KOREA
- Checking
for contact with other buried services 
- survey of buried pipeline ...
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A steel
pipeline replaced a cast iron line which had been abandoned but
left in place. Two other cast iron lines crossed the steel line.
There were also numerous power and street lighting cable lines
buried close by. The location was under a well-used carriageway
and the ‘cover’ was tarmacadam and concrete - up to 2 metres thick
in places.
The cathodic protection (CP) potential was being ‘drained’ from
the steel pipe and numerous attempts - using traditional survey
methods and excavation - had been made to locate the source
without success.
2 ‘current loss’ areas were identified by a leading pipeline
survey company using the 
system. This was particularly difficult at one site where
12 buried services were uncovered during the excavation. At
both these sites, cast iron lines - or sections of old cast
iron pipes - were found to be in contact with the steel pipeline.
The situation was rectified and a good level of cathodic protection
achieved over the whole pipeline.
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