Post on 29-May-2020
Is ISCO Right for Your Site?Is ISCO Right for Your Site?gg
Michelle CrimiMichelle CrimiClarkson University Clarkson University
Fritz KrembsFritz KrembsAquifer Solutions, Inc.Aquifer Solutions, Inc.
RITS Fall 2010
*In Situ Chemical Oxidation (ISCO)
SDMS DOCID#1142175
Presentation Overview
• Introduction to ISCO
• ISCO Technology Practices Manual (TPM):ESTCP Project Background and Overview of Results
• ISCO Screening
ISCO Conceptual Design• ISCO Conceptual Design
• ISCO Detailed Design, Implementation, and Monitoring
• Case Studies
• Summary
2
• Summary
RITS Fall 2010: Is ISCO Right for Your Site?
Definitions and ISCO Fundamentals
• ISCO: In situ chemical oxidation (formerly ChemOx)– Delivery of oxidants into the subsurface to destroy contaminants
in groundwater
– Chemical reactions occur primarily in aqueous phase though some treatment of NAPL and sorbed phases may occur
• COCs: Contaminants of concern
• NAPL (DNAPL): non-aqueous phase liquid (dense) ( ) q p q ( )
• NOD/SOD: natural or soil oxidant demandM f id t d f di t t d
3
– Mass of oxidant consumed per mass of media contacted
RITS Fall 2010: Is ISCO Right for Your Site?Introduction to ISCO
Definitions and ISCO Fundamentals (cont.)
• Chemical oxidants can rapidly destroy many contaminants of concern (COCs)co ce (COCs)
– Chlorinated hydrocarbons, fuel related compounds, phenols and PAHs, energetics, pesticides, etc.El t t f– Electron transfer C2HCl3 + 2MnO4
- 2MnO2 + 3Cl- + 2CO2 + H+
– Free radical oxidation Fe2+ + H2O2 Fe3+ + OH- + OH●
• Common oxidants• Common oxidants– Permanganate (electron transfer)– Activated persulfate (free radical)Activated persulfate (free radical)– Catalyzed hydrogen peroxide (CHP or Modified Fenton’s reagent)
(free radical)O (b h l f d f di l)
4
– Ozone (both electron transfer and free radical)
RITS Fall 2010: Is ISCO Right for Your Site?Introduction to ISCO
Definitions and ISCO Fundamentals (cont.)
• Oxidant Dose: ISCO design parameter R ti f f id t d li d t f l i di i t t t – Ratio of mass of oxidant delivered to mass of geologic media in treatment zone, typically reported in units g oxidant/kg of treatment zone
• Pore Volumes (PVs) Delivered: ISCO design parameter – Ratio of volume of oxidant solution injected to volume of pore space in
treatment zone, unitless parameter
T t t l• Treatment goals– MCLs: Maximum contaminant levels (EPA or state regulatory levels)– ACLs: Alternative Concentration Limits (risk-based)ACLs: Alternative Concentration Limits (risk-based)– Mass flux: Rate of contaminant release from a source zone (mass discharge)– Percent concentration or mass reduction
5 RITS Fall 2010: Is ISCO Right for Your Site?Introduction to ISCO
Definitions and ISCO Fundamentals (cont.)
• TPM: Technology Practices Manual– Funded by ESTCP to enable more predictable, cost-effective
application of ISCOWill be available at SERDP/ESTCP Web site– Will be available at SERDP/ESTCP Web site
• DISCO: Database for ISCO • ISCO Protocol components
– ISCO Screening– ISCO Conceptual Design– ISCO Detailed Design and Planning
6
– ISCO Implementation and Performance MonitoringIntroduction to ISCO RITS Fall 2010: Is ISCO Right for Your Site?
Definitions and ISCO Fundamentals (cont.)
• Application of ISCO requires delivery of oxidants into and throughout a target treatment zone (TTZ) t oug out a ta get t eat e t o e ( )
– Delivery methods • Direct-push probes, drilled wells, or specialized injectors, with some use of fracturing
or mixing techniques; Reactive barriers recirculation schemes multiple delivery or mixing techniques; Reactive barriers, recirculation schemes, multiple delivery modes, or other strategies
– Viability of a given delivery method depends on the oxidant used and site-specific conditionssite specific conditions
• Remedial action objectives and site cleanup goals have varied– Reduce the concentration or mass by some percentage (e.g., ≤90%)Reduce the concentration or mass by some percentage (e.g., ≤90%)– Achieve a target concentration (e.g., ≤100 µg/L or ≤1 mg/kg)– Achieve a concentration in a plume at some compliance plane
d di t f
7
downgradient from a source zone
RITS Fall 2010: Is ISCO Right for Your Site?Introduction to ISCO
ISCO Performance
• At some sites, clean up goals have been met in a di t bl t ff ti d ti l i ISCOpredictable, cost-effective and timely manner using ISCO
• At other sites, ISCO performancehas not met expectations
– Inability to achieve site cleanup goalsbased on predictions for the ISCOsystem that was designed andimplementedp e e ted
– So-called “rebound” in groundwaterconcentrations following the end of
8
active ISCO operations
RITS Fall 2010: Is ISCO Right for Your Site?Introduction to ISCO
Reasons for Poor Performance
• Poor performance is often attributed to…Site heterogeneities and low permeability zones– Site heterogeneities and low permeability zones
– Excessive oxidant consumption by soil and aquifer media– Presence of large masses of contaminants (e.g., NAPLs)Presence of large masses of contaminants (e.g., NAPLs)– Poor design: Insufficient oxidant DOSE or VOLUME
• Example regulator comments on ISCO case studyp g y– “Residual DNAPL in the soil appears to inhibit the
success of the injected solutions.”“Th h t b d d ti Actual Injection– “The source has not been removed and continues as a source for groundwater contamination.”
– “Insufficient quantities of [ISCO product trade name]ma limit the s ccess of the treatment ”
Actual Injection Conditions:
Injected Volume = 0.00012 PV
9
may limit the success of the treatment.”
RITS Fall 2010: Is ISCO Right for Your Site?Introduction to ISCO
Dose = 0.002 g/kg
Reasons for Poor Performance (cont.)
• Common mistakesf f– Not fully identifying or understanding site conditions
• Geochemistry, geology, contaminant mass distribution, etc.
Underestimating interaction of oxidants with natural media– Underestimating interaction of oxidants with natural media• Not conducting oxidant demand or oxidant persistence evaluations
– Trying to achieve unrealistic goalsy g g• For example: treatment of NAPL sites to MCLs
– Assuming a single application will do the job– Not delivering enough mass of oxidant
• This does not mean increasing concentration will necessarily do the job!
10 RITS Fall 2010: Is ISCO Right for Your Site?
– Not delivering enough volume of oxidant
Introduction to ISCO
ISCO's Sweet Spot
• ISCO performs well when adequate contact with contaminants occursoccurs
– Hydrogeology• Permeable media• Homogeneous media
– Heterogeneous media meets treatment goals less frequently, costs more, and experiences more frequent reboundexperiences more frequent rebound
– Contaminant characteristics• Dissolved phase and low sorbed mass
– Adequate design• Oxidant volume and mass
11
• Delivery frequency and duration
RITS Fall 2010: Is ISCO Right for Your Site?Introduction to ISCO
Presentation Overview
• Introduction to ISCO
• ISCO Technology Practices Manual (TPM):ESTCP Project Background and Overview of Results
• ISCO Screening
ISCO Conceptual Design• ISCO Conceptual Design
• ISCO Detailed Design, Implementation, and Monitoring
• Case Studies
• Summary
12
• Summary
RITS Fall 2010: Is ISCO Right for Your Site?
