Tuesday, September 30, 2014

Toilet to Tap: A reality in Bangalore

All of us Facebook users were swept away by the ice bucket challenge created for raising money to patients being treated with amyotrophic lateral sclerosis (ALS) disease. Of all the positive and negative statements about the challenge, one activity has stood out. Matt Damon, (an Actor and founder of water.org) reusing toilet water (https://www.youtube.com/watch?v=DlGhuud-s4w ) to take the challenge while raising awareness about finite resource like water. Owing to the extreme drought like condition in California (Check the link given below) and other parts of the world, a search for reusing wastewater and minimizing dependence on extraction of water is getting priority.

But why go till California when we have our own "toilet to tap" working efficiently!

TZED Homes is 95 flat complex located in Whitefield, Bangalore. Again, like most of the Bangaloreans, this apartment also doesn't get Cauvery water supply. The primary sources of water were borewell and tanker water. The campus is huge in area with 5 acres and large garden space. With the increasing dependence on tanker and borewell water and observing liters of wastewater go down the drain, the need was felt to harvest rain water and waste water for reuse.

As one can imagine the resistance for such concept, many residents had reservations about recycling of waste water for uses other than for garden, carwash and house keeping. There was no precedence of any other apartment complex anywhere in India reusing STP-treated water for uses other than the above. A water committee was formed of passionate individuals to look at these issues.

Srinivasan Sekar, who was a member of the committee, started researching on whether any community around the world was re-using treated waste water for other purposes. He also initiated regular water testing of the treated water, bore well water and tanker water, and found to his (and others’) surprise that STP-treated water consistently came out to be equal or better quality than bore well and tanker water. This discovery led to exploring use of STP treated water for other purposes beyond gardening, car wash and housekeeping purposes.

Several discussions, research into water purification and a series of redundant filters later, TZED Homes designed a system which allows for STP-treated water, after further filtration, to be reused along with bore well water and rain water (tanker water was stopped completely) as input for the RO system, and be re-circulated to residences for general and potable use as well.

Below table is comparative mark up of changes over the years at TZed Homes:

(10 X 7000L) Tanker + (40-60KL) Borewell water to RO unit
40-50KL Borewell/ Rain water and 30KL of STP treated water to RO unit (latter after additional filters)
Daily water need was 90KL RO water with about 30-40KL of RO Reject sent to storm water drain
Daily water need is about 50-60KL of RO water and 20-30KL of RO Reject sent to gardens
40-50KL of STP treated water – about 30-40 KL used for gardens, car wash and housekeeping, rest to storm water drain and/or recharge wells
40-50KL of STP treated water, with about 10KL mixed with RO Reject for gardens, car wash, housekeeping, rest to further filters for RO unit
STP treatment is SBR, with one carbon, one pressurized sand and one Chlorine dozer unit.
After STP treatment, an additional pressurized sand, activated carbon, ozonizer is used before RO unit (which has one more sand, carbon and micron filters)
3 borewells dry (at 250,300ft), one borewell at 650ft yielding intermittent water
All 4 borewells yielding water at 80 ft. Only two used each day alternating.
Water rationing – no water from10AM-4PM; 12 midnight-4AM; lots of water leakages into ground
No water rationing; no water leakages; replaced flushes with timed flushes; aerators on taps; a large swimming pool is included in the water cycle too.

In summary, TZed uses approximately 30-40 KL of total treated wastewater generated in all houses. It is essential to keep in mind that along with the several advantages of reducing pressure on groundwater, the technology needs regular monitoring. STP needs an operator and maintenance cost of approximately 1Lakh per month. In addition, ways should be devised to utilize the amount of sludge generated as a result of wastewater treatment. As mentioned above, TZed being a large campus with big garden space is making manure out of the sludge and reusing it in their garden.

Moreover, it is useful to look at this initiative not only as a technology solving the water problem as technology has always been there but also from a behavioral and psychological perspective as it is the residents who have shown courage and innovation to take up such initiative and took a conscious step towards solving the issue. As Mr. Srinivasan Sekar, a flat owner of TZed and the man behind this change says cheekily, "People have become conscious of what they put into their drainage. Because whatever you put in (paint, chemicals, crackers) is going to come back to you".

