As summer wanes, the crew at AST would like to share a few fascinating projects with you as well as announce our 2024 Fall Webinar Series.
CAT 100 reduces TCE from over 100,000 ug/L to under 100 ug/L in less than 1 year at geologically complex site in New Jersey
In 2023 the AST team completed an application of CAT 100CAT 100 is a fusion of RPI’s BOS 100® and biotechnology to produce technology capable of achieving results beyond the capabilities... at a large manufacturing site located in New Jersey. The design was based on the collection of almost 700 soil samples and 150 groundwater samples across a 45,000 square-foot area where chlorinated ethenes were detected at the highest levels. A 3-D quantitative High Resolution Site CharacterizationAbreeviated as qHRSC. High-resolution quantitative groundwater and soil sampling and analysis, geophysical methods, and aquifer characterization are combined to develop... (qHRSC) model was developed by AST, and a series of “heat” maps were generated from the model to identify areas of concentrated impacts, and to determine the dosage of CAT 100. The injection work was completed over a 6-month period while renovations of the building were underway. The most impacted well had a concentration of 136,000 ug/L trichloroethylene (TCE) reported (June 2023) and is currently below 100 ug/L (July 2024). The investigation techniques and remediation approaches utilized at this site will be discussed during the first of our technical webinars this fall. Our client, TriHydro, along with the AST project manager, Duane Guilfoil, will present the site in more detail during our second technical webinar. Details regarding both events can be found below.
These “heat’“ maps represent the TCE concentrations in 2023 (baseline) and 2024 (approximately 1 year post injection).
AST installs PRB in Yellowstone National Park
We’ve all worked on project sites located in less than spectacular settings. This summer AST had the privilege to complete a complex project within the confines of beautiful Yellowstone National Park, along the Yellowstone River. AST has been involved with this project for three years and over this timeframe have generated large scale qHRSC models and a combined remedy strategy to limit the flux of contaminants entering the river. This August a Permeable Reactive Barrier (PRB) was installed along the bank of the river and in-situ chemical oxidation (ISCO) was applied in the source area via DPT injection. Thank you to the National Park Service (NPS), the Wyoming Department of Environmental Quality (WDEQ), and the Environmental Protection Agency (EPA) for working with us and our client to install this remedy within one of our national treasures.
Fall 2024 Webinar Series
#1 – Transition Zone Characterization and Remediation &“The Passaic Gap” Series I
October 1st, noon-1pm EST
Register HereOne of the most challenging regimes for in situ remediationRefers to the process of treating contaminated sites or areas by applying various techniques directly to the location of the... is a transition zone; this is a zone that separates the overburden from competent bedrock and is typically partially weathered bedrock, weathered bedrock, or saprolite. There is no better example of this geologic setting than the Passaic Formation – a mapped bedrock unit that is predominantly located in New Jersey, Pennsylvania, and New York states. As an example, in New Jersey, much of the historical manufacturing and industrial sector was situated above this geologic unit and, typically, their historical impacts are realized as volatile organic compounds (VOCs) in overburden, transition zone, and bedrock.
While most remediation efforts in the Passaic Formation have focused primarily on overburden impacts, and to a limited extent the competent bedrock, the transition zone is typically not well characterized or remediated. At AST, we call that transition zone the “Passaic Gap”. For many sites, this is the most problematic zone keeping a site from closure or monitored natural attenuation.
Yet, as many of our clients know well, AST has unlocked the secret to treating this geologic zone with specific approaches and equipment. This presentation will describe how to characterize the Passaic Gap, and other analogous formations, using both conventional and modern techniques, and design successfully and succinctly for high-energy injections. Considerations and planning during the characterization phase will work towards the intent to inject specific reactants utilizing high-capacity pumps, with deference to the necessary overburden and/or competent bedrock remediation efforts. Multiple case studies from the “Passaic Gap” setting will be reviewed, including in the second part of this webinar series a focus on a performance-based contract site with serious transition zone and overburden impacts, including dense non-aqueous phase liquid (DNAPLDNAPL stands for dense non-aqueous phase liquid. It refers to a group of liquid organic compounds that are denser than...).
#2 – Reductive Dechlorination with Concurrent Sequestration of PFAS and 1,4-Dioxane in a Large Commingled Plume at a Former Manufacturing Facility & “The Passaic Gap” Series II
October 23rd, noon-1pm EST
Register HereContinuing AST’s focus on a combination of remedial techniques for weathered bedrock and competent bedrock, we are grateful to welcome Raymond Vaske, Senior Remediation Engineer, of Trihydro Corporation to present an in-depth look at the deployment of CAT 100 in the challenging Passaic Formation. This webinar encompasses the deployment of techniques discussed in Fall Webinar Series #1 with an advanced remediation technology for halogenated volatile organic compounds and emerging contaminants.
The 3.85-acre confidential site, located in a heavy industrial/commercial area in New Jersey, includes an 82,500 square-foot manufacturing building where electroplating, and other operations were conducted for nearly 50 years. Site investigation activities conducted from 2020 to 2021 in overburden and bedrock groundwater detected high levels of chlorinated ethenes, including TCE, cis-1,2-dichloroethene, vinyl chloride, and 1,1-dichloroethene, as well as high levels of per- and polyfluorinated substances (PFASPFAS stands for per- and polyfluoroalkyl substances. These are a group of synthetic chemicals that have been widely used in...) and 1,4-dioxane impacts to soil and groundwater. Regional geology in the vicinity of the site is characterized by an upper unit consisting of river alluvium and eolian deposits of Holocene Age, underlain by glacial unconsolidated deposits (clay, silt, sand, and gravel) of Pleistocene Age, and finally bedrock of the Passaic Formation, consisting of thin bedded shales, mudstones, and sandstones.
This was a challenging geologic setting and a complex commingled plume. Yet, preliminary groundwater monitoring results indicate that reducing conditions have been engendered, as designed and intended, in all the injection areas with over 99 percent reduction in TCE in the target wells. This presentation will include a full evaluation of chlorinated ethenes, PFAS, and 1,4-dioxane, noting trends and exceptions. Complete details regarding site challenges, plus design and technology synergies, will be provided.
#3 – Mackinawite Structured Iron Sulfide for Heavy Metals Remediation: Abiotic vs. Biotic Formation and Case Studies
November 13th, noon-1pm EST
Register HereSeveral iron species for treatment of heavy metal (inorganic) contaminants are well known. Yet the efficiencies of various irons– for example, zero valent ironZero-valent iron (ZVI) is a type of iron that has a high reactivity due to its zero oxidation state. ZVI... (ZVI), ferrous or ferric sulfate, and iron sulfides – differ greatly in reactivity, efficiency, and cost. Reactive iron sulfides (FeS) can be used for the reduction and co-precipitation of inorganic contaminants such as chromium, arsenic, and mercury. This presentation focuses on the use of mackinawite structured iron sulfide for heavy metals treatment, noting that it is inexpensive compared with ZVI ($/wt.) and more chemically efficient and persistent in the environment than ferrous sulfide or calcium polysulfide – other common products that produces reducing conditions in situ. Case studies, including injection installations, will be reviewed after a discussion of the chemistry and technology of iron reactants for heavy metals treatment.
