February 22, 2011 Picatinny Team Meeting Edison, New Jersey

Transcription

1 February 22, 2011 Picatinny Team Meeting Edison, New Jersey

2 Updated Groundwater Model and Remedies Mid-Valley Groundwater (PICA 204) February 22, 2011 Imagine the result

3 Review of Field Program Scope Completed 2009 June 2010 Installation of 18 wells Rock coring in 5 wells Packering during drilling for vertical aquifer profiling of VOCs in 3 borings (Color-Tec field analysis and quick TAT lab analysis) Geophysical logging in 3 borings Collection and analysis of groundwater samples from 25 wells Collection and analysis of 5 surface water samples Collection and analysis of 5 soil samples Multiple rounds of water level gauging June 2010 Conceptual Site Model Meeting Conclusions TCE plume was delineated in the vicinity of Bldg 3109 TCE was not delineated upgradient 3

4 Review of Field Program 4 Scope Completed June September 2010 Drilled 2 wells (171MW-11B, 171MW-12) to complete delineation Collected rock core at 171MW-11B, 120 to140 ft bgs = interval with highest TCE concentrations at 171MW-11. Submitted 4 rock samples for VOC analysis Packering during drilling for vertical aquifer profiling (Color-Tec field analysis and quick TAT lab analysis) Geophysical logging at 171MW-11B (caliper, optical & acoustical televiewer, gamma, temp, and fluid conductivity logging) Lab hydraulic characterization of 3 rock samples Hydraulic packer testing of 171MW-11B boring Constructed and developed 171MW-11B (screened ft bgs) 171MW-12 was being constructed as of 9/2 meeting (screened ft bgs) September 2010 Meeting Conclusions

5 Well Installation Status Since September 2010 Meeting Completed construction & development of 171MW-12 Surveying of wells installed in March - September 2010 and collection of water levels in hot-spot area HydraSleeve sampling of new wells 171MW-11B & to 3- hr pump tests at 171MW-6, 171MW-6B, 171MW-6C, 171MW-8, 171MW-10, 171MW-10B (hotspot area) & 161MW-7 (central Mid-Valley) Step-test and 72-hr constant rate test at 171MW-6C Quarterly water level gauging being conducted in 2011 Upgradient delineation is complete. 5

6 Source Area Longitudinal Cross-Section March-April A A PICA /Mid-Valley Activities - Longitudinal X-Section Well screens sampled for VOCs via hydrasleeves and passive diffusion bags Rock coring All wells surveyed Multiple rounds of well gauging (new & existing wells) 171MW-11B New wells surveyed Aquifer Testing in Bldg 3109 Area Vertical aquifer profiling by packering during drilling (Color Tec & quick TAT lab) August October 2010 Activities 171MW-12 Hydrophobic dye testing at 110 ft bgs Vertical aquifer profiling by packering during drilling (Color Tec & quick TAT lab) Geophys logging to 120 ft bgs Rock coring & sampling for VOCs 120 to 140 ft bgs Hydraulic testing of packered intervals Geophys logging 0 to 200 ft bgs Well installation & development Geophys logging to 121 ft bgs Geophys logging to 170 ft bgs

7 [31 51] 6.99/ /10 A A PICA 204/Mid-Valley - Longitudinal X-Section SW [60 80] 272 [30 50] 72/125 04/10 [80 100] 171 [ ] 136 [ ] 141/104/ [29 39] /09 [ ] 182 [65 85] 1,580/1,930 01/ [38 58] 466/167 11/ [70 90] 1,310/871 [ ] 152 [ ] 83.4 [ ] 125 [ ] 117/55.9/ [ ] μg/l 100 μg/l [60 80] <1 [80 100] 1.73 [ ] 247 [ ] 406 [ ] 282/338/102 [ ] MW-11B Depth water first encountered (91.5 ) [ ] 6.00 [ ] 4.73 [ ] 269 / 3.43 [60 80] Groundw ater Sampling Interval (ft bgs) 466 Trichloroethene (TCE) (ug/l), HydraSleeve sample 871 TCE (ug/l), Passive diffusion bag sample 125 TCE (ug/l), Packer / Post-installation sample - Groundw ater Elevation (ft msl) 12/09 Sample Date 171MW-11B & -12 Installed 171MW-11B completes vertical delineation in source area [TCE] decreasing with depth Transmissive fractures ~134 ft bgs Slow recharge Slow recharge Pumped 0.3 gpm Pumped 0.3 gpm Pumped 0.5 gpm Pumped <0.5 gpm Insufficient recharge Pumped 2 gpm [ ] ND / ND Pumped 2 gpm Pumped < 1 gpm [40-60] ND [60-80] ND [ ] Not sampled Depth water first encountered (56 ) [80-100] ND [ ] ND [ ] ND [ ] ND [ ] ND NE 171MW MW-12 completes horizontal delineation along regional strike TCE ND

