Red Water from Portable Water Line

The red water is probably caused by dissolved iron.

Don't wash your clothes in it or they will turn pink.

Is it a "portable water line" or a "potable water line"?

Ha ha.. Thank you for the question. Its potable water line in plant.

Well you've got the wrong material, because the colour is unlikely to be beetroot juice, cranberry juice, strawberry crush, raspberry and lime squash, or scotch whiskey. It's got to be rust.

The colouration would suggest that some steel part is rusting from the inside, making the water by definition non-potable.

Replace the sections of the system made of the wrong material with something more suitable. Preferably before it bursts.

I assume portable=potable. Is it chlorinated and filtered?

Red water suggests iron and carbon steel has lots of iron as does the galvanized pipe. How old is the pipe? What is the water quality in terms of Langlier Index and major ions, alkalinity, pH, microbial, conductivity, etc. The chemical and microbiological quality has strong relationships to problems with red water. Where is the source water originated? Is it surface source or is it groundwater? Is usage continuous or intermittent? Sorry too many questions before you can get answers. Testing may be a first step.

Cannot use plastic pipes, since this is inside a gas plant. Also cannot deviate from the Design Engineering practice.

I am not sure whether the water is chlorinated or not. But 25 ppm chlorine is usually found. Chlorides are below 500 ppm, Langelier index is near to zero, and not negative, and PH ranges from 7 to 7.5. Temp is approx 27 to 25 deg C. These are the information I have. It is clear before entering and reddish when coming out.

25ppm of free chlorine would make this stream highly toxic. You need to get your act together, and correct your mistaken data before I can help.

Replace the galvanized line with copper.....or pvc....

I saw a TV show where it turned out to be a dead body in the cistern. I hope that's not your problem.

I'd replace the existing pipe with plastic pipe.

It depends on the water source/purity that is coming into the system. Has it changed?

What is the composition of the water before, and after it enters your system.

Does it get lighter in color as it runs and flushes the pipes with "new" water?

Is this a new problem?

More information, please.

Thanks for the reply.

I understand the cause, is due to internal corrosion of the CS pipe, Gal internal is intact. I saw the internals of Gal after isolating and removing the threaded assemblies randomly.

Can anyone suggest a solution for this problem? Replacing is not at all practical since this line is travelling all over the plant. Can we have any corrosion inhibitors or can we add CaCO3 to make some precipitation over the internal surfaces to prevent further corrosion? I am looking for a good economincal and easy solution.

Now you're looking for a solution. This is good progress.

What is the internal diameter of the pipes involved?

We would re-line larger pipes as it's cost effective, but small pipes are just replaced using current suitable materials. Downtime and such to perform internal treatment of pipes under 100mm dia just isn't worth the effort. Remember that whatever treatment you use will need to be suitable for potable water during and after treatment. (Use the question "Would I like my children to drink the water?" as part of your decision process.)

It might be worthwhile leaving the current pipes in place (until they fail) for use as process water, sanitation and so on and run a smaller dedicated potable water line for drinking and canteen operations.

You could feed a continuous injection of polyphosphate. It will sequester the iron and also form a molecular coating on the piping to prevent corrosion. Once started you will have to maintain the feed. The only drawback on starting it on old pipe is that it may already be beyond prevention. Did I read the prior post correct that you have 25 ppm of chlorine or is that 2.5 ppm? Either way the residual is high and you may want to cut back if possible. Excessive chlorine could also lead to corrosion.

You also state that the pipes cover a large area. Does that mean there are dead end where water is seldom flowing? Some purge valves may be required to be installed to assure stagnating water is periodically flushed from all dead ends.

Based strictly upon the information you have provided:

(1) call the water supplier, and tell to knock it off with the high-in-orbit chlorine levels before they kill whoever actually drinks this stuff.

(2) apply cathodic protection the CS pipe, such as an electrically couple magnesium rod internal to the pipe, but this will only protect the pipe for a limited distance in the true line of sight (for reasons that are not entirely clear to me, but it is nevertheless true).

