DERR-2024-011226

David Bird <[e-mail]>
Mayflower Meeting Summary
3 messages
Bill Rees <[e-mail]>Mon, Oct 7, 2024 at 2:09 PM
To: "Fawcett, Kent" <[e-mail]>
Cc: David Bird <[e-mail]>, Megan Housdeshel <[e-mail]>, Kimberlee McEwan
<[e-mail]>
Kent,
Thanks for meeting with us on Friday. We thought the discussion went well and will be following up with comments, if any,
on the surface water, groundwater, bus area (paving?) and Remedial Report (Upon receipt of tables and revised
appendices. We do have the figures and revised text). We will finish reviewing the draft Supplemental RAP (water
management). As you recall, the original RAP included the consolidation of soil and management of water from the
portal. Over time, additional actions have been necessary to divert water from the Repository, which has the added
benefit of reducing leaching of mine waste and possible impacts to water leaving the site.
Regarding water management, below are several thoughts we have regarding various actions that have been
implemented over the past several years. Among others, these are some of the items that we will be evaluating as we
review the proposed Supplemental RAP. Some of these will likely carry forward to the SMP for future management.
1. Install a french drain at the base of the eastern slope to allow a path for water from the base of the mine waste to the
inlet of the culvert going under Highway 40. Create a property line sump and inspection port.
2. Cutting a trench in the Big Dutch Pete Hollow (BDPH) drainage upgradient and to the west of the Repository to identify
how much shallow groundwater was entering the mine waste from this source. Because of the volume identified at this
location, Extell proposed a cutoff wall with associated piping about 300 yards upgradient of the mine waste pile.
3. Extell installed additional wells upgradient of the mine waste pile to the west and northwest in order to obtain
information about groundwater upgradient of the mine waste in this direction.
4. Extell installed piezometers in the mine waste pile to gather information about the groundwater.
5. A pond for collection of surface water upgradient of the mine waste to the west was removed along with the associated
piping, as this was thought to be a possible source for infiltration of water into the mine waste.
6. Installation of water bars on the mountain to the south of the mine waste. The purpose of these was to direct water
into the BDPH drainage and associated storm water piping, rather than overland flow onto the southern edge of the mine
waste pile. These water bars were modified/refined in 2024 in response to the large spring runoff of 2023.
7. In the fall of 2023, Extell installed a second cutoff wall/collection box in the BDPH approx. 500 yards upgradient of the
mine waste in the hopes of capturing more of the shallow groundwater in this drainage. This was successful, and this
source of water has been piped to the new replacement wetlands that have been installed to the east of the mine waste.
8. Extell is in the process of moving the detention pond (with associated piping into the storm water system) that was
immediately west of the mine waste pile, approximately 100 yards up the BDPH drainage.
9. Extell is in the process of repairing the areas of subsidence at the western edge of the mine waste pile (Repository).
This involved surcharging this area with at least 20 feet of material near the end of 2023, and removing the surcharge in
July of 2024. Additional fill with an asphalt layer will restore the cover of the Repository in this area.
As we discussed, many of these actions above have had a positive impact on the overall water quality. We encourage
your team to evaluate the data against baseline data and formulate your own conclusions (surface water - pre and post
VCP from the Campground sample location and groundwater - initial in 2018 versus last few years). From our review,
there has been a reduction in concentrations, although cadmium is slightly above the MCL in the interior of the
Repository.
Regarding the overall Mayflower Remedy, we will want it to be easily understood via the original RAP, RAR, and
Supplemental RAP. Key elements of the remedy:
- Contaminated soil removal, consolidation to an engineered repository (designed to prevent exposure and manage
stormwater) and confirmation samples
- Off site soil removal for petroleum soil
- management of mine portal water (UPDES Permit)
- groundwater monitoring and future restrictions on gw access
- Pumping water from the property line sump and large slough area (literally millions of gallons of water) to the POTW
10/7/24, 2:52 PM State of Utah Mail - Mayflower Meeting Summary
https://mail.google.com/mail/u/0/?ik=9ad96c2360&view=pt&search=all&permthid=thread-f:1812287226634801169&simpl=msg-f:18122872266348011…1/4
- re-route water, minimize flow into the Repository by diverting groundwater and surface water around the Repository
(see individual components above)
- Environmental Covenant
- Site Management Plan with inspections, on-going monitoring and contingency measures (items below may be future
components of the plan as its drafted)
* McHenry Canyon siltation basin from possible upstream source
* Parking Lot/Repository and associated water management features (above)
* RR Grade
* Mine Portal
* Groundwater and surface water locations
* Water management items noted above
This is only a snapshot based on my limited notes from Friday so it is possible we may have overlooked something which
may still come up, but a good starting point for future discussions and making a list of activities so we can stay on
target. We agreed to use the 2024 water monitoring plan and carry it forward into 2025, until a final Site Management
Plan can be adopted. We will work toward closure as soon as possible. The end of the year seems aggressive and likely
unattainable based on the sheer amount of work and schedules.
Please let me know if we missed anything or your team saw the meeting differently. We also agreed to more frequent
meetings to check in. We are happy to meet in a few weeks to evaluate progress.
We are meeting with DWQ tomorrow to answer some of their questions regarding the site and Extell's request to close
out the Order from DWQ???????? I'll let you know if anything unusual comes of the meeting.
Regards,
Bill
Bill Rees
Section Manager
VCP/Brownfields Section
P: [phone]
environmentalresponse.utah.gov
Emails to and from this email address may be considered public records and thus subject to Utah GRAMA
requirements.
Fawcett, Kent <[e-mail]>Mon, Oct 7, 2024 at 2:12 PM
To: Bill Rees <[e-mail]>
Cc: David Bird <[e-mail]>, "houdeshel.megan" <[e-mail]>, Kimberlee McEwan
<[e-mail]>
thanks Bill for this summary.

