&EPA
                                       United States
                                       Environmental Protection
                                       Agency
                                                   April 1982
   El nvironmental
   E
   R
   U
       Capability
mergency

esponse


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SEFA
          E
          E
          R
          U
nvironmental
mergency
esponse
nit
Capability
          April 1982
      Top photo - Mobile Physical-Chemical Treatment Trailer, nicknamed the "Blue Magoo",
      see page 12 for further information.
      Bottom photo - Mobile Incineration System, see page 18 for further information.

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                  Disclaimer

    Mention of trade names or commercial products in
this brochure does not  constitute  endorsement or
recommendation for use  by the U.S. Environmental
Protection Agency.

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                                  Contents
Introduction	iv
Currently Available Equiprnent
   Acoustic Emission Monitoring Device 	  1
   Carbon Adsorption Pilot Plant :	  2
   Cyclic Colorimeter	  3
   Foam Dike System	  4
   Hazardous Material Detection Kit	  5
   Hazardous Material Identification Kit	  6
   Hazardous Materials Spill Warning System	  7
   Mobile Decontamination Station for Field Personnel	  8
   Mobile Field Office  	  9
   Mobile Flocculation-Sedimentation System 	10
   Mobile Laboratory	11
   Mobile Physical-Chemical Treatment Trailers	12
   Mobile Stream Diversion System	13
   Multipurpose Gelling Agent	14
   Pesticide Detection Apparatus 	15
   Portable Collection  Bag System  	16
Equipment Under Development
   In-Situ Containment/Treatment System	17
   Mobile Incineration  System	18
   Mobile Independent Physical-Chemical (IPC)
       Wastewater Treatment System 	19
   Mobile Reverse Osmosis Treatment System	20
   Mobile System for Detoxification/Regeneration of
       Spent Activated Carbon  	21
   Mobile System for Extracting Spilled Hazardous
       Materials from Soil	22

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                                      Introduction
    The  Environmental Emergency Response  Unit
(EERU) is the U.S. Environmental Protection Agency's
(EPA) hazardous material spill response and control
organization for situations where the use of complex
cleanup  equipment and  techniques  are  required.
EERU  is  engaged  in  the  shakedown  and  field
demonstration  of  prototypical  equipment  and
techniques that  have  been  developed under the
direction   and sponsorship  of  EPA's  Municipal
Environmental Research Laboratory (MERL).

    The  concept  of  EERU involves  a cooperative
effort among  spill  response  research personnel  at
MERL's Oil and Hazardous Materials Spills Branch in
Edison, NJ,  EPA's Environmental  Response Team
and  operational   personnel  (of  the  Hazardous
Response Support  Division,  Washington, DC),  and
contractor personnel, to provide the  most effective
use of the technologies  under  development.  EPA
efforts through EERU include the use  of government
owned equipment during  emergency response  and
hazardous waste site cleanup activities, as well as
the operation of  a  pilot plant facility and  a  mobile
analytical chemical laboratory.

    During the past several years, the Environmental
Emergency Response  Unit  has  supported  EPA
Regional  and  Headquarters personnel at a variety  of
emergency incidents  involving contamination  of
groundwater,  surface  waters,  and  potable  water
supplies by spills of hazardous materials and oils, as
well as at emergency responses to  uncontrolled
chemical waste sites.

    The  cooperative  effort  between  EPA  and
contractor personnel enables EERU to bridge the gap
between  "research"  and   "commercially usable"
equipment. This   effort  is intended to  inspire
enterprising   commercial  development  and
application of spill control and cleanup technology.

    For further information  on  EERU  activities and
capabilities, contact:

    James J. Yezzi, Jr.
    Oil & Hazardous Materials Spills Branch
    Municipal Environmental Research Laboratory-Ci
    U.S. Environmental Protection Agency
    Edison, NJ 08837
or:
    Telephone: (201) 321-6703  FTS: 340-6703
    J. Stephen Dorrler, Chief
    Environmental Response Team
    U.S. Environmental Protection Agency
    Edison, NJ 08837

    Telephone: (201) 321-6740  FTS: 340-6740
                                                IV

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CURRENTLY AVAILABLE EQUIPMENT

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                                     Acoustic  Emission
                                     Monitoring  Device
    Recently, Federal,  state and  local government
agencies have become concerned by the existence of
hundreds  of  thousands of diked areas  containing
hazardous materials. Earthen-dam waste ponds in the
U.S. can be found at numerous industrial facilities and
chemical  waste  disposal sites.  Many of  these
impoundments  are  unstable and,  with  slight over
stressing (such as from heavy rains), may collapse and
spill their contents into the environment with potentially
drastic  consequences.   In  order  to  prevent  such
occurrences, simple monitoring/warning techniques
are needed to evaluate  the stability of earthen dams,
locate the site of instability, and detect/locate seepage.

    An Acoustic Emission Monitoring  Device has been
developed to provide early warning of potential failure of
earthen dams containing hazardous materials  (EPA
Grant No. R-802511). The technique  is based on the
detection of noises that are generated by interparticle
movement. The intensity and frequency of these sounds
- acoustic emissions — has been correlated with stress
level for  many soils and, therefore,  can be used to
indicate stability of dam structures.
    The components of the monitoring device include
metal wave guides, an accelerometer, an amplifier, and a
display system counter. The electronic components are
battery operated. Acoustical emissions are transmitted
to the surface  through  waveguides  driven  into the
impoundment walls. These sounds are converted to
electrical  analogues,  amplified,  and  recorded for
analysis. The counter responds to those signals above a
preset  threshold  level and  records the rate of signal
generation.

    The  portable,  easy-to-use  Acoustic  Emission
Monitoring  Device can  be  operated periodically  or
continuously. The system is inexpensive and requires
little maintenance because only the wave guides must
be left at the site for periodic monitoring. Commercially
available acoustic emission systems are being used to
ascertain  and   monitor  the structural integrity  of
numerous surface  impoundments. On  a number of
occasions, these  monitoring devices have provided
adequate warning of earthen dam  collapse. Acoustic
emission monitoring has been used for industrial waste
impoundments and dams that range in size from 1.8m (6
ft) to 45.7m (150ft) high and 6.1 m (20 ft) to 10 km (6 mi)
long   Further   discussions of  acoustic  emissions
monitoring  may be found  in  an EPA Technology
'transfer report.  EPA-625/2-79-024.

