BCM Construction was awarded the renewal of five HV Feeder Routes running between sub-stations: Victoria to Queens Road, Graveney to Faversham, Herne Bay to Reculver, Reculver to Minnis Bay, and Canterbury East to Bekesbourne a total distance of around 22 kilometres. Network Rail praised BCM for their quick start on site “Well done to you and your team for your opening works at Victoria - a great result.”
The HV Feeders and associated Pilot Cables were installed in the late 1950’s and were life-expired. The old HV cables were oil filled which posed a significant environmental risk. CEEQUAL (The Civil Engineering Environmental Quality Assessment and Awards Scheme) requirements were used as standard to recognise possible environmental gains and to improve general best practice.
Materials and Waste Efficiency:
Various materials and waste efficiency approaches where implemented, including:
- Cleaning and re-use of existing through route (where possible.)
- Cable oil recycling. Cable oil was recovered by purging with oxygen-free nitrogen increasing the amount of oil recovered through the larger nitrogen molecules. The purged oil was confirmed as Linear Alkyl Benzene (LAB), which is a high-grade high-value mineral oil, which can be recycled. A major oil recycler agreed to remove oil from site free of charge for recycling and selling on to users thus providing 100% re-use and zero cost for oil disposal. Slow purging was done over sensitive sites to prevent cable blowouts.
- Cable recycling. Sections of cable were analysed for recovery and disposal purposes. The value of materials recovered not only lead to commercial efficiencies but also ensured that about 80% of recovered cable would be recycled.
Pollution Prevention:
Although LAB oil is readily biodegradable in aerobic conditions, if spillages did occur, the strictest pollution control measures were employed especially when working near water bodies. Zero spillages have been reported to date as a result. LAB oil can cause significant pollution issues in water under anaerobic conditions (buried cable).
Other Environmental Aspects:
- Protected areas with valuable ecological and biodiversity aspects were avoided in most instances.
- Consents obtained included consents for crossing designated main rivers.
- Sites infected with Japanese Knotweed were managed according to the Environment Agency code of practice.
- Written communication to nearest neighbours was conducted.
