Evaluation and Closure of NAPL Sitesebcne.org/wp-content/uploads/2018/03/02-27-18-MASTER-Evaluation... · • Stability Action Levels not exceeded ... – Background ... –Natural

EBC Site Remediation & Redevelopment Program:

Evaluation and Closure of NAPL Sites

Environmental Business Council of New England

Energy Environment Economy

Welcome from the Committee Chair

Jon Kitchen

Chair, EBC Site Remediation &

Redevelopment Committee

Senior Project Manager

Civil & Environmental Consultants, Inc.



Program Introduction & Overview

David Austin

Program Chair & Moderator

Leadership Team, EBC Site Remediation

& Redevelopment Committee

Technical Leader, AECOM



NAPL – A Regulatory Evolution

and Case Study Implications

Matthew Heil

Project Director & Associate

Sanborn Head & Associates

NAPL – A Regulatory Evolution and Case Study Implications

February 27, 2018

Presented by: Matthew Heil, P.E., LSP

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)

Post-2014 MCP

1. “Non-stable NAPL” – footprint expandinglaterally or vertically

2. “NAPL with Micro-scale Mobility” – footprintnot expanding, but visibly present in thesubsurface in sufficient quantities to migrateand visibly impact an excavation, boring ormonitoring well (e.g., observation of a sheen)

2 new NAPL performance standards for mobility and recoverability (based on principles of M-P Fluid Flow in Porous Media [FFPM]):

½ - Inch

UCL

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)

NAPL Related Notifications

1. 2-hour

• > Reportable Quantity (RQ)

• NAPL Sheen on surface water

• NAPL that poses/could pose an Imminent Hazard (IH)

2. 72-hour

• > ½” in well, excavation or subsurface structure

• SRM - Volatile LNAPL > 1/8” within 30 feet of school, daycare, or occupied residence

3. 120 days

• > Reportable Concentration (RC)

• > 1/8” in well, excavation, or subsurface structure

(mostly unchanged)

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?

LNAPL and the MCP: Guidance for SiteAssessment and Closure, Policy #WSC-16-450

“Voluntary” Guidance Only For:

• LNAPL

• Porous Media

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 & LNAPLConceptual Site Model [LCSM])

2. “Simplified” Approach

• Analogous to Generic Method 1

• Sounds good, but conservative & prescribed

• Must be used in its entirety

“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?


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


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 thickness3. No Longer Feasible if:

• LNAPL Transmissivity < 0.8 ft2/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

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

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?

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

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

NAPL Take Aways

1. MCP has been updated to current NAPL science – this is good!

2. If your old NAPL site is “stuck” like Pooh (Temporary Solution or ROS), it might be finally suitable for a Permanent Solution – this is even better!

½-Inch UCL



Navigating the MassDEP LNAPL Guidance Document:

A Case Study & Introduction to LNAPL Transmissivity

Steven Gaito

Project Manager

AECOM

Navigating the MassDEP LNAPL Guidance Document: A Case Study

and

Introduction to LNAPL Transmissivity

Steven Gaito

February 27, 2018

Case StudyLNAPL and the MCP: Guidance for Site Assessment and Closure

– MCP Performance

Standards: CSM

• Nature and Extento LNAPL Presence & Characterization

• Mobilityo LNAPL Micro-Scale Mobility and

AULs

o Non-Stable NAPL

• Recoverability

o LNAPL Removal

– “if and to the extent feasible”

LNAPL Presence and Characterization

Page 25

Measurable LNAPL

in monitoring wells

SCALE IN FEET

0 140 280

N

LNAPL not detected

in monitoring wells

Nature and Extent

• Describe the source

• Define the extent

• Identify the risks

LNAPL Micro-Scale MobilityIs the LNAPL mobile?

