Can You Be More Selective With Potable Groundwater Production and Contaminant Extraction?

Transcription

1 Can You Be More Selective With Potable Groundwater Production and Contaminant Extraction? By Potable Water Supply Wells Groundwater Pump and Treat Noah Heller, MS PG (CA 5792) President, BESST, Inc. 50 Tiburon Street, Suite 7 San Rafael, CA Office: Mobile: nheller@besstinc.com New BESST Partner Office: Field Data Solutions Houston TX, Office Contact: Mitchell Brourman President Mobile: mbrourman@fielddatasolutions.com

2 Dr. John Izbicki 120 Peer Reviewed Articles Lead Author 90 Papers Recipient of California Groundwater Resources Association Lifetime Achievement Award Inventor of Dye Tracer 2

3 Some Reasons for Profiling Groundwater Production Wells Helping Disadvantaged Communities Treatment Avoidance (Independent Well Modification) Treatment Reduction (Synergistic Well Modification) New Well Failure (Water Quality and Sanding): Pilot hole results do not match New Well Results. Cannot supply water from new well! Focused Rehabilitation (reduce cost focus where it matters) Well Repair (finding leak points) Rehabilitation Audits (Before and After) Groundwater Exploration (Siting Drilling Locations) Well Field Expansion (Community Growth Plans) Hydraulic Well Field Management (Zonal Hydraulic Conductivity) Well Replacement (first fix a stranded asset) Blending Studies (hydraulically manipulate screen intervals with surface blending) Water Rights and Litigation (no subsurface barriers below political boundaries) Desalination (1,001 mg/l) Aquifer Storage and Recovery (injection versus extraction) Water Banking (where does water go)

4 Some Reasons for Profiling Temporary Long Screened Monitoring Wells Reduce Superfund and Overall Site Investigation and Remedial Action Costs Can Investigate Site with Fewer Boreholes Fewer Groundwater Monitoring Wells BIG TOPIC!!!! Groundwater Sample Results Are Flow Weighted (NOT WELL AVERAGE) Treatment Optimization and Reduction Reduce Treatment O&M and Waste Stream Production Shorten Site Life Cycle

5 : BESST Groundwater Database = 1 10 Production Wells Profiled by BESST Arsenic, Nitrate, Mn, Fe, Bacteria, PCE PCE, TCE, Nitrates, Manganese Some Drivers: Drought Ground Water Quality Increasing Land Cost Population Growth Demand for Cash Crop Agriculture >700 Municipal Production Wells Profiled Since 2005 Largest Stratified, Dissolved Aqueous Phase Geochemistry Data Base in California for Production Wells Nitrates, Arsenic, TDS, Boron Nitrates, Manganese, Boron Arsenic, Flouride As, Nitrate, TDS, Uranium, NaCl, TCE, PCE, Perchlorate, Fe, Mn, Bacteria Hex Chrome, Arsenic, Uranium

6 Nevada

7 Texas Arizona Field Data Solutions Houston, TX Office New BESST Partner 2016

8 Application of Tracer Technology Groundwater Production Wells

9 COST versus Technology Apparatus Size versus Rate of Groundwater Profiling Growth (Affordability) $250,000 $200,000 $150,000 Cost Comparison / Well Profiling Technolgies cost Service growth $100,000 $50,000 $0 Low High Low High Low High Straddle Packer Spinner Log Miniaturized Tracer Largest Tools Time Smallest Tools As profiling tools get smaller and wells more accessible, profiling cost decreases

10 Well Access and Incrementally Tiered Access Survey

11 Pump Pedestal (Block) Coring Portable drill is adjustable to various angles and is mounted directly to pedestal. First core hole attempt on north side of 20 inch well (with 14 bowls) found less than ¾ annular clearance with pump column. Core hole was drilled at 5 Degree angle from vertical and at 1.5 in diameter. Pedestal Core Elliptical Piece of Metal From Outer Casing generated from steep angle core hole. Core Hole # 2 was successful and found 5+ inches of annulus on south side of well. Approximate drill time for each of the core holes (1 st attempt north side of well and 2 nd attempt (successful) on south side of well was 2.5 hours per hole. Coring cost was about $125 / hr. The core hole was temporarily lined with a section of PVC pipe to protect the tracer hose from scraping and tearing against any rough surfaces within the hole.

