Auto/Diesel Shop Oil Drain

[bejausa]

A large local shop (auto mechanics, body & detail, diesel) contacted us to clean oil drains (long runs in the floor) to the oil separator. There are 4 separate runs and 6 large 3' square drains with screens underneath. When I inquired about how long it had been - the three guys I talked with gave answers that ranged from "don't know but I've been here [4-12] years and its never been cleaned!!!"

The oil separators apparently run straight into the sanitary sewer - although one guy thought it ran into stormwater system.

Has anyone dealt with something similar? Any idea how to clean the oil separators?

Thanks ...