What is the fine-grained topic of the following text: Engineer Herbert Nyakutsikwa, who is responsible for water and sanitation, said they have so far replaced a 5km sewage system in Dzivaresekwa, Kuwadzana and Mufakose which is almost complete and is set to easy the issue of burst sewage pipes in these areas. Only return the topic.
Replacement of sewage system in Dzivaresekwa, Kuwadzana and Mufakose