EBC Site Remediation & Redevelopment Program: Evaluation and Closure of NAPL Sites

Transcription

1 EBC Site Remediation & Redevelopment Program: Evaluation and Closure of NAPL Sites

2 Welcome from the Committee Chair Jon Kitchen Chair, EBC Site Remediation & Redevelopment Committee Senior Project Manager Civil & Environmental Consultants, Inc. Environmental Business Council of New England Energy Environment Economy

3 Program Introduction & Overview David Austin Program Chair & Moderator Leadership Team, EBC Site Remediation & Redevelopment Committee Technical Leader, AECOM Environmental Business Council of New England Energy Environment Economy

4 NAPL A Regulatory Evolution and Case Study Implications Matthew Heil Project Director & Associate Sanborn Head & Associates Environmental Business Council of New England Energy Environment Economy

5 NAPL A Regulatory Evolution and Case Study Implications February 27, 2018 Presented by: Matthew Heil, P.E., LSP

6 Pre-2014 MCP > ½ NAPL thickness = UCL = No Permanent Solution Relic of original MCP, when DEP needed a reasonably protective bright line standard, before NAPL science evolved Result: ~ 100 sites that otherwise met closure standards were stuck in MCP purgatory of a Temporary Solution or Phase V Remedy Operation Status (ROS)

7 Post-2014 MCP ½ - Inch UCL 2 new NAPL performance standards for mobility and recoverability (based on principles of M-P Fluid Flow in Porous Media [FFPM]): 1. Non-stable NAPL footprint expanding laterally or vertically 2. NAPL with Micro-scale Mobility footprint not expanding, but visibly present in the subsurface in sufficient quantities to migrate and visibly impact an excavation, boring or monitoring well (e.g., observation of a sheen)

8 How do I close my site now? 1. Sites with Non-stable NAPL Permanent Solution cannot be achieved Temporary Solution if NAPL removed and/or controlled if and to extent feasible 2. Sites with Micro-scale Mobility (but no Non-stable) Permanent Solution may be achieved, but only after NAPL removed if feasible and to the extent feasible & all other MCP closure requirements met (e.g., source elimination and control, migration control, site characterization, risk assessment) AUL required (i.e., NAPL Management Plan)

9 1. 2-hour NAPL Related Notifications > Reportable Quantity (RQ) NAPL Sheen on surface water NAPL that poses/could pose an Imminent Hazard (IH) hour > ½ in well, excavation or subsurface structure SRM - Volatile LNAPL > 1/8 within 30 feet of school, daycare, or occupied residence days > Reportable Concentration (RC) (mostly unchanged) > 1/8 in well, excavation, or subsurface structure

10 How do I actually do this? 1. How do I show no Non-stable NAPL? 2. How do I evaluate feasibility of recovery? 3. Do I have Micro-scale Mobility?

11 LNAPL and the MCP: Guidance for Site Assessment and Closure, Policy #WSC Voluntary Guidance Only For: LNAPL Porous Media

12 Two LNAPL Policy Options: 1. Lines of Evidence Approach Analogous to Site Specific Method 3 LSP makes the case based on the science (principles of FFPM & LNAPL Conceptual Site Model [LCSM]) 2. Simplified Approach Analogous to Generic Method 1 Sounds good, but conservative & prescribed Must be used in its entirety

13 Simplified Approach

14 Simplified Approach 1. Is LNAPL Present or Likely Present? Visible in subsurface, sumps, groundwater, or surface water at any time in the past? Soil TPH > 1,000 mg/kg or discoloration/odor? 2. Does LNAPL have Micro-scale Mobility? Visibly present in any amount in any excavation, boring or monitoring well within past 10 years?

