question for mold in pvc supply to house

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snrusnak

Well-Known Member
Joined
Jun 3, 2011
Messages
165
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Location
Gulfport, MS
Hello,
I have a well on my property supplying water to my home. It is a deep well (not sure of the actual depth off hand but I believe it's several hundred feet), but it has a submersible pump and a large bladderless pressure tank. The well provides water through a brass check valve (with pressure switch) and into the pressure tank. It is a galvanized tank and probably 100 gal or more. The water simply comes out of the pressure tank, through a ball valve, and tee's to my shop and to my house.

I recently moved the pressure tank from it's cinder block "foundation" to my car port (temporary move as the blocks were shifting and the pvc pipe was under stress). I poured a slab to move the pressure tank back to to provide a stable foundation. I did minor rerouting of the discharge piping underground (see pictures) and found that the inside of the PVC has minor mildew/mold spores growing. This is about 16 years old, and totally untreated water, but worries me some as this is water we drink. To be clear, this is the pvc lines coming out of our pressure tank and leading to our home and my shop. The house is plumbed with copper, but I guess from the pressure tank to home is PVC.

We have amazing water, probably the best water I've ever seen. It's totally odorless, crystal clear, and has absolutely no taste. Perfect water. I am near the gulf coast in MS.

I'm looking for advice on this mold in the piping. What can I do about it or should I do about it?

I was wondering if there's something I can put in the line that would act as an eductor that I can from time to time fill and run through the piping to treat the system with bleach or something similar.

Thanks for any input! I've also attached a picture of my new slab and where the tank sits for now.

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Why do you think it is mold and not normal mineral build-up?
 
Have you gotten a mold testing kit to confirm that it is mold and not just sediment?

And I wonder if it is possible that you might have some sort of water purifier somewhere along the line.
 
Mold would be very unusual. But with an old air over water style tank, the Schrader valve on that check valve there by the pressure switch sucks in air every time the pump goes off. I have seen these sucking in feathers and dust from being installed in a chicken house. And I guess it could also suck in mold spores if they are present in the area.

If you have perfectly clean water there is no reason to have the old style air over water tank. A diaphragm style tank does not let the water come in contact with air, which could be the cause of the mold.

Then you could even go one step further towards a more modern style pump system by switching to a constant pressure system like the Cycle Stop Valve. With a CSV you would only need a 4.5 gallon size diaphragm tank, which would take up much less space and leave less opportunity for contamination. Plus you would then have "constant pressure" in the house, and the pressure would be so strong you would no longer need soap for a shower. :)
[ame]https://www.youtube.com/watch?v=LPIUufWjbic&list=PLpIZn7LpzYEABUoA0UZPhQkMvT9vUN75H[/ame]
 
Thank you all for the responses.

Great question, I ASSumed it was mold or mildew, and honestly didn't inspect it very closely. When I move the tank back tomorrow, and cut the line on the inlet side to the tank (still original line) I will take pictures of it.

I appreciate the advice on the CSV and smaller, bladder tank, but I honestly love my system. It is so simple and easy to maintain, and I know a whole bunch of people that have above ground pumps with bladder tanks and after just a few years have several costly issues with the systems. My system is 16 years old and really no issues. I did have to replace the pressure switch last year as the contacts jumped off, but the check valve is original, the tank is original, the AVC valve is original (although I want to replace), and I have no noticeable pressure changes inside the house.

There is no schrader valve on the brass check valve either, just the pressure switch. I honestly don't know where, if anywhere, air is being allowed into my tank. I do drain the tank about once a year or so when I notice it begins cycling more often, and that is as simple as opening up the schrader valve on the AVC valve on the side of the tank, and walking to my shop (lower elevation) and opening up the hose. After 30 min or so I just close it all back up, and flip the breaker back on. When I do this, it will go about 5-6 minutes with the kitchen faucet on before cycling the pump on.

Thanks for the help, I will post pictures tomorrow of what's inside the pipe.
 
Also Zanne, no type of purification system in my water line (other than the filter at the fridge). It goes from my pump to pressure tank (all underground), into the tank as seen in the picture I posted, then back underground and Tee's to my shop and house (all underground).
 
Ok so I moved the tank to the slab today and used the liquid stuff (pipe dope) on the threads, and I don't believe there's any leaks now. I've attached pictures. There was no sign of the "black spots" (what I thought was mold) in the pvc on the inlet side of the pressure tank, just some yellowing.

I dug up a section of the discharge side of the pressure tank and cut out a section of pipe then glued in a new piece, and I am not sure now if it's mineral buildup or mold. It looks less mold like now that I took a second look. I've attached pictures.

Also, I see my check valve has a plugged threaded port (for snifter/shrader valve). But how do I know if I need a drain back valve in my well casing? Or is it even necessary?

Thanks for all the help!

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Anyone have any input? Or suggestions on how I can test it to see if it's mold or mineral buildup?

Thanks.
 
have your water tested for iron, hardnes, ph, and etc. Make sure they test for tannins too. You may need a filter system. Or it could be coming from that old tank.
 
Since you have to manually drain the tank and add air, either the system does not have a bleed back system, or it isn't working, which is very normal. Diaphragm style tank systems are much easier to maintain because they do not need the extra check valve, Schrader valve, bleeder orifice, and Air volume control. These are the extra things that need constant maintenance on the old hydro tank type systems.

