Integrated Site Investigation Solutions

Stone Environmental offers high-quality, cost-effective field service solutions and support to environmental consultants who are serious about delivering definitive solutions to their clients’ problems. Our solutions consist of powerful, specialized, technologies and techniques that enable site investigators to more effectively meet their clients’ environmental challenges.

With an increased demand for results, today’s site investigations rely on high-resolution site characterization tools and techniques coupled with dynamic work strategies and detailed Conceptual Site Models (CSMs). Dynamic investigations are far more effective than traditional, soil boring/monitoring well and fixed-laboratory investigations.

The most efficient high-resolution investigations use tools that generate real-time (or near real-time) data in continuous vertical profiles which are incorporated into the CSM and used to dynamically guide the investigation to completion. Investigations utilize both screening-level data and high-quality, fully defensible data to provide a cost effective site investigation. Stone’s integrated site investigation solutions provide a flexible and reliable platform for meeting this unique challenge and delivering defensible results.

Stone’s Integrated Site Investigation Solutions include:

• • Systematic Project Planning and Support
• • Waterloo^{APS TM} Vertical Groundwater Profiling
• • MobiLab^TM: NELAP-Accredited Onsite Laboratories
• • CORE^{DFN TM} Matrix Diffusion Assessment
• • Membrane Interface Probe (MIP)
• • Data Management and Visualization
• • The Triad Approach

Download a two-page summary of our services (156 KB pdf)

Return to top of page

Systematic Project Planning/Support

Stone provides Triad Systematic Project Planning and Support for clients who are new to the Triad Approach. As experienced Triad practitioners and active members of the US EPA’s Triad Community of Practice, Stone’s staff are also highly effective Triad Team participants.

We can assist with Conceptual Site Model (CSM) development and real-time measurement technology selection, particularly for sites where dense non-aqueous phase liquids (DNAPLs) are of concern. Stone can assist with dynamic work strategy development, including decision logic diagram creation to support the effective use of integrated data collection platforms.

As generators of large quantities of field data, we are experienced in data management planning and implementation. Our integrated systems provide easily transferable electronic data deliverables (EDDs). Where required, Stone can provide Demonstration of Method Applicability (DMA) support to help stakeholders realize the unique value of Stone’s integrated site investigation solution technologies.

Return to top of page

The Waterloo Advanced Profiling System (Waterloo^APS) is a subsurface data acquisition system that collects both groundwater samples and an integrated set of companion data in a single, continuous direct push. Uniquely offered by Stone, the Waterloo^APS is a proprietary modification of the original Waterloo Profiler developed by Dr. John Cherry’s research team at the University of Waterloo.

The Waterloo^APS is the premier tool for groundwater profiling because of its short vertical sampling interval and unique dual screen sampling port design. It captures with pinpoint accuracy the significant changes in contaminant concentrations that can occur in just centimeters, while reliably providing defensible quality groundwater samples.

Integrated sensors provide hydrostratigraphic and physiochemical data displayed graphically as the Waterloo^APS tooling is advanced, allowing real-time identification of optimum sampling locations and to ensure formation stabilization required for high quality samples. A sacrificial tip enables retraction grouting of the borehole to prevent vertical migration of site contaminants.

The Waterloo^APS is superior to site characterization technologies offered by other providers as a function of Stone’s advanced proprietary modifications, including:

• • KPRO, unique custom software that provides real-time visual display of:
  • Index of Hydraulic Conductivity (Ik) to:
    • Determine site stratigraphy in vadose and saturated zones
    • Locate optimal depths for samples based on stratigraphy, rather than relying on preset intervals
  • Depth to potentiometric surface (hydraulic head) at each sample depth
  • Depth and rate of penetration
• • Modified sampling tip design, which enables:
  • Increased resistance to sample screen plugging
  • Sample collection in lower hydraulic conductivity settings
• • Integrated data collection:
  • Continuous Index of Hydraulic Conductivity (Ik) record vs depth
  • Hydraulic head measurements
  • Physiochemical properties - pH, specific conductance (SC), dissolved oxygen (DO), and oxidation/reduction potential (ORP)
    • Ensure formation stabilization and provide data to support remedial decisions
  • Near real-time NELAP accredited analytical chemistry results from groundwater samples using MobiLab^TM
• • Nitrogen gas-drive pump allows sample collection when the water table is below the suction limit
• • Constant diameter tooling prevents the vertical movement of fluids along the rod and tip
• • Stainless steel sample tubing rather than PTFE, prevents sorption and desorption of contaminants
• • Unique hybrid drive profiling capability enables profiling to depths of over 500 feet below ground surface
• • Custom data acquisition vehicles house technology, tooling and supplies in self-powered, climate-controlled environments
• • System portability allows easy transport and use at distant locations, such as Europe, Australia and the Caribbean islands

For rapid and reliable high-resolution site characterization, the Waterloo^APS Advanced Profiling System is the clear choice of today’s leading site investigators.

