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Notice of Availability of the Draft Environmental Impact Statement for the Riley Ridge to Natrona Project, Wyoming

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Bureau of Land Management, Interior.


Notice of availability.


In compliance with the National Environmental Policy Act of 1969 (NEPA), as amended, and the Mineral Leasing Act of 1920 (MLA), as amended, the Bureau of Land Management (BLM) Rock Springs Field Office has prepared a Draft Environmental Impact Statement (EIS) for the Riley Ridge to Natrona Project (RRNP or Project) and by this Notice announces the beginning of public review to solicit public comments.


The Draft EIS is now available for public review. To be considered in the Final EIS, written comments on the Draft EIS must be received within 45 days after the Environmental Protection Agency's publication in the Federal Register of a Notice of Availability (NOA) of this Draft EIS.

Four public open houses for the proposed Project will be held in Big Piney, Rock Springs, Lander, and Casper, Wyoming. Meeting times and locations will be announced through local media and the BLM Project website at​2aW727l at least 15 days prior to the event. To be considered in the analysis, all comments must be received prior to the close of the public comment period or 15 days after the last public meeting, whichever is later.


The Draft EIS and supporting documents will be available electronically on the following BLM website:​2aW727l.

Written comments may be submitted by any of the following methods:

  • Email:
  • Fax: 307-352-0329.
  • Mail or Delivery: BLM High Desert District, Attn: Mark Mackiewicz, BLM National Project Manager, Riley Ridge to Natrona Project, 280 Highway 191 North, Rock Springs, WY 82901.

Copies of the Draft EIS may be examined at the following BLM offices from 7:45 a.m. to 4:30 p.m. MDT, Monday through Friday, except Federal holidays:

  • BLM Rock Springs Field Office, 280 Highway 191 North, Rock Springs, Wyoming.
  • BLM Pinedale Field Office, 1625 West Pine Street, Pinedale, Wyoming.
  • BLM Rawlins Field Office, 1300 N. Third Street, Rawlins, Wyoming.
  • BLM Lander Field Office, 1335 Main Street, Lander, Wyoming.
  • BLM Casper Field Office, 2987 Prospector Drive, Casper, Wyoming.
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Mark Mackiewicz, BLM National Project Manager, at:

Persons who use a telecommunications device for the deaf (TDD) may call the Federal Relay Service (FRS) at 1-800-877-8339 to speak with Mr. Mackiewicz during normal business hours. The FRS is available 24 hours a day, 7 days a week, to leave a message or question for the above individual. You will receive a reply during normal business hours.

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The BLM is responding to three applications for right-of-way (ROW) grants submitted by Denbury Green Pipeline-Riley Ridge, LLC (Denbury) and PacifiCorp, doing business as Rocky Mountain Power (collectively referred to as the Applicant), to the BLM for the Project. Denbury submitted an “Application for Transportation and Utility Systems and Facilities on Federal Lands” (Standard Form 299) to the BLM for two underground pipeline projects: (1) The Riley Ridge Carbon Dioxide (CO2) Pipeline Project (WYW-167867) and (2) the Bairoil to Natrona CO2 Pipeline Project (WYW-168290). In addition, Denbury has proposed two hydrogen sulfide (H2 S) injection wells (WYW-181373) to be sited near the proposed Riley Ridge Sweetening Plant, which is included in the Riley Ridge CO2 Pipeline Project application. PacifiCorp submitted an application for ROW for a 230-kilovolt (kV) transmission line (WYW-185369) to supply energy to the Riley Ridge Sweetening Plant. The applications for ROW grants for Denbury's Proposed Action were submitted to the BLM on February 19, 2013 (Denbury), and January 25, 2016 (PacifiCorp); the proposal for the injection wells was submitted to the BLM on September 12, 2013. Collectively, the Project consists of the following components (as proposed):

  • An underground non-gaseousH2 S/carbon dioxide (CO2) pipeline from the existing Riley Ridge Treating Plant (a methane and helium recovery facility) to the proposed Riley Ridge Sweetening Plant, consisting of 31 miles of 16-inch-diameter pipe within Sublette County;
  • A CO2 underground pipeline from the proposed Riley Ridge Sweetening Plant to the Bairoil Interconnect, consisting of 129 miles of 24-inch-diameter pipe, and continuing from the interconnect another 84 miles to the terminus at the Natrona Hub within Natrona County;
  • The 4.3-acre proposed Riley Ridge Sweetening Plant, located on BLM-administered lands, constructed and operated to separate the CO2 from the H2 S; the H2 S would be reinjected into deep geologic formations via two proposed injection wells;
  • An approximately 1-mile-long 230 kV overhead transmission line that would bring power to the Riley Ridge Sweetening Plant from an existing 230 kV transmission line; and
  • Ancillary facilities, such as roads, valves, flowlines, etc.

