Designing a New or Expanding Water System
This page will help you plan or design a new Group B Public Water System, or expand an existing Group B Public Water System.
General Requirements and Applicability
The Group B Public Water System main page has general information about the rule change.
Before starting your design, you need to know if the local health jurisdiction (331-608, PDF) or our regional offices will review and approve your project. The LHJ may have additional requirements beyond the state rule requirements. Use the LHJ link above to find contact information for your county.
If you are not a professional engineer, then your first step is to hire one. Group B system designs submitted to us for review and approval must be submitted by a professional engineer. Some LHJs allow exceptions for non-engineers to complete Group B system designs, so make sure you know who is reviewing your project.
Water Systems Designed to Serve 10 to 14 Dwelling Units
If you plan to serve 10 to 14 dwelling units (residential service connections) with your Group B system, then you must follow the design, planning, and engineering requirements found in chapter 246-290 WAC for Group A systems. Again, your first step is to hire a professional engineer to begin the process for getting your system design completed and approved.
Group B Water System Design Guidelines and Workbook
We updated the key resources you need to successfully complete your new or expanding Group B Water System. The Group B Water System Design Guidelines 331-467 (PDF) walks you through the requirements and provides engineering recommendations. The Group B Workbook 331-468 (Word) is an easy-to-use submittal document that helps you submit a complete packet for our review and approval.
Forms and Templates
You need certain forms and templates to complete your submittal. Please refer to the Group B Water System Design Guidelines 331-467 (PDF) and Group B Workbook 331-468 (Word) for more information.
- Application for Project Approval 331-149 (Word)
- Group B Construction Completion Report 331-121-F-B (Word)
- Approved Satellite Management Agencies
- Covenants for Group B public water supply protection, DOH 331-048 (PDF)
- Example: Informational notice to titles-property disclosure (Word)
If You Need Help
Your engineer will work directly with our regional engineers who review submittals for new and expanding Group B systems.
If you have other questions, visit our Group B Public Water Systems Information webpage or visit our Group B Public Water System Operations and Maintenance webpage.