| Sampling site | Type of sample | Coordinates of the site | Location description |
| Shirere | Sediment and water | 34˚44'30"E 0˚28'30"N | Sand harvesting and farming along the river. |
| Rostaman | Sediment and water | 34˚43'30"E 0˚18'N | Gold mining, informal settlements, illegal wastes and discharges damping site due to mining activity and maize farming along the river banks. |
| Mwibatsiro stream | Sediment and water | 34˚54'0"E 0˚18'N | Maize and Napier grass farming along the river |
| Municipal dumpsite | Soil | 34˚53'20"E 0˚28'30"N | Kakamega town damping site; industrial, agricultural and domestic wastes from the town and the neighborhood localities. |
| Shirere sewage | Soil, sediments and water | 34˚45'0''E 0˚28'30"N | Sand harvesting and maize farming along the river. |
| Ekero | Sediments and water | 34˚33'0''E 0˚28'30"N | Sugarcane farming, and maize farming. |
| MMUST damp site | Soil | 34˚29'20''E 0˚18'N | Main MMUST dumpsite, kitchen wastes and domestic wastes. |
| Mayoni | Sediment and water | 34˚43'28''E 0˚18'N | Sugarcane farming, sand harvesting and car wash along the river banks. |
| Shibeye | Sediments and water | 34˚33'20''E 0˚28'30"N | Sugar cane farming. |
| West Kenya sugar Company | Boiler water and mud filter | 35˚4'30''E 0˚18'N | Sugar processing, accumulation and transportation of mud filter to various farms. |
| Mumias sugar Company | Burnt farm soil and nuclear estate soil | 34˚32'20''E 0˚18'N | Sugar processing, accumulation and transportation of mud filter to various farms. |
| Nzoia sugar Company | Bagasse soil, mud filter and boiler water | 34˚46'30''E 0˚28'N | Sugar processing, accumulation and transportation of mud filter to various farms. |