Blue Well Water

[pwn]

I saw some other threads on this issue, but they were several years old and did not seem to match my situation. We're on a deep well in a rural area in the piedmont of western North Carolina. My well is deep, 500'+ in granite. We do see a blue color in the bath tub and some staining on the shower grout. Our water is somewhat aggressive with a pH of 6.5, alkalinity of 14mg/l and hardness of 8mg/l. BUT, we have pvc piping in the well, pvc from the well to the house, and PEX throughout the home. I took a sample in the bathroom to see if the cu concentration was high enough to cause the color and the sample tested at 1.08mg/l. I find it hard to believe that the color could be coming from brass plumbing fittings. Since the concentrations are not high enough to be a heath concern I'm inclined to let it go, but my wife is still concerned. Am I missing something or should I be concerned? Thanks for any advice you may have.

 

[IRstuff]

The Havasupai reservation south of the Grand Canyon is famous for its waterfall and lagoon with very blue water:

The color is attributed to a heavy lime content in the water. So, it's possible that your water has quite a bit of lime.

TTFN
faq731-376

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[pwn]

Thanks for the comment and the beautiful picture. Unfortunately, we have a calcium concentration on only 2mg/l, part of the low alkalinity issue.

 

[cvg]

copper in the form of sulfides will indeed cause blue water. by the way, Havasupai falls is in the copper state. see attached photo

http://files.engineering.com/getfil...f-4cb5-931f-c15e16d06455&file=2012_0403_3.pdf

 

[bimr]

Lime does not cause a blue color as it is a white color, however calcium sulfate may cause an aquamarine color.

The blue-green shade of the Havasupai falls water is caused by minerals in the river that coat the dirt, and rocks with a creamy-white travertine deposit (calcite). The whitened riverbeds reflect the color of the water, providing a turquoise contrast to the ruddy canyon walls.

Copper sulfide is insoluble and will also not cause blue water. You are thinking of copper sulfate.

You might consider more testing to determine the source of the blue water, in particular obtaining first flush and flushed samples will assist in locating the source of the corrosion.

If you have blue/blue-green stains sinks or plumbing fixtures, you should test your water for copper. To determine if
copper is present, arrange to test your drinking water at a certified laboratory. To evaluate the highest level of copper exposure, collect a sample when water has remained motionless or stagnant in the plumbing system for at least six hours. When collecting the sample, collect the first flush of water from the cold water faucet with the aerator removed. Do not allow any water to run before collecting the sample. This is called a first-draw or first-flush sample. This first-flush will contain the highest copper levels. After the tap has run for one minute, collect a second sample. This is called a flushed sample. The flushed sample provides a water sample that has not been in contact with the plumbing system for an extended period of time.

To interpret the results, consider both the copper concentrations and the comparison between the first-draw and flushed samples. If results show higher levels of copper in the first-draw sample than the flushed sample, the copper is most likely coming from corrosion
of household plumbing components, such as copper or brass fittings. On the other hand, if test results show nearly equal amounts of copper in both the first-draw and flushed samples, the copper is probably coming from a plumbing source outside the house, such as the well pump.

For treatment to increase the pH and eliminate the copper, consider a calcite treatment filter system for pH adjustment.

 

[pwn]

Thanks, As I mentioned in my original post, I've had the water inside tested and it measured 1.08mg/l copper (taken in the bath). Yesterday I took a 5 gallon white bucket and filled it at several locations on the property. The plastic bucket is not as white as the porcelain white bath tub, so the color is more difficult to discern. The blue tint is slight and my eyes are not a good spectrophotometer, but these are my observations. First, at the barn, there was only a marginal color. Then I sampled at the well with the same "marginal" results. Similar results were observed at a hose spigot at the house at the end of the plumbing run. Inside the house, with the white tub background, I could see the bluish tint. Finally, with my eyes "calibrated", I took a second sample at the well. This sample at the well looked identical to the bathroom sample, a noticeable bluish tint. This was after I had drawn 20 gallons of samples at the other locations. This would lead me to believe the copper is either in the water source or something's going on with the well equipment. The water in the well is from two sources, 1.5gpm at 80' and another 3.0gpm at 500'. These two supplies may have different chemical characteristics and static heads, so water could move between the two sources when to well is full. You mentioned the well pump as a possible source. Where would the copper be coming from? The exposed parts are stainless. I guess there could be bronze fittings connecting to the PVC piping and of course the wiring is copper. The well has been in service for about 18 months.
Thanks again for your assistance.

