ContinuousGround-GasMonitoringContinuous ground-gas monitoring is invaluable for understanding and quantifying the landfill gas regime and identifying off-site migration as part of the environmental permit requirements. It can be used to inform improvements to gas management and collection systems, understanding of landfill gas behaviour or assist with environmental permit surrender.
Continuous monitoring of permanent gases (selected bulk gases, trace gases and total volatile organic compounds) and other environmental parameters provides a wealth of information to identify the dominant processes of gas generation and migration, thus leading to an improved understanding of the landfill gas regime and allowing for a more accurate and truly site specific assessment to be completed.
Conventional monitoring programmes can run for several months and still leave uncertainty in the interpretation of the results. Continuous monitoring reduces this uncertainty and can also dramatically shorten the monitoring period.
The collection of continuous data allows further analysis of gas compositions and gas behaviour. This will invariably improve the understanding of complex ground-gas issues such as, gas collection efficiencies and field balancing, sub-surface fires and / or the mechanisms involved in sub-lateral gas transport / migration. GGS routinely undertake concentration duration analysis and borehole / gas well characteristics assessment to provide valuable information to feed into detailed risk assessments or landfill compliance reporting.
Periodic‘Spot’GroundGasMonitoringGGS periodic monitoring includes the measurement of borehole flow rates, bulk gas concentrations (methane, carbon dioxide and oxygen), trace gas compounds (hydrogen sulphide and carbon monoxide) and barometric pressure. A photo ionisation detector (PID) is also used to measure total volatile organic compounds. Groundwater and borehole base depths are measured using a dip meter.
Our highly skilled and trained staff have vast experience in undertaking ground-gas recirculation monitoring (recommended by BS 8576). This method recirculates the gas sample in the monitoring well leading to a representative sample being measured.
PurgeandRecoveryTests(GGSPRT®)The ground-gas purge and recovery test is designed to measure the rate of landfill gas recovery into a monitoring well following inert gas displacement. The landfill gas recovery rate can then be used, in conjunction with well volume, to calculate a ground-gas flux. A ground-gas flux can provide a reliable indication of gas generation rates and can be used within detailed risk assessments and modelling.
Ground-Gas Solutions Limited (GGS) is the UK’s leading environmental consultancy specialising in continuous ground-gas data capture, analysis and interpretation to inform the management and risk assessment of landfill sites.
AdvancedFluxBoxTestsorSurveyThis service is undertaken in line with Environment Agency guidance on monitoring landfill gas surface emissions (LFTGN07 v2 2010). GGS use Tuneable Diode Laser technology in conjunction with a GFM gas analyser to measure both methane and carbon dioxide (ppm) being emitted from the landfill surface. Methane and carbon dioxide measurements and flux calculations can provide a valuable insight to methane oxidation occurring through the landfill cap.
OtherSpecialistLandfillServicesGGS offer a range of other services, such as active and passive gas sampling, Tedlar bag gas samples and air quality assessments.
ClosedLandfillSiteAppraisalServicesThe assessment of risk at closed landfill sites is an integral part of the aftercare process. The monitoring of the methane emissions forms part of this process, not only to confirm landfill cap integrity and potential gas migration but also to assess Greenhouse Gas Emissions (GHGs).
After a landfill site is closed, alternative beneficial uses are often sought to establish an income for the site owner. Closed landfill site appraisals can form part of this evaluation exercise to determine whether a site can be safely developed, and if it can, what if any additional protection measures may be required. GGS staff have experience of assisting with the safe development of former landfills for residential developments and other sites for renewable energy projects including solar farms.
SurfaceEmissionSurvey(SES)A SES can be used to verify cap integrity and to maximise gas collection efficiency or provide a ‘line of evidence’ of potential gas risk to nearby properties. It can also be used to inform the design of an intrusive gas migration investigation. The monitoring of landfill surface methane emissions is an integral part of demonstrating compliance with the landfill directive. This service is undertaken in line with Environment Agency guidance on monitoring landfill gas surface emissions (LFTGN07 v2 2010). GGS have invested in the latest Tuneable Diode Laser, FID and GPS technologies for SES.
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For a no obligation quotation, or just a simple discussion to
help you consider your options please contact a specialist
within our Landfill Monitoring team on 0161 232 7465.
Purge & Recovery Test (GGS PRT®) on former landfill site.
Continuous Landfill Gas Data
SES using Tuneable Diode Laser and GPS on former landfill.
Contour plot of surface emission data
Quantification of landfill gas emissions to atmosphere based on 5m2 grids.
Advanced Flux Box Emissions Monitoring on former landfill
