Residents and business owners in all areas of Johannesburg were told not to bring out their bins until further notice.
"It is unfortunate that our employees have resorted to an unprotected strike in relation to their grievances," Pikitup managing director Amanda Nair said in a statement on Sunday.
Nair said the illegal strike was expected to begin on Monday.
Comment from the South African Municipal Workers Union was not immediately available.
"We will not tolerate such disregard for the law and will take swift legal action in dealing with all involved."
She said workers' grievances included implementation of biometric access control, breathalyser tests for drivers, and transport for workers.
Nair said the digital access system would make operations more efficient. The current transport system for workers was not sustainable and a new solution was needed.
"Previously Pikitup employees requiring transportation were picked up and dropped off at central points on a daily basis using Pikitup trucks."
Residents and business owners in all areas of Johannesburg were told not to bring out their bins until further notice.
"It is unclear as to how long the workers will be on strike for but management is working to resolve the matter with the Samwu union."
Motorists have also been advised to avoid the areas around the Nelson Mandela bridge and De Korte Street in Braamfontein. – Sapa