Utilising Interception Ditches to Provide Passive, Rain Ready, Water Treatment on Linear Construction Sites - Case Studies Cited from Across the United Kingdom

Exploring how the novel use of interceptor ditches can enhance water treatment on linear infrastructure projects during construction. Case studies from sites in the UK will be used to demonstrate the pollution risks during temporary works and how sediment control interventions can be incorporated into ditches to provide a low carbon, rain ready treatment.

Participants will gain knowledge of the increased pollution risk during the construction phase, the need for a dynamic approach to surface water management and awareness of a range of simple interventions that can result in significant water quality improvements in a constrained footprint.

Linear construction sites can often present lively topography resulting in extensive material movement for cut and fill operations, tight site boundaries with limited capacity for water attenuation as well as plenty of exposed ground on linear construction sites can result in surface water management challenges.

The role of interceptor ditches will be explored from how they can be play an important role in the movement and management of water on a linear scheme, where physical adaptations can offer additional attenuation and solid removal, and how the use of easily available materials and sediment control products can be used to polish water. It will also cover how Gel Flocculant can be applied within an interceptor ditch to both improve the performance of attenuation ponds, quickly separating the solid loading from the surface water.

Once installed, the treatment ditch system can be operated as ‘rain ready’ meaning that no further action is required when it starts raining, the system can simply treat water under gravity, retaining the mud on-site and allowing clean water to be discharged. As with any sediment control measure, the continual monitoring and maintenance of the system is key to its success.