 

[bimr]

Flushing is a valid treatment option when test results from flushed water samples show little to no copper concentrations compared to the first flush or first draw samples. You are indicating that there is little difference between flushed samples and non-flushed samples. That would indicate the copper is coming from the well itself, not from the piping downstream of the well pump.

By the way, if you have not done it already, you should have a complete water analysis done including testing for coliform bacteria. Note that zinc may also cause "blue water".

Copper Originating In The Well: The well pump is not completely fabricated from stainless steel. You probably have bronze bearings in the well pump. In the case of type steel to be used for casing and well screen, there are several choices: mild steel, copper-bearing steel, high-strength low allow steel, and stainless steel. Each of these are different relative to their performance and cost. When not properly defined by specifications, the types of construction materials chosen by each contractor may vary markedly from bidder to bidder. Because of this, their long-term performance also differs markedly. This is a recipe for problems.

http://www.roscoemoss.com/documents/TechMemo012-1MessagetoWellOwners-Haveityourway.pdf

Have you contacted your well driller for his thoughts? The well driller should be able to inform you of the materials of construction of the well. Are there wells in the vicinity with the same problem?

Here are some ideas for further testing of the stains:

http://www.wou.edu/las/physci/ch462/Proposals_09/Proposal4_Cu.pdf

If the copper is originating in the well, the least expensive solution is to use a water softener to remove the copper. Copper levels if present in the water entering the home may be reduced at the point of entry by water softening.

 

[QualityTime]

If the source of the copper is in the well water I don't think softening the water is the answer because home water softeners use sodium to soften water and then you have to use a filter to capture the bound copper. It is not a good idea to drink water with a high sodium content.

I am sure you probably searched the internet and saw this link

http://www.ehow.com/how_12121201_removing-copper-potable-water.html

 

[bimr]

The amount of sodium is dependent on the quantity of cations present. It may or may not be an issue.

Probably worse to drink the copper than sodium. Sodium consumption would only be an issue for those with hypertension.

A water softener removes copper. The capacity of a water softener for soluble copper removal is about the same as that for iron removal.

 

[pwn]

I'm noot concerned about any heath issue at this point. The concentration in the health dept. test is below the allowable limit. Also we would need to drink 2.5-3.0L/day just to reach the recommended amount for copper(excluding other sources). The only issue is cosmetic. My wife is concerned with the blue color she can see in the white bath tub. I have purchased a copper test kit that I will use to confirm that the copper is coming from the well, and not some source inside the house. I'll post what I find out.

 

[pwn]

Test results!

Bath Tub:
Cold Water: Non-Detect(ND)
Hot Water: 1.0mg/L

Kitchen Sink:
Cold Water: ND
Hot Water: 1.0mg/L

Refrigerator: <0.1mg/L

Tentative Conclusions. The only copper piping in the house is between the the water heater and the geothermal HVAC unit. Water is circulated through the HVAC unit to recover waste heat and reduce the cost for electrical resistance heating of the water. I will consider replacing that pipe with PEX. Except for some brass fittings there shouldn't be any copper in the water heater. I'll check with the HVAC people to see if their heat exchanger contains much copper. The refrigerator may use copper tubing internally or the supply line could be copper tubing, but I doubt it.

Any comments/suggestions.

 

[bimr]

Happy to hear that you have figured out the issue.

You many find that the heat exchanger is constructed of copper as well.

Another option may be to increase the pH. The usual remedy for raising the pH is a calcite filter. However, a calcite filter may not be adequate with your water parameters.