When working on unstable ground, the surface should be observed continually to spot any movement or dipping; this may indicate subsidence and possible collapse into unidentified voids.
Incident commanders should consider channelling water run-off to sacrificial areas, moving vehicles to avoid entrapment and containing, diverting or controlling the use of firefighting media to reduce the impact on ground conditions.
See National Operational Guidance: Environmental Protection – Fire water run-off.
Working on or moving vehicles on unstable ground should be avoided. Care should be taken whenever vehicles are driven off purpose-built vehicle routes. An assessment should be made to ensure that the surface can take the weight of the vehicle, avoiding the possibility of it becoming stranded.