CARBON IN THE BRAZOS RIVER ALLUVIUM AQUIFER

Alluvial aquifers are under increasingly intense scrutiny in order to determine their groundwater/surface-water interactions as well as their viability as secondary water sources. There is also interest in carbon due to increased awareness and concern surrounding global climate change. Despite this interest there is a gap in the scientific literature regarding carbon within the groundwater. Work has been conducted regarding the transport of hydrocarbons in the groundwater in reference to contamination, and in regard to the ecological significance of carbon to microbial communities. These studies discuss science parallel to understanding the extent of carbon movement and presence in groundwater however they do not full characterize these things and are therefore typically not as useful for examining the role groundwater might play in the global carbon cycle. The current study seeks to examine the carbon in a local aquifer (Brazos River Alluvium Aquifer) in order to characterize it in a purely hydrogeological and geochemical fashion. The study area has an accessible well network and Baylor University hydrogeology students have a positive relationship with the local groundwater conservation district which improves well access. The methods used include field sampling and in-situ measurements of pH, dissolved oxygen, specific conductance, water levels, and temperature. These in-situ measurements coupled with lab analyses of dissolved carbon species allow evaluation of the carbon system and its interactions with the river, surface recharge, and lateral boundaries. The work may also help to delineate groundwater and surface water interactions in the Brazos River Alluvium aquifer which could be extrapolated to other alluvial systems.