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On an urban community managed water system

November 11, 2013

The traditional in the modern – a community at work

zenrainman@gmail.com

At first glance you see a protective fence which is not impressive but as you approach the magnificence of the structure strikes you , a beautiful 120 feet diameter open well full of water and you wonder whether this is the Bangalore where groundwater is supposed to have sunk to 1250 feet. This residential layout on the South of the city has done a magnificent job of managing its water purely through community action. A dynamic association has taken charge and the committed team first cleaned up the ‘Rajakaluve’- the main stream linking water above and beyond , passing through the layout. Its attention was then focused on the beautiful heritage well on campus. The well was cleaned and a 100 truck loads of silt removed. The silt was place in the gardens and the open spaces rich in fertile soil.

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A beautiful old well revived and recharged – full of water 

The well now becomes a supplemental source of water for non-potable use and in case of an emergency with treatment for all uses. Each house in the layout has been encouraged to go in for rainwater harvesting. In the storm drains which run around, all of them are maintained clean and percolation wells are being placed so that the road run-off is recharged into the ground. Ultimately all run-off will be sent into the aquifer with the site becoming a zero discharge area for storm-water.

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Modified storm-water drain for silt trap and recharge – easy to replicate

A waste water treatment plant hums daily, treating and cleaning 200,000 litres of sewage from the entire colony. This treated waste-water too is reused in the layout. A 100 trees are planted every year and the waste water is used to feed the trees and the parks.

The community building where the residents meet , collects every drop of rainwater falling on the roof in large rain barrels and reuses them.

Begur 080Rainwater Barrels collect rooftop rain

 

 

On the day one visited the campus children had gathered at a science fair and were demonstrating various experiments that they had set up. Most of them centred around water. A group of them had already been taken for a tour  of the layout explaining what was happening with water and the necessity to keep the roads and storm water drains clean as well as to take care of the trees for the birds that are around.

A turtle was spotted in the well and was swimming about merrily, a cause for some excitement.

When communities come together it is possible to achieve the unthinkable, that is a clean environment and plenty of water with a bit of heritage thrown in. The more we expand thisn space the better for our urban areas. In this community awareness and action lies water wisdom.

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On the sump tanks of Bangalore

October 31, 2013

On the ubiquitous sump tanks of urban India

 

One of the significant urban features of India is the permanent HDPE tank on buildings. Usually black but with an assortment of colours including a somber black, a bright blue and a brilliant yellow with a shining white also thrown in. This reflects the water and electricity reality of cities, intermittent supplies of both which means storage is the only way that 24/7 supply can be ensured.

There is another ubiquitous structure which is also present in most buildings but which goes unnoticed because it is below the ground and hidden from view and that is the sump tank. Since water is not provided for construction purpose by the water utility the first construction on a site is an underground water storing tank called a sump. This sump is built even before a watchman’s shed sometimes. Here water will be purchased from private water tankers and stored to be used for construction. One estimate has it that there a million sumps in the city alone with an average capacity of 6000 litres. This means that the water storage capacity created is a staggering 6000 million litres. Remember that the city gets in about 1000 million litres every day.  Added to the fact that there is about 1000 million litres stored in overhead tanks the water storage by the city far outstrips that created by the utility.

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A sump tank under construction – Every building in Bangalore has one

 

Once the construction is completed the very same sump tank will be used to store the intermittent supply from the water utility. From here a pump will send it to the overhead tank to be reticulated by gravity to all the water points in the building.

Usually the sump tank is located in the North East corner of the site, especially for those who believe in Vaastu. The overhead tank is located in the South West for that is supposed to be the highest point of a building. Beliefs aside there are many technical things that should be carefully thought through to ensure that the sump delivers efficiently what it is supposed to.

The sump should be based on firm earth and with a good bed concrete. If the soil below is clayey or non-homogeneous it is better to build a RCC raft slab below. The side walls should not be compromised on and should be with good brick work using a nine inch wall. Alternately concrete blocks or hollow concrete blocks of good quality can be used. In high water table areas or areas of loose soil both sides of the wall should be plastered. The inside of the sump tank wall should be plastered with a waterproof compound on a wire mesh base. This will ensure that the sump tank does not leak.  After it is built the tank should be filled with water and checked that there is no leak. Any leak should be detected and fixed immediately.