15 Simplified Approach 3. Is LNAPL Non-stable? (footprint expanding?) Stable if after 1 year of monthly gauging if: Stability Action Levels not exceeded LNAPL not observed migrating in preferential flow paths or discharging into building, utilities, drinking water wells or surface water bodies, and Thicknesses did not consistently or significantly increase in downgradient monitoring wells

16 Simplified Approach 4. Feasible to recover LNAPL? 1. Categorically Infeasible if: Never exceeded > 1/8 ; or Quarterly gauging < 1/8 for 1 year 2. Conditionally Infeasible if: max thickness in quarterly gauging in previous 1 year period < Fig 8 screen out thickness 3. No Longer Feasible if: LNAPL Transmissivity < 0.8 ft 2 /day (ASTM 2856); or Total NAPL volume recovered < 1 gallon in any 3 month period; or Decline curve analysis of at least 12 months shows asymptotic condition

17 Case Study No. 1 ~ 8,000-gallons Release of No. 2 Fuel Oil from Large AST in 2002 Background Industrial Site with reworked glacial till fill (terraced) over thin glacial till over bedrock Good News = Contained in concrete walled containment area Bad News = Earthen bottom Initial IRA Actions: pumping 6,560 gallons from containment area, excavation 321 tons impacted soil, weekly NAPL gauging/removal Assessment & Comprehensive Remedial Action 18 borings (15 monitoring wells) with soil and groundwater sampling Bi-weekly NAPL manual gauging/removal and bi-annual groundwater sampling ~ 30 gallons NAPL manually recovered

18 Case Study No. 1 Remedy Operation Status (ROS) achieved in 2006, but Permanent Solution precluded since continued periodic > ½ NAPL in single bedrock well By 2014 MCP changes, < ½ NAPL and Other MCP closure requirements were met Audience Poll Would you record an AUL with the Permanent Solution? If you had Micro-scale Mobility remaining (< ½ NAPL) but No Significant Risk, would you record an AUL?

19 Final NAPL Policy - AUL Clarification DEP clarified as a matter of enforcement discretion that they DO NOT expect AULs for < ½ NAPL (i.e., sites with Micro-scale Mobility that would otherwise need an AUL per the MCP) To be fixed in the pending wave of MCP revisions

20 Case Study No. 2 Historical Coal Gasification & Tarpaper Manufacturing Site Background Urban Commercial/Office Site Urban fill over organic silt (tidal flat) over marine clay Primary COCs VPH/EPH fractions, petroleum VOCs, PAHs and cyanide Phase II concluded no significant dissolved phase groundwater, but impacted soil & Coal Tar DNAPL at one location (> ½ ) below building Class C RAO w/ AUL in 2004, but Permanent Solution precluded since continued periodic > ½ DNAPL in single well After 2014 MCP revisions: Focused sampling to update media of concern (indoor air & groundwater) AUL Amended by adding NAPL Management Plan Permanent Solution w/ Conditions in 2016

21 NAPL Take Aways 1. MCP has been updated to current 2. If your old NAPL site is stuck like Pooh (Temporary NAPL science this is good! Solution or ROS), it might be finally suitable for a Permanent Solution this is even better! ½-Inch UCL

22 Navigating the MassDEP LNAPL Guidance Document: A Case Study & Introduction to LNAPL Transmissivity Steven Gaito Project Manager AECOM Environmental Business Council of New England Energy Environment Economy

23 Navigating the MassDEP LNAPL Guidance Document: A Case Study and Introduction to LNAPL Transmissivity Steven Gaito February 27, 2018

24 Case Study LNAPL and the MCP: Guidance for Site Assessment and Closure MCP Performance Standards: CSM Nature and Extent o LNAPL Presence & Characterization Mobility o LNAPL Micro-Scale Mobility and AULs o Non-Stable NAPL Recoverability o LNAPL Removal if and to the extent feasible

25 LNAPL Presence and Characterization N Measurable LNAPL in monitoring wells LNAPL not detected in monitoring wells SCALE IN FEET Nature and Extent Describe the source Define the extent Identify the risks Page 25

26 LNAPL Micro-Scale Mobility Is the LNAPL mobile? Measurable LNAPL in wells

27 LNAPL Macro-Scale Mobility Is the LNAPL migrating? Measurable LNAPL in wells Dissolved-phase stability Pore Entry Pressure

28 LNAPL Extent 2000s N Measurable LNAPL in monitoring wells LNAPL not detected in monitoring wells SCALE IN FEET Page 28

29 LNAPL Extent 2014 N Measurable LNAPL in monitoring wells LNAPL not detected in monitoring wells SCALE IN FEET Page 29

30 Unconfined LNAPL on Fluctuating Water Table Source ITRC

31 9/27/97 6/23/00 3/20/03 12/14/05 9/9/08 6/6/11 3/2/14 Elevation (feet) LNAPL Thickness (feet) MW-1: Hydrograph Potentiometric Surface LNAPL Thickness

