Sewage Hatch
From Drug Dealer Simulator Wiki
The sewage hatch is a route between Sector A and Sector B.
It can be found slightly north east of where Eddie's place is.
You can use it to travel freely between Sector A and Sector B, but you cannot take a backpack with you. With skill points invested in the Pockets skill, you can take a small amount of drugs with you.
To move large quantities of substances with your backpack, you could alternatively use the Old Technical Tunnels.