Thursday, June 22, 2017

Visit to Kaikondrahalli Lake for collecting data (Part 2) - March 10, 2017

This is a continuation from the previous post - http://biometrust.blogspot.com/2017/06/visit-to-kaikondrahalli-lake-for.html.


Instead of eating lunch, we go on to the next agenda item - to check the water level sensors. We noticed one part of the lake path cordoned off for construction activity.

--------------------------------------------------------

Odyssey water level sensor


This is the Odyssey water level sensor that has been installed. The counterweight makes sure that the sensor wire is held taut or straight so that water levels are logged accurately. The other end is the logger which logs the readings.

The sensing element is actually the teflon coated wire which is immersed in the water. So the wire inside forms one plate of a capacitor, the teflon acts as the dielectric and the surrounding water forms the other plate of the capacitor. The varying water level causes corresponding changes to the capacitance, which is detected and correlated to the actual water level through a process of calibration.

--------------------------------------------------------



The water level sensor was also installed at the same time as the DO sensor (Feb 16). It was installed in the 2 sewage inlets of the lake. This is one of the inlets. 

The data logger is inside the metal box at the top, the counterweight is resting on the sewage inlet floor and the Teflon-coated sensing element (the wire) is going up from the counterweight through the PVC pipe to the data logger. The frequency of sensing (how often the reading is taken) is set to 15 mins for this sensor.

--------------------------------------------------------



The logger is kept inside the metal housing, enclosed in a plastic bag to protect it from rain.

--------------------------------------------------------


The sewage water velocity is measured at different times by using a velocity meter - a different instrument. It can also be measured by a manual method. 

By multiplying the depth of the sewage water by the width of the channel and the velocity of sewage water flow, one can arrive at volume flowing per unit of time or in other words the flow rate of sewage. This multiplied by time (say a day) can give the amount of sewage that is flowing into the lake in a day. 

Shown in the above picture is a graphic illustration of the same with some example values.

--------------------------------------------------------


The data logger is connected to the laptop to download the readings for the last 3 weeks

--------------------------------------------------------

Scrutinising the readings to see if they look ok.

--------------------------------------------------------


The path to the next sewage inlet was blocked (intentionally) by a thicket of uprooted branches. We had to pry our way in through one side. Sid keeps the mobile lab box in the middle, to be picked up after we reach the other side.

--------------------------------------------------------


Stepping over the branches on the side to make our way and then climb up over the ditch to get on to the path.
--------------------------------------------------------



We reach the second sewage inlet where another Odyssey water level sensor is installed.

--------------------------------------------------------

Taking a look at the downloaded data readings from this sensor
--------------------------------------------------------


Starting the process of doing a field calibration of the sensor. The earlier one had been calibrated right after installation.

For calibration, readings are taken at 2 known heights (minimum and maximum) of immersion into the sewage. The actual sensor readings are compared with the known min and max values by the software and the differences are recorded. And the needed adjustment is automatically applied to subsequent data readings from the sensor.

--------------------------------------------------------




For marking the max point on the wire sensing element we find a plastic straw lying nearby and tie it around the wire.

And soon after (for which I have no picture trail) there was a mishap. Sid accidentally dropped the logger end into the sewage and despite scrambling quickly to retrieve it and cleaning it up, it appeared to have got messed up based on the readings that were observed after the fall.

So Sayan decided to take back the instrument with him to ATREE to check if it was just a temporary issue due to the liquid entering the instrument or whether it had got damaged permanently.

--------------------------------------------------------


After an exhausting day, we went to nearby Nandini's for lunch - at around 4 pm. Sayan and Sid catching up with the world.

                                       #ORCLCitizenship #tripszee #OracleGiving #atree_org

Friday, June 16, 2017

Municipal Water OR Rejuvenation and Better Management of Existing Water Structures


Perumbalam is a beautiful, green, practically untouched  island close to Ernakulam, accessible only by ferry. There are 15 common ponds and 8 common wells in the village - the kind that you only get to see in magazines.  There are about 2000 homes in the village and possibly  as many open wells and borewells. While water is available at fairly shallow levels people have taken to digging borewells as shallow as 8ft. It costs only Rs 4,500 to dig such a borewell (Bangaloreans may find it hard believe !!).

