United States
Environmental Protection
Agency
Municipal Environmental
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-84-084 June 1984
Project Summary
Capture-and-Containment
Systems for  Hazardous  Material
Spills  on  Land
Men/in D. Marshall
  Methods were investigated for seal-
ing the  surface of soils and thereby
preventing the intrusion of spilled
hazardous materials into the underlying
ground water. Such techniques were
sought to provide immediate, short-
duration protection of spill sites (such
as transportation accidents) until more
permanent cleanup could  be initiated.
The goal was to develop a portable, self-
contained,  universal sealing system
that could be operated by one person,
retain the spilled materials for 24 hr,
and create no hazards for the user orthe
environment.
  The initial plan was to study sprayable
sealants, but  laboratory and pilot
testing soon showed this  approach to
be impractical since leak-free coatings
could not be achieved. Three classes of
sealants were evaluated, including non-
reactive, reactive,  and  repellent or
surface-modifying coatings. Several
different  commercially available film-
forming  materials in each category
were tested, but none of the resulting
films were free of defects. Even poly-
urethane foams, which were the most
encouraging, required a thicker coating
than was practical. The effectiveness of
all spray sealant systems also depended
heavily on weather and soil conditions.
  Tests with polyethylene waxes and
films suggested that the latter would be
a useful barrier for a wide spectrum of
hazardous waste spills.  Thus evolved
the use of polyethylene tubes, which
appeared to meet the project's require-
ments of capacity, portability, ease of
deployment, and safe operation. Based
on  several  iterations, a  preliminary
design was generated that consisted of
a double-walled polyethylene bag  or
one-end-closed tube about 6 ft (1.8 m)
in diameter and  20 ft (6 m) long. An
apron at the open end can be positioned
beneath the leak, and a smaller tube
attached  at the  opposite end allows
liquid to  be drained or transferred to
secondary containment. The package is
less than 2 ft3  (0.05 m3) in volume and
weighs less than 16 Ib (7.5 kg). Such
systems could easily be carried by bulk
transporters and deployed by a  single
operator.
  This Project Summary was developed
by EPA's Municipal Environmental
Research Laboratory, Cincinnati, OH,
to announce key findings of the research
project that is fully documented in a
separates report of the same title (see
Project Report ordering information at
back).

Introduction
  The incidence of accidental land spills
of chemicals  has increased with the
growing use and transport of chemicals.
Concern over such spills and the possible
contamination  of  the soil and ultimately
of ground water has been accompanied by
only limited development of methods
for preventing  such contamination, par-
ticularly during the critical hours immedi-
ately after an incident.  This project was
undertaken  to develop methods that
would seal the surface  of soils at a spill
site and prevent the seepage of hazardous
wastes into the groundwater. Application
of such soil sealants immediately after a
spill would confine the spilled material to
the minimum area until  more permanent
containment and cleanup procedures
could be implemented.
  The design criteria outlined for such an
emergency containment system are quite

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severe. Since site preparation would be
minimal, the sealant must be suitable for
different soils and terrains and must have
resistance to punctures by rocks, twigs,
and  other debris.  Since accidents  fre-
quently occur during inclement weather,
any  universal system must also  be
unaffected  by  rain, snow,  cold, frozen
ground, etc. Even under such conditions,
the system should be capable of reducing
soil penetration by 95% over a 1 200-ft
(100 m2) area under a 1 -ft (30 cm) head of
liquid for  a 24-hr period (based on  a
hypothetical  10,000-gal (37900-L) spill)).
Spilled material  should not be able to
seep around or  under the  edge of the
sealed area. Such a system should not
create any  permanent environmental
damage or be a  danger to the operator.
For prompt implementation,  the system
should be portable and self-contained so
that  it can either be carried by  the
transport vehicle or be brought to the site
by the first emergency response unit. The
system also should be deployable by one
person, even  under  adverse weather
conditions. Once the emergency is over, it
should be possible to remove or deactivate
the system. And last  (if possible), the
system should be fabricated from com-
mercially available components.
  The planned program called for using
these criteria to  evaluate various in-situ
film-forming systems rather than manu-
factured films.  Laboratory  tests soon
demonstrated that no candidate sealant
would be able to assure an effective seal
under the expected adverse field condi-
tions and also meet the other criteria.
Consequently,  efforts were shifted to
other methods  based on the  use of
manufactured film barriers. Polyethylene
was selected as the  most economical,
widely compatible, and widely available
film for field purchase and installation as
a pond liner.
   From this barrier-film approach evolved
the  concept of  a capture-and-contain-
ment-bag in which a spill,  such as that
from a leaking tankcar, could be collected
and  held until a temporary holding pond
was prepared. The obvious extension of
this idea was to use the bags instead of a
holding pond  if strength and capacity
criteria could be met.  The scope of the
project was then redirected to evaluate
various bag designs  and constructions
with this goal in mind.