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                                    Carbon Adsorption
                                            Pilot Plant
    Granular activated carbon  (GAC) can be used to
remove most organic chemicals from water to generally
acceptable levels at a reasonable cost. Prior to initiating
full-scale granular carbon treatment in the field, pilot-
scale column tests may be  performed to evaluate
feasibility  and cost effectiveness. Pilot-scale tests are
also  useful  for  establishing  optimum  operating
conditions in  a timely manner.

    Several GAC pilot-scale systems and a testing area
have been constructed at the Edison facility by EERU;
portable as well as fixed based systems are available.
Treatability studies are  conducted on  contaminated
samples from spill sites and uncontrolled hazardous
waste  dumps. During  these  studies, the  following
parameters may  be evaluated in  order to  establish
specific operating conditions: flow rate, contact time,
pressure  drop,  bed depth,  pH,  temperature,  and
backwash  requirements.

    One pilot-scale unit consists of 4 glass columns
(7.62 cm [3 in] i.d., 122 cm  [4 ft] high) mounted on a
portable rack. Influent and effluent solutions are stored
in sealed 2,270 I (600 gal) tanks. Influent flows through a
closed system to final disposal. An automatic system is
used for unattended sampling for periods as long as 24
hours. Sampling is controlled by a microcomputer, and
samples are collected/stored in a nitrogen-blanketed
refrigerator.  Prior to discharge, all effluent is passed
through a 475-cm (15-ft) carbon column.

    The pilot-scale test area is constructed to ensure
safety  of  operating   personnel.  Individual   safety
equipment—disposable  splash-resistant   coveralls,
rubber boots, gloves, full-face respirators—is used. Fire
extinguishers,  an emergency shower, and eye-wash
equipment are available in the pilot-plant area.

    Pilot-scale systems have been used to assess the
treatability   of  chemical  waste  solutions  and
contaminated  leachate from uncontrolled hazardous
dumpsites at Niagara Falls and Oswego, New York. The
pilot system has  also been used to evaluate full-scale
carbon treatment for cleanup of  gasoline and mixed
chemical spills. In addition, detailed adsorption studies
have  been  conducted  on  phenol,  m-cresol, and
quinoline.

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                                     Cyclic  Colorimeter
    When a spill of hazardous materials occurs, rapid
detection and identification of the amount and extent of
contamination is imperative. Prompt sensing not only
permits   cost-effective   treatment  of  concentrated
materials, but also enables prompt response to the
incident, which reduces the length of exposure of plants
and animals,  including  humans, to spilled hazardous
substances.
    Often,  the  reporting of  a  spill  depends on
notification either  by  persons responsible  for  the
situation  or by untrained observers who,  by chance,
notice changes in the environment. In areas with a high
probability of spillage, such as harbors and rivers in
industrial  locations,  the use of  an automatic  spill
detection  alarm system  for heavy metals  may be an
effective monitoring approach. In order to minimize the
costs of the system, it should be capable of reacting to a
wide spectrum of heavy  metal, pollutants. The system
should require  little  maintenance  and  should be
resistant  to the variable and hostile environments in
which it  may be located (e.g., sewers,  contaminated
waterways).  The field monitoring equipment  should
provide  both  qualitative and  semi-quantitative
information about the spilled materials.
    The Cyclic Colorimeter (developed  under EPA
Contract Nos. 68-03-0110 and  68-03-0287)  may  be
useful  for field monitoring of heavy metal  spills.  It
incorporates  hydraulic,  optical,  and  electronic
components  that  are  designed  for the automatic
detection of most  heavy metal  pollutants. When  an
indicator, sodium sulfide, is injected dropwise  into a
sample  stream,  the  presence  of  a  heavy  metal
contaminant  causes  cyclic  variations  in  optical
transmittance  at the  indicator  injection  frequency.
These variations are detected by a lamp and photocell,
coupled to  an electronic subsystem, which produces
either a quantitative indication of the pollutant or  an
alarm when a threshold level is exceeded.

    The Cyclic Colorimeter is capable of detecting low
levels of many heavy metals in water of widely varying
temperatures.  The  detector   maintains adequate
sensitivity  for  a period of about two weeks without
maintenance. Scale buildup and stream turbidity do not
affect its performance.

    The  Cyclic  Colorimeter  is  now  commercially
available.   Instrument  design   specifications  and
descriptions of laboratory and field tests are included in
the final report, EPA-600/2-79-064.

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                                     Foam Dike  System
    When a spill occurs during the transportation of
hazardous substances by land vehicles, the immediate
problem  is  to  prevent  the  materials from  entering
adjacent  land and water systems. Unless spills can be
controlled  at  their  source,  damage to  the  water
ecosystem may be extensive.

    Frequently, spilled hazardous  chemicals can be
controlled at the site of the accident by the construction
of dikes or diversionary barriers until complete cleanup
can be accomplished. Although  natural  barriers and
depressions can be used to divert spills, not all surface
materials are amenable to the formation of dikes. In the
latter  case, structures made from synthetic materials
can be used to envelop or divert the flow of spilled
liquids. Such diking  materials should be resistant to
chemical  attack,   nontoxic,   disposable,   and
nonflammable or fire retardant. Under EPA  Contract
Nos.  68-01-0100 and 68-03-0206, two materials were
identified   as  possessing   the   aforementioned
requirements:  polymer foam and  foamed  inorganic
materials.

    The  polymer Foam Dike  System,  incorporating
polyurethanes and a portable dispensing unit, provides
a rapid response method for enveloping or diverting the
flow  of  many  spilled hazardous  chemicals.  The
commercially available portable unit weighs less than
18 kg (40 Ib) and has two pressurized tanks that can
deliver approximately 0.3 m3 (10  ft3) of foam (with an
expansion of 25:1)  at  a rate  of approximately  0.03
mVmin (1 cfm). The rigid foam can effectively contain or
divert chemical spills, including: water-based liquids
except strong acids, nonpolar organics, chlorine, and
ammonia. Polyurethane foam is effective on dry hard
surfaces (concrete or asphalt), but provides only limited
control on dirt, gravel, or vegetated ground.
    Larger-sized,  commercially  available  units are
capable of generating approximately 2  m3 (65 ft3)
of foam, which provides sufficient material to construct
a barrierO.3 m (1 ft) high byO.Sm (1 ft) wide by 6m (20ft)
in diameter, which would impound approximately 7,600
I  (2,000 gal). The foam is also effective in sealing sewer
openings and storm drains.

