Applications of AC-based amendments for in situ subsurface remediation of chlorinated solvents and petroleum hydrocarbons, started emerging in early 2000s. Interest in AC-based amendments grew over the last five years when competing products became available to the remediation industry. Although the majority of the sites have relatively small foot print (e.g., gas stations and dry cleaners), applications at large industrial sites are also common. The list below links to published, reported, and presented case studies, including both federal sites and non-federal sites.

Applications at Federal Sites

AquaGate+PAC™ and SediMite™ at Hunters Point Naval Shipyard

Bioavailability Assessment In Activated Carbon Treated Coastal Sediment With In Situ And Ex Situ Porewater Measurements
Yan, S., M. Rakowska, X. Shen, T. Himmer, C. Irvine, R. Zajac-Fay, J. Eby, D. Janda, S. Ohannessian, and D.D.Reible. | Water Research 185:116259(2020) [Abstract]

Passive sampling and bioaccumulation assessments were used to evaluate AquaGate+PAC™ and SediMite™ for remediating offshore PCB-contaminated sediment of Hunters Point Naval Shipyard. After 8 months, PCB tissue concentrations in the Macoma nasuta clam were reduced 75-80% in pilot amendment areas and 84-87% in non-lipid normalized tissues after 14 months confirming the amendments' effectiveness in reducing PCE bioavailability. In situ polydimethylsiloxane passive samplers showed that although activated carbon composite materials were placed at the surface, 80% reductions were observed to a depth of 16 cm after 8 months and up to 26 cm after 26 months in the AquaGate+PAC treatment area. Total PCB porewater concentrations in surface sediments (1-6 cm) were reduced by 89% (AquaGate+PAC) and 91% (SediMite) during final sampling. An evaluation of in situ and ex situ porewater measurements suggest that the bioaccumulation factor in the deposit-feeding clam is better estimated by equilibrium ex situ porewater measurements.

AquaGate+PAC at Puget Sound Naval Shipyard

Approaches For Managing Contaminated Sediments
Michalsen, M. and G. Rosen | SERDP & ESTCP Webinar Series, Webinar #124, December 2020

Two webinars presented as part of the SERDP and ESTCP series focused on DoD-funded research efforts to measure and manage contaminated sediments. The first presentation discussed an approach to develop and validate a standardized polymeric sampler method to quantify freely-dissolved organic contaminant concentrations of PAHs and PCBs in sediment porewater. The second discussed research results following long-term monitoring of AquaGate+PAC™ to reduce PCB availability in surface sediment at Pier 7 of the Puget Sound Naval Shipyard. Additional information on the Puget Sound Naval Shipyard Pier 7 project

Long-Term Monitoring of an In Situ Activated Carbon Treatment to Reduce Polychlorinated Biphenyl Availability in an Active Harbor
Wang, P.A., J. Conder, B. Chadwick, and G. Rosen.
Environmental Toxicology and Chemistry 41(6):1568-1574(2022) [Abstract]

An activated carbon amendment was placed within a 0.5-acre amendment area adjacent to and underneath Pier 7 at the Puget Sound Naval Shipyard and Intermediate Maintenance Facility to reduce PCB availability. Multiple postplacement monitoring events over three years showed an 80%-90% reduction in PCBs, stability of activated carbon, and no significant negative impacts on the benthic community. A follow-on ~seven-year postplacement event was conducted to further evaluate the long-term performance. In situ porewater and bioaccumulation evaluations agreed with previous observations, indicating overall PCB availability reductions of ~80%-90% from pre-amendment conditions. Multiple measurement approaches for quantifying the presence of activated carbon and amendment indicated the amendment was present and stable in the area and that the activated carbon content was similar to levels previously observed. Results from carbon petrography corresponded within a factor of 1.3 (on average) with data for the black carbon content using a black carbon chemical oxidation method.

