Section 17-141. Service of orders

a. Service of any order of the department
  or board shall be deemed sufficient if made:
    1. Upon a principal  person  interested  in  the  business,  property,
  matter  or  thing, or the nuisance or abuse to which such order relates;
  or
    2. Upon a principal officer charged with a duty in  relation  thereto;
  or
    3.  Upon  a person, officer or deparment, or an officer or employee of
  such a department, who may be most interested  in  or  affected  by  its
  execution.
    b.  If  such  order  relate to any building or the drainage, sewerage,
  cleaning, purification or ventilation thereof, or of any lot  or  ground
  on  or  in which such building stands, used for or intended to be rented
  as the residence or lodging place of several persons or  as  a  multiple
  dwelling,  service  of  such order on the agent of any person or persons
  for the renting or for the collecting of rent thereof, or of  the  parts
  thereof  to which such order may relate, shall be of the same effect and
  validity as due service made upon the principal of such  agent  or  upon
  the  owners,  lessees,  tenants or occupants of such buildings, or parts
  thereof, or of the subject matter to which such order relates.