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Acidic water supply?


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Does anyone know if there are any specs available for water supplies to French homes?

Ours is miles from anywhere, but IS on mains water, for which we pay the Mairie.

Last year, as part of the bill, we got a resume of the characteristics etc of the water, on which I noted that the pH was quite low, certainly acidic.

Now we have quite a lot of new copper piping in the extension, and last visit, I noted that the shower stall, the bidet, and the sink in the shower room, all white, were showing signs of turning blue[8-)]

It cleans off, yes, but it's OBVIOUSLY copper salts, (I KNEW my "O" level Chemistry would come in useful sometime[;-)]), so is it leaching copper out of the new pipes?

And what of the HOT acidic water in the new heating pipes?

Ought I to be worried, and if so, what redress, if any, do I have?

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If the external surfaces of the pipes are turning significantly blue, then you probably have water leaks!

It may be simple condensation, caused by changes in the ambient temperature allowing water vapour to condense out of the air.

Most copper pipes terminate in brass fittings: you then have bi-metal electrolysis (Copper + Zinc), which may be the cause.

The Heating Pipes should be protected by:-

1.  Adding anti-corrosion fluid in any case: and;

2.  Water treatment systems.

How acidic was your water analysis?

It's quite normal for mains water to demonstrate either alkaline or acid bias: neutral would be unusual.

More important are the trace elements such as heavy metal salts and high nitrogen levels caused by farming.

Worse are other nasties leaching into the water table from (e.g.) garbage infill sites. Your local water company or syndicate are normally pretty careful about killing people!

 

 

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A low pH is not good and could certainly be the cause of the blue stains that you see in the sanitaryware, etc.  Acid plus copper or brass gives blue /green copper salts.

It's essential that a corrosion inhibitor is added to the heating system.

Regarding the hot and cold water supply - there is not much that you can do.

It's worth speaking to any neighbours (near or far), because they are likely to have the same water supply and if its known to be cuprosolvent they will probably be able to confirm or say otherwise.  It's fairly rare, but there are a few places in the UK where this is a known problem. 

Most UK water is slightly alkaline and I would expect the same in France.  Water from limestone strata is always alkaline but other strata can give acidic water - this is often corrected at the water treatment plant - if for no other reason than to preserve the water distribution pipes (frequently ductile iron that is mortar lined - neither the mortar nor iron last long if constantly bathed in dilute acid).    PE pipes are of course completely immune but iron predominates in France for all but service connections.

   

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[quote]A low pH is not good and could certainly be the cause of the blue stains that you see in the sanitaryware, etc.  Acid plus copper or brass gives blue /green copper salts.[/quote]

But where is the salt coming from? Leaks? Condensation?

Very doubtful that it has osmoted through the copper pipe! 

 

[quote]Regarding the hot and cold water supply - there is not much that you can do. [/quote]

Yes there is!

Treat the water at the main riser: as I already suggested.

 

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OK: firstly, Gluestick, the blue isn't on the pipes, it's on the sanitary ware, so it's not condensation, leaks etc, or osmosis[:D]

Secondly, I can't remember HOW acidic it was, but I DO remember that the pH value made me raise my eyebrows. Ours here in the UK is VERY hard and usually has a pH around 7.5. The French water bill even pointed out that the acidity was over limits.

I THINK the French water was 5.6, or so. Certainly enough to cause eyes to sting in the shower, etc.

My two main worries are, the integrity of my pipework, and our health.

HOW do you treat/arrange to be treated water at the mains riser?

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[quote user="Gluestick"]

When you say that the blue staining is "On the sanitary wear", whereabouts?

Is it where the water hits the china from (e.g.) the tap, rather like calcification stains?

 

[/quote]

It's wherever the water has been, GS, so all over, except where water rarely goes, so mostly around the bottom of the shower cubicle, up to water level in the sink and bidet. No staining as if taps are leaking.

Thanks for that link, btw.

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With Ph levels at 5.6, I would guess the villain may well be Carbonic Acid which in reaction with copper would form Copper Carbonate (CuCO3), which is green but may well appear to be "Blue".

Normally, the Carbonate would form an internal coating which itself would be reasonably inactive thereafter.