Sump tanks are extremely unsafe spots on a site especially for children of construction workers and for others. They should immediately have a cover slab cast with an inspection cover securely locked. The sump cover should be rust proof. Aluminum covers are now available which are excellent.

The other things to remember are to use a submersible pump which is energy efficient. The submersible pump will save space being inside the sump. The pipeline from the sump to the overhead tank should be as straight as possible and with as few bends as possible. PVC or GI pipes of the right gauge and size should be used.

A ball valve regulates the water intake into the sump. This should be of good quality and should function effectively. In Bangalore the sump can also double up as a rainwater harvesting structure thus being multi-purpose in use. During the rains rainwater and during the non-rainy season water from other sources can be stored.

While digging in most places in the city good red earth will be obtained. This can be used for gardening and even for the making of earth blocks for the building.

An annual cleaning and maintenance is recommended preferably without wasting the water inside it.  During summer and during water borne disease outbreaks it is best to dose the sump water with bleaching powder and to measure the residual chlorine as 2 mg per litre after about 4 hours of the dosing. This will keep waterborne infections like cholera at bay.

Even though hidden from view the sump tank has an important role to play in the use of a building. A good design and maintenance will help extend its life and for it to perform optimally. In this understanding lies water wisdom.

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On the need for professional plumbing courses in India

October 3, 2013

The crisis of plumbing, where are the skilled plumbers?

 

Everyday miracles occur in our homes and apartments daily and yet we are oblivious to it. You open the tap in the kitchen sink and fresh clean water flows from it to wash the vegetables for cooking. You go and use the toilet and the flush takes away the waste from your sight cleanly and into a vast underground network of pipes which hopefully will then clean it up in a sewage treatment plant somewhere at the end of it. If anything distinguishes a civilized world from a less civilized one, it is plumbing. The provision of treated piped water inside homes and the taking away of waste-water has been the single largest lifesaver ever, decreasing mortality , increasing life span , reducing morbidity and improving quality of life overall. The great cities of the world are those which have built water supply networks bringing potable water home and underground sewers capable of handling all wastes including for a growing population. The invention of the flush toilet, which many regard as one of the world’s greatest inventions, also called for skilled plumbers to connect them to the sewage systems emerging.

From the days of Harappa and Lothal circa 2500 B.C.E or thereabouts, when the cities had a good sewerage and drainage system, to the current day’s plumbers seem to be a non-formal, ‘learn on the job as you apprentice’ trade. Great cities were built in the past and disappeared into the mists of history. Presently a construction boom grips our cities and yet one of the most crucial jobs that of providing water remains in the hands of a trade where there is no formal training institution and which has not professionalized itself. The most expensive fittings in the market for taps , showers , baths and flushes are put in place by untrained hands.

While it is true that skills not necessarily have to be learnt in formal institutions yet that there is no single poly-technic which teaches plumbing as a formal course to those wanting to enter the job market looks like a missed opportunity for the construction sector. There is also a great need to improve the skills of those who are already in the trade and who would want to take their income earning opportunities to the next level , perhaps even as as contractors or entrepreneurs.

Skill training for plumbers will improve the efficiency of design of buildings, improve water and sanitation handling abilities, ensure fire-safety and ensure the increased life of buildings since leaking water and sanitation lines are one of the biggest culprits for the reduction of life of buildings. Leaking pipes cause fungus and mold to develop and directly impact the health of the occupants. Blockages of pipes and sewers are a nuisance taking tremendous efforts to repair once a problem occurs.

Meanwhile Babu goes about his work in putting in place a new plumbing system for the house recently expanded and a first floor built. He has been in the trade for 13 years. He uses the crudest of methods to heat and join pipes. He has no idea on say putting a siphon type rainwater drain-out pipe which can reduce the diameter of the pipe and thus reduce cost for the owner. He has no clue on how to build a rainwater harvesting system which can collect at least 100,000 litres of rainwater for the building annually. The joints of the drainage pipe are reasonably well done but he has no idea how to have a dual pipe system which can reuse grey-water from the building and recycle it. The building owner and the contractor trust him completely and therefore are condemned to a sub-optimal design for the rest of the life of the building.

