Learn the grades
Focus on litter and refuse. The A–D grades below follow the Defra Code of Practice ↗, which Brent’s Veolia contract adopts.
ANo litter or refuse
BPredominantly free apart from some small items
CWidespread litter or refuse with minor accumulations
DHeavily affected with significant accumulations
Try four local photos
Choose a grade to see a suggested answer. One photo shows only part of a street at one moment.

Photo 1 · Clear pavement

Photo 2 · Near a bin

Photo 3 · Tree pit

Photo 4 · Pavement

What about unswept leaves?
Fresh leaves are not litter. Rotted, broken-down leaves become detritus, which has a separate A–D scale. Leaf build-up can still be a street-cleaning concern, particularly around drains.