Lake Bio-remediation meeting

BIOME, WIPRO, MAPSAS and other lakes communities have come together to try and understand how bio-remediation technologies can be applied to deal with the sewage inflow into some of the rejuvenated/to be rejuvenated lakes around Sarjapura Road.

Hence on 25^th November the first meeting was arranged to discuss bioremediation methods, to bring together the community working on different lakes in Bangalore on a same platform and decide on the further agenda for 15 lakes selected for the project was the objective of the meeting.

Following are the key points/deliberations happened during the meeting:

   A.     The lakes that have been narrowed down for this project are:

 

   B.     An initial discussion was led by Priya from MAPSAS who explained about the links between the lakes through kaluves and hence the importance of controlling the sewage entering in the lakes.

   C.     Mr. Vishwanath explained about viewing lakes as an ecosystem with space for biodiversity, treatment, recharge zones, etc. He cited example of Jakkur lake wherein a treated sewage water from BBMP maintained STP goes into a constructed wetland and then into the lake. He suggested that things that can be studied for lake should include percolation study, water balance, nitrate and phosphate removal, biodiversity, etc.

   D.    Some legal issues were also discussed:

1. Areas without BWSSB underground drainage network are not allowed to dispose of their sewage either with or without treatment. Zero discharge i.e. 100% reuse of wastewater generated within the premises
2. Areas with BWSSB underground drainage network are allowed to dispose of their sewage with at least secondary treatment 
3. The discharge standards for sewage treated water are close to drinking water standards

   E.     An important part of the meeting was presentations by vendors implementing bio-remediation technologies. Presentations were made by Visionearthcare on soil biotechnology (SBT), Hydrocreatives on Phytorid, and CDD on Decentralized wastewater treatment system (DEWATS).

  

Soil biotechnology (SBT): Have done for Herohalli Lake in Bangalore.

Their detailed presentation can be found http://www.slideshare.net/biomeshubha/sbt-for-lakes-bioremediation

a.     No external aeration is required as the different porous layers in the medium/bed help in aeration.

b.     One time media installation. No need to change soil media frequently

c.      No sludge formation

d.     Space: 1 sq.m/KLD

e.     No foul odor

f.       Have established 65 plants across India. Also experience in designing for lakes

g.      Not designed for removal of nitrates and phosphates specifically yet it works in their removal

h.     Herohalli plant details: Design capacity-1.4 MLD, Area- 1650 sq. m, cost- 3 crores, power consumption-125 units/day

Phytorid technology

Their detailed presentation can be found here: http://www.slideshare.net/biomeshubha/phytorid-for-bioremediation-of-lakes

a.     Plants have been designed particularly for BOD reduction and some amount of COD reduction also happens

b.     Power Cost: Rs. 1/KL

c.      Sedimentation tank: needs to be cleaned once in a year

d.     Issues with phytorid bed: Plants grow over a period and hence need to be cut as suited by the community. The disposal of cut plants is similar to other plants.

e.     No foul odor as water is not seen from above, no exposure

f.       Bacterial addition: once in a lifetime of the plant

g.      Space: for sedimentation tank/underground primary settling tank- 0.2/0.3 sq.m/KL and for phytorid bed- 0.9 sq.m/kl

h.     Cost per MLD: 1.3 crores

i.       Sensor based system

j.       Capacity range: 3 KLD -1.5 MLD

k.      The system needs to be placed in open as it needs sunlight for the plants to grow

l.       Water load fluctuation: the plants can survive without water (especially this may happen in dry season) for two months. Even if little amount of water is available, the plants can survive on fewer nutrients.

m.   If slope/gradient is available then no pumping is required

Decentralized wastewater treatment system (DEWATS):

Their detailed presentation is available here: http://www.slideshare.net/biomeshubha/how-dewats-can-be-implemented-to-bioremediate-lakes

a.     Shared case study of Bandhwa Talab in Raipur, Chattisgarh.

b.     This system based on phytotechnology which uses Canna indica plant which has shallow fibrous root system

c.      No color, odor and pathogens after passing the water through the bed of plant

d.     Based on requirement design can be customized

e.     The flow should be checked daily, sludge removal from the settling tank (primary treatment) is also required

f.       Treats only organic waste, domestic sewage

g.      Cost varies with capacity

   F.      Further deliberations and studies are needed on:

1.     Assuming that some amount of sewage already exists within the lakes, which of the systems would be useful?

2.     It is essential to conduct water balance study for every lake. Water balance means, calculating percentage of water coming, sewage coming, water percolating, evaporation, etc.

3.     Understanding the suitability of the system based on cost, maintenance, power consumption and mostly its ability to handle water load fluctuation, etc.

Based on primary data collection from each of the implemented technologies, water balance for some of the lakes and finally deliberations on bio-remediation technologies would help in seeking most suitable method to tackle the issue at hand.

