1. Municipal Solid Waste Defined in 40 CFR Part 258.2
Regulated by 40 CFR Part 258:
RCRA Subtitle D

2. Landfill Diagram Solid Waste
Diagram of a typical municipal solid waste landfill.
The two major environmental concerns in a landfill are gases and leachate.
After local siting and a permit is obtained, the landfill is constructed.
After the excavation is completed,…

3. Liner HDPE Liner Compacted Clay Liner
… compacted clay is placed in the excavation and overlain by a high density polyethylene or HDPE liner.
HDPE Liner
Compacted Clay Liner

4. Liner Purposes To prevent leachate from seeping into groundwater
To prevent landfill gas from migrating out of the landfill below grade

5. Liner Purposes To prevent leachate from seeping into groundwater
To prevent landfill gas from migrating out of the landfill below grade
Typical Materials
3-foot layer of compacted soil, underlying
60-mil high density polyethylene (HDPE)

6. Leachate Drainage Blanket and Collection System
Leachate means liquid that has been in direct contact with a solid waste (this includes liquids placed with the waste and infiltrating water). Leachate is collected in slotted pipes and delivered to a holding tank where it can be trucked or piped to a waste water treatment plant.
Leachate
Drainage Blanket
Collection Pipes

7. Leachate Drainage Blanket and Collection System
Purposes
To enhance the effectiveness of the liner by minimizing leachate head
To protect the liner from puncture

8. Leachate Drainage Blanket and Collection System
Purposes
To enhance the effectiveness of the liner by minimizing leachate head
To protect the liner from puncture
Typical Materials
Blanket: 1 foot of sand or gravel, underlying
Collection System: HDPE or PVC piping

9. Final Cover System FML Liner Low Permeability Layer Protective Layer
Vegetation
The low permeability layer and flexible membrane liner or FML provide a barrier. The protective layer provides a vegetation base.

10. Final Cover System Composed of: Low Permeability Layer
Protective Layer

11. Low Permeability Layer of Final Cover System
Purposes
To minimize leachate production by shedding
precipitation rather than allowing it to
percolate through waste

12. Low Permeability Layer of Final Cover System
Purposes
To minimize leachate production by shedding
precipitation rather than allowing it to
percolate through waste
To prevent leachate popouts

13. Low Permeability Layer of Final Cover System
Purposes
To minimize leachate production by shedding
precipitation rather than allowing it to
percolate through waste
To prevent leachate popouts
To provide a barrier (along with the protective
layer) between the waste and receptors

14. Low Permeability Layer of Final Cover System
Purposes
To minimize leachate production by shedding
precipitation rather than allowing it to
percolate through waste
To prevent leachate popouts
To provide a barrier (along with the protective
layer) between the waste and receptors
To prevent uncontrolled emission of landfill
gas into atmosphere through top of landfill

15. Low Permeability Layer of Final Cover System
Typical Materials
Compacted soil and
30 or 40-mil polyethylene or PVC flexible membrane liner (FML)

16. Protective Layer of Final Cover System
Purposes
To protect the low permeability layer from freeze/thaw, desiccation cracking, root penetration and puncture
To provide a durable, low maintenance surface

17. Protective Layer of Final Cover System
Typical Materials
Uncompacted soil with
Grass on surface

18. Gas Monitoring System Purposes
To characterize gas production within the landfill
To detect any methane moving out of the landfill either below grade or through the final cover system

19. Groundwater Monitoring System
Monitoring Well
Groundwater monitoring wells are installed outside the waste limits.

20. Groundwater Monitoring System
Purpose
To detect any groundwater contamination caused by the landfill

21. Surface Water Control System
Purposes
To enhance the effectiveness of the final cover system in shedding precipitation, and
To prevent surface water contamination

22. Landfill Operation Dry Entombment
Attempt to prevent introduction of water or air to the landfill – Minimal degradation.
The landfill diagram we just went through was an example of a dry entombment operation.

23. Landfill Operation Dry Entombment
Attempt to prevent introduction of water or air to the landfill – Minimal degradation.
Bioreactor
Any liquid (other than leachate) is added in a controlled fashion into the waste to accelerate or enhance the anaerobic (without oxygen) biodegradation of the waste.

24. Gas Production Graph
Gases begin with the normal air composition of nitrogen and oxygen. Landfill gases are produced by bacterial decomposition, volatilization, and chemical reactions. Carbon dioxide is generated during the first and second phase, and levels off at 40 to 60% of landfill gases. Methane is generated in Phase III after the elimination of oxygen and reaches about 45 to 60% of landfill gases. Nitrogen is reduced to about 2 to 5% of landfill gases. Hydrogen is generated during Phase I, reaches a concentration of about 20% of landfill gases at the end of Phase II, and is eliminated in Phase III.