United States
Environmental Protection
Agency
Office of Emergency and      Environmental
Remedial Response  ... _     Response
Emergency Response Division    Team
Treatment Technologies
for Superfund
Environmental Response
Training Program

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                                       FOREWORD
This manual is for reference use of students enrolled in  scheduled training  courses of the U.S.
Environmental Protection Agency (EPA).  While it will be useful to anyone who needs information
on the subjects covered, it will have its greatest value as an adjunct to classroom presentations
involving discussions among the students and the instructional staff.

This manual has been developed with a goal of providing the best available  current information,
individual instructors may provide additional material to cover special aspects of their presentations.

Because of the  limited  availability of the manual, it should not be cited  in bibliographies or other
publications.

References to products and manufacturers are for illustration only; they do not imply endorsement
by EPA.

Constructive suggestions for improvement of the content and format of the manual are welcome.

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      TREATMENT TECHNOLOGIES FOR SUPERFUND

                                  (165.3)

                                 4 DAYS
This course instructs participants in the concepts and techniques for containment,
treatment, and disposal of hazardous materials associated with accidental releases and
uncontrolled waste sites. It emphasizes the practical applications of incident
mitigation and treatment technologies.

The objectives of the course are:

•      To provide an overview of containment and treatment practices for mitigating
       releases  into air, surface water, soil, and groundwater

•      To  address environmental, financial, and regulatory considerations in the
       application of treatment and disposal options

•      To  identify the  logical progression of  clean-up operations at uncontrolled
       waste sites

•      To  describe principles of physical, biological,  and chemical  treatment and
       present the practical application of field-tested treatment systems.

After completing the course, participants will be  more knowledgeable about the
principles  and  applications  of  containment,  handling,  treatment,  and  disposal
technologies used at hazardous materials incidents.
                                    111

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                              CONTENTS
Section 1






Section 2






Section 3






Section 4






Section 5






Section 6






 Section 7






 Section 8






 Section 9






 Section 10






 Section 11






 Section 12






 Section 13






  Section 14
Field Categorization






Chemical Characteristics






Waste Treatability






Groundwater Containment






Recovery Processes






Volatilization






 Inorganic Treatment






 Carbon Adsorption






 Biological Treatment






 Incineration






 Soil Flushing and Washing






 Immobilization






  Disposal Options






  Alternative Treatments

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Section 1

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                          FIELD CATEGORIZATION
STUDENT PERFORMANCE OBJECTIVES:



At the conclusion of this section, participants will be able to:



       •      Describe the advantages and disadvantages of field categorization and bulking

       •      Briefly describe the following site operations:

                   Site preparation
                   Drum handling
                   Drum sampling and labeling
                   Drum segregation and storage

       •      Describe basic field categorization analytical methods

       •      Briefly describe typical bulking procedures.
5/93

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                                                     NOTES
  CHEMICAL INCOMPATIBILITY
 The combination of two or more reactive
 materials resulting in uncontrollable
 and undesirable conditions.
   PRACTICAL CONSIDERATIONS OF
        CHEMICAL REACTIVITY
  Heat Generation
  Fire
  Explosion
  Formation of Toxic Vapors
  Formation of Flammable Gases
  Volatilization of Toxic or Flammable Substances
  Formation of Substances of Greater Toxiclty
  Formation of Shock-Sensitive Compounds
  Pressurlzatlon In Closed Vessels
  Solubility of Toxic Substances
  Dispersion of Toxic Dust, Mists, and Particles
  Violent Polymerization
    COMPATIBILITY TESTING
           CONSISTS OF

  • Gross Identification of Wastes

  • Segregation into Waste Categories

  • Bench-Scale Compositing of
    Compatible Materials
5/93
Field Categorization
         page 1

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                            POSSIBLE REASONS FOR
                            COMPATIBILITY TESTING
                           • Gross Identification

                           • Segregation for Storage Purposes

                           • Determine Shipping Requirements

                           • Determine Disposal Method

                           • Economic
                            PROCESS DESCRIPTION
                              Site Preparation
                              Handling and Movement
                              Opening and Sampling
                              Labeling and Recording
                              Compatibility Testing
                              Segregation and Storage
                              Bulking
                           SITE PREPARATION
Field Categorization
page 2
5/93

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                         NOTES
  HANDLING AND
    MOVEMENT
     OPENING
  AND SAMPLING
   LABELING AND
    RECORDING
5/93
Field Categorization
    page 3

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       NOTES
                             COMPATIBILITY
                                  TESTING
                                COMPATIBILITY TEST
                                     SCHEMES
                            • Knowledge of Waste Materials at the Site
                            • Criteria Selected by the Oversight Agency
                            • Contractor's Experience and Preference
                            • Criteria of the TSD Facility
COMPATIBILITY TREE
1 Sample 1 (non-radioactive)

Strong Acid 4-fpH « 5,
,— ORP t— 0
1.O«TdU*r LOxIdlier
2. Reducing Agent

soluble
•*'" I U.....J
IpH




pH 5-9 pH > 9 1— » Strong B«M
1 (oh.ck CN-, 8.)
RP i LQBP
Z.Rtducmg Agent

add w
aier
V
1.O«ldlz*r
I.Rtduelng Agent



. Insoluble


no density density
gradients gradients
Water check Or
•olubto
floate
5% HCI
b»olubl«
L6% NlOH
Base
sinks
B*
po.1
IntoluU*
etelnTett
«M|MS<«<

nashjOlnt organic A?ld /Hal. Hydro.
. (cluck FP) S (eh«ck PCB)
Flammable Non-flammable
Hvdroc
iarbon
Hvdrocir

rtt

>on
Liquid Liquid '(chtcS FP) '(check FP)
Field Categorization
page 4
5/93

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                                                NOTES
               PH
   • Potentially Dangerous Situations
   - Toxic Gases
   - Heat
   - Uncontrolled Reaction Products

   • pH Paper

   • pH Meter

   • Classification
  OXIDIZERS AND REDUCERS
     • Titanium Sulfate Indicator
      - Colorimetrlc
      - Yellow ; Organic Peroxides
      - Brown ; Organic Oxidizers
      - Problems with Complex Wastes

     • Redox Potentiometer
      - Simiiiar to pH Meter
      - Uses mv Scale
      - Problem Simiiiar to pH Meter
  SCREENING FOR OXIDIZERS
         AND REDUCERS
 • Use Standard Test Solution that
   Generates a known ORP

 • Measure ORP Between a Sensing
   Electrode and a Reference Electrode

 • Add Unknown

 • Remeasure ORP
5/93
Field Categorization
        page 5

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        NOTES
                                 STANDARD TEST SOLUTIONS
                                • To Screen for Oxldlzers :
                                 - 0.001 N Ferrous Ammonium Sulfate which
                                   Generates 380mv; Positive if >430mv

                                • To Screen for Reducers :
                                 - 0.001 N Potassium Chromate which
                                   Generates 630mv; Positive If <580mv
                                      WATER REACTIVITY

                                        AND SOLUBILITY
                                   • Normally One of the First Tests

                                   • Characteristics when Mixed with Water
                                   - Reacts Violently
                                   - Forms Potentially Explosive Mixtures
                                   - Generates Toxics, Vapors, or Fumes

                                   • Small Volume of Waste Is Added to Water
                                   - Reaction?
                                   - Soluble?
                                   - Floats/Sinks?
                                   - Hexane Soluble?
                                ORGANICS AND HALOGENATED
                                            ORGANICS

                                • PID at Drum Head

                                • Floaters — Organics

                                • Sinkers -- Halogenated Hydrocarbons
                                 - Beilstein Test
                                 - GC Scan
                                 - PCB Check
Field Categorization
page 6
5/93

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                                                 NOTES
       FLAMMABILITY

     • Temperature at which the Vapors
      of a Substance will Ignite

     • Ignitability Test
     - 0.1 gram or 0.1 ml Sample
       Heat to Ignition

     • Observations
     - Flame jumps to Sample
     - Flame touches Sample
     — Heating Sample is required
          FLAME TEST
 Sample Composition

 Aromatlo


 Lower Aliphatic*


 Oxygenated Compounds


 Hctogenated Compounds


 Aqueous Solutions


 Polyhalogenated Compounds
General Behavior

- burn with smokey flame


• almost smokeless flame


- bluish flame


• smokey flame


• no Ignition - sizzle


- no Ignition - smokey
 SEGREGATION AND
         STORAGE
5/33
                                   Field Categorization
                                           page 7

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     NOTES
                       BULKING
Field Categorization
page 8
5/93

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                             FIELD CATEGORIZATION
       Drumming/Bulking Wastes

              General Description

              Stockpiled drums and small containers of potentially hazardous wastes can pose unique
              problems in cleanup and disposal.  Costs associated with analysis and repackaging of
              numerous containers can be staggering.

              Mixing compatible wastes and disposing  of them in  bulk  quantities can effectively
              reduce such costs. However, the volume of wastes or the number of containers directly
              affects cost  savings.

              Repackaging usually involves  placing original leaking containers into larger vessels,
              sampling the contents, labeling the vessels for identification, and providing storage prior
              to  shipment  or  treatment.   Bulking  usually  involves  staging  the  containers,
              recontainerizing leaking vessels, labeling the vessels for identification, sampling the
              contents, conducting  compatibility tests, performing bench  scale compositing  of
              compatible materials,  field bulking wastes, and storing or treating the wastes.

       Applicable Wastes

       Drummed or containerized wastes.

       Process Description

       It is important to collect as much information as possible about the stockpiled material before
       attempting to move it.  This  information may assist in development of site safety and work
       plans.  General procedures applicable to drumming or bulking operations include:

       •      Site survey  and staging layout

       •      Container handling

       •      Container opening and sampling

       •      Container labeling and data recording

       •      Compatibility testing (bulking  operations)

       •      Bench compositing of compatibles  (bulking operations)

       •      Container segregation and storage

       •      Bulking  of compatibles (bulking operations).
5/93

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FIELD CATEGORIZATION

      Each site is unique, so schemes for compatibility testing are site specific.  However, each
      site-specific scheme follows a flowchart similar to the one shown in FIGURE 1.   The
      scheme chosen for a specific action is based on the following factors:


      •      Knowledge of waste materials at the site


      •      Criteria selected by the oversight agency


      •      Contractor's experience and preference


      •      Criteria of the treatment, storage, and  disposal (TSD) facility receiving the waste.
                              Drum Handling Operations
                                          !
                              Locate and Excavate Drums
  Locate and Separate.
  Radioactive Drums
                                  Stage for Sampling
                                          !
                                  Open and Sample
                                          I
                                *Test for Compatibility
                        Incompatible	|	Compatible
                              I                         !
                      Isolate and Handle        Stage for Bulking
                           Separately                  |
                                                 Bulk Wastes
                                                      !
                                                 Solidify or Treat
                                                       I
                                                Transport and Dispose
                                     FIGURE 1
              FLOW DIAGRAM FOR DRUM HANDLING OPERATIONS
•"See FIGURE 2 for an example of a decision tree used for compatibility testing.


Note that incompatible wastes, including radioactive, water and air reactive, PCB, sulfide, and
cyanide wastes, are disposed of separately either in their original containers or overpacked.
5/93                                     10

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FIELD CATEGORIZATION

       The  site survey should include use of a gamma survey  instrument to determine whether
       containers emit gamma radiation above background levels (0.01 to 0.02 milliroentgen per
       hour).  If gamma radiation is above 1  milliroentgen per hour, a health physicist should be
       contacted and the site safety and work plans should be amended as required.  Containers
       emitting gamma radiation above background levels should be considered potential sources of
       radiation and are to be segregated from other materials.

       All  workers performing  radioactive  drum  handling, sampling,  or  analysis  should be
       monitored by documented radiation dosimetry techniques.

       A level area accessible to drum handling equipment such as backhoes or light duty cranes is
       selected for staging.  The contents of leaking  containers should be transferred to sound
       vessels before staging. Containers are then relocated to the staging area (normally through
       the use of  drum grapplers or  slings)  and are arranged in rows  of two.   This allows for
       relatively easy access to any single container.

       Remote methods should be used to  open drums.  This may be done by using a backhoe with
       a brass or beryllium spike affixed  to its bucket.  Pneumatic devices are also available for
       opening containers of various sizes.

       Containers  must be labeled either before or during sample collection. Labeling should be  in
       a sequential order so that containers may be located easily.  Labels may  be tags that are
       wired to  a container or they  may be painted directly on the container.   If tags are used they
       must be weatherproof and should be affixed  to the container with a heavy wire. If paint is
       used it must not  cover  any original information about the ownership or contents of the
       container.

       Sampling of the container's head  space  with total  vapor analyzers can reveal whether a
       potentially  explosive condition exists.  Such an atmosphere exists when  a direct-reading
       instrument, such as a photoionization detector (PID), reads at 2000 units or more.  Samples
       that  yield detector readings at  such levels should be considered flammable until additional
       material  tests indicate otherwise.   Instruments such as  the PID  and the organic vapor
       analyzer-flame ionization detector (OVA-FID) have unique sensitivities and specificities  to
       identical  substances, and the response of such  instruments to "unknowns" may not yield
       quantitative results.  Furthermore,  some dangerous substances such as  phosgene, hydrogen
       cyanide,  and chlorine gas cannot be detected by PIDs or OVA-FIDs.

       Samples of the container's contents are taken using drum thieves. Drum thieves are hollow
       glass rods,  approximately four feet long and  lh inch in diameter.  The rods are inserted into
       the drum to their full length, the individual who is taking the sample places a finger over the
       top of  the rod and makes an airtight seal, the rod is withdrawn from the drum and inserted
       into  a  sample container, the sampler's finger is  withdrawn, and the sample flows from the
       rod  into  the container.   This is  repeated until a sufficient sample  volume is collected.
       Because the drum contains a material that is assumed to be contaminated, the drum thief must
       be left in the drum or must be decontaminated.
5/93                                         11

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FIELD CATEGORIZATION

       As the sample is transferred from its original container, to the sample container it is visually
       examined.  Air  reactive  substances may ignite, emit  fumes or gases, or release pressure.
       Samples exhibiting these traits are considered to be air reactives, and containers holding such
       substances must be separated from other containers.   Furthermore,  any drum  found
       containing solids submerged in liquid should be considered to contain an air or water reactive
       substance.  These drums must be separated from other containers.

       Samples are delivered to  a field laboratory for  compatibility testing.  The field laboratory is
       often set up near the site.  Field laboratories may be as complex as a mobile laboratory or
       as simple as table  space  set up near  the staging operations.  The specific tests that will be
       conducted to determine which wastes are compatible are selected based upon available site
       information.  FIGURE 2 shows a compatibility tree that has been used at a site to  assist in
       determining some  waste  characteristics.  Flowcharts and compatibility trees are developed
       for use at a specific site.  However, many of the compatibility tests which are conducted on
       waste samples are  commonly used.

       Stockpiled drums at hazardous waste sites pose special problems in cleanup  and disposal.
       Laboratory analysis, overpacking, and disposal on a drum-by-drum basis can be cost and
       time prohibitive.  Removing the wastes from drums, tanks, ponds,  and lab packs and
       combining compatible  contents into larger volume containers is more economical  and less
       time consuming, especially  for sites with more  than 500 drums.  However, wastes must first
       be tested for compatibility  before  they are  bulked  and  incompatible wastes  must  be
       segregated.

       Compatibility  testing  is neither as  extensive  nor  as  costly  as  standard laboratory
       characterization  procedures.  A set of simple chemical tests  like pH and water solubility is
       performed following a flowchart  scheme. These tests ultimately classify the material into
       general categories.  Enough information on the chemical characteristics can be generated to
       develop a hazardous waste  classification for shipping and disposal.

       There is no standard compatibility testing scheme.  The only requirements for establishing
       a system are that analytical techniques and bulking protocols be effective, environmentally
       sensitive, and  safe. System selection factors include:

       •      Types  of wastes suspected to be onsite  as in the initial site survey

       •      Criteria chosen by the supervising government agency

       •      Contractor experience and preference

       •      Disposal facility criteria

       •      Treatment or recovery possibilities
5/93                                         12

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FIELD CATEGORIZATION

      Compatibility testing is only part of the remedial project. Although each scheme is unique,
      most follow a similar flowchart (the system shown in FIGURE 2 is used by O.H. Materials
      Co.).
COMPATIBILITY TREE
1 Somple I (non-radioactive)

1
PH
I




•Slrono - pH«5 pH 5-9 pH»9 r _ t-t.»~p Base
Acid ^^ 1
1
ORP O
/ /
1. Oxidizer 1. Oxidizer
2. Reducing Agent

soluble
*wir|
|(ch
P ORP
X X
2. Reducing 1. Oxidizer
eck CN'.S1)



Agent 2. Reducing Agent
odd water
insoluble
floats sinks
Wale
|"| Reactive
j 5 V. HCI
no density
density gradients
soluble insoluble
k
gradients 1 . .
j J SXNoOH P°*"'
1 T sol. insol. ,

Water check Ba*»e 4 Halogen*
flash point Organic Acid Hydrocor
>^N. (check FP) Uneek pC
Flammable Non-flammable Hydrocarbon
Liquid Liquid (ch.ck FP)





Beilslein Test
neaolive

ft


aled
bon
B)
Hydrocarbon
(check FP)
SCREENS FOR: 1. Strong Acids 6. Water Rtodives
2. Strong Bases 7. Flammable Liquids
3. Oxldiieri 8. Halogenated Hydrocarbons
4. Reducing Agents $• PCB's
5. Cyanides & SullideJ


                                   FIGURE 2
                             COMPATIBILITY TREE
5/93
13

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FIELD CATEGORIZATION

       Tests Conducted Prior to Drum Opening:

       Prior to drum opening, during the initial stages of evaluation radioactive wastes should be
       identified. Using a gamma survey instrument as part of the air monitoring task, radioactivity
       levels can be checked by scanning near the closed drums. (Low-level emitters may not cause
       a response on the instrument.  However, unless  these sources are airborne they pose little
       hazard.)  Normal environmental background radiation level is 0.01 to 0.02 milliroentgen per
       hour (mR/hr). Levels above 1 mR/hr is the maximum exposure limit without the advice of
       a health  physicist.  It is recommended that the area  be reanalyzed during compatibility
       testing.

       Tests Conducted at the Drumhead;

       Following radioactive testing and separation of radioactive containers, the drums are staged
       and opened for sampling.  It is recommended that a remote method of drum handling and
       opening such  as a drum grappler and a backhoe equipped with a spike for piercing drums be
       employed as a safety measure for workers.  Drums must be staged for access to each, usually
       in rows of two.  Each drum must be labeled at the time of sample acquisition.

       After opening, samples are taken of total vapor concentrations. A direct reading instrument
       such  as  a photoionization or  flame  ionization  detector may be used  for this  task.  A
       potentially explosive  atmosphere may exist in the drum headspace denoted by a reading of
       2000 ppm or 0.2% or greater on the instrument.  Drums at or above 2000 ppm are classified
       as flammable until  more flammability  data is available.    (Limitations  and  operation
       characteristics of the detection instrument must be taken into account.   Proper calibration
       when dealing with unknowns  is  impossible and also  dangerous gases  such  as  hydrogen
       cyanide,  phosgene, or chlorine are undetectable by PID or FID.)

       The  next test is  for  air reactivity.  This test is performed by  visual  observation during
       sampling.  Any  sample taken from a drum containing a solid  that subsequently ignites,
       fumes, gases, or releases pressure is considered air reactive  and the drum is immediately
       isolated.  Separate any drum containing a metal packed in liquid. Additional sampling will
       be necessary  to determine the type of metal but extensive  safeguards must be employed.
       (Phosphorus,  and sodium are examples of  air and water reactive substances packed under
       liquid for shipment.

       Sample Acquisition;

       Samples  of 1  1 are common.  If the drum contains several phases then a sample of each is
       necessary along with  an estimate as to the relative volume of each.   The drum  number and
       the volume in the drum is noted, along with  comments concerning drum type, condition, and
       existing labeling.  Results of drumhead tests are  logged as are any special conditions. The
       sample may be acquired  using a drum thief or any device that is effective and will not
       interfere with  subsequent analysis.  Laboratory clean glass jars are used as sample containers.
       All appropriate safety and decontamination  procedures are observed.
5/93                                        14

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FIELD CATEGORIZATION

       Compatibility Tests on Collected Samples;

              Water Reactivity/Solubility

              This is one of the first tests performed and can yield a good deal of information on
              the waste.  (Sample size for testing is 1  ml for  suspected reactives and 10 ml for
              nonreactives.)

                                 Characteristics of Reactivity

              •      Reacts violently with water

              •      Forms potentially explosive mixtures with water

              •      When mixed with  water, generates toxic  gases, vapors, or fumes in
                     a quantity sufficient to present a  danger  to  human  health or to  the
                     environment.

              A small volume of the material  is added to water and the mixture is observed for
              miscibility, temperature exotherm, precipitation,  and gas formation.  If any of these
              occur, the substance is water reactive.  (Following this definition, acids and bases are
              considered reactive  but will later be separated by a pH test.) When a liquid sample
              is placed  in water  and is nonreactive, it will either be soluble or insoluble.   If
              insoluble, it will either sink or float.  Samples that  are soluble are often inorganic
              substances.  The solubility of these samples is then  determined in hexane, and if it
              is soluble in hexane, the  substance is classified as  a nonhalogenated organic.   If
              insoluble in hexane, the classification  is inorganic liquid.

              Organics and Halogenated Organics

              Samples  that are insoluble in water  and  float on water are classified  as organic
              liquids.   The vapor concentration above the sample  may be checked with a PID or
              a FID to determine  potential volatility (2000 ppm is  classified as volatile organic).

              Insoluble samples that sink in water are classified as halogenated organics. Further
              tests to confirm halogen content using either a copper loop flame test, halogenated
              organic GC scan, potentiometric titration,  and  total organic halogen  (TOX) are
              necessary.  All drums classified as organics must  be  analyzed for PCBs to determine
              disposal  options.   This test is conducted prior to  bulking,  usually at the bench
              compositing stage.  (It is  recommended that no  more than 10 drums at a time be
              composited for sampling.) Any drums determined  to contain  >50 ppm PCBs are
              classified as PCS contaminated.
5/93                                         15

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FIELD CATEGORIZATION

              Flammability

              Flammability is an arbitrary range of flash points chosen by EPA, DOT, and NFPA.
              Flash  point is  the temperature at which the  vapors  of a  substance will ignite as
              determined through testing equipment such as the Setaflash,  Pensky-Martins Flash
              Point testers, and other approved testers.

              For compatibility testing purposes  the  field test should be referred  to  as an
              "ignitability" test. It has also been called pyrolysis testing,  ignition testing, flame
              tests, and other terms.

       The ignition test procedure which is generally accepted is:

       1.      Place about 0.1 g (or 0.1  ml) of sample in a crucible  cover

       2.      Bring  the cover up to a flame

       3.      Heat gently until  ignition takes place

       4.      If no ignition takes place, char the sample to observe  combustibility

       5.      Ash and residue are  used  for other tests (e.g., metals  content).

       A few  interesting extrapolations  can be made from the ignition test.  The first involves the
       estimation of the flash point (flammability) of the sample, because  the ease of ignition is
       related to flammability. As the test sample is brought  very slowly toward the flame, ignition
       may take place before contact between the two—the flame seems to  "jump" to the sample.
       Such rapid ignition can be interpreted as a very low  flash point (usually less than 100°F).
       If the flame must contact the sample to ignite it, the  flash point can be anywhere between
       100°F and 200°F. If the sample must be heated before ignition, the flash point is usually well
       over 200°F.

       Another extrapolation  relates the  ignition test to the flame test. The behavior of the flame
       is dependent on the composition of the sample.  Some generalities may be made from this
       test:

       aromatic compounds                burn with a smoky flame (sooty)
       lower aliphatic compounds          burn with an almost smokeless flame
       compounds containing oxygen       burn with a bluish  flame
       halogenated compounds             burn with a smoky flame
       aqueous solutions                   do not ignite but will sizzle when heated
       polyhalogenated compounds         in general, do not ignite but can momentarily
                                         render the burner's flame smoky
5/93                                        16

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FIELD CATEGORIZATION

              pH
              Mixing acidic and  caustic wastes  can result in  the evolutions of toxic gases i.e.
              cyanide and  sulfide.    The pH measurements  are taken  to  separate  potentially
              dangerous drums.  (Cyanide and sulfide wastes are usually buffered at a pH  >9 to
              remain in aqueous solution.)

              Water-soluble samples  are tested using  either a pH  meter  with temperature
              compensation adjustment or indicator strips (pH paper).  There are disadvantages to
              both when used on samples containing organic layers or sludges.  Meter probes are
              easily fouled  requiring frequent cleaning, recalibration, and replacement.  Multiband
              pH paper is  recommended to  limit interference caused by grease, sludges, opaque
              solutions, and chemicals that can cause false color changes.

              •      Wastes with pH  < 2 are classified as acids

              •      Wastes with pH between 2 and 7 are considered aqueous acidic solutions

              •      Wastes with pH between 7 and 12 are basic aqueous solutions

              •      Wastes with pH  > 12 are classified as bases.

              Samples with  a pH greater than 10 are further tested by wet methods and ion selective
              electrodes to determine the presence of cyanides or sulfides. Positive results require
              that the drums be carefully separated to prevent accidental mixing during the bulking
              process.

              Acids and cyanide and  sulfide-free bases  may be mixed onsite  for neutralization.
              However, the reaction is exothermic so care must be taken  in the bulking process to
              limit volumes, monitor temperature, and monitor  for cyanide and sulfide production.

              Oxidizers and Reducers

              Compatibility test procedures for classifying samples as oxidizers or reducers include
              wet methods, test papers, and instrument methods.

              Colorimetric  methods  can  be used to identify oxidizers and reducers.  For example,
              titanium sulfate can be used as a yellow color indicator for organic peroxides in solid
              unknowns,  and manganous chloride  can be  used as a brown color indicator for
              organic oxidizers. Various test papers are used, but may some not accurately identify
              oxidizers and reducers in complex waste samples.

              Potentiometric determination of redox potential using a portable instrument may also
              be used. This method  involves using an electrolyte of known potential and measuring
              the change in this potential after the addition of a small portion  of the waste sample.
5/93                                         17

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FIELD CATEGORIZATION

              (Ferrous ammonium sulfate is used as the standard electrolyte solution for oxidizers
              and potassium chromate for reduction measurement.)

              Probes require frequent cleaning and recalibration as with the pH probe.

              Caution is recommended in extrapolating inorganic test methods for use in organic
              materials.

              Labpacks

              Small  volume containers of laboratory wastes are frequently packed for disposal in
              drums. Often  the containers are unlabeled and incompatibles are packed together.
              These labpacks pose some  unique problems in characterization and disposal. After
              the drum is opened, the contents are examined container by container. Similar items
              are then repacked in  sorbent materials for disposal.  Unknowns are separated into
              solids, liquids, and multiphase.  Compatibility testing can be  performed on each
              container, the small containers can be disposed of using detonation, or they may be
              crushed and solidified for land disposal.

       Bench  Compositing:

       Compatible waste categories  are composited in volume representative aliquots within each
       category and  then perhaps between  similar categories.   Care is taken to establish a  safe
       bulking order of mixing.  Certain tests such as PCB tests may be conducted on composited
       samples to guard  against mixing wastes,  which  can cause disposal problems.   It  is
       recommended that items  be  composited in groups of 10 prior to PCB testing  to avoid
       contaminating a very large composite.

       Bulking;

       The bulking process is done  in a controlled chamber, usually 5000-gallon volume or less.
       Air and temperature monitoring are a must.  Bulking may be done by pumping directly from
       the drums or containers or lagoons into a tanker, or by pouring drum contents into an open
       container.

       Liquids and sludges may be subsequently solidified for disposal.  Empty drums are crushed.
       (Empty =  less than 1" heel or hardened substance in bottom of drum.)

              Limitation of Compatibility Testing Procedures

              Compatibility testing is a gross identification procedure used to place waste materials
              in broad categories.   Chemical reactions requiring heat, catalyzing effects, or long
              reaction times are not detected.  The identification of highly toxic substances, such
              as  some pesticides and  carcinogenic materials,  is beyond the scope of  the test
              methods.   Major classes such as isocyanates, epoxides, nitriles, and polymerizable
              materials cannot be determined.
5/93                                        18

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FIELD CATEGORIZATION
             Representative samples of the drums themselves can be difficult to acquire and can
             then affect the validity of test results.

             The tests are by no means  comprehensive,  and increasing the  complexity  of the
             scheme increases time and cost investments that can eventually render the system non-
             cost-effective. Research continues to develop procedures that can better identify drum
             contents,  maintain  rapid turnaround time for  analysis,  and be less  costly than
             laboratory procedures.
5/93                                        19

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Section 2

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                       CHEMICAL  CHARACTERISTICS
STUDENT PERFORMANCE OBJECTIVES:
At the conclusion of this section, participants will be able to:
              State the three criteria used to determine the chemicals shown in U.S. EPA
              Priority Groups I and II

              List at least three families of chemicals that  are  commonly found on
              Superfund NPL sites

              Define  the  terms  molecular weight,  specific gravity, solubility, vapor
              pressure, Henry's Law Constant, organic carbon partition coefficient
              octanol/water partition coefficient (Kow), and biodegradability

              List at least one treatment technology affected by each of the following:

                    Molecular weight
                    Specific gravity
                    Solubility
                    Vapor pressure
                    Henry's Law Constant
                    Organic carbon partition coefficient (K^)
                    Octanol/water partition coefficient (Kow)
                    Biodegradability.
5/93

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                                                              NOTES
        Priority List Substances

   1  Lead         7 pQgs
   2  Arsenic       a Chloroform
   3  Mercury       9 Benzo(b)fluoranthene
   4  Vinyl Chloride lOTrichloroethylene
   5  Benzene      11 Chlordane
   6  Cadmium     12 Benzo(a)pyrene
        Priority List Substances

      Chemical Toxicity

      Frequency of Occurrence

      Potential for Human Exposure
        Priority List Substances
    Pol/cyclic Aromatic
    Hydrocarbons
    B«nzo(b)fluoranthene (9)
    B«nzo(a)pyrene (12)
    Chrysene (95)
Chlorinated Organic
Compounds
Vinyl Chloride (4)
PCBs (5)
Trlchloroethylene (10)
              Inorganics
           Metals         Non-metals
           Lead (1)       Cyanide (25)
           Arsenic (2)      Ammonia (141)
           Chromium (19)   Chlorine (192)
5/93
                                         Chemical Characteristics
                                                        page 1

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           NOTES
                                                 Priority List Substances
                                                Amines
                                            N-Nitrosodi-N-Propylamine (83)
                                            N-Nitrosodiphenylamine (186)
                                            N-nitrosodimethylamine (195)
                                                          Phthalates
Aromatic Ring
Compounds
Benzene (5)
Ethyl Benzene (66)
Styrene (266)
                                                      Di-N-Butyl Phthalale (28)
                                                      Di-(2-Ethylhexyl)Phthalate (56)
                                                      Butyl Benzyl Phthalale (133)
                                              WASTE CHARACTERISTICS
                                                  • Molecular Weight, g/mole
                                                  • Specific Gravity, ratio
                                                  • Solubility (water), mg/L
                                                  • Vapor Pressure, mmHg
                                                  • Henry's Law Constant, atm-m 3/mol
                                                  • K  , ml/g
                                                     oc   "
                                                  • K  , ratio
                                                     ow
                                                  • Biodegradability, subjective
                                                  MOLECULAR WEIGHT
                                          The mass of a specific number of molecules
                                          for a known compound.
                                               -Mobility:
                                                  High Mol. Wt. vs Low Mol. Wt.
Chemical Characteristics
page 2
              5/93

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                                                           NOTES
          SPECIFIC GRAVITY
 •  The weight of a given volume of substance
    compared to the weight of water at 4°C.

 •  Specific gravity can be used to predict
    whether compounds are likely to float or
    sink.
          SPECIFIC GRAVITY
         OF SEVERAL COMPOUNDS
    COMPOUND
       Phenol
       PCBs
        TCE

     Chrysene
    Vinyl Chloride
SPECIFIC GRAVITY
       1.07

      1.4-1.5

       1.46
      1.274

      0.912
              SOLUBILITY
    • The maximum concentration of a chemical that
     dissolves in pure water at a given temperature.

    • Highly soluble
        Aqueous contamination

    • Insoluble
        Pure product recovery

    • Factors that influence solubility
        Polarity
        Temperature
        PH
5/93
                                          Chemical Characteristics
                                                       page 3

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         NOTES
                                             VAPOR PRESSURE
                                       •  The pressure exerted at a given temperature
                                         when a solid or liquid is in equilibrium with its
                                         own vapor.
                                       •  Inversely proportional to boiling point.
                                       •  Directly proportional to temperature.
                                       VAPOR PRESSURE OF WATER
                                          VARIATION WITH TEMPERATURE
                                                DEGREES C
                                                    5
                                                    10
                                                    20
                                                    50
                                                    100
mmHg
 6.54
 9.21
 17.5
 92.5
 760
                                          HENRY'S LAW CONSTANT
                                        Expression which relates the concentration of a
                                        chemical dissolved in the aqueous phase
                                        to the concentration of the chemical in the
                                        gaseous phase when the two are in equilibrium.
                                        VP/S
                                           VP - Vapor Pressure, atm
                                           S - Solubility, mol/m"
Chemical Characteristics
page 4
               5/93

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                                                            /VOTES
          ORGANIC CARBON   /lx  .
          PARTITION COEFFICIENT   (Koc )
   • Indicates the tendency of a chemical to be
     adsorbed.

   • Ranges 1 to 10,000,000
     The higher the value, the greater the sorption.

   • Koc influenced by:
        Temperature
        Grease and oils
        Solids
          ORGANIC CARBON
        PARTITION COEFFICIENT (Koc)
      '.oc'
            mg compound adsorbed / Kg organic carbon
                mg dissolved / liter solution
            (Koc) VALUES
         Chemical Name      «,„
         PCBs             53,000
         DCM              8.8
         Benzene           83
         Toluene            300
         TCE              126
         Tetrachloroethylene   364
         Vinyl Chloride       57
         Benzo(b)pyrene      550,000
5/93
Chemical Characteristics
              page 5

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         NOTES
                                             OCTANOL/WATER
                                             PARTITION COEFFICIENT
                                        Relates the partitioning of a specific
                                        compound between non-polar and polar
                                        phases.
                                                     [X] OCTANOL
                                           ow
                                                     [X] WATER
                                                K^VALUES
                                             Chemical Name     KgW

                                             PCBs            6.04

                                             DCM             1.30

                                             Benzene          2.13

                                             Toluene           2.73
                                             TCE             2.38
                                             Tetrachloroethylene   2.60
                                             Vinyl Chloride       1.38
                                             Benzo(b)pyrene     6.06
                                             BIODEGRADABILITY
                                        • The susceptibility of a substance to
                                          decompose by microorganisms.

                                        • Subjective
                                             Degradable
                                             Non-Degradable
                                             Refractory
Chemical Characteristics
page 6
5/93

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                                                      NOTES
         BIODEGRADABILITY
     • The susceptibility of a substance to
       decompose by microorganisms.

     • Subjective
         Degradable
         Non-Degradable
         Refractory
5/93
Chemical Characteristics
            page 7

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                      CHEMICAL CHARACTERISTICS
INTRODUCTION

Usually, several different types of hazardous chemicals are found on a CERCLA (Superfund) site,
and the chemicals differ from site to site.  CERCLA stands for the Comprehensive Environmental
Response, Compensation and Liability Act.

Different types of hazardous chemicals have different physical and  chemical characteristics and
require different treatment technologies.  The characteristics determine the proper treatment
technology for each type of chemical.

Because several types of chemicals are present on most Superfund sites, more than one treatment
technology is usually needed at the site. When two or more treatment technologies are used together
to clean up a site, the combination is typically referred to as  a treatment train.
SUPERFUND SITE CHEMICALS

       Priority List I and II Chemicals

       In 1987 and 1988, two lists were prepared of hazardous chemicals found on the Superfund
       National Priority List (NPL) sites.  These lists are the Hazardous Substances Priority Lists.
       They are commonly called Priority List I and Priority List II.  Each list contains 100
       chemicals.

       The lists were required by CERCLA Section 104, as amended by the Superfund Amendments
       and Reauthorization Act (SARA). They were prepared by the U.S. EPA and the Agency for
       Toxic Substances and Disease Registry (ATSDR), which is part of the U.S. Department of
       Health and Human Services. The lists were to be in order of priority based on the following
       criteria:

       •      Chemical toxicity - determined using the reportable quantity scoring scheme.

       •      Frequency of occurrence  - obtained from data listed by the Contract Laboratory
              Program (CLP).

       •      Potential for human  exposure - determined from several sources including CLP
              data, and selection of the  chemical  for detailed exposure and  risk assessment at
              Superfund sites.
5/93

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CHEMICAL CHARACTERISTICS
      The first list was published April 17, 1987, and the second list was published October 20,
      1988. They are found in 52 FR 12866, April 17, 1987, and 53 FR 41279, October 20,
      1988, respectively.

      List of 25

      The list of 25, FIGURE 1, is a list of the 25 chemicals most often identified on Superfund
      sites.  It was developed by McCoy and Associates (an independent contractor). Because
      these chemicals are commonly found on Superfund sites, there is a good chance you'll find
      them (or similar chemicals) on your site.
                  25 MOST IDENTIFIED CHEMICALS
                           ON SUPERFUND SITES
         TRICHLOROETHYLENE
        LEAD AND COMPOUNDS
              TOLUENE
              BENZENE
                 PCBs
            CHLOROFORM
       TETRACHLOROETHYLENE
               PHENOL
      ARSENIC AND COMPOUNDS
      CADMIUM AND COMPOUNDS
     CHROMIUM AND COMPOUNDS
        1,1,1 -TRICHLOROETH ANE
                 ZINC
            ETHYLBENZENE
             XYLENE o,m,p
        METHYLENE CHLORIDE
     TRANS-1,2-DICHLOROETHYLENE
              MERCURY
       COPPER AND COMPOUNDS
              CYANIDES
           VINYL CHLORIDE
         1,2-DICHLOROETHANE
           CHLOROBENZENE
         1,1 -DICHLOROETH ANE
       CARBON TETRACHLORIDE
                                FIGURE 1
                                LIST OF 25
      Types of Commonly Found Chemicals

      •      Polycyclic aromatic hydrocarbons - organic compounds containing three or more
            ring  structures.  Examples  of polycyclic  aromatic hydrocarbons are  chrysene,
            anthracene, and benzo(a)pyrene.  Many of these chemicals are known or suspected
            carcinogens.
5/93
10

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CHEMICAL CHARACTERISTICS
              Chlorinated organic  compounds  -  organic  compounds containing  chlorine.
              Examples of chlorinated organic compounds are polychloro-biphenols (PCBs) and
              trichloroethylene (TCE).  These types of chemicals are frequently toxic, some are
              skin absorbable, and many are known or suspected carcinogens.

              Inorganics - include both metals and non-metals. Chromium (VI), lead and mercury
              are examples of hazardous metals.  These chemicals are toxic, and some (chromium
              (VI)) are water soluble.

              Cyanide is an example of a hazardous inorganic non-metal.  Cyanide is poisonous,
              skin absorbable and, in combination with acids, forms a poisonous gas.

              Amines - organic  chemicals  that contain  nitrogen compounds as  NH groups
              (generally derived from ammonia).  An example of a commonly found amine is N-
              nitrosodiphenylamine. Some amines are toxic, some are suspected carcinogens, and
              at high concentrations, some are explosive.

              Aromatic ring compounds - organic compounds arranged in ring structures. One
              very commonly found example of an aromatic ring compound is benzene.  Benzene
              is toxic and it is a known carcinogen.

              Phthalates - compounds formed by combining organic acids (acids combine at the
              COOH groups with the  removal  of a water molecule).   One example is Di(2-
              ethylhexyl) phthalate.  Phthalates are irritants and some are suspected teratogens.
HAZARDOUS CHEMICAL CHARACTERISTICS

A number of different physical and chemical characteristics affect the type of treatment technologies
chosen to clean up a Superfund site.  They include molecular weight, specific gravity, solubility,
vapor pressure,  Henry's Law Constant, organic carbon partition coefficient  (K^), octanol/water
partition coefficient (Kow), and biodegradability.

       Molecular Weight

       This is the weight of one mole of a chemical.  One mole equals 6.02 x 1023 atoms or
       molecules.  Molecular weight is measured in grams per mole.  It is the total weight of all
       atoms or ions that are part of a molecule.  For example, the molecular weight for sodium
       chloride (NaCl or table salt) is calculated as follows:

              Na     =  23 grams/mole
              Cl     =  35.5 grams/mole
              NaCl   =  58.5 grams/mole
5/93                                       11

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CHEMICAL CHARACTERISTICS

       The larger the molecule, the higher the molecular weight.

       Molecular weight affects mobility.  Generally the higher the molecular weight, the less
       mobile  the  chemical.   Less  mobile  chemicals  are  frequently good candidates for
       immobilization techniques.  More mobile (lower molecular weight) chemicals may be more
       easily removed using air stripping, vacuum extraction, or similar techniques.

       Specific Gravity

       The weight of a given volume of a chemical compared to the weight of an equal volume of
       water at 4 degrees Celsius (4°C). The unit of measure for specific gravity is determined as
       follows:

              1.0 =  water
              > 1.0 is heavier than water (sinks)
              < 1.0 is lighter than water (floats)

       Specific gravity  indicates whether a chemical will  float or sink when mixed with  water.
       Insoluble floaters are generally easier to remove with pure product recovery methods such
       as skimming.  Insoluble sinkers typically require more extensive treatment technologies such
       as dredging or soil removal followed by immobilization or incineration.

       Solubility

       The maximum amount (concentration) of a chemical  that will dissolve in pure water at a
       given temperature (usually 4°C).  Solubility is usually measured  in grams/liter for  highly
       soluble  chemicals, or in  milligrams/liter (parts per million - ppm) for low solubility
       chemicals.

       A low solubility  chemical will either float or sink on water, it won't mix with it.  This may
       allow pure product recovery, immobilization, or incineration. A more soluble chemical may
       mix with water and then require aqueous cleanup techniques such as air stripping or carbon
       adsorption.

       NOTE: some chemicals are so  toxic that even though they have low solubilities (measured
       in pans per million) aqueous cleanups are still needed.

       Vapor Pressure

       The pressure exerted at a given temperature when a solid or liquid is in equilibrium with its
       own vapor.  Basically this is the pressure exerted by the vapor that's coming off a solid or
       liquid. Vapor pressure is measured in millimeters of mercury (mm Hg) or in atmospheres
       (760 mm hg = 1 atmosphere).
5/93                                        12

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CHEMICAL CHARACTERISTICS

       Vapor pressure is a measure of the relative volatility of a chemical.  Generally the more
       volatile a chemical, the better for air stripping or vacuum extraction. However, other factors
       [i.e., solubility, soil structure, etc.]  also affect these techniques.  Lower vapor pressure
       chemicals are  usually  treated using carbon, adsorption, soil washing,  immobilization,
       incineration, or some similar technology.

       Henry's Law Constant

       This is an expression which  relates to the concentration of  a chemical  dissolved in an
       aqueous phase to  the concentration (or pressure) of the chemical in the gaseous phase when
       the two are in equilibrium.  Basically, it is a measure of the volatility of a chemical when
       it's dissolved in water.  A high Henry's Law Constant value indicates a chemical with an
       affinity for air rather than water.

       Henry's Law Constant can be measured in  Atm  per  meterVmole, but this  varies.  For
       instance it is often shown dimensionless.  It is one of the primary measurements used in
       determining the effectiveness of air stripping (high Henry's Law Constants  indicate good
       candidates for air stripping).

       Organic Carbon Partition Coefficient  (KOT)

       This is a value which indicates the tendency of a chemical to be adsorbed on organic carbon.
       K^ is usually shown as ml/gm of carbon.

       I^ is  one of the primary  measurements used  in determining the effectiveness  of carbon
       adsorption.  A chemical with a high K^ is probably a good candidate for carbon adsorption.

       Octanol/Water Partition Coefficient (K.,.)

       Basically  this is  a value which relates  the partitioning of a chemical between  non-polar
       (hydrocarbon) and polar (aqueous) phases. However, it can also include a lipid or fatty  acid
       phase. A  K,,w is measured as a dimensionless ratio ranging from less than one to greater  than
       10,000. Due to a wide range of measurements,  Kows are often shown as logarithmic values.

       Kow measurements help determine the feasibility  of chemical removal/recovery using solvent
       extraction or soil  washing techniques.  These technologies are generally more efficient when
       used to treat chemicals with a  relatively high Kow.

       Biodegradabilitv

       The susceptibility of a chemical to be decomposed by micro-organisms. Biodegradability is
       a unitless measurement.  Chemicals are usually listed as degradable, non-degradable, or
       refractory. The term refractory has several definitions, the most commonly used one seems
       to be  partially degradable.   Biodegradability  is the key component  in determining the
       feasibility of biological treatment  techniques.
5/93                                         13

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 CHEMICAL CHARACTERISTICS

 CONCLUSION

 A number of different hazardous chemicals are usually found on Superfund sites.  One of the keys
 to a successful, cost-effective cleanup is using the  chemicals' characteristics to help choose the
 correct treatment technologies.
5/93                                     14

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Section 3

-------
                            WASTE TREATABILITY
STUDENT PERFORMANCE OBJECTIVES:
At the conclusion of this unit, participants will be able to:
       •     Briefly describe the advantages of treatability studies as part of the remedial
             investigation and feasibility study process

       •     Briefly describe technology screening

       •     Briefly describe the differences between the following types of treatability
             studies:

                    Laboratory scale
                    Bench scale
                    Pilot scale

       •     List at least four sources of information for treatability studies.
5/93

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                                                NOTES
  TREATABILITY STUDIES
           Definition:
Research conducted on a specific
waste to determine whether
a treatment, or combination of
treatments, will effectively reduce
the hazardous nature of the waste
WHY CONDUCT A TREATABILITY STUDY
  • Statutory mandate, CERCLA 121 (b)
      Permanent solutions
      Alternative treatments
      Resource recovery

  • Reduce volume, toxicity, or mobility

  • Maximum extent practicable (MEP)
TIMING OF TREATABILITY STUDIES
    • Information gathered at listing
        Technology prescreening

    • Concurrent with RI/FS
        Remedy screening (Tier 1)
        Remedy selection (Tier 2)

    • Post ROD (Record of Decision)
        RD/RA (remedial design/
        remedial action) (Tier 3)
5/93
                                                       Waste Treatability
                                                              page 1

-------
        NOTES
Waste Treatability
page 2

The Role
Scoping ^
~f»RI/Fg~?
Tochnologx
Praacraanin(
and
Traatabllfty
Study
Scoping

of Treats
Hunt
ft
Sill
_Ch«r«c1«rt
"and Tachfl
Beroan
ibility S
Hal Invaal
aalMHty S
Mantifi
of Altar
mlon
oloey"*
ng
Itudies in the RI/FS and RD/RA Process
»g«ion/ B.cord Htm.di.l D.tian/ -J
tudy ^bt B«
Mtion "•"
n«bv» 8*<«
	 Evaluation •>
of *H»m«Ov»» "^
REMEDY SCREENING
TREATABILITY
to datarmin*
potential faaalbiUty




REMEDY SELECTION
TREATABILITY
to 4«v«lDp p«r1orm«ic«
•nd con d«<



a«on B.m.di«l Action ^
Didy
-tion
	 Implamintation 	 ^
of n«m«dy
RD/RA TREATABILITY
to d«v«lop datallid diilgn
•nd co«t data and to
GOnRrm parformanc*

                              TECHNOLOGY PRESCREENING
                               • Literature/databases search
                               • Data needs/data quality objectives
                               • Treatability study sources/contractors
                               • Work assignment/plan
                                   LITERATURE SEARCH
                                 • Training courses and conferences
                                 • Vendors and contractors
                                 • Publications and bulletin boards
                                 • Databases
                                                             5/93

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                                                       NOTES
   DATA NEEDS/OBJECTIVES

  • Existing site information

  • Data quality objectives (DQOs)

  • Adequate site data

  • Information needed for technology evaluation
      Total organic carbon (TOG)
      PH
      Clay content
      Withdrawal rate
      Other
TREATABILITY STUDY SOURCES
           • Vendors

           • Consultants

           • Federal agencies
      TREATABILITY STUDY FLOWCHART
                Determine
                Data Needs
                       Evaluate Existing
                          Site Data
                           YES
               Data Adequate to
               Screen or Evaluate
                Alternatives?
                    NO
               Treatability
                 Study
            Detailed Evaluation
5/93
                                                               Waste Treatability
                                                                       page 3

-------
        NOTES
                             REMEDY SCREENING (TIER1)
                                    • Potential feasibility
                                    • Performance goals
                                    • Additional data needs
                             REMEDY SCREENING (TIER1)
                                • Laboratory/bench scale
                                • Small quantities, quick results
                                • Batch reactions, yes/no answers
                                • Hours to days
                                • $10,000 to $50,000
                              REMEDY SELECTION (TIER 2)
                                  • Performance and cost data
                                  • Verify cleanup criteria
Waste Treatability
page 4
                                                          5/93

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                                                NOTES
 REMEDY SELECTION (TIER 2)
    • Bench/pilot scale
    • Batch or continuous processes
    • Days to weeks
    • $50,000 to $250,000
REMEDIAL DESIGN/ACTION (TIER 3)
     • Detailed design
     • Cost and performance data
REMEDIAL DESIGN/ACTION (TIER 3)
    • Pilot/full scale
    • Batch or continuous reactions
    • Weeks to months
    • $250,000 to $1,000,000
5/33
                                                       Waste Treatability
                                                             page 5

-------
        NOTES
                                  RCRA EXCLUSION RULE
                                  TREATABILITY STUDIES
                               • Exempts waste samples from permit
                                 requirements
                                   One-time exclusion of
                                   1,000 kg/wastestream per
                                   treatment process

                               • Only effective in non-RCRA-authorized
                                 states
Waste Treatability
page 6
                                                             5/93

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                           TREATABILITY REFERENCES

USEPA.   1987.  U.S. Environmental  Protection Agency, Data quality  objectives for remedial
       response activities: Development process.   EPA-540/G-87/003.   OSWER Directive  No.
       9355.0-7b. OERR-OSWER Washington, D.C.

USEPA.  1988.  U.S. Environmental Protection Agency, Technology screening guide for treatment
       of CERCLA soils  and sludges. EPA-540/2-88/004.  OERR-OSWER, Washington, D.C.

USEPA.  1990.  U.S. Environmental Protection  Agency, Technical support services for Superfund
       site remediation.  EPA-540/8-90/001.  OERR-OSWER, Washington, D.C.

USEPA.   1990.  U.S.  Environmental Protection Agency, Engineering Bulletin  -  Chemical
       dehalogenation treatment: APEG treatment.  EPA-540/2-90/015. RREL-ORD, Cincinnati,
       OH; OERR-OSWER, Washington, D.C.

USEPA.   1991.  U.S.  Environmental Protection Agency, Accessing  federal  data bases for
       contaminated site  clean-up technologies.  EPA-540/8-91/008.   Member Agencies of the
       Federal Remediation Technologies Roundtable,  Washington, D.C.

USEPA.   1991.  U.S. Environmental  Protection  Agency,  Bibliography of federal  reports  and
       publications describing alternative and innovative treatment technologies for corrective action
       and site remediation.  EPA-540/8-91/007.  Member Agencies of the Federal Remediation
       Technologies Roundtable,  Washington, D.C.

USEPA.  1991.  U.S. Environmental Protection Agency, Engineering Bulletin - Thermal desorption
       treatment. EPA-540/2-91/008. RREL-ORD Cincinnati, OH; OERR-OSWER, Washington,
       D.C.

USEPA.  1991.  U.S.  Environmental Protection Agency, Engineering Bulletin - In situ soil vapor
       extraction treatment. EPA-540/2-91/006.  RREL-ORD, Cincinnati, OH;  OERR-OSWER,
       Washington, D.C.

USEPA.  1991.  U.S. Environmental Protection Agency, Engineering Bulletin - In situ soil flushing.
       EPA-540/2-91/021.  RREL-ORD, Cincinnati, OH; OERR-OSWER, Washington, D.C.

USEPA.  1991.  U.S. Environmental Protection Agency, Engineering Bulletin - Chemical oxidation
       treatment. EPA-540/2-91/025. RREL-ORD, Cincinnati, OH; OERR-OSWER, Washington,
       D.C.

USEPA.  1991.   U.S. Environmental Protection Agency, Engineering Bulletin - Air stripping of
       aqueous  solutions.  EPA-540/2-91/022.  RREL-ORD, Cincinnati, OH;  OERR-OSWER,
       Washington, D.C.

USEPA.  1991.   U.S. Environmental Protection Agency, Engineering Bulletin - Air stripping of
       aqueous  solutions.  EPA-540/2-91/022.  RREL-ORD, Cincinnati, OH;  OERR-OSWER,
       Washington, D.C.
5/93

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TREATABILITY REFERENCES

USEPA.  1991. U.S. Environmental Protection Agency, Superfund Engineering Issue - Treatment
      of lead-contaminated soils.  EPA-540/2-91/009.   RREL-ORD, Cincinnati,  OH; OERR-
      OSWER, Washington, D.C.

USEPA.  1991. U.S. Environmental Protection Agency, Engineering Bulletin - Control  of air
      emissions from materials handling during remediation.  EPA-540/2-91/023.  RREL-ORD,
      Cincinnati, OH; OERR-OSWER, Washington, D.C.

USEPA.  1992. U.S. Environmental Protection Agency, Guide for conducting treatability studies
      under CERCLA.  EPA-540/R-92/071a.  OSWER Directive No. 9380.3-10.  RREL-ORD,
      Cincinnati, OH; OERR-OSWER, Washington, D.C.

USEPA.  1992. U.S. Environmental Protection Agency, Guide for conducting treatability studies
      under CERCLA: soil washing. EPA-540/2-9l/020a.  OERR-OSWER, Washington, D.C.

USEPA.  1992. U.S. Environmental Protection Agency, Guide for conducting treatability studies
      under  CERCLA:  chemical  dehalogenation.    EPA-540/R-92/013a.    OERR-OSWER,
      Washington, D.C.

USEPA.  1992. U.S. Environmental Protection Agency, Guide for conducting treatability studies
      under CERCLA: solvent extraction.  EPA-540/R-92/016a.  OERR-OSWER, Washington,
      D.C.

USEPA. 1992. U.S. Environmental Protection Agency,  Guide for conducting treatability studies
      under CERCLA: aerobic biodegradation screening. EPA-540/2-91/013a.  OERR-OSWER,
      Washington, D.C.

USEPA.  1992. U.S. Environmental Protection Agency, Guide for conducting treatability studies
      under CERCLA: soil vapor extraction. EPA-540/2-92/019a. OERR-OSWER, Washington,
      D.C.

USEPA.  1992.  U.S. Environmental  Protection Agency, Engineering Bulletin - Technology
      preselection data requirements. EPA-540/S-92/009. RREL-ORD, Cincinnati, OH; OERR-
      OSWER, Washington, D.C.

USEPA.  1992.  U.S.  Environmental Protection  Agency,  Engineering Bulletin -  Air  pathway
      analysis. EPA-540/S-92/013. RREL-ORD, Cincinnati,  OH; OERR-OSWER, Washington,
      D.C.

USEPA. 1992. U.S. Environmental Protection Agency, Engineering Bulletin - Supercritical water
      oxidation. EPA-540/S-92/006. RREL-ORD, Cincinnati, OH; OERR-OSWER, Washington,
      D.C.

USEPA.  1992. U.S. Environmental Protection Agency, Engineering Bulletin - Slurry walls.
      EPA-540/S-92/006. RREL-ORD, Cincinnati, OH; OERR-OSWER, Washington,  D.C.
5/93

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TREATABILITY REFERENCES

USEPA. 1992. U.S. Environmental Protection Agency, Engineering Bulletin - Pyrolysis treatment.
      EPA-540/S-92/010. RREL-ORD, Cincinnati, OH; OERR-OSWER, Washington, D.C.

USEPA. 1992. U.S. Environmental Protection Agency, Engineering Bulletin - Rotating biological
      contactors. EPA-540/S-92/010. RREL-ORD, Cincinnati, OH; OERR-OSWER, Washington,
      D.C.

USEPA. 1992. U.S. Environmental Protection Agency, Engineering Bulletin - Selection of control
      technologies  for remediation of lead battery recycling sites.  EPA-540/S-92/011.  RREL-
      ORD, Cincinnati, OH; OERR-OSWER, Washington, D.C.

USEPA.   1992.   U.S. Environmental Protection Agency, Engineering  Bulletin  - Design
      considerations for ambient air monitoring at Superfund sites. EPA-540/S-92/012. RREL-
      ORD, Cincinnati, OH; OERR-OSWER, Washington, D.C.

USEPA.   1992.   U.S. Environmental Protection Agency, Superfund Engineering  Issue  -
      Considerations for evaluating  the impact of metals partitioning during the incineration of
      contaminated soils from Superfund sites. EPA-540/S-92/014. RREL-ORD, Cincinnati, OH;
      OERR-OSWER, Washington,  D.C.

USEPA.  1992.  U.S. Environmental Protection Agency, Guide for conducting treatability studies
      under CERCLA: thermal desorption. EPA-540/R-92/074B. OERR-OSWER, Washington,
      D.C.

USEPA.  1993.  U.S. Environmental Protection Agency, Engineering Bulletin - Landfill covers.
      EPA-540/S-93/500. RREL-ORD, Cincinnati, OH; OERR-OSWER, Washington, D.C.
5/93

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                         TREATABILITY DATABASES
Database

RREL Treatability Database
ATTIC
COLIS
VISITT
Super fund TSP
Engineering TSC
ERT-TSC
    Contact

    Glenn Shaul
    RREL-ORD
    USEPA
    (513) 569-7408

    Greg Ondich
    OEETD
    USEPA
    (202) 260-5747

    Robert Hillger
    RREL-ORD
    USEPA
    (908) 321-6639

    VISITT Hotline
    (800) 245-4505

    Marlene Suit
    TIO-OSWER
    USEPA
    (703) 308-8800

    Ben Blaney or Joan Colson
    RREL-ORD
    (513) 569-7406

    Joseph LaFornara
    ERB-OERR
    USEPA
    (908) 321-6740
5/93
10

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                    United States
                    Environmental Protection
                    Agency
                    Office of
                    Solid Waste and
                    Emergency Response
Directive 9380.3-02FS
December 1989
       &EPA
TREATABILITY STUDIES UNDER
CERCLA:  AN OVERVIEW
  Office of Emergency and Remedial Response
  Hazardous Site Control Division OS-220
                                         Quick Reference Fact Sheet
       Section 121(b) of CERCLA mandates EPA to select remedies that "utilize permanent solutions and
 alternative treatment technologies or resource recovery technologies to the maximum extent practicable" and to
 prefer remedial actions in which treatment "permanently and significantly reduces the volume, toxicity, or mobility
 of hazardous substances, pollutants, and contaminants as a principal element." Treatability studies provide data to
 support treatment technology selection and remedy implementation and'should be performed as soon as it is evident
 that insufficient information is available to ensure the quality of the decision. Regional planning should factor in the
 time and resources required for these studies.

       This fact sheet provides a synopsis of information to facilitate the planning and execution of treatability
 studies in support of the RI/FS and the RD/RA processes.  Detailed information on designing and implementing
 treatability studies for the RI/FS process is provided in the "Guide for Conducting Treatability Studies under
 CERCLA," Interim Final, EPA 540/2-89/058, December 1989. A summary of Chapter 2 (Overview of Treatability
 Studies) is incorporated in this paper.  The remainder of that document provides protocols for implementing the
 studies.
DEFINING TREATABILITY STUDIES

   Treatability studies are laboratory or field tests de-
signed to provide critical data needed to evaluate and, ul-
timately, to implement one or more treatment technolo-
gies. These studies generally involve characterizing un-
treated waste and evaluating the performance of the tech-
nology under different operating conditions.  These re-
sults may be qualitative or quantitative, depending on the
level of treatability testing.  Factors that influence the
type or level of testing needed include:  phase of the
project [e.g., remedial investigation/feasibility study (RI/
FS) or remedial design/remedial action (RD/RA)], tech-
nology-specific factors, and site-specific factors.

   •  Treatability studies conducted during the RI/FS
      to support remedy selection are generally used
      to determine whether the technology can achieve
      the anticipated Record of Decision (ROD) goals
      and to  provide information to support the nine
      evaluation criteria to the extent possible.
                            Treatability studies to support remedy implem-
                            entation during RD are generally used to verify
                            that the technology can achieve the ROD goals,
                            optimize design and operating conditions nec-
                            essary to ensure performance, and improve cost
                            estimates.

                     LEVEL OF TREATABILITY STUDIES

                         Treatability studies should be performed in a sys-
                     tematic fashion to ensure that the data generated can
                     support the remedy evaluation and implementation proc-
                     ess. A well-designed treatability study can significantly
                     reduce the overall uncertainty associated with the deci-
                     sion, but cannot guarantee that the chosen alternative
                     will be completely successful. Care must be exercised
                     to ensure that the treatability study is representative of
                     the treatment as it will be employed (e.g., sample is rep-
                     resentative of waste to be treated) to minimize  the
                     uncertainty in the decision. The method presented  be-
                     low provides a resource-effective means for evaluating
                     one or more technologies.

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    There are three levels or tiers of treatability studies:
laboratory screening, bench-scale testing, and pilot-scale
testing. Some or all of the levels may be needed on a
case-by-case basis. The need for and the level of treata-
bility testing required  are  management  decisions in
which the time and cost necessary to perform the testing
are balanced against the risks inherent in the decision
(e.g., selection of a treatment alternative). These deci-
sions are  based  on the quantity and  quality of data
available and on other decision factors (e.g., State and
Community acceptance of the remedy, new site data).
The flow  diagram for the tiered approach in Figure 1
traces the stepwise review of study data and the decision
points and factors to be cqnsidered.

    •  Laboratory screening is the first level of test-
       ing. It is used to establish the validity of a tech-
       nology to  treat a  waste.   These studies are
       generally low cost (e.g., $ 1OK-50K) and usually
       require hours to days to complete. They yield
       data that can be used as indicators of a technol-
       ogy's potential to meet performance goals and
       can identify operating standards for investiga-
       tion during bench- or pilot-scale testing. They
generate little, if any, design or cost data and
generally are not used as the sole basis for selec-
tion of a remedy.
Bench-scale testing is the second level of test-
ing. It is used to identify the technology's per-
formance on a waste-specific basis for an oper-
able unit. These studies generally are of moder-
ate cost (e.g., $50K-250K) and may require
days to weeks to complete. They yield data that
verify that the technology can meet expected
cleanup goals and can  provide information in
support of the detailed  analysis of the alterna-
tive (i.e., the nine evaluation criteria).

Pilot-scale testing is the third level of testing. It
is  used to provide quantitative performance,
cost, and design information for remediating an
operable unit.  This  level of testing also can
produce data required to optimize performance.
These studies are of moderate to high cost (e.g.,
$250K-1,OOOK) and may  require  weeks  to
months to complete. They yield data that verify
                                                 Figure 1. Flow Diagram of the Tiered Approach
                                                                     MANAGEMENT DECISION FACTORS: |
                                                                      • SUI« «nd Community AcwpOne*
                                                                      • Sditdul* Coi««ru
                                                                      • AMilontl 0«U

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       performance to a higher degree than the bench-
       scale and provide detailed design information.
       Theyaremostoftenperformedduringthe remedy
       implementation phase of a site cleanup, although
       this  level  may be appropriate to support the
       remedy evaluation of innovative technologies.

Technologies generally are evaluated first at the labora-
tory screening level and progress through the bench-
scale to the pilot-scale testing level.  A technology may
enter, however, at whatever level is appropriate based on
available data on the technology and site-specific fac-
tors. For example, a technology that has been studied ex-
tensively may not warrant laboratory screening to deter-
mine whether it has the potential to work. Rather, it may
go directly to bench-scale testing to verify that perform-
ance standards can be met.
DETERMINING THE NEED FOR
TREATABILITY STUDIES

    Treatability studies for remedy evaluation and im-
plementation represent good engineering practice. The
determination of the need for and the appropriate level of
  Figure 2. Decision Tree Showing When Treatability
  Studies Are Needed to Support the Evaluation and
  Selection of an Alternative
          DETAILED ANALYSIS
          OF ALTERNATIVES
                           MANAGEMENT DECISION FACTORS:

                            • Sao wd Community ArapUno

                            • Adtflonri teu
a treatability study(ies) required is dependent on site-
specific factors, the literature information available on
the technology, and technical expert judgment.  The
latter two elements — the literature search and expert
consultation — are critical factors in determining if ade-
quate data are available or whether a treatability study is
needed  to provide those data.  Figure 2 provides  a
decision tree for treatability studies in the RI/FS. Addi-
tional studies may not be needed if previous studies or
actual implementation  have  encompassed essentially
identical site conditions. The data and  information on
which this  decision is  based should be documented.
Given the lack of full-scale experience with innovative
technologies, pilot-scale testing will generally be neces-
sary in support of remedy selection and implementation.
SUPERFUND PROCESS-TIMING OF
TREATABILITY STUDIES

    Treatability studies should be planned and imple-
mented as soon as it is evident that insufficient informa-
tion is available in the literature to support the decision
necessary for remedy selection or implementation.
Treatability testing of technologies may begin during the
scoping phase, the initial phases of site characterization
and technology screening, and continue through the RI/
FS and into the RD/RA to support remedy implementa-
tion. Additional treatability studies of alternate tech-
nologies or treatment trains also may be needed later in
the  RI/FS process as other promising remedial alterna-
tives are identified.

    For many site  types, initial data  are available to
identify potentially applicable technologies early during
the scoping phase of the RI/FS for all or parts of the  site.
In those cases, the literature search, the planning, and the
implementation of the treatability  study can proceed.
The planning of the studies should coincide with the
scoping of the RI/FS to the extent practicable to ensure
that data are gathered during the RI to support the tech-
nologies and associated treatability studies.

    Similarly, treatability studies to support the remedy
implementation also should be conducted as early in the
RD as appropriate.  As with the RI/FS trcatability study,
additional technology-specific site characterization  data
may be needed to aid in the design and implementation
of the study.
TREATABILITY STUDY GOALS

    Each level of treatability study requires appropriate
performance goals. These goals should be specified be-
fore the test is conducted.  The goals may need to be
reassessed to determine appropriateness following test-

-------
ing performance as a result of new information (e.g.,
ARARs), treatment train considerations or other factors.
Pre-ROD treatability study goals will usually be based
on the anticipated performance  standards to be estab-
lished in the ROD.  This is because cleanup criteria are
not finalized until the ROD is signed due to continuing
analyses and  ARARs determinations. The treatability
goals should consider the following factors independ-
ently or in combination:

    •   Levels that are protective of human health and
        the environment (e.g., contact, ingestion, leach-
        ing) if treated waste is left unmanaged or is
        managed;

    •   Levels that are in compliance  with ARARs,
        including the land disposal restrictions;

    •   Levels that ensure a reduction of toxicity, mobil-
        ity, or volume;

    •   Levels acceptable for delisting of the waste; and

    •   Levels set by the State or Region for another site
        with contaminated media with similar charac-
        teristics and contaminants.

    Further, the program has as the treatment goal and
expectation that treatment technologies and/or treatment
trains generally achieve a 90 percent or greater reduction
in the concentration or mobility of individual contami-
nants of concern. This goal complements the site-spe-
cific risk-based goals. There will be situations where re-
ductions outside this range that achieve health-based or
other site-specific remediation goals, may be appropri-
ate. Treatment technologies should be designed and op-
erated  such that they achieve reductions beyond  the
target level indicated to  ensure that the stated goals are
achieved consistently.

    Laboratory screening of treatability study goals al-
lows for a go/no-go decision. For example, the goal may
be a 50 percent reduction in mobility which  would
indicate the potential to  achieve greater reduction (e.g.,
90 percent) through additional refinement of the study.
The achievement of this goal might indicate the advisa-
bility of expending additional resources on a bench-scale
test to obtain a more definitive evaluation of the technol-
ogy.  Bench- and  pilot-scale testing  goals are those
needed to select and/or implement the technology. For
example, the bench-scale testing goal for solidification/
stabilization could be to achieve  a 90 percent or greater
reduction in mobility of the principal constituents.  In
addition, the goals for the bench- or pilot-scale studies
 also may involve multiple waste treatment levels — the
 performance of which dictates the ultimate disposition
 of the waste (i.e., clean closure or landfill closure).

    Post-ROD treatability study goals should reflect
 those performance standards specified in the ROD. They
 should also be achieved in the most resource-efficient
 manner.
 ADMINISTRATIVE PLANNING

    The planning process for treatability studies begins
 during the budget cycle in the year prior to the planned
 performance. At that time, the potential need for treata-
 bility studies and their cost is estimated to ensure ade-
 quate resources and to factor the study into the planning
 for the site (e.g., scheduling the RI/FS). In many cases,
 the RI/FS will not have been initiated at this time, and
 assumptions will need to be made. In view of the limited
 literature information that is currently available on tech-
 nology performance, it is anticipated that one or more
 treatability studies may be necessary for most sites.
 Funding for treatability studies  is separate from RI/FS
funding and is over and beyond the target of RI/FS cost
 of$750K.

    Planners  need to take into consideration treatability
 studies to be performed by contractors, EPA, and other
 Federal Agencies (e.g., Corps of Engineers) to support
 the ROD and the RD/RA. Treatability study funds will
 be needed for Fund-lead sites and for selected Enforce-
 ment-lead sites if the Responsible Party (RP) is not per-
 forming the  study.    Funds also will be needed for
 oversight of the studies. Oversight of Fund-lead treata-
 bility studies will be allocated as part of the treatability
 study. Oversight of RP-lead treatability studies will be
 funded through the enforcement budget.
 FUNDING

    Treatability studies in support of the RI/FS or the
 RD/RA are funded from the "Other Remedial" account
 if they are Federally-funded. The amount of treatability
 study funding required is dependent on technology and
 site-specific factors.  The section in this fact sheet en-
 titled "Levels of Treatability Studies" provides a rough
 estimate of resources and time required to perform the
 studies. Resources required may vary greatly depending
 on site conditions and data needs.

    In the event that treatability study funding require-
 ments exceed planned treatability study allocations (ei-
 ther due to the costs of the studies or due to the need for

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studies which were not planned for), these studies should
be funded from the Region's "Other Remedial" account
or other Regional monies through the SCAP process.
Regions should contact Tom  Sheckells (OERR/OPM,
FTS 382-2466) for clarifications.

    All treatability studies, whether performed by a con-
tractor or EPA, are funded out of the Regional SCAP ac-
count. Procurement Requests (PR) used to initiate work
should have activity code "9" to ensure proper record
keeping.
CERCLIS

    Treatability studies are coded in CERCLIS under the
event code "TS" that provides for separate event coding
for each treatability study for a given site. This allows for
multiple treatability studies with separate funding (e.g.,
Federal-, State-, or Responsible Party-lead treatability
studies).
PERFORMANCE OF TREATABILITY
STUDIES

    Fund-lead treatability studies generally will be con-
ducted through the REM or ARCS contractors or their
sub-contractors or contractors working for States. A list
of vendors that, have expressed interest in performing
treatability studies has been compiled in the "Inventory
of TreatabiJity Study  Vendors."  A preliminary draft
copy is scheduled for distribution in January 1990. Com-
panies on this list should be notified of requests for pro-
posals (RFPs) for treatability studies in accordance with
the Federal Acquisition Regulations.

    EPA and other Federal Agencies such as the Bureau
of Mines also may perform select treatability studies on
a case-by-case basis. Again, the funding of these activi-
ties is through the Regional SCAP allocations.

    Enforcement-lead treatability studies generally will
be accomplished through the RP contractor. There may
be exceptions to this where the complexity of the site
requires alternative options (e.g., State- or Federal-lead
treatability studies for all or part of a site). The planning
and performance of the study should be directed by the
Region to ensure that  the study results in the type and
quality of data needed to support the decision.
TREATABILITY STUDY PROTOCOLS

   Treatability studies need to be carefully planned to
ensure that sufficient data of known, documented, and
appropriate quality are generated to support the decision.
The site-specific treatability study protocol is outlined in
the Work Plan and the Sampling and Analysis Plan.
These plans should, among other things, clearly de-
scribe: the experimental design, the treatability study
goals, the Quality Assurance Project Plan, data manage-
ment and interpretation, and reporting.

    The treatability study work assignment is to require
that the treatability study be developed in accordance
with Agency guidance, factoring in literature, site-spe-
cific information, and expert consultation.  The "Guide
for Conducting Treatability Studies Under CERCLA"
provides a general approach for treatability studies and
provides  a  protocol  for the preparation of the Work
Assignment, Work Plan, Sampling and Analysis Plan,
Health and  Safety Plan, and the Community Relations
Plan.  The Agency  also is developing a number of
technology-specific treatability guidances which should
be followed; the first of these on soil washing is sched-
uled to be issued in the second quarter of FY 1990.  For
more information on  these documents, other sources of
treatability .study information, and for technical assis-
tance in reviewing and performing treatability studies
please contact Ben Blaney (ORD) at FTS/684-7406 or
com. 513/596-7406.
TREATABILITY STUDY REPORT

    The Agency has initiated an effort to ensure the
consistency of treatability study reports and to provide a
central repository  of treatability studies to facilitate
information dissemination. The "Guide for Conducting
Treatability Studies under CERCLA" contains a stan-
dard report format that is to be followed for all treatabil-
ity study reports.  All work assignments and consent
decrees are to contain a statement requiring that docu-
ments be developed in accordance with Agency policy.

    Further, all Fund-lead and enforcement-lead over-
sight treatability work assignments are  to include  a
provision requiring that a camera-ready master copy of
the  treatability study  report be  sent to the following
address:

    Attn: KenDostal
    U.S. Environmental Protection Agency
    Superfund Treatability Data Base
    ORD/RREL
    26 W. Martin Luther King Drive
    Cincinnati, Ohio 45268

Information contained in these reports will be available
through the Alternative Treatment Technology Informa-
tion Center (ATTIC). For more information on ATTIC
please call FTS 382-5747 or com. 202/382-5747.

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TECHNICAL ASSISTANCE

    Literature information and consultation with experts
are critical  factors in determining the need for and
ensuring the usefulness of treatability studies. A refer-
ence list of sources on treatability studies is provided in
the "Guide for Conducting Treatability Studies Under
CERCLA."

    It is recommended that a Technical Advisory Com-
mittee (TAG) be used. This committee may include ex-
perts on the technology(ies) to provide technical support
from the scoping phase of the treatability study through
data evaluation.  Members  of the TAG may include
representatives from EPA (Region and/or ORD), other-
Federal Agencies, States,'and consulting firms. Techni-
cal assistance may be obtained through the following:

    •   The Office of Research and Development
       (ORD)  provides technical assistance on site
       remediation and treatability studies. The Super-
       fund Technical  Assistance  Response Team
       (START)  provides long-term site-specific sup-
       port from  the scoping phase through remedial
       design for sites identified by Regional manage-
       ment and  selected for START support.  The
       Technical Support Project (TSP) provides short-
       term support  of a similar nature. ORD assis-
       tance in the planning, performance, and/or re-
       view of treatability studies can be accessed
       through either mechanism. ORD also has the
       Treatability Assistance Program (TAP) which is
       developing technology-sped fie treatability stu dy
       protocols, bulletins, and a computerized data-
       base.  For further information on treatability
       study support or the TAP please contact Ben-
       Blaney (ORD) at FTS 684-7406 or com. 5137
       569-7406, Rich Steimle (OSWER) at FTS 382-
       7914 or com. 202/382-7914, or a Regional
       Forum member.

       Bureau of Mines (BOM) has technical exper-
       tise and experience in the development of tech-
       nologies to remove metals and other inorganic
       chemicals from solids and liquids. Contact Wil-
       Ijam Schmidt at FTS 634-1210orcom. 202/634-
       1210 for information.

       The U.S. Army Corps of Engineers (COE)
       may perform or oversee  treatability studies
       required for RI/FS or RD/RA.   For informa-
       tion, contact  Joe Grasso (COE) at com. 402/
       691-4532.
FOR FURTHER INFORMATION

    In addition to the  contacts identified above, the
appropriate Regional Coordinator for each Region lo-
cated in the Hazardous Site Control Division/Office of
Emergency and Remedial Response or the CERCLA
Enforcement Division/Office of Waste Programs En-
forcement should be contacted for additional informa-
tion or assistance.

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&EPA
              United States
              Environmental Protection
              Agency
              Office of Research and
              Development
              Washington DC 20460
Office of Solid Waste and
Emergency Response
Washington, DC 20460
              Super) und
              EPA/540/R-92A)71a
October 1992
Guide for Conducting
Treatability Studies under
CERCLA
              Final

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                                                 EPA'54C'-R-92'C7ia
                                         OSWER Directive No. 9380.3-10
                                                   November 1992
          GUIDE FOR CONDUCTING
TREATABILITY STUDIES UNDER CERCLA
                      FINAL
              Risk Reduction Engineering Laboratory
              Olfice of Research and Development
              U.S. Environmental Protection Agency
                  Cincinnati, Ohio 45268

                         and

           Office of Emergency and Remedial Response
           Olfice of Solid Waste and Emergency Response
              U.S. Environmental Protection Agency
                  Washington, DC 20460
                                             Prinled on Recycled Paper

-------
                      NOTICE
The information in this document has been funded wholly or in part by
the U.S. Environmental Protection Agency (EPA) under Contract No.
68-C9-0036. It has been subjected to the Agcncy'srcvicw process and
approved for publication as an EPA document.

The policies and procedures set forth here arc intended as guidance to
Agency and other government employees.  They do not constitute
rulcmaking by the Agency, and may not be relied on  to create a
subsiamivc or procedural right enforceable by any other person.  The
Government may take action thai is ai variance with the policies and
procedures in this manual.  Mention of  trade names or commercial
products docs nol constitute endorsement or recommendation for use.

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                   FOREWORD
Today's rapidly developing and changing technologies and industrial
products and practices frequently carry with them the increased gen-
eration of materials that, if improperly dealt with, can threaten both
public health and the environment. The U.S. Environmental Protec-
tion Agency (EPA) is charged by Congress with protc ;ting theNation's
land, air, and water resources.  Under a mandate of national environ-
mental laws, the Agency strives to formulate and implement actions
leading to a compatible balance between human activities and the
ability of natural systems to support and nurture life. These laws direct
the EPA to perform research to define our environmental problems,
measure the impacts, and search for solutions.

The Risk Reduction Engineering Laboratory is responsible for plan-
ning, implementing, and managing research, development, and dem-
onstration programs to provide an authoritative, defensible engineer-
ing basis in support of the policies, programs, and regulations  of the
EPA with respect  to drinking  water, wastcwalcr, pesticides, toxic
substances, solid and hazardous wastes, and Superfund-rclated activi-
ties. This publication is one  of  the products of that research and
provides a vital communication link between the researcher and the
user community.

The purpose of this guide is to provide information on conducting
treatability studies.  It describes a three-tiered approach that consists of
1) remedy screening, 2) remedy-selection testing, and 3) remedial
design/remedial action testing.  It also presents a protocol for conduct-
ing treatability studies in a systematic and stepwise fashion for  deter-
mination of the effectiveness  of a technology (or  combination  of
technologies) in remediating a  CERCLA site.
                                    E.Timothy Oppelt, Director
                         Risk Reduction Engineering Laboratory
                             111

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                   ABSTRACT
Systematically conducted, well-documented treatability studies are an
important component of the removal process, remedial investigation/
feasibility  study (RI/FS)  process and the remedial design/remedial
action (RD/RA) process  under the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA).  These stud-
ies provide valuable site-specific data necessary to aid in the screening,
selection, and implementation of the site remedies. This guide focuses
on both treatability studies conducted in support of remedy screening
and selection [i.e., pre-Record of Decision (ROD)] and treatability
studies in support of remedy implementation (i.e., post-ROD).

The guide describes a three-tiered approach for conducting trealability
studies that  consists of 1)  remedy screening, 2) remedy-selection
testing, and 3) RD/RA testing. Depending on the technology infor-
mation gathered during RI/FS scoping, pre-ROD trcatabilily studies
may bcgn. at cither  the remedy-screening or remedy-selection tier.
Remedial design/remedial action trcatabilily testing is performed post-
ROD.

The guide also presents an  11-stcp generic protocol for conducting
treaiabiliiy studies.  The steps include:

      •  Establishing data quality objectives
      •  Identifying sources for treatability studies
      •  Issuing the Work Assignment
      •  Preparing the Work Plan
      •  Preparing the Sampling and Analysis Plan
      •  Preparing the Health and Safety Plan
      •  Conducting community relations activities
      •  Complying with regulatory requirements
      •  Executing the study
      •  Analyzing and interpreting the data
      •  Reporting the results

The intended audience for this guide comprises Remedial Project
Managers, On-Scenc Coordinators,  Federal facility environmental
coordinators, potentially responsible parties, contractors,  and technol-
ogy vendors. Although Resource Conservation  and Recovery Act
(RCR A) program officials may find many sections of this guide useful,
the RCRA program is not expressly addressed in the guide.
                             IV

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                              TABLE OF CONTENTS
Section                                                                                       Page
NOTICE	ii
FOREWORD	iii
ABSTRACT	iv
FIGURES	vi
TABLES	vii
ACRONYMS 	viii
ACKNOWLEDGMENTS	ix
1.  Introduction	1
   1.1    Background	1
   1.2    Purpose	1
   1.3    Intended Audience	1
   1.4    History of the Guide 	2
   1.5    Use of the Guide	2
2.  Overview of Trcatabilily Studies	5
   2.1    The Role of Trcatability Studies Under CERCLA	5
   2.2    Three-Tiered Approach to Treatability Testing	7
   2.3    Applying the Tiered Approach	12
   2.4    Treatability Study Test Objectives	1?
   2.5    Special Issues	15
3.  Protocol for Conducting Trcauibility Studies	23
   3.1    Introduction	23
   3.2    Establishing Daui Quality Objectives	23
   3.3    Identifying Sources for Trcatability Studies	26
   3.4    Issuing the Work Assignment	29
   3.5    Preparing the Work Plan	31
   3.6    Preparing the Sampling and Analysis Plan	35
   3.7    Preparing the Health and Safety Plan	38
   3.8    Conducting Community Relations Activities	39
    3.9   Complying With Regulatory Requirements	41
   3.10  Executing the Study	,	45
   3.11   Analyzing and Interpreting the Dam	46
   3.12  Reporting the Results	52
REFERENCES	55
APPENDIX A. Sources of Trcauibilily Information	57
APPENDIX B. Cost Elements Associated with Trcatability Studies	61
APPENDIX C. Technology-Specific Characterization Parameters	65

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                                             FIGURES

Figure                                                                                                Page
   1     Decision tree showing when treatabilily studies are needed to support the evaluation and selection of an
         alternative	6
   2     The role of trcatability studies in the RI/FS and RD/RA process	9
   3     Flow diagram of the tiered approach	14
   4     Information contained in the ORD Inventor)' of Treaiability Study VenJors	28
   5     Example test  matrix for zeolite amendment remedy-selection treatabilily study	32
   6     Example project schedule fora two-tiered chemical dehalogcnation ueatabilily study	36
   7     Example project organization chart	37
   8     Facility requirements for treatability testing	42
   9     Shipping requirements for offsite treatability testing	43
  10     Evaluation criteria and analysis factors for detailed analysis of alternatives	48
  11     General applicability of cost elements to various treatability study tiers	62
                                                     VI

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                                            TABLES
Table
  1     General Comparison of Remedy-Screening. Remedy-Selection, and RD/RA Treaiability Studies ................... 8
  2     Aqueous Field Treatability Studies:  Generic Versus Vendor Processes [[[ 20
  3     Soils/Sludges Field Treatability Studies:  Generic Versus Vendor Processes .................................................. 20
  4     Summary of Three-Stage DQO Development Process [[[ 24
  5     PARCC Parameters [[[ 25
  6     Suggested Organization of Treatability Study Work Assignment [[[ 30
  7     Suggested Organization of Treatabilily Study Work Plan [[[ 31
  8     Typical Waste Parameters Needed to Obtain Disposal Approval at an Offsitc Facility ................................... 34
  9     Suggested Organization of a Treatability Study Sampling and Analysis Plan .................................................. 38
 10     Suggested Organization of a Trcatabiliiy Study Health and Safety Plan [[[ 39
 1 1     Suggested Organization of Community Relations Plan [[[ 40
 12     Regional Offsite Contacts for Determining Acceptability of Commercial Facilities
        to Receive CERCLA Wastes [[[ 45

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                                       ACRONYMS
AOC       Administrative Order on Consent                OSWER
ARAR      applicable or relevant and appropriate
           requirement                                 PARCC
ARCS      Alternative Remedial Contracts Strategy
ATTIC     Alternative Treatment Technology              PAH
           Information Center                           PCB
CERCLA   Comprehensive Environmental Response,        PRP
           Compensation, and Liability Act of 1980 (aka     QAPP
           Supcrfund)                                  QA/QC
CFR       Code of Federal Regulations                    R A
COLIS     Computerized On-Line Information Service       RCRA
COE       U.S. Army Corps of Engineers
CRP       Community Relations Plan                     RD
DOD       Department of Defense                        RD&D
DOE       Department of Energy                         RFP
DOT       Department of Transportation                   RI
DQO       Data quality objective                         ROD
EPA       U.S. Environmental Protection Agency           RPM
ERCS      Emergency Response Cleanup Services          RREL
ERT       Emergency Response Team                    SAP
ETSC      Engineering Technical Support Center           SARA
FAR       Federal Acquisition Regulations
FR        Federal Register                             SCAP
FS        feasibility study
FSP       Field Sampling Plan                          SITE
HSP       Health and Safety Plan
HSWA     Hazardous and Solid Waste Amendments of      SOP
           1984                                       SOW
ITSV       Inventory of Trcatability Study Vendors          START
LDRs      Land Disposal Restrictions
MCLs      Maximum Contaminant Levels                 TAT
MSDS     Material Safety Data Sheet                     TCLP
NCP       National Oil and Hazardous Substances          TIX
           Pollution Contingency Plan                    TOC
NIOSH     National Institute  for Occupational Safety and     TOX
           Health                            '        TSDF
NPL       National Priorities List                        TSC
O&M      Operation and Maintenance                    TSP
OERR      Office of Emergency and Remedial Response     TST
ORD       Office of Research and Development            USCG
OSC       On-Scene Coordinator                        USPS
OSHA     Occupational Safety and Health Administration     UST
Office of Solid Waste and Emergency
Response
Precision, Accuracy, Representativeness,
Completeness, and Comparability
Polynuclear Aromatic Hydrocarbon
Polychlorinated biphenyl
Potentially responsible party
Quality Assurance Project Plan
quality assurance/quality control
remedial action
Resource Conservation and Recover)' Act
of 1976
remedial design
research, development, and demonstration
request for proposal
remedial investigation
Record of Decision
Remedial Project Manager
Risk Reduction Engineering Laboratory
Sampling and Analysis Plan
Superfund Amendments and Reauthoriza-
tion Act of 1986
Superfund Comprehensive
Accomplishments Plan
Superfund Innovative Technology
Evaluation
standard operating procedure
Statement of Work
Superfund Technical Assistance Response
Team
Technical Assistance Team
toxicity characteristic leaching procedure
Technical Information Exchange
total organic carbon
total organic halogen
treatment,  storage, or disposal facility-
Technical Support Center
Technical Support Project
Technical Support Team
United States Coast Guard
United States Postal Service
Underground Storage Tank
                                                 Vlll

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               ACKNOWLEDGMENTS
This guide: was prepared for the U.S. Environmental Protection Agency, Office of
Research and Development, Risk Reduction Engineering Laboratory (RREL), Cincin-
nati, Ohio, by IT Corporation. Mr. Eugene F. Harris and Mr. David L. Smith served
as the EPA Technical Project Monitors, assisted by Ms. Robin M. Anderson. Office
of Emergency and Remedial Reponse, and Mr. Jonathan Herrmann, RREL.  Mr.
Gregory D. McNeily was IT's Work Assignment Manager. The project team included
Jeffrey S.Davis, Mary Beth Foerst, E.RadhaKrishnan, Jennifer Plait, Michael Taylor,
and Julie Van Deuren. Ms. Judy L. Hessling served as IT's Senior Reviewer, and Ms.
Martha H. Phillips served as the Technical Editor. Document layout was provided by
MJ. James I. Scott, III.
The following personnel have contributed their time and comments by participating in
the Guide for Conducting Treatability Studies Under CERCLA workshop:
    Lisa Askari
    John Barich
    Edward Bates
    Benjamin Blaney
    John Blevins
    Randall Brecden
    JoAnn Camacho
    Jose Cisncros
    Paul Flathman
    Vance Fong
    Frank Freestone
    Tom Greengard
    Eugene Harris
    Sarah Hokanson
    Norm Kulujian
    Donna Kuroda
    John Quandcr
    Jim Rawe
    Ron Turner
U.S. EPA, Office of Solid Waste
U.S. EPA, Region X
U.S. EPA, Risk Reduction Engineering Laboratory
U.S. EPA, Risk Reduction Engineering Laboratory
U.S. EPA, Region IX
U.S. EPA, Office of Emergency and Remedial Response
U.S. EPA, Environmental Response Team
U.S. EPA, Region V Emergency Response
OHM Remediation Services Corporation
U.S. EPA, Region IX
U.S. EPA, Risk Reduction Engineering Laboratory
EG&G Rocky Flats
U.S. EPA, Risk Reduction Engineering Laboratory
Clean Sites, Inc.
U.S. EPA, Region III
U.S. Army Corps of Engineers
U.S. EPA, Technology Innovation Office
Science Applications International Corporation
U.S. EPA, Risk Reduction Engineering Laboratory
                                  IX

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                                           SECTION 1
                                      INTRODUCTION
1.1    Background

Under  ihc Supcrfund Amendments and Rcauihori/.aiion
Aci of 1986 (SARA), the U.S.  Environmental Proicclion
Agency (EPA) is  required lo select remedial actions in-
volving treatment  ihai "permanently and significantly re-
duces the volume, toxicity, or mobility of the hazardous
substances, pollutants, and contaminants" [Comprehensive
Environmental Response, Compensation, and Liability Act
(CERCLA), Section  121(b)].

