwellings, Archaeological, Historical or Cultural Sites:

 1. The closest source of semi-permanent water in the project area is Red Creek, which is 

located approximately five (5) miles to the southwest of the Scotty Lake CBNG Pilot 

Project area. 

 2. There are no occupied dwellings with a twenty (20) mile radius of the proposed project 

area. 

 3. Hudson Group, LLC will be responsible for informing all persons associated with this 

project that they will be subject to prosecution for damaging, altering, excavating or 

removing any archaeological, historical, or vertebrate fossil objects or site(s). If 

archaeological, historical or vertebrate fossil materials are discovered, Hudson Group, 

LLC will suspend all operations that further disturb such materials and immediately 

contact the Authorized Officer. Operations will not resume until written authorization 

to proceed is issued by the Authorized Officer. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

21

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 13 

12. OTHER INFORMATION - Continued

 C. Proximity of Water, Occupied Dwellings, Archaeological, Historical or Cultural Sites:

 3. Within five (5) working days the Authorized Officer will evaluate the discovery and 

inform Hudson Group, LLC of actions that will be necessary to prevent loss of 

significant cultural or scientific values. 

Hudson Group, LLC will be responsible for the cost of any mitigation required by the 

Authorized Officer. The Authorized Officer will provide technical and procedural 

guidelines for the conduct of mitigation. Upon verification from the Authorized Officer 

that the required mitigation has been completed, Hudson Group, LLC will be allowed 

to resume operations. 

 D. Additional Requirements for Operations on Lands Administered by the Bureau of 

Land Management:

 1. Hudson Group, LLC will be responsible for weed control on disturbed areas within the 

exterior limits of this permit and will consult with the Authorized Officer and/or local 

authorities for acceptable weed control measures. 

A “Pesticide Use Proposal” (form #WY-04-9222-1) and pesticide label will be 

submitted by Hudson Group, LLC to the Authorized Officer no later than December 1st

for use during the following spring/summer period. 

 2. As indicated in Item #4B3, a comprehensive Permanent Water Management Plan is 

being prepared for the proposed Scotty Lake CBNG Pilot Project and will be submitted 

under separate cover for review and subsequent approval (see Appendix D). 

13. LESSEE’S OR OPERATOR’S REPRESENTATIVE AND CERTIFICATION 

 Representative 

Kirk W. Hudson, Petroleum Engineer 

Hudson Group, LLC 

330 South Center, Suite 307 

Casper, Wyoming 82601 

Telephone: 307-237-3083 

 Certification 

All lease and/or unit operations will be conducted in such a manner that full compliance is made 

with all applicable laws, regulations, Onshore Oil & Gas Orders, the approved plan of 

operations, and any applicable Notice to Lessees. 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix C 

22

Hudson Group, LLC 

Scotty Lake CBNG Pilot Project 

Plan of Development and Master Field Permit 

Surface Use and Operations Plan 

Page 14 

13. LESSEE’S OR OPERATOR’S REPRESENTATIVE AND CERTIFICATION 

 Certification - Continued 

Hudson Group, LLC will be fully responsible for the actions of their subcontractors. A copy of 

these conditions will be furnished to the field representative(s) to ensure compliance. The dirt 

contractor will be provided with a copy of the Surface Use Plan from each approved 

Application for Permit to Drill. 

Each individual drilling permit will be valid for a period of one (1) year from the date of 

approval. After permit termination, a new application will be filed for approval for any future 

operations. 

I hereby certify that I, or persons under my direct supervision, have inspected each proposed 

drill site and access route; that I am familiar with the conditions which currently exist; that the 

statements made in this plan are, to the best of my knowledge, true and correct; and that the 

work associated with the operations proposed herein will be performed by Hudson Group, LLC, 

their contractors and subcontractors in conformity with this plan and the terms and conditions 

under which it is approved. This statement is subject to the provisions of 18 U.S.C. 1001 for the 

filing of a false statement. 

 __________________________________________ Date Kirk W. Hudson, Petroleum Engineer 
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

APPENDIX D 

Scotty Lake CBNG Pilot Project Water Management Plan 

Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

HUDSON GROUP, LLC 

SCOTTY LAKE CBNG PILOT PROJECT 

TABLE OF CONTENTS 

 Page 

Project Location - Geographic & Geologic Settings 1 

Watershed Delineation 2 

Produced Water - Project Related 2 

Produced Water- Non-Project Related 3 

Surface Water 4 

Ground Water 4 

Discharge Point Siting & Design 6 

Peak Flows 8 

Project Flows - Channel Capacity 8 

Conveyance Loss 8 

Water Balance 9 

Downstream Impacts 9 

Erosion Control Plan 9 

Monitoring & Mitigation 10 

Lessee’s or Operator’s Representative and Certification 10 

References 11 

APPENDIX A: TABLES 

 1. Project Wells

 2a. Water Analysis - Picket Lake #1 

 2b. Water Analysis - Osborne Spring 

 3. Surface Water Rights 

 4. Ground Water Rights 

 5. Observation Point Locations 

 6. Discharge Points 

 7. Pit/Pond Specifications

 8. Peak Flow Estimates

 9. Estimated Velocities & Discharge Rates for CBNG Surface Water

10a. Flow Distances in Tributaries Using Conveyance Loss Factor 1500 bpd/mi

10b. Flow Distances in Tributaries Using Conveyance Loss Factor 750 bpd/mi

11a. Water Balance - Drainage Basins A, B, C - 550 bpd/well; 1500 bpd/mi

11b. Water Balance - Drainage Basins A, B, C - 1200 bpd/well; 1500 bpd/mi

11c. Water Balance - Drainage Basins A, B, C - 550 bpd/well; 750 bpd/mi

Appendix D 

i
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

APPENDIX B: FIGURES 

 1. #40-13 Water Well Schematic Diagram

 2. Typical Riser-type Outfall 

APPENDIX C: PHOTOGRAPHS 

Observation Point Description

13 View down tributary to reach 4 near DP #7/25 in DB C; channel slope 3°, 

width 1 to 2’, depth < 1’ 

38 View down tributary to reach 2b near well #15 in DB A; slope 2.4°, width 1 to 

2’, depth < 1’ 

31 View up tributary to reach 3 in DB B south of well #28;slope 0.5°, width 3 to 

4’, depth 0.5’ 

16 View up reach 4 in DB C; water is snowmelt; slope 1.5°, width 3 to 4’, depth 

1’

27 View up reach 4 in DB C; water is snowmelt; slope 0.5°, width 6’, depth 1.5 

to 2’ 

42 View up reach 2c in DB A near DP #15; slope 1.2°, width 2 to 3’, depth 0.5’ 

29 View down reach 5 in DB A @ site of PT 2; slope < 1°, width 5 to 6’, depth 

1.5 to 2’ 

34 1 to 3’ head cut on tributary 3 in DB B, above DP #16 

18 5 to 6’ head cut on tributary 1a in DB C, above DP #3 

 8 DP #6 near well #2; perforated pipe in rip-rap blanket in channel 

10 Rip-rap inlet to recharge pond at well #4 

19 Stock pond at well #1 

USDI/BLM flowing well in Section 25, T23N, R96W:

a. Outlet from pond receiving well water 

b. Channel below pond outlet; width 1 to 2’, depth < 0.5’ 

Appendix D 

ii
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

APPENDIX D: MAPS AND CHARTS 

Water Management Map 

Drainage Basin & Channel Reach Index Map 

Type Log - Picket Lake #1 

Appendix D 

iii
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

HUDSON GROUP, LLC 

SCOTTY LAKE CBNG PILOT PROJECT 

WATER MANAGEMENT PLAN

Project Location - Geographic & Geologic Settings 

Hudson Group, LLC has proposed the development of their Scotty Lake CBNG Pilot Project. The 

purpose of this project is to determine the feasibility of establishing commercial natural gas

production from the Scotty Lake Coals contained within the Tertiary (Eocene) Fort Union 

Formation. The development of this pilot project will also provide the opportunity to collect sitespecific hydrologic and geologic data for possible use in future analyses. 

