Development background

Development of our product started back in 2005 when one of our clients had a large, heavily-silted lake to clear for a residential development. 

After an initial investigation it was found that the site of the lake had very little land available to dewater the silts using traditional methods, before they could be removed from the site. 

The silt could not go straight to landfill because of the change in regulations preventing wet waste going to landfill. It was also found that some of the silt was contaminated with heavy oils.

The initial proposal was to bring in mobile treatment equipment to dry the silts out and then send the material directly to a hazardous landfill. After some research into alternatives we proposed a small trial using 1m³ fabric bags to hold, dewater and treat the silts to attempt to remove the contamination and reduce the quantity of waste by removing the water.

The trial ran in 2005/6 and was very successful in dewatering and treating the oil content of the silt. It also provided proof that the bags could be successfully stacked on top of one another, reducing the foot print needed to treat and hold the silts.

In 2006 we made a larger version of the Sedi-filter (7m x 15m) and desilted a further part of the lake. This was also very successful with the silt dewatering by 90% over two months. 

Based on this performance and the original trials we expanded the Sedi-filter usage to desilt the lake completely and treat the contaminated silts to reduce the contamination. Through 2006 to 2008 several further Sedi-filters were deployed at the site. Each bag was monitored and the silts tested. 

In 2008 the lake had been desilted enough for the requirements of the residential project and the contaminants had been reduced to such a level that the dried silts did not have to be removed to a hazardous landfill. The silts were actually reused as top soils and mixed into the landscape.

Following this success the Sedi-filter was developed for wider applications.