Wageningen: CVOC and TEX ***

In-situ remediation technique: (Enhanced) natural attenuation, aerobic, (Enhanced) natural attenuation, anaerobic

Project name: Wageningen: CVOC and TEX *** Case submitted by: BioSoil Contact: Mw. C. v.d. Steenoven Address: Nijverheidsweg 27 3341 LJ Hendrik Ido Ambacht Telephone number: +31 (0)78 - 682 01 40 Email-address: c.vandesteenoven@biosoil.com

Country: The Netherlands City/region/county: Wageningen, Gelderland (future) use of location: Industrial Built-up location during the active remediation phase?: Yes

In situ saneringstechniek: (Enhanced) natural attenuation, aerobic, (Enhanced) natural attenuation, anaerobic

Explanation technique: There was a toluene- and PCE contamination, which were vericaly seperated (toluene on top and PCE below). The layers are also seperatly treated. The toluene contamination is aërobic degraded and the PCE-contamination anaërobic. Also other remediation techniques applied?: Yes, a part of the upper layer of the parking lot with mostly a toluene contamination has been digged out to groundwater level. The contaminated soil was cleaned up in a landfarm on a nearby location and brought back into it's original location (3000 m³). After care needed?: Yes, a foundation strip has been filled with (PCE and TCE containing) garbage. This strip has been cleaned out of leniency with the use of pump & treat. The contamination underneath the built-up site has been no part of the remediation measure. After the remediation, the groundwater has been extracted, cleaned and drained for a while until an acceptable contamination level was achieved. Rationale for the chosen technique: Given the amount of contamination, this was the only possibility.

Treated contaminant(s): Chlorinated Volatile Organic Compounds (CVOC); Volatile aromats, excluding benzene and TEX. In the past a printing office was established on the site. A toluene contamination has occurred because of leakage. Chlorinated solvents have also been used in the printing office. Contaminant phase: Soil/pure product and groundwater Size contamination: 200.000 m3 Depth contamination: 10 m below surface

Soil type: Mainly sand with clay layers Saturated/unsaturated zone?: Saturated zone and unsaturated zone Permeability: > 0,1 m/day, based on field records Flow velocity or gradient groundwater: ca 75 m/year

Remediation goal: final concentration PCEconcentration: 10 µg/l TCE concentration: 125 µg/l cis-DCE concentration: 5 µg/l VC concentration: 76 µg/l The goal for toluene was 250 µg/l Remediation goal achieved?: Yes Initial and final concentration and load removal: CVOC initial concentration: free product; final concentration: < 50 µg/l , total initial load: remark; total final load: <0,1 [kg] Toluene initial concentration: free product; final concentration: < 250 µg/l total initial load: remark; total final load: < 0,1 [kg] Active remediation phase: 9th November 1999 until 2004 Passive remediation phase: The passive phase is completed. Realization period: 2004 until mid 2006 Total costs passive/after care phase: in total budget Total costs active phase: € 1.250.000

Problem owner: VADA/Compotex Contractor: BioSoil Remediation plan: BioSoil Remediation research: DHV Competent authority: Provincie Gelderland Contact information stake holders:

Lessons learned: See 'remarks'for the soil profile, as it was described in all reports. In the field, the soil profile differed significantly from this description. For example, the first clay layer was not present at several locations. This influenced the distribution of the contaminant and the remediation system. At the adjecent parcel, sewage works were on going, inclusing extraction of groundwater. The consultant didn't make allowance for the contamination, which resulted in transport of the toluene contamination outside of the remediation location. Remarks: Soil profile: 0,0 - 3,0 m-mv; clay, with locally thin sand layers 3,0 - 3,5 m-mv; sandy clay 3,5 - 4,0 m-mv; moderately loamy fine sand 3,5 - 30 m-mv; well drained gravelly sand 30 - 35 m-mv; first non-permeable layer; clay The contamination of chlorinated hydrocarbons extended to the first non-permeable layer. Since contaminted groundwater from the cisty centre of Wageningen was being transported to the site, the remdiation was limited to a depth of 10 m below surface. In a next phase, it should be decided which measures should be taken in the deeper groundwater. This second phase didn't start yet. A bio-barrier has been installed along the Costerweg and the Walstraat in order to prevent new contamination. In the area with the toluene contamination, a system was applied in two layers. In the first layer to about 6.5 m below surface aerobic conditions were created for the degradation of toluene. In the underneath package, anaerobic conditions were created for the anaerobic conversion of TCE and PCE. The composition of the nutrient mixture to apply for toluene degradation was adapted to the deeper anaerobic remediation package. At the conclusion of the remediation it seemed that some re-contamination occured in the clean layer of the deeper water (below 10 m-mv) due to convention and dispersion The inflowing groundwater was cleaned in the bioscreen, causing an overall decline in load of chlorinated hydrocarbons. Partly for that reason, no further action is required by the competent authority.

Related techniques: (Enhanced) natural attenuation, aerobic, (Enhanced) natural attenuation, anaerobic

Related HIP-pilots: HIP-pilot Assessing stable end situation CVOC 1, HIP-pilot Assessing stable end situation CVOC 2, HIP-pilot Direct push shock load protamylasse – radius of influence and effect substrate, HIP-pilot Field comparison 2 substrates for anaerobic degradation CVOC, HIP-pilot Specific monitoring biological degradation