2016 EnviroReporter.com comments on Aerojet Rocketdyne Chino Hills cleanup
Read EnviroReporter.com’s May 1, 2009 comments to DTSC on the OB/OD closure here.
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Aerojet Chino Hills drains to the west down to the Santa Ana River in Orange County.
The 800-acre facility is operated for over 40 years developing, producing and testing munitions, chemicals and depleted uranium.
Aerojet Chino Hills drains to the east down to the Prado Dam in San Bernadino County.
Carbon Canyon Regional Park is five miles downstream from the OB/OD area. People fish in a lake supplemented by runoff from the Aerojet site that flows down Soquel Canyon Creek.
Over 47,000 ordnance-related objects were removed from the OB/OD area from 2003 to 2006. See Timeline.
Excavation, stockpiling and screening areas at the OB/OD
Four trained technicians manned the giant soil screening machine that processed tons of dirt, removing fragments 1/2" or larger.
The machine, connected by conveyor belts, used clod crushers, vibrating screens, magnets and manpower to sift the material.
In 2003, the machine was modified to reject wet material and to handle larger clods and rocks.
how 'The Dirterminator' works.
Dirterminator' 2004-2005 layout
2003-2006 areas to be excavated and screened
Where munitions and ordnance was dug up in 2005, to the west of the 14-acre area that Aerojet had later remediated.
2003-2006 areas to be excavated and screened
The next five blue-colored maps show the results of sweeping the OB/OD in 2005, according to the DTSC-supplied report "GEOPHYSICAL MAPPING WITHIN THE OB/OD AREA PHASE I AND II."
The report says "The purpose of this survey is to conduct third-party digital geophysical mapping within the bottom of the OB/OD excavation to provide additional confirmation that URS Corporation was successful in removing unexploded/ ordnance explosive (UXO/OE) items from the OB/OD excavation area.
UXO/OE is also known as munitions and explosives of concern (MEC).
The report says "A threshold of 3 mV was used to select anomalies from the data for both the single coil hand towed system and the multi-coil ATV towed array system."
On the color scale, 3 mV is green for normal and anything blue means no UXO/OE. Yellow, orange, red and pink indicate finds of MEC. There are many pink hits in some maps here.
The above January 2005 map was the original area to be double-checked. When the actual double-checking began in August 2005, the area to be tested shrank considerably.
Excavation and support areas
Survey areas, MEC finds and Quality Control grid locations
This October 2006 Third Party Quality Assurance Survey is disturbing in that it shows numerous areas that still read quite likely for MEC detection.
2003 survey map
2003 grid map
2002 topographic survey
Undated topographical map of OB/OD area excavation boundaries and elevations. Final grid mapping shows that a much smaller area was actually tested.
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