Landfills

By Nabil Shoeb

---

To ensure that our garbage does not harm the public health or the environment, today's modern state-of-the-art landfills are technically sophisticated. These are commonly referred to as "Municipal Solid Waste (MSW) Landfills" to distinguish them from the open dumps.

Modern landfills include protective ground liners, leachate (water percolating through waste) collection system to prevent contamination of ground water and gas collection system.

Liner system are typically constructed with layers of high density polyethylene. The leachate is later treated. The gases are usually methane which is collected and can be used to produce energy or can be destroyed in flares. Waste is placed in layers, compacted and covered at the end of each day to reduce odors and control rodents. Once the landfill is full, it is closed and covered with topsoil to support planting vegetation.

* The writer is consulting engineer