8 Conceptual Site Model Overview 8

9 Berkshire Valley Fault Picatinny Fault Green Pond Fault Site - Projected Bedrock Geologic Map of the Dover Quadrangle Morris County, NJ West East Site Mt. Hope Mine Conclusions: Regional-scale NE-SW trend in rock units Regional-scale NE-SW faults control surface water drainage and gw flow Rock units beneath site dip steeply to SE Scale in Miles Mt. Hope Mine and Mt. Hope Fault are major hydrogeo features within 1-mile of Site

10 Topographic Map with Site, Faults, and Mt. Hope Mine 710 msl 930 msl Taylor Fault Not Mapped by NJGS 950 msl Site El 950 msl Mt. Hope Mine drifts oriented along regional trend NE portion of Site plume oriented along regional trend, then heads west along fault 798 msl Mine Sump PWL = -170 msl in 1930 PWL = -1,870 msl in

11 Site Bedrock Characteristics Mapped as hypersthene-quartz-plagioclase gneiss of the Losee Metamorphic Suite (Volkert and Drake, 1999). Light-gray to tan weathering, green, gray, brown, medium-grained, moderately layered and foliated, gneiss (Volkert and Drake, 1999). Heterogeneous mixture of different metamorphic rock types, fractured, with zones of localized weathering along fractures 11

12 Site Outcrop Matrix 6 (n=0.02) Fracture (n=0.0001) 12 Photo taken along road east of Bldg 3109

13 Site Bedrock Characteristics Three different rock types shown Weathering on Fracture Walls Fractures Vein Pores in Matrix 6 Imagine the result

14 Bedrock Matrix Data Sample Location and Depth Bulk Density (g/cc) Porosity (% v/v) Hydraulic Conductivity (cm/sec) Total Organic Carbon (mg/kg) 171 MW-5 (37-38 ) <1 x MW-7 (42-43 ) <1 x MW-6 (38-39 ) <1 x 10-8 <100 Average <1 x Imagine the result

15 Bedrock Fracture Data 171MW-11 ( ) 171MW-10B (60-80 ) Example of Fracture Set 1 Example of Fracture Set 2 Fracture Spacing = 6.9 ft Fracture Spacing = 17.5 ft 171MW-6C (55-75 ) Example of Fracture Set 3 Fracture Spacing = 41 ft Imagine the result

16 Hydraulic Conductivity Testing Results 10-5 cm/s 10-3 cm/s Imagine the result Observation Wells

17 SW Average Fracture Spacing and Hydraulic Conductivity Results NE 10-5 cm/s 10-3 cm/s μg/l 100 μg/l Fracture Spacing (ft) Avg = Fracture Spacing (ft) Avg = Fracture Spacing (ft) Avg =

18 Diffusion Into the Rock Matrix Geochemical alteration in bedrock matrix along fracture wall Imagine the result 171MW-5 (19-20 )

19 SW Hot-Spot Longitudinal Cross-Section NE 10 μg/l 100 μg/l Q ~ 100 gpd* i = 0.01 Fracture Set 1 (Shallow Dip) Spacing = 7 ft * Ambient GW flux through target treatment zone.

