At such time as a public sewer comes available to a property served by a private sewage disposal system, a direct connection shall be made to the public sewer in compliance with this chapter, and any septic tanks, cesspools, and similar private sewage disposal facilities shall be abandoned, cleaned of sludge, and filled with clean bank-run gravel or dirt within sixty days of notification to do so by the city. (Prior code § 4-1-58)