Water resources around the world are contaminated with per- and polyfluoroalkyl substances (PFAS) due to releases from point sources on military installations, fire training centers, and chemical manufacturing sites. Non-point sources have also been identified including wastewater effluent, landfills, and biosolids application. PFAS are a major concern to myriad stakeholders as some are known to bioaccumulate, they have eco-toxicity effects, and they are highly recalcitrant. PFAS are often called “forever chemicals” due to their environmental persistence but many precursor PFAS are transformed in the environment by microbes. Recent work has shown that PFAS can be biologically degraded in laboratory studies, but the microbial populations catalyzing degradation are poorly characterized. We conducted laboratory microcosm experiments to investigate the biotransformation of perfluorohexane sulfonamido propyl amine (PFHxSAm), a predominant precursor in 3M Aqueous Film Forming Foam (3M AFFF), by native microbial populations in upwelling sediment-water slurries from Ashumet Pond, MA. Ashumet Pond is affected by multiple PFAS-contaminated groundwater plumes from Joint Base Cape Cod, MA. The field collected samples were used to construct aerobic microcosms for monitoring PFHxSAm biodegradation. Microbial community composition was analyzed at 4 timepoints using Illumina 16S rRNA gene iTag sequencing and quantitative PCR (qPCR) targeting bacterial 16S rRNA genes. Experiments were performed in triplicate and abiotic controls were included in each experiment. The data release contains the results of Illumina iTag sequencing and qPCR for microbial community characterization. Four tables are provided that describe the experimental bottles, the results of DNA quantification, the results of biomass estimates using qPCR, and the taxonomic data based on sequencing results (provided as a biom file).