United States
                    Environmental Protection
                    Agency
Municipal Environmental Research
Laboratory
Cincinnati OH 45268
                    Research and Development
EPA-600/S2-83-112 Dec. 1983
&EFW         Project  Summary
                    Evaluation  of a  Containment
                    Barrier  for  Hazardous  Material
                    Spills  in  Watercourses
                    Thomas N. Blockwick
                                                                                         »/
                      This project was undertaken to design,
                    develop, and evaluate a physical barrier
                    system  to  contain  accidental
                    concentrated spills of insoluble hazard-
                    ous materials in water. The system was
                    to be effective in flowing water, light-
                    weight, easily transportable, and cap-
                    able of being deployed by a minimum
                    number of trained personnel.
                      A prototype barrier designed to meet
                    the above criteria was constructed of a
                    flexible, fiber-reinforced plastic curtain
                    with air-inflatable flotation. To prevent
                    escape of polluting materials from the
                    contained mass of water, the bottom of
                    the barrier is sealed against the bottom
                    of the watercourse with a liquid-filled
                    bladder held in place  with  several
                    anchors. The ends of the curtain are
                    laced together  to give  a cylindrical
                    shape.
                      Full-scale field testing of the barrier
                    system was initially conducted in 1971
                    and 1972 to  evaluate  deployment
                    techniques, to determine the amount of
                    leakage from the barrier by using dye as
                    a  simulated hazardous material, and to
                    measure the  loads  imposed on the
                    barrier by  currents. Testing was again
                    conducted in 1976 with an improved
                    barrier system  incorporating changes
                    based on the earlier tests.
                      As a result of the field tests, it was
                    concluded  that a properly  designed
                    barrier system could contain spills and
                    leaks that were not rapidly dispersed
                    into the water environment. Such spills
                    would include releases of concentrated
                    insoluble hazardous  substances  that
                    pool on or near the  bottom. But the
                    studies  also demonstrated  that the
                    hazardous material barrier (HMB) had
serious  shortcomings,  the  greatest
being its sensitivity to currents, the time
required for deployment, and weight-
related  handling  difficulties.  Rapid
technological advancements in plastics
and their fabrication, coupled with the
experiences gained  from  this  study,
may now make it possible to construct a
barrier that can  be deployed  more
rapidly and with less difficulty.
  Though this report is being  issued
several years after project completion,
information on the study was presented
at the 1972 National Conference  on
Control of Hazardous Materials Spills,
and technical advice has been provided
on this topic to EPA Regions making
inquiries. We hope that the release of
the report  will stimulate those  in the
user community that  may  want  to
further  the development of this
concept.
  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 separate report of the
same title (see Project Report ordering
information at back).

System Description
  The barrier is  constructed of a  highly
flexible, fiber-reinforced plastic material
that can be deployed around a spill source
such as a sunken barge, rail car, ortanker
truck containing concentrated insoluble
hazardous materials that pool on or near
the  bottom  of  the  waterbody.
Incorporated into the barrier are an air-
inflated flotation collar that supports the
barrier and a liquid-filled bladder that

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seals the bottom of the barrier to  the
bottom  of the waterway in which  the
barrier  is deployed. The ends  of  the
barrier  are  laced together   before
deployment to give the cylindrical shape
needed for the confinement  of  a spill.
Figure 1 shows the barrier fully inflated
on the water surface.
  Five explosive embedment anchors are
used  by divers to moor the  barrier in
place.  These  anchors  were selected
because of their very high holding power-
to-weight ratio and the speed with which
they  can be  installed  relative   to
alternative anchoring   systems.  Each
anchor  assembly weighs approximately
100 Ib in the ready-to-fire configuration.
  Equipment   used  in  deployment
includes special devices for pulling  the
barrier to the bottom and mooring it to the
anchor pendants, equipment for inflating
the  air bladder and  filling  the water
bladder,  vessel(s)  for  deploying   the
barrier, and marker buoys and anchors
for temporarily mooring the barrier until it
can be permanently anchored.
  A small boat with at  least  a  1000-lb
capacity is required for installation of the
system. The boat should be equipped with
at least a 5-hp outboard motor  if it is used
to deploy the barrier. If the barrier is to be
deployed in a watercourse where there is
a current, then a larger, more powerful
motor is required for towing of the barrier.

