SRA Letter to County Officials re: Slope Stability and Hazard

April 28, 2021, 5:58 p.m.

Sent to Hal Hart and Lisa Janicki

Hal and Lisa, 

I have attached a record of the documents that we have been able to find regarding the very significant concern of destabilization of the approximately 800 foot nearly vertical rock face (slope destabilization) from further mining activity. 

As you can see from this record of documents, this concern has been repeatedly identified by both Skagit County Planning and Development Services (SPDS) and Washington State Department of Natural Resources (DNR). Both SPDS and DNR have repeatedly conditioned any further mining activity on a thorough geotechnical slope stability study and a plan for mining operations which minimizes the potential of slope destabilization.

Immediately after Kiewit withdrew their mining application to SPDS on September 6, 2019, Cunningham Crushing notified SPDS that they intended to "commence mining activities". Among other permitting requirements, SPDS again reminded Cunningham Crushing of the requirement for a geotechnical slope stability study. 

As explained by DNR, the slope stability study requirement comes from the complex structural nature of the site coupled with a mining plan which proposes removal of slope restraining force (talus) as the initial phase of mining. DNR also determined that the study must detail the geologic structure of the site, map and analyze the joint sets for adverse bedding conditions, address how mining operations will affect slope stability, and if applicable, give recommendations for mining operations which minimize the potential of slope destabilization.

We are not aware of DNR either requesting or receiving this study. 

Has SPDS received this study as was requested? If so please provide us with a copy.

As you are aware from your history of involvement at this site, this is a very serious safety concern for workers, neighbors, and the public on Rockport Cascade Road.

Thanks for your attention and concern.

Jose Vila
Skagit River Alliance

 
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MAKE SOME NOISE!
You can send concerns to
-Responsible Official: Casey R. Hanell, State Geologist and Director, 1111 Washington St. SE, Olympia, WA 98504, 360-902-1439, [email protected]
-Rian Skov, chief reclamation geologist, 360.704.0963, [email protected]
-Joe Smillie, communications manager, cell 360.688.3392, [email protected]
-Hillary Franz, Commissioner of Public Lands: [email protected]
-Ana Shafer, Assistant State Geologist, Assistant Director of Surface Mine Reclamation, 253-569-2307
-Hal Hart, Director of Skagit County Planning and Development, 360-416-1328 direct, 360-416-1320 main desk, [email protected]

 

Big Bear Mountain Geologic Slope Stability Considerations History

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Old timers who have lived here their whole lives are very familiar with the big faults and fractures on the back side of the more than 900 foot tall (above ground level) rock wall. They say one large fault running parallel behind the face is about 1-2 feet wide at the top and goes all the way down to the bottom. Their parents warned them not to play up there for fear they would never be seen again if they fell in. This is also the basis for DNR’s slope stability concern should the slope restraining force (the ancient talus formation) be removed causing the slope (the rock wall) to become destabilized.

DNR has repeatedly identified this concern and conditioned any further mining activity on a thorough geotechnical slope stability study detailing the geologic structure of the site, addressing how mining operations will affect slope stability and, if applicable, give recommendations for mining operations which minimize the potential of slope destabilization. Skagit County Planning and Development has repeatedly called for this study. Kiewit acknowledged this concern and agreed to complete the study as required by SPDS and DNR, but abandoned their proposed operation before undertaking it.

For this latest proposal, SPDS has reminded the applicant that the geotechnical study is still required (Item 8 below), but for unexplained reasons DNR is ignoring this extremely significant operational, neighborhood, and roadway safety issue. DNR has so far refused to address this concern and explain how the proposed mining operation to remove the entire 300’ high talus formation estimated at 1.2 million tons will be conducted safely and minimize the potential of slope destabilization. Without further removal of the slope restraining force (talus) the rock wall has been determined by DNR to present little risk to human health or the environment.

The timeline below provides some of the history of this issue for context. _____________________________________________________________________________________________________

DNR Records of an earlier attempt to mine the site and records of unpermitted operations 1. June 6, 2011, Rian Skov, DNR to Ryan Bradley, Merit Engineering, RE Marblemount Quarry Technical Assistance Visit

Ryan: Thank you for meeting John Bromley and I at your client’s proposed quarry site. After discussing the proposed mining plan; to remove talus material as the initial phase, followed by quarrying rock from the hillside; and observing the site geology, the Department of Natural Resources (DNR) determined that a thorough geotechnical slope stability study will be required along with the standard materials for a reclamation permit application (SM-8A form, SM-6 form signed by Skagit County, Map set, Narrative and $2500 application fee) if mining is to be conducted on site. The slope stability study requirement comes from the complex structural nature of the site coupled with a mining plan which proposes removal of slope restraining force as the initial phase of mining. The study must detail the geologic structure of the site, address how mining operations will affect slope stability and, if applicable, give recommendations for mining operations which minimize the potential of slope destabilization.

