Treatment Of TCE-Contaminated Soil And Groundwater Via. Stabilisation And ISCR
The Challenge
Design and delivery of a remediation strategy to treat extensive TCE-contaminated soil and groundwater, ready for development of 260 new homes.
The derelict 3.03ha site had once been home to Manchester’s Itron gas meter factory, which opened its doors in 1933 before closing for good in 2016.
Operational processes had left behind:
- 4,300m3 TCE-impacted soils
- >1 acre TCE-impacted groundwater plume
- Non-chlorinated hydrocarbons
Limited early site investigation data had resulted in a preliminary remediation strategy and remedial targets, but our client needed greater certainty.
Our Solution
Geostream UK worked with its international partners to conduct additional site investigations, revise the DQRA, and agree remediation targets values aligned to our proposed technology.
This involved sending samples to the USA for project-specific treatability studies to determine the site-specific half-lives of TCE and 1,1,1 TCA. Resulting data demonstrated proof of concept to regulators.
Groundwater remediation
We agreed a combined programme of ISCR and anaerobic bioremediation, using UK-exclusive patented substrate, Anaerobic BioChem Plus (ABC®+), from Redox Tech and Carus.
Injection of a slow-release electron donor established reducing conditions suitable for the degradation of chlorinated solvent contamination, via the TCE>>DCE>>VC>>ethene sequence.
Zero Valent Iron (ZVI) was injected simultaneously to provide immediate, direct reduction of chlorinated solvents via abiotic degradation.
This approach enabled a more rapid reduction in chlorinated solvents versus other slow-release methods, allowing for a reduced monitoring period post treatment.
Soil remediation
After a detailed review of available technologies, we selected Stabilisation for soil remediation. This allowed us to chemically fix contamination, while simultaneously achieving 130kPa soil bearing capacity to support the piling rig.
The Results
- Saved 20 weeks off the original programme through regulatory engagement
- Achieved contamination reduction targets through application of ABC ®+ technology
- Prevented 10,000 tonnes of material from going to landfill
- Reused 99.7% of material on site
