Specifications include, but are not limited to: Contractor shall follow locate request response requirements as indicated by the Digger’s Hotline system. Contractor’s underground utility locating equipment and processes are subject to WisDOT inspection and approval. All underground utility facilities shall be electronically located, except where electronic locating is impossible. Contractor shall locate underground utilities utilizing map data and measurements when electronically locating is impossible. Contractor shall contact the WisDOT Regional agency when locating underground utilities is impossible by other means identified above. Contractor shall contact the excavator when marking instructions are unclear and/or incomplete. It is the responsibility of the contractor to identify errors and omissions with excavators locate requests and take corrective action to complete the utility locate request on time.