Summary

Case submitted by: NTP Milieu
Country: The Netherlands
Built-up site?: Yes
Soil type: Mainly sand and layered soil; clay/peat
Follow-up required?: Nee
Treated contamination: Chlorinated Volatile Organic Compounds (CVOC)
Medium contamination: Groundwater
Dimension contamination: 245.000 m3
Remediation goal:
final concentration
PCE concentration 20 µg/l
TCE concentration: 262 µg/l
Cis concentration: 10 µg/l
VC concentration: 2,5 µg/l
Load removal percentage: > 95%
Remediation goal achieved?: Yes, for 2 layers in the source area.
No, remediation of the plume has not yet completed.
Initial and final concentration or load removal:
VC initial concentration: 5.700 µg/l; final concentration: 2,5 µg/l
Active remediation phase: June 2006 until July 2011
Passive remediation phase: The passive phase is not yet started.
Added reports:

Case detailed information

General information
Project name: Den Haag (W. Royaardsplein): CVOC *** Case submitted by: NTP Milieu Contact: De heer G.B.J. Borggreve Address: Postbus 6280 7503 GG Enschede Telephone number: +31 (0)53-4614905 Email-address: g.borggreve@ntp-enschede.nl
Location
Country: The Netherlands City/region/county: Willem Royaardsplein te Den Haag, provincie Zuid Holland (future) use of location: Residential Built-up location during the active remediation phase?: Yes
Technique
Explanation technique: TCE-concept applied to the upper soil; cultivation of the dehalococcoides ethenogenes. Also other remediation techniques applied?: No After care needed?: Nee Rationale for the chosen technique: Stimulation of anaërobe demolition is the best option for the remediation of CVOC in the groundwater, it's the most logical decontaminationvariable in a cultivated environment.
Contamination
Treated contaminant(s): Chlorinated Volatile Organic Compounds (CVOC) Contaminant phase: Groundwater Size contamination: 245.000 m3 Depth contamination: 20 m below surface
Soil
Soil type: Mainly sand and layered soil; clay/peat Saturated/unsaturated zone?: Saturated zone Permeability: > 0,1 m/day Flow velocity or gradient groundwater: 1,4 m/km 17 m/year
Result, duration, expense
Remediation goal: final concentration PCE concentration 20 µg/l TCE concentration: 262 µg/l Cis concentration: 10 µg/l VC concentration: 2,5 µg/l Load removal percentage: > 95% Remediation goal achieved?: Yes, for 2 layers in the source area. No, remediation of the plume has not yet completed. Initial and final concentration and load removal: VC initial concentration: 5.700 µg/l; final concentration: 2,5 µg/l Active remediation phase: June 2006 until July 2011 Passive remediation phase: The passive phase is not yet started. Total costs passive/after care phase: Total costs active phase: € 324.000 ,-
Stakeholders
Problem owner: Gemeente Den Haag Contractor: NTP Milieu Enschede Remediation plan: NTP Milieu Enschede Remediation research: Royal Haskoning / Witteveen en Bos Competent authority: Gemeente Den Haag Contact information stake holders: De heer G. Borggreve NTP Milieu
Additional information
Lessons learned: Diffusion of substrate and added bacteria, in order to stimulate degradation, to the deeper groundwater is hampered by a poorly permeable layer at a depth of 8-9 m-mv. As a result, the source area above this layer was rehabilitated within two years after the start; in the layer of 9-12 m-mv progress is stagnated. Remediation of the plume zone is stagnating because below the average lowest groundwater level measured no groundwater may longer be extracted, which in practice often appears to occur. Due to this limitation, this extraction system is periodically out of order and less water can be extracted and re-infiltrated. Remarks: www.royaardsplein.nl
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