    An alternate diking system, utilizing foamed, fast
setting (2-3 sec)  concrete is available. Mixtures of
foamed concrete (approximate density 640 kg/m3 [40
Ib/ft3]) and sodium silicate can be used to form a gelled
structure with sufficient strength to  build  a dike in
excess of 0.6 m (2 ft) high. Barrier strength is a function
of water/cement ratio, temperature, and type of cement.

    The foamed concrete  can be applied over  large
areas on most surfaces. On-site use of foamed concrete
typically requires the following: a mixer for blending a
cement-water slurry, a slurry pump, a foam generator, a
storage tank, a nozzle, and a sodium silicate solution.

    The  portable  polymer  Foam  Dike  System is
frequently used by firefighters and other first-on-scene
personnel to control  the  flow  of  spilled hazardous
substances.  Additional information on foam diking
systems is contained in the EPA final reports, EPA-R2-
73-185 and EPA-600/2-77-162.

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                                    Hazardous  Materials
                                         Detection  Kit
    Over 3,000 spills of hazardous polluting materials
(other than oil) enter the waterways of the United States
each year. These spills often result from accidental
releases   of  hazardous  materials during  in-plant
operations and storage, as well as from accidents that
occur during transport by barge, tank truck, railway tank
car,  and  pipeline.  Additionally,  large amounts of
pollutants  reach  rivers,  streams,  and  lakes  from
agricultural use of chemicals.
    Effective response  to a spill frequently requires the
ability to detect hazardous materials in waterways. In
order to facilitate rapid detection, a Hazardous Materials
Spills Detection Kit for performing non-specific tests
with a broad response to many contaminants has been
developed (IAG-D4-0546). The kit is designed for use at
spills when the identity  of thecontaminant isknownand
the important consideration is tracing  the spill  plume
until countermeasures  can be taken.
    The Hazardous Materials Detection Kit  can be
carried by one person and is versatile enough to be
modified for special applications. 11 contains a pH meter,
conductivity meter, spectrophotometer, filter assembly,
effervescent jar, miniature chromatographic columns,
enzyme "tickets", and  data  sheets. The  instrument
components are battery-powered forfield use, although
the spectrophotometer and conductivity meter can be
modified  for 120- or 240-V a.c. operation  using the
adapter and cable that are provided. The kit has all the
necessary instrumentation, equipment,  and  reagents
that may be needed by a field investigator to detect and
trace contaminants in waterways.
    Hazardous Materials  Detection  Kits,  which are
commercially   available,  have  been   used  during
emergency responses to  hazardous materials spills.
Additional information about the kits may be found  in
the EPA report, EPA-600/2-78-055.

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                                   Hazardous Materials
                                      Identification  Kit
    During the response to hazardous chemical spills
and uncontrolled hazardous waste sites, the identity of
contaminants is  often unknown. Compact, portable
analytical  equipment for rapid pollutant identification
is  critical  to  effect efficient  emergency response
activities. However, nearly 300 materials are classified
as hazardous substances by EPA (Federal Register, 16
February 1979), and a field kit capable of rapidly and
accurately identifying each of these substances would
be  too  unwieldly  to be  practical.  Thus, thirty-six
representative  hazardous  materials  (toxic  metals,
anions, organic compounds) were selected and a field
kit  was  designed  to  identify  these  and  related
substances (IAG-D6-0096).
    The identification (ID) kit consists of two major
components: (1) an inverter/shortwave UV lamp unit for
photochemical and thermal reactions and (2) a package
with reagents and auxiliary equipment, including test
papers,  detector  tubes,  spray reagents,  spot  test
supplies, and thin-layer chromatography apparatus.
Equipment to facilitate the recovery of contaminants
from  water  and  soil  is also  included. The field
identification  kit  contains  detailed  operating
instructions  and  data cards  for  each  of  the  36
representative hazardous substances.
    Identification  of groups  of contaminants, rather
than  quantification  of specific  substances,  is the
intended use of the identification kit. The ID kit can be
used  in conjunction  with the Hazardous Materials
Detection  Kit,   which  contains  a   pH   meter,
spectrophotometer,  conductivity  meter,  and  other
analytical  equipment.  Utilization  of  both kits can
improve  identification  capability,   particularly  for
inorganic materials. For example, cyanide and  fluoride
cannot be distinguished by the ID kit alone; however,
when  the  kits are used  concurrently,  identification
becomes possible.

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                                   Hazardous  Materials
                                  Spill  Warning System
    When natural and energy resources are extracted,
processed, converted, and used, accidental discharges
occur that impact our environment and may threaten the
public health  and  welfare. EPA's OHMS Branch  is
committed to spill prevention and the development  of
methods to  rapidly detect  accidental discharges  of
hazardous substances in waterways  before extensive
damage occurs. Rapid detection of spillsand immediate
notification  of response   personnel  will  facilitate
initiation of appropriate pollution abatement measures.

    An in-stream system capable of detecting a variety
of spilled hazardous materials has  been developed
(EPA   Contract  No. 68-03-2080).   The  integrated,
operational components of the spill alarm  system are
housed in an air-conditioned 8.2-m (27-ft)  automotive
trailer  for increased  mobility. The system  operates
continuously  at  an  unattended  station,   without
maintenance, for a period of 14  days. A submersible
pump in the  watercourse supplies uninterrupted water
samples to three instrument consoles in the trailer.

    The instrument consoles contain  the following: (1)
pH, electrical conductivity, and  oxidation-reduction
potential sensors for the detection of acids and bases,
ionic   compounds,  and   oxidizing  and  reducing
substances,  respectively,  (2) a total organic carbon
analyzer with a built-in recorder for the detection of
organic compounds,  (3)  a  differential   ultraviolet
absorptimeter for the detection of aromatic compounds,
and (4) a control console with strip chart recorders.

    The strip chart recorder channel for each detection
component has a built-in  alarm circuit, the response
level of which can be pre-set. When an alarm condition is
detected, several automatic and simultaneous events
occur: (1) the chart recorders, which run at a rate of 1.3
cm/h (0.5 in/h) under normal conditions, speed up to 15
cm/h  (6 in/h) to record additional  detail,  (2) a grab
sample is collected in a 3.8-I (1-gal) sample bottle, and
(3) if the system is in an untended state, a telephone
dialer is activated and will transmit a recorded message
to any pre-selected telephone station.

    The spill  warning  system has been successfully
demonstrated  in  the  laboratory  and in  the  field.
Recently, it has  been used to monitor discharges from
uncontrolled hazardous waste disposal sites.

