Greening Tinker: Safeguarding hazardous material Published April 24, 2012 By Mike W. Ray Staff Writer TINKER AIR FORCE BASE, Okla. -- Tinker AFB produced approximately 12,500 barrels of hazardous wastes each of the past two years, records reflect. To no one's surprise, the bulk of that material, about 90 percent, was generated by the industrial processes necessary for aircraft maintenance, said James Dawson, Tinker's Hazardous Waste Program manager in the 72nd Air Base Wing Civil Engineering Directorate. Hazardous waste from Tinker is discarded through contracts with the Defense Logistics Agency Disposition Service (formerly DRMO), Mr. Dawson said. "Our waste goes to whatever certified disposal facility their contractor chooses to use." Some of the waste is recycled, some is buried in landfills, and some is blended into a fuel that's burned in a cement kiln in Kansas, he said. One common, hazardous substance at Tinker is hexavalent chromium (Cr6+). For example, hexavalent chromium has been detected, among other places, in two of the six now-closed landfills at Tinker, according to Albert Aguilar, chief of the 72nd ABW/CE Environmental Restoration Branch. Van Nguyen, a pollution prevention engineer in the Civil Engineering Directorate, said hexavalent chromium is found in paint primers, conversion coatings, sealant, etc., to provide corrosion protection and improved surface/paint adhesion. Hexavalent chromium also is found in 76th Propulsion Maintenance Group chrome plating, a technique of electroplating a thin layer of chromium onto a metal object. Hexavalent chromium "provides excellent resistance against corrosive environments," said Gary McCracken, Chief, Pollution Prevention Branch, Civil Engineering Directorate. In April 2009, the Department of Defense released a policy memo requiring Cr6+ reduction due to human health and environmental risks, Ms. Nguyen related. Inhaled Cr6+ is a human carcinogen, resulting in an increased risk of lung cancer, and is listed as a hazardous air pollutant. Engineering controls and proper protective equipment are required when working with Cr6+. In recent years the Oklahoma City Air Logistics Center has concentrated on reducing and eliminating Cr6+ because of its high toxicity and cost for control, treatment, and disposal, Ms. Nguyen said. The focus on hexavalent chromium in air emissions at Tinker has resulted in a 43 percent reduction in the carcinogenic, toxic substance since 2005, she reported. "We continue to look for suitable environmentally friendly alternatives" to hexavalent chromium, Mr. McCracken added. The largest recycled waste stream at Tinker is used blast media, Mr. Dawson said. Blast media is employed in several shops on the base, to literally blast paint off planes and parts. The primary blast media is acrylic/plastic, steelshot, or baking soda. "The plastic media is most commonly used, and that is the waste stream we recycle," Mr. Dawson said. 76th MXW leases new plastic media, and the used blast media gets blended to make another product, he said. Spent blast media is collected in 55-gallon drums and sent to the barrel yard at Bldg. 808. The contractor that leases the original material to Tinker "picks up the spent blast media when we have a full truckload." They blend the SBM with other products and sell that material to companies that manufacture blocks for use in the construction of industrial and commercial buildings, Mr. Dawson said. Because the material is recycled, it is exempt from hazardous-waste regulations, he said. "If it were not recycled, a lot of this waste stream would be shipped out as a hazardous waste because of the heavy-metal content." Tinker also recycles office paper, cardboard, aluminum cans, printer cartridges, glass and plastics; however, the revenue producer for the recycling program is scrap metal, according to Randy Joiner, Qualified Recycling Program operations director. Salvageable metals include copper wiring, steel garage doors, steel desks, file cabinets, junk metal, even I-beams from buildings; however, metal from Air Force aircraft is off-limits, Mr. Joiner noted. The QRP collected 781,000 pounds of scrap metal in a recent five-month period, records reflect. Including spent blast media, Tinker produces approximately 600 hazardous waste "profiles," Mr. Dawson said. "A profile just designates the different waste types so we know how to handle it and where to send it." The federal Resource Conservation and Recovery Act identifies how a substance is classified as a hazardous waste. "We analyze the profiles" of the barrels of waste to determine how each should be disposed of properly, said Gary McCracken, chief of the Pollution Prevention Branch in the 72nd ABW Civil Engineering Directorate. "When you factor in the number of decisions that have to be made for each waste stream, and the number of waste streams at Tinker, a multitude of profiles is required so we can correctly identify each waste stream," Mr. Dawson explained. A few examples of hazardous-waste profiles include one for acid scale conditioner used in pumping out some acid tanks; paint chips from two-part stripping processes; nickel-cadmium batteries; disposal of aerosols; rags and other debris from cleaning and maintenance operations; plus used petroleum, oils, lubricants and diesel.