Top Banner

Click here to load reader

Characterizing Contaminant and Water Fluxes in Contaminant and Water Fluxes in Fractured Rock Systems ... FRPFM packer or inflating fluid ... Selection of Sorbents and Resident Tracers

Mar 13, 2018

ReportDownload

Documents

hoangngoc

  • Characterizing Contaminant and Water Fluxes in Fractured Rock Systems

    GQ 2013

    Kirk Hatfield University of Florida

    April 25, 2013

    ESTCP Project ER0831

  • Project Technical Objectives

    The objective of this ESTCP project is to demonstrate and validate the fractured rock passive flux meter (FRPFM) as an innovative closed-hole technology. Specific project objectives are:

    1. Demonstrate and validate an innovative technology for the

    direct in situ measurement of cumulative water and contaminant fluxes in fractured media

    2. Formulate and demonstrate methodologies for interpreting contaminant discharge from point-wise measurements of cumulative contaminant flux in fractured rock

  • Technology Description

    Unfractured Bedrock

    Ground Surface

    Water Table

    Fracture planes and flow directions

    FRPFM packer or inflating fluid

    FRPFM impermeable flexible liner and attached sorbent layer

    Flow through matrix blocks

    Unfractured Bedrock

    Ground Surface

    Water Table

    Fracture planes and flow directions

    FRPFM packer or inflating fluid

    FRPFM impermeable flexible liner and attached sorbent layer

    Flow through matrix blocks

    Packer minimizes vertical cross-flow between fractures

    FRPFM Packer Design

  • Technology Description

    The FRPFM is essentially an inflatable packer or impermeable flexible liner that holds a reactive permeable fabric against the wall of the borehole and to any water-filled fractures intersected by the borehole.

    Reactive fabrics capture target contaminants and release non-toxic resident tracers (e.g., visible dyes and branch alcohols).

    Tracer loss is proportional to ambient fracture flow.

    Leached visible tracers reveal location and orientation of active fractures and flow direction.

    Contaminant mass captured is proportional to ambient contaminant flux.

  • Inflatable Packers

    Nominal 4-inch

    Diameter Borehole

    Inflatable Core with mesh 5 mm Sorbent (AC Felt 2.5 mm) K =0.08 m/d

    Sock with visual tracer

    Air line to packers Air line to core

    Inflatable Shield-Packer

    FRPFM Shield

    Air line to shield-packer

    Accelerometer

    FRPFM Prototype with Shield

    Dimensions Borehole ID = 3.8 in (9.652 cm) Nominal 4 in borehole Un-Inflated Dimensions Shield packer OD = 3.5 in Shield OD = 3.5 in Packer OD = 3.3 in Core OD = 3.2 in (with sorbent and sock) Note: When inflated all dimensions match borehole ID

  • Selection of Sorbents and Resident Tracers Suite of Non-toxic Branched Alcohols

    Batch Tracer Sorption Isotherms on Felt 1300

  • Laboratory Fracture Simulator

    Fracture Dimensions: Horizontal Aperture = 500 m Width = 26 cm Length = 53 cm Conductivity ~0.7 cm/s

    Borehole: Diameter 10.16 cm

    Flow Convergence: Maximum = 1.76

  • Flow Front

    Up Gradient

    Left

    Right

    Back Down Gradient

    Visual Tracer Reveals Fracture Location and Orientation and Flow Direction

    Front Up Gradient

    Back Down Gradient Left Right

    0.5 mm fracture aperture Q = 1.5 ml/min, q = 2500 cm/day Duration 1 day Visual fracture zone (max) aperture 4 mm Visual fracture zone length along circumfrance147 mm

    4 mm

    Visual indication of flowing fracture

    FRPFM Performance in the Laboratory

  • Visible Tracer Elution Patterns

    Dyed fabric

    AC-felt

    metal mesh

    Water

    Tracer Front Streamlines

  • 0

    40

    80

    120

    0 40 80 120

    CumulativeContaminantFlux

    Measured Flux [ mg/cm2 ]

    True Flux [ mg/cm2 ]

    Cumulative Contaminant Flux

    0

    2000

    4000

    6000

    8000

    0 2000 4000 6000 8000

    Cumulative WaterFlux

    True Flux [ cm ]

    FRPFM Performance

    Measured Flux [ cm ]

    Cumulative Water Flux

  • Large Aquifer Box (High contrast flow zones)

    Flow

    Screened Wells (4-inch diameter PVC)

