- Nzoia Water Services Company Limited (Nzowasco) was formed under the Companies Act (CAP 486) on 4th February 2004 and became operational a year later on 9th February 2005.
- The company is mandated to provide water and sewerage services within the County Governments of Bungoma (Bungoma, Webuye & Kimilili) and Trans Nzoia (Kitale). The services have extended to Kakamega and Busia counties.
- The company is fully owned by the county Governments of Bungoma and Trans Nzoia.
- The company operates several water treatment works: Nabuyole, Matisi, Kapkateny, Chesikaki in Bungoma county and Kapolet & Nzoia in cherangani county. They serve Webuye, Chwele, Kapkateny, Kimilili, Bungoma and Kitale towns. A pumping system is used in Nabuyole and Matisi water treatment works and the rest relies on gravity.
The Company sewerage plants exist in three regions namely Bungoma, Webuye and Kitale regions. In Kitale the company operates two sewerage treatment systems. The convectional system located at Matisi and lagoon system located at Bidii. The major source of waste water includes municipal sewerage, industrial sewerage, storm water and urban runoff.
Municipal sewage contains high percentage of both organic and residues and plant nutrients, while industrial sewerage encompass the entire spectrum of pollution with both dumping of heavy metals and organic materials. Finally storm water urban runoff contains pollutants such as grease from garages, heavy metals and agricultural pollutants.