The versatile and environmentally attractive nature of vacuum technology often presents a viable solution when faced with difficult circumstances. Old towns with narrow streets often do not allow sufficient access for the essential trench digging machinery required for conventional gravity sewage systems. Due to its requirement of only simple trenching at shallow depths, a vacuum sewage system can be the ideal alternative.

The vacuum technology offered by Iseki Redivac only requires shallow narrow trenches using small bore pipes. The reduced depths of 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, Hong Kong, are prime examples where a vacuum sewage system has be implemented to overcome access issues related to narrow streets. The shallow, narrow trenches required for Iseki Redivac technology enabled approximately 400 buildings to be connected to a proper sewage system and finally allow the old septic tank system to be discarded. The trenches had to be dug be hand and the small bore sewage pipes used facilitated the complexity of the pipe runs required.  At Tai Po the substantially lower installation costs and the need for fewer pumping stations made the Iseki Redivac system the preferred choice based on cost efficiency alone.