Collection of ground-water samples from monitoring wells is a critical component of environmental investigations at many sites.  Traditional ground-water sample collection methods, including well-volume purging and sampling using bailers and high-flow-rate pumps, and purging wells to dryness prior to sampling, are subject to significant sources of  bias and error that commonly result in either over- or under-estimation of actual sample concentrations and poor precision and accuracy.  Given the magnitude of the decisions that are made based on these data, the technical and economic impacts of using these outdated sampling methods can be enormous.  It is thus exceedingly important to use more up-to-date methods, like low-flow purging and sampling and no-purge sampling, which have been demonstrated by many field research studies to produce higher quality samples so all stakeholders can have much higher confidence in sample analytical results. 

This 13-module E-Course comprehensively covers the topic of ground-water sampling using the U.S. EPA-developed and approved procedure referred to as low-flow purging and sampling (and sometimes as low-stress purging, Micropurging or minimal drawdown purging), and the newer methodology referred to as no-purge sampling.  This E-Course explains why and how low-flow purging and sampling and no-purge sampling produce dramatically improved and more consistent sampling results AND significant cost savings.  The first 2 modules of the course set the stage for the remainder of the course by covering the science behind ground-water sampling, including collection and use of water-level data; sources of bias and error in water-level measurement; correct procedures for measuring water levels in wells; the importance of developing an understanding of the physical and chemical properties of ground-water samples; how samples should be collected and handled to preserve these properties; how traditional (well-volume) purging and sampling methods can result in significant sources of error in field and lab analyses; and how and why more up-to-date (low-flow and no-purge) sampling methods provide much-improved sampling results. 

The remainder of the course focuses on the elements included in conducting low-flow purging and sampling and no-purge sampling programs; what types of ground-water sampling equipment are compatible with low-flow sampling (electric submersible pumps, bladder pumps and other positive-displacement pumps); selection, operation and use of no-purge sampling devices (HydraSleeve, passive diffusion bag sampler and snap sampler); proper use of water-level measurement equipment during low-flow purging and sampling; how to measure critical field water-quality indicator parameters during low-flow sampling; field equipment decontamination procedures;  implementation of field quality assurance/quality control protocols to ensure both precision and accuracy in ground-water sampling events;  ground-water sample pre-treatment methods (filtration and preservation); ground-water sample handling and shipment; and documentation of ground-water sampling events to ensure defensibility of data.

The field video portions of these modules focus on all of the field practices and procedures used to effectively implement low-flow and no-purge ground-water sampling events, including operation and use of a variety of pumps; pump setting and operation for low-flow purging and sampling; water-level measurement and field water-quality indicator parameter measurement to stabilization; assembly, deployment and retrieval of no-purge sampling devices (HydraSleeve and PDBS);  sample collection, filtration and preservation; proper collection of field quality control samples; sample packaging and shipment; and field equipment decontamination.

Modules included in the course