This is a Technology Guide developed under SERDP project, “Development and Field-Testing of Advanced Passive Samplers for PFAS". The DGT passive sampler is a kinetic passive sampler for PFAS in water. It accurately measures dissolved PFAS concentrations in a wide range of water conditions via two-week sampler deployment, laboratory extraction, and sampling-rate-based calculation of time-weighted-average PFAS concentrations. This practical guide will explain the necessary steps to deploy and extract the DGT sampler, and calculations necessary for determining PFAS concentration.