From: KENT Mavis D

Sent: Wed Feb 21 14:16:16 2007

To: 'Chris Kimmel'; Chaput, Kenneth G; Sarah Prowell

Subject: RE: Selected screen interval for BOP-71(ds)

Importance: Normal

Your approach seems reasonable to me.

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

-----Original Message-----

From: Chris Kimmel [mailto:CKimmel@landauinc.com]

Sent: Wednesday, February 21, 2007 1:09 PM

To: KENT Mavis D; Chaput, Kenneth G; Sarah Prowell

Subject: Selected screen interval for BOP-71(ds)

Hello Mavis,

During the drilling activities for BOP-71(ds), located along the ROW of Sandy Boulevard, we encountered the Upper TSA from 267 to 308 ft below ground surface. Per the Work Plan, three borehole groundwater samples were collected throughout the Upper TSA interval *upper, middle, and base). The analytical results (received today) for the three zones indicate TCE was not detected at concentrations above the reporting limit. Based on this information, we recommend placing the 20 ft screen toward the top (270-290 ft) of the Upper TSA unit to match the geologic setting of the screened interval at well BOP-22(ds).

Please let me know your thoughts on this matter. The drillers will work with the agencies to obtain a variance to backfill the boring with cement grout to within 1 foot of the planned base of the screen interval.

Thank you,

Christine Kimmel, L.G.

Landau Associates

Senior Project Geologist

main (425) 778-0907

fax (425) 778-6409

cell (206) 786-3801

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