Glossary

Glossary
Bentonite
Clay minerals which swell when wet. Used to seal wells and make liners.
CellWaste is tipped into discrete areas, called cells, which have engineered bases and side walls to separate the waste from the environment.
Construction Proposals
Before work begins to construct a new cell or install landfill infrastructure, the Environment Agency agrees a written document detailing the design of, the materials to be used in, and the Construction Quality Assurance programme (CQA) which will be followed during the works. This also known as the CQA Plan.
Construction Quality Assurance (CQA)
Written management system which sets out how construction will be managed, checked, tested and recorded to demonstrate that completed works meet required standards and perform as designed.
CoverMaterial is used to cover the wastes tipped in landfills: daily cover is used on tipping faces at the end of the working day to minimise odour and pests.
CQA validation report Report which demonstrates the completed works onsite are fit for purpose. It sets out how engineering works met the agreed construction proposals and is signed off by an independent qualified engineer.
Compliance Assessment Report (CAR)
A CAR is a written report compiled by Environment Agency officers when assessing compliance with an environmental permit. The CAR is used to record the findings of our site inspections, audits and monitoring activities, reviews of monitoring and other data/reports.
Environmental Permit
A permit consists of conditions which the operator must comply with when carrying out operations, to control the risk to human health and the environment. Environment Agency officers assess whether operators are in compliance with these conditions and record this in a Compliance Assessment Report (CAR).
Flame Ionisation Detector (FID)
Hand-held gas detector which measures flammable gases such as methane. FID surveys are carried out to monitor gas emissions from the surface of landfills.
FlareUsed to burn landfill gas extracted from the landfill cells at high temperatures.
Fugitive emissionsThese are emissions not controlled by emissions limits specified in an environmental permit, which may be unintended.
Gas Utilisation Plant (GUP)
Engine used to generate electricity through the combustion of landfill gas. This destroys the gas and significantly reduces pollution, whilst also providing electricity that can be supplied back to the grid.
Geomembrane
Engineered geosynthetic material made to have low permeability, used for permanent capping of full cells before application of restoration soils and landscaping.
Geotextile
Geosynthetic permeable material, used in construction to help strengthen, support, filter or drain soils.
Hydrogen sulphide (H2S)
A colourless, flammable gas with a characteristic odour of rotten eggs. It is produced both naturally and through human activity.
Katabatic flow
Katabatic flow or cold drainage flows – This is the metrological phenomenon, by which cold, dense air, flows downhill in certain conditions, notably on clear, cold nights when there is little wind to disperse it. We’ve produced a short animation to help explain this phenomenon here: https://youtu.be/Ll8iNtzpr64(External link).
Landfill Gas
Gas produced from the landfilled waste consist mainly of methane and carbon dioxide. It also contains varying amounts of nitrogen and oxygen (from the air) and small amounts of other trace components. The gas produced will vary with types of waste and age of the landfill.
Landfill Gas Management System
The system by which gas produced by the decomposing waste is actively removed by a pipework system embedded in the landfill, then sent to gas engines to produce electricity or burnt off via a flare.
Leachate
This consists of rainwater which has percolated through the waste in the landfill, dissolving substances, which then collects at the base of the landfill. It can contain high levels of contaminants, including ammonia. Under the permit, the operator is required to have a leachate management plan.
Leachate Management System
A drainage layer and pipework system at the bottom of a landfill cell which collects leachate. The leachate is pumped out of the cell and treated at an onsite plant before discharge to a watercourse. Leachate can also be sent off site by tanker or discharged into foul sewer drains for treatment offsite.
Liner
Material used to line the base, sides and top of a landfill to contain the waste and reduce the rate of leachate and gas emissions.
Mobile Monitoring Facility (MMF)
MMFs are specialist units that can be towed to a location and left for several months to carry out monitoring. A MMF usually contains a power distribution system, weather station and a data logger. Additional analytical equipment may be installed.
Permanent Capping
A permanent layer of material with low permeability to water and gas, such as a geomembrane or clay, which is used to seal a full cell before application of restoration soils and landscaping.
Permeability
Measure of the rate at which a gas or liquid passes through material.
Pollution
Legislation defines this as “any emission as a result of human activity which may (a) be harmful to human health or the quality of the environment, (b) cause offence to a human sense, (c) result in damage to material property, or (d) impair or interfere with amenities and other legitimate uses of the environment.”
Restoration
Landfill restoration is the placement of an even layer of material on top of the landfill to return the land to beneficial use.
Surrogate
A surrogate, in relation to odour monitoring is something which can be easily measured and which has a reliable and consistent relationship with the odour being produced. This allows the measurement of the surrogate to be used to give an indication of how much odour is present where direct measurement is difficult.
Technical Competent Manager (TCM)
Suitably qualified individual, who must be on site for the required time each week.
Temporary Capping
Capping placed to cover waste when tipping is temporarily halted before the cell is completely filled with waste.
Tipping area
The area in the cell where waste is deposited, also called the tipping face or working area.
Waste Acceptance Criteria (WAC)
The criteria for the acceptance of different types of waste at landfill. To ensure that the criteria are met, certain waste must be tested to determine organic content and show what substances will leach from it.
Waste Classification
The process of classifying waste into different types, either non-hazardous or hazardous, in accordance with published technical guidance and definitions.
Well
A sealed engineered hole in a cell used to sample, monitor and extract gas or leachate.


