The Santa Fe Group aquifer is an important source of water to communities within the Middle Rio Grande Basin, including the Albuquerque-Rio Rancho metropolitan area and Kirtland Air Force Base, New Mexico. In November 1999, Kirtland Air Force Base personnel observed fuel-stained soils at the Bulk Fuels Facility on the base. Subsequent pressure tests identified pipeline leaks. Fuels stored at the Bulk Fuels Facility have included aviation gasoline, jet propellant 4, and jet propellant 8. The fuels migrated about 480 feet down to the water table. Ethylene dibromide, the constituent making up the most extensive part of the plume and a component of leaded aviation gasoline, has formed a plume that, in December 2016, was 400 to 1,300 feet wide, extended about 5,800 feet northeast from the Bulk Fuels Facility, and was about 3,700 feet from the nearest downgradient water-supply well.

Prior to widespread development of groundwater resources in southeastern Albuquerque, groundwater near the present-day location of the Bulk Fuels Facility flowed to the southwest. Groundwater began flowing northeast in about 1980 towards a large area of lowered water levels caused by groundwater pumping.

In 2013 and 2014 the Albuquerque Bernalillo County Water Utility Authority, the U.S. Air Force, and the U.S. Geological Survey began a cooperative study to characterize the geology and hydrology of the Santa Fe Group aquifer in the vicinity of the ethylene dibromide plume and to develop a local-scale groundwater flow model to delineate areas contributing recharge and zones of contribution to selected water-supply wells.

For this study, a previously developed Middle Rio Grande Basin regional groundwater-flow model was updated, and a smaller local-scale model was developed. Advective groundwater-flow paths were delineated and visualized with the MODPATH particle-tracking program.

Of 11 wells included in the historical pumping analysis of areas contributing recharge, only wells K-3, K-7, and RC-4 derived a portion of their water from simulated recharge sources within the local-scale model. None of the areas contributing recharge overlap the Bulk Fuels Facility area or the ethylene dibromide plume footprint as delineated using December 2016 ethylene dibromide data.

For the historical pumping analysis of zones of contribution, particles for the 11 selected wells generally moved southwest from the north and east boundaries of the local-scale model, moved past their target well, but reversed direction and moved back towards their target well after 1980 when groundwater flow changed to the northeast. Of the 11 wells, only BR-5, RC-5, and VH-2 had 1980–2013 particle pathlines that overlap the December 2016 ethylene dibromide plume footprint, and wells BR-5 and VH-2 have 1980–2013 particle pathlines that overlap the Bulk Fuels Facility area. Particles that were north of the Bulk Fuels Facility when groundwater flow reversed direction would not have the opportunity to interact with the ethylene dibromide plume. Wells BR-5, K-15, and VH-2 did have particles southwest of the Bulk Fuels Facility in 1980. Particles traveling to BR-5 and K-15 passed under or very near the Bulk Fuels Facility area in the 1980–2013 period, but none of the pathlines were shallow enough to interact with ethylene dibromide at the Bulk Fuels Facility. A few particles traveling to VH-2 passed through the Bulk Fuels Facility area at shallow enough depths to interact with ethylene dibromide at the Bulk Fuels Facility in the 1980–2013 period. Ethylene dibromide has not been detected in water samples collected in 2012 through 2015 from the VH-2 well.

Of 10 water-supply wells near the ethylene dibromide plume included in the future pumping analysis of areas contributing recharge, only wells K-3, RC-3, and RC-4 had areas contributing recharge within the local-scale model. The areas contributing recharge for wells RC-3 and RC-4 do not overlap the Bulk Fuels Facility area or the December 2016 ethylene dibromide plume footprint, but K-3 derives part of its recharge prior to 1980 and during 1980–2015 from within the area of the December 2016 plume footprint.

The analysis of the future pumping scenarios indicated that wells BR-5, K-3, K-16, RC-5, and VH-2 have pathlines for 1980–2015 and wells K-16 and VH-2 have pathlines for 2015–50 that when projected in plan view pass through the December 2016 plume footprint. Of these five wells, only K-3 and RC-5 have pathlines for 1980–2015 that are above an elevation of 4,800 feet and could interact with the ethylene dibromide plume if ethylene dibromide was present when the particles were present.