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Water System Design Manual

Scroll down to select the highlighted chapter you want to download.  All files require Microsoft Word or the free Word viewer.  For information on availability of the Design Manual in other formats please contact Amy Swecker.

The complete Manual can be downloaded in Word with this self-extracting file (design_manual.exe).

Manual cover and table of contents  (downloadable)


 

TABLE OF CONTENTS

CHAPTER & SECTION

CHAPTER & SECTION TITLE

  PAGE

PREFACE
GLOSSARY

1

..........

INTRODUCTION  .......................................................................

1-1

 

1.0

Purpose and Scope  ...................................................................

1-1

 

1.1

Applicability  ................................................................................

1-1

 

1.2

“Must” versus “Should” etc.  ........................................................

1-2

 

1.3

Relationship with Planning Requirements  .................................

1-2

 

1.4

Engineering Requirements  ........................................................

1-3

 

1.5

General Engineering Project Submittal Requirements ...............

1-4

 

1.6

Minimum System Design Requirements  ....................................

1-4

 

1.7

Sizing Criteria and Water Rights  ...............................................

1-4

 

1.8

DOH Policies, Procedures and Guidelines…...............................

1-4

 

1.9

Ten States Standards  ................................................................

1-5

 

1.10

State Environmental Policy Act (SEPA) Considerations  ..……..

1-5

 

1.11

Other Referenced Documents and Standards  ..........................

1-5

2

..........

PROJECT REPORTS  ...............................................................

2-1

 

2.0

Relationship to Water System Plan (WSP)  ...............................

2-1

 

2.1

Submittal to DOH for Review and Approval  ..............................

2-1

 

2.2

Project Report Contents  ............................................................

2-1

3

..........

CONSTRUCTION DOCUMENTS  ..............................................

3-1

 

3.0

Relationship to Water System Plan (WSP)  ...............................

3-1

 

3.1

Submittal to DOH for Review and Approval  ...............................

3-1

 

3.2

Design Drawings  ........................................................................

3-2

 

3.3

Project Specifications  ................................................................

3-3

 

3.4

Change Orders  ..........................................................................

3-4

 

3.5

Contracted Components for a Project …………………..  ...........

3-4

4

..........

PROCESS FOR REVIEW AND APPROVAL OF PROJECT REPORTS AND CONSTRUCTION DOCUMENTS  ...................

 

4-1

 

4.0

When Documents Required  .......................................................

4-1

 

4.1

Coordination with Local Approving Authorities  ..........................

4-1

 

4.2

Project Report Requirements  ....................................................

4-1

 

4.3

Project Report and Construction Document Screening and Review Process  .........................................................................

 

4-2

 

4.4

Submittal Exceptions - Miscellaneous Components and Distribution Mains  ......................................................................

 

4-3

 

4.5

Submittal Exceptions for Distribution-Related Projects  ..............

4-4

 

4.6

Source Approval and Water Rights  ...........................................

4-7

 

4.7

Resolution of Disputed DOH Review Decisions  ........................

4-8

 

4.8

Review Fees and Invoice  ..........................................................

4-8

 

4.9

Project Approval Letter & Construction Completion  ..................

4-9

 

4.10

Construction Completion Report (CCR) Forms  .........................

4-9

5

..........

WATER DEMAND REQUIREMENTS  .......................................

5-1

 

5.0

Applicability  ...............................................................................

5-1

 

5.1

Estimating Demands vs. Actual Use Data  .................................

5-1

 

5.2

Residential Water Demand Design Criteria  ...............................

5-2

 

5.3

Documentation of Water Demand  .............................................

5-9

 

5.4

Estimating Nonresidential Water System Demand  ....................

5-11

 

5.5

Water Demand Forecasting  .......................................................

5-16

 

5.6

Other Regulatory Considerations  ..............................................

5-17

 

5.7

General System Reliability ………………………………………….

5-17

6

..........

WATER SYSTEM PHYSICAL CAPACITY ANALYSIS (ERUs)

6-1

 

6.0

Applicability  ................................................................................

6-1

 

6.1

Background  ................................................................................

6-2

 

6.2

Relationship Between System Capacity and Physical Capacity

6-2

 

6.3

Fundamental Design Principle for Physical Capacity Analysis  ..

6-2

 

6.4

The Concept of Equivalent Residential Units (ERUs)  ................

6-2

 

6.5

Design Factors  ...........................................................................

6-5

 

6.6

The Relationship Between Physical Capacity and Drinking Water Operating Permits (Chapter 246-294 WAC)  ...................

 

6-6

 

6.7

Methodology to Determine System Physical Capacity  ...............

6-6

7

..........

SOURCE OF SUPPLY  ..............................................................

7-1

 

7.0

Water Resource Analysis and Water Rights  …………………….

7-1

 

7.1

Source Water Quantity  ……………………………………………..

7-2

 

7.2

Source Water Quality and Protection  …………………………….

7-3

 

7.3

Ground Water Sources (Wells)  ……………................................

7-6

 

7.4

Spring Sources  ……………………………………………………...

7-9

 

7.5

New Surface Water Supplies  ……………………………………...

7-11

 

7.6

Interties  ......................................................................................

7-11

 

7.7

General Reliability Considerations ………………………………..

7-12

 

7.8

General Source Considerations  …………………………………..

7-12

8

..........

TRANSMISSION AND DISTRIBUTION MAIN DESIGN  ...........

8-1

 

8.0

Transmission and Distribution Main Definitions  .........................

8-1

 

8.1

System Distribution Facility Sizing  .......……………....................

8-1

 

8.2

Hydraulic Analysis  .....................................................................

8-4

 

8.3

Materials  ....................................................................................

8-12

 

8.4

General Design Consideration for Mains  ...................................

8-13

 

8.5

Appurtenant Design Considerations  ..........................................

8-14

 

8.6

Layout of Mains  .........................................................................

8-16

 

8.7

Detail Drawings  ..........................................................................

8-17

 

8.8

Standard Construction Specifications  ........................................

8-17

 

8.9

Cross-Connection Protection  .....................................................

8-19

 

8.10

Chapter