Hamilton Street Bridge Periodic Review: Public comment period 5/30-6/30/23

Dear Mr. Loftenius:

Avista Corporation (Avista) appreciates the opportunity to review and provide comments on Ecology's draft Periodic Review Report for the Hamilton Street Bridge site in Spokane. Periodic reviews are undertaken to make sure that clea...↓nups continue to protect human health and the environment. This is the third periodic review for the Hamilton Street Bridge site. Ecology concludes in this report, as it did in the two earlier periodic reviews, that the remedy "continues to be protective of human health and the environment." Avista agrees with this conclusion.

As you know, Avista and BNSF Railway Company (BNSF) implemented the remedy at this site nearly twenty years ago. Since then, Avista and BNSF have maintained the components of the remedy and have conducted compliance monitoring, both in accordance with plans approved by Ecology. Monitoring data show that groundwater at the site is not harming aquifer or the Spokane River. We are pleased that, as a result of our efforts and those of Ecology, the remedy remains protective.

Although we agree with the report's ultimate conclusion, we disagree with certain statements made in the report. Landau Associates' letter dated December 1, 2022 explained the basis for our disagreement. Ecology revised the report in response to some of our comments, which we appreciate. However, we still stand by the comments that Ecology did not accept. I have attached a copy of Landau's December 2022 comment letter. With the exception of comments Ecology has already accepted, please consider all comments in that letter to be comments on this public-review draft of the Third Periodic Review report.

We also welcome the opportunity to review Sagamore's proposal to repair the damaged trees and bioengineering that was documented in October of 2022.

Thank you again for the opportunity to comment on this report.