The project consists of 18 wells, including three alternate wells, and 15 discharge points. There are 

also three existing CBNG wells and three existing discharge points within the project area, which 

were included in this analysis. Produced water will be pumped to direct surface discharge points,

stock ponds or recharge pits with outlets. This project is located within the Picket Lake Field, which 

has produced natural gas from the Cretaceous Lewis Formation since the field’s discovery in 1978.

The project will be developed in three phases, commencing with the drilling of four wells in phase I 

this year. NPDES discharge points have already been permitted with the Wyoming Department of 

Environmental Quality (WDEQ). The Water Management Map shows the project outline by phases, 

proposed CBNG well locations, discharge point locations, stock ponds, pits and existing wells. 

The pilot project covers an area of 4.5 square miles (mi2

) and lies in the northern portion of the Great 

Divide Basin (GDB) at an elevation of approximately 7000 to 7100 ft. The GDB covers an area of 

3500 mi2, lying NE of Rock Springs and NW of Rawlins. The GDB is both a topographic and 

structural basin with internal drainage, meaning surface water drains towards the center of the basin.

Water loss is by evaporation, transpiration by plants and infiltration or seepage into the subsurface. 

The climate is arid, with average annual rainfall of 9.8 inches (Lowham 1988). Evaporation is

approximately 10 times the annual precipitation rate (Welder et al 1966). Photographs OP 13, 16, 

27, 29, 31, 34, 38 & 42 document the nature of the terrain within the project area. Drainages are 

established and ephemeral, flowing only in response to precipitation events and snowmelt. 

Sandstone lenses outcrop in the project area. Sediments in the drainages are silty and sandy. 

The structural geology of the GDB is an asymmetric syncline trending NW-SE with the synclinal

axis located towards the northern flank of the basin. Geologic dips are approximately 3° 

northeasterly off the Rock Springs uplift. The syncline is bounded on the north by the Wind River 

Thrust fault and associated normal faults. Surface outcrops in the project area are the Eocene-age 

Cathedral Bluffs tongue of the Wasatch Formation, consisting of shale and siltstone with interbedded 

sandstones. These rocks overlie the Tipton Shale tongue of the Green River Formation (Welder et al

1966). The Scotty Lake coals are a localized deposit in the northern portion of the GDB, covering 

an area of approximately 55 mi2

; this is different than the deeper Big Red coals, which have been 

deposited basin-wide. The Scotty Lake coals occur at a depth of between 2000 and 5000 ft in the 

project area. These are multiple coal beds ranging in thickness from 2 to 50 ft each. The Big Red 

coals are almost 3000 ft deeper. These relationships can be seen on the Type Log. 

Appendix D 

1
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Watershed Delineation 

Water discharged by the Scotty Lake project will enter one of three local drainage basins (DB),

designated A, B and C in this report. These sub-basins are defined relative to their respective

confluence with Red Creek. The areas and basin slopes of these sub basins are: 

Drainage Basin (DB) Area, mi2 Slope, ft/mi

A 6.51 246

B 3.97 155

C 10.07 204

The Red Creek watershed, defined from the confluence of DB C with Red Creek covers an area of 

119 mi2

. The total area of DB’s A, B and C is 20.55 mi2, or 17.3 % of the Red Creek watershed, as 

defined here. The project drainage area is 0.59% of the area of the Great Divide Basin. Red Creek 

terminates in Hay Reservoir, approximately 8.7 miles south of the confluence with DB C. The 

Wyoming Department of Environmental Quality (WDEQ) conducted a use attainability analysis

(UAA) on Red Creek and its tributaries in September 2002 (WDEQ 2002). The UAA found no 

significant wetlands present and resulted in the reclassification of Red Creek and its tributaries from

3B to 4B. 

The tributaries contained within DB’s A, B and C have been subdivided and given numbered

designations for this study. The DB’s and reaches are presented on the enclosed Index Map. All of 

the designated tributaries are ephemeral (dry most of the time) and are losing streams. That is, the 

water table is below the base of the channels, so water in the channels will infiltrate or seep 

downward into the alluvial sediments in the drainages and the underlying weathered bedrock. The

total length of the tributaries within DB’s A, B and C that will receive CBNG water is 35.58 miles.

Produced Water - Project

The 18 project wells are expected to initially produce CBNG water at the rate of 550 bpd (16 gpm)

per well. Wells will be drilled on an average spacing of 128 acres, one well per location. The

maximum, total initial production from 21 wells (18 new, 3 existing) will be approximately 11,550 

bpd (336 gpm or 0.755 cfs). Hudson Group has received approved NPDES permits for up to 19,286

bpd (0.81 mgpd). Because the Scotty Lake coals are normally pressured, the rate of water 

production is expected to decline at an annual rate of 10 to 30% per year. CBNG water decline rates 

have been documented for the Powder River Basin by Advanced Resources International (2002)

(BLM 2003a) and numerous press releases and talks by the Wyoming Oil & Gas Conservation 

Commission. It should be noted that only enough water will be removed from the coals to lower the 

reservoir pressure to allow the adsorbed gas to break free from the coal and flow to the wells. For 

example, this volume of water has been estimated at 20% of the recoverable water volume contained 

in the Wasatch and Fort Union Formations in the Powder River Basin (BLM 2003a). When

production ceases, water levels will mostly recover - rapidly at first - then more slowly as the water 

levels approach original static conditions. Proposed well locations are shown on the enclosed water 

management map and listed in Table 1. 

Appendix D 

2
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Table 2a presents the water quality analysis dated 3/9/03 for the PL #1 well completed in the Scotty

Lake Main coals. A summary of the produced water quality and the standards imposed by the 

approved project NPDES permit are as follows: 

Parameter Analyzed Well Permit

Total dissolved solids @ 180° C, mg/l 1060 ---

Specific conductance @ 25° C, μmhos/cm 1750 7500

pH, su 8.24 6.5 - 8.5

Sulfate, mg/l ND 3000

Chloride, mg/l 74.1 2000

Sodium adsorption ration 42.9 ---

Total radium 226, pCi/l 1.6 60

Total petroleum hydrocarbons, mg/l 1.5 10

Dissolved iron, μg/l 212 ---

Total barium, μg/l 8440 ---

Dissolved manganese, μg/l ND ---

Total arsenic 1 ---

ND = not detected

This water is Class III groundwater, suitable for livestock & wildlife consumption. The alluvial 

sediments and soils in the project area contain sulfate, which is expected to react with the barium in 

the produced water, precipitating as barite, a stable, inert mineral. Soil samples from the project area

contained sulfate concentrations between 710 and 1490 mg/kg-dry.

Produced Water - Non-Project Related 

Existing Wells

There are two existing, permitted water wells within a one-mile radius of the project: PL #1 WW

(NW1⁄4SE1⁄4, Section 24, T26N, R97W) and PL #40-13 WW (SW1⁄4SE1⁄4, Section 13, T26N, R97W).

Both wells are operated by Hudson Group. The PL #1WW is the only water well within 1⁄2 mile of a 

CBNG well. 

Potential Development

It is anticipated that additional leases within the Red Creek watershed may be developed in the 

future. The occurrence of the Scotty Lake coals is limited to an area of 55 mi2. However this area is

the zero-line for the coal. The area for potential development is more like 40 mi2. A maximum

development scenario for the Red Creek drainage basin is 200 wells on 120-acre spacing with one 

well per location. This includes the 18 project wells and 3 existing wells. It is premature to evaluate

this scenario at this time. The pilot project will provide site-specific data for further analysis if

additional exploration and/or development is warranted in the future.

Appendix D 

3
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Surface Water

Surface water rights permitted with the Wyoming State Engineer’s Office (WSEO) are listed in 

Table 3 (WSEO 2004). There are no surface water rights within a one-mile radius of the project

area. Osborne Springs, which is discussed in this report, is located three miles southwest of the 

project area. All tributaries within and downstream of the Scotty Lake project are ephemeral, losing 

streams classified 4B by WDEQ.

Ground Water 

Ground water rights near the Scotty Lake Project that are permitted with the WSEO are listed in

Table 4 (WSEO 2004). There are no springs within a one-mile radius of the Scotty Lake project. 