ISCO Technology Practices Manual (TPM)
• ESTCP funded development of a TPM including protocols d t l t bl it ifi i i f ISCOand tools to enable site-specific engineering of ISCO
(ER-0623)S C O f G– “In Situ Chemical Oxidation for Groundwater Remediation –
Technology Practices Manual”, will be available at SERDP/ESTCP Web site
• Project focus and overall goalTh l i t bl di t bl t ff ti li ti – The goal is to enable more predictable, cost-effective application at DoD sites by providing knowledge and know-how within an ISCO TPM
13 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Technology Practices Manual
ISCO TPM Foundation and Description
ISCO ISCO TPM Contents
I. ISCO processes and techniquesII P t l f ISCO t TPMTPMII. Protocols for ISCO system
selection, design, and implementation
III. Field applications, case study d t b d l i l database and analysis, lessons learned
IV. FAQ guide
Literature review
Case study Technology
practicesSERDP/
Literature review
Case study Technology
practicesSERDP/
14 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Technology Practices Manual
analysis practices workshop
ESTCP projects
analysis practices workshop
ESTCP projects
ISCO Literature
• Critical review of the literature relevant to ISCO science and technologytec o ogy
– Extensive search of published literature revealedabout 600 ISCO-relevant publicationsS h li it d t id t– Search limited to common oxidants
• Permanganate• Persulfate• Hydrogen Peroxide• Ozone
S i iti ll h t i d d l ifi d d th th hl B. Petri
– Sources initially characterized and classified and then thoroughly reviewed for key findings
– Literature review forms the basis for part of the Technology Practices Man al
15
Manual
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Technology Practices Manual
ISCO Literature (cont.)Study TypesA – Reaction Chemistry, Water PhaseB – Reaction Chemistry, Soil PhaseC – Transport and ModelingD Technology Coupling
Catalyzed Hydrogen Peroxide (CHP)n = 239
Ozonen = 82
D – Technology CouplingE – Field Case StudiesF – Application Guidance
A32%
E13%
F5%
A36%
E10%
F10%
200
250
of xida
nt Permanganate
CHP
B28%
C6%
D16%
B6%
C21%
D17%
100
150
ativ
e N
umbe
r St
udie
s by
Ox CHP
Persulfate
Ozone
8% 6%
A26%E
F9%D
2%
E2%
F11%
Persulfaten = 44
Permanganaten = 207
0
50
1988 1990 1992 1994 1996 1998 2000 2002 2004 2006
Cum
ulLi
tera
ture
26%
C
E23%
B25%
2%
C0%
Year ISCO Literature Published
16 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Technology Practices Manual
B15%
C18%D
9%
A60%
ISCO Case Studies
• Critical analysis of ISCO case studies f SCO f– Design of the ISCO database, obtain and extract project information,
populate database and analyze information– ISCO database includes 242 ISCO projects (42 states, 7 nations)p j ( , )
• Federal sites (46)• Manufacturing/Industrial facilities (45)• Dry cleaners (45)• Service stations (25)• Former manufactured gas plants (11)• Former manufactured gas plants (11)• Others
– Database available as “DISCO”
17
• ISCO design vs. site conditions vs. cost and performance…
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Technology Practices Manual
F. Krembs
ISCO Case Studies (cont.)
Oxidants used vs. timen = 182
ISCO applications to different site conditionsn = 149
A34
E9
F8
70
80
90
ts b
y O
xida
nt
PermanganateCHPPersulfateOzone
B3
D21
30
40
50
60
ber o
f Pro
ject Ozone
PercarbonatePeroxone
C740
10
20
1995 1997 1999 2001 2003 2005 2007mul
ativ
e N
um
A - Permeable and Homogeneous; B - Impermeable and HomogeneousC - Permeable and Heterogeneous; D - Impermeable and Heterogeneous
E - Fractured Rock w/low matrix porosity; F - Fractured Rock w/high matrix porosityPermeable K>10-5cm/s = 0 028ft/d
Cum Year ISCO Project Completed
18 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Technology Practices Manual
Permeable K>10-5cm/s = 0.028ft/dHomogeneous Kmax/Kmin < 1,000 (modified from NRC 2004)
Workshop of ISCO Professionals
• Technology practices workshop convened at Colorado School of Minesconvened at Colorado School of Mines
– 2-day workshop included 43 participants representing chemical companies, In Situ Chemical Oxidation for
R di ti f C t i t drepresenting chemical companies, technology vendors, environmental consultants, academics, RPMs
P t ti l i d b k t
Remediation of ContaminatedGround Water
Summary Proceedingsof an
ISCO Technology Practices Workshop
• Presentations, panel sessions, and breakout sessions
• Exercise where 6 scenarios were used to obtain
Convened at the
Colorado School of MinesGolden, Colorado
March 7-8, 2007
views regarding ISCO design and performance
• A proceedings document has been published
19 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Technology Practices Manual
Source: Siegrist et al. 2008
ISCO TPM Foundation and Description
ISCO ISCO TPM Contents
I. ISCO processes and techniquesII P t l f ISCO t TPMTPMII. Protocols for ISCO system
selection, design, and implementation
III. Field applications, case study d t b d l i l database and analysis, lessons learned
IV. FAQ guide
Literature review
Case study Technology
practicesSERDP/
Literature review
Case study Technology
practicesSERDP/
20 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Technology Practices Manual
analysis practices workshop
ESTCP projects
analysis practices workshop
ESTCP projects
Introduction to ISCO Protocol
• ComponentsTraditional Cleanup Process Systematic Design of ISCO
Preliminary Assessment
– Screening ISCO as an Option for a Site
Site Inspection
Remedial Investigation ISCO Screening
– ISCO Conceptual Design
– Detailed Design and Pl i
Remedial Design ISCO Detailed Design d Pl i
ISCO Conceptual Design
Record of Decision
Feasibility Study
Planning
– Implementation and Performance Monitoring
Remedy in Place
g
Remedial Action Construction
and Planning
ISCO I l t tiPerformance Monitoring Remedial Action Operations
Monitoring and Performance Assessment
Implementation and Performance
Monitoring
21 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Technology Practices Manual
Monitored Natural Attenuation and/or Long-Term Monitoring
Response Complete
Presentation Overview
• Introduction to ISCO
• ISCO Technology Practices Manual (TPM):ESTCP Project Background and Overview of Results
• ISCO Screening
ISCO Conceptual Design• ISCO Conceptual Design
• ISCO Detailed Design, Implementation, and Monitoring
• Case Studies
• Summary
22
• Summary
RITS Fall 2010: Is ISCO Right for Your Site?
How does ISCO work?
• Electron transfer
– Simpler chemistry, more predictable, less powerfulOxidant + Contaminant → Innocuous Byproducts
• Free radical oxidationOxidant + Activator → Radicals
– More complex chemistry less predictable more powerful
Oxidant + Activator → Radicals Radicals + Contaminant → Innocuous Byproducts
More complex chemistry, less predictable, more powerful
Matching the oxidant and delivery system to the CONTACT CONTACT CONTACT!
23 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
g y ycontaminants of concern and site conditions is
critical to achieving performance goals
What goals can ISCO achieve?
• Large concentration reductions (e.g., 90-99%+) are achievable
• Significant risk reduction and mass flux reduction goals are achievable
Frequency of Goals • Ability to meet goals
depends onContaminant mass
Goal% Meeting
Goaln = 122
q ySET for Sites
Evaluate Effectiveness/Optimize
– Contaminant massand distribution
– Hydrogeology
n 122
MCLs 21%
ACLs 44%
R d b X% 33%
MCLsReduceMass/TTC
– Proper designReduce by X% 33%
Reduce Mass/TTC 82%
Eval. Effectiveness/Optimize 100%
ACLs
TTC
24 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
OptimizeReduce by X%
When does ISCO work best?
• Hydrogeology– Permeable media with range of distribution approaches; lower
heterogeneity
• Contaminant characteristics– Dissolved phase and low sorbed mass
When appropriate delivery and
contact occur!p
• Proper designCorrect reagent at adequate mass and– Correct reagent at adequate mass andvolume
– Adequate number and frequency of
25 RITS Fall 2010: Is ISCO Right for Your Site?
– Adequate number and frequency ofdelivery events
ISCO Screening
What conditions are challenging for ISCO?
• Significant NAPL mass – Particularly trapped in fractured rock
• HOWEVER reduction of mass flux is feasible
– Particularly when present as highly saturated pools• HOWEVER ISCO is a viable polishing step following source removal
• Treatment to MCLs in source areas
• Large diffuse plumes• Large, diffuse plumes
• Presence of natural materials that arehi hl ti ith id t
26 RITS Fall 2010: Is ISCO Right for Your Site?
highly reactive with oxidants
ISCO Screening
Is pre- or post-ISCO treatment beneficial?
• Pre-ISCO mass recovery or Post-ISCO polishing↑ b bilit f ti l ↓ t ↓ ti↑ probability of meeting goals; ↓ costs; ↓ time
• Examples from case histories– Pre-ISCO excavation, pump & treat, and soil-vapor extraction are
most common (in that order)
– Post-ISCO enhanced bio and Monitored Natural Attenuation (MNA) are most common
• MNA used post-ISCO at 19% of sites in database, likely an underestimate
– Post-ISCO coupling more common at DNAPL sites
27 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
What ISCO chemistry options are out there?
• Permanganate• Catalyzed hydrogen peroxide (CHP or Modified Fenton’s reagent)• Catalyzed hydrogen peroxide (CHP, or Modified Fenton’s reagent)
– Natural iron– Chelated-iron (wide range of chelating agents)( g g g )– Iron + low pH
• Persulfate/Activated Persulfate– Alkaline pH (i.e., base)– Chelated-iron– Hydrogen peroxide (H O )– Hydrogen peroxide (H2O2 )– Heat
• Ozone
28
• Others (e.g., Peroxone, Percarbonate)RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
What ISCO delivery options are out there?
• Most common Delivery Method (n=148) Count Percent
– Vertical well injection
– Direct push probe
y ( )
Injection Wells 53 35.8
Direct Push 35 23.6
• OthersOften due to CONTACT
Sparge Points 24 16.2
Infiltration 17 11.5
Injectors 11 7 4– Often due to CONTACTlimitations
Injectors 11 7.4
Recirculation 9 6.1
Fracturing 8 5.4g
Mechanical Mixing 3 2.0
Horizontal Wells 2 1.4
29 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
How do I choose the best option?