Kent

Kent Fawce
Vice President, Civil Infrastructure and Public Improvements
EX Utah Development LLC
10/7/24, 2:52 PM State of Utah Mail - Mayflower Meeting Summary
https://mail.google.com/mail/u/0/?ik=9ad96c2360&view=pt&search=all&permthid=thread-f:1812287226634801169&simpl=msg-f:18122872266348011…2/4
9109 N Mayflower Village Drive, Park City, UT 84060
t: [phone] |c: [phone]
[e-mail]|www.extell.com
[Quoted text hidden]
[e-mail] <[e-mail]>Mon, Oct 7, 2024 at 2:44 PM
To: [e-mail], [e-mail]
Cc: [e-mail], [e-mail]
Hi Bill,
Thanks for this summary. We are reviewing and will incorporate into the updated deliverables we
discussed during the meeting.

Regarding the DWQ closeout you mention in the last paragraph of your e-mail, this relates to the
very old DWQ consent order that was originally issued to the Stichtings. As you’ll recall, the
implementation of the Earthfax Plan was accepted by DWQ as the remedy for the original order.
This was documented in a letter from Erica Gaddis. The VCP Agreement/RAP addressed some of
the areas identified in that Earthfax Plan for remediation (i.e. Yellow Pond and Mayflower Portal),
but the Deer Camp area and Star Mine area in Glencoe Canyon are outside of the VCP boundary,
and were remediated under DWQ jurisdiction. We are working with DWQ to close out those areas
in Glencoe Canyon to receive a no-further-action letter for the portion of the consent order
addressing those areas. We’ve submitted a draft close-out report to DWQ, and will be delivering
some additional as-built drawings for DWQ that show the remedy at Star Mine and Deer Camp.

Let me know if this answers your question below. Happy to chat further about this if it’s helpful.

Thanks,
Megan

Megan Houdeshel
Partner, Practice Group Leader, Regulatory Affairs
Pronouns: She/Her/Hers
DORSEY & WHITNEY LLP
111 S. Main Street Suite 2100 | Salt Lake City, UT 84111-2176
P: [phone]
C: [phone]
WWW.DORSEY.COM :: SALT LAKE CITY :: BIO :: V-CARD
10/7/24, 2:52 PM State of Utah Mail - Mayflower Meeting Summary
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From: Bill Rees <[e-mail]>
Sent: Monday, October 7, 2024 2:10 PM
To: Fawcett, Kent <[e-mail]>
Cc: David Bird <[e-mail]>; Houdeshel, Megan <[e-mail]>; Kimberlee McEwan
<[e-mail]>
Subject: Mayflower Meeting Summary

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10/7/24, 2:52 PM State of Utah Mail - Mayflower Meeting Summary
https://mail.google.com/mail/u/0/?ik=9ad96c2360&view=pt&search=all&permthid=thread-f:1812287226634801169&simpl=msg-f:18122872266348011…4/4