BOS-100^® Application at Statesville, North Carolina Superfund Site

Angled Injection to Mitigate PCE Intrusion into a Stream at a Federal Superfund Site in the Piedmont Region of North Carolina
Krouse C., Fitzgerald S., Noland S., and Thacker N.
10th International Conference on Remediation of Chlorinated and Recalcitrant Compounds. Palm Springs, CA (May 2016)

An in situ reactive barrier using BOS-100^® was installed at OU3 of the FCX Superfund site in Statesville, North Carolina, to mitigate the impact of a PCE plume (up to ~20 µg/L) to a small surface stream. Angled injection of amendments was applied to intercept the vertical movement of contaminated groundwater towards the streambed. A pilot test was conducted in October and November 2013, and the full-scale implementation was conducted in 2015. Contaminant concentrations in both porewaters of the streambed and surface water were monitored since the implementations.

PlumeStop™ Application at a RCRA site in South Carolina

Accelerated Biodegradation of Chlorinated Contaminants Facilitated Using an In-Situ Liquid Activated Carbon: A Pilot Study and Full-Scale Application in South Carolina
Valentine, M.
RemTEC 2017. Denver, CO (March 2017) [Abstract]

A RCRA corrective action site in South Carolina applied colloidal AC-technology (PlumeStop) to mitigate the migration of a long and narrow chlorinated VOC plume to a downgradient residential area. A pilot study was conducted in 2014 to confirm the effectiveness of contaminant removal and degradation using a combination of PlumeStop and enhanced reductive dechlorination. Full-scale application was subsequently conducted in 2016 by injecting PlumeStop suspension in three transects along the concentration gradient of the plume. The electron donor solution and bioaugmentation culture were injected slightly upgradient of the PlumeStop barriers. This remedy was coupled with an ongoing source-reduction remedy. Contaminant concentrations, production of daughter products, and microbial data were collected to monitor the remedy performance.

PlumeStop™ Application at Grayling Army Airfield

Colloidal Activated Carbon Used To Reduce Pfas And Chlorinated Solvent Concentrations In Groundwater To Below Detection Limits At A Michigan Army National Guard Site
Moore, R. | Design and Construction Issues at Hazardous Waste Sites Virtual Meeting, 26-28 October, 35 slides, 2020 [Abstract]

In 2016, PFAS were found commingled with a chlorinated solvent plume at the Grayling Army Airfield in Michigan that was migrating towards the property boundary. A single application of PlumeStop in an in-situ reactive barrier was used to remediated PFAS. Monitoring results demonstrated that PlumeStop distribution was achieved using direct-push injection, and PFAS and chlorinated solvent concentrations were reduced to below laboratory detection limits within one month. Concentration reductions were sustained for over 1.5 years. Additional information: Slides

PlumeStop™ Application at Santa Clara, California Superfund Site

Final Close Out Report Intel Santa Clara 3 Superfund Site Santa Clara, California
U.S. EPA Region 9, 19 pp, 2018

In September 2016, a pilot test using PlumeStop™ was conducted at two monitoring wells at the Santa Clara Superfund Site after previous remediation failed to reduce TCE concentrations below the site's 5 µg/L maximum contaminant level. Follow-up injections were conducted around well SC3-1Rep in September 2017 after TCE concentrations rebounded. After the second injection, TCE was not detected above the MCL for seven consecutive monthly monitoring events. All 18 post-injection results for well SC3-3Rep were non-detect for TCE. No further remedial actions were required and the site was subsequently closed.

BOS-100^® Application at Vandenberg Air Force Base Site 15

Pilot-Scale Permeable Reactive Barrier Installation Using Deep Soil Mixing and BOS100^®
Gerber K., Mora R., White K., and Noland S.
7th International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Presentation E-084. Monterey, CA (May 2010)

One of the first applications of an activated carbon-based remedy for chlorinated solvent contamination was at Site 15 at Vandenberg Air Force Base, California. BOS-100^®, a product consisting of granular activated carbon impregnated with zerovalent iron, was emplaced by deep-soil mixing to form a permeable reactive barrier. The goal of this pilot-scale implementation was to determine if the PRB could limit the impact of a mixed chlorinated solvent plume to an adjacent creek. Soil mixing was selected as the emplacement approach after two rounds of direct push injection (both low- and high-pressure) failed to give good amendment distribution. One year of post-remedy data was reported, including concentrations of PCE, cis-DCE, and VC in various monitoring wells downgradient of the PRB.

