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Friday, January 18, 2013

Complete Guide on New Borewell Drilling AtoZ


How to identify a suitable site for borewell?


Vertical Electrical Sounding is one of the very common geophysical methods used for domestic borewell exploration. However, sufficient open area around the location is needed for conducting the survey. Geologists charge around Rs.1,500 to 5,000/- for identifying a borewell site. Other methods of geophysical survey are used in special cases and they are quite expensive.
Local well diviners who use wooden sticks or magnetic blocks are also to some extent successful in identifying borewell sites. But this method may not be always reliable, especially in areas where the geological formation is critical.

Is there a best suited time for drilling a borewell?

As such there is no prescribed season for drilling a borewell if the location of site has adequate ground water potential. However, identifying a suitable site and drilling the borewell in summer months would give the worst possible scenario in the location at the point of time. Therefore, summer months are usually preferred by some experts as the best suited period for drilling a new borewell. Also, as most agricultural sites can be accessed by drilling rigs only during summer months, they are usually available in these periods.

What are the common methods adopted for drilling borewells?




Methods of drilling to be adopted depends on factors like suitability of a method for a particular type of geological formation (i.e. such as alluvial, bouldery and hard rock), cost factors, diameter and depth of borewell and the purpose intended.
Most commonly used types of drilling methods are;
Water Jetting - Shallow bores in alluvial formations
Augur Drilling - Shallow bores in alluvial formations
Calyx Drilling - Shallow borewells in both hard rock and alluvial formation
Percussion Drilling – Deep bores in bouldery formation
Rotary Drilling - Most common method used for drilling large and deep bores in alluvial formations.
Down the Hole Hammering (DTH) Drilling – Most common method for drilling large and deep borewells in hard rock formations.

What is the standard diameter of borewells drilled for domestic purposes?

For domestic purposes, 4.5 and 6 inches dia borewells are usually drilled. While 4.5 inch is most commonly drilled borewells for domestic purposes, 6 inch borewells are drilled when higher yield is required for large apartments or buildings and also for agricultural purposes. Initially larger diameter bits are used to place the casing pipes up to the hard rock zone prior to drilling specified size of the borewell.

How charges for drilling a borewell are usually calculated?

Charges for drilling a specified size of borewell include
drilling cost per feet,
cost of casing pipe per feet,
cost of drilling and installation charge for casing pipe per feet,
flushing charges per hour for flushing the borewell after drilling and
transportation charges of the rig to the site from nearest town per km.

Drilling rates are sometimes charged in slabs for specified ranges especially when deep borewells are drilled. As drilling rates usually vary depending on the availability of rigs, local demand and site conditions, it is better to cross check with few drillers to get a competitive quote.

What are the types of casing pipes used in borewells?

Currently, PVC pipes are very widely used as casing pipe. GI/Mild steel casing pipes which were used earlier are not being recommended due to the problem of corrosion. PVC casing pipes installed in borewells must confirm to IS 12818: 1992 that governs the specification for unplasticized PVC screen and casing pipes for borewell of the Bureau of Indian standard. This standard covers the requirements of ribbed screen, plain screen and plain casing pipes of nominal diameter 40 to 400 mm produced from unplasticized polyvinyl chloride for borewell for water supply.
Slotted PVC casing pipes are used if aquifer yields through sandy zones to protect collapse of borewell side walls and to prevent entry of fine sand into the borewell which might clog the borewell. This requires detailed study by Geologists to decide slot size and at what depths these have to be provided along with gravel packing around the casing pipe.

What is the safe distance between a borewell and septic tank/soak pit?

Maintaining sufficient distance between a borewell and septic tank is always recommended as there are chances of contamination. If the situation warrants location of them in close proximity, it advisable to properly grout the borewell casing pipe with cement slurry till hard rock formation. In shallow aquifer zones, it is not advisable to locate borewells used for drinking purposes and the septic tank in close proximity. It is better to take professional assistance in such cases to take preventive steps around the borewell as well as the septic tank.

