Soak pit in an apartment in Chennai,TN getting filled quickly and overflowing - What can be done to solve the problem

I live in Chennai. The apartment has 4 flats(2 in ground floor, 2 in first floor; 4*4 members) with a single soak pit. This single soak pit is to collect the waste water from kitchen.  The existing soak pit is circular and is of 5 feet dia and 4 feet depth. We have a septic tank for collecting human waste.(which is not creating any problem)

Due to space constraint builder had constructed only one soak pit. I'm not sure whether the soak pit has been constructed as per the guidelines or not. But it has been getting filled frequently and requires pumping out every 10 days.

The soak pit is in a common area between my flat and my neighbour's flat. i.e 4 feet away from my flat entrance and 3 feet away from my neighbour's flat entrance door. The new soak pit is planned to be placed near the entrance of my flat.  Also the EB connections(meter boxes very near to ground level) are fitted on the wall at 6-7 feet away from my house entrance.

 My queries are as follows: 

1. Is it possible to increase the depth of the existing soak pit?  

2. Are there guidelines that govern the placement of soak pits?

3. What can be done to troubleshoot and fix the original soak pit?

Please advice,