Tuesday, July 27, 2021

Strategic In-stream Systems” “STRAINS” at Soul Kere


In-Stream Decontamination system is a small-scale collaborative project constructed near the southern inlet of Soul Kere.  This intervention is part of an ongoing collaboration which includes diverse partners spanning Design, Engineering, Civil Society, and Science perspectives.  The six-fold partnership includes input from Biome Environmental Trust (project management, collaboration, coordination), MAPSAS (community engagement), Eco Paradigm (engineering and construction), Commonstudio (design), ATREE (monitoring), and Wipro (fiscal sponsorship).


This small scale intervention “model Nallah”, approximately 2M Wide and 8M long has been constructed next to the STP at Soul Kere.



Within this space, we will run a series of experiments with jelly stones and terracotta rubble materials. The first treatment will test the removal of organic contaminants by means of jelly and Terracotta rubble material. Terracotta has properties which makes it a viable biofilter media for urban wastewater. We plan to test the system for flows between 2.4 and 9.6 KLD.



The ultimate aim is to use the insights of the Sowl Kere studies to develop a series of larger interventions which can be placed directly within nallahs to prevent the contamination and eutrophication of urban lakes. We call this larger approach “Strategic In-stream Systems” or “STRAINS”— decentralized, frugal, flexible, and inclusive.



Progress Report


Objectives


  • Evaluate the performance of STRAIN system with respect to materials(Gravel and Terracotta)

in treating wastewater

  • Optimize the design of STRAINS for efficient removal of contaminants

  • Develop an approach to enhance community participation and to hand over the maintenance of systems to the communities. This will help in promoting community engagement that will lead to a greater impact.



The project was implemented and monitored for a year. Please find detailed project report here


Conclusion


  • STRAINS showed good potential for dealing with highly variable influent quality. The removal efficiency was good for TSS and organic matter and satisfactory for nutrients in both setups. According to the results an average percentage removal of pollutants from the system was found as follows: TSS - 86% for gravel, 80% for terracotta; COD - 70% for gravel, 66% for terracotta; BOD - 80% for gravel, 79% for terracotta; TN – 13% for gravel,26% for terracotta; TP - 38% for gravel, 53% for terracotta

  • STRAINS showed similar performance for gravel and terracotta setup for total suspended solids and organic matter removal (p>0.05). According to the results terracotta showed better nutrient removal efficiency than gravel.

  • Higher organic loading rate of highly soluble effluent is decreasing the treatment performance of TSS, COD, BOD5, and nutrients. STRAINS achieved the better effluent quality when the system was loaded with COD ≤ 300g/m2/d. The corresponding removal efficiency observed in both gravel and terracotta setup was 69% and 50% respectively. Similarly, the optimum loading rate for BOD5 and TSS are found to be 44g/m2/d and 140g/m2/d respectively. At this optimum loading rate, the maximum removal efficiency of BOD5 recorded in gravel and terracotta setup was 80 and 83% respectively. Meanwhile, the TSS removal efficiency of gravel and terracotta setup was found to be 68 and 58% respectively.

  •  The pollutants (TSS, organic matter, nutrients and coliforms) removal efficiency of pollutants in the lower half (4 -8 m) of the system was higher than overall efficiency (0-8m). Increase in contaminants levels were observed at the center of both the systems. This could be attributed to breaking down contaminants into simpler form as greywater moves towards the centre of the system.

  • STRAIN system is a pilot system which is deployed  in the natural environment, with the construction activities going in the catchment, the quality of inflows to the system were highly variable which is interfering with the effluent quality. 

Nanjapura-Vabasandra-Kyalasanahalli Lakes


A Visit to Vabasandra, Nanjapura, Kyalasanahalli lakes  was done in February 2020 along with Mr. Anand Malligavad who has rejuvenated these lakes. All these lakes are located close to the Bommasandra Industrial area near Bangalore. The area adjacent to the lakes has agricultural fields, Layouts, Buildings and Factories.  His aim is to rejuvenate 45 lakes in 12 streams  by 2025.


Before rejuvenation the lakes were dry. Post rejuvenation all these lakes have water and the groundwater level has increased in the surrounding areas. The villagers adjacent to the lakes mentioned that Borewells and wells around the lakes have more water post rejuvenation


All Lakes have been funded for rejuvenation by different companies. 


