(a) Where a right holder has asserted a Tribal reserved right in writing to the State and EPA for consideration in establishment of water quality standards, to the extent supported by available data and information, the State must:

(1) Take into consideration the use and value of their waters for protecting the Tribal reserved right in adopting or revising designated uses pursuant to § 131.10;

(2) Take into consideration the anticipated future exercise of the Tribal reserved right unsuppressed by water quality in establishing relevant water quality standards; and

(3) Establish water quality criteria, consistent with § 131.11, to protect the Tribal reserved right where the State has adopted designated uses that either expressly incorporate protection of or encompass the right. This requirement includes developing criteria to protect right holders using at least the same risk level (e.g., cancer risk level, hazard quotient, or illness rate) as the State would otherwise use to develop criteria to protect the State's general population, paired with exposure inputs (e.g., fish consumption rate) representative of right holders exercising their reserved right.

(b) States and right holders may request EPA assistance with evaluating Tribal reserved rights. EPA will provide such assistance to the extent practicable. In providing assistance to States as they adopt and revise water quality standards consistent with paragraph (a) of this section, EPA will engage with right holders.

(c) In reviewing State water quality standards submissions under this section, EPA will initiate the Tribal consultation process with the right holders that have asserted their rights for consideration in establishment of water quality standards, consistent with applicable EPA Tribal consultation policies, in determining whether State water quality standards are consistent with paragraph (a) of this section.

[89 FR 35747, May 2, 2024]