U.S. ENVIRONMENTAL PROTECTION AGENCY
POLLUTION/SITUATION REPORT
McDermitt and Cordero Mercury Mine Sites - Removal Polrep

EPA Emergency Response

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Region IX
Subject: POLREP #5
Final
McDermitt and Cordero Mercury Mine Sites
NVN000909006
McDermitt, NV
Latitude: 41.9135613 Longitude: -117.7081702

To:
From: Tom Dunkelman, OSC
Date: 6/25/2013
Reporting Period: May 9 - May 23, 2013

1. Introduction
  1.1 Background
   
Site Number: 09WL    Contract Number: EP-S9-12-01
D.O. Number: 9027    Action Memo Date: 10/16/2012
Response Authority: CERCLA    Response Type: Time-Critical
Response Lead: EPA    Incident Category: Removal Action
NPL Status: Non NPL    Operable Unit: Site Wide
Mobilization Date: 4/15/2013    Start Date: 4/15/2013
Demob Date: 5/23/2013    Completion Date: 5/23/2013
CERCLIS ID: NVN000909006    RCRIS ID: N/A
ERNS No.: N/A    State Notification: Yes
FPN#:    Reimbursable Account #:

1.1.1 Incident Category

Time Critical Removal Action

1.1.2 Site Description

The McDermitt and Cordero Mercury Mine sites consist of several non-contiguous locations:  the McDermitt Mine, the Cordero Mine, areas within the town of McDermitt where apparent mine waste has been used as fill, and areas of the Fort McDermitt Pauite Shoshone Reservation (the Reservation) where apparent mine waste has also been used as fill.  The Cordero Mine operated from the 1930s until 1970, and is located on land managed by the BLM and on private land.  The adjacent McDermitt Mine was operated from 1973 until the late 1980s.  The McDermitt Mine is located on private land.  The McDermitt Mine was closed under a permit from the Nevada Division of Environmental Protection (NDEP), and a final closure report was submitted in December, 1994.

The EPA Site Assessment program conducted a Site Inspection in 1988 which recommended no further action.  Upon request from the Fort McDermitt Pauite Shoshone Tribe, EPA Emergency Response conducted an additional site visit in November 2009.  At that time, EPA was notified of the possibility that mine waste had been used as fill at locations within the town of McDermitt and on the Fort McDermitt Paiute Shoshone Reservation.

In September and October of 2010, EPA conducted sampling of areas of red-colored fill located in the town of McDermitt and on the Reservation.  The town of McDermitt straddles the Nevada/Oregon border and numerous areas were identified which contained mercury and arsenic in soil at concentrations which exceeded the EPA Region 9 residential Soil Remediation Goals (SRGs).  Two areas were identified on the Reservation  which contained mercury and arsenic in soil at concentrations which exceeded the residential SRGs.

In June 2011, EPA conducted additional sampling of the mine waste present at the mine site and present in the town and on the Reservation.  The goal of this sampling effort was to evaluate the bioavailability and mineral speciation of the mercury and arsenic.  The USGS provided technical and analytical support to EPA in this effort.

On October 16, 2012, EPA signed an Action Memorandum describing removal activities to be performed.  EPA also issued a Unilateral Order to both Sunoco and Barrick Gold requiring these companies to participate in the cleanup process.  To date, both companies have declined to participate in work under these Orders. 

1.1.2.1 Location

The town of McDrmitt is located roughly 70 miles north of Winnemucca, NV, along Highway 95.  The town straddles the Nevada/Oregon state line.  The Fort McDermitt Pauite Shoshone Indian Reservation is located 3.5 southeast of the town of McDermitt and the McDermitt and Cordero Mines are located 7.2 miles southwest of the town of McDermitt.

1.1.2.2 Description of Threat

Mercury and arsenic are present in calcine material located on school property and on residential property in excess of site specific cleanup standards of 60 mg/kg arsenic and 80 mg/kg mercury.

1.1.3 Preliminary Removal Assessment/Removal Site Inspection Results

Removal assessment results are presented in Removal Assessment reports produced by the START contractor.  These reports are available on the epaosc web page.  The removal assessment documented the presence of mercury and arsenic at levels in excess of the site specific cleanup levels at approximately 40 residential properties.
2. Current Activities
  2.1 Operations Section
    2.1.1 Narrative

2.1.2 Response Actions to Date

During this reporting period, the following actions were completed:

Borrow Pit. The borrow pit at National MIne Road was regraded so that the side slopes were no more than 3:1 grade.  BLM confirmed that EPA had met its obligations with regard to leaving the pit in an acceptable manner.