Check some other initiatives in California, Singapore, and Namibia for wastewater reuse:

Monday, September 22, 2014

Participating at the ELCIA Expo 2014

BIOME Trust got to participate in the the Electronics City Industries Association Expo 2014. The stall was put up to create awareness about ground water and the ground water mapping project. Some of the visitors were keen to know how they could directly benefit from this project. A lot of the queries were also around Water Quality test meters - costs, where one can purchase them from and methodologies to treat water (this is useful information and merits a separate blog). The video "How water comes to the borewell" was also of interest to many
How much energy does it take to
convert ground water to drinking water 

TDS/pH meters

Dinni and Rajiv explain

Wednesday, September 17, 2014

The Economics of being a Water Tanker Operator

This blogpost is written with the explicit intent of getting a volunteer/intern who can help us with a specific problem.

Problem StatementMany apartments/layouts on Sarjapura Road (elsewhere in Bangalore too)  have excess treated STP water - after flushing/gardening. Since there is no UGD in the area, tankers are called to take this water away and there is a price that is paid for this transportation (alternately this water is disposed off quietly ot the nearest low lying area). On the other hand Parks/Trees on medians need to be watered. Water (Ground water) is separately bought for this watering of trees. Ideally it would be a good match if this excess treated water could be used for these landscaping purposes. We think that this is an idea worth exploring and could result in a scalable solution for management of treated waste water - especially in areas where there is no BWSSB water supply and groundwater is depleting very quickly.  And yes - there will be issues like chlorine/smell/pathogens in treated waste water - but we will have to deal with that in a separate post

The solution should be such that it is environmentally wise as well as ensures that the expenses/profits are managed optimally.

This where the economics part actually starts
  1. A water tanker/honeysucker (vaccuum pump truck for picking up sewage) costs between 12 lakhs to 15 lakhs to put together (About 10-12 lakhs for the chassis + 1.5 lakhs - 2.5 lakhs for the body building + 50k - 60k for the insurance/registration)
  2. Banks finance upto 80% of the chassis cost. On an average the installments for a loan of about 4.5L is Rs 16,100/- monthly for a period of 3 years. (works out to 5,79,600 paid back in 3 years)
  3. The drivers are paid a salary of about 10k - 12k per month. The operator typically also buys them insurance. 2 drivers work on near 12 hour shifts so that the tankers run all 24 hours. Making about 24 trips a day. So we can put salary costs at about 25k per tanker
  4. Annual insurance is 30k
  5. Diesel at about Rs 65/- per liter and gives a mileage of 4.5km - 5km to the liter
  6. Maintenance costs (servicing, tyre changes, other repairs) are at about 60k per year
  7. A tanker load of 6000 liters costs about Rs 500 to the buyers. The tanker operator himself is typically buying this water from the borewell operator at about Rs 270/- per tanker
  8. The costs of picking up sludge/waste water 4,500 litres is Rs 1,500/- 
How do we get all this to work ? And will this work at all ? 

If you would like to know more/help out with the specifics - please reach out to water@biome-solutions.com

Monday, September 15, 2014

Water management at two government schools in Narasapura, Kolar

Narasapura region in Kolar district has become synonymous with industries over some period of time. Amidst this industrial township, two government schools also exist.

The first school is at Jodi Krishnapura and the second one is at K.B. Hosahalli. Like many of the peripheral areas in Kolar district, this region also faces the problem of high fluoride content in the water. Tackling high fluoride content becomes more important in the context of this school as research has shown that continuous and long term exposure to fluoride affects children more than adults as they are more vulnerable with soft enamel. Thus, providing safe drinking water becomes imperative. Jodi Krishnapura school has been lucky in this sense because Canara bank has put up a de-fluoridation plant in this village and hence, safe drinking water is available to this school. An interesting fact that came into light is that the fluoride reject water is collected in a tank which is reused for hand washing, etc. This system is not available to the school of K B hosahalli and for this school depends on Tata Swach filter to treat the water. However, this doesn't solve the issue of fluoride in water.

