Attachment_7_-_PPNM_Stabilization_-_Appendix_F.pdf

APPENDIX F:

FINDING OF NO SIGNIFICANT IMPACTS: POMPEYS PILLAR

NATIONAL MONUMENT STABILIZATION

Pompeys Pillar National Monument Stabilization

DOI-BLM-MT-C010-2022-0002-EA

February 2022 Pompeys Pillar National Monument

3039 US Highway 312 Pompeys Pillar, MT 59064

Finding of No Significant Impact (FONSI)

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Introduction The Pompeys Pillar National Monument is undergoing natural processes that threaten the integrity of this National Historic Landmark as well as the safety of the public who visits the location every year. The geologic makeup of the Pillar (sandstone, shale, and siltstone) lends itself to degradation through wind, moisture, and temperature changes.

Professional consulting has resulted in proposed measures to address the site’s issues. These measures include scaling, foliage removal, drainage controls, stabilization or environmental protection for the shale and siltstone layer, buttressing at Signature Block, underpinning of Turtle Rock, and rock bolting at both Signature Block and Turtle Rock.

The purpose and need of this project is to address ongoing natural destabilization and degradation of the Pompeys Pillar National Monument and National Historic Landmark through remediation measures designed to stabilize the rock formation, prevent future degradation, manage the risk to the public, and allow for future enjoyment while maintaining the character of the site.

The selected alternative resulting from analysis is Alternative A which utilizes the following remedial measures to achieve protection of the Pillar:

Scaling Foliage Removal Top of Sandstone Drainage Control Shale and Siltstone Stabilization Buttressing at Signature Block Rock Bolting at Signature Block 1a Underpinning at Turtle Rock Rock Bolting at Turtle Rock

Finding of No Significant Impact Determination Based upon a review of the environmental assessment (incorporated herein by reference), and the supporting documents, I have determined that this project will not significantly impact the quality of the human environment. No environmental effects meet the definition of significance in 40 CFR 1501.3, and do not exceed those effects described in the 2015 Billings Field Office and Pompeys Pillar National Monument Approved Resource Management Plan. An environmental impact statement is not needed. This finding is based on the Potentially Affected Environment and Degree factors of the project as described below.

Potentially Affected Environment The potentially affected environment consists of the Pillar itself. Pompeys Pillar is both a National Monument and National Historic Landmark. The site is most famous for the inscription left by William Clark from the Corps of Discovery Expedition. After Clark left his name on the rock, various other travelers from fur trappers to homesteaders left their own inscriptions on the sandstone. Due to the nature of the sandstone, most, if not all, of the petroglyphs and pictographs postdate the 1700s, and even more visible elements postdate 1900. Because of these historically significant inscriptions and the site’s special status, it is a spot frequented by the public.

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The project will not adversely affect districts, sites, highways, structures, or other objects listed in or eligible for listing in the National Register of Historic Places, nor will it cause loss or destruction of significant scientific, cultural, or historical resources. Consultation with SHPO has been completed in accordance with Section 106 of the NHPA and they have concurred with a “no adverse effect” on cultural resources.

Although bald eagles occupy habitat over 0.6 miles from the project boundary, it has been determined that they will not be affected because the nest itself is screened from view of the Pillar by trees and therefore construction activities are not expected to effect courtship, breeding, or nesting behaviors of the birds. No other threatened or endangered plants or animals are known to occur in the area.

Degree of Effects Consider the following, as appropriate to the specific action. (40 CFR 1501.3 (b)(2))

1. Short- and long-term effects of the selected alternative None of the effects contribute to meeting the threshold for significance. The project is designed to meet the goals of stabilization and protecting the public’s well-being while meeting the management goals of the site. The Pillar will maintain its historic character as all design features are built to blend into the natural environment or be hidden away from public view.

2. Impacts may be both beneficial and adverse None of the environmental effects discussed in detail in the EA and associated appendices are considered significant. Overall, the project is expected to have beneficial impacts to the resource by preserving it for future generations while maintaining public safety. There is expected to be only slightly noticeable changes to the monument itself as nearly all measures are expected to be hidden from public view or blend into the natural environment. There will be a short-term disruption to the public viewing of the site during certain parts of the construction process in the interest of public safety.

3. The degree to which the selected alternative will affect public health or safety

Public safety is a key driver for doing the project. All measures aimed at stabilizing the monument will in turn help maintain and improve public safety. Due to the construction and design features, there is not expected to be an impact to public safety during the construction of this project. The TARP will continue to be implemented during and post construction.

4. Whether the action threatens a violation of a federal, state, local law or requirements imposed for the protection of the environment

The project does not violate any relevant/applicable federal, state, local or tribal law or requirement imposed for the protection of the environment. Federal, State, and local interests were given the opportunity to participate in the environmental analysis process (see Section 4 of the EA). Furthermore, letters were sent to potentially affected Tribes, State and Federal agencies, and organizations. No issues or concerns were brought up in this outreach.

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John Reffit Date Monument Manager Pompeys Pillar National Monument

JOHN REFFIT Digitally signed by JOHN REFFIT Date: 2022.02.17 14:46:15 -07'00'

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