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Appendix 3. Design Requirements for Water and Wastewater Extensions
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A. General.

1. Purpose. The purpose of these design standards is to provide engineers, designers, draftsmen, inspectors, and others with a reference to City of Redmond’s requirements for the design and installation of improvements to the water and sewer systems. No extension or modifications to the City’s utility system shall be made without the approval of construction drawings prepared in accordance with these standards.

The design standards included herein are intended to result in utility systems which will:

a. Provide the needed source, storage, and distribution facilities system to maintain desirable levels of service during periods of maximum use.

b. Provide the needed sewer facilities to carry all anticipated sewage flows within a basin.

c. Conform to the City’s Water System Plan and General Sewer Plan.

d. Be of material strong enough to resist all expected loads, both internal and external, in order to preserve the purity and potability of the water supply, and protect ground and surface waters from the escape of wastewater.

e. Be safe and economical to maintain. Alternate materials and methods will be considered for approval on the basis of these objectives and conformance to all requirements indicated elsewhere in these standards.

2. Revisions to These Requirements. It is anticipated that revisions to these requirements will be made from time to time. The date appearing on the title page is the date of latest revision. Users should be sure that they are using the most recent revision to these requirements. This edition was approved in January 2000. Contact the Public Works Department Water/Wastewater Division to ensure this copy is the most current edition.

3. Referenced Standards. Reference herein is made to the latest edition of standards, tests, methods, and specifications of research as follows:

a. American Standards, prepared by the American Water Works Association (AWWA).

b. American National Standards, prepared by the American National Standards Institute (ANSI).

c. Standard Specifications, prepared by the American Society for Testing and Materials (ASTM).

d. Federal Specification, prepared by the Federal Government (FS).

e. Guide Book for Determination of Required Fire Flow and Grading Schedule for Municipal Fire Protection, prepared by the Insurance Services Office (ISO).

f. Standard Specifications for Road, Bridge and Municipal Construction, prepared by the Washington State Chapter, American Public Works Association (APWA) as modified by the Water/Wastewater Division.

g. Rules and Regulations of the State Board of Health Regarding Public Water Systems, prepared by the Water Supply and Waste Section, Health Services Division, State of Washington Department of Health (DOH), latest edition.

h. City of Redmond Standards, Specifications and Details, prepared by the City of Redmond.

i. Criteria for Sewage Works Design prepared by the State of Washington Department of Ecology.

j. City of Redmond Design Requirements – Water and Wastewater System Extensions.

Effective on: 4/16/2011