a. In addition to the purposes outlined under Division 1 of these Design Standards, the purpose of these Standards is to ensure the development of a water distribution system which will:
1) be of adequate design to meet all expected domestic, commercial and industrial demands including fire flows within the design life;
2) have sufficient structural strength to withstand all external loads which may be imposed;
3) be of materials resistant to both corrosion and erosion with a minimum design life of 75 years;
4) be economical and safe to build and maintain;
5) meet all design requirements of the Oregon Health Authority - Drinking Water Services (OHA-DWS).
Alternate materials and methods will be considered for approval on the basis of these objectives.
b. These Standards cannot provide for all situations. They are intended to assist but not to substitute for competent work by professional design engineers.