Tuesday, February 25, 2014

VIRTUES OF A SANITARY LANDFILL SITE

CONTRASTING PARADIGMS

Technically a sanitary landfill site is an essential and integral infrastructure component of a robust and successful solid waste management system for any urban centre. However, one school of thought – primarily representing environmental activists of varied hues has attempted to project it as “least preferable” or “least favoured” option.  This is so because of, among others, the misplaced perception as regards its footprint, and possible emissions of leachate and landfill gas, if any.  This school of thought perceives that a bulk of the problem can be solved by the ‘3R’ principle – reduce, reuse and recycle. This school of thought also perceives that municipal waste - being ‘solid’ as it is termed to be, warrants ‘recovery’ of residual matter/value  to the maximum extent without taking into account the multitude of social, behavioural, climatic, technological, institutional and financial challenges which together undermine the techno-economic viability of the proposition. Accordingly it offers a hierarchy of options for municipal solid waste management which corresponds to an inverted pyramid as shown in Exhibit 1.

EXHIBIT 1: INVERTED HIERARCHY OF MUNICIPAL SOLID WASTE MANAGEMENT OPTIONS


This is a noble paradigm which attempts to reduce consumption, minimise waste and maximise recovery, however it appears to be oblivious of increasing urbanisation, changing life styles, partial affluence and the juggernaut of ‘consumerism’ percolating down to the lowest strata of the society; and the sustained impetus by the national and state governments for higher economic growth – more so driven by the overwhelming forces of globalisation. This paradigm attempts to balance a pyramid on its head and defies the conventional engineering wisdom (and that of the Egyptian civilisation!) of ensuring a wide base for any structure or system to be stable and long lasting. To the hardcore professionals who have spent all their lives working in the field of SWM, this inverted pyramid only represents imagination of poets or work of an artist/ graphic designer. It is not surprising that across India, cities which have been prevailed upon to embrace this paradigm are finding their solid waste management systems falling flat and urban landscape characterised by unmitigated and indiscriminate disposal of waste.

In contract to this, across the world cities where solid waste management systems have been implemented successfully have relied on the hierarchy of options which is represented by an upright pyramid as illustrated in Exhibit 2. In this hierarchy a sanitary landfill site (as against an open dump site) forms the bedrock of a robust infrastructure and management system as it recognises that bulk of the problem is addressed by this option while the other options - corresponding to the numerous ‘Rs’, being still relevant but have only selective and decreasing role to play.

EXHIBIT 2: UPRIGHT HIERARCHY OF OPTIONS FOR SUCCESSFUL MANAGEMENT OF MSW




VIRTUES OF AN SLF

From land area requirement point of view while a sanitary landfill site may still be ‘least favoured’, but it is most essential (and therefore desired) because of a wide range of virtues, as listed below, that it offers to city managers and public health engineers.
·   Reliable: A properly constructed, operated and maintained sanitary landfill site works under all weather conditions, irrespective of precipitation or variations in temperature, etc.

·         Elastic: An SLF can easily accommodate shock loads or variations in waste quantities arriving at the site without any problem of process disruption or malfunctioning on account of overloading, etc.

·         Forgiving: An SLF does not have any specific requirements as regards waste characteristics, and therefore can accept mixed MSW of any composition throughout the year. It does not penalise for, or malfunction due to presence of contraries, inerts or toxins which is usually the case with mixed MSW.

·        Accommodative: An SLF does not require segregation of waste as a prerequisite which apparently is turning out to be an insurmountable proposition as experienced over the last 14 years after the introduction of MSW Rules, 2000. An SLF can accept waste pre- or post- treatment without demanding or mandating any specific levels of organics or inerts; without making distinction between food waste from five star hotels and pathogenic sludge from street drains, between slaughterhouse waste and road sweepings, between wholesale vegetable market waste and construction debris, between domestic waste and non-hazardous hospital or industrial waste, etc.

·    Dependable: In the event of a plant shut down or closure or under any unforeseen events, an SLF offers backstopping so that waste is never left open in unsafe manner.

·    Robust: A well constructed, operated and maintained SLF safeguards surface and groundwater resources; prevents nuisance due to odour, insects, birds, other vectors; and protects public health at all times.

·      Affordable source of resource recovery: Under proposer boundary conditions and operating parameters, an SLF enables sustainable recovery of landfill gas as a renewable source of energy at least cost.

·         Affordable: An SLF involves least cost of operation and maintenance and represents least life cycle cost option.

Given the multiple virtues, an SLF can be compared to a ‘mother’ which helps in keeping the house in order and safeguarding health of urban residents at all times. On the other hand, treatment plants (based on diverse technologies) which apparently have been given high priority for ‘resource recovery’ are characterised by, among others, tough requirements for (a) consistency in feedstock quantity – aversion to overloading or in some cases even under-loading (b) consistency in feedstock quality - extreme aversion to toxicity or fall in calorific value, rise in moisture content, inerts, etc. (c) consistency in weather conditions, (d) consistency in operating conditions, e.g., temperature, pH, etc., (e) unavoidable adverse environmental footprint, (f) high operating and maintenance costs, (g) high and unsustainable replacement costs, and last but not the least, (h) woefully and disproportionately low returns on investment, etc.