Due to the proximity of the wells to the sea, unlined pits for sanitation disposal , no open well maintenance and poor solid waste management practices (especially for the plastic and rejects) the groundwater is reasonably contaminated. TDS is high and there is bacteriological contamination in the ground water.

A Japan aided water scheme brings clean water to the village from the Muvathupuzha river which is commonly referred to as  Japan Water. The connection charges are low/high depending on how you see it and are waived off/lowered  in certain cases (BPL, SC/ST etc).  The lowest monthly tariff is Rs 61/- and monthly billing has not started as yet. Japan Water is certainly the preferred source of water given its availability and assurance of quality. Due to the possible availability of Japan Water and the reduced confidence in the qulaity of the open well water, the dependence on the ponds and wells and hence the maintenance of the ponds and wells has deteriorated over a period of time. There are small schemes to promote RWH and recharge of wells (a subsidy of Rs 6,000) - but that does not seem to have many takers.

The main trunk line for Japan Water has not been laid all across the village and  hence not everyone has access to this water. Not everybody has paid and bought connections either. People are however borrowing/lending water (where possible) and have worked out some system of payments between themselves - once the billing starts. The laying of remaining trunk line will cost a large amount of money and there are no monies or immediate plans for the laying of the remaining trunk line

The panchayat (and the village) thinks that any intervention to help them alleviate their water issues would be to raise the remaining money for laying the JW trunk line so that the entire island  can have Japan Water.  While there is lip service to the need for maintaining open wells they do not really believe that the open well can be a reliable source of water. The wells still exist, have water and it seems hard to imagine that this cannot be cleaned up

It is inevitable that JW will eventually come to the entire village. It also seems inevitable (given the state of our rivers and our demand for water) that the river will not be able to keep up with the water demand over a period of time. But in that time would Perumbalam have lost its groundwater and its knowledge too ?

This must be an oft played out story. Every time that municipal water has become the water source replacing local ground water. Over a period of time both sources have run out and recovery difficult. Bangalore could also be a case in point.  But this is one more time. And the same questions are to be answered.

What would be good steps to take so that the immediate water issues are addressed ? How do we ensure that shallow groundwater continues to remain in peoples' memories and is well managed ? 

The ferry

The island

A well

A recently cleaned pond

plastic

A dirty pond

The jetty



Thursday, June 15, 2017

The Dutch Well and Konkini Well in Chellanam

A Dutch Well and a Konkini Well in Chellanam ( a 40 min drive from Ernakulam) have been cleaned up and rejuvenated  with help from the Rotary. The wells are alongside the main road, fairly non descript unless someone pointed it out to you  and barely about 100m from the Arabian Sea. Both these wells used to be sources of clean drinking water for each of the communities. They are quite unremarkable in how they look but the age of the wells sure makes one want to look at them again. Water is available at just about 5-6ft below ground level

The Konkini well is said to be 500 years old. The well has a square cross section. The inner walls are lined with laterite.  The stones are as old too. Only the Gaud Saraswat Brahmins used to drink from this well

The Dutch well is slightly modern in comparison, only 350 years old. Circular in Cross section. This was for the Dutch

Due to the proximity to the sea, the water in both wells is fairly saline. TDS 1400 ppm. Hence rainwater harvesting has also been undertaken to redirect water from the rooftops of nearby homes into this well. Due to the availability of municipal supply not many people look to these wells as a source of water and perhaps hence the indifference. However when water is in short supply in the village, the community does look to these wells for water. Both wells do not dry up all through the year.

Both these wells are not far from each other and it makes for a good vision to imagine the dutch and the GSBs drawing water from adjacent wells !!

Laterite wall for the Konkini well

The Konkini well

Dutch Well

Now lined with  cement




 

Mr. Anthony's home in Chellanam

 Mr Anthony is 67 years old and lives in Chellanam, a 45 minute drive from Ernakulam, with his wife, son and daughter-in-law and his 2 grandkids. While there is Municipal water supply in the village he has chosen to not take the connection. He manages with rainwater and groundwater alone. This might not be uncommon in many parts of Kerala where people depend on their wells for water supply. However, in Chellanam, where there is municipal supply and where groundwater is otherwise saline - due to its proximity to the sea - this makes for an interesting story

TDS in some of the neighbouring wells in the area varies upto 1600 ppm. However Mr Anthony's well has 480ppm TDS (the home is right next to the sea !!) Some part of his rooftop runoff rainwater has been redirected to his open well which he uses for all his domestic water needs except drinking and cooking. The well is used both as a source of water as well as for recharge. Hence the water is a lot less harder than the neighbouring wells