Selection of remedial actions involves several risk manage-
ment decisions. Uncertainties with respect to performance,
reliability, and cost of treatment alternatives underscore the
need for well-planned, well-conducted, and  well-docu-
mented (Testability studies, as  evident in the following
quote from Management Review of the Superfund Program
(EPA 1989a):

    "To evaluate  the application of treatment tech-
    nologies 10 particular sites, it is essential to con-
    duct laboratory or pilot-scale tests on actual wastes
    from the site, including, if needed and feasible,
    tests of  actual operating units prior to remedy
    selection. These  'treatability tests' arc not currently
    being performed at many  sites to the necessary
    extent, or their quality is not adequate  to support
    reliable decisions."

Treatability studies provide valuable site-specific data nec-
essary to support Supcrfund remedial actions. They serve
two primary purposes:  1) to aid in the selection of the
remedy, and 2) to aid in the implementation of the selected
remedy. Treatability studies conducted during a remedial
investigation/feasibility study (Rl/FS)  indicate whether a
given technology can meet the expected cleanup goals for
the site and provide important information to aid in remedy
selection, whereas ircatability  studies conducted  during
remedial design/remedial action (RD/RA) establish the de-
sign and operating parameters necessary for opiimi/ation
of technology performance and implementation of a sound,
cost-effective remedy.  Although the purpose and scope of
these studic> differ, they complement one another because
information obtained in support of remedy selection may
also be used to support the remedy design and implementa-
tion. Treatability studies also may be conducted under the
CERCLA Removal Program to  support removal actions
that involve treatment.

Historically, ircatability studies have been delayed unu'l after
the Record of Decision (ROD) has been signed. Although
certain post-ROD ireatability  studies arc appropriate, con-
ducting treatability studies during the RI/FS (i.e., prc-ROD)
should reduce the uncertainties associated with selecting the
remedy, provide a sounder basis for the ROD, and possibly
facilitate negotiations with potentially responsible panics with-
out lengthening the overall cleanup schedule for the  site.
Because  ircatability studies may be expensive and time-
consuming, however, the economics of cost and time must be
taken into consideration when planning trcaiability studies in
support of the various phases of the Supcrfund program.
1.2   Purpose

This document presents guidance on conducting ircaubility
studies under CERCLA. Us purpose is to facilitate efficient
planning, execution, and evaluation of trcatability studies
and to ensure that the data generated can support remedy
selection and implementation.
1.3   Intended Audience

This document is intended for use by EPA Remedial Project
Managers (RPMs), EPA On-Sccnc Coordinators (OSCs),
potentially responsible parties (PRPs), Federal facility en-
vironmental coordinators, trcatabiliiy study contractors, and
technology  vendors.   As  described  here,  each  of  these
persons plays a different  role  in conducting ircaiabiliiy
studies under CERCLA. Although the Resource Conserva-
tion and Recovery Act (RCRA) program is noi expressly

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addressed, many sections of the guide may be useful in the
planning of trcatability studies in support  of corrective
action.  Some parts may also be applicable  in the Under-
ground Storage Tank (UST) program.

 1.3.1  Remedial Project Managers

Remedial Project Managers arc EPA or State officials re-
sponsible for remediation planning and oversight at a site.
Their role in trcatabiliiy investigations depends on the des-
ignated lead agency (Federal, State, or private) and whether
the site is a fund-financed or enforcement-lead site.  Their
activities generally include scoping  the treatabiliiy study,
establishing the data quality objectives, selecting a contrac-
tor, and issuing a  work assignment,  or obtaining  EPA-
sponsorcd trcaiabilily study support, overseeing the execu-
tion of  the study, informing or involving  the public as
appropriate, reviewing project dclivcrables, and  using
treatability study data in decision making.

 7.3.2  On-Scene Coordinators

On-Scene Coordinators arc  Federal officials prcdesignatcd
by the EPA or U.S. Coast Guard (USCG) to coordinate and
direct removal actions at both National Priorities List (NPL)
and non-NPL sites. Their role in treatabiliiy studies is
similar to that of the RPM.

 7.3.3  Potentially Responsible Parties

Under CERCLA Sections 104(a) and 122(a), EPA has the
discretion  to allow PRPs to perform certain Rl/FS  activi-
ties, including trcatability studies.  The EPA or an autho-
rized  State agency oversees the conduct of PRP-lcd
trcatabilily studies, but the  PRP is responsible for project
planning, execution, and evaluation.

 7.3.4  Federal Facility Environmental
        Coordinators

Environmental coordinators at Federal facilities may con-
duct trcatability studies under CERCLA or agency-specific
programs such as the Department of Defense (DOD) Instal-
lation Restoration Program  and the Department of Energy
(DOE) Environmental Restoration  and Waste Management
Program. The roles and responsibilities of these personnel
will vary by agency and program; however, for trcaiabilily
studies they will be similar to those of the EPA RPM.

7.3.5  Contractors/Technology  Vendors

Treatability studies arc generally  performed by remedial
contractors or technology vendors. Their roles in ircatability
investigations include preparing the  Work Plan and other
supporting documents, complying with regulator) require-
ments, executing the study, analy/.ing and interpreting the
data, and reporting the results.
 1.4   History of the Guide

 In December 1989, EPA published the interim final Guide
for Conducting Treaiability Studies Under CERCLA (EPA
 1989b). This generic trcatabilily guidance was one compo-
 nent of the EPA's Office of Research and Development
 (ORD) trcaiability study initiative to identify trcatability
 capabilities, to consolidate trcatabilily data, and to develop
 standard operating protocols. The objectives of the guide
 were threefold:

   1)  To provide guidance to RPMs and Supcrfund re-
      medial contractors for conducting trcauibiliiy stud-
      ies in support of remedy selection (i.e., prc-ROD;.

   2)  To serve as a framework for developing technol-
      ogy-specific protocols.

   3)  To be a dynamic document  thai evolves as the
      Agency gains trcaiabilily study experience.

 As part of the development of the generic trcaiability guid-
 ance, EPA sponsored a  trcatability protocol workshop in
 July 1989, which was attended by more than 60 representa-
 tives from EPA Headquarters and Regional offices, con-
 tractors/technology  vendors, and  acadcmia.  The tiered
 approach to treatabiliiy  studies and  the 11-step protocol
 that evolved  during the workshop and subsequent docu-
 ment peer review process form  the basis of the trcaiabilily
 guidance.

 In keeping with the original objcciivc of  producing a  dy-
 namic document,  comments on the utility of the  interim
 final guidance after approximately 18 months of use were
 solicited through a survey of potcmial users (principally
 RPMs and their contractors) and  a  second workshop in
 August  1991. Although the general content and format
 have not changed, the document  has been expanded to
 address a broader audience and updated to reflect current
 regulations, policy, and guidance/information sources.  In
 addition, the "tier" terminology has been revised to reflect
 the intended use of the data rather than the scale of testing.
1.5   Use of the Guide

 7.5.7  Organization of the Guide

The guide  is organixcd  into iwo principal sections:  an

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overview of ireatability studies and a stcp-by-sicp protocol.
Section 2 describes the need for trcatability studies and
presents  a three-tiered approach consisting of 1) remedy
screening, 2) remedy selection, and 3) remedial design/
remedial action. This section also describes the application
of the tiered approach to innovative technologies, treatment
trains,  and in  situ technologies; circumstances in  which
treatability studies can and cannot  be  performed generi-
cally; and PRP-conductcd ireauibility studies.

Section 3 presents a general approach or protocol for con-
ducting treatability studies,  li contains information on
planning, performing, and reporting the results of treatabilily
studies with respect to the three ucrs.  Specifically, this
section include information on:

  •  Establishing data quality objectives.

  •  Identifying qualified  sources for performance of
    treatability studies and selecting a contracting mecha-
    nism.

  •  Issuing the work assignment, with emphasis on writ-
    ing the scope of work.

  •  Preparing the Work Plan, with emphasis on designing
    the experiment.

  •  Preparing  the Sampling and  Analysis Plan  for a
    treatability study.

  •  Preparing the Health and Safety Plan for a treatability
    study.

  •  Conducting community relations activities in support
    of treatability studies.

  •  Complying  with regulatory requirements for testing
    and residuals management.

  •  Executing the trcatability study, with emphasis on col-
    lecting and analyzing samples.

  •  Analyzing and interpreting the data, including a dis-
    cussion on statistical analysis techniques.

  •  Reporting the results in a logical and consistent format.

The text  of each subsection presents general information
followed (when applicable) by specific details pertaining to
the three tiers of ireatability testing.
Appendix A contains additional  source  of ucaunility
information.  Appendix B discusses the major cost ele-
ments associated with trcatability studies.   Appendix C
contains  technology-specific wastc-charactcri/ation  pa-
rameters.

7.5.2  Application and Limitations of the
        Guide

Treatability  studies are an integral part of the  Supcrfund
program.  This guide is intended to supplement the infor-
mation on development, screening, and analysis of alterna-
tives contained in the interim final Guidance for Conduct-
ing Remedial Investigations ana Feasibility Studies Under
CERCLA (EPA 1988a), hereinafter referred to as the RI/FS
guidance.  Generic in nature,  the guide encompasses all
waste matrices (soils, sludges, liquids, and gases) and all
categories of technologies (biological treatment, physical/
chemical treatment, immobilization, thermal treatment, and
in situ treatment). The guide addresses trcatahility studies
conducted in support of  remedy screening and selection
(i.e., prc-ROD)  and  remedy design and  implementation
(i.e., post-ROD). Companion  documents providing tech-
nology-specific ircatability guidance arc being prepared for
soil vapor extraction, chemical dchalogcnalion, soil  wash-
ing, solvent extraction, biodcgradation, thermal dcsorption,
and solidification/stabilization.

In an effort to be concise, supporting information in other
readily available guidance documents is referenced through-
out this guide rather than repeated.  For example, details on
the preparation of a site Sampling and Analysis Plan (which
includes a Field  Sampling Plan and a Quality  Assurance
Project Plan), a Health and Safety  Plan, and a Community
Relations Plan arc not included herein.

Although this guidance is written to support the  ircaiability
study activities of an EPA  RPM  under CERCLA, it has
wide applicability to many other programs. For this reason,
the term "project manager" has been used, when appropri-
ate, to signal the potential applicability of the subject cov-
ered to both the CERCLA Remedial  and Removal Pro-
grams and to non-CERCLA trcauibility studies.

This document was drafted  and reviewed by representa-
tives from EPA's Office of Solid Waste and Emergency
Response, Office of Research  and Development, and the
Regional offices, as  well as by contractors  and vendors
who conduct trcauibility studies. Comments obtained dur-
ing the course of the peer review  process have been inte-
grated or addressed throughout this guide.

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                                         SECTION 2
               OVERVIEW  OF TREATABILITY STUDIES
This section presents an overview of ireatability studies
under CERCLA and provides examples of the application
of treaiability studies in the RI/FS process.  Subsection
2.1 outlines the role of trcauibiliiy studies in the Super-
fund program.  Subsection 2.2 provides details  on the
three tiers of trcaiabiliiy testing. Subsection 2.3 presents
the methodology for applying the tiered approach.  Sub-
section 2.4 discusses treatability  study test objectives.
Subsection 2.5 addresses special issues associated with
CERCLA treatabiliiy studies, including examples of how
the tiered approach can be applied to investigations of unit
operations, treatment trains, and in situ technologies; when
testing can and cannot be performed generically  (i.e.,
without the assistance of  vendors using proprietary re-
agents and processes); the involvement and oversight of
PRPs; and the funding of ircaiability  studies.
2.1    The Role of Treatability Studies
       Under CERCLA

2.1.1  Pre-ROD Treatability Studies

As discussed in the RI/FS guidance, site charactcri/jtion
and treaiability investigations arc two of the main compo-
nents of the RI/FS process.  As siic and technology infor-
mation is collected and reviewed, additional data needs
for evaluating alternatives arc  identified.  Trcaiabiliiy
studies may be required to fill some of these dam gaps.

In the absence of data in the available technical literature,
treatabiliiy studies can provide  the critical performance
and cost information needed to evaluate and select treat-
ment alternatives.  The purpose of a prc-ROD trcaubility
investigation is to provide the data needed for the dcuiilcd
analysis of alternatives during the FS.  The 1990 revised
National Oil and Hazardous Substances Pollution Contin-
gency Plan (NCP) (55  FR  8813), Section 3()(>.43()(c),
specifies nine evaluation criteria to be considered in this
assessment of remedial altcrnaiivcs.  Trcaiabiliiy studies
can generally provide dam to address the firsi seven of
these nine criteria;

  1) Overall protection of human health and ihc en-
     vironment

  2) Compliance with applicable or relevant and ap-
     propriate requirements (ARARs)

  3) Long-term effectiveness and permanence

  4) Reduction of toxicily, mobility, and volume
     through treatment

  5) Short-term effectiveness

  6) Implcmenuibiliiy

  7) Cosl

  8) Slate acceptance

  9) Community acceptance

The first iwo criteria, which relate directly to ihc statutory
requirements each remedial  alternative must meet,  arc
catcgori/ed as threshold criteria.  The next five arc the
primary balancing criteria upon which the selection of
the remedy is based.  The final two modifying  criteria,
Slate acceptance and community acceptance, arc addressed
in the ROD when comments arc received on the RI/FS  and
the proposed remedial plan. (The RI/FS evaluation criic-
ria arc discussed in detail in Subsection 3.11.2.)

Prc-ROD ircaiability studies may be needed when poten-
tially applicable treatment technologies arc being consid-
ered for which no or limited performance or cost informa-
tion is available in the liicraiurc  with regard to ihc wasic

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types and site conditions of concern. The general decision
tree  presented  in Figure  1  illustrates when trcatability
studies arc needed to support the evaluation and selection
of an alternative. After the existing data on the physical
and chemical characteristics of the waste have been re-
viewed, a literature  survey is conducted to obtain any
existing trcatability data for the contaminants and matri-
ces of concern.  (Sources of technical support and
ireatahiHty information available through EPA are dis-
cussed in Subsection 3.3 and Appendix A.) Based on the
results of a review of available site data and a literature
search, remedial technology types arc prcscrecncd to elimi-
nate those that  arc clearly  not  applicable  for the site.
Potentially and definitely applicable technologies arc as-
sembled  into alternatives  and evaluated  in  terms of the
nine RI/FS criteria to identify any data gaps.  Site- and
technology-specific data needs arc then identified for each
of the alternatives retained for investigation.

The need to conduct a trcatability study on any part of an
alternative is a  management decision.  In addition to the
technical considerations, certain nontechnical management
decision factors must be considered.  As shown in Figure
1, these factors  include the expected level  of State and
community acceptance of a proposed alternative;  lime
constraints on the completion of the RI/FS and the signing
of the ROD; and the appearance of new site, waste, or
technology data.

If the existing data arc adequate for an evaluation of the
alternative for remedy selection (i.e., sufficient to perform
a detailed analysis against the nine RI/FS evaluation crite-
ria), no  trcatability  study  is required.  Otherwise, a
trcatability study should be performed  to generate the data
necessary to conduct a detailed analysis of the alternative.

2.1.2  Post-ROD Treatability Studies

Although a  substantial amount of data  on  the selected
remedy may be available from the RI/FS. treatability stud-
ies may also be necessary during remedial design/reme-
dial action if treatment is part of the remedy. Post-ROD
or RO/RA trcatability studies can provide  the  detailed
design, cost, and performance data needed  to optimize
treatment processes and to implement full-scale treatment
systems.  In the process of implementing a remedy, RD/
RA trcatability studies can  be used  1) to select among
multiple vendors and processes within a  prescribed rem-
edy (prequalificaiion), 2) to implement the most appropri-
ate of the remedies prescribed  in a Contingency ROD, or
3) to support preparation of the Agency's detailed design
specifications and the design of treatment trains.
          REVIEW AVAILABLE
             SITE DATA
         SEARCH LITERATURE
         TO OBTAIN EXISTING
         TREATABILITY DATA
              IDENTIFY
             DATA GAPS
  YES
MANAGEMENT DECISION FACTORS

• Sun ind Commumry Acnpunce |
• Scnt
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provided with a standard sample of waste. Each vendor
designs and performs a ireaiability study based on  that
sample and provides treatment results to the lead agency.
The lead agency  uses these results to determine which
vendors are qualified to bid on the RA.  Generally, the
vendor should achieve results equivalent to the cleanup
criteria defined  in the ROD  to be considered  for
prequalification.

This prequalification approach has been used at the Selma
Treating Company Superfund Site, Region 9. Selma, Cali-
fornia.'  Part 9 of the  Federal  Acquisition Regulations
(FAR) describes policies, standards, and procedures ap-
plicable to this approach.

Contingency RODs

There are situations in which additional flexibility in the
ROD  may be required to ensure implementation of ihe
most appropriate technology for a site.  In these cases, the
selected remedy may be accompanied by a proven contin-
gency remedy in a Contingency ROD.  The Contingency
ROD option was developed for  two purposes: 1) to pro-
mote the use of innovative technologies, and 2)  to allow
different technologies offering comparable performance
to be carried through to remedial design.

Although treatability studies of an innovative technology
will be  conducted during the Rl/FS to support remedy
selection,  it may not be feasible  to  conduct sufficient
testing to address  all of the significant  uncertainties asso-
ciated with the implementation of this option. This situa-
tion, however, should not cause  the option to be screened
out during the detailed analysis  of alternatives in the FS.
If the  performance potential of an innovative technology
indicates this technology would provide the best balance
of tradeoffs from among the options considered despite
its uncertainties,  CERCLA  Section  12l(b)(2) provides
support for selecting such  a technology in  the  ROD.
Implementation of the technology, however, may be con-
tingent  upon the  results of RD/RA ireatabiliiy testing.
When an innovative technology  is selected and its perfor-
mance is  to be verified through additional trcatability
testing, a proven  treatment technology may also be in-
cluded in the ROD as a contingency remedy. In the event
the RD/RA treatability study results indicate that the full-
scale innovative remedy cannot achieve the cleanup goals
at the site, the contingency remedy could then be imple-
mented.

If two different technologies for treatment of the same
contaminant/matrix  emerge from the FS and each offers
comparable performance with respect to the five primary
balancing criteria so that either one could provide the best
balance of tradeoffs, one of the alternatives may be named
in the ROD as the selected remedy and the other as the
contingency remedy.  Based on the results of post-ROD
RD/RA treatability testing, the most appropriate remedy
can then be identified and implemented.

Detailed Design  Specifications

To support  the  remedial  action bid package, the lead
agenry may choose to develop detailed design specifica-
tions.  If technical data available from  the Rl/FS arc
insufficient  for design of  the remedy, an RD/RA treat-
ability study may be  necessary.  Post-ROD  ircatability
studies can provide the detailed cost and performance data
required for optimization of the treatment processes and
the design of a full-scale treatment system.

If an RD/RA trcatabilily study is required to support the
detailed design  specifications, the designer will be re-
sponsible for planning the study and defining the perfor-
mance goals and objectives. Trcatabilily study oversight
will be provided  by the RPM and the Oversight Assistant.

Post-ROD RD/RA trcaiability studies can  also be per-
formed to support the design of treatment  trains.  Al-
though all parts  of a treatment train may be effective for
treating the wastes, matrices, and residuals of concern,
issues such as unit sizing, materials handling, and systems
integration must also be addressed. Trcaiability studies of
one unit's operations can assist in identifying characteris-
tics of the treated material that may need to be taken into
consideration in the design of later units.  A trcatability
study of the entire train can then provide data to confirm
compliance with ARARs and the cleanup criteria outlined
in the ROD. Because a treatment train will often involve
several different technologies and vendors, the designer
will coordinate ireaiability testing of the entire system and
prepare the final ircatability study report.
2.2   Three-Tiered Approach to
       Treatability Testing

Trcaiability sludics arc laboratory or field tests designed
10 provide critical data needed 10 evaluate and implement
remedial treatment technologies ai waste siles.  As an aid
in ihe planning and performance of cosi-cffcciivc, on-
limc, scientifically sound  trcatabilily siudics, a ihrcc-
liercd  approach has been developed.  The  ihrcc-iicrcd
approach applies 10 all ireaiability siudics conducted in

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suppon of Superfund site remediation. Figure 2 presents
the treatabilily  tiers  and iheir conceptual relationship to
the RI/FS and the RD/RA processes.  Table 1 lists general
similarities and differences among the three tiers.

2.2.1   Technology Prescreening and
         Treatability Study Scoping

Prescreening is  an important first step in the identification
of potentially applicable treatment technologies and the
need for ireatabilily testing. Because of the strict time sched-
ules and budget constraints placed on the completion of an
Rl/FS, it is crucial for the planning and scoping of trcatabiiiiy
studies to begin  as early as possible. As shown in Figure 2,
these efforts should be initiated during the Rl/FS scoping.

Technology prescreening  and treatabilily study scoping
will include searching technology literature and ireatability
data bases, consulting wiih technology experts, determin-
ing dam needs, identifying potential ircaiabilily study sources
or contractors, identifying preliminary data quality objec-
tives, and preparing a work assignment.  Determination of
the tier or tiers of ireauibiliiy testing to be conducicd will be
based on the technology- and contaminant-specific data needs.

Technology experts arc available within EPA to assist project
managers with  technology prescreening and ireatabiliiy
study scoping. (In-house consultation services available to
EPA  project managers  arc discussed in Subsection  3.3;
additional information is presented in Appendix A.) Early
consultation may save time and money by preventing the
trcaiability testing of inappropriate technologies.

2.2.2   Remedy Screening

Remedy  screening, ihe  firsi  sicp in  ihc tiered approach,
provides the gross performance data  needed to determine
the potential feasibility  of the technology for treating the
contaminants and matrix of concern.  Remedy-screening
instability studies may not be necessary when ihc litera-
ture contains adequate data for an assessment of the feasi-
bility of a technology.  The results of a remedy-screening
study are used to determine whether additional, more-de-
tailed instability testing should be performed  al the rem-
edy-selection lier.

Feasibility is determined by assessing how well a technol-
ogy achieves ihe ireatability study's performance goals,
which arc based on available knowledge of the operable
unit's cleanup criteria and arc set prior 10 the study. Typi-
cally, remedy-screening studies arc conducicd under con-
ditions  representative of those in the proposed full-scale
system. If a technology cannot achieve the predetermined
performance goals  under these  conditions, ii  should be
screened oui.  If all technologies arc rejected, the project
manager should recvaluatc the screening performance goals
to determine if they arc appropriate.

As shown in Figure 2, remedy-screening ireauibiliiy stud-
ies are  initiated  during the prc-ROD site characterization
and technology screening activities and may continue
through the identification of alternatives. General charac-
teristics of the remedy-screening tier (outlined in Table 1)
are discussed here.

Study Scale

Performed  in Ihe laboratory, remedy-screening  ircaiabilily
siudies are limited in size and scope to bench-scale tcsis with
off-the-shelf equipment. Investigations of some technologies
may require additional small-scale field tests at the screening tier.

Type of Data Generated

Remedy-screening studies provide qualitative daia for use
in assessing ihc poicntial fcasibilily of a technology for
 Table 1.  General Comparison of Remedy-Screening, Remedy-Selection, and RD/RA Treatability Studies

Tier
Remedy
screening
Remedy
selection

RD/RA

Study scale
Bench scale
Bench or pilot scale
Pilol or lull scale
(onsite or offsite)
Full scale
(onsite)
Type
of data
generated
Qualitative
Quantitative
Quantitative
Quantitative
No. of
replicates
Single/
duplicate
Duplicate/
triplicate
Duplicate/
triplicate
Duplicate/
triplicate
Process
type
Batch
Batch or
continuous
Batch or
continuous
Batch or
continuous
Waste
stream
volume
Small
Medium
Large
Large
Time
required^
Days
Days/
weeks
Weeks/
months
Weeks/
months

Cost, S
10,000-
50,000
50,000-
100,000
50,000-
250,000
250.000-
1,000,000
   Indicates duration of testing only.

-------
   Scoping  __
~~the     ~"~~
  Technology
 Prescreening
     and
  Treatability
    Study
    Scoping
               Remedial Investigation/
                  Feasibility Study
                                 Identification
                                of Alternatives
Record of
Decision

 Remedy
Selection
Remedial Design/
 Remedial Action
                         Site
                   Characterization
                   and Technology
                      Screening
                                Evaluation
                              of Alternatives'
REMEDY SCREENING
   TREATABILITY
      to Determine
   Potential Feasibility
                                      REMEDY SELECTION
                                         TREATABILITY
                                       to Develop Performance
                                           and Cost Data
               Implementation
                of Remedy
                                                                        RD/RA TREATABILITY
                                                                        to Develop Detailed Design
                                                                           and Cost Data and to
                                                                           Confirm Performance
                    Figure 2.  The role of treatabilily studies in the RI/FS and RD/RA process.

-------
 treating a contaminant/matrix combination.  No cost  or
 design information will be generated. The project manager
 must determine the overall qualitative data needs based on
 the intended use of the information and the availability of
 time and funds.

 During remedy screening, a single indicator contaminant is
 often monitored to determine whether a reduction in toxic-
 ily, mobility,  or  volume is occurring.   If a technology
 appears to meet or exceed the performance goal for that
 contaminant, it is considered  potentially feasible and re-
 tained  for further evaluation.  Remedy screening is also
 useful  for identifying critical parameters for investigation
 at the remedy-selection tier.

 Number of Replicates

 In most cases, little or no test sample replication (single or
 duplicate) is required at the screening tier.  A less stringent
 level of quality assurance/quality control (QA/QC) is suffi-
 cient because a technology thai is found to be feasible must
 still undergo remedy-selection testing before it is selected
 in the ROD.

 Process Type/Waste Stream  Volume

 Screening will generally involve batch tests and the use of
 small-volume samples of the waste stream. For example,
 remedy screening of an ion exchange process designed to
 treat aqueous wastes may require sample volumes on the
 order of 500 millilitcrs per run with only three runs through
 the test column.

 Time/Cost

 The duration and  cost of  remedy screening depend prima-
 rily on the type of technology being investigated and the
 number of parameters considered. Generally, remedy screen-
 ing can be performed in  a few days  at a cost of between
 510,000 and 550,000.  This estimate of duration covers the
 time spent in  the testing laboratory; it does not include
 sample analysis or dam validation, as these elements depend
on the analyticaJ laboratory used. Neither docs it include the
time required for  study planning and reporting. The cost
estimate docs include all of these elements, however.

The nature of remedy screening (i.e., simple equipment,
small number of test samples and replicates, less-stringent
QA/QC requirements, and minimum reporting requirements)
makes  it the least costly and time-consuming of the three
instability study tiers. Cost and time savings arc increased
by limiting sampling and analysis objectives to address
only indicator contaminants  thai arc rcprcscniaiivc of the
families of chemicals present and their concentrations.
2.2.3   Remedy-Selection Testing

Remedy selection is the second step in the tiered approach.
A remedy-selection trcatability study is designed to verify
whether a process  option  can  meet  the operable unif
cleanup criteria and at what cost.  The purpose of this tier is
to generate the critical performance and cost data necessary
for remedy evaluation in the detailed analysis of alterna-
tives during the FS.

After the feasibility of a treatment  alternative has been
demonstrated, either through remedy-screening studies or a
literature review, process operating parameters are investi-
gated at the remedy-selection tier. The choice of param-
eters to be studied is based on  the goal of achieving  the
operable unit's cleanup criteria  and  other waste-specific
performance  goals.  Investigation of equipment-specific
parameters should generally be  delayed until posi-ROD
RD/RA studies.

Results of remedy-selection trcatability studies also should
allow for estimating  the costs associated with full-scale
implementation of the alternative within an  accuracy of
+50/-30 percent, as required for the FS.

As shown in Figure 2, remedy-selection trcatabilily studies
are initiated during the prc-ROD site characterization and
technology screening activities and continue through  the
evaluation of alternatives.  General characteristics  of  the
remedy-selection tier (outlined in Table 1) arc discussed here.

Study Scale

Remedy-selection trcatability studies are performed in  the
laboratory or field with bench-, piloi-, or full-scale  equip-
ment.  The scale of equipment used  is often technology-
specific, and it will also depend on the availability of funds
and time and the data needs.  Equipment should be de-
signed to simulate the basic opcraiions of the full-scale
treatment process. Combinations of bench and field testing
arc also possible at this tier.

Type of Data Generated

Remedy-selection studies provide quantitative data for use
in determining whether a technology can meet the operable
unit's cleanup criteria and at what cost.  The operational
and performance information resulting from remedy-selec-
tion studies will be used to estimate  full-scale treatment
costs and schedules and to assess the technology against the
RI/FS evaluation criteria.

For example, bench-scale remedy-selection studies of some
technologies can provide the dcuiilcd performance data
                                                      10

-------
needed to assess the technology againsi the reduction of
toxicity, mobility, or volume criterion.  Pilot-scale testing
may identify waste-stream characteristics that could ad-
versely affect the implementability of a technology. Treat-
ment train considerations, such as the need for further
processing of treated waste or treatment residuals, can also
be addressed at this tier.

When  planning remedy-selection treatability studies, the
project manager, in consultation with  management,  musi
determine the overall quantitative data needs for a technol-
ogy based on the intended use of the information and the
availability of lime and  funds.  Early consultation  with
technology experts and vendors  is important when deter-
mining data needs for innovative and proprietary technolo-
gies.

Number of Replicates

Remedy-selection treaiability studies require duplicate or
triplicate test sample replication. Because the daui gener-
ated at this tier will be used for remedy selection in the
ROD,  moderately to highly stringent levels of QA/QC are
required. A stringent level of QA/QC is needed to increase
the confidence in the decision that the selected remedy can
achieve the cleanup goals for the site.

Process Type/Waste Stream Volume

Remedy-selection treaiability studies may be conducted as
either a batch or a continuous process. Waste-stream sample
volumes should be adequaie to simulate full-scale opera-
lions.  For example, the waste-stream  volume needed to
perform continuous, bench-scale testing of an ion exchange
treatment process for an aqueous waste may be on the order
of 1  liter per minute for a treatment duration of 8 hours
(which would require approximately 500 liters of waste).
Waste-handling operations, such as pretreatment blending,
also should be designed to simulate those expected for full-
scale treatment.

Time/Cost

The duration and cost of remedy-selection testing depend
primarily on the type of technology being investigated, the
types of analyses being performed, and the level of QA/QC
required. Most bench-scale studies can be performed within
a period of days to weeks.   Pilot-scale  testing usually
requires a longer period (i.e., weeks  to months).   This
estimate covers only the actual performance of ihc lest. It
does not include sample analysis'or data validation, as
ihese elements depend  on the analytical laboratory used;
nor does it include study planning and reporting.  Depend-
ing on its scale  and  complexity, a  remedy-selection
ireaiability siudy can be performed ai a cost of between
550,000 and S250.000, including analytical suppo:;.

The higher cost and longer lime requirements of remedy-
selection treatability testing compared with remedy screen-
ing are directly related lo the need for stringent QA/QC and
the greater number of test samples and replicates to be
analyzed.

2.2.4   RD/RA Testing

Treatability lesling to support RD/RA activities is the final
step in ihe three-iiered approach.  The purpose of an RD/
RA treatability study is to generate the detailed design,
cost, and performance data necessary to optimize and imple-
ment the selected remedy.  As shown in Figure 2, RD/RA
instability studies are conducted after the ROD has been
signed.   These studies arc  performed 1) to select  among
multiple  vendors and processes within a prescribed remedy
(prcqualification), 2) to implement the most appropriate of
the remedies prescribed  in a Contingency ROD, and 3) to
support the Agency's detailed design specifications (if pre-
pared) and the design of treatment trains.   Most RD/RA
trcatability studies are performed by remediation contrac-
tors and technology vendors. The EPA RPM monitors the
performance of  these studies and  reviews  the results 10
assess  their acceptability with  regard 10 ihe ROD, RA
goals, and, if applicable, the settlement agreement.  Gen-
eral characteristics of the RD/RA tier (outlined in Table 1)
are discussed here.

Study Scale

Most RD/RA ircatabiliiy studies arc performed in the field
with pilot- or full-scale equipment.  Some prequalification
treaiabilily studies will  be performed in the laboratory;
however, the system should closely approximate the pro-
posed full-scale operations.

Type of Data Generated

Remedial design/remedial action ircatability studies pro-
vide the detailed, quantitative design and cost dam required
to optimize critical parameters and  to implement  the se-
lected remedy.  The following arc issues that may be ad-
dressed with RD/RA study data:

  • Full-scale performance

  • Treatment train performance

  • Materials-handling characteristics

  • Process upset and recovery
                                                      11

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  • Side-stream and residuals generation and treatment

  • Energy and reageni usage

  • Site-specific considerations, such as heavy equipment
    access and waste-feed staging space

  • Field-screening analytical methods

The parameters investigated at the RD/RA tier may include
feed rates (continuous processes), number of treatment
cycles (batch processes), mixing rates,  heating rates, and
other equipment-specific parameters.   Remedial design/
remedial action testing also may identify waste-stream char-
acteristics that could adversely affect the implementabilily
of the full-scale system.

When planning RD/RA treauibility studies, the technology
vendor, in consultation with the designer  and the  lead
agency, must determine the overall quantitative data needs
for a technology based on the intended use of the informa-
tion. Early consultation with vendors is important in the
determination of data needs for proprietary technologies.

Number of Replicates

Remedial design/remedial action  trealability studies  usu-
ally require duplicate or triplicate test sample replication.
The  data  generated at this tier  arc used to  design and
optimize the process; therefore, stringent levels of QA/QC
are required.

In the case of prcqualification trcatability studies, QA/QC
requirements will be determined by the designer. The num-
ber and  types of samples to be submitted by vendors will be
outlined in the designer's prequalification announcement.

Process Type/Waste-Siream Volume

Remedial design/remedial action  trcatability studies may
be conducted  as either a  batch or a continuous  process,
depending on the operation of the full-scale system.  Waste-
stream sample throughput and volume should achieve lev-
els projected for  full-scale operations.  For example, the
waste-stream sample volume needed to perform continu-
ous, full-scale testing of an ion exchange treatment process
for an aqueous waste may be on the order of 25 liters per
minute  for a treatment duration of 16 hours per day for 21
days (which would require more than 500,000 liters of waste).

Time/Cost

Because of the potentially significant mobilization require-
ments  associated  with any onsite operation, performing
RD/RA trcatabilily studies is significantly more time-con-
suming and costly than pre-ROD studies.  The duration and
cost depend primarily  on the type of technology  being
investigated, the types  of analyses being performed, and
the level of QA/QC required.  Most RD/RA studies can be
performed within a period of weeks to months. This esti-
mate covers only the actual performance of the test. It docs
not include the time required for mobilization, construc-
tion, shakedown, or  demobilization of the unit,  as these
procedures are specific to the site and to the technology
being tested; sample analysis or data validation,  as these
elements depend on the analytical laboratory used; or study
planning and reporting.  Most RD/RA trcatabiliiy studies
can  be performed at a  cost of between 5250,000 and
51,000,000.

Prequalification treatability testing is an exception to these
time and cost estimates because the tests are  performed at
the vendors' cost.  Analytical  support, however, is usually
provided by the Agency.
2.3   Applying the Tiered Approach

The purpose of a pre-ROD trcaiability investigation is to
generate data needed for a detailed analysis of the alterna-
tives and, ultimately, the selection of a remedial action thai
can achieve the operable unit's cleanup criteria.  Pre-ROD
trcatability studies are performed  to enable the decision
maker to evaluate all treatment and nontrcatmcni alterna-
tives on an equal basis.

The need for pre-ROD treauibility testing at a Supcrfund
site  is a risk-management decision in which the cost and
lime required  to conduct ircaiability studies arc weighed
against the risks  inherent in the selection of a remedial
technology.  Factors in this decision are specific  to the
waste matrix,  waste contaminants, and treatment technol-
ogy.  Determining  whether pre-ROD  trcatabilily studies
should be conducted may also depend on such nontechnical
factors as State and community acceptance of an alterna-
tive; time constraints on the completion of the Rl/FS and
the ROD; and the discovery of new operable unit-, wasic-,
or technology-based data that may have an impact on treat-
ment performance.

Of the management decision factors listed, schedule con-
straints may be of the most consequence. The performance
of pre-ROD trcatability studies thai were planned and sched-
uled early (i.e., during the scoping of the RI/FS) generally
should not delay the ROD. In some instances, however, the
need for treatability studies  may conflict with RI/FS and
ROD schedule commitments.  For example, if an innova-
tive technology is being considered as pan of an altcrna-
                                                      12

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live, significant gaps in the technical literature may lengthen
the lime required to plan and perform a thorough trcaiability
investigation.   When the potential  benefits of the  inno-
vative technology are known, pursuing the treatability study
at the expense of ROD scheduling goals may be appropri-
ate. The EPA's Guidance for Increasing the Application of
Innovative Treatment Technologies for Contaminated Soil
and Ground Water (EPA 199la) and il&  cover memoran-
dum indicate the Agency's willingness to adjust program
goals and  commitments, when appropriate, to achieve bet-
ter cleanup solutions through innovative treatment technol-
ogy development.

The  flow  diagram in Figure  3  traces the stepwisc data
reviews and management decisions that occur in the tiered
approach.   Site  characterization  and technology
prescreening/trcatabiliiy study scoping initiate the process.
Technologies that are determined to be potentially appli-
cable (based on effectiveness, implemcntability, and cost)
are retained as alternatives; all others arc screened out. The
decision to conduct a ircatability study on an alternative is
based on the availability of technology-specific ircatabiliiy
information  and on inputs from  management.  If a  treat-
ment technology is well demonstrated for the particular
contaminants/matrix and sufficient  information exists to
permit ils  evaluation against the nine evaluation criteria in
the detailed analysis of alternatives, a pre-ROD treatability
study is not required.

If significant questions remain about the feasibility of a
technology for remediating an operable unit, a remedy-
screening  treatability study should be performed. Innova-
tive technologies or wastes that have not  been extensively
investigated should almost always be subjected to trcaiability
testing at  this tier.  If a technology has been shown to be
effective at treating the contaminants/matrix of concern but
insufficient  information  exists for detailed analysis,  the
remedy-screening tier may be bypassed in favor of a rem-
edy-selection treatability study. If a remedy-selection study
indicates that a  technology can meet the cleanup criteria, a
detailed analysis of in is alternative  should then  be per-
formed. If ihe  altcmaiivc is selected in ihe ROD, a post-
ROD RD/RA ircaiability study may be required to design
and optimize ihe full-scale system, to obtain detailed cost
data, and to confirm performance.
2.4   Treatability Study Test Objectives

Each tier of ircatabiliiy testing is defined by its particular
purpose: remedy screening, to determine potential feasibil-
ity; remedy selection, to  develop performance and  cost
data; and RD/RA, to develop detailed design and cost daia
and to confirm full-scale performance. For achievement of
these purposes, the planning and design of trcatabiliiy stud-
ies  must reflect specific,  predetermined test objectives.
Depending on the tier of testing, test objecii vcs may call for
making qualitative engineering assessments, achieving quan-
titative performance goals, or both. Because test objcctives
are  technology-, matrix-, and contaminant-specific, setting
universal objectives for each tier of testing is impossible.

Qualitative assessments of performance arc often appropri-
ate  at the remedy-screening tier.  Simply demonstrating a
reduction in contaminant concentration, for example, may
be sufficient to confirm the potential feasibility of using an
innovative treatment technology.  For other technologies, a
quantitative performance goal such as 50 percent reduction
in contaminant mobility might indicate the potential to
achieve greater reduction through process refinements and
thus confirm the feasibility of a process option and justify
additional testing at the remedy-selection tier.

Test objectives at the remedy-selection tier will include
achieving quantitative performance goals based on the an-
ticipated cleanup criteria to be established in the ROD. For
example, if the cleanup criterion for a contaminant in the
soil at a site is 1 ppm, the performance goal for a remedy-
selection treatability study might also be 1  ppm.  If no
cleanup criteria have been established for the  site, a 90
percent reduction in the contaminant  concentrations  will
generally be an appropriate performance goal.  This level
of performance is in agreement with EPA's guideline es-
tablished in the 1990 revised NCP, which states that ". .  .
treatment as part of CERCLA remedies should generally
achieve reductions of 90 to 99 percent in the concentration
or mobility of individual contaminants of concern, although
there will be situations where reductions outside the 90 to
99 percent range that achieve  health-based or  other site-
specific remediation goals (corresponding to  greater or
lesser reductions) will be appropriate"  (55 FR 8721).  Ad-
ditional guidelines upon which a project manager should
base remedy-selection performance goals arc as  follows:

  •  Protection of human health and  the environment

  •  Compliance with ARARs

  •  Attainment of contaminant levels acceptable for waste
    dclisting

  •  Attainment of contaminant levels accepted by the State
    or Region at other sites with similar waste characteristics

Remedy-selection ircaiability studies will generally have
additional prc-ROD test objectives designed to provide the
specific cost and engineering information necessary for a
detailed analysis of the alternative.  Cost data should be
                                                      13

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SITE
CM»R»CTEfW«ON



TECHNOIOGY PRESCREENNCV
TBEATMUFTY STUDY SCOP NG
                                                             MANAGEMENT DECISION FACTORS:

                                                              •  Stale and Community Acceptance
                                                              •  Schedule Constraints
                                                              •  Additional Data
REMEDY-SCREENING
   TREAWBimr
     STUDIES
                          REMEDY-SELECTION
                            IflEATABILtTY
                              STUDIES
                                                                                RD/RA
                                                                             THEATABILmr
                                                                                STUDIES
         Figure 3.  Flow diagram of the tiered approach.

-------
sufficiently detailed to allow for the development of cost
estimates with an accuracy of +51' to -30 percent.

Post-ROD  test objectives  depend  on  the  nature of the
instability study. If a study is conducted to prcqualify
vendors, performance goals will be equivalent to the cleanup
criteria defined in the ROD. Treatabilily studies conducted
to select the most appropriate technology among those in a
Contingency ROD will also have performance goals equiva-
lent to the cleanup criteria.  Additional test objectives may
include investigation of materials-handling methods, con-
firmation of field-screening analytical techniques, and gen-
eration of detailed cost data. If an RD/RA instability study
is required to support the detailed design specifications, the
designer will be responsible for defining the  test objectives
and performance goals.  Test objectives will be focused on
obtaining specific design daia, optimising performance,
and minimizing cost.  Treatment train  issues such as unit
sizing, materials handling, and systems integration can also
be addressed through specific test objectives. A trcatabiliiy
study of an entire train can provide data to confirm compli-
ance with ARARs and the cleanup criteria outlined in the
ROD.
2.5   Special  Issues

2.5.7   Innovative Treatment
         Technologies

One of the advantages of treatability testing is that it per-
mits the collection of performance data on innovative treat-
ment technologies.  These newly developed technologies
often lack sufficient full-scale application to be routinely
considered for site  remediation.  Nevertheless, Guidance
for Increasing the  Application  of Innovative Treatment
Technologies for Contaminated Soil and Ground Water
(EPA 199la) states:

    "Innovative treatment technologies are to be rou-
    tinely considered as an option in feasibility stud-
    ies for remedial sites and engineering evaluations
    for removals in the Superfund program, where
    treatment is appropriate  commensurate with  the
    National Contingency Plan (NCP) expectations... .
    Innovative technologies considered in the remedy
    selection process for Superfund, RCRA, and UST
    should not be eliminated solely on the grounds
    that an  absence  of full-scale experience or
    treatability  study  data makes their operational
    performance and cost less certain than other forms
    of remediation.

    "When assessing  innovative  technologies, it is
    impurtant to fully account for their benefits.  De-
    spite the  fact that their costs may be greater than
    conventional options, innovative technologies may
    be found to be cost-effective, after accounting for
    such factors as increased protection, superior per-
    formance, and greater  community acceptance. In
    addition, experience gained  from the application
    of these solutions will help realize their potential
    benefits at other sites with similar contaminants."

Example 1 illustrates how instability studies can be used to
investigate innovative and  conventional technologies con-
currently on a single waste stream.  Three innovative treat-
ment technologies-thermal dcsorption, solvent extraction,
and biorcmediauon-arc investigated at various tiers. Deci-
sions on testing are based on existing data in the literature
and on prior ircaiubility study results. Solidification/suibi-
li/ation, a conventional  option, is  also tested because its
performance for the particular waste stream was not estab-
lished in the literature. This example reflects how trcatability
studies can be designed and tailored by the project manager
to provide specific pieces of information required  for rem-
edy selection.

2.5.2   Treatment Trains

Treatment of a waste stream often results in residuals  that
require further  treatment to  reduce toxicily, mobility, or
volume.  Treatment technologies operated in scries (treat-
ment trains) can be used  to provide complete treatment of a
waste stream  and  any resulting residuals.

Treatment-train requirements for a waste stream may be
evaluated by applying the tiered approach.   Example 2
outlines a remedy-selection trcatabiliiy study of a treatment
train consisting of low-icmpcraiurc volatilization followed
by chemical  treatment and solidification. The literature
contains enough data concerning the individual unit opera-
tions to indicate that they arc appropriate  technologies for
the specific contaminants.  Treauibilily  testing of these unit
operations as a treatment  train, however, is  necessary to
evaluate  the most effective combination of operating pa-
rameters for treating the matrix.

2.5.3   In Situ Treatment  Technologies

Testing of in  situ  treatment technologies during ihc RI/FS
may entail remedy screening, bench-scale remedy-selec-
tion testing, and pilot-scale remedy-selection testing in the
Held.  Remedy screening of in situ treatment technologies
is conducted  in the laboratory to determine process feasi-
bility.  Bench-scale testing is generally conducted in soil
columns  designed to simulate the subsurface environment.
Field testing,  however, is important for an adequate cvalua-
                                                      15

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            EXAMPLE 1. TREATABILITY STUDIES OF MULTIPLE TECHNOLOGIES

                                Old Petroleum Refinery Site

Background

An old petroleum refinery site contained oily sludges and contaminated soils. The primary contami-
nants of concern were polynuclear aromatic hydrocarbons (PAHs), mainly benzo(a)pyrene. The
literature survey identified five potentially applicable technologies for treating the hydrocarbon
wastes: 1) incineration, 2) stabilization/solidification, 3) thermal desorption, 4) solvent extraction,
and 5) bioremediation.

The literature survey also produced a significant amount of performance data for incineration and
bioremediation. Because these data indicated that both technologies were valid for the types of
wastes and contaminants of concern at the site, neither incineration nor bioremedialion was evalu-
ated at the remedy-screening tier.

Conversely, little data w^re found on thermal desorption, and the available performance data for
solvent extraction and stabilization/solidification were inconclusive for hydrocarbon wastes. There-
fore, these three technologies were evaluated at the remedy-screening tier to determine their
feasibility for treatment of the site's wastes.

Remedy Screening

Samples of worst-case soils and sludges (most highly contaminated with PAHs) were collected for
treatability studies of each technology.  A performance goal of 90 percent reduction in the indicator
contaminant benzo(a)pyrene was set.

Thermal desorption was evaluated at three temperatures. Solvent extraction was evaluated by
using three solvents at two solution concentrations. Stabilization/solidification was evaluated by
using organophilic clays at three mix ratios with 28-day curing.  Benzo(a)pyrene concentration in
duplicate samples of the untreated soil was determined by total waste analysis (EPA SW-846
Method 8270). Duplicate samples of the treated material from thermal desorption, solvent extrac-
tion, and stabilization/solidification (after sonication of the solidified monolith) were then analyzed
for benzo(a)pyrene by Ihe same  method.

The results of the remedy screening showed that, of the three technologies, thermal desorption
achieved the. highest percentage removal of the indicator contaminant  (greater than 95 percent)
Solvent extraction showed a 90 percent removal efficiency. Stabilization/solidification, however,
fixed only 50 percent of the contaminant. Thermal desorption and solvent extraction were thus
retained for further analysis because both technologies achieved the screening performance goal.

Remedy-Selection Tenting

Quantitative performance, implementability, and cost issues still remained unanswered after the
remedy screening.  Also, information from  the literature on biodegradation rates and mechanisms
for benzp(a)pyrene (the principal PAH of concern) was inconclusive. In addition, the anticipated
cleanup criterion for benzo(a)pyrene in soils was very low (250 ppb). Therefore, thermal desorp-
tion, solvent extraction, and bioremediation were examined in bench-scale, remedy-selection
testing.  Performance goals were set at 250 ppb benzo(a)pyrene with a 95 percent data confidence
level. Waste samples representing average and worst-case scenarios were tested, triplicate test
samples were collected and analyzed, and several process variables were evaluated. After 6
months of testing, only low-temperature thermal treatment was found to meet the low cleanup levels
required for benzo(a)pyrene.

Although thermal desorption was found to  meet the cleanup requirements in bench-scale  testing,
this technology had not been previously demonstrated at full scale for similar contaminants and
waste. Therefore, cost and design issues  had to be addressed as pan of the detailed analysis of
alternatives. The RPM decided to conduct pilot-scale testing on thermal  desorption and to compare
the costs of constructing and operating the unit with those for incineration.
                                            16

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              EXAMPLE 2. TREATABILITY STUDIES FOR TREATMENT TRAINS
                         Former Chemical Manufacturing Company

Background
At a former chemical manufacturing company and current Supertund site, the contaminants of
concern in the soils were dichloromethane, tetrachloroethene, benzene, polynuclear aromatic hydro-
carbons (PAHs), cyanide, and arsenic. The cleanup criterion for each of these compounds had been
identified.  Both onsite treatment and offsite incineration were being considered as options for site
remediation.
Remedy-Selection Testing
Remedy-selection testing of a treatment train to treat the contaminated soils on site was designed to
include the following unit operations: 1) thermal desprption, 2) chemical treatment, and 3) stabiliza-
tion/solidification.  A schematic of the treatment train is presented below.


                                   CONTAMINANTS OF CONCERN
                            ORGANICS
ARSENIC
                                                          STABILIZATION/
                                                          SOLIDIFICATION
                      Schematic Representation of the Treatment Train


Bench-scale treatability testing of the treatment train was designed to meet the following three
objectives:
  •  Objective 1 - Provide performance confirmation of the operation of the thermal desorptioh unit for
    removal of volatile and semivolatile organics.  Determine the minimum operating conditions
    (temperature, residence time) necessary to achieve the site cleanup criteria. Determine the need
    for subsequent treatment units (chemical treatment, solidification).
  •  Objective 2 - Provide performance confirmation of the operation of the chemical treatment unit for
    destruction of cyanide. Determine the preferred reagent and dosage necessary to achieve the
    site cleanup criteria.
  •  Objective 3 - Provide performance confirmation of the operation of the stabilization/solidification
    unit for immobilization of arsenic.  Determine the preferred binder and dosage necessary to
    achieve the site cleanup criteria.
Prior to initiating any treatability tests, the test plan called for the soil to be characterized for the
following physical and chemical parameters:
  •  Moisture content
  •  Soil bulk density
  •  Grain size distribution
  •  Volatile and semivolatile organics
  •  Cyanide
  •  Arsenic (total and TCLP)
The remedy-selection testing consisted of the following three subtasks:
 1)  Perform bench-scale tests of thermal desorption at two temperatures (300 and 550°C) and three
    residence times (5,15, and 30 minutes) to determine the efficacy of the unit for removal of
                                            17

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 Example 2 (continued)
        organics.  Analyze the treated soil lor the pollutants of concern (organics, cyanide, and arsenic).
        If cyanide is present in the soil residue at concentrations exceeding the cleanup criterion, con-
        tinue with Subtask 2. Similarly, if arsenic is present, continue with Subtask 3.  (This subtask
        addresses Objective 1.)
      2) Perform bench-scale tests on the soil residue from the thermal desorption unit to investigate the
        effectiveness of hydrogen peroxide and hypochlorite for treatment of cyanide as a function of  pH,
        the strength of solution, and the reagent-to-soil ratio.  Analyze the treated soil for cyanide. (This
        subtask addresses Objective 2.)
      3) Perform bench-scale tests of stabilization/solidification to immobilize arsenic in the soil residue
        from'chemical treatment (if cyanide was  present) or thermal desorption (if cyanide was not
        present) using three binders (Portland cement, lime/fly ash, and fly ash/kiln dust) at  two binder-to-
        soil ratios (0.20 and 0.50).  Determine the unconfined compressive strength of the solid monolith.
        Extract the crushed solid in accordance with the toxicity characteristic leaching procedure and
        analyze the leachate for arsenic. (This subtask addresses Objective 3.)
     Data from the remedy-selection treatability tests were used 1) to determine if the proposed treatment
     train could achieve the test objective of reducing all contaminant concentrations to the site cleanup
     criteria, and 2) to provide a preliminary basis for estimating the costs of full-scale remediation.
 lion of in situ treatment. Because of the unique difficulties
 associated with simulating in situ conditions and monitor-
 ing the effectiveness of in situ treatment in the laboratory,
 field testing often may be the only way to obtain the critical
 information needed for the detailed analysis of alternatives
 during the FS.  Example 3 demonstrates  how the tiered
 approach may be applied to evaluate in situ soil Hushing.

 2.5.4  Generic Vs.  Vendor Treatability
        Studies

 When planning a ircatability study,  the project manager
 musi determine whether results from treatability tests in
 which widely available chemicals and processes are used
 ("generic" studies) will be as useful as  vendor-conducted
 tests involving the use of proprietary chemical reagents and
 treatment systems ("vendor" studies).

 Because generic trcatabiliiy studies eliminate the need for
 establishing contracts and schedules with a specific vendor,
 they can  often be performed quickly and  inexpensively;
 however, they may not always provide an adequate evalua-
 tion of a  technology. For example, a generic trcatability
 study may fail to meet site cleanup goals that could have
 been achieved by an experienced technology vendor using
proprietary processes and equipment developed  through
years of research.

Generally, remedy-screening trcatabiliiy  studies can be per-
 formed generically because quantitative performance data
are not required. Vendor-specific equipment or experience
are often required, however, at the remedy-selection tier to
assure the generation of high-quality quantitative data and
the best performance of the technology. Remedial design/
remedial action trcalability studies should generally be per-
formed in consultation with technology vendors. Tables 2
and 3 were adapted from tables developed by personnel ai
ihc U.S. EPA's Risk Rcduciion Engineering Laboratory
(RREL) to provide general technology-specific guidance
on this issue (dePcrcin, Bates, and Smiih 1991). Informa-
tion in these tables should not be used without consider-
ation being given to site-specific contaminant and matrix
ircaiabiliiy data.

Under 48 CFR Scciion  1536.209 of ihe Federal Acquisiiion
Regulations, subcontractors performing ircaiability sludics
in support of remedy scleciion or remedy design arc not
prohibiicd from being awarded a coniract on ihc construc-
lion of ihc remedy (55 FR 49283). For prime contractors
performing ircaiability sludics, however, approval by ihc
Responsible  Associate Director in the EPA Procurement
and Contracts Management Division  may  be necessary
before they can be awarded the consiruciion coniract.  In
reviewing requests  for approval, EPA will  lake into ac-
couni its policy of promoiing the  use of innovative tech-
nologies in the Supcrfund program.

2.5.5  PRP-led  Pre-ROD Treatability
        Studies

Prc-ROD ircaiabiliiy sludics may be conducicd by potcn-
lially responsible panics wiih EPA oversight to evaluate
PRP-proposcd alternatives at cnforccmcnt-lcd sites. The
steps involved in a PRP-lcd study include  performing a
                                                    18

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      EXAMPLE 3. TREATABILITY STUDIES FOR IN SITU TREATMENT TECHNOLOGIES

                                    In Situ Soil Flushing

Background
An estimated 80,000 cubic meters of soil contaminated with chlorinated phenols, semivolatile organ-
ics, sultur-containing compounds, and lead at an industrial facility requires corrective action. In situ
soil flushing has been proposed as an alternative treatment technology. A two-tiered treatability study
has been designed to evaluate its effectiveness.
Remedy Screening
Remedy screening will be performed to evaluate the effectiveness of various flushing reagents for
enhancing the removal of the contaminants.  A performance objective of 90 percent or greater
reduction was set for evaluation of flushing reagent feasibility. Any reagent that achieves this level of
contaminant reduction for each target contaminant will be evaluated at the remedy-selection tier. All
others will be screened out. (Analyses of all samples for all site-specific contaminants will not be
economically feasible; therefore, target compounds, each representative of a class of compounds
present at the site, will be identified.)
The following general testing procedure will be used:
 1) Analyze untreated soil samples for target compounds.
 2) Place a known mass of soil in a small glass bottle. Add a measured volume of flushing reagent.
    Shake for a set period of hours. Centrifuge the mixture.
 3) Analyze the supernatant liquid phase for target contaminants.
 4) Analyze the treated soil phase for target  contaminants.
Remedy-Selection Testing

Bench Scale
All flushing reagents identified as feasible during the remedy-screening treatability study will be
evaluated in a bench-scale column test. The performance objective of this tier is to achieve contami-
nant reduction levels equal to the anticipated site cleanup criteria.
The following general testing procedure will be used:
 1) Analyze untreated soil samples for target compounds.
 2) Pack a large glass column with untreated soil to approximate the actual density of soil in the
    contaminated area. Introduce the soil-flushing solution into the top of the column.
 3) Collect the column leachate at regular intervals (e.g., daily) and analyze for target contaminants.
 4) Terminate the column test when the contaminant concentrations in the leachate remain the same
    for three consecutive leaching  periods. Remove representative samples of the treated soil from
    the glass column and analyze them for target contaminants.
All flushing reagents that reduce the target contaminant concentrations in the soil to the site cleanup
levels will be evaluated  in the field.
Pilot Scale
The twofold purpose of this field pilot-scale treatability study is to evaluate the hydraulics of the
treatment process under site conditions and to verify reagent  performance under site conditions.  The
field test will yield site-specific flow, injection, and capture rates for the flushing system. These rates
must be established to quantify the total time necessary for site-wide treatment and to estimate full-
scale treatment costs.  These and other data will be used in the detailed analysis of  alternatives.
The field treatability study will involve the following tasks:
 1) Prepare a treatment cell. Install an interception trench.
 2) Install the irrigation and soil-flushing system.
 3) Collect the cell leachate at regular intervals and analyze for all contaminants of interest.
 4) Terminate the field test when the target contaminant concentrations in the leachate remain the
    same for three consecutive leaching periods. Remove representative samples of the treated soil
    from the cell and analyze them for all contaminants of interest.
                                             19

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   Table 2. Aqueous Field Treatability Studies:
       Generic Versus Vendor Processes8

Treatment technology
Physical
Oil/water separation
Sedimentation
Filtration
Solvent extraction
Distillation
Air/steam stripping
Carbon adsorption
Ion exchange
Reverse osmosis
Ultra filtration
Chemical
Neutralization
Precipitation
Oxidation
Reduction
Dehalogenation
Thermal
Incineration
Biological
Suspended growth
systems
Aerobic
Anaerobic
Fixed growth systems
Aerobic
Anaerobic
Constructed wetlands
Pact
In situ biological
Remedy
screening

NA
NA
NA
G
G
G
G
G
G
G

NA
G
G
G
G

G



G
G

G
G
G
G
NA
Remedy
selection

G
G
G
G/V
G
G
G
G
G/V
V

G
G
G
G
G/V

G/V



G
G

G/V
G/V
G
G/V
G

RD/RA

G
G
G
G/V
G/V
G/V
G
G/V
V
V

G
G
G
G
V

V



G
G/V

G/V
G/V
G
V
V
  aG =  Generic studies appropriate.
    V =  Vendor studies appropriate.
 G'V =  Generic ana vendor studies appropriate.
  NA =  Not applicable at this tier.
literature search, submitting the Technical Memorandum
identifying candidate technologies, designing the study,
preparing  the Project  Plans  (Work  Plan,  Sampling and
Analysis Plan, and Health and Safety Plan), performing the
lest, analyzing the data, and preparing a final report on the
results.

During the study, the EPA project manager will  provide
oversight and assistance.  The EPA's Guidance on Over-
sight of Potentially Responsible Party Remedial Investiga-
tions and  Feasibility Studies (EPA  I991b) recommends
thai the EPA project manager and the oversight assistant
perform the following activities to oversee PRPs:

  •  Provide the PRPs with relevant  guidance documents
    and sources of other technical  information (Appendix
    A presents sources of ircatability information).
  •  Review and approve the Technical Memorandum pre-
    pared by Ihc PRP that identifies  candidate treatment
    technologies and describes the literature search.

  •  Meet with the oversight assistant, the Technical Sup-
    port  Team (TST), and representatives from ORD to
    review the list of candidate technologies.  Innovative
    treatment technologies  should be adequately  repre-
    sented.  Decisions on the  need for ircatabiliiy studies
    should be made for each technology.

  •  Review and approve the PRP's schedule of trcatability
    activities.

Table 3.  Soils/Sludges Field Treatability Studies:
       Generic Versus Vendor Processes"

Treatment technology
Physical
Oil/water separation
Sedimentation
Filtration
Solvent extraction
Soil washing
Vacuum extraction
Distillation
Air/steam stripping
Thermal stripping
Carbon adsorption
Ion exchange
Chemical
Neutralization
Precipitation
UV photolysis
Ozonation
Oxidation
Reduction
Dehalogenation
Thermal
Incineration
Biological
In situ treatment
Composting
Stabilization
Pozzolanic tor
inorganics
Pozzolanic for organics
Asphalt
Polymerization
Vitrification
Material handling
Screening
Conveying
Remedy
screening

G
G
G
G/V
G
G
G
G
G
G
G/V

G
G
G
G
G
G
G/V

G

G
G/V

G

V
G
V
G/V

NA
NA
Remedy
selection

G
G
G
V
G/V
V
G
G/V
V
G/V
V

G
G/V
V
G/V
V
V
V

G/V

G
G'V

G/V

V
V
V
V

G
G

RD/RA

V
V
V
V
V
V
V
V
V
V
V

V
V
V
V
V
V
V

V

V
G/V

V

V
V
V
V

G/V
G/V
      =   Generic studies appropriate.
   V  =   Vendor studies appropriate.
 G/V  =   Generic and vendor studies appropriate.
  NA  -   Not applicable at this tier.
                                                     20

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  • Revise and amend the original PRP Pro.icci Plans to
    address the treatability study work to be performed.

  • Verify the qualifications of all personnel involved in
    the test, including the PRP, the PRP's contractor, and
    the analytical laboratory. In addition, the EPA project
    manager should verify that the PRP laboratory proto-
    cols conform to EPA standards.

  • Verify the  test objectives and performance goals of
    each study.

  • Conduct a site visit during the initial stages of a study.

  • Collect and analyze split  samples before  and after
    treatment.

  • Review and validate the data generated by each study.

  • Monitor compliance with ARARs.

  • Review and approve the draft PRP Treatability Study
    Evaluation Report whh input and comments from the
    TST, ORD, other suppon staff, and the Stale.  (The
    report should be prepared in the standard formal pre-
    sented in Subsection 3.12.)

  • Continually update the Administrative Record File and
    cost recovery documentation.

ConductorPRP-led treatability studies will be based on the
language of the Administrative Order on Consent (AOC)
and the Statement of Work (SOW).  The model Adminis-
trative Order  on Consent for Remedial Investigation/Fea-
sibility Study (EPA 1991c) contains standard language for
requiring PRPs to conduct treatabiliiy studies. The Model
Statement of Work for a Remedial Investigation and Feasi-
bility Study Conducted by Potentially Responsible Parties
(EPA 1989c) provides standard language for requiring PRPs
to perform treatability studies in accordance with the Rl/FS
guidance. (Note: The Model SOW docs not yet incorpo-
rate the treatabiliiy study terminology and guidance  pre-
sented in this document. Until the Model SOW is updated,
every effort should be made to require PRPs to conduct
instability studies in accordance with this guidance.)

2.5.6   Treatability Study Funding

The planning process  for ircaiabilisy sludies should begin
during  the budget cycle in  ihc year prior 10 ihc planned
performance. The poiential need for and scope of ircauibility
sludies should be idcniificd and their costs estimated  10
ensure  that adequate  resources will  be available.  This
informaiion will be used to prepare the Region's Supcrfund
Comprehensive Accomplishments Plan (SCAP).

Federally funded trcauibility studies performed in support
of the RI/FS or the RD/RA are funded as a line item in the
Region's "Other Remedial Account"  Should treauibility
study funding requirements exceed planned allocations (be-
cause of the cosi of Ihe sludies or the  need for studies that
were not planned for in ihc SCAP), ihc SCAP should be
updated to reflect the necessary additional funding.

Funding  for ircatabilily studies is currently separate from
Rl/FS funding and is not included in the RI/FS target cost
of 5750,000.  The Agency is considering a revision of ihis
procedure, based on the need lo fund direct site work through
a Siie-Spccific  Allowance.   This will facilitate efficient
iracking of direct site costs.
                                                     21

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                                          SECTION 3
   PROTOCOL  FOR CONDUCTING TREATABILITY STUDIES
3.1    Introduction

Trcatability studies should be performed in a systematic
fashion to ensure that the data generated can support rem-
edy selection and implementation. This section describes a
general protocol for conducting  trcalability studies that
EPA project managers, PRPs, and contractors should fol-
low. The protocol  includes:

  •  Establishing data quality objectives

  •  Identifying sources for treatability studies

  •  Issuing the Work Assignment

  •  Preparing the Work Plan

  •  Preparing the Sampling and Analysis Plan

  •  Preparing the Health and Safety Plan

  •  Conducting community relations activities

  •  Complying with regulatory requirement

  •  Executing the study

  •  Analyzing and interpreting the data

  •  Reporting the results

These elements  arc described in  detail in the remaining
subsections.  General  information  applicable 10 all
treatabilily studies  is presented first, followed by informa-
tion specific to remedy screening, remedy-selection test-
ing, and RD/RA testing.

Pre-ROD treatability studies for a particular site will often
entail multiple tiers of testing, as described earlier in Sub-
section 2.3.  Duplication of effort can be avoided by recog-
nizing this possibility  in the early planning stages of the
project.  The  Work Assignment, Work Plan, and other
supporting documents should include all expected activities.
Generally, a single contractor should be retained to ensure
continuity of the project as it moves from one tier to another.
3.2    Establishing Data Quality
       Objectives

Data quality objectives (DQOs) arc qualitative and quanti-
tative statements that specify the quality of the data required
to support decisions concerning remedy selection and imple-
mentation. The end use of the ircatabilily study data to be
collected will determine the appropriate DQOs. At all tiers of
ircatabilily lesiing, the establishment of DQOs will help to
ensure that the data collected  arc of sufficient quality 10
substantiate ihc decision. Established DQOs arc incorporated
into the Work Plan, the study design, and the Sampling and
Analysis Plan (SAP). Because trcalability icsting is used to
help select and implement a site remedy, establishing DQOs
is a critical initial step in the planning of ircatabilily studies.

The quality and quantity of trcatability daia required  for a
study should correspond to the  significance and ramifica-
tions of Ihc decisions that will be based on these data.
Limited QA/QC is generally required for remedy-screen-
ing data used to decide whether a treatment process is
potentially feasible and warrants further consideration. More
rigorous QA/QC is required for remedy-selection testing
data used 10 determine whether a technology can  meet the
expected cleanup criteria or to compare the costs of several
treatment alternatives, as ihcsc data have a greater impact
on ihc decisions required for icchnology sclcciion. Rigor-
ous QA/QC is also required for RD/RA lesiing when quan-
litativc performance, design, and cost daia will he used in
ihc implementation of the selected remedy.

3.2.1   General

The guidance document Data Quality Objectives for Reme-
dial Response Activities (EPA  1987a)  defines the framc-
                                                  23

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work and process by which  DQOs are developed.  This
document (hereinafter referred to as the DQO guidance)
focuses on site investigations during the RI/FS; however,
the same framework and process may be applied to DQO
development for treatability studies. The DQO guidance
describes a process that includes the following three stages:
1) identification of decision types and study objectives, 2)
identification of data uses/needs, and 3) design of the data-
collection program. The three stages of DQO development
summarized in Table 4 can be applied to each of the three
tiers of testing. The stages provide a systematic process for
development of-the DQOs for treatability studies.

Stage 1

The  type and magnitude of the decisions to be made are
determined in Stage 1. Tasks include identifying the data
users and coordinating their efforts for the establishment of
the DQOs, evaluating existing data, developing a concep-
tual  model, and  specifying the test objectives (including
performance goals) of the treatability study. Stage 1 efforts
should result in  the specification of the decision-making
process and the identification of any new data needed and
why. Stage 1 of the DQO process corresponds to technol-
ogy prescreening and treatability study scoping as described
in Subsection 2.2.1.

The data users will be those who rely on treatability results
to support their decisions. They may include the RPM, the
OSC, the PRP project manager, technical specialists, the
State, enforcement personnel, U.S. Army Corps of Engi-
neers, and others. Project review and audit personnel should
be involved to help ensure the integrity of the QA progr. m
and compliance with program policy.

Stage 1  also  includes a detailed evaluation of available
information.  Useful information may include site charac-
terization data, technology-specific information, and previ-
ous treatability study data.  Several factors should be con-
sidered in an evaluation of the quality of these data and
their relevance to the  DQO establishment process, inclu<:-
ing the age of the  data, the analytical methods used, the
detection limits of  those methods, and the QA/QC proce-
dures applied.

A conceptual model of the site and site conditions should
be developed and  included in Stage 1.   A  model may
already have been developed for the site; if so, it should be
adopted for use in the ircatabiliiy study DQO development
process.

Test objectives for  the trcatability study are determined in
Stage 1.  Identifying these objectives also entails identify-
ing the problems to be solved (i.e.,  whether the study is
needed to determine the potential feasibility of the technol-
ogy or to confirm the attainment of a treatment standard).
Test objectives will include achieving quantitative perfor-
mance goals and collecting data to support qualitative engi-
neering assessments and cost estimates.

Stage 2

During Stage 2, the data required to meet the test objectives
specified in Stage  1  arc determined, and the criteria for
                     Table 4.  Summary of Three-Stage DQO Development Process
                                                   Stage 1
           Identify data users.
           Consult appropriate data bases for relevant information.
           Develop a conceptual model of the site.
           Identify the treatability study test objectives and performance goals.
                                                   Stage 2
           Identify data uses.
           Identify data types.
           Identify data quality needs.
           Identify data quantity needs.
           Evaluate sampling and analysis options.
           Review precision, accuracy, representativeness, completeness, and comparability
           parameters.
                                                   Stage 3
           Determine DQOs; select methods for obtaining data of acceptable quality and quantity.
           Incorporate DQOs into the Work Plan and the SAP.
                                                     24

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determining daia adequacy are stipulated. Data must be of
sufficient quality  to determine whether the lest objectives
have been met.

Data types are identified by broad categories such as envi-
ronmental media  samples or source samples.  Specifying
data type by medium helps to identify overlapping data
needs and analytical efforts.

Data quality and quantity are defined  in Stage 2. The
EPA's  Quality Assurance  Procedures for  RREL (EPA
1989d) establish four quality assurance categories for use
in research and development projects.  Categories IV, III,
and II are applicable to trcauibility studies. In general, QA
Category IV applies to remedy-screening trcatabilily stud-
ies, and QA Categories III  and  II apply to botli remedy-
selection and RD/RA ircauibility studies.  In determining
the  appropriate QA  category, the  decision maker must
consider the intended use of the data and the risks associ-
ated with selecting an ineffective  remedy based on the
quality and quantity of the trcatability data collected.

When the data quality needs for a  project have been de-
fined, confidence limits can be established for ihe data to be
generated. Specific confidence limits have not been estab-
lished for each treatability study tier. Rather, the intended
use of  the data and  the limitations and costs of various
analytical methods will assist the decision maker in defin-
ing  appropriate confidence limits for the tier  of  testing
being planned.   Sampling and analysis options are re-
viewed in Stage 2 of the DQO development process. Issues
to be considered during the review process include the data
                              uses; duu types; data quality needs; data quantity needs;
                              precision, accuracy, representativeness, completeness, and
                              comparability (PARCC) parameters (Table 5);  analytical
                              costs; and the time required for analysis.

                              The PARCC parameters arc defined by the intended use of
                              the data and are indicative of data quality.  As the data
                              quality and quantity needs increase, the PARCC parameter
                              goals must rise. It is not practical to set universal PARCC
                              goals for treatability testing because  of the variability in
                              sites, technologies, and contaminants.

                              Stage 3

                              Methods for obtaining data of acceptable quality and quan-
                              tity are chosen and incorporated into the project Work Plan
                              and SAP during Stage  3.  The purpose of. Stage 3 is to
                              assemble the data collection  components into a compre-
                              hensive data collection program.  As data quality needs
                              increase, the need for detailed goals and  documentation
                              components in the collection program will increase.

                              3.2.2  Remedy Screening

                              The DQOs established  for remedy screening arc usually
                              stated in qualitative terms. Remedy screening provides a
                              qualitative engineering  assessment of the potential feasi-
                              bility of a technology  (i.e.,  go/no go).  Therefore, QA
                              Category IV usually provides data of sufficient quality for
                              remedy screening. According to Quality Assurance Proce-
                              dures for RREL, QA Category IV  is designed  to support
                              basic research  that may change direction several times in
                                      Table 5.  PARCC Parameters
 Precision



 Accuracy


 Representativeness



 Completeness


 Comparability
A quantitative measure of the variability of a group ot measurements, normally
stated in terms of standard deviation, range, or relative percent difference.
Precision is determined from analytical laboratory replicates (split samples) and
test replicates (collocated samples).
A quantitative measure of the bias in a measurement system, normally stated
in terms of percent recovery. Accuracy is determined by QC samples and
matrix spikes with known concentrations.
A qualitative statement regarding the degree to which data accurately and
precisely  represent a population or condition.  Representativeness is addressed
by ensuring that sampling locations are selected properly and that a sufficient
number of samples are collected.
The percentage of the measurements that are judged to be valid. Regardless
of the use of the data, a sufficient amount of the data generated should be
valid.
A qualitative statement regarding the confidence with which one data set can
be compared with another. Comparability is achieved through the use of
standard techniques to collect and analyze samples and to report results.
                                                    25

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the course of testing. The PARCC requirements arc therefore
broadly defined in this category to permit flexibility during
the actual testing. Confidence limits established for data
derived from remedy screening are typically wide, in keeping
with the  characteristics of this tier (i.e., low cost, quick
turnaround, and limited QA/QC).  A minimum number of
QC checks are required to assess  accuracy and precision.
Remedy screening does not require a significant amount of
replication in  the test samples and the analytical  tests
performed. The need for accuracy checks such as matrix
spikes and blanks is also limited.

3.2.3  Remedy-Selection Testing

For remedy selection, DQOs are primarily quantitative in
nature.  For example, a performance goal  for remedy-
selection testing involving solvent extraction and chemical
dehalogenation may be to reduce polychlorinaicd biphe-
nyls (PCBs) to less than 30 ppm in soils (the target cleanup
goal specified for the site). The data required to meet this
quantitative goal are derived from detailed waste character-
ization and performance testing. These data will be used to
select one of the technologies in the ROD.

Because  data used in support of remedy selection must
have a high level of confidence,  QA Categories III or II
are recommended for remedy-selection testing.  These
categories are designed to support the evaluation  and
selection of technologies.  The PARCC parameters are
therefore narrowly defined and test data arc well docu-
mented.  The selection of Category III (less stringent) or
Category  II  (more stringent)  for ircatability testing de-
pends on the intended use of the data and on time and cost
constraints.

Narrow confidence limits are typically required at this tier.
Quality control checks for accuracy and precision will be
more  thorough than  for remedy screening.  A significant
amount of test sample and analytical sample replication
will be required to determine accuracy and precision pa-
rameters.  The representativeness of the data must be care-
fully documented, and a sufficient amount of the data
generated should be judged valid.  Standard sampling and
analysis techniques should be used whenever possible to
assure data comparability. The testing apparatus should be
designed to generate enough treated material to support this
QA program.

The need for detailed analyses and high-quality data at the
remedy-selection tier will result in  significantly higher ana-
lytical  costs and  longer turnaround times compared with
those for remedy screening. These factors must be consid-
ered when establishing DQOs  for  remedy-selection
ireatability studies.
3.2.4  RD/RA Testing

The principal objective of RD/RA testing is to obtain quan-
titative performance, design, and cost data for use in the
implementation of the selected remedial technology.  Data
quality objectives for RD/RA trcatabilily studies arc there-
fore primarily quantitative.

The need  for design, cost, and performance information
will dictate the  frequency of sampling and testing, the
required confidence limits, and the level of QA/QC.  The
uses for RD/RA trcatability study data differ from those for
remedy-selection data, but the required level of data quality
will be the same or less. Therefore, QA Categories III or II
are recommended for RD/RA testing.

In general, RD/RA testing will involve significant replica-
tion in test sampling (collocated samples) and laboratory
analyses (split samples).  Typically, PARCC parameters
arc narrowly defined and test daui arc well  documented.
Confidence limits will be similar to those  for remedy-
selection testing.
3.3   Identifying Sources for Treatability
       Studies

3.3.7  General

Once the decision to conduct a trcatabilily study has been
made and the scope of the project has been defined, the
project manager must identify a qualified program contrac-
tor or technology vendor with the requisite technical capa-
bilities and experience to perform  the work. Trcatabilily
studies can be performed in house or via several contract
mechanisms thai exist for the remedial and removal pro-
grams under CERCLA.

In-house Capabilities

In support of Supcrfund, EPA has created several programs
and documents to assist EPA site managers in the perfor-
mance of treaiability studies.  These include the Supcrfund
Technical Assistance Response Team (START), the RREL
Remedy-Screening Treatability Study Laboratory, the En-
vironmental Response Team (ERT),  and the Inventory of
Treatabilily Study Vendors.

Superfund  Technical Assistance Response Team.  Site-
specific, long-term assistance is available to project man-
agers through START.  Sponsored  by  ORD-RREL. the
START program provides comprehensive engineering as-
sistance from early Rl/FS scoping through RA implemen-
tation at a limited number of sites.  Sites arc chosen by the
                                                     26

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Regions for START support because of ihcir complex con-
taminants and matrices.

Treatability support services available to project managers
through START include:

  • Identification of potentially applicable technology op-
    tions

  • Determination of need for trcatability studies

  • Performance of remedy-screening trcatabiliiy studies

  • Review of trcatability study Project Plans

  • Oversight of PRP-conducied ireatability studies

  • Review of PRP dclivcrublcs and final reports

Treatability support through the  START program  can be
obtained by contacting the RREL Technical Support Branch
in Cincinnati, Ohio.

RREL Remedy-Screening Trcatabiliiy Study Laboratory.
The RREL has developed  a series of  remedy-screening
ueatability  tests. These protocols arc designed to provide
the Regions with inexpensive, preliminary assessments of
the potential feasibility of a given technology for remediating
contaminated soil.  In-house testing can be performed for:

  • Soil vapor extraction

  • Solvent extraction

  • Soil washing

  • Soil flushing

  • Biological degradation

  • Chemical dehalogcnaiion

  • Solidification/stabilization

  • Thermal desorption

  • Incineration technologies

Regions can have these tests performed by contacting the
RREL Technical Support Branch in Cincinnati, Ohio (sec
Appendix A).

Environmental Response Team. Serving as the EPA's in-
house consultants on Supcrfund  issues and oil spills, the
Environmental Response Team  provides technical sup-
port to OSCs and RPMs for both emergency removal and
long-term remedial actions.  With support from the Re-
sponse Engineering and Analytical Contractor, the ERT's
Alternative Technology Section  can design and perform
remedy-screening and remedy-selection treatability stud-
ies for a wide range of technologies.  The Section can
provide  testing oversight and  evaluate  and  interpret
trcaiability lest results.  Regions can request ircatabiliiy
study support by contacting the ERT in Edison, New
Jersey (see Appendix A).

Inventory of Treatabiliry Study Vendors.  The  ORD has
compiled a list of vendors and contractors who have ex-
pressed an interest in performing  trcatabiliiy studies. This
document, entitled Inventory of Treatability Study Ven-
dors. Volumes I and II (EPA 199()a), was compiled from
information received from contractor/vendor responses to a
published request.  It  lists commercial firms  thai offer
trcaiability study services and describes their capabilities.
(This information has not been  verified by EPA.)  The
inventory is sorted by treatment  technology, contaminant
group, and company name. It  can be searched electroni-
cally by contacting the EPA Alternative Treatment Tech-
nology Information Center (ATTIC) (sec  Appendix A).
Figure 4, an example page from the document, shows the
types of information the inventory contains.

Contractor.1; or Vendors

Three available methods for obtaining trcauibiliiy study
services from contractors arc discussed here.

ARCS, ERCS, and TAT  Contracts.  Alternative Remedial
Contracts Strategy (ARCS) contracts arc used to obtain the
program management and technical services needed to sup-
port remedial response  activities at CERCLA sites.  To
retain a  ircatabiliiy study vendor  through  this contract
mechanism,  the EPA project manager (in conjunction with
the EPA contract officer) must issue to the prime contrac-
tor a Work Assignment  outlining the required tasks. The
prime contractor may clcci to perform this work or  to
assign ii to one of iis subcontractors. Emergency Response
Cleanup Services (ERCS) and Technical Assistance Team
(TAT) contracts  provide similar support services  al
CERCLA removal sites. Both ERCS and TAT contractors
can be directed to perform trcauibility studies.

Technical Assistance and Support Contracts. When a spe-
cific waste at a particular site requires the specialized ser-
vices of a contractor that can treat that waste (e.g., a mixed
radioactive/hazardous waste) and such services arc not avail-
able from firms accessible through existing contracts, the
EPA project manager may need to investigate which firms
                                                     27

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                           TICATMUITT ITUOt VENDORS iT COMPANY NAME
O COMPANY:
Address:
City:
Contact:
Treatment Technology: ACTIVATED CARBON
Other Treatment Capability: 5 TECHNOLOGIES
CURRENT AVAILABLE FACILITY: LABORATORY
Permitting Status: EPA ID AS SMIL KNERATOR
Mobile Facility? YES
Bench Scale? YES
Unit Capacity: INFORMATION NOT PROVIDED
Price Information: INFORMATION NOT PROVIDED
Media Treated: 1. AQUEOUS MEDIA
3.
5.
Contaminant 1. HALOCENATEO NONVOLATIIES
Croups 3. NONNALOCfNATED NONVOt.ATII.ES
Treated: S. NONVOLATILE METALS
7. ORGANIC CTAN1DES
9. VOLATILE METALS
11.
Other Contaminant Croups That Can Be Treated:
Experience at Superfuid Sites?
OSUPERFUND SITE * 1: A 1 F MATERIAL RECLAIMING
Site Location: GREENVILLE
Start Date: 00/64
Unit Utilized for/at Site: INFORMATION NOT PROVIDED
Price Information: INFORMATION NOT PROVIDED
Media Treated 1. AQUEOUS MEDIA
3.
5.
Contaminant 1. VOLATILE METALS
Croups 3.
Treated: 5.
7.
9.
11.
Other Contaminant Croups Treated:
RJPERFUND SITE « 2: AMERICAN CREOSOTE
location: JACKSON
Start Date: 00/86
Unit Utilized for/at Site: INFORMATION NOT PROVIDED
Price Information: INFORMATION NOT PROVIDED
Hedia Treated: 1. AQUEOUS MEDIA
3.
5.
Contaminant 1. NONVOLATILE METALS
Croups 3. CREOSOTE
O Treated: 5.
7.
9.
11.
Other Contaminant Croupe:
Company Type: SMALL BUS
State: Zip:
Phone:


Studiet/Month: INP
Fined Facility? YES
Pilot Scale? NO
Location: ATLANTA, CA

2. ORGANIC LIQUID
4.
Other:
2. HALOCENATED VOLAT1LES
4. NONNALOCENATEO VOLATILES
6. ORGANIC CORROSIVES
6. PCS*
10.
12.
NOT SPECIFIED
YES
EPA Region: 5 ID f: 17
State: IL
End Date: INP


2.
4.
Other:
2.
4.
6.
8.
10.
12.

EPA Region: S ID •: 72
State: in
End Date: INP


2.
4.
Other:
2. PCBs
4.
6.
8.
10.
12.
OTNEI ORGAN ICS
Figure 4.  Information contained in the ORD Inventory of Treatability Study Vendors.
                                        28

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with this specialized capability are accessible through other
contracting mechanisms.   Access to technical assistance
and support contracts may be available through the RREL,
the U.S. Bureau of Mines, or the U.S. Army Corps of
Engineers.

Request for Proposal. In the absence of an existing con-
tracting mechanism for accessing the required treatability
study services for a specific waste at a particular site, a new
contracting mechanism can be established.  This will gen-
erally be the prime  mechanism by which PRPs obtain
treatability  study  services.   Obtaining  the services of a
specific firm through a new contracting mechanism usually
involves three steps:  1) a request for proposal (RFP), 2) a
bid review and evaluation, and 3) a contract award. (Note:
This can be a time-consuming process.)

An RFP is an invitation to firms to submit proposals to
conduct specific services,  li usually contains the following
key sections:

  • The type of contract to be awarded (e.g., fixed-price or
    cost plus fixed fee)

  • Period of performance

  • Level of effort

  • Type of personnel (levels and skills)

  • Project background

  • Scope of work

  • Technical evaluation criteria

  • Instructions for  bidders (e.g.,  due date, format, as-
    sumptions for cost proposals, page  limit,  and number
    of copies)

Appropriate firms listed in ORD's Inventory ofTreatabiliry
Study Vendors should be notified of the RFP in accordance
with the Federal Acquisition Regulations. Proposals sub-
mitted  by a fixed due date in response to an RFP  go to
several reviewers to determine the abilities of  the prospec-
tive firms to conduct the required services. The technical
proposals should  be evaluated  (scored) with a  standard
rating system  that is based on the technical evaluation
criteria  presented  in the RFP.  Contract award should be
based on a firm's ability to meet the technical requirements
of the testing involved, its qualifications and experience in
conducting similar studies, the availability and adequacy of
its personnel and  equipment resources, and (other things
being equal) a comparison of cost estimates.
3.3.2  Remedy Screening

Remedy screening involves relatively simple tests that re-
quire no special equipment.  These studies can often be
performed generically (as discussed in Subsection  2.5.4)
by the RREL; by the ARCS, ERCS, or TAT contractor; or
by the State or PRP prime support services contractor.

3.3.3  Remedy-Selection Testing

Remedy-selection testing of proven or demonstrated tech-
nologies can sometimes be performed by the ARCS, ERCS,
or TAT contractor.  Tests involving innovative technolo-
gies, however, may  require special vendor-specific capa-
bilities that are only accessible through technical assistance
and support contracts or an RFP.

3.3.4  RD/RA Testing

Post-ROD testing entails more complex tests involving the
use of specialized equipment.  Because such capabilities
may not  be available through any existing contracting
mechanism within the Agency, it may be necessary to issue
an RFP to obtain RD/RA ircauibility study services.  The
RFP will generally be issued by the designer.
3.4   Issuing the Work Assignment

The Work Assignment is a contractual document thai out-
lines the scope of work to be provided by the contractor.  It
presents the rationale for conducting the study, identifies
the waste stream and tcchnology(ics) to be tested, and
specifies the tier(s) of testing required. Table 6 presents the
suggested organization of the trcauibility study Work As-
signment.

3.4.7  Background

The background section of the Work Assignment describes
the site, the waste stream, and the treatment technology
under investigation. Site-specific concerns that may affect
waste handling, the experimental design, or data interpreta-
tion, as well as specific process options of interest, should
be  duly noted.  The results of any previous trcatability
studies conducted at the site also should be included.

3.4.2  Test Objectives

This section defines the objectives of the treatability study
and the intended use of the data (i.e., to determine potential
feasibility; to develop performance or cost data for remedy
selection;  or to provide detailed design, cost, and perfor-
mance data for remedy implementation).  The test objcc-
                                                     29

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 Table 6.  Suggested Organization of Treatabiiity
             Study Work Assignment

 1.  Background
     1.1  Site description
     1.2  Waste stream desjription
     1.3  Treatment technology description
     1.4  Previous treatability studies at the site
 2   Test Objectives
 3.  Approach
     3.1  Task  1 - Work Plan preparation
     3.2  Task  2 - SAP, HSP, and CRP
          preparation
     3.3  Task  3 - Treatability study execution
     3.4  Task  4 - Data analysis and
          interpretation
     3.5  Task  5 - Report preparation
     3.6  Task  6 - Residuals management
 4.  Reporting  Requirements
     4.1  Deliverables
     4.2  Monthly  reports
 5.  Schedule
 6.  Level of Effort
lives will include performance goals  that are based on
established cleanup criteria for the site or, when such crite-
ria do not exist, on contaminant levels that are protective of
human health and the environment. If the treatability study
Work Assignment is issued before site cleanup goals have
been established, the test objectives should be written with
enough latitude to accommodate changes as the trcatabiliiy
testing  proceeds without modifying the Work Assignment.

