I'm hoping to purchase a small plot for a new build project (single 3/4 bedroom detached house)
There is no mains sewer, just mains water.
The land is very solid and I had permission to dig 3 1m square holes and filled them with water, none of which had drained away after 24 hours. In order to keep away from our own property and 2 neighbours we are now digging 2.5m pits further away, after the initial 1.5m of clay we reached a bed of shale and after being left overnight no water has so far infiltrated the pit, so this could be good news.
The problem I have is with cost.
To ensure that nothing comes back to bite us later on we are not scrimping on quality of design and materials. Our initial estimate was £10k, if we didn't need to dig deep.
Now though we've been advised it will probably be between £25k & £30k due to being much deeper, further away and larger baskets.
The plot is in an area that does get a fair amount of rain and we've seen the results of cutting corners and the results are not pretty.
Would rain harvesting help in this situation?, the drainage company who don't utilise harvesting have said that the cost would be similar.
So my two questions are, does £25k sound excessive for complete installation of suitable drainage, and could harvesting be a suitable alternative and at what cost?
Any help or pointing me in the right direction for advise would be greatly appreciated.
Many thanks