DCE Contamination at Industrial Sites: Why Cleanup Can Stall and How Remediation Companies Respond

Chlorinated solvent remediation projects often hit an unexpected wall when contaminant levels plateau or rebound despite active treatment. Dichloroethylene (DCE) contamination often causes this stall, leaving facility teams facing rising costs and regulatory pressure. Understanding why DCE persists and how to vet providers with documented evidence can turn stalled cleanup into regulatory closure.

Why DCE Persists After TCE or PCE Treatment

DCE forms as a transformation product when trichloroethylene (TCE) or perchloroethylene (PCE) breaks down through biological processes in the subsurface. The phenomenon known as DCE and vinyl chloride stalling occurs when reductive dechlorination halts at DCE rather than progressing to vinyl chloride and, eventually, ethene. This is a documented occurrence across many contaminated sites rather than a sign of remedy failure.

Complete reductive dechlorination of PCE or TCE to ethene requires three conditions. First, a sufficient electron donor must be present as a fermentable carbon source. Second, the aquifer must maintain an appropriate redox potential with strongly reducing conditions. Third, microbial communities capable of complete dechlorination must exist at the site.

When any of these conditions falls short, the breakdown process often stops at cis-1,2-DCE. Chlorinated ethenes become easier to dechlorinate when more oxidized, meaning compounds with more chlorine atoms break down more readily.

How Site Conditions Affect Bioremediation and Other DCE Remedies

Site-specific geology, hydrogeology and geochemistry determine which remedy will work. Bioremediation depends on favorable microbial conditions, while chemical reduction or oxidation approaches respond differently to soil permeability and groundwater chemistry. The success of in situ remedies ties directly to a thorough understanding of site and subsurface conditions. When remedies fail, it’s often because teams developed an insufficiently detailed conceptual site model.

Required characterization parameters include geology and stratigraphy, hydrogeology and geochemistry with attention to electron acceptors and metals mobilization risk. At one 20-acre site, inadequate characterization caused a bioremediation program to fail outright. The site required a complete remedy change to extraction, resulting in $380,000 in additional expenses and a two-year delay.

What Evidence to Request From a DCE Remediation Provider

Operations managers and facility engineers should request evidence from any provider under evaluation in several key areas. Site characterization documentation should include boring logs, monitoring well data and groundwater flow modeling that demonstrate the provider’s understanding of subsurface conditions at similar sites.

Remedy design rationale documentation should show how the proposed remedy addresses site-specific geology and accounts for potential DCE stall conditions. Performance verification protocols should detail post-installation monitoring plans, including sampling frequency and the specific concentration targets needed to demonstrate regulatory closure.

Providers to Evaluate for DCE Contamination

The following companies span remediation technology manufacturing, environmental engineering consulting and field installation services.

1. Remediation Products Inc. (RPI®)

RPI® manufactures in situ remediation technologies for treating chlorinated compounds in subsurface soil and groundwater. Its BOS 100® product uses granular activated carbon with zero-valent iron as part of its structure to adsorb contaminants and degrade them through reductive dechlorination while producing no degradation products. For sites where DCE has stalled, CAT 100 adds sustained microbial activity to abiotic reduction.

The company’s RDC process enables surgically precise injections by beginning with high-resolution site data collection to guide custom design and optimize treatment zones. RPI®’s Project Support Laboratory analyzes thousands of samples annually at no charge.

Key features:

• Activated carbon technology: BOS 100® and BOS 200+® address different contamination scales with granular and powdered formats tailored to site conditions.
• Precision injection approach: High-resolution characterization via the RDC process enables targeted placement within contaminated zones.
• Laboratory support: No-cost sample analysis helps facility teams monitor treatment progress and verify regulatory closure metrics.

2. Regenesis

Regenesis provides in situ remediation technologies for chlorinated volatile organic compounds, including PCE, TCE, DCE and vinyl chloride. The company notes that chlorinated solvent sites present particular challenges because contamination often persists in source areas, low-permeability soils and fractured rock long after the original release.

Its approach combines enhanced reductive dechlorination, in situ chemical reduction, bioaugmentation and in situ chemical oxidation to address source areas and dissolved plumes. One documented application involved a permeable reactive barrier combining multiple technologies to treat chlorinated compounds at a former dry cleaner site.

Key features:

• Multiple technology integration: It combines biological and chemical treatment approaches rather than relying on a single remedy type.
• Bioaugmentation options: Bio-Dechlor INOCULUM® Plus provides microbial cultures when native populations can’t support complete dechlorination.
• Long-term containment: PlumeStop® and colloidal activated carbon products address back-diffusion and rebound concerns after active treatment.

3. EnviroForensics

EnviroForensics operates as an environmental engineering and consulting firm rather than a technology manufacturer. The company has performed thousands of environmental site investigations and manages the full remediation life cycle from characterization through regulatory closure.

Its site characterization work includes exploratory borings, stratigraphy analysis, soil gas sampling, monitoring well installation and groundwater modeling. Remediation services span alternative evaluation, bench- and pilot-scale testing, and treatment system design and permitting. The firm selects from multiple technologies, including soil vapor extraction, thermal treatment and in situ groundwater treatment based on-site findings.

Key features:

• Engineering expertise: It provides guidance on remedy selection and design rather than promoting a specific proprietary technology.
• Regulatory navigation: The company manages permitting and regulatory closure documentation to support state and federal compliance requirements.
• Bench and pilot testing: It conducts treatability studies before full-scale implementation to reduce the risk of poor remedy performance.

4. Cascade Environmental

Cascade Environmental serves as a field services contractor delivering site investigation, drilling and remediation installation support nationwide. The company offers both traditional and high-resolution site characterization tools to refine conceptual site models before remedy design.

Its remediation services include custom injection design for chemical or biological amendments and thermal remediation through its TerraTherm subsidiary. Thermal options include electrical resistance heating and thermal conductive heating. The company also provides pneumatic and hydraulic environmental fracturing to improve amendment delivery in tight soils and fractured rock.

Key features:

• Installation expertise: The company performs the physical drilling and injection work as designed by engineers or as specified by technology providers.
• Delivery enhancement: Fracturing capabilities help overcome low-permeability conditions that limit treatment effectiveness.
• Thermal options: TerraTherm subsidiary offers high-temperature treatment for source zone elimination when biological or chemical approaches prove insufficient.

Turning DCE Data Into a Confident Remediation Decision

DCE persistence after TCE or perc treatment reflects well-documented chemistry rather than remedy failure. The quality of site characterization drives remedy performance more directly than brand reputation alone. Before committing to any provider or technology, facility teams should request site-specific evidence showing how the approach addresses their site’s geology, hydrogeology and geochemical conditions.

*Please note that this list includes sponsored content. Some of the companies, products, or services featured have entered into commercial agreements for placement. Sponsored placements do not necessarily reflect an endorsement and should be considered alongside other options in the marketplace.