U.S. ENVIRONMENTAL PROTECTION AGENCY
POLLUTION/SITUATION REPORT
A&B No. 3 AUM - Removal Polrep
Initial and Final Removal Polrep
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Region IX
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Subject:
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POLREP #1
First and Final
A&B No. 3 AUM
A946
Cameron, AZ
Latitude: 35.8759568 Longitude: -111.4238129
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To:
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From:
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Jason Musante, OSC
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Date:
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8/25/2014
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Reporting Period:
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8/17/14 - 8/22/14
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1. Introduction
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1.1 Background
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Site Number: |
A946 |
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Contract Number: |
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D.O. Number: |
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Action Memo Date: |
7/9/2014 |
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Response Authority: |
CERCLA |
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Response Type: |
Time-Critical |
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Response Lead: |
EPA |
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Incident Category: |
Removal Action |
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NPL Status: |
Non NPL |
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Operable Unit: |
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Mobilization Date: |
8/17/2014 |
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Start Date: |
7/23/2014 |
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Demob Date: |
8/22/2014 |
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Completion Date: |
8/22/2014 |
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CERCLIS ID: |
NND983466731 |
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RCRIS ID: |
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ERNS No.: |
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State Notification: |
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FPN#: |
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Reimbursable Account #: |
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1.1.1 Incident Category
Site type: Mining (MI); subtype: Uranium Mining (UM)
1.1.2 Site Description
1.1.2.1 Location
The A&B No. 3 AUM (Site) is one of approximately 520 AUMs located on the Navajo Nation. The Site is a reclaimed surface mine covering approximately 22.5 acres located on tribal trust land of the Navajo Indian Reservation. The Site is located in the Cameron Chapter on the Navajo Nation Indian Reservation, Township 29 North, Range 9 East, Section 22, NW ¼ (Latitude: 35.8759567587 N, Longitude: -111.423812903 W), Coconino County, Arizona.
The land in the surrounding area is primarily rural, with residential structures and livestock grazing. The Site is immediately bounded to the north by the Little Colorado River, which is one of two major tributaries to the Colorado River. An associated drainage feature is located within ½ mile to the west of the Site. Surface water runoff from the Site flows directly into the Little Colorado River. Over 50 residential structures are located within ½ mile south of the Site and the closest is within 300 feet of the Site boundary. The Cameron Trading Post, a highly trafficked tourist stop, and U.S. Route 89 are approximately ½ mile to the east.
The mine was identified as being operational from 1954 to 1955. While operational, the mine had a total production volume of 586 tons.
1.1.2.2 Description of Threat
Surveys at the Site have identified elevated gamma radiation measurements attributable to uranium and its progeny (i.e., radium-226 and radon). Radium-226 and its progeny are listed hazardous substances pursuant to 40 CFR § 302.4, Appendix B. Erosion from rainfall and wind can cause these materials to migrate into the nearby Little Colorado River and nearby residential properties. Considering the proximity of nearby residents and public roadways, the Site represents a significant threat of release affecting nearby populations and direct exposure to trespassers.
1.1.3 Preliminary Removal Assessment/Removal Site Inspection Results
Screening assessment of the Site in November 2010 was documented in the Navajo Abandoned Uranium Mine Site Screen Report, dated January 2011, prepared by EPA-contractor Weston Solutions, Inc. A total of 11,884 gamma radiation measurements were collected from across the Site, ranging from 4,730 counts per minute (cpm) to 638,013 cpm. Many small waste piles were observed throughout the Site, with larger piles sloping towards the Little Colorado River. The measurements collected at the waste piles were found at maximum levels ranging from approximately 40,000 cpm to 640,000 cpm. The average measured background gamma radiation activity was 17,198 cpm.
Beginning in 2014, EPA Regional Navajo AUM Project Team staff conducted community involvement outreach and PRP-search activities to determine next steps for the Site. Nearby residents have expressed concern to the Navajo Nation Environmental Protection Agency (NNEPA) regarding the potential for direct exposure to radioactive materials at the Site. In the spring of 2014, it was requested that the Emergency Response Section help prevent potential exposures to contaminants at the Site. OSC Musante, Remedial Program staff, NNEPA Superfund staff, and the Navajo Nation Cameron Chapter President visited the Site and discussed installing signage to warn of the nearby hazards and discourage trespass.
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2. Current Activities
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2.1 Operations Section
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2.1.1 Narrative
2.1.2 Response Actions to Date
8/17/14 - 8/22/14
8/17: The ERRS contractor mobilized a Response Manager and a Tech to be ready to begin work on 8/18.
8/18: OSC Musante mobilized to the Site and met the ERRS contractor onsite. OSC Musante also met with Cameron Chapter President Milton Tso to inform him of the planned work. ERRS began augering postholes with a mini-excavator and discovered that rock units under the topsoil were not possible to penetrate with the equipment. A request to the equipment vendor for a heavier excavator was made. OSC Musante marked out locations for the warning signs around the perimeter of the Site.
8/19: A 10,000 pound excavator with a pneumatic hammer attachment was delivered to the Site. The ERRS personnel and OSC Musante completed the installation of 9 signs along the southern and eastern boundaries. CIC Amanda Pease visiteid the Site to observe progress. OSC Musante and CIC Pease met with representatives from the nearby Cameron Trding Post to delineate property boundaries. The Trading Post property is fee-land and directly adjacent to the Site.
8/20: Ten additional signs were installed along the southern and western boundaries. OSC Musante met with RPM Zizi Searles and Associate Director Clancy Tenley who were leading a tour of elected officials in the area. The group briefly observed the progress of sign installation and asked question related to the AUM work.
8/21: The final 6 signs were installed along the western boundary on 8/21. It was not necessary to install signs along the northern boundary as the Site terminates in this direction at a high cliff along the Little Colorado River. A total of 25 signs were installed around the boundaries of the Site.
8/22: ERRS and OSC Musante demobilized.
2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)
EPA has identified a PRP and is drafting an AOC to outline proposed actions to address contamination at the Site.
2.1.4 Progress Metrics
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Medium |
Quantity |
Manifest # |
Treatment |
Disposal |
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2.2 Planning Section
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2.2.1 Anticipated Activities
Install up to 40 signs around the perimeter of the Site to warn of hazards.
2.2.1.1 Planned Response Activities
-Mobilize personnel to the site,
-Take delivery of materials and equipment,
-Utilizing heavy equipment, auger post holes at designated location,
-Attach signs to posts,
-Install post/sign, backfill, and compact hole.
2.2.1.2 Next Steps
None at this time.
2.2.2 Issues
None at this time.
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2.3 Logistics Section
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No information available at this time.
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2.4 Finance Section
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No information available at this time.
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2.5 Other Command Staff
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No information available at this time.
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3. Participating Entities
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No information available at this time.
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4. Personnel On Site
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No information available at this time.
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5. Definition of Terms
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No information available at this time.
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6. Additional sources of information
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No information available at this time.
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7. Situational Reference Materials
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No information available at this time.
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