DOCUMENTING SALTWATER INTRUSIONS IN AGRICULTURAL LANDS OF EASTERN NORTH CAROLINA

Saltwater intrusion has the potential to adversely affect agricultural lands in low-lying regions of eastern North Carolina. In this study, the authors use several approaches to document saltwater intrusion in an agricultural field in Hyde County (North Carolina). Multiple clusters of piezometers were installed at varying depths at various locations in the agricultural field to monitor salinity and water levels in the surficial aquifer. Additional monitoring sites were established to monitor salinity and water levels in surface water bodies that included creeks, canals, and drainage ditches. Preliminary results reveal high concentrations of saline water (1.5 to > 18 ppt) in nearby surface water bodies. Salinity measurements taken at varying depths from piezometers also reveal high concentrations of saline water (3.9 to > 8 ppt) in the surficial aquifer. The measurements from the cluster in problem areas highlight an unusual trend in salinity: the shallowest well displays the lowest salinity and the intermediate well displays the highest salinity, whereas the deepest well displays intermediate salinity. Water level measurements collected from several piezometers show that the vertical flow direction is generally upwards at the field site. These results suggest that the saline water may emanate from both shallow (e.g., canals) and deeper water sources (i.e., aquifers). It is envisioned that this study will be useful to environmental managers for addressing saltwater intrusion problems in low-lying coastal regions in the State.