Evaluation Program and
Results

Spray Films
   This program initially sought to evaluate
film-forming sealant systems that could
                                    2
be field-applied at a  spill  to  prevent
leaking of materials into the soil in the
vicinity of the spill. When pilot-scale
testing made it clear that leak-free films
were unlikely to be obtained under field
conditions, this phase of the program was
terminated. The following is an abbreviated
description of the experimental work that
led to that conclusion.
  Candidate film-forming materials  had
been selected using criteria as follows:
  • able to form a continuous film;
  • sprayable by a portable system;
  • able to form a protective skin in a
    relatively short time; and
  • pose no serious threat to operator or
    environment.
  Initial testing consisted of applying
each material to a cardboard backing and
observing the time for film formation and
the nature  of the film. Resistance to
chemicals under a pressure head of 1 ft
(30.5  cm) was then screened using the
film-on-cardboard as the sample. Water,
sulfuric acid, sodium hydroxide, trichloro-
ethylene, methanol, naphtha, and methyl
ethyl ketone were  the screening chemi-
cals used. This techniquequickly reduced
the number of promising candidates to
the following five:
'Mention of trade names or commercial products
 does not constitute endorsement or recommenda-
 tion for use
               Polyco 2607,* an  adhesive from the
               Borden Chemical Co.
               Resin 115, a urethane from the Gallery
               Chemical Co.
               EP  65-86/88, a  urethane  from the
               Ashland Chemical Co.
               Zonyl RP, a surfactant from the duPont
               Chemical Co.
               Clindrol 100CG, a  superamide  from
               the Clintwood Chemical Co.
               These candidate systems were subjec-
             ted to more extensive laboratory evalua-
             tion in a specially designed spray
             chamber, which is  described in the
             original report. Compatibility  with  and
             resistance to a wide range of organic and
             inorganic chemicals likely to be encoun-
             tered  in spill situations were  then
             determined by exposing a 6-in. (15.2-cm)
             disk  of the  coated and cured asbestos
             paper to a liquid head of about 1 ft  (30.5
             cm)  of the challenge chemical  and
             observing the loss of head with time. This
             apparatus also is described in the original
             report. Selected results for the promising
             candidates appear in Table 1.
               Some evaluations were also carried out
             after low temperature cures, as might be
             experienced in an actual spill situation.
             Though cure  times  were necessarily
             longer, the chemical resistances measured
             by the  liquid  transmissions  were not
             significantly different. Results of these
             tests are included in Table 1.
 Table 1.    Compatibility and Permeation Test Results on Asbestos
Film Material
Challenge Liquid
  Liquid Transmission
      (ml/24 hr)
   at            at
20°-22°C*      3°-5°C*
Borden' s 2607





Clintwood's Clindrol
roocc
duPont's Zonyl RP




Gallery's Resin 115




Ashland's EP 65-86/88






Gasoline
Cresol
Naphtha
Water
Sodium hydroxide
Sulfuric acid
Naphtha
Trichloroethylene
Gasoline
Cresol
Naphtha
Water
Trichloroethylene
Gasoline
Cresol
Trichloroethylene
Sodium hydroxide
Sulfuric acid
Gasoline
Cresol
Trichloroethylene
Naphtha
Water
Sodium hydroxide
Sulfuric acid
13.4
1.3
3.9
—
3.4
2.1
2880-576Cr\
5760-7 200^
5-7
13
9-225
19-380
8-140
0
11.3
2.4
12.7
4.2
7.7
2.8
2.0
3.5
6.9
377
153
15.5
1.8
6.0
56.8
66.2
37.1



—
—
—
—
5.5
2.3
4.8
3.6
14.5
30.3
2.5
—
—
—
100
1
 "Cure temperatures
 ^Breakthrough occurred within a few minutes.

