DSHW-2018-004781 - 0901a0688082ac61

DSHW-2018-004781 195 North 1950 West • Salt Lake City, UT Mailing Address: P.O. Box 144880 • Salt Lake City, UT 84114-4880 Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov Printed on 100% recycled paper
State of Utah
GARY R. HERBERT Governor SPENCER J. COX
Lieutenant Governor
Department of
Environmental Quality
Alan Matheson Executive Director DIVISION OF WASTE MANAGEMENT AND RADIATION CONTROL Scott T. Anderson Director
June 4, 2018 Christopher J. Nolan, P.G. Senior Project Geologist
Wasatch Environmental, Inc.
2410 California Avenue Salt Lake City, Utah 84104 Re: Additional Indoor Air and Soil Gas Sampling Results
Park East Apartments, 1717 East Murray-Holladay Road, Millcreek, Utah
The Division of Waste Management and Radiation Control has completed its review of the results of the additional indoor air and sub-slab soil gas samples collected at the Park East Apartments. The data was collected to determine if the indoor air at the Part East Apartments has been impacted as a result of the
presence of vapor forming chemicals in groundwater beneath the apartments.
The groundwater monitoring data in the Soil Gas and Groundwater Sampling Investigation Report dated December 13, 2017 indicated a release of volatile organic compounds (VOCs) from an east-adjoining dry-cleaning facility. The reported concentrations of trichloroethylene (TCE) and vinyl chloride (VC),
when compared to the US EPA target groundwater vapor intrusion screening levels (VISLs), indicated
the potential for impacts to indoor air for a residential dwelling. Based on this information, the Division recommended evaluation of the vapor intrusion risk. The Sampling and Analysis Plan Implementation Report submitted on May 21, 2018 provided an
assessment of the vapor intrusion risk to residents based on the additional indoor air and sub-slab vapor
data. The results clearly indicated concentrations of tetrachloroethylene (PCE), TCE and VC were either non-detect or were below the residential indoor air screening values and sub-slab vapor concentration screening values. In summary, the data supports the conclusion that there are no current impacts to indoor air or the sub-
slab environment due to the presence of vapor forming compounds in groundwater. However, due to the presence of vapor forming compounds in the groundwater at levels that have the potential for vapor intrusion into buildings, the Division recommends continued groundwater monitoring at the site. The monitoring data will assist in determining whether additional vapor intrusion assessments are warranted or alternatively, if groundwater monitoring may be discontinued.
(Over)

Please submit a groundwater monitoring work plan that provides details on the location and number of wells and sampling frequency within 60 days of the date of this letter.

If you have any questions, please call Eric Baiden at [phone]. Sincerely,

Scott T. Anderson, Director Division of Waste Management and Radiation Control
STA/EB/km
c: Gary Edwards, MS, Health Officer, Salt Lake County Health Dept. Royal DeLegge, MPA, EHS, Environmental Health Director, Salt Lake County Health Dept.