Air In Water System

Yes, though it is unlikely to persist. For how long has there been air in the water?

What does the air taste like?

You see we live close by to the reservor, each time the pumps start and in operation mode this is when we have a lot of air comming through.

Raise the level of water in the reservoir or lower the pump intakes.

You should not have air in the water.

<or an air leak in the suction side of the pump> #12

You could also have an air leak in the suction side of the pump....

Yes, a split inlet pipe would do just that.

AP #1-

1. What is the elevation of the reservoir above the pumps (how much higher is the reservoir than the pumps?

#2 What is the elevation of the reservoir above the place where the water is being used and the bubbles show up at? Again how much higher are the pumps above the usage point.

Again, questions in #6 would be very helpful in developing a clearer source and a better answer for you.

Good Luck, Old Salt

I think you might be suffering the results of cavitation If you can hear it.

Nope. Cavitation does not normally mix air bubbles into water.

This sounds like a common problem of repaired main lines by the utility, it should only last for a day....there is no way for air to enter a pressurized system unless it is being pumped in by a pump....now if this is the case, everybody on the system would be having the same problem, and it would get increasingly worse....If there was work on the line, and it lost pressure, there should have been a boil water alert issued to all users....In any case I would report this to your water company and see what they say....

AP #1

More information in your question would probably produce better results:

How much is "so much air being released"? 1 liter, 100cu ft, 100,000 cu ft? continuous?

How large is the water system?

What is the source of the water? municipal operated well, private well, city water, artesian well, etc.

Is the source of the water above or lower than the placed where the air is being entrapped?

What are the sizes of the pipes involved?

What is the volume of water that is involved? 100gal.day, 5 gal/day, 1,000gal/day, 100,000 gal/day?

What is the type of operation is the water supplying? residential, large residential, industrial with water clean up, water used in product production (soda/pop factory). Car/truck washing facility?

What type piping is involved?

Has there been this type of problem before?

Are there any mechanical devices that both have water and air connections?

What gases utility piping is near the water piping? Natural gas? CO₂, N₂?

In general, the better and more descriptive the question, the better the answer.

Good Luck, Old Salt

Air in your water and high water bills? Perhaps there is a leak between your meter and your house, letting water leak out and letting air in.

You should contact your water company and tell them this - if you haven't already.

You're kidding, aren't you?

There are multiple potential causes for this in a water network near the reservoirs. Some here have focussed on the pumps, but there could also be air entering through air valves in the line if negative pressure is ever achieved.

It could also be that the pumps are creating a low pressure effect in the line you are connected to and the dissolved gasses are being released.

There could also be issues with air entry when the pumps are turned off. The inertia of the water in the pumped line can draw air valves open and pull significant volumes of air into the lines. We use "balance tanks" to provide a source for water in our system in places where this could happen. One line we have draws around 1.5ML each time the pumps are shut down. (600mm diameter main running a little more than 600L/sec.)

This is definately an issue for the water supply authority to be made aware of and to deal with.

Someone marked Lyn off topic because he asked if the water smelled but maybe he is on to something. If gases like H2S or HS get into the water supply and have not been removed, the gases may have a smell. There can be several other candidates for gas dissolving into the water supply and then coming out of solution or even getting trapped in the pipes. C02 and O2 as well as methane (CH4) can supersaturate within pressure pipes. None of the last three will impart an odour but can act as entrained air within the plumbing. Perhaps OP should check for these gases and that can be done readily by someone at the utility. Although it does not explain high water consumption.

However, gases aside, that does not mean air is not getting into the system through some syphon such as a wall hydrant might cause. These wall hydrants should be equipped with anti syphon devices to prevent that situation but many older ones were not protected. If the tap is leaking and there is a pressure difference in the city line back flowing can occur. An outside tap leak, plumbing leak, filter leak, or line break on OP's property may be the reason for high water consumption. Check your softener for running water to drain.

Of course if this "air" is methane (natural gas), then you should not try the match test at home!!!

