Wednesday 24 July 2019

All is *well*. We are monsoon-ready!

A brief documentation of my first visit to an apartment complex in Harlur Road, to understand recharge wells with the help of a well-digger: 

“There are about 2000 flats and 40 recharge wells, that store rainwater collected from the terraces of all the towers in this apartment complex!” says Bullet Ravi, a well digger at an apartment complex in Harlur Road. “And all the recharge wells have water!” he says, gleaming with pride.

Photograph of an apartment in Harlur Road

Ravi escorts me into the property from the entrance and he pauses briefly pointing towards the direction of Kasanavahalli lake, located just a few meters away from the apartment complex. For a first timer, it’s hard to notice this huge lake as it is concealed by the trees in the park that borders the perimeter of the apartment. The park not only has trees and a lawn but also has many recharge wells! As we step into the park, we examine three different recharge wells, located a few meters away from each other– all of which have 4 feet diameter but varying depths of 12 ft, 20 ft and 30 ft. Most of the wells have water at depths of 6ft to 10ft below ground level.

Recharge Wells

Ravi passes on bits of information as I jot down the details of these wells. He says these wells are interconnected by pipes allowing surplus water from one well to easily flow to adjacent wells. Although, some of the pipes are still being installed most of the recharge wells are interconnected.  

Installing pipes to connect recharge wells

Standing beside a recharge well, all that I had to do was to look up at the skies to picture the journey a raindrop would take: falling from the sky, to the roof of the apartment towers, flowing through a system of pipes into the basement and finally to the network of recharge wells that lie beneath my feet. 

Journey of a raindrop

I clicked a few more pictures and thanked Ravi for his patience and his work in making this apartment monsoon-ready!

- Jeevitha Balakrishnan

Saturday 6 July 2019

Fecal Sludge Treatment Plant- Devanahalli


This is the first faecal sludge treatment plant in India. It is situated in Devanahalli, Bengaluru, India. It costed around Rs 1 crore. 

Area of this plant is 625 sqm.
Treatment capacity is 4000litres/day.
Households Served is 4,000
Dried Sludge Generated is 35,188 kgs
Total Sludge Treated is 821,900 litres
Total Wastewater Treated is 405

Process- Truck load of 4000 liters of discharged into the feeding tank which is screened in a screening chamber.  

The sludge water is left to settle. 
The water from this component is formed on the sludge. 
The separated water is taken to the anaerobic baffled reactor(ABR) 
The sludge from the feeding tank is taken to the biogas digester where the biogas is produced since it is anaerobic process. The process is shifted to the aerobic system, since the efficiency of the biogas digester was low. Hence, the sludge is directly taken to the stabilization tank where the water is further squeezed out. Sludge from this process settles down and separated water. This separated water is taken to the ABR. 
The water in ABR is made to screen through the baffles in the reactor. The treated water is fed to the plants. Further the screened sludge is collected in the collection pit.
Sludge from the stabilization tank is taken to the sludge drying bed, where it is left to dry. This is sent to the percolation pit. Percolation pit consists layers- Gravel bed at the bottom, sand bed on top and terracotta tiles on it. This helps to dry the sludge. The dry sludge is then collected.

This dry sludge is been mixed with the vegetable compost to make Co-compost

Process- 250kg of fecal sludge and 500kg of vegetable(wet) waste to create the co-compost. 

The fecal sludge and the vegetable waste are layered alternatively for 6 feet.
The layered waste is kept 4 days. It is then turned and kept for 7 days, again to repeat this cycle and kept 7 more days. This is the process of 20 days to form Co-compost.
This is then sold for Rs7/kg. This compost is used for growing grapes, banana, coconut, tomato, brinjal and jowar

Process Flow 

Feeder Tank 
Feeder Quality Tester

ABR - Anaerobic Baffled Reactor


Planted Gravel Filter 

Percolation pit 


Co-composting area

MY TAKE-AWAY:

  • One treatment plant can feed as compost to so many industries- agriculture, water recycle, plant. It definitely serves as a long term investment.
  • The process is not difficult. It is simple with logic.
  • It prospers green by feeding all the plants nearby.
  • It becomes income generation, also the way of the recycling the waste-water.
  • They collect wet waste to create the co-compost. It prevents the waste filling the landfill.
  • We found less labors on the site. To function this, there is a necessity to maintain.
  • This uses mostly natural materials for the construction, which makes it nature-friendly.
  • It was neatly kept with no smell.



By 
Kavina, Kruthika, Milan, Shimoli, Surabhi 


Lake Rejuvenation by Secondary Treated Wastewater


440 MLD Secondary treated water from KC valley and Bellanduru STP in Bangalore is being pumped to fill 126 tanks of Kolar district.
Lakshmipura Lake
On Tuesday 2nd July 2019, we visited Lakshmisagra Lake, the first lake in the series of lakes revived by treated waste water. Daily 440 MLD of secondary treated waste water from 56 km far is being discharged into the lake which overflows through the other end and is flows into the next lake. 

Lake Inlet
Inlet Channel

Overflow at the Outlet
This water is to be utilized just for ground water recharging and not for drinking or irrigation. Though, the surrounding farmlands were using this water through one open well which was completely filled, for their irrigation. They were growing various crops like tomatoes, chilies, cauliflower, and many more. Due to the lake, ground water table was quite high in that region.

Open well near the lake
Farmlands irrigated due to the open well


High water table
Many species of native fishes are also added in the lake. They act as bio-indicator to assess quality of water.A total of 1280 crores INR is estimated for the entire project.
Due to waste water, these lakes will be filled for the full year. So the farms will get water throughout the year, benefitting their yield.

By 
Kavina, Kruthika, Milan, Shimoli, Surabhi