32 10/28/95 7/24/98 4/19/01 1/14/04 10/10/06 7/6/09 4/1/12 12/27/14 9/22/17 Elevation (feet) LNAPL Thickness (feet) MW-2: Hydrograph Potentiometric Surface LNAPL Thickness

33 LNAPL Macro-Scale Mobility Is the LNAPL migrating? Measurable LNAPL in wells Dissolved-phase stability Pore Entry Pressure

34 Dissolved Phase EPH Concentrations 1998 versus 2014 N MW-403 MW-504 9/30/1998 9/22/2014 C11-C22 AROMATICS 127 <100 C19-C36 ALIPHATICS <112 <100 C9-C18 ALIPHATICS 118 <100 MW-401 MW-502 9/30/1998 9/22/2014 C11-C22 AROMATICS <115 <100 C19-C36 ALIPHATICS <115 <100 C9-C18 ALIPHATICS 132 <100 MW-406 9/30/1998 9/18/2004 C11-C22 AROMATICS 116 <100 C19-C36 ALIPHATICS <112 <100 C9-C18 ALIPHATICS 142 <100 Page 34 MW C11-C22 AROMATICS 218 C19-C36 ALIPHATICS 68 C9-C18 ALIPHATICS SCALE IN FEET MW-407 9/30/1998 9/16/2013 C11-C22 AROMATICS <112 <100 C19-C36 ALIPHATICS <112 <100 C9-C18 ALIPHATICS 148 <100

35 LNAPL Macro-Scale Mobility Is the LNAPL migrating? Measurable LNAPL in wells Dissolved-phase stability Pore Entry Pressure

36 Pore Entry Pressure Location Air-Water Displacement Pressure Head (centimeters) Critical LNAPL Thickness (feet) Current LNAPL Thickness Observed (feet) For water wet media Flow SB SB Flow SB SB Source: ITRC

37 LNAPL Removal if and to the extent feasible Comparison to Residual Saturations LNAPL transmissivity Natural source zone depletion evaluation

38 LNAPL is mobile when field saturation exceeds residual saturation (ITRC 2009). No field saturations exceeded residual saturation, indicating that LNAPL is immobile as defined by the ITRC (ITRC 2009). RSWD: Residual Saturation Water Drive FPM: Free Product Mobility Field vs Residual Saturation Location ID Depth (feet bgs) Field LNAPL Saturation (%) Residual LNAPL Saturation (%) Petrophysical Test SB RSWD SB FPM SB RSWD SB RSWD SB FPM SB RSWD

39 LNAPL Removal if and to the extent feasible Comparison to Residual Saturations LNAPL transmissivity Natural source zone depletion evaluation

40 LNAPL Transmissivity Evaluation Well ID MW-01 Date Initial Thickness (ft) LNAPL Thickness after ~24 hours (ft) LNAPL Transmissivity (ft 2 /day) NA Comments Does not meet testing requirements No test conducted MW Below MassDEP Guidance of 0.8 ft 2 /day MW No test conducted <0.8 Not quantified

41 LNAPL Recoverability and Degradation Comparison to Residual Saturations LNAPL transmissivity Natural source zone depletion evaluation

42 NSZD Evaluations Results N T-01 (Background) SCALE IN FEET T T-03 1,800 T-04 2,900 Carbon Dioxide Flux Trap NSZD rate in units of gallons per acre per year Page 42

43 Summary No ongoing source LNAPL source is controlled LNAPL has micro-scale mobility LNAPL is stable o Not non-stable LNAPL is not practicably recoverable Natural processes are depleting the LNAPL

44 Intro to LNAPL Transmissivity

45 LNAPL Recoverability More Recoverable Gasoline Sand Recent Release VERSUS Less Recoverable Mineral oil Clay Old Release This makes sense, but how can we quantify recoverability??

