Water System Design

The fee estimator tool (Excel) will help water system owners and consultants estimate the total fee charged by DOH for various fixed fee for service activities, such as review of engineering and planning documents.

The estimator covers all areas of our fee regulation, WAC 246-290-990, and includes user instructions, examples, and a list of hourly fee for service activities.

Water System Planning Guidebook 331-068 (PDF)
Revised 2020. The Guidebooks' purpose is to help water system governing bodies and managers understand their role in water system planning, and work with their consultants to prepare a useful water system plan. At more than 100 pages, it covers key technical, managerial, and financial elements important to developing a good plan and overall water system management. These key elements range from source water protection to financial management, and include many tips to support all parties involved develop a quality plan.

Water System Design Manual 331-123 (PDF)
Revised 2020. The design manual is a start-to-finish reference for engineers and others involved in water system design. It covers design, review and approval of sources, storage reservoirs, booster pump stations, water treatment facilities, and other aspects of designing water systems. Here's a content summary. Worksheet 4-1—ERU Capacity Summary: a fillable Word document for water systems to calculate capacity analysis.

How to Hire an Engineer 331-044 (PDF)
A four-page brochure with information for small public water systems on how to hire an engineer when improvements are needed.

Sanitary Protection of Reservoirs—Hatches 331-249 (PDF)
A one-page illustrated guide with tips for small water system operators on how to deal with storage reservoir hatches.

Sanitary Protection of Reservoirs—Vents 331-250 (PDF)
A one-page illustrated guide with tips for small water system operators on how to deal with storage reservoir vents.

Simple Fixes for Wellhead Openings 331-232 (PDF)
A one-page illustrated guide to fixing common problems that small drinking water systems encounter in protecting wellheads from contamination.

Well Source Approval Guidance: For Group A Public Water Systems 331-674 (PDF)
This guidance document intends to assist public water systems in gaining DOH source approval for adding a ground water well to a Group A public drinking water system.

Group A Transient Non-Community Water System Design Guidelines 331-676 (PDF)
These guidelines explain how to design Group A-TNC water systems to ensure safe, adequate, and reliable drinking water for those the water system will serve. They will also help you prepare a complete Group A-TNC Design Workbook 331-677, linked below.

Group A TNC Water System Design Workbook 331-677 (Word)
Completing this fillable Workbook satisfies project report, design, and source approval requirements for a new or expanding Group A-TNC water system (WAC 246-290-110, -120, and -130, respectively). Useful information for completing this workbook is found in the Group A-TNC Water System Design Guidelines 331-676, linked above.