Another part of the rooftop is redirected to an 8000 liter tank where he filters and stores rain water. This water is used for drinking and cooking all year round

All other parts of the rooftop runoff is held in small drums around the house - that his wife continually lays out and manages when there is rain. This water is used in toilets and for cleaning

They have a biogas plant too - supplies them fuel for about 1-2 hours everyday. The garden is a small forest - with all kinds of plants. There is a certain ease with which the couple seem to manage their home and lives

Mr Anthony is happy going about and managing his small systems. There is certain spark and happiness in Mr Anthony's eyes and speech as he goes about tending and talking about his systems 
The biogas plant
Rooftop water directed to the well

Rooftop water stored in an 8000 liter tank

The Arabian Sea - right behind his house

All drums are called in for storage

Mr Anthony and his systems


PAQM in the Apolitical

A participatory mapping project is enlisting local people to reform how aquifers are used in India


https://apolitical.co/solution_article/bengaluru-residents-fight-water-shortages-backyards/

Friday, June 9, 2017

Visit to Kaikondrahalli Lake for collecting data (Part 1) - March 10, 2017


Location of Kaikondrahalli lake

This is a photo-narrative blog of a trip to Kaikondrahalli lake in Bangalore. This is the first post of an ongoing narrative about a project that we are involved in. The intent behind this specific post is to expose the readers to some sensors that can be used to measure lake data, what they measure, the use of this data, and some practical difficulties that we encounter in the field. The next post will be about the results coming out of these sensors and what they are telling us. These sensors were installed 3 weeks ago and this is the first trip to check on them.

This ongoing initiative is part of the Citizen Lakes Dashboard Project - a joint project undertaken by ATREE (http://www.atree.org/), Biome Environmental Solutions (http://www.biome-solutions.com/) and Yuktix Technology (http://www.yuktix.com/) and funded by Oracle India Pvt Ltd. The objective is to create an open source platform for lake data that can inform citizens groups on how much water is actually entering and leaving lakes and real-time information on lake water quality. This data will be presented to the citizens over time to trigger informed conversations and play a role in the restoration and maintenance of lakes. Many thanks to MAPSAS (http://mapsas.org/) for helping facilitate this study.
Regarding the principal characters in this photo-narrative - Sayan is a research associate with ATREE, Siddharth & I are working as part of Biome and Venkatesh is the fisherman for the day.

----------------------------------
A view of the lake from the bridge close to the lake entrance

----------------------------------



I am meeting Sayan (blue t-shirt) from ATREE for the first time. Sid (in orange t-shirt) from Biome is talking to the fisherman Venkatesh. He will be rowing us to the point where the Dissolved Oxygen sensor is anchored. The security person is watching the proceedings with curiosity and the lake supervisor Das (donning the cap) seems to be amused about something!

----------------------------------

Sayan has brought an intriguing "mobile laboratory" and we will soon see this put in action in the middle of the lake!
----------------------------------

The coracle that we will be boarding soon. 

It has become very hot by now and there will be no shade once we get on board

----------------------------------



A quick primer about dissolved oxygen (DO): It is a critical component of the water which keeps aquatic life alive. 

It can drop to low levels due to domestic sewage flowing into the lake, which has organic matter that increases the oxygen demand. A combination of low DO and ammonia toxicity due to the input of nutrients from domestic sewage can lead to "fish kill" in a matter of minutes like it has happened in Ulsoor and few other Bangalore lakes in the past.

----------------------------------


We approach the DO (dissolved oxygen) sensor which is anchored in the lake bed and kept afloat at the other end with the ATREE buoy. This is ATREE's first experience with continuous monitoring of DO concentration in a lake

The units of measurement are in milligram per litre (mg/l). If DO level falls below 5 mg/l, it can affect aquatic life. This DO sensor has been set to take a reading every half an hour.

----------------------------------


The first task of the day: lab calibration of the DO sensor by taking 2 water samples at the same depth as the immersed DO sensor, take them back to the ATREE lab and measure the DO values of the samples. By comparing those values with the immersed DO sensor readings, the degree of error or "sensor drift" as it is termed can be determined. This drift occurs due to "biofouling" which is the build up of algae etc on the sensor casing due to continuous immersion in the lake.

