The rehabilitation of the Homa Bay town sewerage system at a cost of Sh215 million has started.
The process is expected to take five months.
Officially launched on Thursday, the project is expected to eradicate pollution in Lake Victoria.
The project involves construction of a new pond and repair manholes.
Deputy Governor Hamilton Orata thanked the World Bank, through Lake Victoria Environmental Management, for funding the project.
Orata said the plant was designed to cater for a very small population yet the town has since expanded.