BOS-100^® Application at the Former Lowry Air Force Base (OU5), Colorado

Second Five Year Review, Former Lowry Air Force Base, Colorado
Lowry Assumption, LLC. (October 2013)

BOS-100^® was applied at OU5 of the Former Lowry Air Force Base in Colorado to address a carbon tetrachloride (CT) plume. The first injection in 2008 emplaced 15,000 lbs of amendment into both the bedrock source area and overlying saturated alluvium. A smaller injection (600 lbs) in 2010 addressed residual CT in the vicinity of one monitoring well. AC-based technology was selected because prior injection of activated sodium persulfate reduced CT concentration in groundwater but later rebounded and did not achieve the 5 µg/L Colorado Basic Groundwater Standard for CT.

COGAC^® Application at the Hill Air Force Base, Utah

LNAPL Remediation Combining Mobile Dual-Phase Extraction with Concurrent Injection of a Carbon-Based Amendment
Barranco F.T., Taylor J., Hoyt D., Bradley K., and Roginske M., Barranco F.
11th International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Session C6-70. Palm Springs, CA (April 2018)

This case study illustrates an example where activated carbon-based technology was coupled with a more aggressive treatment technology to address source area contamination. The soil and groundwater of the site are contaminated by petroleum hydrocarbons as a result of leaks from tanks and piping. The presence of LNAPL and a smear zone acts a continuing source of dissolved-phase contamination. The selected remedy for this treatability study was concurrent operation of mobile dual-phase extraction (mDPE) and direct injection of COGAC^®, a combination of activated carbon and chemical oxidants. The concept was to removal free-phase product and dissolved-phase contaminants as much as possible with mDPE and control the mass flux coming out of the residual contamination with emplacement of COGAC^®.

Applications at Multiple Sites

Long-Term Stability And Efficacy Of Historic Activated Carbon (Ac) Deployments At Diverse Freshwater And Marine Remediation Sites
Bridges, T., S. Newell, A. Kennedy, D. Moore, U. Ghosh, T. Needham, H. Xia, K. Kim, et al., U.S. Army Corps of Engineers Engineer Research and Development Center, Document No: ERDC/EL TR-20-9, 98 pp, 2020

The long-term performance of activated carbon (AC) was assessed at two pilot-scale demonstration sites, Grasse River in NY, and Canal Creek, Aberdeen Proving Ground (APG) in MD, representing two distinct physical environments. Sediment core samples were collected after 6 years (APG) and 10 years (Grasse River) of remedy implementation. Core samples were sectioned to determine the current vertical distribution and persistence of AC in the field. The concentration profile of PCBs in sediment pore water with depth was measured using passive sampling. Sediment samples from the untreated and AC-treated zones were also assessed for bioaccumulation in benthic organisms. The data collected enabled comparison of AC distribution, PCB concentrations, and bioaccumulation measured over the short- and long-term (months to years).

Technical Report: In Situ Activated Carbon Case Study Review
NAVFAC Engineering and Expeditionary Warfare Center, 27 pp, 2020

Activated carbon (AC)-based amendments can be applied for the in situ remediation of a wide range of organic contaminants in groundwater. These amendments combine AC for enhanced sequestration of the contaminants, along with chemical or biological additives that promote further contaminant destruction. Rapid contaminant removal and limited rebound have been reported during field applications, which suggests a potential role for the technology in addressing back diffusion from residual sources in low permeability zones. This white paper describes the types of amendments available, the contaminants treated, and provides lessons learned from DOD case studies.

Top of Page

Applications at Non-Federal Sites

AquaGate+PAC^® Application to Treat PCBs

Season Two In Situ Treatment Completion Report Lockheed Martin Middle River Complex 2323 Eastern Boulevard Middle River, Maryland
Lockheed Martin Corporation, 54 pages, 2018

This completion report summarizes placement of 2,504 tons AquaGate+PAC^® 10% dry weight over 13.7 acres of PCB-contaminated sediment from October to December 2017. The report describes construction performed to place the material and summarizes site preparation, the pre-project pilot study, and quality control procedures. Quality control tests and laboratory analytical sampling results for the surficial sediment confirm that the design intent and project objectives were achieved. The activated carbon concentrations currently in Dark Head Cove sediment are considered adequate to reduce PCB concentrations within the pore water, resulting in an overall reduction of bioaccumulation.

