Mich. Comp. Laws § 129.123

Sec. 3. Subject to the provisions of this act, the governing body of any public corporation may authorize the cremation or disintegration of obligations or interest coupons. As an alternative, subject to the provisions of this act, any public corporation may enter into an agreement with a paying agent for the cremation or disintegration of its obligations and interest coupons, which agreement shall be approved and its execution authorized by the governing body.