3.4.3  Approach

The approach describes the manner in which the treatability
study is to be conducted. It should address the following
six  tasks:  1)  Work  Plan preparation;  2) Sampling and
Analysis Plan (SAP), Health and Safely Plan (HSP). and
Community Relations Plan (CRP) preparation; 3) ircauibiliiy
study execution; 4) data analysis and  interpretation; 5)
report preparation; and 6) residuals management.

Task 1  - Work Plan Preparation

This task oullincs the elements  to be included in the Work
Plan. If a project  kickoff meeting is needed to define ihc
objectives of ihc ircatability study or 10 review ihc experi-
mental  design, it should be specified here. The contractor
should  not begin work on subsequent tasks until receipt of
ihc  project manager's approval  of the Work Plan.
Task 2 - SAP. HSP, and CRP Preparation

This task  describes activities specifically related  to the
treatability study that should be incorporated into the exist-
ing site SAP, HSP, and CRP.  Examples of such acuviiics
include field sampling and waste stream characterization,
operation of pilot-plant equipment, and public meetings to
discuss treatabilily study findings.

Task 3 - Trealability Study Execution

Requirements for executing the treatability study are out-
lined in this task. It should include requirements uV; the
contractor review the literature and site-specific informa-
lion, identify key parameters for investigation, and specify
conditions of the test  This task also should identify guid-
ance documents (such as this guide or other technology-
specific protocols) to be consulted during the planning and
execution of the study.

Task 4 • Data Analysis and Interpretation

This lask describes how dala from the trcatability study will
be  used in the evaluation of the remedy.  If statistical
analysis of the data will be necessary, the requirements
should be stipulated here.

Task 5 - Report Preparation

This lask describe? the contents and  organization  of the
final project report. If multiple tiers of testing are expected,
an  interim  report may be requested upon completion of
each tier. The contractor should be required to follow ihc
reporting format outlined  in Subsection 3.12.

Task 6 - Residuals Management

Residuals generated by trcatability testing must be man-
aged in an environmentally sound manner. This uisk  should
specify whether project residuals arc to be rciurncd to the
site or shipped 10 an acceptable offsitc facility.  In the latter
case, the responsible waste generators (lead agency, PRP,
or contractor) should be clearly identified.

3.4.4  Reporting Requirements

This section identifies the project dclivcrablcs and monthly
reporting requirement.  Project dclivcrablcs include the
Work Plan; ihc SAP, HSP, and CRP (as appropriaic); and
interim and final reports.   It  should  indicate  the  formal
specifications (as outlined in this guidance) and ihc number
of copies 10 be delivered.  All remedial and removal Work
Assignments must include a requirement for one camera-
ready master copy of ihc trcauibiliiy study report to be
                                                     30

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provided to the Office of Research and Development (EPA
1989e) for use in updating  the RREL Trcatability Data
Base. (The report should be sent to the address listed in
Subsection 3.12.)

Monthly reports should summarize the progress made in
the current month, projected piogress for the coming month,
any problems encountered, and expected versus actual costs
incurred.

3.4.5  Schedule

The schedule establishes the timcframe for conducting the
treatability study and includes due dates for submission of
the major  project dclivcrablcs.  Sufficient time should be
allowed for approval of the Work Plan, subcontractors, and
other required administrative approvals;  site  access and
sampling; analytical turnaround; equipment setup and shake-
down; data analysis and  interpretation; and review and
comment on reports.

3.4.6  Level of Effort

The level of effort estimates the number of technical hours
required to complete the project. Special skills or expertise
are required for most trcaiability studies, and these require-
ments should be so noted.
3.5   Preparing the Work Plan

Treatability studies must  be carefully planned to ensure
that the data generated are useful for evaluating the feasi-
bility or performance of a technology.  The Work  Plan,
which is prepared by the contractor when the Work Assign-
ment is in place, sets forth the contractor's proposed techni-
cal approach for completing the tasks outlined in the Work
Assignment. It also assigns responsibilities and establishes
the project schedule and costs.  Table 7 presents the sug-
gested organization of a ireatabilily study Work Plan. The
Work Plan must be approved by the project manager before
subsequent tasks are initiated. Each of the principal Work
Plan elements is described in the following subsections.

3.5.1  Project Description

The project description section of the  Work Plan provides
background information on the site and summarizes exist-
ing waste characterization data (matrix type and character-
istics and the  conceniraiions and distribution of the con-
taminants of concern). This information can be obtained
from  the Work Assignment or other background docu-
ments such as the Rl. The project description also specifics
the type of study to be conducted, i.e., remedy screening.
 Table 7. Suggested Organization of Treatability
                 Study Work Plan

    1.   Project Description
    2.   Treatment Technology Description
    3.   Test Objectives
    4.   Experimental Design and Procedures
    5.   Equipment and Materials
    6.   Sampling and Analysis
    7.   Data Management
    8.   Data Analysis and Interpretation
    9.   Health and Satety
   10.   Residuals Management
   11.   Community Relations
   12.   Reports
   13.   Schedule
   14.   Management and Staffing
   15.   Budget

remedy-selection testing, or RD/RA  testing. For ircatabilily
studies involving multiple tiers of testing, this section states
how the need for subsequent  testing will be determined
from the results of the previous tier.

3.5.2  Treatment Technology
        Description

This section of the Work Plan briefly describes the treat-
ment technology to be tested.  It may include a flow dia-
gram showing the input stream, the  output stream, and any
side streams generated as a result of the treatment process.
For ireatability studies involving treatment trains, the tech-
nology description addresses.all the unii operations the
system comprises. A description of the prc- and posurcai-
mcnt requirements also may be included.

3.5.3  Test Objectives

This section of the Work Plan defines the objectives of the
trcaiability study and the intended  use of  the data (i.e.,  to
determine potential feasibility; to develop performance  or
cost data for remedy selection; or to provide detailed de-
sign, cost, and performance data for remedy implementa-
tion).  The lest objectives will include performance goals
that arc based on established cleanup criteria for the site or,
when such criteria do not exist, on contaminant levels that
arc protective of human health and  the environment.

3.5.4  Experimental Design and
        Procedures

The experimental design identifies the tier and scale  of
                                                    31

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testing,  the volume of waste material lo be tested, the
critical parameters, and the type and amount of replication.
Examples of critical parameters include pH, reagent dos-
age, temperature, and reaction (or residence) time.  Some
form of replication is usually incorporated into a ireatability
study to provide a greater level of confidence in the data.
Two methods are used to collect different types of test
sample replicates:

  1)  Dividing a sample in half or thirds at theend of the
      experiment and analyzing each fraction.  This
      method provides information on laboratory error.

  2)  Analyzing two or three samples prepared inde-
      pendently of each other under the same test con-
      ditions.  This method provides information on
      total error.

The data quality  objectives and the costs associated with
replication must be considered in the design of the experi-
ment. A matrix outlining the test conditions and the num-
ber of replicates, such as the example in Figure 5, should be
included in the Work Plan.

The specific steps to be followed in the performance of the
ireatability study are described in uv standard operating
procedures (SOP). The SOP should be sufficiently detailed
to permit the laboratory or field technician to conduct the
lest, to operate the equipment, and to collect the samples
with minimal supervision, as shown in Example 4.  The
SOP can be appended to the Work Plan.

3.5.5   Equipment and Materials

This section lists the equipment, materials, and  reagents
that will be  used in  the  performance  of the ireatability
study. The following specifications should be provided for
each item listed:

  • Quantity

  • Volume/capacity
  • Calibration or scale

  • Equipmenl manufacturer and model number

  • Reagent grade and concentration

A diagram of the tesi apparatus also should be included in
the Work Plan.

3.5.6  Sampling and Analysis

A Sampling and Analysis Plan is  required for  all  field
activities conducied during ihe  Rl/FS.  This section de-
scribes how the existing SAP will be modified to address
field sampling, waste characterization, and sampling and
analysis activities in support of the treaiability siudy. It
describes the  kinds of samples thai will be collected and
specifies the level of QA/QC required. (Preparation of the
ireatability study SAP is discussed in Subsection 3.6.)

Appendix C contains waste feed characterization param-
eters  specific lo biological,  physical/chemical, immo-
bilization, thermal, and in situ treatment technologies.  Gen-
erally, these are ihe  characterization parameters that  must
be established before a trcaiabiliiy test is conducted on the
corresponding technology.  Site-specific conditions may
necessitate the use of additional parameters.

3.5.7  Data Management

This section of the Work Plan describes the procedures for
recording observations and raw data in the field or labora-
tory, including the use of bound notebooks, data collection
sheets, and photographs.  If proprietary processes are in-
volved, this section also describes how confidential informa-
lion will be handled.

3.5.8  Data Analysis and Interpretation

This section of ihe Work Plan describes ihe procedures that
will be used lo analyze and interpret data from ihe treatabiliiy

Soil
X
Y
1
A%
3
3
- Zeolite 1
B%
3
3
C%
3
3
A%
3
3
- Zeolite
B%
3
3
C%
3
3
III • limestone
3
3
IV • control
3
3
       Figure 5.  Example test matrix for zeolite amendment remedy-selection treatability study.
                                                     32

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             EXAMPLE 4. TREATABILITY STUDY STANDARD OPERATING PROCEDURE
     Standard Operating Procedure for Thermal Desorption Remedy-Screening Treatability Study

      1.  Define and record planned experiment in the data book (i.e., time, temperature, soil, etc.).
      2.  Weigh the empty clean tray.
      3.  Transfer a representative aliquot of prepared soil from the jar to the tray with a stainless steel
         spatula.
      4.  Weigh the soil and tray and adjust the soil quantity to achieve a uniform layer approximately 2.5
         to 3 mm deep in the bottom of the tray.
      5.  Distribute and level the soil within the tray.
      6.  Turn on the purge-gas flow to the proper setting on the  rotameter.
      7.  Place the tray with soil in the oven at ambient temperature and close the oven door.
      8.  Set the oven temperature controller set-point to the target test temperature and start the timer.
      9.  Monitor and record  the temperatures and time periodically throughout the test period.
      10. When the prescribed residence time at the target temperature is reached, shut off the oven
         heater and purge-gas flow and open the oven door.
      11. Cautiously withdraw the hot tray and soil with special tongs, place a cover on the tray, and
         place the covered tray in a separate hood to cool tor approximately 1 hour.
      12. Weigh the tray (without cover) plus treated soil.
      13. Transfer an aliquot  (typically  about 20 g) of treated soil  from the tray to a tared, 60-cm3, wide-
         mouth, amber bottle with Teflon-lined cap. Code, label, and submit this aliquot for analysis.
         Transfer the remainder of the treated soil to an identical type bottle, label, and store as a
         retainer.
      14. Clean the tray, cover, and nondisposable implements by the following procedure:
           • Rinse with acetone and wipe clean.
           • Scrub with detergent solution and rinse with hot tap water followed by distilled water.
           • Rinse with acetone and allow to dry.
           • Rinse three times with methylene chloride (i.e., approximately 15 to 25 ml each rinse for
             the tray).
           • Air dry and store.
study, including methods of data presentation (tabular and
graphical) and statistical evaluation.  (Dam analysis and
interpretation are discussed in Subsection 3.11.)

5.5.9  Health and Safety

A Health and Safety Plan is required for all cleanup opera-
tions involving hazardous substances under CERCLA and
for all operations involving ha/ardous wastes that arc con-
ducted at RCRA-rcgulatcd facilities. This section of the
Work Plan describes how ihe existing site  or facility HSP
will be modified to address the  hazards associated with
ireatability testing.  Hazards may  include, but arc not lim-
ited to,  chemical exposure;  fires, explosions, or spills;
generation of toxic or asphyxiating gases; physical haz-
ards; electrical ha/ards; and heat stress or frostbite. (Prepa-
ration of the trcatability study HSP is discussed in Subsec-
tion 3.7.)

3.5.10  Residuals Management

This section of the Work Plan describes the management of
treatability study residuals.  Residuals generated  by
ircaiability testing must be managed in an environmentally
sound manner.  Early recognition of the types and quanti-
ties of residuals that will be generated, the  impacts lhat
managing these residuals will have on the project schedule
and costs, and the roles and responsibilities of the various
                                                  33

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panics involved in ih> generation 01 residuals is irvporiant
for their proper disposal.

The Work Plan should include estimates of both the types
and quantities of residuals expected to be generated during
treaiability testing.  These estimates should be based on
knowledge of the treatment technology and the experimen-
tal design. Project residuals may include the following:

  • Unused waste not subjected to testing

  • Treated waste

  • Treatment residuals  (e.g., ash,  scrubber  water,  and
    combustion gases)

  • Laboratory samples and sample extracts

  • Used containers or other expendables

  • Contaminated protective clothing and debris

This section outlines  how trcatability study residuals will
be analyzed to determine if they arc hazardous wastes and
specifies whether such wastes will be returned to the site or
shipped to a permitted treatment, storage, or disposal facil-
ity (TSDF) (see Subsection 3.9).  In the latter case, this
 section also identifies the waste  generator (lead agency,
 responsible party, or contractor) and delineates the param-
 eters that will be analyzed for properly manifesting the
 waste and for obtaining disposal approval from the TSDF
 (see Table 8).

 3.5.7 7  Community Relations

 A Community Relations Plan is required for all removal
 and remedial response actions under CERCLA.  This sec-
 tion describes the community relations activities that will
 be performed in conjunction with  the treaiability study.
 These activities include, but arc not limited to,  preparing
 fact sheets and news releases, conducting workshops or
 community meetings, and maintaining an up-to-date infor-
 mation repository. (Conducting community relations activi-
 ties for trcatability studies is discussed in detail in Subsec-
 tion 3.8.)

 3.5.72  Reports

 This section of the Work Plan describes the preparation of
 interim and final reports documenting  the results of the
 ircaiabilily study. For trcaiabiliiy studies involving more
 than one tier of testing, interim reports (or project brief-
 ings) provide a means of determining whether to proceed to
 the next tier. This section also describes the preparation of
    Table 8.  Typical Waste Parameters Needed to Obtain Disposal Approval at an Offsite Facility8
 Incineration parameters
     Total solids
     % Water
     % Ash
     PH
     Specific gravity
     Flash point
     Btu/pound
     Total sulfide
     Total sulfur
     Total organic nitrogen
     Total cyanide
     Total phenolics
     Total organic halogen (TOX)
     Polychlorinated biphenyls (PCBs)
     Total RCRA metals (eight)
     TCLP metals
     TCLP organics (D-list)
     Priority pollutant organics
          Volatile
          Semivoiatile (BN/A-extractabie)
          Remaining F-listed solvents
Treatment parameters
    pH
    Specific gravity
    Oil and grease
    Total organic carbon (TOC)
    Total sulfide
    Total cyanide
    Total phenolics
    Total metals (RCRA plus Cu, Ni, Zn)
    TCLP metals
    TCLP organics (D-list)

Landfill parameters (solids only)
    % Water
    % Ash
    pH
    Specific gravity
    Total sulfide
    Total cyanide
    Total phenolics
    PCBs
    TCLP metals (extraction and RCRA)
    TCLP organics (D-list)
    TCLP solvents (F-list)
 aAnalysis of these  parameters may be required unless they can be ruled out based on knowledge of
  the waste.
                                                    34

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monthly reports detailing the current and projected progress
on the project. (Trcatability study reporting is discussed in
detail in Subsection 3.12.)

3.5.75 Schedule

The Work Plan should contain a schedule indicating the
planned starting and ending dates for the tasks outlined in
the Work Assignment. The length of a trcaiability study
will vary with the technology being  investigated and the
level of testing being conducted. Entire remedy-screen ing
studies  can  usually be  performed within a few  weeks.
Remedy-selection studies, however,  may require  several
months. In addition to the time required for actual testing, the
schedule must allow time for obtaining approval of the vari-
ous plans; securing any necessary environmental, testing, or
trdnsporuu'on permits; shipping analytical  samples  and re-
ceiving results; seeking review and comment on the project's
delivcrables; and disposing of the project's residuals.

The schedule may be displayed as a bar chart, such as that
shown in Figure 6. In this example, both remedy-screening
and remedy-selection trcatability studies arc planned. Per-
formance of the selection studies is  contingent  upon the
results of the screening studies, which arc presented in the
Interim  Report.   In this particular schedule, the actual
treatability tests (Subtasks 3b and 7a) will require only 1 to
2 weeks to perform. The entire two-tiered study, however,
spans a period of 8 months.

3.5.74 Management  and Staffing

This section of the Work Plan identifies key  management
and technical personnel and defines specific  project  roles
and responsibilities.  The line of authority is usually pre-
sented in an organization chart such as that shown in Figure
7.  The EPA Project  Manager is responsible for  project
planning and oversight.  At Federal-  and  State-lead sites,
the remedial contractor directs the trcatability study and is
responsible  for the execution of the project tasks.   At
private-lead  sites, the PRP performs this function.  The
trcatabiliiy study may be subcontracted wholly or in part to
a vendor or testing facility with expertise in the technology
being evaluated.

3.5.75 Budget

The treatability study  budget  presents the projected costs
for  completing  the  ircatability  study as described in the
Work Plan.  Elements of a budget include labor, adminis-
trative costs, and fees: equipment and reagents; site prepa-
ration (e.g., building a concrete pad) and utilities; permit-
ting and regulatory fees; unit mobilization; on-sccnc health
and safety requirements; sample transportation and analy-
sis; emissions and effluent monitoring and treatment: um;
decontamination and demobilization; and residuals trans-
portation and disposal. Appendix B discusses these vari-
ous cost elements.

The size of the budget will generally reflect the complexity
of the treatability  study.  Consequently, the number of
operating parameters chosen for investigation at the rem-
edy-selection tier and the approach used to obtain these
measurements will often depend on the available funding.
For example, for some treatment processes it may be less
costly lo obtain data on contaminant reduction versus reac-
tion time at the completion of a test run rather than periodi-
cally  throughout the test.  This kind of information can be
obtained from the technology vendor during the planning
of the ircatability study.

Analytical  costs can have a  significant impact  on  the
project's overall budget.  Sufficient funding  must be allot-
ted for the amount of analytical work projected, the chemi-
cal and physical parameters to be analy/.cd, and  the re-
quired turnaround lime. Specially analyses (e.g., for diox-
ins and furans) can quickly increase the analytical costs.

A 34-week rcmcdy-scrccning/rcmcdy-sclcction ircatability
study such as the one presented in Figure 6 can be per-
formed at a cost of between 550,000 and 5100,000.
3.6   Preparing the Sampling and
       Analysis Plan

3.6.7  General

A Sampling and Analysis Plan is required for all field and
lest activities conducted to support a ircatabiliiy study. The
purpose of the SAP is to ensure that samples obtained for
characterization and testing arc representative and that the
quality of the analytical data generated is known.  The SAP
addresses field sampling, waste characicri/ation, and sam-
pling and analysis of the treated wastes and residuals from
ihc icsiing apparatus or ircaimcm unit.

Table 9 presents the suggested organi/Jtion of the trcatabiliiy
study SAP. The SAP consists of two parts-thc Field Sam-
pling Plan  (FSP) and the Quality Assurance Project Plan
(QAPP).

Field Sampling Plan

The  FSP component of the  SAP describes ihc  sampling
objectives; the type, location, and number of samples to be
collected:  the  sample numbering system; the necessary
equipment  and procedures for collecting the samples; the
                                                      35

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TASK
Taskl
Work Plan Preparation
Task 2
SAP & HSP Preparation
Task 3
Remedy Screening
Treatabiliiy Study Execution
3a - Field Sampling/Waste Characterization
3b - Equipment Setup/Testing/Sampling
3c - Sample Analysis
Task 4
Data Analysis and Interpretation
Tasks
Interim Report Preparation * Review
Task 6
Test Plan Revision (if necessary)
Task 7
Remedy Selection
Treatabiliiy Study Execution
7a - Equipment Setup/Testing/Sampling
7b - Sample Analysis
Tasks
Data Analysis and Interpretation

Task 9
Final Report Preparation and Review
Task 10
Residuals Management
Span,
Weeks

3
5


4
1
3

1

4

1


2
3

2





Weeks from Project Start
i

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r ^
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M





















16
^•
1
M 19
V
I
Ml  Submit Work Plan                      Wk 2
M2  Receive Work Plan Approval              Wk 3
M3  Submit SAP and HSP                   Wk 6
M4  Receive SAP and HSP Approvals          Wk 8
M-5  Collect and Submit Field Samples          Wk 9
M6  Receive Waste Characterization Results     Wk 12
M7  Submit Treatabiliiy Samples              Wk 13
M8   Receive Treatability Results    Wk 16
M9   Submit Interim Report         Wk 19
M-10  Project Briefing              Wk 20
Mil  Submit Revised Work Plan     Wk 21
M 12  Submit Treatabiliiy Samples    Wk 23
M-13  Receive Treatability Results    Wk 26
M-14  Submit Draft Report          Wk 30
M-15  Receive Review Comments    Wk 32
M 16  Submit Final Report          Wk 34
M-17  Submit Disposal Application    Wk 28
M 18  Receive Disposal Approval     Wk 32
M 19  Ship Residuals lot Disposal    Wk 34
              Figure 6.  Example project schedule for a two-tiered chemical dehalogenation treatabiiity study.

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sample chain-of-custody procedures; and the required pack-
aging, labeling, and shipping procedures.

The sampling objectives must support the test objectives of
the treaiability study. For example, if an objective of RD/
RA testing is to investigate process upsets and recovery,
the objective of field sampling should be to collect samples
representing the "worst case." If soils will be blended in
the full-scale process, however, the field sampling objec-
tives should be to collect samples representing "average"
conditions at the site.

Whatever the sampling objectives, the samples collected
must be representative of the conditions being evaluated.
Guidance on representative samples and statistical sam-
pling is contained in Test Methods for Evaluating Solid
Waste (EPA 1986).

Additional  guidance for the  selection  of field methods,
sampling procedures, and chain-of-custody requirements
can be  obtained from A Compendium of Supcrfund Field
Operations Methods (EPA 1987b).

Quality Assurance Project Plan

The second component of the SAP, the QAPP, details the
quality assurance objectives  (precision, accuracy, repre-
                            sentativeness, completeness, and comparability) for criti-
                            cal measurements and the quality control procedures es-
                            tablished 10 achieve the desired QA objectives for a spe-
                            cific trcatability study. Guidance for preparing the QAPP
                            can be obtained from Quality Assurance Procedures for
                            RREL (EPA 1989d) and Interim Guidelines and Specifi-
                            cations for Preparing Quality Assurance  Project Plans
                            (EPA 1980).  In general, QAPPs arc based on the lypc of
                            project being conducted and on the intended use of the
                            data generated by the project. The  QAPP recommended
                            in Table 9 corresponds to the QA Category II plan pre-
                            sented in Quality Assurance Procedure for RREL. This
                            plan should be implemented only  for remedy-selection
                            treaiability studies requiring  exceptionally high levels of
                            QA (i.e., where  ucatability data  will play an important
                            role in the ROD). As discussed in the following subsec-
                            tions, less stringent QAPPs will be adequate for all other
                            ircatability studies.

                            3.6.2  Remedy Screening

                            Remedy screening requires  a less stringent level of QA/
                            QC. Technologies determined to be potentially feasible
                            through remedy screening arc evaluated  further at the
                            remedy-selection tier; therefore, thcQA/QC requirements
                            associated with this screening arc less rigorous. Never-
                            theless, the test  data should be well documented.  The
       Quality Assurance Officer
     hi
        Health & Safety Officer
       Work Plan
       Preparation
       Task Leader
                                                   EPA
                                             Remedial Project
                                                 Manager
                                                     EPA
                                               Technical Experts
                                                Contractor
                                             Work Assignment
                                                 Manager
SAP & HSP
Preparation
Task Leader
                                                Subcontractor
                                                   Manager
Treatability Study
   Execution
  Task Leader
Data Analysis &
 Interpretation
 Task Leader
Final Report
 Preparation
Task Leader
                             Figure 7.  Example project organization chart.
                                                    37

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      Table 9.  Suggested Organization of a
  Treatability Study Sampling and Analysis Plan

  Field Sampling Plan
    1.  Site Background
    2.  Sampling Objectives
    3.  Sampling Location and Frequency
    4.  Sample Designation
    5.  Sampling Equipment and Procedures
    6.  Sample Handling and Analysis
  Quality Assurance Project Plan
    1.  Project Description
    2.  Project Organization and Responsibilities
    3.  Quality Assurance Objectives
    4.  Site Selection and Sampling Procedures
    5.  Analytical Procedures and Calibration
    6.  Data Reduction, Validation, and Reporting
    7.  Internal Quality Control Checks
    8.  Performance and Systems Audits
    9.  Calculation of Data Quality Indicators
  10.  Corrective Action
  11.  Quality Control Reports to Management
  12.  References
    Appendices
    A.  Data Quality Objectives
    B.  EPA Methods Used
    C.  SOP for EPA Methods Used
    D.  QA Project Plan Approval Form	

Category IV QAPP is recommended for remedy-screening
ircatabilily studies.

3.6.3  Remedy-Selection Testing

Remedy-selection testing requires a moderately to highly
stringent level of QA/QC. The dan generated in remedy-
selection testing  are generally used  for evaluation and
selection of the remedy; therefore, the QA/QC associated
with this tier should be rigorous and the test data well
documented. The Category III QAPP will provide a suffi-
cient level of quality assurance for most remedy-selection
ircatabilily studies. In cases where remedy-selection
data will be highly scrutinized or have a significant im-
pact on decision making, the Category II QAPP may be
required.

3.6.4  RD/RA Testing

Trcatability testing to support remedial design/remedial
action requires a moderately to highly stringent level of
QA/QC. The data generated in RD/R A testing arc used in
 support of remedy optimization and implementation; there-
 fore, the QA/QC associated with this tier should be rigor-
 ous and the test data well documented. In most cases, the
 Category III QAPP will provide data of sufficient quality
 forRD/RA trcatability studies.
3.7   Preparing the Health and Safety
       Plan

3.7.7  General

A project-specific Health and Safety Plan is required for all
ircatabilily studies conducted on site or at an offsitc labora-
tory or testing facility permitted  under RCRA, including
research, development, and demonstration facilities.  The
vendor or testing facility should submit the HSP  with the
ircatabilily study Work Plan. The HSP describes ihc work
lo be performed in the field and in the laboratory, identifies
ihc possible physical and chemical hazards associated wiih
each phase of field and laboratory operations, and pre-
scribes appropriate protective measures to minimize worker
exposure.  Hazards that  may be  encountered during
trcatability studies include the following:

  •  Chemical exposure (inhalation, absorption, or ingcs-
     lion of conuminaied soils, sludges, or liquids)

  •  Fires, explosions, or spills

  •  Toxic or asphyxiating gases generated during storage
     or treatment

  •  Physical hazards such as sharp ohiccts or  slippery
     surfaces

  •  Electrical hazards such as high-voltage equipment

  •  Heat stress or frostbite

Table  10 presents  the suggested organization of the
instability study HSP, which addresses the Occupaiional
Safety and Health Administration (OSHA) requirements in
29 CFR 1910.120(b)(4). Guidance  lor preparing  the  HSP
is contained in two documents-/! Compendium of Super-
fund Field Operations Methods (EPA 1987b) and Occupa-
tional Safety and Health Guidance Manual for Hazardous
Waste Site Activities (N1OSH/OSH A/USCG/EPA  1985).

Supervisors, equipment operators,  and field technicians
engaged in onsitc opcraiions must satisfy the iraining re-
quircmcms in 29 CFR 1910.120(c) and  must participate in
a medical surveillance program, as described in  29 CFR
1910.120(0- Laboratory personnel must be iraincd  with
                                                   38

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      Table 10.  Suggested Organization of a
     Treatability Study Health and Safety Plan

    1.   Hazard Analysis
    2.   Employee Training
    3.   Personal Protective Equipment
    4.   Medical Surveillance
    5.   Personnel and Environmental Monitoring
    6.   Site Control Measures
    7.   Decontamination Procedures
    8.   Emergency Response Plan
    9.   Conlined-Space Entry Procedures
  10.   Spill Containment Program


regard to container labeling and Material Safety Data Sheets
(MSDS) in accordance with the OSHA Hazard Communi-
cation Standard in 29 CFR 1910.1200.  Before any treat-
ability studies arc initiated, the Health and Safety Officer
should conduct a briefing to ensure that all personnel arc
apprised of the HSP. The Health and Safety Officer also
should  conduct inspections during the course of the
treaiability study to determine compliance with and effec-
tiveness of the HSP.

3.7.2  Remedy Screening

The safciy and health  ha/jrds associated with remedy
screening  are relatively minor  because of ihc small vol-
umes of wastes that arc handled and subjected to testing. In
general, the HSP should provide for skin and eye protection
during the handling of wastes. It need not require respira-
tory protection if the tests arc conducted in a fume hood.

3.7.3  Remedy-Selection Testing

The HSP  for a remedy-selection trcatabilily study must
provide  for skin and eye protection during the handling of
wastes.  It also may require respiratory protection when
treatment processes tested at the bench scale  involve mix-
ing or aeration (e.g., solidification/stabilization, aerobic
biological  treatment) that could generate dust or volatilize
organic  contaminants. Because pilot-scale testing involves
significanUy greater volumes of waste, the health and safety
risks will increase.

3.7.4  RD/RA Testing

Pilot- and  field-scale RD/RA trcatability studies may pose
significant health and safety hazards to operators and onsitc
personnel.  The HSP must outline skin, eye, and respiratory
protection  (Level C or higher); decontamination proce-
dures; and emergency procedures ^such as equipment shut-
down and personnel evacuation).
3.8   Conducting Community Relations
       Activities

3.8.1   General

Community relations activities provide interested persons
an opportunity to comment on and participate in decisions
concerning  site actions, including  the performance of
treatability studies. Public participation in the removal, Rl/
FS, and RD/RA processes ensures that ihc community is
provided with accurate and timely information about site
activities. From the beginning of the RI/FS,  a description
of the ireatability study activities  that will be  performed
during the feasibility study should be included in the dis-
cussion on how the alternatives will be delineated for the
particular site.  Presenting clear, concise explanations of
trcatability studies (accompanied by appropriate graphics)
before activities have been performed will create a more
open and positive Agency/public relationship.

The Agency designs and implements community relations
activities according 10 CERCLA and the National Oil and
Hazardous Substances Pollution Contingency Plan.   The
NCP requires the lead  Agency to prepare a Community
Relations Plan for all remedial response actions and for all
removal actions of more than 45 days' duration, regardless
of whether RI/FS activities .arc fund-financed  or conducted
by PRPs  (40 CFR 300.67). This plan outlines all commu-
nity relations activities  that will be conducted  during the
RI/FS and projects the  future activities required  during
completion of remedial design and implementation. These
future activities arc outlined more clearly in a revised plan
developed after the feasibility study and before the reme-
dial design phase.

Guidance for preparing a CRP and conducting community
relations  activities can be acquired from Community Rela-
tions in Supcrfund: A Handbook (EPA I988b).  Table 11
presents the CRP organization suggested in this handbook.

Community  interviews should be conducted before the
CRP is prepared. These interviews arc informal discus-
sions held with Suite and local officials, community lead-
ers, media representatives, and interested citizens to assess
the  public's concern and desire to be involved in site re-
sponse activities.  Discussions with citizens regarding the
possible need for conducting onsilc trcauibilily studies will
allow the Agency to anticipate and respond better to com-
munity concerns as ihc trcauibility testing process proceeds
and will allow government officials and citi/cns to under-
                                                    39

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       Table 11.  Suggested Organization of
            Community Relations Plan

    1.  Overview of Community Relations Plan
    2.  Capsule Site Description
    3.  Community Background
    4.  Highlights of the Community Relations
       Program
    5.  Community Relations Activities and
       Timing
    Appendices
   A.  Contact List of Key Community Leaders
       and Interested Parties
   B.  Suggested Locations of Meetings and
       Information Repositories


suind that several technologies may be tested before the
preferred alicmaiive(s) are listed in the final FS report.

Conducting treatability studies on site is a potentially con-
troversial issue within a community and may demand con-
siderable effort on the  part of the Agency.  As  the site
investigation  progresses,  community relations activities
should focus on  providing information to the community
concerning the technology screening process and on ob-
taining feedback on community concerns associated with
potentially applicable treatment technologies.   Activities
may include, but are not limited to, the following:

  •  Preparing  fact sheets  and news releases  describing
    treatment technologies identified during the develop-
    ment and screening of alternatives.

  •  Discussing the possibility of treaiability studies  being
    conducted during the initial public meeting.  Present-
    ing professionally produced video tapes or slide shows
    on treatabiliiy studies at the public meeting can demon-
    strate that the Agency is attempting to educate the
    public regarding the treatability study process.

  •  Conducting a workshop to present to concerned citizens,
    local officials, and the media the Agency's rationale for
    choosing the treatment technologies to be studied.

  •  Holding small group meetings with involved members
    of the community at regular  intervals throughout the
    Rl/FS process to discuss trcatability study findings and
    site decisions as they develop.

  •  Ensuring citizen access to treatabilily study information
    by maintaining a complete and up-to-date information
    repository.
   •  Presenting results of the treatabilily studies performed
     and explaining how these results influenced the selec-
     tion of the remedy at the final RI/FS public meeting.

 Fact sheets on the planned  ireatability studies should be
 made available to the public and should include a discus-
 sion of trcatabiiity-spccific issues such as the following:

   •  Uncertainties  (risk) pertaining to  innovative tech-
     nologies

   •  The degree of development of potentially applicable
     technologies identified for trcauibiliiy testing

   •  Onsitc treaiability testing and analysis

   •  Offsitc transportation of contaminated materials

   •  Materials handling

   •  Residuals management

   •  RI/FS schedule changes resulting from the unexpected
     need for additional trcatability studies

   •  Potential disruptions to the community

 3.8.2  Remedy Screening

 Remedy-screening treatabilily studies  arc relatively low-
 profile and, if conducted offsite, will require relatively few
 community relations activities. Distributing fact sheets and
 placing the results from remedy screening in  the informa-
 tion  repository will generally be sufficient.

 3.8.3  Remedy-Selection  Testing

 Bench-scale remedy-selection testing may not be particu-
 larly controversial if conducted offsite.  Onsitc bench-scale
 testing, however, may require more community relations
 activities.

 Onsitc,  pilot-scale  testing  may attraci  considerable com-
 munity interest. In some cases (e.g., onsite thermal treat-
 ment), the strength of public opinion concerning trcatability
 testing may not have been indicated by  the level of interest
 demonstrated during the RI and previous treaiability stud-
 ies.  Because  of ihe very real poicntial for  conflici  and
misunderstanding at the remedy-selection testing stage of
 the FS, it is vital  that a strong program of community
relations and public  pariicipaiion  be established well in
advance of any trcatability testing.

Community acceptance is one of the nine RI/FS evaluation
                                                     40

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criteria. Remedy-selection testing may provide daL ih.jt
can convince a community of a technology's ability  to
remediate  a site effectively.  Early, open, and consistent
communication with the public and their full participation
in the decision-making process  may help 10 prevent the
testing, development,  and selection of a remedy that is
unacceptable to the community and results in delayed site
remediation and higher remediation costs.

3.8.4  RD/RA  Testing

Post-ROD trcaiability testing may not be especially contro-
versial within  a community because the remedy or rem-
edies being investigated have already been reviewed and
selected during the RI/FS. Fact sheets and news releases
covering RD/RA ircatabilily study progress may be appro-
priate.
3.9   Complying With Regulatory
       Requirements

Trcatability studies involving Supcrfund wastes arc subject
to various requirements  under CERCLA (as amended in
1986 by SARA] and RCRA [as amended in 1984 by the
Hazardous and Solid Waste Amendments (HSWA)]. The
applicability of these requirements depends on whether the
studies arc conducted on  site (e.g., in a mobile trailer) or at
an offsitc laboratory or testing facility.

Figure 8 summarizes the facility requirements for treatability
testing. Figure 9 summarizes the shipping requirements for
offsitc  trcaiabilily testing.  These  requirements arc de-
scribed in the succeeding subsections.

3.9.1  Onsite Treatability Studies

Onsitc  trcatability studies under  CERCLA may be con-
ducted without any Federal, State, or local permits |40 CFR
300.400(e)(l)];  however, such studies must comply with
ARARs under Federal and State environmental laws to the
extent practicable or justify a waiver under CERCLA Sec-
tion 121(d)(4).  For example, ircatability studies  involving
surface-water discharge must meet effluent limitations even
though a discharge permit is not required.

5.9.2  Offsite Treatability Studies

Section 121 (d)(3) of CERCLA and Revised Procedures for
Implementing Off-Site Response Actions (the "Revised Off-
Site Policy") (EPA 1987c) generally state that offsitc facili-
ties that receive CERCLA wastes must be 1) operating in
compliance with applicable Federal and State laws, and 2)
controlling any  relevant  releases  of hazardous substances
to the environment. Currently, the Revised Off-Site Policy
docs not specifically exempt the transfer of CERCLA wastes
offsite for trcatability studies; therefore, off site laboratories
or testing facilities that receive CERCLA wastes must be in
compliance with the offsitc requirements.

Offsitc ircatability studies under CERCLA must be con-
ducted under appropriate Federal or Slate permits or autho-
rization and other legal requirements. Two alternatives to a
full RCRA facility permit arc available to technology ven-
dors and other laboratory  or  testing facilities for compli-
ance with these requirements: a Research, Development,
and Demonstration (RD&D) permit, which covers limited-
duration and limited-quantity tcsiing of actual hazardous
wasic, and the ucalability exclusion under RCRA, which
may exempt small-scale icsting activities from certain RCRA
permitting requirements.*

Research, Development, and Dcmonairaiion Permits

Hazardous waste treatment facilities thai propose to use an
innovative and experimental ircaimcm technology or pro-
cess for which RCRA permit  siandards have  not been
promulgated under Pan 264 or 266 may obtain an RD&D
permit  (40 CR 270.65).  This provision  is imcndcd 10
expcdilc the permit review and issuance process.

An RD&D permit may be required  for laboratories or
testing facilities that perform pilot-scale tests lhat arc likely
lo exceed  ihe sioragc and treatment  rair limits  specified
under the trcatability  exclusion.  Limitations on  the lypcs
and quantities of hazardous waste lhai can be received and
ircatcd by the facilily  under an RD&D permit and  the
requirements for icsting, reporting, and protection of hu-
man health and the environment (as deemed necessary by
ihc Agency) arc specified in ihc icrms and condiiions of ihc
pcrmii.  The RD&D  pcrrniis arc issued for a period of 1
year and may be renewed up 10 ihrcc limes for  one addi-
tional year each.

The suuus of ihc RD&D  permit authority  in a  particular
State can  be determined by contacting the appropriate
Region's RCRA Coordinator for that Slate.
*The Agency  intends to address  large-scale trcaiabiliiy
studies in separate rulcmaking ai some  fuiurc  date; the
Agency also is considering developing rcgulalions under
40 CFR Part 264, Subpart Y, thai would establish pcrmit-
ling  standards  for experimental facilities conduciing re-
search and dcvclopmcni on the sioragc, ircatmcm, or dis-
posal of hazardous wasic.
                                                     41

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                   Will
            trettability study be
           conducted on site or
                 off site?
                  Do the
             Federal treatability
       study sample exemption rule in
    40 CFR 261.4(e) and (I) (or equivalenl
    State regulations) or other exclusions
            in 40 CFR 261.4(b)
                  apply1?
               Will quantity
           of 'as received" waste
      subjected to initiation of treatment
          in any single day exceed
                 250 kg?
               Will quantity
           of "as received" waste
      stored at the facility for purposes
             of testing exceed
                1000-kg?
No Federal, State, or local permits
required  |40  CFR  300.400(e)(l)|;
however, facility must comply with
applicable   or   relevant   and
appropriate  requirements  under
Federal and  State  environmental
laws to the extent practicable  (or
justify a waiver).
                                                         Subject  to  regulation  under
                                                         appropriate  Federal  and  State
                                                         environmental   laws  and   the
                                                         Revised Off-Site Policy (OSWER
                                                         Directive 9834.11).
                       No
Conditionally  exempt from RCRA treatment,
storage, and permitting  requirements set forth
in 40 CFR Parts 264, 265, and 270  provided
notification,   recordkeeping,   and  reporting
requirements  are  met  [40   CFR  261.4(1)].
Facility  must  comply with  Revised Off-Site
Policy (OSWER Directive 9834.11).
             Figure 8.  Facility requirements for treatability testing.
                                          42

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                               Do the
                           Federal treatability
                    'study sample exemption rule in"
                  40 CFR 261.4(e) and (f) (or equivalent
                   State regulations) or other exclusions,
                          in 40 CFR 261.4(b)
                               apply?
                                    Yes
                            Will quantity of
                        sample shipment exceed'
                     1000 kg of nonacute hazardous
                  waste. 1 kg of acute hazardous waste,
                   ^or 250 kg of soils, water, or debris^
                          contaminated with
                          .acute hazardous^
                                    No
           Subject  to  regulation   under
           appropriate  Federal  and State
           environmental  laws  and  the
           Revised Off-Site Policy (OSWER
           Directive 9834.11).
               Conditionally exempt from RCRA generator
               and transporter requirements set forth in 40
               CFR   Parts   262   and  263   provided
               recordkeeping  and  reporting  requirements
               are met [40 CFR 261.4(e)].
                      Figure 9.  Shipping requirements for oftslte treatability testing.
Treatabiliry Exclusion

Effective July 19,1988, the sample exclusion provision [40
CFR 261.4(d)], which exempts waste samples collected for
the sole purpose of determining their  characteristics  or
composition  from regulation under Subtitle C of RCRA,
was expanded to include waste samples used in small-scale
treatability studies (53 FR 27301). Because it is considered
less stringent than authorized State regulations for RCRA
permits, the Federal Treatability Study Sample Exemption
Rule is applicable only  in those States that do not have final
authorization or in authorized Suites that have revised their
program to adopt equivalent regulations under  State law.
Although  the provision is optional, the EPA has strongly
encouraged authorized  States to adopt the exemption or 10
exercise their authority to order instability studies (in case
of imminent and substantial cndangcrmcnt to health or the
environment) or to grant a general waiver, permit waiver.
or emergency permit authority to authorize trealability stud-
ies. The status of the ircaiability exclusion in a parucular
State  can be determined by contacting the appropriate
Region's RCRA Coordinator for that State.

Under the ireatabilily exclusion, persons who generate or
collect samples of hazardous waste (as defined under RCRA)
for the purpose of conducting trcalability studies arc condi-
tionally exempt from the generator and transporter require-
ments (40 CFR Parts 262 and 263) when the samples arc
being collected, stored, or transported to an offsite labora-
tory or testing facility [40 CFR 261.4(c)] provided that:

  1)   The generator or sample collector uses no more
      lhan 1000 kg of any nonacutc ha/ardous waste, 1
      kg of acute hazardous waste, or 250 kg of soils,
      water, or debris contaminated with acute hazard-
      ous waste per waste stream per treatment process.
                                                       43

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      On a casc-by-casc basis, the Regional Adminis-
      trator  or State Director may  grant requests for
      waste stream limits up to an additional 500 kg of
      nonacute hazardous waste. 1  kg of acute hazard-
      ous waste, and 250 kg of soils, water, or  debris
      contaminated with acute hazardous waste.

  2)  The quantity of each sample shipment docs not
      exceed these quantity limitations.

  3)  The sample is packaged so that it will not leak,
      spill, or vaporize from its packaging during ship-
      ment, and the transportation of each sample ship-
      ment complies with U.S. Dcpartmeni of Trans-
      portation (DOT), U.S. Postal Sen-ice (USPS), or
      any other applicable regulations for shipping haz-
      ardous materials.

  4)  The sample is  shipped to a laboratory or testing
      facility that is exempt under 40 CFR 261.4(0 or that
      has an appropriate RCRA permit or interim status.

  5)  The generator or sample collector maintains cop-
      ies of the shipping documents, the contract with
      the facility conducting the  ircaiabiliiy study, and
      records showing compliance with the shipping limits
      for 3 years after completion of the treaiabilily study.

  6)  The generator provides the preceding documenta-
      tion in its biennial report.

Similarly, offsilc laboratories or testing facilities (includ-
ing mobile treatment units) arc conditionally exempt from
the treatment, storage, and permitting requirements (40
CFR Parts 264,265, and 270) when conducting ircaiabiliiy
studies [40 CFR 261.4(f)] provided that:

  1)  The facility notifies the Regional Administrator or
      Slate Director that it intends to conduct trcaiability
      studies.

  2)  The laboratory or testing facility has an EPA iden-
      tification number.

  3)  The quantity of "as received" hazardous waste
      that is subjected to initiation of treatment in all
      instability studies in any single day is less than
      250kg.

  4)  The quantity of "as received" hazardous waste
      stored at the facility  docs  not exceed 1000 kg,
      which can include 500 kg of soils, water, or debris
      contaminated with acute hazardous waste or 1 kg
      of acuie hazardous waste.
  5)  No  more than 90 days  have elapsed since ihe
      trcatability study was completed, or no more than
      1  year has elapsed since the gcncraior or sample
      collector shipped the sample to the laboratory' or
      testing facility.

  6)  The treatability study involves neither placement
      of hazardous waste on the land nor open burning
      of hazardous waste.

  7)  The facility maintains records showing compli-
      ance wilh the ircatment rate limits and the storage
      lime and quantity  limits for 3  years following
      completion of each study.

  8)  The facility keeps a copy of Uic ircatability study
      contract and all shipping papers for 3 years after
      the completion date of each study.

  9)  The facility submits to the Regional  Administra-
      tor or Stale Director an annual report estimating
      ihe number of studies and the amount of waste to
      be used in ircaiability studies during the current
      year and providing informauon on trcaiability stud-
      ies conducted during ihe preceding year.

  10) The facility determines whether any unused sample
      or residues generated by the trcatabilily study arc
      hazardous waste [unless they arc returned to the
      sample originator under the 40 CFR  261.4(c) ex-
      emption].

  11) The facility notifies the Regional Administrator or
      State Director  when it is no longer planning to
      conduct any instability studies at the site.

Laboratories or testing facilities lhai perform bench-scale
tests generally meet the  storage and ircatment rale limits
outlined in the preceding items.   Faciliiics noi operating
within these limiiaiions arc subject to appropriate regula-
tion.

3.9.3  Residuals Management

Treaiabilily study residuals  generated at an offsilc labora-
tory or testing facility may be rciurncd 10 the sample origi-
nator under ihe Federal Trcatabilily Study Sample Exemp-
tion Rule (or  equivalent State regulations) if the storage
lime limits in 40 CFR 261.4(0 arc not  exceeded.  This
includes any unused sample or residues.  If the cxcmpiion
docs not apply, Ihe disposal of treaiabilily study residuals is
subject to appropriate regulation, including the RCRA land
disposal restrictions for contaminated soil  and debris when
these  regulations become cffcciivc. Trcauibiliiy siudy re-
                                                       44

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siduals managed offsile  must be  packaged, labeled, and
manifested in accordance with 40 CFR Pan 262 and appli-
cable DOT regulations for hazardous materials under 49
CFR Part 172.

As discussed earlier, the Revised Off-Site Policy does not
specifically exempt the transfer of treatability study residu-
als offsile for disposal; therefore, offsile treatment or dis-
posal facilities that receive these wastes must be in compli-
ance with the offsite requirements. The acceptability of a
commercial facility for receiving CERCLA wastes can be
determined by contacting the appropriate Regional Offsile
Contact, as shown in Table 12.

     Table 12.  Regional Offsite Contacts for
    Determining  Acceptability Of Commercial
      Facilities to Receive CERCLA Wastes"
 Region
   Primary
contact/phone
   Backup
contact/phone
    I      Lin Hanifan
          (617)573-5755
    II      Gregory Zaccardi
          (212)264-9504
    III     Naomi Henry
          (215)597-8338
    IV     Alan Antley
          (404) 347-4450
    V     Gertrude Maluschkovitz
          (312)353-7921
    VI     Trish Brechlin
          (214)655-6765
    VII     David Doyle
          (913)236-2891
   VIII     Felix Fiechas
          (303)293-1524
    IX     Diane Bodine
          (415)744-2130
    X     Al Odmark
          (206)553-1886
                    Robin Biscaia
                    (617)573-5754
                    Joe Golumbek
                    (212)264-2638
                    John Gorman
                    (212)264-2621
                    Rita Tale
                    (215)597-8175
                    Gregory Fraley
                    (404) 347-7603
                    Paul Dimock
                    (312)886-4445
                    Randy Brown
                    (214)655-6745
                    Marc Rivas
                    (913)236-2891
                    Mike Gansecki
                    (303)293-1510
                    Terry Brown
                    (303)293-1823
                    Jane Diamond
                    (415)744-2139
                    Ron Lillich
                    (206) 553-6646
 aThese contacts are subject to change.
3.10  Executing the Study

Execution of the trcatability study begins after the project
manager has approved the Work Plan and other supporting
documents. Steps include collecting a sample of the waste
stream for characterization and testing, conducting the test.
and collecting and analy/ing samples of the treated waste
and residuals.

3.10.1   Field Sampling and Waste
          Stream Characterization

Field samples should be collected and preserved in accor-
dance with the  procedures outlined  in the SAP.  They
should be representative of either "average"  or "worst-
case" conditions (as dictated by the test objectives), and the
sample should be large enough 10 complete all of the re-
quired tests and analyses in the event of some anomaly.
Collocated field  samples also should be collected in accor-
dance with the QAPP. To the extent possible, field sam-
pling should be coordinated wiih oihcr onsile activities to
minimize costs.  Samples shipped to an offsile laboraiory
for icsu'ng or analysis must be packaged, labeled,  and
shipped in accordance with DOT, USPS, or other applicable
shipping  regulations  (sec  Subsection 3.9).  A chain-of-
custody record must accompany each sample shipment.

The waste sample should be thoroughly mixed to ensure
that it is homogeneous.  This permits a comparison of
results under different test conditions.  Small-volume soil
samples can be mixed with a Hobart mixer, and large-
volume samples can be mixed  with a drum roller. Stones
and debris should be removed by screening. Care must be
exercised during these procedures to avoid contaminating
the waste samples (or allowing volatiles to escape) and to
ensure effective  homogcnizaiion.

Characterization samples should be collected from the same
material  that will  be used in the performance of the
treatability study.  Characterization is necessary to deter-
mine the chemical, physical, and/or biological properties
exhibited by the waste  stream so that  the results of the
ircatability study can be properly gauged.

3.10.2   Treatability Testing

The treatability  study should be performed in accordance
with the  test matrix  and standard operating  procedures
described in the  Work Plan. Any deviations from the SOP
should be recorded in the field or laboratory notebook.

The EPA or a qualified contractor should oversee testing
conducted by vendors and PRPs.  Oversight activities were
discussed in Subsection 2.5.5.

3.10.3   Sampling and Analysis

Samples of ihc  treated waste and process residuals (e.g.,
off-gas, scrubber water, and ash for incineration tests) should
be collected in accordance with the SAP.  The SAP spcci-
                                                    45

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fies the location and frequency of sampling, proper con-
tainers, sample preservation techniques, and maximum hold-
ing times. Quality assurance/quality control samples will
be collected at the same time as the trcatability study samples
in accordance with the QAPP. All samples must be logged
in the field or laboratory notebook. Samples shipped to an
offsite laboratory  must be packaged, labeled, and shipped
in accordance  with DOT, USPS, or other applicable ship-
ping regulations,  and a chain-of-custody record must ac-
company each sample shipment.

Treatability  study samples should be analyzed in accor-
dance with  the methods specified in the SAP.  Normal
sample turnaround lime is 3 to 5 weeks  for most analyses;
the laboratory may charge a premium if results are required
in less lime.
3.11  Analyzing and Interpreting the
       Data

3.17.1   Data Analysis

Upon completion of a treatability study, the data must be
compiled and analyzed. The first goal of data analysis is to
determine the quality of the data collected. All data should
be checked to assess precision,  accuracy, and complete-
ness.  Both testing and analytical error must be assessed to
determine total error. If the QA objectives specified in the
QAPP have not been met, the project manager and the EPA
Work Assignment Manager must determine the appropri-
ate corrective action.

Data are generally summarized in tabular or graphic form.
The  exact presentation of the  data  will depend on the
experimental design and the relationship between the vari-
ables being  compared.   For  data presented graphically,
independent variables, which arc controlled by the experi-
menter, are generally plotted on the abscissa; whereas depen-
dent variables, which change in  response to changing the
independent variables,  are plotted on the ordinate.   Ex-
amples of independent variables are pH, temperature,  re-
agent concentration, and  reaction time.  Examples of de-
pendent variables are removal efficiency and substrate uti-
lization.

For determining whether statistically significant differences
in treatment effectiveness exist between two or more val-
ues of an independent variable, the use  of analysis of
variance and other statistical techniques may be appropri-
ate.  These techniques  can assist in identifying the  most
cost-effective combination of parameters  in a  treatment
system with multiple independent variables.   Statistical
analysis of treatability study data, however, should only be
performed when planned and budgeted for.

3.11.2   Data Interpretation/Pre-ROD

Interpretation of treatability study data must be based on
the test objectives established prior to testing. Data inter-
pretation is an important pan of the ircatability study re-
port.  Therefore, the contractor or other parly performing
the sludy and preparing ihe report must fully understand the
study objectives and the role the results will play in remedy
screening, selection, or implementation. The investigating
party, not ihe RPM,  is responsible  for  inierprciing ihc
ireatability sludy data.

The purpose of a pre-ROD ircatability invesiigation is to
provide ihe daia needed for a detailed analysis of alterna-
tives and, ultimately, the selection of a remedial action that
can achieve the site  cleanup criteria.  The results of  a
trcatability sludy should enable the RPM to evaluate ull
ircaimem alternatives on an equal basis during the detailed
analysis of alternatives.

The Work Plan outlines ihe ircatability study's test objec-
tives and describes how these objectives will be used in the
evaluation of  the technology (i.e., remedy  screening or
remedy selection). As discussed in Section 2, the  1990
revised NCP Section  300.430(c) specifies nine evaluation
criteria  10 be  considered in ihe assessment of remedial
alternatives. These criteria were developed to address both
ihe specific  statutory  requirements of CERCLA Section
121 (threshold criteria) and the icchnical and policy consid-
erations  that are important in ihe selection of remedial
alternatives (primary balancing criteria and modifying cri-
teria). The nine RI/FS evaluation criteria arc as follows:

Threshold criteria:

  • Overall  proicction of human health and ihc
    environment
  • Compliance with ARARs

Primary balancing criteria:

  • Long-icrm effectiveness and permanence
  • Reduction of toxicity, mobility, and  volume ihrough
    treatment
  • Short-term effectiveness
  • Implcmcntability
  • Cost

Modifying criteria:

  • State acceptance
  • Community acceptance
                                                      46

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As discussed in the following subsections, ircatability stud-
ies provide important data for use in the assessment of an
alternative against both the threshold criteria and the pri-
mary balancing criteria. The results of treaiability studies
can also influence evaluations against the State and com-
munity acceptance criteria. Figure 10 lists factors impor-
tant to the analysis of the Rl/FS evaluation criteria. These
factors arc often technology-specific, as arc the treatability
study data that support the analysis of each factor. Example 5
outlines some of the specific analysis factors applicable to
chemical dchalogcnation treatment technologies and several
types of data from a chemical dchalogenation  trcatability
study that provide information for each of these factors

Evaluations against the nine criteria are performed for the
overall alternative,  of which the treatment technology  is
only a pan. The alternative will generally include additional
treatment, containment, or disposal technologies.  Detailed
guidance  on the  Super!und program's  remedy-selection
process as established in the 1990 revised NCR Section
300.430(0 is available  in the Rl/FS guidance and in  A
Guide to Selecting Supcrfund Remedial Actions (EPA 1990b).

Threshold Criteria

The two statutory-based threshold criteria should be used
to set instability study performance goals.  Only  those
alternatives that satisfy the threshold criteria arc eligible for
remedy selection.

Overall Protection of Human Health and the Environment

This evaluation criterion provides an overall assessment of
how well each alternative achieves and  maintains protec-
tion of human health and the environment. The analysis of
overall protection will draw on the assessments conducted
under the primary evaluation criteria and the compliance
with ARARs. It will focus on the ability of an alternative to
eliminate, reduce, or control overall site risks.

Trcatabilily studies will provide general data for the evalu-
ation  under this criterion. Target contaminant concentrations
in the treated product and any treatment residuals will dem-
onstrate how well the process or treatment train can eliminate
site risks.  If an ecological risk assessment is  being con-
ducted, bioassessmcnts of these materials will generate the
data required to evaluate the reduction in risk to  site biota.

Compliance with ARARs

Applicable or relevant and appropriate  requirements arc
any local. State, or Federal regulations or standards that
pertain to chemical  contaminant  levels, locations, and ac-
tions  at CERCLA sites.  Trcatabilily study performance
goals are generally  based on ARARs.  Performance data
indicaung how well the process achieved these goals will
aid in evaluating the  technology against the compliance
with ARARs criterion.

Chemical-specific ARARs arc health or risk-based numeri-
cal values  or  methodologies that, when applied  to site-
specific conditions, result in the establishment of maxi-
mum acceptable amounts or concentrations of chemicals
that may be found in or discharged to the ambient environ-
ment.  For example,  chemical-specific  ARARs may  in-
clude RCRA Land  Disposal Restrictions (LDRs) on  the
placement of treated soil or Safe Drinking Water Act Maxi-
mum Contaminant Levels (MCLs) and  Clean Water Act
Water Quality Criteria for the treatment and discharge of
wastcwatcr. Chemical-specific ARARs  will be expressed
in terms of contaminant concentrations in the treated prod-
uct and treatment residuals. Often, these ARARs define  the
"target" contaminants for the trcauibility study.

Location-specific ARARs arc restrictions  placed on  the
concentration  of hazardous  substances or the conduct of
activities solely because they arc in a  specific location,
such as a floodplain, a wetland, or a historic place. Loca-
tion-specific cleanup  criteria may include, for example,
biotoxicity requirements for  treated product and ircaimcnt
residuals if runoff from the ircaimcnt area or the disposal
site could have an impact on  a sensitive wildlife habitat.

Action-specific ARARs arc technology- and activiiy-bascd
requirements or limitations on actions taken  with respect to
hazardous  wastes.  Action-specific  requirements  may be
particularly applicable to the  discharge of residuals such as
wastcwater.  Target  contaminant concentrations  in  the
ircatability study wastcwatcr will aid in identifying action-
specific ARARs.

The actual  determination of which requirements arc appli-
cable or relevant and appropriate will be made by the lead
agency.  Detailed guidance  on  determining whether  re-
quirements are applicable or relevant and  appropriate is
provided in CERCLA Compliance with Other Laws Manual:
Interim Final (EPA  1988c) and CERCLA Compliance with
Other Law Manual: Part II (EPA 1989Q.

Primary Balancing Criteria

The five primary balancing  evaluation criteria should be
used for guidance in setting trcatabiliiy study  test objectives.

Long-Term Effectiveness and Permanence

This evaluation criterion addresses risks remaining at  the
site aflcr ihc remedial response objectives have been mci.
                                                      47

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            Overall Protection of
           Human Health and the
                Environment
           How Alternative Provides
           Human Health and
           Environmental Protection
                                             Compliance With ARARs
                                             Compliance With
                                             Chemical-Specific ARARs
                                             Compliance With Action-
                                             Specific ARARs
                                             Compliance With
                                             Location-Specific ARARs
                                             Compliance With Other
                                             Criteria. Advisories, and
                                             Guidances
Long-Term
Effectiveness and
Permanence

Reduction of Toxicity,
Mobility, or Volume
Through Treatment

Short-Term
Effectiveness

Implementability

Cost
  Magnitude of
  Residual Risk
  Adequacy and
  Reliability of
  Controls
Treatment Process
Used and Materials
Treated
Amount of Hazardous
Materials Destroyed or
Treated
Degree of Expected
Reductions in Toxicity,
Mobility, and Volume
Degree to Which
Treatment Is Irreversible
Type and Quantity of
Residuals Remaining
Alter Treatment
Protection of
Community During
Remedial Actions
Protection of
Workers During
Remedial Actions
Environmental
Impacts
Time Until Remedial
Response
Objectives Are
Achieved
State
Acceptance'

Community
Acceptance*
Ability to Construct
and Operate the
Technology
Reliability of the
Technology
Ease of Undertaking
Additional Remedial
Actions. If
Necessary
Ability to Monitor
Effectiveness of
Remedy
Ability to Obtain
Approvals From
Other Agencies
Coordination With
Other Agencies
Availability of Offsite
Treatment, Storage,
and Disposal
Services and
Capacity
Availability of
Necessary
Equipment and
Specialists
Availability of
Prospective
Technologies
Capital Costs
Operating and
Maintenance
Costs
Present Worth
Cost
"These criteria are assessed following comment on the RI/FS report and the proposed plan.
EPA 1988a
     Figure 10.  Evaluation criteria and analysis factors lor detailed analysis of alternatives.
                                                    48

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EXAMPLE 5. APPLICABILITY OF CHEMICAL DEHALOGENATION TREATABILITY STUDY DATA
                              TO RI/FS EVALUATION CRITERIA
    Evaluation Criteria
      Analysis Factors
      Treatability Study Data
 Long-Term Effectiveness
 and Permanence
Magnitude of residual risk
Target contaminant concentrations in
treated product and treatment
residuals
Presence of specific reaction
byproducts in treated product
Results of bioassays performed on
treated product	
 Reduction of Toxicity,
 Mobility, or Volume
 Through Treatment
Reduction in toxicity
                          Irreversibility of the treatment
                          Type and quantity of, and
                          risks posed by, treatment
                          residuals
Percent reduction in target
contaminant concentrations
Comparison of bioassay results
before and after treatment
Material balance data combined with
target contaminant concentrations in
treated product and treatment
residuals
Target contaminant concentrations in
treatment residuals
Presence of specific reaction
byproducts in treatment residuals
Results of bioassays performed on
treatment residuals
Volume of treatment residuals   	
 Short-Term Effectiveness
Time until remedial response
objectives are achieved
Reaction time
 Implementability
Reliability and potential for
schedule delays
Reliability and schedule delays curing
testing
Reaction time/throughput
Physical characteristics of waste
matrix
Contaminant variability in untreated
waste
 Cost
Direct capital costs
Reaction time/throughput
Reagent usage/recovery
Reaction temperature
Physical characteristics of waste
matrix
Site characteristics
 Compliance with ARARs    Chemical-specific ARARs
                               Target contaminant concentrations in
                               treated product and treatment
                               residuals
Overall Protection of
Human Health and the
Environment
Ability to eliminate, reduce,
or control site risks
Target contaminant concentrations in
treated product and treatment
residuals
Presence of specific reaction
byproducts in treated product and
treatment residuals
Results of bioassays performed on
treated product and treatment
residuals
                                             49

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Assessment of the residual risks from untreated waste and
treated product left on site must involve the same assump-
tions and calculation procedures as those used in the base-
line risk assessment.  If engineered controls (e.g., contain-
ment systems) are to be used to manage these remaining
materials, their  adequacy and reliability also should be
evaluated under this criterion.

Remedy-.1 election treatability studies can often provide data
on the site's  post-remediation residual  risk.  If treated
product will remain on site, the contaminant concentrations
in this material must meet the site's cleanup criteria.  As
discussed in Subsection 2.4, these cleanup criteria translate
into  specific performance goals.  The concentrations of
target contaminants  in  the treated product and treatment
residuals after treatability testing indicate the magnitude of
the site's residual risk after treatment.

If an ecological risk assessment is to be  performed, the
residual risks posed  to biota by the replacement  of the
treated product on site can be assessed under this criterion.
The  literature survey may provide adequate data to evalu-
ate the biotoxicity of treated soils. If the literature contains
little or no biotoxicity data on the contaminants/matrix of
interest, this data need can be addressed  by performing
bioassays at the remedy-selection tier. A treatability study
test objective  that stipulates a reduction  in the loxicity of
the treated  product to test organisms will provide data for
the assessment  of the  technology against the long-term
effectiveness and permanence criterion.

Reduction ofToxicity. Mobility, and Volume Through Treat-
ment

This evaluation criterion addresses the statutory preference
for selecting technologies that permanently and  signifi-
cantly reduce the toxicity, mobility, or volume of the haz-
ardous substances. This preference is satisfied when treat-
ment is used to reduce the principal threats at a site through
destruction of toxic  contaminants, reduction of the total
mass of toxic  contaminants, irreversible reduction in con-
taminant mobility, or reduction  of the  total volume of
contaminated media.

Treatabilily studies should provide detailed  performance
data  on the percentage reduction in the toxicity, mobility,
or volume of the treated product  As discussed in Subsec-
tion  2.4, a performance goal of greater than 50 percent
reduction in toxicity, mobility, or volume may be appropri-
ate at the remedy-screening tier. If this performance goal is
met,  the technology is considered to be potentially feasible.
At the remedy-selection tier, the process should be capable
of achieving the site cleanup criteria with an acceptable
level of confidence. If no cleanup criteria have been estab-
lished for the site, a 90 percent reduction in contaminant
concentration will generally be an appropriate performance
goal.

Another measure of reduction in loxicity is the comparison
of bioassay results from tests performed on the waste be-
fore and after treatment. If treated product is to remain on
site, a  reduction in biotoxicity should be identified as a
trcaiability test objective for remedy-selection testing.

Irreversibility of the treatment process is another  factor in
the evaluation of a technology against this criterion.  Mate-
rial balance data from a treatability  study combined with
the target contaminant concentrations found in the treated
product and treatment residuals can indicate the level of
irreversibility achieved through treatment. These  daui can
be used to construct a mass balance for the target contami-
nants, which will approximate the contaminant destruction
efficiency of the treatment process.

Taking  the treatment  residuals into consideration is an
important part of the assessment of a technology against the
reduction in toxicity, mobility, and volume criterion. Con-
centrations of target contaminants in ircatabilily study re-
siduals  indicate  the risks  posed by  onsitc treatment and
disposal of the process residuals. Data on the biotoxicity
and volume of  ireatability  study  residuals also provide
information for this assessment.

Short-Term Effectiveness

The short-term effectiveness criterion is concerned with
the effects of the alternative on  human health  and the
environment during its construction and implementation.
The RI/FS guidance outlines several factors that may be
addressed, if appropriate, when assessing an alternative
against  this criterion. Treatability studies can provide in-
formation on three  of these factors:  1)  protection  of the
community during  remedial actions, 2)  protection  of the
workers, and 3) lime required to achieve remedial  response
objectives.

If a site is located near a population center, any short-term
health  risks posed  by the remedial aciion musi be ad-
dressed. The instability sludy wasic characterization can
idcnu'fy some of ihcsc risks.  For example, physical charac-
icrisiics of the waste matrix, such as moisture content and
particle-size distribution, could indicate a potential for the
generation of contaminated dust during material-handling
operations. The presence of volatile contaminants in the
waste also could pose risks to community  health during
material handling and treatment. Treatment residuals should
be carefully characterized to assist in the posuROD design
of proper air and water treatment systems.
                                                       50

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For the protection of workers during implementation of the
remedy,  the phys.cal and chemical characteristics of the
untreated waste matrix and the treatment residuals are im-
portant data to be collected during treatability testing. These
data will aid in the assessment of any threats  posed  to
workers and the effectiveness and reliability of the protec-
tive measures to be taken.  Treatability systems can also be
monitored  for any adverse conditions thai may develop
during testing.

The time required  to achieve the remedial response objec-
tives for the site depends on the volume of soil to be treated
and the throughput of the  full-scale unit or treatment  train
system.  Treatability studies of  some  technologies will
generate treatment duration data  sufficient to allow  esti-
mates of throughput to be  made.

Implemeniabiliiy

This evaluation criterion assesses the technical and admin-
istrative  feasibility of implementing an alternative and the
availability of the equipment an'! services required during
implementation. The process of designing and performing
treatability studies may assist in the analysis of the follow-
ing implementability factors:

  • Difficulties associated with construction and operation

  • Reliability and potential for schedule delays

  • Ability to monitor treatment effectiveness

  • Commercial availability of the treatment process and
    equipment

The literature survey should provide historical information
regarding most of the preceding factors.  If an alternative
has been shown to be  capable of achieving the desired
cleanup  levels  but has never  been demonstrated at full
scale, reliability data may be insufficient for its assessment
under the implementability criterion.  In  this case,  data
from a pre-ROD pilot-scale test may be required.

The reliability of the pilot system,  including any schedule
delays encountered during its testing, will serve as an indi-
cator of the implementability of the full-scale system.  The
treatment duration and throughput can also provide infor-
mation on potential schedule delays. Characteristics of the
matrix that could lead to equipment failure or diminished
treatment effectiveness, such as high clay content, can  be
investigated during a prc-ROD treatability study.  Con-
taminant variability in the untreated waste could  also lead
to schedule delays  by requiring repeated treatment of some
soils.   Treatability testing of  multiple  waste types  with
differing contaminant concentrations  can  provide  impor-
tant data for analysis of the reliability factor and the imple-
mentability evaluation criterion.

Cost

The cost criterion evaluates the full-scale capital and opera-
lion and maintenance (O&M) costs of each remedial action
alternative.  The assessment of this criterion requires the
development of cost estimates for the full-scale remedia-
tion of the site.  These estimates should provide an accu-
racy of +50 percent to -30 percent.  A  comprehensive
discussion of costing procedures for CERCLA sites is in-
cluded in Remedial Action  Costing Procedures Manual
(EPA 1,985). The cost estimate prepared under this crite-
rion will be based on information obtained from the litera-
ture  and  from  technology vendors.  Preparation  of the
estimate may also require remedy-selection instability study
data.

Direct capital costs for treatment will include expenditures
for the equipment, labor, and materials necessary to install
the system.   If  the technology vendor has already  con-
structed a  mobile, full-scale treatment unit, treauibility study
data will  not be required to determine direct equipment
costs.  If no full-scale system exists, however, trcatabiliiy
studies can provide the .operational data necessary for equip-
ment scale-up.  Characteristics  of (he matrix identified
during treatabilily testing,  such as particle-size distribution
and moisture content,  will have an impact on decisions
regarding  front-end material handling operations and equip-
ment and  post-treatment equipment for processing of the
product and residuals in a treatment train.  Characteristics
of the site that may have an. impact on the logistical costs
associated with  mobilization and  onsitc treatment  can  be
identified  during the ircatabiliiy study  sample-collection
visit.

Estimates of utility costs, residuals treatment and disposal
costs, and O&M costs will depend on the physical/chemi-
cal characteristics of the waste and residuals (which affect
the difficulty of treatment) and the throughput (which af-
fects the total time for treatment).  These data arc available
from remedy-selection treatability studies.

3.11.3  Data Interpretation/Post-ROD

As opposed to  pre-ROD trcauibility studies, no  clearly
defined criteria exist on which  to base the interpretation of
post-ROD RD/RA trcatability  study results. The purpose
of an RD/RA trcaiability study  is to generate specific,
detailed design, cost, and performance data. These data arc
then used  1) to prcqualify vendors and processes within the
prescribed remedy, 2) to implement the most appropriate of
                                                      51

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the remedies prescribed in a Contingency ROD, or 3) to
support preparation of the Agency's detailed design speci-
fications and the design of treatment trains.

When an RD/RA treatability study is performed to prequalify
vendors, data interpretation consists of a straightforward
determination by the lead agency or the designer regarding
whether the vendor has attained  the preset performance
goals. Little or no cost data are generated by prequalification
treatability studies. Based on these results, the lead agency
determines which vendors are qualified to bid on the RA.
Generally, the vendor should achieve results equivalent to
the cleanup criteria defined in the ROD  to be considered for
prequalification.

In the case of a Contingency ROD, implementation of the
selected remedy may depend  on the results of RD/RA
treatability testing. Treatability studies performed to sup-
port a Contingency ROD are designed to obtain perfor-
mance and cost data on the selected remedy that were not
available during the RI/FS.  After this information is ob-
tained, data interpretation focuses  on determining whether
the selected  remedy will provide superior protection of
human health and the environment at a cost comparable to
that of the contingency remedy.  If so, the  selected remedy
is designed and implemented.   If not, the  contingency
remedy is implemented.

Post-ROD treatability study results are also used to sup-
port the preparation of the detailed design specifications
and the design of treatment trains.  Because the treatability
study is designed to provide specific detailed operations
data on the remedy for use by the remedial design contrac-
tor, the designer is generally responsible for data interpre-
tation.
3.12  Reporting the Results

3.12.1   General

The final step in conducting a treatability study is reporting
the lest results. Complete and accurate reporting is critical,
as decisions about  treatment alternatives will  be  based
partly on the outcome of the treatability studies.  Besides
assisting  in the selection and implementation of the rem-
edy,  the performance of treatabiliiy studies will increase
the existing body of scientific knowledge about treatment
technologies.

To facilitate the reporting of ireatability study results and
the exchange of treatment technology information. Table 13
presents a suggested organization for a treatability study
report. Reporting ireatability study results in this manner
will expedite the process of comparing treatment alterna-
tives.  It will also allow other individuals who may be
studying similar technologies or  waste matrices to gain
valuable insight into the applications and  limitations of
various treatment processes.

If a treatment technology is to be tested at  multiple tiers,
preparau'on of a formal report for each tier of the testing
may not be necessary.  Interim reports  prepared  ai the
completion of each tier  may suffice.   Also,  it may be
appropriate to conduct a project briefing with the interested
panics to present the study findings and to  determine the
need for additional testing. A final report that encompasses
the entire study should be developed after all testing is
complete.

As an aid in the seleciion of remedies and the planning of
future  treatability studies,  the Office of  Emergency and
Remedial Response requires that a copy of  all  treatability
study reports be submitted  to the  Agency's RREL  Treat-
abilily Data Base repository, which is being developed by
the ORD (EPA 1989e). This requirement applies to both
the removal and remedial programs of Superfund. Submit-
ting treatability study reports  in accordance with the sug-
gested organization will increase  the usability of this re-
pository' and  assisi in maintaining and updating the data
base.  One camera-ready master copy of each  treatability
study report should be sent  to  the following address:

       Mr. Glenn M. Shau)
       RREL Treatability Data Base
       U.S. Environmental Protection Agency
       Office of Research and Development
       Risk Reduction Engineering Laboratory
       26 W. Martin Luther King Drive
       Cincinnaii, Ohio 45268

The  following subsections describe the  contents of the
treatabilily study report.

Introduction

The introductory section of the treatability study  report
contains background  information about the site,  waste
stream, and treatment technology.  Much of this informa-
tion  will come directly from the previously prepared
ireatability study Work Plan.  This section also includes a
summary of any treatabilily siudies previously conducted
at the site.

Conclusions and Recommendations

This seciion  of the repon  presents the conclusions and
recommendaiions regarding the applicability of the treat-
                                                      52

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      Table 13.  Suggested Organization of
             Treatability Study Report

 1. Introduction
    1.1  Site description
         1.1.1   Site name and location
         1.1.2   History of operations
         1.1.3   Prior removal and remediation
                activities
    1.2  Waste stream description
         1.2.1   Waste matrices
        •1.2.2   Pollutants/chemicals
    1.3  Treatment technology description
         1.3.1   Treatment process and scale
         1.3.2   Operating features
    1.4  Previous treatability studies at the site
 2. Conclusions and Recommendations
    2.1  Conclusions
    2.2  Recommendations
 3. Treatability Study Approach
    3.1  Test objectives and rationale
    3.2  Experimental design and procedures
    3.3  Equipment and materials
    3.4  Sampling and analysis
         3.4.1   Waste stream
         3.4.2   Treatment process
    3.5  Data management
    3.6  Deviations from the Work Plan
 4. Results and Discussion
    4.1  Data analysis and interpretation
         4.1.1   Analysis of waste stream
                characteristics
         4.1.2   Analysis of treatability study data
         4.1.3   Comparison to test objectives
    4.2  Quality assurance/quality control
    4.3  Costs/schedule for performing the
         treatability study
    4.4  Key contacts
 References
 Appendices
 A.  Data summaries
 B.  Standard  operating procedures	
ment process tested.  It should aucmpi 10 answer questions
such as the following:

  •  Were the performance goals met?  Were the other test
    objectives achieved? If not, why not?

  •  Were there any problems with  the treatability study
    design or procedures?
  • What parts of the test (if any) should have been per-
    formed differently? Why?

  • Are additional tiers of trcatability testing required for
    further evaluation  of the technology?  Why or why
    not?

  • Are data sufficient for adequately assessing the tech-
    nology against the Rl/FS evaluation criteria (if prc-ROD)?

  • Are data sufficient for designing and implementing the
    remedy (if post-ROD)?

The conclusions  and recommendations should be  stated
briefly and succinctly.  Information that is pertinent to the
discussion and exists elsewhere in the rcpon  should  be
referenced rather than restated in this section.

This section should  provide an analysis of the results as
they relate to the objectives of the study and the relevant
evaluation criteria. When appropriate, the results should be
extrapolated to full-scale operation  to  indicate areas of
uncertainty in the analysis and the extent of this uncertainly.

Treatability Study Approach

This section reports why and how the trcaiability study was
conducted.  It describes in detail the procedures and meth-
ods that were used to sample and analyze the waste stream
and documents any deviations  from the Work Plan.  Like
the introduction, this  section contains information from the
previously prepared Work Plan.

Results and Discussion

The final section of the trcatability study report includes the
presentation and  a discussion of results (including QA/
QC).  Results for the contaminants of concern  should be
reported in terms of the concentration in the  input and
output streams and  the percentage reduction in toxicity,
mobility, or volume  that was achieved.  The use of charts
and graphs may aid  in the presentation of these results.
This section also includes the costs  and time required to
conduct the study and any key contacts for future reference.

Appendices

Summaries of the data  generated and the standard operat-
ing procedures used arc included in appendices.

3.12.2  Remedy Screening

Remedy screening results will be reported in  the format
shown in Table 13; however, some of the sections mav be
                                                    53

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abbreviated  if remedy-selection lesung is planned.  The
conclusions and recommendations will focus primarily on
whether the technology investigated is potentially feasible
for the site and will attempt to identify critical parameters
for future treatability testing.  Data will  be presented in
simple tables or graphs. Statistical analysis is generally not
required. Because remedy screening does not involve rig-
orous QA/QC, the discussion of this subject will be brief.

3.12.3  Remedy-Selection  Testing

Conclusions and recommendations resulting from remedy-
selection testing will focus primarily  on the technology's
performance (i.e., ability to  meet the performance goals
and test objectives) and will attempt to  identify critical
parameters for  future treatability testing, if needed.  A
detailed discussion of data quality should be included in the
results section.   The results section  may also include a
statistical evaluation of the data.

3.72.4   RD/RA Testing

Conclusions and recommendations resulting from RD/RA
testing will focus on the technology's ability to achieve the
performance goals and test objectives. Any process opti-
mization  parameters that were identified should also  be
discussed. The results should include a detailed discussion
of data quality.
                                                      54

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                                      REFERENCES
dcPercin, P., E. Bales, and D Smith.  1991.  Designing
Treaiability Studies for CERCLA Sites:  Three Critical
Issues. J. Air Waste Manage. Assoc., 41(5):763-767.

National Institute for Occupational Safely and Health/Oc-
cupational Safely and Health Adminisiration/U.S.  Coast
Guard/U.S. Environmental Protection Agency.  1985. Oc-
cupational Safety and Health Guidance Manual for Haz-
ardous Waste Site Activities.  DHHS (N10SH) Publication
No. 85-115.

U.S. Environmental Proteciion Agency.  1980.  Inierim
Guidelines and Specificaiions for Preparing Quality Assur-
ance Projcci Plans. QAMS-005/80.

U.S. Environmental Proiection Agency. 1985. Remedial
Action Costing Procedures Manual.  EPA/600/8-87/049.
OSWER Directive No. 9355.0-10.

U.S. Environmental Protection Agency.  1986. Test Meth-
ods for Evaluating Solid Wasie. 3rdcd. SW-846.

U.S. Environmental Proteciion Agency. 1987a. Daia Qual-
ity Objccuves for Remedial Response Activities. Develop-
ment Process (Volume I).  EPA/540/G-87/003, OSWER
Directive 9355.0-7B.

U.S. Environmental Proteciion Agency. 1987b. A  Com-
pendium of Supcrfund Field  Operations Methods.  EPA/
540/P-87/001.

U.S. Environmental Proteciion Agency. 1987c. Revised
Procedures for Implemeniing Off-Site Response Actions.
OSWER Directive No. 9834.11, November 13,1987.

U.S. Environmental Protection Agency.  1988a. Guidance
for Conducting Remedial Investigations and Feasibility
Siudies Under CERCLA.  Interim Final. EPA/540/G-89/
004. OSWER Directive 9355.3-01.
U.S. Environmental Protection Agency.  198Sb.  Commu-
nity Relations in Supcrfund:  A Handbook.  Interim Ver-
sion. EPA/540/G-88/002. OSWER Directive 9230.0-3B.

U.S. Environmental Proteciion Agency.  1988c. CERCLA
Compliance with Olhcr Laws Manual:  Interim Final. EPA/
540/G-89/006.

U.S. Environmental Proteciion Agency.  1989a.  Managc-
mcni Review of ihc Supcrfund Program.  EPA/540/8-89/
007.

U.S. Environmenial Protection Agency.  1989b. Guide for
Conducting Treaiabiliiy Studies Under CERCLA. Interim
Final. EPA/540/2-89/058.

U.S. Environmental Protection Agency.  1989c.  Model
Staiemcnt of Work fora Remedial Investigation and Feasi-
bility Sludy Conducted by Potentially Responsible Parties.
OSWER Directive No. 9835.8, June 2, 1989.

U.S. Environment! Proicction Agency.  1989d.  Quality
Assurance Procedures for KREL. RREL Document Con-
trol No.  RREL(QA)-001/89.

U.S. Environmcntal Proicciion Agency.  1989c. Treaiabil-
ity Studies Coniracior Work Assignments.  Memo from
Henry L. Longest, II, Dirccior, Office of Emergency and
Remedial Response, 10 Supcrfund Branch Chiefs, Regions
I ihrough X. OSWER Directive 9380.3-01, July  12, 1989.

U.S. Environmental Proicciion Agency.  1989f. CERCLA
Compliance wiih Olhcr Laws Manual: Pan II. Clean Air
Aci and Olher Environment! Siaiutes and Stale Require-
ment EPA/540/G-89/009. OSWER Directive No. 9234.1-02.

U.S. En vironmenial Proicciion Agency.  1990a. Inventory
of Treaiabiliiy Sludy Vendors, Volumes 1 and II. EPA/
540/2-90/003a and b.
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U.S. Environmenial Protection Agency.  1990b. A Guide    U.S. Environmental Protection Agency. 1991b. Guidance
to Selecting Superfund Remedial Actions. OSWER Direc    on Oversight of Potentially Responsible Party Remedial
live 9355.0-27FS.                                       Investigations and Feasibility Studies.  Volume  1. EPA/
                                                      540/G-91/010a. OSWER Directive No. 9835. l(c).
U.S. Environmental Protection Agency.  1991a. Guidance
for  Increasing  the Application of  Innovative Treatment    U.S. Environmental Protection Agency. 199lc. Administra-
Technologies for Contaminated Soil and Ground Water.    live Order on Consent for Remedial Investigation/Feasibility
OSWER Directive 9380.0-17, June  10,1991.               Study. OSWER Directive No. 98353-2A, July 2,1991.
                                                   56

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                                       APPENDIX A
           SOURCES OF TREATABILITY INFORMATION
A wide range of technical resources exists within the EPA
to assist in the planning and performance  of treaiability
studies.  These resources include reports  and guidance
documents, electronic dam bases, and Agency-sponsored
technical support.  This appendix describes the primary
treaiability study resources currently available.


Reports and Guidance Documents

Knowledge gained during the performance of treaiability
studies is available in reports and technical guidance docu-
ments.  The following documents can be used to identify
technology-specific treaiability resources.

    Superfund Treatability Clearinghouse Abstracts. U.S.
    Environmental Protection Agency, Office of Emer-
    gency and Remedial Response, Washington, DC. EPA/
    540/2-89/00 I.March 1989.

    Inventory of Treatability Study Vendors, Volumes  I
    and II. U.S. Environmental Protection Agency, Office
    of Emergency and Remedial Response, Washington,
    DC. EPA/540/2-90/003a and b, February 1990.

    The Superfund Innovative Technology Evaluation Pro-
    gram: Technology Profiles. U.S. Environmental Pro-
    tection Agency, Office of Solid Waste and Emergency
    Response and Office of Research and  Development,
    Washington, DC. EPA/540/5-90/006, November 1990.

    Guide to Treatment Technologies for Hazardous Wastes
    at Superfund Sites.  U.S.  Environmental Protection
    Agency, Office of Solid Waste and Emergency Re-
    sponse, Washington, DC. EPA/540/2-89/052, March
    1989.

    Treatabilily Potential for EPA Listed Hazardous Wastes
    in Soil.  U.S. Environmental Protection Agency, Of-
    fice of Research and Development, Ada, OK. EPA/
    600/2-89/01 I.March 1989.
    Catalog of Superfund Program Publications. U.S. En-
    vironmental Protection Agency, Office of Emergency
    and Remedial Response, Washington, DC. EPA/540/
    8-90/015, October 1990.


Electronic Information Systems

Several electronic data bases and information systems arc
available to Federal, Slate, and private sector personnel for
retrieving innovative technology and ircatability data.


RREL Treatability Data Base

Contact:   Glenn Shaul
          Risk Reduction Engineering Laboratory
          Office of Research and Development
          U.S. Environmental Proicciion Agency
          (513)569-7408
Developed by ihe Risk Reduction Engineering Laboratory
(RREL), this data  base provides dam on the ircaiability of
contaminants in water, soil, debris, sludge, and sediment.
Target users include Federal and State agencies, acadcmia,
and the private sector. For each contaminant, the data base
provides physical/chemical properties and treatabiliiy data
such as technology types, matrices treated, study scale; and
treatment levels achieved. Each data set is referenced and
quality-coded based on  the analytical methods used, the
quality assurance/quality control efforts reported, and op-
erational information.
Version 4.0 of the data base is provided on a computer
diskette free of charge. The menu-driven program is com-
piled and docs not require specialized software. Computer
hardware and software requirements arc as follows:

  • IBM-compatible personal computer and monitor
  • 8-mcgabyte hard disk storage
  • 640-K RAM memory
  • DOS versions 2.0 to 3.3 or 5.0
  • 12-pitch printer
                                                 57

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Requests for the data base must specify diskette format
(3'A HD, 5'A HD, or DD).


Alternative Treatment Technology
Information Center

Contact:   Greg Ondich
          Office of Environmental Engineering and
           Technology Demonstration
          U. S. Environmental Protection Agency
          (202) 260-5747
          System Operator
          (301) 670-6294
          System (online)
          (301) 670-3808
The Alternative Treatment Technology Information Center
(ATTIC) is a comprehensive information retrieval system
containing up-to-date technical information on innovative
methods for treatment of hazardous wastes.  Designed for
use by remediation personnel in the Federal, State, and
private sectors, ATTIC can be easily accessed free of charge
through an online system or the system operator.

The ATTIC system is a collection of hazardous waste data
bases  that are  accessed  through a  bulletin board.   The
bulletin board includes features such as news items, special
interest conferences (e.g., the Bioremediation Special In-
terest Group), and a message board that allows direct com-
munications between users and with the ATTIC System
Operator (i.e.. Chat Mode). Users can access any of four
data bases:  1) the main ATTIC Data Base; 2) the RREL
Treatability Data Base; 3) the Technical Assistance Direc-
tory, which identifies experts on a given  technology or
contaminant type; and  4) the Calendar of Events,  which
contains information on  upcoming relevant conferences,
seminars, and workshops.
The main ATTIC Data Base contains abstracts of Federal,
State, and private sector technical reports collected into a
keyword searchable format. Technologies are grouped into
five categories:  1) biological treatment, 2) chemical treat-
ment, 3) physical treatment, 4) solidification/stabilization,
and 5) thermal treatment.

In 1992,  users of ATTIC will have online  access to the
Inventory' of Treatability Study Vendors OTSV) data base.
The ITSV will aid in identifying vendors possessing quali-
fications  to perform specific  types of treatabilhy studies
and will supplement the existing two-volume, hard-copy
publication of the same name  developed by RREL.  The
online version  of the ITSV will give users the ability to
screen the data base electronically and to review the infor-
mation by each  of three main categories:   technology,
media, and contaminant group.
Users can access ATTIC directly with a personal computer
and a modem.  New users can  register themselves and
assign their own password by calling the ATTIC System.
Communications software should be set according to the
following parameters prior to dialing:

  • Baud Rate: 1200 or 2400
  • Terminal Emulation: VT-100
  • Data Bits: 8
  • Stop Bits: 1
  • Parity: None
  • Duplex: Full

The ATTIC User's Guide is available by calling the System
Operator or leaving a message on the bulletin board.


