Plumbing Issue (Bathroom Sink) in Chicago Area

Hi everyone,

I have an issue regarding a bathroom sink in my rental unit. There is a slow leak under the sink, which seems to be coming from the supply line. I may be able to fix this myself by replacing the supply line, but not sure. There is also an issue with the water color . It does not seem to be as clear as the water from other sinks in the unit.

I am curious if anyone has any thoughts on how to fix or a reference for a plumber in Chicago (specifically 60605 area)?

Thanks!