After reviewing the scope of the Project, the BLM, as the lead Federal agency, determined that the Proposed Action is a major federal action and would require preparation of an EIS in compliance with requirements of NEPA, as amended by the Council on Environmental Quality regulations for implementing NEPA (40 CFR 1500-1508).

On June 9, 2014, the BLM published in the Federal Register a Notice of Intent to prepare the EIS. Thirteen agencies are participating as cooperating agencies in preparation of the EIS, including the U.S. Fish and Wildlife Service (USFWS), the National Park Service and the U.S. Army Corps of Engineers (USACE); the State of Wyoming (and associated departments); Fremont, Lincoln, Sublette, Sweetwater, and Natrona counties, Wyoming; and four conservation districts, Natrona County, Popo Agie, Sublette County, and Sweetwater County, in Wyoming. To allow the public an opportunity to review the Project information, the BLM held public meetings from July 14 to July 17, 2014, in Casper, Lander, Big Piney, and Rock Springs, Wyoming. Issues and potential impacts on specific resources were identified during the Start Printed Page 12811scoping and preparation of the Draft EIS.

In the preparation of the Draft EIS and in consideration of scoping comments, an initial evaluation was made of a full range of alternatives. All reasonable alternatives were considered, including one route variation to accommodate avoidance of conflict with existing oil and gas development. Alternative routes that were (1) ineffective (i.e., did not meet the agency's purpose and need), (2) technically or economically infeasible, (3) inconsistent with the basic policy objectives of the management of an area (e.g., land-use plans), (4) remote or speculative (i.e., could not be analyzed), or (5) substantially similar in design or effects to another alternative being analyzed were eliminated from further consideration. The alternative routes considered and eliminated based on screening are briefly described below:

  • Route Option E: South Pass. This route option was eliminated from further review because it was inconsistent with basic policy objectives. This route option crosses an exclusion area within the Lander Field Office, a national historic landmark, a Visual Resource Class II area, a sage-grouse core area, and four National Historic Trails that share the same alignment (crossed three separate times). Also, the route would be inconsistent with the Green River Field Office Resource Management Plan (RMP), as amended by the Jack Morrow Hills Coordinated Activity Plan (Rock Springs Field Office). In May 2015, Sweetwater County submitted a letter stating the county's preference for Alternative Route E and requesting that the BLM analyze the route in detail in the EIS. However, due to the reasons listed above, the BLM has determined the route is not feasible, therefore, the route remains eliminated from detailed analysis.
  • Route Variation: Poison Spider Road. This route variation was eliminated because it would be technically infeasible. The route would be congested with multiple rights-of-way, would have limited space for new infrastructure, and would result in substantial challenges for constructability and reclamation.
  • Route Option F: Beef Gap. This route option was eliminated because the corridor is considered closed in the Lander Field Office RMP because development within the Black Rock designated corridor would not be feasible due to geological resource conflicts (specifically no additional room to site a utility in this corridor).

In addition to these pipeline alternative routes, an aboveground crossing of the pipeline at the Green River was considered as a design alternative to avoid environmental effects on water quality and associated impacts on wildlife and fish if a leak in the pipeline were to occur. However, the CO2 that would be carried by the pipeline would be in “supercritical” form, which, in the case of a leak, would immediately become a gas and would disperse into the atmosphere. The CO2 would turn into a gas quickly. While no contamination of water resources would be anticipated, atmospheric release of large quantities of CO2 would be a larger hazard to health and safety given that CO2 is an asphyxiant. Further, its release may lead to lower temperatures in operations of structures and instrumentation outside of their design temperatures. The Applicant proposes to use horizontal directional drilling (HDD) to install the pipeline underneath the Green River at a depth of at least 30 feet below the river bed. The entry and exit points for HDD would be at least a quarter mile from either side of the Green River. Because the design alternative would be ineffective in avoiding or reducing resource effects and inconsistent with the basic policy objectives of the management of the area, it was eliminated from detailed analysis.