I would probably go for a Reverse Osmosis system on the mains riser and therefore filter ALL the supply entering the house.

I would also send a sample of the water for independant analysis. Many labs offer this service and can be contacted on the web.

Or you could opt for a Ph balance device, such as here:

http://www.acornwater.com/showprod.php?id=15

 

 

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Interesting thread and a problem that most French households suffer from to a variable degree.

Is the hard water not in fact caused by "alkalinity"? Our soil is chalk and then more chalk and we have to descale kettles etc very regularly to remove the calque as they call it here.

My old pipes had lots of blue traces where joints ahd weeped and finally sealed with calc.

I know it may sound flippant to suggest that you clean your basin and shower trays etc but I have been using a vinegar based spray (bought in ASDA) every time that I leave the shower which dissolves the calque before it has time to build up and perhps turn blue.

The fact that it is acetic acid makes me think that hard water is alkaline but I cannot remember what a +ve PH indicates.

You are certainly not alone and in your original post asked if you had any recourse against the water company, I would say no especially considering that the water quality(?) is considerably better than you have in the UK.

Editted.

Does a low PH indicate acidity? Hence 4.5 is more acid than the 7.5 Uk prelevement?

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Yes, a lower than 7.0 pH means acidic, above 7.0 means alkaline.

It's definitely NOT calque. Our kettle is as clean as a whistle, and there is no calque build up on any taps, the shower head etc.

Yes, we can clean it off, that's hardly a problem. I was, and still am, just a little worried on two counts:

1. Is it slowly but surely eating our copper pipes away?

2. Is the constant ingestion of tiny amounts of copper salts injurious/detrimental to our health?

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[quote] Is the constant ingestion of tiny amounts of copper salts injurious/detrimental to our health?[/quote]

In a word: yes.

We never drink the tapwater in France: we use, like the French, large bottles of water for the kettle and cooking.

That said a good Reverse Osmosis filter will provide excellent potable water. If one is really paranoid, then after the RO filter, a high intensity UV filter will also negate any risk of biological pipe contamination too.

I'm whacking one in when I redo the kitchen: finally! Plus a Whole of House pre-filter too.

The two most likely acids are Carbonic and Acetic at a Ph of 5.6 (Mild Acid) and Nucleic traces perhaps.

Copper Carbonate:

Section XI. Toxicological Infomation

  • RTECS Number:  GL6910000

  • Routes of Exposure: Eye contact. Ingestion. Inhalation. Skin contact.

  • Toxicity Data:  Orl-Rat LD50:1350 mg/kg, Orl-Rbt LD50:159 mg/kg, Orl-Brd LD50:900 mg/kg

  • Chronic Toxic Effects:  Symptoms of systemic copper poisoning may include: capillary damage, headache, cold sweat, weak pulse, kidney and liver damage, central nervous system excitation followed by depression, jaundice, convulsions, paralysis and coma. Death may occur from shock or renal failure.

  • Acute Toxic Effects:  Harmful if swallowed, inhaled, or absorbed through skin. Causes severe eye irritation. Causes skin irritation. Material is irritating to mucous membranes and upper respiratory tract. Exposure can cause: coughing, chest pains, and difficulty in breathing. Gastrointestinal disturbances nausea, vomiting, diarrhea

Copper Acetate (Reactant from Copper +Acetic Acid)

Health Hazard

Inhalation of dust causes irritation of throat and lungs. Ingestion of large amounts causes violent vomiting and purging, intense pain, collapse, coma, convulsions, and paralysis. Contact with solutions irritates eyes; contact with solid causes severe eye surface injury and irritation of skin. (USCG, 1999)


 

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Forget acetic acid - it has nothing to do with tap water.

Hard water has to contain calcium and magnesium ions to be hard, and it usually also contains bicarbonate and sulphate ions. Usually the cause is rain falling on limestone or chalk and occasionally certain types of sandstone.  In any case the evolved water is as a result usually slightly alkaline.

