From: Jennifer Cline
Sent: Fri Dec 04 11:35:49 2015
To: Gerald Fisher
Cc: Dan Huff
Subject: RE: WWTP Lagoon Research
Importance: Normal
Nice work!
Jennifer Cline, P.E. | Public Works Director
Licensed in OR, WA
117 N Molalla Ave. | PO Box 248 * |Molalla, OR 97038
O: 503.759.0218 | F: 503.829.3676
From: Gerald Fisher [mailto:geraldf@pdgnw.com]
Sent: Friday, December 04, 2015 11:02 AM
To: Jennifer Cline (Molalla) <jcline@cityofmolalla.com>
Cc: Dan Huff <dhuff@cityofmolalla.com>
Subject: RE: WWTP Lagoon Research
Good morning Jennifer,
Just got off the phone with Tim McFetridge at DEQ about the guidance documents on the website. He agreed that they are old and also noted that if the lagoons are older than the 2007 date then they are under the requirement of a maximum of ¼” drop over a 7-10 day test. He also said that Mike Pinney (503.229.5310) is our design contact for this area.
Regards,
Gerald Fisher, PE | Senior Project Manager
PROJECT DELIVERY GROUP, LLC | 3150 22nd Street SE; Salem, OR 97302
www.PDGNW.com | 503-364-4004 (O) | 503-679-9237 (C)
** CONFIDENTIALITY NOTICE: The information contained in this email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient and have received this communication in error, please contact the sender by reply email and destroy all copies of the original message. Thank you.
From: Gerald Fisher
Sent: Thursday, December 03, 2015 7:19 PM
To: Jennifer Cline (Molalla) <jcline@cityofmolalla.com>
Cc: Dan Huff <dhuff@cityofmolalla.com>
Subject: WWTP Lagoon Research
Jennifer,
As suspected, I couldn’t find anything on the Oregon DEQ website for guidance other than the one document that they say you can’t use because it is too old. So, I looked at Idaho which has quite a bit of info. According to the 2009 Guidance for Evaluation Wastewater Lagoon Seepage Rates, the maximum allowable seepage rate is 3,400 gallons per day per acre. That essentially equals a 1/8” drop in water level. That value matches the old document DEQ says that you can’t use but, as I understand it, they have not provided you with any guidance document to perform a test that they are requiring. So back to the 1/8”, it doesn’t matter if you have one acre or twenty acres. You can only drop 1/8”. The important part of that statement is that the 1/8” standard applies for “municipal lagoons constructed after April 15, 2007” and your plant and lagoon was constructed in 1980, which predates 2007. Is Oregon DEQ requiring all lagoons predating 2007 in the state to now meet this new requirement?
So, they gave the City one year from June 01, 2014 to comply with Schedule D, Condition 14. The City tried to perform the test in the summer of 2015 and had difficulties with some of the equipment and measurement. The City is working on making the repairs and DEQ want a third party review to:
1. Verify the accuracy of the flow measuring devices.
2. Verify the accuracy of the water level measuring devices.
3. Verify the flow path assumptions used.
4. An evaluation of the leakage at the DAF.
5. Documentation of lagoon sizes (areas).
6. Annual flow balance (water in vs. water out).
I’ll need to get with you tomorrow to identify the data necessary to complete the information above. If we can demonstrate that the leakage is within allowed limits then this threat of violation is void. If we can’t then our recommendation will be to retest next summer. If DEQ is not satisfied with a retest then they have to provide you with reasonable time to address any lagoon related issues. From what I’ve read so far, lagoons are leak tested approximately once every 10 years. See you tomorrow.
Regards,
Gerald Fisher, PE | Senior Project Manager
PROJECT DELIVERY GROUP, LLC | 3150 22nd Street SE; Salem, OR 97302
www.PDGNW.com | 503-364-4004 (O) | 503-679-9237 (C)
** CONFIDENTIALITY NOTICE: The information contained in this email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient and have received this communication in error, please contact the sender by reply email and destroy all copies of the original message. Thank you.