Anaerobic digestion (AD) integrated with combined heat and power (CHP) can enhance agricultural waste management through renewable energy generation, emission mitigation, and resource recovery. However, conventional environmental impact assessments (EIAs) often overlook interactions among environmental performance, resource circularity, and operational sustainability. This study presents an integrated EIA framework for a full-scale cattle manure AD–CHP system in Jordan, combining operational monitoring, greenhouse gas (GHG) accounting, resource recovery indicators, water management assessment, and uncertainty considerations. The assessment was conducted using one stabilized operating year of monitoring data covering feedstock characteristics, biogas quality, energy production, water flows, digestate properties, and operational parameters. The system boundary was defined as gate-to-gate, including manure reception, anaerobic digestion, gas cleaning, CHP operation, digestate handling, and water reuse. Within this defined boundary, the AD–CHP system provided an estimated net GHG mitigation of approximately 38,800 tonnes CO2-equivalent per year relative to unmanaged cattle manure storage, accounting for methane capture, residual methane losses, and project-related emissions. Electricity displacement was evaluated separately as a co-benefit and was not included in the core manure-management GHG mitigation balance. The system generated approximately 7,253 MWh/year of net electricity export, reduced external freshwater withdrawal by approximately 55% (80,300 m3/year) through process-water reuse, and enabled recovery of approximately 180 tonnes/year nitrogen (N), 55 tonnes/year phosphorus pentoxide (P₂O₅), and 60 tonnes/year potassium oxide (K₂O) nutrient equivalents. The proposed framework demonstrates how integrated EIA approaches can support comprehensive evaluation of AD–CHP sustainability performance while emphasizing transparent boundaries, monitoring, and uncertainty characterization.