Question about sump tank (underground)

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Question about sump tank (underground)

Postby sun244 » January 2nd, 2017, 9:52 pm

I have existing sump tank which is small. I want to increase the size of the tank before summer. This tank is currently in use and we want to increase the size with minimal impact to people living and existing tank structure. One of the contractor has suggested digging the earth adjacent to existng sump, build three walls and break the middle wall between new and old structures and finish. This way the tank will be unavailable only during breaking of walls between old and new tanks. My question is, can the existing tank's wall and structure get disturbed while earth excavation and wall breaking work? Can someone please comment? Also, can you please suggest the approximate price for building 8feet by 4 feet sump tank? thank You

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Re: Question about sump tank (underground)

Postby swamy_blr » January 3rd, 2017, 10:31 am


Not sure how much Litres of water is required per day for your existing house, Just assuming 2000 Litres.

My suggestion would be go for Renting the Sintex Tanks (2000 litres 2 nos) for some 15 days. Use this sintex tanks for pumping to Overhead tank and storing the water till your New Sump is ready for use.

Demolish the existing tank completely and increase size of the Tank as per your requirement (You mention 8 x 4 feet and height 7.5 Feet)
Especially for Water Sump, don't go for patch work with Old structure with New structure, there is chance of Water leakage if there is some gaps.

The approximate cost of constructing the Sump is Rs 10 - 12 Per litre (Labour Work), You need 500 - 600 Red bricks and 8-10 bags Cement & 1 Tractor load of River sand. ( Total cost would be around 13K - 15K)


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Re: Question about sump tank (underground)

Postby sudheerkeshav » January 3rd, 2017, 10:53 am

I second with the idea of having a sintex tank and storing water inside that , if you have space , rather than alter the sump tank totally. You will disturb the sump , prone to leakages,

You can have water pumped to your over head , and from there , a pipe to your new sintex tank , .
have a gate valve from your sintex tank to the sump , whenever you need to recharge the sump.


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Re: Question about sump tank (underground)

Postby ardesarchitects » January 3rd, 2017, 7:54 pm

Hi sun
While planning to extend the exiting sump few things to be looked at .
1. You will hit the wall foundation if your existing sump is 3-4' away from external walls
2. Going deeper is also a risk process because it will make the soil below the wall foundation to settle down and there by cracks are formed
3. You can look at using sintex ready made sump tank rather than patching up the existing sump
4. If you have sufficient ground space, Placing a tank above ground is a better option but need to understand that cauvery water may not fill in to the same because of high invert levels
5. IF you are looking at upgrading sump volume to store more bore / tanker water then ground level tank will solve the problem

Ardes Architects and Interior designers

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Joined: May 1st, 2011, 7:10 am

Re: Question about sump tank (underground)

Postby sun244 » January 9th, 2017, 6:28 am

Thanks for all the responses.

Praveen, The tank is indeed 3-4' away from external walls. This is 30x40 site. The current storage capacity is low hence we need to increase the sump size.

I am hearing Sintex readymade sump tank for first time. Do we need to do earth work and place the tank? OR some other process? Can you please guide? Do you have comparison from cost perspective.

with regards

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