Glossary
Bentonite
Clay minerals which swell when wet. Used to seal wells and make liners.
CellWaste is tipped into discrete areas, called cells, which have engineered bases and side walls to separate the waste from the environment.
Construction Proposals
Before work begins to construct a new cell or install landfill infrastructure, the Environment Agency agrees a written document detailing the design of, the materials to be used in, and the Construction Quality Assurance programme (CQA) which will be followed during the works. This also known as the CQA Plan.
Construction Quality Assurance (CQA)
Written management system which sets out how construction will be managed, checked, tested and recorded to demonstrate that completed works meet required standards and perform as designed.
CoverMaterial is used to cover the wastes tipped in landfills: daily cover is used on tipping faces at the end of the working day to minimise odour and pests.
CQA validation report Report which demonstrates the completed works onsite are fit for purpose. It sets out how engineering works met the agreed construction proposals and is signed off by an independent qualified engineer.
Compliance Assessment Report (CAR)
A CAR is a written report compiled by Environment Agency officers when assessing compliance with an environmental permit. The CAR is used to record the findings of our site inspections, audits and monitoring activities, reviews of monitoring and other data/reports.
Environmental Permit
A permit consists of conditions which the operator must comply with when carrying out operations, to control the risk to human health and the environment. Environment Agency officers assess whether operators are in compliance with these conditions and record this in a Compliance Assessment Report (CAR).
Flame Ionisation Detector (FID)
Hand-held gas detector which measures flammable gases such as methane. FID surveys are carried out to monitor gas emissions from the surface of landfills.
FlareUsed to burn landfill gas extracted from the landfill cells at high temperatures.
Fugitive emissionsThese are emissions not controlled by emissions limits specified in an environmental permit, which may be unintended.
Gas Utilisation Plant (GUP)
Engine used to generate electricity through the combustion of landfill gas. This destroys the gas and significantly reduces pollution, whilst also providing electricity that can be supplied back to the grid.
Geomembrane
Engineered geosynthetic material made to have low permeability, used for permanent capping of full cells before application of restoration soils and landscaping.
Geotextile
Geosynthetic permeable material, used in construction to help strengthen, support, filter or drain soils.
Hydrogen sulphide (H2S)
A colourless, flammable gas with a characteristic odour of rotten eggs. It is produced both naturally and through human activity.
Katabatic flow
Katabatic flow or cold drainage flows – This is the metrological phenomenon, by which cold, dense air, flows downhill in certain conditions, notably on clear, cold nights when there is little wind to disperse it. We’ve produced a short animation to help explain this phenomenon here: https://youtu.be/Ll8iNtzpr64(External link).
Landfill Gas
Gas produced from the landfilled waste consist mainly of methane and carbon dioxide. It also contains varying amounts of nitrogen and oxygen (from the air) and small amounts of other trace components. The gas produced will vary with types of waste and age of the landfill.
Landfill Gas Management System
The system by which gas produced by the decomposing waste is actively removed by a pipework system embedded in the landfill, then sent to gas engines to produce electricity or burnt off via a flare.
Leachate
This consists of rainwater which has percolated through the waste in the landfill, dissolving substances, which then collects at the base of the landfill. It can contain high levels of contaminants, including ammonia. Under the permit, the operator is required to have a leachate management plan.
Leachate Management System
A drainage layer and pipework system at the bottom of a landfill cell which collects leachate. The leachate is pumped out of the cell and treated at an onsite plant before discharge to a watercourse. Leachate can also be sent off site by tanker or discharged into foul sewer drains for treatment offsite.
Liner
Material used to line the base, sides and top of a landfill to contain the waste and reduce the rate of leachate and gas emissions.
Mobile Monitoring Facility (MMF)
MMFs are specialist units that can be towed to a location and left for several months to carry out monitoring. A MMF usually contains a power distribution system, weather station and a data logger. Additional analytical equipment may be installed.
Permanent Capping
A permanent layer of material with low permeability to water and gas, such as a geomembrane or clay, which is used to seal a full cell before application of restoration soils and landscaping.
Permeability
Measure of the rate at which a gas or liquid passes through material.
Pollution
Legislation defines this as “any emission as a result of human activity which may (a) be harmful to human health or the quality of the environment, (b) cause offence to a human sense, (c) result in damage to material property, or (d) impair or interfere with amenities and other legitimate uses of the environment.”
Restoration
Landfill restoration is the placement of an even layer of material on top of the landfill to return the land to beneficial use.
Surrogate
A surrogate, in relation to odour monitoring is something which can be easily measured and which has a reliable and consistent relationship with the odour being produced. This allows the measurement of the surrogate to be used to give an indication of how much odour is present where direct measurement is difficult.
Technical Competent Manager (TCM)
Suitably qualified individual, who must be on site for the required time each week.
Temporary Capping
Capping placed to cover waste when tipping is temporarily halted before the cell is completely filled with waste.
Tipping area
The area in the cell where waste is deposited, also called the tipping face or working area.
Waste Acceptance Criteria (WAC)
The criteria for the acceptance of different types of waste at landfill. To ensure that the criteria are met, certain waste must be tested to determine organic content and show what substances will leach from it.
Waste Classification
The process of classifying waste into different types, either non-hazardous or hazardous, in accordance with published technical guidance and definitions.
Well
A sealed engineered hole in a cell used to sample, monitor and extract gas or leachate.


Page published: 08 Mar 2023, 12:10 PM