JOINT BASE SAN ANTONIO-LACKLAND, Texas -- It was once called the "Tower Plume," a three-mile underground stretch of environmental contamination at the former Reese Air Force Base, near Lubbock, Texas.
Decades of cleaning solvent use while repairing airplanes at the base resulted in groundwater contamination 1,000 times the allowable level. Original cleanup plans estimated it would take 60-70 years of ongoing remediation before the plume could be cleaned to regulatory standards.
However, through a unique partnership with private industry, the Air Force has dramatically reduced the plume by more than 99 percent, taking it from worst-case environmental issue to a base clean-up best practice. All parties involved or affected by the remediation, including the Air Force, regulators, remediation contractor, local residents and community leaders, realized the need to work collaboratively to clean the site up, developing a positive working relationship whose value has been demonstrated by the results.
Reese AFB had a flying training mission until its closure in 1997 under the Base Realignment and Closure Act. As mandated by BRAC, the Air Force Civil Engineer Center, a field operating agency subordinate to the Air Force Civil Engineer, is responsible for cleaning up past contamination at the site. AFCEC recognized that by relying on the expertise of private industry, contaminated sites could be cleaned up and returned to the local community faster.
In 2004, the Air Force awarded the first performance-based remediation contract to ARCADIS, an international company that provides consultation, design, engineering and management services in the fields of infrastructure, water, environment and buildings.
PBR contracts pave the way for creative and innovative technologies to clean up environmental contamination at former installations faster. These contracts also save the Air Force millions of dollars and can allow for more site closures than originally planned because they require performance-based endpoints that allow both the Air Force and contractor flexibility in revising remedial approaches where needed without having to modify the contract, saving money and potential delays. At Reese alone, the savings was approximately $22 million.
PBR contracts are unique because they allow the Air Force to partner with private firms, like ARCADIS, who utilize best practices and creativity to complete environmental cleanup. In other words, the Air Force identifies the desired end results, and the contractor proposes how they will best achieve the prescribed goals in the quickest, most cost-effective manner.
PBR contracts have been so successful that Terry Yonkers, Assistant Secretary of the Air Force for Installations, Environment and Logistics, implemented aggressive cleanup goals for installations closed under BRAC. The goal is to have 95 percent of all sites under a PBR contract by 2014 and complete clean up at a minimum of 75 percent of all contaminated sites by 2015.
The Reese contract was ahead of the curve, creating a partnership between the Air Force, ARCADIS, Lubbock Reese Redevelopment Authority, Environmental Protection Agency and the Texas Commission on Environmental Quality with one goal in mind: to clean up the land faster so the community could benefit from it.
Between the Air Force and ARCADIS, residents' health and safety were always top priorities. Furthermore ARCADIS has worked to minimize any interruption in either Reese business or the business of those who do business at the former base.
Using an innovative approach called remediation hydraulics, ARCADIS developed a 3D computer model to better understand the groundwater flow at the contaminated site and identify what technology would work best in cleaning it up. The results justified the use of enhanced in-situ biodegradation, a process whereby a non-toxic compound (in this case it was molasses) is introduced into the groundwater to stimulate naturally occurring bacteria to consume the contaminant. The end result is a carbon dioxide and chloride byproduct.
Coupled with an innovative directed groundwater recirculation system, ARCADIS used pump-and-treat technology to decrease the size of the plume.
The contractor pumped water from the contaminated site, sent it to an air stripper and activated carbon system to volatilize and remove the contaminants, and returned the water to the area for reuse. The treated water has the added advantage of having elevated dissolved oxygen levels, which help restore those portions of the aquifer that have undergone reductive dechlorination.
The groundwater was continually analytically tested to determine the effectiveness of this approach, and the results were used to adjust the extraction and injection patterns on at least a quarterly basis to target the plume reduction. This approach identified areas of the aquifer that exhibited the highest flow characteristics in the aquifer, which corresponded to the primary path for contaminant migration. ARCADIS used this previously unidentified pathway to guide on-going remedial efforts.
As a result of this technology, the Tower Plume has been shrinking two to three acres a week since 2006. The contractor coordinated this approach with the Air Force, regulators and the public so local residents can continue to use the aquifer as a drinking water and agricultural irrigation source while remediation continues.
From the original 800 acres of contaminated groundwater, today less than one acre remains. Environmental regulators require three annual clean sample results before the Air Force can officially complete remediation of the plume at Reese, which is scheduled for 2014.
Performance has exceeded everyone's expectations, while saving the Air Force more than $20 million.
The partnership at Reese is an example of how a PBR contract can pave the way toward achieving cleanup goals ahead of schedule, and the rest of the Air Force is following suit. The Air Force currently has 18 PBR contracts covering 29 installations across the country.
The introduction of the PBR contract plays an important role in the success of the Reese AFB cleanup program, but it certainly isn't the only key factor. The cleanup program at Reese wouldn't be where it is today without the hard work of the Air Force, ARCADIS, state and federal regulators, members of the community, and the LRRA. It's all of these partnerships that make Reese a real poster child for environmental success.