how do I correct for coliform? : LUSENET : Countryside : One Thread

Our backup water supply is an old,out of service , dug well, which I hooked up w/ a hand pump. But the water test showed it to be high in coliform bacteria. Does anyone know how bad that is? and how do i correct it after i pump the water up?

-- Bob (, November 14, 1999


Coliform bacteria are found in the feces of humans and other warm-blodded animals. These bacteria can enter the water source from agricultural or storm carrying waste from birds and other mammals and from a failing septic system.

Fecal Coliform by themselves are not pathogenic. Pathogenic organisms include bateria, viruses and parastes that cause diseases and illnesses. Fecal coliform bacteria naturally occur in the human digesive tract and aid in the digestion of food.

If the fecal coliform counts are high (over 200 colonies/100ml of water sample) there is a greater chance that pathogenic organisms are also present. Coliform standards for drinking water are 1TC/100ml of water sample. TC-total coliform includes bacteria from cold-blodded animals and various soil organisms. TC counts are normally about 10 times higher than fecal coliform counts.

Diseases and illness such as typhoid fever, hepatitis, gastroenteritis, dysentery, and ear infections can be contracted in waters with high fecal coliform counts.

Pathogenic organisms are relatively scarce in water, hence difficult and time-consuming to monitor difectly. Instead fecal coliform levels are monitored, because of the correlation between coliform counts and the probability of contracting a disease from the water.

Retest your well but first sterilize your sample bottle. Put your glass sample bottle in a preesure cooker for 15 minutes at 15 psi or in the oven at 340 to 390 F from not less than 60 minutes.

If after a retest the Coliform count is still high the water should be treated before use. Methods include: using bleach, 2 drops per quart. 2% tincture of iodine 6 drops per quart. boiling for 8 minutes.

Building a still from a pressure cooker and a length of copper tubing may be an option if you need a larger quantity of water without the use of chemicals.

Good luck!

-- Rich (, November 16, 1999.

Here is some more information for you.

I didn't mean to scare you with the previous posting. Just wanted to let you know why the health departments take the stand that they do.

I have seen very few wells where the coliform levels were very high and that could not be corrected by a method simillar to the following.

The new standard for drinking water is 0 TC/100ml of water sample, not the 1 in the previous posting.

Now for a method that might work for disinfecting the well, but first check with your health department. 1. Pour one (1) gallon of unscented bleach into well. 2. Open all faucets. 3. Run water through a hose back into well, until you smell the bleach coming from the water in the hose. 4. Shut off faucets and hose. 5. Pour one (1) more gallon of unscented bleach into the well. 6. Leave the water system sit for 24 hours. 7. After 24 hours run the water from the well, via the hose to ground, until the chloride level is down to a tolerable level. (Do not discharge the water into the septic system, it will kill all the organisms the are working there.)

Another word of caution - The EPA is considering a drastic reductioon in or possibly an outright ban of chloride and chlorinated organics commonly used today, to disinfect water. many chlorinated organics are either known or suspected carcinogens. Check with your health department, theye may require you to use ozonination process instead.

Talk to local well drillers and plumbers in your area they will generally have a good idea what has been sucessfully used in your area to disinfect wells.

I post more info if I come up with something else.

Good Luck!

-- Rich (, November 17, 1999.

I agree with Rich. The bleach method is used exstensively here in Wisconsin for drilled wells that show high coliform levels. I have no personal experience with dug well bleaching, but Rich's method sure sounds on track to me. As he said, don't run the purging water into your septic system! ! ! GOOD LUCK. DAN

-- DAN (, November 17, 1999.

I got the following email today, so I decide to post my answer.

> What exactly is ozonination, and what does it involve? Is it as >effective as the bleaching method? I've never heard of ozonination >before, and would appreciate any enlightenment you could give me.


Ozone is nature's cleaning agent. After a thunderstorm that clean fresh smell and the brilliant sky are due to ozone.

