United States
Environmental Protection
Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S2-85/028 June 1985
c/EPA Project Summary
Guide for Decontaminating
Buildings, Structures, and
Equipment at Superfund Sites
M. P. Esposito, J. L. McArdle, A. H. Crone, J. S. Greber, R. Clark,
S. Brown, J. B. Hallowell, A. Langham, and C. D. McCandlish
This study produced a general
decontamination guide for use by
those responsible for decontamination
activities at Superfund sites. It con-
tains stepwise guidance for develop-
ing a cost-effective decontamination
strategy, descriptions of methods for
treating or removing contaminants
from structual materials, case studies
illustrating field use of many decon-
tamination methods, cost analyses for
the application of each method to a
model building, a discussion of
worker health and safety precautions,
and a summary of available sampling
techniques for measuring contamina-
tion levels both before and after
cleanup. Additional research is recom-
mended to 1) verify the effectiveness
of existing decontamination methods
for a range of contaminants and
structural materials, 2) develop and
demonstrate new cleanup techniques,
and 3) improve sampling techniques
for determining structural contamina-
tion.
This Project Summary was devel-
oped by EPA's Hazardous Waste En-
gineering Research Laboratory, Cin-
cinnati, Ohio, to announce key find-
ings of the research project that is
fully documented in a separate report
of the same title (see Project Report
ordering information at back}.
Introduction
The Comprehensive Environmental
Response, Compensation, and Liability
Act of 1980 (CERCLA), otherwise known
as Superfund, established a dual-phase
program for responding to environmental
problems caused by hazardous sub-
stances. The removal program involves
cleanup or other actions taken in response
to emergency conditions or on a short-
term or temporary basis. The remedial
program involves long-term responses
that permanently remedy problem sites.
To be eligible for cleanup under Super-
fund, a site must be included on the Na-
tional Priorities List (NPL). As of this
writing, 538 sites appear on the NPL,
which was first promugated by the U.S.
Environmental Protection Agency (EPA)
on September 8, 1983. Currently, the EPA
is proposing the addition of 248 new sites
to the list.
As the number of sites on the NPL
grows and as removal and remedial ac-
tivities at Superfund sites accelerate, the
task of decontaminating buildings, struc-
tures, and construction equipment will
become increasingly important. These
items often represent large capital in-
vestments, and the costs of dismantling
and disposing of such structures in a
secure landfill can be very expensive. The
objective of an effective decontamination
program, therefore, is to return con-
taminated buildings, structures, and
equipment to active, productive status.
The goal of this study was the develop-
ment of a general guide for government
personnel, cleanup contractors, and other
individuals responsible for planning and
executing decontamination activities at
Superfund sites.
Procedures
Initially a survey was conducted of
decontamination activities at 50 Super-
fund sites across the country. These sites
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were thought to have contaminated build-
ings, structures, and equipment, and the
survey gathered information on 1) the
types of contaminants of most concern
and 2) the methods currently proposed or
used for decontamination of the build-
ings, structures, and equipment in place
at these sites. This survey revealed that
the methods used to remove contami-
nants from buildings, structures, and
equipment are few and rarely documented
in detail. For example, it is common prac-
tice to steam clean equipment such as
backhoes, bulldozers, and drilling augers,
but testing to verify that the contaminants
of concern have been adequately removed
is generally not performed. Contaminated
buildings and structures are seldom
cleaned and returned to active use. More
often, they are closed and barricaded to
prevent further entry and exposure, or
they are torn down and buried in secure
landfills. Contaminated underground
structures such as tanks, sumps, and
sewers are sometimes filled in place with
concrete to prevent their reuse. These
and other survey findings clearly pointed
to the need for basic guidance dealing
with the identification and selection of ap-
propriate decontamination methods, as
well as their application to contaminants
and structural materials.
The remainder of the project focused
on development of a decontamination
data base containing current information
on specific cleanup methods and their ap-
plication, as well as guidelines for
developing site-specific cleanup strategies.
