The structure that you reference is a percolation trench, an infiltration trench or an open top drywell. Neither/none of which are designed to filter. It is not a filter, it is not designed to act as a filter and it should not be used as a filter. Sweep, oil absorb and go to washing but do not confuse infiltration or perc with filtering.
Quick copy and paste from a VA state document.:
Infiltration practices are generally suited for low- to medium-density development (38% to 66%
impervious cover). Specific conditions such as drainage area size and development conditions for
each infiltration practice are discussed in the appropriate section of this Standard.
MINIMUM STANDARD 3.10 CHAPTER 3
3.10 - 4
Planning Considerations
Infiltration facilities are subject to clogging and, therefore, are not recommended for areas where
sediment, grease, or oil loadings may be high. Such areas include roadways, parking lots, car
service facilities, etc. To increase the life expectancy of an infiltration facility, a pretreatment
facility such as a settling basin or “cell”, or additional BMP in series should be used to remove
sediments or other substances from the stormwater runoff before it enters the infiltration facility.
Edit to post illustration found with copied text.