53 Pa. Stat. § 16408
Said board of health shall have full power and authority to make and enter into all contracts for cleaning of said streets and the removal therefrom sweepings, manures, ashes, garbage, offal and refuse, and shall advertise in not less than two daily papers published in the city of Philadelphia, for a period of ten days, commencing within twenty days after the passage of this act, for proposals, accompanied with specifications, showing how often and in what manner the proposed work is to be done, and for such periods, not exceeding three years from the date of contract; proposals shall be opened at the time and place fixed in said notice, in the presence of the board of health, or a majority thereof, and in the presence of the finance committee, or such of them as may see proper to attend; and the contract shall be awarded to the lowest and best bidder, to be approved by the majority of said board of health and a majority of said finance committee as may be present.
53 P.S. § 16408