Those with direct experience in programs
involving decontamination of dioxins, ex-
plosives, PCBs, and other toxic wastes
from buildings and equipment were con-
tacted. In addition, the literature was
thoroughly searched for information on
decontamination methods.
Discussion
Figure 1 summarizes the strategy for
dealing with building decontamination, in-
cluding guidance and information for
selecting the least costly method(s) that
are technologically feasible and that will
effectively reduce comtamination to pre-
determined levels. Step 1, determining the
nature and extent of contamination, con-
sists of querying former employees;
searching old business records, inspection
reports, and news stories; conducting a
visual site inspection; and collecting and
analyzing samples from the contaminated
surfaces or structures. Step 2, developing
a site-specific decontamination plan, is
further broken down into the following1
activities: evaluating hazards; identifying
the future intended use of buildings,
structures, and equipment; establishing
decontamination target levels for the con-
taminants present; identifying and eval-
uating potential decontamination meth-
ods; selecting the most cost-effective
method(s) for achieving the decontamina-
tion target levels; determining worker
health and safety requirements (training,
medical surveillance, personal protective
equipment, site safety); writing the site
decontamination plan; estimating costs;
and hiring the contractor and initiating
cleanup. Step 3, evaluating decontamina-
tion effectiveness, involves reinspecting
the site for evidence of residual con-
tamination; collecting and analyzing
samples from the decontaminated area;
determining whether the target levels for
residual contamination have been
reached; repeating, and if necessary,
modifying the decontamination pro-
cedures until satisfactory results are ob-
tained; and determining the need for long-
term monitoring.
The document also describes several
traditional and developmental decon-
tamination methodologies and discusses
their potential applicability to various com-
binations of contaminants and structural
materials. Method descriptions include a
general discussion of the procedure, con-
taminant and surface applicability, en-
gineering considerations (including
building preparation, process description,
and equipment needs), safety require-
ments, waste disposal, and costs. The
following paragraphs briefly describe each
example method:
Absorption is widely used in industrial
settings to clean up chemical and other li-
quid spills. It is also commonly used by
emergency response teams such as fire
departments. This method is most ap-
plicable immediately following liquid con-
taminant spills. Contaminants rapidly
penetrate most surfaces, and absorbents
act to contain them. Depending on the
surface and time elapsed since the spill,
further decontamination procedures may
have to be employed.
Acid etching of a contaminated surface
is used to promote corrosion and removal
of the surface layer. Muriatic acid
(hydrochloric acid) is used to remove dirt
and grime from brick building surfaces in
urban areas and to clean metal parts
(e.g., pickle liquors from metal finishing
operations). The resulting contaminated
debris is then neutralized and disposed of.
Thermal or chemical treatment of the
removed material may be required to
destroy the contaminant before disposal.
Although this technique is not known to
have been applied to chemically con-
Ste
Detei
Natui
Exte
Contan
1 1
Query
Former
Employees
Pi
'mine
e and
nt of
lination
Ste
Dev
* Site-S
Deconta
PI
\ \
Search
Old
Records
Conduct
Visual
Inspection
Collect
and
Analyze
Samples
\
Evaluate
Hazards
p2
e/op
pecific
mination
an
1
Reinspect
Site
1 1 1 1 1
Identify
Future
Use
Establish
Target
Levels
Identify
Potential
Methods
Select
Cost-
Effective
Method(s)
Determine
Health and
Safety
Requirements
1
Step 3
Evaluate
Decontamination
Effectiveness
Collect
and
Analyze
Samples
1 1
Compare
to Target
Levels
Write Site
Decontamination
Plan
Repeat or
Modify
Procedure
as Needed
1
Hire
Contractor
and Initiate
Cleanup
Determine
Need for
Long-Term
Monitoring
Figure J. Flow diagram of steps for developing a decontamination strategy
2
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taminated building surfaces, it is believed
to have good potential.
