Dumping of Phumdi in Moirang Town and its related environmental hazards

Dr. R. S. Khoiyangbam *

Floating islands, locally called as phumdi in the Loktak Lake of Manipur have fascinated us since ancient times. Such floating vegetative masses are quite common in tropical wetlands and are also known to occur in all continents, with the exception of Antarctica. They have been called as sudd in Africa, plav in Romania, matupa in central Amazonia, yechan in Myanmar and floating gardens or radh in Kashmir, tussocks, floatons, etc.

They represent a special habitat different from their surrounding water-spread areas. Structurally, they are made up of dead organic matter and live biomass held together by the network of rhizomes, roots and stems. Presence of aerenchyma, light spongy tissues of low specific gravity and the gases accumulation during decomposition kept them floating.

Worldwide, people living in the vicinity of water, developed skills for uses of floating islands, which over times, became forms of traditional knowledge, passing down from generation to generation. Natural or artificial, floating islands have been in use for fishing, aquaculture, vegetable cultivation, as protected wildlife habitat, human settlement and more recently, as an emerging and engaging field of technology for bioremediation of polluted waters.

In China, man-made floating islands have been known for more than 1600 years, whereas in Bangladesh, they have been used for vegetable cultivation for at least 250 years. In other parts of the world, floating islands are considered sacred, and they find places in myths, folklores and literature.

In the Loktak Lake, neither the existence of phumdi nor its human utilization is new. Phumdis have been used for shelter and athaphum fishing for generations. The only difference, over times, is the abrupt jump in their number in the recent decades. In the past there were certain spatial and temporal restrictions in the practice. However, recent satellite imageries revealed that these round-shaped human-made structures have virtually pervaded the whole lake and have become round the year activity.

Concurrently, there was an exponential raise in numbers of phumdi huts and human perturbation in the lake. There are claims that, these with other associated anthropogenic pressures have led to the rapid proliferation of phumdi in the lake.

Phumdi proliferation in the Loktak is partly attributed to the enrichment of nutrients, which fueled the growth of the aquatic weeds. The fate of the built-up chemicals could be traced back, in a wide scale of catchment erosion, agricultural runoffs, untreated sewage and disposal of wastes in the upstream urban centres. People, on the other hand, had failed the century old, natural mechanism of aquatic weed control in the lake with the advent of Ithai barrage in early eighties. Prior to that, free-floating aquatic weeds – precursor of phumdi, were seasonally flushed down by water courses that drain into the Manipur River.

Of late, the environmental concerns for the rapidly expanding floating islands have taken the centre-stage of lake management. The reasons for this initiative can be clearly linked to increasing difficulties faced due to accumulation of phum along shorelines, blocking lake-access points; interference with recreation and navigation; damaging fishing implements by drifting phumdis, to mention some.

Moreover, unmanaged phums are potent factors for ecological succession of the wetland from open water to marshes and swamps. Hence, to tackle the worsening phumdi menace, the state government had been relentlessly searching for ideas and innovations, before finally, zeroing down on K-Pro Infra Work Private Limited, a Delhi based company, to take up the challenging task of cleaning phumdi in Loktak Lake.

Management of floating islands in Loktak Lake is double edged and a messy business. Firstly, it has to establish the twin goals – curtailing unrestricted growth of phumdi in lake proper while it is imperative to revive the degrading phumdis in Keibul Lamjao National Park. Secondly, the decision on phumdi removal is often difficult because floating islands provide various ecological services, sequesters carbon, purifies waters and act as sink of chemicals including heavy metals, besides their known socio-economic and cultural relevance to local population.

Thirdly, it is equally touchy to intervene an effective clearance programme for the numerous athaphums and phumdi huts. Fourthly, our understanding of phumdis and their role in sustaining lake ecosystems is often confusing and solutions fuzzy. The existing knowledge pool and database is far from adequate to develop a framework of sustainable management strategy.

Big dams started well, but often ended badly – this is precisely what is happening with the Loktak Hydropower Project and its reservoir. Today, Loktak Lake is a water body in trouble rather than struggle. There has been a management failure, but from many quarters. However, in this folklore of environment degradation in the lake, common people are not always innocent victims, but are also colluders. Even though the lake management comes into action, it may already be too late to reverse the ecological damages of past neglect and inaction. In the savage ecological havoc which envelops the lake, ultimately, cleaning of phumdi and aquatic weeds in the lake is indeed a race against time.

