The information below was sent in by one of our clients. We thought we should publish it a) to show how age and experience matter greatly and (b) because it might be of help to future researchers.
Please note that if you decide to publish what I am about to say I would not want my name to be associated with it. Although now in my mid seventies I still have to work occasionally in order to maintain what I consider to be a reasonable quality of life, (the UK is not the best place in which to grow old).
This is about Blue Water – much of it is already in the public domain though probably not in as much detail as I remember the problem.
Some years ago I worked in the architects and estates department of a local authority in a large city in the North of England area around the time when control of water supply was sold off from local authority control to private water companies.
Shortly after the private water companies took over a problem appeared in new build schools that didn’t exist prior to privatisation. Blue water, the water was leaching copper off the inner surface of the new pipes turning the water blue, so blue in fact that people wouldn’t drink it.
The mechanical engineer told me at the time that the city’s water acidity had increased several times above the level it was when under local authority control. However it complied to government legislation and as such there could be no legal redress.
The point that I’m trying to make which may be of some use in your advertising is that private companies, whether they be water supply companies or construction companies are generally controlled by statuary legislation, and that legislation is the minimum standard the product must meet, not the best attainable.
Having worked in the construction industry for sixty years I have never come across a private company that had any policy other than to just comply with statutory regulation. There is no incentive to exceed the standard, only punishment if it’s not achieved.
Obviously you’d need to be careful how this is phrased as any inference that water companies could be supplying a less than perfect product would bring an aggressive response. Something on the lines that water passing through your filters will far exceed the statutory requirements.
If I further explain the problem and how it arose from the beginning it will perhaps give you a better understanding of what occurred.
Copper pipe is not pure copper but an alloy containing very small amounts of other metals. Two events contributed to the generation of blue water, one was the privatisation of the public water supply which saw a sharp rise in the acidity of water in the city – which is a soft water area and therefore already acidic.
The other was the intervention of the EU who stated that copper pipe in the UK contained more alloying metal than allowed under EU regulation for it to be called copper pipe, the result was that manufacturers reduced the amount of alloying metal to meet EU requirements which produces a higher content of copper in the pipe.
When new plumbing installations were completed they were filled with water and testing carried out. After flushing the systems they were left filled with water, the oxygen dissolved in the water reacts with the new copper surface which then develops an oxide layer on the inner surface of the pipe. As the oxide film is impervious to water once it’s formed there is no further reaction between the copper and the water in the pipe and the system becomes chemically stable.
With the higher levels of copper in the new pipe there is insufficient oxygen in the water lying in the pipe to fully oxidise its inner surface. If the plumber has been over generous with flux on fittings and flux gets inside the pipe it continues to etch the pipe exposing raw metal, the problem then is that this can, and usually does result in the establishment of electrolytic cells, two dissimilar metals in an acid solution is a battery, the sacrificial metal in this case is copper which is leached into the water turning it blue.
Once these electrolytic cells are formed there appears to be no way of stopping them.
The authority I worked for consulted with two universities in the city in the hope of finding a solution. One solution considered was to fill the system with an oxidising agent and force an oxide film to generate faster than the electrolytic action could erode it, it didn’t work. I’m sure there were other proposals but they didn’t come to my notice.
The solution to the problem lies in how the installation is installed. Careful use of flux on fittings is recommended; systems are filled with water for testing, and then drained after testing and left empty until just before the client is due to take possession.
A week before the client is due to take possession the system is chlorinated, flushed clean and left filled with water. Taps are left slightly open so that the water in the system is constantly being replaced which ensures there’s sufficient oxygen available to oxidise the pipes inner surface.
For pipes that are on dead end runs such as those to toilets and showers sink taps etc the contractor will establish a regime so that water is drawn though on a regular basis that will guarantee oxidation of the pipe.
I hope that’s not to long winded an explanation, but that’s how I remember blue water affecting the schools I was supervising. The problem has been resolved by good practice, and ensuring that there is a constant supply of oxygenated water in the pipe to guarantee oxidation”.