DSHW-2024-007052

July 3, 2024
Andrew W. Steinberg
Vice President
LE PETOMANE, Inc
35 East Wacker Dr. Suite 690, Chicago, IL 60601
RE:Expectations of Corrective Action for Groundwater at the Former Vertellus Provo, Utah SiteUTD009087644
Dear Mr. Steinberg:
On July 1, 2024, the Vertellus Specialties Environmental Response Trust (Trust) and the Division of Waste Management and Radiation Control had a conference call to discuss recent groundwater
sampling at the former Vertellus site (Site) and to discuss a path forward for the Site. The Trust also asked for clarification and confirmation concerning the Division’s expectations
of what future corrective actions will be necessary with respect to groundwater at the Site.
Based on historical and current sampling data, groundwater at the site is contaminated with certain volatile organic compounds and semi-volatile organic compounds including polycyclic
aromatic hydrocarbons. According to the March 27, 2024, Groundwater Sampling and Analysis Plan that was approved for the most recent sampling round, benzene has historically been used
as the primary constituent of concern for evaluating the impacts to groundwater at the site.
During the July 1 call, the Trust offered the Provo Site 2024 Groundwater Sampling Results and Field Observations Discussion Presentation (Presentation), dated July 1,2024, which was
later submitted to the Division along with the sampling data for the recent sampling round. According to the Presentation, benzene concentrations across the site are in line with historical
sample data, indicating that the benzene plume is stable and not expanding. The Presentation also shows that groundwater at the Site has historically and continues to flow radially
inward from the west, north, and east towards the center of the Site on the southern end.The inward groundwater flow helps to prevent the spread of contamination offsite. The Presentation
also shows that only one of the selected offsite monitoring well, MW-33, had benzene concentrations above the maximum contaminant level this sample round.
Historical reporting for the site has indicated that potential for downward vertical migration of contaminants into the underlying confined aquifer is greatly limited due to the presence
of fine-grained soils at the Site, which serve as a barrier to vertical migration. In addition, significant hydrostatic pressure of the underlying confined aquifers in the area results
in an upward hydraulic gradient from the lower aquifers into the upper aquifer, which also prevents the downward migration of contaminants.
The 2013 Risk Assessments for the Former Reilly Industries included an evaluation of the groundwater pathway for an on-site worker and construction worker. The assessment also included
vapor intrusion. The results indicated that contamination in soil was the primary driver for vapor intrusion issues but identified several hot spots and Solid Waste Management Unit
where combined exposure pathways exceeded the acceptable risk range for site management and engineering controls. However, as groundwater was not the primary source driving vapor intrusion
issues, a site management plan preventing use of groundwater and ensuring engineering controls on future structures over the main plume area is an appropriate institutional control and
consistent with the requirements outlined in the 1996 Stipulation and Consent Agreement.
Based on discussions and presented past and current groundwater sampling, the groundwater plume appears stable, and the nature and extent of the plume has been adequately defined. Monitored
natural attenuation (MNA) coupled with long term monitoring (LTM) of groundwater and a site management plan would be an appropriate corrective action for the groundwater portion of the
Site.
The Division understands that additionalsource removal of contaminated soils above risk-based levels is proposed. Removal of additional source material will contribute to the plume
stabilization and long-term protectiveness of groundwater at the Site. It is also understood that the 2013 Risk Assessments for the Former Reilly Industries will also be used to guide
removals. It is recommended that the risk assessment be updated with post removal confirmation data, to assess the adequacy of removals and the need for additional engineering controls
for the property.
If you have any questions, please call Jasin Olsen at [phone].
Sincerely,
Douglas J. Hansen, Director
Division of Waste Management and Radiation Control
DJH/JO/wa
c:Eric Edwards, Health Officer, Utah County Health Department
Tyler Plewe, Deputy Director, Utah County Health Department
Jason Garrett, Environmental Health Director, Utah County Health Department
Andrew W. Steinberg, Vice President, LE PETOMANE, INC ([e-mail])
Brian Loffman, Senior Program Manager, LE PETOMANE, INC ([e-mail])