Water distribution system

[6] A water distribution system consists of pipelines, storage facilities, pumps, and other accessories.

[4] In general, a water distribution system can be classified as having a grid, ring, radial or dead end layout.

[3] The physical integrity includes concerns on the ability of the barriers to prevents contaminations from the external sources to get into water distribution systems.

[3] The hydraulic integrity is an ability to maintain adequate water pressure inside the pipes throughout distribution systems.

It also includes the circulation and length of time that the water travels within a distribution system which has impacts on the effectiveness of the disinfectants.

The water quality degradations can also take place within the distribution systems such as microorganism growth, nitrification, and internal corrosion of the pipes.

[3] Analyses are done to assist in design, operation, maintenance and optimization of water distribution systems.

[15] Employing mathematical optimization techniques can lead to substantial construction savings in these kinds of infrastructures.

However, when infectious microorganisms enter the systems, they form biofilms and create microbial hazards to the users.

[6] Physical hazards include turbidity of water, odors, colors, scales which are buildups of materials inside the pipes from corrosions, and sediment resuspension.

[6] Water quality deteriorate due to corrosion of metal pipe surfaces and connections in distribution systems.

Pipe corrosion shows in water as color, taste and odor, any of which may cause health concerns.

[17] Health issues relate to releases of trace metals such as lead, copper or cadmium into the water.

[17] Various techniques can be used to control internal corrosion, for example, pH level adjustment, adjustment of carbonate and calcium to create calcium carbonate as pipe surface coating, and applying a corrosion inhibitor.

For example, phosphate products that form films over pipe surfaces is a type of corrosion inhibitor.

During hydrant flushing, consumers may notice rust color in their water as iron and mineral deposits are stirred up in the process.

Biofilms can develop in highly scaled and thus rough-surfaced pipes where bacteria are allowed to grow, as the higher the roughness of the interior wall, the harder it is for disinfectant to kill the bacteria on the surface of the pipe wall.

[20] When an in-situ rehabilitation method is used, one benefit is the lower cost, as there is no need to excavate along the entire water main pipeline.