Removal Action Summary

The Navajo Nation radioactive hogan sites consist of two residences located on the Navajo Nation. The first, belonging Mrs. Elsie Mae Cly is located in the Oljeto Chapter in San Juan County, Utah. The other hogan belonging to Mrs. Betty Clark is located in the Tees Nos Pos Chapter in Apache County, Arizona. The two Navajo traditional hogans were constructed using mining waste rock containing elevated levels of uranium ore. The radiation levels of two hogans were measured as high as 1000 micro Roentgen per hour (m R/h) during an initial survey conducted by U.S. Environmental Protection Agency (USEPA), Region IX in January 2000. In January 2001, USEPA conducted a confirmation radiation survey, which confirmed the initial readings.

The hogan surveys and removal were not part of the Navajo Abandoned Uranium Mines Project. The USEPA investigated them, as part of a citizen complaint. The conditions were evaluated using the criteria established in the National Contingency Plan (NCP). The radionuclides identified at the sites are "hazardous substances" as defined by 40 C.F.R. Section 302.4 and Table 302.4 and Section 101(14) of CERCLA, 42 U.S.C. § 9601 (14). The USEPA believed that releases and threats of releases of hazardous substances were present at the sites, so they fell within the definition of a "time-critical" removal action.

The NSP requested assistance from U.S. EPA to address these contaminated hogans, because NSP does not conduct "time critical" removals. The overall objective of the removal action was to identify situations, which pose imminent and substantial endangerments to the public and the environment at the site, and mitigate them in a cost effective manner in accordance with the criteria set forth in the NCP.

The NSP staff reviewed the U.S. EPA's Time-Critical Contaminated Hogan Removal Plan prepared for Oljeto and Teec Nos Pos. The USEPA removal evaluations were:

Oljeto
Radiation Hazard, Waste Rock Stone Masonry
Structure: Hogan
Current Use: Storage. (New home built within fifteen feet of the hogan)
Location: 2 miles West of Gouldings, Utah
Readings Outside: 10-200 uR/hr, Inside 800-1000 uR/hr
Repository Site: Moonlight Mine

Teec Nos Pos
Radiation Hazard, Waste Rock Stone Masonry
Location: East of Rattlesnake Mine
Readings: Outside: 13-400 uR/hr, no inside readings
Repository Site: Rattlesnake Mine (located south of the site).

Three air monitoring instruments were set at different locations during all phases of the removal action. When there is a potential for an air borne release of contaminants during the operation of heavy equipment, OSHA requires air monitoring,

Each hogan's contents were removed,

Each hogan was watered down before and during the demolition activities,

Each hogan was demolished. The debris was then hauled to a designated Navajo AML repository area in conjunction with ongoing reclamation projects,

Each area was leveled and covered with clean fill brought to the sites, and

A replacement storage shed was installed for Mrs. Cly the following week at Oljeto. Mrs. Clark selected monetary compensation prior to the removal of her hogan.

As follow-up to the removal activities at the two locations:

A radiation survey will be performed by USEPA to insure the cleanup goals are met. Our program has not received this new survey data from USEPA.

The ore tailings pile near Mrs. Cly‘s residence was recommended to be fenced off by USEPA to prevent access, until Navajo AML removes the waste from the site in September or October 2001.

Navajo AML staff working in the area are currently monitoring the contaminated waste/debris placed at the repository site in Oljeto. The waste at Teec Nos Pos has been included in the Navajo AML reclamation.