Knight Brown was appointed to carry out the infrastructure works for the development of Forest Gate business park. As an old gas works site, it was subject to strict planning conditions in relation to ground remediation and sustainable drainage design principles. The scheme involved the construction of access roads, deep drainage, new services, kerbing and footpaths to service the new development.

The initial drainage design was based on the principle of containment using 174m of box culverts, hydro-brake manholes and a pumping chamber. Through Early Contractor Involvement, our site management team redesigned the drainage using ovoid pipes, thereby reducing delivery periods and mitigating costs.

The drainage was installed more than four metres deep, below the high water table. Pumping and dewatering was therefore, required into a lagoon to control the water levels. The trenches were lined with Visqueen GX hydrocarbon UDG protection membrane to protect the controlled waters from potential leachate contamination.

During the development works, contaminated ground, not previously identified was discovered and dealt with in the original programme in accordance with the strict planning conditions.