Antibiotics in Groundwater Tracer Injection

U.S. Geological Survey (USGS) scientists conducted a unique study, which demonstrated that the ecology of natural groundwater bacteria changed after exposure of the bacteria to the antibiotic sulfamethoxazole (SMX). The study was conducted within the zone of the historic wastewater-contamination plume at the Cape Cod Toxic Substances Hydrology Research Site, Massachusetts. SMX and bromide (contained in the plastic drums on the far right) were repeatedly injected into the row wells (in the center of the photo) for 30 days. The SMX traveled through the subsurface to the observation wells on the far left.