Part of a far-reaching transport and development action plan, the Fastlink bus link scheme along the Livingston / Edinburgh corridor required high performance storage and treatment of stormwater runoff in a constrained space.
As West Lothian Council is committed to the principles of SUDS, the infrastructure construction incorporated a Stormcell® Storage system and Downstream Defender® hydrodynamic vortex stormwater treatment separators from Hydro International.
Graeme Hedger, Senior Professional Officer, West Lothian Council, commented: “The Stormcell® and Downstream Defender® installations provided a high performance, storage and treatment solution in a very constrained retrofit situation, where otherwise it would have been difficult to achieve the required runoff control without compromise to the overall design.”
The Fastlink scheme provided an express bus link into Edinburgh, and was one of a number of regional schemes to reduce road vehicle commuting into the City of Edinburgh. Specifically, Fastlink will improve the A899 through Livingston for all road users, with three new bus halts for the Fastlink buses at Knightsbridge and Ladywell, and Howden which also included park and ride facilities. In addition, a new cloverleaf grade separation interchange is being constructed at Houston.
With the addition of extensive non-porous surfaces, it is important to control stormwater runoff safely, especially in a relatively flat locality. Consultant engineers Mouchel Parkman specified Hydro’s Stormcell® modular block storage systems with Downstream Defender® silt protection because they had successfully used Stormcell® on similar projects.
Around 50 m3 of Stormcell® was installed for the bus lay-bys and the park and ride facility, fed from point drainage systems. Additional silt and floating pollutants entrapment was incorporated after the stormwater storage where required, using 1 m diameter Downstream Defender® Separators.
Nearly 90 m3 of Stormcell® storage capacity was specified for the Houston interchange construction between the A899 and A89, in an installation either side of the carriageway. Here, 2 m and 2.55 m diameter Downstream Defender® Separators were used to remove pollutants and silt prior to discharge through the Hydro-Brake® Flow Control devices used to attenuate the higher potential volumes from the highway runoff.