From: Wangerud, Ken To: "David Abranovic" Cc: Catherine D. LeCours ([email protected]); Justin Burning; Kevin Lundmark; Aaron Baird Subject: RE: Existing Salt Deposit Study TM - EPA review/comments Date: Tuesday, May 23, 2017 2:33:00 PM Attachments: image001.png image002.png EPA comments on Existing Salt Deposit Study_Final5Dec2016.pdf David: I apologize for the tardiness of these comments; I appreciate Catherine LeCours reminding me that this remained outstanding. Our PM’s conversation yesterday about the status of the SCTS brine/leach-testing reminded me this was also something needing catch-up. Please incorporate these comments into the SCTS work as consideration of salt-cap possibilities continues towards the FS work for the site. Cheers, Ken Ken Wangerud Remedial Project Manager Superfund Remedial Program Ecosystem Protection & Remediation U.S. EPA – Region 8 1595 Wyncoop Street Denver, CO 80202-1129 Ofc. Tel. 303-312-6703 From: David Abranovic [mailto:[email protected]] Sent: Thursday, September 29, 2016 1:13 PM To: Wangerud, Ken <[email protected]> Cc: R. David Gibby ([email protected]) <[email protected]>; Catherine D. LeCours ([email protected]) <[email protected]>; Justin Burning <[email protected]>; Kevin Lundmark <[email protected]> Subject: RE: Existing Salt Deposit Study TM Ken, Please find attached the US Mag Existing Salt Deposit Study Technical Memorandum for your review. This study was completed according to the methodology in the Tier 1 Salt Cap Treatability Study Work Plan (April 2016) and addresses the first objective of the Tier 1 SCTS to evaluate the weathering of existing salt caps (salt deposits) in order to provide qualitative information on the short-term and/or long-term behavior of salt deposits. Please feel free to call me if you have any questions regarding this submittal. David Abranovic Partner ERM 7272 E Indian School Road, Suite 108 | Scottsdale, AZ | 85251 T +1 480 455 6070 | M +1 602 284 4917 E [email protected] | W www.erm.com ü Please consider the environment before printing this e-mail This message contains information which may be confidential, proprietary, privileged, or otherwise protected by law from disclosure or use by a third party. If you have received this message in error, please contact us immediately at (925) 946-0455 and take the steps necessary to delete the message completely from your computer system. Thank you. Please visit ERM's web site: http://www.erm.com From: Wangerud, Ken To: "David Abranovic" Cc: Catherine D. LeCours ([email protected]); Justin Burning; Kevin Lundmark; Aaron Baird Subject: RE: Existing Salt Deposit Study TM - EPA review/comments Date: Tuesday, May 23, 2017 2:33:00 PM Attachments: image001.png image002.png EPA comments on Existing Salt Deposit Study_Final5Dec2016.pdf David: I apologize for the tardiness of these comments; I appreciate Catherine LeCours reminding me that this remained outstanding. Our PM’s conversation yesterday about the status of the SCTS brine/leach-testing reminded me this was also something needing catch-up. Please incorporate these comments into the SCTS work as consideration of salt-cap possibilities continues towards the FS work for the site. Cheers, Ken Ken Wangerud Remedial Project Manager Superfund Remedial Program Ecosystem Protection & Remediation U.S. EPA – Region 8 1595 Wyncoop Street Denver, CO 80202-1129 Ofc. Tel. 303-312-6703 From: David Abranovic [mailto:[email protected]] Sent: Thursday, September 29, 2016 1:13 PM To: Wangerud, Ken <[email protected]> Cc: R. David Gibby ([email protected]) <[email protected]>; Catherine D. LeCours ([email protected]) <[email protected]>; Justin Burning <[email protected]>; Kevin Lundmark <[email protected]> Subject: RE: Existing Salt Deposit Study TM Ken, Please find attached the US Mag Existing Salt Deposit Study Technical Memorandum for your review. This study was completed according to the methodology in the Tier 1 Salt Cap Treatability Study Work Plan (April 2016) and addresses the first objective of the Tier 1 SCTS to evaluate the weathering of existing salt caps (salt deposits) in order to provide qualitative information on the short-term and/or long-term behavior of salt deposits. Please feel free to call me if you have any questions regarding this submittal. David Abranovic Partner ERM 7272 E Indian School Road, Suite 108 | Scottsdale, AZ | 85251 T +1 480 455 6070 | M +1 602 284 4917 E [email protected] | W www.erm.com ü Please consider the environment before printing this e-mail This message contains information which may be confidential, proprietary, privileged, or otherwise protected by law from disclosure or use by a third party. If you have received this message in error, please contact us immediately at (925) 946-0455 and take the steps necessary to delete the message completely from your computer system. Thank you. Please visit ERM's web site: http://www.erm.com EPA’s Technical Comments on ERM’s Existing Salt Deposit Study