While Jodi Krishnapura doesn't face drinking water issue, it does face problem of access to water in toilets, in kitchen, in an anganwadi, etc. K B Hosahalli school also faces similar problem of access to water as storage is present only in one of school premises and kitchen, toilets, and other school premises are separately placed. 

Under the Swarna Jala Scheme of Government of Karnataka, rainwater harvesting structures were installed in government schools across Karnataka which included these two schools as well. However, both the systems are non-functional with broken pipes, lack of connections, etc.

We understand that, providing technical recommendations would not have a long term and sustained impact on any of the issues. And hence, involvement of school kids (6th/7th class), school principal, school teachers, school development and management committee (SDMC) and Cluster Resource person (CRP) of that district is equally essential. Thus, separate sessions were conducted with each of these stakeholders.

Session with kids and teacher: Water quality testing kit (JAL-TARA Kit) was used to demonstrate the process of water quality testing for fluoride and bacteria. Students were involved in conducting the activities like drawing water sample, mixing up solutions. Teacher was reminded to keep a tab on test time, to check results, and an exercise was given to students to conduct mapping and checking of several water samples within their village.

Separate session with SDMC, Principal and CRP:  Two grampanchayat's in a village have one CRP. Each CRP has 15 schools under him for supervision. The CRP of these two schools is Mr. Kolappa who has been very proactive during our interactions.  SDMC is an association of parents and teachers in the school which takes care of every issue the school is facing. SDMC consists of 13 members from parents, 3 permanent teachers as members and 3 donors making the total of 19 members. This session was also insightful as mutual consent is necessary before taking up any plan and monitoring of the implemented plans would involve this group actively.

Now, the further work will involve:
  • To address the access to water problem in both the schools, construction of overhead tanks with connections to areas where that is needed and repairing the rainwater harvesting system is recommended.

  • In K B Hosahalli, we came across an old, abandoned and dry well in school premises. Recharging this old well through redirecting captured rainwater into it would take care of the water needs.

  • To address the fluoride problem in K B Hosahalli school, we are still pondering over the options.
  • Setting up of new set of toilets, roof over the toilets is also suggested

Water Level Sensors

The Aquifer Mapping Study involves measuring the current water levels in the borewells being monitored. To do this, we make use of a water level sensor. This equipment has a tape marked in feet and meters and wound around a metal spool. One end is connected to a circuit and the other end to a probe. When the tape is lowered into the borewell and the probe hits water, the circuit is complete and sets off a buzzer and/ or a light. The whole equipment is powered by either a 12v battery or a couple of 1.5v cells. Due to issues like the tape and/ or the probe getting stuck in the borehole, we have had to abandon/ replace these equipments over a period of time.

Currently, we are using our third different equipment. ACWADAM helped procure our first equipment from a local vendor in Pune. This had a total depth of 150 meters and tipped the scales at around 6 kgs. It served us for a while before getting stuck with around 80 meters of tape inside a borewell.

The second equipment was bought from Mr. Anil Gangisetti (Sri Laxmi Sai Scientific Services - Hyderabad). It developed issues on the first day of use. Problems were zeroed down to a drained battery and a defective probe.

While awaiting a replacement probe, we procured another one from ATREE where Ms. Apoorva has developed a low cost sensor. While the previous equipments had a submersible probe, this one featured a float based probe and it is immune to intermediate streams of water in the borehole. As the float probe was a tad thicker in diameter than the probes in the previous  equipments, we had issues in inserting the sensor in some borewells having a smaller hole in the borewell top metal cap. This was much lighter than the previous two equipments (~3.5 kgs) and the spool was big enough to have the cable intact unlike the previous equipments in which if the tape was not wound tightly enough, it would start coming out of the spool frame.

The float probe got stuck in one of the borewells but we could retrieve most of the tape except for the final 10 ft.


