Groundwater nitrate profiling by passive sampling over extended depth beneath the water table: A demonstration

A multi-layer sampler, developed on the basis of a previously described dialysis membrane technique, was used to passively sample groundwater nitrate (NO3) in two unconfined aquifers. Monthly sampling performed over a 3 month period at each location has shown the feasibility of using this technique over extended depth, and that it can provide a detailed and highly repeatable characterization of the groundwater chemical profiles.