We are honored to announce that MUTKU will be participating in the upcoming Contaminated Site Solutions Summit in Madrid. Their expertise and dedication to advancing solutions for contaminated site management are highly valued, and we look forward to the impactful insights they will bring to the summit. Thank you, MUTKU, for your commitment to environmental innovation and collaboration! 

Soil vapor studies are experiencing a resurgence in popularity with the increased focus on the Vapor Intrusion pathway and the introduction of new tools and analytical methods.  In this presentation we will discuss why understanding a site's soil vapor conditions is so important, how to collect and interpret soil vapor data, and how to use this information for site characterization, conceptual site model development, vapor intrusion assessment, and vapor mitigation.  Throughout the presentation we will present case studies based on sites where the understanding of the soil vapor conditions have helped to streamline the investigation and remediation processes leading to more successful outcomes.    

Sampling events for site investigations require careful planning to ensure the data collected will yield conclusive results.  Consultants and field teams understand their equipment and preparation are critical to human health risk determination. Are all sampling media created equal? Are they all “good enough”?  Data quality objectives provide direction for active vs passive sampling and there are several types of media within these two main categories. Dive deep into side-by-side comparisons of which work best and provide accurate results in a variety of situations. Understand what to consider for your next field event. 

Choosing the right technology for both risk assessments and remediation studies is the key to address the specific issues of each site.

Membrane Interphase Probe (MIP) technology enables high-resolution detection of volatile organic contaminants (VOCs) along a continuous depth profile. In just one push, the vertical and horizontal distribution of VOCs is acquired simultaneously with the lithological (in combination with Direct Push DP applications) and geotechnical information (in combination with Cone Penetration Testing CPT). Running MIP together with the Hydraulic Profiling Tool (HPT) enables a high-resolution structuring of the subsurface in terms of hydraulics, contamination and lithology. Coupling MIP with an On-Site Mass Spectrometer (OMS) represents an innovative advancement that provides high resolution (1 cm vertical) and fast (while maintaining the standard MIP speed of about 2 cm/s) in situ analysis of individual compounds (e.g. PCE, TCE). Identification of the compounds is based on reference mass spectra, which also enables the search for unknown organic volatiles. The accurate quantification of selected compounds is based on external calibration with compound-specific standards that ensure the performance of the MIP-OMS system and enable detection limits down to the ppb range. The most common VOCs, such as chlorinated hydrocarbons and BTEX, can be easily separated with a standard analytical run. Adapted analysis schemes were used for specific tasks (brominated hydrocarbons, tetrahydrofuran). Comparisons with the results of conventional soil and groundwater samples confirm the results.  

This further development of the investigation method illustrates the usefulness of reliable initial investigation methods for an effective site investigation. Large-scale application of low-invasive initial screening can guide and focus subsequent, more expensive methods of soil and groundwater sampling. In addition, it provides significant added value for the successful design of remediation strategies and land redevelopment scenarios and shortens the entire decision-making chain with associated budget savings. Further practice-specific advantages can be achieved: a significant reduction in the detection limits for all MIP-detectable VOCs (e.g. below 10 ppb for CHC and BTEX), a dramatic expansion of the MIP applicability towards plume edges or low-contaminated areas, a correct depth allocation for individual contaminant species at sites with complex contamination, identification of degradation products and verification of natural degradation or determination of VOCs that are difficult to detect with a standard MIP system (brominated hydrocarbons, MTBE or tetrahydrofuran). 

This rapid and continuous over depth investigation enables high-end analysis directly from the screening phase of a site, regardless of hotspots, different source areas or degradation paths.   Additional investigation-bounded costs can be easy justified through a more efficient, target oriented remedial effort able to save at least one order of magnitude higher remedial costs.

Achieving remediation goals from high contamination levels, even in presence of NAPL  - Non Aqueous Phase Liquid - to concentrations in the micrograms range requires the integration of multiple proven technologies. This abstract presents a comprehensive overview of key remediation strategies: In Situ Chemical Oxidation (ISCO), In Situ Chemical Reduction (ISCR), bioremediation, adsorption/oxidation techniques, and the use of surfactants.

ISCO involves the injection of oxidizing agents (e.g., hydrogen peroxide, permanganate) to transform pollutants into less harmful compounds. ISCR, on the other hand, uses reducing agents (e.g., zero-valent iron) to chemically transform contaminants into benign substances. Bioremediation leverages microbial metabolism to degrade contaminants, utilizing either natural microbial communities or bioaugmentation with specialized strains. Adsorption and oxidation techniques, such as activated carbon and catalytic oxidation, effectively trap and break down contaminants. Surfactants can enhance the solubility and mobility of NAPLs, facilitating their subsequent treatment by other remediation methods.

These technologies are often used in combination to achieve synergistic effects, optimizing contaminant removal efficiency. Field applications have demonstrated their capability to reduce contaminant concentrations to regulatory-compliant levels. This integration of remediation strategies is essential for transforming highly polluted sites into environments that pose minimal risk to public health and the environment, showcasing a path from severe pollution to safe, sustainable land use.

Background/Objectives: 

This applied presentation will explain hydro-geo-chemical fundamentals of hydrophobic organic chemical (HOC) behavior including: petroleum hydrocarbons, chlorinated solvents, PFAS, 1,4 Dioxane, and pesticides, in saturated and unsaturated regimes. This encompasses their physical chemistry characteristics, what drives their tendency to phase partitioning from aqueous phases, what drives sorption (i.e. absorb and adsorb), the consequences of interfacial tension, between NAPL and aqueous phases, and how these kinetically limit the ‘availability’ of contaminants for physical, biological and chemical remediation. The objective in to specifically show how the application of selective, sub CMC, surfactant enhanced remediation (SER®) can overcome the limitation of sorption, phase partitioning and interfacial tension to measurably, and sustainably, enhance contaminant phase-desorption of VOC, SVOC, sorbed, globule and NAPL for enhanced remediation.

Approach/Activities: 

SER® case studies are presented explaining the hydro-geochemical conditions of each site which were hindering effective vapor, soil and groundwater remediation, through the clients’ in-situ SER® integration strategy, evidence based monitoring, with statistically evaluation to quantify the measurable benefits realized at each site. Such as coupling SER® with multi-phase extraction (MPE) and/or aggressive fluid vapor recovery (AFVR) strategies, which significantly truncated the duration of remediation, compared to the predictive models, to achieve regulatory objectives, and/or risk based closure for the involved sites.

The presentation will be technically underpinned by established scientific principles, supported by site data, figures, tables, and three-dimensional computer models for improve audience conceptual command of SER® for sustainable remediation of PFAS, Petroleum Hydrocarbons, and Chlorinated solvents.

Results/Lessons Learned: 

SER® remediation can be employed to overcome the principle hydro-geochemical factors that constrain the availability of NAPL, globule (ganglia), sorbed, and vapor phase contamination, for most physical, biological, and chemical remediation strategies, compared to when combined with SER® to realize synergistic benefits. Additional benefits included resolution of measurable and mobile LNAPL and DNAPL, significant project life-cycle time and cost savings, for achieve regulatory and/or risk-based closure.