12 Lift and Shift No Access Pipe(s)

13 Remove Primary Pump and Reinstall With Test Pump and Access Pipe(s)

14 Tracer Technology

15 Flow and Water Chemistry Profiling are volumetric and chemical mass balance accounting systems Think about a river with blue ping pong balls! Incremental Flow Contribution T 3? Cumulative Flow Contribution Q 2 T 1? Q 1 Cumulative Flow Contribution Incremental Flow Contribution T 2? Cumulative Flow Contribution Q 4 Q 3 Cumulative Flow Contribution Q 5 Cumulative Flow Contribution T 4? Incremental Flow Contribution

16 Cumulative Flow Can Be Defined As Q 1 = V 1 x A 1 V 1 = (d 1 -d 2 )/(t 1 -t 2 ) A1 = r 2 Flow From Well To Fluorometer Fluorometer Incremental Flow Can Be Defined As Q 1 Q 2 When we subtract Q 2 from Q 1, we get the incremental flow (IF or GPM) contribution between the two measured injection points No Flow Contribution No Flow Contribution GPM Distribution Dynamic Flow Profile Under Steady State Draw-Down Dye Injection Shot Points Ft. Below Ground Surface Flow From Fluorometer To Waste Cumulative Flow Q 1 Q 2 Q 3 Q 4 Q 5 Q 6 Q 7 Q 8 Q 9 Q 10 Q 11 Q 12 Q 13 Q 14 Q 15 Q 16 Q 17

17 Flow Weighting Water Chemistry Water Sampling Spool Dye Injection Spool Average Cumulative Contaminant Concentration Can Be Defined As Ca 1 = (Q 1 C 1 Q 2 C 2 )/(Q 1 -Q 2 ) Incremental Average Contaminant Concentration between two imaginary flow planes within the well can be expressed No Contaminant Contribution No Contaminant Contribution Dynamic Groundwater Sampling Under Steady State Draw-Down Groundwater Sampling Points Ft. Below Ground Surface Cumulative Concentration Ca 1 Ca 2 Ca 3 Ca 4 Ca 5 Ca 6 Ca 7 Ca 8 Ca 9 Ca 10 Ca 11 Ca 12 Ca 13 Ca 14 Ca 15 Ca 16 Ca 17 Well Vent Tube

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21 Packer Case History Pump Column 10 (2/11/2010) Well #26 Geologic Log and BESST Dynamic Flow Contribution Profile 500 BESST Dynamic Flow Profile Pumping Rate: 849 GPM Pumping Water Level: 340 Screen Interval: , , , , , ft 650 ft 660 ft Clay Sand and Clay Clay 655 ft 715ft Percent of Total (%) 10% 20% 30% 40 % 50% 11.4% ft Brown Clay 745 ft 785 ft 22.1% ft 900 ft 930 ft Blue Clay Clay Sand & Clay 825 ft 870 ft 890 ft 920 ft 960 ft 1010 ft 31.6% 1.6% 11.4% ft 1075 ft 1150 ft Clay 21.8% ft Sand & Clay 16 Casing ID *Not to scale 1190 ft 1200ft Calculated percent of flow distribution from intervals. Average pumping rate: 849 gpm (2/11/10) 21

22 Sampling Intervales (ft. bgs) 16 Casing ID Pump Column: ft 655 ft 715ft 745 ft 785 ft 825 ft As Sample Depth (ft bgs) Chemical Mass Balance Analysis: Arsenic Screen Interval (ft bgs) Cumulative Flow Per Screen Interval (GPM) Incremental Flow Per Screen Interval As Measured Concentratio n (From Lab) CnQn CnQn- Cn+1Qn+1 Incremental Flow Mass Balance As Incremental Concentratio n % Predicted Discharge Average Spigot 1 Cumulative Spigot 2 Cumulative Casing ID 870 ft 890 ft 920 ft 960 ft 1010 ft 1075 ft 1190 ft below Dynamic Chemical Profile: Well 26 2/11/ GPM Arsenic µg/l

23 Screen Interval (ft. bgs) Well 26: Estimated Arsenic Distribution By Screen Interval Blocking Off 3 rd, 4 th and 5 th Screen From Top Of Well Predicted Discharge Average Sample Depth Screen Interval Cumulative Flow Per Screen Interval Incremental Flow Per Screen Interval Measured Concentration (From Lab) CnQn CnQn- Cn+1Qn+1 Mass Balance Incremental Incremental Flow Concentration GPM 55% of 849 GPM Spigot 1 Cumulative Spigot 2 Cumulative The hypothetical scenario presented represents a worse case scenario in terms of estimated maximum production loss from well. Feasibility testing is recommended to determine hydraulic compensation yield from unblocked zones Dynamic Arsenic Profile: Well GPM As ug/l

