Blue Water

Status
Not open for further replies.
F

flengineer

Member
Location
Miami, FL
The main service entrance for a school comes into the Main Switchgear Room where it is grounded to two ground rods, foundation steel and the cold water pipe. The main switchboards feed satellite electrical rooms in four other buildings. At each satellite room, there is a ground bus tied to two ground rods, foundation steel and cwp. The feeder's EGC from the switchgear room is also bonded to this ground bus.

The school was opened for a year with no visible problems. When the school reopened after the summer, the water was visibly blue in several locations.

Testing revealed high concentrations of copper in the water. Electrolysis caused by a grounding problem is being blamed for the blue water.

The campus has two water services, one serving four buildings and another serving one building. The water pipe outside the building is ductile iron pipe (supposedly not electrically continuous) except for the last 20' at each service entering the building which is copper. Piping within the building is copper. The water from both water services has elevated copper levels.

Any thoughts on how to verify that this is a grounding problem and isolate the problem?
 
Before you accept the explanation of grounding being the problem, have the PH level of the water checked. I have blue water and blue stains in my sinks and tubs due to the high acidity of the water itself, pretty common in the Southeast US.


Roger
 
An open or high resistance neutral could result in significant current flowing in the water pipes, which are probably a better ground than the ground rods (owing to a greater surface area)

Under normal load conditions, try measuring the current in the ground wire that connectes to the water pipes, useing a clamp meter.
Also measure the current in the neutral of the service conductors, again useing a clamp meter.
If the water pipe curent is a significant % of the neutral current, this suggests a possibly defective neutral.
 
flengineer said:
Testing revealed high concentrations of copper in the water. Electrolysis caused by a grounding problem is being blamed for the blue water.


Any thoughts on how to verify that this is a grounding problem and isolate the problem?
Click to expand...



This would be characteristic of a DC source, it is not common in AC systems.

Try looking for a DC system within the building, and see if that system is bonded to the water system in some fashion.
 
As posted in the original post.

"The school was opened for a year with no visible problems. When the school reopened after the summer, the water was visibly blue in several locations."

"Testing revealed high concentrations of copper in the water. Electrolysis caused by a grounding problem is being blamed for the blue water. "

This happens here a lot. the water sits in the piping for the entire summer and comes out bluish when the school reopens. You mention ductile iron water mains. Ductile iron mains especially when new are a source for high concentrations of calcium. Calcium will react with copper if the 2 sit in solution long enough. Did flushing the water system clear this problem up, or are you still getting blue water?
 
There is another possible answer. Chineese Drywall. Yes that is correct. The problem has been found in SW Florida in homes and buildings built around 2006/2007. The bad drywall gives off a sulfur oder and is eating away the copper in the A/C systems and plumbing pipes and electric wiring. Familes are being moved out and the drywall is being replaced at the contractors expence. Whole subdivisions are being effected. This problem is begining to show up all over the country.
 
Mr. Bill said:
I found some info on blue water in copper pipes. Haven't read it all yet.

http://www.copper.org/applications/plumbing/techcorner/staining_bathroom_fixtures.html
Click to expand...

Maybe this is what happend:

"
There may instead be precipitation of bicarbonate and sodium byproducts out of the water in such a way as to loosely adhere to the tube wall and react with the copper surface to form a blue/green copper carbonate. This material is very friable and can easily flake off into the water stream when the plumbing system is put into service. It seems to occur most often when water high in bicarbonates has been allowed to stand in the piping system for some time, especially when exposed to high ambient temperatures. For instance, if a house is built and left standing while waiting for completion or occupancy during the heat of the summer months."

If so, it doesn't sound like it has anything to do with the electrical system or grounding.
 
There are lots of possibilities, but grounding problems are not the most likely, just the one that everyone else likes to point to because they don't understand it. Read this paper, it sheds light on the subject very well and does address some potential issues with regards to grounding. I have seen 2 occasions where everything was done right by the EC when a building was built and inspected, then the Security Alarm contractor hire by the tenant came in later and bonded their power supplies to water pipes rather than run their own EGC. I have even seen an HVAC contractor use the water pipe as a neutral once!
 