Computerized On-Line Information
System

  Contact:  Robert Hillger
           Risk Reduction Engineering Laboratory
           Office of Research and Development
           U.S. Environmental Protection Agency
           (908)321-6639
           System Operator
           (908)906-6851
           System (online)
           (908) 548-4636

The Computerized On-Line Information System (COLIS)
is operated by the Technical Information Exchange (TIX)
at the EPA's Risk  Reduction Engineering Laboratory'  in
Edison, New Jersey. A consolidation of several computer-
ized  data bases, COLIS current!) contains the following
files:

  • Underground Storage Tank (UST) Case History File-
    provides  technical assistance to Federal, State, and
    local officials in responding to UST releases.

  • Library Search System-contains catalog cards and ab-
    stracts for technical documents in the TIX Library.

  • SITE Applications Analysis Reports-provides perfor-
    mance and cost information on technologies evaluated
    under the Supcrfund Innovative Technology Evalua-
    tion (SITE) Program.

  • RREL Treatability Data Base

The system is menu-oriented, and online help is available.
Federal, State, and private sector  personnel  can  access
COLIS free of charge by  using a personal computer, a
modem, and a communications program. The COLIS User's
Guide is available by contacting the System Opcraior.
                                                    58

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 Vendor Information System for
 Innovative Treatment Technologies
Contact:
VISITT Hotline
(800) 245-4505
The Vendor Information System for Innovative Treatment
Technologies (VISITT) is an automated data  base  that
provides information on innovative treatment technologies.
The data base contains information submitted by develop-
ers and vendors of innovative treatment technology equip-
ment and services.  Technologies to treat ground water in
situ, soils, sludges, and sediments are included.
Each vendor file in VISITT includes information on the
vendor,  the technology, and the applicable contaminants/
matrices. Performance data, unit costs, equipment avail-
ability, permits obtained, instability study capabilities, and
references may also be available for some vendors/tech-
nologies.
The VISITT daui base is available on diskette and requires
a personal computer using a DOS operating system. Future
updates  may be available on-line.


Superfund Technical Support Project

Contact:  Marlene Suit
         Technology Innovation Office
         Office of Solid Waste and Emergency
           Response
         U.S. Environmental Protection Agency
         (703) 308-8800
The Office of Solid Waste  and Emergency Response
(OSWER), Regional Superfund Offices, and the Office of
Research and Development (ORD) established the Super-
fund Technical Support Project (TSP) in 1987 to provide
direct, technology-based assistance to the Regional Super-
fund programs through ORD  laboratories.  The project
consists  of a network of Regional Technical Support Fo-
rums, five specialized Technical Support Centers (TSCs)
located in ORD laboratories, and one TSC located at the
Office of Emergency and Remedial Response (OERR) En-
vironmental Response Branch.  The objectives of the TSP
are:

  • To provide siatc-of-lhe-science technical assistance lo
    Regional Remedial Project Managers (RPMs) and On-
    Scenc Coordinators (OSCs).

  • To -improve communications among the Regions  and
    the ORD laboratories.

  • To ensure coordination and consistency in the applica-
    tion of remedial technologies.

  • To furnish high-technology demonstrations, workshops,
    and information to RPMs and OSCs.

  • To facilitate the evaluation and application of alterna-
    tive investigatory and remedial techniques at Super-
    fund sites.
The TSP is accessed by contacting one of the TSC Direc-
tors.  Any Regional staff member involved in the Super-
fund program can contact the Centers directly or with the
assistance of a Forum member from their Region.  Addi-
tional information on the TSP is available in:

    Superfund Technical Support Project: Guide for RPMs/
    OSCs. U.S. Environmental Protection Agency, Office
    of Solid Waste and Emergency Response, Technology
    Innovation Office, Washington, DC.

Engineering Technical Support Center

Contact:   Ben Blaney or Joan Colson
          Risk Reduction Engineering Laboratory
          Office of Research and Development
          U.S. Environmental Protection Agency
          (513)569-7406
One of the TSCs is the Engineering Technical Support
Center (ETSC) located at ORD's RREL Technical Support
Branch in Cincinnati, Ohio. The ETSC provides technical
assistance for reviewing and overseeing treatability work
plans and studies, feasibility studies, sampling plans, reme-
dial designs, remedial actions, and traditional and innova-
tive remediation technologies.  Areas of expertise include
treatment of soils,  sludges, and  sediments;  treatment  of
aqueous and organic liquids; materials handling and decon-
tamination; and contaminant source control structures. The
following arc examples of the  types  of technical assistance
that can be obtained  through the ETSC and the  RREL
Technical Support Branch:

  • Characterization of a site for  treatment technology
    identification

  • Performance of remedy-screening trcatability  studies
    and support for treatability studies of innovative tech-
    nologies at all tiers of testing

  • Review of  treatability study RFPs. work plans, and
    final reports

  • Oversight of trcatability studies performed by contrac-
    tors and PRPs

  • Assistance in design and startup of full-scale systems
                                                   59

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Treatability study assistance through the Superfund Tech-
nical Assistance Response Team (START) discussed in
Section 3.3 is also available  through the ETSC contact
listed here.


Environmental Response Team
Technical Support Center

Contact:  Joseph LaForNara
         Environmental Response Branch
         Office of Emergency and Remedial Response
         U.S. Environmental Protection Agency
         (908)321-6740

The Environmental Response Team (ERT) TSC is located
at the OERR Environmental Response Branch in Edison,
New Jersey.  The ERT provides technical expertise for the
development and implementation of innovative treatment
technologies through its Alternative Technology Section.
The following are examples of the types of technical assis-
tance that can be obtained through the ERT:

  • Consultation on water and air quality criteria, ecologi-
    cal risk assessment, and treatability study test objectives

  • Development and implementation of site-specific health
    and safety programs

  • Performance  of  in-house bench- and  pilot-scale
    treatability studies of chemical, physical, and biologi-
    cal treatment technologies

  • Sampling and analysis of air, water, and soil

  • Provision of onsilc analytical support

  • Oversight of trcauibilily study performance

  • Interpretation and evaluation of treatability study data
                                                   60

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                                        APPENDIX  B
                 COST ELEMENTS ASSOCIATED  WITH
                             TREATABILITY  STUDIES
Section 2 of this guide describes three tiers of trcatability
testing:  remedy screening, remedy-selection testing, and
remedial  design/remedial action testing.   This appendix
presents the cost elements associated with the various tiers
of trcatability studies.  In some cases, unit costs arc pro-
vided; in other cases, project-specific examples arc pro-
vided that lend insight into the costs of various elements of
ircatability studies.

Many cost elements are applicable to all levels of ircatability
testing; however, some (e.g., the volume  of residuals or
cost of analytical services) will increase from remedy screen-
ing 10 remedy-selection testing to RD/RA testing.  Other
cost elements (e.g., site preparation and utilities) are only
applicable  to RD/RA testing.  Figure  11  shows the
applicability of the various cost elements to  the different
treatability study tiers. The following  is a discussion of
some of the key cost elements.

Vendor equipment rental is a key cost clement in the per-
formance of RD/RA testing. Most vendors have estab-
lished daily, weekly, and monthly rates for the use of their
treatment systems. These charges cover wear and tear on
the system, utilities, maintenance and repair, and system
preparation.  In some cases, vendors include their  opera-
tors, personal protective equipment, chemicals, and decon-
tamination in  the rental charge.  Treatment system rental
charges typically run about S5,000 to S20.000 per week.
Also, if the vendor sets up a strict timetable for testing, the
client may be billed S4000 to S5000 a day for each day the
waste is late in arriving at the facility.

Site preparation and logistics costs include costs associated
with  planning and management, site design and develop-
ment, equipment and  facilities, health and safety  equip-
ment, soil excavation, feed homogcnization, and feed han-
dling. Costs associated with the majority of these activities
are normally incurred only with RD/RA testing of mobile
field-scale units;  however,  some  of these cost elements
(e.g., feed homogenization and health and safety) arc also
incurred in bench- and pilot-scale remedy-selection testing.
Analytical costs apply to all tiers of irtalability studies and
have a significant impact on the total project costs.  Several
factors affect the cost of the analytical program, including
the laboratory performing the analyses, the analytical target
list, the number of samples, the required turnaround time,
QA/QC, and reporting.  Analytical costs vary significantly
from laboratory to laboratory; however,  before prices arc
compared, the laboratories themselves should be properly
compared.  The following arc typical of questions that
should be asked:

  • What methods will be used for sample preparation and
    analysis?

  • What detection limits are needed?

  • Does each laboratory fully understand the matrix that
    will be  received (e.g., tarry sludge, oily soil,  slag) or
    interference compounds that may be in the  sample
    (e.g., sulfidc)?

If all information indicates that the  laboratories arc using
the same methods and equipment and understand the objec-
tives of the analytical program, the costs for analysis can be
compared.

One should  also be aware that some analytes cost  more to
analyze than others. Often, the project manager would like
to investigate some analytes  for informational purposes
that may not be critical to the study.  The decision as to
whether to analyze for these parameters could be simple if
the parameter-specific costs were known.  For example,
TOC analysis of soil costs about S90/sample, whereas analy-
sis for total dioxins costs about S650/sample.

The number of samples, turnaround  time, QA/QC, and
reporting also affect analytical costs.  Laboratories often
give discounts on sample quantities greater than 5, greater
than 10, and greater than 20 when the samples arrive in the
laboratory at the same  time.  The laboratory' also applies
premium costs of 25. 50. 100, and 200 percent when ana-
                                                   61

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Cost Element
Labor
Testing
Equipment
Vendor Equipment
Rental
Field Instrumentation
and Monitors
Reagents
Site
Preparation
Utilities
Mobilization/
Demobilization

Permitting and
Regulatory

Health and
Safety
Sample
Transportation
Analytical
Services
Air Emission
Treatment
Effluent
Treatment
Decontamination
of Equipment
Residual
Transportation
Residual Treatment/
Disposal
T Testability Study Tier
Remedy
Screening
•
w

o
w
o
o
o

f~^
^•r



w


O
O
o
x-^
**
9
Remedy
Selection
•
•
O
o
o
o
w
r~N

r^




^


w
e
w
x-N
^
W
RO/RA
•
•
•
•
•
•
•
•






•


•
•
•


•








._. Not applicable
C j and/or no cost
> — ' incurred.
_^ May be applicable
^^ and/or intermediate
^^ cost incurred.

^^ Applicable
^A and/or high cost
^^ incurred.










Figure 11.  General applicability of cost elements to various treatabllity study tiers.
                                      62

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lyucal results arc requested faster than the normal turn-
around lime.  If matrix spike and matrix spike duplicates
are required, the analytical cost will triple for those QA/QC
samples.  Also, whether the laboratory provides a cover
letter with the attached data or a complete analytical report
will affect the analytical costs.

Residual transportation  and disposal arc also  important
elements (hat must be budgeted in the performance of all
treatability studies.  Depending on the tcchnology(ies) in-
volved, a number of residuals will be generated.  Partially
treated effluent, scrubber water,  sludge, ash, spent filter
media, scale,  and decontamination liquids/solids arc ex-
amples of residuals that musi be properly transported and
treated or disposed of in accordance with all local, Sme,
and Federal regulations.  Unused feed and excess analytical
sample material also must be properly  managed.  Typi-
cally, a laboratory will add a small fee (e.g., $5 per sample)
to dispose of any unused sample material; however, the
unused raw material and residuals, which could amount to
a sizeable quantity of material, will cost significantly more
to remove.  Transportation cost for a dedicated truck (as
opposed to a truck making a "milk run") is about S3.25 in
S3.75 per loaded mile.  Costs for treatment of inorganic
wastewatcrs may range from S65 to S200 per  55-gallon
drum.  Incineraiion  of organic-contaminated wasiewatcrs
ranges from  $200  to  SI000 per 55-gallon drum, and
landfilling a 55-gallon drum of inorganic solids could cost
between S75 and S200. Disposal  facilities also may have
some associated fees, surcharges, and other cosis for mini-
mum disposal, wasic approval, Slate and local taxes, and
stabilization.
                                                      63

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                               APPENDIX C

                      TECHNOLOGY-SPECIFIC

              CHARACTERIZATION  PARAMETERS


The tables in Appendix C contain waste feed characterization parameters specific to biological, physical/chemical,
immobilization, thermal, and in situ treatment technologies. Generally, these are the characterization parameters that must
be established before a treatability test is conducted on the corresponding technology. Additional parameters may be
required due to site-specific conditions.

Each table is divided by technology, waste matrix, parameter, and purpose of analysis. These tables arc designed to assist
the RPM in planning a treatabiluy study.
                                      65

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             Table 14.  Waste Feed Characterization Parameters tor Biological Treatment
 Treatment
 Technology       Matrix
Parameter
Purpose
General       Soils/sludges   Physical:
                               Moisture content
                               Temperature


                               Oxygen availability

                             Chemical:
                               PH

                               Total organic carbon


                               Redox potential
                               C:N:P ratio
                               Heavy metals

                               Chlorides/inorganic salts

                             Biological:
                               Soil biometry

                               Respirometry

                               Microbial identification
                               and enumeration
                               Microbial toxicity/growth
                               inhibition
              Liquids        Chemical:
                               PH

                               Dissolved oxygen
                               Chemical oxygen demand

                             Biological:
                               Biological oxygen
                               demand
                               Respirometry

                               Microbial identification
                               and enumeration
                               Microbial toxicity/growth
                               inhibition
                    To identify potential for microbial metabolism inhibition
                    and need for pretreatment.
                    To identify potential for microbial metabolism inhibition
                    and need for pretreatment.
                    To identify potential for microbial metabolism inhibition
                    and need for pretreatment.

                    To identify potential for microbial metabolism inhibition
                    and need for pretreatment.
                    To determine the need for possible organic carbon
                    supplementation to support acceptable levels of
                    biological activity.
                    To determine potential for stimulating and/or enriching
                    growth of indigenous aerobic, anoxic, suHate
                    reducing, and obligate anaerobic microbial
                    populations.
                    To determine mineral nutrient requirements.
                    To identify potential for microbial metabolism inhibition
                    and need for pretreatment.
                    To identify potential for microbial metabolism inhibition
                    and need for pretreatment.

                    To determine biodegradation potentials and to
                    quantify biodegradation rates.
                    To determine oxygen uptake and biodegradation
                    rates.
                    To determine the indigenous or adapted microbial
                    population densities in the inoculum.
                    To determine microbial activity.
                    To identify potential for microbial metabolism inhibition
                    and need for pretreatment.
                    To determine presence or absence of oxygen as a
                    potential indicator, respectively, of the absence or
                    presence of indigenous microbial activity.
                    To determine total oxygen demand, both organic and
                    inorganic, in the liquid matrix.

                    To determine the fraction of the chemical oxygen
                    demand that is aerobically degradable.
                    To determine oxygen uptake and biodegradation
                    rates.
                    To determine the indigenous or adapted microbial
                    population densities in the inoculum.
                    To determine microbial activity.
                                                     66

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        Table 15.  Waste Feed Characterization Parameters for Physical/Chemical Treatment
 Treatment
 Technology
   Matrix
Parameter
Purpose and comments
General
Extraction
 • Aqueous
 - Solvent
 - Critical fluid
 - Air/steam
Chemical
dehalo -
genation
Soils/sludges  Physical:
                Type, size of debris

                Dioxins/lurans,
                radionuclides, asbestos
Soils/sludges  Physical:
                Panicle size distribution
                 Clay content

                 Moisture content
              Chemical:
                 Organics

                 Metals (total)

                 Metals (leachable)

                 Contaminant
                 characteristics:
                 • Vapor pressure
                 • Solubility
                 • Henry's Law constant
                 • Partition coefficient
                 • Boiling point
                 • Specific gravity
                 Total organic carbon,
                 humic acid
                 Cation exchange capacity
                 Chemical oxygen demand
                 pH
                 Cyanides, sulfides,
                 fluorides
              Biological:
                 Biological oxygen
                 demand

Soils/sludges  Physical:
                 Moisture content

                 Particle-size distribution
              Chemical:
                 Halogenated organics

                 Metals

                 pH/base absorption
                 capacity
Liquids        Chemical:
                 Halogenated organics
                    To determine need for pretreatment.

                    To determine special waste-handling procedures.



                    To determine volume reduction potential.
                    pretreatment needs, solid/liquid separability.

                    To determine adsorption characteristics of soil.

                    To determine conductivity of air through soil.

                    To determine concentration of target  or interfering
                    constituents, pretreatment needs, extraction medium.
                    To determine concentration of target  or interfering
                    constituents, pretreatment needs, extraction mediurr,.
                    To determine mobility of target constituents,
                    posttreatment needs.
                    To aid in selection of extraction medium.
                                                         To determine presence of organic matter, adsorption
                                                         characteristics of soil.
                                                         To determine adsorption characteristics of soil.
                                                         To determine fouling potential.
                                                         To determine pretreatment needs, extraction medium.
                                                         To determine potential tor generating toxic fumes at
                                                         low pH.

                                                         To determine fouling potential.
                    To determine reagent formulation/loading.

                    To determine experimental apparatus.

                    To determine concentration of target constituents,
                    reagent requirements.
                    To determine concentration of other alkaline-reactive
                    constituents, reagent requirements.     I
                    To determine reagent formulation/loading.
                                                         To determine concentration of target constituents,
                                                         reagent requirements.
                                                     67

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Table 15.   (continued)
  Treatment
  Technology
    Matrix
         Parameter
              Purpose and comments
 Oxidation/     Soils/sludges  Physical:
 reduction                      Total suspended solids
                             Chemical:
                               Chemical oxygen demand


                               Metals (Cr*3, Hg. Pb, As)
 Rocculation/    Liquids
 sedimentation
 Carbon
 adsorption
 Ion
 exchange
Liquids
               Gases
Liquids
  pH
Physical:
  Total suspended solids
  Specific gravi;y of
  suspended solids
  Viscosity of liquid
Chemical:
  pH
  Oil and grease

Physical:
  Total suspended solids

Chemical:
  Organics

  Oil and grease

Biological:
  Microbial plate count
              Physical:
                Paniculates
Chemical:
  Volatile organic
  compounds, sulfur
  compounds, mercury
Physical:
  Total dissolved solids

  Total suspended solids

Chemical:
  Inorganic cations and
  anions, phenols
  Oil and grease
To determine the need for slurrying to aid mixing.

To determine the presence of oxidizable organic
matter, reagent requirements.
To determine the presence of constituents that could
be oxidized to more toxic or mobile forms.
To determine potential chemical interferences.

To determine reagent requirements.
To determine settling velocity of suspended solids.

To determine settling velocity of suspended solids.

To aid in selection of flocculating agent.
To determine need for emulsifying agents, oil/water
separation.

To determine need for pretreatment to prevent
clogging.

To determine concentration of target constituents,
carbon loading rate.
To determine need for pretreatment to prevent
clogging.

To determine potential for biodegradation of adsorbed
organics and/or problems due to clogging or odor
generation.

To determine need for pretreatment to prevent
clogging.

To determine concentration of target constituents,
carbon loading rate.
                                           To determine concentration of target constituents,
                                           carbon loading rate.
                                           To determine need for pretreatment to prevent
                                           clogging.

                                           To determine concentration of target constituents.

                                           To determine need for pretreatment to prevent
                                           clogging.
                                                     68

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Table 15.   (continued)
  Treatment
  Technology
Matrix
Parameter
Purpose and comments
 Reverse       Liquids        Physical:
 osmosis                       Total suspended solids

                             Chemical:
                               Metal ions, organics

                               PH
                               Residual chlorine
                             Biological:
                               Microbial plate count

 Liquid/liquid    Liquids        Physical:
 ex/raction                     Solubility, specific gravity
                             Chemical:
                               Contaminant
                               characteristics:
                               • Solubility
                               • Partition coefficient
                               • Boiling point
 Oil/water      Liquids        Physical:
 separation                     Viscosity
                               Specific gravity
                               Settleable solids
                               Temperature
                             Chemical:
                               Oil and grease
                               Organics
 Air/steam      Liquids        Chemical:
 stripping                       Hardness
                               Volatile organic
                               compounds
                               Contaminant
                               characteristics:
                               • Solubility
                               • Vapor pressure
                               • Henry's Law constant
                               • Boiling point
                               • Mass transfer coefficient
                               Chemical oxygen demand
                             Biological:
                               Biological oxygen
                               demand
 Filtration       Liquids        Physical:
                               Total suspended solids

                               Total dissolved solids
                                       To determine need for pretreatment to prevent
                                       plugging of membrane.


                                       To determine concentration of target constituents.
                                       To evaluate chemical resistance of membrane.
                                       To evaluate chemical resistance of membrane.


                                       To determine potential for biological growth outside
                                       membrane that would cause plugging.


                                       To determine miscibility of solvent and liquid waste.

                                       To aid in selection of solvent, separation of phases,
                                       etc.
                                       To determine separability of phases.
                                       To determine separability of phases/emulsions.
                                       To determine amount of residual solids.
                                       To determine rise rate of oil globules.

                                       To determine concentration of target constituents.
                                       To determine need for posttreatment.

                                       To determine potential for scale formation.
                                       To determine concentration of target constituents.

                                       To determine strippability of contaminants, size of
                                       units, and need for posttreatment.

                                       To determine stripping factor.

                                       To determine packing height.

                                       To determine fouling potential.

                                       To determine fouling potential.
                                       To determine need for pretreatment to prevent
                                       clogging.
                                       To determine need for posttreatment.
                                                      69

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Table 15.  (continued)
Treatment
Technology Matrix
Dissolved air Liquids
dotation





Neutralization Liquids





Precipitation Liquids

Parameter
Physical:
Total suspended solids
Specific gravity
Chemical:
Oil and grease
Volatile organic
compounds
Chemical:
pH
Metals
Acidity/alkalinity
Cyanides, sulfides,
fluorides
Chemical:
Metals
Purpose and comments

To determine amount of residual sludge.
To determine separability of phases.

To determine concentration of target constituents.
To determine need for air emission controls,
posttreatment.

To determine reagent requirements
To determine need for posttreatment.
To determine reagent requirements.
To determine potential for generating toxic fumes at
low pH.

To determine concentration of target constituents,
 Oxidation      Liquids
 (alkaline
 chlorination)
 Reduction     Liquids
 Hydrolysis     Liquids
  pH

  Organics, cyanides

Chemical:
  Cyanides

  PH
  Organics

  Redox potential
Chemical:
  Metals (Cr+6, Hg, Pb)

Chemical:
  Organics

  pH
reagent requirements.
To determine solubility of metal precipitates, reagent
requirements.
To determine concentration of interfering constituents,
reagent requirements.

To determine concentration of target constituents,
reagent requirements.
To determine suitable reaction conditions.
To determine potential for forming hazardous
compounds with excess chlorine (oxidizing agent).
To determine reaction success.

To determine concentration of target constituents,
reagent requirements.

To determine concentration of target constituents,
reagent requirements, posttreatment needs.
To determine reagent requirements.
                                                     70

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                Table 16. Waste Feed Characterization Parameters for Immobilization
  Treatment
 Technology
Matrix
Parameter
Purpose and comments
Stabilization/   Soils/sludoes  Physical:
solidification
Vitrification    Soils/sludges
             Description of materials

             Particle-size analysis

             Moisture content

             Density testing

             Weight ratio additives to
             waste
           Chemical:
             Total organic content
             pH

             Alkalinity

             Interfering compounds
             Indicator compounds
             Leach testing
             •TCLP
             • TCLP-water
             Heat of hydration
             Total waste analysis
           Physical:
             Depth of contamination
             and water table
             Soil permeability

             Metal content of waste
             material and placement of
             metals within the waste
             Combustible liquid/solid
             content of waste
             Rubble content of waste

             Void volumes

             Moisture content
             Particle-size analysis

           Chemical:
             Leach testing
             Total waste analysis
                   To determine waste handling methods (e.g., crusher,
                   shredder, removal equipment).
                   To determine surface area available tor binder contact
                   and leaching.
                   To determine amount of water to add/remove in S/S
                   mixing process.
                   To evaluate changes in density between untreated and
                   treated waste and to determine volume increase.
                   To determine effects of dilution  due to volume increase.

                   To determine reagent requirements.
                   To evaluate changes in leaching as function of  pH
                   between untreated and treated  waste.
                   To evaluate changes in leaching as function of  alkalinity
                   between untreated and treated  waste.
                   To evaluate viability of S/S process. (Interfering
                   compounds are those that impede fixation reactions,
                   cause adverse chemical reactions, generate excessive
                   heat; interfering compounds vary with type of S/S).
                   To evaluate performance.

                   To evaluate performance  based on regulatory test.
                   To evaluate performance  under natural conditions.
                   To measure temperature changes during mixing.
                   To evaluate performance.

                   Technology is applied in unsaturated soils.

                   Dewatering of saturated soils may be possible.
                   Technology is applied in unsaturated soils.
                   Greater than 5 to 15% by  weight or significant amounts
                   of metal near electrodes interfere with process.

                   Greater than 5 to 15% by  weight interferes with process
                   (may ignite).
                   Greater than 10 to 20% by weight interferes with
                   process.
                   Large, individual voids (greater  than 150 ft^) impede
                   process, may cause subsidence.
                   To determine power requirements.
                   To determine surface area available for binder contact
                   and leaching.
                               !
                   To evaluate performance.
                   To evaluate performance.
                                                    71

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Table 17. Waste Feed Characterization Parameters for Thermal Treatment
Treatment
Technology
General
Matrix
Soils/sludges

Physical:
Parameter

Purpose

and comments

Liquids
                 Moisture content
                 Ash content

                 Ash fusion temperature

                 Heat value
              Chemical:
                 Volatile organics,
                 semivolatile organics
                 Principal organic
                 hazardous constituents
                 Total halogens

                 Total sulfur, total nitrogen


                 Phosphorus

                 PCBs and dioxins (if
                 suspected)

                 Metals
Physical:
  Viscosity
  Total solids content
  Panicle-size distribution of
  solid phases
  Heat value
Chemical:
  Volatile organics,
  semivolatile organics
  Principal organic
  hazardous constituents
  Total halogens
                Total sulfur, total nitrogen


                Phosphorus

                PCBs, dioxins (if
                suspected)
Affects heat value and material handling.
To determine the amount of ash that must be disposed
or treated further.
High temperature can cause slagging problems with
inorganic salts having low melting points.
To determine auxiliary fuel requirements and feed rates.

Allows determination of principal organic hazardous
constituents.
Allows determination of destruction and removal
efficiency.
To determine air pollution control devices for control ol
acid gases.
Emissions of SOx and NOx are regulated; to determine
air pollution devices.
Organic phosphorus compounds may contribute to
refractory attack and  slagging  problems.
99.9999% destruction and removal efficiency required
for PCBs; safety considerations; incineration is required
if greater than 500 ppm PCBs  present.
Volatile metals' (Hg, Pb, Cd, Zn, As, Sn) may require
flue-gas treatment; other metals may concentrate in ash.
Trivalent chromium may be oxidized to hexavalent
chromium, which is more toxic. Presence of inorganic
alkali salts, especially potassium and sodium sulfate,
can cause slagging. Determine posttreatment needs.

Waste must  be pumpable and atomizable.
Affects pumpability and heat transfer.
Affects pumpability and heat transfer.

Determine auxiliary fuel requirements and feed rates.

Allows determination  of principal organic hazardous
constituents.
Allows determination  of destruction and removal
efficiency.
To determine air pollution control devices for control of
acid gases.  Chlorine could contribute to formation of
dioxins.
Emissions of SOx and NC\ are regulated; to determine
air pollution devices.
Organic phosphorus compounds may contribute to
refractory attack  and slagging  problems.
99.9999% destruction and removal efficiency required
for PCBs; safety  considerations; incineration is required
if greater than 500 ppm PCBs  present.
                                      72

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Table 17. (continued)
  Treatment
  Technology
   Matrix
      Parameter
              Purpose and r jmments
 General
 (cont.)
Liquids
Metals
 Rotary kiln    Soils sludges   Physical:
                                Particle-size distribution
               Debris         Physical:
                                Amount, description of
                                materials
                                Presence of spherical or
                                cylindrical wastes
 Fluidized-bed  Soils/sludges   Physical:
                                Ash fusion temperature
                                Ash content
                                Bulk density
 Thermal       Soils/sludges   Physical:
 descrption                      Moisture content
                                Particle-size distribution
                              Chemical:
                                PH

                                Volatile organic
                                contaminants
                                Volatile metals
                                Nonvolatile metals
                                Total chlorine

                                Total organic content
               Liquids        Physical:
                                Total solids content
Volatile metals (Hg, Pb, Co, Zn, As, Sn) may require
flue-gas treatment; othe. metals may concentrate in
ash. Trivalent chromium may be oxidized to
hexavalent chromium, which is more toxic. Presence
of inorganic alkali salts, especially potassium and
sodium sulfate, can cause slagging. Determine
posttreatment needs.

Fine particle size results in high paniculate trading
and slagging. Large particle size may present feeding
problems.

Oversized debris presents handling problems and kiln
refractory loss.
Spherical or cylindrical waste can roll through kiln
before combusting.

For materials with a melting point less than 1600CF,
particles  melt and become sticky at high
temperatures, which causes defluidization of the bed.
Ash content;; greater than 65% can foul the bed.
As density increases, particle size must be decreased
for sufficient heat transfer.

Affects heating and materials handling.
Large particles result in poor performance. Fine silt or
clay generate fugitive dusts.

Very high or very low pH waste may corrode
equipment.
To determine concentration of target constituents.
posttreatment needs.
To determine concentration of target constituents,
posttreatment needs.
To determine posttreatment needs.
Presence of chlorine can affect volatilization of some
metals.
Limited to ~10 percent or less.

Minimum of 23-30 percent solids required.
                                                      73

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                Table 18.  Waste Feed Characterization Parameters for In Situ Treatment
     Treatment
    Technology
    Matrix
Parameter
Purpose and comments
Vapor extraction
•Vacuum extraction
-Steam-enhanced
-Hot-air-enhanced
Solidification'/
stabilization
(undisturbed)
•Pozzolanic
-Polymerization
•Precipitation
Soil flushing
•Steam/hot water
•Surfactant
•Solvent
Vitrification
Electrokinetics
Microbial
degradation
•Aerobic
-Anaerobic
Adsorption (trench)
Soils/sludges   Physical:
                 Vapor pressure of contaminants

                 Soil permeability, porosity,
                 particle-size distribution

                 Depth of contamination and
                 water table
Soils/sludges   Physical:
                 Presence of subsurface barriers
                 (e.g., drums, large objects,
                 debris, geologic formations)

                 Depth to first confining layer
Soils/sludges   Physical:
                 Presence of subsurface barriers
                 (e.g., drums, large objects,
                 debris, geologic formations)
                 Hydraulic conductivity
                 Moisture content (for vadose
                 zone)
                 Soil/water partition coefficient

                 Octanol/water partition coefficient

                 Cation exchange capacity
                 Alkalinity of soil
               Chemical:
                 Major cations/anions present in
                 soil
Soils/sludges   Physical:
                 Depth of contamination and
                 water table
Soils/sludges   Physical:
                 Hydraulic conductivity

                 Depth to water table
               Chemical:
                 Presence of soluble metal
                 contaminants
Soils/sludges   Physical:
                 Permeability of soil
               Chemical/biological:
                 Contaminant concentration and
                 toxicity
Soils/sludges   Chemical/biological:
                 Contaminant concentration and
                 toxicity
Soils/sludges   Physical:
                 Depth of contamination and
                 water table
                 Horizontal hydraulic flow rate
                       To estimate ease of volatilization.

                       To determine if the soil matrix will allow adequate
                       air and fluid movement.

                       To determine relative distance; technology
                       applicable in vadose zone.

                       To assess the feasibility of adequately delivering
                       and mixing the S/S agents.
                       To determine required depth of treatment.

                       To assess the feasibility of adequately delivering
                       the flushing solution.

                       To assess permeability of the soils.
                       To calculate pore volume to determine rate of
                       treatment.
                       To assess removal efficiency and to correlate
                       between field and theoretical calculations.
                       To assess removal efficiency and to correlate
                       between field and theoretical calculations.
                       To evaluate potential for contaminant flushing.
                       To estimate the likelihood of precipitation.

                       To estimate the likelihood of precipitation: to
                       estimate potential for plugging of pore volumes.

                       Technology is only applied in the unsaturated
                       zone.

                       Technology applicable in zones of low hydraulic
                       conductivity.
                       Technology applicable in saturated soils.

                       Technology applicable to soluble metals, hut not
                       organics and insoluble.

                       To determine ability to deliver nutrients or oxygen
                       to matrix and to allow movement of microbes.

                       To determine viability of microbial population in
                       the contaminated zone.
                                                                     To determine viability of microbial population in
                                                                     the contaminated zone.
                                                                     Technology applicable in saturated zone.

                                                                     To determine if ground water will come into
                                                                     contact with adsorbent.
                                                        74

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Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268

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Section 4

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                      GROUNDWATER CONTAINMENT
STUDENT PERFORMANCE OBJECTIVES:
At the conclusion of this section, participants will be able to:
             Briefly describe the advantages and disadvantages of using groundwater
             containment processes

             Briefly describe the following passive control methods:

                    Slurry trench cutoff walls
                    Grout curtains
                    Sheet piling
                    Permeable treatment beds

             Briefly describe the following dynamic control methods:

                    Groundwater pumping for plume control
                    Groundwater treatment and discharge systems.
5/93

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                                                      NOTES
  THREE ALTERNATIVES AVAILABLE TO DEAL WITH
       CONTAMINATED GROUNDWATER
     • Physical Containment/Control
     • Aquifer Rehabilitation
     • Withdrawal, Treatment, and Use
  PHYSICAL CONTAINMENT/CONTROL MEASURES
    •  Slurry Trench Cutoff Walls
    •  Grout Curtains
    •  Sheet Piling
    •  Permeable Treatment Beds
    •  Hydrodynamic Control
    •  Withdrawal, Treatment, and Recharge
  SLURRY TRENCH CUTOFF WALLS
5/93
Groundwater Containment
             page 1

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           NOTES
                                               Contaminant
                                                Source
Slurry Trench
 Cutoff Wall Production Well
                                                      Confining Bed
                                                   Cross Section of Slurry Trench Cutoff Wall
                                                             Keyed-in Slurry Wall
                                                            Hanging Slurry Wall
                                                   Leaking Fuel Tank
Groundwater Containment
page 2
                        5/93

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                                                                     NOTES
              Cut-Away Cross Section
          of Upgradlent Placement With Drain
   Cut-Away Cross Section of Downgradlent Placement
               Cut-Away Cross-Section
          of Circumferential Wall Placement
  Water
  Table
  Low
  Permeability
  Zone   \
Extraction
Well
Leachate
Level
5/93
                                Groundwater Containment
                                                page 3

-------
         NOTES
                                                 Slurry
                                                 Level'
                                                            Bentonite
                                                            Filter Cake
                                         	Impermeable Bedrock   	  —
                                        Slurry Trench During Construction

Typical Cap

2% Minimum Slop*







t
T

20 mil »ynth«tlo llntr


Topsoll
^ 	 Flb*r
Sand
	 -^
Soil Liner


Ftbrlo
4 i
1 1.
^
.t
*
Waste








                                           ADVANTAGES OF
                                    SLURRY TRENCH CUTOFF WALLS
                                           •  Established Technique

                                           •  Single Construction

                                           •  Very Low Upkeep

                                           •  Long Service Life

                                           •  Relatively Effective
Qroundwater Containment
page 4
5/93

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                                                  NOTES
       DISADVANTAGES OF
   SLURRY TRENCH CUTOFF WALLS

    • Limited to Unconsolidated Materials

    • Relatively Expensive

    • Limited Number of Construction
      Contractors Available
      GROUT CURTAINS
   Contaminant
    Source
Grout
Curtain  Production Well
        Confining Bed
      Cross Section of Grout Curtain Installation
5/93
                                  Groundwater Containment
                                              page 5

-------
          NOTES
                                               Semicircular

                                         Grout Tube8Grout
                                           1,700ft.


                                        Semicircular Grout Curtain Around a Contaminant Source
                                             Grout Injection   5 ^
                                                Tube
Radius of Influence
    of Grout
                                           Typical Two-Row Grid Pattern for Grout Curtain
                                       ADVANTAGES OF GROUT CURTAINS

                                       •  Established Technique

                                       •  Very Low Upkeep

                                       •  Wide Range of Grouts Available

                                       •  Effective in Both Unconsolidated Materials
                                          and Granular/Fractured Rock
Groundwater Containment
page 6
               5/93

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                                                        NOTES
 DISADVANTAGES OF GROUT CURTAINS
   • Very Expensive
   • Difficult to Evaluate Effectiveness
   • Limited Number of Construction
     Contractors Available
   • Costs of Pre-grouting Testing are High
          SHEET PILING
    Contaminant
     Source
Sheet Piling
Cutoff Wall Production Well
         Confining Bed
       Cross Section of Sheet Piling Installation
5/93
                                        Groundwater Containment
                                                     page 7

-------
          NOTES
                                          Straight Web Type
                                           Arch Web Type
                                         Y-Fltfng
                                          v
                                                          Deep Arch Web Type
T-Fitting
                                                                  Z-Type

                                                                 	/
                                             Steel Piling Shapes and Interlocks
                                      ADVANTAGES OF SHEET PILING WALLS
                                           • Established Technique
                                           • Contractors Readily Available
                                           • Relatively Inexpensive
                                           • Low Maintenance Requirements
                                      DISADVANTAGES OF SHEET PILING WALLS
                                      • Only Effective in Unconsolidated Materials
                                      • Difficult to Install in Rocky Materials
                                      • Wall Initially not Waterproof
                                      • Wall Susceptible to Corrosion
Groundwater Containment
page 8
                        5/93

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                                                 NOTES
  PERMEABLE TREATMENT BEDS
   Contaminant
    Source
Permeable
Treatment Production
  Bed   Well
        Confining Bed
      Cross Section of Permeable Treatment Bed
          MEDIA USED IN
  PERMEABLE TREATMENT BEDS
       • Crushed Limestone

       • Activated Carbon

       • Glauconitic Green Sands
5/93
                                  Groundwater Containment
                                             page 9

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         NOTES
                                             ADVANTAGES OF
                                   CRUSHED LIMESTONE TREATMENT BED

                                    •  Can be used to Neutralize Acidic Ground
                                      Water

                                    •  Can Remove Certain Heavy Metals

                                    •  Inexpensive

                                    •  Materials Readily Available
                                            DISADVANTAGES OF
                                   CRUSHED LIMESTONE TREATMENT BED

                                    • Cementation of Limestone Bed May Occur,
                                      Leading to Plugging of Flow

                                    • Not Effective for Removal of Organic
                                      Contaminants

                                    • Maintenance Necessary to Retain Permeability
                                      and Flow Through the Bed

                                    • Channeling of Untreated Water Through the Bed
                                      May Occur
                                             ADVANTAGES OF
                                   ACTIVATED CARBON TREATMENT BEDS

                                     • Very Effective in Removal of Non-polar
                                       Organic Compounds

                                     • Readily Available Materials

                                     • Easy to Install
Groundwater Containment
page 10
5/93

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                                                                  NOTES
           DISADVANTAGES OF

 ACTIVATED CARBON TREATMENT BEDS

 •  Not Effective for Removal of Polar Organic Compounds

 •  Desorption of Adsorbed Compounds May Occur, Resulting in
   Recontamination

 •  Removal/Disposal of Spent Carbon is Difficult and Hazardous

 •  Material is Very Expensive

 •  Plugging of the Bed May Occur, Backing Up Ground Water
   and Result in Flooding

 •  Presence of Certain Chemicals May Decrease Effectiveness
   of Adsorption
                ADVANTAGES OF
  GLAUCONITIC GREEN SAND TREATMENT BEDS

  • Highly Effective in Removal of Many Heavy Metals

  • Short Residence Time Required for Efficient
    Treatment

  • Relatively Little Material Required for Bed

  • Material Abundant in Eastern  U.S.

  • Excellent Permeability
              DISADVANTAGES OF
 GLAUCONITIC GREEN SAND TREATMENT BEDS

 •  Saturation Characteristics Unknown

 •  Area of Application Limited By Availability of Material

 •  May Reduce pH Significantly

 •  Reduction in Permeability and Plugging of Bed May
    Occur

 •  Removal Efficiencies of Metals at High
    Concentrations Unknown
5/93
Groundwater Containment
               page 11

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         NOTES
                                      HYDRODYNAMIC CONTROL
                                                   Confining Bed
                                          Cross Section of Hydrodynamic Control System
                                           Contaminant • contamination
                                            Source   •  p,ume
                           Production
                             Well
                             0
                                                                 Groundwater
                                                                   Flow
        Discharge Pipe
              ;


Plan View of Hydrodynamic Control System
Groundwater Containment
page 12
                                  5/93

-------
                                                           NOTES
/   a
Withdrawal
  Wells
             Qroundwater Divide
             Qroundwater Flowllnes
   Hydrodynamlc Control/ Withdrawal-Recharge System
           ADVANTAGES OF
     HYDRODYNAMIC CONTROL
         • High Design Flexibility
         • Technology Readily Available
         • Contractors Readily Available
         • Construction Relatively Simple
         • Relatively Inexpensive
         • High Reliability
         DISADVANTAGES OF
     HYDRODYNAMIC CONTROL
 • Continued Maintenance Necessary
 • Requires Long-Term Commitment of Both Manpower
   and Materials
 • If Improperly Managed, Extracted Water May
   Become Contaminated and Require Treatment
   Before Injection
 • Operation and Maintenance Costs Relatively High
 • May Require Extensive Monitoring
5/53
                                                     Groundwater Containment
                                                                  page 13

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         NOTES
                                      WITHDRAWAL, TREATMENT,
                                             AND RECHARGE
                                    Recharge
                                     Well
Treatment   _   .,
 System   E*"Sfl?n
         W8II
                                                             Production Wall
                                                  Confining Bed
                                        Withdrawal, Treatment, and Recharge System
                                       Recharge   Carbon
                                       Wells   Adsorption
      Aeration
       Basin
                    Extraction
                     Wells
                                      Schematic of Withdrawal, Treatment, and Recharge System
Groundwater Containment
page 14
                        5/93

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                                                             NOTES
              ADVANTAGES OF
  WITHDRAWAL, TREATMENT, AND RECHARGE
   • Treatment Processes Available for Most
     Contaminants
   • Only Method to Truly "Reclaim"
     Contaminated Ground Water
   • High Design Flexibility
   • High Reliability
            DISADVANTAGES OF
 WITHDRAWAL, TREATMENT, AND RECHARGE
 • Could Be Very Expensive Depending on Type and
   Degree of Treatment
 • Brings Large Volume of Uncontaminated Water to
   the Surface Along with Contaminated Water
 • Very Energy and Labor Intensive
 • Possible Regulatory Problems with Discharge
 • Does Not Work Well in Fine-Grained Material
 COMPARATIVE INSTALLATION COSTS OF
    PHYSICAL CONTAINMENT SYSTEMS
  Method
  Slurry Trench Cutofl Wall
  Grout Curtain
  Sheet Piling
  Hydrodynamic Control
Dimensions
1,700 ft. long x 60 ft d«ep
1,700 ft. long x 60 ft deep
1,700 ft. long x 60 fl deep
1,000 ft long array
Range In Cost
(Thousands of Dollars)
500-840
800-1,400
650-960
200-350
5/93
                                                Groundwater Containment
                                                              page 15

-------
          NOTES
                                       COMPARATIVE COSTS OF AQUIFER
                                           REHABILITATION METHODS
                                       Mtlhod
                                       PKIKMM* Tmtnwit B»d«
                                       Chtmlcal NeuffBlizetian
                                       BiorKtanMJon
                                       Withdrawal, TtMlmtnt. and Recharge
Dlmwitlont
I.OOOIongiSOIl d»^i
to acrn
10 tan
Rang* In Cost
(Thouundi ol DoOvi)
400-4,000
250-400
100-500
Highly Vulibl*
Groundwater Containment
page 16
                     5/93

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                        GROUNDWATER CONTAINMENT
SUBSURFACE BARRIERS

The term subsurface barriers refers to a variety of methods whereby low-permeability cutoff walls
or diversions are installed below ground to contain, capture, or redirect groundwater flow in the
vicinity of a site.  The most commonly used subsurface barriers are slurry walls, particularly soil
bentonite slurry walls.  Less common are cement-bentonite or concrete (diaphragm) slurry walls,
grouted barriers, and sheet piling cutoffs.  Grouting may also be used to create horizontal barriers
for sealing the bottom of contaminating  sites.

       Slurry Walls

       Slurry walls  are the  most common  subsurface barriers  because they  are a relatively
       inexpensive means of vastly reducing groundwater  flow in unconsolidated earth materials.
       The term slurry wall can be applied to a variety of barriers all having one thing in common:
       they are all constructed in a vertical trench that is excavated  under a slurry.  This slurry,
       usually  a mixture of bentonite and water, acts essentially like a drilling fluid.  It forms a
       filter  cake on the trench walls to prevent high fluid losses into  the  surrounding ground.
       Types of slurry walls are differentiated by the materials used to backfill the slurry trench.
       Most commonly, an engineered soil mixture is blended with the bentonite slurry and placed
       in the trench to  form a soil-bentonite slurry wall.  In some cases, the trench is excavated
       under a slurry of Portland cement, bentonite, and water, and this mixture is left in the trench
       to harden into a cement-bentonite  slurry wall.   In the rare  case where great strength is
       required of a subsurface barrier, precast or cast-in-place concrete panels are constructed in
       the trench to form a diaphragm wall.  These types of slurry walls, including hybrids of the
       three, are discussed on the next page.

       Soil-Bentonite Slurry  Walls

       Soil-bentonite slurry walls are backfilled with soil materials mixed with a bentonite and water
       slurry.  Of the  three  major types of slurry  walls, soil-bentonite  walls offer the  lowest
       installation costs, the widest range of chemical compatibilities, and the lowest permeabilities.
       At the  same time,  soil-bentonite  walls have  the highest compressibility (least strength),
       require  a large work area, and, because the slurry and backfill can flow, are applicable only
       to sites  that can be graded to nearly level (Spooner et.al., 1984a).

              Applications and Limitations

              One of the first steps in considering a soil-bentonite slurry wall for a given site is to
              review the configuration options available and determine which best meets the goals
              of the remedial action.  In the vertical perspective,  slurry walls may be "keyed-in"
              or handing, as  shown in FIGURE la.  Keyed-in slurry walls are constructed in a
              trench that has  been excavated into a low-permeability confining layer such as a clay

5/93                                         17

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                       GROUNDWATER CONTAINMENT
              deposit or competent bedrock. This layer will form the bottom of the contained site,
              and a good key-in  is essential to adequate containment.  Hanging slurry walls,
              however, are not tied to a confining layer but extend down several feet into the water
              table to act as a barrier to floating contaminants (such as oils and fuels) or migrating
              gases. The use of hanging slurry walls in waste site remediation is relatively rare,
              and most installations are of the keyed-in variety.

              In the horizontal perspective, slurry walls can be placed (relative to the direction of
              groundwater flow) upgradient, downgradient, or completely  surrounding the waste
              site.  The various horizontal placement options  are shown in  FIGURE la - e.
                                      FIGURE la
                              KEYED-IN SLURRY WALL
5/93
18

-------
GROUNDWATER CONTAINMENT
                             FIGURE Ib
                       HANGING SLURRY WALL
                    SUWnv WALL

                WATEP TABLE \ . H
                  ICJW PEBMEABUTY 2ONt ^-~=T-=-^=^
                             FIGURE Ic
    CUT-AWAY CROSS-SECTION OF CIRCUMFERENTIAL WALL PLACEMENT
5/93
19

-------
GROUNDWATER CONTAINMENT
                           FIGURE Id
       CUT-AWAY CROSS-SECTION OF DOWNGRADIENT PLACEMENT

                           FIGURE le
   CUT-AWAY CROSS-SECTION OF UPGRADIENT PLACEMENT WITH DRAIN
5/93
20

-------
GROUNDWATER CONTAINMENT
              Circumferential  installations are  by  far  the  most  common and  offer several
              advantages.    This  placement  vastly  reduces  the  amount  of uncontaminated
              groundwater entering the site from upgradient, thus reducing the volume of leachate
              generated.   Also, provided there  are no  compatibility problems between the site
              wastes and the wall materials, the amount of leachate leaving the downgradient side
              of the  site will be greatly reduced.  Moreover, when this configuration is used in
              conjunction  with  an infiltration barrier and a leachate collection system (or other
              means  of reducing the hydraulic head on  the interior of the wall), the hydraulic
              gradient can be maintained in an inward direction, thus preventing leachate escape.

              Upgradient placement is  when a slurry wall is installed on the groundwater  source
              side of the wastes.  Although no documented cases of upgradient installations were
              found, this placement can be used to divert clean groundwater around a site in high
              gradient situations.  This method does not halt  the generation of leachate but does
              slow its generation by stagnating groundwater behind the wall.

              Downgradient placement is when a slurry wall is installed on the side  of a waste site
              toward which groundwater is flowing. Although not common, this placement can be
              employed as a hanging  wall to  contain  and  capture  floating contaminants and
              methane. Because there is direct leachate/wall contact in this configuration, extensive
              compatibility testing is essential.

              Another major concern in the application of soil-bentonite walls to site remediation
              is the compatibility of the backfill mixture with site contaminants.  Evidence indicates
              that soil-bentonite backfills are not able to withstand attack by strong acids and bases,
              strong  salt solutions, and some organic chemicals (D'Appolonia, 1980b).  The issue
              of chemical  incompatibility is discussed further under "Design Considerations."

              Certain factors can limit  the application of soil-bentonite  to a particular site.  Most
              limitations can be overcome by increased engineering, but the associated cost increase
              may make some  other alternative, such as groundwater  pumping, a more suitable
              remedial measure.

              Site topography  can limit the use  of a soil-bentonite  wall.   Because  both  the
              excavation slurry and the backfill will flow  under  stress, the trench line must be
              within  a few degrees of level. In most cases, it is possible to grade  the trench line
              level prior to construction, but this is an added expense.  If grading is not possible,
              cement-bentonite  slurry walls are an alternative  for steeply sloping sites.

              If a keyed-in slurry wall  is considered, the depth to, and nature of, the confining
              layer becomes a  concern.  The layer  must be  of sufficiently low permeability to
              significantly retard downward migration at the design head levels.  It must also have
              sufficient thickness to allow for excavation  of an adequate key-in (2 to 3 feet).  The
              depth to the confining layer  will also determine the type of excavation equipment
              used and the completed  wall costs.  Most slurry wall contractors have  available
              modified hydraulic backhoes capable of excavation to depths of 70 feet  or more.
5/93                                         21

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GROUNDWATER CONTAINMENT
              Below this level, more expensive specialty equipment such as clamshell grabs are
              required, and costs increase dramatically.

              Another limiting factor is the amount of work area required for soil-bentonite backfill
              mixing. Ideally, there will be sufficient work area beside the trench to mix and place
              the backfill.   If such room is available, a central  backfill  mixing area can  be
              established, and the backfill can be hauled to the active trench portion.

              Another limiting factor in the use of soil-bentonite slurry walls for pollution migration
              control is the lack of long-term performance data.  Soil-bentonite walls have been
              used for decades for groundwater control in conjunction with large dam projects and
              there is ample evidence of their success in this application. However, the  ability of
              these walls to withstand long-term permeation by many  contaminants is unknown.
              Most contaminant/backfill compatibility  questions have been answered by laboratory
              permeation tests and not  by long-term  studies.   The issue of containment/backfill
              compatibility is discussed further under  "Design Considerations".

              Design Considerations

              Many factors must be  considered in slurry wall design.  The design must be based
              on a detailed, design-phase investigation  characterizing  subsurface conditions and
              materials, as well  as disposition and nature of the waste.  The issue of waste-wall
              compatibility should be addressed early in the design  by  permeability testing  of the
              proposed backfill mixture with actual site leachate or groundwater. The design-phase
              investigation results can then be used to  decide on the  optimum configuration and to
              select any ancillary measures needed to enhance the performance of the wall.  These
              considerations are discussed further below.  These  and other design considerations
              are covered in great detail  in Slurry  Trench Construction for Pollution Migration
              Control (Spooner et. al., 1984a).

              For  most slurry walls installed to control contaminated groundwater,  the  most
              important design consideration will be the permeability of the completed wall. The
              soil-bentonite wall's permeability is dependent on the backfill  mixture.  The lowest
              permeability is obtainable from backfills having 20- to 40-percent fine soil material
              (passing  a number 200 sieve)  and preferably plastic fines (D'Appolonia, 1980b).
              Although plastic fines are essential to achieving low permeability, there is evidence
              to show that long-term wall performance in a contaminated environment will be more
              certain if the backfill is composed of clays with a low activity index (defined as the
              plasticity index divided by the percent by weight  finer than two microns).

              If a  backfill mixture  contains  clays with a high  activity index, the initial low
              permeability of the wall could more easily be increased by physiochemical reactions
              brought about by  contaminants.  This problem  can be avoided by proper backfill
              selection and testing.
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GROUNDWATER CONTAINMENT
              A number of chemical compounds can have a detrimental effect on soil-bentonite
              slurry walls. TABLE 1 shows how some chemicals can affect backfill permeability.
              More recent information  indicates that organic  fluids can cause desiccation  and
              cracking in soil-bentonite backfill mixtures.  This results in permeability increases of
              several orders of magnitude. However, these same data indicate that these organics,
              at or near their solubility limits in aqueous solution, caused no appreciable increases
              in permeability  (Evans, Fang,  and Kugelman, 198S).  Nonetheless, landfill  and
              lagoon leachates are often complex mixtures of chemicals and no pollution control
              slurry wall should be installed without thorough compatibility testing.



TABLE 1
SOIL BENTONITE PERMEABILITY INCREASES
DUE TO LEACHING WITH VARIOUS POLLUTANTS
Pollutant





















N =

M =
H =
* =
+ =
CA++ or Mg+ @ 1,000 ppm
Ca++ or Mg+ @ 10,000 ppm
NHjNOj @ 10,000 ppm
Acid(pH>l)
Strong acid (pHll)
HC1 (1%)
H2SO4(1%)
HC1 (5%)
NaOH(l%)
CaOH(l%)
NaOH (5%)
Benzene
Phenol solution
Sea water
Brine (SG - 1.2)
Acid mine drainage (FeS04, pH * 3)
Lignin (in Ca++ solution)
Organic residues from pesticide manufacture
Alcohol
Backfill*

N
M
M
N
M/H*
N/M
M/H*
N
N
M/H*
M
M/H*
N
N
N/M
M
M
N
N
N
M/H
No significant effect; permeability increases by about a factor of 2 or less at steady
state.
Moderate effect; permeability increases by factor of 2 to 5 at steady state.
Permeability increases by factor 5 to 10.
Significant dissolution likely.
Silty or clayey sand, 30 to 40% fines.
Source: D'Appolonia, 1980a; D'Appolonia and Ryan, 1979
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23

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GROUNDWATER CONTAINMENT
              After it is determined that a backfill mixture compatible with  site  wastes  can be
              designed, an assessment can be made  on wall configuration.  In most pollution
              migration control applications,  the  wall  will  be keyed  into a low permeability
              confining layer beneath the site, and completely surround the site. Only in  special
              applications are hanging walls and partial walls used.

              The design of a slurry wall for source control at a site must always consider how the
              wall fits into the overall remedial response.  Rarely, if ever, are slurry walls (or
              other subsurface barriers) the only action taken in site remediation. At a minimum,
              surface infiltration barriers (caps) are installed to prevent filling of the site interior
              and overtopping of the wall.  In some  installations, extraction wells or drains are
              used to maintain lower groundwater levels inside the wall than outside.  This prevents
              the site from filling and possibly floating the  cover material off, and also keeps
              groundwater flowing toward the interior, thus permeating the wall with groundwater
              rather than leachate.  Although  such an installation  would be more  expensive and
              would require a leachate treatment system, long-term performance of the wall would
              be greatly enhanced.

              Construction Considerations

              Construction of a  soil-bentonite slurry wall is relatively  straightforward.   The
              equipment that  is used is dependent on the depth and length of the wall.  For walls
              up to 80 feet deep, a backhoe or modified backhoe is used for excavation. Deeper
              installations require the use of a mechanical or hydraulic clamshell or, in rare cases,
              a dragline.  Small volume wall installations may allow the use of batch slurry and
              backfill mixing systems, while large jobs would require flash slurry mixers and a
              large backfill mixing area.  FIGURE 2 illustrates a typical slurry wall construction
              site.

              Regardless of the equipment used, the  slurry is introduced just after the trench is
              opened and before the water table is  reached. The primary function of the slurry is
              to act as hydraulic shoring to prevent trench collapse.   There is also evidence to
              indicate that the filter cake formed on the trench  walls by the slurry contributes to the
              low permeability of the completed wall.
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GROUNDWATER CONTAINMENT
                             FIGURE 2
              TYPICAL SLURRY WALL CONSTRUCTION SITE
Source: Spooner et al., 1984a
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25

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GROUNDWATER CONTAINMENT
             After a sufficient length of wall is excavated to the design depth, backfilling can
             begin.  This is usually begun by using a clamshell to lower mixed backfill to the
             trench bottom until the sloped backfill extends to the surface. Thereafter, the backfill
             can be pushed into the trench with a bulldozer or poured from trucks using a trough,
             and allowed to flow (not fall) down the sloped backfill. This procedure, with backfill
             mixing alongside the trench, is shown in FIGURE 3.

             Proper  quality control during  wall installation is essential.  The most important
             factors are checks of trench continuity and backfill mixing and placement.
             BACKFILL MIXING AREA
                                                     TRENCH SPOILS
                                       AREA OF ACTIVE
                                        EXCAVATION
         "•^EMPLACED.-'
          "  BACKFILL :••'.:•
                                                      UNEXCAVATED SOIL
                                    FIGURES
         CROSS-SECTION OF SLURRY TRENCH, SHOWING EXCAVATION
                        AND BACKFILLING OPERATIONS
Source:  Spooner et al, 1984a
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                                        26

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GROUNDWATER CONTAINMENT
              Backfill mixing and placement are carefully controlled during construction. The soil
              that  makes up the majority of the backfill is placed in the  mixing area (either a
              central area or alongside the trench) and slurry is added.  The mixture is bladed and
              tracked by a bulldozer until it is of relatively uniform consistency and of the proper
              density.  The backfill must be fluid enough to flow freely into the trench, but not so
              fluid that it (1) fails to  easily displace the slurry, (2)  forms a slope so gentle that it
              extends into the active excavation area, or (3) requires a great length of trench to be
              kept open.

              For  circumferential installation, a portion of the backfill is  reexcavated when the
              circle is  complete.  The wall  is then allowed to consolidate for up to several weeks.
              Desiccation and consolidation cracks often form in the top few feet during this time.
              These  are  often excavated and a compacted earth cap  is placed along  the  wall to
              prevent further desiccation or cracking.  Where vehicular traffic must cross a wall,
              traffic  caps of aggregate and/or geotextiles are often constructed.  Desiccation caps
              and traffic caps are tied into the site surface cap.

              Operation, Maintenance, and Monitoring

              As passive measures,  slurry walls  require no operation and  little  maintenance.
              Maintenance of the desiccation cap atop  the wall is the only requirement that  is
              specific  to the wall itself.  Maintenance  of ancillary measures  such as caps  and
              leachate  collection systems is important to the wall  as part  of the entire remedy.
              Monitoring of slurry walls usually involves monitoring groundwater levels inside and
              outside the wall to ensure  that design head levels are not exceeded.  Groundwater
              quality monitoring can be used to determine the effectiveness of the entire remedial
              effort.

              Technology Selection/Evaluation

              Soil-bentonite slurry walls are a relatively inexpensive  and effective means of
              controlling groundwater flow. They have been in use  for decades to control seepage
              through, under, and around large dams.  In uncontaminated environments, they have
              been shown to have  long-term effectiveness and require little or no maintenance.
              Although they are  installed  by specialty contractors,  they are  relatively  easy to
              construct and are effective in controlling  groundwater immediately, provided head
              differentials  across  the wall  are within  design  tolerances.    In  contaminated
              environments, however, their effectiveness over the longterm is very dependent on
              the types of contaminants  and their  concentrations.   Consequently, design of such
              installations should  always consider methods and measures of  minimizing direct
              contact of high-strength leachates  with  the wall. The  integrity of any slurry wall
              placed directly through wastes or kept in constant contact with high-strength leachates
              must be  questioned, and where questioned, verified by monitoring.
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GROUNDWATER CONTAINMENT
              The major safety concerns for slurry wall installations arise from the excavation of
              contaminated materials. These can cause disposal problems, increase air emissions
              from the site, and greatly slow the pace of construction by requiring increased levels
              of worker protection (i.e., supplied  air).  This is another reason that excavations
              through deposited wastes should be avoided whenever possible.

              Costs

              Costs for slurry walls and other subsurface barriers are usually expressed in costs per
              unit area of wall (dollars per square foot).  Thus, total costs are determined by the
              depth and the length. Width is determined by the excavation  equipment being used.
              TABLE 2 shows average costs for soil-bentonite and cement-bentonite slurry walls
              and illustrates  the  effects  of both the depth and ease of excavation on  costs.
              Operation and maintenance costs are negligible. These costs have been updated using
              Engineering News Record cost indices for 1979 and 1984.
TABLE 2
RELATION OF SLURRY CUT-OFF WALL COSTS PER SQUARE FOOT
AS A FUNCTION OF MEDIUM AND DEPTH
Medium
Soft to Medium Soil N
Hard Soil N 40-200
Occasional Boulders
Soft to Medium Rock,
Boulder Strata
Hard Rock
Slurry Trench
Prices in 1984 Dollars -
Soil-Bentonite Backfill
(S/ft2)
Depth
<. 30
Feet
3-6
6-10
6-11

21-35

Depth
30-75
Feet
6-11
7-14
7-11

21-35

Depth
75-120
Feet
11-14
14-28
11-35

69-111

Unreinforced Slurry Wall
Prices in 1984 Dollars -
Cemeht-Bentonite Backfill
(S/ft2)
Depth
<60
Feet
21-28
35-42
28^2

42-55

Depth
60-150
Feet
28-42
42-55
42-55

85-132

Depth
> 150
Feet
42-104
55-132
55-118

132-292

Notes: N is standard penetration value in number of blows of the hammer per foot of penetration (ASTM
D1586-67).
* Normal Penetration Only: For standard reinforcement add $1 I/ft2.
For construction in urban environment add 25% to 50% of price.
Does not include cost of working in a contaminated environment.
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28

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GROUNDWATER CONTAINMENT

       Cement-Bentonite Slurry Walls

       Cement-bentonite slurry walls share many characteristics with soil-bentonite slurry walls, but
       are also different in some respects. The principal difference between the two is die backfill,
       and this produces differences in applications, compatibilities, and costs.  This discussion will
       highlight the factors that distinguish cement-bentonite walls from soil-bentonite walls.

       Cement-bentonite walls are generally excavated using a slurry of Portland cement, bentonite,
       and water.  This slurry is left in the  trench and allowed to set up to  form the  completed
       barrier. For extremely deep installations, a normal bentonite slurry is used for excavation,
       then replaced by cement-bentonite.

              Applications and Limitations

              Cement-bentonite walls offer the same configuration options as soil-bentonite walls.
              They are more versatile  than soil-bentonite walls in two  ways.  First, because the
              slurry sets up into a semirigid solid, this type of wall can accommodate variations in
              topography by  allowing  one section to set while continuing  the  next section at a
              higher  or lower elevation.  Second, because the excavation slurry is commonly the
              backfill too, this type  of wall  is better suited to restricted  areas where there is no
              room to mix soil-bentonite backfill.  Also, cement-bentonite  is stronger than soil-
              bentonite, so it is used where the wall must have less elasticity, such as adjacent to
              buildings or roads.

              Cement-bentonite slurry walls are limited in their use by their higher costs, somewhat
              higher  permeability, and  their narrower range of chemical compatibilities.  Cement-
              bentonite walls average over 30-percent higher in cost than soil-bentonite walls.  The
              permeability of a cement-bentonite wall is normally around  1 x 10"6 cm/sec, while a
              well-designed soil-bentonite wall is capable of achieving 1 x 10"8 cm/sec (Spooner et
              al., 1984a).  Cement-bentonite backfills are also more susceptible to chemical attack
              than most soil-bentonite mixtures.   Cement-bentonite is  susceptible to attack by
              sulfates,  strong acids, and bases (pH  <4 and ^7), and  compatibility testing is
              contained in Compatibility of Grouts with Hazardous Wastes (Spooner et al., 1984b).

              Design and Construction Considerations

              The design and construction of a cement-bentonite slurry wall is very similar to that
              of a soil-bentonite wall.  TABLE 3 shows typical compositions of cement-bentonite
              slurries.  Accelerators, retardants, and various other additives may  be used but are
              not common  practice.  FIGURE 4 illustrates the composition  of cement-bentonite
              slurries.
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GROUNDWATER CONTAINMENT
                                    TABLE 3
          TYPICAL COMPOSITIONS OF CEMENT-BENTONITE SLURRIES
                     Constituent
                  Percentage in Slurry
      Bentonite

      Water

      Cement
            without replacements
            when blast furnace slag added, minimums
            when fly ash added, minimums

      Blast furnace slag, maximums, if used

      Fly ash,  maximums, if used
                         4-7

                        68-88


                         8-25
                         1-3
                         2-7

                         7-22

                         6-18
                Non-Setting
                Slurries
                    Semi
                    Fluids
                  Percent.
                  Cement
                    Source: Jefleris. 1981
                   Cut-Off
                   Slurries
                   Bleeding
                   Slurries
                   Percent
                   Bentonite
                                               -Percent Water
                                    FIGURE 4
               COMPOSITION OF CEMENT-BENTONITE SLURRIES
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GROUNDWATER CONTAINMENT

              Construction of a cement-bentonite wall is nearly identical to a soil-bentonite wall.
              However, backfill mixing and the large area requirement are eliminated.  Greater
              care must be taken in slurry mixing because the mixture is more sensitive to small
              changes  in  composition.   Cement-bentonite walls are also usually  finished with
              desiccation caps to prevent harmful cracking.

              Operation, Maintenance, and Monitoring

              As with  soil-bentonite walls,  no  maintenance  is required.    Maintenance  and
              monitoring are usually directed toward ancillary measures, and not toward the slurry
              wall itself.  However, it is important, as a part of the remedial  effort, to monitor
              water levels and groundwater quality to evaluate the success of the wall.

              Technology Selection/Evaluation

              Like soil-bentonite slurry walls, cement-bentonite walls can be an effective, relatively
              inexpensive means of controlling groundwater flow. Most of the site constraints that
              affect the selection of a soil-bentonite wall also apply to cement-bentonite walls.
              Because cement-bentonite walls  are more  expensive, they are generally used where
              (1) there is no room to  mix and place soil-bentonite backfill, (2)  increased strength
              is required, or (3) extreme topography make it impractical to grade a site level.

              As with any barrier installation, thorough compatibility testing is a must.   Cement-
              bentonite mixtures are somewhat more susceptible to chemical attack than most soil-
              bentonites.  They should not be placed directly through wastes or left unprotected
              from attack by high-strength leachates.

       Diaphragm Walls

       Diaphragm walls are  barriers composed of reinforced concrete panels (diaphragms), which
       are emplaced by slurry trenching techniques. They may be cast-in-place or precast, and they
       are capable of supporting great loads. This degree of strength is seldom, if ever,  called for
       at a hazardous waste site and their use is extremely rare.  Because  diaphragm  walls  are
       constructed in slurry-filled trenches, it is possible to include them in cement-bentonite or soil-
       bentonite walls for short sections, such as road or rail crossings, that require greater strength.
       If the joints between the case panels are made correctly, diaphragm walls can be expected
       to have permeabilities comparable to cement-bentonite walls.  The same compatibility  that
       applies to cement-bentonite applies to diaphragm walls.  Diaphragm  walls are a specialty
       item, and rarely used in pollution migration situations,  so they are not discussed in detail
       here.

       Grouting

       Grouting is a process whereby one of a  variety of fluids is injected into a rock or soil mass
       where it is set in place to reduce water flow and strengthen the formation. Because of costs,
       grouted barriers are seldom used for containing groundwater flow in unconsolidated materials


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GROUNDWATER CONTAINMENT

       around hazardous waste sites. Slurry walls are less costly and have lower permeability than
       grouted barriers.  Consequently, in waste site remediation, grouting is best suited for sealing
       voids in rock.  Even in cases where rock voids are transmitting large water volumes, a grout
       can be formulated to  set before it is washed out of the formation. The  various types of
       grouts that are available are discussed below, followed by discussions of the various ways
       grouts may be employed.  FIGURE 5 illustrates the range of grout applicability based on
       grain size.
                                          All Grouts
                                               Acrylamides
                                                Resins
                                             Silicates
                              Clay-Bentonite

                              Cement
                                       Emulsions
             100
  10
  1.0
            0.1
              0.01
          Cobbles
Gravel
                     Coarse
      Fine
              Sand
Coarse
Medium
Fine
                         Silt or Clay
                                       FIGURES
               APPLICABILITY OF DIFFERENT CLASSES OF GROUT
                            BASED ON SOIL GRAIN SIZE
       Cement has probably been used longer than any other type of material for grouting
       applications (Bowen, 1981).  Cement grouts use hydraulic cement which sets, hardens, and
       does not disintegrate in water (Kirk-Othmer, 1979).  Because of their large particle  size,
       cement grouts are more suitable for rock, rather than soil, applications (Bowen,  1981).
       However, the addition of clay or chemical polymers can improve the range of use.  Cement
       grouts have been used for both soil consolidation and water cut-off applications, but their use
       is primarily restricted to more open soils. Typically, cement grouts cannot be used in  fine-
       grained soils with cracks less than 0.1 millimeter wide (Bowen, 1981).
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                  32

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GROUNDWATER CONTAINMENT

       Clays have been widely used as grouts, either alone or in formulations because they are
       inexpensive (Guertin and McTigue,  1982).  Only certain types of clay minerals possess the
       physical and chemical characteristics favorable for use in  grouting.  These characteristics
       include the ability to swell  in the presence of water  and to form a gel structure at low
       solution  concentrations.    These  properties  are  exhibited  most  markedly  by  the
       montmorillonites.  Other types of clay minerals, such as kaolinite and illite, can be used as
       fillers in grout formulations, such as clay-cement mixtures  (Greenwood and Raffle, 1963).

       Bentonite grouts (high  in calcium montmorillonite) can be used  alone as  void  sealers in
       coarse sands with a permeability of more than 102 ft/day (10'1 cm/sec).  Bentonite-chemical
       grouts can be used on medium to fine sands with a permeability  between 102 ft/day (10"1
       cm/sec) and 1 ft/day (10"3 cm/sec).  Both of these grout types can also be used to seal small
       rock fissures (Guertin and McTigue, 1982). Because of their low gel  strengths, bentonite
       grouts are not able to support structures and  therefore can only be used as void sealers
       (Tallard and Caron, 1977b).

       Alkali silicates are the largest and most widely used chemical grouts. Sodium, potassium,
       and  lithium silicates  are  available, with sodium silicates  being used more frequently.
       Chemical grouts (i.e., silicates and organic polymers) constitute less than 5 percent by
       volume of the grouts used in the United States,  although they represent almost 50 percent of
       the grouts used in Europe (Kirk-Othmer,  1979). In addition to their use as a grout, sodium
       silicates may be used as additives to other grouts, such as Portland cement, to improve
       strength and durability.

       Silicates grouts are used for both soil consolidation and void sealing applications.  These
       grouts are suitable for subsurface applications  in  soils with a permeability of less than 10
       ft/day (10'2 cm/sec). Silicate grouts are not suitable for open fissures or highly permeable
       materials because of syneresis (water expulsion) unless they are preceded by cement grouting
       (Karol, 1982a; Sommerer and Kitchens,  1980). Furthermore, tests conducted by the U.S.
       Army Waterways Experiment Station found silicate grouts to be ineffective in waterproofing
       fine-grained soils (Hurley and Thornburn, 1971).

       Organic polymer grouts represent only a small fraction of the grouts in use. These grouts
       consist of organic materials (monomers) that polymerize and crosslink to form an insoluble
       gel.  The organic polymer grouts include:

       •     Acrylamide grouts

       •     Phenolic  grouts

       •     Urethane grouts

       •     Urea-formaldehyde grouts

       •     Epoxy grouts



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GROUNDWATER CONTAINMENT

       •      Polyester grouts.

       Acrylamide grouts have been in use for about 30 years and were the first of the organic
       chemical polymer grouts to be developed.  Acrylamide grouts have the largest use among the
       existing organic polymer grouts and are the second most widely used chemical grouts (after
       silicates) (Karol, 1982a). They may be used alone or in combination with other grouts such
       as silicates, bitumens, clay, or cement (Tallard and Caron, 1977a).

       Acrylic and polyacrylamide grouts are typically used in  ground surface treatment, ground
       treatment  for  oil well  drilling, and  subsurface applications (e.g.,  waterproof concrete
       structures). Aery late grouts are more commonly used for ground surface treatment than for
       soil injection where acrylamide grouts are more frequently used.

       Acrylamide applications include structural support and  seepage  control for mines,  soil
       consolidation for foundations of structures and dams, and water control and soil consolidation
       for tunnels, wells, and mines (Tallard and Caron, 1977a).  Specific applications include grout
       curtains, loose sand stabilization, artesian flow shut-off, and water seepage control in jointed
       and fissured rock (Office of the Chief of Engineers, 1973).  Based on AM-9 applications,
       acrylamide grouts may be used in  a variety of soil materials such as fine gravel; course,
       medium, or fine sand; and some clays (Herndon and Lenahan, 1976).

       Urethane grouts are the second most commonly used type of organic polymer grout (Jacques,
       1981).  Urethane grouts were developed in Germany for consolidation applications and are
       now used  in Europe, South Africa, Australia, and Japan (Sommerer and Kitchens, 1980).
       These  grouts are used  for water and soil applications  and  can penetrate finely  fissured
       material.

       The use of phenolic resin in underground and foundation construction began in the  1960s
       (Kirk-Othmer, 1979; Tallard and Caron, 1977a). These grouts may be used in fine soils and
       sands for a variety of water control and ground treatment applications.

       However,  phenolic  grouts are not widely used alone  but are typically used in conjunction
       with other grouts (Tallard and Caron, 1977a).

       Urea-formaldehyde  resins are  frequently referred to as aminoplasts.  The idea for the use of
       these resins as grouts came from their use as glue in the oil industry (Tallard and Caron,
       1977a). Although urea-formaldehyde grouts have been available since the 1960s, they have
       found limited use (Karol, 1982b; Sommerer and Kitchens, 1980).  These grouts can setup
       only in an acid environment; therefore, they cannot be used in basic formations.

       Epoxy grouts and other glue-like grouts have been in use since 1960. These grouts have had
       limited use in soil grouting primarily because of their high cost (Tallard and Caron, 1977a).
       Most of the applications reported in the literature involve the use of epoxy resins in mortars
       and for sealing cracks.  Epoxy resins can adhere to and  seal  submerged concrete, steel, or
       wood surfaces, and are useful in water applications (Engineering News-Record, 1965). They
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GROUNDWATER CONTAINMENT

       have been used for grouting cracked concrete for structural repairs and grouting fractured
       rock to improve its strength (Office of the Chief of Engineers, 1973).

       Polyester grouts have been in use since the 1960s.  They have been used in a variety of
       construction applications, principally to treat cracks in buildings and structures (Tallard and
       Caron, 1977a).   These grouts have also  been used in mines as well as to stabilize  and
       strengthen porous and fissured  rock (Tallard and Caron, 1977a; Office of the Chief of
       Engineers, 1973).  Polyester grouts have been used infrequently to treat  sand (Tallard and
       Caron, 1977a).

       The compatibility of these grouts with hazardous wastes and leachates has not been studied
       in great detail, and only general incompatibilities are known. One recent study indicates the
       response of several grouts to various organic chemicals  is unpredictable and  often drastic
       (Bodocsi, 1985).  Therefore,  where grouting is considered a remedial option, thorough
       compatibility tests must be performed.

       The component parts of some grouts, such as acrilimides and urea-formaldehydes, are toxic.
       Unless the setting reactions are carefully  controlled, there is a likelihood that unreacted, toxic
       compounds will be released into the  ground.  A thorough characterization of the waste and
       grout chemistry, as well as the site geochemistry, is required.

       Rock Grouting

       One of the greatest potential uses for grouting in hazardous waste site remediation is for
       sealing fractures,  fissures, solution  cavities, or other voids in rock.  Nonetheless, rock
       grouting  at waste sites is uncommon  and no actual applications were found in the literature.

              Applications and Limitations

              Rock grouting may be applied to  a waste  site  to  control the  flow of groundwater
              entering a site.   In theory, grouting could also control leachate flow  in rock, yet in
              many cases, contaminants interfere with grout setting reactions and/or reduce grout
              durability.  In many cases, the waste/grout interaction and compatibility cannot be
              predicted and extensive testing is required.  These issues are discussed in detail in
              Compatibility of Grouts with  Hazardous Wastes (Spooner et al., 1984b).

              Design and Construction Considerations

              As with other types of barrier construction, the ultimate success of a grouting project
              depends on thorough site characterization. The ability to seal water-bearing voids or
              zones is dependent on being able to locate them.

              In many remedial  grouting operations, only a small portion of the rock mass will
              transport water and must be sealed.  Consequently, the exploratory investigation must
              be very thorough.   Detailed geologic  mapping of the site, aided by remote sensing
              techniques and extensive rock coring, is required.  Even with extensive investigation,


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GROUNDWATER CONTAINMENT
              the complexity  of groundwater flow in fractured and fissured bedrock can make a
              grouting project impossible to plan completely in advance.

              Based on  background and  exploratory data,  the location for a pattern of primary
              injection holes is chosen, and injection at one or more zones is identified.  The first
              few primary holes are then drilled and pressure washed with water and air (Millet and
              Engelhardt,  1982).  This step removes drill cuttings and other debris from the hole
              to  allow better  grout penetration.   Each hole is then pressure tested, often using a
              nonsetting fluid of the same viscosity as the grout to be used.  These tests are used
              to  determine the initial grout mixture and are often conducted using the grout plant
              and other equipment to be used for the actual grouting.

              Each zone within each primary hole is then  injected with the grout mixture until a
              predetermined amount is pumped  (grout take) or a  predetermined flow  rate  at
              maximum allowable pressure is reached.  Maximum allowable pressure is typically
              around 1 pound per  square inch (psi) per foot of overburden (Millet and Engelhardt,
              1982).

              Data from the drilling and injection of the first primary holes is analyzed  and,  if
              necessary, the grout mixture or injection pressure is modified before completing the
              remaining primary holes. After the primary hole grouting is completed, the program
              is analyzed again, necessary changes are made, and a pattern of more closely spaced
              secondary holes are drilled and injected.

              The analysis and evaluation of the completed  grouting becomes, in essence, another
              pressure test. Close quality control during drilling and grouting identifies areas that
              require tertiary hole grouting to complete sealing. Such areas are identified by faster
              than expected drilling rates and  higher  than expected grout takes (Millet and
              Engelhardt,  1982).

              For a successful grouting program, each hole  series (e.g., primary or secondary) will
              have lower  grout takes than the  previous one.  Many projects will require that
              tertiary, or proof holes be drilled and injected.  A very low grout take on proof holes
              indicates that most voids are grout filled and the grouting program was successful.

              Operation,  Maintenance, and Monitoring

              As with other  subsurface  barriers, operation  and maintenance requirements are
              negligible.  Monitoring programs, consisting of hydrologic measurements  and water
              quality  assessments, are used to evaluate the  effectiveness of the completed barrier.

              Technology  Selection/Evaluation

              Rock grouting is very much a specialty  operation.   It is performed by a  limited
              number of contractors, and each such program is highly sitespecific.  Because this
              technique  has rarely,  if ever, been applied to  controlling highly contaminated
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GROUNDWATER CONTAINMENT
              groundwater, an assessment of performance and reliability is not possible.  Each
              instance where rock grouting is feasible for site remediation must be evaluated on a
              case-by-case basis.

              Costs

              Each rock grouting job is highly site specific, and valid costs vary widely.  Example
              costs for some common  grouts are shown in TABLE 4.  These  costs have been
              updated using the Engineering  News-Record cost indices for 1979 and 1985.

              Grout  costs for  a completed job  show much less variation.   This is because the
              cheaper, paniculate grouts are used to seal large voids, thus using more  grout,
              whereas the more expensive chemical grouts are commonly used to seal small  voids.
TABLE 4
APPROXIMATE COSTS OF COMMON GROUTS
Grout Type
Portland Cement
Bentonite
Silicate - 20%
30%
40%
Epoxy
Acrylamide
Urea Formaldehyde
Approximate Cost ($/ga!lon)
of Solution (1985)
1.33
1.76
1.76
2.95
3.86
42.15
9.34
8.00
             As an example of costs for rock grouting, assume that a 1,000-foot-long barrier, that
             is 6 feet thick and 30 feet deep is to be placed in rock with 20-percent void space.
             A double row of injection holes,  6 feet on center, will be used (333 holes), and 40-
             percent sodium  silicate grout  will be injected.  Approximate costs are given in
             TABLE 5.
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TABLE 5
APPROXIMATE COSTS ($ 1985) FOR GROUND BARRIER IN ROCK
Unit Operation
Injection Hole drilling
Grout Pipe
Grout injection
Grout - 40%
Approximate Unit Cost
$14. 16 per foot -9990 feet
$8.49 per foot - 99990 feet
$5.66 per cubic yard - 1333
cubic yards
$3.86 per gallon - sodium
silicate - 35,991 gallons
Total Cost *
Approximate Cost
$141,440
$84,869
$7,549
$139,039
$391,097
* Does not include site investigation and characterization
       Grout Curtains

       Grout  curtains are subsurface barriers created in unconsolidated  materials by pressure
       injection.  The various methods of forming a grout curtain are described below under design
       and construction considerations.

       Grout barriers can be many times more costly than slurry walls and are generally incapable
       of attaining truly low permeabilities in unconsolidated materials.  A recent field test study
       of two chemical grouts revealed significant problems in forming a continuous grout barrier
       due to noncoalescence of grout pads in adjacent holes and grout shrinkage.   This study
       concludes that conventional injection grouting is incapable of forming a reliable barrier in
       medium sands (May et al., 1985). Therefore, they are rarely used when groundwater control
       in unconsolidated materials is desired.

              Applications and Limitations

              Grout curtains, like other barriers, can be applied to a site in various configurations.
              Circumferential placement offers the most  complete containment but requires that
              grouting  take place in contaminated groundwater downgradient of the source.  As
              discussed under rock grouting, this could easily cause problems with grout set and
              durability.  As with other techniques,  this requires extensive compatibility testing
              during the feasibility study. Another limitation of curtain grouting is the problem of
              gaps left  in the curtain due to nonpenetration of the grout. Only a few small gaps in
              an  otherwise low-permeability  curtain  can  increase  its  overall  permeability
              significantly.
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GROUNDWATER CONTAINMENT
             Design and Construction Considerations

             The design of a grout curtain must be based on a thorough site characterization.
             Analysis of site characterization data, including boring logs, pump or injection test
             results, and other data, is used to determine whether a site is groutable.  These data
             are also  used to  determine  which grout is most suitable based on  viscosity,
             compatibility, and ultimate permeability.  This is a very involved process and should
             be conducted by an experienced engineer.

             Construction of a grout barrier is accomplished by pressure injecting the grouting
             material through a pipe into the strata to be waterproofed. The injection points are
             usually arranged in a  triple  line of primary  and  secondary  grout  holes.  A
             predetermined quantity of grout is pumped into the primary holes.  After the  grout
             in the primary holes has had time to gel, the secondary holes are injected.  The
             secondary grout holes  are intended to fill  in any gaps left by the primary  grout
             injection (Hayward Baker, 1980).  The primary holes are typically spaced at 20- to
             40-foot intervals  (Guertin and McTigue,  1982).  FIGURE 6 illustrates  a  grout
             curtain.
          Semicircular
         Grout Curtain
                                  Secondary
                                 Grout Tubes
                                           Primary
                                        Grout Tubes
                                      FIGURE 6
             SEMICIRCULAR GROUT CURTAIN AROUND WASTE SITE
Source:  Spooner et. al., 1984b
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GROUNDWATER CONTAINMENT
              Several basic techniques are used to form the grout wall.  These include (Hayward
              Baker, 1980; Guertin and McTigue, 1982):

              •       Stage-up method

              •       Stage-down method

              •       Grout port method

              •       Vibrating beam method.

              Stage-up method: The borehole is drilled to the full depth of the wall prior to grout
              injection.  The drill is withdrawn  one "state,"  leaving several feet  of borehole
              exposed.  Grout is then injected into this length of open borehole until the desired
              volume has been injected. When injection is complete, the drill is withdrawn further
              and the next stage is injected (Hayward Baker, 1980).

              Stage-down method:  Grouting differs from stage-up grouting in that the injections are
              made from the top down. Thus, the borehole is drilled through the first zone that is
              to be grouted, the drill is withdrawn, and the grout injected.  Upon completion of the
              injection, the borehole is redrilled through the grouted layer into the  next zone to be
              grouted and the process is repeated (Guertin and McTigue,  1982).

              Grout port method:  This method uses a slotted injection pipe that has been sealed
              into the  borehole with  a brittle Portland  cement and clay  mortar jacket.  Rubber
              sleeves cover the outside of each slit (or port), permitting grout to flow only out of
              the pipe.

              The injection process begins by isolating the grout port in the zone to be  injected
              using a double packer.  A brief pulse of high-pressure water is injected  into the port
              to rupture the mortar jacket.  Grout is pumped between the  double packers and then
              passes through the ports in the pipe, under the rubber sleeve, and out through the
              cracked mortar jacket into the soil (Guertin and McTigue, 1982).

              Vibrating beam method: This  method places, instead of injects, grout to generate  a
              wall. In this method, an I-beam is vibrated into the soil to the desired depth and then
              raised at a controlled rate. As the beam is raised, grout is  pumped through a set of
              nozzles mounted in the  beam's base to fill the newly formed cavity.

              When the cavity is completely filled, the beam is moved less than one beam width
              along the wall, leaving  a suitable overlap to  ensure continuity (Harr, Diamond, and
              Schmednect, undated).  This method is illustrated in FIGURE 7.
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GROUNDWATER CONTAINMENT
                     Vibrating
                     Hammer
                        Beam
                  Grouted
                  Sections
                    \

                                      Top View
                                        •  n
                                           H
                                           u
                                       Typically
                               FIGURE?
                   VIBRATING BEAM GROUT INJECTION
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              Operation, Maintenance, and Monitoring

              Grout curtains, which require no operation and little or no maintenance, may require
              more monitoring than other barriers.  Even a very small gap left in the barrier can
              enlarge quite rapidly by piping or tunneling if there is a sufficient hydraulic gradient
              across  the wall.

              Technology Selection/Evaluation

              Grout curtains are a specialty technology seldom applied to hazardous waste sites (an
              exception is the vibrating beam wall with  bitumen grout, which  has seen some
              application in recent years).  As such, no detailed assessment of the  performance or
              reliability of this technology is possible.

              Costs

              As with rock grouting, each curtain grouting job is highly site specific.  Each site
              requires differing degrees of investigation and characterization.  The grout injection
              program must be tailored  to its characteristics. The costs given for rock grouting can
              serve as an example of curtain grouting.  Example grout costs are shown in TABLE
              4.

       Sheet Piling

       In addition  to slurry  wall and grouted  cut-offs,  sheet piling  can  be used to  form  a
       groundwater barrier.  Sheet piles can be made of wood, precast concrete, or steel.  Wood
       is an ineffective water barrier.  Therefore, concrete is used primarily  where great strength
       is required.  Steel is the most effective in terms of groundwater cut-off and  cost, so steel
       sheet pilings are discussed here.

              Applications and Limitations

              Steel sheet piling can be employed as a groundwater barrier much like the others
              discussed in this chapter.  Because of costs and unpredictable wall integrity, however,
              it is  seldom used except for  temporary  dewatering for other construction, or  as
              erosion protection where some other barrier, such as a slurry wall, intersects flowing
              surface water.

              One  of the  largest  drawbacks  of sheet piling,  or  any  other barrier technology
              requiring  pile driving, is the  problem caused  by rocky soils.   Damage to,  or
              deflection of, the piles may render the wall ineffective as a groundwater barrier.

              Design and Construction Considerations

              The primary  design parameters for any  barrier are permeability and dimensions.
              Dimensional requirements are based on site characteristics and are straightforward.


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GROUNDWATER CONTAINMENT
            Depth limitations are governed by the soil material at the site.  Design factors for
            ultimate permeability of the cut-off are more complicated and must assume some
            factor to account for leakage through the interlocking joints. Typical shapes for steel
            sheet piling are shown in FIGURE 8.
      Straight Web Type
      Arch Web Type
     Deep Arch
     Web Type
     Z-Type
     Y-Frctina
     T-Fming
                                    FIGURES
                 SOME STEEL PILING SHAPES AND INTERLOCKS
Source:  Ueguhardt et. al., 1962
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              To construct a sheet piling cut-off, the pilings are assembled at their edge interlocks
              before they are driven into the ground. This arrangement ensures that earth materials
              and added pressures will not prevent a good lock between piles.  The piles are then
              driven a few feet at a time over the entire length of the wall.  This process is repeated
              until the piles are all driven to the desired depth.

