Wednesday, August 16, 2017

Dasarahalli Lake Report

Dasarahalli Lake is situated on approximately 20 acres of land located in Dasarahalli, Bangalore just south of the Dasarahalli Metro Station. A 1 MLD STP was constructed in 2013 which discharges treated water into the lake. In addition to the treated STP water, there are five more inlets into the lake - all of which would discharge untreated storm and sewage water into the lake. Water from the naalas which is in excess of the STP’s capacity will flow through a diversion culvert to the next lake. During our visit on 4 July 2017, we observed that there are no constructed wetlands but one region that is separated from the main lake body in order to capture trash and other debris without letting it enter the lake. Note for map below - N: Naala, I: Inlet, POI: Point of Interest. Map labels match up with corresponding legend element. Top of map is north.

Overview and Observations
Dasarahalli Lake is located on about 20 acres in Dasarahalli, Bangalore. It is reported that in 2013, an activated sludge STP of 1 MLD had been commissioned. There are six sources of potential inflow into the lake and one outflow from the lake.

This lake is owned and maintained by the BBMP. There are three entry points into the lake premises. These entrances are in the north, east (main entrance), and southwest parts of the lake. Near the main entrance, there is a small kalyani which will be filled with water for idol immersions. 20170704_084553.jpg
There is also a small building for maintenance workers. The restroom facilities are supplied with Kaveri water for flushing and handwashing. There is a fence around the entire premises and a smaller fence between the paved walking path and the lake.

This lake may also provide livelihoods for contracted fishermen and local residents. Within the lake, there are ropes that hang fish food in the water. Additionally, residents may cut and take home grass as fodder for cows.

The Lake
We identified six distinct inlets where water would enter Dasarahalli Lake.

Culvert 1
Not currently discharging, but the stormwater flows into the lake which is connected to the storm drain outside of the lake. There is a growth of vegetation right at the outlet (lake end) of the culvert.
Treated STP Water
Discharges into the lake and not within the area bounded by the bund.
Naala 1
Not currently discharging into the lake, but would overflow into the lake during heavy rains and sudden flooding. Otherwise it would, through a sewer line, drain into the next lake.  
Naala 2
Through a sewer line, wastewater flows from Naala 2 into the 1 MLD STP where it gets treated. During heavy rains and flooding, the naala would overflow into that area of the lake which is bounded by a bund.
Culvert 2
Storm and sewage water inlet from the slum adjoining the lake. They are not currently discharging into the lake, but would flow when it rains. There is a growth of vegetation at the lake end of the culverts.
Culvert 3
Storm and sewage water inlet from the slum adjoining the lake. They are not currently discharging into the lake, but would flow when it rains. There is a growth of vegetation at the lake end of the culverts.

As stated above, each inlet structures will allow untreated storm/sewage water to flow into the lake during large rain events.

The only outflow from the lake is an overflow system under a bridge in the NW corner of the lake.

There was a clear build-up of algae around the lake. The plant growth around the lake is maintained by individuals who trim the grasses and perform other landscaping tasks.

According to an article in IBT, industrial effluents from the Peenya Industrial Area also discharges into the lake, likely through one of the two naalas. The Karnataka State Pollution Control Board had determined that the dissolved oxygen (DO) level in the lake had been reduced to 0.3 mg/L.1 Dissolved oxygen levels below 5.0 mg/L will put aquatic life under stress. DO levels that remain below 1-2 mg/L for several hours can result in large fish kills.2 At this time, we do not know exactly the number of samples taken nor where (within the lake or in the area within the bund) or when. We are also unsure of how long the low DO levels persisted and what impact that may have had on the lake.

The STP at Dasarahalli is owned by the BBMP and was constructed in 2013. The STP is capable of treating 1 MLD of sewage. The sewage enters the plant from the sewage drain from Naala 2 and then the treated water is piped to the into the lake. If the volume of the wastewater entering the sewer line connected to the STP is more than 1 MLD, the wastewater beyond 1 MLD gets diverted into a separate sewer line and flows into the next lake. The STP operator told us that the discharge is regularly tested to assess its quality.