Repository at Cordero Mine Calcines Pile.  The last load of calcine material from the town of McDermitt was transported to the calcines pile on May 18.  A total of approximately 10,000 tons of calcine material excavated from the town of McDermtt and the Fort McDermitt Paiute Shoshone Indian Reservation were placed at the repository.  The ERRS contractor regraded the area of the calcine pile were material was placed, in order to match the existing grade of the cacline pile.  The portion of the chain link fence at the calcine pile which had been removed in order to allow truck access was replaced.

Residential Properties:  All work at residential properties was completed.  This work consisted of removing calcine material, placing clean backfill material and compacting.  At a few larger properties, calcine material was not removed, but rather a cover of clean material was placed over top.  In total 56 residential properties (54 in town and 2 at the Reservation) were addressed. Within the town of McDermitt, 417,491 sq ft of mine waste at 54 residential properties required remedial action. Of the 417,491 sq ft, 5,942 cubic yards (cy) of mine waste was excavated from 378,090 sq ft at 41 residential properties, and 39,401 sq ft of mine waste was capped in place at 13 residential properties.  At the Fort McDermitt Indian Reservation, 82 cy of mine waste was excavated from 6,197 sq ft at two residential properties.To the best of EPA's knowledge, all residential properties (within the town of McDermitt and at the Reservation) with calcine material were addressed.

McDermitt Combined School.  Cover material was placed over the east side of the football field, the large parking area adjacent to the football field, and the areas surrounding the playground. At the McDermitt School property, 311,682 sq ft of mine waste required remedial action. Of the 311,682 sq ft, 594 cy of mine waste was excavated from 45,958 sq ft located immediately east of the north-eastern school football field, 247,231 sq ft (5.56 acres) of mine waste was capped in place at the school parking lot, and 18,493 sq ft of mine waste was capped in place at the school playground.

Roadways.  

A total of 40,410 sq ft of mine waste was capped in place at two unpaved roads located just east of Buckskin and Reeves Roads in the town of McDermitt. This work was performed in conjunction with the McDermitt GID. Additionally, EPA provided backfill material to Malheur County, Oregon in order to cap 25,270 sq ft of mine waste at one unpaved road, identified as Margarita Road and located west of US 95.  At the Fort McDermitt Indian Reservation, 25,586 sq ft of mine waste was capped in place at one unpaved access road leading to the Tribal transfer station.



2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)

EPA has identified two PRPs for this Site - Sunco and Barrick Gold.  EPA issued a Unilateral Order to both companies requiring that they perform cleanup activities at the site.  Both companies declined to perform work under the Unilateral Order.

2.1.4 Progress Metrics

Total amount of fill produced from the BLM borrow pit:  25,000 tons
Total calcines transported to Repository this reporting period: 10,000 tons
Total number of residential properties remediated:  56
Total properties (residential, school and 4 roadways) remediated:  61
Total square feet of residential property remediated:  423,688
Total square feet of school property remediated:311,682
Total square feet of roads remediated:  91,266
Total square feet remediated:  826,636
  2.2 Planning Section
    2.2.1 Anticipated Activities

All response actions have been completed and personnel have demobed from the site.

2.2.1.1 Planned Response Activities

2.2.1.2 Next Steps

All response actions are complete. 

2.2.2 Issues

During the course of this removal action EPA received excellent cooperation from different groups including BLM, Humboldt County School District, McDermitt GID, Humboldt County Road Department, Malheur County Road Department and the Fort McDermittt Paiute Shoshone Tribe.  The community in McDermitt was extremely patient, cooperative and pleasant to work with.  To the best of EPA's knowledge all residential properties containing calcine material were remediated.  Throughout the process, the community expressed their support for the project and thanked EPA for the quality of the work performed.
  2.3 Logistics Section
    No information available at this time.
  2.4 Finance Section
    No information available at this time.
  2.5 Other Command Staff
    No information available at this time.
3. Participating Entities
  No information available at this time.
4. Personnel On Site
  No information available at this time.
5. Definition of Terms
  No information available at this time.
6. Additional sources of information
  No information available at this time.
7. Situational Reference Materials
  No information available at this time.