Abstract Determination of chemical reactions and their reaction rate coefficients on a field scale is of concern in many hydrogeological and environmental issues. A push-pull test provides an excellent way to determine this. A simplified method for the interpretation is given in the literature. Here, the accuracy of the method is studied by analysing the observations from a push-pull test performed in the Belgian coastal plain with the simplified method, calculating the confidence intervals for the results and interpreting the observations with TRACER3D, a numerical model. It is shown that by calculating the confidence intervals and using the numerical model, additional usable information can be elicited from the test. Aerobic respiration and denitrification were both derived from the single test together with their first-order reaction rate coefficients.

Keywords denitrification; modelling; parameter identification; push-pull test