              The  sheet piling is forced into place by  a drop hammer or a vibratory hammer.
              Heavy equipment is desirable  for fast driving and to  prevent damage to the piles.
              Lightweight equipment  can distort  the top edge of the pile and slow the driving
              (ARMCO, Inc., Baltimore, MD, personal communication, 1980). Often, a cap block
              or driving head  is placed on the top edge to prevent the driving equipment from
              damaging the piles.

              When first placed in the ground, sheet piling cut-offs are quite permeable.  The edge
              interlocks,  which are necessarily  loose to facilitate placement,  allow water easy
              passage.  With time, however, fine soil particles are washed into the seams and water
              cut-off is affected.  The time required for this sealing to take place depends on the
              rate of groundwater flow and the texture of the soil involved.  In very coarse, sandy
              soils, the wall may never seal.  In such cases, it is possible to grout the piling seams,
              but this is a costly operation.

              Operation, Maintenance, and Monitoring

              Steel sheet  piling cut-offs require little maintenance.  In corrosive soils, galvanized
              or polymer-coated piles or cathodic protection can prolong the service life of cut-off.
              However, these measures must be incorporated prior to construction.  Monitoring of
              sheet piling cut-offs parallels that for other barriers and involves monitoring head
              levels and groundwater quality on either side of  the barrier to determine whether it
              is functioning as designed.

              Technology Selection/Evaluation

              The performance life of a sheet piling wall  can be between 7 and 40 years, depending
              on the condition of the soil in which the wall  is  installed.  Sheet piling walls have
              been installed in various types of soils ranging from well-drained sand to impervious
              clay, with soil resistivities ranging from 300 ohm/cm  to 50,000 ohm/cm, and with
              soil pH ranging from 2.3 to 8.6.  Inspections of these installed walls did  not reveal
              significant deterioration of the structure  due  to soil  corrosion (US EPA,  1978).
              Additional protection of the sheet piling wall against corrosion  can be  achieved  by
              using hot-dip galvanized, or polymer-coated, sheets.  Cathodic protection has also
              been suggested for submerged piling (US EPA, 1978).

              Steel sheet piles should not be used in very rocky  soils.  Even if enough force can be
              exerted to push the piles around or through cobbles and boulders, the damage to the
              piles will render the wall ineffective.
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              Costs

              The cost of installed steel sheet piling will vary with depth, total length, type of pile
              (coated  or uncoated),  and relative ease of installation.  Average costs range  from
              approximately $6.50 per square foot up to approximately $16.00 per square foot
              (Godfrey, 1984a; McMahon, 1984a).

       Bottom Sealing

       Bottom sealing  refers to techniques used to place a horizontal barrier beneath an existing site
       to act as a floor and prevent downward migration of contaminants.  Most of these techniques
       involve variations of grouting or other construction support techniques. No documentation
       applicable to hazardous waste sites was found.

       Grouting

       Emplacement of a bottom seal by grouting involves drilling through the site, or directional
       drilling from the site perimeter, and injecting grout to form a horizontal or curved barrier.
       One such technique, jet grouting, involves drilling a  pattern  of holes across the  site to the
       intended barrier depth.

       A special jet nozzle is lowered and a high pressure stream of air and water erodes the soil.
       By  turning the  nozzle through a complete  rotation, a flat, circular cavity is formed.  The
       cavity is then grouted with intersecting grouted masses forming the barrier.  The directional
       drilling method is very similar to curtain grouting except that it is performed in slanted rather
       than vertical, boreholes.

       These techniques are currently under  development.   Therefore, no  detailed analysis  of
       applications, limitations, design, or construction considerations is possible.
PERMEABLE TREATMENT BEDS

       Bed Types

       Permeable treatment  beds  are  essentially excavated  trenches  placed perpendicular to
       groundwater  flow and filled with  an appropriate material to treat the plume as it flows
       through the material (FIGURE 9).  Some of the materials that may be used in the treatment
       bed are limestone, crushed shell, activated carbon, glauconitic green sands, and synthetic ion-
       exchange resins.
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GROUNDWATER CONTAINMENT
                                        Permeable Treatment Bed
                    Groundwater flow
                             FIGURE 9
           INSTALLATION OF A PERMEABLE TREATMENT BED
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       Permeable treatment beds have the potential to reduce the quantities of contaminants present
       in leachate plumes.   The system  is applicable  to relatively shallow groundwater  tables
       containing a plume. To date, permeable treatment beds have not been applied at hazardous
       wastes sites. However, bench- and pilot-scale testing has provided preliminary quantification
       of treatment bed effectiveness.

       Use of a permeable treatment bed poses several problems.  These include saturation of bed
       material, plugging of bed with precipitates, and short life of treatment materials. Therefore,
       permeable treatment should be considered a temporary, not a permanent, remedial action.

       A limestone or crushed shell bed can be used to neutralize acidic groundwater and retain
       certain metals  such as cadmium, iron, and chromium.  The effectiveness of limestone  as a
       barrier depends primarily on the  pH and volume  of the  solution  passing through the
       limestone.   The  nature of the metal  is also an important factor.   A laboratory study
       demonstrated that limestone was more effective at retaining chromium III than chromium VI
       and other metals (Artiola and Fuller, 1979).

       Fuller  and other researchers (US EPA, 1978) have discussed the use  of crushed limestone
       as an effective, low-cost landfill liner to lessen the migration of certain heavy metals from
       solid waste leachates.   The authors state  that dolomitic  limestone (containing  significant
       amounts  of magnesium carbonate)  is less effective in removing ions  than purer limestone
       containing little magnesium carbonate. Therefore, use of limestone with high calcium content
       is recommended in design of a limestone treatment bed.  This design will remove heavy
       metals  and neutralize contaminated groundwater.

       In regard to designing vertical permeable treatment beds, the selection of the particle size of
       the limestone that is used should be based on the type of soil in which groundwater flows and
       the level of contamination.  The type of soil  is important because it controls groundwater
       flow rates. In general, a mixture of gravel-size  and  sand-size limestone  should be used to
       minimize settling through dissolution. Where excessive channeling through the bed by rapid
       groundwater   movement is   expected  or  where  improved  contact  time  between  the
       contaminated groundwater and the treatment bed is required, a higher percentage of sand-size
       particles  is more appropriate.

       One variation  in the use of limestone permeable treatment beds to neutralize plumes is to
       apply layers of limestone or crushed shell over a waste site. This indefinitely stabilizes the
       disposed waste.   This approach  is used  to reduce solubility  of metal hydroxides by
       maintaining highly alkaline conditions in the waste (Francis, 1984).

       Activated carbon is a possible treatment bed material.   It can remove nonpolar organic
       compounds from contaminated plumes, but is not practical for the removal of heavy metals.
       Activated carbon will  not remove polar organics.   However, the high cost of activated
       carbon, the potential for desorption of adsorbed  compounds, and the likelihood of a short
       bed-life in the  presence of high waste concentrations make the cost of activated carbon beds
       prohibitive under most circumstances.
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       Glauconitic greensands have potential for the removal of heavy metals.  Bench-scale studies
       with leachate indicate that the highest removal efficiencies are for copper, mercury, nickel,
       arsenic, and  cadmium and that efficiencies increase  with  contact time  (Spoljaric,  N.,
       Delaware Geological Survey, Newark, DE, personal communication, 1980).

       With contact time in the field being on the order of days, metal removal efficiencies may be
       extremely high.  Experiments indicate that the greensands may also have a high capacity for
       heavy metal cation retention, even when flushed with solutions of highly alkaline or acidic
       pH (Spoljaric, N.,  Delaware Geological Survey, Newark, DE, personal communication,
       1980).

       An in-situ experiment in England (Ross, 1980) demonstrated promising retention capabilities.
       Glauconitic greensands appear promising; however, more research is required to determine
       their sorptive capacity and capability for treating higher concentrations of heavy metals.

       Advantages  of glauconitic  treatment  beds,  based on  studies  to  date,  include  (1) good
       permeability, (2) abundance in the Atlantic Coastal Plain (i.e., New Jersey, Delaware,  and
       Maryland), (3) effectiveness in removal and  retention of many heavy metals, and (4) good
       retention time characteristics for efficient treatment.

       Some disadvantages of  using  glauconitic  treatment beds  are  (1) unknown  saturation
       characteristics and  potential for plugging over time, (2)  potential  reduction in pH, (3)
       limitations of areas of natural occurrence such as the mid-Atlantic region, and  (4) possibility
       of land purchase requirements because glauconite is not commercially mined.

             Costs

             Unit  costs in 1985 for the installation of a permeable treatment  bed  are  shown in
             TABLE 6.  Total closure costs for stabilizing approximately 8,000 cubic yards of
             sludge contaminated with nickel hydroxide by covering the site with a 1-inch layer
             of calcium carbonate are estimated at $100,000 to $200,000, compared with  $900,000
             to $1 million estimated for excavation and removal  (Francis, 1984).
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                                      TABLE 6
      UNIT COSTS FOR INSTALLATION OF A PERMEABLE TREATMENT BED
            Item
       Assumptions
          Costs
  Trench excavation


  Spreading


  Well-point dewatering


  Sheet piling

  Walers, connections, struts

  Liner


  Limestone
20 ft. deep, 4 ft. wide, by
backhoe

Spread by dozer to grade
trench and cover

500 ft. header, 8" diameter,
for one month

20 ft. deep; pull and salvage

2/3 salvage

30 mil PVC
30 mil CPE

Mixed "gravel size" and
"sand size"

Installation (backfill trench,
100 foot haul)
$1.40 cubic yard1


$1/cubic yard1


$115/linear foot1


$7.70/square foot1

$165/ton2

$0.25-0.35/square foot4
$0.35-0.45/square foot

$30-45/ton3


$3.70/cubic yard1
  Godfrey, 1984; Costs are total, including contractor overhead and profit.
  2Godfrey, 1984; Materials only.
  3Schnell, 1985.
  4Cope, Karpinski, and Steiner, 1984.
       Groundwater Pumping

             Description

             Groundwater pumping techniques involve the active manipulation and management
             of groundwater  to contain or remove a plume or to  adjust groundwater levels to
             prevent formation of a plume. Types of wells used in management of contaminated
             groundwater include wellpoints, suction wells, ejector wells, and deep wells.  The
             selection of the appropriate well type depends on the depth of contamination and the
             hydrologic and geologic characteristics of the aquifer.
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GROUNDWATER CONTAINMENT

              Applications/Limitations
              Well systems are very versatile and can be used  to  contain, remove, divert, or
              prevent development of plumes under a variety  of site conditions.

              Pumping is most effective at sites where underlying  aquifers have high intergranular
              hydraulic conductivity.  Pumping has been used with some effectiveness at sites with
              moderate hydraulic conductivities and where pollutant movement is occurring along
              fractured or jointed bedrock.   In fractured bedrock, the fracture patterns must be
              traced in detail to ensure proper well placement.

              Where plume containment or  removal is the  objective, either extraction wells or  a
              combination of extraction and  injection wells  can be used.  FIGURE 10 depicts the
              use of a line of extraction wells  to halt the  advance  of the  leading edge  of  a
              contaminant plume and thereby prevent contamination of a drinking water supply.
              Use of extraction wells  alone is best suited  to situations  where contaminants are
              miscible and move  readily with water, where  the  hydraulic gradient  is steep and
              hydraulic conductivity is high, and where quick removal is not necessary. Extraction
              wells are frequently used in combination with slurry walls to prevent groundwater
              from overtopping the wall and to minimize contact  of  the leachate with the wall to
              prevent wall degradation.  Slurry walls also reduce the amount of contaminated water
              that requires removal, so costs and pumping time are reduced.

              A combination of extraction and injection wells  is frequently used in containment or
              removal where the hydraulic gradient is relatively flat and hydraulic conductivities are
              only moderate.   The function of the injection well  is to  direct contaminants to the
              extraction wells.  This method has been used  with some success  for plumes that are
              not miscible with water.
5/93                                        50

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GROUNDWATER CONTAINMENT

                                   lOa
                            Cross-Sectional View
                                                  Domestic
                                                   Well
                               Extraction Wells
                                with Rodius of
                                 Influences
                                   lOb
                                 Plan View
                               FIGURE 10 a-b
                  CONTAINMENT USING EXTRACTION WELLS
  5/93
51

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GROUNDWATER CONTAINMENT
              FIGURE 11 illustrates an extraction/injection well system for removal. One problem
              with this arrangement of wells is that dead spots (i.e., areas where water movement
              is very slow or nonexistent) can occur when these configurations are used. The size
              of the dead spot is directly related to the amount of overlap between adjacent radii of
              influence;  the greater the overlaps, the smaller the dead spots will  be.  Another
              problem is that injection wells can suffer from many operational problems, including
              air locks and the need for frequent maintenance and well rehabilitation.

              Extraction or injection wells can also be used to adjust groundwater levels, although
              this application is not widely used.  In this approach, plume development can be
              controlled  at sites where the water table intercepts disposed wastes by lowering the
              water table  with  extraction wells.   For this  pumping technique to be  effective,
              infiltration  into the  waste pile must be eliminated  and liquid  wastes must  be
              completely  removed.   If these conditions are not met, the  potential exists for
              development of a plume of contaminants.  The major drawback to using well systems
              for lowering water tables is the continued costs associated with maintenance  of the
              system.

              Groundwater barriers can be created using injection wells to change both the direction
              of a  plume and the speed of plume  migration. FIGURE 12 shows  an  example of
              plume diversion using a line of injection wells to protect domestic water sources. By
              creating an area with a  higher hydraulic head, the plume can be forced to change
              direction.  This technique may be desirable when  short-term diversions are needed
              or when diversion will provide the plume with sufficient time to naturally degrade so
              that containment and removal  are not required.

              Each of the  well types used in groundwater pumping  have their own specific
              applications and limitations. TABLE 7 summarizes the site conditions for which each
              of these well types are most applicable.

              Wellpoint systems are effective in almost any hydraulic  situation.  They are best
              suited for shallow aquifers where extraction is not needed below 22 feet.  Beyond this
              depth, suction lifting (the standard pumping technique for wellpoints) is ineffective.
              Suction wells operate in a similar fashion to wellpoints and are also depth limited.
5/93                                        52

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GROUNDWATER CONTAINMENT
                              lla
                           FLOW
                              lib
                         FIGURE 11 a - b
             EXTRACTION AND INJECTION WELL PATTERNS
                      FOR PLUME REMOVAL
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53

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GROUNDWATER CONTAINMENT
              INJECTION WELLS
                                    FUTURE PLUME MOVEMENT
                                          \
                              FIGURE 12
               PLUME DIVERSION USING INJECTION WELLS
Source: US EPA, 1985a
5/93
54

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TABLE 7
CRITERIA FOR WELL SELECTION
•v; ••:..;.;•:' Parameters • /••••:--
Hydrology
• Low hydraulic conductivities
(e.g., silty or clayey sands)
• High hydraulic conductivities
(e.g., clean sands and gravel)
• Heterogeneous materials
(e.g., stratified soils)
• Proximate recharge
• Remote recharge
Depth of Well
Normal Spacing
Normal Range of Capacity
(per unit)
Efficiency
Wellpointe

Good
Good
Good
Good
Good
Shallow <20ft.
5 - 10 ft.
0.1-25 gpm
Good
Suction Wells

Poor
Good
Poor
Good
Good
Shallow <20ft.
20 - 40 ft.
50 - 400 gpm
Good
Ejector Wells

Good
Poor
Good
Good
Good
Deep >20 ft.
10 - 20 ft.
0.1 -40 gpm
Poor
DeepWelis

Fair to Poor
Good
Fair to Poor
Good
Good
Deep >20ft.
>50ft.
25 - 3000 gpm
Fair
o
»
o
8

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GROUNDWATER CONTAINMENT
              The only  advantage  of suction wells over  wellpoints is that they  have higher
              capacities.  For extraction depths greater than 20 feet, deep wells and ejector wells
              are used.  Deep well systems are better suited to homogeneous aquifers with high
              hydraulic conductivities and where large volumes of water  may be pumped.

              Ejector wells perform better than  deep wells in heterogeneous aquifers with low
              hydraulic conductivities. A problem with ejector systems is that they are inefficient
              and are sensitive to constituents in the groundwater,  which may cause chemical
              precipitates and well clogging.
5/93                                        56

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Section 5

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                           RECOVERY PROCESSES
STUDENT PERFORMANCE OBJECTIVES:
At the conclusion of this unit, the participants will be able to:
             Briefly describe the advantages of hazardous materials recovery

             Briefly describe typical procedures used to recover the following types of
             hazardous materials:

                   Solids on hard surfaces
                   Liquids on hard surfaces
                   Solids on surface water
                   Liquids on surface water
                   Liquids on groundwater
5/93

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                                                     NOTES
   CAUSES OF CONTAMINATION

    • Unintentional Causes
        Tank ruptures and punctures
        Transportation accidents
        Transport line failures
        Leaking tanks, pipes, and drums

    • Intentional Causes
        Illegal discharges
        Illegal dumping
      RECOVERY PROCESSES
     •  Reduce the potential for the spread
       of the contaminant in the environment

     •  Reduce the risk of exposure to the
       public and the environment

     •  Reduce cleanup time and cost
  SOLID SPILL ON A HARD SURFACE


      • Low mobility

      • Gravity, terrain, and weather

      • Size and shape of solid

      • Reactivity with water

      • Gas liberator
5/93
Recovery Processes
         page 1

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         NOTES
                                       SOLID SPILL ON OR INTO WATER
                                       • Solubility
                                            Fast or slow, partial or complete
                                       • Insolubility
                                            Floater or sinker
                                       • Time of day and temperature
                                       • Waterway and turbulence
                                       • Tools and equipment
                                      LIQUID SPILL ON A HARD SURFACE

                                          •  Reaction to gravity and slope
                                          •  Penetration of substrate
                                          •  Collection at lowest point
                                          •  Reactivity of water
                                          •  Solubility or insolubility of water
                                       LIQUID SPILL ON OR INTO WATER
                                        •  Solubility
                                             Fast or slow, partial or complete
                                        •  Insolubility
                                             Floater or sinker
                                          Time of day and temperature
                                          Waterway and turbulence
                                          Tools and equipment
Recovery Processes
page 2
5/93

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                             RECOVERY PROCESSES
CONTAINMENT OF OIL ON WATER

Most containment devices  are designed to hold oil "long enough"  for the oil  to be  removed.
However, no device should be expected to hold oil indefinitely.  Depending on the water current,
wind current, and wave heights, long enough might be a few minutes to several days.  Because of
the wide variety of water conditions, containment devices can be simple homemade devices or
sophisticated commercial booms and air barriers.
AIR BARRIERS

The use of air or pneumatic barriers has been demonstrated to be an effective means of controlling
the movement of floating products in water with little or no current. Air barriers can be classed as
air bubblers or coherent water jets.

Air Bubblers:  The air bubbler is constructed by placing a perforated pipe or manifold in the water
close to the bottom.  Injecting air into the pipe causes bubbles to rise from the openings.  The rising
bubbles produce a vertical  current in the water which causes  a horizontal current or water flow on
the surface. This horizontal movement counteracts the forward  movement of the oil and prevents
the oil from passing.

Advantages of this  system include  rapid startup, unrestricted vessel movement,  and  continuous
operation.  There are a number  of disadvantages including ineffectiveness in high currents, silting
or clogging of openings, high energy consumption, high initial cost, and system design  problems.

Tests  under controlled conditions have shown that the excess water at the surface tends to entrain
oil droplets into the water column. This is because the water sets up a recirculating pattern near the
bubble plant (FIGURE  1).  When a current is present, the  entrainment causes massive oil loss.
Losses occur at current speeds below 0.5 knots (FIGURE 2).

Under ideal conditions (no current or wave action), oil could be contained in areas such as barge
slips with an air barrier. Oil layers up to 5 inches thick could be contained.

Recent experience with air barriers at an angle to the water current have shown them to be nearly
as effective as containment booms.  If large debris or ice is present, they may be the only chance
for containment.                                          >
5/93

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RECOVERY PROCESSES
                                     BUBBLE PLUME
                                   MANIFOLD
                            FIGURE 1
                  AIR BARRIER WITH NO CURRENT
                                            BUBBLE PLUME
                           FIGURE 2
                   AIR BARRIER WITH CURRENT
5/93

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RECOVERY PROCESSES

Silting of the manifold openings is a problem caused by placing the manifold system too close to the
bottom.  Raising the manifold off the bottom may prevent this from happening.  Another problem
can be the accumulation of marine growth such as barnacles and seaweed.

The amount of air required  to operate a system depends on the length of the perforated manifold,
water depth, opening size, number and  spacing of the openings, and the desired surface current.
Systems in the 200- to 300-foot range typically require 400 to 1200 cubic feet per minute, depending
on these variables.

System cost is one of the most prohibitive disadvantages of air barriers.  A complete installation can
run as much as  $500/foot.   Even if a compressor is already available, the cost for an installed
manifold system  can exceed $50/foot.  Add to this the annual maintenance and energy costs and the
operating expenses become high.

Coherent water jets:  One area of new technology in  air barriers is the use of coherent water jets.
From above, a concentrated jet of water is directed vertically into the  water column, and a large
amount of air is introduced.  The air rising back to the surface will act as a typical air barrier. Extra
oil holding  ability is produced by  the splashing of the water and by a standard headwave that is
created.   Tests have  shown that the coherent water jets (FIGURE 3) consume less energy  than
standard air barriers of equal effectiveness.
                                                                          WATER
                                            •'. /WATER WITH AIR BUBBLES
                                       FIGURES
                               COHERENT WATER JETS
5/93

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RECOVERY PROCESSES

BOOMS

A boom is a floating barrier designed with sufficient freeboard and draft to contain oil floating on
the surface of the water.  Most booms will have the following characteristics:

        1.    A means of flotation  or freeboard to contain the oil and to resist waves
             splashing oil over the top.

        2.    A skirt to prevent oil from being carried underneath the boom.

        3.    A longitudinal tensile strength member, such as chain or cable,  to hold the
             boom together and provide a means of anchoring the boom.

        4.    A ballast to aid in maintaining a vertical skirt orientation.

The  following discussion  primarily covers typical floating booms similar to  the one  shown in
FIGURE 4.  Fixed barrier booms, supported from the bottom of a channel, will be discussed later.

To be effective, booms must float and be  stable in currents, winds, and waves.  They should  also
be made of materials that are not subject to deterioration from sun, storage, and chemical attack.
  Freeboard
                            Longitudinal Strength Member
                                      FIGURE 4
         CROSS-SECTION OF A TYPICAL BOOM SHOWING MAJOR PARTS
5/93

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RECOVERY PROCESSES

       Oil Carrvunder

       Booms will contain oil when placed in quiescent water.  If there is only a slight velocity in
       the water perpendicular to the boom, and no wind or waves, the boom will still contain oil.

       As the current moving perpendicular to the boom becomes greater, forces begin acting on
       the trapped oil and cause the oil to escape under the boom. Oil can move under the boom
       by two methods, "leakage" and "entrainment".  Leakage or sheet breakaway, occurs when
       oil builds up to such a depth behind the boom that the oil layer is almost equal to the draft
       and escapes under the skirt.  Entrainment, or droplet breakaway, involves the carryunder of
       oil due to a shearing action at the interface of oil and water at the headwave (FIGURE 5).

       The containment effort fails when oil droplets break away from the oil layer and become
       entrapped in  the flowing water as it passes beneath the  boom.  The amount of droplet
       carryunder is a function of the thickness of the oil layer  and the  velocity  of water.  The
       phenomenon is related to water velocity and the specific gravity of the oil.  Thus, the greater
       the velocity or the greater the specific gravity  of the oil, carryunder increases.

       For a given oil land skirt depth, carryunder will not occur until a critical velocity is reached.
       As the velocity  increases above the critical velocity, the greater the carryunder will be.
        CURRENT
                                      FIGURES
                    BOOM CONTAINMENT FAILURE CAUSED BY
                   ENTRAINMENT OF OIL BY SHEARING ACTION
5/93

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RECOVERY PROCESSES

       Increasing the length of the skirt increases  the ability of the boom to retain oil, but the
       advantage is not substantial. Disadvantages of a longer skirt are the increases in weight,
       cost, and mooring requirements to hold the boom in position. A boom should be effective
       regardless of skirt depth when currents are below 0.75 feet per second for a No. 2 oil. For
       a No. 6 oil, no droplets  are formed if the  velocity  is less than 0.4 feet per second, but
       leakage will occur if the boom has a skirt of less than 12 inches.  Therefore, there is no
       advantage in making the skirt length greater than 12 inches to prevent the movement of oil
       beneath a boom in slow-moving waters.  A longer skirt is required in rough waters.

       Oil Splashover

       Although a properly deployed boom can minimize carryunder, it may be subject to another
       form of failure, "splashover." Splashover will depend on the basic boom design, freeboard,
       angle of the waves to the boom, wave heights, and distance between successive waves.  No
       boom will be capable of holding oil under all sea conditions, but some boom designs are
       more effective than others. Under slow swell conditions in the open ocean, most booms will
       be flexible enough to conform to the waves.  Under choppy conditions, it is difficult to keep
       oil from splashing over the boom.  Such conditions require  a boom with a relatively high
       freeboard and long skirt, but even that type may still be ineffective.
BOOM DESIGN

              General Criteria

              A  bigger  boom is  not  necessarily  a better boom  except for  the  advantage of
              preventing oil splashover  in waves.   Booms can be  classified as round, fence,
              inflatable,  or self-inflating (FIGURES 6, 7, 8,  and 9).   Each boom has specific
              advantages and disadvantages.

              Booms are available in different lengths.  For spills in creeks and rivers, lengths of
              100 and 200 feet are recommended.  Each section of boom should be supplied with
              connector to extend the length as required.

              Anchor points should be constructed in the boom at several places along the length.
              A maximum distance of about 100 feet between anchor points is  acceptable, with a
              50-foot spacing preferable.  Some booms are designed  with handles to assist in
              deployment and recovery. Bright colors such as international yellow or orange make
              booms more visible, whereas dark-colored booms are difficult to see, particularly at
              night.  Dark-colored booms can cause problems for the cleanup personnel and may
              present a navigational hazard.

              Several pieces of auxiliary boom equipment are important, such as line, tow bridles,
              boat attachments, anchor sets, floats, shovels, pipes, and a sledge hammer.  Much
              of this equipment will be used in the field exercises on boom development.


5/93                                        8

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RECOVERY PROCESSES
                                            Self Contained
                                               Float
                                      Ballast Bar
                                           &
                                         Cable
                                    FIGURE 6
                             TYPICAL ROUND BOOM
Possible Advantages

 1.    Good wave
      conformance in chop
      and swell

 2.    Inherent reserve
      buoyancy

 3.    Tows well

 4.    Allows bottom tension
      design

 5.    Floats with punctures
Possible Disadvantages

 1.    Bulky to store

 2.    Not as easy to clean

 3.    Floats can be
      damaged
Representative Types

 1.    Kepner

 2.    Slickbar

 3.    Acme

 4.    Bennett

 5.    American Marine

 6.    Containment Systems

 7.    Parker Systems

 8.    Texas Boom

 9.    Abasco

10.    American Boom and
      Barrier

11.    Skimmex

12.    Versatech
5/93

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RECOVERY PROCESSES
                                     FIGURE?
                              TYPICAL FENCE BOOM
Possible Advantages

 1.    Easy to store

 2.    Abrasion resistant

 3.    Good freeboard
      performance

 4.    Can be stored on reels

 5.    Low cost

 6.    Light for its size
Possible Disadvantages

 1.    Twists and corkscrews
      in wind and current
      (some models)

 2.    Poor towing
      characteristics (some
      models)

 3.    Poor wave conformity

 4.    May require stiffeners
      that can chafe or
      break

 5.    Little reserve
      buoyancy
Representative Types

 1.     Navy boom

 2.     Uniroyal

 3.     Bennett

 4.     Oilfence

 5.     Goodrich
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            10

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RECOVERY PROCESSES
                  Rubber Impregnated
                  Nylon Fabric
                           Inflation Point
        Hollow Inflation
              Chamber
                                    FIGURES
                          TYPICAL INFLATABLE BOOM
Possible Advantages

 1.    Easy to store

 2.    Made in floating-
      sinking configuration

 3.    Good wave
      conformity

 4.    Easy to clean

 5.    Small storage space
      requirements
Possible Disadvantages

 1.    Requires inflation
      prior to use

 2.    Requires deflation
      after use

 3.    Subject to puncture

 4.    Expensive

 5.    May have valve
      problems in freezing
      temperatures
Representative Types

 1.    Vikoma

 2.    Goodyear

 3.    Ro Boom
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            11

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RECOVERY PROCESSES
                             Airtight
                               Bulkhead
              Hoop
                     Buoyancy
                      Chamber
                                                                 (Deflated)
                                   FIGURE 9
                       TYPICAL SELF-INFLATING BOOM
Possible Advantages
1.
2.
3.
4.

5.

Easy to store
Compactable
Easy to tow
Self-inflating

Good wave
conformity
1.
2.
3.

4.

5.
Possible Disadvantages

      Complex design

      Subject to puncture

      Subject to physical
      damage

      Expensive

      May have valve
      problems in freezing
      weather
Representative Types

 1.    Kepner

 2.    Bennett

 3.    Expand!
5/93
                                       12

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RECOVERY PROCESSES
             Any boom will normally  fit  into one of the four  previously mentioned general
             categories. However, some booms, that might fit into one of these four categories
             often distinguish themselves from the others by distinct designs or other features.

             For example, the Oilfence, generally  considered a fence boom, is unique with its
             folding "paddle" flotation units (FIGURE  10).  The boom has some of the generic
             advantages associated with the typical  fence boom.  Distinct advantages include the
             relative ease with which the boom can be stored, deployed, and cleaned.  Also, the
             outrigger  flotation units provide extra stability.  This boom has an extraordinary
             amount of freeboard to help minimize splashover.  Possible disadvantages include
             added  complexity and more parts subject  to damage, although experience has not
             shown this to be a problem. This design will twist in high currents and has caused
             problems when tug boats are used close to the boom.
       BARRIER
                                                          VERTICAL STABILIZERS
                                                          BOTH SIDES
                                      FIGURE 10
                                   OILFENCE BOOM
              Most boom manufacturers offer at least one type of high-current boom (FIGURE
              11).  This option consists of a round boom with a short, solid containment skirt.
              Below this short containment skirt, the boom has a large, open-weave mesh or net.
              The netting, which allows water to pass through while the solid skirt material remains
              near the surface, is designed to contain the floating product.   Distinct advantages
              include the boom's ability to remain stable in  swift currents and to substantially
              reduce the current load on the boom in high currents.
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13

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RECOVERY PROCESSES
                                      FIGURE 11
                                HIGH-CURRENT BOOM
       Floats

       Boom floats should be made of solid, rather than granular, material so that a puncture does
       not result in loss of flotation. The floats should be constructed in relatively short segments
       to better conform to waves.  Detachable floats are easy to repair but can be ripped from the
       skin.  Floats within the skirt material eliminate metal or plastic connector straps but make
       replacement or repair difficult.  A round shape features a built-in reserve buoyancy and is
       more common than a square or rectangular shape. The shape and size of the float can have
       a significant effect on the ease of deployment and use.  Inflatable floats  are  subject to
       puncture and valve malfunction but are very lightweight and  flexible.

       Tension Member

       Nylon belting is strong but may stretch  more than  other parts of the boom.  Should this
       occur, the parts that stretch less could break. For light service and short lengths, elaborate
       tension members may not be necessary.
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14

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RECOVERY PROCESSES

       Cables in a pocket of fabric or attached to the outside of the boom corrode and break or fray
       and become dangerous to personnel handling the boom.  Chains in pockets chafe the fabric
       and eventually wear through unless the fabric is reinforced, which requires more time and
       expense.

       Booms are available that use the fabric  of the boom as the  only tension member.  This
       arrangement solves most of the problems associated with other types of tension members,
       except that these high-strength fabrics are more expensive than the average boom fabric, and
       high tensile strength does not necessarily mean that  the fabric has higher tear strength.

       Ballast

       Ballast should be attached to a boom  so that  it does not shift  or chafe the skirt.  Multi-
       metallic fasteners promote electrolysis and subsequent corrosion. The ballast should be non-
       sparking and be heavy enough to keep the skirt nearly vertical in unexpected currents.  Some
       boom designs with stiff fabric and stable  flotation do not use ballast.

       Skirt

       The skirt should be made of durable material that does not tear easily and resists chafing.
       The skirt should be designed to be compatible in depth to the float.  In any  case, a skirt
       length over  18  inches is  rarely justified.  The  owner's  name should be stenciled on each
       section of boom or otherwise marked for easy identification to avoid confusion when more
       than one company supplies booms for cleanup.

       Skirts can be formulated or coated with an antifouling agent to retard marine growth if they
       are to be left in the water for long periods.

       Methods of Connection

       An ideal connector is one that could be  used by one man from a small boat, is uncomplicated
       and quickly connected, would not have any small parts that could be lost overboard,  would
       be leak-proof (close-coupled) and be  of a  unisex  design.   ASTM developed a standard
       connector based on the design of the Slickbar  Slickhitch. If several booms are used from
       different manufacturers, it is recommended that adapters be available to facilitate connection.
BOOM DEPLOYMENT

To  direct an effective cleanup operation,  a  supervisor must  know  what factors govern boom
operation and understand how to minimize the amount of oil that splashes over, or goes under, a
boom.  The three factors that affect oil containment by booms are:

       1.      Boom design
5/93                                        15

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RECOVERY PROCESSES

       2.      Characteristics of the oil

       3.      Positional method of boom deployment.

Obviously, the cleanup crew has no control over the type of oil spilled.  When a spill occurs, the
cleanup crew must use the available equipment.  The first two factors listed above should be
considered when acquiring a boom.  Booms that are purchased should be compatible with the type
of oil that may be spilled and with design features that work well in the stream, river, or other type
of water body at a particular facility.  After  a  spill occurs, the cleanup crew has only the third
variable to use to its advantage.

As discussed previously, oil carryunder will decrease  as the velocity of the water perpendicular to
the boom decreases.  In currents above 0.5 knots, the only way booms can be used effectively is by
placing them at angles to the current.  For any given  stream condition, the velocity perpendicular
to the boom will depend on how the cleanup crew angles the boom to the current.  FIGURE 12 is
a guide for selecting angles for use in various currents.  The figure is based on a maximum water
velocity perpendicular to the boom of 0.7  knots. For example, if the velocity of the current  in a
stream is 2 knots, the boom should be set at a 24 degree angle with the bank.
                                                                       o
                                                                      SC
                                                                       l_
                                                                       o
                                                                       o.
                                                                        "
                                                                      c
                                                                      o
                                                                      D
                                                                      "a
                         10    2O   X>   *O   SO   6O    70

                          Boom Angle to Bank in Degrees
                  80   9O
                                      FIGURE 12
                     BOOM ANGLES FOR VARIOUS CURRENTS
5/93
16

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RECOVERY PROCESSES
The force on a boom caused by the current is significant.  The force can be calculated using the
following formula:
              Fc

              Vc
      Fc = 1.92 X (Vc)2 X Dft

Force due to current in pound per linear foot of boom

Current velocity in feet per second

Boom skirt depth in the water in feet.
In a worst-case scenario where the boom is placed perpendicular to the current, the load on ropes
and anchors can be calculated.  For example, if 500 feet of a 24-inch boom that has a 16-inch skirt
is stretched across a stream which has a 2.11 feet/second current, the equation estimate would be:

              Fc     =      1.92 x (2.11)2 x  1.33

              F,.     =      11.371bs/foot
               |oul
                            11.39x500 ft. = 5,685 Ibs.
Although this figure represents the worst case, it is useful in planning the types of anchors, ropes,
and boats that could be needed during a spill (TABLE 1).
TABLE 1
CURRENT LOAD IN POUNDS PER LINEAR FOOT OF BOOM
FOR VARIOUS SKIRT DEPTHS
Current Speed
Knot
0.5
1.0
1.5
2.5
Ft. per Minute
51
101
152
253
Ft. per Second
0.84
1.69
2.53
4.22
Skirt Depth
6"
0.68
2.74
6.15
17.10
12"
1.35
5.48
12.29
34.19
24"
2.71
10.96
24.56
68.33
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                17

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RECOVERY PROCESSES

The wind force can also add to boom loading, but compared to current, wind is usually negligible.
In high winds, it is unlikely that a boom will be effective because of large waves.  Also, personnel
safety and equipment damage are concerns.  Wind force can be calculated with the following
formula.

             Fw     =     .00339 x Vw x Hft

             Fw     =     Force due to wind in pounds per linear foot of boom

             Vw    =     Wind velocity in knots

             Hft    =     Height of boom above the water in feet.


             Approximate Safe Working Loads/Tensile Strengths of New Rope

       Rope                 Manilla                Nylon                Polyester

       Inches                Pounds                Pounds               Pounds

      Diameter              tt\  (3 Strand)            (3 Strand)              (3 Strand)

        5/16                200/1000               500/2500               500/2500

        3/8                 270/1350               700/3500               700/3500

        7/16                                      1140/5700

        1/2                 530/2650              1250/6250             1200/6000

        5/8                 880/4400             2100/10500             1950/9750

        3/4                1080/5400              2750/5400            2300/11500

Towing load can be significant when a boom is anchored on one end and pulled against the current.
Boats must have sufficient horsepower  and be properly rigged to tow.  Lines must be capable of
withstanding the forces, and the boom must have a  tension member capable of high loads.  If the
boom is extended behind the tow boat and pulled free in the current, there is  only the frictional drag
along the boom. Because this drag is a function of boat speed, proper motor size becomes a function
of boom size and length, boat size, and water velocity. Although free towing drag is low, when one
end. of the boom is anchored  to the  shore, a small boat may be incapable of positioning the boom
because of the high current drag exerted on the boom.  The boom must also be  able to withstand the
forces.  The tension member must not become detached from the boom  becuase of differential
expansion.
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RECOVERY PROCESSES

Attempting to moor a boom in a straight line across a current (i.e., 90 degrees) is not recommended.
The result is a sag in the boom that will trap free-floating oil at a point inaccessible to the shore.
In swift currents the resulting forces on moorings can cause large lines to break and present possible
safety hazards. The current can be so swift that the boom may tend to dip and become completely
or partially submerged.  If this happens, the boom's position should be readjusted.  The total force
on the moorings points will be a combination of the forces caused by currents, wind, and waves.

Boom positioning is an important  subject.  The first step is to decide where the boom  should be
located.  It is likely that the boom would be positioned on an angle to the current; therefore, the
prime concern becomes  the  location of the upstream end.   If the selected  upstream location  is
inaccessible, a spot farther upstream can be used for access, and the boat and boom can be allowed
to drift to the selected mooring location. The boom may be secured to trees, stakes, anchors, or
other solid objects.

Unless there is little or no current, there will always be a sag in the boom.  The objective is to
reduce the sag sufficiently to provide easy collection access.  Intermediate anchor points  may be
needed to lessen the load on the end mooring points and to reduce the sag.

FIGURE 13 shows a typical mooring setup with anchor, chain, rope, float, and boom. The chain
acts as a shock absorber,  provides ballast, and keeps a low angle between the bottom and the anchor
line. The float keeps the end of the boom from being submerged.
                                         Float
                                                Anchor Line
                                                  Recommended Length
                                                   5-10 ft. Water Depth
                                                       6 Feet of Chain
                                                         Anchor
                                                              Danforth
                                                                Type Anchor
                                      FIGURE 13
                      TYPICAL MOORING SETUP FOR A BOOM
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A practical boom location will meet the following criteria:

       1.    Accessible by truck or boat so that the cleanup crew can collect and remove
             the oil

       2.    In the path of the oil so that the oil will be intercepted

       3.    Have low to moderate currents, which will facilitate handling and collection
             and reduce stress.


      Spills in Creeks

      Deep draft booms should not be used for spills in shallow creeks, streams, or ponds. They
      may be  ineffective because they act as a dam, causing the boom to lie flat or to back up the
      water to such an extent that it overflows the boom.  If the water is too shallow, the stream
      might be deepened by using a dragline or backhoe, or  by constructing a temporary dam
      downstream.  These techniques may require permission of local  or state  agencies.  This
      equipment can also be used to dig an oil collection pit (FIGURE 14).  Oil can be directed
      by a boom to the pit for recovery.
                                                              OIL COLLECTION
                                                                    PIT
       SPACE OIL BOOM
         4 FT.  APART
                                     FIGURE 14
               OIL COLLECTION PIT SHOWING BOOM PLACEMENT
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_     RECOVERY PROCESSES
              Alternatives to expensive commercial booms may be field fabricated.  These "homemade"
              booms use similar designs as  commercially available booms, but  instead of plastic and
              rubber, are made of materials such as fiberglass, plywood, metal sheeting, or metal flashing.
              One simple design uses metal roll flashing with  1x2x4 foot floats alternately spaced
              about 16 inches apart (FIGURE 15).
                                              FIGURE 15
                                      METAL FLASHING BOOM

              NOTE:   Floats should be sufficient to provide adequate flotation and attached above the
              midpoint of the flashing.

              Another device that can be used as a boom consists of wooden or metal stakes driven into
              the ground and spaced across a water body.  Board, planks, or metal sheets can be nailed,
              bolted, or tied to the stakes at the surface to contain oil (FIGURE 16).  If sorbent is placed
              ahead of the dam, a sorbent filter fence has been created.

              Another  kind of filter  fence may be constructed  by using chicken wire and  stakes with
              synthetic sorbents or loose straw upstream of the  fence. The fence should be constructed
              perpendicular to the current so that the sorbent will  remain distributed along the entire length
              and not be carried to the edge of the creek.  For very small creeks,  a log can be placed
              across the water.  Sorbents can be placed ahead of the log.
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RECOVERY PROCESSES
                                      FIGURE 16
                               WOODEN FENCE BOOM
       In small creeks a dam might be constructed with an underflow pipe or conduit (FIGURE
       17).  This design consists of a length of pipe or culvert placed parallel to the direction of
       water flow with  the  upstream end lower than the downstream end.  The dam  can be
       constructed with a shovel, dragline, backhoe, or bulldozer.  The objective is to pass water
       through the pipe, but retain the floating oil. The pipe must be large enough to allow water
       to pass without backing up to a depth greater than the dam.  Several pipes at various depths
       or side by side may be used in the dam to carry the required flow.  An alternate method is
       to add a valve downstream on a level pipe to control the water flow.

       Culverts in a creek will serve as a barrier for  oil if the entire culvert is below the water
       surface.  Existing culverts can be used at some locations along a creek by damming the creek
       downstream and thereby raising the water level  above  the top of the culvert.
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RECOVERY PROCESSES
                                   OIL
                                     FIGURE 17
                              UNDERFLOW PIPE DAM
       Spills in small creeks and ponds can also be contained by dams built of hay bales.  The bales
       should be placed touching each other and perpendicular to the flow to contain and sorb the
       oil.  Bales must be removed and disposed of as necessary.  Hay bales are very heavy when
       soaked with oil and water and may present a handling and disposal problem.

       Spills in Rivers

       River spills may require more than one boom because strong currents or turbulence may
       cause oil losses beneath the boom.  Booms should always be angled; otherwise, a pocket will
       be formed in the center of the river and the loads can be excessive on the boom, mooring
       lines, and anchors  (FIGURE 18).  Booms  deployed completely across a river will hamper
       boat and ship traffic.  Remember, oil slicks moving down a river will eventually drift to
       either side of the channel.
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RECOVERY PROCESSES
                            OIL
                                          OIL
                            BOOM
                              FIGURE 18
             BOOM FAILURE DUE TO IMPROPER DEPLOYMENT
     The tendency of oil to accumulate naturally in certain areas can be taken advantage of by
     placing several booms at strategic points along the river (FIGURE 19).
                                 CONTAINMENT BOOM

                                   BACKUP BOOM
                              FIGURE 19
         BOOM LOCATION ALONG THE OUTSIDE BENDS IN A RIVER
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RECOVERY PROCESSES

       Strategic locations can be the wide places in the river (pools) where the current speeds are
       lower and booms are likely to be more effective.  Bends are also convenient places in the
       river where the floating oil can be more easily intercepted.

       Booms used in rivers usually do not need a skirt deeper than 12 inches. However, floating
       debris is a problem in large rivers.   Debris can destroy booms  and release oil already
       contained.  It may be necessary to keep a patrol boat upstream of booms to protect them
       from floating objects.  Debris booms may also be required (FIGURE 20).
                                     FIGURE 20
                 DEBRIS BOOM MADE OF LOGS WITH CHAIN OR
                         CABLE STRUNG THROUGH A PIPE
      Spills in Lakes, Estuaries, and Bays

      Containment of oil on lakes and bays is complicated by the special problems caused by river
      currents, boat traffic, wind, and tides. Changes in wind velocity and direction will affect the
      movement of oil.
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RECOVERY PROCESSES

       FIGURE 21 illustrates the steps that can be taken to contain an oil spill in a lake or bay.
       After the cleanup crew deploys a boom at the proper angle downstream from the spill (step
       1), a second boom is  deployed as a backup in case any oil flows from wind-generated
       currents (step 2). A third boom is deployed upstream of the first to completely contain the
       spill (step 3). As the oil is skimmed from the pocket, the boom crew can begin taking in the
       boom to reduce the size of the pocket and contain the oil in a smaller area.
                                     Wind'*5*
                                                           Wind
                                      FIGURE 21
                     BOOMING A SPILL IN WINDY CONDITIONS
       Spills in the Ocean

       The most common approach for containing ocean spills utilizes large booms with ocean-going
       skimmers (see the section on skimmers). Large, strong booms are needed for this type of
       service.  Many booms designed for offshore use are inflatable.   Deployment time is not
       greatly increased with inflatable booms.  Inflation usually takes place automatically with
       deployment. Some inflatable booms are fabricated of vulcanized, rubber-coated fabric which
       is sturdy and shows good tensile strength, tear strength, abrasion resistance, and puncture
       resistance.
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RECOVERY PROCESSES

       Storing and Cleaning Booms

       Booms can be stored in several places. A convenient storage area is on the deck of a boat
       so that booms can be deployed as needed. Booms can be stored  on a dock or barge and
       pulled into the water using a ramp or roller, which provide some protection from wear and
       tear. Booms may also be stored in the water by attaching segments to anchors. Considerable
       lengths of booms can be stored in the water in a small area by folding sections back and forth
       similar to the way fire hoses are stored on trucks.  One major disadvantage to this storage
       method is the formation of marine organisms on the boom which add weight and drag.

       Booms can be cleaned by separating the boom into sections and laying each section out on
       a clean, sloping surface.  Oil can be removed by washing the boom with water and steam
       spray.  The boom washing area should direct the washwater to a sump where the oil can be
       collected.  Cleaning a boom coated with heavy layers of viscous oil may be a time-consuming
       and expensive process.
SUMMARY

Containment devices are designed to  contain oil floating on the surface of water.  A properly
installed containment device should contain the oil and cause the oil to move to a selected location
where it can be removed from the water surface. Air barriers use currents and a mound of air and
water generated by air bubbles to contain oil.  They work best in little or no currents.

Barriers constructed of sorbent materials can be effectively used in creeks.  Dams and culverts are
also useful in stopping the movement of oil  slicks.   Series of booms are normally used in spills  in
rivers and other large bodies of water because it is difficult to contain or divert large spills with one
boom, especially when high currents are involved.

Booms are often stored on the deck of a boat or barge, which facilitates deployment.  Booms are also
stored on docks, and a  ramp or roller can be used to assist in launching and recovery.
BOOM SELECTION CHECKLIST

 1.     Booms should be operational in waves with height-to-wavelength ratios of 8 to 1.  Booms
       should work in winds equal to a Beaufort Force 5.

 2.     At an effective current velocity of 0.7 knots, the skirt should remain within 20 degrees of
       the vertical.

 3.     The boom should be capable of being deployed at a 5 knot rate.
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RECOVERY PROCESSES

 4.     The boom should be capable of being towed at 10 knots in a straight line without twisting.
       It should not twist when being towed behind a maneuvering tow boat at 2 knots.

 5.     Sections should be capable of being connected and disconnected, without nuts and bolts or
       tools, from a small craft in not over 2 minutes.

 6.     Recovery and storage should be able to be accomplished by three or less personnel.

 7.     In calm water, the boom should have a freeboard of at least 41A inches.

 8.     The boom should allow 180 degrees folding at least every 10 feet of length or less.

 9.     The boom  should have reserve buoyancy of at least 200 percent.  The  buoyancy should
       double within 18 percent of the normal water line.

10.    The boom should have at least a 0.2 percent UV oxidizer/inhibitor coating or be capable of
       withstanding 2 years of continuous exposure to direct sunlight.

11.    The flotation should have a smooth surface and must be puncture resistant.

12.    Puncturing or cutting of a foam float section should not significantly reduce flotation or allow
       escape of flotation.

13.    The flotation should be an integral part of the entire boom.

14.    Flotation should be closed-cell, foamed plastic resistant to hydrocarbons.  Granular type
       flotation material  is not recommended.

15.    The color should be international orange or yellow or another bright color.  (Some locations
       use orange to identify medical waste. This color may become a poor choice for pollution
       control equipment).

16.    Skirt fabric should show good  break strength and abrasion resistance and be oil resistant.

17.    The base fabric for the skirt should be high strength and UV stable.

18.    No laminated materials should be  used in the skirt.

19.    Stiffeners should not rust and should not wear through or puncture the fabric after use in the
       water with  normal wave action.

20.'    The boom  should be  capable  of  a direct  tensile load, end-to-end, of not less than 3,000
       pounds.

21.    The primary tension member should not elongate more than 10 percent at 60 percent of its
       ultimate tensile strength.


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RECOVERY PROCESSES

22.    Tension members should be attached to the boom flotation at no less than six points every
       10 feet.

23.    Tension members  should not be  located where they would prevent  the freeboard from
       remaining vertical when the boom is used perpendicular to a 0.7-knot current.

24.    Ballast must be nonsparking.  If cable or chain is used,  it should be  designed to prevent
       chafing.

25.    The ballast should not collect static electricity.

26.    For a 0.7-knot current, the following minimum ballasts are recommended per linear foot of
       boom:
                     Skirt Depth

                         6"
                         8"
                        10"
                        12"
                               Ballast Ibs/ft of boom

                                       0.33
                                       0.44
                                       0.54
                                       0.75
27.    The ballast should not be rigid for more than 4 inches in any one piece.

28.    Anchor points should be placed every 100 feet on both sides and directly connected to the
       tension member.

29.    End connectors should not permit oil leakage.

30.    End connectors constructed of metal should only use stainless steel, anodized aluminum, or
       other strong noncorroding material.
LIST OF COMMON BOOMS

The following list of boom types is intended as a guide for the trainee and is not for the purposes
of recommending a particular brand. Because of space limitations, not all types are included in the
list.  If a type is not included, this does not mean that the boom should not be used.  The following
classification system can be used to distinguish among booms appropriate to inland water, bay and
ocean service based on freeboard and draft.
  Classification
Service
Freeboard
Draft
I
II
III
Inland Water
Bay
Ocean
4-10'
10-18'
£18'
6-12'
12-24'
^24' & above
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CONTAINMENT AND RECOVERY OF OIL ON GROUNDWATER

Although spilled oil may adhere to soil particles, roots, and rocks, changes in land geology or water
regimes can cause trapped oil to enter groundwater.  In other cases, spilled oil easily penetrates the
soil to contaminate groundwater.  Because oil on groundwater weathers and degrades slowly,  if at
all, oil can affect potability and its use in  industrial processes for decades or centuries.  This is
important because about one-half of the population of the United States depends on groundwater for
drinking water (primarily the small- to medium-sized communities and  farms).

Many large groundwater spills have been well publicized.  For example, a refinery in Brooklyn,
New York, apparently had tanks,  pipelines, or valves leaking for years. Approximately 20 million
gallons  of  petroleum distillate was estimated to be under  70 acres of industrial and residential
property.  During the first year of cleanup, 95,000 gallons was recovered.  Oil recovery will  take
years.  An  estimated $3 million to $4 million will be spent on recovery and cleanup.

Small spills can also influence groundwater use until the oil product has been removed. This section
will discuss groundwater oil movement, groundwater monitoring, oil containment, and oil recovery
techniques.
OIL ON GROUNDWATER

When oil penetrates the subsoil to the  groundwater or aquifer,  the oil  can move on top of the
groundwater by spreading and by groundwater flow.  The water table is that level of the water
observed in wells.  However, in soils, water can rise above the water table by capillary action. Just
as the liquid level will appear higher in  a straw, or the corner of a towel will transport water into
a towel, water will fill spaces in the soil above the water table. Oil entering this water will spread
and move on the capillary fringe (FIGURE 22). The capillary fringe can  vary from 3 to 72 inches,
depending on soil pore geometry. Permeability indicates a soil's ability to allow fluids to pass from
one space in the soil to other spaces in the soil. Larger spaces due to  large soil particle size have
higher permeability; therefore, low permeability may be one-half inch per year and high permeability
several feet per year.
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RECOVERY PROCESSES
            MNSATURATED
            •  ' SOIL '•
             CAPILLARY
               FRINGE
SATURATION LEVEL (WATER LEVEL)

      «	  WATER FLOW
                                    FIGURE 22
                 OIL ENTERING GROUNDWATER (horizontal view)
At first, oil thickness  increases under the influence of continued descending oil.  The force or
pressure exerted by the accumulation of oil will displace water in the capillary fringe and possibly
in the groundwater.  As gravity influences the oil to spread  and  the pressure is released, the
groundwater returns to its former level.  In a uniform soil (all gravel, sand, or silt), oil will spread
and move with water flow and form an egg-shaped oil plume (FIGURE 23).
                     g;^^
                    S:-:-:v^^?PS^
                                    FIGURE 23
                     OIL ON GROUNDWATER (tangential view)
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RECOVERY PROCESSES

If the oil comes into contact with a different size soil particle layer or rock fissure, it will change
the oil spreading pattern.  An impermeable layer would not only change the shape of the plume, but
also change the direction of oil flow (FIGURE 24).
                                                   AFTER FLOW
                                      FIGURE 24
               OIL ON GROUNDWATER WITH IMPERMEABLE LAYER
As oil flows come oil (25 to 40 percent) will fill pore spaces, adhere to soil particles and rock
surfaces and become  immobile, while soluble oil components can mix into the groundwater.  If
enough oxygen is available, slow bacterial and/or chemical decomposition can occur. In some cases,
decomposition  increases water-soluble components up to 10 times.   The factors that affect oil
movement on groundwater are many, they often interact with each other.  However, oil spreading
can be estimated using the following formula:
       Where:
             S
             V
             A
             R
             D
             K
       R and F values are listed in TABLE 2.
                           S = {(1000)(V) -
maximum spread of oil on the water table in m2
volume of infiltrating oil in m3
area of infiltrating at surface in m2
retention capacity of soil above water table in liters/m3
depth  of water table
the approximate correction factor in various oil viscosities:
       K for gasoline = 0.5
       K for kerosene = 1.0
       K for light fuel oil = 2.0
oil contained above capillary fringe in liters/m2.
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RECOVERY PROCESSES
TABLE 2
R and F VALUES FOR VARIOUS SOIL TYPES
""'•••: •''•:'< : ' • •:'"•.'.'•: cr\n ''•''•' : ' .•'"' '•'.•:- •.'•"*<••' ' .•••;"
••• ... . • .. ••: - ;.- • ' -SOIL . V- ... ••" -;,: .... : . '• :\.-::'
Stones, coarse gravel
Gravel, coarse sand
Coarse sand, medium sand
Medium sand, fine sand
Fine sand, silt
'"•••(: R -^
5
8
15
25
40
' ' F' .
5
8
12
20
40
In using this formula, inherent errors in data can result from seasonal water table fluctuations and
by underestimating or overestimating D (the depth of groundwater). Also, oil thickness on the water
table is not the same as oil thickness measured in wells.  In some fine sand or silty soils, oil in a
well might be lower than  oil  on the groundwater. This is due to a break in the capillary fringe
caused by the well.  However, the thickness of the product in a well is more of an indication of the
rate the product moves through the soil or the position of the well in the plume.

The movement of oil due to groundwater flow can be estimated by the following equation:
       Where:
              Q
              p
              h,
              h2
              L
                                 Q =
flowrate of groundwater in m'/day/m
permeability in m/day
height of groundwater
height of groundwater
length or distance between h, and h2
Both of the estimates are usable for shallow groundwater problems or initial planning for deep
groundwater problems. However, in deep groundwater problems, before time and money are spent
on containment and recovery techniques, a monitoring system should be initiated to delineate plume
characteristics and to aid in effective containment and recovery.
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RECOVERY PROCESSES

OIL IN GROUNDWATER MONITORING

The first step in successful groundwater monitoring is the preliminary investigation.  The following
information sources can be used:  U.S. Geologic Survey maps and tables, Soil Conservation Service
maps and tables, state geologic surveys, water resource personnel, university geology departments,
city water department maps and personnel, past oil company personnel or companies that have drilled
in that area, and consultants.  The information  gathered can help determine:

        1.     Groundwater flow characteristics

        2.     Aquifer to surface water boundaries

        3.     Recharge areas

        4.     Local abstraction  points (i.e., city groundwater wells)

        5.     Flow mechanisms through fissured or highly permeable zones.

The second step in successful groundwater monitoring is field investigation. This investigation may
include soil samples, water samples, or other hydrogeologic tests. Soil samples may  be examined
for grain size to accurately define the nature and location of the soil horizons. The porosity of each
soil horizon  can also be determined from core samples.  Boreholes  may  be used  for  water
permeability measurements.   In  addition, hydrocarbon percolation tests may be performed.  The
groundwater head distribution may be studied by inserting standpipes (for monitoring the water level)
into the completed boreholes.  Ground-penetrating radar can be used to define geologic sequences,
investigate  fractures,  and  locate  buried  objects.   Electromagnetic  frequency  techniques  can
graphically show horizontal and vertical characteristics such as  aquifer boundaries and geologic
interfaces.  Both of these latter methods  can improve mapping of oil plumes over plume estimates
from just drilling wells. Use  of  these  methods, in some cases,  may prevent unnecessary drilling.

With  some highly volatile products,  the spread of the plume can  be monitored  by the  vapors
migrating through the soil surface.  Although presence of vapors in  basements, in  oil wells, in
trenches, and along disturbed  soils (i.e., buried pipelines) can indicate where the oil is, the absence
of vapors does not indicate that the oil  is  not present.  Shallow boreholes and hydrocarbon monitors
or explosimeters can help identify vapor penetration.

Field investigation may also include choosing a water sampling program. A water sampling program
may involve drilling wells, performing  water  and soil analysis,  and/or conducting mathematical
modeling to estimate plume size  and oil movement.

Generally, monitoring wells can be classified into three types:  (1) a piezometer, (2) an observation
well, and (3) a pumping well. A piezometer is a small-diameter  well  that is tightly sealed  so that
detection of static pore water pressure can be used to determine the  true direction  measured of
groundwater  flow.   More than one  piezometer can be installed  in a  well  boring by sealing
piezometers at different depths from each other.  Piezometers can be either pneumatic or electric.

An observation well is larger  in  diameter than  a piezometer well  and is used to measure oil/water
levels. Observation wells have been used to determine the direction of groundwater flow by injecting
a tracer such as fluorescein, Rhodamine WT, or salt water among a number of observation wells.
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RECOVERY PROCESSES

A pumping well is the largest in diameter of the three types of monitoring wells.  Pumping wells are
used to introduce pumps or other equipment.  Water samples can be obtained from observation and
pumping wells.  However, certain problems may arise in each well type.

The type, as well as the placement, of a well is important. Permission must be obtained from those
individuals or companies that  have surface and mineral rights.  The  location of underground
structures such as gas, petroleum, or water pipelines; powerlines; telephone lines; sewer lines; and
storm sewer lines should be identified and visibly marked.

Monitoring wells should be placed in a downgradient direction to the flow of groundwater and spaced
far enough apart to determine plume size. At least one well should be drilled upgradient to ensure
that oil was not missed.  Monitoring wells should be used to confirm the preliminary findings.

Some situations can complicate groundwater monitoring and oil recovery.  One of the more difficult
situations involves  a land spill on or into bedrock.  The oil moves into  fissures and crevices and
along joints of bedded rock and bedding planes.   The upper  layers of limestone, basalt,  and
sandstone  usually  show  pronounced Assuring, especially  if the area is  in a zone of tectonic
disturbance.  Predicting the underground movement of oil in such areas  is quite difficult.  Spilled
oil may follow fault lines in the direction of their dip.   Sometimes recovery  wells may be drilled
along a fault line to intercept the spilled oil (FIGURE 25).  This technique  in  particular requires
sound geological information before attempting any drilling operations.
              PERVIOUS LAYER
              IMPERVIOUS LAYER
                     :
                                      FIGURE 25
                       RECOVERY WELL ALONG FAULT LINE
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RECOVERY PROCESSES

Wide  fissures, crevices,  and solution channels may be present in limestone and  gypseous  and
saliferous rock (FIGURE 26). Solution cavities may hold hydrocarbons for years, releasing them
only in times of drought or flood. In central Pennsylvania in 1958, 50,000 gallons of crude oil was
lost in a limestone terrain honeycombed with  solution channels.  Recovery wells were drilled  and
much  of the product was retained on the site. However, in the mid-1960s a drought caused the water
table to drop and oil stored in the limestone was released, causing water well contamination. The
problem persists today.

One method used in such areas to trace dispersion direction is fracture trace analysis.  Air photo
interpretation  is used to  find the major fractures that could be  transporting the spilled product.
Observation wells may then be drilled to locate the oil.
                                        . '  "  •  PERMEABLE SOIL

                                        •.'"."•.••,-.
                                      '  SINKHOLE     •  .    .  '•
                                                    ',           'I "
                                                     . LIMESTONE
                                                                '-   ,    	
                                                      -   'TRAPPED OIL     	
             SOLUTION CHANNEL                   WATER MOVEMENT
                                      FIGURE 26
                       SOLUTION CHANNELS IN LIMESTONE
These combined data offer a working knowledge of.

        1.    The amount  of hydrocarbon that must be spilled in order to  reach  the
             groundwater

        2.    The direction and rate of migration of the product once the groundwater is
             contaminated

        3.    The geological or hydrogeological boundaries that exist

        4.    The rate at which the product may be extracted from the ground.
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RECOVERY PROCESSES

This information can be translated into a cross-sectional map showing the probable direction of travel
of the oil as it follows the groundwater system (FIGURE 27).
              RAINFALL
              I
                         .WELL
                                                          SPRING
                                                                          STREAM
      l_LJ_i ••'• i  •
     WATER TABLED'I.'
                                     FIGURE 27
                         SAMPLE GROUNDWATER SYSTEM
SAMPLING DEVICES FOR MONITORING WELLS

Sampling devices may be as simple as an observation well with oil-finding paste on a stick or as
complex as intricate well casings that are designed to take samples and pressure readings at various
depths. Although existing wells may be used, data analysis can become complicated.  Drilling fluids
can change the chemical or biological well environment, water from several aquifers can flow into
a single well, surface contamination into a well can occur, and casing materials and pumping
equipment can contaminate  sampled water.  High  concentrations of oil in groundwater may  not
require great accuracy in measurements, so polyethylene pipe casings can be used. However, when
accurate samples are needed, a number of factors should be considered when choosing materials.
5/93
37

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RECOVERY PROCESSES

        1.     Metal surfaces can catalyze certain chemicals (i.e., iron)

        2.     Lubricants  from pumps, oils  on pipes,  and glues from  pipe joints can
              contaminate samples

        3.     Plastics in pipes, transfer hoses, or sample bottles can absorb some organic
              contaminants or bleed contaminated elements, affecting samples.

To avoid problems, metal or plastic materials should be soaked and washed before use in boreholes
and glues should not be  used  to join well casings.  In  constructing  sampling wells for  trace
concentrations of some oils, glass or Teflon* materials may be needed in well casings or sampling
apparatus.

Sample devices vary with the number of samples per well and with well depth. In the past, obtaining
multiple samples at various depths has required sampling in different wells.  Recently, a  single well
with a multiple sampler has been used to obtain the same results.

Shallow aquifer sampling (less than 30  feet from the surface) will allow  the use of vacuum pumps
to transport samples out of wells.  However, deep aquifers (greater than 30 feet from the surface)
will necessitate submerged pumps or air-lift systems. The air-lift system is a pressurized, inert gas
system with chambers and  check valves to force samples to the surface. The advantage of an air-lift
system is that samples are not oxidized because they do not come into contact  with any oxygen in
the air.  Several air-lift systems can be used within a single well if separated by seals. This system
becomes increasingly costeffective with increasing depths.  The major problem with  the air-lift
system is that  the check valves used in sample transfer can become clogged with soil  particles if
samples are not screened properly.

For deep wells, changes in pressure can cause chemical changes, such as precipitation in the sample.
With the additional data  from  samples,  accumulation of oil and direction of flow can be confirmed
and recovery devices can be placed for the most cost-effective program.
PRODUCT RECOVERY

Some of the oil on groundwater can be removed three ways:

        1.     Open trenches

        2.     Back-filled trenches with recovery crocks

        3.     Extraction wells.

Water table depth and embankment slumping are the primary factors in selecting a recovery device.

When water table depth is less than 9 feet from the surface, trenching can be an economical method
in oil removal.  The depth of the trench should be about 3 feet below the groundwater level and the
width no more than 6 feet. Where possible, the trench should span the entire downgradient edge of
the oil plume (FIGURE 28).


5/93                                        38

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RECOVERY PROCESSES

Oil skimmers or vacuum lines can be lowered into the trench to recover oil, and a groundwater
depression pump can be used to increase the rate of oil and water flow to the trench.  If the trench
cannot be extended along the  length of the oil plume, an impermeable barrier can be installed to
divert liquid flow toward the trench.  For example, bentonite clay slurry can be pumped into narrow
slots in the  ground or sheet pilings can be inserted or driven into the groundwater or aquifer base.
                  VO
                                             PLUME

                                             BOUNDARY
                                                                    TRENCH
                                       FIGURE 28
                             AERIAL VIEW OF TRENCHES
When open trenches cannot be maintained because they rapidly fill with mud, or if freezing weather
would freeze water in/an open trench, a recovery crock can be used.  A recovery crock consists of
a pipe that reaches from the surface to about 6 feet below the water  table.  Some pipes can be up
to 6 feet in diameter.  The pipe is perforated with 2.5-inch slots or holes to allow oil and water to
enter. After a hole is dug larger than the diameter of the pipe, peagravel is placed in the bottom of
the hole to decrease turbidity by limiting soil particle movement as water levels change.  Next, the
crock (pipe) is lowered into the trench  so that the end stands on the gravel bed.  Before the trench
is filled in with a porous material (e.g.,  gravel or sand), a plastic lining or other impermeable barrier
is used to line the downgradient side of the trench above and especially below the water  table to
guide oil to the crock and halt oil plume migration (FIGURE 29).  A variation of this system is to
have radiating, interconnecting, perforated pipe at the water table to guide the product to the crock.
5/93                                       39

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RECOVERY PROCESSES
                        Ditch
             IB

                        Top View
Sump
IB
                                                   To The Separator
                                                  -v- v-'- 7-' •-• P;
                                               ir-.'V. ."•"•:::•;-""-rax:
                    Longitudinal
                    Section
     Depreued W«ierublc
            Undisturbed
            Wireruble
                           Cross- Section
                                      FIGURE 29
                           RECOVERY DITCH WITH SUMP
Product in crocks can be removed with skimmers or vacuum devices. In addition, a groundwater
depression pump can be used to create a cone of depression to encourage liquid flow toward the
crock and increase oil recovery rates (FIGURE 30).

For deeper water tables, augers, water jets, driven well points, and rotary rigs can be used to dig
a recovery well (TABLE 3).  Wells should be dug deep enough below the water table to allow for
any groundwater depression techniques used.  Auger types vary. Hand-held power augers with 6-
inch outside diameters can drill to 8 feet. Truck-mounted augers with 2-inch outside diameters can
drill to 120 feet.  Hollow-stem augers may be used to take undisturbed soil samples.  Rotary rigs
can be used for sampling soil when drilling and for sampling water upon  completion of the
observation well. Depths of 1,500 feet can be drilled.
5/93
40

-------
RECOVERY PROCESSES
                          Feed  V
                         Trenches
                                   
-------
I/I

^
Ul

Drill Type
1. Rotary
2. Stem auger
3. Hollow-
stem auger
4. Kdley
auger
5. Bucket
anger

Normal
Diameter Hole
4" -20'
4" -8'
4" -8"
8' - 48"
\2' - 11'
TABLE 3
BASIC WELL-DRILLING METHODS
Maximum
Depth
Unlimited
30 -50 ft.
30 -50 ft.
90ft.
90ft.
Average
Time per Hole
Fast
Fast under suitable
soil conditions
Fast under suitable
soil conditions
Fast
Fast
Normal
Expense
Expensive
Inexpensive to
moderate
Inexpensive to
moderate
Moderate to
expensive
Moderate to
expensive
Advantages
1. Good for deep holes
2. Can be used in soils
and relatively soft
rock
3. Widely available
4. Control caving
1. Widely available
2. Very mobile
3. Can obtain dry soil
samples while drilling
1. Good for sandy soil
2. Can set casing through
hollow stem
3. Very mobile
4. Can obtain dry soil
samples and split
spoon samples
5. Controls caving
1. Can install large-
diameter recovery
wells
2. Drills holes with
minimum soil wall
disturbance or
contamination
3. Can obtain good soil
samples
1 . Can obtain good soil
samples
2. Can install large-
diameter recovery
wells
Disadvantages
I. Need to use drilling
fluid
2. Potential borehole
damage with drilling
fluid
3. Requires drilling water
supply
1 . Difficult to set casing in
unsuitable soils (caving)
2. Cannot penetrate large
stones, boulders, or
bedrock
1. Casing diameter
normally limited to 2*
3" o.d.
2. Cannot penetrate large
rock, boulders, or
bedrock
3. Limited availability
4. Normally cannot be
used for recovery wells
1 . Large equipment
2. Seldom available in
rural areas
3. May require casing
while drilling
1. Hard to control caving
2. At times must use
drilling fluid
3. Normally very large
operating area required

-------
vo
TABLE 3
BASIC WELL-DRILLING METHODS
Drill Type
6. Cable tools
7. Air hammer
8. Casing
driving
9. Dug wells
Normal
Diameter Hole
4" - 16-
4" - 12-
2" - 24"
Unlimited
Maximum
Depth
Unlimited
Unlimited
60ft.
10 - 20 ft.
Average
Time per Hole
Slow
Fast
Slow to moderate
Fast
Normal
Expense
Inexpensive to
Expensive
Expensive
Inexpensive
Inexpensive
Advantages
1. Widely available
2. Can be used in soil or
rock
1 . Fast penetration in
consolidated rock
1. Very portable
2. Readily available
1. Readily available
2. Very large diameter
hole easily obtained
Disadvantages
1. Slower than other
methods
2. Hole often cracks
3. May require casing
while drilliong
1. Inefficient in
unconsolidated soils
2. Very noisy
3. Control of dust/air
release
4. Excessive water inflow
will limit use
1 . Limited to uncon-
solidated soil - cannot
penetrate large rocks,
boulders, or bedrock.
2. Difficult to obtain soil
samples
3. Generally inefficient
method to install
recovery well
1. Caving can be severe
problem
2. Limited depth
3. Greater explosive
hazard during
excavating into
hydrocarbons
                                                                                                                                                                                  8
                                                                                                                                                                                  o
                                                                                                                                                                                  8
                                                                                                                                                                                  c/j
                                                                                                                                                                                  £
                                                                                                                                                                                  V)

-------
RECOVERY PROCESSES

   Basically, wells can be classified into three types:

          1.     Single pump well

          2.     Double pump well

          3.     Double shaft well.

   Single  pump  wells use one device, such as a skimmer or vacuum device to remove oil and
   contaminated  water (FIGURE  31). The major problems with  single pump wells are  (1) large
   volumes of oil and water require large capacity storage, (2) separators are needed to treat oil/water
   mixtures, (3)  some pumps emulsify water with oil, and (4) the pump must be able to handle air,
   liquid,  and debris.  The advantages for the single pump well are that they can be less expensive to
   install and operate than other recovery wells (especially when needed for a short time) and they are
   effective  when low oil/water recovery rates are expected.

                                         FIGURE 31
                            SINGLE PUMP RECOVERY SYSTEM
5/93
44

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RECOVERY PROCESSES

   The double pump well combines a product recovery device and a groundwater depression device into
   a single well (FIGURE 32).  The double shaft well is similar to the double pump well except the
   oil recovery device and the groundwater depressing devices are in separate well casings (FIGURE
   33).  The separation of devices allows better regulation of water level and flow within the well. The
   main advantages of double pump and double shaft wells are (1) they are cost-effective for large spill
   volumes, (2) they can recover relatively pure products, and (3) they can be made fully automatic.
                TO PRODUCT STORAGE
    TO SEWER, DRAINAGE, ETC.
                 :POWER CABLES
                                                   SOLID CASING
                                                   SLOTTED CASING
                                                   (WELL SCREEN)
                                             -4vy?;PRODUCT RECOVERY PUMP
                                             ^$?3K&123:S«3S?j&**:FJL* '^

                                                         R GRAVEL BACKFILL
                                       FIGURE 32
                           DOUBLE PUMP RECOVERY WELL
5/93
45

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RECOVERY PROCESSES
                  — TO COLLECTION TANK      TO DRAIN-
                                                       PERFORATE
                                                     "OUTER SHAFT
                                                                   ,  j
                STATIC LEVELM~1
                                                      INNER SHAFT
                ^iȣEO
                * CONE OF
                DEPRESSION
               r-Jrv**
                *».:».-.*:-AT^-'
                '^••T/ .st;'.-fi»'/-.l
                                       FIGURE 33
                                 DOUBLE SHAFT WALL
   When the groundwater depression device creates a cone of depression, care must be taken to avoid
   pumping the well dry or severely lowering the water level around any one well. Past problems with
   this technique include  oil displacing water  in the soil and causing additional contamination and
   surface subsidence by collapse of geologic structures.

   When using groundwater depression pumps, provisions must be made to handle large volumes of
   water pumped from a well. Oil water separation should be used before water is either transported
   to a waste handling facility or discharged onto the land.  In some cases water can be reinjected into
   the ground to increase the recovery rate by flushing oil to the recovery point.  In other cases, water
   can be added to the surface at the spill location to flush oil through the soil and to increase recovery
   rates. The nonresidual oil droplets  and soluble oils will be moved. It is most effective with light
   products such as gasoline, diesel, and kerosene.  In applying large volumes of water to the spill site,
5/93
46

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RECOVERY PROCESSES

   the cone  of depression must be maintained to keep  flowing oil within the recovery area.   If
   government regulations require purification before discharging water in or on the ground, several
   methods are available for treatment.
   Reverse osmosis uses high pressure to force a solvent (i.e., water) through a membrane but not the
   solute (i.e., oil). It is used primarily for removing dissolved organic chemicals.  Ultrafiltration is
   similar to reverse osmosis but can remove larger organic molecules.  Aeration with the use  of air,
   ozone, or hydrogen peroxide oxidizes dissolved hydrocarbons.  Biological treatment uses bacteria
   to break down organic molecules on specially prepared carbon particles. Some other techniques such
   as ion exchange and  chemical treatment are usually not as effective as the previously mentioned
   techniques.  Where high-quality water is required, a combination of techniques can be devised, such
   as oil-water separation followed by aeration and activated carbon filtration.
    SAFETY

    When flammable materials are being recovered, fire prevention must be considered.  Submersible
    pumps must be explosion proof and sure pumps, engines, and other igniting sources must be at least
    5 feet from recovery wells.  Electric underground cables should always be protected.
    SUMMARY

    Oil on groundwater can be a serious problem. The oil can contaminate water used for drinking,
    irrigation or industrial processes. Characteristics such as oil volume, oil viscosity, area of land that
    is contaminated, depth to water table, and soil permeability will influence the amount of oil reaching
    the groundwater.  The hydrogeologic factors within the aquifer will influence oil migration on the
    groundwater.   Therefore, groundwater monitoring  is  necessary to have effective location and
    recovery of product.

    Monitoring should  include  thorough preliminary  investigation  and  field  investigation.   Field
    investigations require sampling that does not contaminate soil and groundwater samples.  Sampling
    devices vary from sample probes to complicated well borings with intricate  sample casings and
    sample pumps.   Also,  complications can arise in sampling  because  of highly fissured  bedrock,
    solution channels in limestone, and irregularities in bedding planes.

    Products can be recovered using open trenches, filled trenches with recovery cracks, or extraction
    wells.  A properly constructed well can recover oil from a large area surrounding the well.  Care
    must be taken in pumping large quantities of water from an aquifer.  Water that is recovered may
    be required to be treated before discharge.   Well types used are simple pump, double pump,and
    double shaft wells. Well choice will depend on the situation.

    Safety precautions must be taken when dealing with volatile products.


5/93                                            47

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Section 6

-------
                                VOLATILIZATION
STUDENT PERFORMANCE OBJECTIVES:
At the conclusion of this section, participants will be able to:
             Briefly describe the advantages and disadvantages of volatilization

             List at least four factors that influence the operation of a packed tower air
             stripping unit

             Briefly describe the operation of a packed tower air stripping unit

             List at  least two differences between  an air stripping unit and a  steam
             stripping unit

             Briefly describe a typical soil vapor extraction unit.
5/93

-------
                                              NOTES
       AIR STRIPPING
     •  Physical separation
     •  Applicable to volatile wastes
     •  Well established technology
         AIR STRIPPING
          ADVANTAGES
    • High removal efficiency
    • Applicable over a large range
    • Simple design
    • Low cost

         AIR STRIPPING
         DISADVANTAGES
         • Non-destructive
         • Non-volatiles
         • Vapor treatment
5/93
Volatilization
   page 1

-------
        NOTES
                                     FACTORS INFLUENCING
                                   AIR STRIPPING OF WASTES

                                  • Waste component's Henry's constant
                                    >0.003 atm-m3/mole concentration

                                  • Surface area

                                  • Air exchange

                                  • Temperature
                                     FACTORS INFLUENCING
                                   AIR STRIPPING OF WASTES
                                        • Contaminants
                                             Suspended solids
                                             Grease and oils
                                             Biological growth
                                             Minerals
                                       Alr-
                                ConUmlntttd
                                 Ground
                                  Water_
Discharge
                                            DrHuwr Gr1
-------
                                                              NOTES
  Air Stripper
 Contaminated Water
   Influent
  Effluent to Discharge
  or Further Treatment
                    Discharge to Air
            Air Stripping
              Column
          DESIGN DETAILS
          •  Distribution system
          •  Redistribution rings
          •  Packing support
          •  Water seal
          •  Mist eliminator
                Influent
                  A
        Contaminated
        Ground Water
lent J~\
            Mist Eliminator

           •Filter Media
        ^-Redistribution Rings
         Stainless
         Steel Screen
            ir Inlet
             Water
             Level'
           Discharge^
     Packed Column Air Stripping System
5/93
                                                        Volatilization
                                                             page 3

-------
       NOTES
                              AIR POLLUTION CONTROLS

                                • Carbon adsorption
                                • Thermal destruction
                                • Catalytic thermal destruction
                              DESIGN CONSIDERATIONS
                                   PACKED TOWERS
                              • Flow rate - tower diameter
                              • Removal efficiency - tower height
                              • Surface area - packing material
                              • Compound - air-to-water ratio

                              CONSTRUCTION MATERIALS

                                • Aluminum
                                • Fiberglass reinforced plastic
                                • Steel
                                • Stainless steel
Volatilization
page 4
5/93

-------
    AIR STRIPPING COST
     $0.05-0.20/1000 Gallons
     Contaminated Water
       Influent
                      Discharge to Air
Cooled,
Stripped  *i
Effluent to*"
Further
Treatment
 Steam Stripper
                      Condensate to
                       Incinerator
                       Air and Steam
   SOIL VAPOR EXTRACTION


     •  Physical separation

     •  Applicable to volatile wastes

     •  Proven technology
                                                 NOTES
5/93
                                                         Volatilization
                                                             page 5

-------
          /VOTES
                                              Contaminant Flow Toward Well
                                                               To Pump
                                           uum Level
                                         Monitor
Extraction Well
                                                   Soil Vapor Extraction
                                                              Portable
                                                              Vacuum
                                                              Unit
                                                        Vapor/   Quadruple Carbon
                                                        Water    Adsorption Unit
                                                        Separator
                                           Vacuum Extraction Wells
                        Backup
                        Carbon
                        Unit
                                               SOIL VAPOR EXTRACTION
                                                  SYSTEM COMPONENTS
                                                    • Inlet wells
                                                    • Extraction wells
                                                    • Air headers/piping
                                                    • Flow meters/controllers
                                                    • Vacuum pumps/blowers
                                                    • Vapor treatment
                                                    • Impermeable cap
Volatilization
pages
                           5/93

-------
                                                          NOTES
            Volatilization System
                  Extraction air
                  bypass valve
              Extraction air
  Inlet          "ow metor
  we||  Extraction  Extraction air
      manHold  \^ sampling port
     Stone
     vertical
     •xtractlon
     vent pipe
                                    Vapor
                            Impermeable treatment
                            cap

                              Soil contamination
            INLET WELLS
            • Ground surface

            • Passive

            • Active
        EXTRACTION WELLS

      • Vertical > 20 feet

      • Horizontal - trenches

      • Cluster wells - variable strata

      • Spacing-15 to 100 feet
           soil bulk density
           soil porosity
5/93
                                                                      Volatilization
                                                                           page 7

-------
       NOTES
                                 AIR HEADERS/PIPING
                                    • Materials
                                        PVC
                                        steel

                                    • Layout
                                        manifold
                                        grid

                                    • Freeze protection
                            FLOW METERS/CONTROLLERS

                                     • Meters
                                         pilot tube
                                         orifice plate
                                         totalizing

                                     • Control valves
                                         butterfly
                                      .   ball
                              VACUUM PUMPS/BLOWERS

                                  •  Industrial blowers
                                      rotary
                                      turbine

                                  •  Vacuum pumps
                                      positive displacement
Volatilization
page 8
5/93

-------
                                             /VOTES
      VAPOR TREATMENT

        • Air/water separator
            traps
            condenser

        • Carbon adsorption

        • Thermal destruction
      IMPERMEABLE CAP

       • Purpose
           stop infiltration
           direct air movement

       • Materials
           clay
           asphalt
           concrete
           polyethylene
 SOIL VAPOR EXTRACTION COST
     $10.00-50.00/Cubic Yard
5/53
Volatilization
   page 9

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                            VOLATILIZATION
      Air Stripping
            General Description

            Air stripping is a mass transfer process in which volatile contaminants in water or
            soil are transferred to gas.  As shown in FIGURE 1, there are four basic equipment
            configurations used to air-strip liquids.
        PACKED COLUMN

              EXIT AIR

                     DISTRIBUTOR
     DIFFUSED AIR BASIN
         A|R SUPPLY
          EFFLUENT!
                      MATERIAL
                       SUPPORT
                      ^•PLATE

                     ;—INCOMING
                          AIR
                                                                -EFFLUENT
       COKE TRAY AERATOR
                       DISTRIBUTING
                                                          TOWER
                                                           WATER
                                                            INLET
                           OUTLET
                                          WATER
                                          OUTLET
                                                             INLET
                    COLLECTION
                     BASIN
                                  FIGURE 1
                AIR STRIPPING EQUIPMENT CONFIGURATIONS
5/93
11

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VOLATILIZATION
              Air stripping is frequently  accomplished  in a packed  tower equipped with an air
              blower. The packed tower works on the principle of countercurrent flow. The water
              stream flows down through the packing, while the air flows upward and is exhausted
              through the top. Volatile, soluble components have an affinity for the gas phase and
              tend to leave the aqueous stream for the gas phase.

              In the cross-flow  tower,  water  flows  down  through  the packing as  in  the
              countercurrent packed column; however, the air is pulled across the water flow path
              by a fan.  The coke tray aerator is  a simple, low-maintenance process requiring no
              blower. The water being treated is allowed to trickle through several layers of trays.
              This produces  a large surface area for gas transfer. Diffused aeration stripping and
              induced draft stripping use aeration basins similar to standard wastewater treatment
              aeration basins. Water flows through the basin from top to bottom or from one side
              to another with the air dispersed through diffusers at the bottom of the basin.  The
              air-to-water ratio is significantly lower than in either the packed column or the cross-
              flow tower (Canter and Knox, 1985).

              Applications/Limitations

              Air stripping  is used to remove  volatile  organics from  aqueous  wastestreams.
              Generally,  components with Henry's Law constants of greater than  0.003  can be
              effectively removed by air stripping (Conway and Ross, 1980). This  includes  such
              components as   1,1,1-trichloroethane,  trichloroethylene,   chlorobenzene,  vinyl
              chloride,  and dichloroethylene.

              The feed  stream must be low in  suspended solids and may require pH  adjustment of
              hydrogen  sulfide, phenol, ammonia, and  other  organic acids  or bases to reduce
              solubility and  improve transfer  to the  gas phase.  Stripping  is often  only partially
              effective  and must be followed  by  another process such as  biological treatment or
              carbon adsorption.

              Combined  use of air stripping  and activated carbon  can be an effective way of
              removing  contaminants  from groundwater.   The air stripper removes the more
              volatile compounds not removed by activated carbon and reduces the organic load on
              the carbon, thus reducing the frequency (and expense)  of carbon regeneration.

              The  countercurrent  packed tower  has been  the most  widely used equipment
              configuration for  air stripping at hazardous waste sites.  The reasons for this are
              (Canter and Knox, 1985):

              (1)    It provides the most liquid interfacial area

              (2)    High air-to-water volume ratios  are possible because of low air
                     pressure drop through the tower
5/93                                        12

-------
VOLATILIZATION
              (3)    Emission  of stripped organics to the  atmosphere may be
                     environmentally unacceptable; however,  a countercurrent
                     tower  is relatively  small and can be readily connected  to
                     vapor recovery equipment.

              The major disadvantage of the packed column is the high energy cost.

              Design Considerations

              The design of a packed tower air stripper generally involves determining the cross-
              sectional area of the column and the height of the column packing.   The cross-
              sectional area of the column is determined from physical properties of the air flowing
              through the column, the characteristics of the packing, and the air-to-water flow ratio.

              A key factor is the establishment of an acceptable  air velocity.  A general rule of
              thumb used for establishing the  air velocity  is that  an acceptable air velocity is 60
              percent of the air velocity at flooding.  Flooding is the condition in which the air
              velocity is so  high that it holds  up the water in the column to the point where the
              water becomes the continuous phase rather than the air.  If the air-to-water ratio is
              held constant,  the air velocity determines the flooding condition.  For a selected air-
              to-water ratio, the cross-sectional area is determined by dividing the air flow rate by
              the air velocity.  The selection  of the design air-to-water ratio must  be based on
              experience or pilot-scale treatability studies.   Treatability studies are particularly
              important for developing design information for contaminated groundwater (Canter
              and Knox, 1985).

              The height of  column packing may be determined by the foHowing equation (Canter
              and Knox, 1985):
                                 In
                          Z  =
                                     (X2 - Y,
               (l-A)  +  A \L
                                         KLaC(l-A)(l-X)M
              where:
                     Z
                     L
                     X,

                     KLa
                     C
                     H
height of packing, ft.
water velocity, Ib-mole/hr/ft2
influent concentration of pollutant  in groundwater,  mole
fraction
effluent concentration of pollution  in groundwater,  mole
fraction
mass transfer coefficient, gal./hr.
molar density of water = 3.47 Ib-mole/ft3
Henry's Law constant, mole fraction in air per mole fraction
in water
air velocity, Ib-mole/hr/ft2
5/93
          13

-------
VOLATILIZATION
                     A     =     L/HG
                (1-X)M     =     the average of one minus the equilibrium water concentration
                                   through the column
                     Y,     =     influent concentration of pollutant in air, mole fraction

              In most cases, the following assumption can be made:

              (1)    Y,     =     O, there should be no pollutants in the influent air.

              (2)    (1-X)M =    1, the  influent  concentrations should be  too small when
                                   converted to mole fraction to shift this term significantly from
                                   1.0.
In
£ -
X2 (1-A) + A
Xi
>•
KLaC(\-A)
              The mass transfer coefficient, KLa, is determined from pilot-scale treatability studies
              and is a function of type of compound being removed, air-to-water ratio, groundwater
              temperature, type of packing, and tower geometry (Canter and Knox, 1985).

              Calgon Carbon Corporation maintains a computer modeling system that determines
              the appropriate tower diameters, parking heights,  air-to-water ratios, and tower
              packing for a particular  application  (Calgon Carbon Corp.,  1983).   This system
              facilitates rapid mobilization of the packed tower equipment to a site.

              Technology Selection/Evaluation

              In recent years, air stripping has gained increasing use for the effective removal of
              volatile organics from aqueous wastestreams.  It has been used most cost-effectively
              for treatment of low concentrations of volatiles or as a pretreatment  step prior to
              activated carbon.  Calgon manufactures a treatment which combines air  stripping and
              activated carbon.

              The equipment for air stripping is relatively  simple, start-up and shut-down can be
              accomplished quickly, and the modular design of packed towers makes air stripping
              well suited for hazardous waste site applications.

