We are proposing to establish a new rule, chapter 173-135 WAC, for managing the Pasco Basin groundwater subarea, and repeal the existing interim management rule chapter 508-14 WAC.

This rule making is part of a multi-step process to address groundwater management in the Pasco Basin. The project includes designating a groundwater subarea boundary as described in RCW 90.44.130, and establishing an agreement with the United States Bureau of Reclamation for allocating and managing groundwater in the subarea using our revised authority in RCW 89.12.170.

Statutes Authorizing the Agency to Adopt Rules on this Subject: Chapters 43.21A, 43.27A, 90.03, 90.44, 90.54, 89.12 RCW.

Reasons Why Rules on this Subject may be Needed and What They Might Accomplish: In 1967, chapter 508-14 WAC established an interim policy for managing the commingled state and federal groundwater in the Columbia Basin until formal management programs could be established for specific subareas within the basin. In the Quincy and Odessa subareas, jurisdiction over groundwater has been resolved and management programs established through rule making. However, in the Pasco subarea, groundwaters have remained under the interim rule despite numerous efforts over the past 50 years.

In 2021, the legislature revised ecology's authority in RCW 89.12.170 to enter into agreements with the United States Bureau of Reclamation for allocating groundwater. Under the new and preexisting authorities, ecology is proposing to develop a new rule for managing groundwater in the Pasco subarea and repeal the interim rule. This will address the longstanding uncertainty for current and potential future groundwater users.

Other Federal and State Agencies that Regulate this Subject and the Process Coordinating the Rule with These Agencies: United States Bureau of Reclamation. Ecology plans to establish an agreement with the United States Bureau of Reclamation for the allocation and management of the groundwater in the area using our updated authority in RCW 89.12.170.

Process for Developing New Rule: Ecology will follow the standard process for the adoption of rules under the Administrative Procedure Act (chapter 34.05 RCW).

Interested parties can participate in the decision to adopt the new rule and formulation of the proposed rule before publication by contacting Annie Sawabini, Department of Ecology, Water Resources Program, P.O. Box 47600, Olympia, WA 98504-7600, phone 360-701-4432, Washington relay service or TTY call 711 or 877-833-6341, email annie.sawabini@ecy.wa.gov, website https://ecology.wa.gov/Regulations-Permits/Laws-rules-rulemaking/Rulemaking/WAC-173-135. Sign up to receive email notices https://tinyurl.com/42avbhnn.