20 NW Hot-Spot Transverse Cross-Section SE 3 1 Fracture Set 1 (Shallow Dip) Spacing = 7 ft Fracture Set 3 (Steep Dip) Spacing = 20 to 40 ft

21 Conceptual Site Model & Hydrogeologic Framework D D Downgradient TCE present in fractures and matrix Upgradient Φ fracture = 0.01% Φ matrix = 1.9% Area 2 Downgradient Weathered Bedrock K = 6.9 ft/d 171MW MW MW -10B [ / 125 (1/10) MW MW -6B 171MW -6C 171MW /09 1, ,480/ 1,930 (1/10) [ MW MW -11B 10 bgs Weathered rock [ / 167 (10/09) [ ,380/ 871 (10/09) 282 / 338 (4/10) [ (9/10) [ Area 3 Downgradient Bedrock K = 5.9 ft/d 141 / 104 (4/10) [ Area 1 Upgradient Bedrock K = 0.14 ft/d 117 / 55.9 (4/10) [

22 Fracture Spacing Discrete Fracture Fate and Transport Model Diffusion Rate is Governed by Fracture Spacing Matrix Chemical mass is stored in bedrock matrix Mass diffuses from bedrock matrix into the fractures Mass flux is approximated by Fick s First Law: Matrix F D c x Matrix Matrix Concentration gradient is controlled by fracture spacing Assumptions: Mass is distributed uniformly through matrix Concentration in fractures is zero (i.e., flushing through fractures is fast) Orthogonal fracture sets (i.e., cube shaped matrix blocks) 22

23 Hydrogeologic Model & Timeframe Estimation 23

24 Profile Along Robinson Run (TCE) D D 171MW MW -11B 171MW MW -6B 171MW -6C 171MW bgs Weathered rock 171MW MW MW -10B [ / 125 (1/10) /09 1, ,480/ 1,930 (1/10) [65-85 [ / 167 (10/09) [ ,380/ 871 (10/09) 282 / 338 (4/10) [ (9/10) [ / 104 (4/10) [ / 55.9 (4/10) [ Imagine the result

25 Conceptual Site Model & Hydrogeologic Framework D D Downgradient TCE present in fractures and matrix Upgradient Φ fracture = 0.01% Φ matrix = 1.9% Area 2 Downgradient Weathered Bedrock K = 6.9 ft/d 171MW MW MW -10B [ / 125 (1/10) MW MW -6B 171MW -6C 171MW /09 1, ,480/ 1,930 (1/10) [ MW MW -11B 10 bgs Weathered rock [ / 167 (10/09) [ ,380/ 871 (10/09) 282 / 338 (4/10) [ (9/10) [ Area 3 Downgradient Bedrock K = 5.9 ft/d 141 / 104 (4/10) [ Area 1 Upgradient Bedrock K = 0.14 ft/d 117 / 55.9 (4/10) [

26 Model Zones D D 171MW MW -11B 171MW MW -6B 171MW -6C 171MW bgs Weathered rock Area 2 Downgradient Weathered Bedrock K = 6.9 ft/d 171MW MW MW -10B [ / 125 (1/10) /09 1, ,480/ 1,930 (1/10) [65-85 [ / 167 (10/09) [ ,380/ 871 (10/09) 282 / 338 (4/10) [ (9/10) [ Area 3 Downgradient Bedrock K = 5.9 ft/d 141 / 104 (4/10) [ Area 1 Upgradient Bedrock K = 0.14 ft/d 117 / 55.9 (4/10) [

27 One-Dimensional Dual-Domain Model Concept Mobile domain Mass Transfer from immobile domain Flow through mobile domain Immobile domain 27

28 Two-Dimensional Single-Domain Discrete Fracture Model Concept Existing Contaminant Distribution up to 6 inches into the Matrix Space Matrix Space (multiple rows) Diffusion to and from Matrix Space Flow through Fracture Space Fracture Space (single row) 28