Welder et al (1966) indicated that most of the water wells in the Great Divide Basin are completed in 

confined aquifers. By definition, the static water level in a well completed in a confined aquifer will 

rise above the top of the aquifer. This indicates the aquifer is under pressure, which means it is

confined by low-permeability rocks effectively sealing it from the local surface. A review of 

available data on water wells in the northern Great Divide Basin supports Welder’s conclusion. Data 

from water wells in T26N, R96 & 97W have average reported yields of 36.5 gpm from depths of 350 

to 810 ft. Most well depths are between 400 and 600 ft. Static water levels in these wells are all 

above the tops of the water-bearing zones. The mean static water level is 141 ft and the mean top of 

the aquifers is 382 ft. These are confined aquifers. 

Figure 1 is a schematic diagram of the PL #40-13 water well, operated by Hudson and located 1⁄4 mi

north of Phase I of the Scotty Lake CBNG Pilot Project. It is completed in two water-bearing

sandstones at depths of 410 to 445 ft and 460 to 530 ft. The static water level in this well is at a 

depth of 210 ft, therefore the aquifers are confined. There is 150 ft of shale in two zones overlying 

the aquifers, providing good seals from shallow groundwater. Shale has very low permeability and 

therefore does not transmit water very well; it is a good seal. In areas of intense structural geology, 

most shales deform plastically rather than fracturing; a characteristic also making them good seals. 

Ground water is contained in aquifers that are a part of a hydrologic system. These systems can be

local, intermediate or regional in scale. Local systems cover the smallest area and are generally 

located near the source or recharge area for the water in the aquifer. The recharge areas can be the 

outcrop of the aquifer at the surface or water contained in streams, lakes or reservoirs that infiltrates

downward. The water from local hydrologic systems has the best water quality of the three types of 

systems because the water spends the least time in the aquifer and travels the least distance, so it has

less time to dissolve minerals from the rocks and sediments. Regional hydrologic systems have the 

poorest water quality because the water in these systems travels greater distances at greater depths, 

which gives the water in the aquifer a much longer residence time at higher temperatures and 

pressures; this results in a high mineral content in the water.

It is important to note the fact that ground water travels very slowly in the aquifer, at a rate of a few 

ft to 10’s of ft per year. Seasonal or temporary changes in recharge or discharge rates may not even

be detectable in water level data from aquifers in intermediate or regional systems.

Welder et al (1966) reports water quality data from one well in Section 34, T27N, R97W and one

spring in Section 32, T27N, R97W north of the continental divide from the project area. The well 

Appendix D 

4
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

had a conductivity of 580 μmhos/cm and the spring had a conductivity of 980 μmhos/cm. Water

from the Scotty Lake coals has a conductivity of 1750 μmhos/cm. This supports the interpretation 

that the Scotty Lake coals are part of an intermediate hydrologic system separate from the more local 

hydrologic system feeding lakes, springs and shallow aquifers along the continental divide. Thus, 

temporary changes in the water pressures within the Scotty Lake coals should not affect the local 

hydrologic system.

A water sample was collected from Osborne Spring, located three miles southwest of the project 

area. The lab analysis is found in Table 2b. There are significant differences between the water 

from Osborne Spring and the water produced from the Scotty Lake coals. The following is a 

comparison of the differences in the two waters: 

Parameter Analyzed Osborne Spring Scotty Lake coal 

Total dissolved solids @ 180° C, mg/l 2300 1060

Sulfate, mg/l 652 3000

Sodium adsorption ration 28.5 42.9

Dissolved iron, μg/l 5620 212

Total barium, μg/l 146 8440

Nickel, μg/l 48 ND

Zinc, μg/l 85 ND

Aluminum 8460 188

ND = not detected

These two waters have sufficiently different chemistries to conclude they are from different

hydrologic systems. Temporary water pressure changes in the Scotty Lake coals should have no 

impact on Osborne Spring. 

The enclosed type log is from the PL #1 well, an existing well within Phase I of the Scotty Lake

CBNG Pilot Project. The well was originally drilled to 13,652 ft and produced gas from the Lewis 

Formation. It has been plugged back to 4800 ft and recompleted in the main Scotty Lake coals 

between depths of 3604 and 3706 ft on the type log. Shales > 10 ft thick above and below the Scotty 

Lake coal interval have been shaded gray. Coals > 10 ft thick are indicated by black in the well 

column. There is 748 ft of shale between the base of surface casing and the top of the Scotty Lake

coal. There is also 786 ft of shale between the base of the Scotty Lake coal and the top of the Big 

Red coal. The Scotty Lake coal is effectively sealed from overlying shallow hydrologic systems and 

the underlying regional hydrologic system containing the Big Red coal. 

Before full water production begins from CBNG wells in Phase I, an isotopic analysis will be 

performed on a water sample from the producing formation to verify that there is not a connection 

between the CBNG water and the North Platte River system.

Appendix D 

5
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Discharge Point Siting & Design 

Four field days were spent on-site examining drainages and discharge point locations. Observation 

points where data were collected are shown on the Water Management Map and their locations are 

listed in Table 5. There are 43 observation points; most were photographed. Selected photos are 

included in this report. The tributaries were subdivided into reaches within their respective local

drainage basins. These are presented on the Drainage Basin & Reach Index Map. 

Channel reach gradients were determined from USGS 71⁄2 minute topographic maps and field 

checked at the observation points. The map gradients and field gradients are in agreement. 

Drainages near the divides begin as gentle swales, but quickly become small, active channels as they 

progress downslope. Overall, channels are entrenched with defined, vegetated banks. One major 

headcut 5 to 6 ft high was observed at observation point (OP) 18 (photo). No project water will be 

discharged above this point. Smaller headcuts, generally of one ft or less were observed on some of 

the steeper slopes in the upper reaches within the project area (photo OP 34). Channels in the upper

reaches are typically 1 to 3 ft wide and 1 ft or less deep with gradients between 0.02 & 0.03 (1° & 

2°). Channels at the lowest point receiving discharges are typically 2 to 4 ft wide and 1 ft +/- deep

with gradients between 0.010 & 0.018 (0.5° & 1°). The main tributaries leaving the project 

boundaries are typically 3 to 6 ft wide, 1 ft deep sub-channels within a larger 6 to 8 ft wide 3 to 6 ft 

deep draw. Gradients are between 0.010 & 0.016 (0.5° & 1°). All channels are ephemeral with silty 

and sandy bottoms.

Discharge points are shown as triangles on the Water Management Map and are listed in Table 6. 

Some discharge points will be designed to receive water from multiple wells and some wells will be 

able to discharge water at multiple points to allow flexibility and control of water flow. Water will 

be moved off higher elevations and steeper slopes through pipelines to discharge points located in 

stable channels with acceptable gradients. The discharge points are distributed across the unnamed

tributaries within the three drainage basins in the project area; this will keep the volume and velocity

of the discharged water within acceptable limits.

Three methods of handling the surface discharge of CBNG produced water will be utilized for this 

project: 1) direct discharge to drainages, either through perforated pipe encased in rip-rap lying in 

the bottom of a channel or an energy dissipating riser (bubbler) located adjacent to a channel with a 

rip-rap riffle trench into the channel (Figure 2); 2) an off-channel recharge pit with an outlet to a 

drainage; or 3) a stock pond without an outlet with the water source also connected to a surface 

discharge point (photos OP 8, 10 & 19). Conveyance losses are expected to be high in the project 

area. This project is located within a closed basin and the produced water meets WDEQ standards

for direct discharge. Other issues regarding the use of pits and ponds include surface disturbance, 

wildlife, and the distribution of the wild horse populations. Ponds/pits can be designed or fenced to 

manage wildlife, wild horse or livestock access and to address concerns with providing additional

water sources in this area, These concerns will be routinely evaluated during the APD process 

before each phase of the project. 

There is an existing stock pond and a flow-through pit that will be utilized in water management for 

this project. The pond and pit specifications are shown in Table 7. These were described in the EA 

prepared for the recompletion of three existing wells in the Picket Lake Field in February 2003

Appendix D 

6
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

(BLM 2003b). Recompletion work on the three wells is still in progress, so sustained production has 

not yet been achieved. The monitoring, data collection, and analysis described in that document will 

continue.

