Five T&M Abstracts Selected for Battelle’s Chlorinated Conference

May 12, 2026

T&M is proud to be selected to present four posters and one platform presentation at Battelle’s International Conference on Remediation of Chlorinated and Recalcitrant Compounds in Fort Worth, Texas.

Battelle’s Chlorinated Conference is recognized as the signature forum for the environmental remediation industry. The conference is the premier gathering of environmental professionals researching and applying innovative technologies and approaches for characterization, monitoring, cleanup and management of complex sites contaminated with the most challenging classes of chemicals.

Summary of T&M Presentations at Battelle:

LNAPL Plume Characterization and Recovery Network Expansion Using UVOST/LIF/HPT Borings and Recovery Well Data
Platform Presentation: Presented by Scott Blanchard, T&M Associates

A PCB‑impacted LNAPL plume was first identified at an industrial site in the Midwest United States approximately 30 years ago. Initial characterization in the 1990s relied on the presence or absence of LNAPL in shallow piezometers and the thickness of accumulated product, and this information guided the design of an active LNAPL recovery system installed in 2005. More than 30,000 gallons of PCB‑impacted LNAPL have been recovered to date; however, questions remained regarding whether the system was nearing an endpoint or whether recoverable LNAPL remained in areas not well characterized by earlier investigations. Advances in rapid, real‑time, in‑situ LNAPL characterization—such as the Ultra‑Violet Optical Screening Tool (UVOST) and laser‑induced fluorescence (LIF) direct-push instrumentation—provided an opportunity to re‑evaluate the plume and identify potential locations for additional recovery wells or trenches to accelerate progress toward closure.

A grid of UVOST/LIF/Hydraulic Profiling Tool (HPT) borings was installed across and around the known plume footprint, with each boring advanced through the anticipated LNAPL interval and several feet deeper to ensure complete vertical coverage. A Triad approach was then used to refine boring locations and resolve plume boundaries between and beyond the initial grid. Multiple analytical and interpretive methods were applied to the resulting dataset, including 3D modeling of relative emitter (%RE) and HPT data, and 2D evaluations of long‑term recovery trends, transmissivity test results, maximum %RE values, vertical LIF response thickness, and hydraulic conductivity within the LNAPL zone. Individual and weighted composite contouring analyses were used to identify optimal locations for system expansion. Based on these results, the LNAPL recovery system is scheduled for expansion in 2026 to enhance recovery efficiency and move the site closer to achieving an endpoint for LNAPL remediation.

Identification of DNAPL Recovery Locations within a Chlorinated Ethene Source Area
Poster Presentation: Presented by Megan Burns, T&M Associates

Leaks from underground piping associated with a trichloroethene (TCE) aboveground storage tank created a substantial DNAPL source zone at an industrial site in the southern United States. The source area lies within a stratigraphic sequence of silt and clay overlying a shallow sand aquifer and a shaley‑clay aquitard (SCA). DNAPL was first identified during an RI/FS in the early 1990s, and approximately 200 gallons were recovered from monitoring wells between 1993 and 2003. A 2017 sonic drilling investigation, which included continuous logging, PID screening, and soil sampling, delineated roughly two‑thirds of an acre where DNAPL was present on the SCA. Installation of a groundwater extraction well in 2020 provided plume control and unexpectedly yielded 940 gallons of DNAPL within one year, demonstrating the effectiveness and low cost of direct DNAPL recovery. This success prompted additional high‑resolution investigation using Dye‑Laser Induced Fluorescence™ (DyeLIF) to identify locations for further recovery wells.

DyeLIF borings were installed across the previously defined source area, and a Triad approach guided placement of additional borings based on real‑time results. The DyeLIF system was paired with a Hydraulic Profiling Tool™ (HPT) to collect permeability data throughout each boring. Results showed that DNAPL was less continuous than suggested by the 2017 investigation. Multiple datasets—including DyeLIF response, HPT permeability, SCA topography, PID readings, analytical results, and DNAPL thickness—were integrated using both 2‑D and 3‑D visualization methods. Weighted combinations of these datasets were used to refine the interpretation of DNAPL distribution. Based on this analysis, a location was selected for installation of a second DNAPL/groundwater recovery well in 2026, with the potential for additional wells depending on future recovery performance.

