A network of nested wells will be established that will extend from an agricultural field out to an adjacent tidal creek and marsh, located at the Brownsville Research Site. There will be a sampling location at the center of the field, perimeter of the field, creekbank, and marsh. Two samples will also be obtained from Phillips Creek at upstream and downstream locations. Static water levels in the wells will be made with a hand-held water-level recorder and samples will be obtained with a small peristaltic pump.