Research shows that most slums still lack better waste disposal disposal control. Cases of flooded sewage, burst sewers and the discharge of raw or semi-treated sewage into the environment make news every now and then in Kenya today.
According to the Auditor General Edward Ouko, sewerage rehabilitation and expansion of projects undertaken by Athi Water Services Board(AWSBs) have taken longer than their planned completion dates posing danger to the health of the locals. Ouko said that there is delay in the usual maintenance process and completion of the project posing danger to health of the locals. The delay also meant that the environment continued to be polluted awaiting completion of the sewerage projects.
The audit has further revealed that some of the sewerage facilities developed by AWSBs are based on technology that is not appropriate for Kenya.
According to Section 53 (1) of the Water Act (2002), WSBs are expected to deliver sewerage which is economical to operate and maintain.
Though very efficient in treating wastewater, the electromechanical treatment plants are energy intensive and are often abandoned by the WSPs due to high operation and maintenance costs.
Field verification revealed that AWSB recently rehabilitated the mechanized sewerage treatment plants in Nairobi but due to the energy-intensive nature of these plants (Nairobi City Water and Sewerage Company) NCWSC abandoned these plants.
Although the rehabilitation will definitely improve their wastewater treatment efficiency, these plants may still fail to achieve their intended purpose due to the high cost of operation and maintenance involved.
Field observations have further revealed various instances of burst sewers, open and overflowing manholes and blocked sewers within Nairobi.
As a result, the environment has become polluted with raw sewage. The open manholes are at times used as dumping ground for solid waste by the public, hence causing blockages in the system. This poses a risk to the environment and health of the community at large.
Nairobi also lacks adequate sewerage treatment plant. A visit to Dandora Estate Waste Water Treatment Plant (DEWWTP) revealed that the inlet works had broken down in 2010 and has not been repaired since then.
The trash crusher also broke down in 2013 and no repairs have been done to date. As a result, much of the solid waste and plastics, which is intended to be trapped by the machines escape into the ponds thereby reducing the plant’s treatment efficiency.
As a result of inadequate maintenance of sewerage, the treated sewage being discharged back to the environment do not meet Nema recommended quality standards as measured by Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Total Suspended Solids (TSS).