While waiting for answers to our questions and comments about the closure of the Open Burn / Open Detonation (OB/OP) cleanup plan at Aerojet Chino Hills, as addressed in our July 20 “Blow In Place” post, we came across a new set of documents on the Department of Toxic Substances Control’s Envirostor website under DTSC’s Community Involvement page.
There we found a 76-page report called “DRAFT INVESTIGATION REPORT – MUNITIONS AND EXPLOSIVES OF CONCERN – DATA GAP INVESTIGATION” created in July 2009 by Huntsville, Alabama-based Weston Solutions, Inc.
From all indications, Aerojet and Weston have done a good job finding 52 “munitions and explosives of concern” across a 39-acre area of the 800-acre facility, along with 70 pounds of munitions debris. The company used blind “seeding” of planted objects as a quality control measure and all of the seeded objects were found.
Regardless of our concerns with the OB/OP cleanup plan, this Weston-created report seems to have all its bases covered. Indeed, this was literally a “bombs away” operation at Aerojet Chino Hills.
Photos of the company’s operations are available in Appendix E and worth a look.
Below, we’ve cut, pasted and underlined the parts of the report that stood out the most for us:
P. 12/76 PDF pages:
Weston Solutions Inc. and Aerojet-General Corporation (Aerojet) completed the planned munitions and explosives of concern (MEC) detection and removal activities at Aerojet’s Chino Hills Facility and the surrounding study area within areas that were not previously investigated for MEC (data gap investigation). Digital and analog handheld geophysical instrumentation were used to detect MEC to instrument detection depth within accessible areas of each data gap and within areas that did not contain cultural features which may potentially mask MEC. A total of 39 accessible acres were included in the MEC data gap investigation, including approximately 8.7-acres of digital geophysical mapping coverage and approximately 30.2-acres of mag & dig surveys.
A total of 55 items characterized as material potentially presenting an explosive hazard (MPPEH) were recovered during the investigation. MPPEH were recovered within Area 16, South of Area 16, Bonnett, and Lee #4. Fifty-two (52) of the MPPEH items were recovered in Area 16 and South of Area 16 as anticipated based on the site’s conceptual site model. In addition, approximately 70 pounds of munitions debris were recovered during the MEC data gap investigation. No MPPEH were observed within 200-ft of the open burn/open detonation kick out radius and an adaptive clearance was not warranted.
There were several levels of quality assurance and quality control put in place. They included a physics-based test strip approach, a robust site-wide seeding program, establishing individual quality control measurement criteria, and a re-collection program. There were no quality control failures, signifying all detection systems were found to perform in accordance with the California Environmental Protection Agency, Department of Toxic Substances approved project Work Plan. Project data quality objectives of detecting MEC to instrument detection depth were achieved.
Weston Solutions, Inc. (WESTON®) assisted Aerojet with this work between 5 January and 13 February 2009. This project was conducted in consultation with the California Environmental Protection Agency (EPA), Department of Toxic Substances Control (DTSC) as part of corrective action pursuant to the 1994 Agreement on Consent.
The primary objective of this project was to detect and remove MEC within accessible data gap areas. Data gaps included in the technical scope of this project include areas not previously investigated for MEC, that were accessible to geophysical instrumentation and did not contain cultural features which may mask MEC (such as asphalt/concrete surfaces, buildings/structures and piping).
2.3 AEROJET CHINO HILLS FACILITY HISTORY
Before 1954, the study area was undeveloped and used for grazing cattle. Operations began in 1954 and included limited testing of ordnance, and research activities. In the 1960s, Aerojet began loading, assembling, and packing operations for several government munitions systems under contracts with the United States Department of Defense (DOD). During the 1970s, operations expanded and primarily involved testing explosives and propellants. After 1974, operations primarily involved research, development, and testing of high-explosive incendiary (HEI) projectiles, armor piercing incendiary (API) projectiles composed in part of depleted uranium (DU), target practice (TPs) rounds, and fuzes. These activities were conducted in specific and limited areas within the study area which are referred to as the “operational areas.” Aerojet ceased operations at the facility in November 1995.
2.5 MILITARY MUNITIONS SOURCES AND TYPES
A limited variety of ordnance was developed and tested at the facility during its operational history. Numerous MEC items have been recovered from the study area during previous investigations. Based on current findings, 30-mm projectiles are the most frequently encountered munition within the OB/OD kick-out radius, and 20-mm projectiles are the most frequently encountered munition in the vicinity of the suspected aircraft crash site within the Lee/Galstian Area. MEC and munitions debris (MD) previously recovered near the data gap areas include:
Various MD and related components.
3.1 OPERATIONS SUMMARY
Site survey and removal grid layout operations began in December 2008 immediately following the full containment of wildfires which struck the Aerojet Facility and surrounding areas. The wildfires removed vegetation, allowing further accessibility to the survey crew and for subsequent MEC investigations.