Miss. Code Ann. § 17-11-13: Miss. Code Ann. § 17-11-13

In the event any county or city within the region desires to withdraw from the district, having previously voted to become associated with such district as provided in Section 17-11-11 , and at least six months has elapsed since the date the election was held for becoming associated with the district as provided in said section, such county or city shall follow the same procedure for withdrawing from the district as that followed for becoming associated with the district. Withdrawal from said district may also be initiated by petition in the same manner as provided in said section for the election for associating with said district.