Sunday, September 14, 2014

All Weather Station for Aquifer Mapping Study

We are in the process of procuring and setting up a weather station in Sarjapura road to monitor rainfall among other weather parameters. While we were researching on availability of such stations in the market, we chanced upon http://blog.knowyourclimate.org/2014/a-citizen-weather-network/. They (Saurabh Chandra and Pavan) are experimenting to collect and publish real time weather data. The All Weather Station was done in collaboration with a local start up (Yuktix).

We got in touch with Rajeev Jha of Yuktix to discuss about procuring one for the Aquifer Mapping Study. The plan is to install this weather station in Rainbow Drive (a gated community layout) after discussion with their Resident Welfare Association. This system will monitor Rainfall, Temperature, Pressure, Humidity and will beam data to a cloud server every 3 minutes. The system can run either on grid supply or solar power.

Some pictures of the system installed as a part of the Citizen Weather Network



Wednesday, September 10, 2014

Mindtree in Bhubaneshwar: Low footprint campus

Mindtree is building a software training and development facility on 20 acres of land in Bhubaneshwar . Water is currently available at 80ft below ground level.  

Making the mud blocks
So far 6 lakh bricks have been manufactured
Compressed Soil blocks made out of the excavated soil from the campus are being used for construction. All the rainwater that falls on the campus as well runoff from an adjacent hill as well as from a nearby office campus pass through the Mindtree campus. Mindtree has constructed a storage sump of 1 million litres to store and reuse rooftop rainwater. All other runoff from the neighbourhood as well as surface runoff from its own campus it being recharged into the ground through 60 recharge wells of about 7.5 KL (7,500 litres) capacity each - a total static recharge volume of 450KL (450,000 litres). In addition to this a pond of 15 Million litres (15,000,000 litres)  has also been created to hold excess runoff water. After all Bhubaneshwar does receive 1.5 metres (1548mm) of rain in a year and during a cyclone the daily rainfall itself could be in excess of 300mm.  Once the entire system is in place the plan is to manage all water requirements through stored rooftop rainwater or water from the pond and wells as well as STP treated water. Even the borewell is not proposed to be used for as long as possible.
Mixing the soil

The construction with mud blocks as well as the planning for use of rainwater and treated waste water has ensured that this will be a low footprint campus. 

Credits are certainly due to the architects(CnT) & services consultants(McdBerl).

soil blocks

digging the well and placing rings

temporary top cover

walls made of soil blocks

5ft dia for the 10 top 10ft
and 3ft dia for the next 10 ft

Well has filled up before completion

Overflowing well

15 million liter pond
silt trap to the pond

Site office - Rajiv explains

The 2 hills

Monday, September 1, 2014

Water at 9ft below ground Level - on Sarjapura Road

Dewatering and Pumping
Trinity Woods and Acres is a 7.5 acres residential community. As part of Rainwater Harvesting implementation it was decided to dig a 6ft diameter and 40ft deep recharge well at one of the lowest points in the layout that is near their currently yielding borewell (which is adjacent to Sarjapura Road)

6ft of Water
Dewatering with a bucket does not work out
Work proceeded uneventfully till we struck water at about 9ft. The water had no odour, looked clean , pH 7.5 and TDS 1100ppm. The water seemed to continuously flow in at about 6-10 litres per minute. This made further digging difficult and with a dewatering pump we were able to deepen the well only till about 15ft below ground level. Water had to continually be pumped out every 5-10 minutes to aid digging.  Rings were placed immediately to prevent the collapse of the mud walls.

Discussing Next Steps
Work was temporarily put on hold due to Ganesh Chaturthi. When we returned 4 days hence to the well this morning we saw clean water - about 6-7ft of it ( 5000 litres +). The apartment is of course very happy and would like to see the well as a source of water

Some of the key questions to which we would like to find answers for are :

  1. How much water will this well yield per day and for how many days of the year ?
  2. Is this rainwater ? What is causing the high TDS .
  3. Covering the Well temporarily - after End of Day
  4. How are the soil/rock layers below this source of water ? How is it that water is available at 9ft below ground level and not at 1000ft below ground level in the same vicinity
Further monitoring and data collection  will reveal interesting results. We are quite looking forward to it