British Waterways were requested by the Environment Agency to dredge approximately 22,000 m³ of sediment from the River Lee Navigation so as to improve water quality.
Land & Water were commissioned to sample and analyse the sediments and formally classify the material 6 months in advance of the intended start date. The sediment was found to be contaminated with heavy metals and oils which reduced the dissolved oxygen content of the water and caused unsightly duckweed and pennywort in the summer season. In addition the working area was within a source protection zone for a drinking water supply borehole. The works needed to be complete within a short timescale in order not to interfere with the fish spawning season.
A sustainable solution for disposal was of primary importance to the client and therefore as an alternative to landfilling, bioremediation of sediments was undertaken at Biogenie site at Colnbrook as well as sediment blending with compost under a deployment of our mobile treatment license at a SITE facility.
The project was completed in 11 weeks and required close liaison with local interested parties such as the Lee Rowing Club and Canoe Club.