UK water companies face tightening nutrient limits through AMP8 and future regulatory cycles, increasing pressure to achieve lower total nitrogen (TN) levels at many treatment works. Many facilities must meet these standards within constrained footprints, existing assets, and variable influent conditions, driving the need for robust and operationally efficient biological denitrification. Deep bed denitrification filtration—refined over 40 years of global application—has proven highly effective in both conventional and space restricted sites. This presentation draws on international case studies, including the long term performance of the Arlington Water Pollution Control Plant in Virginia. Arlington’s upgrades, featuring advanced biological filtration, optimised backwashing, and controlled carbon dosing, consistently achieved effluent TN below 3 mg/L and phosphorus below 0.1 mg/L, even under peak flows and seasonal shifts. By comparing Arlington with other established installations, the presentation identifies key insights for UK utilities preparing for AMP8: integrating biological denitrification within existing footprints, maintaining full treatment during construction, optimising carbon dosing, and employing filter designs that handle high solids while extending maintenance intervals. These examples provide strong evidence for deploying high performance nitrogen removal technologies to meet long term nutrient compliance goals.