Regulation of Public Water System Drinking Water.  
The Office of Drinking Water (ODW) within the Department of Health (DOH) has received delegated primary authority from the United States Environmental Protection Agency to administer and enforce federal regulations for primary drinking water requirements from the federal Safe Drinking Water Act.  These federal regulations establish primary drinking water requirements for larger public water systems, known as Group A public water systems.  

State laws and state Board of Health and DOH rules and orders provide additional authorities, consistent with federal requirements, to the ODW to ensure that public water systems provide their customers with an adequate supply of safe drinking water at all times.  The rules set drinking water standards and requirements for monitoring, reporting, and responding to emergencies. 

The ODW may impose penalties for non-compliance with public water system laws and regulations, and may direct water system owners and operators to resolve known or suspected public health threats.

Water System Plans.  
The state rules for Group A public water systems include rules relating to public water system planning and emergency response requirements.  The DOH charges fees to Group A public water systems to evaluate and approve water system plans and plan updates, based on the size of the system.

The type of Group A public water system that serves most people in Washington is a Group A community water system, which serves 15 or more year-round service connections, or regularly serves at least 25 or more year-round residents.  Group A community water systems must submit a water system plan or plan update to the DOH for approval under various conditions, including if it serves 1000 or more connections, is proposing to make infrastructure changes, or expand service.  According to the DOH, there are currently 2,209 Group A community water systems that serve a population of 6,289,836.  

Water system plans are intended to demonstrate system capacity, demonstrate how the system will address present and future needs, and establish eligibility for the Drinking Water State Revolving Fund Loan Program.  Water system plans must address several elements, including:

• description of the water system;
• basic planning data;
• demand forecasts;
• system analysis;
• water resource analysis; and
• other plans and documents.

Water System Acquisition and Rehabilitation Program. 
The Water System Acquisition and Rehabilitation Program was first funded in the budget in 2003 as a grant program to finance the transfer of ownership of failing drinking water systems to municipal systems, referred to as consolidations.  It was established as a permanent program in 2008 to partially cover project costs and is jointly administered by the Public Works Board and the Department of Commerce.  The program is subject to appropriation, and must use the procedures and criteria of the Drinking Water State Revolving Fund Loan Program as a model for its guidelines. 

University of Washington Climate Impacts Group.
The Climate Impacts Group at the University of Washington conducts research on climate and climate impacts, and delivers guidance for planning and management, among other approaches, with a focus on the Pacific Northwest.  The research is primarily supported by project-based grants and contracts from federal, state, and local sources.

Climate Resilience Element for Water System Plans. 
Planning Requirements. 
Beginning June 30, 2024, the Department of Health (DOH) must ensure water system plans for Group A community water systems serving 1000 or more connections include a climate resilience element at the time of approval.

The DOH must update its water system planning guidebook to assist water systems in implementing the climate resilience element, including guidance on any available technical and financial resources.
 
To fulfill the planning requirements of the climate resilience element, water systems must:

• determine which extreme weather events pose significant challenges to their system and build scenarios to identify potential impacts;
• assess critical assets and the actions necessary to protect the system from the consequences of extreme weather events on system operations; and
• generate reports describing the costs and benefits of the system's risk reduction strategies and capital project needs.

Technical Assistance.
The DOH must provide technical assistance to public water systems based on their system size, location, and water source, by providing references to existing state or federal risk management, climate resiliency, or emergency management and response tools that may be used to satisfy the climate resilience element. 

Subject to available appropriated funding, the University of Washington Climate Impacts Group must assist the DOH in the development of the technical assistance tools.
 
Financing for Climate Readiness Projects. 
Climate readiness projects are eligible for financing under the Water System Acquisition and Rehabilitation Program, and loans are added as a financing tool under this program.  

Climate readiness projects include: 

• planning to meet the requirements of the climate resilience element; and 
• actions to protect a water system from extreme weather events, including infrastructure and design projects.

The DOH must develop grant and loan eligibility criteria and consider applications from water systems that identify climate readiness projects.  The Water System Acquisition and Rehabilitation Program is now required to be administered by the DOH, instead of jointly by the Public Works Board and the Department of Commerce.