Return to top of page

Stone’s MobiLab^TM is a NELAP-accredited onsite analytical service that provides near real-time, definitive, field-based analysis of volatile organic compounds (VOCs) in groundwater, soil and soil gas media. We generate, manage, and present fully defensible analytical chemistry data onsite, offering the subsurface investigation and remediation community a timely and extremely reliable product.

Our real-time analytical services are essential for today’s expedited site characterization methods which streamline site investigations and remedial decision making. Our field chemists log in, extract and analyze samples in less than 30 minutes using Solid Phase Micro Extraction (SPME), a NELAP-accredited sample preparation technique. Uniquely used by Stone for over 10 years, SPME is now a standard ASTM analytical practice.

The rapid turnaround provided by SPME enables a significantly greater sample throughput than can be achieved using traditional heated head space or purge and trap extraction methods. And SPME sample results are definitive and of equivalent quality to a “fixed-base” laboratory.

Climate-controlled MobiLab^TM trailers are outfitted with GC/X (X = MS, FID, PID or ECD) and supporting systems and materiel. We also establish long-term onsite laboratories to meet client needs during large-scale remediation projects.

Stone’s proprietary Laboratory Information Management System (LIMS) enables us to generate and submit data deliverables in a variety of client-specified formats. We can provide simple daily electronic data deliverables (EDDs), as well as more rigorous formats, such as ERPIMS.

MobiLab^TM provides the following added-value services:

• • Mobile and long-term onsite laboratories to support large projects and remediation
• • Low detection limits and custom analytical programs to meet unique project objectives
• • Level 1 through Level 4 data packages
• • Daily and full data set validation
• • Electronic data deliverables (EDDs), including full ERPIMS compatibility
• • Mass spectrometer compound identification
• • Immunoassay analyses
• • Membrane Interface Probe (MIP) vapor sample analysis

Additional benefits of using MobiLab^TM include

• • Option to analyze an increased quantity of QA/QC Samples
• • Simplified chain of custody and sample administration
• • Longer “per day” field sampling productivity

Return to top of page

CORE^DFN (Characterization of Rock Environments – Discreet Fracture Network Approach) is a unique solution for investigating contamination in fractured, porous bedrock aquifers. Developed by Professor Beth Parker and her research team, CORE^DFN includes specialized techniques for sampling, extracting and analyzing contaminants present within the rock matrix to assess the effects of diffusion of contaminants from fractures into the rock matrix.

In dual porosity rock environments field studies show that nearly all of the contaminant mass may reside in the low permeability rock matrix, but down-gradient transport occurs in fractures. Further, contaminant concentrations in the fractures and the matrix are not in equilibrium, thus sampling only the groundwater from the fractures cannot provide the overall mass distribution.

In fractured sedimentary rock, strong transverse dispersion in the fracture network combined with matrix diffusion can result in very strong plume attenuation. Although the average linear groundwater velocity in fracture networks is much larger than in granular aquifers, the plume fronts in fractured sedimentary rock can advance much slower due to the matrix diffusion effects and sorption in the rock matrix.

Contaminant distributions in chlorinated solvent plumes in fractured sedimentary rock have strong spatial variability due to heterogeneity in source zone contaminant mass distributions, the fracture network, rock matrix characteristics and temporal variability in groundwater flow.

Quantifying the interactions between these domains is essential for understanding site conditions, predicting plume behavior and/or response to site remediation. Conventional fractured rock field investigation methods have proven to be poorly suited for plume delineation or characterization.

• • Boreholes create unnatural flow and contaminant transport conditions within the system known as borehole cross-connection.
• • Monitoring wells and multilevel systems may provide misleading results due to the effects of vertical flow when the borehole is open, allowing cross contamination between fractures with different initial concentrations.
• • Conventional borehole geophysics and hydrophysics provide information on flow under disturbed (cross connected) conditions caused by the open borehole rather than ambient conditions.
• • These conditions will also persist across the screened interval of a conventional monitoring well, and therefore, results from sampling the well will not reflect natural system conditions.
• • Conventional borehole fluid resistivity and temperature logging and borehole flow metering typically indicate only two or three active fractures in each hole, whereas bedrock systems generally have many more active fractures.

CORE^DFN has several advantages over conventional methods in providing contaminant mass and phase distributions more relevant to contaminant behavior than those obtained from monitoring wells or other types of borehole water sampling.

• • Concentration versus depth profiles indicate the occurrence of numerous pathways for contaminant migration in each hole.
• • Matrix contaminant analyses provides a direct measure of contaminant mass storage because the pore space in the rock matrix frequently constitutes nearly the entire contaminant mass storage volume.
• • A time integrated finger print of plume behavior provides better estimations of plume fate and transport.
• • The extent of diffusive contaminant halos in the matrix adjacent to fractures can be used as indicators of the time since contaminant arrival on a fracture by fracture basis.
• • Borehole cross contamination is avoided because the low permeability matrix is not easily cross contaminated during drilling and core retrieval prior to sample collection.