All of the discharge points referenced in this report have approved NPDES permits issued by 

WDEQ. The permits allow the actual location of each discharge point to be administratively moved

within a 1/2-mile radius of the permitted location. All discharge points described in this water 

management plan are within the 1/2-mile radius of the permitted location.

Subject to additional field work in Phases II & III and monitoring of the effectiveness of present

discharge points, individual discharge point designs and locations may be modified, if deemed 

necessary, by BLM. This could include the use of additional pits or ponds at locations with higher 

channel gradients or where erosion downstream is of concern. When discharge ceases, all pits,

ponds and discharge points will be rehabilitated to the original topography using the same standards 

as well pads (reference for well pad rehabilitation). Upon completion of the CBNG project, BLM 

may decide to evaluate some pits or ponds for potential beneficial use, which will require a

dedicated water source (well). If a water source is available and it is determined to be feasible in the

NEPA analysis, the project will be managed as a range or wildlife improvement project. The 

operator will not be responsible for maintenance or rehabilitation of pits or ponds converted to range 

or wildlife improvement projects, but will still be responsible for the rehabilitation of all sites not 

converted to BLM projects. 

The USDI/BLM #25-23-96 flowing well located in Section 25, T23N, R96W is a good analog for

surface discharge. This well has recently been reconfigured by the BLM to flow into a small pond, 

then through an outlet to a small channel. A water sample was collected from this well in 1963 and 

published by Welder et al (1966). The water analysis is as follows: 

Conductivity, μmhos/cm 1750

pH, su 7.6

TDS, ppm 1110

Sodium, ppm 462

Calcium, ppm 3.4

Magnesium, ppm 0.1

Potassium, ppm 3.4

Bicarbonate, ppm 1120

Carbonate, ppm 918

Chloride, ppm 53

Sulfate, ppm 0.2

Nitrate, ppm 0.1

Iron, ppm 0.05

Silicon, ppm 13

Fluoride, ppm 5.5

Boron, ppm 0.09

SAR 67 

Appendix D 

7
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Welder reported the flow from this well as 50 gpm and total depth of the well as 2250 ft. The 

WSEO database currently shows this well with a reported yield of 25 gpm, total depth of 1160 ft, top 

of main water zone 810 ft and static water level 7 ft above ground level (WSEO 2004). The well has 

been flowing for decades with no adverse impacts. The channel receiving the flow from the well is

small (1 to 2 ft wide; 4 inches deep) and stable with riparian vegetation developed adjacent to the 

channel (Photos a & b). The area receiving the discharged water is approximately 30 acres in size, 

containing some wetland habitat. It is providing beneficial use to wildlife.

Peak Flows

Peak flows were computed for drainage basins (DB) A, B and C using the methods published by 

Miller (2003) and Lowham (1988). The input and results are presented in Table 8. The Q 1.5 

through Q 500 nomenclature are recurrence intervals for the type storm events. A Q 1.5 event can 

be expected to occur statistically once every 1.5 years; a Q 100 event once every 100 years, etc. 

However these are statistics. In reality, a 100-year event could occur in consecutive years or even

months. Active channels are generally formed by one or two-year events. The Q 2 events calculated

using Miller’s method range from 20.0 to 35.6 cfs; comparable statistics from Lowham range from 

37.2 to 60.7 cfs. 

Table 8 also contains Q 10 & Q 25 peak flow data in units of cfs/mi for use in culvert sizing. 

Lowham’s method also estimates mean annual flow. These range from a low of 0.11 cfs for DB B 

to a high of 0.24 cfs for DB C. 

Project Flows - Channel Capacity 

Estimated discharge rates and velocities are found in Table 9. This table assumes a per well rate of 

550 bpd (0.037 cfs) and no conveyance loss. Estimates were made for the tributary reaches in DB’s

A, B and C that will receive CBNG water. Discharges range from 0.036 cfs (1 well) to 0.236 cfs 

(6.5 wells). Respective velocities are 0.5 to 1.2 ft/sec. Water depths in the channels for the same

cases are 0.26 and 0.78 inches. These estimates are comparable to Lowham’s mean annual flows 

and are less than 2% of the Q 1.5 estimates by Miller’s method. The project discharges are well

within the capacities of the existing drainages and should not contribute significantly to natural

erosional processes. 

Conveyance Loss 

Conveyance loss (CL) is the cumulative effect of evaporation, transpiration and infiltration on

surface water. Percolation tests (PT) were conducted at two sites in channels receiving water from

the project, one at PT 1 in Section 24 and one at PT 2 in Section 27. These points are shown by 

circles with labels on the Water Management Map. PT 1 resulted in a rate of 3.38 min/inch and PT 2 

was 1.68 min/inch. The test holes were presoaked overnight to allow for any clays that might be 

present to swell. The percolation rates from both of these tests are high. These rates were adjusted

to area in a 3 ft wide channel and units of bpd of loss per mile of channel. To account for channel 

width & sediment variation and the decrease in infiltration rates with increasing saturation, 1% of the 

CL rates estimated from the percolation tests were used for this analysis. These are 996 and 2012 

Appendix D 

8
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

bpd/mi of channel for PT 1 and PT 2, respectively. Losses to evaporation and transpiration were not 

added to this factor, but will be significant additional losses.

Table 10A shows the estimated flow distances down tributaries receiving CBNG water assuming a 

water rate of 550 bpd/well (0.036 cfs/well) and a loss rate of 1500 bpd/mi (0.097 cfs/mi). The 

maximum flow distance is 2.38 mi for reach 1 & 2 in DB C. Available reach lengths are also 

included in the table. In this scenario, no produced water will leave drainage basins A, B or C. 

Table 10B presents the results for a scenario where the discharge rate is 550 bpd/well (0.036 

cfs/well) and the loss rate is 750 bpd/mi (0.049 cfs/mi). The maximum flow distance is 4.77 mi in 

reaches 1 & 2 in DB C. Again, the water does not leave drainage basins A, B or C. 

Water Balance

Three water balance scenarios have been analyzed for the project and are presented in Tables 11a, 

11b and 11c. This includes 18 new CBNG wells in the pilot project plus 3 existing CBNG wells. 

The water balance does not include precipitation and the conveyance loss used in the water balance

does not include evaporation. To provide a conservative view, water production is held constant at 

initial rates and all wells begin production simultaneously. The two existing ponds are used; one 

taking 550 bpd and one taking 225 bpd. Table 11a is based on production of 550 bpd/well and a loss 

of 1500 bpd/mi. Table 11b uses production of 1200 bpd/well and loss of 1500 bpd/mi. Table 11c 

uses production of 550 bpd/well and loss of 750 bpd/mi. All three cases result in a net surplus loss 

capacity.

For the actual project, 18 wells will gradually be installed over a 3-year period; the water produced 

from the wells should decline with time; and evaporation will be a significant additional factor in

conveyance loss. All of these factors will result in less project water than that used in the water 

balance cases. 

Downstream Impacts 

The channels receiving CBNG water should have wetted surfaces below the downstream discharge 

points no further downstream than 3.7 mi in DB A, 2.2 mi in DB B and 4.8 mi in DB C. Project

flows will be much less than natural flows. Velocities for the project flows are less than 2 ft/sec and

most are less than 1 ft/sec. These velocities are below erosion thresholds. Impacts within the wetted

tributaries include possible minor initial erosion in some of the channels and a vegetation change to 

riparian species in close proximity to the channels. There are no irrigation activities in the area, so 

the SAR levels will not have significant impacts.

Erosion Control Plan 

Best management practices (BMP’s) will be used for erosion control and the diversion of overland 

flows away from all facilities. 

Appendix D 

9
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Monitoring & Mitigation 

Each discharge point will be monitored monthly for the first year of operation. Inspectors will note 

the condition of the discharge point, check for evidence of erosion and schedule any remedial work, 

if required. 

All pit/pond outlets and culverts will be checked quarterly, and after major storm events for the first 

year of operation. Inspectors will note the condition of the outlets and culverts, check for evidence 

of erosion and schedule any remedial work, if required. 