THE DESIRABLE AND CURRENT APPROACHES

Therefore construction of an adequate size sanitary landfill should be the first step towards improving solid waste management in a city. Subsequently a city manager can move up the hierarchy of options as illustrated in Exhibit 2 to achieve various ‘Rs’ and thereby reduce load on SLF. This approach corresponds to putting the horse at the right place, i.e., before the cart.

However, the current approach adopted by various cities across the country is reverse of the universally proven approach and therefore it is not surprising that there is no significant forward movement of the ‘cart’ in any part of the country as regards safe disposal of waste. Attempting to change behaviour of lakhs and millions of people is a humongous task – given that a large number of residents in our urban areas are used to open defecation; a large number are not educated or not concerned and committed towards environment, so what to expect for source storage and segregation; given the inconsistencies and weaknesses in collection, transport and delivery system; given the poor administrative and financial resources available with ULBs, etc. Addressing these challenges itself will take a long time, before treatment plants can be expected to perform their defined role of volume reduction, let alone ‘value addition’, if any.

The challenge of finding space?

Until that happens, Indian policy needs to recognise the profound utility and potential of an SLF with regard to protection of environment and public health. Unfortunately after 14 years of the MSW Rules, 2000 the policy does not take into account the overwhelming evidence of a large number of failed treatment plants, instead it deems SLF as an undesirable infrastructure. Moreover, it is intriguing that based on the recently released draft MSW Rules 2013, apparently the recent advisory from the highest policy making authority has even deemed disposal of mixed MSW into SLF as virtually illegal. This hands-off treatment to SLF is given on the premise of paucity of land resources, however we have numerous examples where land has been acquired and allocated for other development purposes. For instance while Noida and Greater Noida (near Delhi) do not have either a treatment plant or an SLF, but a large piece of land was made available for construction of a Formula-1 racing track on the outskirts which is apparently used only for 3-5 days in a year. Likewise, while Raipur does not have an SLF but over 200 sq.km. of area was acquired for development of a greenfield city of Naya Raipur and where over the last 10 years no significant habitation has developed. Likewise, several years back land for special economic zones could be acquired in various parts of the country but none with same zest for SLFs.

The policy influence from an advanced setting

Indian policy of giving least preference to sanitary landfills appears to be based on the policy of the European Union. However, it needs to be recognised that Europe has reached this stage only after undergoing a great deal of experimentation and learning over an extended period of 30 to 40 years. Secondly, European policy recognises that embracing of strict standards needs to be supported by a host of legislations, directives, financial incentives and taxes. For instance restrictions on landfilling and particularly the policy of diversion of organics from landfills which were introduced through the Landfill Direction, 2001 are supported by (a) the directive on Integrated Pollution Prevention and Control (IPPC), (b) the incineration directive, (c) specific Community directives on a range of hazardous waste streams, e.g., waste oils, PCBs/PCTs, battries (d) targets for recycling and recovery on complex waste streams, e.g., packaging, end-of-life vehicles (ELV), waste electrical and electronic equipment (WEEL). Moreover, this strict policy of waste diversion is eventually supported by the ‘principle of producer responsibility’ which was incorporated back in 1996 and which has provided a stable source of financing to offset the cost disadvantage of recycling as against landfilling or energy recovery. The latter places the cost of recycling primarily on producers which in turn encourages them to design products differently, thereby making recycling easier and less expensive (European Commission, 2005[1]). Finally it also needs to be recognised that despite having a rather elaborate framework of policies, legislations, incentives and taxes, and some of the most advanced treatment systems, Europe as a whole relies on well designed and managed sanitary landfill sites for nearly 50% of the waste it produces.

Indian waste policy cannot pick up management principles selectively from advanced economies and hope to achieve equivalent high level of compliance or quality of environment. It needs to give time to the large number of implementing agencies to move up the learning curve, along with a host of incentives, legislative tools as well as support by way of capacity building. Until that happens, the policy needs to allow adequate space for the implementing agencies to follow the practicable waste management hierarchy as depicted in Exhibit 2 and offer appropriate role for sanitary landfills as the bedrock of integrated waste management systems.

Acknowledgement: The Author would like to express his gratitude to Mr. N. C. Vasuki, Former CEO of Delaware Waste Management Authority and Former President of International Solid Waste Authority and Dr. Brajesh Kumar Dubey, Environmental Engineering, School of Engineering, University of Guelph, Canada for their valuable suggestions, inputs and encouragement in developing this paper.




[1] European Commission (2005). The Story Behind Strategy of EU Waste Policy.