Nanjapura, Vabasandra, Kyalasanahalli Lakes in Anekal Taluk



Nanjapura, Vabasandra, Kyalasanahalli Lakes



Nanjapura Lake:  18 acre lake was rejuvenated in 2020.


Nanjapura Lake PC: Anand Malligavad



Vabasandra Lake: A 9 acre lake was rejuvenated in 2019. Overflows into Kyalasanahalli Lake


Vabasandra Lake PC:Anand Malligavad



Kyalasanahalli Lake: A 36 acre lake, was rejuvenated in 2018.  


Kyalasanahalli Lake. PC: Anand Malligavad




Some observations on the design and features of the rejuvenated lakes


Details of desilting works that is carried out :


Desilting is carried out with help from local contractors.  No desilting is carried out for upto a distance of 50m from the bund. This is to ensure that no cracks or destabilisation of the bund happens as a result of the desilting work.   Increase in depth of the lake bottom is gradual from the perimeter to the central parts of the lake. Shallow Depths have been maintained near the perimeter of the lake to ensure safety of people who may walk in. Deep and shallow points also exist within the lake.  


Hadosiddapura Lake after desilting and bund work PC: Anand Malligavad


Bund:

A ring bund is created around the lake. At Nanjapura lake the slope of the bund is 1:4 at the outlet side. The bund is not a single sloped surface but is made up of 3 terraces/steps.  Napier grass has been planted in the lowermost step. This was recommended by Tamilnadu University. Cattle herders come to collect this grass for their cows. It is said that cows prefer this grass.  Plants and trees such as Arjuna which can thrive even under submerged conditions have been planted on the middle step. Ficus and fruit trees are planted on the uppermost step. The thought is that these trees will provide shade and fruit to the birds and the community.


Stone pitching has been kept to the minimum - so as to avoid import of materials from outside the lake..


 In Nanjapura and Vabasandra the bund at the outlet side has the walking path which is 10ft wide. Walking path on the main bund has not been paved with paver blocks or any external material.  Mud and gravel are used to create this walking path. Walking path is created on only one side of the lake. Rest of the area is accessible only for maintenance with a very narrow path. This area also acts as conservation/biodiversity space.


  
Step bund Napier grass

The bund is raised above road level.  To walk from the road level to the bund, steps are provided. This is to ensure that vehicles do not ride on the bund and also prevents encroachment and garbage dumping.

   


Steps from the road leading to the bund  and  Walkway on the bund at Nanjapura lake



Inlets and Outlets


All drains leading to the lake and out of the lake have been cleaned. 


Instead of creating concrete silt traps, a deep pit has been created which serves as a silt trap at the inlets.  Here the silt settles down and water overflows into the lake. Trees and shrubs have been planted around it which prevent accidents and dumping of garbage into the pit.


This pit is emptied as and when required by Mr Anand along with the help from local neighbours of the lake  


Deep pit silt trap at Kyalasanahalli


 

Drain carrying wastewater into the lake  and Clear water after passing through the wetland at Vabasandra lake



Wetlands


At all major inlets a series of 3 to 4 settlement tanks have been built. Each tank is separated by a mud wall/bund  This is treated as a wetland.  Water passes through each tank and gets purified before it enters the next tank. There are openings provided in the center of the separation wall for water to flow from one tank to the next.  A path has been left for JCB to enter the wetland for maintenance. Some of the tanks/wetlands also act as Kalyani for idol immersion and other religious purposes.

 

Series of Wetland / Settlement tank at the inlet - Nanjapura Lake


In case of Vabasandra Lake it was observed that the wastewater drain from the village joins the lake after passing through the wetland. Wetland has alligator weed and knotweed which are growing naturally. No wetland species have been introduced. The water gets filtered here before it enters the lake. 

It was observed that the water entering the lake is of better quality. Many fish and some submerged  macrophytes were found growing in the lake.


       
Submerged macrophyte at Vabasandra lake         A Snake cooling itself in Vabasandra lake



Islands


Islands have been created in the lake using the mud from the lake.  Ficus, fruit and other trees have been planted on the island.  