Technical Memorandum (29 September 2016) U.S. MAGNESIUM NPL SITE, TOOELE COUNTY, UTAH 5 December 2016 The U.S. Environmental Protection Agency (EPA) is providing the following comments on the Existing Salt Deposit Study Technical Memorandum (Tech Memo) dated 29 September 2016. The Tech Memo was prepared by US Magnesium’s contractor, Environmental Resources Management (ERM), and summarizes the observations from the field reconnaissance activities conducted on 6 June 2016 at three existing salt caps/deposits: the former Knolls Solar Ponds 0 and 1, Cargill Salt Ponds 2 and 3 East, and US Magnesium Solar Evaporation Pond 1 South. Mr. Aaron Baird of PWT was onsite to provide EPA oversight of the salt cap reconnaissance activities. Reconnaissance activities were performed in accordance with Sections 4.1 and 8.1 of the Tier 1 Salt Cap Treatability Study Work Plan dated April 2016. EPA generally agrees with the ERM observations documented in the Tech Memo; however, PWT noted additional observations that were not mentioned in the Tech Memo. GENERAL COMMENTS 1. Topography appears to play an important role in salt accumulation and erosion. In the former Knolls solar ponds, west of the sand dunes, the ponds are relatively flat but have a very gradual slope to the west/northwest. The thickness of the salt deposit was significantly greater in the west/northwest portion of the ponds and there was much less erosion. ERM shall revise the Tech Memo to include discussion regarding topagraphical impact on salt accumulation and erosion. 2. In the Weathering Characteristics and Behaviors discussion for the former Knolls solar ponds (second bullet, page 4 of the Tech Memo) it is noted that where external drainage of surface water runoff occurs, erosional features in the salt deposit were observed, including cracks up to 6 inches wide, rills up to 5 feet wide, and channels up to 20 feet wide and 6 feet deep. ERM shall revise the Tech Memo to include photographs of these features if available. Examples of these features are shown in the following photographs taken in Knolls Pond 1 during a site visit in May 2013. 3. Flowing groundwater seeps were present in lower elevation areas along the western portion of the former Knolls solar ponds. Examples of these features are shown in Photograph 17 of the Tech Memo and in the following photograph of Pond 0. ERM shall revise the Tech Memo to include this discussion and additional photographs as necessary. 4. The Tech Memo reports weathering characteristics and behaviors of salt deposits at US Magnesium’s Solar Pond 1S were not observed due to the inundation of brine. The assessment of Pond 1S is incomplete and the pond shall be re-visited during a more optimal time (possibly Fall?) when the weathering characteristics and behaviors can be observed. ERM shall prepare an addendum to the Existing Salt Deposit Study Technical Memorandum to report the observations of Pond 1S. Ken Wangerud, EPA, captured the following photo during a site visit in May 2013. This photograph was taken from the north berm separating US Magnesium Solar Pond 1N and 1S. The view is looking south over brine waters with an approximate 10 to 20 foot diameter dissolution-cavity visible approximately 50 feet south of the berm. The cavity purportedly forms from water moving through the berm from the higher head-elevation water of Pond 1N and upwelling into Pond 1S (per Tom Tripp, US Magnesium). There were numerous such features in Pond 1S along the length of the berm/levee. These are features that warrant attention, particularly as related to ERM’s note that there was also such a feature in the Cargill salt flat (second bullet, page 7 of the Tech Memo). Environmental Technical Memorandum Resources Management To: Ken Wangerud, USEPA 7272 E. Indian School Road Suite 108 From: Lonnie Mercer P.G., ERM Scottsdale, AZ 85251 Kevin Lundmark, ERM (480) 998-2401 (480) 424-1818 (fax) David Abranovic P.E., ERM Date: 29 September 2016 Subject: Existing Salt Deposit Study ------------ IIERM® INTRODUCTION This Existing Salt Deposit Study Technical Memorandum (Tech Memo) has been prepared to describe observations from field reconnaissance activities performed on 6 June 2016 for three salt deposits. Reconnaissance activities were performed in accordance with Sections 4.1 and 8.1 of the Tier 1 Salt Cap Treatability Study Work Plan (SCTS Work Plan) dated April 2016 (ERM-West, Inc. [ERM] 2016). The SCTS Work Plan was prepared by ERM to define the scope of work for a treatability study that will provide basic information about a salt cap barrier remedial alternative that will be evaluated in the feasibility study for the US Magnesium National Priority List (NPL) site in Rowley, Tooele County, Utah. The Tier 1 SCTS Work Plan is the first step in the evaluation process for a salt cap barrier and is designed to provide basic high level information about how a salt cap barrier remedy would perform at the US Magnesium NPL site.