David Lees and Associates was appointed by KBR to provide geological inspections of Sydney Water Sewer Tunnels.

Sydney Water has many kilometers of sewer tunnels dating back to the 1960’s. Many of these tunnels are unlined rock tunnels excavated by drill and blast or mini roadheader through Hawkesbury Sandstone.

Each tunnel has to be traversed and inspected evry five years to ensure they are stable and that no colapse has occurred. The tunnels are a confined space and require significant safety precautions prior to entry.