–Measurable LNAPL in

wells

LNAPL Macro-Scale MobilityIs the LNAPL migrating?


wells

–Dissolved-phase stability

–Pore Entry Pressure

LNAPL Extent2000s

Page 28

Measurable LNAPL

in monitoring wells

SCALE IN FEET

0 140 280

N

LNAPL not detected

in monitoring wells

LNAPL Extent2014

Page 29

Measurable LNAPL

in monitoring wells

SCALE IN FEET

0 140 280

N

LNAPL not detected

in monitoring wells

Unconfined LNAPL on Fluctuating Water Table

Source ITRC

MW-1: Hydrograph

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

4

5

6

7

8

9

10

9/27

/97

6/23

/00

3/20

/03

12/1

4/05

9/9/

08

6/6/

11

3/2/

14

LNA

PL

Thic

knes

s (f

eet)

Ele

vatio

n (f

eet)

Potentiometric Surface LNAPL Thickness

MW-2: Hydrograph

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

4

5

6

7

8

9

1010

/28/

95

7/24

/98

4/19

/01

1/14

/04

10/1

0/06

7/6/

09

4/1/

12

12/2

7/14

9/22

/17

LNA

PL

Thic

knes

s (f

eet)

Ele

vatio

n (f

eet)

Potentiometric Surface LNAPL Thickness


–Measurable LNAPL in wells



Dissolved Phase EPH Concentrations1998 versus 2014

Page 34 SCALE IN FEET

0 140 280

NMW-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-403 MW-504

9/30/1998 9/22/2014

C11-C22 AROMATICS 127 <100



MW-407 9/30/1998 9/16/2013

C11-C22 AROMATICS <112 <100



MW-406 9/30/1998 9/18/2004

C11-C22 AROMATICS 116 <100



MW01 2013

C11-C22 AROMATICS 218

C19-C36 ALIPHATICS 68

C9-C18 ALIPHATICS 126



wells



Pore Entry Pressure

Location

Air-Water

Displacement

Pressure

Head

(centimeters)

Critical

LNAPL

Thickness

(feet)

Current LNAPL

Thickness

Observed (feet)

SB-1 10.81 0.68 0.44

SB-2 33.49 1.85 0.91

SB-3 36.92 2.34 1.12

SB-4 25.6 1.42 0.87

Source: ITRC

Flow

Flow

For water wet media

LNAPL Removal “if and to the extent feasible”

–Comparison to

Residual Saturations

–LNAPL transmissivity

–Natural source zone

depletion evaluation

Field vs Residual Saturation

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

Location IDDepth

(feet bgs)

Field LNAPL

Saturation (%)

Residual LNAPL

Saturation (%)Petrophysical Test

SB-1 15.45 11.4 11.4 RSWD

SB-2 13.5 7.6 7.6 FPM

SB-2 13.3 8.6 8.6 RSWD

SB-3 23.3 11.4 11.4 RSWD

SB-4 26.4 7.6 7.6 FPM

SB-4 27.1 7.6 7.6 RSWD

LNAPL Removal “if and to the extent feasible”

–Comparison to Residual

Saturations




Well ID Date

Initial

Thickness

(ft)

LNAPL Thickness

after ~24 hours

(ft)

LNAPL

Transmissivity

(ft2/day)

Comments

MW-01

2012 0.16 0.06 NADoes not meet testing

requirements

2014 0.01 --- --- No test conducted

MW-02

2012 0.58 0.46 0.6Below MassDEP Guidance of

0.8 ft2/day2014 0.91 0.78 0.6

MW-03

2012 0.02 --- --- No test conducted

2014 0.44 0.06 <0.8 Not quantified

LNAPL Transmissivity Evaluation

LNAPL Recoverability and Degradation

–Comparison to Residual

Saturations




NSZD EvaluationsResults

Page 42

SCALE IN FEET

0 140 280

N

Carbon Dioxide

Flux Trap

NSZD rate in units of

gallons per acre per

year

T-01

(Background)

T-04

2,900

T-03

1,800

T-02

800

Summary

–No ongoing source

–LNAPL “source” is controlled• LNAPL has micro-scale

mobility• LNAPL is stableo Not “non-stable”

• LNAPL is not practicably recoverable

• Natural processes are depleting the LNAPL

Intro to LNAPL

Transmissivity

• Gasoline

• Sand

• Recent Release

• Mineral oil

• Clay

• Old Release

More

RecoverableLess

Recoverable

VERSUS

This makes sense, but how can we quantify recoverability??

