The National Environment Management Authority (Nema)on Sunday summoned nine flat owners in Kitengela town, Kajiado county, for discharging raw sewage to the road.
The authority said the summons came after inspection led by acting director general Mamo B Mamo established that the nine flats along Balozi Road were discharging raw sewage into the road.
The nine are expected to appear at the NEMA headquarters on Monday.
The authority in August threatened to prosecute acting Nairobi Water and Sewerage Company managing director for discharging untreated sewage into the Nairobi River.
Nahashon Muguna narrowly escaped arrest for failing to comply with an order to repair the sewer lines said to emitting the discharge.
But he dismissed the summons, saying some Nema orders had already been addressed.
"The problem facing Nairobi is much bigger and cannot be addressed by one agency", Muguna said.
Dagoretti and Kiamaiko slaughterhouses were closed last year for discharging untreated waste into the Nairobi River, he said.
