1.1.1 Incident Category

Mine Category Assessment Protocol (MCAP) reconnaissance in support of the Tronox settlement

1.1.2 Site Description

120 mine claim areas, 26 mine claims are specifically identified in the Tronox settlement, with an additional 6 mine claims determined as 'other mines' within the Tronox settlement

The MCAP Target Sites, historical site screening information, and other relevant layers supporting the MCAP site visits are displayed on the Region 9 Navajo Operational Viewer located at: https://r9.ercloud.org/navajoops/.

1.1.2.1 Location

Red Valley, AZ 86544 - The MCAP effort will take place throughout the Northern agency of the Navajo Nation, extending from the Lukachukai Mountains north to Teec Nos Pos

1.1.2.2 Description of Threat

Potential releases and the threat of future releases of hazardous substances, namely: uranium and its progeny (i.e., radium-226 and radon) and ionizing gamma and alpha radiation associated with those progeny.  The likelihood of direct human exposure, via ingestion and/or inhalation of hazardous substances, and the threat of future releases and migration of those substances, pose an imminent and substantial endangerment to the public health or welfare or the environment based on the factors set forth in the NCP, 40 CFR § 300.415(b)(2). 

2.1.1 Narrative

MCAP Field Teams completed the assessments of all target sites found the primary operational mining area of Mesa I, where large amounts of waste rock was documented as being pushed off the mesas to the shelves and drainages below.  The field team also successfully completed the assessments of many target sites in the Mesa IV area, including the identification of unreclaimed exposed orebodies on the Cove068 AUM site.   The team has continued to be challenged by the road conditions, where deep snow banks and fallen trees are blocking many of the formerly accessible pathways leading to the target sites.

 
2.1.2 Assessment Activities to Date

On April 21, 20 of the 96 planned sites were evaluated. This makes for a total of 46 of the planned 96 mine areas.

2.1.3 Progress Metrics

46 of the 96 site have been evaluated to date, this represents 42% completion.

A list of all of the sites and their MCAP status can be found at:
https://www.epaosc.org/sites/11282/files/MCAP%20Target%20Sites%20042116.xlsx

2.2.1 Anticipated Activities

The team plans on continuing the assessments of target sites on Mesas II, III, and IV, as well as attempting to gain access to the south side of the Lukachukai Mountains, where many of the target sites are located along  the cliff sides.

1 OSC

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