The Board shall not communicate, directly or indirectly, with any party or his representative in connection with any issue involved except upon notice and opportunity for all parties to participate. In addition, the Board shall not take notice of any communication, reports, staff memoranda or other materials, excluding the advice from the Board's Solicitor, unless the parties are afforded an opportunity to contest the material so noticed and shall not inspect the site or its surroundings after the commencement of hearings with any party or his representative unless all parties are given an opportunity to be present. "Board," as used herein, shall include not only the members but also any hearing officer, secretary, clerk, legal counsel, or consultant to the Board.