24 Packer Test Scenario #1 Packer Test Scenario #2 Potential Strategies for a Feasibility Test: Goal: To Produce Less Arsenic at Discharge and Hydraulically Compensate for Groundwater Production Lost From Blocked Zones (red)

25 Side Stream Treatment Before Modification 12 ug/l As 50%/50% US EPA MCL = 10 ug/l Solution For Synergistic Well Modification Treatment 6 ug/l As ND As 12 ug/l As Distribution 25

26 HYDRAULIC MANIPULATION USING PACKER: See Next Page For Plot of Nitrate Reduction with Time For This Southern, California Well: Inflatable Packer Hydraulic Manipulation of Production Well Courtesy General Pump, Inc., San Dimas, CA & Clear Creek Associates, Scottsdale, AZ 26

27 HYDRAULIC MANIPULATION Nitrate City of Ontario 43 Plot Of Nitrate Reduction Versus Time for Southern California Well (Continued): HYDRAULIC MANIPULATION USING PACKER: Plot of Nitrate Reduction with Time in a Southern, California Well: 41 Nitrate Concentration /15/03 11/05/03 11/26/03 12/17/03 01/07/04 01/28/04 02/18/04 03/10/04 03/31/04 04/21/04 05/12/04 06/02/04 06/23/04 07/14/04 08/04/04 08/25/04 09/15/04 10/06/04 10/27/04 11/17/04 12/08/04 12/29/04 01/19/05 02/09/05 03/02/05 03/23/05 04/13/05 05/04/05 05/25/05 06/15/05 07/06/05 07/27/05 08/17/05 09/07/05 09/28/05 10/19/05 11/09/05 11/30/05 12/21/05 01/11/06 02/01/06 02/22/06 03/15/06 04/05/06 Packer Inflated Water sampe during aquifer testing, packer installed, on August 10 & 11, 2004 showed a nitrate drop from 41 to 36 ppm, which continued down to less than 29. Date Courtesy General Pump, Inc., San Dimas, CA & Clear Creek Associates, Scottsdale, AZ 27

28 Zonal Profiling During or After Pump Tests Rules, Recommendations and Insights: 1. Zonal flow profiling assumes dynamic steady state condition. 2. Can be performed during or following pump test. 3. If performed following pump test, then dynamic profile must be performed at same pumping rate as pump test. 4. Use of zonal profiling during or following pump test provides estimate of hydraulic conductivity. 5. Can be performed with primary pump or test pump. 6. Recommend that pump intake depths are the same when dynamic zonal test is performed following pump test. 7. Estimates may be skewed in wells lacking recent rehab; however data may still be very useful on a relative basis and provide clues concerning sections of gravel pack clogging.

29 Using Pump Test and Zonal Flow Results To Calculate Estimated Zonal Hydraulic Conductivity From Production Wells K FM,i K = Q i / Q p b i / B Molz et. al 1989 and 1994 K Q p B Q i = Average hydraulic conductivity from well pump test = Average pumping rate from well = Screened thickness of aquifer = Discharge measured within the i-th sampling interval of vertical thickness b i K FM,i = Estimated value for the hydraulic conductivity representative of the i-th vertical interval 29

30 K FM,1 K FM,1 K FM,1 K FM,2 K FM,2 Compelling Application: K FM,3 K FM,2 K FM,3 Well Field Design, Expansion, Management K FM,3

31 Application of Tracer Technology To Temporary Long Screened Wells

32 Precedents for Long Screened Wells Multi-Screened Support Wells for Westbay Waterloo FLUTe ZIST 32

33 Examples of Multi Level, Long Screened Monitoring Wells Water Filled Borehole Grout Seal Grout Seal Support Casing Bentonite Seal Filter Pack Support Screen Nested Backfill Basin Sediments and Bedrock ZIST and Barcad BESST, Inc. Pipe and Packer Basin Fill and Bedrock Waterloo System Solinst Pipe and Packer Basin Fill and Bedrock Westbay System Westbay Everted Liner Basin Fill and Bedrock FLUTe System FLUTe 33

34 SimulProbe Crust Buster Depth Discrete Groundwater Sampling: Combined With Depth Dependent Dynamic Flow Measurements And Co-Located Groundwater Sampling Ohm m

35 Investigative Phase Using SimulProbe Crust Buster and Mud Rotary Sliding Drive Shoe Assembly Identify Cuttings Factoring in borehole-return lag time. Prepare SimulProbe Assemble SimulProbe using plumbers pipe tripod. Pressure test Probe before deployment. Pressurize Probe and move to rig. Swing and position Probe over borehole.