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Needed-Training institutions and skill up-gradation courses for plumbers

The Indian Plumbing Association, a newly formed body, has brought out its own code for plumbing including a Green Plumbers Code. It is valiantly trying to bridge the skill up-gradation and capacity building gap. They need the assistance of many a poly-technic and the skill up-gradation council of India to develop and deliver a special course to bring trained plumbers into the market. The construction sector will only benefit from such an effort as well as employment opportunities for the young in a trade which is life saving and very important. Water wisdom demands that society invest in skilled plumbers. That time is now.

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On the Twin Leach Pit pour flush toilet -TPPF

September 28, 2013

Of all the countries grappling with a sanitation problem India tops the list. The number of households without access to a toilet and defecating in the open is nearly a staggering 50 % of the total households in India according to the census of 2011. Even where there is a toilet many simply discharge into the open drains and do not ensure safe disposal. An economic loss of 6.4 % of the GDP amounting to a staggering 53.8 billion US dollars annually was one estimate by the World Bank in 2006 for India. Another recent study establishes a distinct link between open defecation and stunting of growth in children having far reaching implications for a young population.

 It is therefore time to revisit a technology more or less developed and fine tuned in India decades ago and which still continues to be extremely relevant for the sanitation sector. This is the Twin pit pour flush toilet – TPPF- to professionals in the sector.

 

The whole toilet users world is divided into sitters and squatters.

Then therImagee are wipers and washers. The Indian populace is largely squatters and washers. Keeping this factor in mind the TPPF has been designed. It makes use of an Indian squatting pan with a steep slope that uses just 2-3 litres of water to flush and clean. It has a trap with a water seal, usually a minimum of 20 mm. This constant presence of water in the seal ensures that there is no foul smell that comes back into the toilet and that no insects or cockroaches come into the toilet. A 75 mm diameter to 90 mm diameter pipe then takes the washed material to an inspection chamber. Here a diversion trap is made wherein at a time one pipe is opened.

These pipes lead to twin pits which are generally honeycombed. A typical pit would be about 1 metre in diameter and about 1 .5 metre in depth with a solid cover on top. The washed material from the toilet ends up in one pit at a time. A pit takes about one year to fill. Once one pit is full at the diversion chamber the pipeline to this pit is blocked and the other pipe is opened to allow the second pit to fill. The distance between the pits is usually at least a minimum of the depth of one pit i.e. about 1.5 mt. This of course depends on the space available.

While it takes one year for the second pit to fill in the meantime through process of bacterial action the first pit is sanitized for most bacteria, virus and worms. This can then be emptied usually using mechanical evacuation methods such as that of the vacuum trucks called Honeysuckers. The emptied material especially in rural areas can be further composted and used as an excellent fertilizer by farmers.

The superstructure of the TPPF can be permanently done with brick or concrete blocks and a roof of sheet or RCC. In other places they can also be temporary with just privacy ensured for use. Typically a TPPF toilet should cost around Rs 10,000 in most places in India.

Water should be made available only in small buckets of 3 litres for ablutions as well as for pour flushing. This will ensure that excess water is not poured into the pit.

Pits can be designed in high water table areas with a concrete bed and with a 50 cm sand cushion all around. The pits should also be a minimum distance of 8 metres from a water source such as a well or a Borewell. Pits can also be lined with charcoal and limestone to further improve performance and remove pollutants.

Experience has shown that a well designed TPPF can provide safe sanitation and containment of excreta and over the life cycle it can also be much safer than toilets connected to underground sewage treatments with no treatment plants which end up contaminating and polluting water bodies such as rivers and lakes.

In urban areas for those without access to sanitation such as construction workers and in rural areas where open defecation is the norm the TPPF should be pursued and made mandatory for all to use, Skills in its construction also can be developed rather easily .

It is time we revisited this sanitation technology seriously and managed it in a safe manner so that all of India becomes open defecation free, safe sanitation is practiced and the health benefits accrue to all especially the young generation.

In safe sanitation lies water wisdom. 

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When the rain gods favour- stock up.

September 21, 2013

Monsoon Blessings

 

Summary:           It is in years of plenty that we should stock up for times of shortage

Many people are moving into a problem solving mode but it needs institutional reinforcement to help achieve maximum benefits.