I suspect this is a winter-time problem from lake water (reservoir mentioned), that is very cold indeed, and that is being pumped through underground piping that is warmer, hence the water will outgass "air" into the piping system (even if there is no fault with the suction piping), and this will seek the highest point. Problem solved, pay the man.

Thanks, but I was just being a jerk.

Seriously, the workmen just installed a new water heater in our office.

For about a day, all the hot water was frothy, but if you let it sit for a few minutes, all the bubbles came to the top and the water was fine.

You do have a valid point about swamp gasses.

I'm struggling with the assumption that some seem to have that air in a line will drive the meter at a higher rate. To me, it seems that the reduced density of frothy water would drive the meter works proportionally more slowly.

Air rushing past the meter might just be at a higher velocity, resuling in a higher than normal metering rate, since the air might be expanding from higher to lower pressure downstream.

Lyn,

I work in a water supply authority and the air "spinning" the meter is a very real phenomenon when it is bulk air from a pipe repair or such.

This is especially the case where the tap that is turned on still is primed with water but the air is in the meter itself. The vanes and gears inside the meter start to record as the air passes (and actually run faster than if water was flowing.) When the tap is turned off, the vanes and gears are not damped by the water and continue to spin at that faster rate until friction eventually stops them.

If the air is only micro bubbles, then the meters will be within their +/-5% range.

OK, I'm convinced that I was wrong, again.

Thanks for this reply.

That certainly would open a new "can of worms" inside the home if that is the case, now wouldn't it?

The term is "venturi effect" and you make a good point.

Venturi effect - Wikipedia, the free encyclopedia

That could account for both the excess meter reading (water leaking out when the faucet is off and there's no flow past the venturi) and the air bubbles when the water is flowing.

Exactly what happened to my swimming pool filter line. The pipe cracked under ground and would suck air when running and mildly leak when off.

Just another one of the many joys of owning an in-ground pool.

I especially like pouring money into them during this cold time of the year.

Here is the lowest cost period in the season. Virtually no chlorine needed, very little vacuuming, and reduced filtration.

Spring and summer are the months where the maintenance goes up.

However, the trick is to never let the pool go into a state where the algae takes over or the chemistry goes out of bounds. As long as the chemistry is stable worst is kept at bay.

Doesn't hurt to have a screened in enclosure, either.

Our pipe problem was due to the previous owner installing cheap lines.

Here, too.

We don't go on that side of the yard now, except to check/maintain chemistry.

Oh, and cut the grass.

Grass in Arizona?

Where did you import that? :-)

It started out as Tiff many years ago. Now, it's just junk yard grass.

Anonymous Hero-

If you maintain a pH of 7.5+ the chlorine lasts a lot longer and does not evaporate, especially with the sun, and stays in the water where it can kill those nasty buggerlugs. Based on many years with an in-ground and comparing its chemistry to the neighbor's. They swore by the pool store analysis then swore at me because mine was much better than theirs.

No diving at the shallow end please!

Good Luck, Old Salt

The pH has not been too much of a problem. As long as the chlorine concentration stays consistent the pH seems to remain the same.

Anonymous Hero-

Cause and effect is the other way around. Maintain the pH level at 7.5+ and the chlorine concentration will stay consistent.

If needed, increase pH, more basic, with Soda Ash (Sodium Carbonate) or reduce the pH, more acidic, with either Sodium Bisulfate or Muriatic Acid. Sodium Bisulfate is better since Muriatic is harder to use and not as safe. Unless your total solids are too low (adjust with Sodium Bi-carbonate) these chemicals should assist in controlling the pH is any adjustments are needed.

Acid rain also makes a big difference in pH fluctuations and adjustments may be necessary after a heavy rain fall.

Good Luck, Old Salt

We don't get the acid rain as the moisture either comes from the Gulf or the Atlantic.

I can imagine other locations in the US have to deal with changing pH issues, but in my case I just keep the water chlorinated.

In summer I add liquid chlorine to periodically shock the pool once or twice a month and keep the floating chlorine tabs filled. The rest of the year we really only use the floating chlorine tab holder.

