"When (water) output exceeds input and when the output is no longer clean, we have a problem with quantity and quality - a problem we are going to pay for."

Gayle Robertson, in The Kingston Whig Standard.

A 1999 report by British Columbia's Auditor General* identified four fundamental means of maintaining high quality drinking water. These four elements can serve as a useful framework for rationalizing the supply of high quality water for drinking and other usage.

click on image to enlarge

These four key elements are:

1. Protection of Water Sources: minimizing contamination, destructive land use etc.
   
   
2. Water Treatment: technologies such as filtration, chlorination, ozone and UV treatments.
   
   
3. Sound, clean distribution systems: establishing and maintaining water distribution infrastructure in good condition and functioning effectively. Corrosion control is of great importance.
   
   
4. Testing and monitoring: directed at detecting potential problems at an early, manageable stage before disastrous and costly consequences set in.
   

Degradation of the water distribution infrastructure by corrosion processes can have far reaching negative effects on all the other elements. For example, leaking pipes and tanks can contaminate water sources. Corroded, leaking pipes place higher demand on treatment and will also necessitate more extensive testing and monitoring. A poorly designed, inadequately maintained and corroding infrastructure clearly is highly undesirable.

* as referenced and adapted in: "Waterproof - Canada's Drinking Water Report Card", a report by Sierra Legal Defence Fund, January 2001.