Prototype Field Tests
  Three field tests were conducted with
the prototype barrier between  October 1,
1971, and April 30, 1972. The first test
was conducted in  Sugar Grove, West
Virginia, to evaluate the  barrier  and
deployment techniques under  still water
conditions. Deployment, mooring,  and
anchoring of the barrier were no problem
under the still water conditions of  the
lake. Some mechanical  problems were
encountered in opening the tapes holding
the barrier bundle together,  and some
minor   leaks   were  observed  in   the
flotation  bladder.  Dye tests with
Rhodamine-B as a simulated spill demon-
strated that nodye leaked from  the barrier
over a 24-hour period.
  The second test was conducted on the
lower   Potomac  River,  southeast   of
Colonial  Beach,  Virginia.  This  site
afforded the depth, currents, and bottom
conditions required to subject  the barrier
and deployment  procedures to more
severe  conditions.  Positioning  and
mooring the barrier at the test  site did
prove more difficult in the river current (1
knot).  Unfortunately, wind, waves,  and
adverse weather conditions caused  the
 Figure 1.    Fully-inflated barrier.


barrier to unfurl prematurely and forced
cancellation of  this  trial  before any
testing could be carried out.
  The site of the third trial was near Lake
Worth  Inlet, Palm Beach, Florida. This
location was considered ideal since there
were tidal currents of 1 to 2 knots and
underwater visibility was excellent. The
purpose  of  this  test was to  observe
certain stages of deployment and aspects
of the in-place barrier. Although mooring
and anchoring were completed rapidly,
the currents at  this site, and perhaps
undiscovered damage during the earlier
tests,  caused the  barrier to tear quite
extensively and ultimately to feather in
the current. The suspected pattern  of
failure is described in the full report.
  Following the 1972 field tests, recom-
mendations were  made  to construct a
new, strengthened barrier, and in 1976,
field testing and  evaluation were con-
ducted at the formerly used site in Palm
Beach, Florida, to benefit from the experi-
ence of that previous test.
  Current  velocities  were  measured
during the field testing to determine the
effects  of  the tidal  currents  on  the
configuration  and  integrity   of  the
improved barrier. Afluorescent dye tracer
study  was  attempted  to evaluate  the
ability  of  the  barrier  to  contain  a
simulated spill. But this procedure could
 not be  completed because the current
flow caused the barrier to collapse into
 itself  on the surface, while the bottom
bladder failed to maintain a seal with the
bottom. Lead weights were subsequently
used to keep the bottom seal in place, but
the flotation collar continued to collapse
in the current.
  Recovery of the barrier for  reuse,  a
necessity  if it  is to  be cost-effective,
proved in all tests to be a time-consuming
and tedious operation, even when using
heavy equipment.

Conclusions and
Recommendations
  The  hazardous material barrier system
can be a viable countermeasure  against
spilled hazardous materials. Field tests
indicate that deployment of the barrier in
currents  faster  than  1  knot  is  not
recommended,  since  the  design
configuration  cannot  be  maintained
effectively and reliably. With currents
above  1 knot, the barrier loses its shape
and tends to close in on itself.
  The self-embedment anchoring system
used  to moor the barrier is extremely
effective. The pull-down system used for
deployment of the barrier worked well,
but a more efficient mechanical handling
system is needed for launching  and
recovering the barrier. Deployment of the
barrier can be  accomplished in  time  to
contain spills that  are not  rapidly dis-
persed or where a significant amount of
the pollutant remains at the source 8 to
12 hr  after the barrier system arrives at
the scene of the accident..
  Recommended  system  changes
include: (1)the use of a stronger or multi-

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ply  material  at critical  points  of  the
barrier; (2) the use of non-kinking hoses
for inflation of the flotation collar and for
filling of the liquid bladder; (3) the design
of a procedure and a system for draining
the  bottom   seal  bladder;  and  (4)
consideration of mechanical aids that will
eliminate or reduce the need for divers.
  The full report was submitted in fulfill-
ment of Contracts No. 68-01-0103  and
68-03-2168  by Samson  Ocean
Systems, Inc., under the  sponsorship of
the  U.S.   Environmental  Protection
Agency.
 Thomas N. Blockwick was with Samson Ocean Systems, Inc., Boston, MA 02110.
 Ira Wilder is the EPA Project Officer (see below).
 The complete report, entitled "Evaluation of a Containment Barrier for Hazardous
 Material Spills in  Watercourses." (Order No. PB 84-123 942; Cost: $10.00.
   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:
         Oil and Hazardous Materials Spills Branch
         Municipal Environmental Research Laboratory—Cincinnati
         U.S. Environmental Protection Agency
         Edison, NJ 08837
                                                •trUS GOVERNMENT PRINTING OFFICE 1983-759-015/7246

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Environmental Protection
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Center for Environmental Research
Information
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