How do I find a soil pipe leak? HELP

[davejold]

I know, start digging!! But seriously we have sewerage leaking under the front retaining wall onto the drive. Our property is sited on a steep hill and the drive is at the bottom, where the leakage appears.
The nearest soil pipes are 25 feet above the drive. I have inspected the manholes and carried out repairs to the cracked cement but the problem is still there.
Is there any easy way of finding the damaged area or do I spend weeks digging?
Appreciate any help,
Regards Dave.

 

[fitz1]

get a drainage company with a camera to inspect your drains.

 

[Nige F]

Put some flourescent drain tracing dye down BIT cheaper than cctv @ £100 per hour