All departments and officers shall submit to the purchasing officer, at such time and in such form as he shall prescribe, reports showing all supplies and equipment which are no longer used or which have become obsolete or worn out. The purchasing officer shall have the authority to sell all supplies and equipment which cannot be used or which have become unsuitable for town use or to exchange the same for or trade in the same for new supplies and equipment. Such sales shall be made pursuant to section 1-11-5 of this chapter. (1988 Code § 3-4-9)