Real-Time, High Resolution Site Characterisation using Direct Sensing Technologies

Announcement posted by Numac Drilling Services Australia 04 Jul 2013

Numac experts explain new technologies for environmental mapping

Numac's David Heicher is a Hydrogeologist with 20+ years in environmental consulting, drilling, and technology with a strong background in environmental site characterisations, contaminant delineation, and contaminant modelling. He has had extensive experience over the last nine years operating high resolution vertical mapping systems – including direct sensing technologies - that provide real-time data and modelling at contaminated sites. David presented at the Melbourne ALGA meeting and was written up in the May ALGA journal about MIP and LIF.

Direct sensing technologies provide a series of versatile tools for mapping soil and groundwater contamination, specifically volatile organic compounds (VOCs) such as halogenated solvents, petroleum compounds, as well as methane. The tools
most widely used are membrane interface probe (MIP), Laser Induced Fluorescence (LIF) and the
(HPT).

Membrane Interface Probe (MIP)
Membrane interface probe tooling is used in conjunction with direct push drilling methodologies whereby a probe is ‘pushed’ into unconsolidated strata to gain high resolution vertical data on contaminants. Under a concentration gradient, VOCs move
across the membrane on the probe via diffusion and then are carried to the detectors at the surface with an inert carrier gas.
This allows for real-time, high resolution vertical mapping of
subsurface contamination on sites such as:
• Retail service stations/depots;
• Petrochemical (Refinery) facilities;
• Landfills;
• Dry Cleaners;
Rail, bus, transport facilities
Defence sites
Industrial/ Commercial, & Manufacturing facilities; and
• Environmental pre- and post-remediation assessments.
MIP can provide real time, high density data (65 data points per meter) which is ideal for delineating the horizontal and vertical extents of a contaminant plume. The data collected
using MIP can also be incorporated into real time interactive 2D/3D Graphics. After each MIP location, data is processed and incorporated into state-ofthe-art visualization software.
Graphics are then generated and regenerated throughout the project to determine horizontal and vertical delineation, contaminant volumes, and data gaps (i.e. where to install next MIP location).

Laser Induced Fluorescence (LIF)
Non-Aqueous Phase Liquid (NAPL) mapping tool used to
delineate the depth and horizontal extent of free product
and residual petroleum contamination. LIF can identify and
differentiate between petrol, diesel, oils (hydraulic, waste,
motor, cutting, crude), creosote, and coal tars on sites such as:
• Gasoline/fuel retail stations and petroleum terminals;
• Underground Storage Tank (UST) sites;
• Oil refineries;
• Manufactured Gas Plants (MGPs);
•Wood treatment facilities;
• Creosote residues; and
• Rail Yards.
Hydraulic Profiling Tool (HPT) with Electrical Conductivity HPT collects real-time, high resolution data that helps determine hydraulic properties and soil lithology. HPT
data can be used to identify preferential contaminant pathways, remedial injection zones, and monitoring/ recovery well screen intervals. Estimated K Values (hydraulic conductivity) can be obtained as well as estimated standing water levels of groundwater. As a combination, HPT and MIP data can provide a comprehensive and complete site characterization model.

For more information visit numac at www.numac.com.au

Numac is a specialist contractor of Drilling, Demolition, Tank Removal (AST's & UST's), Excavation and Remediation Equipment Hire for Site Divestment and Soil and Water Remediation to Professional Consulting firms across a broad range of industry sectors. Untiring customer service, deep knowledge, and a passion for doing it right every single time underpin all that we do.

Our technical expertise is enhanced by our enthusiasm for innovation, resulting in clever and efficient solutions for a diverse range of client needs. So whether it is managing a project around site divestment, soil contamination, environmental drilling or goetechnical drilling, we deliver those solutions with a refreshing level of friendly, personal service.