On Mon, 07 Jun 2010 05:52:34 +0100, Charles Ellson
wrote:
On Sat, 05 Jun 2010 11:00:39 +0100, Bruce
wrote:

On Fri, 04 Jun 2010 22:26:30 +0100, Charles Ellson
wrote:

On Thu, 03 Jun 2010 22:13:18 +0100, Bruce
wrote:
It was mainly due to the closure of Walker's brewery, which used to
draw water from a 2' 6" diameter well that was located very close to
the running tunnel. It burst into the tunnel during construction and
flooded the workings, delaying the contract by many months.

Other businesses drew water from the ground but Walker's was by far
the largest user.

There is also the problem that the groundwater is becoming saline.

That was the wrong sort of water that I had in mind. AFAIR it does not
take a lot of salt to greatly increase any corrosive reactions
involving water.


Indeed.

I don't know why it should be more saline than before. The fresh
water table under the city is rising,

With the proximity of the Mersey I doubt that much in the vicinity is
completely "fresh" with geological features also seeming to queer the
pitch :-
http://www.sciencedirect.com/science...0fd54f15c1804f
[http://tinyurl.com/3xbt53h]


Walkers would not have been able to brew beer with water that had any
measurable saline content. When the Loop Line was constructed, the
groundwater was entirely fresh except where the line joined the
existing Mersey railway tunnel that leaked brackish water, increasing
to salty at mid-river. Now the saline intrusion affects areas of the
Loop tunnel that were previously 100% fresh, such as Moorfields.

Of course providing a drained tunnel will affect the movement of
groundwater over the longer term.


and one would have expected that
to generate a fresh water flow towards the (saline) river, not a
saline flow away from it.

IMAU it is roughly speaking two adjacent bodies of wetness pushing
equally against each other with a resultant gradient of salinity
either side of the boundary.


But the phreatic surface of the fresh groundwater was higher than the
highest of high tides in the river. The tendency to flow should
therefore be towards the river.


Is there a hydrogeologist in the house? ;-)

AOL ;-)