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  Three types of commercially available
equipment were considered for further
testing of these systems: (1) hand-pump
pressurized; (2) propellant  pressurized;
and (3) auxilliary-powered,  pump pres-
surized. Laboratory tests indicated that
80 to  160 Ib (35 to 70 kg) of material
would  be required to seal a containment
area of 1200 ft2 (100 m2). To accomplish
this in a reasonable time (15 to 30 min)
would  require spray equipment capable
of dispensing 2.7 to 10.7 Ib/min (1 to 5
kg/min) of chemical.  Hand-pumped
systems, while small enough to meet the
project's criteria, would not be expected
to give consistent  pressures. Portable
propellant pressurized systems, such as
those used for the application of urethane
foams  (e.g. MSA's  Rigi-Pak 180) came
closest to  meeting  the  criteria of light
weight and adequate capacity. An auxil-
liary-power system could also be developed
using an external power source estimated
at about 2.75 kW or 2 hp, but there would
be a serious weight penalty (275 to 350
Ib) (125 to 160 kg) and  a  significant
increase in cost.
  Pilot scale tests on 10-ft2 (1-m2) areas
using  primarily the Gallery urethane
Resin  115, the MSA Rigi-Pak portable
unit, and a Binks  Model 18  spray gun
demonstrated that operator experience
was a  major factor in obtaining uniform
coverage at the desired 0.2  Ib/ft2 (0.1
g/cm2) application rate.  Surface and
weather  conditions, presence of  debris,
rocks,  water, ice, etc. also appeared to
play a  role. Nevertheless, grassy soil (a
relatively  ideal  substrate)  could  not  be
sealed even  at a  rate of 1.3 Ib/ft2 (6
kg/m2), apparently because of a "shadow"
effect during spraying. The sealant would
have to be applied  from  all  directions to
obtain  complete coverage and adequate
sealing. In view of these considerations,
this phase of the program was discontin-
ued.
Bags
  Experiments during the spray sealant
study  indicated  that  polyethylene film
was an acceptable barrier film. From this
conclusion evolved the concept of using a
polyethylene tube to direct bulk transport
leaks and spills  of hazardous liquids to
an  emergency containment pond. And
because  there is a need  for temporary
storage of such  chemicals until a pond
can be prepared, a larger capacity tube or
bag became the next logical configuration.
This design,  incorporating an apron at
one end to capture the leak  and  a
narrower tube at  the opposite end for
controlled discharge or transfer of the
Figure 1.    Capture-and-contalnment device in use at a simulated site.
contained liquid (Figure 1), became the
subject of further study.
  Such  bags could temporarily replace
polyethylene-lined containment ponds
at the site of a spill if they were capable of
retaining spilled material for a reasonable
length of time and in significant volume.
An added advantage would be a reduction
in vapor problems that often accompany a
spill.
  The design  finally developed  was a
polyethylene, pillow-shaped bag about 6
ft (1.8 m) wide and 20 ft (6 m) long, with
an apron at one end and rope lines for use
in positioning the apron capture section
beneath  the  leak.  A polyethylene  tube
approximately 4 in. (10 cm) in diameter and
30 ft (9 m) long at the opposite end of the
bag served as  an  overflow or transfer
tube.
  Evaluation  of several evolutionary
versions of  these bags consisted of
introducing water (simulated spill materi-
al) at 5 gpm (20 L/min) into the apron of a
bag, either fully deployed or rolled-up,
and observing how well the bag unrolled
or retained its  shape  and position on
sloping  ground  and how much water
could be contained before the bag failed.
In this manner, it was demonstrated that
the seals or seams of the bag and the
junction with the overflow tube were the
primary sites of failure when subjected to
the  internal  pressure  of  liquid. Air
pressure tests on small (6 in. x 9 in. (15.2
cm x  22.8 cm)), 4-mil-thick C\00-/j) bags
suggested that though the film and heat-
sealed seams can be strong enough to
withstand more than 30 in. (75 cm) of
head  pressure, quality control in mass
fabrication was not adequate to assure a
reliable seal for this application.
  Two prototype bags  constructed of
clear  (unreinforced),  4-mil-thick (100-/u)
polyethylene tubes 6 ft  (2 m) wide  and
heat-sealed at one end were found
capable of collecting  and holding several
hundred gallons of water (simulated spill
material) and withstanding a maximum
headpressureof24in. (60.9 cm or 0.6m).
Flow into the bag and the development of
the head pressure depended on the slope
of the land on  which the bag  was
deployed. The one failure occurred at a
fold line in the bag at a head pressure of
about 20 in. (50 cm).
  Several full-scale versions were  then
constructed  of fiber-reinforced polyethy-
lene film to improve tear and puncture
resistance in anticipated field situations.
As  these units were filled with water,
leaks developed  at  or  near the  point
where the  transfer tube was attached,
but not at  the double-stitched seams
covered with a polyethylene mastic tape.
When the leaks were repaired and the
bag was retested, some  seepage  was
observed at the sewn seams, but  only
when the bag contained about 900 gal
(3500 L) of water and was under a head of
about 22 in.  (55 cm). In a later test, a leak
again developed at the junction of the bag
and transfer tube. This bag, about 20 ft (6
m)  long  and 8 ft (2.5  m)  wide  (flat),
weighed only 16 Ib (7 kg) and was readily
deployed in freezing conditions by  a
single operator.
  Three manufacturers  fabricated bags
using both heat-sealed and sewn seams
and fiber-reinforced film. These bags