It makes out that, for both the Loktak Development Authority and the K-Pro Infra Work Private Limited, environmental safeguard and concerns are very close to their heart. But, the callous nature in which the phumdi waste is being disposed in the past few weeks at Moirang, seemingly reflects, their concerns – at least for the moment, are limited to cleaning of the lake, come what may, to the wastes generated. Cleaning Phumdi from the lake is important; equally important is attending to the staggering amount of terrestrially exported wastes.

Removing phumdi from the lake just to get it dumped randomly, in nearby available space is 'out-of-sight is out-of-mind,' carefree approach. This has at the best been a short term topical treatment, which lacks in potential standards of management, if any. In any environmental conscious modern society, such misadventure will find more critics than sympathisers. Moreover, the world must surely be moving on from the period when cheap management tactics overrides all other interests, including that critical one of a healthy environment.

Measuring by its spatial and temporal enormity, the task of Phumdi removal in Loktak is bound to become a gigantic exercise, and management of the huge wastes, a vexed issue for which there can be no easy panacea. Yet, dumping of highly decomposable organic wastes, like phumdi, in densely inhabited, frontline town like Moirang, in line with handling earth-spoils in construction projects, elsewhere in human-free, far flung remote parts of the land is quite appalling.

Whatever may be the reason or the persuasive factor, be it the interest showed by locals, to raised elevation of private lands, dumping of untreated wastes in settlement areas, office premises, playgrounds, educational institutes, etc. in such a haphazard manner, is deplorable and should be immediately done away. Moreover, the agencies involved have no right to pollute at will; they must conform to environmental strictures, however tough, and have to bear the responsibilities for any environmental mistakes. There are other less controversial waste management strategies that they could have used to achieve the same end.

Generally speaking, phumdi disposal in the town is not undertaken in a sustainable way. No serious efforts are made to adapt to latest technologies of waste management. The methods followed are not in keeping with modern practices of waste disposal. For instance, the much required, final touch of topping the dump yards with inert material to prevent from emanating foul smell, avoid scavenging by animals, to protect from flies, rodent, and pests are neglected. There are many loose ends both in terms of management, technology and professional skill. The solutions need deployment of competent persons to streamline the journey of wastes from the lake to ultimate safe disposal site. Such successful waste management is rarely achieved without serious thoughts and efforts.

In Moirang, slowly but surely, all the elements of environmental hazards due to mismanaged phumdi are falling into place. The environmental implications may range from localized air, water, soil and pathogenic contamination to global warming due to release of potent greenhouse gases at the global scale. Going by the nature of waste dumped, geo-environmental set-up and prevailing meteorological condition in disposal sites, the pathway of decomposition of phumdi, will be largely anaerobic in nature. It may take half of a year or more, before the phumdi gets itself partially stabilized. Until then, each cycle of rainfall followed by intense heating, will bring new environmental and health complications for the residents.

Out of the many phumdi related environmental nuisance, release of offensive odour may be the most contentious issue – pervading roads, market places, residential areas, offices and institutes, defying all known human-made boundaries. As anaerobic decomposition is a slower and less complete, compared to aerobic process, the by-products produced are more complex and odorous. These odorants may be reasons for tension, anger, depression, fatigue, and confusion to the recipient. The factors that contribute to the impact on a recipient include the frequency of occurrence, length of exposure and the offensiveness of the odour.

Ambient air quality around phumdi may affect the health of local residents at different degrees, depending on the levels of exposure. Typically, air quality in close vicinity of phumdi dumping yards is a concern, because their concentrations may exceed the health threshold levels. Gases emanating from the phumdi may be classified as irritants or asphyxiants. Irritants cause inflammation to the respiratory system, while asphyxiants displace oxygen from the air or combine with the haemoglobin reducing its capacity to carry oxygen. Methane and carbon dioxide, the two main gaseous products of anaerobic decomposition displace oxygen in air. Methane is unlikely to be a concern in well-ventilated room and open space. The main danger with carbon dioxide is that it can create an oxygen deficiency and can result in suffocation.

