More than 70 per cent of wastewater generated in Nairobi is discharged untreated into the environment, raising concerns over the growing pollution of rivers and the threat it poses to communities downstream. Environment Cabinet Secretary Deborah Barasa issued the warning on May 5, 2026, during an inspection of industrial facilities discharging effluent into the Nairobi River system in Mlolongo, Machakos County.
She directed the National Environment Management Authority (NEMA) to conduct immediate and comprehensive inspections of all facilities suspected of releasing waste into rivers and their tributaries. Barasa warned that industries operating without functional effluent treatment plants would face closure, insisting that environmental compliance must be enforced.
“Discharge of untreated wastewater is a direct assault on our environment,” Barasa said, blaming industrial effluent, leaking sewer systems and poorly managed solid waste for the continued deterioration of the country's waterways. She warned that pollution originating in Nairobi does not end within the capital but flows downstream into the Athi River system, exposing communities and ecosystems to contaminated water.
The Cabinet Secretary said facilities found violating environmental regulations would be required to comply with established standards or face enforcement action. Her warning came amid growing pressure on environmental regulators to strengthen inspections and hold industries accountable for the pollution of rivers and other water sources.
The government's enforcement record has, however, come under scrutiny from legislators. In July 2026, Barasa told the Senate that NEMA had inspected 101 facilities in the Nairobi Metropolitan area during the 2024–2025 financial year. She further disclosed that the authority had identified and closed 405 illegal discharge points during the 2025–2026 financial year, exceeding its target of 400. Despite these interventions, the Cabinet Secretary acknowledged that illegal waste disposal remains a serious environmental challenge.
The figures have renewed questions about whether inspections and closure orders are translating into lasting improvements in water quality and compliance among industries.
Concerns over the pollution of River Athi have also reached the National Assembly, where lawmakers debated the deteriorating condition of the river on February 17, 2026. Public Petitions Committee Chair Karemba Muchangi called for water agencies to construct modern effluent treatment plants and expand sewer networks to ensure wastewater is treated before being released into the environment.
Dagoretti North MP Beatrice Elachi criticised the enforcement measures taken against industries operating along the Athi River Basin, saying: “Enforcement actions on industries along the Athi River Basin remain unsatisfactory.” Lawmakers also recommended fresh water sampling, stronger coordination between environmental agencies and restoration measures against companies found responsible for pollution.
Beyond Nairobi and the Athi River, environmental concerns have also been raised in other parts of the country. The Tana and Athi Rivers Development Authority (TARDA) has identified pollution, riparian encroachment, soil erosion, siltation, declining water flows and unregulated sand harvesting as major threats to the Athi Basin. On August 10, 2026, TARDA management, led by Managing Director Liban Roba, received findings from a nine-day field data collection exercise covering the Upper and Middle Athi River Basin. The exercise covered Kiambu, Kajiado, Nairobi, Machakos and Makueni counties, with findings expected to inform the preparation of an Integrated Athi River Basin Development Plan.
Similar concerns have previously emerged along the Galana River in Kilifi County, where residents of Bombi village reported discoloured green water and dead fish in September 2025. Residents suspected that waste from a nearby sisal-processing plant could have contributed to the pollution, although the suspected source had not been officially confirmed. The incident raised concerns about the effects of industrial waste on aquatic life, livestock and communities that depend on river water. It also highlighted the need for environmental authorities to investigate pollution reports promptly and establish the actual sources of contamination rather than relying solely on community complaints.
Despite the government's renewed enforcement efforts, the continuing concerns raised by legislators, environmental agencies and river-dependent communities point to the need for sustained action. While NEMA has reported hundreds of closures and inspections, lawmakers continue to question the effectiveness of enforcement against industries discharging untreated waste. The proposed expansion of sewer networks, investment in modern treatment facilities and stronger monitoring of industrial activities will be critical in addressing the problem. Ultimately, protecting Kenya's rivers will require consistent enforcement, accountability from polluters and coordinated action by national and county governments.
For communities living downstream, the success of the crackdown will be measured not by the number of inspections conducted but by whether the water flowing through their rivers becomes safer and cleaner.