Asbestos abatement consists of four
techniques: removal, encapsulation, en-
closure, and special operations (e.g.,
maintenance and monitoring). In removal
operations, all friable asbestos-containing
building materials are completely removed
to eliminate the release of asbestos fibers
into the air. The other techniques leave
the asbestos fibers in place but limit
potential exposure levels through various
treatment, maintenance, and inspection
procedures.
Bleaching formulations are applied to a
contaminated surface, allowed to react
with contaminants, and removed. Ap-
plication usually occurs in conjunction
with other decontamination efforts, such
as the use of absorbents and/or water-
washing. Bleach has been used as a
decontaminant against mustard, G and V
chemical agents, and (experimentally) or-
ganophosphorous pesticides.
Demolition of a building, structure, or
piece of equipment includes complete
burndown, controlled blasting, wrecking
with balls or backhoe-mounted rams, rock
splitting, sawing, drilling, and crushing.
Many of these techniques have been em-
ployed for nuclear facility decontamination
and for the cleanup of military arsenals.
Dismantling refers to the physical
removal of selected structures (such as
contaminated pipes, tanks, and other pro-
cess equipment) from buildings or other
areas. It can be the sole decontamination
activity (e.g., removal of contaminated
structures from an otherwise clean build-
ing), or it can be used in the initial stage
of a more complex building decontamina-
tion effort (e.g., removal of structures
prior to flaming, hydroblasting, or other
cleanup techniques).
Drilling and spa/ling can remove up to
5 cm of contaminated surface material
from concrete or similar materials. This
technique consists of drilling holes (2.5 to
4 cm diameter) approximately 7.5 cm
deep. The spalling tool bit is inserted into
the hole and hydraulically spreads to spall
off the contaminated concrete. The
technique can achieve deeper penetration
(removal) of surfaces than other surface-
removal techniques, and it is good for
large-scale applications. The treated sur-
face is very rough and coarse, however,
and may require resurfacing (i.e., capping
with concrete). The drilling and spalling
method has been used in the decommis-
sioning of nuclear facilities.
Dusting/vacuuming/wiping is simply
the physical removal of hazardous dust
and particles from building and equipment
surfaces by common cleaning techniques.
Variations include vacuuming with a com-
mercial or industrial-type vaccum; dusting
off surfaces such as ledges, sills, pipes,
etc., with a moist cloth or wipe; and
brushing or sweeping up hazardous de-
bris. Dusting and vacuuming are appli-
cable to all types of paniculate con-
taminants, including dioxin, lead, PCB's,
and asbestos fibers, and to all types of
surfaces. Dusting/vacuuming/wiping is
the state-of-the-art method for removing
dioxin-contaminated dust from the interior
of homes and buildings.
Encapsulation/enclosure physically
separates contaminants or contaminated
structures from building occupants and
the ambient environment by means of a
barrier. An encapsulating or enclosing
physical barrier may take different forms;
among them are plaster epoxy, and con-
crete casts and walls. Acting as an im-
penetrable shield, a barrier keeps con-
taminants inside and away from clean
areas, thereby alleviating the hazard. As a
result, contamination of part of a struc-
ture will not result in the contamination of
adjacent areas. Encapsulation has been
used on damaged asbestos insulation,
leaky PCB-contaminated electrical trans-
formers, and open maintenance pits and
sumps contaminated by heavy metals.
Flaming refers to the application of con-
trolled high temperature flames to con-
taminated noncombustible surfaces, pro-
viding complete and rapid destruction of
all residues contacted. The flaming pro-
cess has been used by the Army to
destroy explosive and low-level radioactive
contaminants on building surfaces. Its ap-
plicability to other contaminants is not
well known. This surface decontamination
technique is applicable to painted and un-
painted concrete, cement, brick, and
metals. Subsurface decontamination of
building materials may be possible, but
extensive damage to the material would
probably result. This technique can in-
volve high fuel costs.