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                 Mobile
    Decontamination Station
        For  Field Personnel
    To  prevent  undesirable  spreading  of
contamination  from  hazardous  chemical  site
operations,  a mobile  decontamination trailer has
been developed.

    This 12.2-m  (40-ft) trailer has been outfitted to
provide  on-site  safety  support  for emergency
response  personnel. The  unit  is  placed at the
boundary  of  a cleanup site and all personnel are
required to pass through it when entering and leaving
the  site.  The  trailer  is  divided  into  three
compartments: (1) a "clean room" with 12 lockers for
street clothing, (2) a 3-stall shower room,  and (3) a
"dirty room" with 12 lockers for  work clothing. The
dirty room includes a container for soiled garments,
and a clothes washer and dryer.

    The decontamination station has  an  on-board
water system, a hot water heater,  and a holding tank
for used water. Fittings have been provided to enable
connection to commercial water and sewer systems.
Contaminated water is processed before discharge.
Heat, ventilation, lighting, and air conditioning are
provided in the mobile station. However, power must
be obtained  from outside sources.

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          Mobile Field Office
    In  accordance  with  provisions of the National
Contingency  Plan, a Federal On-Scene Coordinator
(OSC)   is  designated  by  the  U.S.  Environmental
Protection Agency or U.S. Coast Guard to direct Federal
cleanup operations during the response to accidental
releases of hazardous materials, as well as oil spills. The
OSC has final responsibility for all activities at the site,
including: (1) assessing the environmental damage, (2)
determining the most suitable cleanup techniques, and
(3) ensuring the safety of those living near the impacted
areas, as well as of those participating in the cleanup.

    The OSC maintains close contact with primary and
advisory agencies, local agencies, and elected officials.
He  issues bulletins on a regular basis to  the public
through the media  and keeps complete records for
subsequent evaluation by Federal and state agencies.
    In  order  to carry out  these activities, the  OSC
requires  a  base  of operations convenient  to the
impacted site.  Accordingly, a 10.7-m (35-ft) trailer,
which can be transported by either a pickup truck or
tractor, has been outfitted by EERU. The mobile office
contains  communications   and  support  facilities
including:  telephone,  electric  power, water   lines,
running  water,   sanitary  facilities,  a  shower for
emergency decontamination of personnel, heat, air
conditioning, and  safety equipment.

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                                           Mobile
                           Flocculation-Sedimentation
                                           System
    When contaminated wastewater contains high
levels of suspended solids, single stage treatment
techniques, such as carbon contact processes, are
not practical because  the  suspended solids may
interfere with efficient utilization  of the adsorption
medium. Therefore, a system  that can remove the
bulk of the  suspended solids should be used to
pretreat  the  wastewater. A physical-chemical
treatment   system  capable  of  flocculation,
sedimentation, and  filtration  of  suspended  solids
from wastewater prior to the removal of hazardous
materials has been developed.
    This mobile system is completely enclosed in a
12.2-m  (40-ft)  long   van-type  trailer. The  major
components  of  the  system  are  a  pipe reactor,
chemical addition equipment, flocculation chambers,
an  inclined  tube settler,  and  a tri-media  filter.
Chemicals,  including  powdered  carbon,   lime,
aluminum  salts,  iron salts, clays, polyelectrolytes,
acids, and bases can be introduced into the 170-m
(560-ft)  long, looped pipe reactor at various locations.
Adsorbents, coagulants, and polyelectrolytes may be
added  at the end of the  pipe reactor, while pH-
adjusting chemicals may be introduced midway in the
system. Three  positive  displacement pumps are
provided to  feed chemicals into the reactor,  and
static mixers are located at each  chemical addition
point to assure rapid and effective mixing.
    After the wastewater is chemically treated in the
pipe  reactor,  it  flows  through  gently  agitated
flocculation chambers. Floe collects in a tube settler
and is discharged to a sludge collector. The final
treatment phase of the system is the tri-media filter,
which insures effective solids removal at the design
flow rate of 265 Ipm (70 gpm).

    The  original  system,  designed  as   a field
demonstration  pilot plant, was used to evaluate the
efficiency  of  treating  combined  sewage  and  raw
municipal wastewater. The system was shown to be
highly  effective  for  treating  this   wastewater.
Subsequent controlled field studies demonstrated
that the flocculation/sedimentation system  is highly
effective  for  pretreating  wastewater  that   is
contaminated with hazardous  materials. Additional
information on the system  is contained in  the EPA
report, EPA-R2-73-149.
                                               10

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                                   Mobile Laboratory
    As part of a continuing effort to provide prompt
emergency response to the uncontrolled release of oil
and hazardous  materials, a Mobile  Laboratory has
been developed. The Mobile Laboratory was designed
to provide analytical services  during the cleanup of
hazardous  materials at spill sites  and uncontrolled
waste  dumpsites.  Decisions  concernng  cleanup
efforts  are  based  upon  identification  of  the
pollutants,  their concentrations, and  the  physical
extent of contamination. Having analytical capability
at the site avoids delays inherent in shipping samples
to a central laboratory facility.

    The  Mobile  Laboratory is constructed  within a
10.7-m  (35-ft)  semitrailer equipped with a  heating,
ventilating, and air conditioning system designed for
once-through  air handling.   In order  to  provide
optimum analytical  services  during environmental
emergency response episodes, and  to assure an
analytical capability for virtually  all  organic  and
inorganic  hazardous substances  (e.g.,  pesticides,
RGB's, heavy metals), the Mobile Laboratory  contains
a broad range of instruments. These include: a gas
chromatograph/mass spectrometer (GS/MS), two gas
chromatographs equipped with flame ionization and
electron capture detectors, automatic samplers that
permit  overnight  operation, an atomic  absorption
spectrometer  with graphite  furnace,  infrared  and
fluorescence  spectrometers,  an  argon-plasma
emission spectrometer, and a total  organic carbon
(TOC)  analyzer.  In  order  to  permit  two-way
communication with a central laboratory, the Mobile
Laboratory  is  equipped  with  an  automated
telefascimile.  Additionally,  the  laboratory has a
15-kW  electric  generator,  running  water, and all
necessary  glassware,  solvents,  reagents,  and
supporting  equipment  to  allow fully independent
operation at remote field locations.

    For reasons of safety, the laboratory is fitted with
a fume hood, vented solvent locker,  explosion-proof
refrigerator, safety shower,  eye  wash station,  fire
alarm, and fire extinguishers. Vented  glove boxes are
available to permit safe  handling of  concentrated
hazardous waste samples. Protective equipment for
personnel  includes full face mask respirators,  self-
contained   breathing  apparatus,  safety  goggles,
gloves and  disposable coveralls. Geiger counters are
used to detect the presence of nuclear radiation in
samples.

