Wednesday, May 1, 2013: 3:15 p.m.
Regency East 1 (Hyatt Regency San Antonio)
The Nueces River, located in the South Texas Gulf coast area, represents one of the main sources of freshwater to nearby communities and industry such as the City of Corpus Christi, Flint Hills Refinery, and San Patricio Municipal Water District. There is emerging concern that this vital resource is threatened by water quality degradation, specifically pertaining to increased total dissolved solids and salinity concentrations in the river segments; adjacent to Hazel Bazemore Park and the Calallen Pool. Groundwater, which can accumulate exceptionally high concentrations of contaminants, has been shown to contribute to water quality degradation in coastal systems worldwide. Given the arid nature of south Texas embayments, it is conceivable that groundwater represents a significant source of freshwater and contaminants and may play a critical role in surface water quality degradation. However, groundwater contribution is entirely unknown for this area as well as for most of the Texas coastal area. Preliminary electromagnetic and magnetotelluric data along with groundwater and surface water quality parameters collected from Hazel Bazemore Park indicate that total dissolved solids concentrations gradually decreases with proximity to the river bank. This suggests the possibility of groundwater-surface water interaction through mixing processes such as diffusion and dispersion. The purpose of this project is to evaluate the salinity source to the Nueces River through extensive analyses of groundwater-surface water interaction near Hazel Bazemore Park and the Calallen Pool. To accomplish these objectives a combination of geophysical methods will be implemented. Land and marine resistivity soundings for vertical profiling of subsurface groundwater discharge and direct detection of upwelling conductive groundwater will be conducted along several transects across the river and banks. Magnetotelluric soundings will complement land-resistivity data for improved nearbank hydrostratigaphic analysis.
