At PROCEMS, We Believe in Reduce, Reuse, Recycle!

The most common form of waste disposal is in landfill sites, but in many countries space for these landfills is rapidly disappearing. Water and oxygen are required to break down garbage. But water and oxygen are in short supply deep in a landfill, so decomposition takes place very slowly.

In addition, the sites produce environmental problems of their own. Toxic substances occur, and are produced, in landfill. Methane gas builds up and seeps into the atmosphere, and liquid toxins such as leachate leak into water courses and surrounding land. As far as global warming is concerned, methane gas is said to have 60 times the effect of carbon dioxide on the atmosphere.

Incineration (burning) of rubbish is not a workable solution, as it releases carbon dioxide, sulphur dioxide, mercury, arsenic, lead and numerous other undesirable substances into the atmosphere. These substances are often carried by prevailing winds to other areas many miles away from the sources. Ecologically, mercury is an especially dangerous substance as it builds up within the food chain rather than disappearing in the environment. These pollutants must be treated with expensive air pollution control equipment to avoid contributing to acid rain, ozone depletion and air pollution.

It is evident that the increasing amount of waste must stop, not only because of the pollution problems, but because of the depletion of the earth’s natural resources. Recycling is just one way to reduce wastes. To be really effective, we have to incorporate the 3Rs: Reduce, Reuse, Recycle into our daily routine.

CASE STUDY 1: Dr Peter M Forster PhD

Suva , capital of Fiji : Effects of the Lami Landfill Site on its Surroundings

The population of Suva , capital of Fiji , is about 187,000. Three kilometres west of Suva , adjacent to the sea, is a six-hectare landfill site called "Lami Dump". The site was mangrove until 40 years ago. Today, about 60,000 tones of waste from factories, shops and households are brought in annually (figures from Fiji 1 website). The waste matter has been piled up several meters high. The land lease contract with the owner has expired, and it will soon be impossible to add further waste to the site. There are no pollution prevention measures in place. An offensive odour spreads several hundred metres to surrounding homes and businesses. The site hosts flies, cockroaches and rats, which spread endemic diseases like bacillary dysentery. In addition, high concentrations of toxic substances like arsenic, cadmium, mercury and lead, and persistent organic pollutants (POPs) such as organic acids, are leaching into the soil and seawater around the site, resulting in degradation of marine water quality, destruction of habitat, loss of property values and reduced fish marketability, amongst others (UNEP Report number 174, 2000).

World-wide, levels of these metals in seawater are not high and landfill sites are not the main source of elevated levels. Lead, for example, arrives mainly from rainwater dissolving atmospheric tetraethyl lead, which is an additive to petrol (South et al, 1996). However, the level of pollutants adjoining landfill sites can be high before dispersal takes place and there is also the problem of some marine organisms, particularly shellfish, concentrating metals in their tissues, as the following table illustrates:

Metal

Level in seawater (ppb)

Level in mussel tissues

Cadmium

8 x 10 -2

1 x 10 5

Lead

2.1 x 10 -3

4 x 10 3

Mercury

1 x 10 -3

1 x 10 5

Table 1. Biomagnification of metals by marine organisms (from South et al, 1996).

Once into the food chain, these toxic metals can damage all the organisms above them in the chain, including humans. These metals can cause neurological disorders, cancer, birth defects and death (UNEP Report number 174, 2000).

Organic acids also leach into the sea from landfill sites. Again, world-wide there will be little effect on seawater because of the combined effects of dilution and buffering – seawater acts as a buffer because of the presence of carbonate. However, there will be localised increases in toxic organic compounds near landfill sites. These compounds can also enter the food chain, to the detriment of organisms that take them in and those above them in the chain.

Part of the problem is that leachate from landfills in the region has not been quantified, although it is thought to be significant. Research is needed simply to understand more about the magnitude of the problem posed by landfills.

We have a challenge too!

Please read CASE STUDY 2 adapted from
Singapore : Drive towards Zero Landfill

Land set aside for landfill cannot be used for other purposes like housing, factories and offices. Despite the best prevention measures, minor or undetected leaks may accumulate over the years and contaminate the land.

Land is a scarce resource that Singapore can ill-afford to waste. With limited resources available for waste disposal, the government’s policy for waste management necessitates the incineration of all incinerable waste that are not recovered, reused or recycled. Non-incinerable waste such as concrete slabs, bulky waste materials and incineration ashes are disposed of at the offshore Semakau Landfill, the only landfill in Singapore .

As the quantity of refuse disposed of at the incineration plants and the landfill has been increasing over the years, a parallel policy of waste minimisation is gradually proving to be effective in solid waste management. In 2001, waste minimisation was actively promoted in all sectors of the community in an effort to accommodate land constraints and offset the rising costs of waste disposal.

Nevertheless, with refuse disposed of in 2001 tipping the scales at 2.80 million tonnes, the availability of land to cope with the increasing rates of refuse disposal, can become a pressing problem. Daily average for refuse disposal was 6,783 tonnes per day for 2004, a decrease of 1.2% over the amount of refuse disposed of in 2003. The reduction in refuse disposed of was due to more aggressive promotion of waste minimisation and recycling programmes

Bibilography

1. Gulf Weekly,  September 29-October 4, 1995, http://rkw.hct.ac.ae/ilc/ex/reuse.htm

2. http://www.ns.ec.gc.ca/udo/reuse.html

3. http://www.blue-oceans.com/environment/landfill.html

4. National Environmental Agency (Singapore) TOWARDS ENVIRONMENTAL SUSTAINABILITY (State of the Environment 2005 Report)