Archive for April, 2012

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Gujarat and 50 towns plan

April 26, 2012

Concrete plan for Gujarat’s rurbanization involves the selection of 50 towns and setting up a virtuous cycle starting with the setup of waste water treatment plants and solid waste management projects in these towns. The treated water from  towns and villages would be distributed to nearby villages for irrigation and the solid waste used to make fertilizer. Increased water for irrigation is expected to increase the farmers’ yield but the boldest aspect of the plan is to make organic farming a focus and target organic produce for export to global markets.

 

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Some research agenda possibilities around groundwater-wastewater-lakes of Bangalore

April 24, 2012

POSSIBLE RESEARCH AGENDA FOR BANGALORE

  1. The Groundwater Bill has been passed by the assembly and the rules and regulations drafted. This will now be enforced. This is the time to understand and ensure that the sustainable management of groundwater in Bangalore becomes the vision of the Groundwater bill. Bangalore is the only city in India where thanks to the BWSSB an inventory of bore-wells exist. This is due to the fact that the BWSSB charges Rs 50 per bore-well or open well as Sanitary Cess.

Using this database it should be possible to slowly move into a regime of collection of a water cess on bore-wells and use the funds to reinvigorate the water bodies around Bangalore. These can then become recharge structures filling up the groundwaters and ensuring that the investment of Rs 5000 crores made on the bore-wells of Bangalore ( 5 lakh bore-wells at Rs 1 lakh per bore-well at minimum current costs) is not rendered defunct but actually contributes to the water supply needs of the city.

  1. Certain urban water bodies around Bangalore have been taken up for rehabilitation and revival. One of them is Jakkur tank part of the series of tanks detailed in the map below. This rehabilitation has been taken up by the BDA. Upstream of the tank is also a waste-water treatment plant taken up by the BWSSB capable of treating 10 million litres per day. With adequate removal of nitrates and phosphates and with further wetland treatment occurring naturally in the lake the groundwater availability can actually be a steady 20 million litres per day at least. Studies need to be taken up to understand the impact of both the tank revival as well as the waste-water treatment plant becoming fully functional on the groundwaters both on quantity and quality. With adequate treatment can this be integrated into the city water distribution system particularly since the Arkavathy layout is likely to come up here in some time ?

http://www.youtube.com/watch?v=seChnWR_v3g

The Cubbon park waste-water treatment plant has been set up by the BDA and now handed over to the BWSSB. This is almost a state of the art waste-water treatment plant. A study can be undertaken to find out how the quality if the treated waste-water can be improved for recharge and a small recharge pilot set up at Cubbon park and tests undertaken to see if the groundwater is suitable for potable use.

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With water quality where does the buck stop ?

April 17, 2012

http://www.youtube.com/watch?v=FVMdq5Qn2io

The blame game apparently has begun when accusations of bad quality water being supplied in several areas and causing sickness is being reported. What is the water quality to be ensured by any supplier of drinking water ? The water has to meet BIS-10500 norms. These constitute physical, chemical and biological standards with more than 30 parameters.  Unfortunately these are not legally binding norms but just standards. How does a water utility ensure that the water is potable ? Typically any water utility reduces physical turbidity through a filtration process and then doses the water with enough chlorine to kill bacteria. It then ensures that there is residual chlorine when the water reaches the consumer. Typical numbers are 2 mg/litre after 30 minutes of chlorination and 0.2 mg/litre after 24 hours of chlorination. Since the water supply is typically limited and usually more than 24 hours in cycle utilities absolve their responsibility the moment the water enters the premise. Water in sump tanks or overhead tanks is the responsibility of the consumer. Caveat Emptor is the motto.

 Most water utilities do not have any treatment against chemical contamination and rely on the fact that surface water sources do not have chemical contamination. In small and medium towns where the source is groundwater there is generally no treatment against such chemical contaminants as Nitrates, Fluorides and salts.

So what can be done? The only solution to no contamination of water in piped utilities is a 24/7 pressurized supply. This is the only way that it can be ensured that no sewage contamination enters pipes when there is no flow. All utilities must design systems for 24/7 supply. Secondly they must all be legally bound to supply BIS 10500 water. This should also be the norm for commercial water supply through private tankers for domestic purpose. Otherwise the water supplied should clearly specify that it is non-potable water. Water sourced by consumers directly through bore-wells, open wells and rainwater harvesting systems is the responsibility of the consumer and should be frequently checked for potability. Chlorine dosing and checking for residual chlorine is easy and every consumer wo is concerned should learn how this is done and check the water regularly.

Households who can afford it can and do take recourse to end of the pipe treatment systems such as filters, R.O. systems etc.  In the end while the blame games continue the consumer is wisest who has taken all precautions.