    Since August 1977, the Mobile  Laboratory has
been  used to  perform  several  thousand sample
analyses  in  a  variety  of  emergency  response
situations,  including:   pentachlorophenol  in
groundwater  and  polychlorinated  biphenyls,  oil,
phenol,  hexachlorocyclohexane,  dichlorobenzene,
dichlorotoluene,  and  various  pesticides  at
uncontrolled hazardous waste disposal sites.
                                                11

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                                           Mobile
                                  Physical-Chemical
                                  Treatment Trailers

    One  effective approach to on-site cleanup of
hazardous material spills is the highly flexible, Mobile
Physical-Chemical  Treatment  Trailers  developed
under EPA Contract No. 68-01-0099. Treatment units
are  provided  for flocculation,  sedimentation,
filtration,  and  carbon  adsorption.  Contaminated
water  is  pumped  into  a settling  tank  where
flocculation and sedimentation  occur. The clarified
fluid is passed through mixed-media filters  before
entering the carbon adsorption  columns.  Sludge is
removed from the sedimentation tank and  stored for
ultimate disposal. Treatment schemes can be varied
(i.e., each step in the process may be bypassed) to
facilitate the recovery of spilled materials. If required,
additional storage tanks  are  provided  for  filter
backwashing or temporary  storage of unprocessed
materials.

    Two   Mobile  Physical-Chemical  Treatment
Trailers are maintained by  EERU for operation at
hazardous materials spill sites. One system, mounted
on a 13.7-m (45-ft) trailer, incorporates three mixed-
media filters, three pressure carbon columns (which
may be used in parallel or in series), pumps, piping,
controls,  and a 100-kW diesel generator. A support
trailer is  equipped  with additional pumps, fittings,
and several collapsible rubber tanks, which permit
the treatment trailer to be located up to 150-m (500-ft)
from the  spill  site. Contaminated water can  be
processed at flow rates between 380 and 2,270 Ipm
(100 to 600 gpm).
    A smaller unit is equipped with one mixed-media
filter and one pressure carbon column. This system is
mounted on a small trailer, which is transported by a
stake  truck.  Additional   equipment,  such  as
collapsible  tanks  and  gasoline  engine pumps, is
carried  on the  truck. Contaminated water can  be
processed at flow rates of 110 Ipm (30 gpm).
    The  Mobile   Physical-Chemical   Treatment
Trailers have  been used by EERU during the past
several  years. They   have  facilitated cleanup
operations at  hazardous  materials  spill  and
uncontrolled waste disposal sites. Response to these
situations  included  the treatment  of complex
mixtures  of industrial  wastes. Development of the
physical-chemical treatment  systems is described in
the EPA report, EPA-600/2-76-109.
                                               12

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                                     Mobile  Stream
                                   Diversion  System
    When small waterways  are  contaminated  by
sudden  discharges of insoluble sinking hazardous
materials, several  pollution  abatement  options
exist—dredging,  vacuuming,  and  isolation of the
impacted area. Dredging and vacuuming techniques
often lead to downstream spread of the contaminant
as a result of resuspension of bottom muds and silts.
Further, there  are significant  problems associated
with treatment of the water-sediment slurry produced
by the dredging.

    Isolation  is accomplished  by  damming the
stream above the impacted area and bypassing the
normal stream flow. This stream diversion technique
will permit the spill-impacted segment  to dry, thus
facilitating cleanup  (manually or with  mechanical
earthmoving  equipment). The  problems  of sediment
resuspension and treatment  of large  volumes of
contaminated dredge water are exchanged for the
requirements of pumping and piping to achieve the
bypass.

    The decision to design and develop a Mobile
Stream Diversion System (MSDS), EPA Contract No.
68-03-2458, was predicated upon  the following: (1)
considerable quantities of  hazardous materials are
often  spilled  into  inland  waterbodies,  (2)
approximately 85% of the stream miles in the U.S.
have moderate flow rates (i.e., roughly 0.28-m3/sec
[4,400-gpm]),  and  (3)  nearly one-half of  the  EPA-
designated  hazardous  substances  are either
insoluble sinkers or form insoluble precipitates on
contact with  water.
    The  MSDS  is  a  completely  self-contained,
independent  system  that  can   maintain  flow
continuity   around   an   area   undergoing
decontamination   processing.   The  system  was
designed   to   use   standardized,  readily
available/replaceable components  and  is  easily
maintained. The major components of the system are
booster pumps, submersible pumps,  generators, a
crane, and  aluminum irrigation  pipe  with ancillary
fittings. Over level  terrain the system is capable of
pumping 0.35-m3/sec (5,600-gpm) a distance of 0.3-km
(1,000-ft)  and,  if supplemental  piping is provided,
0.09-m3/sec  (1,425-gpm)  for  a  distance  of
approximately 11-km (36,000-ft).

    To provide flexibility and reliability, the system
has been assembled as two totally independent units
mounted  on trailers  so  that spills will be readily
accessible   via  state   or  interstate  highways.
Components are fastened on the trailers so they can
be quickly unloaded for air shipment to more distant
locations. Once on site, the system can be assembled
and placed in operation by a crew of five in a matter of
hours. The MSDS has been recently used during an
emergency response to a spill episode that adversly
impacted a  public water supply;  use of the system
insured uninterrupted  service  to  the affected
communities.

    Additional information  about  the  stream
diversion system may be found  in the EPA report,
EPA-600/2-81-219.
                                              13

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             Multipurpose
             Gelling Agent
    Limiting the spread of hazardous liquid materials
after a spill is an important  countermeasure that can
prevent chemical contaminants from further damaging
the environment. Immobilization of hazardous liquid
materials in order to (1) reduce the size of the affected
land area, (2) retard the percolation of toxic materials
through the subsoil and into the groundwater, and (3)
prevent chemicals from entering adjacent waterways is
a critical concern during an emergency spill response.

    One  method of preventing the  spread  of spilled
hazardous liquid materials is immobilization by means
of a  gelling  agent.  Ideally, the gelling  agent  will
transform the liquids into a semi-solid material that can
be easily removed by mechanical means.