(3) corrosion inhibitors that have traditionally been used with good success in potable or fire water systems include sodium metasilicate and sodium hexametaphosphate. It does not take a really high level with these. Probably good results with 1 mg/L to 2 mg/L total phosphate increase, or 1.0-10.0 mg/L metasilicate, but be careful to carry this out within the guidelines of local potable water ordinances. Consult with the water utility about these issues.

Get a sample of water on the source and have it checked on the lab on manganese and iron and have it compared on the quantity standards for potable water, if its present in significant amount? You need to treat the water to potable.

Deoxygenate the water prior to entering the header. A very simple test could be to sample the water at the entry point and farthest point on the header for dissolved oxygen and ORP, and compare the results.

This may not be practical, but I remember a webinar on Globalspec for membranes for this purpose.

Otherwise, replace or line the header. Anything that will make a significant difference to iron dissolution is probably not something you want in potable water.

I completely disagree. I think the OP should: (1) aerate the water in an open vessel large enough to allow a minimum of 30 minutes residence time to partially remove chlorine, and to saturate with oxygen, and (2) filter using a greensand media filter (helps traps manganese and iron, may have to regenerate this with small additions of permanganate once in a while), and (3) pass the filtered water over a marble gravel bed to saturate calcium/carbonate. This will produce a passive water with respect to corrosion of the pipe header, remove unwanted metal ions, lessen the very chlorine level, and generally provide something healthier with respect to potable use.

Does the "RED" water cause any Plant Process issues?

What is the water used for?

I would try a filter of some type to remove the coloration?

Of course you don't want to spend any money on a new piping system. No one wants to......especially the MBAs that run the plant

However, you have to balance the cost of continuous treatment of your potable water system versus a one-time permanent piping upgrade.

Since you have ruled out plastic and since copper is reactive, expensive and presents a theft risk,........ consider thin walled stainless steel.

304 and 316 systems (5S or 10S) with mechanical crimping devices present a viable alternative for potable water systems

Lyn #15.

GA for interesting links.

Now I'm all behind with my Sunday chores.

I once worked in a building with bad "potable" water. The company reacted by removing the water fountains and replacing them with these:

Problem solved.

Are you located in Japan? If yes then it is very much surprising. Why have you not complained to local water supply dept?. If int/ext. galvanising of CS pipes is o.k then I presume it might be some chemical pollution of water. Please check up. At present you will have to manage with mineral water purchased from store.

Hii I am located in Japan, but the problem is not here...

Then is it in South India?. It is common to receive such complaints here in India.

Are there many branches and take-off points in your pipework system over a large area, and does the 'red' water appear at every tap, or just one or two?. Knowing this might help pinpoint where 'red' comes from.

I have seen red (pink) water in both the mill where I worked and at home (~13 miles away). We both had the same water supplier using a single source (lake water). It usually occurred in the winter months. As best I could determine it was due to algae in the lake water source.

I don't know if my question has been answered but here I go again. Does the RED water cause a problem. If yes. Then what is the problem? If NO then what is the problem?

If you get reddish water when you open the tap in wash room, is it ok? The company has fixed their own standards, such problems are considered as worst by HSE dept as well. As I already stated the source of corrosion is the header line of 12" NPS, and not the branches which are galvanized and of 2" NPS.

If the problem is not rust from your CS header, then it must originate from the municipal side of the supply. This is not so uncommon, especially if you have reddish earth ion the vicinity of the underground pipes. (Contamination occurs from the surrounding soil when the municipal workers open the pipework for maintenance purposes).

Extreme flushing is generally the answer, although it may talke several days to rid the system of the last remnants of contaminan. I do not subscribe to adding even more contaminants to the system as a solution to the problem. Alert the municipality and also your senior management (it's amazing how effective they are when they personally may be at risk, or staff may take off sick...God forbid, they may actually become responsible for a production loss!)

If rusty pipes and sediment are the source of your problem you might find compressed air scouring can clean them. Try this link for useful info.

http://factair.co.uk/_webedit/uploaded-files/All%20Files/PS150D%20Pipe%20Scouring%20Unit%20Datasheet.pdf

PS: No commercial plug here. They are our competitors.

I guess if the only problem is the coloring and the taste why don't you try a bottle of your favorite water.

Your chemicals are out of range and your system is suffering excessive oxidation.

If you do not correct the issue the system will fail.