Origin of solids
Origins of solids - Surface solids entry through catch basins
The stormwater runoff from unsealed and sealed surfaces (i.e. open space, tree grates, yards, parks, roads, etc.), which enters the separate or combined sewer systems through catch basins contains the highest amount of solids.
Nearly half of all combined sewer, and 100% of all storm sewer solids come from this source [Artie1988].
Origin and type of solids from the surface runoff [Source: visaplan GmbH]