In addition to the Applicant's Proposed Action Alternative, the Draft EIS considers the No Action Alternative, five alternative routes, and one route variation in three Project segments. For this Draft EIS, the No Action Alternative means that the BLM ROW authorization for the Project to cross Federal lands would not be granted and the pipelines and associated facilities would not be constructed.

The BLM, in coordination with the cooperating agencies, developed the Agency Preferred Alternative (APA) through a comparative evaluation of routing opportunities and constraints and relative potential impacts among the various alternative routes. Through a systematic analysis, the alternative routes were compared to determine the most environmentally acceptable routes to be addressed in the EIS and to select the APA on Federal lands. The APA on Federal lands is the alternative route that the BLM, in coordination with the cooperating agencies, believes would fulfill its statutory mission and responsibilities, considering economic, environmental, technical, and other factors.

The APA is a recommendation derived from currently available information and is not a decision. The APA for this Project consists of the following alternative in each segment:

  • Segment 1: Alternative 1C: Figure Four. This is an alternative to the Alternative 1A: Proposed Action route in the Pinedale and Rock Springs Field Offices and is approximately 38 miles in length. This alternative route follows the same alignment as Alternative 1B: Dry Piney but continues farther south along State Highway 235, cuts east crossing U.S. Highway 189 north of the Town of La Barge, and connects to the proposed Riley Ridge Sweetening Plant. This alternative route follows existing disturbance and is anticipated to minimize potential effects on wildlife more than the other alternative routes being considered in this segment.
  • Segment 2: Alternative 2A: Proposed Action. This route is approximately 129 miles of 24-inch pipeline, which would transport the CO2 from the Riley Ridge Sweetening Plant eastward. The route travels east through southern Sublette County crossing into northern Sweetwater County. It continues southeast across Bush Rim and into the Red Desert and then turns northeast until it reaches the Bairoil Interconnect about 50 miles northwest of Rawlins, Wyoming.
  • Segment 3: Alternative 3B: Lost Creek to Lost Cabin. This is an alternative to the Alternative 3A: Proposed Action route in the Lander Field Office and is approximately 73 miles in length. This alternative heads northeast from the Bairoil Interconnect crossing U.S. Highway 287 and parallels the Proposed Action route until it crosses State Highway 136. The alternative route continues north near Moneta, Wyoming, and ties into the Lost Cabin Interconnect near Lost Cabin, Wyoming. This alternative route was developed to use a utility corridor designated in the Approved RMP for the Lander Field Office and to tie into the Greencore Pipeline at Lost Cabin instead of the Natrona Hub.

The BLM is inviting the public to offer comments on the APA, as well as the other alternative routes and route variations presented in the Draft EIS document.

Ongoing consultations with Native American tribes will continue in accordance with policy, and tribal concerns, including impacts on Indian trust assets, will be given due consideration. Federal, state, and local agencies, along with other stakeholders that may be interested in or affected by the BLM decision on this Project, are invited to participate.

Input is important and will be considered in the environmental analysis process. All comment Start Printed Page 12812submissions must include the commenter's name and street address. Comments, including the names and addresses of the commenter, will be available for public inspection at the locations listed above during normal business hours (7:45 a.m. to 4:30 p.m. Mountain Daylight Time), Monday through Friday, except Federal holidays.

Comments on the Draft EIS may be submitted in writing to the BLM at any public comment meeting or through one of the methods listed in the ADDRESSES section. The BLM requests that comments be structured so they are substantive and contain sufficient detail to allow the BLM to address them in the Final EIS. All comments must include a legible full name and address on the envelope, letter, fax, postcard, or email. Copies of the Draft EIS have been sent to affected Federal, State, and local governments; public libraries in the Project area; and interested parties that previously requested a copy.

Before including your address, phone number, email address, or any other personal identifying information in your comment, you should be aware that your entire comment—including your personal identifying information—may be made publicly available at any time. While you may request in your comment that your personal identifying information be withheld from public review, we cannot guarantee that we will be able to do so.

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Authority: 40 CFR 1501.7.

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Mary Jo Rugwell,

State Director.

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[FR Doc. 2018-05858 Filed 3-22-18; 8:45 am]