Blanked 110mm pipe located on self build plot

[Saints1]

Hello, I wondered if somebody could help or offer some advice. 
 

we are just digging out for our self build plot. The foundation is a raft design and as we have dug close to the neighbouring boundary (their drive way) we have located a 110mm pipe with a blanking cap on the end coming on to our land by about 1 meter. 
Now I know the neighbouring property was built in 2020 and at the time the guy who built it was also hoping to build on the land that we are now developing but he was refused planning. 
I am wondering if he was future proofing it at the time in the hope he would get planning. 
There is an inspection chamber on the neighbouring properties driveway approximately 3 meters from where I have discovered the pipe on my land. 

My question are;

1. Am I able to connect on to it? 
2. Do I need to notify the utilities company? 
 

just for context the whole road is on a combined system, unfortunately the ground isn’t suitable for a soakaway to be installed (SUDS) as it’s got clay all over the land.  

 

3. Am I able to send/direct both foul and rainwater to this pipe? 
 

any help or assistance is greatly appreciated? 

[Nickfromwales]

You'll need to find out if it's 'adopted' or not. Contact the utility company and then if it's adopted then you should be able to connect into it.

 

Will be a gift if you can.

[Saints1]

I contacted the utilities company some months back to get a drainage plan from them. Unfortunately they hold no plans until around 4 doors down. 
I know that the main drainage route/pipe goes through the back of the gardens until 4 doors down and then kicks out to a big inspection chamber at the back in a farmers field. (This is were the utilities have their plans from) 
The utilities company said that this will be because the pipe is on private land that they’ll hold no record. 
 

My only current issue I have is the utilities company won’t discharge my final pre-commence by condition until they seen my full drainage plan. Which is fine but they are adamant I have to explore all avenues in soaking away the rain water, despite having trial holes dug for soil sampling which states the ground is unsuitable for a buried soak away. 

[Nickfromwales]

6 minutes ago, Saints1 said:

I contacted the utilities company some months back to get a drainage plan from them. Unfortunately they hold no plans until around 4 doors down. 
I know that the main drainage route/pipe goes through the back of the gardens until 4 doors down and then kicks out to a big inspection chamber at the back in a farmers field. (This is were the utilities have their plans from) 
The utilities company said that this will be because the pipe is on private land that they’ll hold no record. 
 

My only current issue I have is the utilities company won’t discharge my final pre-commence by condition until they seen my full drainage plan. Which is fine but they are adamant I have to explore all avenues in soaking away the rain water, despite having trial holes dug for soil sampling which states the ground is unsuitable for a buried soak away. 

Show them the pipe, where it goes, and that next door is also on a combined network sewer.

 

You can provide percolation test results, DIY'd, to fortify.