Waste generated in municipalities is defined as municipal solid waste, and is also called municipal refuse. Increased technological advancement and population growth has resulted in the identification of a new type of waste i.e. pollutants called hazardous waste which damages land and environment. Environment Protection Agency (EPA) of USA has defined hazardous waste in the following terms: “any waste or combination of waste of a solid, liquid, gaseous, or semisolid form which because of its quantity, concentration, or physical, chemical, or infectious characteristics, may (1) cause or significantly contribute to an increase in mortality or an increase in serious irreversible or incapacitating reversible illness, or(2) pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed, or otherwise managed.”
In Nepal, hazardous waste is not clearly defined yet, but waste which are ignitable, corrosive, reactive, or toxic, and thus may be potentially hazardous because of the danger they pose to the public, are subject to regulatory control and are generally known as regulated waste. Regulated waste handling requires an integrated tracking system to track the waste from its source to disposal. Decisions with respect to what constitutes regulated waste are obviously critical, since strict management of such waste is required. To decide whether a specific substance is hazardous, it is useful to set some criteria or tests regarding the properties of the material. Hazardous waste generally falls under “other” types of waste in major Nepali cities.
These neglected “other” types of waste, which are generally hazardous in nature, have many adverse impacts on the land and environment. This waste is often haphazardly discharged into the environment, where it contaminates ground water and decreases the agricultural potential of the land. Earlier, hazardous waste was not a problem because the population was small, urban growth was low, the land available for assimilation of waste was sufficient, and the impact of waste on health was not fully understood. Now, immense population growth has resulted in a great increase of pressure on waste management.
The content of hazardous waste in municipal solid waste is estimated to be 0.1 percent to one percent. Hazardous waste found in municipal solid waste is significant because even a small percentage of hazardous waste impacts the environment. So, it should be treated separately right from the source of its generation, but municipalities in Nepal simply dump everything in dumping sites without separating hazardous waste. The practice of waste disposal along riversides, found in several major cities of the country, is extremely dangerous to human health and environment.
Hospital waste is significant in this respect, and a lot of research is done to quantify the waste. Out of this waste found in hospitals, 85 percent is non-hazardous and 15 percent is infectious, with a very small percentage of very hazardous waste. Approximately 1.72 kg per bed of hazardous waste is generated in the capital city, and one kg in other cities every day. The total hospital waste generation is about a ton daily. There are no guidelines or regulatory bodies to monitor the waste management of health institutions. Hospitals, clinics and nursing homes seldom manage their severely hazardous waste properly.
Besides, every household produces hazardous waste which is mixed up with municipal waste and disposed at the same landfills as other waste. The adverse effects of such negligence may not be apparent in the short term, but are severe in the long term. Kathmandu municipality is handling hospital waste separately, where hospitals are primarily responsible for managing their waste, but even then, it has not paid attention towards household waste, which is posing a great threat to human health. With an integrated waste management approach, Biratnagar is making efforts towards hospital waste management, but it is also facing problems in managing hazardous household waste. Biratnagar produces approximately a ton of hazardous waste daily, and dumps it at the same place where other waste is dumped.
In the last few days, I read about the problems of hospital waste management in two major cities Chitwan and Pokhara. Both these cities were previously dumping hazardous waste in the same ordinary landfill site where municipal waste is dumped, and these cities had recently allocated different landfills for hazardous waste management. This is a very positive step at a time when private partners involved in solid waste management in cities are disposing of hospital wastes in dump sites. Community involvement and participation is very important for public waste management, and equally important for private sector involved in waste management.
Hazardous wastes are subject to stringent regulatory control. These controls can cover all aspects of waste generation, from collection, handling, recycling and reuse to storage and final disposal. For the waste generator, the process of obtaining regulatory approval is often tedious and time taking. It is better for them if they minimize the generation of hazardous waste instead. Otherwise, they should take steps to detoxify and neutralize such waste material, or even use alternative technology in production of goods.
The most environmentally sound disposal of hazardous waste is its destruction and conversion into non-hazardous substances, but in many cases it may be expensive. Currently, the most widely used method of disposing hazardous waste is special landfills which are designed for long-term protection of public health and environment. Hazardous waste landfills differ from ordinary landfills in the degree of care taken to ensure minimum environmental impact. The overall philosophy is strict segregation from the environment. These above ground storages are actually delaying schemes rather than disposal schemes. True disposal of hazardous waste is left to the future generations.
The author is senior engineer and Chief of Environment Division at Biratnagar sub-metropolitan office