2. September 17, 2011, Bill Griffith letter to Rian Skov, DNR
Dear R(i)an, I am writing to you to provide a record of our conversation regarding my concerns about what appears to be

unsafe mining practices taking place at the quarry on parcel P45543 in Skagit County.

On a visit to the site I observed what appeared to be an unsafe mining operation. I came to this conclusion through observation and from some information disclosed by the operator of the quarry. As you know the quarry is at the base of a steep rock wall. Over time rocks have fallen off the mountain to the valley below. The operator is allowed to break up rocks that have fallen down the mountain up to a height of 30 feet. The mountain I am told by the operator has a fissure about two feet wide at the summit. He said that an old timer in the area recalled that when he was a child the fissure was only a foot wide.

Here are my main safety concerns, not only for the operator but to all those who travel on the Rockport Cascade Rd.

  1. The entire rock face is geologically unstable due to the widening fissure.

  2. Undermining the rock face (talus formation) to a height of 30 feet will loosen the boulders that have lodged at least

    temporarily above 30 feet.

  3. A road that has been built to reach the higher boulders allows the tracked rock crusher to transmit its vibrations further up

    the mountain beyond the 30 foot height restriction.

____________________________________________________________________________ Kiewit Marblemount Quarry

3. November 21, 2018, Element Solutions, Project Issues or Key Questions for Marblemount Jetty Rock Quarry Project Pre- Application Meeting

1. We are planning to include the following technical studies with our application: o Geotechnical Report/Slope Stability Analysis

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4. April 23, 2019, John Bromley, DNR email to Karen Marks

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Ms. Marks, The Marblemount Quarry doesn’t currently have a Surface Mine Reclamation permit. I have been to the site several times since early 2004 and was told by a previous DNR Inspector that the permit had been terminated sometime in the past. I have not reviewed the terminated file for details.

The rock wall at the site is jointed and fractured, I believe the letter you refer to from 2011 describes these features and potential risk to miners should mining resume. However, the rock wall is a good distance away from the road and I would say that under static conditions drivers on the Rockport Cascade Road are not at risk. DNR has requested that the joint sets be mapped and analyzed for adverse bedding conditions as supporting documentation for a Surface Mine permit
application. Thanks for your inquiry.

5. January 15, 2019, Kiewit, Marblemount Quarry, Geologically Hazardous Area Report, February 8, 2019, Element Solutions, Geologically Hazardous Areas (SCC 14.24.400)

Page 3, Section 1.4

SCC regulates Geologically Hazardous Areas through Title 14, Chapter 14.24, and Article 4 – Geologically Hazardous Areas. General “Geologically Hazardous Areas” as defined in Section 14.24.400 of the SCC are described in the following statement:

“Geologically hazardous areas shall be designated consistent with the definitions provided in WAC 365-190-080(4). These include areas susceptible to the effects of erosion, sliding, earthquake, or other geologic events. They pose a threat to the health and safety of citizens when incompatible residential, commercial, industrial, or infrastructure development is sited in areas of a hazard. Geologic hazards pose a risk to life, property, and resources when steep slopes are destabilized by inappropriate activities and development or when structures or facilities are sited in areas susceptible to natural or human- caused geologic events. Some geologic hazards can be reduced or mitigated by engineering, design, or modified construction practices so that risks to health and safety are acceptable. When technology cannot reduce risks to acceptable levels, building and other construction in, above and below geologically hazardous areas should be avoided.”

Page 5, Section 1.4 Geologically Hazardous Areas Designation and Applicable Code, Mine Hazard Areas

SCC 14.24.410(5) states that Mine Hazard Areas are “as designated on the Department of Natural Resources Map: Coal Measures of Skagit County (1924) or within 200 feet of any other current or historic mine operations determined to be a suspect or known geologically hazardous area by the Administrative Official.”

In SCC 14.24.430, Skagit County has defined a series of requirements which apply to all development activities occurring within Geologically Hazardous Areas. The requirements include a mitigation plan prepared by an environmental professional describing the proposed project and discussing the design measures being utilized to avoid and minimize impacts to the Critical Areas described above. Mitigation plans must include “the location and methods of drainage, locations and methods of erosion control, a vegetation management and/or restoration plan and/or other means for maintaining long-term stability of geologic hazards.”

In addition, the plan should also address “the potential impact of mitigation on the hazard area, the subject property and affected adjacent properties.” Mitigation plans must be approved by the Administrative Official, and must be implemented as a condition of project approval.

