Direct Push Technology - As Useful as Ever...and Cost Effective Too

Direct-Push Technology (DPT), including Cone Penetrometer Testing (CPT), Membrane Interface Probe (MIP), laser induced fluorescence (LIF), and in-situ groundwater and soil samplers provide efficient, cost-effective methods for environmental professionals to investigate and remediate contaminated sites. The relatively high costs of evaluating groundwater quality for site assessments, coupled with regulatory agency compliance requirements, create an increasing financial burden on prospective clients. This combined technology can provide an edge in an increasingly competitive environmental industry. This workshop will provide an overview of DPT for investigation and remediation applications.

DPT data are objective, reproducible, and can be used to define site stratigraphy, and differentiate between granular aquifer and aquitard units. In-situ soil and groundwater DPT samplers may be used to collect soil and groundwater samples at select or targeted depths.  The CPT tool provides a cost-effective method to help determine the targeted sampling intervals.

DPT, in conjunction with laboratory analysis of the sampled soil and groundwater, can aid in interpreting the following without drilling wells or borings:

• Site stratigraphy
• Soil and aquifer characteristics
• Groundwater chemistry
• Type/concentration of groundwater contamination
• Vertical and horizontal extent of groundwater contamination
• Presence of free product and its thickness

 

Hydrogeologic and geologic data obtained from these methods can maximize the design, efficiency and cost-effectiveness of groundwater monitoring systems. Well location and screened interval placement can be optimized prior to initiating the actual field installation.

DPT provides a clean and less intrusive means of geologic and environmental investigations, with minimized risk of exposure to subsurface contaminants. Site disturbance and investigation-derived waste generation are minimized using DPT; with no soil cuttings generated and producing a small-diameter hole which is sealed with grout. Therefore, an important benefit of using the DPT methods is that few soil or groundwater investigation-derived waste products are produced, thus reducing disposal costs and minimizing personnel exposure.

 

The direct push tools and sampling methods can be used in suitable geologic material including unconsolidated clays, silts, sands and fine gravels. The DPT can be driven with CPT or Geoprobe^® (truck) rigs or can be combined with conventional drilling methods. Special equipment may also be used to address limited access conditions.

This course will explain CPT; Geoprobe®; soil and groundwater samplers; LIF including UVOST; and MIP equipment, operations, measurements, sampling, calibration, and interpretation of data. Additionally, this course will provide a discussion on the framework and criteria for the use of DPT in the design for subsurface remediation (treatment). Examples from investigations and remedial actions using DPT will be highlighted throughout the course; to demonstrate the applicability of these methods.

The instructors will review a large number of “hands-on” project examples as part of this workshop. Attendees are encouraged to bring their own DPT data they have questions about; to discuss them with the instructors and workshop attendees.