29 Parameters Area 1 Area 2 Area 3 Bedrock Zone Competent Weathered Competent Model Setup 2D singledomain 1D dualdomain 2D singledomain Approximated Zone Length (ft) Observed Fracture Spacing (ft) Modeled Length (ft) Modeled Width (ft) 7 N/A 2.5 Numerical Model Parameters Columns (no.) Rows (no.) 801 N/A 601 Fracture width (micron) 120 N/A 274 Measured Bulk Conductivity (ft/d) Modeled Bulk Conductivity (ft/d) N/A 6.9 N/A Matrix Conductivity (ft/d) N/A Fracture Conductivity (ft/d) 3,800 N/A 19,809 Fracture or Mobile Porosity (%) Matrix or Immobile Porosity (%) Hydraulic Gradient (ft/ft) Effective Diffusion Coefficient (cm 2 /sec) 9.60E-06 N/A 9.60E-06 Mass Transfer Coefficient (day -1 ) N/A 6.96E-05 N/A 29 Notes: 2D = two dimensional 1D = one dimensional N/A = Not Applicable

30 Concentration Profiles 30

31 Updated Remedial Timeframe Estimates Remedial Status Area-1 max conc (ppb) Approximate time to reach 1 ppb at respective downgradient (yrs) Area-1 Area-1A Area-1B Area-2 Area-3 Area-1 Area-2 Remedial Timeframe (yrs) Area-1B + Area-3 Maximum Time MNA Post-remediation MNA only - > 200 years Active Remedy in Area 1A 35 years This timeframe assumes that VOCs from the hot spot are cut off from being transported both horizontally and vertically 31

32 MNA Concentration Profile 32

33 Post-Remediation Concentration Profiles 33

34 Remedial Alternatives 34

35 Alternative 1 - MNA Implementation of LUCs Continued monitoring of CVOCs over time Estimated time to achieve remedial goals 200 yrs Estimated cost - $540,000 35

36 MNA Concentration Profile 36

37 Alternative 2 -Treatment Trench Fractured (blasted) trench near MW bgs, 100 long, 4-8 wide Cannot be in actual hot spot due to safety considerations (too close to active building) Trench will increase permeability, but not overall porosity (mobile porosity may increase from 0.01% to 0.2 %, but total porosity will still be ~2%) Can use the trench for: extraction, above ground treatment, and reinjection at opposite end of trench (creates a clean water flush) injection of EVO (create a reactive zone) 37

38 Alternative 2 Treatment Trench Extraction well Clean water injection well Monitoring well pair INTERMEDIATE WELLS 8 38

39 Alternative 2 Treatment Trench D D Blasted Trench 171MW MW -6B 171MW -6C 171MW MW -11B 171MW bgs Weathered rock Area 2 Downgradient Weathered Bedrock K = 6.9 ft/d 171MW MW MW -10B [ / 125 (1/10) /09 1, ,480/ 1,930 (1/10) [65-85 [ / 167 (10/09) [ ,380/ 871 (10/09) 282 / 338 (4/10) [ (9/10) [ Area 3 Downgradient Bedrock K = 5.9 ft/d 141 / 104 (4/10) [ Area 1 Upgradient Bedrock 117 / 55.9 (4/10) [ Still K = 0.14 allows ft/d vertical flow of VOCs

40 Alternative 2 Concentration Profile Timeframe governed by Area 1a, like MNA 40

41 Alternative 2 Treatment Trench (cont d) Intercepts/treats flow to Robinson Run Zone 2 also cleans up quickly Time to achieve remedial goals 200 yrs (downgradient shallow flow is treated, but downward flow through hot-spot continues to affect groundwater quality). Estimated cost - $2,500,000 assumes 200 yrs of O&M to meet remedial goals 41

42 Alternative 3 Pump & Treat Hot-spot containment with 5 extraction wells 4 diameter, 100 -deep wells, open boring Vertical groundwater flux through hot-spot ~1.25 gpm Pump at 0.25 gpm/well (based on aqf test results) Downgradient capture of diffuse plume with 5 extraction wells 4 diameter, 100 -deep wells, screened bgs Groundwater flux across 150 x 50 thickness ~10 gpm Pump at 2 gpm/well (based on aqf test results) Downgradient injection into 7 wells 4 diameter, 100 -deep wells, screened bgs Located ~100 downgradient from extraction line 42

