A well water aeration (true) story.

-- Note: Aeration of a standing water tank is pretty simple.

All this came to and end when I replaced our 40-year old water storage tank with a rubber bladder pressure tank.

After that, my water began to smell and never stopped.

The best I could hypothesize was that the old tank allowed the hydrogen sulfide to vent into the air space in the tank . The new tank with the bladder allowed no venting . Now enter Malibu Water Resources...

After a lot of E-mail, the Grand Exalted Poobas at Malibu Water Resources helped me decide on an in-well aeration set-up with a Koenders Electric Aerator pump -- and 2 X 12" aeration stone | air diffuser. My well is approximately 120 feet deep with a 6" casing.
The well pump is at 107 ft. and
the top of the water is at 18 ft. The Koenders Electric Aerator air pump output
is 1.5 cu.ft./min @ 5 PSI with a max of 35 PSI.
So, I was limited to the depth at which I could place the Aeration Stone | Air Diffuser.

I wanted it as deep as possible to maximize the amount of water treated and decided to try running the pump at 75% of maximum pressure.

Applying Boyle's Law...
This allowed me to place the aeration stone 58 ft. below the surface of the water
or 76 ft. into the well,
providing an 85 gallon column of oxygen treated (aerated) water.

To ensure that the aeration stone would not contact the side of the well casing, centering bumpers seen in the the photo above were added above and below the point of attachment.

The air line was then attached every 5 ft. or so along the way up the pipe and then routed out through one of the bolt holes of the well cap.

Everything was now checked and wiped down to minimize contamination and then with the help of my 16 year-old son, the assembly was lowered into the depths. Once in place, the well cap was secured with two of the four original bolts. The remaining holes were used for the air supply line and a vent line.

My well head is below grade and is contained inside a 30" culvert pipe with a concrete cap 6" under the sod of my front lawn. I needed a solution that would allow adequate venting and a place to house the Koenders Electric Aerator pump.  After a few delicate discussions with my wife, we decided that a wishing well would be the way to go. A little digging, two loads of landscape blocks, and some wood gave us what we wanted. We still need to add a crank, rope, and bucket.

and power the Koenders Electric Aerator pump installed inside. I added a pressure gauge to monitor operation, the level of water in the well, and to check for leaks. Additionally, I installed a valve after the pressure gauge for a positive check on the output of the Koenders Electric Aerator pump.

Shutting the valve shows me full pressure output of the Koenders Electric Aerator to assess any erosion in pump performance.

The pressure runs between 26-27 PSI... BOYLE'S LAW WORKS!  The only problem I had was overcoming the startup back pressure. The Koenders Electric Aerator will not start with a head pressure that high. The fix was fairly easy: Create a small leak. A small leak, which allows the pressure to drain off over several minutes is perfect.  Malibu Water Resources Note:
26-27 PSI may be too close to the max of 30 psi.
Placing the Air Stone at a depth less than 58 ft. under water
may place less stress on the Koenders Electric Aerator and still achieve the result of properly oxygenating the water and venting off Hydrogen Sulfide. PSI.
I have seen 35 PSI and 30 PSI in different places...
but certainly the manufacturer is the bible on this: MAX 30 psi.

In my HARD PRESSURE TEST: closing off the valve I installed... the max pressure appears to be in the 32-34 PSI range.  When I do the dissolved oxygen tests... I will re-think the depth of the aeration stone and position of the submersible pump also. I'll let you know as I progress with my backyard science project!  Dissolved Oxygen Meter I am looking for a reasonably priced dissolved oxygen meter.
So far the best I have found is a Milwaukee DO-600. Do you know of any others? Milwaukee DO-600: $171.00
is a portable dissolved oxygen meter designed for various applications from school laboratory work to waste water treatment. It is reliable and accurate yet simple to operate. DO-600 is used together with our ruggedly designed polarographic probe, MA840, which is conic in shape making it suitable for use in BOD applications. It also has a built-in temperature sensor and replaceable membrane.

I am working on the on-off cycle times . I intend to measure the level of dissolved oxygen in the well and at the tap and will then set the run time to achieve optimum oxygen saturation in the water (approximately, 11.5mg / l with a water temperature of 50°F.)  Once the cycle time is determined, each time the well-pump runs, a timed relay will be kicked off to run the aeration pump to restore the oxygen saturation level. Overall, the whole project is working out pretty well. The water is good...
No sign of any odor! My wife has another area of the yard to plant flowers and the kids have decided to stay... for a little bit longer anyway.