• Understand site conditions!– Ability to degrade COCs
– Deliverability with respect to site-specific hydrogeology and geochemistry
A i l f i – Appropriate treatment goals for site conditions
There is no one oxidant and/or delivery approach that works
for all contaminant, hydrogeology & geochemical
30 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
hydrogeology, & geochemical conditions!
ISCO Screening: Lessons Learned
• Successful ISCO depends on:– Understanding site conditions
• Basic geology, geochemistry, contaminant mass and its distribution
– Selecting the correct oxidant for the site contaminants and geochemical conditions
Selecting the correct delivery approach for the oxidant and site – Selecting the correct delivery approach for the oxidant and site hydrogeological conditions
– Appropriate treatment goals for site conditionspp p g• Understanding ISCO’s ability to meet these goals
– Coupling ISCO with other pre- or post-ISCO conditions appropriately
31
– Appropriate design: mass, volume, frequency, duration
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
ISCO Screening ProcessSTART:
1. ISCO Screening
Data Collection: Characterization data, COCs, risk pathways,
PRGs/RAOs preliminary target 1Is ISCO applicable to site COCs and A
No
Is the CSMadequately defined
for screening
PRGs/RAOs, preliminary target treatment zones
1conditions?
STOP:Evaluate other technologies
No
Yes
B
purposes?
ISCO Screening Process:Determine viable ISCO options
Consider pre-ISCO technologies/processes 2 C
Are pre-ISCO processes previously implemented,
required or already
Yes
Yes
technologies/processes
Detailed ISCO Screening 3
required or already occurring?
No
Determine if value is added by couplinga pre- or post-ISCO process
4
Are viable ISCO ti il bl ?
DSTOP: Evaluate other technologies or review
No viable options
options available?
Is data support adequate? E
technologies or review site approach
No
Viable options exist
32 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
Proceed to conceptual design with a limited number (e.g., 1–3) of higher scoring options
for ISCO and/or coupled approaches
Yes
Data CollectionSTART:
1. ISCO Screening
Data Collection: Characterization data, COCs, risk pathways,
PRGs/RAOs preliminary target 1Is ISCO applicable to site COCs and A
No
• Data– Conceptual Site Model (CSM)
Is the CSMadequately defined
for screening
PRGs/RAOs, preliminary target treatment zones
1conditions?
STOP:Evaluate other technologies
No
Yes
BConceptual Site Model (CSM)• Contaminant • Hydrogeology
purposes?
ISCO Screening Process:Determine viable ISCO options
Consider pre-ISCO technologies/processes 2 C
Are pre-ISCO processes previously implemented,
required or already
Yes
Yes
• Geochemistry• Goals and objectives• Site plan
technologies/processes
Detailed ISCO Screening 3
required or already occurring?
No
• Site plan
– ISCO-specific • Collect soil and groundwater to
Determine if value is added by couplinga pre- or post-ISCO process
4
Are viable ISCO ti il bl ?
DSTOP: Evaluate other technologies or review
No viable optionsg
store if ISCO is even a remote possibility
–For oxidant demand/persistence d t t bilit l ti
options available?
Is data support adequate? E
technologies or review site approach
No
Viable options exist
33
and treatability evaluations
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
Proceed to conceptual design with a limited number (e.g., 1–3) of higher scoring options
for ISCO and/or coupled approaches
Yes
Basic ScreeningSTART:
1. ISCO Screening
Data Collection: Characterization data, COCs, risk pathways,
PRGs/RAOs preliminary target 1Is ISCO applicable to site COCs and A
No
Is the CSMadequately defined
for screening
PRGs/RAOs, preliminary target treatment zones
1conditions?
STOP:Evaluate other technologies
No
Yes
B
purposes?
ISCO Screening Process:Determine viable ISCO options
Consider pre-ISCO technologies/processes 2 C
Are pre-ISCO processes previously implemented,
required or already
Yes
YesCategory 1
Contaminant classes highly amenable to effective
degradation by commonly
Category 2Contaminant classes
degradable by common ISCO oxidants but effectiveness is
Category 3Contaminant classes not
amenable to ISCO treatmenttechnologies/processes
Detailed ISCO Screening 3
required or already occurring?
No
degradation by commonly used ISCO oxidants
oxidants but effectiveness is less certain
Chloroethenes Chloroethanes Heavy metalsBTEX Chlorinated/brominated methanes Radionuclides
Determine if value is added by couplinga pre- or post-ISCO process
4
Are viable ISCO ti il bl ?
DSTOP: Evaluate other technologies or review
No viable options
TPH Explosives (RDX, TNT, etc.) Inorganic saltsPAHs Organic herbicides or pesticides Perchlorate
Chlorobenzenes NDMA Nutrients (nitrate, ammonia, h h t )options available?
Is data support adequate? E
technologies or review site approach
No
Viable options exist
phosphate)Phenols (e.g., chlorophenols) Ketones
Fuel oxygenates (MTBE, TAME) PCBsAlcohols Dioxins/Furans
34 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
Proceed to conceptual design with a limited number (e.g., 1–3) of higher scoring options
for ISCO and/or coupled approaches
Yes1,4-dioxane
Basic Screening (cont.)START:
1. ISCO Screening
Data Collection: Characterization data, COCs, risk pathways,
PRGs/RAOs preliminary target 1Is ISCO applicable to site COCs and A
No
Is the CSMadequately defined
for screening
PRGs/RAOs, preliminary target treatment zones
1conditions?
STOP:Evaluate other technologies
No
Yes
BLow Contaminant Concentration/MassConcentration purposes?
ISCO Screening Process:Determine viable ISCO options
Consider pre-ISCO technologies/processes 2 C
Are pre-ISCO processes previously implemented,
required or already
Yes
YesType of ISCO Treatment Goal:
Concentration Reduction Mass Reduction Mass Flux Reduction
Removal magnitude (%) 50-90 90-99 99-99.9 50-90 90-99 99-99.9 50-90 90-99 99-99.9Unconsolidated mediaHomogeneous permeable 1 1 2 1 1 2 1 1 2Heterogeneous permeable 1 2 2 1 1 2 1 1 2
technologies/processes
Detailed ISCO Screening 3
required or already occurring?
No
Homogeneous low permeability 1 2 2 1 1 2 1 1 2Heterogeneous low permeability 1 2 2 1 1 2 1 1 2Consolidated media (fractured)Sedimentary 1 2 2 1 1 2 1 1 2Igneous/metamorphic 1 2 3 1 2 3 1 1 2Karst 1 2 3 2 2 3 1 2 3
Determine if value is added by couplinga pre- or post-ISCO process
4
Are viable ISCO ti il bl ?
DSTOP: Evaluate other technologies or review
No viable options
Karst 1 2 3 2 2 3 1 2 3High Contaminant Concentration/Mass
Type of ISCO Treatment Goal:Concentration
Reduction Mass Reduction Mass Flux ReductionRemoval magnitude (%) 50-90 90-99 99-99.9 50-90 90-99 99-99.9 50-90 90-99 99-99.9
Unconsolidated mediaoptions available?
Is data support adequate? E
technologies or review site approach
No
Viable options exist
Homogeneous permeable 1 1 2 1 1 2 1 1 2Heterogeneous permeable 1 2 3 1 1 2 1 2 3Homogeneous low permeability 1 2 3 1 2 3 1 2 3Heterogeneous low permeability 1 2 3 1 2 3 1 2 3
Consolidated media (fractured)Sedimentary 1 2 3 1 2 3 1 1 2
35 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
Proceed to conceptual design with a limited number (e.g., 1–3) of higher scoring options
for ISCO and/or coupled approaches
YesSedimentary 1 2 3 1 2 3 1 1 2Igneous/metamorphic 2 2 3 2 3 3 1 2 3Karst 2 3 3 3 3 3 2 3 3
Basic Screening(cont.)
Low Contaminant Concentration/MassType of ISCO Treatment Goal: Concentration Reduction Mass Reduction Mass Flux Reduction
Removal magnitude (%) 50-90 90-99 99-99.9 50-90 90-99 99-99.9 50-90 90-99 99-99.9Unconsolidated mediaHomogeneous permeable 1 1 2 1 1 2 1 1 2H t bl 1 2 2 1 1 2 1 1 2(cont.) Heterogeneous permeable 1 2 2 1 1 2 1 1 2Homogeneous low permeability 1 2 2 1 1 2 1 1 2Heterogeneous low permeability 1 2 2 1 1 2 1 1 2Consolidated media (fractured)Sedimentary 1 2 2 1 1 2 1 1 2Igneous/metamorphic 1 2 3 1 2 3 1 1 2Karst 1 2 3 2 2 3 1 2 3
High Contaminant Concentration/Mass
Type of ISCO Treatment Goal: Concentration Reduction Mass Reduction Mass Flux ReductionRemoval magnitude (%) 50-90 90-99 99-99.9 50-90 90-99 99-99.9 50-90 90-99 99-99.9
Unconsolidated mediaHomogeneous permeable 1 1 2 1 1 2 1 1 2
Heterogeneous permeable 1 2 3 1 1 2 1 2 3Homogeneous low permeability 1 2 3 1 2 3 1 2 3Heterogeneous low permeability 1 2 3 1 2 3 1 2 3Heterogeneous low permeability 1 2 3 1 2 3 1 2 3
Consolidated media (fractured)Sedimentary 1 2 3 1 2 3 1 1 2Igneous/metamorphic 2 2 3 2 3 3 1 2 3Karst 2 3 3 3 3 3 2 3 3
High Contaminant Concentration/Mass
Type of ISCO Treatment Goal:Concentration
Reduction Mass Reduction Mass Flux ReductionRemoval magnitude (%) 50-90 90-99 99-99 9 50-90 90-99 99-99 9 50-90 90-99 99-99 9Removal magnitude (%) 50-90 90-99 99-99.9 50-90 90-99 99-99.9 50-90 90-99 99-99.9
Unconsolidated mediaHomogeneous permeable 1 1 2 1 1 2 1 1 2Heterogeneous permeable 1 2 3 1 1 2 1 2 3Homogeneous low permeability 1 2 3 1 2 3 1 2 3
36 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
Homogeneous low permeability 1 2 3 1 2 3 1 2 3Heterogeneous low permeability 1 2 3 1 2 3 1 2 3
START:1. ISCO Screening
Data Collection: Characterization data, COCs, risk pathways,
PRGs/RAOs preliminary target 1Is ISCO applicable to site COCs and A
NoPre-ISCO Processes
Is the CSMadequately defined
for screening
PRGs/RAOs, preliminary target treatment zones
1conditions?