BOS-100^® Application to Treat Residual DNAPL

Innovative Injection Technique to Treat DNAPL in Granular and Fine-Grained Matrices
Noland S., Boyle R., and Harp T.
8th International Conference on Remediation of Chlorinated and Recalcitrant Compounds. Monterey, CA (May 2012) Battelle Press, Columbus, OH. 8 pp

Obtaining High-Resolution Data to Demonstrate BOS-100^® Performance in a Large TCE Plume with Extensive DNAPL Present
Harp T.
9th International Conference for Remediation of Chlorinated and Recalcitrant Compounds, Monterey, CA (May 2014)

This case study highlights the importance of having a comprehensive understanding of complex site conditions to improve the effectiveness of an activated carbon-based remedy. High-energy, low-volume pulses of a water-based suspension of BOS 100^®, granular activated carbon impregnated with metallic iron, were employed to remediate a TCE source area and associated plumes at a large urban industrial facility. Injections were facilitated using conventional hydraulic fracturing. Although large portions of the dissolved-phase plume responded to this technique, some areas were resistant, suggesting input from unknown sources. High-resolution sampling indicated the presence of localized thin seams of DNAPL-impacted soil at several locations in the vicinity of the former TCE underground storage tank with extremely high vertical heterogeneity. A modified "jetting" approach was developed that allowed extremely accurate placement and greater amount of injectant/soil mixing over a relatively thick zone.

BOS-100^® Application for Treating PCE in Bedrock

Karst Bedrock Remediation of PCE in Kentucky
Guilfoil, D.
33rd Annual International Conference on Soils, Sediments, Water, and Energy. Amherst, MA (October 2017)

This study describes an early application of activated carbon-based technologies where long-term monitoring data (up to six years post implementation) is available. PCE was the main contaminant found in both overburden and epi-karst type of bedrock at a former dry-cleaning facility in Kentucky. PCE concentrations initially ranged from 0.4 mg/L to 87 mg/L in the groundwater and from <1 mg/kg to 500 mg/kg in the soil. A combination of down-hole camera and borehole geophysics was used to determine the specific fracture intervals to target hydraulic tests. BOS-100^® was injected into each fracture using a straddle packer under pressure. Loading was determined based on the PCE concentration. Subsequent groundwater sampling monitored the effectiveness of injection and the disappearance of PCE as well as the production of daughter products, chloride, and final dechlorination products.

Pilot Injection of Carbo-Iron at a PCE site in Europe

Carbo-Iron as Improvement of the Nanoiron Technology: From Laboratory Design to the Field Test
Mackenzie K., Bleyl S., Kopinke F., Doose H., and Bruns J.
Science of the Total Environment. 563-564:641-648 (2016) [Abstract]

This peer-reviewed article details a long-term pilot injection of Carbo-Iron at a PCE-contaminated site in Europe. Carbo-Iron is a non-commercial product that consists of colloidal activated carbon (< 1 µm) impregnated with nano zerovalent iron (nZVI). The suspension is stabilized by carboxymethylcellulose to prevent aggregation and improve subsurface transport of the colloidal particles. The suspension was injected in a highly contaminated area where the highest PCE measured concentration in groundwater was 120 ppm. Two rounds of injections (roughly one year apart) were conducted. Concentrations of PCE, DCE, and VC were monitored for more than three years. The impact of Carbo-Iron injection on microbial population and dechlorination activity was also characterized at the conclusion of the monitoring event. Potential abiotic and biotic transformation pathways of PCE and its daughter products were proposed. The scientific insights revealed in this study provides independent verification for some claims made for commercial AC-based products used for remediation in the U.S.

