Chlorination after Installing a Well Pump

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I am planning to install a well pump in a water well in a rural area which has no other water source.

Should I perform shock chlorination in order to avoid Coliform bacteria contamination or should I test the water for Coliform bacteria after installing the pump and react only if the test is positive?

How do I best approach the installation and maintain water quality?

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30 Answers

  3. After well has been constructed (assuming proper encasement and sealing has been made) chlorination is done on line prior to distribution.

  4. collect sample after dewatering entire water from well to study quality.The probable sources of bacterial contamimation shall b identified 4 elimination if possible

  5. The short answer to your question is Yes.  However, as some have already mentioned more information is needed.  I do not believe this is a treatment question as many others have assumed, but that would be a next step.

    Is this well intended for single private household usage?  Additional requirements may apply for commercial or community usage.

    What are the well construction details?  Dug/drilled/bored, casing type and integrity, annular seal integrity, well surface condition?  Basically is the well protected from surface contaminants (surface water entry, animals/insects, vegetation intrusion/tree roots, etc.)?  This is essential to prevent ongoing bacterial contamination.

    Has the well been used regularly or left abandoned for an extended period of time?  If the well has been sitting for a while the water within the casing is likely to be stagnant.  Install your new pump and run it for an extended period to develop the well.  You will want to do this even if the well has been used regularly, as introducing your new pump will stir up the water column.  Ideally you should run the pump until the water is clear, which could take several hours. If your well has poor recovery be careful not to run your pump dry.

    Once you have sufficiently developed the well, yes, complete the shock chlorination process.  I'm not sure where you are located, but in Canada there are several guidance documents available on the proper procedures.  Generally you add a calculated volume of chlorine bleach based on the well dimensions, run your pump (and household taps if connected to house) until you smell chlorine, allow everything to sit for 12-24 hours, and then flush water to an outdoor area where it can infiltrate into a non-sensitive vegetated area (NOT to a septic system or surface water feature) until chlorine dissipates.

    Once chlorine has been fully flushed from the well (free chlorine residual

  6. Better to get the water tested first to see the amount of bacterial contamination. After that you have to go for online continuous dosing until you get the bacteria free water from the source. One time shock chlorination can solve the issue for some time only.. This is my opinion.

  7. Hi Bojan. Seems you have received many correct answers below. 

    If possible filtration is the best way to reduce organic matter that acts as a food source for bacteria. Water is also seasonal so the analysis you have now could change in future but regardless is important.

    After filtration you could look at a storage tank for the water and place a UV-C light in the tank. The problems with inline UV-C is that the lamp needs 15-20 min to heat up and have enough UV-C emitted on the passing water.Always remember that about 1/3 of the wattage is UV-C and wear protective eyeware.

    www.ozoneuv.co.za offers many chemical free water sanitation methods. 

    Please see attached spec sheet on the Sani Submersible UV-C 

  8. When testing the borehole it is necessary to run the borehole for a suitable period to waste first so that the sample is representative of long term production. Typically without doing this the metals such as iron will be higher, turbidity elevated and there may be contaminants resulting from the well drilling.

  9. First of all, you ​analyse water for detail analysis for heavy metals bacteria, Hardness & total Coliform. You can use cheap Solar Water system, that is approved by TUV for producing mineral drinking water. For pathogenic microorganism’s chlorine, chlorine dioxide, and ozone are used. Chlorine tablets are also used. physical disinfectants include ultraviolet light, electronic radiation, and heat are also used.

  10. Normally in a none contaminated field, a bore water is sufficient to be treated by chlorination or combined with a MF filtration. If it were contaminated field, it would require a RO polishing.

     

    The chlorination in a remote area can be normally treated by a tablet dissolving system with more than 30 minutes contact period. The dose rate should be to guarantee a free chlorine at approx. 0.5 ppm in the water.

    1 Comment

  11. Firstly there is the issue of needing an analysis to base decisions on. If there are coliforms present then it is likely to need rather more than shock treatment and something more continuous.
    Then there is the installation of the pump and pipework. This should be flushed out and shock chlorinated to ensure that contamination that may have entered while it was in pieces is removed.  

