Case Study: Air in Water Lines from a Water Well

Case Study: Air in Water Lines from a Water Well

The case of the mysterious clinging bubbles. In this article we explore this phenomenon, multiple hypothesis, and possible solutions.

Water Issue: Well Water with Bubbles that seem to stay stuck on the sides of a glass and do not easily gas off.

Today, we got a question from one of the many laboratories that help provide information to private well owners throughout the United States. In the email, the private well owner reported that he had “bubbles that seem to stay stuck on the sides of a glass and do not easily gas off.” So, like any good expert, I jumped to the conclusion that the problem was air in the system, because he had just reported he had changed the well pump. Then, I thought, wait a minute, I am not just an expert, I am a water professional and a scientist and I cannot develop a theory (solution) until I develop a hypothesis and look at some data and test my hypothesis.

After looking through the available water quality data, I found the following:

The water was Total Coliform positive, but E. coli. negative, but since the laboratory did a presence-absence test I do not know the level or number of Bacterial colonies and they only tested the total coliform group.  

  1. The sample was collected from the kitchen sink and therefore I can not be 100% sure that part of the bacterial contamination may be related to the regrowth of bacteria in the water piping or distribution system or the sampling point.  I also do not know the type of fixture at the point of sampling.
  2. The level of salts was relatively low, but the potassium level was over 3 mg/L and Manganese was just below the secondary drinking water limit of 0.05 mg/L.
  3. Alkalinity and Total Hardness were above 180 mg CaCO3/L and the reported pH (after 24 hours + of outgassing) was about 7.5.  Therefore, the system may have some Scale accumulation in the water heater, piping, and screens.
  4. The other important piece of information was “do not easily gas off” and because of that, I did not suspect a methane problem. Since there was no reported odor problem, I did not suspect hydrogen sulfide and because the strontium was relatively low and uranium not detectable I did not suspect it was a radiological issue.   With respect to radon,  the site is located in Steuben County, NY within a Zone 1 area, i.e., Indoor Airborne Radon Levels > 4 pCi/L and we did suggest radon air and radon in water testing.

My Hypothesis (multiple):

  1. The source of the gas was related to bacterial regrowth in the well and distribution system and therefore could be carbon dioxide.  I did not suspect methane (no fizz) or Hydrogen Sulfide (no odor)
  2. Since the well had a relatively higher-than-anticipated Potassium and the water was bacterial positive, the bubble was not really an air bubble, but evidence for the presence of a surfactant in the water.
  3. The well pump was recently changed and maybe the bubbles are “air” or other Dissolved Gasses in the water related to an issue with the new pump or the pump installation. 
  4. The glassware is dirty and has a film or coating that may be permitting air bubbles to more easily attach to the surface of the glassware. 

My Recommendations:

  1. Because of the high Alkalinity and Hardness, it is likely that the glassware may have a coating. Carefully hand-wash a glass and allow it to dry and then compare the air bubble formation in this very clean glass to the normal glassware that is used.
  2. If possible, field check the pH of the first flush and a flushed sample of the water and see if the level of air bubbles is different.   Do this with and without the aeration device this will help determine if the aeration device is the source of the bubbles.    If the initial pH is lower and there are more gas bubbles, this could mean the problem is bacterial regrowth.    

Another question you may want to ask is, do all the taps or faucets in the household create this problem or only certain faucets? To see how widespread the problem may be within the home, you may want to check the other faucets in the home and I would suggest looking in the back of the toilet tank for evidence of Bacterial regrowth, i.e., metallic sheen, slimy coatings, bacterial films, and/or coatings or colored staining.

  1. Shock Disinfect the well and distribution system and retest for Total Coliform, standard plate count, and perhaps Nuisance Bacteria using an enumeration method.  (Currently, there are two general types of bacterial testing: the first is just basically a Presence or Absence Test, and the second is an enumeration method.  The first says if the bacteria is absent or not detected or if the target bacteria is present, but provides the estimated or actual amount of bacteria.  The enumeration method offers the best of both; you learn if the bacteria is present and how many are estimated to be present, and the result is typically reported in the number of colonies per milliliter (ml)  or number of colonies per 100 ml. ) 
  2. Have the system inspected by a professional because the following are some of the main reasons for air or gasses in a well water system.  Since the bubbles did not out-gas immediately, I do not suspect the problem is methane, and since no odor was reported, I do not suspect the problem is hydrogen sulfide
private water well

Air in My Well Water

Air and carbon dioxide in well water can cause the water to appear very turbid and cloudy. Levels of air or carbon dioxide may be high within a water source for a number of reasons which include a change in temperature that causes the dissolved gas to start coming out of solution or bacterial regrowth in the distribution system which increases the level of carbon dioxide in the water.  As the carbon dioxide comes out of solution, the pH of the water will increase. Typically, the water may appear "milky" and if you allow a glass of water to sit undisturbed on the counter, the water clears in a few minutes from the bottom up. If it takes over 2 minutes for the gas and water to separate and if this is associated with an increase in the pH of the water, the gas may be carbon dioxide.  A few causes for air in your well water system:

  1. The system may have a faulty check valve.  If this is the case, the users or well owner may also be experiencing water hammer or irregular or inconsistent flow that reduces water flow and pressure. 
  2. The system may have a leak and you may need to look for wet patches in the yard and in the basement.  In some cases, the faucets may sputter when used.  Sputtering may also be associated with a dirty aeration device, faulty valve cartridge in the fixture,  or an issue where the water heater is being overheated.  It may be necessary to flush accumulated sediment from the water heater. 
  3. The pressure tank may be damaged or waterlogged or air bound; there may be a problem with the air charger.  If this is the case, the pump may short-cycle, i.e., run and then shut off repeatedly, and/or the tank may be overfilled or the tank does not maintain the proper ratio of air to water. Old-fashioned “galvanized tanks” utilize an air control valve. If it malfunctions, the tank will fill with air. Also, if someone has changed one of these tanks out for a modern, diaphragm style tank and neglected to remove the bleeder (drain back valve) from the well, there will be an air problem (Cresswell, 2024).

  1. The problem could be the pump in the well.  The pump could be drawing air into the system or the well screen or intake is clogged or coated.  This may be related to a problem with pump alignment which can decrease pump efficiency and the wear and tear on the pump.
  2. The yield or capacity of the well has changed and the well is being overdrawn, i.e., the dynamic level of the water in the well is dropping too close to the pump intake or there is a lot of cascading water into the wellbore because the water has dropped below a major water-bearing zone.  You can also experience these types of issues if there were structural issues or changes in the wellbore, such as: a collapsed casing, blockage in the wellbore, or collapsed wellbore.
    At this time, this case does not have a resolution.  I suspect the private well owner will find and identify more than one problem that contributed to this nuisance for the private well owner, but the information we provided the laboratory and the private well owner was a guide to get them ON the Path to Clean Water.
  3. Certain water treatment systems utilize air injection and there will be bubbles due to that. However, excessive air may indicate a mechanical problem within the treatment system (Cresswell, 2024).

The homeowner would be better served to call a contractor such as a well driller who also does water treatment to evaluate the issue. (Agreed- Find a Professional)

The KnowYourH2O Team would like to thank Mr. Scott Cresswell for his review and input into this educational article. Mr. Cresswell is the owner of Cresswell Drilling Company, Inc. of Dalton, Pennsylvania.  You can review the company professional profile at Cresswell Drilling Company, Inc