It is an activated sludge treatment plant with aeration, secondary, and tertiary treatment processes. The filters are backwashed for a minimum of 10 minutes each day - the backwash is recycled to a previous step in the treatment process. Regular maintenance of the entire facility is performed annually.
      STP process overview (Picture from Dorekere used as a reference because the process is identical)

The Wetland
There is no wetland in Dasarahalli Lake. Instead, there is a small area on the eastern side of the lake which is separated from the main waterbody by a rock bund.

This area is intended to hold any trash and sewage that may get washed into the lake due to heavy rains which can then be easily gathered and removed from the lake. This pollution may come from any of the two naalas or three storm drains that discharge into the lake. It should also be noted that the storm drains may also contain sewage from the nearby slum community. This trash is then placed in a fenced area to dry before being collected and removed from the premises.

1. Dasarahalli STP Incharge: Mr. Varadaraj- 09071281789


PAQM2 Closure Workshop : Q & A session

A transcription of the workshop held on 11th Aug 2017

Vishwanath (Biome) : This is the first experience of urban groundwater management; previous experiences have been in rural areas. What were the key learnings and what are these learnings translated at the national level?

Himanshu Kulkarni (ACWADAM): From our experience in the rural sector in terms of participation, engaging citizens or stakeholders in the science of understanding groundwater, I think we have reached a stage/change where groundwater, which has gone through a very atomistic development rather than a public systems development…I think the solution lies only when people come together and decide on certain things. So this is not a very fashionable agenda of science, its also a very strategic agenda in engaging the scientific fraternity on a dialogue with the stakeholders through a process where both become a part of a process that involves science, even if its sort of partial, imperfect, dirty looking science, as compared to conventional science. But using that dialogue with the community in a manner where there is a collective decision making and that decision making will lead to a set of improved or robust actions and I think that’s what everyone desires.

So we have had a fair amount of success in rural India, across partners, across institutions, across communities.  And we thought it might be encouraging to use the same experiments/routine with urban India. Now there is one big difference and I think it was quite overwhelming when we started talking about this. Because a city like Bangalore is like, maybe a 1000 villages, and I think that is where the problem lies. Having reached a certain stage I can clearly see the connect between the science sort of decision making, the action and all of that coming back into a sort of form, to make public policy better. Again we are not striving for something that is imagined to be perfect. We have never strived for perfection neither in the science nor in the participation nor in the governance part.

Let me also flag something very important which I think we probably forgot to mention at the beginning – that a lot of what we talk today is also a derivative of the dialogue we had at the interim workshop, which was I think, at the end of the first year. We had a dialogue with a lot of you – you suggested a lot of new dimensions for example how do you modify the research a bit to take into account certain factors, how do you communicate with communities, someone mentioned even then that why are you working in this watershed, you won’t be able to achieve anything 2 years down the line? Why don’t you look at bits and pieces in the watershed which are representative of citizens’ problems? So we were able to customise that entire process on the basis of this constant dialogue with people. I think that is the way to go. So we believe although we might have had a formal partnership, between the 3 organisations, I think the informal partnership is really what was the big change.

Let me end by making this comment – see we could have done this in Pune. I have spent 56 years of my life, 35 years of my professional life based out of Pune. We were never able to come up with an effort like this. And I think its also the pulse of a place, the maturity of a place where people tend to come together, I’m sure Bangalore has come together on many fronts. On a lighter note, we have too many intellectuals in Pune and when you have that you have a problem.

