Projects
Selected Landfill, Gas & Energy Projects
A selection of recent assignments demonstrating practical landfill engineering, gas recovery, environmental risk and renewable-energy work in the UK and internationally. Client and site names are omitted where confidentiality applies.
Major Middle Eastern Landfill Gas System
Detailed landfill-gas engineering for a major municipal landfill. Holden Environmental developed the gas model and collection-system design, including a DN400 PE100 ring main, DN250 feeders, 102 gas wells, condensate management and a 5,000 m³/h enclosed flare. The work included temporary and permanent extraction strategy, hydraulic checks, setting-out, quantities, fire detection and detailed buildability review..
Key scale: 102 wells · 10 manifolds · approximately 3,330 m³/h design collection flow · 5,000 m³/h flare.
Landfill Gas Upgrading & Renewable Energy Hub
Feasibility and concept development for integrating landfill-gas upgrading with anaerobic digestion and carbon-dioxide recovery. Work included gas-availability forecasting, technology selection, process integration, preliminary plant layout and commercial assessment.
Key scale: Up to 1,800 Nm³/h landfill gas · approximately 60 GWh/year renewable-gas target.
Landfill Gas, H₂S & Odour Risk Assessment
Independent technical assessment of landfill-gas and odour risks associated with major waste excavation and remediation works. The study combined site gas monitoring, source-term scenarios, dispersion modelling, receptor assessment and worker-exposure analysis to determine whether the proposed works could be undertaken safely.
Key scale: Approximately 118,000 m³ of waste assessed · H₂S exceeding 5,000 ppm in parts of the gas field · six sensitive receptors modelled.
Renewable Methane Research & Process Development
Applied research into ex-situ biological conversion of hydrogen and carbon dioxide into additional methane from declining landfill gas. The work examines reactor configuration, gas recirculation, staged hydrogen addition, mass-transfer limitations, temperature control and hydrogen-slip management, with the aim of extending productive landfill-gas utilisation.
Current output: Technical paper selected for presentation at the Venice 2026 International Symposium on Energy from Biomass and Waste.