 

The major Public Sector undertaking has a very large campus and has a huge water demand. It draws water from the Bangalore Water Supply and Sewerage Board and pays a hefty Rs 60 per kilo-litre for the water. Being water smart, it has set-up a waste-water recycling unit and ensures that all waste-water is treated and reused for non-potable purpose particularly gardening .Lawns are extensive in the campus and is needed for dust suppression. The unit has also set up a huge lake to harvest run-off from its vast land. More than 170 million litres of storm-runoff is stored in this vast lake.

Their attention has turned to the large rooftop areas they have on campus. From 11,500 square metre of roof area, they simply connected the rainwater downpipes and brought it into a small 20,000 litre sump tank. From here they have put a pump to send the water directly into a much larger sump tank which takes water through a Reverse Osmosis unit. This R.O. water is needed for their manufacturing purpose. The investment they had to make was Rs 10 lakhs.  Was the investment worth it?

The benefits translate as follows. They are likely to harvest 10 million litres of water annually. This will result in a savings of Rs 6 lakhs annually. The payback period for the investment is thus less than 2 years. There are other benefits. The embodied energy in alternate water, either from the BWSSB or bore-wells, is roughly 2 units of power per kilo-litre of water. The industry will therefore save nearly 20,000 units of power annually. This also translates as a savings in carbon emissions.

There are other benefits. The harvested rainwater is very soft with a Total Dissolved Solids of less than 50 ppm. This is likely to reduce further as the initial leaching of cement from the sump tank and the pipes become less.  As against this the water they used from bore-wells had a TDS level of nearly 1000 ppm. The life of the membrane used for R.O. now increases. The reject water from the R.O. has fewer salts and can be recycled more easily than before.

The advantage is clear and it is likely that the industry will move quickly ahead to cover all roof-tops with rainwater harvesting systems. This means that over 100,000 square metres can be covered and over 100 million litres of rainwater harvested. No small feat for an industry located in a water scarce city.

A University: The University of Agriculture with a sprawling 1200 acres campus was once outside the city. Now it has become integral and falls within the Corporation Limits. Its water demand for agricultural crops is high. Most of the water comes from bore-wells. These are over exploited and many have gone dry. It has designed for itself a watershed based rainwater harvesting system. Thanks to a bountiful September rain a great amount of water has been collected and allowed to percolate into the ground. Many bore-wells have revived and are humming with water. The University is able to meet its water demands and students and Professors can continue to develop knowledge with experiments on the ground.

Groundwater banks are being created in the city by institutions that occupy large tracts of lands and have large rooftops. These efforts supplement the water delivery to the city and make the city water smart. Things have to be scaled up and more such institutions brought into the rainwater harvesting community. Further deeper understanding of how much water is actually recharged into the ground, what is a reasonable water demand to keep the groundwater banks humming for 2 to 3 years will ensure that the water shortfall in the city is overcome. Creative solutions using knowledge is the hall mark of the city and in this lies water wisdom.

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Building bye-laws and sanitation in urban india

September 16, 2013

Summary:

1. Building bye-laws should recognize and insist on the provision of a rainwater harvesting recharge well within the site.

2. Building bye-laws should also recognize that non-sewered areas will have to make provision for two concrete ring lined pits for sanitation waste. One pit for black water and one pit for grey water. These can be mechanically emptied using vacuum trucks. The pits too should be located within the site of the building and not be allowed to discharge into storm water drains for public safety, health and hygiene.

 

Building bye-laws help regulate and maintain a certain discipline regarding the management of water and waste-water in urban areas apart from their role as a major urban planning tool.

Some of the good things they do are for example the insistence on identifying a toilet of a minimum dimension in any house construction before approval .In the Bangalore context rainwater harvesting is made mandatory and the building approval plan to be submitted has to show the recharge structure that is to be implemented.

It is surprising therefore that they miss out on some basics and do not refine the old. Take the rainwater harvesting detail that the Bruhat Bangalore Mahanagara Palike insists on. This is how the design looks like, a recharge pit filled with crushed stone and sand with a splash pad on top.

 

 

 In the days were sand dredging or mining has caused devastation to rivers and soil why insist on an archaic design that uses sand and gravel inside it? The design by the Bangalore Water Supply and Sewerage Board (BWSSB) is much better, a recharge well with no sand inside it. It works perfectly well and in fact, if the hydro-geology favours, a recharge well can easily become a withdrawal well. This building bye-law for a recharge well instead of a sand filled pit can easily be made mandatory for all the towns in Karnataka.

