View Public Works' open solicitations, and learn more about how to register as a supplier and submit a bid or proposal. The standard purchasing process for Allegheny County involves: requisitioning; public solicitation; bid and proposal receipt; evaluation and contract award.BID PROPOSAL: Please see the form located in section 004123. Iii) Proposal Format. Proposals must be made on the Authority's form and in accordance with the Plans and Specifications and the "Instructions to Bidders"'. Allegany County is soliciting a Request for.