Works involved provision of cut-off drains to intercept existing drainage systems to divert drainage to a suitable outfall positions, followed by additional headers to replace drainage damaged by intensive use of the easement.

Pre-construction drainage consisting of 15,000 metres of 160mm / 100mm diameter header drains commenced on 7th April and was completed by 1st May.

Following installation of the pipeline, White Horse Contractors returned to site a month later to lay 25,000 metres of post construction drainage, in the main 80mm diameter, simultaneously re-constructing cross drains using concrete beams over the pipeline trench. A total of 6.500 tonnes of aggregate were used over an 18km stretch of the pipeline running through the Thames Valley where the drainage works were concentrated.

Installation was carried out by White Horse Contractors' workforce using their fleet of Mastenbroek trenchers and tracked gravel hoppers (including the latest CT12).

"White Horse Contractors Limited installed the pre and post construction land drainage to the Chalgrove to East Ilsley and Abingdon IP gas pipelines in a thoroughly professional manner. The company, which was responsible for the design and construction, completed the works to a high standard within budget and on time.
An impressive array of modern plant was supported by a suitable experienced workforce and a thoroughly professional management team".

Martin Sperrink, Project Manager, Laing O'Rourke.