Conn. Agencies Regs. § 16-50j-16
In addition to the designation of parties and intervenors in the initial notice and in response to petition, the Council may add parties and intervenors at any time during the pendency of any proceeding.
In the event that the Council shall name or admit any party or intervenor after service of the initial notice of hearing in a proceeding, the Council shall give written notice thereof to all parties or intervenors theretofore named or admitted. The form of the notice shall be a copy of the order of the Council naming or admitting such added party or intervenor and a copy of any petition filed by such added party or intervenor requesting designation as a party or intervenor. Service of such notice shall be in the manner provided in these rules.
Any person granted party or intervenor status is responsible for obtaining and reviewing all materials for the proceeding, including, but not limited to, any notices, orders, filings, or other documents filed or issued in the proceeding prior to the Council's designation of the person as a party or intervenor.
Conn. Agencies Regs. § 16-50j-16