Hydrogen sulphide is the most dangerous among the gaseous constituents generated in the process. It interacts with the haemoglobin to block oxygen from being carried to the body's vital organs. At concentrations of 1-3 ppm, a person fails to sense as it numbs the olfactory nerves. In high concentrations, it may result into instant paralysis and death. Besides the biotic effect, it causes corrosion of iron. Ammonia, another smelly gas produced during anaerobic decomposition, can cause respiratory diseases in livestock when exposed to significant levels over an extended period. High ammonia levels in air may cause eye irritation, respiratory problems, and illness in human and animals.

During the process of decomposition, some of the nitrogen present in the phumdi gets bio-chemically converted into nitrate. Nitrate can be subjected to leaching, contaminating the groundwater and causing significant health problems. It may lead to methemoglobinemia, a disease causing oxygen starvation. The recommended maximum acceptable level for human and animal occupancy is 10 ppm. High contents of nitrate in drinking water may be fatal for the infants.

Leachate containing various chemicals and microbes may form and disperse from disposal sites, as water percolates, either from the top due to continuous rainfall, or laterally due to groundwater flow intercepting the disposed phumdi. Many species of aquatic plants, and some found in phumdi have the potential to accumulate and bio-concentrate hazardous chemicals and heavy metals present in the water. Releasing back of such chemicals at higher concentrations to the immediate environment of dumping sites due to decomposition of phumdi wastes cannot be completely ruled out.

Floods during the monsoons and droughts during the dry spells have become Loktak's man-made legacy to its peripheral lands. During rainy season, possibility of surface water contamination increases due to flooding. Pools of dirty water will propagate the breeding of mosquitoes that transmit malaria, dengue, etc. Moreover, the prevailing high water table does not isolate the disposed waste from the rest of the environment; in fact, the opposite is true. The soils provide an easy conduit for the drained liquids.

Breathing difficulties can arise from the fungi that develop on phumdi tips. Thus, it is hard to dispute that many medical problems can arise from mismanagement of phumdi. To add to the despair is the deadly cocktail of communicable diseases that the summer brings. Moirang town, in fact is just above the worst possible place to be a site for Phumdi disposal.

Phumdi disposal sites, may act as significant source of greenhouse gases, specifically, methane, carbon dioxide and nitrous oxide. Greenhouse gases are the trace gases in the atmosphere which are relatively transparent to the higher energy sunlight, but trap or reflect the lower energy infrared radiation, causing the present global warming. In nature, floating islands act as storehouse of carbon, sequestered by the phumdi vegetations. Due to anaerobic condition, the organic-carbon in the sub-surface phumdi degrades over time, generating carbon dioxide and methane, as main gaseous end-products. These gases are continuously emitted to the atmosphere. Currently, carbon dioxide, methane and nitrous oxide, contributes 60%, 20% and 6%, respectively, of the anthropogenic radiative forcing.

Not all of the gases produced in the floating islands are release directly to atmosphere; some get entrapped within the phumdi. Agitation of the phumdi during the course of removal from the lake, transportation and subsequent land-filling, releases the entrapped gas into the atmosphere. In lowland dumping sites, the phumdi undergoes anaerobic decomposition due to inundation, releasing carbon dioxide and methane. These two gases are also the two most important greenhouse gases causing the present global warming.

Nitrous oxide, on the other hand, is produced during nitrification and de-nitrification processes, involved in phumdi mineralisation. Even though less in quantity, emission of nitrous oxide from phumdi is significant, as it has a warming potential 300 times greater than that of carbon dioxide. The warming potential of methane is 30 times greater than carbon dioxide in gram per gram basis.

Solid waste management is one among the basic essential services provided by municipal authorities in the country. However, it is among the most poorly rendered services in the urban centres of the land. The Municipal authority at Moirang is not keen in taking up the present problems of phumdi menace as an issue. They seem least bothered about the risks involved and hence the issue fails to get the attention it deserves. Besides, human and environmental health implications, phumdi dumps and litters are unsightly.

Aesthetic values, though difficult to define, are also environmentally important. It lowers the morale of communities. Management of phumdi wastes may not be a business of Municipal office, but attending to phumdi related health and sanitation problems in the town will be under its supervision. Failure of the local government, to focus seriously on the phumdi related menace, to tackle and address them, is nothing more than disowning responsibility.