Soft water has no or very little calcium and magnesium.  It usually comes from ground that has igneous rock, such as granite or peaty soil.  This doesn't contribute any calcium or magnesium ions, but rain water is naturally slightly acid because of dissolved carbon dioxide (mainly) plus also sulphur dioxide and nitrogen oxides - these give dilute acids - carbonic, sulphonic and nitrous.  When these acids and their derivatives react with copper they give blue / green copper salts - copper carbonate, copper sulphate, copper nitrate, etc., - essentially it is Verdigris. 

 

 

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our tapwater was too acidic for the swimming pool test kit - basically the water out the taps was off the scale, so managing the swimming pool was a nightmare!

Two years down the line they've changed the water treatment plant. We still get blue deposits in the sink and loo, but the Ph is more neutral than it was. Oh, and the pool developed a leak so it went to the tip. Can't win! :)
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[quote user="buckdendave"]

There is no connection between tap water and acetic acid, regardless of some obscure method of making verdigris as a pigment.

[/quote]

Well, you used the term: not me![:)]

And that was one reference only that I quoted: there are many.

http://pubs.acs.org/cgi-bin/abstract.cgi/jpcafh/2006/110/i13/abs/jp0567974.html

None of which helps the OP, of course.

 

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This thread is not getting any more sensible. This last referrence from Gluestick is a complete red herring as it's all about atmospheric acetic acid. This is not surprising as it what's known as a Volatile Fatty Acid, the only places you are likely to get it in an aqueous solution or rather colloid are in the bottle you shake over your chips or in the anterior digestive compartment of a ruminant.

Getting back to the origional problem, it's pretty much as Buckdendave says. If the water in the heating system is self contanied then a corrosion inhibitor is a good idea. Treating the water for the showers, taps etc is not so easy but a lot easier than going down the reverse osmosis route which is hideously wasteful of water and bound to cost an arm and a leg when the bill hits the mat.

I would suggest running the main supply through a header tank as is done in the UK and lobbing some Tufa rock into it. This is basically magnesian limestone which is dissolved by the acid in the water until it neutralises it (actually because of a time lag in the reaction it can take the water up to about 8.5 but no more). Tufa rock is available from any good aquarium shop as it is used to replicate certain aquatic ecosystems and it is also SERIOUSLY CHEAP!

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[quote user="Motorhead"]

This thread is not getting any more sensible. This last referrence from Gluestick is a complete red herring as it's all about atmospheric acetic acid. This is not surprising as it what's known as a Volatile Fatty Acid, the only places you are likely to get it in an aqueous solution or rather colloid are in the bottle you shake over your chips or in the anterior digestive compartment of a ruminant.

[/quote]

No you are correct. It isn't getting more sensible.

The reference to atmospheric acid was intended towards the normal creation of Verdigris on (e.g.) copper clad roofs: and not the "production of artistic pigment etc"

[quote]

Getting back to the origional problem, it's pretty much as Buckdendave says. If the water in the heating system is self contanied then a corrosion inhibitor is a good idea. Treating the water for the showers, taps etc is not so easy but a lot easier than going down the reverse osmosis route which is hideously wasteful of water and bound to cost an arm and a leg when the bill hits the mat. [/quote]

In fact, 'twas I who first suggested anti-corrosion inhibiter in the CH system.

The effluent water can always be cycled into ground storage and used in the garden, e.g.

And as grey technology becomes ever more common in France, ground storage tanks of rainwater and treatable waste water discharge are becoming and will become more usual.

[quote]

I would suggest running the main supply through a header tank as is done in the UK and lobbing some Tufa rock into it. This is basically magnesian limestone which is dissolved by the acid in the water until it neutralises it (actually because of a time lag in the reaction it can take the water up to about 8.5 but no more). Tufa rock is available from any good aquarium shop as it is used to replicate certain aquatic ecosystems and it is also SERIOUSLY CHEAP!

[/quote]

Nice idea: however not permitted in France: outside the normes!

Next brilliant suggestion??

Of course, the OP could always could sell up and return to the UK where they could lob rocks into a header tank with impunity.

Provided they didn't have a combi boiler................................................

[Www]

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The verdigris on copper clad roofs is mostly hydrated basic copper carbonates; the acetate content, if any at all, will be minimal. Copper acetate is easy soluble in water, so the rain would wash it off. Copper carbonate is to all intents and purposes insoluble, so it stays on. Traces (part per billion amounts) will come through, which is why much of the copper we get in our diet comes from tap water. Verdigris pigments may share a name, but they are not necesarily the same thing: verdigris for paints was historically a byproduct of wine making, and that was copper acetate.

