The operator shall maintain in good condition every bed cot, bunk, and bed spring. He shall also maintain in a clean and sanitary condition every sheet, pillowcase, blanket or other bed cover, and mattress bag which he provides. Sheets, towels, and pillowcases shall be laundered at least once a week. Blankets or other bed covering shall be washed or otherwise cleaned at least every three months. Mattress bags shall be washed and filling changed at least every six months.