46 LNAPL TRANSMISSIVITY (FT 2 /DAY) LNAPL T vs. Gauged LNAPL Thickness Source: ASTM GAUGED LNAPL THICKNESS (FT)

47 Water Transmissivity Water transmissivity integrates hydraulic conductivity over entire water column K b Tw w w b w In a homogeneous setting water hydraulic conductivity is constant throughout the vertical interval

48 LNAPL Transmissivity LNAPL transmissivity integrates LNAPL conductivity over the formation LNAPL thickness T n =Kn b n b n In a homogeneous setting LNAPL hydraulic conductivity is variable throughout the vertical interval LNAPL transmissivity reflects soil permeability, LNAPL viscosity, and LNAPL saturation

49 Transmissivity Measurement Short-term tests Instantaneous applied stress LNAPL baildown test Manual skimming test Long-term tests Relatively long-term stress LNAPL recovery data analysis LNAPL tracer test Transmissivity is proportional to hydraulic LNAPL recovery rate Sources: ITRC, Beckett and Lyverse

50 Former Refinery Case Study In-Well Thickness LNAPL Extent, Not Migrating Transmissivity Low Transmissivity/High Thickness High Transmissivity/High Thickness Pilot Test Location Source: ITRC

51 Former Refinery Case Study Pilot test results LNAPL Skimming (gallons) Dual Pump Liquid Extraction (gallons) High Transmissivity Area (>10 ft 2 /day) Low Transmissivity Area (<0.01 ft 2 /day) hours test duration

52 LNAPL Transmissivity (ft 2 /day) LNAPL Recovery Rate (gpd) Water Recovery Rate (1000 gpd) Short Term Recovery Evaluation LNAPL Transmissivity LNAPL Recovery Rate Water Recovery Rate Dec-06 Jan-07 Feb-07 Mar-07 Apr-07 0

53 LNAPL Transmissivity (ft 2 /day) LNAPL Recovery Rate (gpd) Water Recovery Rate (1000 gpd) Short Term Recovery Evaluation LNAPL Transmissivity LNAPL Recovery Rate Water Recovery Rate Dec-06 Jan-07 Feb-07 Mar-07 Apr-07 0

54 LNAPL Transmissivity (ft 2 /day) LNAPL Recovery Rate (gpd) Water Recovery Rate (1000 gpd) Short Term Recovery Evaluation LNAPL Transmissivity LNAPL Recovery Rate Water Recovery Rate T o T w r Q o Q w 10 0 Dec-06 Jan-07 Feb-07 Mar-07 Apr-07 0

55 Questions and Discussion Thank You! Steven Gaito Providence RI TPG Leader, LNAPL (401)

56 Additional Content if Necessary Page 56

57 Risk Based NAPL Management Composition soluble/volatile fractions Saturation Is there a dissolved-phase risk? Is NAPL Mobile? Is there a vapor-phase risk? Is NAPL Migrating?

58 MassDEP NAPL Terminology Residual LNAPL present, but cannot flow into wells LNAPL Micro-Scale Mobility (mobile) LNAPL can flow into wells Recoverable Non-Stable Source: ITRC Increase in LNAPL Saturation

59 Stability Lines of Evidence 8. LNAPL Tracer Testing Approximate Water Table

60 LNAPL transmissivity for remediation Recovery Start Metric Magnitude of LNAPL recoverability is more accurate o Accounts for varying soil types and hydrogeological conditions o Estimated via field tests on individual wells Results in improved well location and site prioritization for LNAPL recovery Recovery Stop Metric Observed field data transmissivity and saturation estimates o Provide an absolute reference point where hydraulic recovery of LNAPL is likely to be ineffective even though gauged well thickness exists o Can be estimated for additional sites using existing monitoring well network or historical recovery system performance data

61 The Duplex Dilemma: Two Owners, Two Insurance Companies, A Half-Dozen Inquiring Minds & One UST Jack Mannix Senior Project Manager EndPoint LLC Environmental Business Council of New England Energy Environment Economy

62 Open Discussion Moderator: Jonathan Kitchen, Civil & Environmental Consultants Panel Members: Steven Gaito, AECOM Matthew Heil, Sanborn Head & Associates Jack Mannix, EndPoint LLC Environmental Business Council of New England Energy Environment Economy

63 EBC Site Remediation & Redevelopment Program: Evaluation and Closure of NAPL Sites