We would like to thank the participants:

Vendors: Sharan Kumar from Visionearthcare for SBT, Mr. Himanshu from Hydrocreatives for Phytorid, Mr. Andrew Jacobs from CDD for DEWATS

Devarabisanahalli lake/Adarsh residents

Halanayakanahalli lake group

Priya representing MAPSAS

WIPRO

Students from Christ University

RWH in Vivek Khanna's home, Shubh Enclave, Haralur Road

Vivek Khanna at Kasavanahalli kere

Rainwater Harvesting was implemented in Vivek Khanna's residence in Shubh Enclave in early 2009.  The system comprised storage of rooftop rainwater in a large 15,000 liter sump as well as 2 recharge wells of 5ft diameter and 30ft depth. 

A chance encounter with Vivek Khanna at Kasavanahalli lake today revealed that his sump fills up with water every time it rains reducing his dependence on ground water. His recharge wells have not only kept his borewell running but also resulted in water in the newly dug borewells of his downstream neighbours (probably because of the recharge) where as some of the other newly dug borewells in the layout do not yield !! His new neighbours are now interested in getting RWH implemented in their homes

Recharge Well - just completed in 2009

Each of these stories reiterates the benefits of rainwater harvesting - both storage and recharge. Many thanks to him for sharing this story with us

The relationships between the recharge wells in his home as well as the nearby borewells would also be good cases to study as part of the aquifer mapping project

Newly constructed recharge well in 2009

Underground RWH filter construction in progress

Biome attends the WEDC International Conference to present research from the Resource Recovery and Reuse Project

Since April 2014, Biome has been working on a multidisciplinary research initiative funded by the Swiss Development Corporation (SDC) lead by an international partnership of organizations that includes the International Water Management Institute (IWMI), the World Health Organization (WHO), the Swiss Tropical and Public Health Institute (STPHI) and Sandec (Department of Water and Sanitation in Developing Countries) at the Swiss Federal Institute of Aquatic Science and Technology (Eawag).

The ‘Resource Recovery and Reuse: From Research to Implementation Project’ aims to find enterprises and business models that have demonstrated their capacity for the safe reuse of waste, and to find ways in which these business models can be adopted or scaled up within their own setting or in other regions. The funding partner, SDC, has indicated that it would be inclined towards funding some of the scaling up activities after the research is completed. The project currently runs in four cities, Kampala, Lima, Hanoi and Bangalore with the aim that lessons can be shared across different contexts. Biome leads the institutional component of the research in Bangalore (the other components are lead by other partners that include the Community Health Department at St. Johns Hospital, IISc and Waste Wise Trust). This involves understanding both the larger environment around which activities and businesses that work with waste have arisen as well as the more localised conditions that influence the way institutions operate and function. Together with partners[1], our work has involved selecting a small number of interesting cases that demonstrate safe reuse and in order to understand how they function. Research was conducted primarily through interviews with the most important government agencies that deal with waste and wastewater, businesses that are at the centre of this work, and desk based study on the larger context of solid waste and wastewater management in the city.

 In September, a short paper based on the research conducted for the project was presented at the 37^th WEDC International Conference held in Hanoi, Vietnam. The conference has a long history with a strong focus on presenting the work of practitioners from the WASH sector working in developing countries and this year’s theme was ‘Sustainable Water and Sanitation Services for all in a Changing World’.

The paper, titled ‘Formal Approaches to Wastewater reuse in Bangalore’ was presented at the session on Sanitation Institutions and looked at the different approaches taken by the BWSSB and the KSPCB with regards to wastewater. It presents the contrasting perspectives of the utility and the regulator - the former’s concern with managing wastewater infrastructure and its approach of taking delicate steps towards expanding public treatment and reuse, while the latter’s challenge in regulating pollution and monitoring the city’s large number of private treatment plants. 

This is the first of three posts that will discuss the research and findings of the institutional component of the RRR project, whose first phase ends in December this year. 

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[1] Acknowledgments to Alexandra Evans (Loughborough University) and our research partners at IWMI with whom we have worked closely on this project.

Borewell pump test at SJR Verity

Yesterday (Nov 9, 2014), ACWADAM and Biome performed a pump test on one of the yielding borewells in SJR Verity which is located in Kasavanahalli road. This borewell is generally switched on for a period of 3 hours and switched off for 3 hours and then again the cycle restarts.

We started the test at around 830 AM by switching on the borewell and also measuring the static water level (distance between ground level and water level in the borewell). This level was around 17.5 m during the start of the pump test. We measured the yield or discharge rate of the borewell by catching the water falling in the sump in a 15 litre bucket and measuring the time taken for the same. Since we did not have a stop watch in both our mobile phones, played a song and stopped once the bucket got full to measure the time taken in minutes and seconds. The discharge rate came out to be 762 litres per hour. Subsequently, we kept measuring the static water level at every 5 minute interval and then at every 10 minute interval from the 40th minute. The discharge rate was again measured at the 90 minute and 150 minute mark respectively and it came out to be 692 litres per hour both times. The static water level stabilized at 19.4 m and we measured the levels till the 160th minute. Since the levels stabilized, we did not measure for 180 minutes.
For the recovery part, the borewell motor was switched off and then the rise in water levels was monitored. This rise was documented every 5 minutes for the first 40 minutes and then at a 10 minute interval. The rise stabilized at around the 16 m level and we recorded readings till the 150th minute mark.

