|
1. Introduction
|
|
|
1.1 Background
|
|
|
|
|
Site Number: |
09SY |
|
Contract Number: |
EP-W-07-022 |
|
D.O. Number: |
022-9075 |
|
Action Memo Date: |
9/27/2010 |
|
Response Authority: |
CERCLA |
|
Response Type: |
Time-Critical |
|
Response Lead: |
EPA |
|
Incident Category: |
Removal Action |
|
NPL Status: |
Non NPL |
|
Operable Unit: |
|
|
Mobilization Date: |
3/28/2011 |
|
Start Date: |
11/1/2010 |
|
Demob Date: |
|
|
Completion Date: |
|
|
CERCLIS ID: |
|
|
RCRIS ID: |
|
|
ERNS No.: |
|
|
State Notification: |
|
|
FPN#: |
|
|
Reimbursable Account #: |
|
Please see POLREP #1 for additional Site Background information.
|
|
2. Current Activities
|
|
|
2.1 Operations Section
|
|
|
|
2.1.1 Narrative
2.1.1.1 Current Situation
The main activity has been installation of the HDPE top liner and the soil cap over it. Top liner installation was delayed a few days due to the subcontractor, but has been completed. The ERRS contractor completed installation of soil cap material over the HDPE liner and began installation rock “bio-barrier” over the soil cap. The “bio-barrier” is a layer of rock that will prevent animals and plant roots from breaching the top liner due to burrowing activity. ERRS continues restoration activities and preparation of equipment for demobilization. Completion of all Site activities is anticipated during the week of October 17th.
September 26 – October 1, 2011
OSC Musante onsite this week.
This week ERRS:
-Completed restoration of operational areas in the valley floor area.
-Completed installation of clean cover soil over the waste in the repository.
-Continued decontamination of equipment in preparation for demobilization.
-Began installation of HDPE top liner and geotextile.-Began restoration of operational areas on top of Mesa.
START conducted radiation surveys and confirmation sampling activities. Also demobilized instruments and equipment. Air sampling has been discontinued now that transport of contaminated materials is complete.
October 3 – 8, 2011
OSC Musante onsite this week.
This week ERRS:
-Completed installation of HDPE top liner and geotextile.
-Completed installation of leachate collection valve and riser.
-Completed installation of an 18” layer of <1.5” soil cap material over the top liner.
-Completed backfilling of top liner anchor trenches.
-Continued decontamination of equipment in preparation for demobilization.
-Continued restoration of operational areas on top of Mesa.
-Began installation of a 12” layer of a 2” – 4” rock “bio-barrier” over the soil cap.
START was not present this week, but will return next week to conduct radiation surveys over the finished repository surface.
2.1.2 Response Actions to Date
Mobilization for removal activities and site setup began the week of March 28, 2011. Construction of the repository began the week of April 4, 2011, and was completed at the end of May. Excavation of mine waste from valley floor areas on the north side and the upper slope below the mine opening of Oljato Mesa was completed by July 24. Transport of excavated wastes to the repository was completed on September 20.
2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)
EPA to date has been unable to identify any existing PRPs. EPA will continue to analyze the voluminous responses to the information requests it sent to numerous parties associated with mining in general on the Navajo Reservation. Because of the urgency of this removal, EPA is proceeding with a fund-lead action. EPA will continue to review the information referenced above to determine whether viable and liable parties may be identified, and will pursue recovery of the removal costs if appropriate.
2.1.4 Progress Metrics
Off-site disposal is not planned for this removal. A total of approximately 25,072 cubic yards of mine waste and contaminated soils were excavated and transferred to the on-site repository. The following is an estimate of the approximate total volumes removed from specific areas of the Site:
-former AML repository: 4,540 cubic yards
-upper slope below mine opening: 2,196 cubic yards
-valley floor (incl. TSDA, TLDA, and arroyo): 18,336 cubic yards.
|
|
|
2.2 Planning Section
|
|
|
|
2.2.1 Anticipated Activities
2.2.1.1 Planned Response Activities
1) Archeological clearance of all areas impacted by removal activities;
2) Construction/improvement of limited access road on southern side of Oljato Mesa;
3) Secure a water supply for dust suppression activities, including the potential development of a groundwater well near the Site;
4) Development and implementation of an effluent dust monitoring program to prevent offsite release of contaminated particulate;
5) Construction of a subsurface repository on top of Oljato Mesa near the Skyline AUM;
6) Relocation of contaminated soils from the existing NN AML Skyline AUM repository to allow access to mine tailings on the edge of Oljato Mesa;
7) Excavation and internment of contaminated soils from the TLDA, TSDA, and unnamed arroyo in the onsite repository;
8) Development and implementation of a confirmation survey and sampling plan.
2.2.1.2 Next Steps
-Once all the mine waste has been placed in the repository, another plastic liner will be installed over the top. Then a soil cap will be placed over the top liner to protect it from sun and wind.
-Areas impacted by removal activities will be seeded with native plant species to help restore the land.
-Demobilization of equipment and personnel.
2.2.2 Issues
During installation of the soil cap, the ERRS contractor damaged the HDPE liner and geotextile. A small, seven-foot long tear was created by the bulldozer blade when grading the soil layer. The liner subcontractor will repair the damaged area as soon as possible. The location of the damage was near the side of the repository and will not impede installation of additional cap layers across the repository surface.
|
|
|
2.3 Logistics Section
|
|
|
|
N/A
|
|
|
2.4 Finance Section
|
|
|
|
No information available at this time.
|
|
|
2.5 Other Command Staff
|
|
|
|
2.5.1 Safety Officer
N/A
2.6 Liaison Officer
N/A
2.7 Information Officer
2.7.1 Public Information Officer
N/A
2.7.2 Community Involvement Coordinator
OSC Musante will attend the Oljato Chapter monthly meeting on October 10th to give an update on site progress and answer questions.
|
|
3. Participating Entities
|
|
|
3.1 Unified Command
N/A
3.2 Cooperating Agencies
Navajo Nation EPA Superfund (NN EPA)
Navajo Nation Abandoned Mine Lands Reclamation Program (AML)
Navajo Nation Department of Water Resources
|
|
4. Personnel On Site
|
|
|
1 EPA OSC
1 START – E&E
13 ERRS – EQM, Liner subcontractor
|
|
5. Definition of Terms
|
|
|
No information available at this time.
|
|
6. Additional sources of information
|
|
|
6.1 Internet location of additional information/report
website: www.epaosc.org/SkylineAUM
6.2 Reporting Schedule
The next POLREP will be submitted on 10/24/11.
|
|
7. Situational Reference Materials
|
|
|
-maps: Skyline Fig 1 Site Location, Skyline Fig 2 Site Features
|
