We believe Cognition Land and Water to be one of the most dynamic and multifaceted specialist contractors in the Land Remediation and Ground Engineering industry.
What we do
We offer our clients a 'one-stop-shop', providing a wide range of services from civil engineering, to enabling, remediation, earthworks and groundworks. We have the necessary skills and experience to solve your ground engineering challenges and we offer innovative solutions to save time and money.
The client:South East England Development Authority (SEEDA)
Services:Bioremediation, segregation, groundwater treatment, soil washing, stabilisation, chemical oxidation, PRB.
The 1.7 hectare former PD Fuels Depot at Tipner formed part of the 44 hectare Tipner Regeneration Project that would transform the geographical area and provide a new gateway to Portsmouth. The site was located in a sensitive busy residential area adjacent to Tipner Lake, an SPA, Ramsar Site and SSSI designated tidal water body interconnected with Portsmouth Harbour. The site was heavily contaminated with a range of pollutants including TPH, PAH, SVOCs/VOCs and asbestos due to historic industry including a fuel depot, tar works and timber yard leaving the site contaminated.
Cognition was contracted by SEEDA to remediate site soils and groundwater in order to reduce the health risk to future residents. The key elements of these works included;
Remediation trials investigating a range of treatment options including Soil Vapour Extraction (SVE), Multi-Phase Extraction (MPE), soil washing, chemical oxidation, soil stabilisation/encapsulation and permeable reactive barriers;
Detailed studies investigating several bioremediation additives;
Concrete slabs broken out and trial pits excavated to delineate contamination;
Excavation, chemical testing and delineation of contamination;
Ex-situ bioremediation using cultured indigenous bacteria, biosurfactants, soil enhancers and nutrients;
Additional chemical additives applied to soils with a high BTEX concentration;
Groundwater and surface water treatment;
Pre-processing/screening of soil;
Soils stabilised prior to backfill and compaction with upper layers forming piling mats;
Environmental monitoring and controls put in place to manage dust and odour;
Clean capping installed across site to protect workforce during construction phase.
Cognition processed 80,000m3 of soil with 30,000m3 successfully bioremediated to meet the agreed re-use criteria and backfilled. Other remediation techniques such as groundwater treatment and a PRB were employed on the site to aid remediation. Treatment and re-use delivered significant savings over conventional disposal, as well as other benefits such as reducing site traffic and disruption in the local area.