Combined Chemical and Microbiological Degradation of Tetrachloroethene during the Application of Carbo-Iron at a Contaminated Field Site
Vogel M., Nijenhuis I., Lloyd J., Boothman C., Poritz M., and Mackenzie K.
Science of the Total Environment. 628-629:1027-1036 (2018) [Abstract]

Injection of PlumeStop^® + HRC^® at a chlorinated solvent site in Italy

Combining In Situ Sorption and Bioremediation for the Management of a Chlorinated Solvent Plume at Low Concentration
Petrangeli Papini M, Arjmand F., Ciampi P., Esposito C., Bimstingl J., Carboni M., Goria P., Rossetti S., Matturo B., Cesta Incani L., and Bacchi M.
11th International Conference for Remediation of Chlorinated and Recalcitrant Compounds, Palm Springs, CA (April 2018)

The first full-scale application of PlumeStop^® in Europe was commissioned to the University of Rome "La Sapienza" to evaluate the effectiveness of combining adsorption and reductive dechlorination. The contaminated area is beneath a high-speed railway station in Bologna, Italy, with low concentration of chlorinated aliphatic hydrocarbons (CAH) present. The remedial goal was to reach the stringent Maximum Contaminant Levels for PCE and TCE set by the Italian government. Four zones with the highest CAH concentrations were selected for this remedy. Parent and daughter products Almost two years of monitoring data of parent and daughter products were available when this study was presented.

Injection of PlumeStop^® + HRC^® at a chlorinated solvent site

Site goals Achieved in Two Months at a Santa Barbara Manufacturing Facility Using a Dispersive Colloidal Activated Carbon
Haro E., Nunez D.
11th International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Palm Springs, CA (April 2018)

This site is a former manufacturing facility with low concentrations of PCE and TCE. Previous remediation using limited excavation and permanganate oxidation did not achieve the cleanup level. Due to the urgency of development, PlumeStop^® coupled with enhanced reductive dechlorination was selected to rapidly remove contaminants from aqueous phase. Detailed site characterizations were conducted to identify the transmissive zones and high mass zones, according to which the full-scale injection plan was developed.

Applications of AC-based technology for Petroleum Hydrocarbons

Lessons Learned and Paths to Success with Activated Carbon Injections
Winner E. and Fox T.
ASTSWMO Workshop, Pittsburgh, PA (April 2016)

Petroleum Remediation Using In-situ Activated Carbon (A review of results)
Fox T.
National Tanks Conference. Phoenix, AZ (September 2015)

This presentation reviews performance results of some early applications of AC-based technology in treating petroleum hydrocarbon-contaminated sites in Colorado. It highlights several important lessons learned that have been used to develop and adopt best practice for implementing AC-based remedial technology.

Applications of AC-based technology for Per- and Polyfluoroalkyl Substances (PFASs)

PFAS Treatment Trials with Granulated Activated Carbon
Galbraith, F., D. McMillan, M. Edwards, R. Pennell, and M. Goulden.
REMTECH 2020: The Remediation Technologies Symposium, 14-15 October, Virtual Meeting, abstract, 2020

Source control treatment of surface water containing hydrocarbons, PAHs, metals, and PFAS contamination was conducted within a retention pond in the Fire Fighting Training Area of Canadian Forces Base Comox, Lazo, in British Columbia. Granulated activated carbon (GAC) and components of an existing water treatment system were used to treat PFAS-impacted surface water within the pond and from a recent spill of a newer formulation of aqueous film-forming foam at a separate base area. In addition, advanced oxidation was evaluated on samples of surface water. Results from the treatment of PFAS with GAC and advanced oxidation are presented along with considerations for improving performance and optimizing the long-term treatment of these compounds at the site. Additional information: Presentation

SediMite Application to Treat PCBs

Summary of Environmental Investigation and Remediation, A-Street Ditch Segment 1 Pilot Study
BrightFields, Inc. on behalf of the Delaware Department of Natural Resources and Environmental Control (DDNREC), 31 pp, 2020

This report summarizes data collected one year after SediMite™ application to clean up PCB-impacted sediments in the A-Street Ditch. Results of sampling conducted in July 2020 showed reduced concentrations of dissolved PCBs in the sediment porewater across the entire project area. Two of the nine samples (one surface water sample and one sediment sample) showed localized increases in PCB concentrations. Potential reasons for these increases are being evaluated. DNREC is planning to assess PCB concentrations in sediment, surface water, and sediment porewater in July 2021.

Top of Page