2010-01-28_PERMIT FILE - M2009082 ‎(3)‎

• Permit No: M2009082
• IBM Index Class Name: PERMIT FILE
• Doc Date: 1/28/2010
• Doc Name: Response to Adequacy Review #4, email
• From: Deere & Ault
• To: DRMS
• Email Name: JLE
• Media Type: D
• Archive: No

,M-ZOt?-O?tZ 'i 1?'a?'?S4u15 ?'l//1:'.•?n-?
to-. b ZVN 5 Frovw ! Dee r t Ai t-'
Ebert, Jared 5qe, -cO ACJ grivaat Nvi(evi
From: Scott Palmer [[e-mail]]
Sent: Thursday, January 28, 2010 3:23 PM
To: Ebert, Jared
Cc: 'Jennifer Vecchi'; 'Hors, Pam'; [e-mail]; [e-mail]
Subject: Parsons Jan 28 Slope Stability Comments
Attachments: 4C highest water.pdf
Jared,
Peter Hays asked for an email response to the comments he faxed earlier today. Here it is. Would you please forward
this to him.
1. The depth of overburden used for the stability analysis model (6 feet) does not match the depth (4 feet) indicated on
Table 1: Parson Mine Borings and MW-03 Borehole Log. Please explain the discrepancy.
The overburden thickness at the location of MW-3 seems to be quite thin in comparison to the other borings. The
overburden thickness was left thicker because as a weaker material thicker overburden would result in a more
conservative analysis.
2. Please confirm the stability analysis model labeled "Phase 1B Boring:ET02-TP05" is actually the Boring Log for ET02-
BH01 within Phase 1B.
The label should say "ET02-BH01 ". The stratigraphy encountered in ET02-BH01 was analyzed to check stability near the
northwestern portion of the pit.
3. The depth to bedrock used for the Boring No.5 analysis (20 feet) does not match the depth to bedrock indicated on
Table 1: Parsons Mine Borings and boring log (15 feet). Please explain the discrepancy.
The analysis was left in line with an earlier analysis to save time. It is our opinion that a depth to bedrock of 20 feet
produces a more conservative analysis than a depth to bedrock of 15 feet.
4. Please provide the source of the ground water data for Boring No.5.
Exihibit G indicates that the groundwater levels in MW-01 and MW-13 are approximately 10 feet below the ground
surface or more during the monitoring period. Based on this information a depth to groundwater of 10 feet was
selected.
5. The cross section profile analyzed for Boring L103-BH02 does not match the profile indicated on Table 1: Parson Mine
Borings and L103-BH02 Borehole Log. The Stability analysis does not include the Silt and Clay layer from 24 to 29 feet.
Please explain the discrepancy.
Upon further review this clay layer appears in L103-BH01 but not in L103-BH02. Per a phone conversation between the
DRMS and Deere and Ault Consultants, Inc. staff it was agreed to disregard this comment.
1