    Multipurpose Gelling Agent  (MGA),  developed
under EPA Contract Nos. 68-01-0110 and 68-01-2093,
can immobilize many spilled hazardous liquids within
minutes.   An  optimum  formulation—four  organic
polymers  and  a fumed  silica—requires  a minimal
amount of gelling agent in order to immobilize a wide
variety of hazardous materials.

    The system used to distribute the MGA is mounted
on  a  4-m (13-ft)  long  utility trailer  that can  be
transported to a spill site. The auger-fed/pneumatic
conveyor system is driven by an  air-cooled gasoline
engine and consists of a hopper that introduces the
MGA into a 5-cm  (2-in) hose, through  which it  is
transported up to distances of 60 m (200 ft). The MGA
then flows through  delivery nozzles at a rate of 5.4 kg
(12 lb)/min. The nozzles accurately direct the agent an
additional 6 m (20 ft). Approximately 1 kg (2 Ib) of MGA
can gel 10 I (2.6 gal) of spilled liquid.
    Additional information about the gelling agent and
dispensing  system  may be  found  in the EPA  final
reports, EPA-600/2-78-145 and EPA-600/2-77-151.
                       14

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                                    Pesticide Detection
                                           Apparatus
    Spills or discharges of toxic pesticides in waterways
pose a serious threat to the aquatic environment and
municipal water  supplies. With the increased  use  of
organophosphate pesticides, which are toxic at very low
levels,  precautions are needed to reduce this  threat.
Because of the  stability of toxic organophosphate
pesticides under  "normal" environmental conditions, it
is  imperative  to  rapidly  detect  these  hazardous
compounds.
    Automatic systems have been developed to monitor
water  for  the  presence of  organophosphate  and
carbamate insecticides. The principle used fordetecting
these  cholinesterase-inhibiting  toxic  substances  is
based upon: (1) the collection of enzyme inhibitors on
immobilized cholinesterase, (2) the chemical reaction of
immobilized  cholinesterase  with  a substrate,
butyrlthiocholine esterase, in the presence of enzyme
inhibitors, and (3) the electrochemical monitoring  of
substrate hydrolysis products.
                     CAM-1
    The Cholinesterase Antagonist Monitor (CAM-1),
developed under EPA Contract No. 68-01-0038, is an
automatic pesticide detection instrument. CAM-1  is
intended  to be used  in a laboratory environment for
monitoring potable water supplies and effluents from
pesticide  manufacturing  facilities.  An alarm signal is
produced when cholinesterase antagonists are detected
above a pre-set level.
                                                                            CAM-4

                                                          The Cholinesterase Antagonist Monitor (CAM-4),
                                                      developed under EPA Contract No. 68-03-0299, is a
                                                      more rugged instrument that  is designed for rapid
                                                      detection of toxic materials in a river, stream, or pond.
                                                      The portable apparatus can be used from alongside the
                                                      banks of a stream or from a boat. An operator is needed
                                                      to note the presence  of enzyme inhibitors when the
                                                      baseline voltage increases 10 or more millivolts in one
                                                      sampling cycle, as  indicated  on the printout of a strip
                                                      chart   recorder.  The  CAM-4  can  operate
                                                      continuously—with little maintenance—for an  8-hour
                                                      period  when using a 12-V automobile battery or a 110-V
                                                      a.c. power source.
                                                          A complete description of the pesticide detection
                                                      apparatus, including design  specifications as well as
                                                      results of laboratory and field  tests, may be found in the
                                                      following EPA reports: EPA-R2-72-010, EPA-600/2-77-
                                                      219, and EPA-600/2-80-033.
                                                  15

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                                    Portable  Collection
                                          Bag System
    Frequently, a first step in a hazardous material spill
response is containment of the spilled material (e.g., by
foam dikes or gelling agents). Emergency collection and
temporary storage of spilled hazardous materials is vital
for hazardous liquids that are temporarily impounded in
a diked area  or sumped pool, or are leaking  from a
damaged transportation vehicle.

    A pre-packaged system for collection, containment,
and temporary storage of spilled hazardous materials in
a group of  large, interconnected, flexible plastic bags
has been developed  (EPA Contract  No. 68-03-0206).
The system is mounted on a 1.2 - by 1.2-m (4 - by 4-ft)
reinforced plastic pallet fortransporting by pickuptruck
or van. Components include: a self-priming centrifugal
pump, two 15-m (50-ft) lengths of 5-cm (2-in) hose, and
four furled, self deploying plastic bags (a header with
three fingers) with a total capacity of 26,5001 (7,000 gal).
The collection bags are made of a puncture-resistant
plastic  material that has sufficient mechanical strength
to be minimally affected by most hazardous substances
during  short-term storage periods.
    Two models of the Portable Collection Bag System
are currently available. One model is powered by an
explosion-resistant, gasoline engine and has a nominal
pumping rate of 300 Ipm (80 gpm). A single tank of fuel
provides 2 hours of pumping time, which is generally
sufficient to fill the  bags. The other model, which is
explosion-proof,  is battery-powered. It has a nominal
pumping rate of 200 Ipm (50 gpm) and will operate for 2
to 2'/2 hours without requiring a battery recharge.

    An  8 - by 6-m (25 - by 20-ft) area is needed to
assemble the system.  The collection  bags  must be
placed on level surfaces, or on inclines no greater than
30°, in order to prevent sliding as they are filled. Where
static electricity may build up, as with low conductivity
fluids, a cable should  be  used  to  ground the pump
chassis.

    The Portable Collection  Bag System has been
successfully used to contain materials from leaking tank
trucks.  Details  of the system,  including operating
manuals for the battery-powered and gasoline-powered
models, are contained in EPA-600/2-77-162.
                                                   16

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EQUIPMENT UNDER DEVELOPMENT

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                                            In-Situ
                              Containment/Treatment
                                           System

    When spills of hazardous materials contaminate
soils and threaten nearby surface water or underlying
groundwater, an  effective method  of  preventing
percolation through the soil is needed. Excavation
and  hauling  of  soil  contaminated  by  hazardous
materials  to a  secure  landfill  is  one  solution.
However, this approach is not feasible for those spills
where  a  large  volume  of  contaminated  soil  is
involved. An alternate  approach is  to flush  the
contaminated  soil  with  water;  however,  this
procedure generally requires large volumes of water,
which  become contaminated  and,  subsequently,
must  be  contained and treated. An  innovative,
alternative method for treating contaminated soils is
in-situ detoxification by chemical  reaction.