Got a call once for something similar. During a property walk-thru, corrosion was seen on the copper water pipes, both hot and cold. It was a whitish crumbly looking with green coloring. This was near every joint in the pipe, by every fitting.
One glance and I said blame the lazy plumber! He did nt wipe his solder joints clean after soldering. Some of the flux remained on the pipe and started to corrode turning the copper green.

Don't know if the plumber sabotaged you!
 
masterinbama said:
As posted in the original post.

Did flushing the water system clear this problem up, or are you still getting blue water?
Click to expand...

Flushing helped some, but didn't resolve the problem. The water is no longer blue, but copper levels are still much higher than the recommended levels. The lines were flushed at the backflow preventor (there is a mile-long water main serving just this school) and at multiple points within the school.
 
tshea said:
Got a call once for something similar. During a property walk-thru, corrosion was seen on the copper water pipes, both hot and cold. It was a whitish crumbly looking with green coloring. This was near every joint in the pipe, by every fitting.
One glance and I said blame the lazy plumber! He did nt wipe his solder joints clean after soldering. Some of the flux remained on the pipe and started to corrode turning the copper green.

Don't know if the plumber sabotaged you!
Click to expand...

There were metallurgical tests done on the copper piping and they proved that there was no poor-quality copper used (which could have been another source) or evidence of the flux or any other installation-related method having caused the copper deterioration.
 
Jraef said:
There are lots of possibilities, but grounding problems are not the most likely, just the one that everyone else likes to point to because they don't understand it. Read this paper, it sheds light on the subject very well and does address some potential issues with regards to grounding. I have seen 2 occasions where everything was done right by the EC when a building was built and inspected, then the Security Alarm contractor hire by the tenant came in later and bonded their power supplies to water pipes rather than run their own EGC. I have even seen an HVAC contractor use the water pipe as a neutral once!
Click to expand...

Security systems and access control systems require a CWP bonding, per installation instructions. In fact, some access control systems will have communications issues in high EMF envrioments without being grounded properly. Without it, in a lightning strike, it would be a fire hazard.

Are you speaking to grounding the primary power supply (120 VAC) for a hardwired low volt power supply to the CWP? That, of course, would be an issue.
 
Last edited:
nhfire77 said:
Security systems and access control systems require a CWP bonding, per installation instructions. In fact, some access control systems will have communications issues in high EMF envrioments without being grounded properly. Without it, in a lightning strike, it would be a fire hazard.

Are you speaking to grounding the primary power supply (120 VAC) for a hardwired low volt power supply to the CWP? That, of course, would be an issue.
Click to expand...

Yes, grounding of the AC input for the power supply / DC UPS for the security systems. In both cases they only ran 2 wires to the locations where the power supplies were located, then ran a shorter bare copper ground to the nearest water pipe. I wasn't aware of the other requirements you mentioned above though, so maybe they knew that but extended the requirement too far? It's a problem I have only seen with Limited Energy specialty contractors who take on the AC input part of a project themselves rather than bring in another EC to give them an outlet or jcn box to work with.
 
Jraef said:
Yes, grounding of the AC input for the power supply / DC UPS for the security systems. In both cases they only ran 2 wires to the locations where the power supplies were located, then ran a shorter bare copper ground to the nearest water pipe. I wasn't aware of the other requirements you mentioned above though, so maybe they knew that but extended the requirement too far? It's a problem I have only seen with Limited Energy specialty contractors who take on the AC input part of a project themselves rather than bring in another EC to give them an outlet or jcn box to work with.
Click to expand...

That's totally unacceptable. I agree that LV contractors (which I am) shouldn't be touching any 120v work, even if its the AC for the LV equipment. The only exception is when swapping out existing panels, or hooking up to a circuit installed by an electrician.
 
If you going to ever draw water for testing, ask that it will tested within 24 hours, this will assure that all foreign items will be identified correctly!
 
Status
Not open for further replies.
Top