Sahuarita Air Force Range 

The Army Corps of Engineers (Corps) is initiating a Site Inspection of the former Sahuarita Air Force Range(a former bombing range, part of which lies within the City limits) (see location map).  While efforts were made by the Corps to clear the Range of ordnance in the 1970s, the Site Inspection will look at any remaining safety issues related to the explosives used at the Range as well as possible environmental contamination the munitions may have caused.  This Site Inspection is being conducted as part of a nation-wide investigation of formerly used defense sites.

When the Sahuarita Range was active from 1942 to 1962, it included four bomb targets, a ground-to-air gunnery range, and two air-to-ground gunnery ranges (see site map).  The Range site occupies 40 square miles within and south of the City limits.  The site is irregular in shape, averaging about 5 miles from east to west and 8 miles from north to south.  Approximately 10 of the 40 square miles lie within the City limits, about 8 square miles in Ward 5 and 2 square miles in Ward 4. 

Most of the property is undeveloped, owned by the State Land Trust and used for cattle grazing.  Some residential properties are found in the southern part of the Range outside of City limits.  Nine Tucson Water production wells are located within the site boundary. 

The Army Corps of Engineers conducted ordinance-clearing activities on the Range in the 1970s.  Since that time the Corps has conducted a multi-phased review of the Range, including a Site Survey (1993), Inventory of Munitions used at the site and possible environmental conditions (1993), and an Archive Search (1996). 

For the Site Inspection, the Corps will verify what was found in its previous review phases, specifically looking for at 2 concerns: unexploded ordnance and environmental contamination.

Potential Unexploded Ordnance

Safety concerns related to ordnance used at the Sahuarita Range focus primarily on the southern bombing ranges (outside City limits) where high explosives were used.     The Corps believes only practice bombs were used in the two northern bombing ranges.   According to the Corps, only  ball ammunition was used in the ground-to-air and air-to-ground ranges within the City limits.  This ammunition does not carry an explosive charge.   Though remains of ordnance, such as shell casings, have been found within the Range, staff could find no Corps document stating that unexploded ordnance was ever found within the Range.

Potential Environmental Contamination

The Corps will investigate possible soil and groundwater contamination related to the munitions used on the range.  The Corps contractor will collect ten soil samples and three groundwater samples (see map) to evaluate whether metals and munitions-related chemicals have impacted soil and groundwater.  The sampling will likely begin in November 2006.  The report of this investigation will be completed in six to nine months.  It is worth noting that while water from all active Tucson Water production wells is regularly tested to ensure compliance with water safety standards, testing for munitions-related compounds is not a routine part of Tucson Water s compliance monitoring (but testing for metals is part of this monitoring).  As a pro-active measure, Tucson Water recently collected groundwater samples from their wells in the area and these are being analyzed for munitions-related compounds at this time.

The Army Corps of Engineers has contacted all jurisdictions that overlie the Sahuarita Range site to explain the upcoming Site Inspection. Property owners within the Range boundary will also receive notice of the Inspection if the Corps requests access for testing.

After the Site Inspection is complete, the Corps will rank the site (according to types of ordnance, chemicals identified by soil analyses that are due to munitions and proximity to populace) and a public notice will be published in the newspaper.  All landowners within the Range boundary will receive copies of the Corps report.

Based on the findings of the Site Inspection, the Corps may schedule a Remedial Investigation.  The Remedial Investigation could include a subsurface investigation or geophysical survey to detect buried ordnance (a geophysical survey is a surface-based survey that might use some form of electronic imaging to identify subsurface features).  If a Remedial Investigation is required, it might not be conducted until all Site Inspections nationwide are complete in 2010.

Environmental Services is the designated lead City contact with the Corps of Engineers for the Site Inspection, and will coordinate with other departments as necessary.  Environmental Services and the Tucson Fire Department will continue to advise the Mayor and Council of any new developments that occur during this inspection process.  Interested parties should direct questions to City of Tucson Environmental Services (520) 791-5414 or alison.jones@tucsonaz.gov and these questions will be forwarded to an expert who can answer them. 

You can read the Corp's work plan for the upcoming Site Inspection and earlier reports by clicking on the links below.

Site Inspection Work Plan (2006)

Inventory Project Report (1993)

Archives Search Report (1996)