    A mobile In-Situ Containment/Treatment System
capable of containing a 40-m3 (10,000-gal) spill  has
been developed under EPA Contract No. 68-03-2508.
The system is mounted on a 13.1-m (43-ft) drop deck
trailer and includes: a diesel electric generator, an air
compressor,  mixing tanks, hoses,  a solids feed
conveyor, pipe injectors, soil testing apparatus,  and
accessory items. In-situ containment  and treatment
is  accomplished  by  direct  injection of  grouting
material into the soil around the contaminated area in
order to isolate the spill. The hazardous materials are
then  treated in  place  by  oxidation/reduction,
neutralization, or  precipitation.  When  necessary,
contaminated water can be withdrawn from wet wells
and treated by other means.
    A  decision  matrix  has  been   prepared  to
determine if in-situ grouting and chemical injection is
the most  time  and cost effective  treatment  for a
particular land spill. Several critical variables must be
considered:  type of hazardous  materials  spilled,
interaction with  soil,  "groutability"  of  the  soil
(permeability), void  loading,  geometry,  water  table
level, volume of contaminated soil,  feasibility of an
alternate treatment method (such as excavation), and
availability of treatment  material  and equipment.
Grouting is limited to the relatively coarsed-grained
soils (sand and gravel) through which contaminants
can rapidly permeate. Where small-grained soils (silts
and clay)  preclude the  use of grouting techniques,
surface treatment  of contaminated  soil  may  be
effective.
    Some chemicals are not amenable to in-place
detoxification. For example,  long  chain  organics,
many  pesticides, and heavy metals  are  relatively
insoluble in water and could not be  treated using in-
situ, inorganic treatment techniques. However, they
may be contained by a grout curtain until alternate
pollution abatement measures are initiated.
    The   mobile  In-Situ  Containment/Treatment
System is  currently undergoing shakedown by EERU.
    Additional information is contained in  the EPA
report,  EPA-600/2-81-085.
                                                17

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                                             Mobile
                                  Incineration System
    Surveys by Federal,  state,  and local agencies
have  revealed the  presence  of  thousands  of
abandoned or uncontrolled industrial waste dumpsite
throughout  the  country.  Some  sites  contain
hazardous chemicals that present  a severe threat to
public health and safety. Leachates containing toxic
chemicals threaten contamination  of adjacent water
supplies, while noxious vapors released from these
sites  often  comprise the  air quality surrounding
communities.

    Many methods are  being investigated  to deal
with the  problem of  hazardous  wastes.  Several
include:  incineration,  deep  well   injection,
solidification, biological degradation, and disposal in
secured  landfills.  The  OHMS  Branch,  of  EPA's
Municipal Environmental  Research Laboratory, is
currently evaluating the operating characteristics of a
15 million BTU per hour  Mobile  Incineration  System
with fuel oil alone prior to undertaking an exhaustive
test plan with specific hazardous substances. The
unit will be capable of on-site thermal detoxification
of many hazardous materials, such  as RGB's, kepone,
malathion,  and  TCDD.  The  basic system   was
designed and the major parts fabricated and mounted
on three over-the-road trailers under EPA Contract No.
68-03-2515. Under EPA Contract No. 68-03-2647, much
of the basic piping and instrumentation was  laid out
and  installed  at  the  OHMS  Branch  facility.
Subsequently,  under EPA Contract  No.  68-03-3069,
the system was shaken down, suitably modified and
operated with fuel oil.
    The  system is mounted on three over-the-road
semitrailers. The first trailer carries a refractory-lined
rotary kiln incinerator that provides long dwell times,
high temperature, and a choice  of operating modes
(controlled atmosphere and excess air). Solid wastes
are fed  to the incinerator by a  hydraulic ram feed,
while pumpable sludges  and liquids are injected
directly into the incinerator. Residual ash, consisting
of inert  materials  and metal residues, are collected
for disposal at an appropriate landfill facility. Exhaust
gases carry vaproized and partially combusted toxic
components  into  the  excess  air  secondary
combustion chamber (SCC) that  is mounted on  a
second trailer.  Off-gases from the SCC are water-
quenched in a  ground-level venturi scrubber before
passing to the third trailer on which are mounted  a
wetted  fiber   glass filter  to   remove  residual
particulates including  phosphorus  pentoxide,  a
caustic sprayed packed mass transfer unit to remove
acid gases (HCI and SO2 for example), a demister, an
induced draft fan, a sound attenuator, and the stack.
The system is maintained under negative pressure to
prevent out-leakage.  Sophisticated instrumentation
for monitoring temperature, flow,  and the levels of
process gases and vapors are mounted in a fourth
trailer. A complex system of automatic interlocks and
alarms is provided to ensure that  the system shuts
down should it  fail  to  meet permit requirements.
Permitting  requirements  further  mandate that
detailed analysis of all  waste streams—stack gas,
processing fluids,  and  ash—be carried  out  on  a
scheduled basis.

    Design processing rates, with 20% excess  air,
are 284-I (75-gal) of contaminated fuel oil per hour, or
4,050-kg (9,000-lb) of contaminated  dry sand per hour,
or 675-kg (1,500-lb) of water per hour. (An additional
90.8-I [24-gal]) per hour of "clean" fuel is required for
the SCC). Nomographs are available  for estimating
the throughput  of  mixtures; these depend on  fuel
value,  bulk  and  gas volume of   the  combustion
products, and inert N2.

    The  incineration  system  will require several
support trailers  to supply fuel and  water, as well as
physical-chemical  treatment  equipment  for spent
process water. Separate  systems are needed for site
preparation, feed stock  handling,  and ash removal.
Analytical facilities are  essential  to identify waste
materials,  prepare  feed  stock,   and  monitor  all
discharges from the system.  Additional  trailers
provide office   space and  clothes  change/shower
facilities. A PCB trial burn of the incinerator by EERU
is scheduled during 1982.
                                                18

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       Mobile  Independent
    Physical-Chemical (IPC)
     Wastewater Treatment
                 System
    Emergency  response  personnel  at  hazardous
materials spills and uncontrolled waste-site cleanups
are frequently  faced with  the  problem  of selecting
effective  treatment methods for  large  volumes  of
complex wastes. When the cleanup is expected to last
over an extended time period, wastewater treatment can
be both cost  and labor intensive. Treatment of the
contaminated wastewater in a timely and cost effective
manner can be facilitated by  a flexible,  automated
system that is capable of providing several types  of
treatment  (e.g.,  clarification,  filtration,  adsorption,
neutralization,  disinfection).

