Bird Flu and Water Tanks in the Roof

[John Cartmell]

Wigan has long been in advance of the rest of the country iro local authority rules and provision.

[Markus Kuhn]

David Hansen writes: |> The water in a cold tank is not stagnant. Provided it is designed |> and installed properly such a tank is no great risk to health. It |> has the advantage of preventing back-siphonage, which can cause the |> supply to other premises to be infected.

The pressure-reduction valves installed in other countries (to reduce ~10 bar street mains pressure to about 4 bar in the house at the water meter) offer the same protection against back-siphonage, but they are much cheaper, smaller, and easier to install. Any they are far more hygenic, because without an open-vented tank, the water remains pressurized at all points in the distribution system until it comes out of the tap, allowing the added chlorine to keep microorganisms at bay throughout.

Markus

[Andy Hall]

Until there is zero or even negative pressure because of a burst main...

[Andy Hall]

For example, the pier....

[Markus Kuhn]

tony sayer writes: |> >There still seem to be deeply rooted fears in Britain with regard to |> >pressurised water. Why does the mains pressure in my street Cambridge rarely |> >go above 1 bar? In other countries, the street pipe is at up to 10 bars, |> >and a simple pressure-reduction valve at the water meter reduces that to |> >about 4 bars inside the house, which is about right for a decent shower. |> |> Have you complained to the Cambridge Water Co?....

According to

promise only the (disappointingly low) pressure of 0.7 bar, so I guess they would treat my wish for 3-4 bar (the usual guaranteed supply pressure e.g. in Germany) as a bit excessive. I suspect that, as others have noted, a leaky supply system in predominantly Victorian developments may force them to stay near the very lowest pressure that still gets water to the customer's third floor at all. A suggestion I got from a Cambridge Water employee was to upgrade our own supply pipe (lead!) to a larger diameter, to avoid that the rather low pressure they provide me drops even much further on its way into the house due to the flow resistance of the pipe.

Markus

[David Hansen]

On 29 Nov 2005 10:13:12 GMT someone who may be n05W48+ [e-mail] (Markus Kuhn) wrote this:-

In theory. I wonder if anyone has done a survey of double check valves in the UK to see how many of them are still working after say

20 years?

Provided the cold water tank is properly designed and installed the added chlorine will remain in the water in the tank.

It is of course possible to design and install things badly, but this applies to everything.

[tony sayer]

Yes they do have a very large antiquated Victorian system to contend with, and IIRC they have said their going to need a lot of money to replace it all, let alone the traffic problems!.

Which is probably why their putting it off till the time the oil runs out, so they can actually then do the job;-!.....

[Aidan]

I'd prefer not to use water from lead pipes or lead tanks, if I can help it.

If, like us, they'd had plastics then it would have been. Mostly it wasn't plumbed at all.

[David]

That's something else that the Romans haven't done for us then...