Lead water supply pipe observed after inspection

[Adam Cherko]

I am looking to see if anyone has experience in their rental properties containing lead supply lines from the street before the water meter. I am purchasing a duplex in New Rochelle, NY and while having an inspection completed yesterday we found this situation. The outgoing landlord has no filtration in the either of the two units that I can tell. 

Does anyone have experience with this. Am I required to tell tenants they can not drink the water. Am I required to have the water tested? Am I required to have reverse osmosis filters under each sink with a separate drinking water faucet? 

Any guidance is greatly appreciated!