DERR-2024-006304

VCP/Brownfields Section - Site Visit Report

SITE NAME: Mayflower Mine

SITE LOCATION: Wasatch County

DATE OF SITE VISIT: 15 April 2024

PURPOSE OF SITE VISIT: DERR (David Bird) oversight of Phase 1 remedial action.

FIELD OBSERVATIONS: The DERR visited the Mayflower VCP site at ~10:30 am on 15 April to meet with
Extell personnel and observe conditions at the site. The DERR met with Extell (Kent Fawcett and “CJ”)
and discussed progress on final construction details for the Phase I Remedial Action Plan (RAP), including
actions to mitigate and minimize groundwater getting into the mine waste in the repository, and the
activities planned for spring and summer.
Extell indicated they expect to begin moving the stormwater detention pond ~100 yards up the Big
Dutch Pete Hollow (BDPH) away from the repository, in one or two months when things dry out.
Repairs (from the past spring runoff) to the BDPH drainage are on-going and will continue as long as
needed.
We looked at the revised sedimentation pond at the confluence of Glencoe Canyon to the McHenry
Canyon drainage. This pond is deeper than before and has a larger exit structure connected to piping
which carries the water beyond the areas for the new bases of ski lifts in this location. We also looked at
areas of McHenry Canyon near the MIDA Hotel where further improvements to the drainage channel
will be added this year.
The DERR and Extell also viewed the replacement wetland area east of the repository and the adjacent
(to the south) stormwater drainage structure. Both are about 90% complete. The DERR left the site at
~12:07 pm.

SPLIT SAMPLES COLLECTED: No

IS THE WORK BEING PERFORMED IN A MANNER CONSISTENT WITH THE ACCEPTED WORKPLAN?
Yes