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were tested under field conditions (Table
2).
  To  reduce the strain on  the seams
further,  the next design consisted of
double-walled bags, with the outer bag
intended to supply support. Two  units
were purchased  and tested. The  first,
manufactured  by the Sheldahl Corp.,
consisted of an  innner, 6-mil (150-/u)
polyethylene bag and an outer bag of
fiber-reinforced polyethylene.  Though
leakage was minor with this unit,  even
when filled to a maximum of 42 in. (105
cm) of liquid head, post-test examination
showed that the inner bag had  failed at
some earlier time near the transfer tube
in a manner typical of poorly heat-sealed
seams.

  The  second double-walled bag, fabri-
cated by  Silco Industries, was a quarter-
scale unit. The inner bag was 4-mil (100-
fj) polyethylene with a continuous, heat-
sealed seam. The outer  bag was  con-
structed  of  polyethylene mesh with a
double-stitched  seam.  This double-
walled bag successfully contained a
water pressure head of 46.5 in. (115 cm).
A full-scale  version of similar construc-
tion used a fiber-reinforced polyethylene
film  outer  bag  (9-mil  (226-u)  total
thickness) with a double-stitched seam.
Unfortunately, the outer bag was slightly
larger  than  the  inner bag and did not
provide the expected support. The inner
bag seam failed near the transfer  tube
connection after only  150 gal (600 L) of
water had been introduced.
  A field demonstration was carried out
at the contractor's facilities using two
prototype bags: a Silco double-walled bag
and  a single-ply Katz Co.  bag.  The
simulated accident was a railroad tanker
laid on its side with leakage around the
top hatch (see Figure 1). Water was the
simulated spill liquid at a  leak rate of 5
gpm  (20  L/min).  The Silco bag had an
inner bag of 6-mil (150-/u) polyethylene
with continuous, heat-sealed seams and
an outer bag of fiber-reinforced polyethy-
ene film  with double-sewn seams. The
Katz Co. bag was constructed of a single-
ply (9-mil  (225-fj)), fiber-reinforced
polyethylene film with seams heat-
sealed by a proprietary process. The site
had only a  gentle slope, which  limited
both the  potential head buildup and the
total capacity of the bags.  The tests did,
however, demonstrate the ease  with
which  the bags could be  deployed and
positioned to capture  a spill, even by an
operator  in full safety gear, and the use of
the bags  in a modular  or tandem scheme
to increase capacity. Water (the simulated
spill  liquid) was easily transferred  from
 Table 2.   Tests on Fiber-Reinforced Bags
Supplier
Griff olyn Co.
Griff olyn Co.

Griffolyn Co.

Griffolyn Co.

Silco Ind.
Katz Bag Co.

Katz Bag Co.

Fabrication
Heat-sealed
Double-stitched
and silicone taped
Double-stitched and
polyethylene taped
Heat-sealed with
hot air
Heat-sealed
Extrusion process

Mechanical seal
at transfer tube
Pressure
(in.)*
ofHzO
12
12

29.5

5

5
48

12

Observations
Failed near seams
Small leaks at corners

Filled to capacity;
seams seeped
Zipper-like failure

Zipper-like failure
No failure; 1/4 scale;
some seepage
Leakage around seal

* 1 in. = 2.5 cm.
the first, or capturing bag, to a second
downhill bag without the operator having
to re-enter  the  immediate area of the
spill.


