provided for areas currently served with piped water and those with the potential of being served with piped water soon, as identified. The following trunk sewers have been identified in the project area using the natural drainage patterns; i. This sewer follows the Mugutha River and will drain parts Mugutha River Trunk Sewer: of Mugutha and Theta sub-locations in Ruiru. This sewer will empty in to the Theta River Trunk Sewer. ii. This follows the Theta River and is proposed to drain parts of Theta River Trunk Sewer: Theta sub-location in Ruiru and Milimani sub-location in Juja as well as flows conveyed by the Mugutha River Trunk Sewer. This sewer will empty into the Thiririka River Trunk Sewer. Figure 1 Mugutha, Thiririka and Interceptor Trunk sewers iii. Thiririka River Trunk Sewer: This will follow the Thiririka River and will serve Milimani and Kalimoni sub-location. It will empty to the Interceptor Trunk Sewer and eventually to the Treatment plant. iv. Kamuguti River Trunk Sewer: This sewer will follow the Kamuguti stream and empty into the Komu River Trunk Sewer. The sewer will serve Witeithie sub- location. vii. Komu River Trunk Sewer: This will follow the Komu River draining the Karimenu (Ngoingwa), Komu, Weteithie, Kianjau and Komo sub-locations of Thika. It will eventually empty into the Treatment Plant at Thika. Figure 2 Komo and Kamuguti Trunk Provision of a sewerage system will require the construction of a reticulation system to serve areas that are either already developed or are in the process of development. The secondary sewers have been proposed as collectors for the laterals and are planned such that they discharge the flows at appropriate points to the proposed trunk sewers. Tertiary sewers have been located on the residential/estates road network so as to facilitate ease of property connection. 2.3 ALTERNATIVE SITES FOR SEWAGE TREATMENT WORKS An initial consideration in the selection of a site for sewage treatment is whether treatment should be carried out at one central location or whether a number of different sites would be more appropriate. Factors affecting this consideration include; Pattern and rate of development Shape and size of the catchment area Topography of the area
provided for areas currently served with piped water and those with the potential of being served with piped water soon, as identified. The following trunk sewers have been identified in the project area using the natural drainage patterns; i. Mugutha River Trunk Sewer: This sewer follows the Mugutha River and will drain parts of Mugutha and Theta sub-locations in Ruiru. This sewer will empty in to the Theta River Trunk Sewer. ii. Theta River Trunk Sewer: This follows the Theta River and is proposed to drain parts of Theta sub-location in Ruiru and Milimani sub-location in Juja as well as flows conveyed by the Mugutha River Trunk Sewer. This sewer will empty into the Thiririka River Trunk Sewer. Figure 1 Mugutha, Thiririka and Interceptor Trunk sewers iii. Thiririka River Trunk Sewer: This will follow the Thiririka River and will serve Milimani and Kalimoni sub-location. It will empty to the Interceptor Trunk Sewer and eventually to the Treatment plant. iv. Kamuguti River Trunk Sewer: This sewer will follow the Kamuguti stream and empty into the Komu River Trunk Sewer. The sewer will serve Witeithie sub- location. vii. Komu River Trunk Sewer: This will follow the Komu River draining the Karimenu (Ngoingwa), Komu, Weteithie, Kianjau and Komo sub-locations of Thika. It will eventually empty into the Treatment Plant at Thika. Figure 2 Komo and Kamuguti Trunk Provision of a sewerage system will require the construction of a reticulation system to serve areas that are either already developed or are in the process of development. The secondary sewers have been proposed as collectors for the laterals and are planned such that they discharge the flows at appropriate points to the proposed trunk sewers. Tertiary sewers have been located on the residential/estates road network so as to facilitate ease of property connection. 2.3 ALTERNATIVE SITES FOR SEWAGE TREATMENT WORKS An initial consideration in the selection of a site for sewage treatment is whether treatment should be carried out at one central location or whether a number of different sites would be more appropriate. Factors affecting this consideration include; Pattern and rate of development Shape and size of the catchment area Topography of the area
Environmental00uja0and0Thika0South.docx