36 Lower Probe To Bottom of Borehole Mark Drive Distance on Drill Rod Install smash plate and then swing 5,000 lb. air or 6,000 lb. hydraulic hammer into position

37 Conventional Backfill Zone Test (BFZT) Method Review Advance Borehole Resistivity and Log Cuttings Geophysics Ohm m BFZT (Method 1) Four Depths Zone 1 Zone 2 14 Hole Zone 3 Zone 4 Bentonite Seal

38 Profiling Temporary Long Screened Wells Multiple Pump Intake Location Surveys: Injection and Sampling Plans Pump Intake Location 1 Steady State Profile #1 Legend: Steady State Profile #1 Pump Intake Location 2 Steady State Profile #2 Injection Point 50 ml Rhodamine Red FWT 50 Pump Intake Location 3 Steady State Profile #3 Groundwater Sampling Location

39 Cumulative Flow Can Be Defined As Q 1 = V 1 x A 1 V 1 = (d 1 -d 2 )/(t 1 -t 2 ) A1 = r 2 Incremental Flow Can Be Defined As Q 1 Q 2 When we subtract Q 2 from Q 1, we get the incremental flow (IF or GPM) contribution between the two measured injection points No Flow Contribution No Flow Contribution GPM Distribution Dynamic Flow Profile Under Steady State Draw-Down Dye Injection Shot Points Ft. Below Ground Surface Cumulative Flow Q 1 Q 2 Q 3 Q 4 Q 5 Q 6 Q 7 Q 8 Q 9 Q 10 Q 11 Q 12 Q 13 Q 14 Q 15 Q 16 Q 17

40 ft bgs Example Profile From Long Screened Monitoring Well Incremental groundwater contribution (%) by zone: pump set at 271±1 ft bgs % Contribution Pump below 317

41 ft bgs Incremental groundwater contribution (%) by zone: Pump set at 296 ft bgs % Contribution Pump below 322

42 ft bgs Incremental groundwater contribution (%) by zone: Pump at 308 ft bgs % Contribution Pump below 322

43 Flow Weighting Water Chemistry For Long Screened Monitoring Wells Average Cumulative Contaminant Concentration Can Be Defined As Ca 1 = (Q 1 C 1 Q 2 C 2 )/(Q 1 -Q 2 ) Incremental Average Contaminant Concentration between two imaginary flow planes within the well can be expressed No Contaminant Contribution No Contaminant Contribution Dynamic Groundwater Sampling Under Steady State Draw-Down Groundwater Sampling Points Ft. Below Ground Surface Cumulative Concentration Ca 1 Ca 2 Ca 3 Ca 4 Ca 5 Ca 6 Ca 7 Ca 8 Ca 9 Ca 10 Ca 11 Ca 12 Ca 13 Ca 14 Ca 15 Ca 16 Ca 17

44 2005 Britt Study Tells Us That even the slightest ambient vertical gradient inside of monitoring wells causes in-well smearing! Injected From Middle From: S.L. Britt/ Ground Water Monitoring & Remediation 25, no. 3: Observation: Study shows that what is outside the pipe is not the same as inside the pipe. Question: Therefore, does passive and active grab sampling tools and methods force industry into overestimating cost and scale for contaminant treatment? 44

45 1. The Problem With Monitoring Wells In General is that Grab Samplers and Low Flow Sampling Does Not Always Differentiate Between What is Inside the Pipe versus Outside the Pipe! 2. They may be similar to each other inside the pipe, but not similar to vertical distribution outside the pipe. 3. Both provide composite samples inside the pipe but not flow weighted distribution of contamination outside the pipe. 45

46 µg/ µg/ Concentrations Measured At Depth: Well GPM 9/14/2011 TCE 3.8 Inside Well Cumulative Non Flow Weighted WELL 1 WELL below 710 Sampling Intervals No locations above MCL Supply Well BEFORE: Non Flow Weighted Concentrations Measured At Depth: Mill St Well 1420 GPM 10/5/10-10/6/10 PCE Supply Well AFTER: Flow Weighted PUMPING Outside Well Flow Weighted Zonal Dynamic Mass Balance Profile: Well GPM 9/14/2011 TCE Only location above MCL below Sampling Intervals Dynamic Mass Balance Profile: Mill St Well 1420 GPM 10/5/10-10/6/ PCE