The National Park Service (NPS) completes comprehensive radiological survey of the Grand Canyon Unified School District athletic fields

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Date: April 29, 2009
Contact: Maureen Oltrogge, 928-638-7779
Contact: Greg Nottingham, 303-415-1483

GRAND CANYON, Ariz. -  A report of the results of the radiological survey of the Grand Canyon High School Athletic Fields (April 15, 2009) confirmed that there are no elevated radiation levels at the fields and that there is no indication that uranium-bearing waste rock is present in the soils underlying the fields.  The Report also concluded that there is no discernible health risk from radiological exposure to people who use the fields or to workers involved in subsurface maintenance activities on the fields.  These conclusions should give the community confidence and assurance that the school athletic fields are safe.


The radiological investigation was conducted to address the sporadic but recurring concerns expressed by members of the Grand Canyon community related to the possibility of elevated radiation levels existing at the Grand Canyon School athletic fields associated with waste rock from various uranium mines in the area reputedly having been used as fill for field construction.  The NPS had previously conducted a thorough search of park documents concerning the fields and had found no evidence or indication that mine tailings or waste rock from uranium mines were ever used in field construction; consequently, the NPS had no reason to believe that concerns about the fields had any factual basis.  Nevertheless, the NPS conducted a rigorous and comprehensive radiological investigation to address and bring to closure lingering concerns about the fields and any possible radiological contamination. 


The conclusions of the investigation are as follows:


1.      Radiological activity levels of soils present in the upper 0.6 meters of the athletic fields is not distinguishable from radiological activity levels of soils present in the background areas, and all such levels are typical of the Grand Canyon region as a whole.


2.      There is no indication (and it is, therefore, highly unlikely) that uranium-bearing waste rock is present in the soils investigated underlying the athletic fields.


3.      There is no discernible health risk from radiological exposure for persons who use the athletic fields or for workers involved in subsurface maintenance activities on the athletic fields.


Investigation activities were conducted by URS Corporation from July 24 to July 28, 2008, and included both a gamma radiation survey and soil characterization of the athletic field and representative background areas.  The Report describes the investigation, data analysis, and data interpretation.   The investigation included gamma radiation measurements at 28,848 surface locations and radium concentration measurements for soil collected from 200 locations.  The large number of locations represented in this investigation reasonably assures that the presence of uranium-bearing waste rock would be discovered if it had been used as a construction material.  The similarity between measurements in the athletic field and background area provides a high degree of confidence in concluding that uranium-bearing waste rock is not present in the material used to construct the athletic fields.


For more information about the Report, please contact Greg Nottingham, National Park Service, Environmental Protection Specialist, at 303-415-1483 or Maureen Oltrogge, Grand Canyon National Park, Public Affairs Officer at 928-638-7779.  For a copy of the report please send an electronic request to e-mail us or log onto the park’s website at




To download Radiological Evaluation of GC Unified School District Athletic Field in .pdf format, CLICK HERE

Last updated: December 11, 2017

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