Channels receiving discharge water will be monitored monthly for the first year of operation in that 

channel. If accelerated erosion is noted (i.e., a vertical change of one ft or a lateral change of three

ft), the BLM will be notified and remedial work will be scheduled subject to BLM approval. The 

GPS locations of the downstream limits of the wetted channels will be documented as part of the 

inspection process.

After the first year of operation, inspections will only occur annually, unless specific sites have 

required remedial action. If the wetted limits of the channels are still moving downstream after one 

year, monthly monitoring and documentation will continue until the channels reach equilibrium.

LESSEE’S OR OPERATOR’S REPRESENTATIVE AND CERTIFICATION

I hereby certify that I, or persons under my direct supervision, have inspected the watershed area(s)

affected by our coal bed natural gas drilling and production plans; that I am familiar with the 

conditions that currently exist; that the statements made in this plan are, to the best of my 

knowledge, true and correct; and that the work associated with operations proposed herein will be

performed by Hudson Group, LLC and its contractors and subcontractors in conformity with this

plan and the terms and conditions under which it is approved. This statement is subject to the 

provisions of 18 U.S.C. 1001 for the filing of a false statement. 

Date August 2, 2004 

Name s/Kirk W. Hudson 

for Hudson Group, LLC 

Title Kirk W. Hudson, Petroleum Engineer

Appendix D 

10
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

Appendix D 

11

HUDSON GROUP, LLC 

SCOTTY LAKE CBNG PILOT PROJECT 

REFERENCES 

Advanced Resources International, Inc. 2002. Powder River Basin Coalbed Methane Development 

and Produced Water Management Study, Advanced Resources International, Inc., U.S 

Department of Energy, Office of Fossil Energy and National Energy Technology 

Laboratory

Bureau of Land Management. 2003a. Final Environmental Impact Statement and Proposed Plan 

Amendment for the Powder River Basin Oil and Gas Project, WY-070-02-065, U.S. 

Department of the Interior, Bureau of Land Management, Buffalo Field Office 

_____. 2003b. Surface Discharge of Produced Water from Picket Lake Unit Wells No. 1, No. 2, and 

No. 4. Bureau of Land Management, Rawlins Field Office. Rawlins, Wyoming. February 

2003. WY-030-03-EA-053 

Love, J.D. & Ann Coe Christiansen. 1985. Geologic Map of Wyoming, U.S. Geological Survey 

Lowham, H.W. 1988. Streamflows in Wyoming, Water-Resources Investigations Report 88-4045, 

U.S. Geological Survey 

Miller, K.A. 2003. Peak-flow Characteristics of Wyoming Streams, Water-Resources Investigations 

Report 03-4107, U.S. Geological Survey 

Welder, G.E. & L.J. McGreevy. 1966. Ground-water Reconnaissance of the Great Divide & 

Washakie Basins and Some Adjacent Areas, Southwestern Wyoming, Hydrologic Atlas HA219, U.S. Geological Survey 

Wyoming State Engineer’s Office (WSEO). 2004. Electronic water records compiled and 

maintained by the Wyoming State Engineer’s Office. Cheyenne, Wyoming. Information 

acquired via the Internet at website: http://seo.state.wy.us.
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

APPENDIX A: TABLES 

Appendix D 
Phase Well Name API No. QtrQtr Section Tshp. Range Lat. N, Dec. Long. W, Dec. Coal Dep

I Scotty Lake 9 APD Filed SE NW 24 26N 97W 42.2148 -108.3556 Tfu Scotty Lk 36I Scotty Lake 10 APD Filed SE NE 24 26N 97W 42.2149 -108.3455 Tfu Scotty Lk 36I Scotty Lake 11 APD Filed SE SE 24 26N 97W 42.2087 -108.3482 Tfu Scotty Lk 36I Scotty Lake 12 APD Filed SE SW 24 26N 97W 42.2087 -108.3543 Tfu Scotty Lk 36

II Scotty Lake 7 APD Not Filed NE NE 19 26N 96W 42.2162 -108.3242 Tfu Scotty Lk 36II Scotty Lake 22 APD Not Filed C SE 18 26N 96W 42.2182 -108.3241 Tfu Scotty Lk 36II Scotty Lake 23 APD Not Filed NW NW 20 26N 96W 42.216 -108.3144 Tfu Scotty Lk 36II Scotty Lake 24 APD Not Filed C SW 17 26N 96W 42.2179 -108.3123 Tfu Scotty Lk 36II Scotty Lake 25 APD Not Filed com. corner 17 18 19 20 26N 96W 42.2179 -108.3167 Tfu Scotty Lk 36

III Scotty Lake 8 APD Not Filed C com. line 14 23 26N 97W 42.2201 -108.3721 Tfu Scotty Lk 36III Scotty Lake 13 APD Not Filed NW SW 14 26N 97W 42.225 -108.3765 Tfu Scotty Lk 36III Scotty Lake 14 APD Not Filed NE NW 23 26N 97W 42.2166 -108.3757 Tfu Scotty Lk 36III Scotty Lake 15 APD Not Filed C SW 23 26N 97W 42.2091 -108.3764 Tfu Scotty Lk 36III Scotty Lake 19 APD Not Filed SE SE 22 26N 97W 42.2088 -108.3853 Tfu Scotty Lk 36III Scotty Lake 20 APD Not Filed C NE 22 26N 97W 42.2165 -108.3863 Tfu Scotty Lk 36III Scotty Lake 26 APD Not Filed C NE 23 26N 97W 42.2165 -108.3668 Tfu Scotty Lk 36III Scotty Lake 27 APD Not Filed C SE 14 26N 97W 42.2237 -108.3668 Tfu Scotty Lk 36III Scotty Lake 28 APD Not Filed SE SE 23 26N 97W 42.2074 -108.3646 Tfu Scotty Lk 36III Scotty Lake 16 APD Not Filed C com. Line 23 26 26N 97W 42.2057 -108.3716 Tfu Scotty Lk 36III Scotty Lake 17 APD Not Filed NW NW 26 26N 97W 42.2022 -108.3772 Tfu Scotty Lk 36III Scotty Lake 18 APD Not Filed C NE 26 26N 97W 42.2018 -108.3667 Tfu Scotty Lk 36

I Picket Lake 1 49-037-21309 NW SE 24 26N 97W 42.2119 -108.3509 Tfu Scotty Lk 36

---- Picket Lake 2 49-037-21388 SE NW 19 26N 96W 42.2149 -108.3355 Tfu Scotty Lk 36

III Picket Lake 4 49-037-21387 NW SE 23 26N 97W 42.2115 -108.3699 Tfu Scotty Lk 36

OPTIONAL WELLS

EXISTING WELLS

TABLE 1

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

PROJECT WELLS



Appropriation Township Range Section Quarter QtrQtr Head Gate- Outlet-Well Status Supply Type SW Permit Uses SW Permit Facility Name SW Permit Applicant SW Permit Priority 

Pe

Am

P1325R 26N 97W 3 9 NESW X ADJ ORI STO, DOM Lower Seven Lake Reservoir William Daley Co. 7/6/1908 P4935R 26N 97W 4 13 NESE X PUO ORI STO, IRR, DOM Third Lake Reservoir Arthur R. Carpenter 11/7/1938 1C29/289A 26N 97W 8 5 NENW X ADJ ORI ND ND ND ND P1332R 26N 97W 8 5 NENW X ADJ ORI STO, DOM Upper Seven Lake Reservoir Angus Murray 7/6/1908 P4934R 26N 97W 8 4 SENE X EXP ORI STO, IRR, DOM Second Lake Reservoir Arthur R. Carpenter 11/7/1938 21ND = No Data Available

TABLE 3 

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

SURFACE WATER RIGHTS
Permit # Priority Status Township Range Section QtrQtr Applicant Facility Name Uses Yld Act Well Depth Static Depth Mwbz Top Mwbz Bottom W

P49870W 7/16/1979 CAN 26N 96W 7 NWSW DAVIS OIL CO.**USDI, BLM MICHELLE FEDERAL #1 MIS ND ND ND ND ND P41983W 2/20/1978 CAN 26N 96W 8 SWSW

