Provider of an underground takeaway service for the public (5)
I believe the answer is:
This clue could be a double definition.
'provider of an underground takeaway service' is the first definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'public' is the second definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'for the' acts as a link.
Can you help me to learn more?
(Other definitions for sewer that I've seen before include "Drainage channel" , "Embroiderer; soil pipe" , "dressmaker?" , "Needlewoman" , "One working with material?" .)