Water Pipe Systems

A water pipe system has construction requirements that must be met in order to maintain water quality.

Typically, water pipes are buried in the earth for:

• convenience
• frost protection
• prevention of physical damage
• restraint of the forces of internal pressure

Where pipes are not buried, they should be protected from thermal and physical damage by, for example, suspending a pipe underneath a bridge at a river crossing.

Where pipes cross major highways or railways, further protection in the form of encasement by a larger diameter protective pipe may be necessary.

The selection of materials for constructing a water pipe system should consider:

• working pressure
• surging pressure
• depth that pipe will be buried
• corrosiveness of soils
• earth-loading ground water
• accessibility
• proximity to other utilities
• potential sources of contamination, such as sewers

Buried pipes should be surrounded by compacted sand or gravel, or bedding, to protect the pipe from damage during and after construction.

Water quality may deteriorate within a watermain and bacteria can flourish in pipes with:

• poor source water quality
• low flow
• dead ends

Dead ends can be avoided if the system layout includes looping. If system looping is not possible, frequent watermain flushing may improve the water quality.