DERR-2024-013241

6952 South High Tech Drive, Suite B
Midvale, Utah 84047
P [phone]
Terracon.com
December 19, 2024
Salt Lake City Corporation
Department of Sustainability
451 South State Street, Room 148
Salt Lake City, Utah 84114-5470
Attn: Ms. Catherine Wyffels
Air Quality & Environmental Program Manager
P: [phone]
E: [e-mail]
Re: VIMS Installation Project Status Report
The Other Side Village, VCP Site C121, Phase I
1850 West Indiana Ave, Salt Lake City, Utah
Terracon Project No. 61237263
This letter presents Terracon’s current observations of the installation of vapor mitigation
systems for structures at The Other Side Village (TOSV) Voluntary Cleanup Program (VCP)
site. During the course of subsurface investigations conducted at the site, elevated
concentrations of chloroform were identified in soil gas with the potential for vapor intrusion
into future structures. In order to mitigate the potential for vapor intrusion, vapor intrusion
mitigation systems (VIMS) were designed for each building in the site development plan.
Exbibit 1 displays the development plan for the site, with designations for the type of VIMS
indicated for each building. There are multiple building designs, each designated with one of
three VIMS design types:
slab-on-grade foundation with vapor barrier membrane
vented crawl-space foundation
slab-on-grade foundation with vapor barrier membrane and soil gas collectors
TOSV is currently developing the north portion of the proposed development, Phase I,
shown on Exhibit 1. Construction of buildings on the southern portion of the Site has not yet
commenced. The north portion of the proposed development identifies two VIMS designs for
structures: Slab-on-grade foundations with vapor barrier membrane, and vented crawl-
space foundations.
VIMS Installation Project Status Report
The Other Side Village | Salt Lake City, Utah
December 19, 2024 | Terracon Project No. 61237263
2
Phase I includes 15 residential units and one community building (the Pavillion) that require
a slab-on-grade foundation with vapor barrier membrane (red outlined buildings) and 42
residential units that require a vented crawl-space foundation (green outlined buildings).
As of December 17, 2024:
There are 13 residential units and one community building that have
completed the installation of the slab-on-grade foundation with vapor barrier
membrane.
There are 32 residential units installed that have vented crawl spaces. These
units have been constructed on a foundation with a vented crawl space to
provide adequate ventilation in the crawl space such that vapors do not
collect beneath the floor with the potential to infiltrate into the structure.
As development of the Site proceeds, Terracon will continue to inspect the buildings for the
installation of the required VIMS. A full report documenting the completion of the vapor
mitigation systems will be compiled once site development is completed.
Sincerely,
Terracon Consultants, Inc.
Nancy Saunders Amy Austin
Project Manager Authorized Project Reviewer
Attachment: Exhibit 1 Vapor Mitigation Systems
Amy Austin