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My under ground sump (9 x 7 x 7.5 ft) comes under living room with man-hole outside of the house and planning to have partition wall at mid 7ft . Sump is constructed by brick wall 9". Due to space constrain 3' 3" my contractor say to go with single brick wall 4" partition wall at mid. Please let me know its would be issue for later time.

1. Do I need to take care since my sump slab coming under the ground floor living room. My neighbour is suggesting to go with Cranking rod for RCC slab.

2. I'm using IWP (Integrated water proofing liquid) Fosroc liquid bonding for cement mixture. I heard wall surface water coating will be effective. Let me know which water proofing we can go different application like sunken slap, tank, utility area..

Thanks,
Pradeep

RCC sumps are the only solution to a efective waterproof storage. Brick wall sumps are never durable, inspite of any waterproofing solutions, primarily because those waterproof solutions do have a life expectancy with them, unlike RCC, which is life time guaranteed !!

Do you want to have a partition wall inside the sump??? WHy would that be necessary??? If i understand your question correctly....you forsee that the RCC slab over the sump, would not sustain the weight of the brickwall???

As you told RCC sump could be effective in all means but for me the constrain is with high cost factor. Also my contractor told me, soil strength around the sump is good enough to bear the load. Also the hydrostatic pressure towards the inner wall of the sump is considerable less considering my water capacity.

Actually I'm going for partition wall in between sump to have bore water (Not good) at one side & BBMP water (Later one day kaveri) on other side usage. I went to this option for water usage feasblity.

today they have raised sump with brick wall, any one can throw light on good water proofing for inner wall surface either plastering cement mixture or wall coating after cement curing done.

Pradeepcr
I have noticed in many houses that they directly pump the borewell water to the overhead tank and only store the cauvery or BBMP water in UG storage for subsequent pumping. What are the benefits of storing borewell water in UG and then pumping to overhead?.

Thanks,
Selva

Selva,

Its true. It depends upon few factor depending upon the bore depth,the yield capacity, pump rating, number of bends till OHT, power fluctuation in that area one will go with pumping directly to OHT. In my case bore depth & yield could be issue I foresee, anyway I'm planning to have two connection one to OHT & to sump controlled by valve. If my sump yield or pump fails to lift water to OHT, I will redirect bore water to sump and then pump by 1HP motor. bore pump after reaching the ground level needs to reach OHT with one or two bends, bends really matters for high depth bore pump considering it efficiency.
This my little consideration for going with bore water directed to sump.

-Pradeep

Friend.....if someone gives you a reason of not being able to pump water to OHT due to power considerations, you have been severely misquoted. We are only talking about the additional 30 feed in case yours is a G+2. The number of bends do not matter for the HP/ Stage considerations. There could be numerous horizontal bends.

Yes, I do agree with you that in case your sub pump fails, there is a storage water in the sump which can be pumped to the OHT separately, till the time the sub pump gets repaired. I am too working with this similar arrangement.

Thanks for your replies. It is indeed good idea to have a valve controlled connection to the Sump in addition to OHT for borewell pipe to take care of unforeseen scenarios. As far as pump efficiency is concerned, the Texmo pump dealer said it is advisable to consider a pump efficiency of 85% while choosing the pump. For example if the bore depth is 850 feet, then the motor should be chosen with approximate capacity of (1000 feet + building height.)

pradeep,

Borewell water can be pumped anytime at your convenience. Whereas Kaveri water is precious and comes on alternate dates in the south & West Bangalore and there is no time line in rest of the city. So utilise full sump space only for BWSSB Kaveri Water. Instead of partitioning the sump for borewell water, you can invest little more money and get a higher capacity pump itself, so that you can directly pump to the OHT.

Moreover, over a period of time or if the construction quality of sump is not that good, how do you control the seepage of borewell water with kaveri water within the sump ??

Thanks for your sharing your perspectives. Really it helps to rethink my option.
I have planned to go with single sump only, having Bore, Kaveri, CMC connected to single sump.
If my bore fails to pump to OHT, I will have control valve to directing water to sump and then pump to OHT.

-Pradeep

Hi,
I have my borewell pump(50 stage, 4hp, texmo taro) installed at a depth of 900 feet and the bore yield was 1.5 inch. I have connected a 1inch plastic pipe on the outlet and the water pressure was quite high at the ground floor level. Now as the construction has advanced to the second floor, I notice that the water pressure has reduced noticeably when the outlet pipe is extended up to the second floor. Will the water pressure drop further if the over head tank is say built at G+ 4 level. Did any of you face this issue and any solution for this?.


Regards,
Selva