Click on each letting date for contract details and documents. The Bid Sheets and other required bid documents are ONLY available in the full bidding package.To file invoices for all DEP contracts, vendors must use the DEP Invoice Platform. Vendors will need to create an account upon initially accessing the platform. In order to fulfill this requirement, you must complete the Vendor Responsibility Questionnaire. In this article, we will delve into what bid proposals are, how they work and some best practices for proposing bids in the construction industry. Learn how to write a winning bid proposal for construction projects. All Proposals must meet the requirements listed in the RFP.