Sole source procurement is permissible if a requirement is available from only a single vendor. Examples of circumstances that might necessitate a sole source procurement are as follows: Only one source exists which meets the requirements; The compatibility of equipment, accessories, or replacement parts is the paramount consideration; A sole vendor's item is needed for trial use or testing; or Public or regulated utility services are to be procured and only one source exists. The LEA shall submit a written sole source justification to the IAC or its designee.