Are you sure that the city engineer understood that you wished to pay for
the run of pipe to your house along the street? My guess is that he thinks
you are trying to get your neighbors to pay for this. I'm not sure why you
would need to acquire any easements.
You need to be clear on who pays for what and how much everything will
cost. There is the cost of running the sewer lines along the road to your
house. Then there is a hook up fee to the sewer pipe. Most likely you'll pay
the city for this. Then you hire a private plumber to dig up your lawn and
connect your house to the sewer line.