Page 12, Section 2.7 Limitations

No subsurface evaluation or bedrock mechanics analyses were performed in this assessment, and as such all conditions below grade are inferred from surficial topographic indicators, exposed geology, and visual observation of several shallow hand dug test pits and soil probing (= 24 inches below ground surface). The bedrock cliffs could not be visually inspected at the time of the site assessment due to physical access limitations; the cliffs are too steep to ascend/descend from the subject parcel without technical rigging. In recognition of the reasonable feasibility constraints of this assessment, no warrantee regarding the competency, composition, or quality of any geologic

site characteristic that was not directly evaluated is expressed or implied by this communication.

Appendix A, Shannon and Wilson Rockfall Hazard Study, page 3 of 9

1. The reconnaissance visit did not include geologic mapping, evaluation of rock mass structural conditions, or slope stability evaluations. Our observations are summarized below.

6. January 22, 2019, Kiewit, Marblemount Quarry, SEPA Environmental checklist (WAC 197-11-960)

A Conditional Use Permit (CUP) for operation of a rock quarry was approved by Skagit County Planning and Development Services and the Skagit County Board of Adjustment on May 11, 1982. The CUP was approved for small-scale mining of the existing talus field and limited hauling. An associated Forest Practice Conversion was approved in 1990. Pursuant to SCC

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14.16.440(3)(c), an expansion of mining operations triggers the need for a new SUP. Skagit County has determined that the mining of the site combined with increased traffic volumes constitutes an expansion of use. Therefore, a new SUP is needed.

7. April 23, 2019, Kiewit Marblemount Quarry, John Bromley, DNR email to Karen Marks

Ms. Marks, The Marblemount Quarry doesn’t currently have a Surface Mine Reclamation permit. I have been to the site several times since early 2004 and was told by a previous DNR Inspector that the permit had been terminated sometime in the past. I have not reviewed the terminated file for details.

The rock wall at the site is jointed and fractured, I believe the letter you refer to from 2011 describes these features and potential risk to miners should mining resume. However, the rock wall is a good distance away from the road and I would say that under static conditions drivers on the Rockport Cascade Road are not at risk. DNR has requested that the joint sets be mapped and analyzed for adverse bedding conditions as supporting documentation for a Surface Mine permit
application. Thanks for your inquiry. ___________________________________________________________________________________________________

Cunningham Crushing, Cascade Big Bear Mine
8. September 15, 2019, Hal Hart, Skagit County Planning and Development Services, letter to Cunningham Crushing

Dear John and Ann Parker,

Thank you for your notice to commence mining activities on parcel P45543 as per condition 2 of conditional use permit #12- 76, auditors file # 8205110031. Your notice has been forwarded to the County Engineer, Mr. Paul Randall Grutter, Engineering Division of Skagit County Public Works, for his review.

Please be sure that your mining operations comply with all provisions and conditions of Skagit Countys conditional use permit #12-76. The Washington Department of Natural Resources has indicated that a reclamation plan is required for mining the talus slope and a geotechnical report shall be submitted with the reclamation plan to evaluate the rock fall risk resulting from the Talus slope mining operations. Please be sure that your mining operations complies with all the mining, permitting and regulatory requirements of the State of Washington, including the Washington Department of Natural Resources and the Washington Department of Ecology.

If you have any questions regarding this matter, please contact my office at (360) 416-1328. Sincerely,

Hal Hart, Director
Skagit County Planning and Development Services

9. August 6, 2020, Cunningham Crushing, Cascade Big Bear Mine, Cascade Big Bear Mine, SEPA Environmental Checklist

Page 3 of 18

A.11 - Give brief, complete description of your proposal, including the proposed uses and the size of the project and site.

The 38-acre Cascade Big Bear Mine operations plan is for removal of the talus that has accumulated at the foot of a nearly vertical rock face that rises approximately 800 feet above the elevation at the toe of the talus.

Page 5 of 18, B.1.d
Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. A summary of the geologic setting for the Cascade Big Bear Mine is attached as Appendix A.

Soils are the mine floor are flat and stable. The talus deposition at the base of the mine’s rock face of Shuksan Greenschist is the result of historic rockfall. This rockfall may continue to occur periodically (Appendix A). Isolated rockfall is a natural geologic process, and in the absence of development, presents little risk to human health or the environment. The presence of shallow, competent bedrock across the site suggests a low probability of significant rockfall.

No modification to or disturbance of the mine’s rock face is included in the mining plan. The proposal, therefore, would not result in increased instability.

10.August 6, 2020, Cascade Big Bear Mine, Geo Report, April 10, 2020, Impact Design, Geologic Conditions Summary Page 4, Section 1.2 Topography

A talus apron below the cliff is about 300 feet high at the base of the cliff. The talus slopes about 35 to 40 degrees and includes boulders up to about 40 feet in diameter.