STOP:Evaluate other technologies
No
Yes
B
purposes?
ISCO Screening Process:Determine viable ISCO options
Consider pre-ISCO technologies/processes 2 C
Are pre-ISCO processes previously implemented,
required or already
Yes
Yes
Pre-ISCO Advantages Disadvantagestechnologies/processes
Detailed ISCO Screening 3
required or already occurring?
No
Technology Advantages Disadvantages
Excavation • Rapid implementation• Easy to apply oxidant at
the infiltrative surface
• Hotspots may remain• Preferential flow may occur
through backfillDetermine if value is added by coupling
a pre- or post-ISCO process4
Are viable ISCO ti il bl ?
DSTOP: Evaluate other technologies or review
No viable options
the infiltrative surface• Soil mixing approaches
may be more easily implemented
through backfill• Contaminated or highly
organic backfill may cause excessive oxidant demandOxidant treatment of clean options available?
Is data support adequate? E
technologies or review site approach
No
Viable options exist
• Oxidant treatment of clean backfill represents inefficient oxidant use
37 RITS Fall 2010: Is ISCO Right for Your Site?
Proceed to conceptual design with a limited number (e.g., 1–3) of higher scoring options
for ISCO and/or coupled approaches
Yes
ISCO Screening
START:1. ISCO Screening
Data Collection: Characterization data, COCs, risk pathways,
PRGs/RAOs preliminary target 1Is ISCO applicable to site COCs and A
No
Screening Tool for Si S ifi
Is the CSMadequately defined
for screening
PRGs/RAOs, preliminary target treatment zones
1conditions?
STOP:Evaluate other technologies
No
Yes
B
Site-Specific Conditions
purposes?
ISCO Screening Process:Determine viable ISCO options
Consider pre-ISCO technologies/processes 2 C
Are pre-ISCO processes previously implemented,
required or already
Yes
Yes
technologies/processes
Detailed ISCO Screening 3
required or already occurring?
No
Determine if value is added by couplinga pre- or post-ISCO process
4
Are viable ISCO ti il bl ?
DSTOP: Evaluate other technologies or review
No viable options
options available?
Is data support adequate? E
technologies or review site approach
No
Viable options exist
38 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
Proceed to conceptual design with a limited number (e.g., 1–3) of higher scoring options
for ISCO and/or coupled approaches
Yes
Screening Tool for Site-Specific Conditions (cont.)
• Site factorsBasic geology– Basic geology
– Contaminants and co-contaminants– Geochemistry (e.g., pH, alkalinity, chloride, organic carbon content)Geochemistry (e.g., pH, alkalinity, chloride, organic carbon content)– Aquifer hydrology parameters (e.g., permeability and heterogeneity)
• Lookup categoriesp g– Appropriate oxidant and activation approaches for
contaminant(s)A i t id t d ti ti h f
Options
– Appropriate oxidant and activation approaches for geochemistry
– Appropriate delivery approach for viable oxidants
39
– Appropriate delivery approach for geology
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
Screening Tool for Site-Specific Conditions (cont.)
• Outputf f f– Narrower range of viable options for the site based on site-specific
factors– These are the options that can be carried to the Conceptual Design p p g
phase
• NOTE– There is room for practitioner experience and expertise in the process!– Other key considerations in selecting the oxidant and delivery
approachapproach–Issues of implementability
• Are there operations/activities or structures that cannot be disrupted?
40
• Are there subsurface utilities that must be considered?
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Screening
Presentation Overview
• Introduction to ISCO
• ISCO Technology Practices Manual (TPM):ESTCP Project Background and Overview of Results
• ISCO Screening
ISCO Conceptual Design• ISCO Conceptual Design
• ISCO Detailed Design, Implementation, and Monitoring
• Case Studies
• Summary
41
• Summary
RITS Fall 2010: Is ISCO Right for Your Site?
How many injection points?
• Function of– Oxidant characteristics – reaction and/or decomposition
– Oxidant depletion/decomposition rate
– Delivery duration and rate
– Delivery volumeTO WHAT EXTENT ARETHESE VALUES WELLUNDERSTOOD WHENDelivery volume
– Porosity
Contaminant mass and mass distribution
UNDERSTOOD WHENINITIATING ISCO DESIGN?
– Contaminant mass and mass distribution
42 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
How many injection events?
• Typical number of injections is 2-3– Average number of injection events in case study database is ~3
– Survey of professionals: 78% said 2 or more injection rounds was their average experience of ISCO for dissolved plumes in sandy media (Cooper et al., 2006)
• Will not know exact number of events before project start
• Observational approach is critical component of executionpp p– Forms basis for decision based on site-specific experiences
43 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
What volume of oxidant?
• More successful sites tend to have longer injection duration per injection event AND greater total volume of oxidant deliveredinjection event AND greater total volume of oxidant delivered
• Review of case histories– PCE sites with >90% reduction = 0.51 PV
– PCE sites with <90% reduction = 0.24 PV
– TCE sites with >90% reduction = 0.49 PV
– TCE sites with <90% reduction = 0.24 PV
• Survey of professionals– 10-30% of PV is average injected volume specified in design
44
g j p g(Cooper et al., 2006)
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
What are treatability and pilot tests?
• Treatability tests are:– Laboratory-scale ISCO simulations
– Also called “bench tests”
– Batch reactors or flow-through columns/tanks
– Used to evaluate ISCO chemistry issues (additional details to follow)Used to evaluate ISCO chemistry issues (additional details to follow)
• Pilot tests are:– Initial ISCO application performed at field site
– Generally smaller scale than anticipated full scale application
45 RITS Fall 2010: Is ISCO Right for Your Site?
– Used to evaluate oxidant delivery issues (additional details to follow)
ISCO Conceptual Design
Why perform lab treatability tests?
• Improve understanding of system chemistry– Contaminant destruction extent and rate under idealized
conditions
– Oxidant depletion extent and rate
– NAPL destruction
– Byproducts/intermediates and other geochemical impacts(e.g., metals mobilization)
• Optimize reaction chemistry– Oxidant dose and/or activation approach
Basic oxidant demand test and contaminant treatability test: typically under $10-20KDuration: 1 week to 2 monthsMore complexity = greater cost and longer duration
46 RITS Fall 2010: Is ISCO Right for Your Site?
O da t dose a d/o act at o app oac
ISCO Conceptual Design
p y g g• Byproducts/intermediates analysis, transport evaluations, complex contaminant mixtures,
extensive number of reaction conditions
Why perform lab treatability tests? (cont.)
• Will the oxidant sterilize the soil and prevent future i bi l d d ti f t i t ?microbial degradation of contaminants?
C ISCO b d t i hibit h bi ?NO!
• Can ISCO byproducts inhibit or enhance bioprocesses?
Does ISCO mobilize metals?BOTH!
• Does ISCO mobilize metals?
• What other effects does ISCO have?Be aware of and prepare for possibility
• What other effects does ISCO have?pH, solids, gas, temperature, DO, specific conductanceTHESE ARE GREAT MARKERS OF DELIVERY…
47 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
Why perform field pilot-scale tests?
• To assessAbilit f f ti t t l f id t d/ t f d li– Ability of formation to accept volume of oxidant and/or rate of delivery
– Impact of heterogeneities on oxidant distribution– Radius or zone of influence of oxidant– Radius or zone of influence of oxidant– Design uncertainty– Treatment effectiveness– Rebound potential– BONUS: initial contaminant mass destruction
• Example from case histories– In heterogeneous media with DNAPL, the percentage reduction of
48
chlorinated VOCs was greater at full-scale sites that performed pilot tests
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
What does ISCO cost?