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History water and all that

April 13, 2012

Learning From history

S.Vishwanath

www.rainwaterclub.org

Over the years the shortage of rainwater is biting harder and harder. This year for example has seen a severe drying up of bore-wells. Private tankers scurry about and prices are up as is the waiting time. Quality of the water has deteriorated and worms are reported from taps which source water from groundwater.

Lakes and tanks are dry and command areas where once paddy grew, is now filled with construction debris to build the next large project. Storm-water drains are built upon or rerouted so that they flood nearby areas with the smallest storms.  There is no sense that a land –use plan is at work which respects water and its course and that we are fast running out of a precious resource due to sheer mis-management and callousness bordering on stupidity.

The only solution touted is the drilling of more bore-wells and deeper too. This deeper exploitation is magically supposed to solve water problems only it will end up exacerbating the situation in the long run.

Rainwater harvesting and protecting and deepening of lakes and tanks is resented as an imposition. Recycling water using treatment plants is objected to on the basis of a psychological barrier.

In the midst of this collective gloom there are some bright spots. Schools which have built large rainwater storage tanks find that they have better access to good quality water. They can use the tanks for additional storage and one filling lasts them months.

Layouts which could have collectively worked at exploiting water by drilling 450 bore-wells , one for each site, have invested in sharing the waters by drilling only a limited number of bore-wells and sharing it. The rest of the money has gone towards recharge and ensuring that every drop of rainwater is harvested.  Wastewater treatment and a well functioning system closely monitored helps access non-potable water.

In another house an existing open well has been recharged using a simple filter connected to the roof. This small well is holding out bravely in the summer and continues to provide the 500 litres needed daily.

In another layout , a large number of recharge wells connected to storm water drains have ensured that the bore-wells not going dry.

We need to find systems of multiplying good practices such as reducing demand, recycling water and harvesting rain. We need to eliminate bad practices such as leaking pipes, deeper bore-wells and filling up water bodies and drains.

A society that does not provide space for water is condemned to die of thirst. Older civilizations have collapsed in our own country when they mismanaged rivers and soil. Ours too should not share the fate. A virtuous cycle of development which involves more focused attention on preserving, protecting and investing in our water bodies is an urgent need. It is now or never.

 

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On looking after sump tanks

April 5, 2012

The sump in question

S.Vishwanath

www.rainwaterclub.org

Almost every house and apartment in urban India would have to have a sump tank to store water, a sump being an underground storage tank. Since water from city lines would be infrequent in supply, sometimes once in four to five days, stocking up is the only way to have access to it 24/7. The pressure at which water is delivered by city utilities is also generally abysmal. This means water will not rise to any level but an underground sump tank to be subsequently pumped into over head tanks for gravity based distribution. When water runs short sumps become the place to receive water from public or private water tankers.

Here is a list of things one needs to do to ensure that sumps work well.

Check for leaks: Sumps can leak copious amounts of water without us being aware about it. Fill up the sump tank to a level. Mark the level and observe overnight. If the water level has fallen by even as much as a centimeter it means the sump is leaking. Call in a professional service to repair the leak which is also done with a coat of leak-proof paint nowadays. Repairing a leaking sump will save you and the city thousands of litres of water annually.

Observe for silt: Too much silt may sometimes come in from the water source. By itself silt may not be harmful but it can choke up water lines especially damaging to washing machines, dish washers and solar water heaters. Removing the silt periodically and placing a floating intake outlet to the overhead tank can help.

Algae and moss: The rapid growth of algae and moss can indicate nutrient rich water and can also spoil the water as well as choke water lines. Cleaning the sump, scraping the algae and using bleaching powder to clean it once again should control this issue.

The float valve: A malfunctioning float valve from the inlet pipe can cause the sump tank to overflow and waste water. Check and repair the float valve periodically.

Outlet to sump: Sometimes an overflow outlet is given to sump tanks especially if it also used for rainwater harvesting. Ensure that the outlet is not blocked and cover with a mesh on either side to prevent lizards and cockroaches from entering.

Sump cover: These tend to be the weak points of sump tanks allowing dirt and dust to enter and sometimes rust too. The hinges need to be periodically oiled and painted with a rust proof paint and rubber sealed if possible.

Pumps: The inlet valve of pumps may choke or be blocked by dirt and silt; these need regular cleaning to ensure the efficiency of the pumps and not to overload the motors.

Residual chlorine: The city utility ensures quality of water through residual chlorine of 0.2 mg/l at the sump level. This ensures that all bacteria are destroyed and the water is not harmful. Using a small chlorine testing kit periodically check whether the residual chlorine is of the requisite level, if not take it up with the authorities.

http://www.youtube.com/watch?v=FVMdq5Qn2io

The overall storage of water created in cities like Bangalore through individual sump tanks built using ordinary brick or concrete blocks runs into millions of litres capacity. It is only fair that the city utility and individual owners look after this asset and ensure that it is in prime condition without leaking or jeopardizing water quality. After all the responsibility of the city water utility ends where the individual sump tank begins.

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