              An important factor in the consideration of whether  to use air stripping technology
              for the removal of volatile contaminants is the air pollution implications of air
              stripping.  The gas stream generated during treatment  may require collection and
              subsequent treatment or incineration.
5/93                                         14

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VOLATILIZATION

             Costs
             Packed  tower  air strippers have higher  removal efficiencies than induced-draft
             systems, which are similar to diffused aeration systems. However, the induced-draft
             system is lower in capital cost and requires less energy  to operate than a packed-
             tower system.

             TABLE 1 describes the installed cost of an induced-draft stripper manufactured and
             marketed by the Calgon Carbon Corporation.  As shown  in TABLE 1, the installed
             cost of  an  induced-draft stripper capable of treating 700 gpm and removing 75
             percent  of the TCE contamination is about 31 percent ($19,000 vs. $61,300) of the
             cost of a packed-tower capable of removing 95 percent of the TCE.  Assuming that
             a well pump with a minimum discharge head of 25  psig is required to feed both
             units, the packed-tower also uses an additional $5,100 per year in electrical energy
             for operation of the blower.
                                       TABLE 1
                         AIR STRIPPING COST ESTIMATES
                      (Basis: 700 gpm; 1000 micrograms/Iiter TCE)
                                     Induced-Draft1 Stripper
                                         (75% Removal)
                     Packed-Tower2 5-ft.
                   Diameter (95% Removal)
  Air Stripping Equipment3
  Stripper Assembly & Installation
               Equipment Subtotal
  Recharge Pump; Assembly &
  Controls
  Foundation/Sump4
  Equipment Freight
  Project Management
  Project Contingency
                             Total
  $15,000
   4.000
  $19,000
 $42,300
  19.000
 $61,300
  $16,000
  18,000
   2,000
  10,000
   7.000
  $72,000
 $16,000
  23,700
  5,000
  20,000
  20.000
$146,000
  'Calgon Model No. 909B (8'0" x 9'1" x 9'0").
  2Tower is made of fiberglass-reinforced plastic and contains 15 ft. of 1-in. diameter
  polypropylene pall ring packing.
  3Cbst includes tower, packing, packing support, demister, 4,000 cfm fan with 10 hp motor,
  damper, piping valves, and ductwork.
  4Sump 5'  x 5' x  8' below-grade concrete.
Source: O'Brien and Stenzel, undated
5/93
15

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IS\

VO
CONTAMINATED WATER
     INFLUENT
                         I    HEAT
                         EXCHANGER
               COOLED STRIPPED
               EFFLUENT TO FURTHER
                   TREATMENT
ORGANIC
VAPORS
                                INTERNAL WATER
                                DIRECTION OF FLOW
                                                                     CONDENSER
                                                                                      DISCHARGE
                                                                                       TO AIR
O
r
H
i—i
r
N
H
O
                     .   CONDENSATE TO
                        INCINERATOR
                                                                 INTERNAL STEAM AND
                                                                 AIR DIRECTION OF FLOW
                                    STRIPPED EFFLUENT
                                                                    STEAM INPUT
                                                    AIR BLOWER
                                                FIGURE 2
                                             STEAM STRIPPER

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VOLATILIZATION

              In a typical treatment system, repumping of the treated water would be required.
              Adding the cost of a sump, flow control, and a pump, the overall project cost for the
              induced-draft system would be about one-half the cost of the packed tower system
              (Calgon Carbon Corp., undated).

       Steam Stripping

       Steam stripping is a unit process that uses steam to extract organic contaminants from a liquid
       or slurry. Direct injection of live steam or multiple pass heat exchangers are the two most
       prominent methods described as steam stripping. Steam stripping by direct injection of steam
       can be used to treat aqueous and mixed wastes containing organic contaminants at higher
       concentrations and/or having lower volatility than those streams which are air strippable.  It
       is an energy-intensive process and the steam may account for a major portion of the operating
       costs  (FIGURE 2).

       This process is similar to steam distillation except that reflux of recovered material is usually
       not done. It can handle  solids in the waste that may foul the heating coils of a distillation
       unit.  In addition, wastes  of more variable composition can be processed.  The disadvantages
       of this technique include the addition of water to the treated waste and the high energy
       requirements.

              Waste Type Handled

              Steam stripping has been widely used to strip hydrogen sulfide (H2S) and ammonia
              (NH3)  from refinery wastes.   Volatiles, organic compounds, as well as phenols,
              ketones and phthalates, can be removed from aqueous wastes, slurries, and solids by
              this process. Effective removal of high concentrations (1-20 percent) of organics can
              be accomplished.  However,  concentrations of  less than 1 percent can be  more
              effectively treated by other treatment techniques.

              Restrictive Characteristics

              Water-miscible organics and metal  contaminants are  not removed by this process.
              Contact between steam and solid materials is more difficult to achieve than in liquid
              streams.

              Mobile System Considerations

              The system can be transported in a horizontal position and hydraulically raised to a
              vertical position for onsite treatment.  Electric or diesel-powered steam generators
              and condensers, as well as collection and storage equipment, are required for this
              process.  Energy requirements usually limit the size and performance of this process.
              Adequate utilities have to be provided for steam stripping. The concentrated bottom
              and top streams may require additional  treatment.
5/93                                         17

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VOLATILIZATION

              Environmental Impacts

              Concentrated overhead vapors are condensed into a liquid form and must be treated
              further or sent directly to a fume incinerator.  The stripped  aqueous waste may
              require further treatment (e.g., carbon adsorption) if the desired level of removal is
              not achieved by steam stripping.

              Costs

              Costs vary widely depending on the  flow rates, heating requirements, and ease of
              component separation.   The operating costs will be mostly affected by the energy
              requirements and  labor costs.

              Commercial Applications

              No mobile steam stripping units have been applied  to hazardous waste treatment.  A
              number of companies have, however, expressed interest in developing a mobile unit.
              Several petroleum companies may also be developing mobile systems.

       Soil Vapor Extraction

              General Description

              Soil vapor extraction is known by several names, including soil venting, forced soil
              venting, in-situ air stripping,  and in-situ volatilization.   Regardless of the name it
              goes by, the process is generally the same.  An extraction well is placed within the
              unsaturated zone of a contaminated site. Air is then drawn out of the extraction well
              by a vacuum pump or blower. As air passes through the soil,  volatile components
              diffuse from the soil particles and are carried with the air as it passes out of the well.
              A wide range of pilot- and full-scale vapor extraction systems have been constructed
              and studied under a variety of conditions.  This remediation technology  has been
              selected for use at 13 percent of the sites which have selected treatments according
              to  the 1988  Records of Decision (RODs).   Additionally, this technology  has been
              applied to underground storage tank cleanups and RCRA corrective actions.

              Applicable Wastes

              Contaminants with low solubilities and high vapor pressures (substances with Henry's
              Law constant values greater than 0.003 atm-m'/mole) found within the unsaturated
              zone may  be removed using this technology. However, the efficiency in removing
              these  contaminants  is  highly  dependent on specific  site   geology  and soil
              characteristics.  TABLE 2 lists the characteristics that impact process feasibility.
5/93                                        18

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VOLATILIZATION
                                           TABLE 2
                                 TECHNOLOGY SUMMARY
       Characteristics
      Impacting Process
       ;   Feasibility
      Reason for Potential Impact
  Data Collection
  Requirements
  Presence of:
    •   Less volatile organics
    •   Metals
    •   Cyanides
    •   Inorganics
Only volatile compounds with a Henry's Law
constant of approximately  >3 x 10"3 atm-m3
/mole can be effectively removed by vacuum
extraction; theoretically, steam or hot air
extraction should apply to  less volatile
compounds.
Analysis for priority
pollutants; Henry's
Law constant or
vapor pressures for
organics.
  High solubility of volatile
  organics in water
Dissolved organics are more mobile and harder
to remove from aqueous phase.
Contaminant
solubilities.
  Unfavorable soil
  characteristics:
    •   Low permeability
    •   Variable soil
        conditions

    •   High humic content
        High moisture content
Hinders movement of air through soil matrix.
Inconsistent removal rates.
Inhibition of volatilization.
Hinders movement of air through soil.
Percolation test; pilot
vapor extraction tests.

Soil mapping.
Analysis for organic
matter.

Analysis of soil
moisture content.
               Soil  vapor extraction  techniques may also be used as a pretreatment to remove
               volatile contaminants from the vadose zone prior to the use of other technologies.

               Process Description

               Soil  vapor extraction is  a physical process; therefore,  no destruction of the waste
               components occurs without the addition of specific equipment items designed for that
               purpose. It is a process that is limited by the ability of a contaminant to desorb from
               a soil particle and diffuse into air.  Soil vapor extraction is becoming a widely used
               technology because of the following benefits:

               •      No extensive site excavation

               •      Relatively simple installation

               •      Applicable to numerous volatile contaminants
5/93
                19

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VOLATILIZATION

              •      May be used to clean under existing structures

              •      Flexible design

              •      Relatively, low cost.

              Many variations  of soil vapor  extraction systems have  been used effectively at
              numerous sites.  FIGURE 3 shows common system components:

              •      Extraction wells

              •      Inlet wells

              •      Air headers/piping

              •      Vacuum pumps/blowers

              •      Flow meters/controllers

              •      Vapor treatment

              •      Impermeable cap.

              Extraction wells should be designed to penetrate the unsaturated zone to the capillary
              fringe.  Vertical wells  are installed when this  depth is greater than 20 feet.  When
              groundwater is at a  shallow depth or if the contamination is confined to near-surface
              soils, then extraction wells may be placed horizontally in trenches.  If the stratigraphy
              of the soil presents  significant variations in permeability, cluster wells  may be used
              to selectively treat individual strata.  This is done by screening the wells so that the
              screened section of  an individual well within the cluster is  set within a specific area.
              Vacuum  applied to  each  well head can be varied to improve air movement through
              a given strata.

              Well spacing is determined by the soil's bulk density and its porosity. In general, the
              lower the bulk density  and the higher the porosity of the  soil, the  farther apart
              extraction wells may be  placed.  In practice the distance between  wells  is usually
              determined by pilot  testing and ranges from 15 feet for soils with high bulk densities
              and low porosities to 100 feet for soils with low bulk densities  and  high porosities.
5/93                                         20

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VOLATILIZATION
             Extraction
                Well
Control
 V«l»t
                                       Air/Water
                                       Separator
         Inlet
         Well
**/«»"  Blower
  n    I      =
                                                                  Vapor
                                                                Treatment
   i «
Ml
                       u
                                                                       Cap
                                     Contaminated
                                         Soil
                                                                   3§jr Groundwater
                                                                         Table
                                       FIGURE 3
                         SOIL VAPOR EXTRACTION SYSTEM
             Proper installation of the extraction wells is one of the keys to ensuring proper
             operation of the system (FIGURE 4).  A  10 inch or larger diameter hole is drilled
             into the areas that are documented as having the highest level of contamination.  The
             hole must only penetrate down to the capillary  fringe to ensure that only minimal
             amounts  of water are withdrawn during process operations.  The well is normally
             screened the full length of the installed depth, except for the upper 5 feet (this  may
             vary depending on site stratigraphy).  A grout plug may be placed at the bottom of
             the well hole to serve as an anchor and positive seal for the well screen.  A 4- or 6-
             inch diameter PVC well is then installed plum with coarse sand packing surrounding
             the screened length of the casing. If no grout plug has been provided, the foot of the
             screened casing should be capped.  Bentonite  is packed around the upper section of
             the casing to within 2 feet of the surface. A grout plug extending several inches
             above the surface and down to the bentonite finishes the installation. The grout seal
             ensures that there will be no air leakage from around the well head during system
             operation.
5/93
                21

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VOLATILIZATION
                     Riser
       2' to 4' PVC Casino
         10' Auper Hole
                                                     Concrete Cap
                                                    mmma^m    Ground Surface
        Cemenl-Bentonlte Grout


        Bentonite Pellets


         Course Sand


        Centralirer (optional)
                                                PVC Cap
                                    FIGURE 4
            TYPICAL EXTRACTION/AIR INLET WELL CONSTRUCTION
            Variations on extraction well installations are common. However, the sealing of well
            heads is essential to minimize loss of vacuum.

            Inlet wells are constructed  similarly  to extraction wells and provide necessary air
            supply to the system.  Air inlets may include:

            •      Ground surface
5/93
22

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VOLATILIZATION
              •      Passive wells

              •      Active wells.

              The ground surface provides the greatest amount of surface area exposed to the
              atmosphere. Therefore, when an extraction well is under vacuum, air will be drawn
              from the ground surface immediately adjacent to the well (FIGURE  5). The zone
              of influence will vary relative to soil characteristics and the capacity of the vacuum
              pump or blower.  Regardless, the zone of influence diminishes as distance from the
              extraction well increases.

              Passive wells may be installed to provide direct venting within specific subsurface
              strata.   These wells are constructed similarly to extraction  wells;  however, well
              screening will be limited to accommodate a specific strata.  They remain open to the
              atmosphere, thereby providing an air inlet source. Normally inlet wells are installed
              in a circular pattern surrounding the extraction wells. These wells may also be used
              as extraction wells if redirection of the air flow through the subsurface is desired.
                                       FIGURES
          AIR FLOW PATTERNS IN VICINITY OF A SINGLE EXTRACTION
                                   WELL (NO CAP)
5/93
23

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VOLATILIZATION
              Active wells force air into the subsurface.  These wells are essentially passive inlet
              wells that have been fitted with an air blower (FIGURE 6). Injected air, along with
              vacuum, should provide a push-pull effect.  However, it is difficult to balance air
              flows in soils. This means that active inlet wells often serve as a means to diffuse
              volatiles from soils immediately adjacent to the well screen and distribute them within
              other soil strata.

              These wells may also be installed into contaminated aquifers.  Air injected into the
              aquifer tends to strip volatiles from contaminated groundwater, forcing them up into
              the  capillary  fringe  and the unsaturated  zone.   Once  the  volatiles  are  in  the
              unsaturated zone, they will migrate to the extraction wells.



                                        FIGURE 6
                         AIR FLOW FROM INJECTION WELLS
5/93
24

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VOLATILIZATION
              Once the extraction wells have been installed, they are connected by a piping system.
              The pipe that is normally used is Schedule 40 PVC; however, fiberglass-reinforced
              plastic  and steel pipe have been used.  Piping is laid  out to connect the vacuum
              system to the extraction wells in a manifold or grid network.  These types of layouts
              minimize friction loss through the pipe and maximize system flexibility.

              Piping  may  also be installed underground when systems must be  installed across
              active roadways or walk  areas.  This may also provide freeze protection for the pipes.
              Such protection is warranted for soil  vapor extraction systems installed in northern
              climates because moisture collecting in the piping network could freeze and crack the
              pipes.

              The vacuum for extracting  soil air  is developed  by typical vacuum pumps or
              blowers. Positive displacement vacuum pumps will usually provide high vacuum but
              low total air flow.  For example,  at one  site,  a vacuum pump  was installed  that
              moved 18 cfm of air at vacuums ranging from 25 to 30 inches of mercury.

              Alternately,  at a site where an industrial blower was used, up to 3000 cfm of air  was
              moved at vacuums up to 9 inches of mercury.  Therefore, blowers such as those of
              rotary or turbine design will provide high volumes of air movement at lower vacuum.
              Electric motor drives  for these systems are low (10 horsepower or less).  Pressure
              from the outlet side of  the pumps or blowers  is often used to drive the  exit gas
              through a treatment system.  Such  treated  air may  be piped  into  the system's inlet
              wells.

              Knowledge of gas flow rates and total volume is essential to determine the mass of
              contaminants removed from the soil.  Gas  flow meters should be installed  on a
              straight pipe run between an extraction well and the vacuum source.  This location
              minimizes turbulent flow conditions that could influence the accuracy  of the meter
              and is representative of the vapors that are being extracted.  However, because this
              location remains under vacuum during operation, any meter installation must remain
              airtight to minimize leakage. Meters  that are used include pilot tubes, orifice plates
              with manometers, or totalizing designs.  Flow measurements from  individual wells
              are useful for optimizing the system.   For  example, if a zone of contamination lies
              close to one extraction well, it may be beneficial to concentrate vacuum on that well
              to  encourage rapid movement  of the contaminant.   This may be accomplished by
              installing control valves in the piping system.  Installation  of a control valve at the
              head of each extraction well can maximize operational flexibility of the system.   The
              valves  that are used should  minimize moisture retention within  the piping.  Both
              butterfly valves and ball valves have been used successfully in this application.

              Subsurface conditions vary considerably from one  site to  another.  Soil moisture
              content is one parameter that can affect operating efficiency of the system.  When a
              vacuum is drawn on soils, water associated with the soil will volatilize. As water
              vapor exits the well, it condenses on the inside of the piping network and will enter
              the vacuum pump. Eventually, moisture buildup will result in greater maintenance
5/93                                        25

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VOLATILIZATION
              requirements for the system.  To minimize such effects and to provide protection for
              the vacuum pump, an air/water separator should be installed between the extraction
              well and the vacuum source.  These separators are often fabricated from standard
              materials such as 55-gallon drums.  The drum is baffled  so that the influent vapor
              entering near the top of the drum impinges on it and is driven downward.  Vapor
              exits the separator through an opening on the opposite side of the drum.  The baffle
              extends to only about three-fourths of the depth of the drum. At the base of the drum
              is a valved opening for release of the fluids that collect during operation. To enhance
              condensation, stainless steel mesh may be packed in the base of the unit.

              The highest concentration of volatile organic chemicals (VOCs) will be extracted from
              the soil when the system is started up and equilibrium is reached. Because the system
              itself is a physical means of separation, there is no destruction of the VOCs that are
              removed from the soil.  Direct discharge  of  VOCs  to the atmosphere  may  be
              restricted  by  state or local  regulatory agencies.   If VOCs are  released to  the
              atmosphere provisions  must  be made  to  control  the emissions.   Control  is
              accomplished by one or more of the following:

              •       Mass flow rate control

              •       Vapor phase carbon adsorption

              •       Exhaust gas combustion.

              Mass flow rate control  is simply limiting vapor extraction flow rates so that the total
              mass of VOCs discharged is below permit limits. This is the least expensive option
              but results  in extending the  time  required to clean up  the site  and  provides  no
              destruction of the VOCs.

              Vapor phase carbon adsorption  is used most frequently  on small systems.   In
              practice, two  or more canisters of carbon are placed in series either at the inlet or
              outlet of the vacuum source. The efficiency of the system may be increased. Carbon
              adsorption is also a nondestructive technology.  Therefore, the carbon itself must be
              disposed of in an approved landfill, incinerated, or regenerated by means of a thermal
              desorption.

              Exhaust gas combustion is the most expensive option, but results in destruction of
              the VOCs.   Combustion may  be accomplished in  a number of different ways.
              However, in all cases, the goal is to heat the VOCs to about 2000°F.  Because the
              vapors that are extracted normally contain low concentrations of VOCs with respect
              to concentrations of oxygen, high-temperature combustion will oxidize the VOCs to
              carbon dioxide, water vapor, and trace by-products.  Catalytic vapors are heated in
              a  combustion chamber  to temperatures  only about half that of incinerators.  The
              heated vapors are then passed through a catalyst chamber. In the chamber, the rate
              of the oxidation reactions is increased, which results in combustion of VOCs at lower
              temperatures.
5/93                                        26

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VOLATILIZATION

              Moisture within the soil around the vapor extraction area affects system operations
              in several ways.   Moisture may solubilize  some volatile substances.   This may
              increase the mobility of the substance within  the subsurface and carry the substance
              to greater depths with additional infiltration. Soil moisture also can fill voids between
              soil particles, thereby limiting  the amount of exposed particle surface area as air is
              drawn  past.  Therefore, limiting the amount of moisture in the subsurface  can
              maximize performance of soil  vapor extraction systems.  This is normally done by
              capping the area that is to be controlled with  an impermeable cap of clay, asphalt,
              concrete, or polyethylene.

              Polyethylene is usually the least expensive option. However, if it is used, drainage
              must be provided to prevent water from pooling on the surface. Capping the site may
              also be used to direct air infiltration.  Because the soil surface is the main  source of
              inlet air to the system, limiting air infiltration via an air cap will result in greater air
              volumes being drawn from  outside the capped area.

              Monitoring

              The highest recovery rates of VOCs for any given system are normally found during
              the initial start-up. Therefore, exhaust gas controls are most  important at this point
              in the operation.  As the clean-up progresses, concentrations of VOCs in the exhaust
              gas decrease.  The rate of diffusion limits the recovery of VOCs.  Several methods
              are used to determine how well a clean-up is  progressing. These include:

              •      Exhaust gas monitoring

              •      Soil borings

              •      Onsite soil gas analysis.

              Exhaust gas monitoring is normally done by analyzing gas samples collected from
              the extraction wells.  The concentration of VOCs multiplied by the flow rate yields
              the total mass of VOCs extracted per unit time.  It is important to adjust the flow to
              standard units (usually dry standard cubic feet per minute [dscfm]) to ensure that the
              calculations of mass values are accurate.  Eventually, analysis of gas samples may
              show that VOCs are no longer present in the exhaust gas.  This means that for the
              zone of influence  swept by the system, the rate of diffusion of VOCs is sufficiently
              low so that none are detectable.

              If the vacuum is shut off and left off for  a period of time, the VOCs in the soil may
              continue to diffuse into the surrounding air space.  If the vacuum is restarted, analysis
              of the exhaust gas will reveal measurable VOC concentrations. Therefore, weekly
              monitoring of exhaust gases for VOCs can indicate that the clean-up is progressing.
              When no VOCs are detected,  the vacuum should then be restarted, and the exhaust
              gas should be analyzed. If no  VOCs are detected (or the concentration of VOCs is
              within acceptable levels), then the vacuum should be shut down for a period of about


5/93                                         27

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VOLATILIZATION
              1 month. Exhaust gas analysis should then be resumed to determine whether further
              operation of the system is warranted.

              Soil borings can be used to indicate when residual VOCs remain in the treated area.
              They can also be used to indicate where a treatment zone ends.  Borings should be
              used to identify  VOC contamination  within the area to be treated.  The contaminant
              map that is generated may then be compared directly to similar samples taken after
              obtaining negative exhaust gas analyses as discussed above. Obtaining samples from
              soil borings on a routine basis  is not recommended because exhaust gas monitoring
              will be a better indicator of system operation.

              Onsite soil gas analysis involves  the  use  of colorimetric  tubes to  determine
              qualitatively whether specific contaminants remain within the soil.  These field tests
              are relatively inexpensive and can give  a quick indication of whether specific areas
              have been swept by the system. The  analysis makes use of colorimetric detector tube
              and pump systems to which a tygon  or silicon sample tube has been attached.

              The site of interest is located and  a  hand tool  is used to bore out a hole of about 1
              inch in diameter to  the depth of interest.  Results  are  read directly from the tube
              according  to  manufacturer's  directions.   Such  tests  may be  used  to  provide
              information to determine whether extraction wells  should be removed from service
              or  whether  additional vacuum may be required in a given area.

              Costs

              Soil vapor extraction systems should  be pilot tested before numerous extraction wells
              are set at any site.   Piloting these systems involves the installation of one or more
              extraction wells, pipe and fittings, valves, orifice plate and manometer, blower with
              motor, and a carbon adsorption unit.

              Capitol costs:

                 Schedule 40 PVC pipe, 6 inch, slotted                         $25/ft

                 Schedule 40 PVC pipe, 6 inch                                 20/ft

                 PVC fittings                                                100/each

                 Blower  with motor (varies with capacity)                     300-3,000

                 Orifice plate and manometer                                   500

                 Carbon  adsorption canister                                     800
5/93                                        28

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VOLATILIZATION

              Installation costs:

                Well installation                                             60/ft

                Pipe fitting                                                  20/ft

                Concrete base for blower and carbon                         300-500

                Electrical                                                  5-10/ft

              Operation and maintenance costs:

                Regenerate/replace carbon                                  400/each

                Blower/pump operation
                    Calculate using the following formula:
                    $/year  =  fan  brake hp x  0.746 kw/hp x  8,760
                    hrs/yr x $/kw-hr

                Maintenance                                          4% installed cost
5/93                                       29

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Section 7

-------
                           INORGANIC TREATMENT
STUDENT PERFORMANCE OBJECTIVES:



At the conclusion of this section, participants will be able to:



       •      List three types of inorganic wastes

       •      List at least two waste characteristics that affect inorganic treatment

       •      Briefly describe the following types of inorganic treatment technologies:

                   Neutralization
                   Precipitation
                   Cyanide destruction
                   Oxidation and reduction
                   Ion-resin exchange.
5/93

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                                                    NOTES
            HAZARDOUS
        INORGANIC WASTE
             • Corrosives

             • Metals

             • Cyanides
           CORROSIVES
     •  Characteristics
         D002 characteristic waste
         pH
         Steel corrosion
         K062 listed waste for spent
          pickle liquors
              METALS
           HSWAOF1984
     • Landfill ban priority metals
         Ni, Tl, Cr(VI)
         "Subtitle C" - Sec. 3001 & 3004
         D002 • characteristic waste

     • RCRA wastes
         F006 - electroplating operations
         K002 to K008 - inorganic pigments
         K061 & K069 - emission control dust
         D004 to D011-TCLP metals
5/93
Inorganic Treatment
         page 1

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        NOTES
                                            CYANIDES
                                      F007toF009
                                         Electroplating solutions

                                      F010toF012
                                         Metal heat-treating solutions

                                      K011toK013
                                         Acrylonitrile production
                                 TYPICAL INORGANIC WASTES

                                    • Hydrochloric acid etching solution
                                        pH1.5

                                    • Copper plating waste
                                        25,000 mg/L Cu* *
                                        pH 6.0, 500 mg/L NaCN

                                    • Chromium rinse water
                                        pH 7.0,15,000 mg/L Cr(VI)
                                    WASTE CHARACTERISTICS
                                     AFFECTING TREATABILITY
                                          • Physical form

                                          • Concentration

                                          • Solids content

                                          • Other contaminants
                                              Organics
                                              Metals
                                              Chelating agents
Inorganic Treatment
page 2
5/93

-------
                                                   /VOTES
     TREATMENT PROCESSES

         • Neutralization
         • Precipitation
         • Cyanide destruction
         • Oxidation & reduction
         • Ion exchange
         NEUTRALIZATION
     • Concentration
          Exothermic reactions
     • Solids & sludges
     • Corrosion-resistant equipment
     • Creating water, H+, OH"
    CHEMICAL PRECIPITATION

        • Solubility
        • Metal hydroxide sludges
        • Optimum pH
        • Treat effluent
5/55
                                                         Inorganic Treatment
                                                                  page 3

-------
        NOTES

CHELATE - (che
ion in which a m
bond from the or


e, "crab's claw") a compound or
3tal ion is held by more than one
iginal molecule.


Chemical
Precipltants
^S]~
Liquid
Feed 	 1
01
Precip
Tank

Flocculants/
Settling Aids
"O 4 — 1 Flocculation
£d^ Well — >
n \ r-r-
V \ ff
f" fc 1 "* k
/ lo--f
U3b
tator ^ ^
Flocculating
Paddles
fc*t c«,..-,
7^, 	 I"1"0"1
IL-. 	 Baffle
_k. Qliirlna
Flocculator-
Clarifier

CYANIDE DESTRUCTION BY
ALKALINE CHLORINATION
• pH sensitive
• Non-selective
Chlorinated organics
• Metal hydroxide sludges
• Treat effluent
Elevated pH
Chlorinated organics
Inorganic Treatment
page 4
5/93

-------
                                                       NOTES
     ALKALINE CHLORINATION
        CHEMICAL PROCESS


  1)   Cl, + NaCN —> CNCU NaCI
     chlorine  cyanide    cyanogen   sodium
                    chloride   chloride
  2) CNCI + 2NaOH —t NaCNO
    cyanogen  caustic
    chloride   soda
sodium
cyanate
                      water   sodium
                           chloride
        Sample Chemical Oxidation •
      Alkaline Chlorination (Destruction of Cyanide)
                                Carbon
                                Column
Heat
       Covered, Jacketed Reactors
1st Stage
                 ZM »t>J« Efficiency)
     CHEMICAL REDUCTION BY
      REDUCTION / OXIDATION

         • Reducer & oxidizer

         • Soluble metals non-toxic

         • Cr(VI), Pb, Hg

         • Metal hydroxide sludges

         • Treat effluent
5/93
                                                       Inorganic Treatment
                                                                page 5

-------
        NOTES
Sample Chemical Reduction
Acid Reducing Agent
F««d Feed Lima

H

•
-+G~ Tr~

so,
pH Control /•«, ..,
ChramWkste // Mlxer
Water Fast) r

_xwf r
r^T
1 f*,>' t. ^ri<
| or — ^ ur

Chrome Reduction Tank
Slurry Hopper
Ca
(OH),
^
i[^ /r
--NX— -»'v^'vofXk
%
Cr"+OH>Cr(OHf
^v
/
1 	 >j
Chrome Precipitation
^Effluent
ydroxlde
ludge
                                           ION EXCHANGE
                                   •  Removes low concentrations of soluble
                                     metals

                                   •  Recovers concentrated metal streams for
                                     recycling

                                   •  Removes cations (+) and anions (-)

                                   •  Types of resins
                                       Naturally occurring
                                       Synthetic
                                          ION EXCHANGE
                                         • Limitations
                                              PH
                                              Suspended solids
                                              Other organics
Inorganic Treatment
page 6
5/93

-------
                                                                           NOTES
                   Ion Exchange
             Acid
Waste Containing  Regenerant
Compound MX
            -li
 Removal
 Regeneration

 MR+2H '> H, R+M"
                Cation
               Exchanger
                            Caustic
                            Regenerant
u
                              Anion
                             Eichingtt
                                   Removal
                 RX+20H"
                                   Regeneration
                                       Deionized
                                       Effluent
                                    ^ Spent
                                      Regenerant
5/33
                                                                                    Inorganic Treatment
                                                                                                 page 7

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                            INORGANIC TREATMENT
CHEMICAL TREATMENT TECHNOLOGIES

       Chemical Redox Treatment

       Reduction-oxidation (redox) reactions involve the chemical transformation of reactants where
       the oxidation state of one is raised while the other is lowered. The process will destroy or
       reduce the toxicity of many toxic organics and heavy  metals. Specific solution pH, rapid
       agitation,  and chemical addition requirements  must be met to ensure a complete chemical
       reaction.  Oxidizing agents used  for  chemical  oxidation  include ozone, hypochlorite,
       hydrogen peroxide, chlorine, and potassium permanganate.  Reducing agents include ferrous
       sulfate, sodium sulfate, sulfur dioxide, iron (+12), aluminum,  zinc, and sodium borohydride.
       Oxidation-reduction potential (ORP) electrodes are used to monitor the reaction progress.
       Redox reactions  are applied to  a number of different contaminants; either oxidizing agents
       or reducing  agents are applied  to the waste under separate facilities.  FIGURE 1 shows a
       typical oxidation system.

              Waste Type Handled

              Reduction-oxidation has most commonly been  applied to aqueous wastes with low
              organic  concentrations  (<100 ppm)   and  heavy metals.  However, efforts have
              recently focused on applying it to slurries,  sludges,  and soils. Wastes amendable to
              oxidation include benzene,  phenols, most organics,  cyanide, arsenic, iron, and
              manganese.  Wastes amendable to reduction include chromium (VI), mercury, lead,
              silver, chlorinated organics, and unsaturated hydrocarbons.  Applying a water-reagent
              mixture to sludges and flushing system may improve performance.

              Restrictive Characteristics

              Contact between the reagents and the contaminants is crucial for efficient chemical
              reaction.  Therefore, special precautions need  to be  exercised when applying the
              reagents to solid (soil) materials.  Oxidizing agents are strong oxidizers and do not
              discriminate  between natural organics  and contaminants, so excess agents may be
              required. Narrow pH ranges need to be controlled for optimum reaction rates. A
              wide range of contaminants may complicate the process.  For example, if oxidation
              of organics is conducted in the presence of chromium (III),  the chromium will also
              be oxidized to the more toxic and mobile chromium (VI).  In-situ soil systems may
              be affected by decreased permeability of soils (due to hydroxide precipitation) or loss
              of adsorption capacity (due to oxidation/reduction of soil organics).

              Mobile System Considerations

             Equipment required for aqueous waste treatment  is  relatively  simple.  Enclosed
              cylindrical tanks with rapid mix  agitators are used as  the reaction vessel.  Controls

5/93                                        9

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INORGANIC TREATMENT
             may include pH,  ORP,  and meter pumps.   Storage tanks for  reagents and pH
             adjustment materials are also required.  Slurries and soils may require larger reaction
             vessels for longer detention times. In-situ methods would require subsurface injection
             of reagents/water.
                                                 Lime
                                                 SMry
                                                       Cr3+	Cr(OH)3
                   Mixing look
                                                                            lo Fdlrolioo/
                                                                            Seaimenloiion
                                                          Mixing lonk
                                      FIGURE 1
           CHEMICAL REDUCTION OF HEXAVALENT CHROMIUM (Cr6+)
             Minimal site preparation would be required for a mobile system and, in many cases,
             properly graded access roads would be sufficient. Precipitated sludges may result
             from this operation and would require dewatering and proper disposal. Minimal labor
             would be  required with automatic controls in  place for metering pH control and
             reagent addition.  Power requirements include pumping, agitation, and, if ozone is
             used, ozone generation. Water may be required for slurrying of solid materials.
5/93
10

-------
INORGANIC TREATMENT

              Environmental Impacts

              Sludges/residuals may need  further treatment or offsite disposal (i.e., dewatering
              solidification and/or landfilling).  The system is operated in a closed vessel, so no air
              pollution impacts would be expected.  The treatment of contaminated materials from
              the site will  reduce the potential of offsite migration.

              Costs

              Capital costs for an aqueous waste treatment system can run from $200,000 up to
              $2,000,000  for flow rates of 0.1 to  1.0 million gallons per day (MGD).  Annual
              operating and maintenance costs often approximate total capital costs; however, costs
              may  vary greatly depending  on volume treated, composition of waste and required
              treatment. Also, mobile systems may have high initial costs but the capital cost can
              be spread over several sites.  Potential rental of a mobile system could run from
              $2,000-$10,000/month.

              Commercial Applications

              Rexnord has incorporated chemical  oxidation (hypochlorite) into  its mobile van
              (groundwater cleanup response system) for pilot/full-scale cleanups.

              For more information contact:             Rexnord C.R.I.G.
                                                       5103 W.  Beloit Rd.
                                                       P.O.  Box 2022
                                                       Milwaukee, WI
                                                       414/643-2762

       Neutralization

       Neutralization is the interaction of an acid (pH < 5) or base (pH > 9) to adjust the pH of a
       solution or mixture  to between 5 and 9.   It is achieved by adding either an acid or base to
       a solution to obtain the  desired pH.   Neutralization can be used as a final waste treatment
       process or as a pretreatment process to  prepare a wastestream for further treatment.  The
       process of neutralization is widely used in commercial applications and has a wide range of
       applicability for waste treatment. It is a simple process involving mixing the neutralization
       agent with the waste, so it can be accomplished in almost  any setting (e.g., mobile).
       Sodium hydroxide, lime, or sulfuric acid are the most common components added to
       neutralize a waste.  The quantity and concentration will depend on the influent pH and the
       desired effluent pH.   The reaction products include water,  salts and  solids that  may
       precipitate out. FIGURE 2 presents a typical neutralization system.
5/93                                        11

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INORGANIC TREATMENT
                               |.H COK1ROILCR
                                      MtUlRAUIAUOH TANK

                                         2a
                                        H£UTRALirATIOK
                                          2b
                                      ptt CONTROLLER

                                        1
                          ALKALI rtto
           I
          6
                                              K* « OH' • H;0 -f SALT
                                                                TRIM CO
                                                                CFFLUCIIT
                                                                (TO ClARIf IW
                                                                IF IICCCSSART)
                                          2c
                                      FIGURE 2
                                  NEUTRALIZATION
5/93
12

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INORGANIC TREATMENT

              Waste Type Handled
              Neutralization is  most often performed on liquids.  It can also  be performed on
              sludges, slurries,  and gases; organic and inorganic wastestreams; and spent acid and
              alkali wastes with pH values below 4.0 and above 9.0.  Contaminants can include
              organic acids,  metal alkali  solutions,  and other organic and inorganic  wastes.
              Concentration of the waste will  determine the amount  of  neutralizing  reagent
              required.  Buffer capacity of the waste will also affect the dosage requirements for
              neutralization.

              Restrictive Characteristics

              Rapid  mixing of contaminated materials  containing cyanide,  chlorides, etc.  may
              liberate toxic gases.  High temperatures may result from the release of solution heat.
              This may cause potential hazards. Solids and sludges may require  excessive dosages
              of chemicals  because of limited mixing effectiveness and buffer capacity.

              Mobile System Considerations

              Neutralization requires simple off-the-shelf equipment that can easily be set up in a
              mobile system. The equipment for neutralization usually consists of a chemical feed
              system and a rapid mixing operation, followed by another physical/chemical process
              for by-product removal  (if necessary).  The system is flexible  and can be modified
              into many different configurations depending on the specific waste material.

              Minimal  site preparation may be required (e.g., a properly graded access road).
              Additional equipment may be needed for sludge disposal. However, additives should
              be selected to reduce the quantity and toxicity of the generated sludge.  Electricity
              would  be needed for pumping and mixing the wastes.   Preparation of neutralizing
              agents may require a water source (i.e.,  lime  slaking).  The  resulting neutralized
              wastestream may require additional processing.

              Environmental Impacts

              Toxic  gases  (e.g., ammonia, hydrogen sulfide, and hydrogen cyanide),  may be
              released  if  wastes  are  not mixed  slowly  and  are  not  properly  pretreated.
              Neutralization may precipitate out heavy  metals from solution and produce significant
              quantities of sludge  depending on the waste characteristics.  Soil matrix and  high
              solids may produce chemical complexes that may not be effectively removed during
              further processing.   If both  acid  and  alkali wastes are present  on the  site,
              neutralization can  be  accomplished  without  the  addition of  offsite  materials.
              Neutralization is a simple treatment process that can reduce the hazardous nature of
              corrosive wastes.
5/93                                         13

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INORGANIC TREATMENT

              Costs

              The capital and operating costs for neutralization depends on the specific process
              selected.  Capital  costs for a permanent system can range from $400,000 for a 0.1
              MGD system up to $15,000,000 for a 10 MGD system (including sludge disposal).

              Operating costs can also vary widely because the major  system components are
              chemicals and labor.   Neutralization has been incorporated into a complete mobile
              water treatment system (softening, filtering, activated carbon, etc.) where costs for
              rental of the  complete package may be as high as  $25,000/month for a 600 gpm
              system.

              Commercial  Applications

              Ecolochem,  Inc.  has  incorporated neutralization  (pH adjustment)  into its water
              treatment plant on wheels for cleanups of up to 600 gpm.

              For more information  contact:              Ecolochem, Inc.
                                                       4545 Patent Rd.
                                                       P.O. Box 12775
                                                       Norfolk, VA  23502
                                                       800/446-8004

       Precipitation

       Chemical precipitation is a physiochemical process in which a dissolved  contaminant  is
       transformed into an insoluble solid, facilitating its subsequent removal from the liquid phase
       by sedimentation or filtration.  The process usually involves  (1) adjustment of pH to shift the
       chemical equilibrium to a point that no longer favors solubility, (2) addition of the chemical
       precipitant, and (3) flocculation in which precipitate particles  agglomerate into larger particles
       (FIGURE 3).
5/93                                      14

-------
VO
u>
                                                           2:
                                                           i
                                                           o
                 PrecipitoTion
    Flocculatlon
Clarification
r>
H
       Precipitating Chemicols
     Flocculotlon end
     Sedimentotion Aides
     Inlef

    Waste water
                 Rapid Mix Tank
                                             o    o
                                             C
                                            O-H
                                                     C
      a era
Flocculotion Chamber
                                                                          Clorlffer

                                                                            4-
                                                                           Sludge
                                            Outlet
                                            Stream
                                                           H
                                                           s
                                                           w
                                                FIGURE 3

                         CHEMICAL PRECIPITATION AND ASSOCIATED PROCESS STEPS

-------
INORGANIC TREATMENT

       This technology is well  suited for detoxifying aqueous  solutions  containing toxic  heavy
       metals.  A precipitating reagent is added to the solution to react with the heavy metals in
       solution to form solid products which can then be removed by sedimentation or filtration.
       Substances extensively employed to promote precipitation reactions include  calcium oxide,
       sodium  sulfide, ferrous sulfide,  sodium  hydroxide,  aluminum  salts,  carbonates,  and
       phosphates. Flocculating agents may be added to aggregate small particles into larger ones
       that are then more easily removed.

              Waste Type Handled

              Precipitation has  been  extensively used to treat heavy-metal-bearing wastewaters.
              The heavy  metals include zinc, arsenic, cadmium, chromium, copper, lead,  iron,
              nickel, manganese, and mercury.  Organics are not removed by this process.  There
              is no concentration limit for precipitation; however, highly viscous wastes will inhibit
              settling.  Solubility of metal salts  as a function of pH will determine residual metal
              in  the wastewater.

              Restrictive Characteristics

              Organic  compounds  may interfere with  precipitation by forming  organometallic
              complexes.  Cyanide and other ions may also  compile with metals, reducing the
              precipitation  potential   or  requiring  much  higher  stoichiometric  quantities  of
              chemicals.

              Each metal salt has a different optimum pH for maximum removal and precipitation.
              A  mixed solution may require a trade-off on specific metals removals.

              Mobile System Configurations

              Equipment  requirements include a reaction  tank with rapid mixing, chemical storage
              tanks, chemical feed pumps and pH controls that can be easily contained in a mobile
              system. Additional equipment for the separation of liquid and solids will be required.
              This may include clarification, filtration, or centrifugation.  High-rate clarifiers are
              ideal for mobile systems because of their compactness.

              Minimal  site preparation will be required for a mobile precipitation  system (e.g., a
              properly  graded access  road). Electric requirements may include pumping, mixing,
              and sludge dewatering.   The treated water from this process may  require further
              treatment for organic removal. The sludge generated from this process  will contain
              heavy metals.

              Environmental Impacts

              Proper mixing of the chemicals with the wastes and/or waste pretreatment  should
              minimize the potential releases of  toxic  gases.   The generated sludge  from this
              process must be leach tested for EP toxicity, and appropriate treatment and disposal


5/93                                        16

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INORGANIC TREATMENT
              of the  sludge  must be considered.   This  system can  be incorporated  into  a
              groundwater recovery system or as a wastewater regeneration step in a soil flushing
              system.

              Costs

              The capital costs and operating costs for precipitation depend on the specific process
              selected.  Capital  costs can range from $300,000 for a 0.1 MGD  system up to
              $2,000,000 for a 1.0 MGD that includes solids separation but not solids disposal.
              Operating costs can vary widely because the  major  components are chemicals and
              labor.   Mobile wastewater treatment systems have been developed which  include
              neutralization, precipitation, sedimentation, filtration, and carbon adsorption. Costs
              for rental of  this  complete package  can range  from  $5,000  to $25,000/month
              depending on flow rate.
       Precipitation/Flocculation

              General Description

              Precipitation  is a physiochemical process whereby some or all of a substance in
              solution is transformed into a solid phase. It is based on alteration of the chemical
              equilibrium relationships affecting the solubility of inorganic species.  Removal of
              metals as  hydroxides  or sulfides is the most common precipitation application in
              wastewater in a rapid mixing tank along with flocculating agents (described below).
              The  wastewater flows to a flocculation  chamber  in which adequate mixing  and
              retention time is provided for agglomeration of precipitate particles.  Agglomerated
              particles are separated from the liquid phase by  settling in a sedimentation chamber
              and/or by other physical processes such as filtration. FIGURE 4 illustrates a typical
              configuration for precipitation flocculation and sedimentation.
5/93                                        17

-------
INORGANIC TREATMENT
                                   rioccucATiox
   FMCIMTATlNC CHIMICALI—,
                                                             SCDIMINTATION
  IHLTT II
1
A'
^
NO M
1 TANK


C
D^
r v
r 

CMIMICAU THt rnicirrTATiON KIACTIOH COMMINCit TO FORM VIRY (MA.U TAk. iicut CAUID rMcirrTATioM NUCUI. T*(l riOCCULATIMC AC1NTX ALLOW THCII f ARTICLLt TO ACCLOMrKATt r-AHTicitl. AIOIO IT TMI PIOCCULATIHC ACIHTS. COLUDl. ACCIOMIRATT. AND CHOW INTO LA*CC« UTTXlAtU rARTICLIl ouun nouio JEIDIMINIATION KAIIN TMt WTTUAHJ rAimCUf • r TMI noccuiATiON rrrr ARI «muD. COU.ICTTO AND rtniOOICAULT 01 MO VI 0 HGURE4 REPRESENTATIVE CONFIGURATION EMPLOYING PRECIPITATION, FLOCCULATION, AND SEDIMENTATION Source: DeRenzo, 1978 Although precipitation of metals is governed by the solubility product of ionic species, in actual practice, effluent concentrations equal to the solubility product are rarely achieved. Usually, the amount of lime that is added is about three times the stoichiometric amount that would be added to reduce solubility due to the common ion effect. FIGURE 5 gives solubilities of several metal hydroxides and sulfides at various pH levels. 5/93 18


-------
INORGANIC TREATMENT
   o
   E
   2
   •o
   c
   o
   O
       10'
        •6
        n-8
      ia
        10
      10-12
         0   1
                                 CuS
                                             1   '
                                         9   10  11  12   13
                              FIGURE 5
            SOLUBILITY OF METAL HYDROXIDES AND SULFIDES
5/93
19

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INORGANIC TREATMENT
              The  metal  sulfides  have  significantly  lower  solubility  than their  hydroxide
              counterparts over a broad pH range. Many metal hydroxides, on the other hand, are
              stable only over a narrow pH range; metals reach a minimum solubility at a specific
              pH,  but further  addition  of  lime causes  the metal to  become  soluble again.
              Therefore, dosages  of lime  need to  be accurately  controlled.    This may  be
              particularly challenging when working with aqueous wastes from waste disposal sites
              where  wide variations in flow  rates and quantities of metals  are  present.  The
              stabilities of metal carbonates are also quite dependent on pH.

              Flocculation is used to describe the process by which small, unsettleable particles
              suspended in a liquid medium  are made to agglomerate into larger,  more settleable
              particles.  The mechanisms by which  flocculation occurs involve surface chemistry
              and particle charge phenomena.  In simple terms, these various phenomena can be
              grouped into two  sequential mechanisms (Kiang and Metry, 1982):

              •      Chemically induced destabilization of the requisite surface-related forces, thus
                     allowing particles to stick together when they touch and

              •      Chemical  bridging and physical  enmeshment between the now nonrepelling
                     particles,  allowing for the formation of large particles.

              Flocculation involves three basic steps:

              •      Addition of flocculating agent to the wastestream

              •      Rapid mixing to disperse the flocculating agent

              •      Slow and  gently mixing to allow for contact between small particles.

              Typically, chemicals used to cause flocculation include alum, lime, various iron salts
              (e.g.,  ferric chloride and ferrous sulfate), and organic  flocculating agents, often
              referred to as "polyelectrolytes."  These materials generally consist of long-chain,
              water-soluble polymers such as polyacrylamides.  They are used either in conjunction
              with the inorganic flocculants, such as alum, or as the primary flocculating agent.

              A polyelectrolyte may be termed cationic, anionic, or ampholytic depending on the
              type of ionizable  groups, or nonionic  if it contains no ionizable groups.   The range
              of physical/chemical characteristics (e.g., density, viscosity, toxicity, and molecular
              weight) of the several thousand available polymers is extremely broad.

              The inorganic flocculants, such as alum,  lime, or iron salts, make use of precipitation
              reactions.  Alum (hydrated aluminum sulfate) is typically added to  aqueous waste-
              streams as a solution.  Upon mixing, the slightly higher pH of the water  causes the
              alum to hydrolyze and form fluffy, gelatinous precipitates  of aluminum hydroxide.
5/93                                         20

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INORGANIC TREATMENT
              These precipitates, partially due to their large surface area, enmesh small particles
              and thereby create larger particles.  Lime and iron salts also have a tendency to form
              large fluffy precipitates of "floe" particles.

              Many precipitation reactions, such as the precipitation of metals from solution by the
              addition of sulfide ions, do not readily form  floe particles, but rather precipitate as
              very fine and relatively stable colloidal particles.  In such cases, flocculating  agents
              such as alum and/or polyelectrolytes must be added to cause flocculation of the metal
              sulfide precipitates (Canter and Knox, 1985).

              Once suspended particles have been flocculated into larger particles, they usually can
              be removed from the liquid by sedimentation,  provided a sufficient density difference
              exists between the suspended matter and the liquid.

              Applications/Limitations

              Precipitation is  applicable to the removal of most metals (e.g., zinc, cadmium,
              chromium, copper, fluoride, lead, manganese, and mercury) from wastewater.  Also,
              certain  anionic species (e.g.,  phosphate,  sulfate, and fluoride can be removed by
              precipitation.

              Precipitation is  useful for  most  aqueous hazardous wastestreams.   However,
              limitations  may be imposed by certain physical or chemical characteristics.  In some
              cases, organic compounds may form  organometallic complexes with metals,  which
              could  inhibit precipitation.   Cyanide and other ions in the wastewater  may  also
              complex with metals, making treatment  by precipitation less efficient.

              Flocculation is  applicable to any  aqueous wastestream  where particles must be
              agglomerated into larger, more settleable particles prior to sedimentation or other
              types of treatment.  There is no concentration limit for precipitation or flocculation.
              Highly viscous wastestreams  will inhibit settling of solids.

              In addition to being used to treat wastestreams, precipitation can also be used as an
              in-situ process to treat aqueous wastes in surface  impoundments.   In an  in-situ
              application, lime  and flocculants are added directly to  the  lagoon,  and mixing,
              flocculation, and sedimentation are allowed  to occur within the  lagoon.  In some
              cases, wind and pumping action can provide the energy for mixing.

              Design Considerations

              Selection of the  most suitable precipitate or flocculent and their optimum dosages is
              determined through laboratory jar test studies.   In  addition to determining the
              appropriate chemicals and optimum chemical dosages, other  important parameters
              which need to be determined as part of the overall design include (Canter and  Knox,
              1985):
5/93                                         21

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INORGANIC TREATMENT

              •      Most suitable chemical addition system

              •      Optimum pH requirements

              •      Rapid mix requirements

              •      Sludge production

              •      Sludge flocculation, settling, and dewatering characteristics.

              Technology Selection/Evaluation

              Precipitation and  flocculation  are well-established technologies and the operating
              parameters are well defined. The processes require only chemical pumps, metering
              devices, and mixing and settling tanks. The equipment is readily available and easy
              to operate.  Precipitation and flocculation can be easily integrated into more complex
              treatment systems.

              The performance and reliability of precipitation  and flocculation depend greatly on
              the variability of the composition of the waste being treated. Chemical addition must
              be determined using laboratory tests. In addition, chemical addition must be adjusted
              and compositional  changes  of the waste  must be treated or poor performance will
              result.

              Precipitation is nonselective in that compounds other than those  targeted may be
              removed.  Both precipitation and flocculation are nondestructive and generate a large
              volume of sludge which must be disposed of.

              Precipitation and  flocculation pose minimal  safety  and  health  hazards  to field
              workers. The entire system is operated at near ambient conditions, which eliminates
              the  danger of high  pressure/high temperature  operation  encountered  with  other
              systems.  Whereas the  chemicals employed are often  skin  irritants, they can  easily
              be handled in a safe manner.

              Costs

              TABLE  1 shows a breakdown  of costs for  the  40 gpm sulfex heavy  metal
              precipitation system illustrated in FIGURE 6.

              The precipitator is sized to  operate at a surface rate of 1.6 gpm/ft2 and the filter at
              a surface rate of 3.2 gpm/ft2. Chemical costs for the Sulfex process and a hydroxide
              precipitation process are shown in TABLE 2.  These costs were estimated  for
              treatment of an influent containing 4 mg/1 Cu, Cd, Cr3"1", Ni, and Zri at pH 6.0.
5/93                                        22

-------
INORGANIC TREATMENT
                                     TABLE 1
                       1985 CAPITAL COSTS* FOR SULFEX
                     HEAVY METAL PRECIPITATION SYSTEM
 Equipment
                                Price
  1.     Precipitator with clear well, centrifuge for dewatering, chemical
        feeds and agitators, and engineering drawings
  2.     Filter with transfer pump and engineering drawings
  3.     Neutralization system including agitators, chemical feeds, pH
        controls, sump pump, and engineering drawings
                                            TOTAL SELLING PRICE
        Installation Cost (estimated by outside contractor)
                                                            TOTAL
                                $68,768
                                  7,623
                                 86,126
                               $162,517
                                 66,657
                               $229,174
  *  Costs were updated to 1985 dollars using the 1983 and 1985 ENR Construction Cost Index.
Source:  Metal Finisher's Foundation, 1977
5/93
23

-------
WASTE
         CITY WAtER FOR FILTER  BACKWASH
              PUMP WITH STROKE
                ADJUSTMENT
         r
            LIME
0
         4
                       SHUT-OFF
                                                                  Is
                                                         POLYMER
                                                         IRON SULFIOE
                                 \
                              PRECIPITATOR
                                     FILTER BACKWASH
                                        EFFLUENT
CLEAR
WELL
                                                             €T
                                           BLOWDOWH

                                             CENTRIFUGE
                                                  SLUDGE
                                                                         f l
                                                                       4fl *

                                                                      FILTER
                                                                           TO SEWER
                                       Z
                                       o
                                       I
                                       0
                                       I
                                       FIGURE 6
       40 GPM SULFEX PLANT FOR COMBINED REMOVAL OF Cr<+, An, Cu, Cd, Ni, and Fe

-------
INORGANIC TREATMENT
TABLE 2
COMPARISON OF CHEMICAL COSTS* OF
HYDROXIDE AND SULFIDE PRECIPITATION PROCESSES

Eff.
Qual.
(mg/1)
Chemical
Dosage
;ib/l,000 gal.
Cost
c/1,000 gal.
(1) Hvdroxide Process

Cu
Cd
Cr
Ni
Zn
PH7.5
0.1
3.8
< 0.5
2.3
1.3


U
Cu
Cd
Cr
Ni
Zn
Eff.
pH 10
< 0.1
< 0.1
< 0.1
< 0.1
< 0.1

Ca(OH)2
Polymer
H2S04
PH7.5
0.33
0.33
(2) Sulfex Process
Qual.
(mg/1)
PH8.5
0.01
0.1
< 0.05
0.05
0.01
Chemical

71 % NaHS
FeSo47H20
Polymer
Ca(OH)2
pH 10
0.92
0.03
0.61
c/lb pH7.5 pH 10
3.16 1.05 2.99
105.4 3.16 4.22
8.8 - 5.45
Total 4.21 12.66

Dosage
lb/1,000 gal.
pH 8.5
0.
0.
0.
1.
* Costs were updated to 1985 dollars using the 1977 and
09
77
03
13
Cost
C/l,OOOgal.
c/lb gH
19.77 1.76
3.95 2.99
105.4 3.16
3.16 3.51
Total 11.42
1985 ENR Construction Cost Index.
Source: Metal Finisher's Foundation, 1977
             FIGURE 7 shows capital and operating costs for a flocculation system including
             chemical storage, chemical feeding, and rapid mix.  A polymer dosage of 1 mg/1 at
             0.25-percent solution is assumed. Construction costs also include piping and building
             to house the feeding equipment and bag storage.
5/93
25

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INORGANIC TREATMENT

                                                                         CO9 1 j
                                                         TT
                                                                        I ; i I? '    .... IT'
                                                                        ^Ezziirnff
                                                          iTTTi.
                                                                                 ' I '
                                                        I  I I
                                                                                   II
                                                               1C
                                                              W«u»w«l«-c
                                                                                     100
                                       FIGURE?
                 FLOCCULATION OPERATING AND CAPITAL COSTS
       Cyanide

       Cyanide, as sodium cyanide (NaCN) or hydrocyanic acid (HCN), is a widely used industrial
       material.  Cyanide waste streams result from  ore extracting and  mining,  photographic
       processing, coke furnaces,  synthetic  fiber  manufacturing, case hardening of steel, and
       industrial gas scrubbing.  Cyanide is produced as a side reactant in the catalytic cracking of
       petroleum feed and in coking of distillation residues. A major source of waste cyanide is the
       electroplating industry.  Electroplaters use concentrated cyanide baths to hold metal!.: ions
       such as cadmium, copper, and zinc in solution. Dragout of the plating solution, containing
       cyanide  ions and metal-cyanide complexes, contaminates rinsewater.

       Several methods of treating cyanide wastes are in current use.  The process most frequently
       employed is cyanide destruction by chlorination.  Cyanide may be either partially oxidized
       to  cyanate (CNO'),  or completely oxidized  to  carbon dioxide (C02) and nitrogen (Nj).
       Another cyanide destruction process, electrolytic decomposition, is applicable where waste
       cyanide concentrations are very high, although new technology shows promise of application
       to more dilute solutions. Ozone oxidation of cyanide has been employed with some success,
       and is claimed  to be equivalent to destruction by chlorination, on the basis of effectiveness
5/93
26

-------
INORGANIC TREATMENT

       and costs.  Evaporative recovery has also  been successfully employed to  treat cyanide
       wastewaters. Other cyanide treatment processes, which are still primarily in the development
       state, include reverse osmosis, ion exchange, and catalytic and thermal oxidation.

       Destruction of cyanide by chlorination may be accomplished by  direct addition of sodium
       hypochlorite or by  addition of chlorine gas plus sodium hydroxide to the waste. Sodium
       hydroxide reacts with the chlorine to form sodium hypochlorite. Selection between the two
       methods is on the basis of economics and safety. Chlorine gas treatment is about half as
       expensive as direct hypochlorite  addition, but handling is more dangerous and equipment
       costs are higher.  The hypochlorite  added or produced  oxidizes  cyanide to cyanate.
       Oxidation of cyanide to cyanate is accomplished most completely and rapidly under alkaline
       conditions at pH  10 or higher, and this cyanide treatment process is often termed alkaline
       chlorination. An oxidation period of 30 min-2 hr is usually allowed. To avoid solid cyanide
       precipitates which may resist chlorination, the  wastewater should be continuously agitated
       during treatment.   Close  process control, utilizing  pH  and ORP  sensors and automated
       chemical  feed techniques,  is required to assure maximum reaction rate, minimum detention
       time, and complete reaction (FIGURE 8).
1 Caustic Chlor
**** oK Controller *>*
1 p 	 1 1
\ 0

uyanioc j -*• 	 — ii, , i / J
Liquid u J ' •/ — Ttg
Feed F^/ f
_^_ ' o4 T
ine

[L- Mixer
Jf=-
-> 7',.lL ^
tn
cfe Un
Covered, Jacketed Reactors
1st Stage 2nd Stage
(Increased
Destruction
Efficiency)

Column

Effluent


SOX
-* Reaction
used Chlorine
pture/Reactlon
                                       FIGURE 8
                          SAMPLE CHEMICAL OXIDATION -
             ALKALINE CHLORINATION (DESTRUCTION OF CYANIDE)
5/93
27

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INORGANIC TREATMENT
       The resulting cyanate is much less toxic than cyanide, but can  if necessary  be further
       oxidized to carbon dioxide and nitrogen.   Oxidation of cyanate to carbon dioxide and
       nitrogen can be accomplished by additional chlorination, or to carbon dioxide and ammonia
       by acid hydrolysis. Acid hydrolysis must take place at pH 2-3, however, usually  obtained
       by addition of sulfuric acid.  Thus,  acid hydrolysis requires  addition of acid to achieve the
       required pH, and subsequent neutralization of the acidic wastewater before the effluent can
       be discharged. These stages of pH adjustment increase the treatment costs as well as the
       total dissolved solids of the wastewater. Cyanate will be destroyed by acid hydrolysis within
       about 5 minutes of contact time.

       Complete cyanide oxidation to CO2 and N2 can be accomplished solely through chlorination,
       if close pH control is maintained.   After initial oxidation to cyanate, further oxidation to
       yield C02 and N2 will occur slowly over several hours at pH 10+.  However, if the waste
       pH is reduced to  8-8.5, cyanate oxidation by chlorine can be completed  within 1 hour.  At
       the lower pH, sufficient chlorine must be added to ensure an excess beyond that needed to
       oxidize the cyanide to cyanate, in order to avoid liberation of highly toxic cyanogen chloride
       gas.  Cyanogen chloride is the intermediate product of the oxidation of cyanide to cyanate.
       It breaks down very rapidly at pH  10+ and temperatures above 20°C.  However,  at lower
       pH or temperature, excess chlorine is needed to  speed the breakdown.  Complete cyanide
       treatment at high pH, although requiring long reaction times, may be advantageous if the
       treated wastewater can be utilized to neutralize acidic waste  streams in the plant.

       This process normally proceeds in two steps although it can proceed further in the  presence
       of excess chlorine, the cyanate reacting with more chlorine to form bicarbonate and nitrogen.
      C12
    Chlorine
2)   CNC1
  +NaCN
  Cyanide
  +2NaOH
Caustic Soda
              Reaction of Cyanate with Chlorine

              2NaCNO = 3C12 + 4H2O + 6NaOH

              Overall Reaction
                                                          CNC1
                                                         Cyanogen
                                                         Chloride

                                                         NaCNO
                                                         Sodium
                                                         Cyanate
                                                                          +NaCl
                                                                          Sodium
                                                                          Chloride

                                                                       +HO + NaCl
                                                       2NaHCO3 + N2 + 6NaCl + 6H20
              NaCN + 2.5C12 + SNaOH
                                              NaHCO3 + O.5N  + SNaCl + 2H0
              Notice that the first step, which is almost instantaneous results in the formation of
              cyanogen chloride which is a gas and is very toxic.  This occurs regardless of pH.
              It is therefore important to ensure that the reaction illustrated by the second equation
              takes place to prevent the evolution of cyanogen chloride and this is done by ensuring
              that the pH is at least as high as 8.5 and preferably as high as 10.5 to accelerate the
              reaction.  Also that 2.5 times as much chlorine is used if the cyanate is taken through
              to the nitrogen stage.
5/93
                                           28

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INORGANIC TREATMENT
              However, it is unlikely that it would be necessary to take the reaction as far as this
              since as mentioned earlier, the toxicity of sodium cyanate is so low that it is normally
              acceptable to environmental authorities to discharge tailings water containing it into
              water courses, etc.   This is fortunate since as already mentioned, the amount of
              chlorine required to take the reaction through to nitrogen and bicarbonate is 2.5 times
              the amount necessary to take the reaction through to the cyanate only.

              In addition to the reaction with cyanide, chlorine will react with thio salts  such as
              thiocyanate and thiosulfate.  Therefore more than the theoretical 2.73 parts of C12 per
              part of cyanide is normally  required.

              The potential hazards associated with chlorination are:

              •      The hazard due to chlorine itself which, however, is not a significant hazard
                     if the equipment is properly designed and the operators are properly trained,
                     and,

              •      The possibility of the formation of cyanogen chloride if there is not sufficient
                     alkalinity present to keep the pH over 8.5.

              Costs

              Capitol cost will  vary with system design.  TABLE 3 gives estimated cost for some
              of the types of systems that are available.  FIGURE 9 shows two different types of
              cyanide destruction.    These estimates do not include operating and maintenance
              costs.

              Commercial Applications

              Rexnord, Ecolochem and Dravo all have complete wastewater treatment system on
              wheels for cleanup.

              For further information contact:

              Rexnord C.R.I.G.       Ecolochem Inc.          Dravo Corp.
              5103 W.  Beloit Rd.       4545 Patent Rd.          412/777-5235
              P.O. Box 2022          P.O. Box 12775
              Milwaukee,  WI          Norfolk, VA 23502
              414/643-2762            800/446-8004
5/93                                        29

-------
INORGANIC TREATMENT
                                 TABLE 3
           ESTIMATED COST FOR CYANIDE DESTRUCTION PLANTS
 Package Plant System
       15 gpm @ 450 ppm
       30 gpm @ 350 ppm
            $30,000 - $35,000
 Batch Plant
       2 gpm
       30 gpm
                $12,000
                $30,000
 2 Stage Units
       15 gpm - 40 gpm
       25 % additional for installation
            $35,000 - $45,000
5/93
30

-------
INORGANIC TREATMENT
                                   a.
         CNO EFFLUENT
         WASTE CN
           RINSE
T '-'
n
1
_l
—
r*
	 i
-^
— i
\ i
.
J
^
i
T T
J
RECEIVING SUMP



                                   b.
       CHLORINATOR
                  CL,
                  WASTE CN
                    RINSE
                           e
                           .-t-,
                           -4-'
           RECEIVING
             SUMP
      NaOH
     CNO
                                                        NaOCL
                      CO»
                     EFFLUENT
                                 FIGURE 9
     COMMERCIAL PACKAGE PLANTS FOR CYANIDE WASTE TREATMENT.
                a.  Retention-tank package cyanide treatment plant.
              b.  Reaction-tower-type package cyanide treatment plant.
5/93
31

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INORGANIC TREATMENT

       Ion Exchange and Sorptive Resins

              General Description

              Ion exchange is a process whereby the toxic ions are removed from the aqueous
              phase by being exchanged with relatively harmless ions held by the ion-exchange
              material.    Modern ion-exchange  resins are primarily synthetic organic materials
              containing  ionic functional groups to which exchangeable ions are attached.  These
              synthetic resins are structurally stable (i.e., can tolerate a range of temperature and
              pH conditions),  exhibit a high exchange capacity, and  can be tailored  to show
              selectivity toward specific ions.  Exchangers with negatively charged sites are cation
              exchangers because they take up positively charged ions.   Anion exchangers have
              positively charged sites and,  consequently, take up negative ions.  The exchange
              reaction is reversible and concentration dependent, and  it is possible to regenerate the
              exchange resins for reuse.  Sorptive (macroporous)  resins are also available for
              removal of organics, and the removal mechanism is one of sorption rather than ion
              exchange (Ghassemi, Yu, and Quinlivan, 1981).

              Applications/Limitations

              Ion exchange is used to remove a broad range of Sonic species from water, including:

              •      All metallic elements when  present as soluble  species, either  anionic or
                     cationic

              •      Inorganic  anions such as halides, sulfates, nitrates, and cyanides

              •      Organic acids  such as carboxylics, sulfonics,  and  some phenols, at a pH
                     sufficiently alkaline to produce the ions

              •      Organic amines when the solution acidity is  sufficiently acid to form the
                     corresponding acid salt (De Renzo, 1978).

              Sorptive resins can remove a wide range of polar and  nonpolar organics.

              A  practical upper concentration limit for ion exchange is about 2,500-4,000 mg/1.
              A  higher concentration results in rapid exhaustion of the resin and inordinately high
              regeneration costs.  Suspended solids in the feed stream should be less than SO mg/1
              to  prevent plugging the resins, and wastestreams must be free of oxidants (De Renzo,
              1978).
5/93                                        32

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INORGANIC TREATMENT

              Design Considerations
              Specific ion-exchange and sorptive resins systems must be designed on a case-by-case
              basis. It is useful to note that although there are three major operating models (fixed
              bed concurrent, fixed bed counter current, and continuous countercurrent), fixed bed
              countercurrent systems are most widely used. FIGURE 10 illustrates the fixed bed
              countercurrent   and continuous   countercurrent   systems.     The   continuous
              countercurrent system is suitable for high flows. Complete removal of cations and
              anions ("demineralization") can be  accomplished by using the hydrogen form of a
              cation exchange resin and the hydroxide form of an anion-exchange resin.  For
              removal of organics as well as inorganics, a combination adsorptive/demineralization
              system,  can be used.  In this  system, lead  beds would carry  sorptive resins that
              would act  as organic scavengers, and the end beds would contain anion- and cation-
              exchange resins.  By carrying different types of adsorptive resins (e.g., polar and
              nonpolar), a broad spectrum of organics could be removed (Ghassemi,  Yu, and
              Quinlivan, 1981).
5/93                                        33

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INORGANIC TREATMENT
       Types
                             Countercurrent Fixed Bed

                            Service          Regeneration
                                                 Continuous Countercurrent
  Description of
  Process
  Indications for use
  Advantages
  Disadvantages
Regeneration flows opposite in direction to
influent.  Backwash (in regeneration) does
not occur on every cycle to preserve resin
stage heights.  Resin bed is locked in place
during regeneration.

Handles high loads at moderate thruput or
low loads at high thruput (GPM x IDS or
GPM  x PPM removal = 40,000 or more).
Where effluent quality must be relatively
constant, regeneration cost is relatively
critical, disposal of single batch waste
volume no problem.  .
Moderate capital cost. Can be operated with
periodic attention.  Moderate regeneration
cost. Lesser volume of waste due to less
frequent backwash. Consistent effluent
quality.
Increased controls and instrumentation,
higher cost.  Requires mechanism to lock
resin bed.  Large single batches of waste
disposal.  Moderate water consumption thru
dilution and waste.  Requires substantial
floor space.
Multistage Countercurrent movement of
resin in closed loop providing simultaneous
treatment, regeneration, backwash, and
rinse.  Operation is only interrupted for
momentary resin pulse.

Highloads with high thruputs (GPM x IDS
or GPM x PPM removal = 40,000 or
more). Where constant effluent quality is
essential, regeneration costs critical, total
waste volume requires small, concentrated
stream to be controllable.  Where loss of
product thru dilution and waste must be
minimized. Where available floor space is
limited.

Lowest regeneration cost.  Lowest resin
inventory. Consistent effluent quality.
Highest thruput to floor space. Large
capacity units factory preassembled.
Concentrated low-volume wastestream.
Can handle strong chemical solutions and
slurry. Fully automatic operation.

Requires automatic controls and
instrumentation, higher capital cost. More
headroom required.
                                             FIGURE 10
                  PERTINENT FEATURES OF ION EXCHANGE SYSTEMS
5/93
                              34

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INORGANIC TREATMENT

              Technology Selection/Evaluation

              Ion exchange  is a well-established  technology  for removal of heavy metals and
              hazardous anions from dilute solutions.  Ion exchange can be expected to perform
              well for these applications when fed wastes of variable composition, provided the
              system's effluent is continually monitored to determine when resin bed exhaustion has
              occurred.   However,  as  mentioned previously, the reliability  of ion exchange  is
              markedly affected by  the presence of suspended solids.   Use of sorptive resins is
              relatively new and  reliability under various conditions is not as  well known.

              Ion-exchange systems are commercially available from a number of vendors.  The
              units are relatively compact and are not energy intensive.  Start-up or shut-down can
              be accomplished easily and quickly  (Ghassemi,  Yu, and Quinlivan,  1981).  These
              features allow for  convenient use of  ion-exchange  and  sorptive resin systems  in
              mobile treatment systems.

              Although exchange columns  can be operated manually  or automatically, manual
              operation is better suited for hazardous waste site applications because of the diversity
              of wastes encountered.  With manual operation, the operator can decide when to stop
              the  service cycle and  begin the backwash cycle.  However, this requires use of a
              skilled operator familiar with  the process (Ghassemi, Yu,  and Quinlivan,  1981).

              Use of several exchange columns at a site can provide considerable flexibility.  As
              described previously, various  resin types can be used to remove anions, cations, and
              organics. Various columns can be arranged in series to increase service life between
              regeneration of the lead bed  or in parallel for maximum hydraulic capacity.  The
              piping arrangement  would  allow for one  or  more beds  to be  taken out for
              regeneration while the remaining  columns would remain in service. (Ghassemi, Yu,
              Quinlivan, 1981).

              Consideration must be given to disposal of contaminated  ion-exchange regeneration
              solution. In addition to proper disposal, another  important operational consideration
              is the selection of regeneration chemicals. Caution must be exercised in making this
              selection to ensure the compatibility of the regenerating chemical  with the waste being
              treated. For example, the use of nitric acid to regenerate an ion-exchange column
              containing ammonium ions results in the formation of ammonium nitrate, a potentially
              explosive compound.

              Costs

              Costs for various sizes of ion-exchange units are presented in TABLE 4.  The
              construction costs assume fabricated steel contact vessels with baked phenolic linings,
              a resin depth of 6 feet,  housing for the columns, and  all piping  and  backwash
              facilities. Operation and maintenance costs include electricity for backwashing (after
              150 bed volumes have been treated) and periodic repair and replacement costs.  Costs
              for  regenerant chemicals are not  included because they vary depending on the types
              and concentrations of target chemicals to be removed from the wastewater.


5/93                                         35

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INORGANIC TREATMENT
                                       TABLE 4
        GENERAL COST DATA FOR VARIOUS SIZES OF EXCHANGE UNITS
     Plant Capacity (gpm)
Construction Cost ($)'
   Operation and
Maintenance Center
   Costs ($/year)*
              50
             195
             305
             438
             597
       84,105
       116,200
       134,770
       154,000
      180,270
       14,530
       21,260
       24,280
       27,590
       31,531
  * Updated from 1979 to 1984 dollars using third quarter Marshall and Swift Index.
       Ion Exchange

       Anions and cations dissolved in an aqueous waste matrix can be removed from solution
       through the process of ion exchange. As the name implies, one ion, electrostatically attached
       to a solid resin material, is exchanged for a dissolved toxic ion.  The exchange reaction is
       reversible, which allows for resin regeneration, and occurs because of the increased affinity
       the divalent and trivalent toxic metal anions or cations have for the charged sites  on the
       surface of the resins. These resins are originally coated with weakly held monovalent anions
       or cations such as chloride, hydroxyl, sodium,  or hydrogen ions.

       It is possible to remove both dissolved, toxic anions and cations by placing a cation-exchange
       column and anion-exchange column in series.  This system has the capability, depending
       upon the choice of resins, to remove a wide range of inorganic and organic dissolved
       contaminants.  These include:

       •     All metallic anions and cations such as
             Cr2O7~, SeO4-, As04-, Ni2+, Cd2+, or Hg2+

       •     Inorganic anions such  as halides, sulfates, and cyanides

       •     Organic acids such as  carboxylics, sulfonics, and some phenols

       •     Organic bases such as  amines.
5/93
         36

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INORGANIC TREATMENT

       These systems are commercially available from a number of vendors.  They are compact,
       do not require large energy inputs, and can be started up and shut down with relative ease.
       An experienced  operator is required for start-up, but the system can be operated in an
       automatic mode once operational parameters are established for a particular waste.

              Waste Types Handled

              This process is applicable mainly as a polishing step for removing dissolved chemical
              species.  The  species must be  in an ionic form and should be free of suspended
              solids, nondissolved organic  liquids,  and oxidizing  agents  such  as perchlorates.
              Metal plating and finishing industries  use this technology as a waste management
              strategy.  Recovery  of inorganic acids such as HNO3 and H2SO4 by  chemical milling
              operations has also recently been accomplished.

              Restrictive Characteristics

              Highly concentrated wastestreams containing contaminant levels greater than 2,500
              mg/1 or suspended  solid concentrations greater than 50  mg/1 should be  avoided.
              Otherwise, clogging of the column due to the solids or rapid resin exhaustion due to
              the high levels of exchangeable species could occur. It should also be noted that this
              technology, after regeneration, produces a concentrated contaminant solution that will
              require consideration of additional disposal alternatives.

              Mobile System Consideration

              Small, trailer-mounted ion-exchange systems have been in operation since at  least
              1977.  The typical range of pressure vessels are from 2- to 6- foot diameter systems
              up to a custom size of 12 feet in diameter. Corresponding flow rates range from 25
              gpm up to a maximum of 1,150 gpm.  These vessels could easily be truck mounted
              and moved from site to site.

              Environmental Impacts

              During resin regeneration, a concentrated toxic backwash stream is produced.  This
              stream could pose significant environmental impacts on water and air, if disposed of
              improperly.  Because of this, an ion-exchange system must, as part of a complete
              system, fully address this potential threat. Depending on the waste characteristics,
              additional treatment, storage,  and disposal options must be considered, such  as
              precipitation/neutralization systems.
5/93                                        37

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INORGANIC TREATMENT

             Costs
             The costs of small, mobile, ion-exchange systems are not available.  However, an
             ion-exchange system servicing a flow of 50 gpm required an initial capital investment
             of $84,000 and an annual Operation and Maintenance fee of $14,500.  This cost is
             based on 1984 dollars and will be less for mobile system designed  for lower flows.

             Commercial Applications

             Since 1977, Eco-Tec Limited has marketed a skid-mounted,acid waste purification
             and recovery system. They report a 50-percent (w/w) recovery of nitric acid from
             a nickel-stripping process.  A large  number of companies market ion-exchange
             systems (e.g.,  Eastman Kodak, Pennwalt Corp., VOP Inc., and Darcel Chemical
             Industries), but these companies do not market a mobile system at  this time.
5/93                                      38

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Section 8

-------
                            CARBON ADSORPTION
STUDENT PERFORMANCE OBJECTIVES:









At the conclusion of this section, participants will be able to:








       •      Briefly describe the advantages and disadvantages of carbon adsorption




       •      List at least three factors that influence the use of carbon adsorption systems




       •      List at least three design considerations for carbon adsorption systems




       •      Briefly describe typical carbon adsorption system operations




       •      Briefly describe the carbon regeneration process.
5/93

-------
                                       NOTES
    CARBON
 ADSORPTION
     CARBON ADSORPTION
        Treatment Applies To:
  • Polycyclic Aromatic Hydrocarbons

  • Aromatic Ring/Cyclic Hydrocarbons

  • Chlorinated Organic Compounds
    (Volatiles and Extractables)
     CARBON ADSORPTION
       Chemical Characteristics
   • Solubility Less Than 1% (Nonpolar)

   • Molecular Weight > 50 Grams/Mole
    (4 To 20 Carbon Atoms Work Best)

   • Aromatics Better Than Aliphatics
    (Double Or Triple Bonds Inhibit)

   • Adsorptive Capacity At Least 50
    Milligrams Per Gram of Carbon
5/93
Carbon Adsorption
      page 1

-------
         NOTES
                                        CARBON ADSORPTION
                                            Physical Phenomenon

                                        • Chemisorption 0.99%
                                        • Ionic Bonding 0.01%
                                        • Van Der Waals Forces 99%
                                         ACTIVATED CARBON
                                             Starting Materials
                                         • Bituminous Coal - Calgon
                                         • Coconut Shells - Columbia
                                         • Lignite - Darco
                                         • Pulp Mill Residue - Nuchar
                                         • Wood - Norit
                                         ACTIVATED CARBON
                                                Production
                                   • Dehydration - Thermal and Chemical
                                     Drives Off the Water
                                   • Carbonization - Thermal/Limited Oxygen
                                     Crystalizes Carbon
                                   • Activation - Thermal and Steam
                                     Drives Out Impurities and Leaves Pores
Carbon Adsorption
page 2
5/93

-------
                                                    NOTES
        ACTIVATED CARBON
               Pore Sizes
  t 60% to 80% of the Pores < 40 Angstroms
  • Macropores > 1000 Angstroms
  • Micropores <  1000 Angstroms
  • Iodine Number - 800 to 1200 (< 10
    Angstroms)
  • Molasses Number - 200 to 400 (< 28
    Angstroms)
        ACTIVATED CARBON
          Physical Characteristics
  •  Bulk Density 26 to 40 Lbs. Per Cubic Foot
  •  Pore Volume .70 to .90 cc Per Gram
  •  70% to 90% Void Space
  •  Effective Sizes - .55 to 1 mm Gac
    .15 to .55 Pac
        ACTIVATED CARBON
              Surface Area
   • 500 to 1400 Square Meters Per Gram
   • 150 Acres Per Pound
5/93
Carbon Adsorption
       page 3

-------
         NOTES
                                         ACTIVATED CARBON
                                               Applications


                                         • Aqueous Phase Materials

                                         • Vapor Phase Materials
                                         ACTIVATED CARBON
                                          Aqueous System Design
                                       • Suspended Solids < 50 ppm

                                       • Grease and Oil Removed

                                       • Temperature Variable

                                       • pH  Variable

                                       • Parallel or Series Arrangement
                                         ACTIVATED CARBON
                                           Aqueous System Design
                                  • Upflow Systems (Pressure)
                                    Expanded Bed - Continuous Backwash
                                    Pulsed Bed - No Backwash

                                  • Downflow Systems (Pressure or Gravity)
                                    Require Special Backwash
                                    Effluent Quality Varies
                                    Most Common Mobile Design

                                  • Sizes From 50 to 5000 GPM
Carbon Adsorption
page 4
5/93

-------
                                                     NOTES
        ACTIVATED CARBON
         Vapor Phase System Design
   •  Humidity < 50%

   •  Operating Temperature < 250 F

   •  Flow Rates 10 to 200 CFM

   •  Suspended Solids and Grease/Oil
     Removal Similar to Aqueous Systems
        ACTIVATED CARBON
               Field Setup

  • Prewet with Clean Water for 24 Hours
    (Aqueous Systems)

  • Pretreat for the Following:
    - Suspended Solids and Greases/Oils
    - Scale-Forming Inorganics and Iron
    - Bacteria

  • Use Compatible Plumbing
        ACTIVATED CARBON
             Field Operation


  • Do Not Exceed Design Flow Rates and
    Pressures

  • Backwash Regularly

  • Monitor Effluent
5/93
Carbon Adsorption
        page 5

-------
         NOTES
                                          ACTIVATED CARBON
                                               Waste Treatment

                                     Backwash Water (To Aqueous Treatment)

                                     Spent Carbon
                                     Some Contaminants Need Special
                                     Handling
                                     Land Bans May Apply
                                     BEFORE USE Check with Disposal Facility
                                          ACTIVATED CARBON
                                             Carbon Regeneration

                                   • Desorb Organics - Thermal
                                     (Generally, Desorbed Organics are
                                     Destroyed by Combustion)

                                   • Reactivate Carbon - Thermal and Steam
                                     (Reactivation Restores about 85% to 90%
                                     Capacity)
                                          ACTIVATED CARBON
                                                   Costs
                                   • Cost of Carbon Per Pound
                                     - $1.05 to $1.30 for Virgin Carbon
                                     - $0.85 to $1.10 for Regenerated Carbon

                                   • Total Costs Per 1000 Gallons Treated
                                     - $0.22 to $0.55 (Influent in ppb)
                                     - $0.48 to $2.50 (Influent in ppm)
Carbon Adsorption
page 6
5/93

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                              CARBON ADSORPTION
       Activated Carbon Treatment

              General Description

              The process of adsorption onto activated carbon involves contacting a waste stream
              with  the carbon, usually by flow through a series of packed bed reactors.  The
              activated carbon selectively adsorbs hazardous constituents by a surface attraction
              phenomenon in which organic molecules are attracted to the internal pores of the
              carbon granules.

              Adsorption depends on the strength of the molecular attraction between adsorbent and
              adsorbate,  molecular weight, type and characteristic of adsorbent, electrokinetic
              charge, pH, and surface area.

              Once the micropore surfaces are saturated with organics, the carbon is "spent" and
              must either be replaced with virgin carbon or removed, thermally regenerated, and
              replaced.  The time to reach "breakthrough," or exhaustion, is the single most critical
              operating parameter.   Carbon longevity  balanced against  influent concentration
              governs operating economics.

              Most hazardous waste treatment applications involve the use of adsorption units that
              contain granular activated carbon (GAC) and operate in a downflow series mode such
              as that shown in FIGURE 1 (Brunotts et al., 1983).

              The downflow fixed bed series mode is usually the most cost-effective and produces
              the lowest  effluent concentrations relative to other carbon adsorption configurations
              (i.e., downflow in parallel, moving bed, and up flow-expanded).  The units may be
              connected in parallel to provide increased hydraulic capacity.

              Applications/Limitations

              Activated carbon is a well-developed technology that widely used in the treatment of
              hazardous wastestreams. It is especially well suited for removal of mixed organics
              from aqueous wastes. TABLE 1 provides an indication of the treatability of organics
              commonly found in groundwater.

              TABLE 2  delineates  various factors that influence the  applicability of activated
              carbon treatment for any given waste (Nalco Chemical Co., 1979).  Because carbon
              adsorption is  essentially an electrical interaction phenomenon, the polarity of the
              waste compounds will largely determine the effectiveness of the adsorption process.
5/93

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CARBON ADSORPTION
              Highly polar molecules cannot be effectively removed by carbon adsorption.  Another
              factor to consider in determining the likely effectiveness of carbon adsorption is
              aqueous solubility. The more hydrophobic (insoluble) a molecule is, the more readily
              the compound is  adsorbed.  Low solubility humic and fulvic acids which may be
              present in the groundwater can sorb to the activated carbon more readily than most
              waste contaminants and result in rapid carbon exhaustion.
             FEED WATER
   REGENERATED/MAKEUP
     ACTIVATED CARBON '
         BACK WASH EFFLUENT
          BACK WASH FEED
                           ADSORBER I
                                                  ADSORB Eft I
REGENERATED'MAKEUf
ACTIVATED CARBON
                                                              BACKWASH EFFLUENT
                                                                BACK WASH FEED
                                                         TREATED EFFLUENT
                                                J
                                                                         VALVE CLOSED

                                                                         VALVE OPEN
                                       FIGURE 1
             TWO-VESSEL GRANULAR CARBON ADSORPTION SYSTEM
5/93

-------
CARBON ADSORPTION
                                        TABLE 1
                         FACTORS AFFECTING EQUILIBRIUM
         Compound adsorbability favored by:

                Increasing carbon chain length
                Increasing aromaticity
                Decreasing polarity
                Decreasing branching
                Decreasing solubility
                Decreasing degree of dissociation

         Functionality:

                Relative adsorbability:  acids  > aldehydes >  esters > ketones >
                alcohols > glycols when number of carbon atoms is < 4

         pH effects:

                Undissociated species are more easily adsorbed

                       - Low pH favors adsorption of acids (e.g., volatile acids,
                        phenol)*
                       - High pH favors adsorption of bases (e.g., amines)

                Other compounds: adsorption can be favored  by higher pH

                       - Postulated general effect:
                             Partial neutralization of surface acidity reduces
                             hydrogen-bonding of surface groups eliminating steric
                             blockage of micropores

         Temperature:

                Increased temperatures can increase rate of adsorption due to viscosity
                and diffusivity effects

                Exothermic adsorption  reactions are favored by decreasing temperatures,
                usually a minor  effect on equilibrium level
  "This often is the most significant pH effect, so adsorption generally is increased with
  decreasing pH.
Source: Conway and Ross, 1980

5/93

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CARBON ADSORPTION
TABLE 2
CARBON INFLUENT AND EFFLUENT

Organic Compounds in
Groundwater
Carbon tetrachloride
Chloroform
ODD
DDE
DDT
cis-1 ,2-Dichloroethylene
Dichloropentadiene
Diisopropyl methylphosphonate
Tertiary methyl-butylether
Diisopropyl methylphosphonate
1 ,3-Dichloropropene
Dichloroethyl ether
Dichloroisopropylether
Benzene
Acetone
Ethyl acrylate
Trichlorotriflorethane
Methylene chloride
Phenol
Orthochlorophenol
Tetrachloroethylene
Trichloroethylene
1,1, 1-Trichloroethane
Vinylidiene chloride
Toluene
Xylene
Number
of
Occurrences
4
5
1
1
1
8
1
2
1
1
1
1
1
2
1
1
1
2
2
1
10
15
6
2
1
3
Influent*
Concentration
Range
130 Mg/1-10 mg/1
20 Mg/1-3.4 mg/1
lMg/1
lMg/1
4 Mg/1
5 /xg/1-4 mg/1
450 Mg/1
20-4 Mg/1
33 Mg/1
1,250 Mg/1
10 Mg/1
1.1. mg/1
0.8 mg/1
0.4-1 mg/1
10-100 fig/I
200 mg/1
6 mg/1
1-21 mg/1
63 mg/1
100 mg/1
5 /xg/1-70 mg/1
5 Mg-16 mg/1
60 Mg/1-25 mg/1
5 Mg/1-4 mg/1
5-7 mg/1
0.2-10 mg/1
Carbon Effluent*
Concentration
Achieved
< 1 Mg/1
< 1 Mg/1
<0.05g/l
< 0.05 Mg/1
<0.05 Mg/1
< 1 Mg/1
< 10 Mg/1
< 1 Mg/1
< 5.0 Mg/1
< 50 Mg/1
< 1 MS/1
< 1 Mg/1
< 1 Mg/1
< 1 Mg/1
< 10 mg/1
< 1 mg/1
< 10 Mg/1
< 100 Mg/1
< 1 Mg/1
< 1 mg/1
< 1 Mg/1
< 1 Mg/1
< 1 Mg/1
< 1 Mg/1
< 10 Mg/1
< 101 Mg/1
* Analyses conducted by Calgon Carbon Corporation conformed to published U.S. EPA protocol methods.
Tests in the field were conducted using available analytical methods.
              In  addition,  some  metals  and inorganic  species have  shown  excellent  to  good
              adsorption potential, including antimony, arsenic, bismuth,  chromium, tin, silver,
              mercury, cobalt, zirconium, chlorine, bromine, and iodine.

              Carbon adsorption is frequently used following biological treatment and/or  granular
              media filtration to  reduce  the  organic and  suspended  solids load  on the carbon
              columns or to remove refractory organics that cannot be biodegraded. Air stripping
              may also be  applied prior to carbon adsorption to remove a portion of the volatile
5/93
10

-------
CARBON ADSORPTION

              contaminants, thereby reducing the organic load to the column. These pretreatment
              steps all minimize carbon regeneration costs.