• What are typical or expected costs?$ / 3 ( )– Median: $94/yd3 (n=33)
– Median total project cost: $220,000 (n=55)
f ?• What are the primary determinants of cost?– COC group
C t i t l bilit d h d h bi it M di b f d li• Contaminant solubility and hydrophobicity• Amenability to biodegradation
– Geology
Median number of delivery events = 2 (n=27)
Median duration of delivery events = 8 days (n=19)Geology
• Permeability and heterogeneity
– Contaminant mass density
events = 8 days (n=19)Median PVs = 0.2 (n=21)
(above includes only sites with unit cost data, and omits ozone projects,
49
• DNAPL treated at higher cost
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
p jwhich typically last longer but are
automated systems)
What does ISCO cost relative to other technologies?
• McDade et al., 2005 study found median costs of treatment at DNAPL source zones of:sou ce o es o
– Bioremediation $29/yd3
– Thermal $88/yd3
– ISCO $125/yd3
– Surfactant/Cosolvent Flushing $385/yd3
• Industry thinking is that total costs are: Bioremediation < ISCO < Thermal
• Industry thinking is that total time required to achieve treatment is:
Th l < ISCO < Bi di ti
50
Thermal < ISCO < Bioremediation
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
What do ISCO reagents cost relative to other options?
• Approximate ISCO Reagent Costs– Permanganate $2/lb
– Persulfate $2/lb
– Hydrogen Peroxide $0.5/lb (50% to 67% water)
– Ozone costs depend on generatorOzone costs depend on generator
• Approximate Bioremediation Reagent Costs– Molasses $0.4/lb
– Sodium Lactate $1/lb
51 RITS Fall 2010: Is ISCO Right for Your Site?
– Emulsified Oils $1 to $2/lb (~50% water)
ISCO Conceptual Design
ISCO Conceptual Design: Lessons Learned
• Successful ISCO depends on:Understanding interaction of oxidants with natural media– Understanding interaction of oxidants with natural media
• Relationship of rate of oxidant depletion to rate of oxidant delivery
– Applying the appropriate mass, concentration, and volumepp y g pp p , ,• Increasing delivery volume has been associated with success
– Planning for multiple delivery events– Understanding design uncertainty
• If focused on chemistry/geochemistry, reduce uncertainty with lab tests• If focused on issues of deliverability, reduce uncertainty with pilot testsIf focused on issues of deliverability, reduce uncertainty with pilot tests
– Understanding cost variables and appropriately reducing cost uncertainty
• Costs are minimized through solid design and real time decision making
52
• Costs are minimized through solid design and real-time decision making
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
Ti 1 C t l
START:2. Conceptual Design
Select Target Treatment Zone (TTZ) 1
Tier 1 ConceptualDesign: CompareISCO alternatives (e.g., 1-3 options from screening)
Select design tool input parameters 2
Mass balance and experience
3a Spreadsheet design tool
3b
STOP:Reconsider treatmentISCO Conceptual
Is at least one technologically and
economically feasible option
available?
A
Reconsider treatment objectives, TTZ, CSM
certainty, ISCO assessment tool input
and outcome (screening process), and coupling
approaches
No
Yes
ISCO Conceptual Design Process
Tier 2 Conceptual Design: Iteratedesign tool to refine design
Is cost and performance B
Rank and select oxidantand delivery approach options based on certainty of delivery and effectiveness, and cost
4
Yesrefine design. p
confidence acceptable?
B
Consider additional data needs 5STOP:
If fatal design
No
Consider additional modeling needs 6
Refine design with new information 7
Perform FS cost estimation 8
If fatal design flaw is identified
during data collection
and/or modeling efforts
53 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
Proceed with remediation alternatives comparison or
detailed design and planning
Ti 1 C t l
START:2. Conceptual Design
Select Target Treatment Zone (TTZ) 1
Tier 1 Conceptual
Tier 1 ConceptualDesign: CompareISCO alternatives (e.g., 1-3 options from screening)
Select design tool input parameters 2
Mass balance and experience
3a Spreadsheet design tool
3b
STOP:Reconsider treatmentTier 1 Conceptual
Design: Design ToolIs at least one
technologically and economically
feasible option available?
A
Reconsider treatment objectives, TTZ, CSM
certainty, ISCO assessment tool input
and outcome (screening process), and coupling
approaches
No
Yes
Tier 2 Conceptual Design: Iteratedesign tool to refine design
Is cost and performance B
Rank and select oxidantand delivery approach options based on certainty of delivery and effectiveness, and cost
4
Yesrefine design. p
confidence acceptable?
B
Consider additional data needs 5STOP:
If fatal design
No
Consider additional modeling needs 6
Refine design with new information 7
Perform FS cost estimation 8
If fatal design flaw is identified
during data collection
and/or modeling efforts
54 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
Proceed with remediation alternatives comparison or
detailed design and planning
Example: Radial Flow
Radial Flow 1-D Column Flow Radial Flow & Drift
Choose your Flow Type
p
Tier 1 Conceptual Design Tool
Value Units
61 days1 day30 ft5 days
50 mg/L
Model Set Up (see "Model Description" worksheet)
Minimum Oxidant Concentration to Calc ROI
Modeling DurationTime Step
Model LengthTarget Number of Days to Calc ROI
• Soil and oxidant demand characteristics
Design Tool g
30 ft bgs40.00 ft bgs
10 ft5.0000 ft0.30 L/L
Hydrogeologic Characteristics
Thickness of Mobile Zone (Z)
Top of Injection Interval
Porosity
Bottom of Injection IntervalAquifer Thickness
• Injection design parameters– Concentration
Duration
3.0000 ft10.00 ft/day
15 ft
1.60 Kg/L3.0 g MnO4/Kg
Bulk Density
Longitudinal Dispersivity
Total NOD
Soil and NOD Characteristics
Depth to Water TableHydraulic Conductivity (k)
– Duration– Rate
• Desired outcomes
0.500.0030 L/mmol - d
Potassium Permanganate158.03 g/mol0.00 mg/L
Fraction Instantaneous
Oxidants Information
Name of Oxidant
Initial Oxidant Concentration
2nd Order Slow NOD Consumption Rate (K2S)
Molecular Weight of Oxidant
– Concentration at radius of influence (ROI) perimeter
– Duration for oxidant to Borden et al., 2009
TCE131.40 g/mol1.00 mg/L
Contaminants Information
Name of Contaminant
Initial Contaminant ConcentrationMolecular Weight of Contaminants
Period 1
Injection Condition
55 RITS Fall 2010: Is ISCO Right for Your Site?
remain at that point
ISCO Conceptual Design
,Duration 4 DaysContaminant Conc. 0.004 mMol/LMnO4 Conc. 35.23 mMol/LInjection Rate 68,137.41 L/Day
Tier 1 Conceptual Design Tool (cont.)
Oxidant Concentration vs. Radial Distance
7000
8000
(mg/
L)
3 days
5 days
33 days
4000
5000
6000
7000
ncen
tratio
n 61 days
Target Oxidant Conc.
1000
2000
3000
4000
Oxi
dant
Con
00 5 10 15 20 25 30 35
Radial Distance (ft)
O
50 mg/L
56 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
Tier 1 Conceptual Design Tool: Examples
• Base case60 day model duration; minimum oxidant concentration to achieve = 50 mg/L– 60 day model duration; minimum oxidant concentration to achieve = 50 mg/L
– Treatment area = 50’ x 75’– Injecting into 10’ thickness at 30-40’ depth interval WELL DELIVERY
• 5 foot mobile zone within the 10 foot thickness– Longitudinal dispersivity = 3 ft– Hydraulic conductivity = 10 ft/day
• 2” well • 25 psi inj. pressure• 10 hours/day
= 6 000 gpd/well– Hydraulic conductivity = 10 ft/day – Natural oxidant demand = 1 g MnO4
-/kg porous media• Fraction instantaneous = 0.5
= 6,000 gpd/well
• 2nd order rate for slower fraction = 0.003 L/mmol-d– Radius of influence (ROI) overlap desired = 20%– Five days of injection (2 injection events)
57 RITS Fall 2010: Is ISCO Right for Your Site?
Five days of injection (2 injection events)– 5,000 mg/L oxidant concentration
ISCO Conceptual Design
Tier 1 Conceptual Design Tool: Examples (cont.)
Oxidant Concentration vs. Radial Distance
8000
mg/
L)
3 days
5 days
33 days
3000
4000
5000
6000
7000
Con
cent
ratio
n (
61 days
Target Oxidant Conc.
Base Case (NOD = 1 g/kg)• ROI = 28 ft
0
1000
2000
3000
0 5 10 15 20 25 30 35
Oxi
dant
• wells needed = 2• Cost = $68,500
Oxidant Concentration vs. Radial Distance 3 daysRadial Distance (ft)
5000
6000
7000
8000
ntra
tion
(mg/
L) 5 days
33 days
61 days
Target Oxidant Conc.
NOD = 3 g/kg• ROI = 18 ft• wells needed = 5• Cost = $112,0001000
2000
3000
4000
Oxi
dant
Con
ce
58 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
00 5 10 15 20 25 30 35
Radial Distance (ft)
Tier 1 Conceptual Design Tool: Examples (cont.)
