Strategies For Survival

Blog No. 5. I have already given the information in my earlier blog that I was involved in the Water Resources Management Project at the Institute of Water Studies, Taramani, Chennai – 600113, reported earlier in my Blog. I was in the project for almost four years during 1986 to 1989. I did have opportunities to have intimate discussions with the consultants on various aspects of managing the water resources. I was told that we do not have anymore water resources within Tamilnadu to manage but have to manage only the demand of water. So we have to evolve strategies to reduce the demand of water. One of the components of consumption of water is the quantity required for raising food crops. Reducing this demand is one of the strategies. We must think how the agricultural demand of water could be minimized. Again I asked myself do we really need the amount of food stuffs we consume daily. There is an interesting episode which will be published at a later date as I still require some additional information to gather from my papers. Another strategy I could think of is the reducing the domestic water supply demand. I thought of a strategy with reference to the existing conditions of Madras, now Chennai. This strategy should attack both the pollution and water supply at one stroke. I was of the opinion that it is not possible to supply potable grade water by the present water supply mines as it gets mixed up with sewage from sewerage network. The Metro Water and Public Health authorities advise boiling of water for drinking and cooking. In almost al the developing countries only mineral water is used for drinking. So I thought it will be the case in our country also in the future. So it is enough non-potable grade water is supplied through the water supply system. The domestic non-solid waste is conveyed miles together to a distant place for treatment and the partially treated effluent is drained to the sea, en route it pollutes the water supply mains. Similarly water supply is also to be decentralized. Both sanitation and water supply should be managed in an integrated way. The following suggested approach is expected to meet the water requirements: 1. The individual houses in the thickly populated area is to be grouped together and sewage is to be collected in a place within the area and treated using advanced space saving technology to potable grade and the effluent used for recharging groundwater. 2. Community sanitation blocks to be built to be used for all the purposes including washing clothes and bathing etc., and the effluent treated to non-potable grade and used in the complex and the surplus, if any treated to potable grade used to recharge groundwater. 3. Business establishments and multistory flats should have their own sewage treatment facilities within their campuses and the effluent treated and recycled for non-potable uses and the surplus, if any, treated to potable grade to be used for recharge of groundwater. 4. For water supply, wells or bore wells to be sunk at selected places in the above area and the water after RO treatment to potable grade may be supplied to the residents of the locality at subsidized cost. 5. Business establishments and multistory flat complexes to make their own

arrangements for the water supply may be bore well with RO plant. 6. The fertilizer manufacturers to lift the sludge for further processing and distribution to the farmers. This will help the farmers to switch over to organic farming, save the import of raw materials for the manufacture of fertilizers, the recharged aquifers will provoke subsurface flow to the streams, Cooum and Adyar facilitating perennial flow and will clean them in due course of time. This was in my mind when I prepared a paper ‘Strategies for Survival’. At the epoch I was attached to Shanmugavel & Associates and practicing as a Valuer and civil engineering consultant. One day Er. Shanmugavel asked me to contribute a paper to the National Seminar on environmental Engineering (Traffic through Madras Water Courses) held at Dr.Dharmambal Govt., Polytechnic for Women, Madras – 600 113 for women during 3 &4, March 1994 and said it is urgent. I am attaching a copy of the paper without sketches mentioned in the paper for perusal and comments. STRATEGIES FOR SURVIVAL

S.N.Mahalingam, Professional Engineer "FOR ONE WHO LIVES ACCORDING TO ETERNAL LAW, THE WINDS ARE FULL OF SWEETNESS, THE RIVER POUR SWEETS" - A VEDIC POET "THE MOVING WATERS AT THEIR PREIEST LIKE TASK OF PURE ABLUTION ROUND EARTH'S HUMAN SHORES" - KEATS Water is essential for survival of life next tom air. This water acts as a medium, which dissolves the nutrients for the consumption of the life forms for their sustenance. The same water removes the toxic wastes from the living organisms as well as watersoluble inorganic and organic wastes. For example, toxic wastes from the human body, in the form of urine sweat and excreta. Similarly the toxic wastes accumulated in the landmass are flushed during floods to the sea through the rivers. The quantity of toxic elements present, for example in urine and blood will indicate the state of health of a human body. Just like that the toxic elements present in streams and rivers will indicate the state of their catchments, i.e., the degree of degradation. That is to say that if the water flowing in the rivers and streams is sweet and potable then we can certainly say that the area drained by the river has not degraded or undergone minimum degree of degradation. Generally a river draining an area untouched by humans, virgin land, is found to have sweet and sweet and potable water. When man trespasses into a virgin land and starts exploiting the resources in the name

