From: KENT Mavis D

Sent: Tue Sep 12 08:09:34 2006

To: 'Sarah Prowell'

Subject: Tech Memo Monitoring Contingency Plan

Importance: Normal

Sarah, I have reviewed the 8/28/06 Tech Memo Monitoring and Contingency Plan for PBWW Pumping Events. The plan reflects our discussions on which wells are most appropriate to represent the current extent of the plume in the TSA under PBWW pumping scenarios. I just wanted to point out that the PBWW 2006 Well Field Pumping Plan only lists four plume control threshold decision wells, as opposed to the six listed in this contingency plan. While I agree with the six wells that you identify, you may want to consider distinguishing the 2-well difference between your contingency plan and the PBWW pumping plan.

I approve the monitoring and contingency plan. Please let me know if the version that I have is the final version. I will put a copy of it, or another version if you choose to revise, in the file along with this email to document plan approval.

Mavis D. Kent

Cleanup & Emergency Response Section

DEQ Northwest Region - East Side Office

1550 NW Eastman Parkway, Suite 290

Gresham, Oregon 97030

503-667-8414 X55008

503-674-5148 Fax

kent.mavis.d@deq.state.or.us