Oxidant Concentration vs. Radial Distance
8000
mg/
L)
3 days
5 days
33 days
Base Case (5 days injection)• ROI = 28 ft3000
4000
5000
6000
7000
Con
cent
ratio
n (
61 days
Target Oxidant Conc.
• wells needed = 2• Cost = $68,500
0
1000
2000
3000
0 5 10 15 20 25 30 35
Oxi
dant
Oxidant Concentration vs. Radial Distance 3 daysRadial Distance (ft)
5000
6000
7000
8000
ntra
tion
(mg/
L) 5 days
33 days
61 days
Target Oxidant Conc.
1 day injection• ROI = 12 ft• wells needed = 11• Cost = $88,0001000
2000
3000
4000
Oxi
dant
Con
ce
59 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
00 5 10 15 20 25 30 35
Radial Distance (ft)
Tier 1 Conceptual Design Tool: Examples (cont.)
Oxidant Concentration vs. Radial Distance
8000
mg/
L)
3 days
5 days
33 days
Base Case (5,000 mg/L MnO4-)
• ROI = 28 ft3000
4000
5000
6000
7000
Con
cent
ratio
n (
61 days
Target Oxidant Conc.
• wells needed = 2• Cost = $68,500
0
1000
2000
3000
0 5 10 15 20 25 30 35
Oxi
dant
Oxidant Concentration vs. Radial Distance 3 daysRadial Distance (ft)
5000
6000
7000
8000
ntra
tion
(mg/
L) 5 days
33 days
61 days
Target Oxidant Conc.
7,500 mg/L MnO4-
• ROI = 30 ft• wells needed = 2• Cost = $74,5001000
2000
3000
4000
Oxi
dant
Con
ce
60 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
00 5 10 15 20 25 30 35
Radial Distance (ft)
Tier 1 Conceptual Design Tool: Examples (cont.)
Oxidant Concentration vs. Radial Distance
8000
mg/
L)
3 days
5 days
33 days
Base Case (5,000 mg/L MnO4-)
• ROI = 28 ft3000
4000
5000
6000
7000
Con
cent
ratio
n (
61 days
Target Oxidant Conc.
• wells needed = 2• Cost = $68,500
0
1000
2000
3000
0 5 10 15 20 25 30 35
Oxi
dant
Oxidant Concentration vs. Radial Distance 3 daysRadial Distance (ft)
5000
6000
7000
8000
ntra
tion
(mg/
L) 5 days
33 days
61 days
Target Oxidant Conc.
2,500 mg/L MnO4-
• ROI = 21 ft• wells needed = 3• Cost = $73,7001000
2000
3000
4000
Oxi
dant
Con
ce
61 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
00 5 10 15 20 25 30 35
Radial Distance (ft)
Tier 2 Conceptual DesignTi 1 C t l
START:2. Conceptual Design
Select Target Treatment Zone (TTZ) 1
• Tools available
Tier 1 ConceptualDesign: CompareISCO alternatives (e.g., 1-3 options from screening)
Select design tool input parameters 2
Mass balance and experience
3a Spreadsheet design tool
3b
STOP:Reconsider treatment
– Treatability test procedures• Oxidant demand
Is at least one technologically and
economically feasible option
available?
A
Reconsider treatment objectives, TTZ, CSM
certainty, ISCO assessment tool input
and outcome (screening process), and coupling
approaches
No
Yes
– Pilot test procedures
• Sophisticated modelingTier 2 Conceptual Design: Iteratedesign tool to refine design
Is cost and performance B
Rank and select oxidantand delivery approach options based on certainty of delivery and effectiveness, and cost
4
YesSophisticated modelingtools
• Refined cost estimation
refine design. pconfidence acceptable?
B
Consider additional data needs 5STOP:
If fatal design
No
• Refined cost estimationtools
Consider additional modeling needs 6
Refine design with new information 7
Perform FS cost estimation 8
If fatal design flaw is identified
during data collection
and/or modeling efforts
62 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Conceptual Design
Proceed with remediation alternatives comparison or
detailed design and planning
Presentation Overview
• Introduction to ISCO
• ISCO Technology Practices Manual (TPM):ESTCP Project Background and Overview of Results
• ISCO Screening
ISCO Conceptual Design• ISCO Conceptual Design
• ISCO Detailed Design, Implementation, and Monitoring
• Case Studies
• Summary
63
• Summary
RITS Fall 2010: Is ISCO Right for Your Site?
Are there regulatory issues for ISCO?
• Similar for all oxidantsR l t P
• Secondary containment• Regulatory Programs
– RCRA Hazardous Waste RSD forex-situ systems
• Occupational Safety and Health Administration (OSHA)
f f– CERCLA “release” or “process” definition
– EPCRA reporting
• Potential for exacerbation of indoor air exposure
Impacts to secondary water • State approval for materials
(variances have been granted)
• Impacts to secondary water quality standards
– Taste and odor• Underground injection control
(UIC)• Homeland Security Top Screen
• Manganese, sulfate, etc.
• Metals residuals after ISCO
64 RITS Fall 2010: Is ISCO Right for Your Site?
• Homeland Security Top-Screen
ISCO Detailed Design, Implementation, and Monitoring
What are the important safety precautions?
• Careful health and safety planning, training, and monitoring is mandatorya dato y
• Common hazards– Chemical potential energyp gy– Exothermic reaction heat and gases– Chemical incompatibility – High pressure– Acids/bases– Electrical– Dust hazards
Leak potentials
65
– Leak potentials
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Detailed Design, Implementation, and Monitoring
What should be monitored?
• Dynamic, adaptive, flexible• Real-time (optimization)
• Two phases
Real time (optimization)• Baseline, routine, closure
• Two phases– Delivery/Operational
Man of the prod cts of ISCO (e g pH gas dissol ed o gen solids etc ) • Many of the products of ISCO (e.g., pH, gas, dissolved oxygen, solids, etc.) are excellent indicators of successful delivery
• Delivery should be confirmed BEFORE treatment monitoring is initiated
– Treatment/Performance• Verification of desired COC treatment
66 RITS Fall 2010: Is ISCO Right for Your Site?
• Can include sampling of groundwater and/or soil phases
ISCO Detailed Design, Implementation, and Monitoring
How is design optimized real time?
• Triad Approachhttp://meso.spawar.navy.mil/Newsltr/Images/fy92_no1.gif
Marine Environmental Update, Vol FY 92, No. 1
Sequence of steps in the Observational Method
• Observational Method– Integrate performance monitoring
results and decision logic REAL-TIMEScoping
Scoping
Traditional RI/FSObservational Methodand comparison with the RI/FS process.
g• Operation/injection can be adapted
“as you go”– Relies on understanding of and
Determine response action
Establish site conditionsRemedial investigationg
planning for uncertainties• Reasonable bounds of conditions
and response plans
Probable condition and reasonable deviations
Feasibility study
Remedial investigation
Feasibility study, record of decision
• Techniques– Direct push technologies (DPT)
In sit sensors ith data loggers
Design remedial action
Implement remedial action
Design remedial action
Implement remedial action
67 RITS Fall 2010: Is ISCO Right for Your Site?
– In situ sensors with data loggers(e.g., temperature, conductivity)
ISCO Detailed Design, Implementation, and Monitoring
Respond to deviations Implement contingency plan
Is rebound a problem?
• Rebound defined– Increase in aqueous phase COC concentrations that occur after ISCO
following an initial reduction in concentration that resulted from the ISCO application: NOT influxpp
• CausesContaminant mass remains untreated– Contaminant mass remains untreated
• Post-ISCO equilibration/partitioning
• ATTRIBUTES• ATTRIBUTES– Marking transfer of contaminants to more treatable aqueous phase
C h l l t k NAPL/ b d
68
– Can help locate unknown NAPL/sorbed
RITS Fall 2010: Is ISCO Right for Your Site?ISCO Detailed Design, Implementation, and Monitoring
ISCO Detailed Design, Planning, Implementation and Monitoring: Lessons LearnedMonitoring: Lessons Learned• Successful ISCO depends on:
– Regulatory compliance– Understanding and planning for hazards associated with
handling oxidantshandling oxidants– Real-time, dynamic monitoring
• Delivery and treatment performance considered independently• Delivery and treatment performance considered independently
– Applying the Observational Method or Triad Approach• Real-time decision making and optimization• Real-time decision making and optimization• Contingency planning
– Planning for and exploiting “rebound” or contaminant
69
Planning for and exploiting rebound or contaminantre-equilibration
PreliminaryDesign
START:3. Detailed Design and Planning
Prepare preliminary basis of design report 1
STOP:
Meet and AgreeP i t P di
A
Is the preliminarydesign basis adequate for
detailed design?
Identify operational objectives and prepare ti d ti l
2
STOP:Perform data
collection, modeling, and/or pilot testing to
refine design and reduce uncertainty
Yes
No
ISCO Detailed D i d
Final Design
Prior to Proceeding
B
Is a performance-based contract
feasible and cost-
operation and contingency plan
Prepare performance specifications
3aPrepare detailed
design specs and drawings
3bNo Yes
Design and Planning Process
feasible and costeffective?
