Ppl living in Middle to high class neighbourhoods are more likely to swap out their in home lead pipes because they got the money to do it. They're probably also more likely to raise concern about it to the city.
Because i's on the government to change the street pipes. I don't think it's a reach to suggest some regions would place the lowest priority on lower income neighbourhoods. Because these things take time and cost money and u know how that story goes.
Actions gotta be demanded, but in the meantime ppl need to be put in the know about lead, its effects, and ideally be provided help with buying and setting up filtration systems.