Vertex Environmental Inc.

Transcription

1 Vertex Environmental Inc. Case Study: Innovative Use of the MIP and LIF to Direct In-Situ Remediation RPIC Conference Toronto, ON May 1, 2012 Bruce Tunnicliffe

2 Agenda Vertex Background Subsurface Impacts Laser Induced Fluorescence Technology Overview Membrane Interface Probe Technology Overview Case Study Questions

3 Vertex Background Environmental Contracting Provider of technology, expertise, injection services Clients are consultants Consultant: Phase II ESA Vertex: Remedial Design, Remediation (bench, pilot, full-scale)

4 Subsurface Impacts Is there a difference between contaminant distribution in the subsurface and site measurements we collect? Source EPA (1996)

5 Free Product Delineation Install monitoring well (MW), collect a NAPL thickness measurement Estimate NAPL thickness in aquifer Various Techniques: Method of de Pastrovich (1979) Method of Hall, et al. (1984) Method of Ballestero et al. (1994) Method of Schiegg. (1985) Method of Lenhard and Parker (1990) Uncertainties associated with: single NAPL measurement assumptions in models geology, NAPL distribution Source EPA (1996)

6 Free Product Delineation Experiment in EPA document: Diesel spill in a column containing a MW Five spills, same volume Thickness in MW ranged from 6 cm to 84 cm Using EPA estimation methods: Data from: EPA Guide for State Regulators How to Effectively Recover Free Product at Leaking Underground Storage Tank Sites (Sept 1996). Method Avg. Product in MW (cm) Predicted Product Thickness in Formation (cm) Ballestero Pastrovich Schiegg cm to 105 cm thickness = 525 times difference Hall Lenhard & Parker Lenhard & Parker

7 Advanced Characterization Better Characterization = Better Remediation Laser Induced Fluorescence (LIF) Free Phase / Free Product / NAPL Membrane Interface Probe (MIP) Dissolved Phase

8 Advanced Characterization Laser Induced Fluorescence (LIF)

9 Laser Induced Fluorescence Spectroscopy molecules absorb light (gain energy) and then emit light (lose energy = fluoresce) Aromatic molecules (PAHs) readily absorb and emit light kerosene gasoline diesel oil UVOST (Ultra Violet Optical Screening Tool) Equipment: UV light, fibre optic cable, sapphire window, direct push rig

10 Laser Induced Fluorescence

11 Laser Induced Fluorescence naphthalene pyrene phenanthrene benzo[e]pyrene

12 Clean Sand 350 ppm 1,100 ppm 10,000 ppm 84,000 ppm Gasoline

13 Example LIF Output Orange and red coloring = heavier NAPL

14 Advanced Characterization Membrane Interface Probe (MIP)

15 Membrane Interface Probe Nitrogen Carrier Gas VOCs to Detector Dissolved phase: Depth Relative conc. Lithology Probe Body VOCs in Soil Semi-permeable Membrane

16 Membrane Interface Probe Membrane Heater Block

17 Contaminant Distribution MIP Pre-Injection MIP Post-Injection Source: Chemco

18 Case Study Significant fuel loss at Site Estimated 19,000 L of fuel lost to ground Security camera set up to catch unauthorized and/or unscheduled fuelling No fuel stolen, all NAPL leaking to subsurface Excavation completed fire during dig Remediation system installed After time: <1 cm of NAPL in wells ISCO (In-Situ Chemical Oxidation) LIF to confirm no NAPL present MIP to examine dissolved distribution

19 Case Study Former Fueling Area Highest Groundwater Concentrations

20 Case Study LIF Results No NAPL detected

21 Case Study Results No NAPL identified Strategic locations targeted with high probability of free phase ISCO could safely commence MIP delineation Contract defined with set oxidant loading per vertical m MIP used to better define dissolved phase PHCs Injection re-designed to target vertical zones of dissolved phase contamination

22 Case Study MIP Investigation

23 Case Study MIP Results Dissolved phase plume 3 m to 11 m below ground

24 Case Study MIP Results North MIP Cross Section

25 Case Study MIP Results North MIP Cross Section

26 Case Study MIP Results South MIP Cross Section

27 Case Study MIP Results South MIP Cross Section

28 Case Study Re-Design of ISCO based upon MIP MIP logs: Majority of impacts 3 m to 11 m bgs Oxidant loading per m redesigned Oxidant mass and budget kept the same Original Design: Average of 29.6 kg/m from 3 m bgs to 23 m bgs (Heavily Impacted Area) Re-Design: Increased some zones to 44 kg/m oxidant loading Decreased some zones to 19 kg/m

29 Oxidant Loading Rates Original Design (kg/m) Re-Design (kg/m)

30 Case Study ISCO redesign accepted by client ISCO injection program commenced Second round of MIP completed assess changes in the dissolved phase plume

31 MIP Results Before ISCO Black Line May 13/2011 Before ISCO After ISCO Green Line Sept 27/2011 After ISCO

32 JHL-2-II

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34 R3

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36 ECO-1

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38 Case Study Average PHC groundwater reduction across Site = 96% Laser-Induced Fluorescence safe commencement of ISCO Membrane Interface Probe ISCO re-design Intelligent use of Advanced Characterization tools resulted in excellent in-situ treatment

39 Closing Laser-Induced Fluorescence (LIF) Excellent to define free phase, horizontally and vertically Membrane Interface Probe (MIP) Dissolved phase Both tools can be used to enhance probability of remedial success

40 Questions? Thank You for Your Time Bruce Tunnicliffe Vertex Environmental Inc. (519) x304 (519) mobile