Is the project constructible
and biddable?
C
specificationsand drawings
Prepare a constructioncost/ engineer’s
estimate5
Refine preliminary basis of design report,
operation plan, and performance specs/
detailed design specs d d i
7
No
Yes
Is the projected cost
within the budget?
D
Perform value engineering or design optimization assess-
ment to improve constructibility and
biddability
4Perform value
engineering or design optimization
assessment to costs
and drawings
6
No
No
Yes
PlanningMeet and Agree Prior to Proceeding
Assemble procurement packages, conduct bid process,and select contractors
8
Prepare quality assurance, health and safety, and performance monitoring plans
9
70 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Detailed Design, Implementation, and Monitoring
Proceed to implementation and performance monitoring
sa e y,a d pe o a ce o o g p a s
ISCO Detailed Design and Planning Process (cont.)
• Key features– Preliminary design
• Refine conceptual design– Rerun design tools with new data
– Detailed evaluation of logistics of well locations, oxidant delivery, etc.
• Document design in Design Basis Report• Document design in Design Basis Report
• Reassess adequacy of information
• Prepare contingency plans PreliminaryD i
START:3. Detailed Design and Planning
Prepare preliminary basis of design report 1Prepare contingency plans Design
A
Is the preliminarydesign basis adequate for
detailed design?
STOP:Perform data
collection, modeling, and/or pilot testing to
refine design and reduce uncertainty
No
71 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Detailed Design, Implementation, and Monitoring
Meet and AgreePrior to Proceeding
Identify operational objectives and prepare operation and contingency plan
2
yYes
ISCO Detailed Design and Planning Process (cont.)
• Key features (cont.) Final Design
Is a performance-b d t t
Prepare Prepare detailed No Yes
– Final design and planning
Bbased contract feasible and cost-
effective?
Is the project constructible
and C
performance specifications
3adesign specs and drawings
3b
Prepare a constructioncost/ engineer’s 5
Refine preliminary basis of design report,
operation plan, and 7
Yes
• Decide on contracting approach
• Evaluate constructability Is the
projected cost within the D
biddable?
Perform value engineering or design optimization assess-
ment to improve4
estimate
Perform value engineering or design
performance specs/ detailed design specs
and drawings
7
6
No
Noyand cost
• Prepare contracting packages and plans
PlanningMeet and Agree
within the budget?
ment to improve constructibility and
biddability
g g goptimization
assessment to costs
Assemble procurement packages, conduct bid process and select contractors
8
6
Yes
packages and plans Prior to Proceeding
Proceed to implementation
bid process, and select contractors
Prepare quality assurance, health and safety, and performance monitoring plans 9
72 RITS Fall 2010: Is ISCO Right for Your Site?ISCO Detailed Design, Implementation, and Monitoring
Proceed to implementation and performance monitoring
ImplementationComplete pre-construction activities 1
START:4. ISCO Implementation and Performance Monitoring
Implementation and Performance Monitoring
Do baseline monitoring results confirm CSM and
affirm the path forward?
A
Install ISCO implementation infrastructure and complete baseline monitoring
2
Refine the CSM
3No
Review and modifyoperation and
contingency plan to account for learned site
conditionsMeet and agree
prior to proceeding
4
Performance Monitoring Process• Key features
forward?
Are site conditions significantly
different to require re-design?
BInitiate operation plan, including delivery,
process monitoring, and optimization programs
5No
Yes
Yes
• Key features– Re-assess approach after
baseline data collection
Delivery Performance MonitoringAre delivery monitoring
results meeting process
performance criteria?
C
Are modifications
achieving delivery
performance milestones?
D
Execute delivery
contingency plan
6No No
– Separate and highlight DELIVERY performance monitoring from Are
difi tiAre
treatment
Implement treatment performance monitoring program 7
Execute
STOP:Re-evaluate the ISCO approach
No
Yes
No
Yes
Yes
monitoring from TREATMENT performance monitoringNote contingency
modifications achieving
performance milestones?
Ftreatment
results meeting performance
criteria?
E
Havetreatment
objectives been G
treatment contingency
plan
8No
Yes
No
No
73 RITS Fall 2010: Is ISCO Right for Your Site?
– Note contingency implementation
ISCO Detailed Design, Implementation, and Monitoring
Treatment Performance Monitoring
STOP: ISCO Treatment Complete
objectives been achieved?
Yes
Presentation Overview
• Introduction to ISCO
• ISCO Technology Practices Manual (TPM):ESTCP Project Background and Overview of Results
• ISCO Screening
ISCO Conceptual Design• ISCO Conceptual Design
• ISCO Detailed Design, Implementation, and Monitoring
• Case Studies
• Summary
74
• Summary
RITS Fall 2010: Is ISCO Right for Your Site?
Case Study 1 – NTC Orlando OU-4 (2000 to 2003)
• COC ConditionsPCE d d d ti d t i t ti i GW PCE 26 000 – PCE and degradation products, maximum concentrations in GW: PCE 26,000 µg/L, TCE 13,000 µg/L, 3,900 µg/L cis-DCE, DNAPL assumed to be present
• Geologic Conditions– Fine to medium sand, average hydraulic conductivity (K) = 30 ft/day
• Project Goals– Attain Florida MCLs of 3 µg/L PCE and TCE, 70 µg/L cis-DCE in groundwater– Up to 99.99% concentration reduction required
• ISCO Full Scale Design– Permanganate recirculation
5 i t NOD b h t t il t d MODFLOW
75 RITS Fall 2010: Is ISCO Right for Your Site?
– 5-minute NOD bench test, pilot, and MODFLOW
Case Study 1
Photo courtesy of M. Singletary, NAVFAC SE
Project Results
• Injection and extraction rates declined significantly over time Attributed to solid manganese dioxide (MnO ) precipitation– Attributed to solid manganese dioxide (MnO2) precipitation
– Well rehabilitation and alternative filtration efforts unsuccessful– Resulted in fewer than expected PVs recirculatedResulted in fewer than expected PVs recirculated– Outcome significantly different than that predicted by MODFLOW
• Project goals not achieved, and COCs persisted at j g , pconcentrations above MCLs
• Bioremediation with emulsified oil used in source area after ISCOISCO
• Subsequent 5-day NOD testing indicated high NOD (0.5 to 7 mg/kg) and reactive transport modeling indicated short to very
76
mg/kg) and reactive transport modeling indicated short to very short permanganate transport distances
RITS Fall 2010: Is ISCO Right for Your Site?Case Study 1 – NTC Orlando OU-4
Key Lessons Learned
• Results highlight the importance of NOD– Significant amount of oxidant consumed due to non-target
reactions
• Traditional groundwater models (e g MODFLOW) may not • Traditional groundwater models (e.g., MODFLOW) may not predict ISCO result
– Groundwater flow ≠ Oxidant flowGroundwater flow ≠ Oxidant flowbecause oxidant reacts during transport
– ISCO can change aquifer hydraulicpropertiesproperties
• Project goals were very aggressive, and unrealistic in most situations
77 RITS Fall 2010: Is ISCO Right for Your Site?
and unrealistic in most situations
Case Study 1 – NTC Orlando OU-4
Photos courtesy of M. Singletary, NAVFAC SE
Case Study 2 – NAS South Weymouth Bldg. 81 (2000)
• COC ConditionsC i l d PCE d BTEX f UST d l t i – Commingled PCE and BTEX from UST and solvent use, maximum concentrations in GW: PCE 1,000 µg/L, 850 µg/L BTEX, DNAPL likely present
• Geologic Conditions– Fractured granite bedrock, average K = 0.4 ft/day– Fractures spacing generally less than 1 ft, though borehole geophysics
indicate that hydraulically significant fractures are more widely spacedindicate that hydraulically significant fractures are more widely spaced
• Project Goals– Reduce COC concentrations in GW by 90%Reduce COC concentrations in GW by 90%
• ISCO Pilot Design– 2 events of CHP into vertical wells, 1 PV of 50% H2O2 mixed with iron catalyst
78 RITS Fall 2010: Is ISCO Right for Your Site?
2 events of CHP into vertical wells, 1 PV of 50% H2O2 mixed with iron catalyst
Case Study 2
Project Results
• Significant COC reductions observed in GW, followed by rebound rebound
– 90% reductions only achieved for short timeR b d d ithi i t l 2 th f i j ti– Rebound occurred within approximately 2 months of injection
– Rebound occurred in only one third of monitoring wells
• Project goals not achieved as COC reductions were not permanent
• Monitoring data indicated that oxidant solution may have flowed preferentially through larger fractures
79
• Another source zone remedy to be selected in 2011RITS Fall 2010: Is ISCO Right for Your Site?Case Study 2 – NAS South Weymouth Building 81
Key Lessons Learned
• ISCO can be performed in fractured rock, but significant challenges existchallenges exist
– Preferential flow through fractures– Diffusion of COCs out of rock matrix (“back-diffusion”) leading to Diffusion of COCs out of rock matrix ( back diffusion ) leading to
rebound– Very difficult to assess mass of COCs in non-aqueous phases, so mass
reduction calculations also very difficultreduction calculations also very difficult
• Rebound was limited to small portion (~33%) of treatment zoneSi il b ti t th ISCO f t d k li ti i – Similar observations at other ISCO fractured rock applications in DISCO
– May suggest that ISCO rebound data can help refine location of
80
y gg psubsurface hot spots
RITS Fall 2010: Is ISCO Right for Your Site?Case Study 2 – NAS South Weymouth Building 81
Case Study 3 – Allegheny Ballistics Lab., WV (2005)
• COC Conditions1 000 lbs TCE disposed of each month in unlined pits from 1970 to 1978 – 1,000 lbs TCE disposed of each month in unlined pits from 1970 to 1978 (96,00 lbs total?), GW concentrations up to 50,000 µg/L, DNAPL presence very likely
G l i C diti• Geologic Conditions– Heterogeneous sand and gravel alluvial deposits
Project goals • Project goals – Evaluation of ISCO as potential mass reduction technology
• ISCO Pilot Design• ISCO Pilot Design– Persulfate injected into vertical wells, activated by iron first, followed
