Ever so often you meet someone and somehow certain conversations with them
start destroying your perception of reality a small chunk at a time.
After that the only thing that you can do is to pick up the pieces of
your shattered world-view and construct a better model. I've been
fortunate enough to meet quite a lot of these people over my arguably
short lifespan. This is about one such conversation with one such
person. The details of the person have been changed.

The Person

We will call this person Priya. Priya was born in Mumbai. Priya has an
ancestral house in Uttar Pradesh. Priya is nice and funny and smart
and intelligent and kind and all the good things. She visits her
ancestral house about once a year for 2 months. Priya knows a lot
about farming and soil and farm animals etc.

The Event

Me, Priya and another friend went for a trek. I grew up in a city all
my life so I am not used to the "village life". So during this trek I
was asking a lot of questions about village life to Priya. For some
reason that I do not recall now a mentioned that toilets were being
built in the village after Narendra Modi came to power.

This took some time to register. What Priya meant was that toilets
were being installed for the first time since ever. I asked Priya
a bunch of questions. This is how the conversation went:

Me : Toh iske pehle kya hota tha ?

Priya : Iske pehle sab khet me hi jate the

Me : Aurat e bhi ?

Priya : Ha, aurate generally subah suraj nikalne se pehle aur suraj doobne ke bad hi khet me jati thi

Me : Kisi ko din me bathroom jana hua toh ?

Priya : Din me generally aurate bathroom nahi jati. Koi pregnant hota hai toh wo khet me jati hai

Me : Tu kabhi gayi hai ?

Priya : Ha.. bohot bar. Saal me do mahine mai bhi subah subah mug leke chal parti. Ye log generally groups me jati hai

Priya : Abhi toilets banne ke bad log use hi use karte hai, dheere dheere change ho raha hai

Me : Experience kaisa tha ?

Priya : As a kid it was okay. Zyada nahi soch ti thi. But as I started growing up I became more and more insecure. But it was for a short amount of time so I didn't think about it.

Translations

Me : what used to happen previously ?

Priya : Previously everyone used to the farm land

Me : Even the women ?

Priya : Yes, the women generally use the fields before sunrise and after sunset

Me : What if someone needed to use the washroom ?

Priya : Well, generally the women do not go to the bathroo during the day. If someone is pregnant then they use the farm land

Me : Have you ever done this ?

Priya : Yup. for about two months when we used to visit during vacations. Even i used to go to the farm land with these people carrying a bucket of water warly in the morning. They generally go in groups

Priya : After the toilets are being built people use those. Things are gradually changing

Me : How was the experience ?

Priya : As a kid it was okay. I didn't think of it much. As I started growing up I became more and more insecure. But it was for a short period during the year so I adjusted.

All this happened in like about half an hour. It took me some time to digest this.

Being a city-kid i had heard about open defecation in the news and on
the internet but hearing the experience from a person who has
literally wlaked in those shoes is another experience. I think what
bothered me the most was how she spoke about it in a "matter of fact"
way, like it was not a big deal. To me its a huge deal. Even today
almost a week after the conversation I am still thinking about it. I
did some more research into this. Turns out toilet technology is
pretty cool and this problem isn't as simple as "build toilets".

Let's talk about waste disposal

Wikipedia page for Mumbai says that Mumbai has a population of 1.84 crores in 2011.
And the average weight of a humans daily poop is about 500 gms.

So Mumbai produces about 92500000 kgs of poop a
day. (this is a rough estimate because I am not accounting for personal
differences in poop weight and irregular bowel movements). So Mumbai
has to deal with that much amount of waste per day. That is a lot of
waste and that is quite a big problem to deal with.

In a city all this is abstracted away from us so we do not have to
worry about the logistics of poop; all we need to do is flush the
toilet and everything goes away magically. But turns out that managing
human waste efficiently and effectively is a big and an interesting
problem.

The process of human waste management is almost similar in cities and
rural areas. Both the processes involve a primary treatment facility
which is the first stage in the entire process. These are generally
septic tanks in cities. If you live in a city in an apartment
building chances are that there is a septic tank on-site. This septic
tank is the place where the fecal sludge is collected. The idea is to
separate the human from the waste. These tanks generally have a
capacity after which they have to be pumped out.

In rural area the septic tank designs are much more simplified and
they are generally called a pit. The pit design depends on the type of
toilet that is used. For example if we are talking about a dry toilet
where there is no water involved in flushing the waste, the pit design
is considerably different from the ones where water is involved. But
basically the poop collects there and it sits there for some
time. Typically 2 years.

This is just the beginning. There is whole another level of complexity
involved in the removal and management of fecal sludge. We wont get
into that now. There is a Wikipedia page dedicated to this. Read it if
you want to.

What is the problem ?

Before we go about fixing anything we need to identify the problem
first. This is not as simple as building a toilet in the middle of
nowhere. A proper functioning toilet needs a lot of supporting
infrastructure to function properly and most of the time the lack of
the supporting infrastructure and the cost associated with
establishing not just a toilet but also the additional infra is
huge. In a city this is a non-issue because the infrastructure already
exists.

Thus it is evident that the sanitation solution that we use in cities
in not ideal for rural areas. Moreover the sanitation in cities isn't
that good either. It is highly inefficient and expensive.

We need to design better sanitation solutions that can process human
waste with less electricity, less water and less money.

Why does this matter ?

Sanitation is one of the most important aspects of modern
civilization. Poor sanitation causes diseases and diseases make a
person/community under-productive. A person can not work or a child can
not go to school unless they are not healthy.

Moreover, efficient sanitation is a problem that if solved once, will
affect a lot of different areas. For example, the restrictions that
apply on the ideal sanitation solution are the same restrictions
that apply technically every where.

Think about it. If we have a sanitation solution that is compact, uses
less electricity, uses less water and is safe then were else can we
use it ?

We could use it for space travel, interplanetary travel, buses, trains
etc etc. Literally everywhere.

Reinvent the Toilet Challenge

The Bill and Melinda Gates
Foundation launched the Reinvent
the Toilet Challenge in 2011 to promote global innovation in better
toilet designs.

They also came up with the
Omniprocessor. This is
generally a machine that employs a group of physical, biological and
chemical processes designed to process fecal sludge. The name was
proposed by the Bill and Melinda Gates Foundation.

Its called the "Omni" processor because it can process a variety of
waste stream (dry, wet etc etc) and using a variety of fuel sources.

Many interesting toiler designs have flourished as a result of this
challenge. The Janicki Omni Processor is one of them.

The Janicki Omni Processor : A special mention

This processor produces drinking water, electrical energy and ash after
processing sewage sludge. This is a really really cool piece of technology.

This was funded by the Bill and Melinda Gates Foundation.

A pilot project of Janicki Bioenergy's Omniprocessor was installed in
Dakar, Senegal, in 2015 and can now treat the fecal sludge of
50,000-100,000 people.

In fact in a
video. Bill
Gates actually drinks a glass of water produced from this same
machine.

More information about this can be found in their
website.

That's about it

I'll admit that before this encounter I had never put too much thought
into this whole toilet thing. But anyway.. here we are and now I (and
you) know.

I don't think that me writing about this will benefit the world too much. But I
like talking about things that I find interesting; so, here we are!!