DNAPL to non-detect: Six orders-of-magnitude reduction of chlorinated solvents on a large-scale site

Language: English
Presenter: Jack Shore and Marcello Carboni (REGENESIS)

In this webinar, Marcello Carboni and Jack Shore present a case study on the in situ remediation of a large former manufacturing facility, highly contaminated with chlorinated solvents. Very high concentrations, suggestive of DNAPL, were remediated down to ‘non-detection’ levels (six orders of magnitude reductions) to achieve regulatory closure of the site.

The >6,000 m² contaminant plume was targeted using a staged approach; firstly Enhanced Reductive Dechlorination (ERD), using a range of electron donors, was used to deplete the contaminant mass followed by in situ sorption and biological degradation to achieve low contaminant concentrations. Colloidal Activated Carbon was applied as an injectable Permeable Reactive Barrier (i-PRB) protecting the adjacent river and achieving compliance with very stringent boundary remedial targets (TCE <1.5 μg/L; VC <0.5 μg/L).

The webinar discusses the pilot studies completed to create a full-scale design, tailored to the concentration and hydrogeology on each part of the site. The full-scale application planning and injection is demonstrated and explained. The remediation results are extensive due to the demanding compliancy requirements for the site and have been compiled over a number of years. These are used to explain how the technologies selected work under challenging conditions for geology setting, degree of contamination levels and regulatory targets. The commercial aspects of the project are also of interest as REGENESIS provided a fixed price, turn-key solution to guarantee success to the client.

Using this example, an overview of different in situ options for chlorinated solvent treatment are discussed, including pros and cons and a guide to selecting the most appropriate approach.

The key points covered are:

• Review of the geological and hydrogeological setting, comprising low permeability silty sands and sandy silt layers
• Comparative pilot testing phase to determine substrate choice and dose to create a tailored full-scale design
• The applicability of different controlled-release electron donors (3-D Microemulsion and HRC) depending on location within source-plume system, concentration and hydrogeology
• Use of PlumeStop Liquid Activated Carbon to further promote biodegradation through in situ sorption, rapidly reducing residual contamination down to non-detect, and maintaining these over the long term
• Commercial and project management of large scale in situ treatment to meet budget and time expectations
• Overview and guidance on the selection of in situ injectable technologies for chlorinated hydrocarbons (ERD, ISCR, ISCO, in situ sorption)

About the presenters:

Ing. Marcello Carboni
Regional Manager, Europe | REGENESIS

Marcello Carboni is the European Regional Manager at REGENESIS. In his current role, he coordinates technical and sales activities in Europe and assesses development potential in new countries. From 2011 to 2018, Marcello covered the role of Mediterranean District Manager, providing support to clients in several Southern European countries. Before joining REGENESIS, Marcello gained ten years of experience in the design and implementation of investigation and remediation activities at an Italian environmental consulting company. Marcello obtained his master’s degree in Environmental Engineering from the Polytechnic University of Turin, Italy in 2001, after spending part of his studies at the Technical University of Delft (TUDelft) in the Netherlands and at the Universitat Politècnica de Catalunya (UPC) in Barcelona, Spain.

Jack Shore
Senior District Manager | REGENESIS

Jack is the Colloidal Carbon Technologies Lead for REGENESIS in Europe and oversees the UK and Scandinavian districts within the company. As part of these roles, he manages a team providing technical support and design work to a mix of Design and Build Consultancies, Remediation Contractors and Blue-Chip Clients. Jack has over 12 years of experience within the remediation industry and most recently has successfully implemented the first injection of PlumeStop to effectively manage a PFAS plume in the EU. His expertise ranges from supervising site investigations, developing in situ remediation designs, and managing large-scale remediation projects with multiple stakeholders.