Water quality at Chaco Culture National Historical Park and the potential effects of hydrocarbon extraction

Groundwater in Chaco Culture National Historical Park, sourced from the Gallup Sandstone aquifer, is among the oldest and most geochemically evolved on record, with a median age of approximately 41,000 years. A comprehensive geochemical analysis revealed evidence suggesting mixing between aquifers and potential contamination by hydrocarbons, likely facilitated by numerous extraction boreholes. Key indicators include fractionated noble gases, trace hydrocarbon-related volatile organic compounds (VOCs) in the park’s main supply well, and major ion trends pointing to cross-aquifer mixing. While these findings hint at possible impacts from oil and gas extraction, further research is needed to distinguish between natural processes and anthropogenic influences.

Linhoff, B. S., Beisner, K. R., Hunt, A. G., & Shephard, Z. M. (2023). Water quality at Chaco Culture National Historical Park and the potential effects of hydrocarbon extraction. Journal of Hydrology: Regional Studies, 47, 101430. https://doi.org/10.1016/j.ejrh.2023.101430