Normal rate:

6.5 inch bore

0-250 feet -> Rs 62
250-350 -> Rs 72
350-450 -> Rs 82
450 - 550 -> 92
550 - 650 -> 107 (Rs 15 increase)
650 - 750 -> 122
750 - 850 -> 137
850 - 950-> 157( Rs 20 increase)
950 - 860-> 177

MS Pipe(7inch dia , 2.5 mm thickness, 6Kg per cmsq strength) -> Rs 320 per feet
(3 diferent thickness: 2mm-Rs.270/ft,2.5mm-Rs.320/ft,3mm-Rs.390/ft)

PVC pipe(10 inch dia) -> Rs 300 per feet (Starts from Rs.200/feet)


MS Collar and Welding charges per joint - Rs 300 (150 for collar and 150 for welding) (every 20 feet)
61/2" Dia cap 100

Labour and Transportation charges Rs. 1000

For 950 feet bore it will take 2 days

Selecting Pump:
First read this:
How to calculate the HP of the water pump


You might have found that there are only two variables required to calcuate the water pump HP. 1) height of total lift of water 2) required flow Please take total height in meters and flow required in liter per minute. now multiply height(in meters) and flow (in liters per minute) now divide this by 4500 you will get theoretical HP of the pump.
Now there is a secret to calculate actual HP of the pump In my practical experience i did not find pump efficiency more than 30 %. In most cases it is less than 30 %. So to calculate actual HP you should multiply theoretical HP by 4. Actual HP is 4 times more than theoretical HP.
Second secret, Please calculate total suction lift from pump to sump bottom. please ensure water pump is capable of producing so much suction.
Third secret, please add 20 % to your actual height of water lift. These are called frictional losses.
Fourth secret, submersible pumps are more efficient than monoblock pump.
Mono block pump -usually Rs.15000(1.5HP)

Submersible Pump-Usually 25000(1.5HP)

Tips:
1. Try to find 3 phase availablity in your street.
2. Do you require really 3 phase or single phase pump KW ( 3 phase deposit is higher than Single phase, I think for monthly bill be same for 3 phase or Single phase). Check with pump expert.
3. Speak with nearby house people having bore, to know about water availablity during summer. (Which helps to select the pump) Sometimes, if you go for higher suction power motor and if your bore can't yield for the motor capacity it will be problem.
4. Anyway have pipe routed to Sump & OHT with control valve. It will helps during summer time, if your bore or pump losses it efficieny.
5. Try to avoid number of bends at delivery line from bore.

Please place the borewell motor at 20 to 30ft from the bottom point of the borewell in case if the yield falls down too u will not face a problem in the water supply. if you place at 400 ft and yield is less in summer then you have to rework to down the motor further and if motor runs without water there is a risk of motor failure.
As one time effort place the motor at maximum best point. Dont look at the pipe and wire cost, Do it right at the first time, Be pessimistic for this work

HDPE Pipe: Rs.63/m (eg:270 feet Rishi brand)
Finolex cable: Rs.60/m (eg:290 feet,20feet extra)
1.5hp 15stage single phase texmo submerged nearly 25000
Total cost for 300 feet borewell 31500(Not for drilling borewell,only pump and installation charge)

Different Pump brands:
Texmo (Best in Industry)
CRI
PEW
Suguna Submersible Pump vs Monobloc pump vs Air Compressor Pump
V-Guard


What is good Water Yield: More than 2" +
http://www.derm.qld.gov.au/factsheets/pdf/water/w4.pdf

Water Tanks (Over head and Under Ground)


Best brand: Sintex
Capacity: 200litres per day is the average consumption of Indian peoples
If 4 people living in a house and every 2 days water need to be filled then 2*4*200 = 1600lires.
2000litre tanks are idle.
Price : Normally Rs.6 per litre.
So 2000 litre tank price nearly 12000

Read complete article on water tanks here


47 comments:

  1. http://carnationconstruction.com/techniques/006-Techniques-WellHouseDesign.html

    http://www.britishdowsers.org/learning/what_is_dowsing.shtml

    http://en.wikipedia.org/wiki/Dowsing

    http://www.groundwateruk.org/Does_divining_work.aspx

    ReplyDelete
  2. Great Article Deepak. I was planning to drill one borewell today. Your information certainly gave more insight and details.

