Section Phy 209.01 - Intervention Procedure(a) Petitions for intervention shall:(1) Describe in writing the petitioner's interest in the subject matter of the proceedings;(2) Be submitted to the presiding officer; and(3) Be mailed in copy form to all parties identified in the notice commencing the hearing.(b) A petition for intervention shall be granted by the presiding officer if the petitioner complied with (a) above at least 3 days before the hearing and the presiding officer determines that: (1) The petition states facts demonstrating that the petitioner's rights, duties, privileges, immunities or other substantial interests might be affected by the proceedings or the petitioner qualifies as an intervenor under law; and(2) The intervention sought would not impair the interests of justice and the orderly and prompt conduct of the proceedings.(c) The presiding officer shall grant a petition for intervention at any time if: (1) The petitioner complied with (a) above; and(2) The presiding officer determines that the intervention sought would be in the interests of justice and would not impair the orderly and prompt conduct of the proceedings.N.H. Admin. Code § Phy 209.01