Leiden: CVOC

In-situ remediation technique: In situ chemical Reduction (ISCR)

Project name: Leiden: CVOC Case submitted by: Groundwater Technology BV Contact: Yvo Veenis Address: PO Box 12115 3004 GC ROTTERDAM Telephone number: Email-address: yve@gtbv.nl

Country: Netherlands City/region/county: Leiden/ Zuid-Holland (future) use of location: Industry and urban area Built-up location during the active remediation phase?: yes

In situ saneringstechniek: In situ chemical Reduction (ISCR)

Explanation technique: 11 direct injection were performed in the zone of 6-8.5 m-mv and in total 1500kg EHC was injected. The goal was to remediate the pure product underneath a former chemical laundry. At the location there is a road, pavement, parkinglot, and buildings with offices and apartments. The technique is based on chemical reduction, where a slurry of water and nano-particles of zero-Fe was injected. The advantage is a faster degradation compared to biological degradation. This way all pollutant will be degraded immediately and therefore not spread by groundwater flow. Also other remediation techniques applied?: No After care needed?: Yes, only when the situation is not stable, aftercare is needed in the plume. Rationale for the chosen technique: A fast solution was needed, to minimize spreading of the pollutant. The source is treated and the plume is monitored to measure a stable end situation. If necessary, when no stable end-situation is obtained, additional remediation techniques will be applied. This will be chemical oxidation by injecting ozone and hydrogen-peroxide or by anaerobic natural attenuation by injecting a C-source.

Treated contaminant(s): Chlorinated volatile organic compounds (CVOC) Contaminant phase: Groundwater Size contamination: Source: 1000 m3 Depth contamination: 9 [m-mv]

Soil type: Layered soil: clay/peat/sand Saturated/unsaturated zone?: Saturated zone Permeability: 0,01-0,1 m/day, estimation based on geology. Flow velocity or gradient groundwater: nil

Remediation goal: Stable end situation Remediation goal achieved?: Yes Initial and final concentration and load removal: Perchlooretheen: initial concentration 2300 µg/l, end concentration 25 µg/l Trichlooretheen: initial concentration 1700 µg/l, end concentration 6,2 µg/l Cis-dichlooretheen: initial concentration 13.000 µg/l, end concentration 1.300 µg/l Vinylchloride: initial concentration 1.500 µg/l, end concentration 1.90 µg/l totale vracht start: [kg] totale vracht eind: [kg] Active remediation phase: 23/07/2010 till 25/07/2010 Passive remediation phase: 01/01/2009 till 01/01/2010 Total costs passive/after care phase: Total costs active phase: € 35.000,- excl. VAT

Problem owner: Gemeente Leiden Contractor: Groundwater Technology BV Remediation plan: Groundwater Technology BV Remediation research: Groundwater Technology BV Competent authority: Milieudienst West-Holland Contact information stake holders: Groundwater Technology BV

Lessons learned: Remarks:

Related techniques: In situ chemical Reduction (ISCR)

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