    ReplyDelete
  3. Deepak.. any suggestions or modern methods and cost to dig traditional wells instead of bore well. I do have a half finished well 16 feet depth ( size 6 feet x 15 feet) left unattended but thinking of reviving the well. Any suggestions. Thanks.

    ReplyDelete
  4. hi, deepak do u have any idea of borewell business in african nations??if u got pls send me the info to my mail a/c bharath_nsw @yahoo.com

    ReplyDelete
  5. Hi Deepak,

    I drilled a borewell 5 days back in south bangalore and failed to get any water source.Dtrilling depth was 700ft.many of neibours have got water at 350-400ft.

    The drilling agency owner says that I can still get around 1200 ltrs to 1500 ltrs per day from the failed borewell, he asked me to wait for 5-6 days and then check the water level in the drilled hole, Is this true information?.What is your suggestion on this.

    I consulted a Geologist and showed him my failed borwell point and he said that ' There is no water source at my site(20.0'x30.0' plot) and chances of getting water are very rare.


    Your openion/suggestions are appreciated.

    Regards,
    Abdul Nabi
    nabikm@gmail.com

    ReplyDelete
    Replies
    1. Hi Abdul, You get your borewell point scanned which helps you to determine whether the bore well has the water or not.

      Delete
  6. HI Deepak, this is very very good information you have provided, thanks alot for you information

    ReplyDelete
  7. Hi Deepak,
    This information helped me a lot. Thanks very much.

    ReplyDelete
  8. Hi Deepak,

    I drilled a borewell & I got water at 500 feet however we went up-to 560 feet and stopped, the water level is 2 inches, now I need your suggestion to buy a good pump , we are constructing G+2 building.

    Thanks & regards,
    Naveed
    naveedahmed3418@gmail.com

    ReplyDelete
  9. Really a wonderful ^ detailed information...thanks a lot

    ReplyDelete
  10. Fantastic article. Never thought that this much science is behind it. Cheers.

    ReplyDelete
  11. What is the depth upto which casing is to be provided. How to know if soil is sufficiently hard or not

    ReplyDelete
  12. Great article Deepak wonderful job and its big help for the people.

    ReplyDelete
  13. what is hand drill bore well

    ReplyDelete
  14. Great stuff , Deepak . Itz really A to Z of Borewell. By the way I m also from salem .

    ReplyDelete
  15. Really wonderful article and I am planning to dig one bore well for my plant at Hassan district and this article helped me lot.... thanks Deepak.... if possible what could be cost now? they are telling below mentioned quote;

    75rs - till 300ft
    and after that even 100ft 5rs raising ... is this good deal? casing is 280per feet ... please suggest me

    ReplyDelete
    Replies
    1. Hi - who is yr bore-well contractor as I too want to a bore ( 6") at my estate at Sakleshpur ( Hassan Dist.) and was looking for a contractor - 300ft & with PVC casing - Compressor pump?
      Please reply to - santosh.ferrisprabhu@gmail.com

      Delete
  16. HI Deepak, this is very good information you have provided, thanks a lot for you information
    I also wrote some articles on civil check it on www.multiconstructions.net

    ReplyDelete
  17. Mr. Deepak it is very informative thanks a lot......

    ReplyDelete
  18. Thanks Depak....I appreciate your hard work for putting this article together...very informative!!

    ReplyDelete
  19. I am planning for a borewell of depth 700feet.
    Water will normally come at 250 feet in my area. Please suggest the pump capacity i have to buy. Which is better submersible or outer type. Mail answer to vimalakeerthy@gmail.com

    ReplyDelete
  20. Hi Deepak, Is there any drilling method for borewell drilling of around 1000 feet, under the slab height of 10 ft (Parking area). Mail answer to sivaramaprasad.tv@gmail.com

    ReplyDelete
  21. hi mr.deepak
    v already have a bore in d farm but d water depth has gone down,,, so v r plannin 2 drill further n increase d depth..
    pls help us... how much is it gonna cost... thank u

    ReplyDelete
  22. We digged borewell of depth 300feet and used submersible pump. Now, there is a problem with pump. The technical personnel tried to pull out the pump but failed to do so. Please, advice in the matter at the earliest.

