Sweden CVOC remediation

PlumeStop & S-MicroZVI Barrier Reduces Chlorinated VOCs by 95% in 1 Month

Case study highlights:

  • Treatment approach consisted of in situ chemical reduction with PlumeStop in a permeable reactive barrier (PRB)
  • Approximately 32,000 lbs. of the colloidal PlumeStop and S-MicroZVI amendments were co-injected to form the PRB
  • The colloidal PlumeStop and S-MicroZVI amendments rapidly reduced CVOC concentrations to below or near the detection levels

At an ongoing residential development in Southwest Sweden, low CVOC levels in the groundwater required a remedial solution to protect the newly constructed buildings against vapour intrusion. RGS Nordic (now: Sortera) asked REGENESIS for an in situ remediation solution. PlumeStop® Liquid Activated Carbon and S-MicroZVI® were injected during the ongoing construction of the residential building complex. Despite spatial limitations to complete the work, the injection was successfully carried out, quickly reducing the concentrations of chlorinated volatile organic compounds (CVOCs) by 95% and removing the potential risk for vapour intrusion of CVOCs into the residential complex.

Finland in-situ remediation

Effective In-Situ Treatment of a 3,280 Ft. PCE Plume in Finland

Case study highlights:

  • PCE concentrations were reduced to below the drinking water limit at the water supply well
  • Results indicate that the ERD and PlumeStop approach can be successfully applied in cold groundwater aquifers with low organic carbon content
  • Integrated source area/PlumeStop-ERD barrier treatment is an effective strategy for treating elongated chlorinated solvent plumes

In Eastern Finland, a fast-moving PCE (perchloroethene) plume beneath a metal-processing facility was remediated to reduce impacts on a municipal drinking water source. The demonstration project achieved PCE concentration reductions of approximately 80% in the plume within months and 90 to 95% by 18 months, ultimately reducing PCE to below the drinking water limit at the municipal water supply well. The in situ remedy applied enhanced reductive dechlorination (ERD) beneath the source area at the industrial building, combined with downgradient plume area treatment comprising ERD plus adsorption, facilitated by PlumeStop, to form an injectable permeable reactive barrier. The progressive approach uses relatively few injection points to reduce the contaminant flux into the plume and to impede contaminant migration downgradient, resulting in the effective and economical treatment of a 3,280-ft.-long chlorinated solvent plume to mitigate the potential exposure risk.

PFAS Eliminated for 4.5 Years and Counting

Case study highlights:

  • Results 4.5 years post-application show PFAS and PCE reduced to non-detect
  • New, innovative approach using an in situ colloidal activated carbon barrier to eliminate PFAS exposure pathway and protect the community
  • Collaborative effort amongst various State of Michigan and military departments
  • Results 4.5 years post-application show PFAS and PCE reduced to non-detect
  • Economical and effective pilot study design

This case study reviews a pilot test to remove PFAS risk via an in situ colloidal activated carbon barrier at Camp Grayling in Crawford County, Michigan, a large year-round military training center operated by the Michigan Army National Guard (MIARNG). Colloidal activated carbon was selected because of the expected rapid reductions of PFAS by removal from the dissolved mobile phase, as well as its expected lower total project costs when compared to operating a mechanical system over a similar time. The MIARNG decided to conduct a PlumeStop pilot test to determine if this treatment would meet their site goals prior to a possible full-scale application. The goals for this pilot project were to utilize an approach that could both protect the Grayling community from exposure and cost-effectively expand to a full-scale application.

Sustainable PFAS remediation

Full Life Cycle Analysis Conducted by Ramboll Finds PlumeStop Has 98% Lower Carbon Footprint than Pump & Treat for PFAS Remediation

Case study highlights:

  • Study concludes that PlumeStop results in a 98% lower total carbon footprint than pump & treat
  • Immobilization with PlumeStop offers >64% lower costs compared to ex situ treatment approaches
  • Colloidal activated carbon (CAC) requires no operational energy, maintenance, or PFAS-saturated waste products

A recent independent sustainability study (full Life Cycle Analysis) conducted by Ramboll, a global environmental consulting and engineering firm, evaluated the use of PlumeStop vs. conventional pump and treat technology to eliminate PFAS. The findings revealed the use of PlumeStop technology would reduce GHG emissions by 98% and would reduce the cost by >64%. This study included a Life Cycle Cost Analysis (LCCA) and a Tier 2 sustainability assessment using Ramboll’s SURE model. The overall Sustainability Assessment Score for PlumeStop was 100% higher than the ex situ, pump & treat alternatives. PlumeStop also exceeded pump & treat in each of the sustainability categories, ‘Environment’, ‘Society’ and ‘Economy’.

In Situ Treatment of Hexavalent Chromium Results in Site Closure

Case study highlights:

  • Commodity ZVI and 3-D Microemulsion/CRS rapidly reduced Cr(VI) concentrations, achieving remarkable reductions within months.
  • S-MicroZVI® and 3-D Microemulsion offered improved distribution and reactivity, addressing previous limitations in the remediation process.
  • The use of S-MicroZVI® and 3-D Microemulsion led to a rapid 99% reduction in Cr(VI) concentrations, securing regulatory closure for a long-standing contamination case.

