Using Diffusion Samplers to Obtain Volatile Organic Compound Concentrations in Wells is an Internet-based course designed to help state regulators, environmental consultants, site owners, and community stakeholders use Use of Polyethylene-Based Passive Diffusion Bag Samplers to Obtain Volatile Organic Compound Concentrations in Wells (DSP-1). This training focuses on the compounds for which this method is appropriate and presents a procedure for standardizing the use of diffusion samplers.The training course is archived on the web and available twenty four hours a day, seven days a week at http://clu-in.org/studio/seminar.cfm.