oEPA NAVAJO NATION ABANDONED URANIUM MINES U.S. Environmental Protection Agency Region 9 San Francisco, CA March 2018 Cove Area Abandoned Uranium Mines Investigation Activities Cove Wash Watershed Assessment From 2015 to 2017, the U.S. Environmental Protection Agency (USEPA), along with Navajo Nation EPA and Dine Environmental Institute of Dine College, sampled sediment and water in the Cove Wash watershed and conducted various surveys and studies. Sampling determined that the watershed has elevated uranium concentrations in surface and ground water around and below the historically mined areas. Sampling goals included: 1. Identifying sources of contamination and potential areas of concern. 2. Determining the baseline contaminant levels in the Cove Wash. The types of sampling completed are shown in the table below During the time sampling occurred, USEPA also installed warning signs at unregulated water wells. Upcoming activities include livestock assessments and air sampling. About the Cove Wash Watershed The Cove Wash watershed is approximately 47 square miles and includes 42 abandoned uranium mines within the Lukachukai Mountains. Year- round water is found in peaks and canyons above 7,000 feet elevation, where springs and seeps are above ground. Developed springs and wells are also part of the watershed. | HUMANS SHOULD NOT DRINK FROM THIS WATER SOURCE Water well warning signs installed at unregulated water wells. Completed Cove Wash spring snowmelt sampling Cove Wash low-flow sampling Mexican spotted owl survey Cove Wash wetland survey Crop and irrigation study Sampling in the Cove Wash watershed ------- Remedial Investigation/Feasibility Study Activities for the Cove-Area Tronox Mines In late June 2016, USEPA entered into an agreement with the U.S. Army Corps of Engineers (USACE) to develop a planning document for addressing the Cove Chapter abandoned uranium mines. This planning document is called a conceptual site model (CSM). The CSM will help USEPA figure out which areas need further study and which areas will move straight to cleanup. USACE presented an introduction to the CSM to the Cove community in November 2016 and received their feedback. As part of the agreement, USACE will also do an assessment that identifies mining areas where more data will need to be collected. To complete the assessment, USACE created picture models that show how exposure to uranium can occur and to whom. Next Steps for the CSM Results of the CSM will be presented to the Cove community in Spring 2018. Superfund Process on the Navajo Nation Assessment Decision Making Clean Up I uli 0" ~= i' &= r! i= Access Agreements Resources Surveys Signs and Fences Removal Site Evaluation Engineering Evaluation / Cost Analysis Łą3 Public Comment Period Action Memorandum o*ov Removal Action Community Involvement and planning for a site's future are ongoing throughout the process Coordination with the Navajo Nation government including NNEPA, Navajo AML, and the Dine Uranium Remediation Advisory Commission For More Information If you have questions about the Cove Wash Watershed Assessment and Remedial Investigation/Feasibility Study, please contact: Gaelle Glickfield Remedial Project Manager USEPA Region 9 (415) 972-3045 glickfi eld.gaelle@epa .gov Secody Hubbard Community Involvement Coordinator USEPA Region 9 (415) 972-3241 hubbard.secody@epa.gov For more information visit: www.epa.gov/navaio-nation-uranium- cleanup/cove-arizona-mines-cleanup o Printed on 50% post-consumer recycled paper Processed chlorine-free ------- |