Geochemistry of a septic-system plume in a coastal barrier bar, point Pelee, Ontario, Canada

摘要

The major ion and trace geochemistry of a septic system plume in a shallow sand aquifer was characterized to assess geochemical processes controlling the transport of nutrients and their release to a nearby wetland. The plume was generated from a 16-year-old tile bed, and is more than 60 m long, 40 m wide and 7 m thick. The groundwater pH at the site is near neutral, but up to 0.4 units lower in the plume core as a result of H~+ generated from NH_3 and DOC oxidation in the unsaturated zone. The plume can be divided into distinct redox zones, which show differences in nutrient mobility.