Describe four difficulties associated with locating and developing new landfill
sites.
Location;
Any two points from;
• Planning permission is required which can delay the landfill becoming
operational by several years.
• A permit is required for operation which requires that full surveys have
been carried out. This process is time consuming and adds to the upfront
cost for the operator.
• There may be objections from local residents due to noise / odour /
issues. This will delay planning permission being granted and
subsequent award of a permit.
• Suitable transport links are required so that waste can be brought to the
site in heavy goods vehicles.
Development;
Any two points from;
• Once a permit / licence has been granted it takes a further 18 months
from the beginning of construction to operation adding to up-front
investment costs.
• The site must be geographically suitable so that the polluting leachates
from the site cannot affect the surrounding land and water.
• A detailed site survey is required prior to operation to ensure that the
landfill site will not cause movement of the surrounding land.
• An environmental assessment is required to confirm that the effect of the
landfill site on the local environmental is minimal.
• The landfill must include leachate and landfill gas treatment measures to
minimise water and air pollution.
• Leak detection is required as flammable methane gas can be released.
Methane gas is a greenhouse gas.
Explain two reasons why the Northern Ireland Waste Management Strategy
seeks to end the over-reliance on landfill. {4}
Any two from:
* Decomposing waste can produce methane and carbon dioxide {1} which
contribute to global warming {1}.
* There is the potential for pollutants to leach into nearby soil {1} and
contaminate it and waterways {1}.
* Valuable materials such as metals and plastics {1} are not being recycled
and cannot be reused {1}.
* Landfills can release smells / attract vermin {1} which affects people
living nearby {1}.
Name one major waste type.
Any one from;
• Municipal waste
• Commercial and industrial waste.
• Construction, demolition and excavation waste.
• Hazardous waste.
• Agricultural waste.
List four priority waste streams identified in the Northern Ireland Waste
Management Strategy. {4}
Any four from:
* Packaging waste {1}
* Waste electrical and electronic equipment {1}
* Batteries and accumulators {1}
* End of life vehicles {1}
* Tyres {1}
The Waste Management Hierarchy lists several waste management options
from most desirable to least desirable. Explain the following waste management
options.
Reuse: {2}
Recovery: {2}
Disposal:
Reuse: If waste cannot be prevented or minimised an attempt should be made
to reuse the waste. [1] It can either be reused in its original form (e.g. refilling a
water bottle) or repairing a broken item to make it fit for purpose again (e.g.
repairing a broken chair). Reusing items leads to less waste being sent to
landfill. [1]
Recovery: If it is not possible to prevent, reduce, reuse or recycle all the waste
that is produced, the next priority is to extract value from the residual waste [1]
in the form of energy and other by-products (e.g. burning waste in an incinerator
to produce energy). [1]
Disposal: The least desirable of the options. Disposal refers to waste which
cannot be eliminated by any of the higher options. [1] This waste will end up in
landfill. [1]
What is the most desirable option in the waste management hierarchy? {1}
Prevention
Identify four categories within the waste management hierarchy.
Any four of the following: Prevention. [1]
Reduce. [1]
Re-use. [1]
Recycling. [1]
Recovery. [1]
Disposal. [1]
Discuss the landfilling and recycling of waste, referring in detail to the following:
* The process of waste recycling at a Materials Recovery Facility {*5}
The process of waste recycling at a Materials Recovery Facility
* Waste recycling begins with the user
* Mixed recyclables are taken to a Materials Recovery Facility (MRF)
* Only certain items can be recycled, e.g. glass, aluminium, paper, some
plastics
* Materials are sorted manually and mechanically
* Single materials are then sorted by grade, size and crushed or shredded
into bales for sale
Name one material which can be sorted in a materials recovery facility and the
method used to separate it from other waste types.
Material: {1}
Separation method: {1}
Any one of the following:
• Air jets are used to separate [1] light plastic containers [1] from
waste.
