Anaerobic Digestion of Sewage Sludge
Anaerobic digestion of sewage sludge for biogas production and nutrient recovery, reducing methane emissions and displacing fossil energy.
Substantial Contribution to Climate Change Mitigation
The anaerobic digestion facility must achieve a methane capture rate of at least 99% of the biogas produced. The captured biogas must be used for energy generation (electricity, heat, or combined heat and power) or upgraded to biomethane for injection into the gas grid or use as transport fuel. Flaring of biogas is permitted only as a safety measure, not as a routine disposal method.
The facility must demonstrate a net GHG emission reduction compared to alternative sludge management methods (landfilling or incineration without energy recovery). A life-cycle GHG assessment must be provided, showing positive climate impact including avoided methane emissions, displaced fossil energy, and reduced need for synthetic fertiliser through digestate use.
Substantial Contribution to Climate Change Adaptation
A CRVA must assess risks to the digestion facility from flooding, temperature extremes affecting process stability, and changes in sludge characteristics due to upstream climate impacts on wastewater flows.
DNSH: Climate Change Adaptation
The facility must be designed to withstand climate hazards identified through the Appendix A assessment, including flood protection for biogas storage and process equipment, and thermal management for digester stability.
DNSH: Water and Marine Resources
Digestate storage and application must prevent leaching of nutrients and pathogens into surface water and groundwater. Digestate quality must comply with the Sewage Sludge Directive (86/278/EEC) and any applicable national standards for land application.
DNSH: Circular Economy
Digestate must be processed and used as a soil amendment or fertiliser product, recovering phosphorus and nitrogen. Sludge pre-treatment processes must maximise volatile solids destruction and biogas yield to optimise resource recovery.
DNSH: Pollution Prevention and Control
The facility must control odour emissions through enclosed handling and biofilter systems. Fugitive methane emissions from the entire biogas chain (digester, storage, upgrading) must be monitored and kept below 1% of total production. Heavy metal and micropollutant concentrations in digestate must be below regulatory thresholds.