This case study focuses on the successful remediation of hexavalent chromium (Cr(VI)) contamination at a chrome plating facility in the Midwest. Decades of ineffective pump & treat (P&T) operations led to the need for a cost-effective and rapid solution to achieve regulatory closure. Enviroforensics, an environmental engineering and remediation firm, directed the pilot test efforts, which aimed to determine the optimal remedial approach for Cr(VI) treatment. The study found that in situ chemical reduction combined with in situ bioremediation (ISCR-BR) effectively reduced Cr(VI) concentrations, with promising results from two different remediation amendments: a viscous zero-valent iron (ZVI)/organic mixture and a 3-D Microemulsion/Chemical Reducing Solution® (CRS) mixture. Demonstrating that the combination of S-MicroZVI® and 3-D Microemulsion for ISCR-BR is a highly effective and efficient solution for remediating Cr(VI) contamination, particularly in situations where minimal disruption is crucial. These colloidal amendments offer superior distribution capabilities, making them ideal for treating a wide range of contaminants in various subsurface environments.

RRS PlumeStop application

PlumeStop Shuts Down Pump & Treat System at Superfund Site

Case study highlights:

  • 224,800 lbs. of PlumeStop colloidal activated carbon were safely injected into the target treatment zones
  • PlumeStop treatment prevents plume migration and protects nearby community drinking water wells
  • This sustainable approach eliminates the massive carbon footprint created by outdated pump-and-treat approaches

This case study reviews a large federally operated Superfund site where REGENESIS Remediation Services (RRS) completed a large-scale PlumeStop application to eliminate the risk of exposure to chlorinated solvents. Amentum, a leading American governmental and commercial services contractor, is the responsible party’s contractor. Amentum has worked with the client at this site for years, providing oversight and management of their contracting partners. The project’s sensitive nature required an enhanced awareness of health, safety, and security issues and seamless coordination between RRS, Amentum, and their client.

PlumeStop Eliminates PFAS for Seven Years

Case study highlights:

  • PlumeStop application reduces PFAS to non-detect within 3 months, maintaining for seven years thus far
  • Remediation company IRSL collects critical treatment zone information to ensure successful application
  • Sampling confirms PlumeStop fully distributed through the treatment zone
  • Modeling indicates that PlumeStop will halt PFAS migration out of the treatment zone for more than 60 years

This case study reviews the first known full-scale in situ PFAS treatment worldwide completed in 2016 at a manufacturing and former firefighting training site in Ontario, Canada, where aqueous film-forming foams (AFFF) were used. A single application of PlumeStop resulted in a significant reduction of contaminant concentrations to below standards for 7+ years since the injection. An independent fate and transport modeling expert predicts that PlumeStop will halt PFAS migration out of the treatment zone for more than 60 years, preventing exposure risk and reducing liabilities for the site owner.

Chlorinated solvent remediation

In-Situ Chlorinated Solvent Treatment Protects Municipal Drinking Water

Case study highlights:

  • Remediation solution from REGENESIS protects municipal water pumping station from chlorinated solvent contamination
  • Following injection the PCE was rapidly degraded by 99.98%
  • Long term monitoring shows that no rebound in parent or daughter contaminant concentrations has occurred

This case study reviews a site in Sweden where a single injection of REGENESIS controlled release electron donor technology resulted in the degradation of the contaminant plume and protection of a downgradient drinking water pumping station. Environmental consulting firm RGS Nordic worked with REGENESIS to design an in situ remediation solution for the chlorinated solvent plume. In situ remediation using Enhanced Reductive Dechlorination (ERD) was chosen to provide the most cost-effective solution for the groundwater plume. Prior to application, the contaminant plume primarily consisted of PCE with a small amount of daughter products. Following injection the PCE was rapidly degraded by 99.98%. All daughter products were degraded sequentially and the presence of ethene showed that full reductive dechlorination had occurred.

PetroFix Barrier Prevents Offsite Risk at Active Gas Station

Case study highlights:

  • Groundwater samples taken post-application demonstrated that all remedial objectives had been met
  • PetroFix IPRB was the most sustainable option for the site
  • Application completed at a significantly lower cost and in less time than pump and treat

This case study reviews an active gas station in the United Kingdom where dissolved phase contamination at high concentrations in groundwater migrated beyond the site boundary, resulting in a potential off-site liability. An in situ permeable reactive barrier (IPRB) using PetroFix colloidal activated carbon was installed to prevent offsite risk. Environmental consulting firm SLR Consulting partnered with REGENESIS to design and apply the solution, which met site objectives within 12 months. The PetroFix IPRB was the most sustainable option for the site; compared to a source excavation approach, the project prevented up to 55 loads of soil disposal. Substantial energy savings were also made when compared with operating a groundwater pump and treat system. The project was completed for <£100K ($127,300 USD), with only minimal disruption to site operations.