OVERVIEW OF LAS VEGAS VALLEY PERCHLORATE REMEDIAL EFFORTS

OVERVIEW OF
LAS VEGAS VALLEY
PERCHLORATE
REMEDIAL EFFORTS
Prepared for:
Perchlorate Task Force Meeting
Union Station, Los Angeles, California
July 20, 2004
Todd Croft
Nevada Division of Environmental Protection
(702) 486-2871, [email protected]
Perchlorate Manufacturing Operations
Henderson, NV
Pepcon (AMPAC): 1958 – 1988
•
•
US Government – Navy (1945 – 1962)
Kerr-McGee & Predecessors (1945 – 1998)
•
•
July 1998: Curtailed Perchlorate Production
March 2002: Process Shut Down
May 1988: Destroyed in Explosion
March 1998: Purchased Manufacturing Line &
Customer Base from Kerr-McGee
Perchlorate Plumes & Remediation Infrastructure
LAS VEGAS WASH
SEEP
SEEP AREA
WELL FIELD
WASH IX
COH-RIB
ATHENS ROAD
WELL FIELD
PABCO ROAD
PIPELINE
ON-SITE IX
GW-11 POND
DX WELLS
&
PILOT TESTING
INTERCEPTOR
SLURRY WALL
& ON-SITE
WELL FIELD
KMCLLC
PEPCON
FBR SYSTEM
2002
1997
–
–
Initial Discovery – Source traced back to
Las Vegas Wash
–
1998
–
–
Plume Characterization
On-Site Capture (Kerr-McGee)
–
Seep Capture (Kerr-McGee)
–
–
1999
Full-Scale Plant (ISEP-PDM):
Construction Completed
Start-up Initiated
• Heat Exchanger Fouling
• Reactor Pressure Spikes
• Corrosion
One-Pass IX System Replaces ISEP-PDM
All Collection Points Operating
(October 2002)
2003
–
2000
–
–
–
Seep Area Characterization
Pilot Plants Constructed
ISEP-PDM Design Initiated
–
Full-Scale GW Treatment System (ISEPPDM) Constructed
All Well Fields & Infrastructure Installed
Permitting Finalized
On-Site Slurry Wall Constructed
–
2001
–
–
–
5 Additional Seep Area Wells Installed
• Operating March 2003
• Compliments the 4 Existing Seep
Area Wells
Full-Scale Ex-Situ Fluidized Bed Reactor
(FBR) Biological Treatment System
• Will Replace ISEP-PDM & IX
• Design, Permitting, & Construction
Initiated
2004
–
FBR Full-Scale Operation Planned by
Summer 2004
On-Site IX
Perchlorate
Remedial
Systems
Full-Scale GW Treatment System
Current
Recent Past
Capture & Treatment
Wash IX: ~ 300 gpm @ ~ 30 - 120 ppm
• Seep Area Collection
On-Site IX: ~ 700 gpm @ ~ 200 - 300 ppm
• Athens Road
• Seep Area Collection
• On-Site Pond with Return Flow
Full-Scale System: ~ 850 - 1,000 gpm @ ~ 250 ppm
•
•
•
•
Athens Road Well Field
On-Site Pond
On-Site Well Field
Seep Area Collection - GW & Surface
Perchlorate Removal Rate:
June 2004
Location
Perchlorate Removed from the Environment:
Through June 2004
Mass
(Pounds per Day)
Location
Mass
(Tons)
Seep Area
156
Seep Area
312
Athens Road
757
Athens Road
265
706
On-Site
1,044
On-Site
Total
1,957
Total
1,283
AMPAC Pilot:
Biodegradation of Perchlorate
• Flow Rate - 10 GPM
• Approximately 600 ppm perchlorate near source area
• Carbon Source – Ethanol/Citric Acid/Potassium Oleate
• Bio-fouling Control – Ultrasonic/Citric Acid/ Chlorine
Dioxide
• Degraded ~ 600 ppm to < 2ppb in approximately 110 days
• Evaluated Several Electron Donors
• Corrected Chemical and Biological Fouling Issues
Conceptual Model of Perchlorate Loading to the Las Vegas
Wash Prior To October 2002 Capture and Treatment
Northshore Road
LM2
Existing Upstream Flow
10 lbs/day
LM8
LM6
200 lbs/day
500
lbs/day
Kerr-McGee Treatment
400 lbs/day
Wash Flow
S
E
E
P
Athens Road
y
/da
bs
l
0
50
Groundwater Discharge to
Wash
250 to 300
lbs/day
Horse Spring
Formation
Extraction Wells
leo
a
P 00
9 ay
/d
lbs
Wash Gravels
el
n
n
a
Ch
Former
Complex Loading
Fault
Slurry Cutoff Wall
500
lbs/day
Breakthrough Curve: 90% Efficient Model Results, Mass
1000
900
P e rc h lo ra te M a s s F lu x (lb s /d a y )
Lower 95% Confidence
Median
Higher 95% Confidence
October 2002
~ 420 - 580 lbs/day
800
Northshore Rd
Expon. (Northshore Rd)
700
600
500
October 2004
~ 80 - 120 lbs/day
400
300
200
October 2003
~ 150 - 300 lbs/day
100
0
0
1
2
Time (Years)
3
4
Predicted Perchlorate at Whitsett Intake*
Medium Lake Mead Storage Condition
Perchlorate (ppb)
10
Original Projection
8
Revised Projection
(90% capture at Athens Rd.)
6
4
2
0
'04
'05
'06
'07
'08
Year
*Provided by Metropolitan Water District and Flow Science
'09
'10
Perchlorate Concentration
Perchlorate Detection Limit
Specific Conductance
Jan-05
Oct-04
Jul-04
Apr-04
Jan-04
Oct-03
Jul-03
Apr-03
Jan-03
Oct-02
Jul-02
Apr-02
Jan-02
Oct-01
Jul-01
Apr-01
Jan-01
Oct-00
Jul-00
Apr-00
Jan-00
Oct-99
Jul-99
Apr-99
Jan-99
Perchlorate Concentration ( µ g/L)
20.0
1200
18.0
1080
16.0
960
14.0
840
12.0
720
10.0
600
8.0
480
6.0
360
4.0
240
2.0
120
0.0
0
Specific Conductance ( µ S/cm)
Willow Beach Sampling Point
Perchlorate Concentration (µg/L)
On-Going Activities
Entities Involved
• Investigation of LV Wash
& BMI Areas to Evaluate
Other Potential
Perchlorate Sources
• US Environmental
Protection Agency
• NV Division of
Environmental Protection
• Southern Nevada Water
Authority
• Metropolitan Water
District
• City of Henderson
• Kerr-McGee
• AMPAC
• BMI
• Continued Evaluation of
Remedial Technologies
• Consideration of
Opportunities to Further
Refine Capture &
Treatment