  12. You will often get a lot of conflicting advice on how to treat a borehole.  The analysis is not optional but absolutely essential, not only for the bacterial content but the physiochemical content.  There may be metals in the water such as arsenic, which will require one form of treatment, there are boreholes containing iron or manganese, which will require oxidising prior to specialised filtration using green sand, base iron removal or fylox.  There may be suspended solids present which may be filtered, and the pH may need to be corrected if it is acidic.  Filtration may well help reduce any bacterial load in the water.  If there is a significant bacterial content, then it should be pre-filtered to assist in bacterial removal.  Dryden Aqua have produced a filtration media AFM, which works like sand but doesn't get colonised by bacteria.  UV is very good at reducing bacterial levels and will kill protozoa such as Giardia or Cryptosporidium (which should be pre-filtered first) but there is no residual effect so bacteria can grow in the water on storage.  If there is iron or manganese present then chlorination may be used as an oxidant, I haven't successfully used ozone, but there needs to be a reaction time between injection and filtration.  Chlorine is effective at controlling coliforms and many bacteria at relatively low levels on clean water.  The starting point is the analyses.  From there, you will know what needs removing.  It will also dictate how the water is treated and whether further treatment is required to control corrosion in the pipes.   

    Answered on by

  13. We need more information on the construction of the well and the method, and type of pump for installation. Is this a hand dug well? Is the well sealed or subject to surface water intrusion? You can do all the testing you want, but first must ensure the integrity of the well.

  14. Dear Bojan,

    Definitely you need to analyse water if it is for human consumption. I suggest at least Total Coliforms, heavy metals and hardness. If water is hard you will probably have carbonates precipitation in the downstream. Also I recommend a brief analyse of your well ¿How depth it is?  Do you have any potential source of impact in the aquifer (septic tank? for example?)

    If it is located in rural area you may chose an easy and economic alternative...I agree with TUV, however everything will depend on your analytical results...groundwater is normally free of coliforms or other if the aquifer is depth enough and no impacted by external sources. 

  15. Firstly, you should take sample of your water at the source then have it tested for possible pollutants ( eg. heavy metals,...), then from the result you will know whether a kind of treatment is needed before distributing it. however if water doesn't contain any pathogen or harmful substance and yet it has to pass through a pipeline from the source to the end users, you will need to either do the chlorination to help the desinfection along the distribution line just in case any pathogen get into that network is deactivate and leave the people safe  or you can use the TUV to achieve the same results.

    Have a nice day.

  16. Better get it tested before any chemical treatment 

  18. You can use the cheap Solar Water device, that is approved by TUV for producing mineral drinking water from any kind of sources, no maintenance, easy use, 20 years life span, and 100% natural process. Please ask me if u need more infos

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  19. Get your sample tested first for Ecoli and chemical analysis so that you can determine your dosage requirements,I would advise super chlorination of the well for 24hrs then pump this water out then continue on with dosing of chlorine making sure FAC is at 0.3-0.7mg/l

  20. Hi Bojan,

    I suggest you perform a microbiological and physicochemical analysis of the raw well water before installation of the pump. If the results are friendly (safe), you can instal the pump and do your simple disinfection. If the results are not very friendly (unsafe water), you might need to instal other simple treatment equipment (like multimedia filters, etc)  that can rid the water of the contaminants. Very important if the water is for drinking.

    Regards

    Justin

  22. In my experience it is standard to shock chlorinate following the pump installation. In some places, depending on permitting, it is also required that the well water pass 2 consecutive bacteria tests. In any event, one follow up bacteria test after the chlorine is run off should be performed.

    1 Comment

  23. Standard procedure in the US well codes is to follow all well pump installations with shock chlorination. This is considered a preemptive measure in case the water was contaminated during the installation process. Once the chlorine has been flushed out, sample for coliform to ensure potability. 

  24. If for human uses, It is Ok to do shock chlorination, what is more important to be sure that the storage and distribution facilities to be disinfected too.

    Be sure no one will use water unless free Cl2 in the acceptable level for human uses.