Similar data collected from the other borewells would help us in getting a deeper understanding of the aquifer.

Thanks to SJR Verity residents for all the coordination.
 

Junasandra and Devarabisanahalli lake teams: Working out solutions

Google Maps with Inlets

The meeting started at 8:15am sharp -  unusually early for a Saturday morning. A group of  8 enthused people who live around the Junasandra lake were looking for help/advice on how they could go about rejuvenating the lake. Some homework had been done diligently -  inlets marked, lake marked on Google Maps, conversations with the BDA that is responsible for this lake,  some thoughts on how the lake could be taken up for rejuvenation. The key questions were around - how to identify/handle encroachment ? How/Where to get the relevant maps that mark the boundary of the lakes as well as the raja kaluves. What would be a good model for the lake ? Would it be ok to have boating ? Was it only to looked at as a place for bio diversity ? How would the maintenance of the lake be funded

Junasandra team - with Priya

First thoughts on lake improvement

2 points that came across quite strongly were that  1) it would be useful to have some place/document where a lot of this information about "how one could go about rejuvenating a lake" be available.  2) Even though all the infrastructure might be in place its only when the people come together, plan out their lake and then actually visit/use it that the lake actually comes to life.

What plant is this ? 

Junasandra + Devarabisanahalli team

Full Gazebo

The Devarabisanhalli lake team meeting was next. 9:15 sharp. Thanks to great time keeping by Priya. They had a different agenda. Their lake had overgrown with a certain kind of water plant. They got  a sample for us to see (need help with the identification of the plant).  There was waste water going into their lake from the nearby village as well as the neighbourhood and this had resulted in the growth of a "water hyacinth" like plant. There seemed to be very many more mosquitoes in their area and a few incidences of dengue. They were not sure as to what their next steps should be. How do they keep the sewage from coming in ? What do they do with the water that is already in the lake ? Was it likely that the lake was responsible for the rise in the number of mosquitoes ?  The 2 key questions from this group were around how to keep the lake free of sewage as well as prevent mosquito breeding.

The "Lakes Project" hopes to address some such queries

Phytorid at Rainbow Drive, Sarjapura Road

Reed Bed

Rainbow Drive on Sarjapura Road with its 320+ recharge (with 400+ plots on 36 acres) wells is pretty much the oasis on Sarjapura Road where the borewells on their campus are able to yield sufficient water to fulfill their water demand. In addition to this they felt a need to recycle their waste water and use it appropriately.

The  2 existing STPs  of about 200KL capacity required about Rs 1 lakh per month for maintenance and repairs and the water was not of expected quality at all times. This meant that they evaluated various technologies for the replacement of their STP. SBT (from IIT Mumbai) was the technology that they first considered in detail and then decided to drop for various reasons. 

During implementation

Mr KP Singh - instrumental in the implementation

The technology that they finally decided upon was Phytorid from NEERI . This was to be implemented through a company called Petrichor (alumnus of IIT Guwahati). This decision came after a long study of the technical as well as financial implications of the system implementation. Involved visits to the various sites where Phytorid had already been implemented as well as several meetings with the vendors as well as NEERI. Once the committee made its recommendations it was placed before the larger resident group through several open houses that were held for all residents.  All queries (including ownership of land where the plant would be setup) were discussed and resolved with great diligence. The Phytorid plant was expected to offset its investment in about 3 years time. As against the 1 lakh maintenance costs for the older STP, the new Phytorid system is expected to cost only about Rs 10,000 per month for maintenance as there only 2 motors running at any given point in time and there are no moving parts requiring repair. The costs for setting it up so far has been about 55 lakhs. . The system with a capacity to treat 250 KL of waste water  has an anaerobic baffle reactor of 8m * 8m * 4m depth and a reedbed of 100ft x 30ft x 2.5m depth 300 tonnes of variously sized aggregates has been placed in this system and 900 plants ( 3 each at 300 spots of various nitrate removing species) have been planted.

Water coming out of the baffle filter

The system has just been commissioned for very controlled testing with some raw sewage as well as output from the existing STP and is seeming to work well. 

Visibly Clean water - at the outlet point

Once the treatment system stabilizes there is a plan to pipe this water back to the various houses for gardening. In the interim there are talks with a local organic farmer who will be willing to use this water for agriculture. With continuous recharge of ground water, frugal use of water , a sound tariff system that supports economic use , water education and now waste water treatment and reuse, Rainbow Drive is on its way to be a totally water sustainable layout.  The design through till implementation has been a labour of love for the core committee which is keenly looking forward to the performance of the system. Our best wishes to them