Comparison of HRSC Tools for Investigating a DNAPL Source Zone
Poster Presentation: Presented by Scott Blanchard, T&M Associates

Leaks from underground piping associated with a trichloroethene (TCE) aboveground storage tank created a DNAPL source zone covering approximately 27,000 square feet at an industrial site in the southern United States. The horizontal and vertical extents of the DNAPL source area were characterized in two high-resolution site characterization (HRSC) investigations completed in 2017 and 2025. The 2017 investigation utilized sonic borings with soil samples analyzed onsite using USEPA SW-846 Method 8265 (Sonic/8265). The 2025 investigation used a combined Dye-Enhanced Laser-Induced Fluorescence™ and Geoprobe® Hydraulic Profiling Tool (DyeLIF/HPT).

Both HRSC approaches provided reliable data for the elevation of the SCA interface and stratigraphy the combined data were contoured to identify low spots on the SCA where DNAPL could have accumulated. The DyeLIF/HPT provided greater daily production at about 200 feet/day compared to 150 feet/day for the Sonic/8265. The DyeLIF/HPT borings produced less waste and were less expensive per boring and per foot. The Sonic/8265 borings were able to penetrate the SCA for additional characterization not possible with the DyeLIF/HPT. The Sonic/8265 approach provided an overall higher confidence in the identification of DNAPL and provided both speciation of NAPL contents and component concentrations. Three of the four DyeLIF/HPT borings completed adjacent to Sonic/8265 borings with known DNAPL failed to detect DNAPL, and overall, the DyeLIF/HPT borings depicted comparatively less DNAPL. This result is not surprising given a complex distribution of DNAPL in the subsurface and the need for the narrow DyeLIF window to be in close proximity to free-phase DNAPL for a positive response. Positive responses did occur with the DyeLIF but at a significantly lower frequency compared to the Sonic/8265 borings. The Sonic/8265 borings could identify DNAPL in the general proximity of the boring through elevated TCE concentration, even if the boring did not directly encounter DNAPL. This provided significant advantage for the Sonic/8265 approach in a study intended to map the architecture of DNAPL in the subsurface.   

Comparing Three Approaches for Identifying Soil Impact beneath an Industrial Building Slab Using Soil Gas
Poster Presentation: Presented by Jamie G. Kuder, T&M Associates

A soil gas investigation was conducted in 2025 at a former industrial manufacturing facility in the Midwest to evaluate the presence of residual DNAPL beneath a one‑million‑square‑foot slab slated for removal as part of ongoing remediation. The objective was to determine whether subslab soils required treatment prior to or during slab demolition and to identify the most effective sampling method for a full‑scale investigation. A pilot study compared three commonly used subslab soil gas sampling approaches—active sampling with Summa canisters, and passive sampling using Beacon and amplified geochemical imaging (AGI) adsorbers—to assess differences in analytical results, deployment practicality, and overall suitability for large‑scale application.

Pilot testing at three slab locations showed that all methods detected chlorinated VOCs, including PCE, TCE, and cDCE, with PCE present in every sample. The Summa canisters produced the fewest detections, while the Beacon adsorbers identified the greatest number of constituents, including low‑level detections of additional compounds such as benzene and xylenes. Passive sampler installation and retrieval were more efficient and required less equipment than active sampling. Considering analytical sensitivity, ease of use, and cost, the investigation concluded that a passive method was preferable for the full‑scale study. Beacon samplers were ultimately selected due to their broader detection range and lower per‑unit cost compared to AGI adsorbers.

Assessing LNAPL Transmissivity and Recoverability for Wells within a PCB-Impacted LNAPL Plume
Poster Presentation: Presented by Sarah N. Olszewski, T&M Associates

Recovery of PCB‑impacted light non‑aqueous phase liquid (LNAPL) has been conducted for approximately 30 years at a remediation site in the Midwest United States, yielding roughly 30,000 gallons of recovered product from 52 wells. Although many wells continue to accumulate LNAPL, only a small subset contributes the majority of recoverable product, highlighting the need for an objective method to determine when individual wells can be decommissioned. This study evaluates the use of baildown transmissivity testing, following API guidance, as a tool for assessing LNAPL recoverability and compares transmissivity results with actual long‑term recovery performance.

Transmissivity tests were performed at 21 wells and compared to a year of consistent LNAPL recovery data. Initial tests provided a useful screening tool but, in some cases, overestimated recoverability, likely due to LNAPL drainage from the sand pack surrounding the recovery well. A year of consistent LNAPL recovery appears to provide a more accurate measure of LNAPL recoverability, although no convenient literature value for recoverability could be identified for this method. A second round of transmissivity testing produced results similar to the findings of the yearlong recovery efforts, with the added benefit of the API guidance values for establishing LNAPL recoverability. If the results of the first transmissivity tests had been used for decision-making, some unproductive recovery wells would have been retained in the recovery system and a few productive wells would have been abandoned.