wstb groundwater webinar presentation

Alternatives for Managing the
Nation’s Complex Contaminated
Groundwater Sites
Webinar
1 pm Eastern Time Zone
Wednesday December 12, 2012
Water Science and Technology Board
National Research Council

Committee on Future Options for Management in
the Nation’s Subsurface Remediation Effort
MICHAEL KAVANAUGH, NAE, Chair, Geosyntec
WILLIAM ARNOLD, University of Minnesota
BARBARA BECK, Gradient Corporation
YU-PING CHIN, The Ohio State University
ZAID CHOWDHURY, Malcolm Pirnie
DAVID ELLIS, DuPont Engineering
TISSA ILLANGASEKARE, Colorado School of Mines
PAUL JOHNSON, Arizona State University
MOHSEN MEHRAN, Rubicon Engineering Corporation
JAMES MERCER, Tetra Tech GEO

KURT PENNEL, Tufts University
ALAN RABIDEAU, State University of New York, Buffalo
ALLEN SHAPIRO, U.S. Geological Survey
LENNY SIEGEL, Center for Public Environmental Oversight
WILLIAM WALSH, Pepper Hamilton LLP

Background
• For 30 years, remediation has eliminated or controlled acute risks;
many hazardous waste sites with contaminated groundwater now
“closed”.
• But, reaching unlimited use and unrestricted exposure (UU/UE) (i.e.,
drinking water standards or highest beneficial use) remains a
significant challenge.
• A substantial number of sites exhibit attributes that make restoration
unlikely for many decades.
• DoD has invested heavily in addressing legacy contamination in
groundwater ($30 billion to date).

Central theme of this report is how the nation should deal with
sites where residual contamination remains above UU/UE levels


Stringfellow, CA, cerca 1995
34 million gallons of liquid
hazardous waste released
Site placed on NPL in 1983
Exposure pathways controlled
Restoration will take ~ 500 yrs
Future cost in excess of $200
million; Cost to Date > $500 M.
State is RP. Have requested a
TI Waiver for two of the four
“zones”. ROD 5 in progress.
Long-term management!

Statement of Task
• What is the size of the nation’s hazardous waste
problem?
• How much contamination can current technologies
remove?
• What is the future of treatment technologies?

• Can mass removal be better correlated with sitespecific risk?
• How can better decisions be made?

Magnitude of the Problem
• Estimated the number of sites that
have not yet reached “closure”
• Tabulated remediation costs
expended to date
• Summarized costs estimated by
others to reach “closure” as
defined by regulatory program
• Estimated number of sites affecting
public water supply sources

• DoD
• CERCLA
(Superfund)
• RCRA
• UST
• DOE

• Other federal sites
• State Sites

Information listed above was not
available for some programs
Sources: DoD & DOE annual reports to Congress; EPA website; RCRA and UST program managers; EPA (2004); USGS reports

Estimated Number of Sites/Facilities with Conditions not
allowing for Closure and Costs to Complete
Program/Agency

Number of Facilities

DoD

Number of Sites

Estimated Cost to
Complete ($B)


4,329

$12.8

CERCLA

1,364

$16 -23

RCRA

2,844

$32.4

UST

87,983


$11

DOE

3,650

$17.3 – 20.9

Other Federal Sites

>3,000

$15 - 22

State Sites

>23,000

$5


TOTALS

>126,000

$110 - 127

See Table 2-6 in report

Chapter 2 Main Conclusions
• 126,000 sites that have not yet reached closure is likely an
underestimate.
• Could not determine the total number of sites with residual
contamination above levels allowing for UU/UE (must be > 126,000).
• More than 12,000 sites are “complex”.
• Estimated future cost of $110-127 billion likely an underestimate.
• ~10% of Superfund sites affect drinking water supply sources.
• Nomenclature for site closure inconsistent between federal
agencies, the states, and the private sector; confusing for public.
• More consistent and transparent terminology needed.


Analysis of 80 NPL-Delisted Groundwater Sites
• The Committee evaluated 80 contaminated groundwater sites,
identified by EPA personnel, already deleted from the NPL.
• Site documents* were queried to consider several questions:







What were the remedial goals? (e.g., MCLs or other)
Contaminants of concern?
Were MCLs met? If not, what levels were achieved?
What remedial actions were used?
Does monitoring continue?
Were alternative strategies used? (e.g., TI Waivers)

*SOURCES: CERCLIS, including 5-year reviews, fact sheets, Records of Decision, and close-out
documents available on-line.


Did the 80 Delisted NPL Sites Reach MCLs?
MCL Characterization
Not a Groundwater Site
5

MCL Achievement Unknown

Remedial Objective
Other Than
Meeting MCLs

MCLs Achieved: Active Remedy, No LTM
14

6

4
12


4
MCLs Not Achieved: Deleted
Based on Risk Assessment: LTM

19

2

MCLs Not Achieved: Deleted
Based on Risk Assessment: No LTM

14

MCLs Not Achieved: LTM

MCLs Achieved: Active
Remedy, LTM

MCLs Achieved: No Active
Remedy, No LTM


Chapter 2 Main Conclusions
• 126,000 sites that have not yet reached closure is likely an underestimate.
• Could not determine the total number of sites with residual contamination
above levels allowing for UU/UE (must be > 126,000).
• More than 12,000 sites are “complex”.
• Estimated future cost of $110-127 billion likely an underestimate.
• ~10% of Superfund sites affect drinking water supply sources.

• Nomenclature for site closure inconsistent between federal
agencies, the states, and the private sector; confusing for public.
• More consistent and transparent terminology needed.

Capabilities of Current Technologies – An Update
TECHNOLOGIES

• Thermal Treatment
• In Situ Chemical Oxidation
• Surfactant and Co-solvent
Flushing
• In Situ Bioremediation
• Pump and Treat for hydraulic
containment
• Physical Containment
• Permeable Reactive Barriers
• Monitored Natural Attenuation
• Combined Remedies

PERFORMANCE
Thermal Treatment