DSHW-2024-006163

DSHW-2024-006163 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. 711
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 WASTE MANAGEMENT AND RADIATION CONTROL Douglas J. Hansen Director May 15, 2024
Kris Blauer, Manager Environmental Services Northrop Grumman Systems Corporation
P.O. Box 707 Brigham City, UT 84302-0707 RE: Solid Waste Management Unit 233 RCRA Facility Investigation Report Response to Comments Northrup Grumman System Corporation – Promontory Facility
UTD009081357 Dear Mr. Blauer:
The Division of Waste Management and Radiation Control (Division) has reviewed the Response to Comments for the Solid Waste Management Unit (SWMU) 233 Resource Conservation and Recovery Act (RCRA) Facility Investigation Report (Response) dated May 6, 2024, for the Northrup Grumman Systems Corporation (NGSC) – Promontory Facility. The Response is acceptable and is hereby approved.
NGSC will conduct additional sampling at SWMU 233 to determine the nature and extent of contamination. Based on the waste streams associated with SWMU 233 and the data from the initial investigation, the additional sampling will include analysis for xylene, cadmium, perchlorate, dioxins, furans, and polycyclic aromatic hydrocarbons (PAH) in addition to volatile organic compounds (VOC), metals, HMX, and
nitroglycerin. Results from the additional investigation will be screened against current and applicable screening levels. Please submit a work plan to further characterize the site within 60 days of the date of this letter.
If you have any questions, please call Karen Wallner at 385-499-0218 or Hao Zhu at 801-558-9833. Sincerely,
Douglas J. Hansen, Director Division of Waste Management and Radiation Control (Over)

DJH/KHW/jk c: Jordan Mathis, Health Officer, Bear River Health Department
Grant Koford, EHS, Environmental Health Director, Bear River Health Department Tara Hubner, U.S. EPA, Region 8 Kris Blauer, Manager, Environmental Services, Northrup Grumman Systems Corporation (Email and Hard Copy) Tim Jimenez, Northrop Grumman Systems Corporation (Email)
Blair Palmer, Northrop Grumman Systems Corporation (Email) Hao Zhu, Division of Waste Management and Radiation Control, UDEQ