This site at Elnaryd in central Sweden had been used for treatment of timber by impregnation with chemicals including Arsenic V and Chrome VI between 1945 and 1968. The groundwater level on the site was very near the surface, between 0.5 and 1 metres deep. In order to excavate soil from the site for treatment the client had to lower the groundwater level to a maximum depth of 7 metres. The site was divided into several shafts where the excavation took place.

The remediation project commenced in early 2007 with Oil Pollution Services responsible for providing equipment to treat the contaminated groundwater. OPS quoted and supplied a containerised water treatment skid to Ragn Sells Avfallsbehandling AB who served as a subcontractor to the National Road Administration, the principal contractor. The contaminants were mainly Arsenic, Chrome, Copper and PAH.

Insulated containerised water treatment package including prefilters and bulk media vessels.

The process consisted of prefiltration through both sand filters and finer 25 micron cartridge filters, followed by removal of dissolved contaminants in 800kg media beds filled with three different types of media including RM 25 to remove the PAH.

The dissolved contaminant levels were originally estimated to be:
	Average mg/l	Maximum mg/l
Arsenic V	0.3	2
Chrome VI	0.3	2
Zinc	0.3	2
PAHcar	0.3	2
TPH+PAHtot	12	35

The required outlet targets were:
	µg/l
AS V	0.02
Cr VI	0.02
Zn	0.2
PAHcar	0.01
PAHtot	0.02

Containerised unit on site at Elnaryd beside treatment pond.

In practice, the actual levels in some areas of the site turned out to be more than 10 times the level originally estimated. A total of 75,000 tonnes of soil were removed and 35,000 cubic metres of water was pumped and treated. The project started in January 2007 and water continued to be pumped until the end of July. The whole project was completed in November 2007.