Vishwanath: One of the things that we saw, for example RBD, has now become an exemplar for the nation. When the smart city or the Amrut city or the ministry of urban development wants to showcase examples of integrated urban water management – teams come to RBD, from Delhi, from all over India, to Jakkur lake and RBD, so these have been exemplars for India itself. One of the broad movements with groundwater is to push it from being a private resource to a common pool resource.  Small steps have been taken, like in RBD, where individual borewells are banned, many layouts are doing that – at least this is happening at the layout level, perhaps not at the sub-aquifer level. At least from the surface template, can we start to imagine groundwater as a common pool resource? These examples are happening in rural areas. These examples are also happening in urban areas, in these kinds of gated communities as a beginning. It would have to democratise itself and get into wards and get into cities at a larger scale.

So Himanshu, since you lead the charge for pushing the institutional and legal framework of India with regard to groundwater management, how do you see it actually progressing, do you think that it will actually be achieved, and especially in Urban India?

Himanshu: We have got called into policy because of our work on the ground. I think that is going to be a game changer. We need policy change, but I think policy change around groundwater in India will happen only when we have a critical mass of exemplars on the ground. And I think when policy makers call you; you are sitting at a different position on the talking table than when you go lobbying about an idea with policy makers. If you can create a critical mass on the ground, I think that is the only combination with which policy change will happen in India. So we keep doing efforts at various levels; honestly I think a lot of us will continue to do efforts to make policy changes but I think we need a much larger critical mass to change the game on the ground … for the commons to be acknowledged as commons, I think we need the common folk in India to be part of the movement.  Currently there is intense competition on the ground around water.  What are the mechanisms of changing that competition to cooperation? And I think that is what we should focus upon. Policy will take its own way and I think it will change eventually.

Priya (Arghyam): The communication material is very well designed and I’m sure we can help you give it more visibility through the India Water Portal. I had a question on the findings of the research – a lot of it was on the process and the different stakeholders, the participation and collecting this information. So what does it say about the aquifer in Sarjapur? Is it different from whatever data the government or CGWB have found there? Is it more current that the public data that is available? And I had a question about Rainbow Drive layout (RBD). So while a lot of people from different parts of the country are coming to RBD and learning from it, are other parts of the city where they are facing similar problems learning from RBD?

Vishwanath: On the first part we don’t have an answer yet.  Addressing K P Singh – Are you cloning yourself more? Are more K P Singh’s going to more places?

K P Singh: I think in and around Bangalore every community is trying to do that. When I am in Bangalore, and I have been traveling the last one year, almost on a weekly basis we have teams visiting us.

Vishwanath asks the (Sekar)T Zed representative about his experience.

Sekar Srinivasan (T Zed representative): We are taking sewage treated water and making it potable and recirculating it, hence you don’t need too much of surplus of fresh water everyday. The only water you need is what evaporates or what you use in the garden. The rest of the water you just keep reusing. There was a lot of interest and we have been and still keep getting visitors wanting to learn how we do it. There is only one other apartment complex nearby, where we have done this close-loop recycling, which is what the new water technology of Singapore does.  But by and large there is a lot of psychological resistance – that is the main barrier to cross.

Vishwanath: these are the only 2 communities in India which are using treated wastewater. The T Zed example is more difficult to emulate because of the yuck factor associating with potable use, whereas the RBD example is much more doable; They are progressing one step at a time, they are having their own wastewater treatment plant, non-potable use is going on, there is indirect recharge and then you tap it from ground water. Then there is no yuck factor. So somewhere you have to crack that. And I’m sure we will crack it in the coming years.

Question from ?: 1) On the aquifer mapping - is the data publicly available for consumption and is there confidence in the quality of data? 2) Is there a way to measure the age of the water that is being sucked out of a borewell?

Himanshu: 1) In a way it is a first of its kind experiment. How do you establish the relative confidence between a classically scientifically collected data, even instrumented for that matter, versus a data that comes up through narratives? We have, in some instances, tried to validate the narratives with a classical approach. If you throw the question around the room you will get various levels of confidence. From my gut intuition, I would say I would put around 65-75% confidence around the data. But you are right, if we are going to port all this data to the public domain, then we might need to apply certain filters and establish where this data is likely to be of greater and lesser confidence.

