Centralised water treatment and a piped distribution network have had a mixed history primarily due to high initial costs and operation and maintenance, inadequate access to training, management and finance sufficient to support a fairly complex system for the long term. These complete systems are also slow to be implemented so waterborne disease continues in the interim.
==Construction, operations and maintenance==
'''Comparing centralised plants with decentralised plants'''
For the rural stand-alone treatment plants (decentralised plants), the type of technology employed has a marked effect on the sustainability of the treatment scheme. The tendency is more towards low-tech technologies requiring minimal operation and maintenance inputs. The reason is the lack of skilled and trained personnel to operate and maintain the plant, poor access roads in the deep rural areas hampering delivery of chemicals and equipment, and management challenges resulting from the remoteness of these rural plants.
As such, [[Slow sand filter]]s are often used in the rural areas, but even these plants present challenges with operation and maintenance, and the treatment is often compromised by these challenges. The concept of using automated high-tech technologies has gained popularity because it can be operated with minimal input from the local operator, be serviced and maintained by a roving technician under contract, and can also be operated remotely with the aid of telemetry. Some of these technologies are also packaged in such a way that it largely eliminates the use of chemicals, contains one or more treatment barriers, have automated cleaning regimes, can operate by gravity alone and therefore obviate the need for electricity, and can be pre-manufactured and packaged on a skid-mount or in a container.
For decentralised treatment systems, the use of automated more sophisticated systems operated and maintained under contract by reputable water treatment companies are therefore likely to present a “best” treatment option in terms of performance, compliance and sustainability.
==Costs==
