L1 landfill

Question 1

what is the terminology used on the conceptual design of a landfill

Answer 1

linear system

1. drainage layer
2. collection pipe
3. geocomposite drainage net
4. geomembrane HDPE
5. Geosynthetic clay liner
6. compacted cohesive soil
7. structural bedrock

final cover system

1. vegetation
2. top soil
3. protective cover soil
4. geocomposite drainage net
5. geomembrance
6. working surface materials
7. compacted remediation waste

Question 2

what are the basic engineered components of a landfill

Answer 2

landfill liner system: seperates waste and subsequent leachate from groundwater

cells (old and new)- the stored waste within the landfill

storm water drainage system- intercepts rain water, prevents it from entering the landfill

leachate collection system- liquid that is released from the waste furing decomposition contains contaminating substances (leachate)

landfill gas collection system- collects landfill gas (methane and co2) formed during the breakdown of waste

covering or cap (partially shown)- seals off the top of the landfill; promotes vegetation

Question 3

in enginerring terms, the design tasks relate to:

Answer 3

• hydraulic conductivity of barrier systems
• slope stability- side slopes
• leachate and gas collection systems
• leachate treatment systems
• permeability of wastes
• impact of waste settlement on long term containment

in the longer term (post closure):

• monitoring systems
• after care and reuse

Question 4

design is based on risk

Answer 4

considered the likely activities and risks to be faced by SITA and its contractors for operation activities. this included specific human and environmental aspects