Conclusions
  Polyethylene film is a suitable barrier
film for the rapid fabrication of emergency
holding ponds. Polyethylene film (6-mil
(150-/u))  can contain water (simulated
spill material) with more than a foot (30
cm) of liquid head over natural terrain
containing rocks, twigs, and other debris.
This  material  is  readily  and widely
available, inexpensive, chemically resis-
tant, and amenable to handling under the
adverse weather conditions (except
strong wind) frequently encountered at
bulk transport spill sites.
  Properly  fabricated bags or tubes
constructed from 6-mil (150-ya) polyethy-
lene  can capture and  hold  materials
spilled during bulk transport  accidents.
These bags are attractive candidates for
onboard spill containment equipment,
since  they can be deployed readily by a
single operator  immediately after an
incident. The seams of such bags are the
major weak point and the primary source
of leaks. The best strength and resistance
to leakage caused by internal pressure
(liquid head) is obtained with a double-
walled bag  consisting  of an  inner bag
with heat-sealed seams and an outer bag
with sewn seams.
  A prototype design includes an apron at
one end  of a 20-ft-long (6 m), 6-ft-wide
(2 m) pillow-type bag. Through the
manipulation of ropes, the apron can be
positioned to capture leaking material. A
transfer tube at the opposite end of the
bag (about  4 to 6 in. (10-15 cm) in
diameter and 30 ft (9 m) long) allows for
transfer  of  the  contained liquid to  a
second, downhill bag or to a prepared
containment  area without the operator
having to re-enter the immediate area of
the spill.
  Such bags can contain more than 1000
gal (3785 L) of liquid  on a reasonably
sloping terrain,  weigh less than 16 Ib (7
kg), occupy a volume of less than  2 ft3
(0.0566 m ), and are readily deployable
by a single person encumbered with full
safety  gear and facing  adverse weather
conditions. Such bags could probably be
purchased in volume for $50 to $200.
  The  use of film-forming materials for
onsite sealing of soils is not practical. The
terrain frequently encountered is not
likely to permit achievement of a continu-
ous, leak-free  film,  even when using
relatively high application rates. Adverse
weather conditions would also contribute
to an expected high frequency of failure for
such sealant films.
  More specific conclusions  can be
drawn  for the three types of film-forming
systems evaluated. Nonreactive sealants
dispensed as solutions or dispersions are
slow to  form  films under inclement
weather conditions and could create fire or
air-emission problems  if used with an
organic solvent. The films produced often
have pinholes. Reactive sealant systems,
though capable of forming films under
adverse weather conditions, exhibit poor
adhesion to  the soil and form films with
frequent holes or voids where vegetation
or debris protrudes.  Surface modifying
chemicals  such as repellents fail to
provide a sealing effect when sprayed on
soil, even under ideal conditions.

Recommendations
  The capture-and-containment concept
should be vigorously pursued as a first
response to bulk transport spills. Poly-
ethylene bags are attractive candidates for
an onboard spill containment system for
transport vehicles.
  Though polyethylene film has adequate
strength to contain such spills, particular-

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ly when fiber-reinforced, additional work
is needed to fabricate bags with leak-free
seams and junctions (at the transfer tube,
for example).
  Before manufacturers will undertake
full-scale  development of such units,
evidence is needed of a potential market.
Further design evolution should be
explored with both  manufacturers and
spill response personnel.
  The full report was submitted in fulfill-
ment of Contract No. 68-03-2507 by
MSA  Research Corporation  under the
sponsorship of the U.S. Environmental
Protection Agency.
Mervin D. Marshall is with MSA Research Corporation. Evans City, PA 16033.
John E. Brugger is the EPA Project Officer (see below).
The complete report, entitled "Capture-and-Containment Systems for Hazardous
  Material Spills on Land," (Order No. PB 84-186 089; Cost: $11.50, 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:
        Municipal Environmental Research Laboratory
        U.S. Environmental Protection Agency
        Cincinnati, OH 45268

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United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
                                            CrilC«ii.j   1L
                                                                                           U.S. GOVERNMENT PRINTING OFFICE: 1984-759-102/0979

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