From: KENT Mavis D
Sent: Mon Jan 25 17:29:09 2010
To: 'Sarah Prowell'
Cc: Chris Kimmel
Subject: RE: TSA EW-1 Update
Importance: Normal
Just checking, in the last statement you indicate you would like to evaluate options while EW-14 operates continuously. Do you mean EW-1? If so, I am fine with this approach. Thanks for letting me know.
From: Sarah Prowell [mailto:sprowell@ix.netcom.com]
Sent: Monday, January 25, 2010 4:59 PM
To: KENT Mavis D
Cc: Chris Kimmel
Subject: TSA EW-1 Update
Hello Mavis,
On the TSA remedy front, we temporarily discontinued the on-off pulse-pump operation of extraction well EW-1 this winter as a precautionary measure and have instead been pumping continuously. It was scheduled for a 1-month OFF cycle in January 2010, but remained on. (It’s last OFF-cycle was during October 2009.) The temporary change in operation was implemented in response to 2009 data, which showed residual TCE is present in the previously unsaturated Upper TSA area near EW-1 and BOP-13ds. The highest detection was 15 micrograms per liter in BOP-13ds in August 2009.
The good news is that 2009 pulse pump operation of EW-1 has allowed us to answer the question of whether residual TCE is present in the Upper TSA in the area near EW-1. Now we would like to pause and re-evaluate the best way to move forward to remediate and monitor this area.
We’d like to evaluate options and get back with you later this quarter with recommendations, while EW-14 operates continuously. Please let us know if you have any questions and if you approve the temporary operational change.
Thank you. Sarah
Sarah Prowell, R.G.
Prowell Environmental, Inc.
2216 SW Sunset Blvd.
Portland, Oregon 97239
Phone: 503/452-0972
Fax: 503/452-1427