Several years of operations had led to a very substantial contamination at this industrial site. The contamination concerned a mixture of (chlorinated) hydrocarbons, including pure product. For WeGroSan/HMVT the challenge is to remove as much of the product and contaminated groundwater as possible each month, and to purify the released air and water flows prior to discharging these. This is done through a system of dozens of underground Multi-Phase Extraction filters that have been installed across the site. WeGroSan/HMVT carried out this service from 2007 through to 2010 for a fixed amount per month, linked to a minimal up-time of its installations.

Solution
The extraction and purification installations involved the following:

• Installation of 53 stainless steel Multi-Phase Extraction filters and underground pipework.
  Phased laying so as not to hamper business operations. Critical work was carried out at weekends.
• Water purification:
  – Multi-Phase Extraction unit with a capacity of 1,600 m³/hour at approx. 130 mbars absolute
  – Capacity of 6 m³/hour
  – Oil-water separation
  – Removal of iron including acid dosage
  – Aeration using a stripping tower
  – Activated carbon filtration
• Air purification:
  – Two Catalytic Oxidation units at 1,000 m³/hour incl. scrubber connected in parallel.
• All this was assembled in a tailor-made shed.
• In accordance with ATEX regulations.

Results
WeGroSan/HMVT successfully operated this system for several years and extracted and processed many thousands of kilos of contaminants.