Variables: total_organic_carbon electric_conductivity pH Keywords: land use Systems: groundwater Substances: 18-beta-Glycyrrhetinic acid (MPDGHEJMBKOTSU-YKLVYJNSSA-N) 1-Naphthylacetic acid (PRPINYUDVPFIRX-UHFFFAOYSA-N) 4-Dimethylaminoantipyrin (Aminopyrin) (RMMXTBMQSGEXHJ-UHFFFAOYSA-N)