Hammersmith's busy King Street and Broadway areas create a unique drainage environment where residential properties interface with commercial waste systems from restaurants, offices, and retail establishments. Grease and commercial waste can impact residential drainage networks through shared or interconnected systems, particularly affecting basement and lower-ground-floor properties common in converted commercial buildings. Our experience includes managing these mixed-use drainage challenges, having recently completed complex clearance work in nearby Shepherd's Bush where residential and commercial systems required coordinated attention. We understand the regulatory requirements and practical considerations for both domestic and commercial drainage in dense urban environments like central Hammersmith.