2) Yes there are certain techniques to ascertain the age of groundwater. Isotopes is ones of them.  Mr. Subhash Chandra: Water coming out from a confined aquifer system has been determined to be around 4000 years.

Avinash (Biome): the raw data is not on the public space but the outputs of the study are already in the public space – at

Shubha (Biome): was created with the idea that the public would be contributing data to the platform and with that data inferences would be made. But increasingly it was found that while people with open wells with water in them were initially keen to share that information with us, they were reluctant to have the data appear on a public platform. So some of the information is available on, and some more is available with us but as of now it is not available in the public domain.

Meera (Citizen Matters): (regarding learnings from this project for apartments): You have viable integrated water management systems for gated communities like RBD or T Zed – because you have enough open space for recharge wells, STPs and other interventions. What are the learnings for apartments and is it even viable to look at apartments being self-sustainable? And how do we get these learnings into a larger level – say feeding into the master plan, zoning etc?

Bishwadeep (Arghyam): People getting together in urban spaces is much more difficult than rural spaces, at least that has been our experience. So this is really good and one would like to know – how did the people come together to make investment decisions on say 20 recharge wells etc. People are extremely sensitive to costs is what we have realised. Secondly in terms of managing the water resource itself, if we consider the unit, is it enough for the RWAs to come together, or should it be the ULB, because the boundary of the resource is not sitting nicely matching with the boundary of RWA or ULB. So that has been a perennial question – at what unit should the water resource be managed?

Himanshu : If we can get to the point where we have an aggregated platform to respond, that would be ideal but its going to take time. So if we can begin the solutions in slightly more disaggregated ways when opportunities present themselves, and then aggregate as we go along. This is what is going to be very crucial in the urban context. Because, if you wait for scale you may not be able to get the intense engagement that is required for people to come together even at local scales.

Let me present a simple example; we should have included this in the report-out. We looked at a demand-based water balance. It was easier to collect usage statistics. We found that some communities were using 1.5 years of rainfall in 1 year itself. And when you present this to a particular community, they wake up. Communication is also important - where do you communicate what? Instead of saying  “you have less available in your aquifer”, you say that this is what you are using. In the very first instance you have flagged the issue of demand side management. And the community gets more engaged during such communication. Sometimes they will point out that the annual consumption estimate that we have assumed is optimistic and the actual is much more – say 75% more. That is where the participation and cooperation begins. The user becomes part of the solution. Reducing demand for housing is not something we can control from the top, but we can look at ways to bring the per-capita demand down, so that we are able to reduce the water footprint.

Shubha (responding on the learnings for apartments): Making some assumptions – nowadays for every acre of land you have about 100 houses. Earlier the math was – for every 5 acres you had 150 houses. To put it simply, for any house that is 7 stories or taller, even if you harvest all the water that fall on the campus/rooftops, you can harvest an equivalent of only 15-20 days (out of 365) of the water demand. Of course you can try to reduce this through metering etc but it is not easy. However some apartments are going ahead and doing this, observing 20-30% reduction in demand in the process. And one other way, which T Zed and RBD has done is to treat and reuse the wastewater. But yes, as your apartments grow taller it is much harder to be sustainable with respect to your water management.

Veena (ATREE): I was wondering whether you made any attempt to separately measure outdoor water usage. And the reason is that there is a tendency to think that if I am using wastewater for lawns that is ok because it is not ground water or Cauvery water. But should we not be more sensitive to other claimants on that water and perhaps be thinking about shipping that to more water distressed districts like Chikbelapur, Kolar etc? Perhaps we should imagine alternate spaces that would need little to no water. How do we start having that conversation about what is the appropriate outdoor water use?

