Staff at Derry City and Strabane District Council could be tested for drugs or alcohol use under a scheme.
The council's Governance and Strategic Planning Committee approved a new workplace alcohol and drugs policy at Tuesday's meeting. Employees may be tested for drug or alcohol use if a manager is suspicious that an employee has reported for duty under the influence of alcohol or drugs.
The new policy is designed to provide a safe and healthy work environment for employees.
Sinn Fein's Caoimhe McKnight said: "It is good to see the council working to help staff if they have problems."
Awareness training on drugs and alcohol will be given to all new council employees as well as existing employees.
The Workplace Drugs and Alcohol Policy defines the roles and responsibilities for all employees in relation to alcohol and drugs.
"It also provides a framework for employees to seek support for an alcohol or drugs related problem," according to council papers.