DERR-2024-011842

195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144840 • Salt Lake City, UT 84114-4840
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

SPENCER J. COX
Governor
DEIDRE HENDERSON
Lieutenant Governor
Department of
Environmental Quality
Kimberly D. Shelley
Executive Director
DIVISION OF ENVIRONMENTAL
RESPONSE AND REMEDIATION
Brent H. Everett
Director
ERRC-163-24
October 25, 2024
Ryan Dunham
Site Assessment Manager
U.S. Environmental Protection Agency, Region 8
1595 Wynkoop St.
Mail Stop: 8EPR-B
Denver, Colorado 80202-1129
Dear Mr. Dunham:
Enclosed is the Preliminary Assessment (PA) for the 600 West 200 South Plume,
UTN000821006, (herein referred to as the “Site”) in American Fork City, Utah County, Utah. The
Site is located in a mixed-use area within American Fork City, Utah County, Utah, containing
residential and commercial real estate. Portions of the Site appear to have been used as a historic
landfill from the early 1900s until as late as 1990. Since the early 2000s, the Site has been used for
storing landscaping materials, construction materials, and equipment, and for minor livestock
grazing and is currently owned by Nielsen Property Holdings, LLC.
The purpose of this PA is to summarize pertinent results received by the Division of
Environmental Response and Remediation (DERR) regarding the Site. The review of previous
data revealed arsenic, lead, benzo(a)pyrene, and total recoverable petroleum hydrocarbons
(TRPH) in surface and subsurface soil across the Site at elevated concentrations, with the highest
lead concentration of 2,940 mg/kg. Results also indicate that shallow groundwater at the Site is
impacted primarily by tetrachloroethene (PCE) (highest concentration of PCE at 34.8 µg/L), with
additional impacts from arsenic and lead at concentrations also above the U.S. Environmental
Protection Agency (EPA) Maximum Contaminant Levels (MCL). Additionally, a surface water
sample collected from the drainage ditch on the adjacent property to the west of the Site measured
PCE at a maximum concentration of 22.1 µg/L.
The shallow groundwater gradient at the Site is to the southwest and the highest PCE
concentrations are located on the northwest portion of the Site and gradually decrease moving
south; however, PCE concentrations above the MCL was not detected in the southernmost
monitoring well. The DERR was unable to determine if PCE is present in off-site groundwater,
and the vertical extent of groundwater contamination is also unknown. Additionally, PCE
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concentrations exceed the EPA residential vapor intrusion screening level (VISL) target
groundwater concentration benchmark of 14.9 µg/L. Residential properties are present on the
south side of 200 South, approximately 50 feet down-gradient from the Site, with subsurface
vapor intrusion being the pathway of concern.

Surface water at the Site flows into nearby open ditches and culverts, which ultimately
drain to Utah Lake, the Jordan River, and the Great Salt Lake. Currently, the levels of PCE in the
surface water are below the established ecological screening level (ESL), which is also a non-
drinking water source, indicating a low to moderate potential for exposure through surface water.
However, it is unknown if other contaminants are present in surface water near the Site and/or if
there is a relationship between groundwater and surface water at the Site.

Potential impacts via the soil pathway and air pathway appear to be a low to moderate
concern. Contaminated soil at the Site is present at ground surface in some areas up to depths of
two feet below ground surface (BGS). There is no hard surface that covers soil at the Site and visible
landfill debris consisting of glass, metal, and other unknown materials is present at ground surface
and sloughing off of perimeter areas at the Site. Although a gravel cover is present on portions of
the Site within chain-link enclosed areas, the gravel is discontinuous and does not appear to be an
effective cover or cap.

Based on the findings, the DERR recommends a Site Investigation of this Site under
CERCLA.

Thank you for your attention to this matter. If you have any questions, please contact me at
[phone], or via email at [e-mail].

Sincerely,

Kelsey Robinson, Project Manager
Division of Environmental Response and Remediation

KR/es

Enclosed: 600 West 200 South Plume Preliminary Assessment

cc: Eric Edwards, Executive Director, Utah County Health Department
Jason Garrett, Environmental Health Director, Utah County Health Department