All but one of Butler County’s employee bargaining units have agreements.

County commissioners on Wednesday voted to accept an agreement with its administrative clerical/technical unit, represented by Service Employees International Union, Local 668.

The four-year contract — effective Oct. 1 — includes a 2.5 percent pay increase for 2015, a 3 percent increase for 2016, a 2.5 increase for 2017 and a 3 percent increase for 2018. It expires Dec. 31, 2018.

The 115-person unit is the largest bargaining unit in the county and covers employees in a variety of positions at 18 departments at the county, including facilities and operations, the communications center, property and revenue, human services and the controller’s office.

Employees covered by this unit have salaries ranging from $16 per hour to $26 per hour.

County solicitor Mike English said the terms of this agreement are relatively consistent with agreements with the other units.

With this agreement, 415 of the county’s 451 union employees have new contracts. All of the previous contracts expired Dec. 31, 2014.

The only unit the county has not been able to come to an agreement with is the unit of 36 employees represented by the Probation Officers Association.

In April, the county’s four detectives — represented by Butler County FOP Lodge 107 — agreed on a three-year contract. In May, 55 administrative professional employees represented by SEIU, Local 668, approved a four-year contract.

In August, the county accepted arbitration awards for the 98 corrections officers at the county prison and for the 10 assistant district attorneys and assistant public defenders. Corrections officers are represented by the American Federation of State, County and Municipal Employees, and the ADAs and APDs are represented by the United Steelworkers of America.

In September, the county accepted arbitration awards for the 67 court-appointed clerical and technical employees, and the 66 court-related clerical and technical workers — both represented by SEIU, Local 668.