Fluorocarbon extraction of con-
taminants from building materials involves
the pressure-spraying of a fluorocarbon
solvent onto the contaminated surface
followed by collection and purification of
the solvent. RadKleen is an example of a
commercial process that uses Freon 113
(1,1,2-trichloro-1,2,2-trifluoroethane or
C2CI3F3) as the solvent. The RadKleen
process is currently used for cleaning
radioactive material from various surfaces.
It has been applied to chemical agents on
small objects, and thus field capability has
been demonstrated. Studies have been
conducted for agent-contaminated cloth-
ing materials, such as polyester-cotton,
Nomex, butyl rubber gloves, and
charcoal-impregnated cloth. Although this
method has not been demonstrated for
removing contaminants from building sur-
faces, it looks very promising.
Gritblasting is a removal technique in
which abrasive materials (such as sand,
alumina, steel pellets, or glass beads) are
used for uniform removal of contaminated
surfaces from a structure. Gritblasting has
been used since 1870 to remove surface
layers from metallic and ceramic objects
and is currently used extensively. For ex-
ample, sandblasting is commonly used to
clean the surfaces of old brick and stone
buildings. Gritblasting is applicable to all
surface contaminants except some highly
sensitive explosives such as lead azide
and lead styphnate. This method is ap-
plicable to all surface materials except
glass, transite, and Plexiglas.
Hydroblasting/waterwashing refers to
the use of a high-pressure (3500 to
350,000 kPa) water jet to remove con-
taminated debris from surfaces. The
debris and water are then collected and
thermally, physically, or chemically decon-
taminated. Hydroblasting has been used
to remove explosives from projectiles, to
decontaminate military vehicles, and to
decontaminate nuclear facilities. Hydro-
blasting also has been employed commer-
cially to clean bridges, buildings, heavy
machinery, highways, ships, metal coat-
ings, railroad cars, heat exchanger tubes,
reactors, piping, etc. Off-the-shelf equip-
ment is available from many manufac-
turers and distributors.
Microbial degradation is a developing
process whereby contaminants are bio-
logically decomposed by microbes capable
of utilizing the contaminant as a nutrient
source. Conceptually, microbes are ap-
plied to the contaminated area in an
aqueous medium and allowed to digest
the contaminant over time; the microbes
are then destroyed chemically or ttaermalty
and washed away. Microbial degradation
as a building decontamination technique
has not been demonstrated.
Painting/coating includes the removal
of old layers of paint containing high
levels of toxic metals such as lead, the
use of fixative/stabilizer paint coatings,
and the use of adhesive-backed strippable
coatings. In the first technique, paint con-
taining lead in excess of 0.06 percent is
removed from building surfaces by com-
mercially available paint removers and/or
physical means (scraping, scrubbing,
waterwashing). Resurfacing or further
decontamination efforts may be nec-
essary. The second technique involves the
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use of various agents as coatings on con-
taminated surfaces to fix or stabilize the
contaminant in place, thereby decreasing
or eliminating exposure hazards. Potential-
ly useful stabilizing agents include molten
and solid waxes, carbo-waxes (polyox-
yethylene glycol), saligenin (a,
2-dihydroxytoluene), organic dyes, epoxy
paint films, and polyester resins. The
stabilized contaminants can be left in
place or removed later by a secondary
treatment. In some cases, the stabil-
izer/fixative coating is applied in situ to
desensitize a contaminant such as an ex-
plosive residue and prevent its reaction or
ignition during some other phase of the
decontamination process. In the third
technique, the contaminated surface is
coated with a polymeric mixture. As the
coating polymerizes, the contaminant
becomes entrained in the lattice of or at-
tached to the polymer molecules. As the
polymer layer is peeled off, the residue is
removed with it. It may be possible, in
some cases, to add chemicals to the mix-
ture to inactivate the contaminants.
Photochemical degradation refers to the
process of applying intense ultraviolet
light to a contaminated surface for some
period of time. Photo-degradation of the
contaminant follows. In recent years, at-
tention has been focused on this method
because of its usefulness in degrading
chlorinated dioxins (TCDD in particular).
