KLOZUR^® 

The case study shows how a combined ISCO‑ISS approach successfully treated a high‑concentration TCE source zone in challenging, low‑permeability clay. By blending KLOZUR® SP with Portland cement in a single soil‑mixing application, the team achieved rapid contaminant reduction and improved soil stability within days. TCE concentrations dropped by up to 97%, far exceeding the project’s cleanup goals and enabling redevelopment to proceed on schedule. The project also delivered significant cost savings compared with excavation or thermal treatment.

The former manufactured gas plant in Stockholm’s Royal Seaport required a remedy that could reliably manage high PAH contamination while enabling large‑scale urban redevelopment. By applying ISCO‑ISS, the project achieved strong solidification performance, very low hydraulic conductivity, and up to 95% PAH reduction, ensuring long‑term protection against vapor intrusion. The combined approach delivered predictable strength development across clay, moraine, and sediment layers, even under challenging moisture conditions. This performance helped the city safely prepare one of Europe’s largest redevelopment areas for new residential and commercial use.

The rail yard site in Nijmegen, Netherlands had long been impacted by leaks, spills, and filling losses of hydrocarbon fuels, leaving behind significant residual TPH contamination despite earlier remediation efforts. Following a successful bench‑scale evaluation, alkaline‑activated KLOZUR® persulfate was selected and implemented using a fully automated, remotely controlled injection system. This data‑driven approach enabled a predictable and efficient ISCO treatment, achieving the targeted TPH reduction in both laboratory and full‑scale application. The project demonstrates how Evonik’s persulfates support reliable remediation outcomes under demanding technical and contractual conditions.

The case study shows how a combined ISCO–ISS approach with KLOZUR® SP enabled the safe and efficient redevelopment of a former gasoline station in Bolzano. By destroying BTEX and light hydrocarbons and immobilizing heavier TPH fractions, the treatment met all regulatory cleanup targets and eliminated the need for further remediation, as confirmed by authorities. At the same time, the ISS component delivered the required soil strength and low permeability, allowing construction traffic during works and minimizing soil bulking and disposal volumes. 

Diesel‑range organics remaining at the base of two excavations were successfully treated in situ using alkaline‑activated KLOZUR® SP and hydrated lime, avoiding deeper excavation and significant disposal costs. A single three‑day soil‑mixing application reduced DRO concentrations by 78–83%, bringing both areas below the 1,000 mg/kg closure criterion. The approach also stabilized the soil and eliminated the need to import replacement fill, enabling fast regulatory closure

The former Søllerød gasworks site contained deeply tar‑impacted soils that threatened a nearby municipal well and required treatment within a very confined urban setting. A combined ISCO–ISS approach with KLOZUR® SP and slag cement was applied to oxidize the more soluble, mobile low‑molecular‑weight compounds while cementing the heavier tar fractions in place; the cement also created the alkaline conditions needed to activate KLOZUR® SP and accelerate the ISCO reactions. The full‑scale mixing achieved strong reductions in benzene, naphthalene, and phenols while delivering a low‑permeability soil matrix.

ORIN Remediation Technologies remediated a petroleum‑impacted groundwater plume using sodium persulfate and PERMEOX® Plus, reducing benzene concentrations from 4,700 µg/L to below detection within four months. The combined oxidant blend and slow‑release oxygen source enabled rapid contaminant breakdown and sustained biodegradation, even in low‑permeability silty sands. The treatment was delivered through a series of direct push points over a five‑day period, minimizing site disruption and overcoming soil refusal with high‑pressure equipment. This approach delivered cost savings of $28,000–$50,000 compared to traditional remediation, providing a fast, reliable, and economical solution for petroleum‑impacted sites.

