Special Report: Ways to treat Singapore's waste

The Jakarta Post 11 Jul 09;

In the process of day-to-day living, people produce waste. In ancient times, waste could have been animal bones, while today it could be plastic bags or any inorganic materials that take hundreds of years to decompose.

Waste has been a major problem for many countries around the globe, including Singapore. Singapore's waste has been increasing rapidly due to the massive development in the country over the last few decades.

According to the country's National Environment Agency, in 1970, a total of 460,000 tons of waste was disposed of, while in 2008, the number reached 2.62 million tons.

This growth in solid waste increases demands on the capacity of the waste management system, disposal facilities and the environment.

One of the ways of handling the waste was to build incineration plants at Ulu Pandan, Senoko, Tuas and Tuas South to treat thousands of tons of incinerable garbage.

For instance, the Tuas South Incineration Plant (TSIP), the biggest incineration plant located in an industrial area, burns up 3,000 tons of waste daily, says Poh Soon Hoong, the plant's general manager.

It uses an advanced combustion control system at a temperature of 1,000 degrees Celsius to achieve a complete burnout of the waste.

The gas is later cleaned in a catalytic fabric filter system before being released through the two 150-meter-tall chimneys.

"We ensure the gas produced from the incineration process meets stringent emission standards, so it's safe," Poh says.

Although incineration can reduce the volume of incinerable waste, he goes on, the government still needs to build a landfill for non-incinerable waste and the ash resulting from the incineration process.

Due to a lack of land, the Singaporean government later decided to build the offshore Semakau Island sanitary landfill.

There is a widely held perception among the public that a landfill is dirty, smelly and cannot be categorized as an interesting place to visit, as it has mountains of waste.

But the Semakau landfill, located 8 kilometers south of Singapore, belies this image.

The place is clean, has green spaces and even offers interesting recreational spots.

"Years ago, we had a dirty and smelly landfill in Lorong Halus with mountains of garbage in it," says Ong Chong Peng, general manager of the Semakau landfill.

"We later decided to close the landfill, burying the waste under soil."

The landfill has been in operation since April 1, 1999, right after the closure of the Lorong Halus landfill. Semakau currently receives 1,500 tons of incineration ash and 500 tons of non-incinerable waste via the Tuas Marine Transfer Station on a daily basis, says Lim Cheng Choon, a senior engineer at the Environment Technology Office.

The facility is built offshore due to limited land and covers a total area of 350 hectares, with an incineration capacity of 63 million cubic meters.

It was built at a cost of S$610 million (US$419 million) and is expected to meet Singapore's solid waste disposal needs until 2040.

The city-state will eventually create an island made almost entirely from trash when the landfill has reached its full capacity.

Ash from incineration plants and non-incinerable waste, such as construction and renovation debris, are disposed of at the landfill, says Ong. The government also applies a trial use of the ash for road construction on the island.

A perimeter bund, lined with an impermeable membrane, marine clay and rock layers, has been erected around the landfill to contain any possible leachate (liquid that drains or leaches from landfill) within the landfill areas, so that surrounding waters are kept free of any pollutants.

"Water samples are collected every month from the monitoring wells along the perimeter bund and sent to an external laboratory for water analysis," says the Environment Technology Office's Lim.

"This will ensure water quality is in compliance with regulatory standards."

The landfill is also surrounded by mangrove thickets, which are home to a wide variety of plant and animal life.

Two mangrove stands covering 136,000 square meters, or more than 400,000 mangroves, were replanted to replace those affected during the landfill's construction.

In July 2005, the landfill was opened to the public in an effort to raise people's awareness about environmental protection and waste management.

Ong says some hobby groups often visit the landfill, including the Sport Fishing Association, the Raffles Museum of Biodiversity Research, and the Astronomical Society of Singapore.

From fishing and inter-tidal walking to bird watching, the place is an interesting one to spend time with the family.

Visitors can also enjoy night activities, like stargazing, barbecuing and camping on the island, since the landfill management installed "green" electricity through wind turbines and solar panels to light up the southern part of the area.

People can go to the landfill by taking boats from the Pasir Panjang or West Coast ferry terminals.

Besides using incineration and landfills to deal with waste, the government has also promoted recycling and waste reduction to cut down on the need for the aforementioned waste management system.

Yaacob Ibrahim, Singapore's minister of environment and water resources, once said, "Don't call it waste. Call it resources, because you can always turn waste into energy.

"When people are able to recycle and look at waste as a potential energy, then we treat it differently."

- Triwik Kurniasari