Aerojet Chino Hills – OB/OD Maps and Layout
Read EnviroReporter.com’s May 1, 2009 comments to DTSC on the OB/OD closure here.
(Click thumbnail to view entire image)
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.