A modified advanced oxidation treatment using catalyzed KLOZUR® successfully remediated a former MGP site impacted by residual coal tar and persistent benzene leaching. After years of elevated benzene levels, the targeted mAOT approach—supported by bench‑scale testing and SHOC in‑situ delivery—reduced concentrations from 276 µg/L to below detection limits. The one‑week injection program effectively treated both saturated soils and groundwater, eliminating the long‑term contaminant source. With benzene now consistently non‑detect, the site is moving toward closure.

EcoVac Services implemented SURFAC® and ISCO‑EFR® at this gasoline‑impacted site in Alabama to remove separate‑phase hydrocarbons and reduce dissolved BTEX concentrations below the site’s corrective action limits. A single SURFAC® application eliminated SPH from the affected monitoring wells, followed by two ISCO‑EFR® events using activated sodium persulfate to drive BTEX levels down to low or non‑detect concentrations. The combined treatment approach restored groundwater quality in the shallow silty‑clay aquifer and brought the site back into regulatory compliance.

ORIN Remediation Technologies treated PCP‑impacted soils at two former dip‑tank locations using tailored ex‑situ chemical oxidation to meet non‑hazardous disposal standards. Because contaminant chemistry differed between the two areas, ORIN designed separate treatment approaches using Fenton’s Reagent at Location #1 and alkaline‑activated sodium persulfate at Location #4. Both treatments successfully reduced PCP concentrations below the 120 mg/kg standard, enabling cost‑effective disposal at a nearby Subtitle D landfill. In total, more than 650 tons of soil were remediated, delivering significant cost savings and regulatory compliance for the redevelopment project.

Specialty Earth Sciences applied KLOZUR® catalyzed persulfate oxidation to rapidly reduce BTEX impacts in saturated soils and groundwater at Fort Belvoir’s former fuel tank farm. The one‑week injection event, delivered with SHOC in‑situ circulation, introduced more than 5,000 lbs of sodium persulfate along with hydrogen peroxide and proprietary catalysts to accelerate mass removal. Monitoring over 7, 30, and 100 days showed sustained BTEX reductions of up to 99% in most wells, demonstrating strong oxidant persistence and effective subsurface distribution. The treatment significantly shortened the path toward site closure and is now being considered for larger‑scale application beneath adjacent buildings.

JAG Consulting Group applied high‑pH activated sodium persulfate to remediate shallow soils at an active industrial site in Illinois impacted by PCE, TCE, methylene chloride, toluene, and xylenes. A tailored ISCO design—including soil buffering tests, an infiltration gallery to create saturation, and injections through 12 wells—enabled effective oxidant distribution in low‑permeability silts and clays. Within six months, contaminant concentrations were reduced by 88–99%, meeting Illinois EPA cleanup criteria and securing a No Further Action determination for one treatment area.

Panther Technologies used a proprietary, catalyzed persulfate oxidation technology to remediate soils heavily impacted by PCE and TCE at an industrial site in New Jersey. More than 40,000 tons of contaminated soil were excavated, treated ex situ, and restored to below 5 mg/kg, enabling on‑site reuse and eliminating a major source of groundwater contamination. Bench‑scale testing guided the selection of a patent‑pending oxidant blend capable of performing effectively even under winter conditions. This approach delivered rapid mass removal and avoided over $6 million in off‑site disposal costs.
 

ORIN Remediation Technologies treated a 5,920‑cubic‑yard drainage lagoon at a manufacturing plant in Michigan using catalyzed persulfate oxidation to reduce high concentrations of chlorinated solvents to disposal‑compliant levels. The hydrogen‑peroxide and sodium‑persulfate blend was applied and mixed in controlled soil lifts until all samples were below 60 mg/kg. Treating the material on site instead of hauling it for incineration resulted in an estimated $2 million in cost savings.

MECX applied activated persulfate ISCO to remediate a methylene‑chloride plume beneath an active chemical facility in Los Angeles County, achieving rapid contaminant reduction after years of conventional remediation. Twenty‑three application wells—many installed inside the building—delivered catalyzed hydrogen peroxide followed by sodium persulfate into a silty‑clay zone 40–48 ft deep. Within 61 days, methylene chloride concentrations declined by 94–97%, including a drop from 15,000 µg/L to 18 µg/L in the most impacted well. 
 