Three conditions have been found to be
essential for the process to proceed: 1)
the ability of the compound to absorb
light energy, 2) the availability of light at
appropriate wavelengths and intensity, 3)
the presence of a hydrogen donor.
Scarification is a method that can be
used to remove up to an inch of surface
material from contaminated concrete or
similar materials. The scarifier tool con-
sists of pneumatically operated piston
heads that strike the surface, causing
concrete to chip off. This technique has
been used in the decommissioning of
nuclear facilities and in the cleanup of
military arsenals.
Sealing is the application of a material
that penetrates a porous surface and im-
mobilizes contaminants in place. One ex-
ample is K-20, a newly-developed com-
mercial product. The effectiveness of this
product is not fully known. Although it
acts more as a barrier than a detoxifier,
K-20 may facilitate chemical degradation
as well as physical separation of some
contaminants.
Solvent washing refers to the applica-
tion of an organic solvent (e.g., acetone)
to the surface of a building to solubilize
contaminants. This technique has not yet
4
achieved widespread use in building
decontamination, although it is beginning
to be used in the decommissioning of
nuclear facilities. The method needs fur-
ther development in application, recovery,
collection, and efficiency. The hot solvent
soaking process has been shown to be ef-
fective in decontamination of PCB-
contaminated transformers.
Steam cleaning physically extracts con-
taminants from building walls and floors,
and from equipment. The steam is applied
through hand-held wands or automated
systems, and the condensate is collected
in a sump or containment area for treat-
ment. This method is currently used by
explosives handling and manufacturing
facilities. It has also been used to remove
dioxin-contaminated soil from vehicles
and drilling equipment in Times Beach,
Missouri.
Vapor-phase solvent extraction is a
method in which an organic solvent with
a relatively low boiling point (such as
methyl chloride or acetone) is heated to
vaporization and allowed to circulate in a
contaminated piece of equipment or an
enclosed area. The vapors permeate the
contaminated materials, where they con-
dense, solubilize contaminants, and dif-
fuse outward. The contaminant-laden li-
quid solvent is collected in a sump and
treated to allow recycling of the solvent.
This method has not yet been applied to
building decontamination, although it is
believed to have good potential.
In addition to the guidance on develop-
ing a cost-effective cleanup strategy and
the information on various decontamina-
tion methods, the document also includes
several case studies illustrating the actual
application of many decontamination
methods. Table 1 summarizes these case
studies, indicating the contaminants pres-
ent and the decontamination methods
used in each case. Finally, the handbook
includes cost analyses for the application
of each method to a model building, a
discussion of worker health and safety
precautions, and information on available
sampling methods.
Conclusions and
Recommendations
As a result of this study, one can con-
clude that there will often be considerable
merit in assuring that future owners of
decontaminated buildings and structures
on Superfund sites are made aware of the
nature and levels of any residual con-
tamination and of the cleanup methods
used. Ensuring the transfer of such infor-
mation from one site owner to the next
will require a method for permanently
recording this information. Regulations re-
quiring the addition of such information
to the property deed, as is required in the
deed of all RCRA-permitted facilities, may
be a workable solution.
Additional research is needed to bridge
gaps in the state of the art in the follow-
ing three key information areas:
Sampling Methods
First, and perhaps most important,
sampling methods for determining the
type and degree of contamination existing
on building/structure/equipment surfaces,
both before and after cleanup efforts, are
poorly developed, documented, and veri-
fied. Similarly, subsurface sampling tech-
niques (such as corings) for determining
the depth of contamination in porous
substances (such as concrete or wood
floors) have not been adequately devel-
oped and documented. Although "wipe
tests" are often referred to in site records,
the actual methodology used is rarely de-
scribed in enough detail to allow simula-
tion or reproduction by others, and the
technique itself is known to be inadequate
for quantitatively transferring contami-
nants from surfaces to wipes or swabs.
