External/Garden Flooding
How will the contamination to my garden be cleaned up?
Representatives from your sewerage company will carry out a clean up. Excess liquid will be removed. This will be followed by a clean up of solids and debris.
Lawns/borders: It is not normal practice to apply disinfectant to gardens, as this can kill plants and do more harm than good. However, if you feel this would give you extra reassurance then a very mild disinfectant can be applied.
Laboratory testing has shown the best treatment is to allow nature to take its course. As most contaminants will be at or near the surface, this will produce the maximum exposure to the sunlight’s ultra violet (UV) radiation which is very effective in killing bacteria. If the ground is particularly waterlogged your sewerage company may decide to leave the clean up for a day or two to avoid disturbing the ground and spreading the contamination.
Hard Surfaces: Hard surfaces such as paths and drives will be cleaned and disinfected. We suggest you keep off these areas for 3 hours to give the disinfectant time to take effect.
What precautions do I need to take to prevent further contamination of my garden?
It is important that you do not attempt to dig or rake the affected area. This will spread the contamination further into the soil or turf, where lack of sunlight and the damp conditions will enhance the life of the bacteria
Similarly you should not attempt to hose the garden down, as this will saturate the ground and prolong the life of the bacteria.
What happens next if my garden has been flooded?
The bacterial contamination will die off naturally during the days following the flooding. After an appropriate quarantine period your garden should be safe to resume normal activities. (Factors which influence bacteria decay periods include climatic conditions such as temperature and moisture, vegetation and soil type.)
Independent laboratory tests carried out by WRc show that bacteria should, typically, reduce to background levels during the following periods:
- Warm, dry summer conditions: 9 days
- Damper, cooler, spring/autumnal conditions: 12 days for spills onto turf and heavy (clay) soils; and 26 days for spills onto loose soil and sand
- Wet, cold winter conditions: 25 days.