Old towns with narrow streets
Old towns with narrow streets usually have restricted access which restricts the use of heavy plant and machinery used in the construction of traditional gravity sewerage systems. In these circumstances, a Redivac vacuum sewerage system offers the ideal solution as it utilises narrow, shallow trenches for the small bore pipes used. This allows lighter duty equipment to be used during the construction phase of the project.
These smaller trenches not only offer a cost saving on excavation and a reduced installation time, but also permit hand digging should access by mechanical diggers be restricted. Furthermore, the flexibility of the piping allows the system to fit around existing services such as telephone and electrical cables.
The villages of Tai Wai and Tai Po in Hong Kong, are prime examples where a vacuum sewage system has been successfully installed overcoming these access issues. Redivac vacuum sewerage technology allowed 400 buildings to be connected to the mains sewerage system allowing the old septic tank system to be discarded. Where access was very difficult, some of the trenches were dug manually and the flexibility of the small bore sewage pipes used allowed complex pipe runs to be achieved.
The substantially lower installation costs and the need for fewer pumping stations made the Redivac shallow sewer solution the preferred choice.