The other day I was traveling through city of Bengaluru by BMTC
bus, suddenly I happen to see a big channel beside, parallel to the road.
Initially I thought it’s just a water passage or something. After getting down
I went to check it, yes it was a water stream but a stinky one. Yes it was a sewage
water channel. And I even saw a heap of plastic in it, which was not only
filthy looking but it was looking like a growing devil which had potential to
choke the entire passage. Suddenly a thought struck me while major cities including
Bengaluru are facing acute water crisis, why are we wasting huge amount of water
mixed with sewage and let it flow into our valuable water bodies(lakes, ponds
and even to river)?
Instead cant we reuse this generated gray water to clean up our
vehicles or may be to feed our garden?
Sounds simple right? But it is not, this simple matter has made a
so much ruckus in the city.
After going back to home 'curious me' went to search about these huge
sewages around the city. As expected I came to know so many astonishing facts
about our poor sewage/water management.
Here I have tried to put those facts and ways of better management
of it below.
Water source to Bengaluru: The capital city Bangalore nicknamed as
garden city.
It actually had gardens and city full of
lakes. Before urbanization of the city it had more than 500 lakes. As the city
started filling up with buildings; the industries started budding and ultimately
the farms, gardens and lakes started to vanish. Well unfortunately the city is
not longer a garden city anymore.
In
early 90s the Bangalore had more than 500 lakes. Those were potential sources
of water of people. Now most of the lakes have either drained or filled to
build the city, and the count it has gone down to only 17 good lakes (https://en.wikipedia.org/wiki/Lakes_in_Bangalore)
. Once with self sufficient lakes and
ground water level the city was independent for its water supplies. But now it mainly takes water from Kaury River
which is approximately 100 km s away from the city and urgent needs are
fulfilled by sucking up the leftover ground water.
80 percent of this used water being converted as sewage and only
40 percent of the it is treated. Bangalore in total generates approximately
1400 MLD (million liters a day) of sewage a day if its 60 percent is
untreated then the number would be 840 MLD well that is a huge number and more
dangerously all of these untreated
water, including chemicals from industries are contaminating our water bodies
every single day. This number for whole Karnataka state is 2500 MLD.
This contamination is not only making the water sources
inaccessible it is also contributing contamination of ground water surrounding
city. In fact this whole process is one of the contributors towards city’s
water crisis. This year Bangalore city was about to hit acute water crisis and
in 2022 city is expected to witness zero day.
As we are near to the line of limit I strongly believe this is the
high time to address this problem with higher priority. This is not only a
story of Bangalore, over 21 major
cities of our country including Bangalore are expected witness worst water
crisis of all time in 2022 according to data. If we consider quality
level of available water, it is not really drinkable state. Facts shows us,
India is in 120th position in 122 countries as per as the water
index is concerned.
Question for you, isn’t it
a freaking factor that we are not actually recognizing it? Cant we come to a common solution by treating sewage and
reusing it?
______________________________________________________________________________
zero day is a term used in cape town south Africa to explain zero ground
water level and apocalyptic stress among citizen of it.
This very same situation is expected to occur in 21 major cities
including Delhi, Bengaluru and Chennai.
_______________________________________________________________________________
Where does the sewage come
from and go? is it a serious issue?
The sewage mainly consists of used water
mainly domestically. If the sewage used is in the kitchen and washbasin, obviously,
it will have less of suspended partial and it will be less polluted, such type
of water is called as gray water. The gray water will have larger scope of reuse
with less efforts in treating it. But only
problem is that we don’t have proper STPs at societal level. And hence it is
mixed with other sewage and it goes untreated.
____________________________________________________________________________
BASICS OF SEWAGE TREATMENT (IN INDIA):
Sewage is basically used water with suspended waste
materials in it. To make the sewage completely reusable we have to treat it in
three stages those are primary, secondary and tertiary. In primary treatments the floating debris and floating materials are removed with meshed and other
filters and this allowed for sedimentation of some waste materials. This makes
a consistent watery feed for secondary treatment where anaerobic microorganisms are added which helps in digesting
organic materials in the waste water. This microorganisms are later removed
with addition of chlorine to the water. This secondary treated water is now eligible for non-potable purposes like
toilet-flushing and gardening.