Vishwanath: We tend to see ourselves in isolation and focus on becoming more water efficient. Of course we should be as efficient as possible but I think eventually we have to place ourselves in a watershed like for example in a lake, and then a basin. And because of the densities that we create, we have to start thinking about sustainability at these scales.

Daniel + Kim (Common Studio): It was difficult knowing all the different actors involved in the water ecosystem. It took us a year to figure it out. It would be great to have a centralized place to understand what everyone is doing, contact information, at your fingertips.

Question from ?: The claim is that by rejuvenating lakes, we also rejuvenate groundwater. How much is this true?

Himanshu: Linked to that - I am not specifically answering that question - what we are finding, and it probably needs a little more probing, is that there is a 4-fold typology of lake-groundwater interaction that one can imagine. A part of it that we are finding is that you can’t necessarily say that lakes are recharging groundwater. And you can’t necessarily also say that groundwater is flowing into all lakes. It is because the rules of the game have changed. Maybe 50 or 100 years ago it might have been a little more common than that. For example the shallow aquifers have depleted, which otherwise if they had been fuller (in earlier years) would have flowed into the lakes. And then there is the seasonality factor also, and we need to get into more details here.

But stepping back, the larger question is this – how do we move the debate or the citizen thinking from a classical case of focus on sources, access and distribution, which really is on the demand side, to the focus on resources? So do we look at lakes as sources or resources? I think we need to try and change the pedagogy in the public water discourse. Similarly do we look at wells as more important or aquifers as more important? Howsoever imperfect our knowledge on aquifers is, if we can shift our focus or attention from source, access and distribution to that of – where does the water come from, where is the larger system of water, what is it doing – I think we will be able to make that change.

Question from ?: I know we have done a lot of work with the community, but can we do some work with the government on some of these initiatives like building recharge wells?

Himanshu: I think it’s a fantastic idea. I have never heard anyone in the urban context talk about public recharge wells. All of us, many of the people in the room, work on watershed projects in rural areas. When we go to a village, we want the village to come together; we want the village to contribute their lands for a public recharge system. Can we not bring the same thing over to an urban context? Urban India has not had any imagination on groundwater recharge. I think that also pegs into what Avinash was saying, that if for example a public utility brings water into a RBD or into the Sarjapur area, can we reimagine the RBD system to be something like a public recharge system, which is for a public good. And can we not then even create incentives for such good practices as being part of a public good?

Shubha: yes the government is also waking up to it. In Koramangala they are going to be digging 150 recharge wells in the storm water drains; they have already started the process. In BTM layout the well diggers called and told me that the corporator has asked them to dig wells. In Indiranagar, the RWAs are talking to the corporators and ward committees. So there are engagements at various levels and now the government, in this case BBMP and in some cases corporator money, is being invested for recharge wells. Of course questions of quality, safety remains.

The other area where we are working with the government is wastewater; can treated wastewater, when brought to an appropriate quality level and monitored by the community, be discharged into a lake? It can be; in certain cases they have given permission, but not easily so especially since Bellandur. And also can that be used for groundwater recharge? And if so, till what depth is ok, what monitoring processes should be in place? We are working with the Pollution Control Board on that because many apartments have extremely good quality wastewater. They would ideally like to reuse it but because of the yuck factor or whatever, they are not able to. So then can we look at discharging it into a lake? How do you do it responsibly? So those are some questions we are working on.

Subhash Chandra: Government has started initiatives in early 2000s – even in Bangalore in several parks they have constructed grey water recharge structures, storm water drains, but unfortunately there are issues with maintenance. Because in the entire project there are no funds earmarked for maintenance.

Vishwanath: just to conclude, two large narratives are running with water supply and wastewater. One of supply side and large projects that transport water from great distances to the city. And the other narrative that is being created is around local sources, water harvesting, demand management, and looking at uses of water, treating and recycling water. At some point of time the scale of these smaller solutions hopefully will build up enough to put pressure on the system to rethink these large-scale supply side systems. That is the work which a lot of us are engaged with.

