Narrator: A gas mask jerry-rigged to pump air
is the only thing keeping this sewer diver
from choking on toxic fumes.
Every day, tens of thousands of people
do one of South Asia's deadliest jobs.
Narrator: As long as underground sewers have existed,
it's been someone's job to keep them clear.
Now, a robot could end this dirty business once and for all.
Meet the Bandicoot.
It has four expandable legs,
four cameras, and a carbon-fiber body capable
of lifting over 250 pounds.
A retractable hose and articulating shovel
can access places that, previously,
only human hands could reach.
Hands like those of Ful Kumar Mandal,
who used to jump into manholes before he got a job operating the robot.
Narrator: The Bandicoot is part of a wave of robots
maintaining cities' mostly unseen
but absolutely critical infrastructure.
And that's good news,
because clogs aren't only a problem in South Asia.
Pipes are stopped up everywhere,
including some of the Global North's richest cities.
Narrator: So why are sewers around the world
getting so much worse?
And what can cities do to prevent from drowning
in worldwide waste?
First, can we just take a minute
to appreciate the miracle that you can wake up,
walk four steps, do your business,
and flush it far, far away?
Many early civilizations had open sewers in the streets.
And up until a few hundred years ago,
people oftentimes just threw their waste out the window.
Things didn't start to change
until the Industrial Revolution,
as city populations exploded
and a deadly disease started to spread around the world.
Cholera killed millions of people
over the course of the 19th century.
It's a real nasty way to die -
diarrhea and vomiting until the body runs out of fluids.
It took decades for science to reach a consensus
that the pathogen spreads through water.
And how'd they solve it?
Beer.
Scientist John Snow noticed that in one neighborhood,
those who drank beer
rather than water from a contaminated well
survived an epidemic.
By the late 1800s,
the world's largest cities kicked off
massive sewer-building projects.
The designs were grandiose
and kind of beautiful.
In Paris, the sewers became a tourist attraction.
Nowadays, much the world's population relies
on an unseen network of pipes and tunnels
to carry away their waste.
All sewer systems rely simply on gravity.
In the modern era,
the biggest innovation has been the addition of pumps
that can help the sewage flow uphill.
That's it.
The most important technology in city planning
hasn't changed that much in hundreds of years.
And there is the problem.
Cities grow, but their sewers can't keep up.
When the London sewers were being built in the 1800s,
Sir Joseph Bazalgette doubled their size
from the original designs.
Smart move. But now,
the poop is hitting the fan.
As are the used cooking oil, baby wipes,
and other things that people flush
but sewers were not designed to handle.
And shifting climate patterns
mean that cities regularly get hit with heavier rains
and rising sea levels.
All that water can cause sewers to back up into the streets.
So cities have to build bigger and bigger tunnels
that come with a huge price tag.
In many cities in India,
it's cheaper to find people willing to unclog faulty pipes
by hand, even though this work has been illegal since 2013.
Abolishing manual scavenging is what inspired
the founders of Genrobotics.
The company claims that robots like the Bandicoot
will actually end up being cheaper over time
and eliminate the danger for workers.
The four cofounders didn't set out to clean sewers, though.
They started out making robotic exoskeletons in college.
Narrator: They shifted their focus
after a deadly sewer accident near their school.
Narrator: Going from Iron Man suits
to sewer robots wasn't easy.
The first challenge? Understanding India's old
and complex sewer systems.
The second problem?
The manual scavengers feared this invention
would put them out of work.
Narrator: Research shows that 80%
of Indian sewage workers die before the age of 60
because of health problems.
Genrobotics set out to educate thousands of scavengers
on the dangers of their job
while also hiring some of them to operate the Bandicoot.
Narrator: Now, the company is up and running,
with almost 300 robots in 18 out of India's 28 states.
Sewers in India are especially bad,
because its dated systems can't keep up
with the booming population.
According to India's Central Pollution Control Board,
fewer than half
of the country's centralized sewers work effectively.
Bandicoot robots get to a cleanup site
on the back of a truck.
Narrator: Unlike when they go underground
without protection, the crews now wear hard hats,
high-visibility vests, gloves, and boots.
Narrator: Now, the only manual part of the process
they still do is removing the manhole cover.
Once the unit is in place,
operators use the control panel to lower what they call
the spider into a manhole.
The arms help guide it,
while cameras give the operator a close-up view.
Narrator: Sensors check for poisonous gas
and trigger an alarm if conditions are dangerous.
Manually cleaning is not only dangerous, it's also slow.
Typically, teams of three to five scavengers
could only clean two manholes per day.
Narrator: India is home to 1.3 billion people.
And Mumbai, the country's largest city,
has over 22 million residents.
And there are dozens of other gigantic cities in India.
The sewers in each one vary.
So that means Genrobotics is always tweaking its designs.
Narrator: Today at Genrobotics' plant in Palakkad,
three Bandicoots will roll off the assembly line.
Narrator: Cutting, bending steel pipes, and welding.
Almost every step of production gets done in-house.
And every part must meet the exact specs
for a city's sewer system.
The software and design teams know
the Bandicoot's operators might be former manual scavengers
with little education.
So they did their best to keep things simple.
Narrator: Genrobotics spent two years
developing the Bandicoot before deploying it in the field.
Workers assemble the frame housing the controls
and the robotic spider arm one bolt and wire at a time.
All the sensitive electronics have to be waterproofed.
Building by hand slows assembly time,
but the company says it's the only way
to ensure quality control.
Genrobotics plans to standardize production eventually
in order to scale up.
Narrator: But even maintained by innovative technology,
sewers everywhere are failing. Why?
First of all, the list of things that people flush
has gotten longer over the years.
More wet wipes, food, and cooking oil enter the system
than ever before.
Underground, their powers combine
to create the unholy monsters known as fatbergs,
masses of inorganic materials and grease
that can block entire tunnels.
Fatbergs prompted politicians around the world
to discourage or even ban nonflushable wipes.
So far, these laws have failed to make an impact.
In 2021, California passed a law
that merely required the makers of sanitary wipes
to label their products with a "do not flush" warning.
And in the UK, lawmakers are pushing
a total ban on selling drain-clogging plastic wipes.
It's their third try in five years.
Secondly, the huge fixes that some places need
are getting way more expensive.
For example, when it was first built,
the London sewer system cost nearly 400 million pounds,
adjusted for inflation.
Back then, London's population sat
at just 2.6 million people.
Now, 9 million residents flush more
than at any time in history.
The city is completing a 15-mile underground tunnel
to transport overflow to treatment plants
instead of dumping it into the Thames.
This single project cost almost 5 billion pounds,
10 times the cost to build the entire sewer system
in the 19th century.
And thirdly, we've entered a new era of climate change,
with heavier storms that test sewer capacity more often.
New York City's sewers handle both wastewater
and storm runoff.
Every time a thunderstorm hits the city,
the storm drains can back up,
spilling billions of gallons of raw sewage
into waterways every year.
And the flooding can be deadly.
In 2022, 11 people drowned in their homes
when severe rains overwhelmed the sewer system.
So it seems that no matter what cities do,
they'll never be able to keep up with their own crap.
The modern marvel of flush toilets
opened a Pandora's box of problems right under our feet.
But there are alternatives.
Historically, farmers came into cities
and paid for human waste to turn it into fertilizer.
Startups are looking into recycling urine
to return nutrients to soil.
And dry-composting toilets are a proven way
to let waste break down without water.
So the next time you have to go,
just think about where what you flush away might end up.