Tertiary
treatment involves more advanced processes like reverse osmosis (RO) and
de-mineralisation. Dissolved solids and nutrients get further removed during
these processes. Depending on the grade of tertiary treatment, recycled water
can be used for drinking, as coolant in industries, or in precision industries
like electronics.
The
most common sewage treatment method used in India is Activated Sludge Process
(ASP), which had been invented in England over a century ago. ASP mainly
reduces BOD (Biochemical Oxygen Demand), fecal coli-form level, turbidity etc.
Extended Aeration, Sequential Batch Reactor (SBR) and Up-flow Anaerobic Sludge
Blanket Reactor (UASB) are some other conventional treatment technologies.
These are mostly variations of ASP itself.
______________________________________________________________________________
As above mentioned in Bangaluru generates total of 1400 million
liters of sewage every day and 60 percentage of it is untreated. This
untreated water eventually gets drains out in lakes, rivers and other water
bodies around the city. Main of such water bodies are Vrasabavati river(AKA Kengeri Mori), Ballandur
lake and Varthur lakes which are well known for the hazards which we have created
and high pollution levels of it. In past these water bodies have also made into
headlines because of fire incidents(by bio gas generated in it) and clouds and
foam formation and death of floura and founa around it.
______________________________________________________________________
Currently, Bangalore generates 1400 MLD
wastewater, as per BWSSB’s conservative estimates. The city has total treatment
capacity of 721 MLD, but only
520 MLD gets treated on average. Here is a map
of the existing and proposed STPs by BWSSB/BBMP in Bangalore.
Below is a list of existing STPs operating in
the city:
|
Plant
|
Capacity in MLD
|
|
Vrishabhavathi Valley
|
180
|
|
K & C Valley
|
248
|
|
Hebbal Valley
|
60
|
|
Madivala
|
04
|
|
Kempambudhi
|
01
|
|
Yelahanka
|
10
|
|
Mylasandra
|
75
|
|
Nagasandra
|
20
|
|
Jakkur
|
10
|
|
K. R. Puram
|
20
|
|
Kadabeesanahalli
|
50
|
|
Rajacanal
|
40
|
|
Cubbon Park
|
1.5
|
|
Lalbagh
|
1.5
|
_____________________________________________________________________
Every year we see videos of froth filled Bellandur lake flashing in the news. You also must have seen incidents of lake water catching fire. People/residents surrounding lake goes to strike, it hardly affects government, BBMP or local corporator for that matter. The fact is that we do not have enough STPs around the city those are there are not effective enough to handle the flood of sewage. We all see the today's state of the river Vrshabavati, we it is known as Kengeri Mori.
How can we solve it
together?
1)Government is being ignorant that is Crystal clear. Now it is left to us, we have to work together and set up small secondary STP s at societal levels such
that we can reuse the water in non portable forms such as gardening and
flushes. This problem was earlier tried to solve and addressed to. it was also made a law to set up mini STPs in
societies and apartments, but people started to retaliate by calling strikes
to oppose it. After seeing this one thing is clear that the problem is not only
a economical problem it’s a social+economical problem.
It is not only an economical problem it is a socio-economical problem.
2)Gray water and its cleaning:
Having small filters, STPs built in at house level and atleast treating
the water in primary level will have its own benefits.
3)Bringing behavioral change:
As it is socio-economical
problem, Bringing behavioral change in
the society by star campaigners, celebs and politicians will have impact. As saving
lakes and sewage as important as other problems its just underrated. AND giving
proper awareness and educating people is much needed.
4)Floating treatment wetlands (FTW) and other modern
techniques will help to solve it. state governments can collaborate or seek suggestions from other state, if they are doing progressively good work.
5)Working together: As most of our city's problems are not yet
solved by miscommunication and lack of cooperation between different government
organizations, working on problems closely and together will definitely give
solution to it.
6)Planting, Rain water harvesting and less water usage are conventional
methods by which the water can be conserved and used to recharge the
groundwater level.
Chennai is first one to make a mandatory law for rainwater
harvesting but its has not been implemented properly.
Bottom-line:
The fact is: we all know that, It is a haunting problem like every other environmental problems. It is a high time to address it but unfortunately the government and citizen are being ignorant about the severity.
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