In Karnes and Wilson counties, the number of new oil and gas production wells has increased substantially since completion of the Phase I report. Few surface water and sediment samples have been collected in the area. The USGS continued long-term sampling at a subset of currently-sampled stream sites and new focused sampling of additional stream sites within the Lower San Antonio River (LSAR) Basin where oil and gas production is most active. The study estimates the change in land cover in the central portion of the LSAR Basin due to the conversion of rangeland to well pads sites, new roads, and storage ponds. In addition, streambed-sediment samples will be collected where oil and gas production is most active and was analyzed for polyaromatic hydrocarbon (PAH) and other potential pollutant concentrations.
See the report on possible environmental effects of processes associated with oil and natural-gas production here.