  25. If you control the well then now is a good time to NOT ever add chlorine. For the filter system a simple Muslin or cheese cloth will take care of micro particles. If any pathogens have been identified in the  water then creating a self made 2 layer of muslin or cheese cloth with Archaea microbial species in a bentonite clay.  We have been using for 40 years and ZERO pathogens on any lab tests.  (in case some are unaware. chlorine kills bacteria. this means you and your stomach "normal gut flora". People become sick, diabetes, cancer, asthma, and many more.  Healthy water, healthy soil, healthy produce, = healthy people. ).  The country of Columbia is using this type of materials for the jungle people. Manufacturer is from the country of Taiwan. Your future is in your hands. Make a wise choice! 

    2 Comments

    1. Cloth filters are better than nothing, but not much. If the pathogens are bound to particulates there will be some removal. Unfortunately, bacteria, viruses and most protozoa are much too small and will pass thru the cloth. Would you trust your life to a cloth filter on a contaminated water source? So, use the cloth filter to reduce turbidity somewhat, then chlorinate with bleach. You probably do not need much after the initial shock treatment, probably less than 1 ppm, unless the water has organic carbon that will react with the chlorine. You would want to leave enough residual chlorine in the water so that it will continue to be safe during pipe transport and storage.

      1 Comment reply

      1.  I appreciate you following protocol Joseph. Sometimes a point of clarification is in order. Are you aware cheese cloth is and has been used in the scientific community for decades.  (filtering of cows milk and others).  As you correctly pointed out that some microbes are too small (even for micro fine cheese cloth). This is why the second choice is to devise a 2 cheese cloth and Archaea membrane. As most microbiologists know nothing survives in an Archaea matrix.  At .5 to .005 microns it can out compete for the food source and other microbes will die off. Then they become food for the Archaea.

    2. I assume this is a joke.

      2 Comment replies

      1.  Sorry Joseph: Working with the leading scientists of the world I find it easier to work with discoveries from nature than inventions of man.  I do understand it is extremely difficult to break through the chlorination cartel. Chlorine does one basic biological function. It kills everything in its path. High or low concentration only a matter of time.  I did not glean this information myself. It was the worlds leading microbiologist Dr Carl H. Oppenheimer. He discovered natures biggest secret. More important than the discovery of fire. RNA microbial group. He named Archaea back in the 1940,s. I share this information freely. This was a promise I made to Dr O. per his request.  He was a firm believer that all knowledge should be shared. His most famous quote was "information is free, product you have to buy". I never joke. I think you would agree the condition of the world is not a joking matter. I have no malice towards anyone. Happy and willing to share. If you wish to learn please use my office email  biozomesales@biozome.com  If you skype: guy_mcgowen.  Another Oppenheimer had it right.  "Learn or die"  My translation of this is "learn to thrive not just survive".  Joseph, you would do well to follow and learn from Trudi.  She is a very bright very young lady that will be here long after I am gone.

  26. Hi Bojan Bosanac,

    What is your aplication:

    - drinking water?

    - for whom? family, comunity, city?

    - who is going to be responsable for the instalation? do you have someone?

    - Do you have energy?

    I recomend that you analise  water quality first, sinse you are in a rural area.

    If ir is a small intalations and just for your family use, you should choose a simple and easy solution. Otherwise you should give more information.

      

  27. Install an UV system ( nowadays not costly anymore)  is less headage for users, less maintenance costs compared to chlorine systems.

    Keep storing capacities of watertanks as small as possible since this is a source for bacteria again.  

    feel free to contact us at info@dutchso.nl, we have built several drinking waterplants in Africa and Middle East region   

  28. I would recommend, chlorination before pump installation. Cl destroys pump parts. Then setup the treatment system best adapted to your situation.

  29. If the water is for potable use, then the cheapest option is to install an ozone injection system on the delivery side of the pump. Normally this is done after the settling tank and before the buffer tank. This is a lot cheaper than chlorination and has no associated health risks. We never use UV or Chlorination in rural areas, as the found lack of maintenance makes such systems fail.

  30. Dear Bojan. Chlorination is used for disinfecting pipe networks but it can be used to deal with Coliform bacteria. In a case of well contamination, you can do well disinfection and monitor future state of bacteria and then occasionally repeat the process. If you have constantly bacteria in your well, then you should provide continually disinfection. Did you consider UV system as Chlorination systems can be costly and require regular maintenance.