LNAPL Recoverability

LNAPL T vs. Gauged LNAPL Thickness

0.0001

0.001

0.01

0.1

1

10

100

0 1 10 100

LN

AP

L T

RA

NS

MIS

SIV

ITY

(F

T2/D

AY

)

GAUGED LNAPL THICKNESS (FT)

Source: ASTM

Water Transmissivity

Water transmissivity integrates hydraulic conductivity

over entire water column

ww bKTw

wb

In a homogeneous setting water hydraulic conductivity is

constant throughout the vertical interval

LNAPL Transmissivity

LNAPL transmissivity integrates LNAPL conductivity over the formation

LNAPL thickness

nn·bKTn=

nb

In a homogeneous setting LNAPL hydraulic

conductivity is variable throughout the

vertical interval

LNAPL transmissivity reflects soil permeability,

LNAPL viscosity, and LNAPL saturation

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 rateSources: ITRC, Beckett and Lyverse

Former Refinery Case Study

In-Well Thickness Transmissivity

Low Transmissivity/High Thickness

High Transmissivity/High Thickness

Pilot Test Location

LNAPL Extent, Not

Migrating

Source: ITRC

Former Refinery Case StudyPilot test results

LNAPL Skimming

(gallons)

Dual Pump Liquid

Extraction

(gallons)

High Transmissivity Area

(>10 ft2/day)40 600

Low Transmissivity Area

(<0.01 ft2/day)0 0

72 hours test duration

Short Term Recovery Evaluation

0

10

20

30

40

50

0

0.1

0.2

0.3

0.4

0.5

Dec-06 Jan-07 Feb-07 Mar-07 Apr-07

LN

AP

L R

eco

ve

ry R

ate

(g

pd

)

Wat

er

Re

cov

ery

Rat

e (

1000

gp

d)

LN

AP

L T

ran

smis

siv

ity

(ft2

/day

)

LNAPL Transmissivity LNAPL Recovery Rate Water Recovery Rate

0

10

20

30

40

50

0

0.1

0.2

0.3

0.4

0.5


LN

AP

L R

eco

ve

ry R

ate

(g

pd

)

Wat

er

Re

cov

ery

Rat

e (

1000

gp

d)

LN

AP

L T

ran

smis

siv

ity

(ft2

/day

)



0

10

20

30

40

50

0

0.1

0.2

0.3

0.4

0.5


LN

AP

L R

eco

ve

ry R

ate

(g

pd

)

Wat

er

Re

cov

ery

Rat

e (

1000

gp

d)

LN

AP

L T

ran

smis

siv

ity

(ft2

/day

)


w

orwo QQ

TT


Questions and Discussion

Steven GaitoProvidence RI

TPG Leader, [email protected]

(401) 854 2810

55

Thank You!

mailto:[email protected]

Additional Content

if Necessary

Page 56

Risk Based NAPL Management

Compositionsoluble/volatile fractions

Is there a dissolved-phase risk?

Is there a vapor-phase risk?

Saturation

Is NAPL Mobile?

Is NAPL Migrating?

LNAPL

Increase in LNAPL Saturation

Micro-Scale Mobility (mobile)

LNAPL can flow into wells

Residual

LNAPL present,

but cannot flow into wells

MassDEP NAPL Terminology

Recoverable

Non-Stable

Source: ITRC

Approximate Water Table

Stability Lines of Evidence

8. LNAPL Tracer Testing

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



The Duplex Dilemma: Two Owners, Two Insurance

Companies, A Half-Dozen Inquiring Minds & One UST

Jack Mannix

Senior Project Manager

EndPoint LLC

Open Discussion

Moderator:

• Jonathan Kitchen, Civil & Environmental Consultants

Panel Members:

• Steven Gaito, AECOM

• Matthew Heil, Sanborn Head & Associates

• Jack Mannix, EndPoint LLC



EBC Site Remediation & Redevelopment Program:

Evaluation and Closure of NAPL Sites

Documents

Evaluation and Closure of NAPL Sitesebcne.org/wp-content/uploads/2018/03/02-27-18-MASTER-Evaluation... · • Stability Action Levels not exceeded ... – Background ... –Natural