of development, the quality of water in the river starts to deteriorate and when overexploited, above the limit of sustainability, the quantity of flow decreases and its quality deteriorates. The flow of water may also finally stop depending upon the extent of degradation. This indicates that the degraded land drained by the river has accumulated toxic substances, organic or inorganic. What was the condition of all the rivers in the past? There was flow of sparkling water with different types of fish roaming about. They were used for drinking and cooking. A century ago, when the Saint Ramalinga Adigalar was discoursing in and around Chennai, the Coovum River was used for his morning ablutions. The Chennai City and its suburbs were studded with a number of irrigation tanks, which charged the ground water, and the private wells contained unfailing quantities of sweet water. Seawater intrusion was not heard of in those days. Of course the population was very much less. At present the rivers and nallahs of Chennai were nothing but sewage drains, the irrigation tanks which recharged the ground water and arrested the sea water intrusion have disappeared due to the materialisation of housing colonies patronised by the politicians. To add to the misery the leaky sewers has contaminated the ground water . The suburbs of the city have their aquifers contaminated by the effluents from the septic tanks. So the water drawn from the dug wells are not potable and they have to depend on the piped water supply or water obtained from the ground water sources supplied through water tankers during the major portion of the year. The reserves of these supplies are diminishing sue to overexploitation and shrinkage of its recharge are due urbanisation. The quality also will be deteriorating and it is not being monitored. It is the price we are paying for the change of our life style from that of the last century. Then people lived in clusters of settlements and the sewage generated then was converted into manure and applied to the agricultural lands without contaminating the ground water aquifers. The size of their settlement was also small enough to provide them the amenities and comforts consistent with their style of living. The settlements were not allowed to grow beyond the limit of sustainability. In those days they never had bathrooms and lavatories in their houses. The people went outside, to the river, channels, tanks or agricultural fields or community latrines for their morning ablutions. The clothes were washed by the riverside or near community wells. Of course their apparel was different from what was today and the polluting detergents did not exist. They brought few pots of water for cooking purposes only. May be that is why the ancient sastras on house building are silent about the location of latrines within the house. The morning walk prescribed now for better health helped easy bowel movement. Even now in villages the above practice is in vogue. This can be said as the cultural practice that evolved to process the wastes produced to be assimilated by the village eco-system and this aspect has to be necessarily to determine the size of the human settlements. But the cities and towns have been allowed to grow to greater sizes resulting the

production of as huge quantity of wastes, a greater proportion of which could not assimilated by the by the local eco-system and has to be subjected further treatment utilising the technology developed in Europe suited to its climatic conditions where then plenty of water was available throughout the year.. This technology, the water carriage system requires huge quantity of water throughout the year to convey the sewage from its origin to the place where it is treated. The sewage delivered at the treatment plant reported contains only one per cent of solid sewage and 99 per cent of water. For the technology to succeed it requires a large quantity of water which is not available in Chennai (Madras) resulting in clogging of sewers and malfunctioning which required periodic inspection and rectification. Also as the size of the city grow in horizontally and vertically the sewerage system has to be redesigned and reconstructed for an efficient functioning, otherwise it will lead an environmental disaster. One of the reasons of the disappearance the ancient cities is attributed to the environmental degradation. So if this state is allowed to continue the day will not be far off when the City of Chennai (Madras) has to be abandoned. To prevent this catastrophe one must look for alternatives to the present system of sewerage and its treatment. One of the alternatives could be to decentralise the water supply and sewerage systems in the water scarce environment. Once this concept has been accepted it is easy to work out details. It will be like this. A city or town should be divided into a number of small divisions and for each there must be community latrines, bathrooms, laundries and etc., adequate in numbers to serve the population of each division. The water required for this facility should be met from the bore wells. The water may have to be treated if necessary to get the required degree of purity. The sewage generated from the community-latrine-bathroom-laundry complex should be treated in the same complex area. The treatment plant should be designed such that, if warranted, sewage from latrines, sullage from bathrooms and laundries are processed separately such that the recycled water is fed back to the input system. The sludge from individual facility may have to be processed separately as different types of organic and inorganic substances will be present. As it is a recycling process net additional requirement of water will only a small quantity to compensate losses. It is to be pointed that the water required as input to this facility need not be potable grade so untreated groundwater may be sufficient. The power required to run this system should be from non-conventional sources such as solar energy, wind power and the gases generated by the sewage treatment. The treated sludge can be applied to the agricultural lands or kitchen gardens. So in the houses the only waste materials that are to be disposed of are kitchen waste, which is organic in nature, combustible wastes like paper, cardboard, plastics and noncombustible materials such as glass, metal pieces and etc.. These have to be deposited by the individual household in individual bins provided by the local authority to be disposed off by appropriate methods. For example organic wastes can be stabilised by vermiculture.

By adopting this approach a large quantity of water required by the households for toilets and bathrooms and washing clothes need not be supplied. A household of five persons will require about 20 litres of potable grade water per day for cooking and drinking purposes. In fact many households get the potable grade water from places about one to two kilometers from their houses as the water in their wells have become brackish due to pollution. The supply of this quantity of water can be entrusted to private enterprises. In fact many households are now consuming only mineral water for drinking and cooking. Another approach is to decentralise the sewerage treatment block by block instead of pumping the sewage to distant places outside the city limits. The city has to be divided into viable blocks, and small and compact treatment plants to be constructed. Where the site conditions do not permit building the possibility construction under the ground is to be explored. The sewage is to be treated to 0 degree BOD and let into the drainage to be let into the rivers after recharging the ground water at the treatment plant site or a place nearby. Similarly one can find a number of variations. Now technology is available by which small treatment plants can handle sufficiently large quantities of sewage By adopting any of the methods by which the sewage is treated at the source itself, Groundwater recharged and the purified water let into the river to generate flow which will ultimately clean the rivers from pollution.