From the Lawrence Daily Journal-World for April 1, 1972:

The innovation of curbside trash pick-up was scheduled to begin after the Easter weekend. Under a new policy, all trash containers were to be placed within two steps of either the street or the alley. George Williams, director of public works, said that a grace period of three or four pick-up days would be granted to let residents get accustomed to the idea; during that time, sanitation employees would continue to haul trash from houses to the truck while leaving a reminder card for the resident. Trash cans were to be limited to 30 gallons and have tight-fitting lids. Plastic bags were permitted as long as they were sturdy enough to contain their cargo and not break or leak.