Hydrochemistry data for Old Crow River mouth, collected between May and October, 2019

Total and dissolved mercury were measured using oxidation, purge and trap, and Cold Vapor Atomic Fluorescence Spectrometry on a Tekran 2600 Total Mercury Analyzer.Methylmercury and dissolved methylmercury were measured by isotope dilution, distillation, aqueous ethylation, purge and trap, gas chromatography and inductively coupled plasma mass spectrometry using a Tekran 2750 Methyl Mercury Distillation System, Tekran 2700 Methyl Mercury Analyzer, and Agilent 7900 ICP-MS.Filterable and nonfilterable residue concentrations (i.e., total dissolved and total suspended solids; TDS and TSS) were derived from masses of, respectively, evaporated, and dried materials of known original volumes.MDL: method detection limit