Kirtland enhances its fuel spill soil vapor removal Published May 2, 2014 By Lee Ross Nucleus editor KIRTLAND AIR FORCE BASE, N.M. -- Kirtland has expanded its investigation and remediation of the vadose zone, the soil layer contaminated by the fuel spill. This interim remediation measure is designed to address the fuel spill, according to information on the New Mexico Environment Department website. Fuel vapor is drawn from purpose-built wells adjacent to the old Kirtland fuel facilities offloading ramp on the west side of the base, where the fuel leaked into the ground. The fuel vapor is drawn out using a catalytic oxidizing soil vapor extraction machine, called CATOX, using a technology similar to a car's catalytic converter. The CATOX, which burns the contaminants at about 1,000 degrees, can now draw vapor from five wells. That's up from just two wells attached to the unit previously. The wells have holes at different depths to draw air from the soil above the light non-aqueous phase liquid, or LNAPL. According to Scott Clark, one of Kirtland's environmental engineers working to resolve the issue, it's important to draw the contaminants from the soil before they settle into the LNAPL. Adding the three wells, which are all attached to a single CATOX unit, helps to optimize the effort, he said. "As the amount of contaminants you draw from one well decreases, you can rotate to another well to optimize vapor removal," he said. "We know we're going to increase what we're pulling out." That's because the CATOX has an effect on the movement of the contaminants as it draws them out of the soil. Pocket of fewer contaminants are created over time, which is why the ability to use other wells helps with efficiency, Clark explained. "The intent is to use the CATOX to maximum efficiency," Clark said.