Veere (Neeltje Jans): Mineral oil***

In-situ remediation technique: (Enhanced) natural attenuation, aerobic, Air stripping, Pump & treat, Soil vapor extraction

Project name: Veere (Neeltje Jans): Mineral oil*** Case submitted by: SITA Remediation B.V. Contact: Pim Vis Address: Postbus 40221, 3504 AA Utrecht Telephone number: +31 (0)30 247 09 11 Email-address: info@sitaremediation.com

Country: The Netherlands City/region/county: Neeltje Jans, Veere, Zeeland (future) use of location: recreation Built-up location during the active remediation phase?: No

In situ saneringstechniek: (Enhanced) natural attenuation, aerobic, Air stripping, Pump & treat, Soil vapor extraction

Explanation technique: Also other remediation techniques applied?: Infiltration of an nutrients through drains After care needed?: No Rationale for the chosen technique: The remediation site is located on an inaccessible dike with different groundwater levels(3-11 m below surface), a heterogeneous soil structure and diffuse pollution. Due to these local conditions, based on oil chracterization and the potential for aerobic degradation (remedial investigation), the aforementioned techniques were chosen.

Treated contaminant(s): Mineral oil Contaminant phase: Soil/pure product Groundwater Size contamination: 10.000 m3 Depth contamination: 11 m below surface

Soil type: Layered soil: clay/peat/sand Saturated/unsaturated zone?: Saturated zone Permeability: > 0,1 m/dag, based on field data Flow velocity or gradient groundwater: Unknown; The remediation site is located on an inaccessible dike with different groundwater levels(3-11 m below surface)

Remediation goal: mineral oil concentration soil: 1000 mg/kg mineral oil concentration groundwater: 600 µg/l Remediation goal achieved?: No, the goal is Initial and final concentration and load removal: Concentration mineral oil (max) initial concentration: 26.000 mg/kg ; final concentration: 7.400 mg/kg total initial load: 8.673 kg; total final load: 3.655 kg Concentration mineral oil (max) initial concentration: 360 µg/l; final concentration: 40 µg/l Active remediation phase: 01/04/2005 until 21/01/2008 Passive remediation phase: Total costs passive/after care phase: Total costs active phase: € 223.500,-

Problem owner: Rijkswaterstaat Contractor: SITA Remediation B.V. Remediation plan: Colsen B.V. Remediation research: Colsen B.V. Competent authority: Provincie Zeeland Contact information stake holders: Wareco (nulonderzoek)

Lessons learned: The pre-remediation investigation has shown that aerobic degradation in a saline environment is possible. Because during construction of the dike in the past residuals (asphalt and tar chunks) have been used, the pollution is very local and very heterogeneous distributed present in the soil. Because of this, it is not feasible to remove all small hotspots. In order to achieve the remediation target, evaluation is based on average concentrations in the soil and during remediation an oil characterization was performed to assess the mobility of residual contamination. Based on cost and limited human and ecological risks, after performing a stop test, in consultation with the competent authority it was decided to terminate the active remediation. Remarks: In December 2008 a decision on the evaluation was obtained. In March 2009 the system was completely removed and the project completed.

Related techniques: (Enhanced) natural attenuation, aerobic, Air stripping, Pump & treat, Soil vapor extraction

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