The MIP coupled with an electrical conductivity sensor will provide continuous stratigraphic information of the soil as well as semi-quantitative concentrations of volatile organic compounds (VOCs). The MIP can be used in both saturated and unsaturated materials to detect VOCs in the gaseous, sorbed, dissolved or free phases. The “Membrane” acts as an interface between the VOCs in the subsurface and gas phase detectors at the surface.
The HPT system is designed to evaluate the hydraulic behavior of unconsolidated materials. As the probe is pushed or hammered at 2 cm/s, clean water is pumped through a screen on the side of the HPT probe at a low flow rate, approximately 300 mL/min. Injection pressure, which is monitored and plotted with depth, is an indication of the hydraulic properties of the soil. That is, a relatively low pressure response would indicate a relatively large grain size, and the ability to easily transmit water. A relatively high pressure response, however, would indicate a relatively small grain size and the lack of ability to transmit water.
The MiHPT is the combination of the MIP with the HPT. This direct-sensing tool detects volatile contaminants with the MIP, measures soil electrical conductivity with a standard (MIP) dipole array, and measures HPT injection pressure using the same down-hole transducer as the Geoprobe® stand-alone HPT system. In post-processing the log data with Geoprobe® DI Viewer software, the user is able to estimate hydraulic conductivity (K) and water table elevation, as well as prepare graphical outputs of the log data.
S2C2 has been providing direct-push sampling services since 1998. S2C2 has three direct-push units (7822DT, 6622DT and a 6600 truck unit) all capable of collecting soil, groundwater and soil gas samples as well as installling permanent monitoring wells. All of our units have moyno grout pumps installed to properly seal the completed boreholes at the conclusion of the investigation.
S2C2 has been a leader in developing on-site characterization methodologies and dynamic work strategies central to streamlined site characterization programs. An integral part of this approach is the ability to manage and visualize large data sets. S2C2 has all the tools and experience to provide complete data management and data visualization services for any size project.
Low Level MIP (LL MIP) is a technology developed by Geoprobe Systems® that greatly increases the sensitivity of the MIP logging tool. The primary feature of LL MIP technology is that the carrier gas stream that sweeps the internal surface of the MIP membrane is pulsed. This results in an increase in the concentration of VOC contaminant delivered to the MIP detectors.
Low Level MIP can be performed with standard MIP probes or MiHPT probes. The addition of the LL MIP to the system is simple and requires only the rearrangement of gas line connections. This controller can then be easily removed from the system to return to standard MIP logging. Switching between methods requires only a few minutes of time.
In addition to the standard MIP setup, S2C2 can run a system that uses a heated trunkline. Unlike traditional MIP setups where the MIP probe is the only portion of the system that is heated, Geoprobe’s HTL will be used to heat the entire trunkline to approximately 100 degrees C along its entire length. The heated trunkline moves the contaminant through the trunkline quicker than a traditional trunkline. This reduces the typical slurred baseline drop seen when dealing with high concentrations of contaminants.
Traditional site characterization techniques fail to provide the data density required to adequately define site conditions and often leads to repeated site characterization events and/or failed remedies. The use of direct-sensing/real-time data technologies and adaptive sampling plans in conjunction with collaborative data sets provides a streamlined methodology to characterize environmental contaminated sites.
The OIP is a powerful tool capable of detecting and logging UV induced hydrocarbon fluorescence in the subsurface.