When we reconstructed our house, we decided to reuse the existing sewage connection, after being fed up with the bribes that need to be paid to the councillor and other metro water officials.

Since this is an old line, it was more than probably 10 feet underground and we had the option to either make the sewage chamber deep enough so that the outlet pipe enters horizontally into the chamber or make the chamber less deeper, and use a bend to make the outlet line enter vertically into the chamber.

Having heard of labourers getting asphyxiated when entering sewage chambers to clear a clog, I decided to go for reduced chamber height with a vertical pipe for the remaining depth. This unfortunately was not the right thing to do, as clearing any clog becomes difficult. Even if the chamber is deep, if the outlet pipe is horizontal, there is sufficient bend radius for the clog clearing rod to be inserted. This is due to the wider area of the chamber vs the small radius of the pipe.

In 2024, we ended up with our first clog with the sewage overlowing from the chamber during heavy inflow during the mornings. Initially, we called a few private people, on the recommendation of a metro water worker, who regularly visits houses to add chlorine to the water sumps. They unfortunately did not have the right tools and were not able to do clear the line.

Next we went to the local metro water office, where there is a register to enter complaints about blocked sewage lines. We added the entry there and the worker on watch helpfully gave chlorine tablet to add to overhead tank. The sewage workers came in two days and said, since the block is in the line to our house we had to pay them separately for the work. With the situation we were in, we agreed to pay what they asked.

On hearing about the vertical pipe in the chamber they complained that this is going to be difficult and said the pipe should have been horizontal. On hearing my worry on the depth that the chamber had to be for a horizontal pipe, they said, "Why do you worry Sir, however deep the chamber is, we will enter it to clear the line". Given our predicament, we asked what the options were.

They asked for a big waste cloth. They screwed it on to the segmented rod that they use for clearing lines. Now using the cloth as a plunger, they inserted it into the pipe. The pipe was under a few feet of sewage that was standing in the chamber. Now, they used a pumping action to oscillate the water in the pipe which miraculously dislodged the clog and the water began to drain.

After a week, we saw sewage, once again, stagnate in the chamber and panicked. Given that it was not sustainable to call the sewage workers every week, I decided to try my luck myself, with the additional knowledge that I had gained.

My theory was that, the clog was due to fat deposits that had not fully dissolved and had once again coalesced to reduce the flow. I had read about Sodium Hydroxide aka Caustic Soda beind used as a chemical agent to dissolve fat deposits clogging sewage pipes. This costed around Rs. 90 per kg vs Rs. 500 per kg for something like Drainex. I added around 1 kg of caustic soda and a bucket of hot water to the chamber. After around 6 hours water drained from the chamber.

Hopefully I can maintain the sewage connection for life without having to get a new one.