Moffett EATS Evaluation Presentation to RAB July 12, 2007
-
Upload
steve-williams -
Category
Economy & Finance
-
view
528 -
download
0
Transcript of Moffett EATS Evaluation Presentation to RAB July 12, 2007
![Page 1: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/1.jpg)
Site 26 Evaluation
RAB PresentationFormer Naval Air Station Moffett FieldJuly 12, 2007
Presented by:Liz BarrNavy Remedial Project Manager
![Page 2: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/2.jpg)
Presentation Outline
• Background • Evaluation Objectives
– Phase I– Phase II
• Results• Summary, Conclusions, and
Recommendations• Schedule
![Page 3: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/3.jpg)
BACKGROUND
![Page 4: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/4.jpg)
Background
• Site 26 Record of Decision 1996 - GW Monitoring, Institutional Controls, and Extraction and Treatment of GW
• COCs- PCE - VC- TCE - 1,2-DCA- Cis-1,2-DCE - 1,1-DCE
• East-side Aquifer Treatment System (EATS) operational Jan. 1999 - July 2003– Recovered <0.5 lbs/month of VOCs– Decreasing monthly recovery– Cost >$29,000 per lb of VOCs
• EATS 5-year review noted that pump and treat may not be efficient, and recommended evaluating alternatives
![Page 5: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/5.jpg)
East-side Aquifer Treatment System
![Page 6: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/6.jpg)
EVALUATION OBJECTIVES
![Page 7: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/7.jpg)
Evaluation Objectives• Per the 5-year Review evaluation of other clean-up
alternatives• Developed Work Plan – Jan. 2003 • Work Plan activities divided into two phases
– Phase I• Evaluate geology / aquifer hydraulics• Assess potential COC rebound• Evaluate plume stability• Groundwater sampling
– Phase II• Conduct nutrient enhancement pilot test• Groundwater sampling
![Page 8: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/8.jpg)
PHASE I
![Page 9: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/9.jpg)
Evaluation of Geology
![Page 10: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/10.jpg)
Evaluation of GeologyResults - Cross Section A-A’
![Page 11: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/11.jpg)
Well / Aquifer Testing
• Performed recovery tests on each extraction well
• Turned off wells one at a time. Measured water level responses in surrounding wells
Results ● No response related to direction● Consistent with a coarse sand to fine gravel
![Page 12: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/12.jpg)
Rebound / Plume Stability
![Page 13: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/13.jpg)
Rebound / Plume StabilityTCE Concentration
Extraction wells off as of July 2003
![Page 14: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/14.jpg)
Rebound / Plume StabilityEXW-2 Plume Interior Well
![Page 15: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/15.jpg)
Rebound / Plume StabilityWU5-18 Plume Boundary Well
![Page 16: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/16.jpg)
Natural Attenuation
• Geochemical indicators support NA process – Low levels of dissolved oxygen, dissolved
hydrogen and the presence of methane (supports anaerobic conditions)
– Degradation products present• Natural attenuation is occurring• Degradation rate slow
![Page 17: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/17.jpg)
Natural AttenuationBreakdown Products
![Page 18: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/18.jpg)
PHASE II
![Page 19: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/19.jpg)
Enhanced Natural Attenuation(HRC® Injection)
• Conducted nutrient enhancement (NE) pilot test
• Injected Hydrogen Release Compound (HRC®) at two groundwater “hot spots”to evaluate the ability for NE to reduce VOCs
![Page 20: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/20.jpg)
Enhanced Natural Attenuation HRC®
Placement
• Pilot test targeted two separate areas • HRC® injected Feb.-March 2005• Injected 7 to 32 ft below ground surface
• 81 injection points (36 at PS-1 and 45 at PS-2)
![Page 21: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/21.jpg)
Enhanced Natural AttenuationLocation of HRC ® Injections and Monitoring Wells
Treatment System
![Page 22: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/22.jpg)
Enhanced Natural AttenuationSampling Schedule
• 13 wells sampled 12 times over 18 months• Sampled chemistry monthly through Sept.
2005 then quarterly until Sept. 2006• Analyzed for VOCs, lactate, and NA
parameters
• Sampled select wells for microbial parameters and specific dechlorinating bacteria. Sampled 5 times June 2005 – Sept. 2006
![Page 23: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/23.jpg)
RESULTS
![Page 24: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/24.jpg)
Extent of TCE Plume Over Time
![Page 25: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/25.jpg)
Extent of CIS-1,2-DCE Plume Over Time
![Page 26: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/26.jpg)
Extent of VC Plume Over Time
![Page 27: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/27.jpg)
W7-10, Within PS-1 Area TCE Concentration vs. Time
![Page 28: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/28.jpg)
EXW-2, Within PS-2 AreaTCE Concentration vs. Time
![Page 29: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/29.jpg)
Bacterial Analysis
• Suitable native bacteria present for reductive dechlorination across entire site
• Added substrate (HRC®) stimulated microbes in pilot test areas, reducing VOCs to less than 50 µg/L
• HRC® had limited impact in pilot test areas where VOCs were less than 50 µg/L
![Page 30: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/30.jpg)
SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS
![Page 31: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/31.jpg)
Summary• 1,2-DCA remained below the ROD cleanup
standard of 0.5 µg/L, except at 2 wells• 1,1-DCE remained below the ROD cleanup
standard of 6 µg/L, except at 1 well• Other COCs generally at low concentrations• Natural attenuation is taking place. Native
bacteria for dechlorination are present • HRC® reduced VOC concentrations to < 50
µg/L in pilot test areas. HRC® not effective when concentrations of VOCs < 50 µg/L
![Page 32: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/32.jpg)
Conclusions
• Very low VOC concentrations remaining
• No VOC rebound
• Stable VOC plumes
• Low potential risk
![Page 33: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/33.jpg)
Recommendations
Based on the plume stability, no contaminant rebound and low potential risk, the Navy recommends:
– EATS remain turned off and on standby– Monitored natural attenuation (MNA)
implemented for completing remediation of groundwater at site
![Page 34: Moffett EATS Evaluation Presentation to RAB July 12, 2007](https://reader034.fdocuments.us/reader034/viewer/2022051617/55a426501a28ab9d038b45bf/html5/thumbnails/34.jpg)
Schedule
• Prepared and submitted a Draft Completion Report – June 2007
• Final Completion Report – fall/winter 2007