(1) Commutation of time for good conduct of county prisoners shall be granted by the board of county commissioners unless, by a majority vote of the board of county commissioners, the board elects to discontinue or revise gain-time policies for good conduct. If the board of commissioners authorizes commutation of time for good conduct, the following deductions shall be made from the term of sentence when no charge of misconduct has been sustained against a county prisoner: up to 5 days per month off the first and second years of the sentence; up to 10 days per month off the third and fourth years of the sentence; up to 15 days per month off the fifth and all succeeding years of the sentence. Where no charge of misconduct is sustained against a county prisoner, the deduction shall be deemed earned and the prisoner shall be entitled to credit for a month as soon as the prisoner has served such time as, when added to the deduction allowable, will equal a month. A county prisoner under two or more cumulative sentences shall be allowed commutation as if they were all one sentence.
(2) For each sustained charge of escape or attempted escape, mutinous conduct, or other serious misconduct, all the commutation which shall have accrued in favor of a county prisoner up to that day shall be forfeited, except that in case of escape if the prisoner voluntarily returns without expense to the state or county then such forfeiture may be set aside by the board of county commissioners if in its judgment the prisoner’s subsequent conduct entitles him or her thereto.
(3) The board of county commissioners, upon recommendation of the warden or sheriff, may adopt a policy to allow for county prisoners, in addition to time credits, an extra good-time allowance for meritorious conduct or exceptional industry not to exceed 5 days per month.
(4) All or any part of the gain-time earned by a county prisoner and any extra gain-time allowed him or her, if any, shall be subject to forfeiture by the board of county commissioners upon recommendation of the sheriff or warden for violation of any law of the state or any rule or regulation of the board or institution.