Thanks for your question!
This is one of the key concerns for the community that has led to the identification of this as a design area. In places where there are no greywater trenches available, the greywater can be released into the environment which can have negative impacts and is illegal in National Park areas. This means that groups, such as rangers, are unable to travel too far from a location with greywater management facilities.
As greywater trenches can be expensive based on the ground conditions at many sites, the interest in alternative design options will enable the appropriate management of greywater runoff so any negative environmental impacts are avoided or mitigated, and can have the flow on effect of enabling longer access to certain areas on Country.
I hope this helps, please reach out with any further questions!