MECX used KLOZUR® activated persulfate ISCO to address a persistent petroleum‑derived NAPL and PAH source at a former chemical plant in Trento, Italy. A recirculating oxidant system was deployed through a three‑well network to enhance distribution in silty‑clay sediments and stop migration toward a nearby river. Within days, NAPL was eliminated from all wells, and dissolved contaminants fell below 50 µg/L, leading to regulatory approval to continue full‑scale remediation.

EXTECH used activated sodium persulfate to reduce a BTEX groundwater plume at a municipal wastewater treatment plant in Atlanta, Georgia. Twenty‑five wells were injected with more than 10,000 lbs of oxidant, selected for its fast reaction time, stability in the subsurface, and compatibility with nearby infrastructure. Three months after injection, groundwater sampling showed a clear overall reduction in BTEX concentrations, allowing the site to transition to monitoring‑only status. 

Churngold successfully applied In‑Situ Chemical Oxidation (ISCO) using lime‑activated sodium persulfate delivered through in‑situ soil mixing to remediate chlorobenzene, dichlorobenzene, TCE, and PCE contamination at the former ICI Burnhall Facility in Thornton, UK.

The ISCO approach ensured direct oxidant–contaminant contact in low‑permeability, heterogeneous soils and achieved rapid mass reduction across the 7,300 m² treatment area. Overall, the ISCO treatment destroyed more than 11,700 kg of contamination in situ, avoiding roughly 48,400 tonnes of soil disposal and meeting regulatory targets within a strict 20‑week schedule.

Exo Tech applied a sodium‑persulfate–based ISCO solution through an innovative in‑situ soil blending approach to help the City of Cullman rapidly remediate a Brownfield site impacted by high concentrations of chlorinated and petroleum VOCs. A targeted treatability study confirmed that lime‑activated sodium persulfate was the most effective ISCO treatment for the site's silty‑clay soils, enabling efficient treatment of 1,500 tons of impacted material. Within weeks, VOC concentrations—including TCE and DCE—were reduced to non‑detect levels above and below the water table, demonstrating the effectiveness of this ISCO‑enhanced blending approach. This fast, low‑disruption remediation strategy supported the customer’s path toward No Further Action and accelerated the site's redevelopment.

Exo Tech implemented an ISCO treatment using iron‑activated sodium persulfate to help an industrial facility in Norcross, Georgia eliminate a PCE plume impacting soil and groundwater, delivering fast and predictable remediation performance. A total of 1,650 lbs of activated persulfate was injected across 15 wells, with field screening confirming that naturally occurring iron levels were sufficient to activate the oxidant without additional additives. Within just 14 days, the site’s most contaminated well dropped to below reporting limits, and all wells achieved MCLs within 120 days, demonstrating the effectiveness and stability of this ISCO approach. This single‑application solution enabled the customer to reach remedial goals quickly, cost‑effectively, and with minimal site disruption.

XDD conducted an ISCO demonstration at a former MGP site in New York as part of a two‑year EPRI‑sponsored study, evaluating activated persulfate for the treatment of TPH, PAHs, and BTEX in impacted soils. Bench‑scale testing and field data confirmed that both alkaline‑activated and iron‑chelate‑activated persulfate effectively degraded MGP residuals under a range of soil conditions, providing essential guidance for site managers considering ISCO applications. A single field application achieved 55–75% reductions in PAHs and TPH and significantly lowered the leachability of key contaminants, aligning with bench‑scale expectations and demonstrating the technology’s efficiency and cost‑effectiveness. This study highlights how tailored persulfate‑based ISCO strategies can help utilities and site owners reach remediation objectives more reliably across complex MGP sites.