Electric Operating Costs Amps x volts (115 or 230 volts)
= watts x hours per day of operation ÷ 1000 x cost per kilowatt hour Koenders Electric Aerator:
-- 1/4 Horse power Energy Efficient Motor
-- Maximum 2.5 amps | operates at 1.75 amps x 110 volts
-- Less than 0.40¢ per day | 365 days x .40¢ = $146.00 per year

By Patrick Udeh, Ph.D.

1.0. Definition of Aeration: Aeration may be defined as the process by which a gaseous phase, such as air and water are brought in contact with each other for the purpose of transferring volatile substances to or from the water. These volatile substances may include, but not limited to oxygen, carbon dioxide, hydrogen sulfide, nitrogen, methane, Trihalomethane compounds such as chloroform, dibromochloromethane, bromodichloromethane, bromoform and other VOCs, as well as various unidentified organic compounds responsible for taste and odor.

2.0. Uses of Aeration: Aeration may be used in water treatment for the following reasons: ß Use for a air stripping of odor causing compounds (taste and odor) such as H2S, NH3, and CO2 ß Used for air stripping of volatile organic compounds (VOCs) such as Trihalomethanes (THMs) from water ß Used to precipitation of inorganic contaminants such as iron and manganese (oxidation of Fe and Mn to form insoluble oxidize that precipitates) ß Used to removed radon and silver. ß Used for water stabilization and disinfection

3.0. Types of Aerator: There are several types of aerator, namely: 1. Waterfall aerators, which may be spray nozzles, cascades, or multiple trays 2. Diffusion or bubble aerators, which bubble compressed air through the water, and 3. Mechanical aerators, which employ motor driven impellers or combination air-injection devices.

4.0. Limitations of Aeration: The greatest application of aeration is absorption and release of gas such as O2,CO2, and H2S. This may render some water to become corrosive.

5.0. Recommended Aerator for well water: Diffused or bubble aeration is recommended for well (tank) water. The process consists of contacting gas bubbles with water for the purpose transferring gas to the water or removing VOCs from the water by stripping. The process can be carried out in a tank or clear-well. In bubble aeration, it is assumed that 1) the liquid phase is completely mixed 2) the gas phase is plug flow 3) the process is at stead state, and 4) the inlet VOC gas concentration is zero. The existing air is in equilibrium with the bulk liquid, which is for the minimum air-to-water ratio for bubble aeration. The minimum air-to-water ratio represents the smallest air-to-water ratio that can be applied to a bubble aeration tank to meet the treatment objective.

6.0. Do we need aeration in our systems? And if so, why is it required?: Yes, aeration is required in our systems for the following reasons: ß We have high THM levels in some of our systems ß By 2006, each monitoring system will have to meet the prescribed 80 ppm MCL, rather than averaging all systems in order to meet the required 80 ppm MCL and ß We have taste and odor problem in some of our systems, evidence from water quality customer complaints.

7.0. Are we sure for certain, that the problem with the THMs and taste and odor could be resolved by the use of aeration? Yes, based on previous works, past and present literatures, aeration can be used to remove THM compounds such as chloroform, dibromochloromethane, bromodichloromethane, bromoform, and other VOCs. Nevertheless, the distributor, Malibu Water Resource, has volunteer to provide us with their "Koender Electric Aerator System" for trial, which means we could use this system for pilot scale studies.

8.0. What is Koender Electric Aerator System? This is a bubble aerator, specifically made for well waters, which is stored in tanks or clear-wells or reservoirs. The system consists of inlet and outlet zones, and air compressor, which are used to bubble compressed air into water. This aerator is powered by a _ horse power (110 AC) energy efficient electric motor. The system is designed to produce 1.5ft3 of air per minute at 5 psi pressure with a maximum 35 psi.

9.0. How much does Koender Electric Aerator System cost?

Koender Electric Aerator Package(1.5 CFM) = $ 500.00 plus Shipping Electric operating costs o _ horse power energy efficient motor o maximum 2.5 amp/operates at 1.75 amps x 110 volts o Less than 0.40¢ per day i.e. 365 days x 0.40¢ = $146.00 per year