Our policy on deep-bored soakaways
In line with advice received from the Environment Agency, ESCC generally oppose the use of deep-bored soakaways as a means of managing surface water drainage on developments. The reasoning for this opposition is two-fold.
- The increased risk of groundwater contamination due to direct discharge of waters into groundwater.
- The potential impact on local groundwater levels and flows which can increase the likelihood of groundwater reaching the surface (and potentially increasing flood risk).
ESCC recommend that deep-bored soakaways are used as a last resort where the ground conditions are suitable, and the groundwater levels are known. The County Council requires that the following criteria are met when deep bored soakaways are proposed:
- Investigations showing there are no other alternative surface water destinations.
- The depth of the system should be no deeper than what is required for soakage.
- A minimum of two water treatment stages using SuDS measures must be provided upstream of the soakaway.
- An unsaturated zone must be provided below the base of the structure. There should be a minimum of 10m between the base of the structure and recorded maximum winter groundwater level.
