Well one way is that in many older systems the gas pipes are knackered. When
they dug up our road after reports of gas it transpired that our clay soil
was all that was containing a lot of the gas supplies, since the pipes had
rusted away, indeed as they disturbed the pipes gas started to bubble up in
peoples gardens and killed some plants, including one of my roses. They have
since used plastic pipes to replace them all, but as I have no gas
installed, they just left a stop end here ready in case its needed in
future.
I was amazed that they let it go this far, but apparently its not uncommon
for water leaks to get into the clay and leach out in the gas supply, even
to cut it off on low spots.
Both gas and water have extensive contracts going on replacing the now very
old pipes, in the case of gas because they are obviously steel and rusting
away, and in the case of water mainly due to them being made of lead, which
although probably safe after all this time does deteriorate of course.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"John" wrote in message
2.236...
How can this happen?


A burst water pipe caused problems that left hundreds without gas in
Wirksworth earlier this week.

More than 900 homes were were affected when water from a burst main
entered
the gas network on Tuesday, October 8.