Venkatesh eagerly volunteered to collect the water sample in a bottle supplied by Sayan. He had to bend down until the bottle was almost at the level of the sensor and then fill the bottle with the lake water.

----------------------------------



The dissolved oxygen in the lake water sample won't stay stable until it is taken back to the lab. Hence the oxygen needs to be "fixed" before its concentration changes. This method of testing for DO is called the Winkler test. The chemically inclined can look up the details at https://en.m.wikipedia.org/wiki/Winkler_test_for_dissolved_oxygen

The first step is to add Manganese Sulphate (MnS04) solution to the lake water sample. Sayan is taking out the MnS04 from its container using a pipette. Brought back dim & distant high school memories of chemistry lab experiments :-)

----------------------------------


After that, an Alkali iodide is added. The lake water sample can be seen in the bottle kept in front of Sayan.


----------------------------------

The bottle is shaken vigorously!

----------------------------------



The dissolved oxygen oxidises the Manganese ions and a brown precipitate starts forming. Sayan critically examining his handiwork :-)

----------------------------------




Now sulphuric acid is added. The acid facilitates the conversion of the iodide ions into iodine. The iodine concentration is what gets measured in the lab (through a process called titration) and is used for working out the dissolved oxygen concentration, through chemical equations.

Pretty darn fascinating! And all this happening on a coracle floating in an urban lake under the hot sun :-)

----------------------------------


Sid diligently notes down various readings including time, temperature, pressure etc.

----------------------------------

Measuring Venkatesh's arm length - this is the depth of the water sample. He stuck in his whole arm to get the lake water into the bottle.

----------------------------------

A second sample is taken. This time Venkatesh goes down deeper (based on the prior arm measurement). And then the same process of "fixing" the dissolved oxygen is repeated. The 2 samples are kept in contact with ice. The average of the lab results from the 2 samples will be taken for calibration. The adjustment is done automatically by the sensor software.

----------------------------------

Taking out the casing from the water, with the sensor inside. A fair amount of biofouling is observed.

----------------------------------


Removing the sensor from the casing.

----------------------------------


The sensor end from where data is transferred. The communication from the sensor to the computer is through light. Also, the principle behind the functioning of the sensor while measuring DO is based on light as it is an optical sensor.

----------------------------------

Attached to the "Coupler"
----------------------------------


The other end of the coupler plugs into the "Shuttle" which reads the data. This shuttle is particularly useful if you don't want to bring a computer to the field to download the readings. You can transfer to this device, take it to your office or home, and then transfer the data to the computer to analyse the readings.

----------------------------------


A closer look at the HOBO Shuttle made by Onset which is a US based company. This entire instrument chain - DO sensor, Shuttle, coupler and the software to read and display the data belongs to the HOBO product series.

----------------------------------

The yellow lit LED indicating that data transfer is taking place

----------------------------------

Venkatesh did not bargain for this endless sitting around. He looks lost in thought

----------------------------------

Cleaning the sensor end with distilled water
----------------------------------


Another kind of field calibration is being carried out. This is to set the 100% saturation reading. A sponge is soaked with fresh water, excess water is squeezed out and kept inside the black casing called the calibration boot. This is then affixed to the sensor.

After attaching, we have to wait for about 15-20 mins to take the reading so that temperature equilibrium is reached. This would correspond to 100% saturation value. Several readings are taken in succession until the readings stabilise.

----------------------------------

While we are doing the 20 mins waiting, Sayan has transferred the DO data for the last 3 weeks from the HOBO Shuttle device to his laptop and is examining it. This is the first time he is viewing data from this sensor (for this lake).

----------------------------------

Something doesn't quite look right! Is the connection ok?
----------------------------------

Something is really looking fishy about this data!!
----------------------------------


Sayan discovers from the data that after 1 week, the DO sensor's readings have drifted to a very low erroneous range. The conclusion is that the biofouling has caused this. The only remedy is that once every week the sensor needs to be taken out, cleaned and put back, to make sure it continues to function correctly.

----------------------------------

2 hours later Venkatesh looks thoroughly fed-up of this coracle sit-out!!
----------------------------------

Phew - we are finally done with the lake measurements. Our resident kayaker takes charge of rowing us to the shore. It's about 2 pm by now.

----------------------------------

#ORCLCitizenship #tripszee #OracleGiving #atree_org