From: BAYUK Dana

Sent: Tue Oct 05 16:56:52 2010

To: Bob Wyatt

Cc: Patty Dost; Rob Ede (robe@hahnenv.com); John Edwards (jedwards@anchorenv.com); Carl Stivers (cstivers@anchorenv.com); Tom McCue (Tom.McCue@siltronic.com); Alan Gladstone (agladstone@davisrothwell.com); 'James Peale'; GAINER Tom; LARSEN Henning

Subject: NW Natural, 2010 Groundwater Monitoring Program

Importance: Normal

Hello Bob.

DEQ reviewed the proposed changes to NW Natural’s groundwater monitoring program for the NW Natural property and adjoining Siltronic Corporation (Siltronic) site. The proposed changes were sent via an e-mail on July 29, 2010. The e-mail was prepared by Hahn and Associates, Inc. (Hahn) for NW Natural.

Based on our review of the July 29^th e-mail and follow-up discussions with Hahn by telephone, DEQ approves the following modifications to the groundwater monitoring program:

·  Removing four monitoring wells (i.e., MW-10-25, MW-11-32, MW-16-45, and MW-18-30) on the NW Natural property where persistent occurrence of DNAPL in the installations precludes collection of samples representative of groundwater.

·  Adding five monitoring wells (i.e., WS-13-69, WS-13-105, WS-16-161, WS-17-52, and WS-17-94) to further assess the nature and extent of MGP contamination in the northern portion of the Siltronic property.

DEQ understands the monitoring program changes will be incorporated into the groundwater monitoring event currently underway.

Please feel free to contact me with question regarding this e-mail.

Mr. Dana Bayuk, Project Manager

Cleanup & Portland Harbor Section

Oregon Department of Environmental Quality

2020 SW 4th Avenue, Suite 400

Portland, OR  97201

E-mail: bayuk.dana@deq.state.or.us

Phone:  503-229-5543

FAX:  503-229-6899

Please visit our website at http://www.oregon.gov/DEQ/