Swachh Bharat may have started on a high note, but cleaning up the country is serious business. Apart from investment, it calls for behavioural changes, expertise and scientific knowledge.If Finance Minister Arun Jaitley chooses to, he could remind citizens about the need to keep the country clean every time they pay for any service. In his Budget proposals, he has taken a provision that will enable him to levy a 2% cess on service tax towards financing and promoting and financing Swachh Bharat initiatives. But a truly clean India is a lot deeper than merely sweeping our streets clean.This is a good time to look at the magnitude of the problem and possible ways to clean up the country. A good place to start is an area far away from the country, a patch of garbage in the middle of the ocean near Hawaii. This swirling mass of plastic is about a 1,000 miles across and growing rapidly, with smaller and growing patches in the Atlantic and the Indian Ocean. A research paper published in the journal 'Science' last month says plastic in the oceans will increase 10 times in the next decade if nothing is done about it.What is the link between Swachh Bharat and plastic in the oceans? Ocean plastics disintegrate into smaller pieces and are eaten by fish, and its toxic constituents work their way back to human beings when they eat fish. When pollution so far away has such profound implications for human health, what about what is so near? What about the garbage dump 100 miles away from your city? It comes back immediately, through water and air that travel long distances these days.Anything we throw away will come back quickly, disguised as food, water or air. Swachh Bharat primarily looks at sanitation and solid waste. Cleaning India takes far more than that, as unseen pollutants work their way into ecosystems and into the food chain.All the environmental scientists and engineers ET spoke to are unanimous about one aspect: cleaning up the country is serious business, and takes major behavioural changes as well as deep expertise and scientific knowledge about biology and ecosystems, not to speak of high investment in technology and R&D. Among the world's major problems, waste management is one of the hardest, with no silver bullets in sight in the near future or even the distant future.Air pollution is hard too, as fossil fuels continue to stay with us and pollution control costs money. As water shortages increase, providing clean water is becoming harder and harder.ET gives you an overview of the problems and some possible solutions. Problems as diverse as these require a large variety of solutions, and so this is just a snapshot of some ideas. ET will look at this problem more deeply over the year, through indepth stories about specific problems and solutions.On the surface, Kerala has some of the cleanest towns and villages in the country. And yet about 80% of the ground water in the state is supposedly contaminated, mostly with sewage. Kerala has small residential plots with toilets and wells in each one of them, and sewage water from septic tanks does not go enough distance for it to be cleaned up through soil filtration. What does this mean for Swachh Bharat?Poor sanitation is not the only reason for poor water quality in Kerala, but it is an important reason. The septic tank is not a good solution for places where wells are too close to each other, or where the ground water table is high. To clean up Kerala water, the state has to come up with a completely different solution for sanitation. The state has to redesign all of its septic tanks or install a large number of sewage treatment plants.According to experts in the field, large plants in big cities, made with the best technology and high investment, work very well and produce high quality treated water. Smaller plants around the country rarely work well; some say 90% have some sort of problem."Most of the smaller plants in India have control and maintenance issues," says Absar Ahmad Kazmi, professor at the Indian Institute of Technology in Roorkee. Among the major tasks of Swachh Bharat, sewage treatment is one of the easiest to solve. The technology is adequate, not too expensive, and one can get reasonably good quality of water fit to be discharged into the environment. There are three widely-used technologies: the Membrane Bioreactor, the Moving Bed Biofilm Reactor and the Sequencing Batch Reactor.The major problems are in the expense, design and management of sewage treatment plants. There are problems in the choice of appropriate technology, as the Kerala example shows. When the population is thin and the water table low, even pit latrines are good choices. Large centralised plants work well in cities, but at a cost. Modern sewage treatment plants work only on electricity; finding enough power is an additional problem.R&D institutions in India are busy developing technology for some uniquely Indian conditions. The zero discharge toilets from IIT Kanpur are being tried in some places around the country; this does not require power, motors or sewerage lines, as it separates the liquid in the sewage for reuse in flushing. It is simple enough to be used in villages and small communities. IIT Madras is developing a small sewage treatment plant that can be run off the grid. Water from the system, instead of seeping to the ground, will be pumped up for flushing again."If you replace the septic tank with this system," says Ligy Philip, IIT Madras professor of civil engineering, "contamination of ground water can be avoided."Delhi tops the charts in the world in terms of air pollution, but the city has good company. Out of the 20 most polluted cities in the world, 13 are in North India, many of them not far from Delhi. Vehicular traffic is considered the main reason behind air pollution in Delhi, but are there other equally important factors as well? Look at a completely different set of data: Cancer rates in Punjab. At 90 patients for every 1 lakh people, this state has higher cancer rates than the national average.Pesticide exposure is often blamed as