Solid waste and its management

Solid wastes are all the non-liquid wastes from homes, streets, industries, shops, institutions, construction sites, towns and farms.

They are dangerous when mismanaged:

• They become breeding grounds for mosquitoes and flies: Aedes mosquitoes spread dengue and yellow fever, Anopheles spread malaria, and Culex spread filariasis.
• Burning them releases cancer-causing chemicals.
• Rainwater seeping through dumps forms leachate, which pollutes rivers and ground water.

In India, an outbreak of plague in Surat and dengue in Delhi were linked to accumulated waste and stagnant water.

Solid waste management covers the whole chain: generation, collection, storage, transport, processing and disposal, guided by principles of public health, economics, engineering and environment. First the types, sources, hazards and amount of waste are identified; then it is collected, transported and disposed of safely. There are two broad approaches: dumping and recycling.

The key is to sort waste at the source:

• Compost organic waste.
• Make fuel bricks from dried vegetable waste.
• Recycle glass and plastic.
• Reuse construction debris as filling material.
• Recycle or bury tyres; never burn them.

Community refuse pits should be fenced and kept away from water sources.

Some wastes need expert handling:

• Medical waste is incinerated or disinfected, and needles destroyed.
• Slaughterhouse waste is disposed of at inspected sites.
• Industrial waste is handled by the industry itself, under environmental rules.
• Toxic chemicals are disposed of as the manufacturer advises.