There are a lot of elements in the argument for and against phased restoration of a landfill. Well before making your decision, it’s going to be important and vital to make sure you know and fully grasp these pros and cons. This article explains some of the important plusses and minuses associated with the development, operation and restoration of landfills in a series of phases of sufficient size for efficient landfill operation.
The method of landfilling is known as phased restoration. It has many advantages, and in many national waste regulation regimes is considered to be a central requirement of sanitary landfill practice, and to show a well planned Restoration Phasing Plan is a pre-requesite of obtaining any site licence. In a number of the industrializing nations this does not apply which appears surprising when there are such huge benefits in:
- increase landfill gas yield
- reduced leachate production.
However, the requirements of pregressive restoration interact with other site aspects, and it is unlikely that all angles can be obtained perfectly at any given site. To be able to make the decision which is correct for you, you will need to know the following:
Benefits: Points In Favor Of phased restoration of a landfill
1. Landfill development should be based on the progressive use of the landfill area, such that at any given time parts of the site may be in the process of being:
– capped and restored
– actively filled
– prepared to receive waste, or as yet undisturbed,
and the aim of the restoration program is always designed to minimize incident rainfall soaking into the waste, and maximize early completion of discrete areas (Phases) to the final restoration profiles to allow maximum landfill gas extraction from full depth vertical landfill gas wells.
2. It allows progressive restoration. Progressive excavation of on-site materials, allows for efficient nearby storage of restoration materials, and minimisation of double handling of development and restoration soils.
One other good reason for the advance planning, development, operation and restoration of landfills in a series of phases, of sufficient size for efficient landfill operation, is minimisation of double handling of development and restoration soils.
This has the additional advantage of avoidance of unnecessary earthworks soils materials handling, that is certain to protect against making the mistake of large quantities of restoration materials being found to be needed toward the end of the landfill period, when otherwise useable material is then covered with waste and cannot be excavated and used.
3. It minimises the area required for active landfill operations and concentrates activities within a sequence of defined areas, reducing nuisance and polluting emissions.
And then there’s less visual intrusion caused by the landfill, and also site restoration funding requirements are more progressve and less peaky.
All these are advantages for the site that is continuously restored and each restoration work construction period is carried out by the site owner every year to 18months. It’s also very important as it could otherwise mean that without progressing restoration very large areas of only temporarily covered unsightly waste would be left for longer, for the alternative non-phased restoration of a landfill.
Also, perhaps all of us will agree that it must surely be best to plan full height restoration, and avoid large areas of waste left open and uncapped for long periods. Once you take that under consideration, then it makes sense to plan, and implement a plan, for phased landfill restoration using progressive restoration techniques.
The points above show the positive aspects of phased restoration of a landfill. There exists a down side also. Here’s a discussion of some of the drawbacks, but never overestimate the drawbacks!
Drawbacks: Arguments Against phased restoration of a landfill.
1. Physically excessively placing a limit on operational space
If you consider the phased restoration of a landfill, some parts may be too steep for the restoration works plant, within the phasing plan – especially for very deep landfills may limit operational space. That’s clearly a bad thingbut should be avoidable with good planning in most cases and all but the narrowest and deepest “quarry filling” landfills.
2. The direction of phasing usually needs to be resolved between screening for visual, wind and noise and allowing adequate flexibility for the passage of vehicles across the site.
Other factors to consider which will be present for the designers of many phased landfills will be
– potential instability in part-filled void, where support from future waste is absent
– need for protection of temporary edge of lining/capping
– need to protect against leachate overflow into unlined areas
– achievement of agreed final landscape plan after settlement.
3. Achieving the normal preference for leachate drainage to start at lowest point, may conflict with topographical requirements
The last pssible justification put forward to avoid phased restoration of a landfill is achieving the normal preference for leachate drainage to start at lowest point admittedly, this may conflict with topographical requirements. Everyone ought to consider this point very carefully, considering the fact that it can cause difficulties later with leachate wells in difficult to access or excessively deep locations if you decide to go for the phased restoration of a landfill. However, despite the complexities of phased landfill design, the fact is that it is genuinely the best option for probably about 90% of MSW landfills.
And so that’s that. There are the positives and negatives of phased restoration of a landfill. It may not be the right thing for some rare landfills, but it is most certainly beneficial to nearly all MSW landfill operations. So, you should carefully look at the above information and comparisons. Hopefully your final decision process will be aided in detail because of the pro and con info offered here.