By Daniel J. Calderon
Los Angeles District
CASA GRANDE, Ariz. — The U.S. Army Corps of Engineers Los Angeles District
began clearing work Jan. 30 following a public involvement meeting the District hosted Jan. 26 to discuss the state of several of the former Williams Field Bomb Target Ranges.
The ranges are now considered Formerly Used Defense Sites. The meeting covered ranges #4, #9, #10 and #12. Each of the FUDS discussed in the meeting are located in Southern Arizona near the towns of Florence or Casa Grande. USACE employees discussed how the District will perform a remedial investigation and feasibility study, to include a treatability study and technology demonstration at the sites under the guidelines set forth in the Comprehensive Environmental Response, Compensation, and Liability Act. This allowed the District to come up with a proposed plan and a decision document for remedial action of the sites.
"We are doing a streamlined CERCLA process," explained Jeff Armentrout, Los Angeles District FUDS Program Manager. "It's an approach we're trying to apply to former practice bomb ranges throughout the Southwest. This will allow us to conduct clearing operations more rapidly."
Activity on the FUDS goes back before World War II. Construction began on what was first known as Higley Air Base in June 1941. In June 1942 it was renamed Williams Army Air Field and used by the West Coast Air Force Training Center for bombardier training. Later that year, construction on bomb targets, including graded roads, wooden pyramid target structures, oiled aiming circles, whitewashed gravel, and fencing began.
Bombardier cadets used sand-filled 100-pound M38A2 practice bombs for their bombardier training. By May 1942,cadets were dropping an average of 2,000 100-pound practice bombs daily onto the Williams Field Bombing Targets.
In February 1943, Army Air Forces moved the Williams AAF Bombardier Training Program to Deming AAF in Deming, N. M. Combat pilots continued to train at Williams AAF until the end of 1943. In the fall of 1944, the Army Air Forces modified the training to include bombardment training and radar observer training using heavy bomber B-17s and B-24s instead of the previously used AT-9s. In 1945, aviators attending the Radar Observer School held at Williams AAF were required to drop five practice bombs. The range closed soon after. At the meeting, District team members spoke with members of the public about the history of the site and about actions involved in the District's work in the area.
"We want the public to hear what we're doing and we want to know what questions they have," Armentrout explained. "We've had meetings with stakeholders and with major property owners. But, we want to make sure the public is informed and we want to know what concerns they have."
In 1994, The Corps conducted preliminary inspections for all four sites. Based on these investigations, the sites were determined eligible for the FUDS program and the preliminary site boundaries were established. In 1997, Archives Search Reports for the sites compiled historical records, including ownership and land usage information. Site visits and community interviews were conducted in support of the ASRs. During the visits, inspectors found munitions debris from practice bombs, spotting charges and spent small-arms casings.
In 2004, ASR Supplements were completed for each site. The supplements indicated one Munitions Response Site for each former target range and assigned a Risk Assessment Code score to each MRS. RAC scores are assigned on a scale from 1 to 5, with 1 being the most hazardous and 5 indicating the least hazardous or lowest risk. The scores are determined primarily by the types of munitions known or suspected to have been used at each MRS. WFBTR #4 was assigned a RAC score of 3, indicating moderate risk. WFBTR #9 was assigned a RAC score of 2, indicating elevated risk. WFBTR #10 was assigned a RAC score of 2, indicating elevated risk. WFBTR #12 was assigned a RAC score of 4, indicating low risk.
In 2007, Site Inspection teams completed their inspections for WFBTRs #4, #9, and #10. The SI for WFBTR #12 was completed in January 2009. During the SIs, a team conducted qualitative reconnaissance and collected soil samples to determine if each MRS warranted further inspection. The team's results of the samples at WFBTR #12 showed there was potential contamination in the surface soil; however, the screening level risk assessments concluded there was no risk or hazard to human health or the environment.
"The process is important because our biggest concern is to ensure the land is safe for public use," said Armentrout "We're working with the streamlined process so we can close out the practice bomb target ranges much more quickly. If it goes as planned, the streamlined process will allow us to get the area to usable levels sooner."
This year, the District will conduct the remedial investigation and feasibility study portion of the process at WFBTR #4, #9, #10, and #12 throughout February. The District will perform treatability studies and technology demonstrations at each site to conduct a surface clearance of potential hazards using three innovative technologies on approximately 65.8 acres of former bomb target training areas.
"I think the meeting was very valuable," said Tony Solano, operations manager for Electrical District No. 3, a local company that will be working to service their customers' electrical needs in the area. "This is really the best way to get people together so the public can get answers to any of their questions. The Corps put out good information and now people should know what to do if they encounter anything."
At the meeting, the Corps had information reminding members of the public of the three Rs of explosive safety -- Recognize, Retreat and Report. The District will post the results in the local public libraries and on its website. More information on FUDS
activities and processes is available.