Septic Tank Treatment & Potable water treatment...

Septic Tank & Potable water treatment...

Dear Saleem,

We are in receipt of the following enquiry.

(1) The prospect is constructing a house in the outskirts of Chennai.
No drainage system is there. All residents are having Septic Tanks
which is fully plastered (he says it's not a soak pit, but how can it be

so?).

Answer: A septic tank does not soak any water. It is always plastered inside water tight, otherwise ground water will be polluted.

The treated water from the top of the septic tank is sent to drain, and if drain is not available ,than it is sent to a soak pit.

And once in 6 months using lorry they transport the wastewater.

Answer: It means they are not having any soak pit. They are simply using their septic tank as collection tank.

In most of the houses the wastewater over flows in to the road.

The total groud area is 60 x 40 = 2400 sq. feet. He is constructing
Ground + 2 floors with car parking. Totally 5 portions will be there.
At the backside of his house he is planning to grow a garden with a
size of 200 sq. feet.

Ground water is available at 12 feet depth

. Even when they dig to
construct pillars, the ground water seeps in to the pits dug for
constructing the pillars.

The size of the septic tank which he is planning to construct is
10 feet (3 Mtr) length x 7 feet ( 2.1Mtr)width x 7 feet depth(2.1Mtr) (perhaps outer dimensions?)= 3x2.1x2.1 =13.23 Cu Mtr x 1000 = 13,230 Liter.

He says the capacity of the tank is

5000 litres. He is worried about the frequent overflow of the septic tank once residents occupy the portions.

Answer: The capacity of the tank is 13,230 Liter, not 5000 liter. Please find out no of person and per person take 200 liter of water to find total capacity of flow per day.

So if number of person is 15 numbers ( 3 floors with 5 persons of a family per floor)

Quantity of discharge = 200 x 15 = 3000 Liter per day. This is a small quantity whereas the capacity of the tank is 13,230 Liter.

So,DEWATS--- modified septic tank system can be adapted very easilly with the size he is building and please use bacterial culture from one another septic tank for faster start up.

He has browsed the net and uses the term Aerobic, Anaerobic, bacteria
culture, etc. He has also enquired with some suppliers for a solution.

He has read an article 3-4 months back in a magazine about the use
of Bacterial Culture (solution) to completely digest the solid waste in
the septic tanks.

(2) He also wants to solve the borewell problem he faces.

That is when the boreweel or well water is stored overnight, it turns
yellow colour. He wants a solution for this.

Answer: This is the problem of Iron in water. If the quantity of Iron is not much than it can be solved using online Iron filters. If the quantity of iron is high , Than oxidation tanks will have to be built followed by activated carbon filter filtration. Please have a test done on water for Hardness , TDS, Iron, Fluoride and sulphur.

Please tell us the solutions that can be given to this prospect for

sewage and potable water treatment.