Swimming Pools

[Veggie Dave]

I have a customer with a tainted water supply. Most of the time it appears to be fine but occasionally it has a very strong chemical taste, which is bizarrely accentuated by tea.

This house is within a small private estate of three houses that all share the same supply, however the other two houses appear to have unaffected water. So, the water supplied to the property boundary is therefore fine.

Next door there's a new swimming pool of reasonable size. The customer isn't sure but they think the problem started around the same time the pool was commissioned. As I've said, though, the problem is very intermittent - it can be days and even weeks between problems.

I've gone through almost everything I can think of in the house and found no problems. But I've tasted and smelt the water when it's been 'off' and I eventually realised it reminded me of the smell of a modern swimming pool - not a very scientific conclusion, admittedly. I can't find any schematics online regarding the pipework for pools (other than the heating/filter system) but I assume the pool must be have a water supply to top it up and indeed fill it when it's drained. I would also assume a simple check or double check valve would not be considered enough protection for a supply of this sort due to the pool water containing both faecal matter (yes, really) and chemicals (Cat 4 or even Cat 5?) and would therefore need at least an AA/AUK1 air gap to stop back-flow?

Does anyone have an installation diagram for a pool water supply or can offer any advice, please?

 

[Reg Man]

You obviously have checked this out in the WRAS book. I would imagine the topping up of the pool from the main supply would require a ED Double Check Valve to prevent back pressure and a DB pipe interrupture with vent to and moving element to prevent back siphonage.

 

[Veggie Dave]

Theoretically then, with two back flow prevention devices, having back flow should be impossible. And that suggests that either it's not the pool at all, two separate devices have failed (seems unlikely) or at least one of them was never installed.

I wonder how I should approach the neighbour - I think high levels of diplomacy are going to be required. 😉

 

[Gas]

Checked for dead animals in the pre and post check valves?

 

[Reg Man]

The DB goes on the outlet side of the tap.

 

[Chalked]

Pools are filled by break tank with ball valve or just a hose pipe. Can't see how it would be getting into the mains.

 

[lame plumber]

just talk to the water board, they will inspect for contamination and do the talking for you. diplomacy not required🙂

 

[Reg Man]

Pools are filled by break tank with ball valve or just a hose pipe. Can't see how it would be getting into the mains.

You would hope a beak tank was used. More likely a hose pipe, hence the double check valve and pipe interrupter, yes fat chance.

 

[Veggie Dave]

just talk to the water board, they will inspect for contamination and do the talking for you. diplomacy not required🙂

But if the pool is responsible then the customer would rather it was fixed than their neighbour be fined for water contamination.

I'm still waiting to hear back from Affinity Water regarding what backflow protection they demand.

Pools are filled by break tank with ball valve

Is this standard practise?

Thanks everyone for the help.

 

[Chalked]

But if the pool is responsible then the customer would rather it was fixed than their neighbour be fined for water contamination.

I'm still waiting to hear back from Affinity Water regarding what backflow protection they demand.



Is this standard practise?

Thanks everyone for the help.

it is standard practice on a tiled pool, it's also a means of auto top up. But if is fitted with a plastic liner it will probably be a bib tap and garden hose. The tap feeding it should have a double check valve. Should also have one fitted on the incoming mains too.
Even without these its a hell of a chain of events to get it to back siphon into your main.

 

[Veggie Dave]

Affinity confirm that they require a AA air gap, which the pool owner says has been fitted. But, quite honestly, even if it wasn't fitted I can't see how only one house would be affected given the supply design, anyway.

I guess it's time to get the supplier involved.

Thanks Chalked and everyone else. 🙂