U.S. Environmental Protection Agency Region IX, San Francisco Navajo AUM Project Navajo Abandoned Uranium Mine Site Screen Report This form is for use at the site of abandoned uranium mines (AUM) located on Navajo Nation lands. Applicable sites include all mine and mine features that have or have not undergone reclamation by the Navajo Abandoned Mine Lands Reclamation Program, including features, adits, pits and waste piles. Applicable sites also include all AUM sites listed in the USEPA CERCLIS database, all sites listed in the 2008 AUM GIS Report issued by USACOE and USEPA, all AUM sites on allotment lands associated with the Navajo Nation, and any and all AUM sites not listed in any database located on Navajo lands. Reconnaissance of any sites located on lands adjacent to Navajo lands that may be impacting Navajo lands will need to be coordinated with the authorities appropriate to those lands. The purpose of the form is to ascertain the status and location of the identified A UM site, and record all immediate site information associated with the mine site. Decisions and recommendations on what additional steps are needed will be provided on a separate document. Juan Horse No. 3 AUM Site Navajo AUM Western Region Prepared by: Weston Solutions, Inc. Contract: W91238-06-F-0083 12767.063.599.1111 January 2011 Juan Horse No. 3, Mine ID # 136 1 January 2011 ------- U.S. Environmental Protection Agency Region IX, San Francisco Navajo AUM Project Part I Site Identification, Location and Status Site Names and ID numbers as applicable Mine ID: 136 Map ID: W52 CERCLIS: NNN000909067 Navajo Abandoned Mine Land Reclamation Program: NA-0139 Local name / Aliases: Juan Horse #3 Chapter and local area: Coalmine Mesa Chapter County: Coconino State: Arizona Lat/Long: 35.8619060315 N / -111.367198022 W Nearby road and highway: Indian Route 6730 Local Post Office: Cameron, AZ Surface Land Status: check one or more and provide ownership and contact information below Tribal Trust Land ^ Public lands Q Private Q Tribal Fee Land Q Bureau of Land Mgmt Q Allotment Q State O Fee land Q Subsurface Mineral Rights: No information on subsurface mineral rights ownership was found in the EPA/AUM Database. Claim and operator information: The mine site surface land status is classified as Tribal Trust Land. Historical documents showed the operator of the mine as Wells Cargo from 1958 to 1959. No additional ownership / lease information was identified in the EPA/AUM database. Number of residential structures within 200 feet of mine: None Estimated volume of mine waste onsite: None Juan Horse No. 3, Mine ID # 136 2 January 2011 ------- ¦G.S. Environmental Protection Agency Region IX, San Francisco Navajo AtlM Project Part II Summary of radiological readings Highest gamma radiation measurement: 212,624 counts per minute (cpm) Describe any other radiological measurements: A total of 4,696 gamma radiation measurements were collected from the mine site, ranging from 7,371 cpm to 212,624 cpm. A petrified log near the structures 0.15 mi west of the site was found at over 200,000 cpm. The measurements are represented in Figures 1 and 2. Background Readings: 11,523 cpm Background Average: 11,523 cpm Distribution Chart and Statistics: The following chart and statistics were generated by ESRI ArcGIS 9.3.1, and show the general distribution of the site gamma radiation measurements. The horizontal X axis represents the gamma radiation reading levels in cpm (lowest levels to the left). The vertical Y axis represents the frequency of each gamma radiation level. 2000- 1500-- 1000-- 500-¦ ceo -cco -cco cco 'Z C o C 'Z o cir.o -CM 0 7371 00000 "I I 1 1 58684.25000 109997.50000 161310.75000 212624.0000 Count: 4696 Minimum: 7371.00000 Maximum: 212624.00000 Sum: 58112939.00000 Mean; 12374,98701 Median: 10635.00000 Standard Deviation: 12271.65629 Juan Horse No. 3, Mine ID # 136 3 January 2011 ------- U.S. Environmental Protection Agency Region IX, San Francisco Navajo AUM Project Part III Status of Reclamation and Mine Waste The following information was obtained from the Navajo Abandoned Mine Land Reclamation Program (NAMLRP) Point Features Database: NAMLRP Status of the mine site: Reclaimed: Yes Waste Pile onsite: No NAMLRP Project Number: NA-0139 NAMLRP Mine features: 1 Rim Strip / Pit The following information was obtained from field observations collected during the 2010 site screening: Provide description and status of all mine sites and features at site. Include all waste piles, adits, pits and other features, and indicate whether they are open, closed, covered, capped, buried or unreclaimed. Indicate approximate size, shape and extent, including description of any reclamation caps. Note condition of all caps. Observed reclamation work and status: Adits None Waste Piles None Pits None Shafts None Other Debris and Mine Features Reclamation cap in the center of the site, approximately 200' x 100' Juan Horse No. 3, Mine ID # 136 4 January 2011 ------- U.S. Environmental Protection Agency