Monday, August 14, 2017

11th Aug 2017 Workshop - in pics

11th Aug 2017 : Closure Workshop of the Participatory Aquifer Mapping Programme

In the media HINDU and TOI

10th Aug 2017 : A fun session on Lakes and Wells with students of Aditi Mallya school

Every year Jayashree of Aditi Mallya school organizes a week long Library week for the students of primary/middle school . This year too there were activities/trips to Lal Bagh, Bhoganandeeshwara temple etc. BIOME was asked to engage with students of Classes 3 and 5 on the topics of Open Wells and Lakes . This tuned out to be quite a lot of fun - with  story reading, some information on lakes + a short quiz. The kids were high energy, well informed and well behaved too !!

Kudos to the teachers/school and especially to Jayashree

Sunday, August 6, 2017

Ravi and Rekha Iyer Grey Water Treatment System Case Study

On 20 July 2017, we visited the site of a grey water treatment (GWT) system in a layout off of Sarjapur Road in Bangalore. The family of five consumes approximately 30 KL of water per month. This water is provided by a combination of the layout sump, stored rainwater, and grey water.  Every month they save approximately 250 litres of water each day by treating and reusing grey water. 


GWT System Details
This system was installed at the home of Ravi and Rekha in 2013. At the time of installation, the total cost was about Rs 40,000 including the civil work. Currently, 250 litres are being treated by the system.

The GWT system currently treats water from the washing machine and bathrooms. The family uses organic/mild detergents and soaps including detergents/dishwash from Eco Store and handmade bath soaps which are easier on the GWT system. They made the switch to these products because the water would smell when they used chemical detergents - there is no smell following the switch to the new products.

As mentioned, there were problems with smell and the water turning black which was solved by changing the detergents. It should also be noted that the inspection/aeration ports and the openings of the pipes into and out of the tank are covered with mosquito nets to prevent reptiles, insects, leaves, etc from entering.

The system consists of the following components:
Baffle Tank
3’ x 2’ x 2’ with 2 baffles
  • Includes a grease trap and settlement chamber
  • Not cleaned so far
Reed Bed
6’ x 4’ x 3’ with 18” of gravel
  • Full of Chinese umbrella
    • Need regular trimming
Intermediate Maintenance Chamber
1’ x 1’ x 1’
  • RO reject water and non-soap wash water from kitchen sink passes through this into the polishing pond
Polishing Pond/ Storage Tank
3’ dia. x 6’ depth
  • Round with a plastic cover and removable mosquito net
  • Previously cleaned regularly, now only pipes are cleaned
  • Created by lowering a 700-1000 litre HDPE tank into the ground

The treated water was tested and gave the following results:
TDS: 1660 ppm
pH: 7.7
H2S: Black after 48 hours - presence of coliform bacteria

20170720_135509.jpgIMG_20170723_152630106[6585] - Ravi.jpg

Earlier they would be very careful about watering the garden so as not to use up too much of the tanker water, but after the GWT system was set up, they are able to water the garden well.

Water Source Overview

The family of four uses about 30 KL of water each month. The breakdown of each water source can be seen in the table below.

Water Source
Layout Sump
  • Piped to houses and is stored in a 15 KL sump, then pumped to an OHT
  • Used for all domestic purposes and some is used in the garden, especially in the dry season
  • Billed every quarter; average Rs 10,000 per quarter
  • Harvested into the 15 KL sump which is mixed with layout water
  • Gutters on sloping roofs are still to be attached
    • Current rooftop runoff is very little
  • Surface runoff goes into a recharge wells on the road
  • System was installed in 2013
Grey Water
  • Treated in a planted gravel bed
  • Used only for gardening every alternate day
  • In dry season, it gets completely emptied and needs to be supplemented with layout water
  • System was installed in 2013