Conn. Gen. Stat. § 3-44

When the semiannual interest due on any bond or note given for moneys loaned from the School Fund or the Agricultural College Fund remains unpaid fifteen days or more after it has become due, the Treasurer is authorized to charge interest thereon from the time the same became due and, if the semiannual interest remains unpaid six months after it becomes due, the interest charged shall be at the rate of nine per cent per annum until the same is paid. The Treasurer is authorized to waive interest due or to become due on unpaid interest.