43 Alternative 3 - Pump and Treat 5 hot-spot extraction wells, 200-ft deep 0.25 gpm/well (1.25 gpm total) 5 downgradient extraction wells, 150-ft deep, 2 gpm/well (10 gpm total) 7 downgradient injection wells, 100-ft deep, 2 gpm/well (11.25gpm total capacity) Extraction well Clean water injection well Monitoring well pair INTERMEDIATE WELLS 8 43

44 Alternative 3 Pump & Treat D D Hot-Spot Extraction 171MW MW -11B Downgradient Extraction Downgradient Treatment & Re-Injection Area 2 Downgradient Weathered Bedrock K = 6.9 ft/d 171MW MW MW -10B [ / 125 (1/10) MW MW -6B 171MW -6C 171MW /09 1, ,480/ 1,930 (1/10) [ bgs Weathered rock [ / 167 (10/09) [ ,380/ 871 (10/09) 282 / 338 (4/10) [ (9/10) [ Area 3 Downgradient Bedrock K = 5.9 ft/d 141 / 104 (4/10) [ Area 1 Upgradient Bedrock K = 0.14 ft/d 117 / 55.9 (4/10) [

45 Alternative 3 Concentration Profiles 45

46 Alternative 3 Pump & Treat (cont d) Hot-spot mass is contained Intercepts/treats flow to Robinson Run Time to achieve remedial goals 35 yrs, assuming continued source control Infrastructure costs and O&M costs into the future Estimated cost - $2,800,000 assumes 35 yrs of O&M to meet goal longer-term O&M not costed, but will be necessary to maintain the clean water front 46

47 Alternative 4 ERD Biennial gravity injection of emulsified vegetable oil (EVO) designed for fractured bedrock (SRS-FR, with lecithin) Hot-spot treatment 6 injection wells 4 diameter, 120 -deep, open boring Downgradient shallow injection line 6 injection wells 4 diameter; screened bgs (stainless steel, wire wrapped) Downgradient deep injection line 6 injection wells 4 diameter; cased to 100 bgs, open hole bgs 47

48 Alternative 4 ERD 6 hot-spot shallow inj wells Arranged in 2 lines Inject across 120-ft open-hole 30-ft spacing 6 downgradient deep inj wells, Inject ft bgs 30-ft spacing 6 downgradient shallow inj wells, Inject ft bgs 30-ft spacing Shallow Injection well Deep Injection well Monitoring well pair INTERMEDIATE WELLS 8 48

49 Alternative 4 ERD D D Downgradient Shallow & Deep Injection Lines Area 2 Downgradient Weathered Bedrock K = 6.9 ft/d Hot-Spot Injection Lines 171MW MW MW -10B [ / 125 (1/10) MW MW -6B 171MW -6C 171MW /09 1, ,480/ 1,930 (1/10) [ MW MW -11B 10 bgs Weathered rock [ / 167 (10/09) [ ,380/ 871 (10/09) 282 / 338 (4/10) [ (9/10) [ Area 3 Downgradient Bedrock K = 5.9 ft/d 141 / 104 (4/10) [ Area 1 Upgradient Bedrock K = 0.14 ft/d 117 / 55.9 (4/10) [

50 Alternative 4 Concentration Profiles 50

51 Alternative 4 ERD (cont.) Hot-spot mass is treated Intercepts/treats flow to Robinson Run Simpler maintenance/operation than P&T Time to achieve remedial goals 35 yrs Estimated cost - $1,800,00 assumes 35 yrs of O&M to meet goal 51

52 Next Steps Preparation of FS Addendum July 2011 Addresses Southern TCE plume FS Addendum Contents CSM Hydrogeologic Model & Timeframe Estimation Evaluation of Remedial Alternatives No Action MNA Treatment Trench Pump & Treat ERD 52