    The Mobile Independent Physical-Chemical (IPC)
Wastewater Treatment System  utilizes  standard
equipment and conventional process  flow schemes.
Wastewater is pumped at a rate of 130 Ipm (35 gpm) from
the wastewater  source to a flash mix tank where
coagulant is added. Chemically treated wastewater and
recycled sludge (from the clarifier) are then mixed in a
flocculation tank  and settleable floe is  formed. The
wastewater then flows to a clarifier, where precipitation
and skimming  of solids are accomplished. Removal  of
settled sludge  from the clarifier is aided by a slowly
rotating rake.  A timer-controlled valve regulates the
recycling  and/or wasting of  sludge.  Clarified
wastewater  flows  over  V-notched  weirs  to  a
neutralization mix tank, where it is treated with acid  or
caustic to adjust the pH. The wastewater then enters a
two stage — upflow and downflow — granular carbon
contact system for removal of organic materials. Next,
the flow enters a pressure sand filter priorto disinfection
in a chlorine contact tank.

    After the neutralization mix tank, the IPC system is
designed to enable flexible treatment schemes. For
example, (1) flow can be directed to the sand filter prior
to the granular carbon contact system or (2) additional
treatment stages can  be added  between the
neutralization mix tank and the chlorine contact tank.
    The Mobile Independent Physical-Chemical (IPC)
Wastewater Treatment System has been developed and
is currently undergoing modification by EERU. This
system is ideally suited for long term cleanup activities
that may require several months of effort. Once it has
been set up, the IPC system requires only minimal
operator  time  for  chemical replenishment, sludge
disposal, and periodic maintenance.
                      19

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     Mobile  Reverse Osmosis
          Treatment System
    Conventional physical-chemical treatment systems
(e.g., activated carbon,  ion exchange) for hazardous
materials can accommodate dilute aqueous  solutions
(several hundred to several thousand ppm).  However,
when a solution of hazardous material approaches a
concentration range greater than 1%, many of these
physical-chemical  treatment  systems are  not as
effective. An existing technology that can be used to
efficiently separate some constituents of concentrated
solutions (> 10,000 ppm) is reverse osmosis.

    Osmosis, a  natural  phenomenon, results when a
dilute liquid and a concentrated liquid are separated by
a semipermeable, selective membrane. For  example,
fresh, pure water will diffuse through such a membrane
into a salt water solution. When pressure is applied to
the salt water, water molecules from the saline solution
will be forced through the membrane into  the fresh
water—reverse  osmosis  (RO).  The  "selective"
permeability of the membrane will act as a barrier to the
passage of salt molecules.

    The heart of the reverse osmosis process is the
membrane.  Although many membrane materials have
been studied, cellulose acetate—one  of  the earliest
materials considered—is the most  commonly used.
Commercially available membranes can hold back all
but a few percent of the salt molecules  in  water. In
addition, these membranes  have been found to retain
other impurities,  including various organic materials,
high molecular  weight  substances,  bacteria, and
viruses. More specifically, experimental work has shown
that RO is capable of removing from dilute solution
better than 99%  of most pesticides and  chlorinated
hydrocarbons  and is  also  effective for  removing
relatively  low  molecular   weight,  polar   organic
compounds.
    A Mobile Reverse Osmosis Treatment System is
currently under construction  for EERU. This system,
which was originally designed as a pilot plant to test the
feasibility of treating acid mine wastewater, is being
modified  for field  use  at  incidents involving
concentrated solutions of hazardous materials (e.g.,
leachate from uncontrolled hazardous waste  sites).
    The  reverse  osmosis treatment process  under
development will separate the influent waste into two
streams:  (1)  a "purified" stream that can be  further
treated, if necessary, or directly discharged  to the
environment, and (2) a concentrated waste stream that
will be  greatly reduced in volume, thereby facilitating
further  processing and/or ultimate disposal.
                      20

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                                    Mobile  System For
                             Detoxification/Regeneration
                                            of Spent
                                     Activated  Carbon
   A commonly used and generally effective method
for  removing  many  dissolved  hazardous  organic
substances from aqueous  solutions is  adsorption by
activated  carbon. During  the treatment process the
activated  carbon  can  become  contaminated  with
relatively  high  concentrations  of hazardous organic
material. When the carbon reaches its adsorptive limit, it
must be disposed in an approved manner or thermally
regenerated. However, in some instances, toxicity of the
pollutant is such that transportation of  the exhausted
carbon  to a  secure   landfill  or  to  a commercial
detoxification/regeneration facility is not acceptable.

   In order to provide a safe and effective method for
Tandling contaminated carbon,  the OHMS Branch has
developed a mobile unit for detoxifying/regenerating
contaminated carbon at the cleanup site. The mobile
detoxification/regeneration system, mounted  on  a
13.7-m (45-ft) long semitrailer, is equipped with a rotary

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                                 Mobile  System For
                                  Extracting Spilled
                                Hazardous  Materials
                                        From  Soil
    Landborne spills of hazardous materials that
percolate through the soil pose a serious threat to
groundwater.  Effective response to such incidents
should  include   the  means  for  removing  the
contaminants and restoring  the soil to its original
condition.  Currently  practiced techniques,  such  as
excavation with transfer to a landfill or flushing with
water in-situ are beset with difficulties — large land
area and volume of materials involved. An innovative
In-Situ Containment/Treatment  System,  previously
described, has been developed to treat contaminated
soils.  However, it  is not suitable for all soils and/or all
chemicals.  Another  novel  treatment  system  is
currently  under  development (EPA  Contract  No.
68-03-2696).

    A mobile treatment system has been designed
for water extracation of  a broad range of hazardous
materials from spill-contaminated  soils. The system
will: (1) treat excavated contaminated soils, (2) return
the treated soil to the site, (3) separate the extracted
hazardous materials  from the washing  fluid for
further  processing  and/or  disposal,  and (4)
decontaminate process fluids before recirculation, or
final   disposal.  A  demonstration  model  will be
developed utilizing  conventional  equipment for
screening, size reduction, washing, and dewatering of
the soil. The  washing fluid — water — may contain
additives, such as acids,  alkalies,  detergents, and
selected  organic  solvents  to  enhance  soil
decontamination. The nominal processing rate will be
3.2-m3 (4-yd3)  of contaminated soil per hour when the
soil particles are primarily less than 2-mm in size and
up to 14.4-m3  (18-yd3) per hour for soil of larger average
particle size.
    The soil  scrubbing system, currently undergoing
laboratory evaluation, is expected to be available in
1982.
                                              22

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