    Alternating Sand and Gravel Layers

    Box Dimensions (length x width x height)

    2.0 x 0.5 x 1.3 m

  • Visual Indication of Flow

  • FRPFM Results in Aquifer Box

  • NAWC Site (West Trenton, NJ)

  • NAWC Site (West Trenton, NJ)

  • Site Description Former Naval Air Warfare Center (NAWC), West Trenton, NJ

    (High flow zones will be used to facilitate remediation)

    Former jet engine testing facility TCE, DCE, and VC Pump and Treat Operations

    Site is well characterized Bedded fractured Mudstones High to low bulk conductivity Exposed Outcrop

    Can leverage project ER1555

  • 0

    10

    20

    30

    40

    50

    60

    70

    80

    90

    100

    110

    120

    130

    140

    150

    160

    170

    10 100 1,000 10,000 100,000 1,000,000 10,000,000

    TCE (ppb)

    Dep

    th B

    LS (f

    t)

    PumpedSamples

    CoreSamples

    A

    B

    C

    D

    E

    F

    Figure 11. Bulk concentration of TCE from samples of rock core taken from 68BR as a function of depth are shown in comparison to the concentrations of TCE from water samples collected from the 6 monitoring intervals in 68BR (A, B, C, D, E, F). (Shapiro SERDP Project ER-1555: Annual Report 2008)

    NAWC Site: Well 68-BR TCE concentrations

    FRPFM tests to date all in Zone D

  • Fracture Rock Passive Flux Meter (FRPFM)

    Shield Packer

    Accelerometer Weight

    Stainless Steel Shield

  • NAWC Site (West Trenton, NJ)

    Figure 7. Location of selected monitoring boreholes at the former Naval Air Warfare Center, West Trenton, NJ. (Shapiro SERDP Project ER-1555: Annual Report 2008)

    FRPFM test well 68BR

    Groundwater Flow Direction

    Pumping well 15BR

  • NAWC Site: Borehole BR-68 target depth 95 ft-bgs

    Bottom

    0 090 180 270 0

    20

  • Black and White picture of the traces Traces with

    Centroids

    Yields: Flow Direction

  • Black and White picture of the traces

    Traces with Fitted Sine Functions

    Yields Trace: Depth Dip Orientation

  • Histograms of Fracture Depth, Dip, Orientation and Centroid angles

    Depth Dip Orientation Centroid Angles

  • Borehole Dilution (BHD) Probe

    Top Packer

    Bottom Packer

    Flow Return Line

    Variable Speed Submersible Pump

    BHD Probe is assembled so that the interrogation zone (1 m) matches that of FRPFM

  • 0 4 891

    92

    93

    94

    95

    960 20 40 60 80

    Specific Discharge (cm/day) D

    epth

    Bel

    ow G

    roun

    d Su

    rfac

    e (ft

    )

    Mass Flux (ug/cm2/day)

    TCE DCE

    Specific Discharge PRE-BHD

    POST-BHD

    Comparisons with Independent Field Measurements

    FRPFM BHD USGS

    q (cm/d) 2.6 2.9 (2.2-3.6)

    TCE Cf mg/l 5.5 6.9 (4-9.8) 10.8

    DCE Cf mg/l 2.7 1.7 (1.7-1.7) 3.1

    Top

    Bottom

  • Project Team

    University of Florida: Michael Annable, Harald Klammler, Mark Newman, Jaehyun Cho, Bidhya Yadav, and Ozlem Acar University of Guelph: Beth Parker, John Cherry, Pete Pehme, Patryk Quinn, Ryan Kroeker, and Bassel Nemer

  • Questions?

    Characterizing Contaminant and Water Fluxes in Fractured Rock SystemsProject Technical ObjectivesTechnology DescriptionTechnology DescriptionSlide Number 5Selection of Sorbents and Resident TracersSuite of Non-toxic Branched AlcoholsSlide Number 7FRPFM Performance in the LaboratorySlide Number 9Slide Number 10Large Aquifer Box (High contrast flow zones)Visual Indicationof FlowSlide Number 13NAWC Site (West Trenton, NJ)NAWC Site (West Trenton, NJ)Site DescriptionSlide Number 17Fracture Rock Passive Flux Meter (FRPFM)NAWC Site (West Trenton, NJ)Slide Number 20Slide Number 21Slide Number 22Slide Number 23Borehole Dilution (BHD) ProbeSlide Number 25Project TeamSlide Number 27

Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.