Profile: Golder Associates

Case Study 1
Lake De-silting using Geotextile-assisted Dewatering
Client: North-East Lincolnshire Council
Location: People’s Park, Grimsby

The restoration of the historic People’s Park, which is registered as a Park of Special Historic Interest (Grade II) by English Heritage, was part of the Heritage Lottery Fund’s Public Parks Initiative. The lake forms a focal point at the centre of the park and it was important that it was restored effectively, while minimising the disruption to the rest of the park.

The primary challenge in restoring the lake was to remove silt accumulation which was affecting the lake ecosystem. Traditional methods of de-silting can be time consuming, expensive and disruptive. Golder Associates developed a cheaper, more environmentally friendly method of silt removal, using the geotextile-assisted dewatering technique.

This method used a sludge pump to pass a dilute mixture of silt and water into large geotextile tubes. The tubes gradually inflated with silt solids whilst clean water (filtrate) bled off and was collected and passed back to the lake. When the tubes were fully inflated, pumping was stopped, but filtrate continued to bleed off as the silt continued to dewater. The geotextile tubes were left in position and, a few weeks after the pumping was stopped, they were cut open, to reveal a dense, relatively dry silt paste, which was re-used on site as a soil ameliorant.

The lake de-silting works were completed in a four week period at a significantly lower cost than traditional methods, with only minimal waste materials (large debris, most of which was recycled off-site) leaving site. This provided significant environmental benefits, such as reduced lorry movements and emissions, compared to traditional methods.

For more information
For further information on this project contact:
Jonathan Buckley, Project Manager, Tel: 01937 837800, email: jbuckley@golder.com

Case Study 2
Site Decommissioning
Client: Danisco
Location: Northampton

As part of a divestment plan, Danisco decided in late 2008 to close its Emulsifier plant in Northampton with the aim of selling the site.

The 2.5 acre site is located on an industrial site on the outskirts of Northampton and comprises steel-framed structures housing the emulsifier plant.

During the planning of the works, and taking into consideration land value optimisation, Golder Associates supported Danisco with the determination of scope of works, i.e. should the site be levelled to ground for sale or should it be sold with the industrial structures still in place but deplanted (empty). In conjunction with the land agents, it was decided to level the site for sale and Golder Associates provided planning, design, tendering and auditing of the deplant.

Golder Associates also assisted with the surrender of operational permits at site including site investigation works as well as holding the role as CDM Coordinator for the works. Dismantling and demolition works are due for completion later in 2009.

For more information
For further information on this project contact: Martin Bjerregaard, Project Manager, Mobile: 07971 492957, email: mbjerregaard@golder.com

For information on their range of services visit our website at golder.com