Decontamination Techniques
Second, the applicability and effec-
tivenes of the decontamination techniques
described in the handbook for treating
various contaminant/structural material
combinations encountered at Superfund
sites have not been fully explored. For ex-
ample, the degree to which steam clean-
ing removes dioxin-contaminated soil par-
ticles from drilling augers has not been
established, even though this method is
routinely used to clean equipment at
dioxin-contaminated sites. Additional
research to verify/demonstrate the effec-
tiveness of currently available and newly
developing techniques under various con-
ditions is badly needed. Also, decon-
tamination methods that have not pre-
viously been applied to specific contami-
nant/substrate combinations but show a
strong potential applicability should be
tested in pilot investigations. In the mean-
time, it is recommended that the in-
dividual method descriptions presented in
the handbook be used as a general guide
in evaluating the potential of each tech-
nique on a site-specific basis for efficien-
cy, wastes generated, equipment and
support facilities needed, time and safety
requirements, structural effects, and
costs. Also, each method or combination
of methods should be pretested in the
laboratory or at the site before full-scale
implementation to determine the effec-
tiveness of the strategy.
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Table 1. Summary of Case Studies
Site
Contaminants present
Decontamination methods
Homes and other buildings
Seveso, Italy
State Office Building
Binghamton, New York
Sontag Road area"
St. Louis County, Missouri
One Mark Plaza Office
Complex
San Francisco, California
Frankford Arsenal
Philadelphia,
Pennsylvania
Office building
New England
Luminous Processes, Inc."
Athens, Georgia
Chemical Metals Industries,
Inc."
Baltimore, Mary/and
TCDD
PCBs, TCDD, TCDF
TCDD
PCBs, PCDD, PCDF
Explosives
Asbestos
Radiological residues
Heavy metals
Asbestos
Low-level radiation
Heavy metals, acids,
alkalis, cynaide- and
ammonia-bearing com-
pounds, salts, and solids
and sludges of unknown
composition
Dusting/ vacuuming/ wiping
Painting/coating
Dismantling
Demolition
Dusting/vacuuming/wiping
Dismantling
Dusting/vacuuming/wiping
Insulation removal
Scrubbing (equipment only)
Steam cleaning (equipment
only)
Insulation removal
Dusting/ vacuuming/wiping
Solvent washing
Scraping
Painting/coating
K-20
Gritblasting
Scarification/jackhammering
Dismantling
Hydroblasting/waterwashing
(equipment only)
Flaming
Demolition
Asbestos removal
Dusting/ vacuuming/wiping
Hydroblasting/waterwashing
Scarification
Gritblasting
Dismantling
Painting/coating
Asbestos encapsulation
Paint stripping/sanding
Hydroblasting/waterwashing
Dismantling
Gritblasting
Dismantling
"Superfund site.
Methodologies for Determining
Acceptable Contaminant
Levels
Third, a formal, systematic approach
for determining acceptable levels of con-
taminants remaining in and on building
and equipment surfaces does not current-
ly exist. As a result, guidance on how
clean is clean and the establishment of
target levels could not be included in this
handbook and must continue be be ad-
dressed case by case.
M.P. Esposito, J.L. McArdle, A.M.
Crone and J.S. Greber are with PEI
Associates, Inc., Cincinnati, OH 45246. R.
Clark, S. Brown, J.B. Hallowell, A.
Langham and C.D. McCandlish are with
Battelle Columbus Laboratories, Colum-
bus, OH 43201.
>U.S.Government Printing Office: 1985 — 559-111/10859
-------
M. P. Esposito. J. L. McArdle, A. H. Crone, and J. S. Greber are with PEI
Associates, Inc., Cincinnati, OH 45246; R. Clark. S. Brown, J. B. Hallowell. A.
Langham. and C. D. McCandlish are with Battelle Columbus Laboratories,
Columbus. OH 43201.
Naomi P. Barkely is the EPA Project Officer (see below).
The complete report, entitled "Guide for Decontaminating Bui/dings, Structures,
and Equipment at Superfund Sites," (Order No. PB 85-201 234/AS; Cost:
$22.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Hazardous Waste Engineering Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
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