The only problem people have with diaphragm tanks is breaking the diaphragm. When you have a CSV the pump does not cycle on/off enough to break the diaphragm, which breaks similar to a wire that has been bent back and forth too many times.

And I would bet you have some pretty serious pressure drop in the shower, you have just gotten use to it and don't notice. If you did switch to a constant pressure type system I bet you would say "wow, never knew I was living with such weak house pressure before". At least that is what I hear from people everyday.

I guess that could be iron bacteria, but it usually coats the inside of the pipe. I have never seen it make spots like that.

Since the points on the pressure switch "jumped off", the pump is cycling more than you think.
 
Ok thanks guys. I gotta figure out how to get my water tested. What's odd is the inlet piping to the pressure tank had none of this black stuff, the outlet side is full of it. So it would make sense (to me), that it could be from the galvanized tank.

I bought a new AVC today, and the guy at the store sold me a shrader (snifter?) valve also to put in my check valve, but he claimed it will not open under vacuum, only if you force air into it. I'm not sure what to believe at this point as everyone tells you something different, but I don't see how it can hurt to install it. I figure I can put my finger on it and see if it sucks in air. I also don't know if I have that drain back valve (don't understand it either), or if I need it.
 
A Schrader valve is simply the proper name of a standard tire valve stem. They do not suck air in.
 
snrusnak said:
I gotta figure out how to get my water tested. What's odd is the inlet piping to the pressure tank had none of this black stuff, the outlet side is full of it. So it would make sense (to me), that it could be from the galvanized tank.
Click to expand...

Strange things can grow in a pressure tank and/or a water heater (or in a well).

GOOGLE well water testing for a company and make sure it is at least NSF certified.

-Air Volume Control (AVC)-
 
snrusnak said:
Ok thanks guys. I gotta figure out how to get my water tested. What's odd is the inlet piping to the pressure tank had none of this black stuff, the outlet side is full of it. So it would make sense (to me), that it could be from the galvanized tank.
I bought a new AVC today, and the guy at the store sold me a shrader (snifter?) valve also to put in my check valve, but he claimed it will not open under vacuum, only if you force air into it. I'm not sure what to believe at this point as everyone tells you something different, but I don't see how it can hurt to install it. I figure I can put my finger on it and see if it sucks in air. I also don't know if I have that drain back valve (don't understand it either), or if I need it.
Click to expand...

definitely your tank. Get a regular bladder tank and the minimal accoutrements that go with it.
 
An AVC lets excess air out, which is the opposite of your problem. A Schrader on the AVC will not suck air in, but a Schrader on the inlet side of the check valve will suck air in. That is as long as you have a bleeder down the well and the check valve is holding good. The above ground check valve has to hold good and take all the pressure off the bleeder, so the bleeder can open. When the bleeder opens, it will suck air into the Schrader (with no cap of course) on the inlet of the check valve.

Schraders for well systems usually have a little weaker spring, so it can be easily sucked open with vacuum.

And since you have spots in the pipe coming out of the tank but not going in, adding air as that style of tank needs, is what is causing the contamination. Either the air is contaminated or adding air is causing something to change in the chemistry of the water. A diaphragm style tank does not let air come in contact with your water until is comes out of the faucet.
 
Valveman said:
An AVC lets excess air out, which is the opposite of your problem. A Schrader on the AVC will not suck air in, but a Schrader on the inlet side of the check valve will suck air in. That is as long as you have a bleeder down the well and the check valve is holding good. The above ground check valve has to hold good and take all the pressure off the bleeder, so the bleeder can open. When the bleeder opens, it will suck air into the Schrader (with no cap of course) on the inlet of the check valve.

Schraders for well systems usually have a little weaker spring, so it can be easily sucked open with vacuum.

And since you have spots in the pipe coming out of the tank but not going in, adding air as that style of tank needs, is what is causing the contamination.

Either the air is contaminated or adding air is causing something to change in the chemistry of the water. A diaphragm style tank does not let air come in contact with your water until is comes out of the faucet.
Click to expand...

...scribble...scribble...scribble... :D

Question- Do you have a PhD or did you learn all of this by experience?

Aerobic Bacteria- Bacteria that grow in the presence of O2, which are the most common causes of clinical infection.
Click to expand...

By allowing air into the system all types of things will begin to grow, some being not good for the human system.
 
KULTULZ said:
Question- Do you have a PhD or did you learn all of this by experience
Click to expand...

The only formal schooling I had was in electrical engineering. Pumps and drilling I learned the hard way. A lot was passed down from my grandfathers, plus 50 years of working on wells and pumps at least makes me sound like I know what I am talking about. :)

Here is a pic of my grandfathers drill rig from the 20's.

Grandad Angels Spudder rig 1923 sized.jpg
 
Thank you so much for the detailed explanations!

Ok, so as resistant as I am to changing my tank, I will consider it ;). The elimination of bacteria growth without presence of air in the water is definitely not something to take lightly.

So, if I were to buy a bladder tank, are there things to look for, things to avoid, or anything else I should know? Also, would anything else in my system need changed (check valve, pressure switch, etc)? Would I still need an AVC? I know the float type I have now wouldn't be the right one, but do you even need one on a bladder tank? And if so, how does that work exactly?

The cycle stop valve that you mentioned, I understand it's basic function, but how does it work specifically? Is it like a control valve (butterfly valve, knife gate valve, gate valve, etc?) How does it limit flow? I also assume it needs a power source? Could I piggy back off my pressure switch?

Sorry for so many questions!
 
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