USDI, BLM**OGLE PETROLEUM, INC. JAKE #1 MIS 40 350 130 230 350 

P46938W 3/5/1979 CAN 26N 96W 17 SWSW DAVIS OIL CO.**USDI, BLM

#1 ZEPHYR FEDERAL WATER MIS 50 810 105 672 679 

P46336W 1/11/1979 CAN 26N 96W 18 Lot 8

DAVIS OIL COMPANY**USDI, BLM

PICKETT LAKE WATER WELL #3 MIS ND ND ND ND ND 

P46335W 1/11/1979 CAN 26N 96W 19 Lot 5

DAVIS OIL COMPANY**USDI, BLM

PICKETT LAKE WATER WELL #2 MIS ND ND ND ND ND 

P155777W 5/6/2003 GSI 26N 96W 19 Lot 3

USDI, BUREAU OF LAND MANAGEMENT**WILLIAM H. & SALLY JOLLEY PICKETT LAKE #2 STO ND ND ND ND ND 

36/9/246W 4/26/2004 UNA 26N 96W 19 SWNW HUDSON GROUP, LLC PICKET LAKE #2 CBM ND ND ND ND ND P46936W 3/5/1979 CAN 26N 96W 28 SENW DAVIS OIL CO.**USDI, BLM FLAT BUTTES UNIT #2 MIS ND ND ND ND ND P50167W 9/21/1979 CAN 26N 96W 28 SENW DAVIS OIL CO.**USDI, BLM FLAT BUTTE #1 MIS ND ND ND ND ND P49876W 7/16/1979 CAN 26N 96W 30 SENW

DAVIS OIL COMPANY**USDI, BLM PICKETT LAKE UNIT #7 MIS ND ND ND ND ND 

P62166W 7/20/1982 CAN 26N 96W 31 SESW

USDI, BLM**OGLE PETROLEUM INC. ATLAS #1 MIS 40 380 155 270 320 

P41981W 2/20/1978 CAN 26N 96W 31 SESW

ROCKY MOUNTAIN ENERGY COMPANY**USDI, BLM ATLAS #1 MIS 40 380 155 270 320 

P49009W 6/27/1979 CAN 26N 97W 4 SENE DAVIS OIL CO.**USDI, BLM SUN UNIT #1 MIS ND ND ND ND ND P51030W 2/4/1980 CAN 26N 97W 7 SWNE DAVIS OIL CO.**USDI, BLM SCOTTY LAKE UNIT #2 MIS ND ND ND ND ND P51032W 2/4/1980 CAN 26N 97W 12 NESW DAVIS OIL CO.**USDI, BLM PICKETT LAKE UNIT #10 MIS ND ND ND ND ND P98702W 4/4/1995 CAN 26N 97W 13 NESE

USDI, BLM** PRESIDIO EXPLORATION, INC. PICKET LAKE 40-13 WW MIS 90 600 210 460 530 

P49015W 7/3/1979 CAN 26N 97W 13 SWNE DAVIS OIL CO.**USDI, BLM PICKETT LAKE UNIT #5 MIS 50 532 200 472 480 P145371W 6/3/2002 GST 26N 97W 13 SWSE

HUDSON GROUP, LLC** USDI, BUREAU OF LAND MANAGEMENT

PICKET LAKE 40-13 WATER WELL STO, MIS 25 600 210 460 530 

P145384W 6/12/2002 GSI 26N 97W 13 SWNE

HUDSON GROUP, LLC** USDI, BUREAU OF LAND MANAGEMENT PICKET LAKE # 5 STO, MIS ND ND ND ND ND 

P49873W 7/16/1979 CAN 26N 97W 14 SWNE DAVIS OIL CO.**USDI, BLM PICKETT LAKE UNIT #9 MIS ND ND ND ND ND P46337W 1/11/1979 CAN 26N 97W 23 NWSE

DAVIS OIL COMPANY**USDI, BLM

PICKETT LAKE WATER WELL #4 MIS ND ND ND ND ND 

P155776W 5/6/2003 GST 26N 97W 23 NWSE

USDI, BUREAU OF LAND MANAGEMENT**WILLIAM H. & SALLY JOLLEY PICKETT LAKE #4 STO 20 600 350 ND ND 

36/8/246W 4/26/2004 UNA 26N 97W 23 NWSE HUDSON GROUP, LLC PICKET LAKE #4 CBM ND ND ND ND ND P156176W 5/6/2003 GST 26N 97W 24 NWSE WILLIAM H. & SALLY JOLLEY PICKETT LAKE # 1 STO 20 600 200 ND ND P43948W 6/16/1978 CAN 26N 97W 24 NWSE DAVIS OIL CO.**USDI, BLM

DAVIS PICKETT LAKE UNIT #1 WATER MIS 60 500 150 300 400 

TABLE 4

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

GROUND WATER RIGHTS
Permit # Priority Status Township Range Section Trot Applicant Facility Name Uses Yld Act Well Depth Static Depth Mwbz Top Mwbz Bottom W

P135633W 6/6/2001 GST 26N 97W 24 NWSE

HUDSON GROUP, LLC** USDI, BUREAU OF LAND MANAGEMENT

PICKET LAKE UNIT # 1 WATER WELL STO, MIS 20 500 150 300 400 

36/1/247W 4/26/2004 UNA 26N 97W 24 SENE HUDSON GROUP, LLC SCOTTY LAKE #10 CBM ND ND ND ND ND 36/10/246W 4/26/2004 UNA 26N 97W 24 NWSE HUDSON GROUP, LLC PICKET LAKE #1 CBM ND ND ND ND ND 36/2/247W 4/26/2004 UNA 26N 97W 24 SWSE HUDSON GROUP, LLC SCOTTY LAKE #11 CBM ND ND ND ND ND 36/6/246W 4/26/2004 UNA 26N 97W 24 SESW HUDSON GROUP, LLC SCOTTY LAKE #12 CBM ND ND ND ND ND 36/7/246W 4/26/2004 UNA 26N 97W 24 SENW HUDSON GROUP, LLC SCOTTY LAKE #9 CBM ND ND ND ND ND P49871W 7/16/1979 CAN 26N 97W 25 SWNE

DAVIS OIL COMPANY**USDI, BLM PICKETT LAKE UNIT #6 MIS ND ND ND ND ND 

P49872W 7/16/1979 CAN 26N 97W 26 SWNE

DAVIS OIL COMPANY**USDI, BLM PICKETT LAKE UNIT #8 MIS ND ND ND ND ND 

P53086W 7/16/1980 CAN 26N 97W 31 SWNE

DAVIS OIL COMPANY**USDI, BLM FAIR UNIT #1 MIS ND ND ND ND ND 

P3687P 12/31/1880 GST 26N 97W 32 SESW CORP. OLSON SISTERS OSBORNE SPRING #1 STO 7 10 -4 ND ND P3686P 6/10/1916 GST 26N 97W 36 NWSW