Region IX, San Francisco Part IV Site observations and Environs Navajo AUM Project Observed Structures: list number of and describe human habitation status of structures at the following distances from mine: 0 to 200 feet: None 200 feet to 0.25 mile: Observed Public or commercial structure: list and describe all schools, clinics, Chapter Houses, places of business and any other structure used by members of the community at the following distances: 0 to 200 feet: None 200 feet to 0.25 mile: None Levels measured around the perimeter(s) of the identified structure(s): Background levels around structures, with exception of petrified log at 200,000 cpm. Observed water sources: list the number and type of wells and surface water sources that are potentially used for human consumption at the following distances from the mine: 0 to 0.25 miles: None 0.25 miles to 4 miles: Windmill Well approximately 1.75 mi S of the site; Little Colorado River Basin approximately 0.5 mi W of the site Sensitive environments: note and describe all sensitive environments located within visible range of the mine site, including: wetlands, endangered species, habitats and approximate locations of sites that may be under protection of the government of the Navajo Nation. None observed Known Site History: include information from interviews with Chapter officials and residents. Note information on mine ownership, type of mining operation, period of operation, known amount of production, and any other information as provided. Juan Horse No. 3 mine consists of an area of 66,121.9 m . The mine was identified as being operational from 1958 to 1959. Historical documents showed the operator of the mine as Wells Cargo from 1958 to 1959. While operational, the mine had a total reported production volume of 2,343 tons. No other historical information or any additional ownership / lease information was identified in the EPA/AUM database. Juan Horse No. 3, Mine ID # 136 5 January 2011 ------- U.S. Environmental Protection Agency Region IX, San Francisco Navajo AUM Project Part V Response Action Summary Summary of Evaluation Factors: Accessibility: Was the mine easily accessible to potential human activity? Yes Radiological Measurements: Were any gamma radiation measurements collected at the mine greater than two times the site-specific background levels? Yes Waste Piles: Were any unreclaimed waste piles observed at the mine with gamma radiation measurements greater than two times the site-specific background levels? No Structures: Were any structures observed within 200 feet of the mine? No Potential Drinking Water Sources: Were any potential drinking water sources observed within 4 miles of the mine? Yes Reclamation: Was the mine reported to be previously reclaimed, or did the mine appear to be reclaimed? Yes (reclamation cap in the center of the site) Juan Horse No. 3, Mine ID # 136 6 January 2011 ------- ¦G.S. Environmental Protection Agency Region IX, San Francisco Part VI Photos Navajo AtlM Project Photo 1. Juan Horse Mo. 3 mine site Photo 2. Juan Horse No. 3 mine site, reclamation cap Juan Horse Ho. 3, Mine ID # 156 7 January 2011 ------- U.S. Environmental Protection Agency Region IX, San Francisco Navajo AUM Project Juan Horse No. 3, Mine ID # 136 Q January 2011 ------- U.S. Environmental Protection Agency Region IX, San Francisco Navajo AUM Project Juan Horse No. 3, Mine ID # 136 Q January 2011 ------- U.S. Environmental Protection Agency Region IX, San Francisco Navajo AUM Project Part VII Contacts Reports and Information Name: Stanley Edison (928) 871-6861 Eugene Esplain (928) 871-7331 Title or official role (if any): Navajo EPA Superfund Program Address: PO Box 2946. Window Rock. AZ 86515 Information provided: Lead Regulatory Agency Name: Title or official role (if any): Address: Telephone number: Information provided: Name: Title or official role (if any): Telephone number: Information provided: Name: Title or official role (if any): Telephone number: Information provided: Juan Horse No. 3, Mine ID # 136 10 January 2011 ------- Figure 1 - Gamma Radiation Measurements, Above Two Times Background Juan Horse No. 3 (136) Coalmine Mesa Chapter, Navajo Nation # * * I / J I c J * * * » ¦ Juan Horse No. 3 (136) Legend Gamma Radiation Measurements • < 2X Backgound > 2X Background Gamma survey conducted 11/2010 Measured as counts per minute (cpm) Average background 11,523 cpm a. ecr General Slope Direction Observed Waste Pile z-zz- Obsea'ed Reclamation Area Mine Site Boundary Feet ------- Figure 2 - Gamma Radiation Measurements Juan Horse No. 3 (136) Coalmine Mesa Chapter, Navajo Nation r. 0 i<( ^ ** i *Ji* -\ ¦ 9m V-Vf* ¦ Juan Horse No. 3 (136) Legend Gamma Radiation Measurements 0-10,000 10,000- 15,000 15,000-20,000 20,000-50,000 50,000- 100,000 > 100,000 Average background 11,523 cpm h."v General Slope Direction Observed Waste Pile - = Observed Reclamation Area I i-eet Mine Site Boundary Gamma survey conducted 11/2010 Measured as counts per minute (cpm) 400 % ^ p ------- |