Water Levels

Old concrete electricity poles with markings have been used as markers in the lakes. They have been placed at multiple places in the lake. These markers help calculate the volume of water in the lake at any given time. They also act as a safety feature so that people can be aware of the depth of water at a particular point and hence be  careful when they go into the deeper area.  

Monitoring the changes in water level by  observing the the marks made by water on the bund helps in understanding seasonal variations in water levels


Water Level markers in the lake


Lines observed on the bund due to evaporation



Devara Kadu - Miyawaki Forest


In some of the lakes two types of forest have been created.  One is the Miyawaki forest where the planting is very close. The other where the trees have been planted 10ft apart.

At Lakes which have space, Miyawaki forests have been created.  This is fenced using barbed wire and  bougainvillea.  Bougainvillea has been planted as this will act as a natural fence and can sustain with minimum maintenance. No one is allowed to enter the Miyawaki forest. 


Miyawaki Forest at Vabasandra lake


Fishing


Before rejuvenation of the lake an agreement is made with the Panchayat that the lake should not be given for commercial fishing.  No net should be used for fishing at the lake.  Individuals can fish any amount at the lake using a rod. This helps the villagers to continue to use the lake for fishing.


Fence

There is no fence around the lake.  However, where required bougainvillea is planted which creates a natural fence.


Space for washing clothes

In some lakes where people use lake water to wash clothes, a space has been created with gradual slope for washing.


Women washing clothes at Kyalasanahalli Lake


Swimming at the Lake and Sign Boards


Swimming is allowed in the lakes.  Sign boards are placed around the lake with ‘Danger do not swim here’ in case there is danger in the area such as boulders etc.


Sign Board - Danger do not swim here



Benches

Benches are provided on the pathway on the bund. 


Benches on the walking path


Preserving old carved stone found at the lake

Old stone with the carving of a snake was found at Nanjapura lake.  It  has been installed at the lake bund. A platform has been created for people to worship it.


Preserving old inscription stone - Nanjapura lake


Lake maintenance :


A gardener is appointed to take care of the plants/trees in the lakes.


Anand Malligavad has a very close connection with the villagers at all the lakes he has been involved with.


Lake groups have been created at each lake.  This group  alerts/stops any unacceptable activities that are carried out in the lake area - like felling of trees, drinking, driving on the bund, cattle grazing on planted trees etc. With the help of the Lake Group / local community the activity is stopped immediately.


Cleaning the lake is done with volunteers from the village when required.



Contact Information


Anand Malligavad : m.anand161980@gmail.com 






Tuesday, June 29, 2021

Presentation on Sanitation Safety Plan by Avinash Krishnamurthy

Sanitation Safety Plan(SSP) is a Manual developed by WHO, is a step-by-step risk based approach to assist in the implementation of local level risk assessment and management for the sanitation service chain - from containment, conveyance, treatment and end use of disposal.

To have a deeper understanding of SSP, on June 2, 2021 Avinash Krishnamurthy gave a presentation explaining what is SSP, its methodology, assessment and also discussed about Devanahalli's SSP example. It is a 50 minutes presentation including QnA session. 

  • Here is the link to the Power point presentation. 
  • Here is the link to the document on Devanahalli's SSP trial
  • Here is the link to listen to the presentation.

-Rakshitha M L

Sunday, June 27, 2021

BIOME's presentation on NIUA's 45th anniversary, 2021

BIOME Environmental Solutions is currently doing a research study funded by National Institute for Urban Affairs (think tank of government of India) with its consortium partners "People in Center" and "Megh Pyne Abhiyan". The study is being carried out in a duration of 9 months starting from January 1st 2021 and ending on September 2021. the aim of the study is to explore the next generation of urban sanitation, wastewater and fecal sludge management challenges in India and contribute to the developing of a body of knowledge that can inform practice in the urban sanitation sector in India and elsewhere.

The study area focuses on formal and informal sanitation practices in 9 Indian cities from 5 states, which are described in the table below:



Mr.Vishwanth Srikantaiah is the research lead for the study and from BIOME Miss.Shubha Ramachandran and Mr.Avinash are also involved.

NIUA completed 45 years of operation. On this special occasion, on 24th June 2021, the study team participated in the webinar on "Formal and Informal Sanitation Practices: Learnings from 9 Indian cities".