A high-value element of CORE^DFN is the unique use of Microwave Assisted Extraction (MAE). To date, traditional extraction methods have been an obstacle to cost-effective bedrock matrix assessment due to weeks to month-long turnaround times and inefficient sample extraction. Purge and trap methods are inappropriate as they do not extract the mass from the matrix. The shake-flask technique takes up to 5 weeks, and is labor intensive.

Requiring only 45 minutes to complete a full extraction, MAE gives equivalent or higher analyte recovery in a fraction of the time. Field preservation minimizes volatilization losses and results in higher measured concentrations. And MAE enables near real-time on-site analyses of bedrock matrix contamination.

CORE^DFN is a powerful solution that can be utilized to cost-effectively answer fundamental and advanced bedrock contamination questions that are critical to successful site characterization and remediation – and that conventional technologies simply are unable to deliver.

Return to top of page

Membrane Interface Probe (MIP)

The Membrane Interface Probe (MIP) is a rapid screening tool for locating volatile organic compounds in the subsurface. Invented and manufactured by Geoprobe, the MIP collects real-time, vertically continuous data on the distribution of VOCs as well as an electrical conductance (EC) log that is indicative of gross stratigraphy. The MIP uses a number of detectors (electron capture detector (ECD), photoionization detector (PID), and flame ionization detector (FID)) at the surface.

The MIP technique is effective in both the saturated and unsaturated zones, and provides data even in clays and silts, which typically make water samples very difficult to collect. The MIP yields a total VOC detector response, and Stone’s onsite analytical chemistry capabilities allow us to identify the compounds that are present using onsite GC methods.

An excellent screening tool for use in rapid-adaptive investigations, the MIP can very quickly generate a large body of data, locating source areas and plume cores in three dimensions. It is capable of completing 200 linear feet of exploration in a typical day, and the data are immediately available to the site investigator for decision making.

Return to top of page

Data Management and Visualization

For today’s site investigations, large quantities of data must quickly be interpreted in three dimensions to create and/or modify CSMs and to support field-based decision making. When an investigation is complete, advanced data imaging is often required to convey the CSM to regulators, clients, and the public. Our field teams are equipped with laptop computers with mobile broadband internet access. The data can be transmitted to our office in real-time where we employ 2-D contouring and 3-D interpolation and visualization tools to analyze and convey complex data sets.

Known for our sound and efficient data management, software knowledge and perhaps most importantly, a scientific understanding of the physical and chemical processes acting on the site, Stone serves as an added-value support to site investigators.

Working closely with our Applied Information Management (AIM) group, Stone can also provide high-level database-GIS services, including web-enabled and data query, posting and viewing.

Return to top of page

The Triad Approach

The Triad Approach is a site investigation and remediation approach that emphasizes three fundamental aspects of effective project execution:

• • Systematic Planning
• • Dynamic Work Strategies
• • Real-time Measurements.

Systematic Planning is performed by stakeholders and key support organization representatives during which decisions that need to be made to support end-state site uses/goals are identified; environmental and other site attributes critical to support site decisions are identified; a Conceptual Site Model (CSM) is developed; critical environmental and site knowledge gaps are identified; specific investigative actions required to resolve knowledge gaps are defined; decision-based data quality objectives (DQOs) are identified; decision makers are identified; and decision-making rules and processes are developed. Stone is experienced in participating in systematic planning efforts.

Dynamic Work Strategies incorporate the flexibility to change or adapt investigation activities to changes in the CSM resulting from information generated during the field investigation activities. As information is gathered at the site, it is used to automatically initiate pre-designated actions outlined in site-specific decision logic diagrams, to make decisions about what actions should be taken to best resolve remaining data and decision uncertainties and/or to meet regulatory requirements. Stone is experienced in developing dynamic work strategy workplans.

Real-time Measurements refer to data generation mechanisms that support real-time and near real time decision-making. These include direct sensing measurement technologies; sampling methods; analytical methods; and data management, evaluation, and presentation technologies. Stone’s Waterloo^APS, MobiLab, CORE^DFN and MIP capabilities directly support real-time measurement requirements.

When applied to the appropriate site, the Triad Approach yields better outcomes in shorter time frames at lower cost than conventional site investigation approaches. This is accomplished by managing a broad range of uncertainties associated with decision making. A significant aspect of this is managing data uncertainty wherein large amounts of integrated and collaborative data are used to support the CSM. Stone is experienced in producing, managing, and presenting these data in near-real-time.

Additional information on the Triad Approach is available via the following Internet websites:

• • http://www.triadcentral.org/
• • http://www.itrcweb.org/gd.asp

This website is copyright © 2004-2008 by Stone Environmental, except for some images (used by permission) and some source code (used by permission of the developers).