              The highest concentration of solute in the influent stream that has been treated on a
              continuous basis is 10,000 ppm total organic carbon (TOC).  A 1-percent solution is
              currently considered the upper limit (De Renzo, 1978). Pretreatment is required for
              oil and grease and suspended solids. Concentrations of oil and grease in the influent
              should be limited to 10 ppm.  Suspended solids should  be less than 50 ppm for
              downflow systems, whereas upflow systems can handle much higher solids loadings.

              Design Considerations

              The  phenomenon  of adsorption  is extremely  complex  and not mathematically
              predictable. To accurately predict performance, longevity, and operating economics,
              field pilot plant studies are necessary.

              To conduct an initial estimate  of carbon column sizing, the following data need to be
              established during pilot plant testing:

              •      Hydraulic retention time (hours)

              •      Flow (gallons/minute)

              •      Hydraulic capacity of the carbon (gallons waste/pounds carbon)

              •      Collected volume of treated waste at breakthrough (gallons)

              •      Carbon density (pounds carbon/cubic foot).

              "Breakthrough" refers to the moment when the concentration of solute being treated
              first starts to rise in the carbon unit effluent.  "Exhaustion" refers to the  moment
              when the concentration of solute being treated is the same in both the effluent and the
              influent.

              Technology Selection/Evaluation

              Activated carbon is  an effective and reliable  means of removing  low-solubility
              organics.   It  is  suitable  for treating a wide  range of organics  over a  broad
              concentration range.  It is not particularly sensitive to changes in concentrations or
              flow rate and,  unlike biological  treatment,  is  not adversely affected  by toxics.
              However, it is quite sensitive to suspended solids and oil and grease concentrations.

              Activated carbon is easily implemented into more complex treatment systems. The
              process is well suited to mobile treatment systems as well as to onsite construction.
              Space requirements  are small, start-up and  shut-down are rapid,  and there are
              numerous contractors who are experienced in  operating mobile units.


5/93                                        11

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CARBON ADSORPTION
              EPA's Mobile Physical/Chemical Treatment System includes three carbon columns
              that can be operated either in series or in parallel. They are designed for a hydraulic
              loading of 200 gpm with a 27 minute contact time. This contact time has been found
              to be adequate for many hazardous wastestreams.  However, longer contact times can
              be provided by reducing the hydraulic flow rate.

              Use  of several carbon adsorption columns at a  site can provide  considerable
              flexibility.   Various columns  can be  arranged in  series to increase service life
              between regeneration of the lead bed or in parallel for maximum hydraulic capacity.
              The piping arrangement would allow for one or more beds to be regenerated while
              the other columns remain in service.

              The  most  obvious maintenance  consideration  associated  with  activated carbon
              treatment  is the regeneration of spent carbon  for  reuse.  Regeneration  must be
              performed for each column at the conclusion of its bedlife so that the spent carbon
              may be restored as close as possible to its original condition for reuse. If the spent
              carbon is not regenerated, it must be disposed of.  Other operation and maintenance
              requirements of activated  carbon technology are minimal if appropriate automatic
              controls have been installed.

              The thermal destruction properties of waste chemicals must be determined prior to
              selection of activated carbon treatment technology. This determination must be made
              because any chemicals sorbed to activated carbon must eventually be destroyed in a
              carbon regeneration furnace. Therefore, of crucial importance to the selection of
              activated carbon treatment is whether the sorbed waste material can be effectively
              destroyed  in the regeneration furnace; otherwise, upon introduction to the furnace,
              the waste materials will become air pollutants.

              The biggest limitation of the activated carbon process is the high capital and operating
              costs.  As described previously, the operating costs can be substantially reduced by
              pretreatment of the waste using biological treatment or air stripping.

              Costs

              The cost of activated carbon units depends  on the size of the contact unit, which is
              influenced by the concentrations of the target and nontarget organic compounds in the
              wastestream and the desired level of target compounds in the effluent. TABLE 3
              presents construction, operation, and maintenance costs for cylindrical, pressurized,
              downflow steel contactors based on a nominal detention time of 17.5 minutes and a
              carbon loading rate of 5 gpm/ft2. The construction  costs include housing; concrete
              foundation; all  necessary pipes, valves, and nozzles for operating the unit; and the
              initial change of carbon. The operation and  maintenance costs include electricity and
              assume carbon replacement once a year.   However, systems for unloading spent
              carbon and loading fresh carbon are not included.
5/93                                         12

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CARBON ADSORPTION
TABLE 3
GENERAL COST DATA FOR VARIOUS SIZES OF ACTIVATED
CARBON CONTACT UNITS
Capacity
"jf (gpiri);, ;>
1.7
17
70
175
350
Column
iDiameter (ft)
0.67
2
4
6.5
9
Column
Length (ft)
5
5
5
5
5
Housing
Area (ft2)
60
150
300
375
450
Construction
Costs*
12,320
23,776
42,425
64,000
93,822
O&M
Costs (F/yr)*
1,690
2,315
4,800
8,110
12,540
* Updated from 1979 to 1984 dollars using third quarter Marshall and Swift Equipment
Index.
              A number of manufacturers market mobile, activated carbon treatment systems.  For
              example, Calgon  Carbon Corporation has a  trailer-mounted, carbon  adsorption
              treatment unit that can be shipped to a treatment location within 24-48 hours.  This
              system can be configured with either single or multiple prepiped  adsorber vessels.
              It can handle flows up to 200 gpm. The following costs are associated with a mobile
              system consisting of two  10-foot diameter,  10-foot  high, skid-mounted  vessels
              capable of handling up to 200 gpm (Calgon Carbon Corp., undated):
                     Delivery, supervision  of installation
                     and startup,  tests to conduct reacti-
                     vation  of carbon,  dismantling  and
                     removal of system (including freight to
                     and from the site)

                     Delivery and removal of one truckload
                     of carbon (2,000 Ibs)

                     (Two truckloads required for a two-
                     vessel  system)   -  Rental  fee  (per
                     month)
                         $25,000
                         $15,200
                      $5,000/month
5/93
13

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CARBON ADSORPTION

       Activated Carbon Adsorption

              Process Description
              Activated carbon, either alone or in combination with other processes, is the most
              frequently applied  technology for the removal of trace organic compounds from
              contaminated water.  Carbon adsorption has been used in  granular form in contact
              beds (fixed  or pulsed bed reactors) and  in powdered form in aerobic biological
              treatment. The overall principle behind this treatment process is the surface attraction
              phenomena between the organic solutes and the large, internal pore surface area of
              the carbon grains.

              The carbon  adsorption process is dependent  on the physical characteristics of the
              carbon and the molecular size of the adsorbates.  Because adsorption is  a surface
              phenomenon, a large surface area, typical of activated carbon (500-1400 m2/g),  is
              beneficial for an effective  removal of organic compounds.  Activated carbon will
              adsorb most organic compounds to some degree; however, it is most effective for the
              least polar  and least  soluble  organic compounds.   Other  factors that affect the
              adsorption process include liquid pH and temperature, carbon pore structure, and
              liquid/carbon contact time. FIGURE 2 depicts a typical carbon adsorption system.

              Waste Type Handled

              Carbon adsorption  can be applied to aqueous  and gaseous wastes containing a wide
              range of organic compounds.  Refractory organics,  volatile organics, pesticides,
              organic nitrogen compounds, and  chelated heavy metals can be successfully removed
              from an aqueous stream.  Removal is enhanced by low water solubility and nonpolar
              characteristics of the organics.  Adsorption capacities of >50 mg/g carbon at influent
              concentrations of 1,000 ^g/1 are usually required for economical operations.

              Restrictive Characteristics

              High solids content (^50 mg/1) cannot be tolerated because of potential clogging of
              columns.  Unassociated metals and highly miscible organic compounds will not be
              removed by this process.  Mixtures of organics may cause significantly reduced
              adsorption capacity because of chromatographic effects. Vapor phase carbon cannot
              tolerate a high humidity gas stream (^50%) because the active pores are blocked by
              water.
5/93                                        14

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CARBON ADSORPTION
                                          CARDON MAKE-UP
    TO CARBON
   REGENERATION
     SYSTEM

                        CARDON DED
    INFLUENT WATER
     WATER
            O
    HIGH PRESSURE     SPENT CARBON SLURRY
      WATER
                                                   Mk**UtM|Mlt|M
                                               CARBON BED
z
                                EFFLUENT
                                                                         (TREATED WATER)
                                      FIGURE 2
                    GRANULAR ACTIVATED CARBON COLUMNS
             Mobile System Considerations

             Carbon contacting beds can be skid mounted and placed on flatbed trucks or railcars
             for transportation to various sites.  Gravity flow and multicolumns in series are the
             most commonly designed contacting systems.  Single units can handle up to 20,000
             Ibs of carbon.  Some units may be larger. Additional required equipment will consist
             of pumps, piping for various configurations (e.g., in series or parallel), backwashing
             equipment,  carbon transfer  equipment,  and,  potentially, carbon  regeneration
             equipment (which is also available in a mobile unit). Hydraulic loading contact time
             and breakthrough characteristics are key operating parameters  for the design of a
             system.
5/93
15

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CARBON ADSORPTION

             Environmental Impacts
             The exhausted  carbon contains all of the removed  waste and must be either
             regenerated (onsite or offsite) or disposed of in a secure landfill (carbon with PCBs
             or dioxin will not currently be regenerated by the vendors).  Thermal regeneration
             of the used carbon is the most common method currently used.  However, solvent
             and steam regeneration are also employed.  Periodic backwashing of the  carbon will
             require holding tanks for the liquids, which can be sent back through the carbon once
             the solids  have settled.  This small amount of sludge will need to be disposed of.
             Slurrying of carbon during changeouts will cause high abrasion of the equipment.

             Costs

             Capital costs for two in-series carbon contactors with 20,000 pounds in each, can
             range from $200,000 to $500,000 depending on the application.  Operating costs are
             heavily dependent on the carbon usage rate because carbon changes  are the largest
             cost factor.

             Commercial Applications

             EPA has an emergency environmental response unit (mobile system)  nicknamed the
             "Blue Magoo" that contains three sand filters followed by three in-series GAC
             columns.  The system has operated at over 20 different sites.  Many commercial
             services companies and vendors supply mobile carbon adsorption systems.  A partial
             list follows:

             EPA/Releases Control Branch             OH Materials
             Woodbridge Avenue                      Nationwide
             Edison, NJ  08837                       419/423-3526
             201/321-6677

             Mobile Industrial Services                 Chemical Waste Management
             Louisville, KY                           Oak Brook, IL
             800/626-2564                            714/940-7971

             Calgon Corp.                            Newpark Waste Management
             Bridgewater, NJ                          Lafayette, LA
             201/526-4646                            713/963-9107
5/93                                       16

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Section 9

-------
                          BIOLOGICAL TREATMENT
STUDENT PERFORMANCE OBJECTIVES:








At the conclusion of this unit, participants will be able to:








       •      Briefly describe the advantages and disadvantages of biological treatment




       •      List and describe at least three factors that influence biodegradation of wastes




       •      State the difference between aerobic and anaerobic biological treatment




       •      Briefly describe a typical aerobic treatment system




       •      Briefly describe the in-situ biodegradation process.
5/93

-------
                                                                NOTES
                 BACTERIA
        Biodegradation of Hazardous Materials

        OH
    y\
                    Mineralization
       Phenol
                             C02+  H20
                      Aerobic     Harmless
                     Respiration  End Product
       ADVANTAGES OF BIOREMEDIATION


       •  Effective in removing hydrocarbons
          and selected organic contaminants

       •  Environmentally sound

       •  Inexpensive

       •  Effective for short-term treatment
          of contaminated water
      DISADVANTAGES OF BIOREMEDIATION


        • Not effective for heavy metals
          or some chlorinated compounds

        • Operating and maintenance costs
          relatively high

        • Long-term effectiveness unknown

        • Possible adverse public reaction
5/93
Biological Treatment
           page 1

-------
        NOTES
RESPIRATION PROCESSES
c
Aerobic Respiration
C6H1206 + 602 *> 6C02 + 6H2
Anaerobic Respiration
8H1206+12NO>
6C02+6H20 + 12N<
0 + 38 ATP

BIOLOGICAL TREATMENT MICROBES
• Bacteria
Bacillus
Micrococcus
• Actinomycetes
Streptomyces
Nocardia
• Fungi
Aspergillus
Acremonium

CHEMICAL CONCENTRATION
GROWTH-SUPPORTING SUBSTRATE
^^^^^^ I Microbial
^^W / Population
^r \ Chemical
^^^ % Contaminant
TIME

Biological Treatment
page 2
5/93

-------
                                                NOTES
NONGROWTH-SUPPORTING SUBSTRATE
0
CHEMICAL CON
-
--—— 	 ""TT
•^•B
Chemical Contaminant
Microbial Population
mmmimf
TIME

COSUBSTRATE ADDITION

;ENT RATION
*
8
_j
UJ
I
O

1 	 \.
^\>
A
y
	 *s
TIME
1 Microbial
I Population

\ Chemical
1 Contaminant


ANALYSIS OF A REPRESENTATIVE SAMPLE
Determine:
• Total bacterial
• Nutrient level
• pH

population


• Chemical constituents
• Moisture
* Temperature


• Oxygen requirements
5/93
Biological Treatment
         page 3

-------
         NOTES
                                        BIODEGRADATION POTENTIAL

                                           Organic Contaminant
                                           Toxicity Assessment
                                                  Done  By
                                        Electrolytic Respirometer
                                            ELECTROLYTIC RESPIROMETER
                                                    VESSELS
                                       NUMBER CONTENTS

                                          Sample + Natural Flora

                                          Sample + Selected Microbes (Augmentation Sample)

                                          Sample + Indigenous Microbes (Indigenous Control)

                                          Negative (Sterile) Control (Sample + HgCI 2, KCN, NaN3)
                                          Sample + Selected Microbes + Glucose
                                          (Positive Control)
                                      6   Selected Microbes + Glucose
                                                                     ER-2
                                                                     ER-1
                                                     Time
Biological Treatment
page 4
5/93

-------
                                                                      NOTES
     CONSIDERATIONS FOR BIOREMEDIATION
  • Identify contaminant
  • Delineate contaminant plume
  • Identify contaminant concentration within plume
  • Determine rate of flow of groundwater
  • Determine nutrient and oxygen requirements
  • Determine type and physical properties of
    geologic materials
               LANDFILL DISPOSAL VS.
          IN-SITU BIOLOGICAL TREATMENT
     7,500 yd3
  Contaminated Soil
100 miles transportation at
$4/mile for disposal at
$100/yd>
$900,000 Landfill Disposal
•$300,000 Biological Treatment
$600,000 cost benefit for
  Biological Treatment
       Cross Section of an In-Situ Biodegradation System
                                    Recovery Well
                   Confining Bed
5/93
                                                      Biological Treatment
                                                                  page 5

-------
            NOTES
                                              Oxygen Source
INJECTION SYSTEM
     Pressure
      Gauge
Nutrients
                                                     BIOLOGICAL TREATMENT SYSTEM
                                                  BIOLOGICAL TREATMENT PROGRAM

                                                     • Innoculation of contaminated area
                                                       with the appropriate microbes
                                                     • Aeration
                                                     • Nutrient addition
                                                     • Monitoring air quality
                                                       (volatile emissions)
                                                     • Monitoring chemical parameters
                                                     • Monitoring biological activity
Biological Treatment
page 6
                            5/93

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                            BIOLOGICAL TREATMENT
       Biological Treatment

              General Description

              The  function of biological treatment is to remove organic matter from the waste-
              stream  through  microbial degradation.   The most prevalent form  of biological
              treatment  is aerobic (i.e., in the presence of oxygen).  A number of biological
              treatment processes exist that may be applicable to treatment of aqueous wastes from
              hazardous waste sites. These processes include conventional activated sludge; various
              modifications of the activated sludge process, including pure oxygen activated sludge,
              extended aeration,  and  contact stabilization;  and fixed film  systems that include
              rotating biological discs and trickling filters.

              In the conventional activated sludge process,  aqueous  waste flows  into an aeration
              basin where it is aerated for several hours.   During this time, a suspended  active
              microbial population (maintained by recycling sludge)  aerobically degrades organic
              matter in the stream and produces new cells.  A simple equation for this process is:

                         Organics + O2 -» CO2 + H2O + new cells

              The new cells produced during aeration form a sludge that is settled out in a clarifier.
              A portion of the settled sludge is recycled to the  aeration basin  to maintain the
              microbial population while the remaining sludge is wasted (i.e., it undergoes volume
              reduction and disposal).  Clarified water flows to disposal or further processing.

              In the pure oxygen activated sludge process, oxygen or oxygen-enriched air is used
              instead of air to increase the transfer of oxygen.  Extended aeration involves longer
              detention times than conventional  activated sludge and  relies on a higher population
              of microorganisms to degrade  wastes.   Contact stabilization involves only short
              contact  of the  aqueous wastes  and  suspended microbial  solids,  with subsequent
              settling  of sludge and treatment of the sludge to remove sorbed organics. Fixed film
              systems involve contact of the aqueous wastestream with microorganisms attached to
              some inert medium such as rock or specially designed plastic material.  The original
              trickling filter consisted of a bed  of rocks over which the contaminated water was
              sprayed.  The microbes forming  a slime layer on the rocks would metabolize the
              organics, while oxygen was provided as air moved countercurrent from the water
              flow (Canter and Knox, 1985).

              Biological towers are a modification of the  trickling  filter.   The medium  (e.g.,
              poly vinyl  chloride [PVC], polyethylene, polystyrene,  or redwood) is stacked into
              towers which typically reach 16 to 20 ft.  The contaminated water is sprayed across
              the top and,  as it moves downward, air is pulled upward through the tower.  A slime
              layer of microorganisms forms on the media and removes the organic contaminants
              as the water flows over the slime  layer.
5/93

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BIOLOGICAL TREATMENT
              A rotating biological contactor (RBC) consists of a series of rotating discs, connected
              by a shaft, set in a basin or trough. The contaminated water passes through the basin
              where the microorganisms, attached to the discs, metabolize the organics present in
              the water.  Approximately 40 percent  of the discs' surface area is submerged as it
              rotates.  This allows the  slime  layer to  alternately  come in  contact with  the
              contaminated water  and  the air where oxygen is  provided to  the microorganisms
              (Canter and Knox, 1985).

              Applications/Limitations

              There is considerable flexibility  in biological treatment because of the variety of
              available processes and adaptability of the microorganisms themselves. Many organic
              chemicals are considered biodegradable, although the relative ease of biodegradation
              varies widely.   Several  generalizations can be made with  regard to the ease of
              treatability  of organics by aerobic biological treatment:

              •      Unsubstituted nonaromatics  or cyclic hydrocarbons  are  preferred over
                     unsubstituted aromatics.

              •      Materials with unsaturated bonds such as alkenes are preferred over materials
                     with saturated bonds.

              •      Soluble organics are usually more  readily degraded than insoluble materials.
                     Biological treatment is more efficient in  removing  dissolved or colloidal
                     materials, which are more readily attacked by enzymes.  This is not the case,
                     however, for fixed-film treatment systems that preferentially treat suspended
                     matter.

              •      The presence  of functional groups affects  biodegradability.   Alcohols,
                     aldehydes, acids, esters, amides, and amino acids are more degradable than
                     corresponding  alkanes, olefins, ketones,  dicarboxylic  acids,  nitriles,  and
                     chloroalkanes.

              •      Halogen-substituted  compounds are the most refractory to biodegradation;
                     chlorinated alphatics are generally more refractory than the corresponding
                     aromatics, although the  number  of halogens  and  their position  is also
                     significant in determining degradation.

              •      Nitro-substituted  compounds are also difficult to degrade although they  are
                     generally less refractory than the halogen-substituted  compounds.

              Although there  are  a number of compounds that are  considered to  be relatively
              resistant to biological treatment, it is recommended in practice that the treatability of
              waste be determined through laboratory biological  oxygen demand (BOD) tests on a
              case-by-case basis.
5/93

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BIOLOGICAL TREATMENT
              Despite the fact that industrial wastes may be refractory to biological treatment,
              microorganisms can be acclimated to  degrade many compounds that are initially
              refractory.  Similarly, whereas heavy metals are inhibitory to biological treatment,
              the biomass can also be acclimated, within limits, to tolerate elevated concentrations
              of metals.

              TABLE 1 presents the biological treatment processes available and the applications
              and limitations of each. The completely mixed activated sludge process is the most
              widely used for treatment of aqueous wastes with  relatively  high organic loads.
              However,  the high-purity oxygen system has advantages for hazardous waste site
              remediation.
TABLE 1
SUMMARY OF APPLICATIONS/LIMITATIONS
FOR BIOLOGICAL TREATMENT PROCESS
Process
Conventional
Completely Mixed Conventional
Extended Aeration
Contact Stabilization
Pure Oxygen
Trickling Filters
Rotating Biological Disc
Applications/Limitations
Applicable to low-strength wastes; subject to shock loads
Resistant to shock loads
Requires low organic load and long detention times; low volume
of
Not suitable for soluble BOD
Suitable for high-strength wastes; low sludge volume reduced
More effective for removal of colloidal and suspended BOD; used
Can handle large flow variations and high organic shock loads;
              In addition, a number of other parameters may influence the performance of the
              biological treatment system.  These are concentration of suspended solids, oil and
              grease, organic load variations, and temperature.  TABLE 2 lists parameters that
              may limit system performance, limiting concentrations, and the type of pretreatment
              steps required prior to biological treatment.

              Design Considerations

              Design of the activated sludge or fixed-film systems for a particular application can
              be achieved best by first representing the system as a mathematical model, and then
              determining the necessary coefficients by running laboratory or pilot tests.
5/93

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BIOLOGICAL TREATMENT
TABLE 2
CONCENTRATION OF POLLUTANTS THAT MAKE PREBIOLOGICAL
OR PRELIMINARY TREATMENTS DESIRABLE
Pollutant or
System Condition
Suspended solids
Oil or grease
Toxic ions
Pb
Cu + Ni 4- CN
Cr6+ + Zn
Cr3*
PH
Alkalinity
Acidity
Organic load variation
Sulfides
Phenols
Ammonia
Dissolved salts
Temperature
Limiting Concentration
> 50-125 mg/1
flotation, lagooning
> 35-50 mg/1
<0.1 mg/1
^1 mg/1
<3 mg/1
< 10 mg/1
< 6, > 9
0.5 Ib alkalinity as
CaCO3/lb BOD removed
Free mineral acidity
> 2:1-4:1
> 100 mg/1
> 70 - 300 mg/1
> 1.6g/l
> 10-16 g/1
13 - 38°C in reactor
Kind of Pretreatment
Sedimentation
Skimming tank or separator
Precipitation or ion exchange
Neutralization
Neutralization for excessive
alkalinity
Neutralization
Equalization
Precipitation or stripping with
recovery
Extraction, adsorption, internal
dilution
Dilution, ion exchange, pH
adjustment, and stripping
Dilution, ion exchange
Cooling, steam addition
5/93
10

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BIOLOGICAL TREATMENT
              The  following  models have been found to be  reliable for designing biological
              treatment systems for wastestreams containing priority pollutants (Cantor and Knox,
              1985).
                     Activated Sludge:
                                              FSJX
                                   V  -
                     Biological Tower and Rotating Biological Contactor:

                                               fst
                                   A   =  ———!	
                                   V
                                   F
                                   X
                                   Si

                                   se
                            UmaxandKB   =
       where:        V      =      volume of aeration tank (ft3)
                                   flow rate (fWday)
                                   mixed liquor volatile solids (mg/1)
                                   influent   BOD,   COD,  TOC,   or  specific
                                   organics (mg/1)
                                   effluent   BOD,   COD,  TOC,   or  specific
                                   organics (mg/1)
                                   biokinetic constants (day"1) max
                     A      =      surface area of biological tower or rotating
                                   biological contactor (ft2)

The  biokinetic  constants are determined by conducting laboratory or pilot plant
studies.  After the biokinetic constants  are determined, the required volume of
aeration tank or the required surface area for a biological tower or rotating biological
contactor can  be determined for any flow rate;  influent  concentration  of BOD,
chemical oxygen demand (COD), TOC, or specific organic; and a required effluent
concentration of BOD, COD, TOC, or specific organic.

Technology Selection/Evaluation

Biological treatment has not been as widely used in hazardous waste site remediation
as activated carbon, filtration, and precipitation/flocculation.  However, the process
is well established for treating a wide variety of organic contaminants. Kincannon
and  Stove  (as reported by  Canter  and Knox  [1985]) have demonstrated the
effectiveness of activated sludge for treating priority pollutants. The results  shown
in TABLE 3  indicate  that activated  sludge was  effective  for  all groups of
contaminants tested except for halogenated hydrocarbons.
5/93
                              11

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BIOLOGICAL TREATMENT
TABLE 3
REMOVAL MECHANISMS OF TOXIC ORGANICS
Compound
Nitrogen Compounds
Acrylonitrile
Phenols
Phenol
2,4-DNP
2,4-DCP
PCP
Aromatics
1,2-DCB
1,3-DCB
Nitrobenzene
Benzene
Toluene
Ethylbenzene
Halogenated Hydrocarbons
Methylene Chloride
1,2-DCE
1,1,1-TCE
1,1,2,2-TCE
1,2-DCP
TCE
Chloroform
Carbon Tetrachloride
Oxygenated Compounds
Acrolein
Polycyclic Aromatics
Phenanthrene
Naphthalene
Phthalates
Bis(2-Ethylhexyl)
Other
Ethyl Acetate
Percent Treatment Achieved
Stripping


21.7
2.0
5.1
5.2
8.0
99.5
100.0
93.5
99.9
65.1
19.0
33.0



1.0
Sorption


0.02
0.19
91.7
0.50
0.83
1.19
1.38




Biological
99.9
99.9
99.3
95.2
97.3
78.2
97.8
97.9
94.9
94.6
33.8
78.8
64.9
99.9
98.2
98.6
76.9
98.8
5/93
12

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BIOLOGICAL TREATMENT

              Although biological treatment can effectively treat a wide range of organics, it has
              several  drawbacks for hazardous waste  site  applications.  The reliability of the
              process can be adversely affected by "shock" loads of toxics.  Start-up time can be
              slow if the organisms need to be acclimated to the wastes and the detention time can
              be long for complex wastes.  However, the  existence of cultures that have been
              previously  adapted to  hazardous wastes  can  dramatically decrease start-up  and
              detention time.

              There are a number of cleanup contractors who have used biological treatment as part
              of a mobile treatment system.  The high-purity oxygen treatment process  is well
              suited for mobile treatment applications because the high oxygen efficiency enables
              use of smaller reactors,  shorter detention time, and  reduced  power consumptions
              relative to other activated sludge processes. A hazard associated with the high-purity
              oxygen  process  is that the presence of low flash-point compounds can present  a
              potential fire hazard. However, the system is equipped  with hydrocarbon analyzers
              and control systems that deactivate the system when dangerously high concentrations
              of volatiles are detected  (Ghassemi, Yu, and Quinlivan, 1981).  Loss of volatile
              organics from other biological treatment processes can also pose some localized air
              pollution and a health hazard to field personnel.

              Rotating biological contactors  also have  advantages  for hazardous  waste  site
              treatment.  The units are compact, they can handle large flow variations  and high
              organic shock loads, and they do not require use of aeration equipment.

              Sludge  produced in  biological  waste treatment may be  a hazardous waste  itself
              because of the  sorption and  concentration of toxic  and  hazardous compounds
              contained in the wastewater. If the sludge is hazardous, it must be disposed of in a
              RCRA-approved manner.  If it is not hazardous, disposal should conform with state
              sludge disposal  guidelines.

              Costs

              Costs for various sizes of activated sludge units are presented in TABLE 4. The
              costs for these units assume a detention time of 3 hours and use of aeration basins,
              air supply equipment, piping, and a blower building. Clarifier and recycle pumps are
              not included.  The basins are sized to the 50-percent recycle flow. The influent BOD
              is assumed  to be no greater than 130 ppm and the effluent BOD is assumed to be 40
              ppm.

              The operation and maintenance costs assume that the hydraulic  head loss through the
              aeration tank is negligible.  Sludge wasting and  pumping energy are not included.

              Union Carbide manufactures a high-purity, oxygen-activated sludge system (UNOX)
              suitable for mobile system applications.  The mobile UNOX systems have a hydraulic
              capacity of 5-40 gpm,  are contained within  40-foot van trailers, and include an
              external clarifier.  The oxygen required  is also supplied by Union Carbide.   The
              customer is expected to provide installation labor, operating manpower, analytical
              support, and utilities.  A typical installation requires 3-4 days.

5/93                                         13

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BIOLOGICAL TREATMENT
              The mobile UNOX system can be either rented or purchased from the Union Carbide
              Corporation.  The estimated rental costs are as follows:

              •      $6,540  for  the  checkout  and  refurbishment  of equipment  to  make it
                     operational

              •      $550/day for onsite service, including engineering consultation on program
                     planning and execution

              •      $9/day rental of equipment

              •      Transportation charges to get the equipment from the manufacturer to the site
                     of operation and back again.

              The purchase price for the UNOX mobile unit is between $260,000 and $330,000
              (Ghassemi, Yu, and Quinlivan,  1981; data updated using 1984 third quarter Marshall
              Swift Index).
TABLE 4
GENERAL COST DATA FOR VARIOUS SIZES OF
ACTIVATED SLUDGE TREATMENT UNITS
Capacity (gpm)
70
140
350
694
Construction Costs ($)*
78,500
85,600
107,000
160,000
O&M Costs ($/year)*
4,300
6,400
10,000
15,700
* Updated from 1978 to 1984 dollars using third quarter Marshall and Swift Equipment Index.
       Aerobic Biological Treatment

       Aerobic biological treatment includes conventional activated sludge processes (FIGURE 1),
       as well as newer modifications of these processes, such as sequential batch reactors, rotating
       biological contactors, trickling filters, genetically engineered bacteria, and fixed-film reactors.
       All of these systems offer effective treatment of aqueous wastestreams contaminated with low
       levels of nonhalogenated organics and/or certain halogenated organics.  These systems may
       be combined with chemical or physical treatment systems to form multiple step treatment
       trains capable  of handling aqueous wastestreams with  significant levels of inorganic and
       organic contamination.  This  includes  systems for removal of contaminants from soils using
       flushing or washing  techniques.
5/93
14

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ISl



VO
                           AERATION STAGE
                       CLARIFIER STAGE
             WASTEWATER


                FEED
                AIR
AIR BUBBLES
                                                 FIXED AIR

                                                 BUBBLE ASSEMBLY
                                                                              IMTTT
                                                                                        EFFLUENT
                                      ACTIVATED SLUDGE RECYCLE
                                                   w
                                                   HN
                                                   o

                                                   s

                                                   2
                                                   n
                                                   >
                                                   r


                                                   i
                                                FIGURE 1

                                ACTIVATED SLUDGE BIOLOGICAL TREATMENT

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BIOLOGICAL TREATMENT

              Waste Types Handled
              Aerobic  biological treatment is  suitable  for aqueous  wastestreams with low to
              moderate levels of organic contamination.  The degree of chlorination of the organics
              will  determine the efficiency and reliability of the biological treatment.  Organics
              with high degrees of chlorination may cause shock loading of the biomass, extended
              biomass acclimation periods, and reduced treatment process efficiency and reliability.

              Restriction Waste Characteristics

              Biological systems require consistent, stable operating conditions, as abrupt changes
              in wastestream  characteristics  can generate shock loading to  the biomass.   The
              biomass  can be vulnerable to highly elevated levels of heavy metals or halogenated
              organics unless  proper acclimation procedures are followed. Equally important is
              maintenance of  stable levels  of key environmental parameters  in the wastestream,
              including dissolved oxygen,  nutrients, pH,  and alkalinity.   Biological systems are
              well  suited  for treatment  of  contaminated  groundwater because groundwater
              characteristics remain relatively stable.

              Mobile System  Considerations

              Equipment required  for aqueous waste treatment is relatively simple.  Large tanks
              equipped with aeration systems and agitators are used for the conventional activated
              sludge biological treatment.   The modified systems such as fixed film reactors and
              trickling filter systems are more space efficient and transportable, and these systems
              are currently offered as mobile units by several firms. Most systems require pumps
              for  circulation  and  aeration.  The treated effluent from these units may  need
              additional treatment  for clarification and removal of remaining organics and heavy
              metals or for discharge to a municipal treatment system. Available mobile systems
              require minimal labor when used with stable, consistent wastestreams.  Fixed-film
              or   trickling  filter   systems  offer significant  advantages   because  of  their
              transportability,  compact size, low operating costs, and high biomass growth surface
              area relative to total volume.  More conventional activated sludge systems require
              sludge disposal for the accumulated biomass, and may be less well suited for mobile
              systems.  Sequential batch reactors can treat aqueous wastestreams  with  elevated
              levels  of contaminants, including certain halogenated organics.   Pilot studies are
              necessary to determine process feasibility. Careful monitoring of the biodegradation
              process  and water  quality  parameters will be  necessary, particularly for more
              concentrated wastestreams, thus requiring on site laboratory facilities.

              Environmental  Impacts

              Settled sludge and/or excess biomass residues will need treatment or disposal and
              may contain elevated levels of organics or heavy metals.  Variation in wastestream
              characteristics may generate  shock loading  and breakdown of the treatment train,
5/93                                         16

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BIOLOGICAL TREATMENT
              necessitating preliminary monitoring.  Undesirable odors may be generated, and it
              may become necessary to drive off volatile organic compounds in the aeration basin.

              Costs

              The capital and operating  costs depend on the specific process selected.  Simple
              treatment  of low-level organic  contamination can  cost  as little as  1/10 of a
              comparable activated carbon system on a cost/gallon basis.  More complicated waste-
              streams may necessitate a more expensive, multiple step treatment train.

              Commercial Applications

              Polybac Corporation offers transportable systems for spill site decontamination using
              microbial biodegradation.

              Contact:       Technical Services Coordinator
                            954 Mancon Boulevard
                            Allentown,  PA  18103
                            215/264-8740

              Detox, Inc., offers a series of portable, fixed-film aerobic  reactors for a variety of
              wastestreams.

              Contact:       Sales Manager
                            64 Marco Lane
                            Dayton, OH 45459
                            513/433-7394

              OH Materials  and Total Recovery offer transportable aeration tanks for aerobic
              biodegradation.

              Contact:       Sales Manager                            Sales Manager
                            OH Materials                             Total Recovery
                            Fudley, OH                              Cleveland, OH
                            419/423-3526                             215/644-6267

              Groundwater  Decontamination Systems offers transportable systems for aerobic
              biological treatment of contaminated groundwater.

              Contact:       Sales Manager
                            Suite 210
                            140 Route 17 North
                            Paramus, NJ  07652
                            201/265-6727
5/93                                        17

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BIOLOGICAL TREATMENT

       Anaerobic Digestion

       Anaerobic  digestion is biodegradation,  a process that has the capability to handle high-
       strength  wastestreams  which would not be efficiently treated by aerobic biodegradation
       processes.  Research has indicated that anaerobic treatment  can  break down halogenated
       organics such as pesticides through reductive dehalogenation of carbon ring structures.
       Additional  advantages of anaerobic digestion processes include low production of biomass
       sludges,  low power requirements and  operating  costs,  and the production of utilizable
       methane  gas.  However, the reliability of anaerobic digesters is not ideal because  of their
       susceptibility to variation in the wastestream and the prolonged time periods required by the
       slow rates of biodegradation.   FIGURE 2 depicts a typical anaerobic digestion system.

              Waste Types Handled

              Anaerobic  biological treatment is suitable for aqueous wastestreams with  low to
              moderate levels of organic contamination. Anaerobic systems can handle  certain
              halogenated organics better than aerobic  systems,  but the biodegradation  process
              (composed of two steps) can be prolonged.

              Restrictive Waste Characteristics

              As with aerobic systems, anaerobic systems are vulnerable to highly elevated levels
              of heavy metals or halogenated organics unless proper acclimation procedures are
              followed.   Stable environmental  conditions must be maintained in the wastestream,
              including dissolved oxygen, nutrients, pH, and alkalinity.  Changes in wastestream
              characteristics  may  result  in damage to the  biomass  and  termination   of  the
              biodegradation process.

              Mobile System Considerations

              Anaerobic  digestors are available  in single tank (standard rate) or two-tank (high
              tank) systems. Volumetric flow through these systems is low and retention times are
              long (10-30 days), which may seriously limit the application as mobile systems. Pilot
              studies are  necessary to determine process feasibility.  Digestors also require careful
              monitoring of operating parameters, necessitating an onsite laboratory.    Sludge
              disposal requirements are  considerably less than for aerobic systems.  Methane gas
              is produced in significant quantities and must be used onsite or disposed of.  Effluent
              from the digestor will require additional treatment (FIGURES 3a, 3b & 3c).

              Costs

              Anaerobic  digestors are  traditionally  used  because  they are  more effective at
              processing  concentrated wastestreams (primarily biodegradable organic by products)
              than comparable aerobic systems, and they have lower operating costs, produce less
              biomass sludge, and produce utilizable  methane gas. Costs for mobile units are not
              available.
5/93                                         18

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SO
VO
         INFLUENT
      WASTEWATER
         WITH
        ORGANIC
        MATERIAL
                                         and C0
  EFFLUENT
WASTEWATER
   WITH
  OXIDIZED
 ORGANICS
                  o
                  s
                  2
                  n
                  >

                  i
                                       FIGURE!
                       SCHEMATIC OF ROTATING BIOLOGICAL CONTACTOR

-------
I/I

VD
                                                                         Gas removal
                Sludge
                inlets
K)
O
                       Digested
                       sludge
                                            Gas storage

                                                Scum Layer

                                                                            Supernatant
                                                                              outlets
Actively digesting
    sludge
                                                                              Sludge
                                                                              outlets
                                               FIGURE 3a
                         CONVENTIONAL, STANDARD-RATE, SINGLE-STAGE PROCESS

-------
  Fixed
   cover
CH4  + C02
                                                ^ Sludge
                                                 outlets
w
1—4
o
s
2
n
                 FIGURE 3b
HIGH-RATE, CONTINUOUS-FLOW STIRRED TANK

-------
LSI
                                                 Digester  gas outlet
               Fixed
                 cover
K)
to
                Floating cover
                                                                                              Scum  layer
                           First Stage

                         (completely mixed)
Second Stage

 (stratified)
                     Supernatant

                      layer and

                      outlets
                                                                                                     Sludge

                                                                                                     outlet$
                                   W
                                   >-*
                                   o
                                   r
                                   o
                                   o

                                   o
                                   >
                                   r

                                   H
                                                                                                              >
                                                                                                              H
                                                   FIGURE 3c

                                 TWO-STAGE TYPICAL ANAEROBIC DIGESTORS

-------
BIOLOGICAL TREATMENT

              Commercial Applications

              There are no commercial mobile units available at present.

       Bioreclamation

              General Description

              Bioreclamation is a technique for treating zones of contamination by microbial
              degradation.  The basic concept involves altering environmental conditions to enhance
              microbial catabolism or cometabolism of organic  contaminants,  resulting  in the
              breakdown and detoxification of  those contaminants.   The technology has been
              developed rapidly over recent years, and bioreclamation appears to be one of the
              most promising of the in-situ treatment techniques.

              Considerable research conducted over the past several decades has confirmed that
              microorganisms are capable  of breaking down many of those organic  compounds
              considered to be environmental and health hazards  at spill sites and uncontrolled
              hazardous waste sites. Laboratory, pilot, and field studies have demonstrated that it
              is feasible to use this capability  of microorganisms  in-situ to reclaim contaminated
              soils and groundwater.

              Microbial metabolic activity  can be classified into three main categories:  aerobic
              respiration, in which oxygen is required as a terminal electron acceptor; anaerobic
              respiration, in  which sulfate  or  nitrate serves as a terminal electron acceptor; and
              fermentation, in which the microorganism rids itself of excess electrons by exuding
              reduced organic compounds.

              The bioreclamation method that has been most developed and is most feasible for in-
              situ treatment is one which relies on aerobic (oxygen-requiring) microbial processes.
              This method  involves optimizing environmental conditions by providing an oxygen
              source and nutrients that are delivered to the subsurface through an injection well or
              infiltration system to enhance microbial activity.  Indigenous microorganisms can
              generally be relied  upon to degrade  a wide range of compounds given  proper
              nutrients and sufficient oxygen.   Specifically  adapted  or  genetically  manipulated
              microorganisms are also available  and may be added to the treatment zone.

              Anaerobic  microorganisms  are   also  capable of degrading  certain  organic
              contaminants.  Methanogenic consortiums, groups of anaerobes that function under
              very reducing  conditions, are able to degrade halogenated aliphatics  (e.g., PCE,
              TCE) while aerobic organisms cannot.  The potential for anaerobic degradation has
              been demonstrated in numerous  laboratory studies and in industrial waste treatment
              processes that  use  anaerobic digesters  or  anaerobic waste lagoons as  part of the
              treatment process.  Using anaerobic degradation as an in-situ reclamation  approach
              is theoretically feasible.
5/93                                         23

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BIOLOGICAL TREATMENT

              Applications and Limitations

              The feasibility of bioreclamation as an in-situ treatment technique is dictated by waste
              and  site characteristics.    The  factors  that  determine  the applicability  of  a
              bioreclamation approach are:

              •       Biodegradability of the organic contaminants

              •       Environmental factors that affect microbial activity

              •       Site hydrogeology.

              Bioreclamation can be expected to reduce the concentration of only those organic
              compounds which  are amenable to biological degradation. These are compounds that
              are either substrates for microbial growth and  metabolism (the organism uses the
              compound as a carbon and energy source) or are cometabolically broken down as the
              microorganism uses another primary substrate as its carbon and energy source.

              An extensive review of research on the relative biodegradabilities of environmental
              pollutants can be found in Evaluation of Systems to Accelerate Stabilization of Waste
              Piles (US EPA, 1985).  Relative aerobic biodegradability of compounds can also be
              estimated  using  laboratory  data  associated   with  oxygen   requirements  for
              decomposition (i.e., 5-day and 21-day biological oxygen demand [BOD5, BOD21],
              COD,  and  the ultimate  oxygen demand [UOD].)  TABLE 5 presents relative
              biodegradabilities  by adapted sludge cultures of various  substances in terms of a
              BOD5/COD ratio.  A Property Estimation Methods (Lyman, Reehl, and Rosenblatt,
              1982) provides additional information on methods of estimating biodegradability.

              TABLE 6 summarizes organic groups subject to microbial metabolism by aerobic
              respiration, anaerobic respiration, and  fermentation.  "Oxidation" indicates that the
              compound is  used as a primary substrate, and "co-oxidation"  indicates  that the
              compound is cometabolized.  These tables and estimation methods provide only a
              general  indication of degradability of  compounds.   In most instances, treatability
              studies will be required to determine degradability of specific waste components.

              For most compounds, the most rapid and complete degradation occurs aerobically.
              There are some compounds, most notably the lower molecular weight halogenated
              hydrocarbons, which will only degrade anaerobically.  (However, recent research
              conducted at EPA's Robert S. Kerr Laboratory  has discovered degradation of TCE
              in  the presence of oxygen and methane gas [Wilson,  1984]).

              It can be generalized that for the degradation of petroleum hydrocarbons, aromatics,
              halogenated aromatics, polyaromatic hydrocarbons, phenols, halophenols, biphenyls,
              organophosphates, and  most pesticides and herbicides,  aerobic bioreclamation
              techniques are most suitable.  For the degradation of halogenated lower molecular
              weight hydrocarbons,  such as the unsaturated alkyl halides PCE and TCE and the


5/93                                        24

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BIOLOGICAL TREATMENT
              saturated   alkyl  halides  1,1,1-trichloroethane  and  trihalomethane,  anaerobic
              degradation under very reducing conditions appears to be the most feasible approach
              in terms of the current understanding of microbial degradative capability. However,
              aerobic degradation in the presence of methane gas appears promising for some low
              molecular weight halogenated hydrocarbons.

              The  availability  of  the  compound  to the  organism  will  also  dictate  its
              biodegradability. Compounds with greater aqueous solubilities are generally more
              available  to  degradative  enzymes.    For  example,  c/s-l,2-dichloroethylene  is
              preferentially degraded  relative  to  frms-l,2-dichloroethylene.   The  most likely
              explanation for this is because the cis configuration is more polar than  trans and is
              therefore more water soluble (Parsons et al., 1982).   The use  of surfactants can
              increase the solubility and therefore the degradability of compounds (Ellis and Payne,
              1984).

              Environmental factors that affect microbial activity and population size will determine
              the rate and extent  of biodegradation.  Hydrogeology will affect not only microbial
              activity, but also the feasibility of in-situ treatment.  These factors include:

              •       Appropriate levels of organic and inorganic nutrients trace elements

              •       Oxygen

              •       Redox potential

              •       pH

              •       Degree of water  saturation

              •       Hydraulic conductivity of the soil

              •       Osmotic potential, including total dissolved  solids

              •       Temperature

              •       Competition,  including the presence of toxins and growth inhibitors

              •       Predators

              •       Types and concentrations of contaminants.
5/93                                         25

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BIOLOGICAL TREATMENT
TABLE 5
BODS/COD RATIOS FOR VARIOUS ORGANIC COMPOUNDS
Compound
Relatively Undegradable
Butane
Butylene
Carbon tetrachloride
Chloroform
1 ,4-Dioxene
Ethane
Heptane
Isobutane
Liquified natural gas
Liquified petroleum gas
Methane
Methyl bromide
Methylchloride
Monochlorodifluoromethane

Ratio

-0
-0
-0
-0
-0
-0
-0
-0
-0
-0
-0
-0
-0
-0

Compound

Nitrobenzene
Propane
Propylene
Propylene oxide
Tetrachloroethylene
Tetrahydronaphthalene
1-Pentene
Ethylene dichloride
1-Octene
Morpholine
Ethylenediaminetetraacetic acid
Triethanolamine
o-Xylene
m-Xylene
Ethylbenzene
Ratio

-0
-0
-0
-0
-0
-0
< 0.002
0.002
> 0.003
< 0.004
0.005
< 0.006
< 0.008
< 0.008
< 0.009
TABLE 5 CONT.
BODj/COD RATIOS FOR VARIOUS ORGANIC COMPOUNDS
Compound
Moderately Degradable
Ethyl ether
Sodium alkybenzenesulfonates
Mineral spirits
Cyclohexanol
Acrylonitrile
Nonanol
Undecanol
Methylethylpyridine
1-Hexene
Methyl isobutyl ketone
Diethanolamine
Formic acid
Ratio

0.012
-0.017
-0.02
0.03
0.031
> 0.033
< 0.04
0.04-0.75
< 0.044
< 0.044
< 0.049
0.05
Compound

Styrene
Heptanol
sec-Butyl acetate
n-Butyl acetate
Methyl alcohol
Acetonitrile
Ethylene glycol
Ethylene glycol monoethyl ether
Sodium cyanide
Linear alcohols (12-15 carbons)
Allyl alcohol
Dodencanol
Ratio

> 0.06
< 0.07
0.07-0.23
0.07-0.24
0.07-0.73
0.079
0.081
< 0.09
< 0.09
> 0.09
0.091
0.097
5/93
26

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BIOLOGICAL TREATMENT
TABLE 5 CONT.
BOD5/COD RATIOS FOR VARIOUS ORGANIC COMPOUNDS
Compound
Relatively Degradable
Valeraldehyde
n-Decyl alcohol
p-Xylene
Urea
Toluene
Potassium cyanide
Isopropyl acetate
Amyl acetate
Chlorobenzene
Jet fuels (various)
Kerosene
Monoisopropanolamine
Gas oil (cracked)
Gasolines (various)
Furfural
2-Ethyl-3-propylacrolein
Methylethylpyridine
Vinyl acetate
Diethylene glycol
monomethylether
Naphthalene (molten)
Dibutyl phthalate
Hexanol
Soybean oil
Paraformaldehyde
n-Propyl alcohol
Methylmethacrylate
Acrylic acid
Sodium alkyl sulfates
Triethylene glycol
Acetic acid
Acetic anhydride
Ethylenediamine
Formaldehyde solution
Ethyl acetate
Octanol
Ratio

< 0.10
> 0.10
< 0.11
0.11
< 0.12
0.12
< 0.13
0.13-0.34
0.15
-0.15
-0.15
< 0.02
-0.02
-0.02
0.17-0.46
< 0.19
< 0.20
< 0.20

< 0.20
< 0.20
0.20
-0.20
-0.20
0.20
0.20-0.63
< 0.24
0.26
-0.30
0.31
0.31-0.37
> 0.32
0.26
0.36
< 0.36
0.37
Compound

Sorbitol
Benzene
n-Butyl alcohol
Propionaldehyde
n-Butyraldehyde
Range oil
Glycerine
Adeponitrile
Ethyleneimine
Monoethanolamine
Pyridine
Dimethylformamide
Dextrose solution
Corn syrup
Maleic anhydride
Propionic acid
Acetone
Aniline
Isopropyl alcohol
n-Amyl alcohol
Isoamyl alcohol
Cresols
Crotonaldehyde
Phthalic anhydride
Benzaldehyde
Isobutyl alcohol
2 ,4-Dichlorophenol
Tallow
Phenol
Benzoic acid
Carbolic acid
Methylethyl ketone
Benzoyl Chloride
Hydrazine
Oxalic acid

Ratio

< 0.38
< 0.39
0.42-0.74
< 0.43
< 0.43
-0.15
< 0.16
0.17
0.46
0.46
0.46-0.58
0.48
0.50
-0.50
> 0.51
0.52
0.55
0.56
0.56
0.57
0.57
0.57-0.68
< 0.58
0.58
0.62
0.63
0.78
-0.80
0.81
0.84
0.84
0.88
0.94
1.0
1.1

5/93
27

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BIOLOGICAL TREATMENT
TABLE 6
SUMMARY OF ORGANIC GROUPS SUBJECT TO BIODEGRADATION

Substrate Compounds
Straight Chain Alkanes
Branched Alkanes
Saturated Alkyl Halides
Unsaturated Alkyl Halines
Esters, Glycols, Epoxides
Alcohols
Aldehydes, Ketones
Carboxylic Acids
Amides
Esters
Nitriles
Amines
Phthalate Esters
Nitrosamines
Thiols
Cyclic Alkanes
Unhalogenated Aromatics
Halogenated Aromatics
Simple Aromatic Nitro
Compounds
Aromatic Nitro
Compounds with
Other Functional
Groups
Phenols
Halogenated Side Chain
Aromatics
Fused Ring Hydroxy
Compounds
Nitrophenols
Halophenols
Phenols-Dihydrides, Poly-
hydrides
Two- and Three-Ring
Fused Polycyclic
Hydrocarbons
Biphenyls
Chlorinated Biphenyls
Four-Ring Fused Polycyclic
Hydrocarbons
Fused Polycyclic Hydro-
carbons
Organophosphates
Pesticides and Herbicides
Respiration
Aerobic
+
+


+
+
+
+
+
+
+
+
+


+
+
+

+



+
+

+

+
+


+


+
+


+

4-

+
Anaerobic
+
+
+
+
+
+
+
+
+
+
+
+
+
+


+
+

+


+
+




+












+
+


Fermination
+
+


+










+







+

+



















Oxidation
+
+
+
+
+
+
+
+




+


+
+
+





+

+



+

+


+










Co-oxidation
+
+
+












+

+




+
+







+












5/93
28

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BIOLOGICAL TREATMENT
              Microorganisms, like all living organisms, require specific inorganic nutrients (e.g.,
              nitrogen, phosphate-phosphorus, and trace metals), and a carbon and energy source
              to survive.  Many organic contaminants provide the carbon and energy and thus serve
              as  primary substrates.   If  the  organic  compound that is the target  of the
              bioreclamation  is  only degraded  cometabolically,  a primary substrate must  be
              available. Aerobes need oxygen, nitrate respirers need nitrate, and sulfate respirers
              need  sulfate.  Various anaerobic populations require specific reducing conditions.
              Optimum microbial activity for bioreclamation purposes occurs within a pH range of
              6.0 to 8.0, with slightly alkaline conditions being more favorable.

              The temperature range for optimal organism growth in aerobic biological wastewater
              treatment processes has  been found to  range from 20° to 37°C  (68° to 99°F).
              According to the "Q-10"  rule, for  every  10°C  decrease in temperature in a specific
              system, enzyme activity  is halved.  FIGURE 4 illustrates  typical  groundwater
              temperatures throughout the United States. Although microbial populations in colder
              waters are adapted  to lower temperatures, biodegradation rates can be expected to be
              much slower than  at higher temperatures.  It may not be feasible to attempt the
              bioreclamation approach in the extreme north.
   52°
           67" 72s
                                       FIGURE 4
                  TYPICAL GROUNDWATER TEMPERATURES (*F)
                     AT 100 FT. DEPTH IN THE UNITED STATES
5/93
29

-------
BIOLOGICAL TREATMENT
              Concentrations of inorganic and/or organic contaminants could be so high as to be
              toxic to the microbial populations. TABLE 7 lists concentrations at which certain
              compounds  have   been  found  to   be  toxic  in  industrial  waste  treatment.
              Microorganisms present  in  the  subsurface may  be more  tolerant  to  high
              concentrations of these compounds.  This determination must be made on a case-by-
              case basis.    Conversely, a  situation may  prevail  in  which  the contaminant
              concentrations are  so low  (<0.1  mg/1) that the assimilative  processes of the
              microorganisms  are sometimes not stimulated.  Thus, adaptation to the particular
              substrate will  not occur and the substrate will not be degraded (SCS Engineers,
              1979).   It is also  possible that even if the  contaminant  is present in acceptable
              concentrations,  if  there  is  another  "preferred"  carbon  source  available,  the
              microorganisms  will catabolize it preferentially.

              It is feasible to  manipulate some of these factors insitu to optimize environmental
              conditions. Nutrients  and  oxygen (or NO3") can be added to the subsurface. It may
              be feasible in some cases to enhance reducing conditions, thereby lowering the redox
              potential.  The pH can be  adjusted with the addition of dilute acids or bases. Water
              could be pumped into an  arid zone.  Bioreclamation could be preceded by other
              treatments that could reduce toxic concentrations to a tolerable level.  Even raising
              the temperature of a contaminated zone by pumping in heated water or recirculating
              groundwater through a surface heating unit may be feasible under conditions of low
              groundwater flow.  This  was done at a bioreclamation site in West Germany to
              increase the groundwater temperature by 10°C (see TABLE  8) (Stief, 1984).

              There are some  factors that cannot be corrected,  such as the presence of predators,
              competition between microbial populations,  or the salinity of groundwater.  This
              points to one of the  advantages of relying on indigenous microorganisms rather than
              added  microorganisms to  degrade  wastes.    Although  the added specialized
              microorganisms  may  have a superior  degradation capability as developed in the
              laboratory or enriched in a surface biological reactor, they may not be able to survive
              subsurface conditions  (e.g.,  salinity,  light  intensity, temperature,  and  type of
              predators). However, through  countless generations of evolution, natural populations
              have developed that   are  ideally suited for survival and  proliferation in  that
              environment.  This  is particularly true of uncontrolled hazardous waste sites where
              microorganisms  have  been exposed  to the  wastes for years  or  even  decades.
              However, use of specialized microorganisms can be expected to have the greatest
              application at spill sites where the exposure time has not been long enough for a
              substantial adapted indigenous  population to evolve.
5/93                                         30

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BIOLOGICAL TREATMENT
TABLE 7
PROBLEM CONCENTRATIONS OF SELECTED CHEMICALS
Chemical
n-Butanol
sec-Butanol
t-Butanol
Allyl alcohol
2-Ethyl-l-hexanol
Formaldehyde
Crotonaldehyde
Acrolein
Acetone
Methyl isobutyl ketone
Isophorone
Diethylamine
Ethylenediamine
Acrylonitrile
2-Methyl-5-ethylpyridine
N,N-dimethylaniline
phenol
Ethyl benzene
Ethyl acrylate
Sodium acrylate
Dodecane
Dextrose
Ethyl acetate
Ethylene glycol
Diethylene glycol
Tetraline
Kerosene
Cobalt chloride
Problem Concentration (mg/1)
Substrate(1)
..
..
> 1000
500-1000
200
	
> 1000
> 1000
> 1000
> 1000
> 1000
> 1000
> 1000
600-1000
> 1000
> 1000
> 1000
> 1000
> 1000
«
~
Nonsubstrate(2)
> 1000
> 1000
> 1000
> 1000
50-100
50-100
> 1000
> 1000
300-1000
100-300
100
100
300-1000
300-600
> 500
> 1000
> 900
> 1000
> 500
> 1000
(1) Substrate limiting represents the condition in which the subject compound is the sole
carbon and energy source.
® Nonsubstrate limiting represents the condition in which other carbon and energy sources
are present.
Source: SCS Engineers, 1979
5/93
31

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UJ
to
TABLE 8
SITE RECLAMATIONS USING BIODEGRADATION, INDIGENOUS MICROORGANISMS
Location
Ambler, PA
1972
Millville, NJ
1976
LaGrange, OR
1982
Biocraft Labs
Waldwick, NJ
1981
Karlsruhe
West Germany
1982
Frankenthal
West Germany
Granger, IN
1984
Kelly Air Force
Base. TX
1985
Contaminant
Gasoline spill
Gasoline spill
Gasoline leak
Methylene chloride,
butanol, dimethyl
online, acetone
Petroleum products,
cyanide
Aromatic and
aliphatic
hydrocarbons
including benzene,
styrene, toluene,
xylene, and
naphthalene
Gasoline leak
Jet fuel
hydrocarbons,
halogenated alkanes
and aromatics, heavy
metals
Waste Site
Characteristics
Soil and groundwater
contamination in a
dolomite aquifer
Soil and groundwater
contamination in a sandy
aquifer
Soil and groundwater
contamination in a
shallow, highly permeable
aquifer
Soil and groundwater
contamination in a layer of
glacial fill
Soil and groundwater
contamination in a
sandy/gravelly aquifer
Soil and groundwater
contamination in a sandy,
high permeability aquifer
Soil and groundwater
contamination in a sandy
aquifer
Hazardous waste disposal
site; soil and groundwater
contamination in clayey,
low permeability aquifer
Treatment
Physical recovery followed by in-situ treat-
ment. Nutrient solution delivered; air
sparged through wells. Producing wells
controlled groundwater flow.
Physical recovery followed by in-situ treat-
ment. Nutrient solution delivered; air
sparged through wells. Producing wells
controlled groundwater flow.
Physical recovery followed by in-situ treat-
ment. Nutrient addition; groundwater
recycled through site. Air supplied at
bottom of injection trench with diffusers.
Physical recovery followed by surface bio-
logical treatment with indigenous micro-
organism; reinjection and in-situ treatment
using aeration wells. Producing wells
controlled groundwater flow.
Groundwater pumped to surface, treated
with ozone, then reinfiltrated.
Physical recovery followed by in-situ treat-
ment. Nitrate respiration enhanced by the
addition of nitrate, recirculated flushing
water stripped and filtered before rein-
jection. Water temperature increased 10°C.
Physical recovery followed by in-situ
treatment. Hydrogen peroxide as oxygen
source and nutrients added in-line to
recycled water.
In-situ treatment planned. Nutrients and
hydrogen peroxide will be added to recycled
groundwater.
Comments
No gasoline left in aquifer
10 months after treatment;
estimated from 744 to 944
barrels degraded
No free product detected at
end of program; phenol
concentrations reduced to
acceptable levels
System operated one year,
after which no free product
detected
Concentrations reduced from
100 to 700 mg/1 down to 0. 1
mg/1 or less in groundwater
after two year program
Drinking water quality
produced
In 3 months aromatics gone
and aliphatics reduced to 1/4
initial concentrations
Program evaluation not yet
available
Treatment to commence
Spring of 1985
Reference
Raymond,
Jamison, and
Hudson, 1976
Raymond et al.,
1978
Minugh et al.,
1983
Jhaveri and
Mazzacca, 1984
Nageietal., 1982
in Lee and Ward,
1984
Stief, 1984
API, Washington,
DC., personal
communication
Wetzel, Henry,
and Spooner, 1985

-------
BIOLOGICAL TREATMENT
              Significant and  active microbial populations have been found  in the subsurface.
              Many types of bacteria have been isolated from subsurface soils and groundwater,
              and a considerable amount of research has recently been conducted to enumerate and
              characterize subsurface populations (e.g., Hirsch and Rades-Rohkohl, 1983; White
              et al., 1983; Ghiorse and Balkwill, 1983; Wilson et al., 1983; Ehrlich et al., 1983,
              Ventullo and Larson, 1983; and Harvey, Smith, and George, 1984).

              Research confirms that substantial adapted populations do exist in contaminated zones
              and  that  bacterial  numbers  are  elevated  in  contaminated  zones  relative  to
              uncontaminated zones (i.e., the organic contaminants are being metabolized, leading
              to an increase in bacterial biomass). For example, in one study, significant bacterial
              populations were found  in groundwater contaminated with gasoline,  fuel oil, and
              other petroleum products (Litchfield and Clark,  1973).  Groundwater containing less
              than  10 ppm  of these hydrocarbons generally had populations of less than 103
              organisms/ml,  whereas  groundwater  with greater  than  10 ppm  hydrocarbons
              contained  populations on the order of 106 organisms/ml.  An investigation  of a
              hazardous waste site contaminated with high concentrations of jet  fuel hydrocarbons,
              industrial solvents, and heavy metals revealed bacterial numbers on the order of 107
              cells/wet gram sample in core samples taken from the upper unsaturated zone and the
              saturated zone (Wetzel,  Henry, and  Spooner,  1985).   A  biodegradation study
              conducted with subsurface soil  and groundwater from this site  revealed that  both
              aerobic  and anaerobic populations were present that were capable of degrading the
              organic contaminants.

              Even if substantial, active  microbial  populations  are  present,  the  wastes  are
              biodegradable,  and  there  are  parameters  that  can  be  altered  to  optimize
              biodegradation insitu, bioreclamation will not be feasible  if the hydrogeology of the
              site  is not suitable.   The hydraulic  conductivity must  be  great  enough and the
              residence time short enough so that added substances, oxygen, and nutrients are not
              "used up" before reaching the distant portions of the treatment zone.   Sandy and
              other highly permeable sites  will be far  easier  to treat than sites containing clayey
              soils.

              There is  also the  possibility  that added substances may  react with the  soil
              components.   Oxidizing the subsurface could result in the precipitation of iron and
              manganese oxides and hydroxides.  If precipitation is extensive, the delivery system
              and possibly even the aquifer could become clogged.  The in-situ bioreclamation of
              a site near Granger,  Indiana,  developed problems with precipitation and clogging of
              the aquifer (TABLE 9).   Addition of phosphates could result in the precipitation of
              calcium and iron phosphates.   If calcium concentrations  are high,  the added
              phosphate can be tied up by the calcium and would therefore not be available to the
              microorganisms.
5/93                                         33

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LA
TABLE 9
EXAMPLES OF BIOLOGICAL RENOVATION AT CONTAMINATED SITES
Waste Site
Contamination
Styrene
Atrazine
Sludge con-
taining Tri-
chlorophenate
Petroleum
Distillate
Acrylonitrile
Formaldehyde
Ortho - Chloro-
phenol
Concentration
(ppm)
25
Saturated
300
12,000
1,000
1,400
15,000
:. , ;Wa^tfe.::&;;- ;•;;. < ::-
Characteristics
Railroad tankcar spill, area
soils contaminated to a
depth of 8 inches
50-acre field
Sludge spread on soil to a
depth of 6 inches
Spill covering 4 acres at an
oil tank farm
Soil and groundwater
contamination
Soil and groundwater
contamination
Soil and groundwater
contamination
Biological
Agent
BI-CHEM SUS-8
BI-CHEM-PBO-6
BI-CHEM-GEC-1
BI-CHEM-SUS-8
PHENOBAC
PHENOBAC
MUTANT
BACTERIA
Treatment Time
(days)
21

28
21
90
22
274
Residual
Concentration
(ppm)
less than 1

less than 1
less than 1
less than 1
less than 1
less than 1
                                                                                                                       w
                                                                                                                       M





                                                                                                                       I


                                                                                                                       NH





                                                                                                                       g
  Source: US EPA, 1982a

-------
BIOLOGICAL TREATMENT

              Heavy metals, bound in the soil matrix, could be mobilized into the groundwater.
              In reduced conditions, especially when there  is ample organic carbon available,
              metals are likely to be bound in the soil as organic/metal chelates and as sulfides.
              When oxidized, the metal cations could coprecipitate with ferric hydroxide and/or
              precipitate in calcium/phosphate complexes.  If iron and phosphate precipitation does
              not occur to a significant extent, the soluble  metallic cations will remain in  the
              aqueous phase. The soils may also plug as  a result of excess biological growth.

              Design Considerations

              Biological  treatment  at  contaminated  sites encompasses  both in-situ treatment
              approaches and treatment approaches involving groundwater withdrawal and treatment
              in biological reactors on the surface. This section addresses in-situ treatment and the
              combined use of in-situ and aboveground treatment.

       Aerobic Bioreclamation

       The  first  site remediation to treat hydrocarbon contamination insitu  was conducted by
       Raymond,  Jamison, and coworkers  at  Suntech in the early  1970s.  The first treatment
       approaches involved stimulating the indigenous microflora through the delivery of nutrients
       and air to the subsurface. Considerable developments have been made since the early 1970s,
       and  many  different  treatment  approaches  have  been used successfully  to  enhance
       biodegradation in contaminated zones.  The indigenous microflora have been used in some
       site cleanups to degrade wastes.  Specialized microorganisms,  either adapted strains or
       genetically altered  strains, have been used at other  site remediations. Air was  used in the
       earlier site remediations to provide oxygen.  Hydrogen peroxide or possibly  ozone now
       appear to  be feasible alternatives to air or pure oxygen as an oxygen source.   The earlier
       applications involved gasoline spills (Raymond, Jamison, and Hudson, 1976).   Biological
       degradation is now being tested  at a hazardous waste disposal site that contains a complex
       range of organics (Wetzel, Henry, and Spooner, 1985).  TABLE 8 lists site reclamations that
       have involved stimulating the indigenous microflora.  TABLE 9 lists site reclamations in
       which specialized microorganisms were used.

              Oxygen Supply

              Oxygen can be provided to the subsurface through the use of air, pure  oxygen,
              hydrogen peroxide, or possibly ozone.  TABLE 10  summarizes the advantages and
              disadvantages of the oxygen supply alternatives.

              Air can be added to extracted groundwater  before reinjection, or it can be injected
              directly into the aquifer.  The first method, in-line aeration,  involves adding air  into
              the pipeline and mixing  it  with a static mixer (FIGURE 5).  This can provide a
              maximum of approximately 10 mg/1 O2.
5/93                                         35

-------
BIOLOGICAL TREATMENT
TABLE 10
OXYGEN SUPPLY ALTERNATIVES
Substance
Air


Oxygen-
Enriched Air
or Pure
Oxygen
Hydrogen
Peroxide


Ozone


Application
Method
In-line


. In-situ wells
In-line

In-situ wells
In-line


In-line


Advantage
• Most economical


• Constant supply of
oxygen possible
• Provides considerably
higher 02 solubility
than does aeration

• Constant supply of
oxygen possible
• Moderate cost
• Intimate mixing with
groundwater
• Greater O2 concent-
rations can be
supplied to the sub-
surface (100 mg/1)
H2O2 provides 50
mg/1 O2
• Helps to keep wells
free of heavy
biogrowth
• Chemical oxidation
will occur, rendering
compounds more bio-
degradable


Disadvantages
• Not practical except
for trace
contamination < 10
mg/1 COD
• Wells subject to
blowout
• Not practical except
for low levels of
contamination < 25
mg/1 COD
• Very expensive
• Wells subject to
blowout
• H2O2 decomposes
rapidly upon contact
with soil, and
oxygen may bubble
out prematurely
unless properly
stabilized


• Ozone generation is
expensive
• Toxic to micro-
organisms except at
low concentrations
• May require
additional aeration
5/93
36

-------
BIOLOGICAL TREATMENT
                Air
 Flow
                                     FIGURES
                       CONFIGURATION OF STATIC MIXER
Source:  US EPA, 1985
             This concentration is sufficient only for degradation of about 5 mg/1 hydrocarbons,
             and would therefore provide an inadequate oxygen supply.  A pressurized line and
             the use of pure oxygen can increase oxygen concentrations.

             The equilibrium oxygen concentration in water increases with increased air pressure
             according to Henry's Law (Sawyer and McCarty, 1967):
5/93
37

-------
BIOLOGICAL TREATMENT

              where:        CL     =      PHk

                            CL     =      concentration of oxygen in liquid (mg/1)

                                   =      volume fraction (0.21 for O2 in air)

                            P      =      air pressure (atm)

                            Hk     =      Henry's Law Constant for oxygen.

              The  value  of Henry's Law  constant is 43.8 mg/1-atmosphere  at  68°F (20°C).
              Pressure increases with groundwater depth at the rate of 0.0294 atmospheres per foot.

              The use of in-situ aeration wells (FIGURE 6) is a more suitable method for injecting
              air into contaminated leachate plumes. A bank of aeration wells can be installed to
              provide a zone of continuous aeration through which the contaminated groundwater
              would flow. Oxygen saturation conditions can be maintained for degrading organics
              during the  residence time of  groundwater flow through the aerated zone.   The
              required time for aeration can be derived from bench-scale studies. Residence time
              (t,) through the aerated zone can be calculated from Darcy's equation (Freeze and
              Cherry, 1979) using groundwater elevations (i.e., head) and hydraulic conductivity
              as follows:

                     t,      =     (La)2/K(hrh2)

              where

                     t,.      =     residence time (sec)

                     K      =     hydraulic conductivity (ft/sec)

                     La     =     length of aerated zone (ft)

                     h!      =     groundwater elevation at beginning of aerated zone (ft)

                     h2      =     groundwater elevation at end of aerated zone (ft).

              In the design of an in-situ aeration well zone system, the zone must be wide enough
              to allow the total plume to pass through. The flow  of air must be sufficient to  give
              a substantial radius of aeration but small enough to not cause an air barrier to the
              flow of groundwater.
5/93                                        38

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BIOLOGICAL TREATMENT
      Plane View
                                                       iont of Aeration
        Surf«c» Contour*.
                                                         Direction of Groundwittr Flow
   Cross-sectional
       View
                       . Air Injection Wells
                   • e •
 •
•
• •
                                        W
                                                   . Aarated Zone
                                   FIGURE 6
         POSSIBLE CONFIGURATION  OF IN-SITU AERATION WELL BANK
Source:  US EPA, 1985
5/93
          39

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BIOLOGICAL TREATMENT
              Various methods can be used to inject air or pure oxygen. Air has been sparged into
              wells using diffusers.  For example, Raymond et al. (1975) sparged air into wells
              using diffusers attached to paint sprayer compressors that could deliver approximately
              2.5 cubic feet per minute.  They were  fitted with steel end plates and fittings to
              accommodate a polyethylene air line and a nylon rope and were  suspended into the
              wells.

              A blower can also be used to provide the flow rate and pressure for aeration.  At the
              groundwater bioreclamation project in Waldwick, New Jersey, 5 pounds per square
              inch pressure is maintained in nine 10-foot aeration wells, each with an air flow of
              5 cubic feet per minute (Groundwater Decontamination Systems, Inc., 1983).

              Microdispersion of air in  water using colloidal gas aprons (CGA) creates bubbles
              25-50 micrometers in diameter.  This is a newly developed method which holds great
              promise as a means of introducing oxygen to the subsurface (Michelsen, Wallis, and
              Sebba,  1984).  With  selected surfactants, dispersions of CGAs can be generated
              containing 65-percent air by  volume.

              Oxygenation systems,  either  in-line or in-situ can also be installed to supply oxygen
              to  the bioreclamation process.  Their advantage over conventional aeration systems
              is that  higher oxygen  solubilities and, hence, more efficient oxygen transfer to the
              microorganisms can be attained.  Solubilities of oxygen  in various liquids are 4-5
              times higher under pure oxygen systems than with conventional aeration. Therefore,
              in-line  injection of pure oxygen  will provide  sufficient dissolved  oxygen to degrade
              20-30  mg/1 of organic material, assuming 50-percent cell conversion.  The higher
              oxygen solubilities may provide some flexibility in the design of cell banks, especially
              at  greater pressures, because the oxygen may not be used up  immediately, as with
              aeration.

              Hydrogen peroxide (H2O2) as an oxygen source has been  used  successfully at the
              cleanup of several  spill sites  (Brubaker, G.R., FMC Aquifer Remediation  Systems,
              Princeton, New Jersey,  personal communication, 1985).  Advantages of hydrogen
              peroxide include:

              •      Greater oxygen concentrations can be delivered to the subsurface.   100 mg/1
                     H2O2 provides 50 mg/1 O2.

              •      Less equipment is required to oxygenate the subsurface. Hydrogen peroxide
                     can be added in-line along with the nutrient solution. Aeration wells are not
                     necessary.

              •      Hydrogen peroxide keeps the well free of heavy biogrowth.  Microbial
                     growth and subsequent  clogging are sometimes  a problem in air  injection
                     systems (Yaniga, Smith, and Raymond, 1984).
5/93                                        40

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BIOLOGICAL TREATMENT
              Hydrogen peroxide is cytotoxic, but research has demonstrated that it can be added
              to acclimated cultures at up to  1,000 ppm  without toxic effects  (Texas  Research
              Institute, 1982).   The remediation at Granger, Indiana, involved  adding  an initial
              concentration of 100 ppm and  increasing it to 500 ppm over the course of the
              treatment (API, Washington, DC, personal communication, 1985).

              Hydrogen peroxide decomposes to  oxygen and water (H2O2-»O2  + H2O).  In the
              subsurface, hydrogen peroxide decomposition is catalyzed by chemical and biological
              factors.  There has been some concern that decomposition could occur so rapidly that
              oxygen would bubble out near the site of injection and no oxygen would be made
              available to the distant portions of the treatment zone.  Research has shown that high
              concentrations of phosphates (10 mg/1) can stabilize peroxide for prolonged periods
              of time  in the presence of ferric chloride, an aggressive catalyst  (Texas  Research
              Institute, 1982).   However,  there are problems associated with adding  such  high
              phosphate concentrations to  the  subsurface.  One problem  is precipitation.  One
              company claims  to have developed  specially stabilized hydrogen peroxide products
              for aquifer  remediation.   However, process  performance  information  on these
              products is not available.

              Ozone is used for disinfection  and chemical oxidation of organics  in water and
              wastewater treatment. In commercially available ozone-from-air generators, ozone
              is  produced at a concentration of  1-2 percent in air (Nezgod,  W., PCI Ozone
              Corporation, West Caldwell, New Jersey, personal communication, 1983).   In
              bioreclamation, this ozone-in-air mixture could be contacted with  pumped leachate
              using in-line injection and static mixing or using a bubble contact tank.  A dosage of
              1-3 mg/1 of ozone can be used to attain chemical oxidation (Nezgod, W., PCI Ozone
              Corporation, West Caldwell, New Jersey, personal communication, 1983).  However,
              German research on  ozone pretreatment of contaminated drinking waters indicates
              that the maximum ozone dosage  should not be greater than 1 mg/1 of ozone per mg/1
              total  organic  carbon;  higher  concentrations  may  cause deleterious effects  to
              microorganisms  (Rice, R.G.,  Rip  G., Rice,  Inc.,  Ashton, Maryland, personal
              communication,  1983).   At many sites, this  may  limit the use of ozone  as  a
              pretreatment method to oxidize refractory organics, making them more amenable to
              biological oxidation.

              A  petroleum products spill  in Karlsruhle, Germany, was cleaned up in-situ using
              ozone as an oxygen source for biological degradation (Nagel et al.,  1982, in Lee and
              Ward, 1984).   The groundwater was  pumped  out,  treated with  ozone, and
              recirculated. Approximately 1 gram of ozone per gram of dissolved organic carbon
              was added to the groundwater and was allowed a contact time of 4 minutes in the
              aboveground reactor.  This increased the oxygen content to 9 mg/1 with a residual of
              0.1-0.2 grams of ozone per cubic meter in the treated water.
5/93                                        41

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BIOLOGICAL TREATMENT

              Nutrients
              Nitrogen and  phosphate are the  nutrients  most  frequently present in limiting
              concentrations in soils.  Other nutrients required for microbial metabolism include
              potassium, magnesium, calcium, sulfur, sodium, manganese, iron, and trace metals.
              Many of these nutrients may already be present in the aquifer in sufficient quantities
              and need not be supplemented.

              The optimum nutrient mix can be determined by laboratory growth studies and from
              geochemical evaluations of the  site.   Caution must  be exercised in evaluating
              microbial needs based on soil and groundwater chemical analysis.  Chemical analysis
              does not necessarily indicate what is available to the microorganisms.  In some cases
              generalizations can be made (e.g., if calcium is present at  200  mg/1 [a very high
              concentration], it is likely that calcium supplementation is unnecessary).

              The form of nutrients may or may not be critical in terms of microbial requirements,
              depending on the site.  Studies have shown that forms of nitrogen and phosphate were
              not critical for microorganisms (Jamison, Raymond, and Hudson, 1976). However,
              it has been recommended that an  ammonia-nitrogen source is preferable to a nitrate-
              nitrogen source  because  ammonia-nitrogen  is  more  easily  assimilated  by
              microorganisms (FMC,  1985).   Nitrate is also a pollutant limited to 10 mg/1  in
              drinking water.

              The site geochemistry may  be a critical factor in determining the form of nutrients,
              as well  as the added concentrations.  For example, use of diammonium phosphate
              could result in excessive precipitation (Jamison, Raymond, and Hudson, 1976), and
              nutrient solution containing sodium could cause dispersion of the clays,  thereby
              reducing permeability (Anderson, D., K.W.  Brown and Associates, Inc., College
              Station, Texas, personal communication, 1985). Where calcium  is high, it is likely
              to lead to the precipitation of added phosphate, rendering it unavailable to microbial
              metabolism.   If a site is likely to encounter  problems with precipitation, iron and
              manganese addition may not be desirable.  If the total dissolved solids content in the
              water is extremely high, it may be  desirable to add as little extra salts as possible.

              The compositions of some basal salts media are given in TABLES 11 and 12. Only
              phosphate and nitrogen had to be added to a site in Ambler, Pennsylvania.  Bulk
              quantities of ammonium sulfate [(NH4)2SO4)], disodium phosphate (NajHPO^, and
              monosodium  phosphate  (NaH2PO4) were mixed  in a 2,200-gallon tank  truck and
              added to the groundwater in the form of a 30-percent concentration in water that was
              metered into the injection wells (Raymond, Jamison, and Hudson, 1976). Phosphate
              concentrations in injection wells varied from 200 to 5,800 mg/1 throughout the site
              cleanup. Phosphate concentrations in all wells were determined weekly and injection
              rates were adjusted accordingly.
5/93                                        42

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BIOLOGICAL TREATMENT
TABLE 11
COMPOSITION OF BASAL SALTS MEDIA
Salt Type
KH2PO4
Na2HOP4
(NH4)N03
MgSO47H2O
Na2CO3
CaCl22H2O
MnSO24H2O
FeSO47H2O
Concentration (mg/1)
400
600
10
200
100
10
20
5
Source: Jamison, Raymond, and Hudson, 1976
                                    TABLE 12
                   BASAL SALT MEDIUM USED BY CDS, INC.
                     Salt
             Concentration (mg/1)
                    NH4C1
                   KH2PO4
                   K2HPO4
                   MgS04
                   Na2CO3
                    CaCl2
                   MnSO4
                    FeSO4
                    500
                    270
                    410
                     1.4
                     9
                     0.9
                     1.8
                     0.45
Groundwater Decontamination Systems, Inc., 1983
             CDS, Inc., used the basal  salt medium listed in TABLE  12  in the  combined
             surface//n-5/m treatment system at the Biocraft site (Jhaveri and Mazzacca, 1984).
             The nutrient solution used at the Granger, Indiana, site was composed of ammonium
             nitrate and disodium phosphate (FMC, 1985).
5/93
43

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BIOLOGICAL TREATMENT
              An organic carbon source, such as citrate or glucose, could be added if the compound
              of interest is only degraded cometabolically and a primary carbon source is required.
              Such additions could also be made when low levels of contaminants are present and
              are not sufficient to sustain  an  active microbial  population.  Citrate, or another
              chelator such as EDTA, could be added to hold metals in solution if water is alkaline,
              a  condition  under  which metals may  precipitate.   Citrate,  however, will  be
              preferentially degraded relative to other organics, and could slow the degradation of
              contaminants. Addition of low concentrations of a source of amino acids, such as
              peptone  or  yeast  extract,  could  promote  biodegradation.     However,  high
              concentrations of these compounds could inhibit degradation of contaminants because
              of preferential degradation.

              Design of Delivery and Recovery Systems

              One of the major factors  determining success of an in-situ  treatment system is to
              ensure that the  injection  and recovery  systems  are designed  to accomplish  the
              following:

              •      Provide adequate contact between treatment agents and contaminated soil or
                     groundwater

              •      Provide hydrologic control of treatment agents and contaminants to prevent
                     their migration beyond the treatment area

              •      Provide  for  complete  recovery of spent  treatment  solutions  and/or
                     contaminants where necessary.

              A number of design alternatives are available for delivering nutrients and oxygen to
              the subsurface and for collecting and containing the groundwater.  These methods can
              generally be categorized as gravity flow or forced methods. Most of the systems that
              have been used for bioreclamation have involved the use of subsurface drains (gravity
              system),  injection wells,  and extraction wells.   Some examples  of  delivery and
              recovery systems are described below.

              FIGURE 7 illustrates a hypothetical configuration in which groundwater is extracted
              downgradient of the zone of contamination and reinjected upgradient. In-situ aeration
              supplies oxygen directly to the contaminant plume, while nutrients and oxygen  are
              added  in-line by  way of mixing  tanks.   Treated  water  is  infiltrated through
              contaminated soil to flush contaminants from the soil. Extraction and injection wells
              can be used  to  treat contaminants to almost any depth in both the  saturated and
              unsaturated zone.   However, their use becomes  cost-prohibitive   in  very low
              permeability soils because  of the need to space the wells very close together to ensure
              complete delivery or recovery. Subsurface drains can be used under  conditions of
              moderately low  permeability,  although delivery and recovery of chemicals will be
              slow.  They  are generally limited to depths of 40 feet or less because of the cost
              associated with excavation (shoring, dewatering,  and hard rock excavation) of  the
5/93                                         44

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BIOLOGICAL TREATMENT
              trench.   Surface gravity  delivery systems (e.g.,  spray  irrigation, flooding,  and
              ditches) that involve application of treatment solutions directly to the surface, as
              illustrated by "surface flushing" in FIGURE 7, are most effective for treating shallow
              contaminated zones located in the unsaturated zone. They can also be used to treat
              contaminants in the saturated zone, provided the following conditions are met:

              •      The soil  above the saturated zone  (through which treatment  solutions
                     percolate) is sufficiently permeable to allow percolation of treatment solutions
                     to the groundwater within a reasonable length of time

              •      Groundwater flow rates must be sufficient to ensure complete mixing of the
                     treatment solutions with the groundwater.

              The feasibility and effectiveness of these methods  are affected by topography and
              climate.

              FIGURE 8 shows the design of a groundwater injection/recovery system that is
              currently being used for bioreclamation at an Air Force site (SAIC/JRB, 1985).  The
              system, which is designed to operate in moderately low permeability soils, consists
              of nine pumping wells and four injection wells.  Groundwater is pumped at an even
              rate from the pumping wells  to  a  central flow equalizer (surge tank).  Flow is
              metered from this tank into a length of pipe  into which measured amounts of nutrients
              and hydrogen peroxide are added. The treated water then flows to a distribution box
              to be distributed at an even rate to each of the four injection wells.  Overflow from
              the equalization tank will flow into an onsite storage tank.

              The injection/recovery system was designed using a two-dimensional, geohydrologic,
              nonsteady flow model that simulated the flow of groundwater at the site in response
              to an injection/recovery pumping  system.

              Important criteria used for the design of the injection/recovery  system include the
              following:

              •      The groundwater injection rate will  be the same as the rate determined during
                     the field  testing program

              •      All injected groundwater and associated elements are  to be kept within the
                     site boundary to prevent the transport of contaminants to adjacent areas (this
                     implies that there may be some net groundwater pumpage at the site)

              •      The distance between the injection-pumping wells  should  be  such  that
                     approximately six  injection-pumping cycles can be completed within a 6-
                     month period.
5/93                                        45

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BIOLOGICAL TREATMENT
         Injtciion
          Wei
                     View of
               BioiccUmition of
               Sol and Groundwaier
      AefnJoo Zone

of CieunOwtltr Flow >—^v

                                  FIGURE?
           SIMPLIFIED VIEW OF GROUNDWATER BIORECLAMATION
5/93
   46

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BIOLOGICAL TREATMENT
                                             KEY t

                                            (7)  Puoplnj We 111

                                            (7)  Injection Veils

                                           	  Untreated Crouadvater Lines

                                           — — —  Treated Groundvater Lines
                                 FIGURES
               PLAN VIEW OF EXTRCTION/INJECTION SYSTEM
                        USED AT AN AIR FORCE SITE
5/93
47

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BIOLOGICAL TREATMENT

              FIGURE 9 illustrates an injection trench used in the treatment of the Biocraft site
              (Jhaveri and Mazzacca,  1983).  The trench was 10 feet deep by 4 feet wide by 100
              feet long. The trench had a IS mil plastic liner installed on the bottom, back, ends,
              and top such that reinjected water only flowed out of the front (downgradient) face
              of the trench. About 40 feet of slotted steel pipe was installed horizontally in the
              trench to carry reinjected water into the trench system.  As water flowed into the
              injection trench, the water was forced to exit only from the front face.  Backflow is
              minimized by this design feature.  Barriers can also be used behind the trench and
              extended to a point where backflow  is further minimized.  In extreme cases, total
              control  over backflow  and plume containment  can  be obtained by  installing a
              circumferential wall barrier.

              Optimum extraction and injection flow rates will many  times be predetermined by
              aquifer yield limits or hydraulic design for plume containment.

              Aquifer flow rates should be sufficiently high so that the aquifer is flushed several
              times over the period of operation.  Thus, if the cleanup occurs over a  3-year period,
              flow rates between injection and extraction wells should be such that a  residence time
              of 6 months or less occurs between the well pairs.  This corresponds  to six or more
              flushes.  Several recycles would result in (1) flushing of soils containing organics,
              preventing the clogging  caused by microorganism buildup because of increased flow
              rate; (2) more even distribution of nutrients and organic concentration within the
              plume;  and (3)  better and more  controlled degradation.  Flow rates  and recycle
              should not be high enough to cause excessive  pumping costs, loss of hydraulic
              containment  efficiency   because  of  turbulent  conditions,   corrosion,  excessive
              manganese deposition, flooding, or well blowout. The operating period will depend
              on the biodegradation rate of the contaminants in the plume  and  the amount  of
              recycle.  If the period of operation is excessively long (e.g. more than 5 years), the
              operating costs of bioreclamation may outweigh the capital costs of another remedial
              alternative.

       Anaerobic Bioreclamation

       Anaerobic treatment is generally not as promising for site remediation as aerobic treatment.
       Anaerobic processes are slower, fewer  compounds can be degraded, and the logistics  of
       rendering a  site anaerobic have not been developed to date.

       Anaerobic metabolism includes  (1) anaerobic respiration, in which nitrate or  sulfate may  be
       used by nitrate or sulfate reducers as a terminal electron  acceptor  and   (2) interactive
       fermentative/methanogenic processes, which are carried out by "methanogenic consortiums."

       If it were possible to provide  proper reducing conditions, degradation by  methanogenic
       processes would be promising.  A considerable body of research indicates that methanogenic
       consortiums are active  in the  subsurface and  are  capable of  degrading certain organics
       (Ehrlich et al., 1982; Parsons et al., 1982;  and Suflita  and Gibson,  1984).  Most notably
       methanogenic consortiums are able to degrade TCE, PCE, and other lower molecular weight


5/93                                        48

-------
u»
             Piano View
                                                                         ol Enilh Mound
                                                                                          I" Wtl
                       4" Dlamoloi Wntliod Stono
              Front View
   4" Dlirnlet Pintle
   W«H Mind Slollid
              ^-Enlh Mound
Wiim^m
    Plltlle Itnst
lOvnlipped 1-3 Tlm««)
                                                                           7" Diimtler Win
                                                                             Hand Slotted
                                                         4" Olnnotot
                                                        Wnl.id Slon*
             Appioi. to*
                                                                                    i  Sind Bin
                                                                                    I   on Top   _ 	
                                                                                    I   ot llnoi   6"
                                                                            Sand Olf*
                                                                            Oelow Llnir
                                                                                              c-.ir
                                                      too1
                                                                                                                    Gridt

                                                                                                                Pintle Unm
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                                                                                                                  4" DUmdtf
                                                                                                                 Wlihtd Slont
                                                                                     Plulk Lhigi

                                                                                     Sind But
                                                                                      on Top
                                                                                      ol Llnci
                                                                                        Sind Bui
                                                                                       Bilow Llnti
                                                                                     (AppfO*. 1 Ft. Thick
                                                                                      No Liu  Thin 8"!
                                                                                                            w
                                                                                                            1—I
                                                                                                            o
                                                                                                            s
                                                                                                            o
                                                                                                            I-H
                                                                                                            n
                                                                                                            >
                                                                                                            r
                                                                                                            H
                                                                                                                                         >
                                                                                                                                         H
                                                                FIGURE 9
                                         CONFIGURATION OF REINJECTION TRENCHES
   NOTE:     Treated water exits only from one side of the trench.