Here is the poster for the webinar:


Listen to the recording of the event on Facebook here.
Here  is the link to NIUA's Twitter post



- Rakshitha M L




Friday, June 25, 2021

12 years after Bengaluru’s water board made RWH a rule ...

 

Summer School for Women in Mathematics and Statistics in 2021

Shubha Ramachadran spoke to the students on June 2021 at ICTS-TIFR in Bangalore.

Topic : Groundwater and Us

Abstract

Nowhere is groundwater more important than in India where a quarter of the world’s groundwater is extracted annually—the highest in the world—which is greater than that pumped up by China and the United States combined. Up to 80 percent of the population relies on groundwater for both drinking and irrigation. In such a scenario how do we manage groundwater ? What is the Million Well campaign in Bengaluru about ? 

The summer school is intended for women students studying in first year B. A./B.Sc./B.E./B.Tech or equivalent degree and having Mathematics as one of the major subjects/courses, during the academic year 2020-21. Over a period of two weeks, the school shall aim at helping students develop problem solving skills in Mathematics and Statistics at the undergraduate level. The below website:

https://www.icts.res.in/program/swms2021 has rudimentary details about the program. 

This is the third edition. Previous year's school blog is at

swms2018.wordpress.com
swms2019.wordpress.com


Recording available here : https://www.youtube.com/watch?v=COqNGXaVH-c&t=45s




Saturday, June 12, 2021

Lalbagh Open Well Rejuvenation

 

Lalbagh botanical garden is a 240 acres (0.97 km2) garden and is located in south Bangalore. It is managed by the Department of Horticulture, Bangalore. There are 5 open wells in Lalbagh. Of these 3 wells have water however, water from these wells are not being used. Two of the wells were closed by filling it with waste materials.  One of the closed wells was taken for rejuvenation in the month of March 2021.  After rejuvenation of the well 5ft of water was seen indicating the presence of shallow aquifer. With a pump house next to these wells indicated that these wells were used before borewell was introduced.


To manage the flooding in the north western part of the park during the rainy season, 100 recharge wells are being dug. This will help in recharging the aquifer and also  mitigate flooding.


Location of Lalbagh, Bangalore

Say Trees approached Biome Environmental Trust to identify a well in the city for rejuvenation.  The objective was to create awareness about the connection between groundwater, shallow aquifers and open wells. Since Lalbagh sees hundreds of people every day, rejuvenating a well in such a location will meet the objectives. 

To create awareness a poster/board will be placed with information next to the well. 

This project was funded by Say Trees.



Open Wells in Lalbagh

There are 5 open wells in Lalbagh.  Of these, 3 wells (Well no. 1,4,5) have water.  2 of the wells (Well no. 2 and 3) were closed by dumping construction debris, garden waste and other waste.  It was decided to take up Well no. 2, located close to the SunDial park, for rejuvenation. The dimension of the well is 10ft diameter  and 29ft depth.


WellDigger Ramakrishna inspecting Well no. 2 for rejuvenation


After taking the necessary permission from the Deputy Director of Horticulture, well digger Ramakrishna and his team started cleaning the well for rejuvenation.


The well was filled with tree branches, leaves, stone, construction debris, paper and plastic waste.  Ramakrishna and  team worked for 14 days to remove the waste and completely clean the well. They used a crane to remove the heavy material and silt. They hit water at the bottom of the well. After cleaning and treating the well  5ft of standing clear water is observed.


Cleaning of the well


Well diggers removing the waste dumped in the well

Paper and plastic waste


        
Stone and construction waste



Tractors carrying the plastic and paper waste out of Lalbagh

Outside of the well after cleaning

8 tractor loads of plastic/paper waste were taken out of Lalbagh.  The stone, garden waste and silt was left in the garden to be used.

Inside the well after rejuvenation

The dimension of the rejuvenated well is 10ft diameter  and 29ft depth. The static volume of the well is 64000 liters.


A perforated metal cover with a door was fixed on top of the well for safety purposes.  This also prevents leaves falling into the well.



Perforated Metal cover 



Next step is to fix the plumbing and motor for using the well water in the garden and for any other requirement.