Summary

Case submitted by: BioSoil
Country: The Neterlands
Built-up site?: Yes
Soil type: Mainly sand, with clay layers
Follow-up required?: Yes, the bioscreen was meant as precaustion and after-care. A polluted groundwater flow originating from the town centre of Wageningen was moving towards the VADA-site. The concentrations in the groundwater were that high that re-contamination would lead to exceedence of the remediation goal. Therefore the groundwater was cleaned to an acceptable contamination level.
Treated contamination: Chlorinated Volatile Organic Compounds (CVOC)
There have been a couple of chemical washeries in the town-centre of Wageningen. The exact location of the washeries is unknown because the city archives were lost in the war. At least three locations were significantly contaminated which has lead to a contaminated groundwater fow from the town centre towards the VADA site.
Medium contamination: Groundwater
Dimension contamination: n/a
Remediation goal: final concentration
PCE concentration: 10 µg/l
TCE concentration: 125 µg/l
cis-DCE concentration: 5 µg/l
VC concentration: 76 µg/l
Remediation goal achieved?: Yes
No, there has been intense contamination removal in the bioscreen, but there is not truly a remediation goal.
Initial and final concentration or load removal:
CVOC initial concentration: 1000 µg/l; final concentration: < 10 µg/l
Active remediation phase: mid 2000 until present day
Passive remediation phase:

In-situ remediation technique:

Case detailed information

General information
Project name: Wageningen (VADA): CVOC *** 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
Location
Country: The Neterlands City/region/county: Wageningen, Gelderland (future) use of location: Industrial Built-up location during the active remediation phase?: Yes
Technique
Explanation technique: Also other remediation techniques applied?: No After care needed?: Yes, the bioscreen was meant as precaustion and after-care. A polluted groundwater flow originating from the town centre of Wageningen was moving towards the VADA-site. The concentrations in the groundwater were that high that re-contamination would lead to exceedence of the remediation goal. Therefore the groundwater was cleaned to an acceptable contamination level. Rationale for the chosen technique: The bioscreen, in which complete anaërobic dehalogenation of the contamination was stimulated, is more cost-effective in terms of performance and maintenance than complete extraction of the groundwater, treatment and discharge.
Contamination
Treated contaminant(s): Chlorinated Volatile Organic Compounds (CVOC) There have been a couple of chemical washeries in the town-centre of Wageningen. The exact location of the washeries is unknown because the city archives were lost in the war. At least three locations were significantly contaminated which has lead to a contaminated groundwater fow from the town centre towards the VADA site. Contaminant phase: Groundwater Size contamination: n/a Depth contamination: 30 m below surface
Soil
Soil type: Mainly sand, with clay layers Saturated/unsaturated zone?: Saturated zone Permeability: > 0,1 m/day Based on field data. Flow velocity or gradient groundwater: Value: ca 75 m/year
Result, duration, expense
Remediation goal: final concentration PCE concentration: 10 µg/l TCE concentration: 125 µg/l cis-DCE concentration: 5 µg/l VC concentration: 76 µg/l Remediation goal achieved?: Yes No, there has been intense contamination removal in the bioscreen, but there is not truly a remediation goal. Initial and final concentration and load removal: CVOC initial concentration: 1000 µg/l; final concentration: < 10 µg/l Active remediation phase: mid 2000 until present day Passive remediation phase: Total costs passive/after care phase: Total costs active phase:
Stakeholders
Problem owner: VADA/Compotex Contractor: BioSoil Remediation plan: BioSoil Remediation research: DHV Competent authority: Provincie Gelderland Contact information stake holders:
Additional information
Lessons learned: Two screens have been constructed. One along the Costerweg and later this was expanded along the Walstraat to fully capture the plume from the center. Technically, the screen along the Walstraat differs from that along the Costerweg. This screen is blocked in the abstraction and injection filters and therefore at the end of its technical lifetime (it has worked nine years). The screen on the Walstraat is still functioning well and can last for many years. Apart from PCE a considerable amount of nitrate and sulphate in the groundwater is coming into the screen. In fact, the majority of electron donor is needed for sulfate reduction and denitrificate in order to achieve a sufficient reduction in the levels of chlorinated hydrocarbons. The memory of a screen is relatively short, because contamination and nitrate keep on flowing into it. A malfunction in the operation of a screen easily leads to contamination passing the screen. Remarks: The screens consist of single or multiple filters, extraction and injection filters. The extracted groundwater is enriched with electron donor and, wtithout further surface treatment, re-infiltrated. In this way the necessary anaerobic conditions are best maintained. Behind the screens there are monitoring filters. A bioscreen is a measure to prevent spread of contamination. In an "infinite source" as in the presence of free product, this is preferably combined with measures for the source.
Related techniques and HIP-pilots