Ozone (O3) is a gas that is created naturally in our atmosphere when oxygen in the air is exposed to high intensity ultraviolet rays. Both the sun and lightning create the ozone. Ozone is trivalent oxygen - O3 - instead of normal oxygen O2. The extra oxygen atom makes ozone one of nature's most powerful oxidizer with its natural by-product-oxygen O2. Ozone is also one of nature's best bleaching agents, restoring discolored water to its naturally clear state. As an oxidizing agent, ozone is 52 percent stronger than chlorine. Ozone has been the preferred treatment in Europe since 1904 for drinking water. Today, there are over 2500 cities worldwide relying on ozone for their water treatment.

Granted ozone technology has been used for water treatment from more than 90 years, it is still in the pioneering stage. Only recently has it been used in the US, it however is readily gaining acceptance and popularity. Most small ozone water treatment systems use ozone aeration with proper filtration. Ozone must have the correct amount of contact time and filtration in order to effectively treat water. There are established tables and formulas available to calculate that balance.

Methods of Generating Ozone

There are two common methods of generating ozone, ultraviolet light and corona discharge. In the UV system, dry oil-free compressed air (dew point less than -40F) is piped past UV lamps in a quartz pipe and is then bubbled though the water. In a corona discharge system air is passed over arc electrodes. Both of these systems add energy to the oxygen that causes O3 to form.

The UV system has several problems that I believe would not make it ideal for the common homesteader. These being dry oil-free air, quartz piping (not glass pipe, normal glass adsorbs UV). And the effectiveness of the UV lamps decreases rapidly with time.

The corona discharge system uses a high voltage arcing electrical source to add energy to the oxygen. Air is based over the electrode and is then bubbled through the water. The biggest problem is the high voltage, typically greater than 25000 volts, although not much current, typically less than 1 milli-amp.

All ozone systems have a problem of corrosion. The ozone will oxidize metal very quickly. I once saw new 2" sch80 piping corrode through in less than 8 hours, the pipe carried the ozone from the generator to the bubbler system at a wastewater treatment plant.

There are commercial units available, however expensive. Therefore, can one be built?

It seems to me that a corona discharge system would be the easiest to construct and maintain, However, there is a real danger of electrical shock. For safety reasons the arc should be from a high frequency source, such as developed by a telsa coil. High Frequency electricity does not penetrate too deeply into the skin.

-- Rich (, November 18, 1999.

Hello from northern Wisconsin. We had a problem with that in our well when we bought our farm. We had it professionally tested and then use POOL cholorine tablets every 9 months or so. We test it by taking water samples in to our hardware store which charges 15.00 so for us that is peace of mind. And for the past 3 .5 years our well has been safe and clear. So I guess the well man knew something!

-- Kalliope Semasogolou (, December 12, 1999.

Many years ago we bought a house with a well that had been in disuse for at least two years, and the previous owner said that the reason they quit using it was a skunk fell in and drowned. They place also had community water, so they just switched over. When we got there we discovered that the community water stayed off more than on, so we revived the old well. We poured a gallon of plain bleach into it, waited 24 hours and pumped it out, took a sample and it passed with flying colors. We had about 15 feet of water in a 36" wide well. We did make sure to drain off the bleach water away from anything we wanted, such as trees, etc. If the coliform bacteria content is high, it could be from surface water contamination. Some states recommend that you cap the area surrounding the well with concrete so that surface water will flow away from and not into the well. If you feel that is not feasible at this time, you could try just putting up an earth berm around the casing where it comes out of the ground and maybe making trenches so that the water will drain away. You also should relocate any nearby animal pens. If all this doesn't work and you don't want to drink water that has bleach added, there is always the old boiling method. We did that a lot with the community water before the well was usable.

-- A. C. Green (, December 13, 1999.

There are several different types of coliform bacteria. The usual test is for "total coliform", which will give a positive reading if you have virtually any organic material in the water. For instance, a single leaf, or a bit of grass.

Coliform is an indicator species; that is, it indicates that there is a problem insofar as foreign material has entered your well, which means that you have the POTENTIAL for contamination with a pathogen.

By the way, virtually ANY surface water will test positive for coliform, since there are always leaves, twigs, smart pills, etc available to contaminate surface water.

-- jumpoff joe (, January 25, 2000.

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