Using a surfactant‑enhanced in situ chemical oxidation (ISCO) approach, this project successfully destroyed more than 90% of coal‑tar–related contaminants at a former roofing products manufacturing site in New York City, including 95% naphthalene and 91% groundwater BTEX reductions. The tailored in situ treatment combined VeruSOL surfactants with alkaline‑activated KLOZUR® persulfate to desorb, mobilize, and oxidize NAPL without impacting the adjacent East River or causing rebound in contaminant concentrations. Post‑treatment monitoring confirmed sustained improvements in soil, groundwater, and vapor quality, enabling regulatory closure under the NY Brownfield Cleanup Program. This case demonstrates how optimized ISCO strategies can reliably achieve deep contaminant destruction at complex urban sites and accelerate redevelopment.

XDD implemented a multi‑level in situ chemical oxidation (ISCO) approach using alkaline‑activated KLOZUR® SP to remediate off‑site coal‑tar impacts at a former MGP site in Mattoon, Illinois. Bench‑scale testing and pilot studies guided a full‑scale in situ treatment strategy that targeted both soil and groundwater impacts beneath an active city street, safely delivering persulfate through permanent and temporary injection wells.

The treatment achieved significant contaminant reductions, including lowering TPH to approximately 2,500 mg/kg and reducing dissolved benzene concentrations by more than 98%—far surpassing the remedial goal. This high‑efficiency ISCO program enabled the site to obtain a No Further Action letter from the State of Illinois, demonstrating how optimized ISCO solutions can reliably close complex former MGP sites while minimizing overall project costs.

ExoTech implemented a targeted in situ chemical oxidation (ISCO) program using KLOZUR® CR to remediate a high‑salinity, petroleum‑impacted UST site at a marina in Savannah, Georgia. Following a treatability study that identified KLOZUR® CR as the optimal oxidant for meeting stringent In‑Stream Water Quality Standards, a single injection event across 21 points achieved substantial BTEX reductions, including significant decreases in benzene and total petroleum hydrocarbons near the adjacent river. The treatment leveraged KLOZUR® CR’s combined chemical oxidation and biostimulation capabilities to deliver effective contaminant destruction in a challenging coastal groundwater setting. The project achieved site closure after just one injection—demonstrating a highly efficient and cost‑effective ISCO solution for sensitive shoreline environments.

Linebach Funkhouser, Inc. applied 1,395 lbs of KLOZUR® CR through in situ soil mixing after excavating 107 tons of contaminated soil, delivering a powerful combination of ISCO, in situ soil mixing, and in situ groundwater treatment to address BTEX impacts at the former fuel facility. Within just 56 days, all BTEX compounds in the downgradient well were reduced to below detection limits, including a three‑order‑of‑magnitude reduction in benzene. This single‑event treatment provided a fast, reliable, and cost‑efficient solution—giving customers confidence in achieving both source‑zone and plume cleanup with one streamlined application.

The New York site remediation applied 24,030 lbs of KLOZUR® CR across 36 direct‑push injection points to treat a 3,600 ft² area with a 10‑ft saturated thickness, delivering a powerful ISCO‑based in situ groundwater treatment for benzene‑impacted conditions. Benzene concentrations decreased from 13,000 µg/L to <500 µg/L, supported by advanced diagnostics confirming true contaminant destruction rather than dilution. Customers benefited from a single‑application solution that combined chemical oxidation with aerobic and anaerobic biostimulation—proving effective even under aggressive geochemical shifts, including pH levels exceeding 12. The approach ultimately achieved 96% treatment efficiency, destroying approximately 10 kg of benzene and demonstrating a reliable, data‑validated ISCO remedy.

Two injection events applied 4,800 kg of KLOZUR® CR to the saturated zone using an in situ treatment approach designed to combine ISCO (in situ chemical oxidation) with enhanced aerobic and anaerobic bioremediation at a former petroleum station in Bologna, Italy.