 

Sanitation: While building plans sent for approval have to show toilets, unfortunately there is no insistence on clearly indicating how the waste is to be disposed. While larger buildings and apartments have Sewage Treatment Plants made mandatory, the smaller ones do not have to show any system of appropriate waste disposal. Since septic tanks are costly precast concrete ring pits are used commonly as they cheap and easy to install. Unfortunately most buildings make only a single large pit located outside the house on the pavement or even sometimes the roads. This makes it very difficult for future road works or for water supply and sewage lines to be placed when infrastructure finally arrives in that area.

To remedy this situation the building bye-laws should insist that each building have two pits for sanitary waste disposal. One of the pits should be for the toilets and one for the grey water. The pits can have a small PVC pipe fit to the covering lid to enable emptying using the vacuum trucks called Honey-suckers. The pits should accessible and located appropriately to the front or to the side of the building.

 This one insistence in the bye-law can eliminate the scourge of manual scavenging, clean up the storm water drains and improve the hygiene of our small towns dramatically reducing the disease burden.

It is time for building bye-laws to recognize reality and become water wise.

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The religious practical disconnect on our behaviour with water in India

August 31, 2013

The spirituality and prosaicness of water

Rivers are the birthplace of civilization and civilization the graveyard for rivers is a very famous quote which rings true in present day India. As the Ganesha festival approaches those who work on keeping water bodies clean are filled with a feeling of dread for the modern day reveler will bring large statues painted usually with toxic lead paint and immerse them in wells, tanks, lakes and rivers not to mention the sea.  Why is it that we have become so dissociated from our spiritual practice and our everyday life and refuse to see the links between what we believe in and what we end up doing is an exercise in sociology and human behaviour? 

The Vrishabhavati River is the only river that originates in Bangalore. One saying in Kannada says do not go hunting for the source of a river or the antecedents of a sage. As much as the Cauvery is supposed to originate at Talacauvery, the Ganga at Gangotri, the Vrishabhavati is said to originate at the famous Bull temple in Basavanagudi. That which originates from the mouth of a bull – Vrishabh being the bull – is a name given to the river on this belief. The temple and hence the river at its source is a place of worship. The desecration of the river begins almost immediately. Sewage and garbage are the components of the desecration of what was once a pristine river and this is the gift of urban Bangalore to the river. By the time it flows out of the city to a magnificently large reservoir at Bhairamangala it is dark, black foamy water polluted beyond redemption one would imagine. Yet nature tackles the river into its embrace as do thousands of farmers forced to use this water for their crops and for their livelihoods. A slow transformation of the waters begins and in about 20 kilometers the river is partially redeemed. The waters that flow then to join the Arkavathy are cleaner than what the city left it. This is called the absorption capacity or the cleaning capacity of nature.

The Cooum originates reputedly from a well close to Chennai.  Cooum- that which originates from a well- hence the name given to the river. It too faces an urban onslaught and is greatly polluted. Unlike the Vrishbhavati where it is land that cleans the river, it is the sea which has to redeem the river, receive its polluted waters, dilutes it and hence cleans it.

The construct of reverence, desecration and redemption runs right through our urban civilization. Efforts are on to put in place waste-water treatment plants and ensure that all sewage is collected and treated but for now it is a losing battle.

What can apartments do about this issue? For one many make arrangements for the Ganesha immersion. Make sure that with due sanctity and respect the whole event is conducted with no net negative impact on the environment.

In many tanks across Bangalore separate Kalyanis have been built to receive the idols and the flowers that come with it. These are then able to be kept clean and prevent pollution of the larger water body. Make use of these. Better still make small Ganesha without paint so that they dissolve in waters without much trace.

Many apartments are now mandated to have their own sewage treatment plants. Make sure that the ones you have are in working condition and treat the water to adequate levels as prescribed. In negotiations with the State Pollution Control Board the treated waste-water can perhaps be release into neighbouring lakes through a constructed wetland. This will not only clean the water up further but keep the lakes full and away from encroachment.

Engage with garbage including segregation. Clear collection and then transportation to the designated treatment sites.

Keeping the environment clean is everybody’s business as is reviving urban water bodies including lakes and rivers. The joy of clean flowing water or a full lake is an experience that all especially children deserve and making that happen in our times is the challenge. That challenge being addressed would be water wisdom. 

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