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the magnitude of the decisions that are made based on these data, the technical and economic impacts of using these outdated sampling methods can be enormous.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

The key to the success of any ground-water monitoring program is the effective placement, drilling, design, construction and development of ground-water monitoring wells.  Ground-water monitoring wells and monitoring well networks must be designed based on site-specific hydrogeologic and geochemical conditions, to monitor site-specific compounds of interest so that ground-water sampling teams will be able to collect representative samples for field and laboratory analysis.  Using proper well design, construction and development techniques is also important from the standpoint of ensuring that monitoring wells will continue to produce representative ground-water samples for their planned lifespan, which may be 30 or more years.

This comprehensive 14-module E-Course covers everything from optimizing monitoring well placement and monitoring system design to environmental drilling to proper methods for design, construction and development of ground-water monitoring wells.  In the first 9 modules of this E-Course, instructors focus on the elements that comprise an effective ground-water monitoring program; the importance of establishing monitoring program objectives, data needs and uses; factors that influence optimal monitoring well location and monitoring system design, including site-specific geology, hydrogeology and geochemistry; collecting existing information to create an initial conceptual site model; using modern site characterization methods and technologies to develop a detailed understanding of site geology, hydrogeology and geochemistry; refining the conceptual site model to optimize positioning of wells and well screens; environmental drilling methods available for characterizing sites and installing boreholes, wells and multi-level monitoring systems; and soil sample collection, description and handling.

The last 5 modules of this E-Course focus on practices used in monitoring well design, construction and development to ensure sediment-free samples, including establishing objectives of monitoring wells; sources of chemical interference in monitoring wells; selection of well casing and screen materials; optimizing well diameter; types and designs of well screens; the importance of selecting the proper well screen length to meet monitoring program and sampling objectives; options available for monitoring multiple zones or formations, including multi-level monitoring systems; selecting filter-pack materials and well-screen slot sizes (including use of pre-packed screens); selecting and installing annular seal materials and surface protection measures; designing and installing wells using direct-push technology; and selecting and using appropriate well-development methods.

The substance of more than a dozen ASTM Standard Guides and Practices for environmental site characterization, environmental drilling, monitoring well construction and well development is covered in this E-Course.  In the field video portions of these modules, students learn how various advanced site characterization methods, including discrete and continuous soil sampling, discrete ground-water sampling, remote sensing methods (including soil electrical conductivity, soil hydraulic conductivity profiling and direct VOC detection), and cone penetration testing can be used along with other information to develop a detailed understanding of subsurface conditions.  Additional video segments focus on how to collect soil samples and install small-diameter monitoring wells using direct-push methods and sonic drilling. 

Total CEUs for This E-Course: 15 CEUs

Modules Included in This E-Course