STATE OF WYOMING**CORP. OLSON SISTERS OLSON #1 DOM, STO 20 192 65 ND ND 

P83969W 10/1/1990 CAN 26N 97W 36 SWNW

WYO BOARD OF LAND COMMISSIONERS**WILLIAMH. JOLLEY CYCLONE WELL #1 STO ND ND ND ND ND 

ND = No Data Available

TABLE 4 - Continued

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

GROUND WATER RIGHTS
 Locations

Quarter Secs. Section Twnshp., N Range, W Latitude, DMS, N Long., DMS, W

1 SE NW 24 26 97 42 12 54.1 -108 21 19.9

2 SE SW 24 26 97 42 12 29.5 -108 21 13.7

3 SE SW 24 26 97 42 12 29.9 -108 21 17.3

4 SE NE 24 26 97 42 12 53.4 -108 20 42.7

5 NE SW SE 24 26 97 42 12 30.5 -108 20 56.6

6 NE SW SE 24 26 97 42 12 30.3 -108 20 58.0

7 SW SE SE 24 26 97 42 12 24 -108 20 50.6

8 NW SE NW 19 26 96 42 12 54.2 -108 20 12.2

9 SW NW SE 23 26 97 42 12 34.7 -108 22 11.8

10 SW NW SE 23 26 97 42 12 38.8 -108 22 14.6

11 E/2 NE SW 23 26 97 42 12 45.3 -108 22 19.7

12 SW NE NE 19 26 96 42 12 47.6 -108 19 29.9

13 NE NW SE 19 26 96 42 12 41.6 -108 19 32.3

14 C NW SE 19 26 96 42 12 39.5 -108 19 37.4

15 SW SE 19 26 96 42 12 28.6 -108 19 48.4

16 SW SW SE 19 26 96 42 12 26.4 -108 19 51.9

17 SW SW NE 23 26 97 42 12 50.0 -108 22 10.9

18 SW NE NE 24 26 97 42 12 00.9 -108 20 50.1

19 SW NW SE 24 26 97 42 12 38.4 -108 21 3.2

20 SW NE 19 26 96 42 12 55.6 -108 19 41.7

21 SW NE 19 26 96 42 12 53.8 -108 19 46.4

22 SE SE NW 19 26 96 42 12 49.0 -108 19 54.9

23 NE SW NE 19 26 96 42 12 52.4 -108 19 36.7

24 SE SW NW 20 26 96 42 12 46 -108 18 52

25 NW NE SW 20 26 96 42 12 41.9 -108 18 50.1

26 C SW 20 26 96 42 12 33.1 -108 18 50.9

27 NW NW 30 26 96 42 12 14.3 -108 20 20.6

28 NW SE 24 26 97 42 12 39.8 -108 20 59.4

29 SW NW 27 26 97 42 12 00.8 -108 23 55.7

30 NE NW 25 26 97 42 12 15.3 -108 21 57.7

31 NW NE NE 26 26 97 42 12 18.7 -108 21 56.4

32 SE SE SW 23 26 97 42 12 23.5 -108 22 21.4

33 NE NE NW 26 26 97 42 12 19.2 -108 22 19.8

34 NE NE NW 26 26 97 42 12 16.7 -108 22 18.3

35 SW NE 26 26 97 42 12 5.9 -108 22 5.3

36 SW SW NE 26 26 97 42 12 4 -108 22 12

37 NE NW NW 26 26 97 42 12 17.3 -108 22 41.2

38 NE SW SW 23 26 97 42 12 32.2 -108 22 38.8

39 NW SW 23 26 97 42 12 38.1 -108 22 41.7

40 NW SW 23 26 97 42 12 40.9 -108 22 42.7

41 NW NW SW 23 26 97 42 12 42.1 -108 22 46.6

42 NW NW SW 23 26 97 42 12 41.4 -108 22 50.4

43 C SE 22 26 97 42 12 32.3 -108 23 11.2

Obs. Pt.

TABLE 5

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

OBSERVATION POINT LOCATIONS
Discharge

Point # 

(Outfall)

Immediate

Receiving

Stream

Mainstem

Distance

from outfall 

to mainstem 

(stream

miles)

Quarter / 

Quarter Section Township Range

Latitude

(decimal

degree

format,

accuracy to 

nearest 5 

seconds)

Longitude

(decimal

degree format, 

accuracy to 

nearest 5 

seconds)

Project

Phase

001 ex Ephem. Trib. Red Creek 6.5 miles NW SE 24 26 97 42.21252 -108.34922 I EX 

002 Ephem. Trib. Red Creek 7.2 miles SW NE 24 26 97 42.21388 -108.34988 I 003 Ephem. Trib. Red Creek 6.9 miles SW NE 24 26 97 42.21538 -108.34883 I 004 Ephem. Trib. Red Creek 6.6 miles SE SW 24 26 97 42.20595 -108.35261 I 

006 ex Ephem. Trib. Red Creek 7.8 miles SE NW 19 26 96 42.21434 -108.33578 EX 

007/025 Ephem. Trib. Red Creek 7.8 miles NW SE 19 26 96 42.21194 -108.32625 II 

008 ex Ephem. Trib. Red Creek 8.0 miles NW SE 23 26 96 42.21085 -108.37110 III EX 

009 Ephem. Trib. Red Creek 6.7 miles NW NE 23 26 97 42.21639 -108.36830 III 010 Ephem. Trib. Red Creek 7.0 miles SE SE 14 26 97 42.22251 -108.36629 III 

013/026 Ephem. Trib. Red Creek 7.1 miles NE NW 23 26 97 42.21994 -108.37137 III 

014 Ephem. Trib. Red Creek 6.7 miles SE NW 23 26 97 42.21632 -108.37479 III 015 Ephem. Trib. Red Creek 6.0 miles NW SW 23 26 97 42.21131 -108.37973 III 016 Ephem. Trib. Red Creek 5.8 miles NW NE 26 26 97 42.20415 -108.37033 III 

(017) Ephem. Trib. Red Creek 5.5 miles SW NW 26 26 97 42.19961 -108.38068 III (018) Ephem. Trib. Red Creek 5.2 miles NW NE 26 26 97 42.20198 -108.36866 III 

019 Ephem. Trib. Red Creek 6.3 miles SW SE 22 26 97 42.20860 -108.38667 III 020 Ephem. Trib. Red Creek 6.6 miles SE NE 22 26 97 42.21440 -108.38573 III 021 Ephem. Trib. Red Creek 6.9 miles C SE 24 26 97 42.20847 -108.34865 I 022 Ephem. Trib. Red Creek 7.9 miles SW NE 19 26 96 42.21445 -108.32947 II 

023/024 Ephem. Trib. Red Creek 8.0 miles C W/2 20 26 96 42.21258 -108.31436 II 

TABLE 6

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

DISCHARGE POINTS
LOCATION

Twnshp, N Range, W

Lat, N dms Long, W dms

PL #1 SW NW SE 24 26 97 156 64 11 0.23 

42 12 38.4 -108 21 3.2

PL #4 E/2 NE SW 23 26 97 88 80 6 0.16 

42 12 45.3 -108 22 19.7

TABLE 7

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

PIT/POND SPECIFICATIONS

Pit/Pond Depth, ft Area, ac 

Qtrs. Sec Length, ft Width, ft
INPUT: High Desert

Drainage Basin Area, mi Lat. N, dd Geog. Factor Avg. Ann. Precip., in

A 6.51 42.1416600 0.65 9.8B 3.97 42.1378695 0.65 9.8

C 10.07 42.1218762 0.65 9.8

PEAK FLOW

ESTIMATES:

cfs

Drainage Basin A B C A B 

Q 1.5 16.7 12.3 22.2

Q 2 27.0 20.0 35.6 48.4 37.2 6

Q 2.33 33.1 24.7 43.5

Q 5 68.7 52.0 89.1 118 91.8 1

Q 10 110.7 84.8 142.1 185.3 144.8 2Q 25 180.5 139.9 229.5 301.8 238.0 3Q 50 245.2 191.6 309.7 405.2 321.0 4

Q 100 321.5 253.1 403.4 530.3 422.0 6Q 200 410.1 325.0 511.8 663.9 528.2 8Q 500 546.2 436.4 676.6 893.2 713.9 10

FOR CULVERTS:

cfs/sq mi

Q 10 17.00 21.35 14.11 28.47 36.48 2Q 25 27.72 35.24 22.79 46.36 59.96 3

 MEAN ANNUAL FLOW: 0.17 0.11 0

cfs

Miller, 2003 Lowham, 1988

TABLE 8

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

PEAK FLOW ESTIMATES
Drainage Basin Reach Channel Width, ft Gradient # Wells Velocity, ft/sec Discharge, cfs Water Depth, ft Water Depth, in

A 1 3 0.0183 1 0.5 0.037 0.023 0.28

2 4 0.017 5 0.9 0.179 0.051 0.613 2 0.0222 2 0.9 0.07 0.041 0.49

B EAST (3 & 4) 3 0.0225 3 0.9 0.107 0.041 0.49

WEST (1 & 2) 3 0.02 1 0.5 0.036 0.022 0.26

C EAST (4 & 5) 3 0.0178 3.5 0.9 0.128 0.049 0.59

WEST (1a & 1b) 3 0.024 6.5 1.2 0.236 0.065 0.78

FOR CBNG SURFACE WATER 

NO CONVEYANCE LOSS

TABLE 9

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

ESTIMATED VELOCITIES & DISCHARGE RATES
INPUT

LOSS FACTOR 1500 BPD/MI

0.097 CFS/MI

43.7 GPM/MI

WATER RATE/WELL 550 BPD

0.036 CFS

16.0 GPM

ASSUME EACH PIT TAKES THE PRODUCTION OF 1 WELL (2 PITS)