Which does rather leave a problem: the copper carbonates from disolved oxygen and carbon dioxide in the wather that form on the inside of copper pipes should pretty much stay there. So if you are getting blue staining through, something in the water is reacting with the carbonate layer and producing a copper salt that is soluble. pH of 5.6 suggests a significant presence of acid, but doesn't tell us which one, though the fact that your eyes are stinging in the shower is faintly alarming. On the bright side, the acid won't be attacking your pipes directly: copper is pretty inert to acids under most conditions, so the corrosion will be limited to the rate at which the carbonate is formed, ie, pretty slow. But eventually...

If it were me, I'd be getting some tests done, but I'd contact the water company first. They might just do them themselves.

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What I said on page one................

[quote]

With Ph levels at 5.6, I would guess the villain may well be Carbonic Acid which in reaction with copper would form Copper Carbonate (CuCO3), which is green but may well appear to be "Blue".

Normally, the Carbonate would form an internal coating which itself would be reasonably inactive thereafter.

I would probably go for a Reverse Osmosis system on the mains riser and therefore filter ALL the supply entering the house.

I would also send a sample of the water for independant analysis. Many labs offer this service and can be contacted on the web.

Or you could opt for a Ph balance device, such as here:

http://www.acornwater.com/showprod.php?id=15

[/quote]

Yawn.................................

 

[blink]

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[quote user="Gluestick"]

What I said on page one................

[quote]

With Ph levels at 5.6, I would guess the villain may well be Carbonic Acid which in reaction with copper would form Copper Carbonate (CuCO3), which is green but may well appear to be "Blue".

Normally, the Carbonate would form an internal coating which itself would be reasonably inactive thereafter.

I would probably go for a Reverse Osmosis system on the mains riser and therefore filter ALL the supply entering the house.

I would also send a sample of the water for independant analysis. Many labs offer this service and can be contacted on the web.

Or you could opt for a Ph balance device, such as here:

http://www.acornwater.com/showprod.php?id=15

[/quote]

Yawn.................................

 

[blink]

[/quote]

Oh sorry - am I boring you?  I do hope Mr Tree posts the results. I'd quite like to know.

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No; not particularly RRE.

Just that since the OP opened the thread and I responded with the best advice I was able to provide, other posters have entered without bothering to read what has already been written: and rendered much the same advice, but no additional assistance to the OP and in some cases negative and/or erroneous advice.

As I'm sure you agree, the core reality is that none of us can possibly know for sure what the type of acid is; only competent lab analysis can provide that answer.

Additionally, the OP seeks a real world putative solution to their problem, as they are understandably concerned about damaging new sanitary ware.

Like yourself, RRE, I am also most interested to learn what the actual chemical composition of their water is.

 

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Lots of psuedo science tied up in some good answers.

 

So:

1.  Most likley culprit carbonic acid - which is present in virtually all water and especially sparkling bottled water - has an effectuve pHof 6.4 and whilst acid will not cause eyes to sting.  Nor are the carbonates created in contact with copper likely to dissolve and give you the blue staining.

2.  Acetic acid will only be in your water through industrial run off - so forget any ideas put your way about that as a possible cause unless you have a vinegar factory or vineyard close to your water source..

3..  So if your result was really 5.6 there has to be something else in your water supply to make it nearly 10 times more acid than bottled water.   Quick check - does your water taste vaguely of vinegar?  If not then forget your recollections of the pH reading and go and find the bill and tell us what it really said.

4.  Possible culprits if it really is 5,6 - agricultural run off from silage or animal effluent (but in the latter case your water would be likely to be unpotable), industrial effluent entering the water supply, after that natural sources of really acidic water are really quite rare, but not impossible.  Most of these usually have the tell tale small of H2S - rotten eggs - associated with them.  Most likely sources of this type will be close to places with hot water springs or close to former/dormat volvanic areas - Auvergne for example.

The best advice given already is to pay 60€ and get a sample analysed by an independent laboratory.

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