Distributed across 18 injection points, the treatment targeted a 5‑meter saturated interval, achieving more than 90% reductions in TPH and MTBE and meeting all BTEX and MTBE remedial goals within 18 months. This in situ groundwater treatment created sustained oxidizing and oxygen‑rich conditions needed for complete contaminant degradation, without requiring excavation or disruptive in situ soil treatment methods. The approach delivered a reliable ISCO‑based solution for contaminated groundwater in a dense urban environment while minimizing operational impacts.

A single application of KLOZUR® CR and PERMEOX® Plus delivered an integrated in situ chemical oxidation (ISCO) and biostimulation treatment to address a gasoline release in Florida’s coastal plain. Applied across the source zone and downgradient plume, this in situ groundwater and soil treatment achieved a 70% reduction in plume area within three months and met all groundwater cleanup goals outside the LNAPL zone. The combined chem‑bio approach paired powerful sulfate‑radical oxidation with sustained aerobic and anaerobic biodegradation, enabling true destructive contaminant removal confirmed through CSIA and microbial diagnostics. This project demonstrates how a single‑event ISCO‑based strategy can accelerate site closure while minimizing operational disruption at active petroleum facilities.

A permeable reactive barrier (PRB) built with alkaline‑activated KLOZUR® KP provided an effective in situ chemical oxidation (ISCO) solution for a mixed plume of 1,4‑dioxane and chlorinated ethanes at a former industrial site in New York. Bench and field pilot tests achieved greater than 99% contaminant reduction, with many compounds treated to non‑detect levels as the PRB maintained oxidizing and alkaline conditions longer than designed. This in situ groundwater treatment leveraged both oxidative and reductive pathways, enabling simultaneous treatment of contaminants that had resisted previous bioremediation approaches. The PRB design offered a reliable, low‑impact ISCO remedy suitable for sensitive areas such as wetlands.

A permeable reactive barrier (PRB) using alkaline‑activated KLOZUR® KP was successfully demonstrated as an in situ chemical oxidation (ISCO) solution to intercept a pentachlorophenol (PCP) plume at a former wood‑treatment facility in the Pacific Northwest. Bench‑scale column tests and a field pilot confirmed >99.9% PCP reduction, with oxidant persistence across the designed treatment duration. The in situ treatment approach provided a low‑impact, long‑lasting barrier capable of preventing downgradient contaminant migration, even improving water quality 40 feet beyond the PRB. This study highlights how KLOZUR® KP enables reliable, scalable ISCO‑based groundwater remediation in complex lithologies such as silty sand aquifers.

Hydraulically placed KLOZUR® KP, activated with a patented chelated‑iron system, delivered an effective in situ chemical oxidation (ISCO) treatment for a deep, low‑permeability sandstone zone contaminated with CVOCs, BTEX, naphthalene, and PAHs at a former industrial site in Germany.

The pilot targeted the most impacted intervals between 7–11 meters below ground surface, achieving rapid contaminant reductions of up to 99.9% within six months as the slowly dissolving oxidant migrated through the fractured matrix. This in situ treatment approach provided a practical alternative where excavation and pump‑and‑treat were not feasible, enabling remediation in challenging geology with minimal surface disruption. The results demonstrate how KLOZUR® KP can reliably treat mixed contaminant plumes in tight formations through sustained ISCO performance.

At a former manufacturing facility in the Netherlands, KLOZUR® ONE delivered a fast and reliable in situ chemical oxidation (ISCO) solution to treat a trichloroethylene (TCE) source zone located beneath the future footprint of a residential redevelopment. The ready‑to‑use persulfate blend enabled efficient injection through a dense grid of fixed wells, ensuring full contact across the 270 m² treatment area.

Within just five weeks, TCE concentrations decreased by 99.6%, with all monitoring wells achieving regulatory cleanup targets and independent verification confirming complete oxidant consumption. This project demonstrates how KLOZUR® ONE provides a rapid, low‑disruption ISCO remedy ideal for chlorinated solvent source zones in urban redevelopment settings.