by heat
81 RITS Fall 2010: Is ISCO Right for Your Site?
– 0.4 g/kg oxidant dose, 0.007 PVs
Case Study 3
Project Results
• Modest reductions observed 3 weeks post-ISCOSi ifi t b d f 6 k t ISCO d i • Significant rebound from 6 weeks post-ISCO onwards, in some cases to concentrations equal to or greater than pre-ISCO concentrations
• No soil sampling performed, groundwater concentrations didn’t decline, how to assess mass reduction?
“ it h b f l t l t l ffi i b i – “…it may have been useful to evaluate removal efficiency by measuring concentrations of COCs in both soil and groundwater… it is possible that removal efficiency achieved by pilot test was underreported based solely on analytical results of groundwater samples.” (NAVFAC 2010)y y g p ( )
– Mass reductions generally greater, sometimes significantly greater, in soil phase relative to groundwater phase based on sites in DISCO
T t l t $407 000 $58/ d3 (NAVFAC 2010)
82 RITS Fall 2010: Is ISCO Right for Your Site?
• Total cost $407,000, or $58/yd3 (NAVFAC 2010)
Case Study 3 – Allegheny Ballistics Laboratory, WV
Key Lessons Learned
• Performance monitoring program not ideal for project goals b l h l dbecause only aqueous phase was sampled
– Aqueous phase COC concentrations only tell a small part of the storstory
– Soil sampling can provide more comprehensive data, including:• Assessment of DNAPL, sorbed, and other phases
• Much stronger basis from which to perform mass reduction calculations
• ISCO project may have been under-designed– Known DNAPL disposal and very high TCE concentrations in GW
83
– Low oxidant dose and very low number of PVs deliveredRITS Fall 2010: Is ISCO Right for Your Site?Case Study 3 – Allegheny Ballistics Laboratory, WV
Case Study 4 – NAS Alameda Point Site 14 (2007 to 2009)
• COC ConditionsVi l hl id (VC) lti f l t t f ll d b ti l d ti – Vinyl chloride (VC) resulting from solvent storage followed by partial reductive dechlorination, maximum concentrations in GW: VC 380 µg/L, no DNAPL
• Geologic Conditions– Heterogeneous fine to medium sand fill materials, average K = 8 ft/day
• Project Goals– Risk-based VC concentration 15 µg/L in
groundwater
• ISCO Full Scale Design
IR Site 14IR Site 14
• ISCO Full Scale Design– Persulfate recirculation, 3 injection events– 1 to 3 g/kg oxidant dose, 1 to 2 PVs
84 RITS Fall 2010: Is ISCO Right for Your Site?
1 to 3 g/kg oxidant dose, 1 to 2 PVs– Bench and pilot studies implemented
Case Study 4
Photo courtesy of T. Chaudhry, NAVFAC ESC
Project Results
• Maximum VC concentration in d t d d f 380 groundwater reduced from 380
to <40 µg/L
• 70% reduction in VC mass
• Remedial goal of 15 µg/L met g µgin 20 of 25 MWs, monitoring ongoing
• Total cost $1,850,000, or$54/yd3 (NAVFAC 2010)
Photo courtesy of T. Chaudhry, NAVFAC ESC
85 RITS Fall 2010: Is ISCO Right for Your Site?Case Study 4 – NAS Alameda Point Site 14
Key Lessons Learned
• ISCO design incorporated health & safety concernsIron activation selected over base activation after verification of – Iron activation selected over base activation after verification of comparable performance in bench study
• Attempted to reduce risk to nearby Oakland Inner Harbor– Clear persulfate solution chosen over dark purple permanganate after
both oxidants performed similarly in pilot study
Observational Method used to guide ISCO application• Observational Method used to guide ISCO application– GW sampling in between ISCO events helped target next phase of work– Recirculation rates modified based on field observations– Recirculation rates modified based on field observations– Extraction wells retrofitted with vacuum to enhance flow rates
• Cost data provide good example of “economies of scale” when
86
Cost data provide good example of economies of scale when treating large sites
RITS Fall 2010: Is ISCO Right for Your Site?Case Study 4 – NAS Alameda Point Site 14
Presentation Overview
• Introduction to ISCO
• ISCO Technology Practices Manual (TPM):ESTCP Project Background and Overview of Results
• ISCO Screening
ISCO Conceptual Design• ISCO Conceptual Design
• ISCO Detailed Design, Implementation, and Monitoring
• Case Studies
• Summary– Take-Home Messages– Acknowledgements
87
• Summary
RITS Fall 2010: Is ISCO Right for Your Site?
– References– Contact Information
Take-Home Messages
1. One or more oxidants can destroy most, if not all, of the common organic COCsorganic COCs
2. Effective in situ delivery is essential3. ISCO can successfully achieve treatment goalsy g4. ISCO has great potential for successful use at some, but not all sites5. ISCO can be, and often must be, synergized with other remedies6. ISCO will normally require two or more delivery events7. ISCO can temporarily perturb subsurface conditions8 Monitoring program must be consistent with project objectives8. Monitoring program must be consistent with project objectives9. So-called “rebound” will often occur, more so at some sites than
others
88
10.The cost of ISCO varies widely
RITS Fall 2010: Is ISCO Right for Your Site?Summary
Acknowledgments: ISCO TPM Project Team
• Principal Investigators • Project Team Members– Robert Siegrist, Ph.D., Colorado
School of Mines (CSM)
– Michelle Crimi, Ph.D., Clarkson
– Fritz Krembs (CSM)
– Ben Petri, M.S. (CSM)
G N (CH2M Hill), ,University
• Co-Principal Investigators
– Gene Ng (CH2M Hill)
– Michael A. Singletary, P.E. (NAVFAC)
– Junko Munakata Marr, Ph.D. (CSM)
– Thomas A. Palaia, P.E. (CH2M Hill)– Kathryn Lowe, M.S. (CSM)
– Nancy Ruiz, Ph.D. (NAVFAC ESC)– Thomas J. Simpkin, Ph.D. (CH2M Hill)
– Tissa Illangasekare, Ph.D., P.E., DEE (CSM)
89 RITS Fall 2010: Is ISCO Right for Your Site?
(CSM)
Summary
References
• Cooper, E., A. Livadas, T. Hanna, J. McAssey, G. Burke, and M. Martin 2006 National Survey of In Situ Soil and Groundwater Martin 2006. National Survey of In-Situ Soil and Groundwater Chemical Oxidation Design Criteria. Fifth International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Monterey, CA.
• McDade, J.M., T.M. McGuire, and C.J. Newell 2005. Analysis of , , , yDNAPL Source-Depletion Costs at 36 Field Sites. Remediation, Spring: 9-18.
• National Research Council (NRC) 2004. Contaminants in the Subsurface: Source Zone Assessment and Remediation. The N ti l A d i P W hi t D C 372
90 RITS Fall 2010: Is ISCO Right for Your Site?
National Academies Press, Washington, D.C., 372 pp.
Summary
References (cont.)
• NAVFAC ESC 2010. Technical Report TR-2333-ENV: Cost and Performance Report for Persulfate Treatability Studies, June.e o a ce epo t o e su ate eatab ty Stud es, Ju e
• Siegrist RL, Crimi ML, Petri B, Simpkin T, Palaia T, Krembs FJ, Munakata-Marr J, Illangasekare T, Ng G, Singletary M, Ruiz N. , g , g , g y ,2009. In Situ Chemical Oxidation for Groundwater Remediation: Site Specific Engineering and Technology Application. ER-0623 Final Report. Prepared for the ESTCP, Arlington, VA, USA. http://docs.serdp-estcp.org.
• Siegrist, R.L., B.G. Petri, F.J. Krembs, M.L. Crimi, S. Ko, T.J. Si ki d T A P l i 2008 I Sit Ch i l O id ti f Simpkin, and T.A. Palaia 2008. In Situ Chemical Oxidation for Remediation of Contaminated Groundwater: Summary Proceedings of an ISCO Technology Practices Workshop. ESTCP P j t ER 0623 J
91
ESTCP Project ER-0623, June.
RITS Fall 2010: Is ISCO Right for Your Site?Summary