the primary cause, but there are other hidden factors as well. For example, in the past few decades, Punjab farmers have been burning crop residue like never before. This increases the amount of particles and carcinogens in the atmosphere, and they travel long distances."We have found high concentrations of carcinogens like benzene,” says Vinayak Sinha, assistant professor of earth sciences at the Indian Institute of Science Education and Research in Mohali. Vehicular pollution is high enough in Indian cities, but burning of waste — crop residue as well as municipal solid waste — is another important factor behind the high levels of pollution in Delhi and other nearby cities. And neither shows any signs of abating. Emission norms for vehicles are improving rapidly, and Bharat V norms are quite stringent even by developed country standards. And yet, they would do little to reduce pollution unless other factors improve simultaneously: phasing out of old vehicles, improving traffic flow, and stopping of burning waste.Burning of waste is a national problem. As the accompanying article shows, there are no easy solutions to solid waste accumulation. Poor traffic flow contributes to pollution in cities. In a study at the Indian Institute of Technology in Guwahati, professor of Civil Engineering Sharad Gokhale found significant improvements in pollution during free flowing traffic, and also significant differences depending on the proportion of petrol and diesel vehicles."We can reduce 15-20% of pollution in cities by mere traffic flow management," says Gokhale. As far as emissions from cars are concerned, improving fuel and vehicle emission standards will reduce pollution significantly. There is a big leap technologically from Bharat IV to Bharat V, and vehicles are improving their performance not just through engine improvements. It may take some time for Bharat V norms to be implemented, but they are a considerable advance over Bharat IV, which itself has not been implemented throughout the country.For example, Bharat V norms demand the use of diesel particulate matter filters and require the use of direct injection of diesel. Cars are in any case becoming lighter and thus more fuel efficient. The current Budget has some measures encouraging electric vehicles, but the country's electric grid may not be able to handle a large population of electric cars. Fuel cell cars might come one day, but not in the foreseeable future."Unless there is a breakthrough soon, the internal combustion engine will be predominant for another 15 years," says CV Raman, executive director of engineering and R&D for Maruti Suzuki.A large metropolis is a good place to study the magnitude of the problems of solid waste management in Indian cities. In Bengaluru, now often called the garbage city, lorries collect and carry solid waste far out from the city and dump or bury them in open grounds. These malodorous landfills and dump yards emit toxic gases and pollute the ground water. The city is still looking for good places to dump wastes.Sometimes, for no apparent reason, garbage dumps sprout by the side of the streets. Experts cite many reasons why Bengaluru has such a crisis of waste accumulation. For example, lorry owners have process contracts but are just transporting the waste. Sound regulations and management could reduce the crisis in the city a bit, but the big problem would remain and not go away: there is no technology that can handle such a heterogeneous collection of wastes."India needs extensive R&D with high investment to solve the solid waste problem," says Absar Ahmad Kazmi, professor of civil engineering at the Indian Institute of Technology in Roorkee. Kazmi has been researching on solid waste management, and is convinced that it is a most difficult problem to solve. Indian waste differs in composition from place to place, and no one in the world has found a technology appropriate to handle any kind of waste. No expert considers landfills a solution. Recycling is hard, as sorting is not done at source and mechanised sorting is inadequate and expensive."The only way out is decentralised handling of waste with segregation at source," says Kumar Suba Rao, founder of Aruna Green Ventures, a company that makes products to recycle organic waste. Kumar, who had worked in the waste management industry in Canada for over two decades, feels segregation at source has to be implemented through legislation.About half of Indian waste is organic, and hence can be used for composting and as manure. Plastics, although a small part of the waste, do present a problem as they do not degrade. Scientists have found bacteria that can degrade plastics, but no such plant exists even on a small scale.One day, synthetic biologists could engineer an organism capable of converting plastic into harmless constituents, but at the moment there are only two ways to handle them: recycling or incineration. In recent times, incineration in a Waste to Energy (WTE) plant is being touted around the world as a solution to handling waste. Many environmentalists criticise this procedure; that it creates too many nanoparticles or that it gives an incentive to produce more waste. However, WTE has its champions too, who say that good pollution control measures can reduce the nanoparticle levels to well below that of coal plants."Waste-toenergy plants can be considered a good mediumterm solution,” says Ranjith Annepu, a solid waste management consultant. "Its main goal is to destroy waste and not to sell power." In the Indian context, however, the process is not easy to implement. Pollution control devices are expensive. The plant may not recover enough money through selling power as Indian waste does burn well and produce high amounts of energy.And yet, since there is no good alternative at the moment, large cities have no option but to use them at a high cost. Reduce the waste we generate, and the plant becomes more expensive to run. Increase the amount of waste, and we spend more money on pollution control. No wonder solid waste is a hard problem to solve.