The National Environmental Management Authority has shut five factories in Nairobi's Industrial Area for discharging dangerous effluent to the environment.
During the crack down, five people whose premises were discharging raw sewage to the environment were arrested.
The factories closed yesterday include Africa Apparel Limited, Mas tannery, Far Horizon hides and skins, Amin Tanners and Nairobi Tanners Limited.
A source at Nema told the Star the firms affected were polluting the environment with toxic waste.
The authority has been undertaking inspections on illegal discharge of raw sewage into the environment.
"The exercise is meant to weed out companies discharging untreated waste water into sewer lines or the environment that mainly ends in rivers,"the source said.
The source said Nairobi Water and Sewerage Company was given restoration orders to repair manholes.
"Several manholes in the area belonging to the firm are not in good shape."
On April 16, Nema closed three companies Nairobi's south over emission of toxic gases.
The authority took the action after investigations following complaints from residents of South B and C.
Residents had been complained of a pungent smell since March 5.
They blamed the smell for hospitalization of at least four children.
Companies closed were Powerex, Edible Oil and Usafiplus.
