English to Polish Tech/Engineering Environment & Ecology

Drain: physical conveyance into which wastewater may be discharged. Types of drains include storm drain and vent, sanitary sewer vent, open floor drains, trenches, sump/pump stations, and shop sinks. The term excludes storm water only collection systems.
cały czas ten tajemniczy fragment ;P nie rozumiem ostatniego zdania pomóżcie