DRAINAGE BASIN CHANNEL REACH REACH LENGTH # WELLS DISCHARGE F

MI BPD CFS GPM 

A 1 1.3 0 0 0.000 0.0 

1 550 0.036 16.0 

2, 4, 5 & 6 7.2 2 1100 0.071 32.1 

5 2750 0.179 80.2 

3 1.83 2 1100 0.071 32.1 

B EAST (3 & 4) 3.13 3 1650 0.107 48.1 

1 550 0.036 16.0 

WEST (1 & 2) 5.15 1 550 0.036 16.0 

0 0 0.000 0.0 

C EAST (4 & 5) 9.05 3.5 1925 0.125 56.1 

WEST (1 & 2) 7.89 6.5 3575 0.232 104.3 

ANALYST: CSBDATE: 6/4/2004

TABLE 10a

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

FLOW DISTANCES IN TRIBUTARIES USING CONVEYANCE LOSS FACTOR
INPUT

LOSS FACTOR 750 BPD/MI

0.049 CFS/MI

21.9 GPM/MI

WATER RATE/WELL 550 BPD

0.036 CFS

16.0 GPM

ASSUME EACH PIT TAKES THE PRODUCTION OF 1 WELL (2 PITS)

DRAINAGE BASIN CHANNEL REACH REACH LENGTH # WELLS DISCHARGE 

MI BPD CFS GPM 

A 1 1.3 0 0 0.000 0.0 

1 550 0.036 16.0 

2, 4, 5 & 6 7.2 2 1100 0.071 32.1 

5 2750 0.179 80.2 

3 1.83 2 1100 0.071 32.1 

B EAST (3 & 4) 3.13 3 1650 0.107 48.1 

1 550 0.036 16.0 

WEST (1 & 2) 5.15 1 550 0.036 16.0 

0 0 0.000 0.0 

C EAST (4 & 5) 9.05 3.5 1925 0.125 56.1 

WEST (1 & 2) 7.89 6.5 3575 0.232 104.3 

ANALYST: CSBDATE: 6/4/2004

TABLE 10b

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

FLOW DISTANCES IN TRIBUTARIES USING CONVEYANCE LOSS FACTOR
 INFLOW excluding precipitation

Rate Total Annual flow Ann

bpd/well gpm/well cfs/well project flow volume flo

(cfs) (cu feet) (

21 Scotty Lake 550 16.0 0.036 0.755 23794091 

OUTFLOW

Estim

Estimated combined los

 evapotranspiration and seepage evaporati

Reservoirs Capacity Rate an

(acre-feet) (bpd) (gpm) (cfs) (

P #1 2.73 550 16.0 0.036 P #2 1 225 6.6 0.015 

Totals 3.73 775 22.6 0.051 

Estim

Tributaries Length Width Conveyance Loss conv

(mi) (ft) (bpd/mi) (gpm/mi) (cfs/mi) 

All in DB A, B & C 35.58 3 1500 43.7 0.098 

OUTFLOW - INFLOW = EXCESS CAPACITY

(acre-feet/yr) (acre-feet/yr) (acre-feet/yr)

2511 546 1965 TRIBUTARY LOSS ONLY2548 546 2001 TRIBS. & RESVS.

ANALYST: CSBDATE: 6/3/2004

# of wells Formation

550 BPD; 1500 BPD/MI

TABLE 11a

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

WATER BALANCE - DRAINAGE BASINS A, B & C
 INFLOW excluding precipitation

Rate Total Annual flow Annual pr

bpd/well gpm/well cfs/well project flow volume flow volu

(cfs) (cu feet) (acre-fe

21 Scotty Lake 1200 35.0 0.078 1.646 51914381 1192

OUTFLOW

Estimated a

Estimated combined losses du

 evapotranspiration and seepage evaporation, tra

Reservoirs Capacity Rate and seep

(acre-feet) (bpd) (gpm) (cfs) (acre-fe

P #1 2.73 550 16.0 0.036 26P #2 1 225 6.6 0.015 11

Totals 3.73 775 22.6 0.051 37

Estimated a

Tributaries Length Width Conveyance Loss conveyanc

(mi) (ft) (bpd/mi) (gpm/mi) (cfs/mi) (ac-ft

All in DB A, B & C 35.58 3 1500 43.7 0.098 2511

OUTFLOW - INFLOW = EXCESS CAPACITY

(acre-feet/yr) (acre-feet/yr) (acre-feet/yr)

2511 1192 1319 TRIBUTARY LOSS ONLY2548 1192 1356 TRIBS. & RESVS.

ANALYST: CSBDATE: 6/3/2004

# of wells Formation

TABLE 11b

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

1200BPD/WELL; 1500BPD/MI

WATER BALANCE - DRAINAGE BASINS A, B & C
 INFLOW excluding precipitation

Rate Total Annual flow Annua

bpd/well gpm/well cfs/well project flow volume flow 

(cfs) (cu feet) (acr

21 Scotty Lake 550 16.0 0.036 0.755 23794091 5

OUTFLOW

Estimat

Estimated combined losse

 evapotranspiration and seepage evaporation

Reservoirs Capacity Rate and s

(acre-feet) (bpd) (gpm) (cfs) (acr

P #1 2.73 550 16.0 0.036 P #2 1 225 6.6 0.015 

Totals 3.73 775 22.6 0.051 

Estimat

Tributaries Length Width Conveyance Loss convey

(mi) (ft) (bpd/mi) (gpm/mi) (cfs/mi) (a

All in DB A, B & C 35.58 3 750 21.9 0.049 1

OUTFLOW - INFLOW = EXCESS CAPACITY

(acre-feet/yr) (acre-feet/yr) (acre-feet/yr)

1255 546 709 TRIBUTARY LOSS ONLY1292 546 746 TRIBS. & RESVS.

ANALYST: CSBDATE: 6/3/2004

550 BPD/WELL; 750 BPD/MI

# of wells Formation

TABLE 11c

HUDSON GROUP, LLC

SCOTTY LAKE CBNG PILOT PROJECT

WATER BALANCE - DRAINAGE BASINS A, B & C
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

APPENDIX B: FIGURES 

Appendix D 


Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

APPENDIX C: PHOTOGRAPHS
Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

HUDSON GROUP, LLC 

SCOTTY LAKE CBNG PILOT PROJECT 

PHOTOGRAPHS

Observation Point Description

13 View down tributary to reach 4 near DP #7/25 in DB C; channel 

slope 3°, width 1 to 2’, depth < 1’ 

38 View down tributary to reach 2b near well #15 in DB A; slope 

2.4°, width 1 to 2’, depth < 1’ 

31 View up tributary to reach 3 in DB B south of well #28;slope 0.5°, 

width 3 to 4’, depth 0.5’ 

16 View up reach 4 in DB C; water is snowmelt; slope 1.5°, width 3 

to 4’, depth 1’ 

27 View up reach 4 in DB C; water is snowmelt; slope 0.5°, width 6’, 

depth 1.5 to 2’ 

42 View up reach 2c in DB A near DP #15; slope 1.2°, width 2 to 3’, 

depth 0.5’ 

29 View down reach 5 in DB A @ site of PT 2; slope < 1°, width 5 to 

6’, depth 1.5 to 2’ 

34 1 to 3’ head cut on tributary 3 in DB B, above DP #16 

18 5 to 6’ head cut on tributary 1a in DB C, above DP #3 

 8 DP #6 near well #2; perforated pipe in rip-rap blanket in channel 

10 Rip-rap inlet to recharge pond at well #4 

19 Stock pond at well #1 

USDI/BLM flowing well in Section 25, T23N, R96W:

a. Outlet from pond receiving well water 

b. Channel below pond outlet; width 1 to 2’, depth < 0.5’ 







Environmental Assessment of the Hudson Group, LLC Scotty Lake Coalbed Natural Gas Pilot Project

APPENDIX D: MAPS AND CHARTS