It's to the point where I almost never test the water and it remains crystal clear.

Problems arise if the chlorine level falls too low. I have had a few algae blooms start a few years ago and have leaned to not let things go to the point where algae has a chance to even get a foothold now. Consistency is the key.

When we first moved in we had a learning curve and had to stabilize the pH to get things under control. Now our maintenance is pretty low and pH has been normal for a long time.

Anonymous Hero-

That's what you want- swimming without a test tube or the CRC Handbook in your hands. Sounds like you have things well under control.

Many people with pools in the eastern states don't realize what an affect all those coal fired power plants in the west and mid-west have on them. Glad to hear you don't have that problem.

Good Luck, Old Salt

Use to live there and when I moved down here the first thing I was stunned by was the lack of dirt when it rains. Much better on cars!

rubbish.

This can be a real problem when the water line runs through sewage contaminated soil. This is a problem in certain underdeveloped countries where both lines are buried in the same ditch. The raw sewage can and often is educted into the fresh watrer thereby contaminating it.

In reviewing all the comments so far it appears that very little consideration had been given to very important factors in this problem.

1. Where is the water meter located? Is it at the supply end or the user end? If the air is in at the supply end vs. the user end it would make a big difference to determine the cause of the air entrapment.

2. What size pipe is involved? 10 gpm through 1/2" pipe will have a much greater velocity than a 6" pipe would. Sucking air back into the pipe through a small leak is very dependent upon the velocity of the liquid.

3. Venturi effect requires a constriction prior to the point of entry in order to create a vacuum to draw water in from the soil. The greater the velocity and the smaller the constriction, the greater the ability to draw air in while water is moving. Likewise any hole big enough to pull air in would be leaking water out at a much higher rate when there was no flow of water. A demonstration of this would be to take a "T" with a small valve on the branch. Flow water through the runs and see if water comes out or air comes in through the branch or water out it as various flow rates through the runs. Next put a valve on the inlet run and adjust it to see what happens at the branch. Use the run valve to regulate the flow of water through the tee and the branch valve to see whether the flow is water out or air in. The various examples cited are dependent upon this practical application. It

There are many different causes that can be hypothesized but the simpler ones and more obvious ones are the most likely cause.

Remember water under pressure inside a pipe is more to leak out than air is too leak into the pipe.

Good Luck, Old Salt

I wonder if the air is coming out of both taps or just the hot water side? As a landlord, I encountered a case where the water was cranked up to the highest temperature possible. That cause some air in the water heater and high gas bills. I guess it was acting more like a boiler in that case. I expected the over pressure device to leak that off but apparently that didn't happen.

It's all history now. I sold all of that rental property. Best decision of all!

In reviewing all the comments so far it appears that very little consideration had been given to very important factors in this problem.

1. Where is the water meter located? Is it at the supply end or the user end? If the air is in at the supply end vs. the user end it would make a big difference to determine the cause of the air entrapment.

2. What size pipe is involved? 10 gpm through 1/2" pipe will have a much greater velocity than a 6" pipe would. Sucking air back into the pipe through a small leak is very dependent upon the velocity of the liquid.

3. Venturi effect requires a constriction prior to the point of entry in order to create a vacuum to draw water in from the soil. The greater the velocity and the smaller the constriction, the greater the ability to draw air in while water is moving. Likewise any hole big enough to pull air in would be leaking water out at a much higher rate when there was no flow of water. A demonstration of this would be to take a "T" with a small valve on the branch. Flow water through the runs and see if water comes out or air comes in through the branch or water out it as various flow rates through the runs. Next put a valve on the inlet run and adjust it to see what happens at the branch. Use the run valve to regulate the flow of water through the tee and the branch valve to see whether the flow is water out or air in. The various examples cited are dependent upon this practical application. It

There are many different causes that can be hypothesized but the simpler ones and more obvious ones are the most likely cause.

Remember water under pressure inside a pipe is more to leak out than air is too leak into the pipe.

Good Luck, Old Salt