• Magnets are used to remove [1] steel cans [1] from waste.
• Eddy currents are used [1] to separate aluminium cans [1] from
waste.
• Rotating discs [1] sort paper [1] from waste.
Discuss the landfilling and recycling of waste, referring in detail to the following:
* The breakdown of waste in landfills {5}
The breakdown of waste in landfills:
* Organic waste breaks down anaerobically
* Methane and carbon dioxide are released
* Methane is a potent greenhouse gas which is linked to global warming
* Methane is a fire hazard
* Leachate is produced, which is contaminated water
* Leachate can enter the environment and cause pollution
* Rotting waste attracts vermin
Identify three factors that influence the rate at which methane and leachate are
produced from modern landfills.
1: Moisture/ water {1}
2: Temperature {1}
3: Oxygen {1}
Explain the key differences between a ‘bioreactor’ landfill and ‘dry tomb’ landfill.
{4}
Bioreactor – encourages the decomposition of the waste through the re-
injection of leachate and microbe rich water. {1}
Plus one from;
• The waste is no compacted to facilitate the flow of air and water thereby
encouraging the chemical decomposition. {1}
• As a result of the decomposition additional waste can be added. {1}
• Gas and leachate are collected and treated. {1}
Dry tomb – discourages reactions taking place. {1}
Plus one from;
• Body of waste is sealed and there are high rates of compaction along
with minimum flow of rainwater and leachate through the landfill. {1}
• Waste can subsequently be stored for material value in the future. {1}
Discuss the landfilling and recycling of waste, referring in detail to the following:
* The design of modern engineered landfill sites such as Dry Tomb and
Bioreactors {*5}
The design of modern engineered landfill sites such as Dry Tomb and
Bioreactors.
* Modern landfills are designed to capture greenhouse gases and
leachates to prevent pollution
* Dry tomb reactors are lined at the base to prevent leakages
* The waste is covered with soil at intervals
* Waste breakdown is very slow
* Bioreactor landfills are designed to break down organic waste rapidly
* They can be aerobic or anaerobic
* Methane and leachate are collected and removed
* Methane can be used to drive a generator
* Bioreactors can be use the leachate to enhance the waster degradation
process
Describe how the following types of landfill function, making reference to how
they deal with landfill gas and leachate.
(i): Bioreactor {3}
(ii): Dry Tomb {3}
Bioreactor:
In a bioreactor landfill controlled quantities of liquid and air are added to the
waste to accelerate biodegradation [1]. Leachate is collected and can be treated
with bacteria to enhance its ability to break down waste. It is then reintroduced
to the reactor to accelerate decomposition [1].
Methane/landfill gas is collected and used as a fuel to drive a generator to
produce electricity [1].
Candidates must provide three clear stages in the system in order to achieve 3
marks. Teachers can award 1 or 2 marks where some but not all stages are
identified.
Dry Tomb Landfill:
Keeping the waste dry and inert should prevent decomposition and therefore
minimise the production of methane and leachate [1]. If the waste gets wet
leachate can be produced and can escape into ground water if the liner is
punctured. Ground water will have to be monitored using monitor wells and
treated if necessary [1]. Any methane gas produced can be collected and used
as a fuel to drive a generator to produce electricity [1].
Landfill Tax is a tax levied by central government through Her Majesty’s
Revenue and Customs (HMRC).
Discuss one way in which Landfill Tax supports the Northern Ireland Waste
Management Strategy.
Any one from:
• Making landfilling waste more expensive encourages waste producers to
use other waste management options (such as recycling) [2].
• The landfill tax raises money to support environmental initiatives such as
the Eco-schools project and advertising campaigns such as Rethink Waste
which encourages the public to reduce, reuse and recycle. [2].
State two aims of the landfill tax.
1: {1}
2: {1}
- Reduction in levels of landfill. [1]
- Supporting environmental initiatives. [1]
