City Hall has put on notice traders who have erected stalls on drainage and sewer lines to vacate and seek alternative spaces to do business.
The traders have been accused of frustrating efforts to unclog drainage system in the county through dumping of solid waste.
Nairobi County Environment executive Vesca Kangongo said that the traders, especially those in slum areas, have irregularly erected racks and stalls on the lines.
"Most of the illegal dumping is done by traders selling vegetables, bananas, maize and electronic traders within residential estates. The traders are expected to have dust bins for their waste but majority of them have defied," said Ms Kangogo.
She said they will soon arrest them for breaking the law by deliberately dumping the waste contrary to laid down regulations.
"The county does not plan to frustrate efforts by young entrepreneurs to make ends meet, but it wants to make the environment they operate in clean," she said.
Early this year, Governor Mike Sonko directed his officers to fully implement the Nairobi City County Solid Waste Management Act to rein on such cases of perennial pollution of the environment.
He said the county has set aside Sh2.7 billion in the current financial year for expansion of water and sewerage infrastructure.
The unclogging of the drainage systems within Nairobi City estates and major highways is still ongoing.