Back to Banjiram

Goggle Earth Image of Banjiram and the location of the taps. At the end of the blog is a view wider view.

My idea of by-passing the tank and pressurizing the water line to get water to flow at the remote taps was a little off base We went back to Banjiram last week to check out some details. One of the main items was to find the specifics of the pump data from the pump box. The box is gone. Someone had a use for it so it was taken out of the storage room and the paperwork is gone. Another was to check the actual distances the water had to travel. I was told 75 meter to a junction and then 150 meters in two directions to the remote tap stands. Actually it is 160 meters and 200 meters. These lengths make my idea not feasible except if you wanted to take 10 minutes to fill a 20 liter container.

Tank outlet configuration

 The next thing was to see what was buried underground. Once we had finished digging up the connection of the tank outlet to the remote taps Yukubu showed me the picture he took when they buried them. This is the pipe coming down from the tank outlet. The 2 inch pipe has two elbows to get around the foundation and underground it has a Tee. The right side stays at  2 inches and only goes about 6 meters where it goes into the School Tap Stand.

School Tap Stand with school in background

The school does not want the people from the town coming to the school to fetch water. They have allowed their borehole and tank to be used to supply more people in the village but they built two remote tap stands closer to the homes.

The picture on the left is the North Tap Stand and on the right is the South Tap Stand. You can see the school and the tank in the background of the North Tap Stand. Notice there are pots only lined up at the end two taps at the North and a well worn path to the school. The South Tap Stand has  buckets at all of the taps but mostly on the north end where the water comes in. The North Tap Stand is actually up hill from the school and the south is slightly down hill. We did an experiment and turned off all the taps at the School Tap Stand and we opened the tank. All the taps at the South got water. Only a little water on the North. Based on my hand level I am guessing the North Tap Stand is 2.5 meters higher than the borehole.

The two remote taps stands get little flow when the school tap stand is open. Resulting in people walking to the school every afternoon to fetch water when the tank is opened at 3:30.

I spent much of the weekend and Monday doing manual mathematical modeling of the piping system trying to come up with a solution that will work. There are also village politics involved. My best solution would not work because the farmer who owns the field will only allow one trench through his field. He had to be convinced to even allow one. He has a tractor plow his field. The plastic pipe will not withstand a plow hit.

Here is the solution I am currently proposing. We will still use a new pipe to by-pass the tank and pressurize the pipes with the pump. This should add up to 2 more meters of water pressure. But the 2 1/2 inch by-pass pipe will now continue down the trench along side the existing 1 1/2 inch pipe and go all the way to the north end of the North Tap Stand and connect there. In my models this solution started to work at a 2 inch pipe. But there are several unknowns that I could not put into the model. The exact elevations is one and the capabilities of the pump and pump controller. This was the first time since college I have run mathematical models by hand. Fortunately, I found a website that would calculate pressure drops for me. I several liters of fuel in my little generator while doing it. I ran the calculations for around 10 different combinations of pipes. If someone like me shows up in the future and sees the way this is piped, they will wonder "What kinds of drugs was the this guy on, when he decided to run the pipes like this?".

Just tot he south of this Google Earth Image is the dry river bed where much of the town gets its water by digging.