    ReplyDelete
  23. Good info Deepak,

    I drilled a 4.5 bore for a depth of 155 feet on JUNE 17 2014.

    Got water from 100 feet.

    Casing is done for the entire depth.

    I am getting white cloudy water still.

    After consulting the borewell guy, he suggested to add a mix of 250gm powdered alum and 250gm bleaching powder to a half bucket water and pour the solution in the well.

    Is it the correct process?

    Please suggest.

    Thanks in advance.

    ReplyDelete
    Replies
    1. Does the water smell like sulfur? Sometimes the cloudiness is just harmless minerals that can be purified out. The minerals might also be good, if you can stand the taste. Are you doing farm irrigation? bungendorewaterbores.com.au

      Delete
  24. Your information about borewell is really useful. Thanks for sharing this informative article.
    Borewell Contractors in Chennai

    ReplyDelete
  25. Hi All,

    Conventional drilling methods using rigs is everyone aware of.. If your lands near by natural water flowing valley (may be dried up now), you can use your single phase pump and embedd the slotted suction pipe 12 to 15 deep inside the sandy stream bed, you can draw a 2inch of water easily.. which we have successfully executed near kunigal on bangalore mangalore highway..Shivakumar BT 9008103425

    ReplyDelete
  26. Good information. Please collect more information and publish. Keep up the good work.........

    ReplyDelete
  27. Deepak bhai, excellent description to give a view to layman. The prices may slightly vary from place to place. All together good ....

    ReplyDelete
  28. I drilled a borewell & I got water at 180 feet however we went up-to 204 feet and stopped, the water level is 1.5 inches, now I need your suggestion to buy a good pump

    ReplyDelete
  29. Hi Deepak,
    This Blog has very useful information for a naive user about borewells drilling .I am planning to drill two borewell for agriculture for a depth of 250 feet . Please suggest the horsepower of the motor that i need to buy and use it for two borewells . Please let me know if i need to go for mono block pump or subimmersible pump . Please reply to r.rajeev.1229@gmail.com
    Thanks
    Rajeev

    ReplyDelete
  30. Hi deepak,

    Today I had geological test, he said water is available after 1000 ft , and only half inch available. I am planning to construct 4 floor building with 15 families . will that be enouhf water for us, please suggest.
    A
    Mail me on er.abhay66@gmail.com

    ReplyDelete
  31. Please sugges anyone. Any help will be appreciated.

    Regards,
    Abhay
    Er.abhay66@gmail.com

    ReplyDelete
  32. nice initiative deepak , thanks for your time for blogging this

    ReplyDelete
  33. There is lot of articles on the web about this on topic of .But
    I like to give you more,although i found one that’s more dateils.It's rather a nice useful little bit of information.

    water drilling contractor quotes

    ReplyDelete
  34. Thank you, its very useful information Mr.Depak.
    by Aravindan

    ReplyDelete
  35. in my site i have 1000Ft bore well. based on my requirement i selected 10hp 30 Stage TEXMO V6 model pump.
    and now i have to do pipeing for that so can i go with HDPE or some thing else?
    please do reply soon.
    thank you.

    ReplyDelete
  36. Where and how do I get geological test to drill a new borewell in my farm land in the region on north karnatak.. Can any one pls elp me with the gelologist contacts. We have huge scarcity of water. Kind help is needed. Thanks, manjunath

    Mail: manjugornal@gmail.com

    ReplyDelete
  37. Thank you. Good job

    ReplyDelete
  38. Can you tell me the geologists who can able to found the ground water in and around salem or sankagiri?
    If so send me their contact details to kesavanmarkkandan@gmail.com

    ReplyDelete

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