Biopolymer Production in the Aquifer of a Groundwater Pump-and-Treat System

Abstract

BACKGROUND: The Kirtland Air Force Base (KAFB) Bulk Fuels Facility (BFF) has served as a central supply for aviation fuels since 1951. During an undetermined period from 1953 to 1999, subsurface vacuum offloading pipeline failures resulted in intermittent release of aviation gasoline (AvGas) and jet propellant fuel grades 4 (JP-4) and 8 (JP-8). AvGas contains ethylene dibromide (EDB), lead scavenger, and regulated compounds referred to as BTEX (benzene, toluene, ethylbenzene, and xylene). The resultant plume of BTEX-EDB-contaminated groundwater is being actively managed and treated. The low density BTEX (light nonaqueous phase liquid, or LNAPL) contamination is present in the vadose zone and is actively being treated using monitored natural attenuation. The EDB contamination is present in the dissolved form in the distal part of the plume under the city of Albuquerque. A pump-and-treat (P&T) process consisting of extraction wells and the site's groundwater treatment system (GWTS) is removing this contamination. These P&T systems, similar to the one at KAFB-BFF, are easy to understand and implement. The GWTS system was designed according to site characterization and treatment needs. In the case of the KAFB-BFF, the treatment consisted of a sorptive removal operation using granular activated carbon (GAC) with minimal filtering or other treatment. Other components of the system provided water movement from the aquifer to the GAC and then to disposal. The aquifer tests prior to installation exhibited a specific capacity of 22.4-44.8 lpm per foot of drawdown. The system was designed on the basis of the assumption that the aquifer would sustain pumping rates of 120 gpm or greater. At the KAFB-BFF, secondary factors emerged that necessitated changes in the primary system designs and operating conditions.