   Source: Jhaveri and Mazzacca, 1983

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BIOLOGICAL TREATMENT

       halogenated organics  that generally  cannot be degraded by aerobic or other respiratory
       processes.   Reductive dehalogenation appears to be the primary mechanism involved in
       degradation.   Methanogenic consortiums are also  able  to  degrade various aromatics,
       halogenated aromatics, and some pesticides. Degradation of petroleum hydrocarbons, as well
       as straight-chain and  branched alkanes  and  alkenes, is not possible under methanogenic
       conditions.

       Methanogenic activity requires a very low redox potential, -250 mv or less.  If O2, NO3", or
       S042" are  present, the redox potential will not be low enough.  Currently, there are no
       demonstrated methods for rendering a site anaerobic.  When the contamination is shallow,
       an aquitard is  below the zone of contamination, and the flow of groundwater  can be
       contained,  it might be possible  to induce reducing conditions by flooding the site, (similar
       to a rice paddy).  Another possible method of rendering the site anaerobic would be to add
       excessive amounts of easily  biodegradable organics so  that the oxygen would be depleted.
       One  other  promising  possibility might be to circulate groundwater to the surface through
       anaerobic digesters or anaerobic lagoons. These methods may  require long retention times
       because of slow degradation rates under anaerobic conditions.  There have been no reports
       of pilot or  field studies using anaerobic degradation under methanogenic conditions.

       Nitrate respiration may be a feasible approach to decontaminating an aquifer.  Denitrification
       (the  reduction of NO3 to NH3 or N2)  has been demonstrated in contaminated aquifers.
       Nitrate respiration was used successfully in the treatment of an aquifer contaminated with
       aromatic and aliphatic hydrocarbons (TABLE 8) (Stief, 1984).  Nitrate can be added in-line
       along with other nutrients and  intimate  mixing with  groundwater can occur.  The cost is
       moderate; all that is required is the nutrient feed system and an in-line mixer.

       Nitrate, however, is a pollutant, limited to 10 ppm in drinking water.  Consequently, it may
       be more difficult to obtain permits for use of nitrate at a site than for oxygen or hydrogen
       peroxide.   Additionally,  degradation rates under aerobic conditions are  more rapid and a
       broader range of compounds can be degraded.  There  is no reason why  nitrate respiration
       would be a better treatment approach given the amount of success that has been demonstrated
       with aerobic treatment approaches to date.

              Operation and Maintenance

              Operation and maintenance of  a bioreclamation process  involve  aspects of  the
              hydraulic system as well as the biological system.  The hydraulic aspects  relate to
              pumps, extraction and injection wells, and injection trenches.

              Monitoring a number of parameters is necessary to determine process performance.
              Monitoring of groundwater can be performed at the injection and extraction wells,
              as well as at monitoring wells. Monitoring wells should be placed onsite to monitor
              process performance and offsite to  monitor for pollutant migration and provide
              background information on  changes  in  subsurface  conditions  due to  seasonal
              fluctuation.   TABLE  13  lists parameters that should  be monitored and  suggests
              methods which can be used to monitor these parameters.


5/93                                         50

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BIOLOGICAL TREATMENT
              In a biological system, pH should be maintained in a range between 6 and 8, and
              concentrations of both nutrients and organics should be kept as uniform as possible
              to protect against shock loading. Dissolved oxygen should be maintained above the
              critical concentration  for the promotion of aerobic activity, which ranges from 0.2
              to 2.0 mg/1, with the  most common being 0.5 mg/1 (Hammer, 1975).

              Clogging of  the  aquifer, injection  wells  or  trenches,  or extraction  wells by
              microbiological sludge is a possibility. CDS  Inc., installed two wells in each of their
              injection trenches in case flushing  was ever  required to remove sludge.   After  IVi
              years of operation,  clogging  had not occurred (Groundwater  Decontamination
              Systems, Inc., 1983). However, problems with biofouling and plugging of sparging
              points was encountered during a spill cleanup conducted by Groundwater Technology
              (Yaniga, Smith, and  Raymond, 1984).  This interfered with oxygen transfer and
              necessitated frequent mechanical cleaning.  When hydrogen peroxide was substituted
              for air sparging in order to deliver  increased  quantities of oxygen to the aquifer, one
              added benefit was that the hydrogen peroxide kept the wells free of heavy biogrowth.

              The permeability of the  aquifer could be  reduced because of precipitation.  Other
              factors,  such  as  dispersion of clays, could reduce aquifer permeability.  When
              calcium concentrations are high in the soil, phosphates can be rapidly attenuated
              because  they  precipitate with calcium,  and become  unavailable for  microbial
              metabolism.  Nutrient formulations should be devised with the help of experienced
              geochemists to minimize problems with precipitation and dispersion of clays.  One
              company  claims  to  have developed  special  soil  preconditioners and nutrient
              formulations which reduce these  problems  and maximize nutrient mobility and
              solubility; however, no process performance data are available on these products.

              Maintenance of the bacterial population at  their optimal levels  is also  important,
              especially for selective mutant organisms which tend  to be more sensitive  than
              naturally occurring species.  A continuous  incubation facility operating at higher
              temperatures and under  more controlled conditions could be used to maintain the
              microbial population.  The high biomass-containing  stream formed from such  a
              facility could then be reinjected via wells or trenches to reinnoculate the subsurface
              continuously with  microorganisms.

              Aeration wells may be particularly susceptible to operational problems.  If injected
              gas fluidizes the material around it, soil substrata shifts can  occur that may cause a
              well blowout (free passage of air to the surface).  The cone of influence in a blown-
              out well will be greatly reduced, requiring the installation of a new well.  The best
              method to prevent blowouts is to keep gas velocities below those necessary to cause
              fluidization, or to place  wells  deep enough  so that overburden pressure prevents
              excessive fluidization, or both (Sullivan, Chemineer Kinecs, Dayton, Ohio, personal
              communication, 1983).   Suntech  stated that a  number of  aeration wells became
              inoperative because of blowout during their groundwater cleanup in 1972 and had to
              be replaced (Raymond, Jamison, and Hudson,  1976).  This suggests that aeration
5/93                                         51

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BIOLOGICAL TREATMENT
            well blowout could become a commonly encountered problem if attention is not paid
            to the design criteria.
TABLE 13
RECOMMENDED PARAMETERS TO MONITOR
Parameter
Total organic carbon (TOC)
Priority pollutant analysis or
analysis of specific organics
Microbiology-cell enumerators
Temperature conductivity dissolved
oxygen (DO) pH
Alkalinity
Acidity, M&P
Chloride
NH3-N
NO3-N
PO4 all forms
SO4
Total dissolved solids (TDS)
Heavy metals (if present)
Hydrogen peroxide (H2O2)
Location
of Analysis
laboratory
laboratory
laboratory
field
field
field
field
laboratory
field
Media
groundwater
soil and
groundwater
soil and
groundwater
groundwater
groundwater
groundwater
groundwater
soil and
groundwater
groundwater
Analytical Method
TOC analyzer
CG/MS(1)
Direct counts. Plate
counts on groundwater
media or enriched media.
Plate counts with portable
water test kits (e.g., Soil
Test Inc., Evanston, IL).
In-situ water quality
monitoring instrument or
prepackaged chemicals;
field test kits.
Prepackaged chemicals/
field test kits; water
analyzer photometer (Soil
Test, Inc., Evanston, IL;
Lamotte Chemical,
Chestertown, MD).
Prepackaged chemicals/
test kits; GC/MS;
AAS.(2>

Prepackaged chemicals
for H2O2, test strips
available. Titanium
sulfate titration and
spectrophotometer
analysis for H2O2 for
greater accuracy.
(1) GC/MS = gas chromatography/mass spectrometry
(2) AAS = Atomic absorption spectrometry
5/93
52

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BIOLOGICAL TREATMENT

              Technology Selection/Evaluation

              Aerobic bioreclamation has been demonstrated to be effective in degrading organics
              at more than 30 spill sites. Although it has not yet been demonstrated at hazardous
              waste sites, it can be expected to be effective and reliable provided the organics are
              amenable to aerobic degradation and the  hydraulic conductivity of the aquifer  is
              sufficiently high. There are substantial research data to suggest that microorganisms
              found  at  uncontrolled  hazardous waste  sites  are wellacclimated  to the wastes.
              Effectiveness  and  reliability could  be  adversely  affected  by factors such  as
              precipitation, which could reduce the permeability of an aquifer.

              Relative to conventional  pump and  treat methods, bioreclamation may be more
              effective because it  is capable of degrading organics sorbed to soils. Sorbed organics
              are not removed using conventional pump and treat methods.

              The nature of the delivery systems can affect the reliability of the bioreclamation
              approach.   Pumping  systems  are prone to  mechanical  and  electrical  failure.
              However,  repairs can be made relatively quickly.  Subsurface drains are less prone
              to failure since  there are no electrical components. When mechanical failures do
              occur, repairs can be both costly and time consuming.

              Implementation  of a remedial action involving bioreclamation will take longer than
              excavation and removal of contaminated soils.  Depending on the site, it could also
              take longer than a conventional pump and treat approach.  The advantage of in-situ
              bioreclamation over a pump  and treat approach is that in-situ biodegradation treats
              contaminated  subsurface  soils,  thereby   removing the  source  of  groundwater
              contamination.

              The increased time  required for in-situ bioreclamation is primarily dependent on the
              degradation rates, which are, in turn, dependent on oxygen availability.  The form
              in which oxygen is delivered to the subsurface  and the aquifer permeability are the
              critical factors.  As discussed previously, far more oxygen  can be delivered to the
              subsurface in the form of hydrogen peroxide.

              Other  aspects  of  implementation are  similar  to implementation of  conventional
              pumping or subsurface drain systems with a few exceptions.  Depending on the
              hydraulic conductivity,  drains or wells must generally be spaced closer together to
              ensure nutrient and  oxygen availability at all portions of the zone being treated. The
              lower the  flow  rate of the nutrient/oxygen-enriched water and the  more rapidly
              nutrients and oxygen are attenuated, the closer the injection  wells or drains must be
              spaced. Well/drain spacing will also be dictated by the need, if any,  to contain the
              contaminant plume  or treatment solution.

              There are few additional safety hazards associated with in-situ bioreclamation aside
              from those hazards normally associated with being on a hazardous waste site or a
              drill site.   Because wastes are treated in the ground, the  danger of exposure to


5/93                                         53

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BIOLOGICAL TREATMENT
              contaminants is minimal during a bioreclamation operation relative to excavation and
              removal.

              A nutrient/oxygen or  nutrient/hydrogen peroxide solution does not  represent an
              environmental threat.  Most of the nutrients will be used and attenuated by microbial
              activity.  If the form of the nutrient is carefully  selected  (e.g., ammonia-nitrogen
              rather  than  nitrate-nitrogen),  the  remaining   nutrients  will not   present  an
              environmental  threat.   The  hydrogen peroxide will rapidly  decompose in  the
              subsurface to oxygen and water.

              The  only treatment reagent that could  pose  a hazard, if used,  is the  concentrated
              hydrogen peroxide solution prior to mixing with groundwater. Worker protection for
              operations involving hydrogen peroxide outside of a closed container or pipe should
              include the use of chemically resistant  gloves, an apron, and a  face shield. Safety
              training in the use of hydrogen peroxide should be provided by qualified personnel.

              Costs

              Costs for biological in-situ treatment are determined by the nature of the site geology
              and  geohydrology, the extent of contamination,  the kinds and concentrations of
              contaminants, and the amount of groundwater and soil requiring treatment.  There
              is no easy  formula for predicting costs.  Costs provided for actual  site cleanups
              indicate that biological treatment can be far more economical as an alternative to, or
              in conjunction with, excavation and removal or conventional pump and treat methods.

              In-situ treatment costs include costs for well construction and pumping. Unit costs
              for chemicals, nutrients, and hydrogen peroxide are provided in TABLE 14.  Cost
              data  for actual and hypothetical site cleanups involving in-situ treatment  are presented
              below.

              Total capital and research and development costs for cleanup  of the Biocraft  site
              (TABLE 15) were $926,158, including $446,280  which was spent on  process
              development (R&D).  Project costs also included the hydrogeological  study, design
              and  operation of  the groundwater   injection  and  collection system,  and  the
              biostimulation plant.  Total operating costs, based on treating 13,680 gallons/day,
              were approximately $226/day, or $0.0165/gal. The total cost including amortization
              based on projected costs is $0.03S8/gal over a 3-year period. Prior to the biological
              treatment program, contaminated  water had  been removed at a  rate of 10,000
              gal/month.   The average disposal cost had been $0.3S/gal (Jhaveri and Mazzacca,
              1984).  The costs of biological treatment of an equal number of gallons is an  order
              of magnitude less than that  for disposal.   The Biocraft site employed  surface
              biological reactors and  enhanced in-situ treatment by reinfiltrating  oxygen  and
              nutrient-treated groundwater.  Costs for in-situ treatment alone would have been less
              because process plant design  and equipment would not be included  in an in-situ
              approach.
5/93                                         54

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BIOLOGICAL TREATMENT
TABLE 14
CHEMICAL COSTS
Category
Acids
Bases
Chelating agents
Fertilizers
(Microbial nutrients)
Liming material
Oxidizing agents
Reducing agents
Precipitating agents
Surfactant
Anionic
Nonionic
Chemical
Hydrochloric acid, 20° Baume tanks
Nitric acid 36° to 42° Baume tanks
Sulfuric acid
Virgin, 100%
Smelter, 100%
Caustic soda, liquid 50%, low iron
Ammonium chloride
Citric acid
Ammonia, anhydrous, fertilizer
Ammonium chloride
Ammonium sulfate
Sodium monophosphate
Sodium diphosphate
Phosphoric acid
75 % , commerical grade
52-54% a. p. a., agricultural grade
Potassium muriate, 60 to 62%, minimum
Potassium chloride
Potassium-magnesium sulfate
Agricultural limestone (dolomite)
Lime
Hydrated lime
Hydrogen peroxide, 35 %
Potassium permanganate
Caustic soda, liquid 50%, low iron
Ferrous sulfate
Heptahydrate
Monohydrate
Witconate 605A
Witconate P-1020BV
(calcium sulfonates)
Adsee 799
Cost/Unit
$55-105/ton
$195/ton
$61-95. 9/ton
$48-65/ton
$255-285/ton
$18/100 Ibs
$0.81-$1.19/lb
$140-$215/ton
$18/100 Ibs
$73-79/ton
$55.75/100 Ibs
$54.50/100 Ibs
$27.5/100 Ibs
$43.10/unit-tona
$0.82-0.92/unit-ton
$105/ton
$59/ton
$3.50-34/tonb
$30.75-45/ton
$32.5-34.5/ton
$0.24/lb
$1.03-1.06/lb
$255-285/ton
130/ton
160/ton
0.65-0. 85/lbc
0.70-0. 88/lbc
0.75-0. 87/bc
* Unit-ton: 1 percent of 2,000 pounds of the basic constituent or other standard of the material. The percentage
figure of the basic constituent multiplied by the unit-ton price gives the price of 2,000 pounds of the material.
b Source: US EPA, J984a.
c Source: Witco Chemical Corp. , Houston, TX, personal communication, 1985: cost varies depending on quantity
purchased (drum, truckload, or bulk).
Source: Schnell, 1985, unless otherwise noted.
5/93
55

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VO
OJ

TABLE 15
SUMMARY OF PROJECT COSTS - BIOCRAFT LABORATORIES, WALDWICK, NJ
Task
A. Hydrogeological study-problem definition
B. In-house process development (R&D)
C. Groundwater collection/injection system total
1 . Design
2. Installation
D. Biostimulation plant design and construction total
1. Engineering design
2. Masonry construction
3. Equipment and miscellaneous installation
Actual
Expenditure
$73,948
$446,280
$184,243
($61,490)
($122,753)
$221,207
($58,400)
($73,975)
($88,832)
Unit Cost
—
Period of
Performance
1976-1978
1978-1981
1980-1981
1981
1981
1981
1981
CAPITAL AND R&D TOTAL $926,158
E. Operation & maintenance (O&M)
1. Utilities
i.) Electricity - 26.4 kw (24 hrs/day)
ii.) Steam - 72 pounds (33kg)/day @
90PSI
2. Maintenance (see text)
3. Nutrient Salts
$47.40/day
($46.82/day)
(58C/day)
$159.93/day
$19.20/day
7.39C/kwh
0.8C/pound
1983 rates
1981
1983
Total water treated - 13,680 gallons (51,779)/day O&M total: $226.53/day $0.0165/gallon
$0.004/1)
BIOLOGICAL TREATMENT
  Source: US EPA, 1984b

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BIOLOGICAL TREATMENT
TABLE 16
ESTIMATED COSTS FOR HYPOTHETICAL BIORECLAMATIONS
USING HYDROGEN PEROXIDE AS AN OXYGEN SOURCE

Contamination
Formation
Flow Rate
Project Time
Estimated Costs
Site A
300 gallons
gasoline
Sand/gravel
50 gpm
6-9 months
$70-120M(1)
SiteB
2,000 gallons
diesel fuel
Fractured bedrock
10 gpm
18-24 months
$200-300M(1)
SiteC
10,000 gallons jet
fuel
Coarse gravel
100 gpm
18-24 months
$500-700M(1)
(1)M = 1000
Source: FMC, 1985
             TABLE 16 presents the estimated site cleanup costs for hypothetical sites involving
             the use of hydrogen peroxide as an oxygen source for the enhancement of in-situ
             biodegradation (FMC, 1985).  The cleanup of 300 gallons of gasoline from a sand
             gravel aquifer over a period of 6 to 9 months is between $70,000 and $120,000 (Site
             A).  Cleanup of 3,000 gallons of diesel fuel from a fractured bedrock formation is
             estimated to require 9 to 12 months and cost from $160,000 to $250,000.
5/93
57

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Section 10

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                                  INCINERATION
STUDENT PERFORMANCE OBJECTIVES:
At the conclusion of this unit, participants will be able to:
       •      Identify at least four applicable wastes  and  briefly describe  why they are
              suitable for incineration

       •      Briefly describe the incineration process

       •      Briefly describe the following incinerator designs:

                    Rotary kiln
                    Fluidized bed
                    Infrared

       •      Briefly   describe   typical   preparations  needed  for  onsite  use   of
              mobile/transportable incinerators.
5/93

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                                              NOTES
         INCINERATION
   • Incinerator
   • Heat materials to combustion
   • Residual solids
   • Combustion products released

         INCINERATION
         ADVANTAGES
      • Established technology
      • Destruction of organics
      • Volume reduction
      • Residues may be delisted

   WASTE CHARACTERISTICS
    • Btu > 8,000 Btu/lb
    • Moisture - energy sink
    • Inorganics > 5% alkali metals
         corrosive
    • Halogens > 8% dry weight
         corrosive

5/93
Incineration
   page 1

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        NOTES
                                    COMBUSTION FACTORS
                                            •  Time

                                            •  Temperature

                                            •  Turbulence

                                            •  Oxygen
                                       PRINCIPLE ORGANIC
                                   HAZARDOUS CONSTITUENTS

                                   POHCs are substances that scientific
                                   studies have shown to be toxic or have
                                   carcinogenic, mutagenic.or teratogenic
                                   effects on humans or other life forms


                                   (Listed at 40 CFR 261 APR VIII)
                                   PERFORMANCE STANDARDS
                                 DESTRUCTION REMOVAL EFFICIENCY (ORE)
                                        DRE=-
                                              W1B-W.
                                                  out
                                               w,
         X100
                                                 in
                                  where  W = Mass feed rate of POHC in the waste
                                            stream feed
                                       W
                                        out
Mass emission rate of the POHC in the
stack gas prior to release into the
atmosphere
                                 RCRA 99.99% most wastes
                                 Specific wastes 99.9999%
Incineration
page 2
                      5/93

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                                                  NOTES
 PERFORMANCE STANDARDS
  • HCI
       >99% reduction or <1.8 kg/hr

  • Particulates
       <180 milligrams/dscm
     INCINERATOR DESIGNS


           • Rotary kiln

           • Fluidized bed

           • Infrared
         Rotary Kiln Incinerator
           Primiry   Secondary   -,
           Conbuitlon  CombuiUen  JLlut
           Ch.mb.r  ctomt*   «"
                   Tank
                L*gtnd
           1 Influent Wutt  4 Secondary Burner
           2 Primary Burner t Scrubber Water
           3 Aah      6 Flue Qa*
5/93
Incineration
   page 3

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         NOTES
                                       Fixed Bed     Fluldized Bed  Circulating Bed
                                                                     Ollga.
                                      Low air flow      Med. air flow   High air flow
                                      (0.5 ft per sec.)    (5 ft. per sec.)  (15 ft per sec.)
                                           Circulating Bed Incinerator
                                      Bolld Umuuni
                                      F««d
                                       INFRARED INCINERATION


                                      • Continuous conveyor belt furnace

                                      • Electric power

                                      • 100 tons per day
Incineration
page 4
5/93

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                                          NOTES
    SYSTEM COMPONENTS

  • Feed hoppers

  • Primary chamber

  • Secondary combustion chamber

  • Scrubber system
      PEAK OIL COMPANY
         TAMPA, FLORIDA
  • Oil rerefinery
      Contaminated sludges and soil
      Contaminated groundwater
       CONTAMINANTS
            • PCBs

            • Lead
5/53
Incineration
   page 5

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       NOTES
                               Mobile Treatment
                               at CERCLA Sites
                                  CHARACTERISTICS OF
                                     MOBILE UNITS

                              • Typically smaller than permanent units
                              • Carried to site by truck or rail
                              • Include several components
                                   MOBILE TREATMENT
                             	ADVANTAGES	
                              • Allows fast response to emerging situations
                              • Enhances availability of innovative
                               technologies
                              • Can easily tailor treatment to each site
                              • Handles most waste
                              • No danger from transportation of waste
Incineration
page 6
5/93

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                                                  NOTES
       MOBILE TREATMENT
         DISADVANTAGES
   • Requires site preparation
   • Operating expenses may be higher
   • Possible negative reaction of local
     community
      ON-SITE INCINERATION
       • Mobilization/demobilization
       • Site preparation
       • Utilities
       • Support equipment
       • Residuals/effluents handling
       SITE PREPARATION
        • Access roads
        • Graded area for setup
        • Concrete base
        • Spill control
        • Site security
5/93
Incineration
   page 7

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        NOTES
                                            UTILITIES
                                          • Process water
                                          • Electric power
                                          • Auxiliary fuel
                                       SUPPORT EQUIPMENT
                                        • Fuel storage
                                        • Waste storage
                                        • Process water
                                        • Ash storage
                                        • Solids preparation/handling
                                        • Wastewater treatment
                                        • Residual disposal
                                          INCINERATION
                                   Small applications: > $1000/ton
                                   Large applications: < $300/ton
Incineration
page 8
5/93

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                                   INCINERATION
              General Description

              Incineration occurs when a substance is heated to the  point of combustion in the
              presence of oxygen.   Hazardous waste  incinerators are  specifically designed to
              incinerate contaminated liquids, solids, and sludges  in an environmentally safe
              manner.  The process is relatively simple:

              1.     Wastes are fed into a specialized piece of equipment called an incinerator.

              2.     Within the  incinerator's combustion chamber  the waste  is heated in the
                     presence of oxygen to combustion temperatures.

              3.     Residual solids, called ash,  are removed following combustion.

              4.     Combustion products are released to the atmosphere.

              Incineration of wastes may be conducted offsite at a  permitted facility  or onsite
              through the use of a mobile/transportable incinerator. Offsite incineration is normally
              used for small volumes of hazardous wastes.  The potential  for waste spills along
              transportation routes and the necessity of material handling  at the remote facility are
              compelling reasons for using onsite incineration  when there are relatively  high
              volumes of waste to be treated.

              A review of all the RODs for NPL sites through 1988 show that for all sites selected
              to receive treatment,  38 percent selected incineration or another form of thermal
              treatment.  Therefore, thermal treatments are the most selected treatments for  NPL
              sites.   Furthermore, incineration of RCRA and TSCA  wastes is  routinely done by
              generators of these wastes.  The reasons for selecting this technology include:

              •      It is an established technology

              •      It results in  destruction of organic contaminants

              •      The volume of waste is reduced

              •      Residues may  be delisted.

              Applicable Wastes

              Liquids, sludges, and solids may be incinerated.  However,  wastes with high organic
              contents, low moisture contents, and  low concentrations of metals are  the best
              candidates for this technology.  Furthermore, wastes that contain high concentrations
5/93

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INCINERATION
              of halogenated materials or organic phosphorus may cause problems with refractory
              linings or pose emission control problems.  TABLE 1 shows the waste characteristics
              that impact incineration processes. Additionally, wastes that have a minimum BTU
              value of 8,000 may sustain combustion without the addition of supplemental fuels.
                                          TABLE 1
            HIGH-TEMPERATURE THERMAL TREATMENT - GENERAL *
    Characteristics
  Impacting Process
      Feasibility
           Reason for Potential Impact
     Data
   Collection
 Requirements
  High moisture
  content
Moisture content affects handling and feeding and has
major impact on process energy requirement.
Analysis for
percent moisture
  Elevated levels of
  halogenated organic
  compounds
Halogens from Hcl, HBr, or HF when thermally treated;
acid gases may attack refractory material and/or impact
air emissions.
Quantitative
analysis for
organic Cl, Br,
and F
  Presence of PCBs,
  dioxins
PCBs and dioxins are required to be incinerated at higher
temperatures and long residence times.  Thermal systems
may require special permits for incineration of these
wastes.
Analysis for
priority pollutant
  Presence of metals
Metals (either pure or as oxides, hydroxides, or salts)
that volatilize below 2,000°F (e.g., As, Hg, Pb, Sn) may
vaporize during incineration. Those emissions are
difficult to remove using conventional air pollution
control equipment. Furthermore, elements cannot be
broken down to nonhazardous substances by any
treatment method.  Therefore, thermal treatment is not
useful for soils with heavy metals as the primary
contaminant.  Additionally, an element such as trivalent
chromium (Cr3*) can be oxidized to a more toxic valence
state, hexavalent chromium (Cr6*), in a combustion
system with oxidizing atmospheres.
Analysis for
heavy metals
  Elevated levels of
  organic phosphorous
  compounds
During combustion processes, organic phosphorous
compounds may form phosphoric acid anhydride (P2O3),
which contributes to refractory attack and slagging
problems.
Analysis for
phosphorous
         Applicable to fluidized bed, infrared, rotary kiln, wet air oxidation, and pyrolytic as well as
         vitrification processes.
Source:  USEPA, 1988
5/93
                      10

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INCINERATION

              Process Description
              Incineration is a combustion process, and all efficient combustion processes depend
              on a balance of four components:

              •      Time

              •      Temperature

              •      Turbulence

              •      Oxygen.

              Combustion is not instantaneous.  It does require time for oxidation reactions to be
              completed.  However, the time it  takes for any  individual  reaction to come to
              completion is related to the temperature at which the reaction is being carried out.
              Normally the higher the temperature, the faster the rate of reaction.  Therefore, less
              reaction  time  is required  for  oxidation reactions to be  carried out  at  higher
              temperatures.   For incinerators that burn hazardous wastes, a  retention time of
              approximately  2 seconds  at a temperature of about 2000°F is sufficient  to oxidize
              hazardous wastes to carbon dioxide, water vapor, and other components.  This
              assumes that the waste is in contact with an excess concentration of oxygen when the
              temperature is reached.  The contact of waste with oxygen inside  the combustion
              chamber  is a function of the turbulence within the chamber. Turbulence  caused by
              air movement through the combustion chamber actually provides mixing of the waste
              with air that is drawn through the incinerator's combustion chamber. If insufficient
              mixing occurs, or if the  quantity of oxygen is low, unreacted or partially reacted
              wastes will be  exhausted.

              Ideally there should be no  unreacted wastes exhausted from an incinerator.  However,
              even under ideal conditions it is difficult to achieve complete combustion for some
              chemicals.   Some  substances  are   more stable  than others under  incineration
              conditions.  These  include  some highly halogenated substances such  as carbon
              tetrachloride and PCBs. The greatest concern is for substances that may be released
              to the  atmosphere that scientific studies have shown to have toxic, carcinogenic,
              mutagenic, or  teratogenic effects on  humans or other life forms  (listed at 40 CFR
              261, App. VIII). Substances identified in that list  which have the highest thermal
              oxidation stability are designated as principle organic hazardous constituents (POHC)
              by permit writers and  are used as indicators of performance for hazardous waste
              incinerators.

              The performance of an incinerator  is based on its destruction removal  efficiency
              (DRE) of a POHC within the wastestream.  It is calculated according to:
5/93                                        11

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INCINERATION
                                         r  _ ur  \
                             DRE   =      —"Lsai   *.  100%
              where:
              Win  =  mass feed rate of a POHC to the incinerator
               1 in
              Wout =  mass emission rate of the same POHC present in exhaust emissions.

              The  DRE for most hazardous wastes must be  a  minimum  of 99.99 percent.
              However, for a number of specific wastes, including PCBs and tetra-, penta-,  and
              hexachlorodibenzo-/?-dioxins  and  F020 through F023, F026,  and F027 wastes (40
              CFR 264.343), the DRE must be greater than, or equal to 99.9999 percent.

              In addition to achieving the appropriate DRE for a given waste, the incinerator  also
              must not discharge paniculate matter in excess of 180 milligrams per dry standard
              cubic meter  (0.08 grains per dry standard cubic foot) based upon excess oxygen
              determinations.  Furthermore, acid gases may be formed when wastes that contain
              chlorine atoms are incinerated.  Therefore, the concentration  of hydrogen chloride
              discharged from a hazardous waste incinerator must be controlled if more than 1.8
              kilograms per hour (4 pounds per hour) is generated.  Both excess particulates and
              acid gases may be controlled through the use of exhaust gas scrubbing systems.

              There are several mobile/transportable incinerator designs that are used for hazardous
              wastes.  These include:

              •      Rotary kiln

              •      Fluidized bed

              •      Infrared

              Regardless of the design, individual incinerators are designed to handle a  limited
              volume of waste per unit time.  The rate at which a given volume of waste can be
              incinerated is its design capacity.  This is given in terms of BTUs, and  may be given
              as tons/day or tons/hour.  The small transportable incinerators may be capable of
              handling  1 ton/hour, whereas some of the larger units may be rated at 100 tons/day.
              These rated  capacities are based on the units' capabilities of heat transfer.   The
              assumption is made that all equipment is operating properly.  In practice, material
              feed systems, ash withdrawal systems, and air pollution control equipment often fail
              to operate at maximum efficiency and, therefore, it  is wise to  find out the actual
              operating capacity for a specific incinerator.  Such information should be available
              from the equipment vendor.
5/93                                        12

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INCINERATION
              The rotary  kiln  design has  been used  more  extensively  for  hazardous waste
              incineration than  other designs.  This is because it is capable of incinerating  both
              solid and liquid waste.  Additionally, the rotary kiln design is easily adapted to a
              mobile/transportable system.  FIGURE 1 is a schematic representation of a rotary
              kiln incinerator.  There are numerous variations of this basic design; however, a
              typical rotary kiln includes:

              •      Solids feed system

              •      Rotary kiln

              •      Ash drop

              •      Air pollution controls

              •      Process stack.
5/93                                         13

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INCINERATION
              Process operation involves the introduction of wastes and auxiliary fuel into the high
              end of a cylindrical, refractory, lined kiln. TABLE 2 shows the waste characteristics
              that impact rotary kiln processes.  The kiln is heated to temperatures of  1,200 to
              1,800°F, or up to 2,400°F if the system uses no afterburner.  When the appropriate
              temperature has been reached, waste materials are fed into the system. Solids often
              are screened through a material classifier that will not permit material greater than
              2 inches in diameter to  enter the incinerator. The larger pieces of wastes may be
              reduced in size by a material  shredder or a pug mill before they are incinerated.
TABLE 2
ROTARY KILN INCINERATION *
Characteristics
Impacting Process
Feasibility
Oversized debris such as
large rocks, tree roots,
and steel drums
Volatile metals (Hg, Pb,
Cd, Zn, Ag, Sn)
Alkali metal salts,
particularly sodium and
potassium sulfate
(NaSO«, KS04)
Fine particle size of soil
feeds such as clay, silts
Ash fusion temperature
of waste
Heating value of waste
Reason for Potential Impact
Difficult to handle and feed; may cause
refractory loss through abrasion. Size
reduction equipment such as shredders must
be provided to reduce solid particle size.**
May result in high metals concentration in
flue gas, thus requiring further treatment.
Cause refractory attack and slagging at high
temperatures. Slagging can impede solids
removal from the kiln.
Results in high paniculate loading in flue
gases because of the turbulence in the rotary
kiln.
Operation of the kiln at or near the waste ash
fusion temperature can cause melting and
agglomeration of inorganic salts.
Auxiliary fuel is normally required to
incinerate wastes with a heating value of less
than 8,000 BTU.
Data
Collection
Requirements
Size, form, quantity of
oversized debris. Size
reduction engineering data.
Soil and stack gas analysis for
subject metals.
Percent Na, K.
Soil particle size distribution,
USGS *** soil classification.
Ash fusion temperature.
BTU content.
* See also TABLE 1, HIGH-TEMPERATURE THERMAL TREATMENT (GENERAL)
** See TABLES 3 and 4.
*** U.S. Geological Survey.
Source:  USEPA, 1988
5/93
15

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INCINERATION
              Immediately upon entering the kiln, the waste is heated. Substances that have low
              thermal oxidation stability,  such as gasoline or other petroleum by-products, will
              combust early in the process and the energy that is released will minimize the need
              for the addition of auxiliary fuel to maintain incineration temperatures.  Substances
              with high thermal oxidation stability will desorb from solids that they may have been
              associated with and will volatilize. These thermally stabile compounds will combust
              at the higher temperatures.  Therefore, many rotary kiln incinerators are designed
              with a secondary  combustion chamber, or afterburner, which heats  the volatilized
              gases to the higher temperatures necessary for combustion.  This secondary chamber
              normally follows  the ash drop and  is just ahead of the induced draft fan.  It is
              important to keep  a hazardous  waste incinerator under negative pressure during
              operation.  This ensures that there will be no leakage of potentially harmful gases out
              of the  kiln or secondary combustion chamber.   It also ensures that there will  be
              excess oxygen and adequate turbulence within the combustion chambers.  The air
              pollution control  equipment may vary from system  to system.  However, many
              incinerators use  a wet scrubber design.   These  scrubbers often use an  alkaline
              scrubbing  fluid  (hydrated lime)  to  neutralize  acid  gases and  remove airborne
              particulates.  Following this treatment, the gases  are exhausted to the atmosphere
              through a process stack.

              Fluidized-bed  incinerators consist of a refractory, lined vessel containing a bed of
              inert, granular, sand-like material (sized crushed refractory). TABLE 3 shows the
              waste characteristics that impact fluidized-bed processes. Solids, sludges, and liquids
              can be injected directly into the bed or at its surface.   If contaminated  soil  is being
              processed,  the soil mass acts as the bed material.   Combustion air is  forced  up
              through the bed to fluidize the material at a minimum critical velocity.  The heating
              value of the waste plus minimal  auxiliary fuel maintains  the desired temperature
              within  the vessel.  Solids may be withdrawn on a continuous basis or they may be
              circulated within the vessel.  The circulating  bed combustor is designed to permit
              feeding limestone along with solids (FIGURE 2).  The limestone will  neutralize acid
              gases that form. Therefore, a baghouse dust collector may be used instead of an acid
              gas scrubber for air pollution control.
5/93                                         16

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INCINERATION
                                        TABLE 3
                           FLUIDIZED BED INCINERATION*
   Characteristics
  Impacting Process
      Feasibility
        Reason for Potential Impact
        Data
     Collection
    Requirements
  Feed particle size
Large particle size affects feeding and removal
of solids from the bed.  Solids greater than 1
inch (2.5 cm) must be reduced in size by
shredding, crushing, or grinding. (Note:
Waste-Tech fluid bed system can handle up to
3-in. feed.)  Fine particles (clays, silts) result
in high paniculate loading in flue gases.
Size, form, quantity
of solid material; size
reduction engineering
data; soil particle size
distribution; USGS
soil classification.
  Low-melting point
  (less than 1,600°F)
  constituents,
  particularly alkali
  metal salts and
  halogens (e.g., Na,
  Cl compounds)
Defluidization of the bed may occur at high
temperatures when particles begin to melt and
become sticky.  Melting point reduction
(eutectics) may also occur.  Alkali metal salts
greater than 5 % (dry weight) and halogen
greater than 8 % (dry weight) contribute to
such refractory attack, defluidization,  and
slagging problems.
Ash fusion
temperature.
  Ash content
Ash contents greater than 64% can foul the
bed.  (Note: Waste-Tech's continuous bed
letdown, screening, and reinjection minimize
this type of problem.)
Ash content.
  Waste density
As waste density increases significantly,
particle size must be decreased for intimate
mixing and heat transfer to occur.
Waste-bed density
comparison.
  Presence of
  chlorinated or
  sulfonated wastes
These wastes require the addition of sorbents
such as lime or sodium carbonate into the bed
to absorb acidic gases or the addition of a flue
gas scrubbing system as part of the treatment
train.
Analysis for priority
pollutants.
  *  See also TABLE 1, HIGH-TEMPERATURE THERMAL TREATMENT (GENERAL)
Source: USEPA, 1988
5/93
                      17

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INCINERATION
           Hot Vy»
                              FIGURE!
            AN EXAMPLE OF A CIRCULATING BED COMBUSTOR
Source: GA Corp., undated
5/93
18

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INCINERATION
             Infrared incinerators (FIGURE 3) use silicon carbide elements to generate thermal
             radiation beyond the red end of the visible spectrum. TABLE 4 shows the waste
             characteristics that impact infrared  incineration processes.  Solid materials that are
             to be treated pass through the primary combustion chamber on a continuous belt and
             are  exposed  to the radiation.  The  gaseous components pass  into a  secondary
             combustion  chamber where  they are further treated with infrared energy or a
             combination of infrared energy and conventional gas-fired burners.  Air pollution
             controls are similar to those used with rotary kiln incinerators.
                                                              Source:  &A-ORD
                                     FIGURE 3
         BLOCK FLOW DIAGRAM OF INFRARED INCINERATION SYSTEM
5/93
19

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INCINERATION
                                      TABLE 4
                        INFRARED THERMAL TREATMENT*
       Characteristics
      Impacting Process
         Feasibility
                        Reason for Potential Impact
       Data
     Collection
   Requirements
  Nonhomogeneous feed size
                    Nonuniform feed size requires pre-
                    treatmem before feeding and con-
                    veyance through the system.  The
                    largest solid particle size processable
                    is 1 to 2 inches.  Debris such as
                    rocks, roots, and containers must be
                    crushed or shredded to allow  for
                    feeding.**
Size, form, quantity
of solid material; size
reduction engineering
data.
  Moisture content
                    Waste material is conveyed through
                    the system on a metal conveyor belt,
                    so soils and sludges must be firm
                    enough  (usually >22% solids) to
                    allow for proper conveyance. Soils
                    and sludges with excess water content
                    (e.g., lagoon sediments) require
                    dewatering prior to feeding.**
Moisture analysis.
  **
See also TABLE 1, HIGH-TEMPERATURE THERMAL TREATMENT
(GENERAL).
See TABLES 2 and 3
Source:  USEPA, 1988
             Onsite incineration of wastes requires a greater degree of preparation and planning
             than offsite incineration.   This is because the  mobile unit must be erected onsite.
             This can be similar to a major construction effort and will require:

             •      Mobilization/demobilization

             •      Site preparation

             •      Utilities

             •      Support equipment

             •      Residuals/effluents handling.
5/93
                                  20

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INCINERATION
              Mobilization/demobilization of equipment involves the set up and take down of the
              incinerator and other support equipment.  The amount  of  time  involved for this
              depends on the specific incinerator and existing site conditions.  For small systems
              a minimum set-up time will be 1 week under ideal conditions.  For  large-scale
              systems, 6-8 weeks  may be necessary.  Furthermore, since onsite construction is
              necessary,  a crane is  often needed to assist in assembly  and take-down  of the
              incinerator.  Demobilization may take an equivalent amount of time and will include
              decontamination and disassembling the incinerator.  The decontamination may be
              operated with clean fuel for a specified period of time and/or the equipment may be
              steam cleaned.

              Before any equipment  arrives onsite it will be necessary to ensure that the site is
              ready to receive it.  Site preparation  includes:

              •      Access roads

              •      Graded, graveled area for setup

              •      Concrete base for incinerator and ancillary  equipment

              •      Spill control/containment

              •      Site security (fencing).

              In addition to these items, consideration must be given to  the equipment that will be
              used to feed the incinerator.  If excavation  is required,  a sufficient  volume of
              excavated material should be stored so that the incinerator can remain in operation
              when excavation equipment is temporarily inoperable.

              All process operations  require utilities so that they  may function.  These include:

              •      Process water

              •      Electric power

              •      Auxiliary fuel.

              Supplying each  of these is site specific.  In  urban areas,  process water may be
              supplied through municipal supplies,  whereas in rural settings, a supply well may be
              necessary.   Check with the technology vendor for the power requirements of the
              specific incinerator and the availability of such power from the local electrical  utility.
              At  some  remote sites  it may be  necessary  to use diesel- or  gasoline-powered
              generators for power supply. Also, propane, natural gas,  or fuel oil will be required
              to operate the system.   Provisions must be made to ensure that a consistent  supply
              will be available onsite before the system is mobilized.
5/93                                         21

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INCINERATION
              Support equipment includes all the equipment necessary to ensure continued operation
              of the systems.  The specific equipment will vary depending on the site and the
              system that will be used.  Some of this equipment includes:

              •      Bulk fuel storage tanks

              •      Waste storage

              •      Process water tanks

              •      Ash storage

              •      Solids preparation/handling

              •      Wastewater treatment facilities

              •      Residual disposal.

              Residuals/effluents include the solids, liquids, and  gaseous materials produced as a
              result of incinerator operation. Solids include the ash, slag, and fly ash that are not
              combusted during the incineration process.  Incineration of soil results in relatively
              little volume reduction, because of its high volumes of incombustible materials.  Wet
              scrubbers produce a liquid wastestream that may contain alkaline wastes.  These may
              require additional  treatment prior to discharge.   Gaseous materials include the
              combustion by-products and products of incomplete combustion (PIC).   These are
              directly discharged to the atmosphere through the process stack.

              Monitoring

              Waste characteristics can directly affect the performance of incinerators.  Therefore,
              it is essential that the data collection requirements outlined in TABLES 1 and 4 are
              obtained prior to initiating processing.

              Monitoring and inspection requirements for  incineration of hazardous  wastes are
              listed in 40 CFR 265.347 and are presented in TABLE 5.  In addition to these,
              individual states may have specific monitoring and inspection requirements which are
              designated as  applicable  or relevant  and  appropriate requirements   (ARARs).
              Provisions should be made  to ensure that ash analysis is completed expeditiously.
              This will minimize the amount of ash storage area necessary and will permit ultimate
              disposal of the ash.
5/93                                         22

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INCINERATION
TABLE 5
MONITORING AND INSPECTION REQUIREMENTS
Monitoring Parameter
Combustion Temperature
Waste Feed Rate
Combustion Gas Velocity
Carbon Monoxide (between the
combustion zone and release
Ash Composition
Exhaust Emissions
Waste Feed Chemical Analysis
Inspection Parameter
Incinerator and Associated Equipment
Emergency Waste Feed Cutoff System
and Alarms
Frequency of Monitoring
Continuous
Continuous
Continuous
Continuous
Upon request of EPA Regional Administrator
Upon request of EPA Regional Administrator
Determined by EPA Regional Administrator
Frequency of Inspection
Daily
Weekly (or Monthly with Regional
Administrator consent)
              Cost

              Mobile/transportable incinerators are  leased  from firms  that specialize  in  this
              technology.  Therefore, lease agreements are normally used to define costs associated
              with this technology. Lease agreements vary from vendor to vendor; however,  it is
              usual to have the vendor supply operating personnel. An important item here is to
              identify the  limits of operation.  Responsibilities for operation of  incinerator feed
              equipment and ash handling must be spelled out in any lease agreement.  Failure to
              do so may mean that the incinerator would be delivered and set up without a means
              of conveying wastes to or from the unit.

              Because many cost-related items are site specific, it is difficult to project overall costs
              for incineration.  However, in general, costs range from $200 to $1,000 per ton.  An
              estimate of the annual operating cost of a rotary kiln system is presented in TABLE
              6. Compared with other technologies, incineration is expensive, but may be the least
              cost option for specific wastes.
5/93
23

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INCINERATION
TABLE 6
ESTIMATE OF ANNUAL OPERATION AND
MAINTENANCE COSTS FOR A ROTARY KILN
Item
Personnel (1 supervisor, 2 operators, 4 yard-crew workers, 1 secretary.)
Electricity (473 hp) (7,200 h/yr.)
Water (3.2 x 108 gal./yr.)
Auxiliary fuel
Startup (10) (8 h) (10 x 105 BTU/h)
Operating (4.8 x 106 BTU/h) (7,200 h/yr.)
Chemicals (2.25 x 106 Ib. lime/yr.)
Effluent disposal:
Scrubber liquid (3.2 x 105 gal./yr.)
Ash (2.88 x 106 Ib/yr.)
Laboratory
Maintenance (10% of total equipment cost)
Refractory replacement (8-yr. life)
Direct operating cost
Value of recovered steam
Net operating cost
1985 Cost $/yr.*
$151,322
130,772
257,393
4,670
430,407
39,128
386,089
14,945
62,272
157,238
26,984
1,661,220
1,245,450
415,770
* Costs updated from 1983 to 1985 dollars using ENR Construction Index.
Adapted from Vogel and Martin, 1984.
5/93
24

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Section 11

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                       SOIL FLUSHING AND WASHING
STUDENT PERFORMANCE OBJECTIVES:



At the conclusion of this section, participants will be able to:



       •      Briefly describe the difference between soil washing and soil flushing, and list
             at least two advantages and two disadvantages of each

       •      List at least four components of a typical soil flushing system

       •      Briefly describe the operation of a typical soil flushing system

       •      List at least four components of a typical soil washing system

       •      Briefly describe the operation of a typical soil washing system.
5/93

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                                            NOTES
        SOIL FLUSHING

  • Desorbing and removing
    contaminants from soil using
    a liquid flushing solution

  • In-situ process
5/93
Soil Flushing and Washing
          paget 1

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         NOTES
Soil Flushing and Washing
page 2
                                                         t
5/93

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                                              NOTES
  SOIL FLUSHING SOLUTIONS
 • Water

 • Acids and bases

 • Complexing and chelating agents

 • Surfactants
       WATER FLUSHING

  • Water-soluble organics
       Ketones, aldehydes, aromatics,
       and some halogenated
       hydrocarbons such as TCE
       (low to medium molecular
       weight)

  • Soil/water partition coefficient
       WATER FLUSHING

    • Water-soluble inorganics
        Metal salts such as nickel,
        zinc, and copper carbonates

    • pH adjustment
5/93
Soil Flushing and Washing
           page 3

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        NOTES
                                     ACID FLUSHING

                                • Metal salts and basic organics
                                   Hydroxides, oxides, and
                                   some carbonates
                                   amines, ethers, and anilines

                                • Weak, low toxicity acids
                                   Acetic acid, dilute sulfuric
                                    acid
                                COMPLEXING/CHELATING
                                    AGENT FLUSHING

                               • Water soluble metal-chelate
                                 complexes

                               • Common agents
                                   Ethylene diamine tetra acetic acid
                                   (EDTA)
                                   Diethylene triamine penta acetic acid
                                   (DTPA)
                                 SURFACTANT FLUSHING
                               • Non-soluble and hydrophobic
                                 organics

                               • Emulsifies organics and desorbs
                                 them from soil particles

                               • Laboratory/bench scale testing
                                 recommended
Soil Flushing and Washing
page 4
5/93

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                                              NOTES
      FEASIBILITY STUDY
      • Site geology
      • Site hydrology
      • Waste characteristics
      • Soil characteristics
   SOIL CHARACTERISTICS
       • Soil type
          Carbon content
          Clay content
          Other minerals
       • Biological activity
       • Soil characteristics
   SOIL CHARACTERISTICS
      • Density
      • Porosity
      • Permeability
      • Water content
      • Depth to contamination
5/93
Soil Flushing and Washing
           page 5

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        NOTES
Soil Flushing and Washing
page 6
                                       SOIL WASHING

                               • Separating soil sizes and/or
                                 desorbing and removing
                                 contaminants from soil using
                                 mechanical action and a liquid
                                 flushing solution

                               • On-site process
                               >r
                               STONES
                               SPENT
                               FLUID
                                                SOIL WASHER
SOIL FINES
SOIL FINES


   CLEAN SAND
                                           RAW FEED  FINES WASHER
                                                    ^
                                                            +
                                                           CLEAN
                                                           SOIL
                                                              5/93

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                                                           NOTES
 SPENT
 FLUID
                RAW FEED    SOIL FLOW
      "-IT
                                   CLEAN
                                   SOIL
SPENT
FLUID
                HAWFEEO  LIQUID FLOW
                                   CLEAN
                                   SOIL
             SOIL WASHING SYSTEM
              Froth Flotation
                 Cells
5/93
                                                             So// Flushing and Washing
                                                                           page 7

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                         SOIL FLUSHING AND WASHING
       Soil Flushing

       Organic and inorganic contaminants can be washed from contaminated soils by means of an
       extraction process termed "soil flushing," "solvent flushing," "ground leaching," or "solution
       mining."  Water or an aqueous solution is injected into the area of contamination,  and the
       contaminated elutriate is pumped to the surface for removal, recirculation, or onsite treatment
       and reinjection.   During elutriation, sorbed contaminants are mobilized  into solution by
       reason of solubility, formation of an emulsion, or by chemical reaction with the flushing
       solution.

       Solutions with the greatest potential for use in soil flushing fall into the following classes:

       •      Water

       •      Acids and bases

       •      Complexing and chelating agents

       •      Surfactants

       •      Certain reducing agents.

       Water can be used  to flush water-soluble or  water-mobile organics  and  inorganics.
       Hydrophilic organics are readily solubilized in water. Organics amenable to water flushing
       can be identified according  to their soil/water partition coefficient or estimated using the
       octanol/water partition coefficient.  Octanol-water partition coefficients are available for a
       large  number of compounds in Substituent Constants for Correlation Analysis in Chemistry
       and Biology (Hansch and Leo, 1979). Chemical Property Estimation Methods (Lyman, Reehl
       and Rosenblatt, 1982) provides various methods for estimating the octanol-water partition
       coefficient using readily available physical and chemical data. Organics considered soluble
       in the environmental sense are ones with a partition coefficient (K) of approximately less than
       1,000 (log K  = 3).  High  solubility organics, such as lower molecular weight alcohols,
       phenols, and carboxylic acids, and other organics with a coefficient less than 10 (log K£l)
       may have already been flushed  from the site by  natural flushing  processes.  Medium
       solubility organics (K = 10 to 1,000) that could be effectively removed from soils by water
       flushing include low to  medium molecular weight ketones, aldehydes, and aromatics, and
       lower molecular weight halogenated hydrocarbons such as trichloroethylene (TCE) and
       tetrachloroethylene (PCE).  Inorganics  that can be flushed from soil with water are soluble
       salts such as the carbonates of nickel, zinc, and  copper.   Adjusting the pH with dilute
       solutions of acids or bases (to be discussed)  will  enhance inorganic  solubilization and
       removal.
5/93

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SOIL FLUSHING AND WASHING

       The  remedial  actions at the  Goose  Farm  site in  Plumstead, New Jersey, involved the
       installation of a wellpoint collection and recharge system and the flushing of contaminants
       from the soil with water (USEPA, 1984b).  Water flushing has been used over a 5- to 6-year
       period to reclaim a former herbicide factory site in Sweden (Truett, Holberger, and Sanning,
       1982).  Cleanup of a TCE spill in Germany involved water flushing of contaminated soils
       and effected a 50-percent decrease in TCE over an  18-month period (Stief, 1984).

       Dilute solutions of acids have  been widely used in industrial processes to extract metal ions.
       Solutions  of sulfuric,  hydrochloric, nitric,  phosphoric, and  carbonic  acid  are  used in
       industrial  applications to dissolve basic metal  salts (hydroxides, oxides, and carbonates).
       However,  because of the toxicity of many acids, it is desirable to use weak acids for in situ
       treatment.   Sodium dihydrogen phosphate (NaH2PO4) and acetic acid (CH3COOH) have low
       toxicity  and are reasonably stable. A stronger dilute acid such as sulfuric acid would be used
       if the soil  contained sufficient alkalinity to neutralize it.  Acidic solutions may also serve to
       flush some basic organics such as amines, ethers, and anilines.

       Complexing and chelating agents may also find use  in a solution mining removal system for
       heavy metals.   Some  commonly  employed substances  are  citric acid, ethylenediamine-
       tetraacetic acid (EDTA), and diethylenetriaminepentaacetic acid (DTPA)  (Rogoshewski and
       Carstea, 1980).  Chelating agents used for in situ treatment  must result in a stable metal-
       chelate complex that is resistant to decomposition and degradation.

       Another possibility for mobilizing metals that are strongly adsorbed to  manganese and iron
       oxides in soils is to reduce the metal oxides which results in release of  the heavy metal into
       solution.  Chelating agents  or acids can then be used to  keep the  metals in solution.
       Treatment agents that may be suitable for this purpose include hydroxylamine plus an acid
       or sodium dithionite/citrate.

       Surfactants can be used to improve the solvent property of the recharge water, emulsify
       nonsoluble organics, and enhance the  removal of  hydrophobic organics sorbed onto soil
       particles.  Surfactants improve the effectiveness of contaminant removal by improving both
       the detergency of aqueous solutions and the efficiency by which organics may be transported
       by aqueous solutions (USEPA, 1985).  Surfactant washing is among the most promising of
       the in situ chemical treatment methods.

       Numerous  environmentally safe and relatively inexpensive  surfactants  are  commercially
       available.  Use of surfactants to date has been restricted to laboratory research. Most of the
       research has been performed by the petroleum industry for tertiary oil recovery (Barakat et
       al., 1983; Cash et al., 1977;  Doe, Wade,  and Schecter,  1977; and Wilson  and Brandner,
       1977).  Aqueous surfactants  have also been proposed for  gasoline cleanup.  In a study
       performed by the Texas Research Institute (1979) for the American  Petroleum Institute, a
       mixture of anionic and nonionic surfactants results in contaminant  recovery of up to 40
       percent. In a laboratory study conducted by Ellis and Payne (1983), crude oil recovery was
       increased from less than 1 percent to 86 percent, and PCB recovery was increased from less
       than 1 percent to 68 percent  when soil columns were flushed with  an aqueous surfactant
       solution.
5/93                                        10

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SOIL FLUSHING AND WASHING

       Characteristics of surfactants and their environmental and chemical properties are listed in
       TABLE 1 (USEPA, 1985).  This table can be used to aid in the preliminary selection of a
       surfactant.  However, laboratory testing  of the surfactant should be performed to verify
       surfactant properties.

       An economically feasible soil flushing method may involve the recycling of elutriate through
       the contaminated material, with make-up solvent being added to the system while a fraction
       of the elutriate stream is routed to a portable wastewater treatment system.  The appropriate
       types of wastewater treatment operations will depend on wastestream characteristics.

       The advantages of the soil  flushing process are that, if the  waste is amenable to  this
       technique, and distribution, collection, and treatment costs are relatively low, solution mining
       can present an economical alternative to the excavation  and treatment of the wastes.

       Extraction/Soil Washing

              Process Description

              The extraction of contaminants  from  soil matrices by mixing the soils with water,
              surfactants, chelating agents, or organic solvents has been applied at a  number of
              hazardous wastes sites.  The process extracts the contaminants  off the soil by the
              principle of partitioning and  then the leachate is treated  for the  removal of the
              contaminants.  Subsequently,  the water may be reinjected  to enhance the process.
              The soils can be excavated into  a loose pile or left undisturbed for in situ treatment
              depending on the soil characteristics and the washing  effectiveness.

              This system can be used in conjunction with a mobile groundwater treatment system
              in order to regenerate the leaching medium.  The leaching of contaminated soils will
              enhance the removal of source contaminants that threaten to enter the groundwater.
              This will reduce the  time required for  site cleanup  and groundwater remediation.
              Combining a groundwater treatment system with  a  soil washing system will save
              costs of both offsite trucking of soil materials and a stand-alone soil washing system.

              A recent evaluation of the use  of water flushing techniques for the extraction of
              hydrophobic and slightly hydrophilic organics revealed that the addition of selective
              water-soluble surfactants greatly enhanced the effective removal of these organics.
              Additional field work has also demonstrated similar results for the removal of metals
              from soils by adding chelating agents to the flushing medium.  The washing fluid
              may contain additives  such  as acids,  alkalies, detergents,  and  selected organic
              solvents that will enhance the transfer of contaminants from the soils.
5/93                                         11

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VO
to
TABLE 1
SURFACTANT CHARACTERISTICS
Surfactant Type
ANIONIC 1) Carboxy lie Acid Salts
2) Sulfuric Acid Ester Salts
3) Phosphoric & Polyphosphoric
Acid Esters
4) Perfluorinated Anionics
5) Sulfonic Acid Salts
CATIONIC 1) Long Chain Amines
2) Diamines & Polyamines
3) Quaternary Ammonium Salts
4) Polyoxycthylenated Long-Chain
Amines
NONIONIC 1) Polyoxyethylenated Alkylphenols
Alkylphenol Elhoxy iates
2) Polyoxyethylenated Straight
Chain Alcohols and Alcohol
Ethoxy iates
3) Polyoxyethylenated
Polyoxypropylene Glycols
4) Polyoxyethylenated Mercaptans
S) Long-Chain Carboxylic Acid
Esters
6) Alkylolamine "Condensates,"
Alkanolamides
7) Tertiary Acetylenic Glycols
AMPHOTERICS 1) pH Sensitive
2) pH Insensitive

Selected Properties & Uses
• Good Detergency
• Good Wetting Agents
• Strong Surface Tension
Reducers

• Good Oil in Water
Emulsifiers
• Emulsifying Agents
• Corrosion Inhibitor


• Emulsifying Agents
• Detergents
• Wetting Agents
• Dispersants
• Foam Control


• Solubilizing Agents
• Wetting Agents

Solubility
• Generally Water
Soluble

• Soluble in Polar
Organics


• Low or Varying Water
Solubility

• Water Soluble

• Generally Water
Soluble
• Water Insoluble
Formulations





• Varied (pH dependent)


Reactivity
• Electrolyte Tolerant
• Electrolyte Sensitive
• Resistant to
Biodegradation
• High Chemical Stability
• Resistant to Acid and
Alkaline Hydrolysis
• Acid Stable

• Surface Adsorption to
Siliceous Materials

• Good Chemical Stability
• Resistant to
Biodegradation
• Relatively Nontoxic

• Subject to Acid and
Alkaline Hydrolysis


• Nontoxic
• Electrolyte Tolerant
• Adsorption to
Negatively Charged
Surfaces
                                                                                                                           CO
                                                                                                                           o
                                                                                                                           CO
                                                                                                                           s

                                                                                                                           2
                                                                                                                           o
                                                                                                                           V)
                                                                                                                           a

                                                                                                                           2
                                                                                                                           o
   Source:  USEPA, 1985

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SOIL FLUSHING AND WASHING

              Waste Type Handled
              Contaminants amenable to this process include heavy metals (such as copper, lead,
              and zinc), halogenated aliphatics (such as trichloroethylene, trichloroethanes, and
              chloroform), aromatics (such as benzene, toluene, cresol, and phenol), and volatile
              motor fuels (such as jet fuel spills and gasoline spills).  Enhanced extraction with
              surfactant additives has  also  been effective  on hydrophobic organics (such as
              polycyclic  aromatic   hydrocarbons,  aliphatic   and  aromatic   hydrocarbons,
              polychlorinated biphenyls, and chlorinated phenol mixtures).

              Soil characteristics such as soil type matrix  (sand, gravel,  or clay), low organic
              content, and high hydraulic conductivity enhance this process.  A sandy porous soil
              with  less than 1-percent organic content would  be well suited for this treatment
              process.

              Restrictive Characteristics

              A soil  matrix with a high organic content  and low water permeability will resist
              desorption of the contaminants and may act as a binding agent, preventing natural
              leaching of the contaminated soil.  Low water permeability might indicate small
              particle size and reduced interparticle void space.  A reduced surface area for contact
              between the water  and the soil matrix will  reduce the rate of contaminant transfer
              from the soil into the water phase.  Clay and silty soils may not be amenable for the
              soil washing technique because interactions between soil  surface and pollutants may
              retard mobility of contaminants.  Other factors that tend  to decrease the mobility of
              pollutants include chemical reactions with  soil,  cation exchange, and pH effects.
              Another hinderance to this process has  been the regeneration of water-surfactant
              solutions losing the surfactants.

              Mobile System Considerations

              All systems employing this process are mobile and are set up at the contamination
              site.  Transportation costs for moving the soil would make this system uneconomical.
              The  most common method to employ this  technique  is  in  conjunction  with a
              contaminated  groundwater treatment system where  the  treated  groundwater  is
              reinjected upgradient (sprayed above soils  if in the unsaturated zone) and  leaches
              through the in  situ contaminated soil matrix.   The leachate  is then recollected,
              treated, and reinjected back into the system,  thus providing for a closed-loop system.
              Variations  to  this process  include  aboveground contacting  systems such as
              countercurrent extraction equipment,  a pug  mill,  a truck-loaded cement mixer, etc.
              A soil  scrubbing system treating excavated contaminated soils can provide a more
              effective removal process through better soil-water contact and enable less water
              volume to be used for an equivalent waste removal process.  The washing fluid may
              contain additives such as acids, alkalies, detergents, and selected organic solvents that
              may enhance soil decontamination.
5/93                                         13

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SOIL FLUSHING AND WASHING
              The major site-specific conditions that dictate the successful implementation of this
              process are the soil properties related to organic content porosity, permeability, pH,
              and temperature.  Each site is truly unique for this application and actual laboratory
              and field studies have to be performed before recommending this process.  The soil
              scrubbing technique in connection with a conventional groundwater treatment system
              can tolerate  much higher soil-water partition coefficients and more washing fluid
              volume throughout than soil washing systems without groundwater treatment systems
              because of the major cost of regenerating the washing medium.

              Environmental Impacts

              The leaching medium must be reused for economic reasons; therefore, regeneration
              of the liquid must also be accomplished along with soil washing.  The leachate
              collected from the contacting process can be recycled by selecting a treatment process
              for the particular contaminants (i.e., air stripping of water for VOC removal). The
              separation of the extracted contaminants from the washing fluid can be accomplished
              by conventional treatment  systems suited to the particular contaminants.  Problems
              have arisen  with the use of water/surfactant systems because a leachate treatment
              system has not yet been developed to selectively remove contaminants and pass the
              surfactants through intact.

              Costs

              Several cost systems have been employed at hazardous waste sites.  However, none
              have been developed to commercial status for estimating costs.  The soil washing
              system  used  at  Lee's  Farm,  Wisconsin,  had  an  estimated  cost  of  about
              $150-$200/yd3 excluding development costs. The major cost of the project is usually
              associated with the leachate treatment system.

              Commercial Applications

              Currently,  several hazardous waste  sites throughout  the  country  employ  this
              extraction/soil washing technique for the cleanup of contaminated soils. Some have
              reached more developed stages than others, but all  have had to test this system on
              the site-specific conditions of concern.

              Sites where this technology has been used include:

              •      Volk Air National Guard Base, Juneau County, Wisconsin, performed by the
                     Air Force Engineering and Service Center, Tyndall AFB, FL  32403-6001.
                     "In Sim Treatment of JP-4 Contaminated Soil."

              Soils  contaminated with  volatile organics were  leached  with  water/2-percent
              surfactant and the leachate was regenerated by air stripping.
5/93                                        14

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SOIL FLUSHING AND WASHING
              •      Lee's Farm Wisconsin, Battery Manufacturing. Wastes include lead, zinc,
                     copper, etc.  Contact Charlie Castle, on-scene coordinator in EPA Region
                     V, 312/535-2318.

              Lead-contaminated soils were leached with water/5-percent EDTA and the leachate
              was regenerated by electrolysis.

              •      Celtor Chemical Works, Hoopa Indian Reservation, Ore Enrichment Plant.
                     Tailings include cadmium, copper and zinc.  Contact Nick Morgan, project
                     manager for EPA Region IX, 916/243-5831.
5/93                                      15

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SOIL FLUSHING AND WASHING
                                        APPENDIX I
                               INNOVATIVE TECHNOLOGY
                                      SOIL WASHING
Technology Description

Soil washing is potentially
effective in treating various
organic and inorganic waste
groups.  It was designed for
the   separation/segregation
and volumetric reduction of
hazardous materials in soils,
sludges, and sediments. The
process involves high-energy
contacting  and   mixing  of
excavated contaminated soils
with   an    aqueous-based
washing  solution in a series
of mobile washing units.  A
typical soil washing treatment
flow  diagram is shown  in
FIGURE 1.

Before  treatment, the  con-
taminated  soil   is   passed
through a coarse-mesh sieve
to remove material   greater
than 2  inches (e.g.,  rocks,
debris).    The  remaining
material  then enters  a soil
scrubbing unit,  where  it is
sprayed with  a washing fluid
and   subsequently    rinsed.
Contaminants  are primarily
concentrated   in  the  fine-
grained soil fraction (i.e., silt
and clay) and are less tena-
ciously   sorbed   on   the
coarser-grained  particles
(i.e.,  sand).   Accordingly,
the sand fraction of the soil
usually   requires  only  the
initial  rinsing treatment  to
meet designated performance
criteria prior to redeposition.
The remaining silt/clay soil
fraction  enters a  four-stage
countercurrent  contactor  to
further separate the co'ntam-
inants from the solids.  The
treated solid fractions  (less
than 74  microns) are  then
rinsed,    dewatered,   and
redeposited.    The contam-
inated  washing fluid,  con-
taining highly  contaminated
fine fractions  (greater  than
74   microns)  is   recycled
through    a   conventional
wastewater treatment  system
and  is reintroduced into the
treatment process.  The fines
are separated, removed, and
dewatered  and  are handled/
disposed  of as  a  manifested
hazardous waste material.

Advantages of soil washing
include   a  closed  treatment
system that permits control
of  ambient   environmental
conditions,  potential  signi-
ficant volume  reduction  of
the contaminant mass (depen-
ding on soil characteristics),
wide application   to  varied
waste  groups,  mobility  of
technology (hazardous wastes
remain  onsite), and  relati-
vely low cost  compared  to
other multicontaminant treat-
ment technologies.   Disad-
vantages   include  (1)  little
reduction of the contaminant
toxicity,    (2)   potentially
hazardous  chemicals  (e.g.,
chelating washing  solutions)
may be brought onsite to be
used in the process, and (3)
The   chemicals   may   be
difficult to remove from the
treated    soil    fraction.
Applications  and limitations
of soil washing are discussed
in the following sections.

Site  Characteristics
Affecting   Treatment
Feasibility

Soil washing has the potential
to  treat  a wide variety  of
contaminants such as heavy
metals, halogenated solvents,
aromatics,  gasoline and fuel
oils, PCBs, and  chlorinated
phenols.   The projected ef-
fectiveness of this treatment
on   general   contaminant
groups   is   provided   in
TABLE 1-1; treatability tests
are required to determine the
feasibility of soil washing for
specific target contaminants
at a particular site.

Factors limiting the effective-
ness of soil washing include
complex    waste   mixtures,
high humic  content  in the
soil,  inhibiting  solvent-soil
reactions,  and a high  fine-
grained clay particle fraction.
5/93
            16

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 SOIL FLUSHING AND WASHING
        f~f^~ff \J~ ~tf~ltfm • /" ¥ J1 1 f
       ^J^**- I/" *f •*.*'
       #   ScTMnog

        ' (Dcbnt
                               FIGURE 1-1

  SCHEMATIC DIAGRAM OF A MOBILE SOIL WASHING TREATMENT FACILITY
5/93
                                   17

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SOIL FLUSHING AND WASHING
TABLE 1-1
EFFECTIVENESS OF SOIL WASHING TREATMENT ON GENERAL
CONTAMINANT GROUPS FOR SOIL AND DEBRIS




Treatability Groups
Halogenated volatiles
Halogenated semivolatiles
Nonhalogenated volatiles
Nonhalogenated semivolatiles
PCBs
Pesticides
Dioxins/furans
Organic cyanides
Organic corrosives
Volatile metals
Nonvolatile metals
Asbestos
Radioactive materials
Inorganic corrosives
Inorganic cyanides
Oxidizers
Reducers
Effectiveness
Q
Q
Q
Q
Q
Q
9
Q
Q
Q
Q
Q
9
O
Q
Q
Q
5/93
18

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SOIL FLUSHING AND WASHING
                           APPENDIX II
                            FIGURE II-l
           VOLUME REDUCTION UNIT - SOIL WASHING PROCESS
5/93
19

-------
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Section 12

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                               IMMOBILIZATION
STUDENT PERFORMANCE OBJECTIVES:



At the conclusion of this unit, participants will be able to:



       •      List at least two advantages of using immobilization

       •      Briefly describe the functional differences between absorbants and stabilizers

       •      Briefly   describe   cement-based,    silicate-based,   and   thermoplastic
             immobilization processes

       •      List four types of immobilization systems

       •      Briefly describe vitrification.
5/93

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                                                  NOTES
         IMMOBILIZATION
• A process designed to render
  contaminants less soluble, mobile,
  and/or toxic

• The process prevents leaching from a
  solid matrix
         IMMOBILIZATION
           ADVANTAGES
      •  Improves waste handling

      •  Decrease in surface area

      •  Limited solubility or toxicity

      •  Readily available materials

      •  Large number of suppliers
         IMMOBILIZATION
         DISADVANTAGES
  •  Not a destruction technology

  • Increase in waste volume

  • Unproven for long-term leachability
5/93
Immobilization
     page 1

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         NOTES
                                            ABSORBANTS
                                    Physically hold liquid waste within
                                    pores by capillary action or tension
                                       Vermiculite
                                       Fuller's earth
                                       Bentonite
                                       Fly ash
                                       Saw dust
                                            STABILIZERS
                                     Chemically react with waste to
                                     remove free liquids and produce a
                                     monolith block
                                       Portland cement
                                       Pozzolanic material
                                        (lime with silicates)
                                       Fly ash
                                       Kiln dust
                                   IMMOBILIZATION PROCESSES


                                       • Cement-based process

                                       • Silicate-based process

                                       • Thermoplastic process
Immobilization
page 2
5/93

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                                                           NOTES
     CEMENT-BASED PROCESS
 • Mixing waste with Portland cement
 • Waste incorporated into matrix
 • Waste not chemically bound and Is subject to
   leaching, needs secondary containment for
   disposal
 • Not effective in immobilizing organics
 • Incompatible waste:
     Sodium salts of arsenate, borate, phosphate,
      iodate, and sulfide
     CEMENT-BASED PROCESS
 • Preparation: limestone, clays, and silicates are fired In
   a rotary kiln at 3000 degrees F
 • Type I - Normal strength
 • Type II • Moderate sulfate resistance
 • Type III - High early strength
 • Type IV • Low heat of hydration
 • Type V • High sulfate resistance
 • Type K • Low matrix shrinkage
     SILICATE-BASED PROCESS
    Stabilizes waste oil, solvents, and metals
       Interference
    Secondary containment required
       Unbound water may leach out
5/93
Immobilization
      page 3

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          NOTES
                                           SILICATE-BASED PROCESS

                                       • Reaction between silicate material and polyvalent
                                         metal ions
                                           Silicate material such as fly ash, blast furnace
                                           slag, or other types of pozzolanic material is
                                           added to the waste

                                           Polyvalent metal ions from the waste or added
                                           setting agents initiate the solidifying process

                                           The best setting agents are lime, gypsum,
                                           Portland cement, and calcium carbonate
                                           (Al, Fe, Mg)
                                           THERMOPLASTIC PROCESS
                                       • Asphalt, paraffin, and polyethylene

                                       • Waste is dried, heated, then added to the
                                         matrix

                                       • Heavy metals and electroplating waste

                                       • Incompatible waste:
                                            Nitrates and perchlorates
                                            Xylene and toluene
                                            Solvents and greases
Immobilization
page 4
5/93

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                                 IMMOBILIZATION
SOLIDIFICATION/STABILIZATION

Solidification and stabilization are terms used to describe treatment systems that accomplish one or
more of the following objectives (USEPA, 1982b):

«      Improve waste handling or other physical characteristics of the waste

•      Decrease the surface area across which transfer or loss of contained  pollutants can occur

•      Limit the solubility or toxiciry of hazardous waste constituents.

Solidification is used to describe processes where  these results are obtained primarily, but not
exclusively, by production of a monolithic block of waste with high structural integrity.   The
contaminants do  not necessarily interact  chemically  with the solidification reagents,  but are
mechanically locked within the  solidified  matrix.  Contaminant loss is minimized by reducing the
surface area. Stabilization methods usually involve the addition of materials  that limit the solubility
or mobility of waste constituents even though the physical handling characteristics of the waste may
not be improved (USEPA, 1982b; Cullinane  and Jones, 1985).  Methods involving combinations of
solidification and stabilization techniques are often used.

Solidification/stabilization methods can be categorized as follows:

•      Cement solidification

•      Silicate-based processes

•      Sorbent materials

•      Thermoplastic techniques

•      Surface encapsulation

•      Organic polymer processes

•      Vitrification.

Detailed discussions of solidification/stabilization methods can be found in Guide to the Disposal of
Chemically Stabilized and Solidified Waste and Technical Handbook for Solidification of Hazardous
Waste (Cullinane and Jones, 1985).
5/93

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IMMOBILIZATION

These  documents  should be consulted for detailed  information on these processes.    Many
manufacturers are marketing processes that use various combinations of alkaline earth materials (e.g.,
lime, cement kiln dust, silicaceous materials,  and cement) combined with  organic polymers and
proprietary chemicals.

       Cement-Based Solidification

              General Description

              This method involves mixing the wastes directly with Portland cement, a very
              common construction material. The waste is incorporated into the rigid matrix of the
              hardened concrete.  Most solidification is done with Type I Portland cement,  but
              Types II and V can  be used for sulfate or  sulfite wastes.  This method physically or
              chemically solidifies the wastes, depending on waste characteristics (USEPA, 1982b).
              The end product may be a standing monolithic solid or may have a crumbly, soil-like
              consistency, depending on the amount of cement added.

              Applications/Limitations

              Most hazardous wastes slurried in water can be mixed directly with cement and the
              suspended solids will  be incorporated into the rigid matrix.  Although cement  can
              physically incorporate a broad  range of waste types,  most wastes  will not  be
              chemically bound and are subject to leaching.

              Cement solidification is  most suitable for  immobilizing metals because at the pH of
              the cement mixture,  most multivalent cations are converted into insoluble hydroxides
              or carbonates. However, metal hydroxides and carbonates are insoluble only over
              a narrow pH range  and are subject to solubilization and leaching in the presence of
              even mildly  acidic leaching solutions (e.g., rain).  Portland cement alone is also not
              effective in immobilizing organics.

              The end product of  cement  solidification will not be acceptable for disposal without
              secondary containment regardless of whether the wastes are organic or inorganic in
              nature.  Another major disadvantage  is that cement-based solidification results in
              wastes that  are  twice the  weight and volume of the original  material, thereby
              increasing transportation and disposal  costs (USEPA, 1982b).   Because of these
              limitations,  Portland  cement is generally used  only as  setting  agent  in  other
              solidification processes,  particularly silicate-based  processes.

              Another problem with cement solidification is that certain wastes can cause problems
              with the set, cure, and permanence of the cement  waste solid unless the wastes are
              pretreated. Some of these incompatible wastes are (USEPA,  1982b):

              •      Sodium salts of arsenate, borate, phosphate, iodate, and sulfide

              •      Salts of magnesium, tin, zinc, copper, and lead
5/93

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IMMOBILIZATION

              •      Sodium salts of arsenate, borate, phosphate, iodate, and sulfide

              •      Salts of magnesium, tin, zinc, copper, and lead

              •      Organic matter

              •      Some silts and clays

              •      Coal or lignite.

              Major advantages to the use of cement include its low cost and the use of readily
              available mixing equipment.

              Costs

              Cement costs range from $60  to $90 per ton at the mill.   However, capital
              expenditure and transportation will vary widely depending on the site and the waste.
              Cost information for specific wastes  should be  obtained from vendors.   Vendors
              include Atcor Washington, Inc., Park Mall, Peeksville, New York, and Chemfix,
              Inc., Kenner, Louisiana.

       Silicate-Based Processes

              General Description

              Silicate-based processes refer to a very broad range of immobilization methods that
              use a siliceous material plus lime, cement, gypsum, and other suitable setting agents.
              Extensive research is currently  underway  on the use of  siliceous compounds  in
              solidification. Many of the available  processes use proprietary additives and  claim
              to stabilize a broad range of compounds from divalent metals to organic  solvents.
              The basic reaction is between silicate material and polyvalent metal ions. The silicate
              material that is added in the waste may be fly-ash, blast furnace slag, or other readily
              available pozzolanic materials. Soluble silicates such as sodium silicate or potassium
              silicate are also used.  The polyvalent metal ions, which act as initiators of silicate
              precipitation  and/or gelation,  come either from the waste solution,  an  added setting
              agent, or both.  The  setting  agent should have  low solubility and a large reserve
              capacity of metallic ions so that it controls the reaction rate.  Portland cement and
              lime are most commonly used because of their ready availability.  However, gypsum,
              calcium carbonate, and other compounds containing aluminum, iron, and magnesium
              are also suitable setting agents.  The  solid that is formed  in these  processes varies
              from a moist, clay-like material to a hard, dry solid similar in appearance to concrete
              (Granlund and Hayes, undated).
5/93

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IMMOBILIZATION
              Some of the additives used in silicate-based processes include (Cullinane and Jones,
              1985):

              •      Selected clays to absorb liquid and bind specific anions or cations.

              •      Emulsifiers and surfactants that allow the incorporation of immiscible organic
                     liquids.

              •      Proprietary absorbents that selectively bind specific wastes.  These materials
                     may include carbon, zeolite materials, and cellulosic sorbents.

              There are a number of silicate-based processes that are currently  available or are
              under research.  Manufacturers' claims differ significantly in terms of the capabilities
              of these processes for stabilizing different waste constituents.

              The Chemfix  process  uses  soluble  silicates  with  cement as  the setting agent.
              Research data  show  that the  process  can  stabilize  sludges  containing  high
              concentrations  of heavy   metals  even under  very acidic   conditions  (Spencer,
              Reifsnyder, and Falcone,  1982).

              The Envirosafe I  process  uses fly ash  as the  source of silicates and lime as the
              alkaline earth material.  This method has been shown to stabilize oil-bearing sludge
              (49 percent oil and  grease) and  neutralize inorganic  metal sludge.  Success was
              demonstrated by suing compressive strength tests following ASTM methods (TABLE
              1) and leaching tests (Smith and Zenobia,  1982) (TABLE 2).

              The DCM cement shale  silicate process is  a proprietary process formulated  by
              Delaware Custom Material, Inc.,  State  College, Pennsylvania.  It involves use of
              cement, an emulsifier for  oily wastes, and sodium silicate. Testing by Brookhaven
              National Laboratories showed  that the process could  stabilize oily wastes with up to
              a   30-percent   volumetric  loading  (Clark,  Colombo,  and   Neilson,  1982).
              Manufacturers  claim that the process can be used to solidify wastes containing acids,
              organic solvents, and oils  (Hayes and Granlund, undated).

              PQ Corporation of Lafayette Hill,  Pennsylvania, has done extensive research on the
              use of silicates. Their research describes successful stabilization of a mixed heavy
              metal/organic sludge; a waste containing high levels of organics and petroleum by-
              products; and a waste containing organic solvents using  modifications of the process
              that uses sodium silicates  (Spencer, Reifsnyder, and  Falcone,  1982).
5/93

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IMMOBILIZATION
TABLE 1
PHYSICAL AND CHEMICAL TESTS
USED IN THE CHEMFIX SITE DEMONSTRATION
Name of test
Unconfmed compressive
strength (UCS)
Hydraulic conductivity
Wet/dry resistance
Freeze/thaw resistance
Oxidation/reduction
Electrical conductivity
Reference
ASFHM D1633
EPA draft protocol
ASTM D4843
ASTM D4842
EPA Method 9045
(modified)
ASA 10.-3.3
Description
Used to assess structural
integrity of monolith
Used to assess resistance of
material to water flow
Indication of durability in
wet/dry environment
Indication of durability in
wet/dry environment
Determine oxidation/
reduction state of waste
matrix
Determine amount of ionic
materials present in solution
TABLE 2
LEACHING TESTS USED IN THE CHEMFIX SITE DEMONSTRATION
Name of Test
TCLP
MEP
ANS 16.1
Reference
40 CFR Part 268
EPA Method 1320
(SW 846)
American Nuclear
Society 16.1
Description
Ground material subject to 18-hour
extraction process with acetic acid
leachate to simulate codisposal
environment with municipal waste
Ground material subject to 24-hour
extraction with acetic acid leachate
followed by nine sequential extractions
with acidic rain simulated leachate
Monolithic material placed in distilled
water that is replaced over discrete
time intervals (diffusion model)
5/93

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IMMOBILIZATION

              Applications/Limitations
              There is considerable research data to suggest that silicates, used together with lime,
              cement, or other setting agents, can stabilize a wide range of materials including
              metals,  waste oil, and  solvents.  However, the feasibility  of using silicates for any
              application must be determined on a site-specific basis, particularly in view of the
              large number of additives and different sources of silicates that may be used.  Soluble
              silicates such as sodium and potassium silicate are generally more effective  than fly
              ash, blast furnace slag, etc.

              There are some data to suggest that lime-fly ash materials are less durable and stable
              to leaching that cement fly ash materials (Cullinane and Jones, 1985).

              Common  problems  with lime-fly  ash  and  cement-fly  ash materials relate  to
              interference in cementitious reactions that prevent bonding of materials.

              Materials  such  as  sodium  borate,  calcium  sulfate, potassium  dichromate, and
              carbohydrates can interfere with the formation of bonds between calcium silicate and
              aluminum hydrates.  Oil and grease can also  interfere with bonding by coating waste
              particles (Cullinane and Jones, 1985).  However, several types of oily sludges have
              been stabilized with silicate-based processes.

              One of the major limitations with silicate-based processes is that a large amount of
              water, which is not chemically bound, will  remain in the solid after solidification.
              In open air, the liquid will leach until it comes to some equilibrium moisture content
              with the surrounding soil.  Because of this water loss, the solidified product  is likely
              to require secondary containment.

              Silicate-based processes can employ a wide range of materials, from those which are
              cheap and readily available, to highly specialized and costly additives.

              The services of a qualified  firm  are generally needed to  determine the most
              appropriate formulation for a specific waste  type.

              Implementation Considerations

              Commercial cement mixing  and handling  equipment can generally be used  for
              silicate-based processes. Equipment requirements include chemical storage hoppers,
              weight-  or volume-based  chemical feed equipment, mixing equipment, and waste
              handling equipment.  Ribbon blenders and single and double shaft mixers can be used
              for mixing.  A number of mobile, trailer-mounted systems are available.

              Silicate-based solidification can also be accomplished  on a batch basis in drums.
              Equipment requirements include onsite chemical storage system, chemical batching
              system, mixing system, and drum handling system.  One company has developed a
              solidification kit for processing wastes in a  drum.  The kit consists  of  a drum
5/93                                         10

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IMMOBILIZATION
              containing a disposable mixer blade with the shaft held by bearings welded to the
              inside of the lid and the bottom of the drum.  The upper end of the shaft is accessible
              through a bung in the lid for turning with an external motor.   The cement can be
              added to  the drum before it is  capped.  The liquid  waste  and silicate are added
              through bungs in the lid. An air-driven motor is  clamped to the drum lid to turn the
              mixer (Granlund and Hayes, undated).

              Solidification can also be accomplished in situ using a lagoon or mixing pit.   This
              would involve the use of common construction machinery such as a backhoe or pull
              shovel to mix  the waste and reagents. However, the ability  of in situ solidification
              to prevent leaching of contaminants would need to be demonstrated on a case-by-case
              basis.

              Costs

              TABLE 3 provides estimated costs for silicate  solidification using three  different
              mixing  methods:   in-drum  mixing,  in situ  mixing,  and a mobile  cement mixing
              system. In all cases it was assumed that 500,000  gallons (2,850 tons) of wastes were
              solidified with 30-percent Portland cement and  2-percent sodium silicate. Onsite
              disposal was assumed. These costs are intended  mainly to show the relative cost of
              various mixing methods and the proportion of total cost for reagents,  equipment, and
              labor.  It should be emphasized that actual costs are highly waste and site specific and
              that specific site and/or waste characteristics could change these cost estimates by
              several  fold.

              In-drum mixing  is by far the  most expensive alternative and  requires the greatest
              amount of labor and production  time. Because of the high cost, in-drum mixing is
              limited  to sites with highly toxic or incompatible wastes in drums (Cullinane and
              Jones,  1985).

              The cost of in situ mixing and mobile treatment are much more comparable. All are
              quite sensitive to reagent cost because this cost  typically makes up from  40 to 65
              percent of the total cost.  The in situ technique is the fastest and most economical of
              the bulk-methods because the wastes typically only have to be handled once, or not
              at all if they are to be left in place.  Labor and equipment each made up less than 5
              percent of the total  treatment  cost.  However,  in  situ mixing  is the least reliable
              because of difficulties in accurate reagent measurement and difficulties in getting
              uniform and/or complete mixing of wastes and treatment reagents.  Mobile mixing
              plants, although giving excellent mixing results and reasonably good production rates,
              require that both the treated and untreated product be handled, thereby increasing the
              costs above those for in situ treatment.
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TABLE 3
SUMMARY COMPARISON OF RELATIVE 1985 COSTS OF
STABILIZATION/SOLIDIFICATION ALTERNATIVES1
Parameters
Metering and mixing
efficiency
Processing days required
In-drum3
Good
374
Plant Mixing3
In-situ4
Fair
4
Pumpable
Excellent
10
Unpumpable
Excellent
14
Cost/ton
Reagent
Labor & per diem
Equipment rental
Used drums @
$11 /drum
Mobilization/demobil-
ization
Cost of treatment
processes
Profit and overhead
(30%)
TOTAL COST/TON
$24.46
(9%)5
61.09
(23%)
44.43
(17%)
57.69
(21%)
18.76
7%
$206.38
61.91
(23%)
$248.29
$21.27
(63%)
1.41
(4%)
1.43
(4%)


1.64
5%
$ 25.75
6.73
(23%)
$ 33.48
$21.27
(53%)
3.97
$10%)
4.07
(10%)


1.48
4%
$ 30.79
9.29
(23%)
$ 40.03
$21.27
(42%)
7.19
(14%)
7.82
(16%)


2.34
5%
$ 38.62
11.59
(23%)
$ 50.21
1 Costs updated from 1983 costs using 1985 ENR Index.
2 Assumed pumpable sludge had a daily throughput of 250 yd3 and the unpumpable
sludge a throughput of 180 ydVday. Remedial action is assumed to be located 200
miles from the nearest equipment.
3 Assumed 49 gallons of untreated waste per drum and a processing rate of 4.5 drums
per hour.
4 Assumed wastes would be mixed by backhoe with a lagoon and left there. Remedial
Action is located 200 miles from its nearest equipment
5 Percent of total cost/ton for that alternative.
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IMMOBILIZATION

       Sor bents

              General Description

              Sorbents include a variety of natural and synthetic solid materials that are used to
              eliminate free liquid  and improve the handling characteristics of wastes. Commonly
              used natural sorbent materials  include flyash, kiln dust, vermiculite, and bentonite.
              Synthetic sorbent materials include activated carbon, which sorbs dissolved organics;
              Hazorb (product of Dow Chemical), which sorbs water and organics; and Locksorb
              (product of Radecca Corp.), which is reportedly effective for all emulsions (Cullinane
              and Jones, 1985).

              Applications/Limitations

              Sorbents are widely  used to remove free liquid and improve waste handling.  Some
              sorbents have been used to limit the escape of volatile  organic compounds.  They
              may also be useful in waste containment when they modify the chemical environment
              and maintain the pH and redox potential to limit the solubility of wastes (Cullinane
              and Jones, 1985).  Although sorbents  prevent drainage of free water, they do not
              necessarily prevent  leaching  of waste constituents and secondary containment is
              generally required.

              Implementation Considerations

              The  quantity of sorbent material necessary for removing free liquid varies widely
              depending on the nature of the liquid phase,  the solids content of the waste, the
              moisture level in the sorbent, and the availability of any  chemical reactions that take
              up liquids during reaction.  It is generally necessary to determine the quantity of
              sorbent needed  on a case-specific basis.  Equipment requirements for addition and
              mixing of sorbents are simple.

       Thermoplastic Solidification

              General Description

              Thermoplastic  solidification involves sealing wastes  in a matrix such as  asphalt
              bitumen, paraffin, or  polyethylene.   The  waste is  dried,  heated, and  dispensed
              through  a heated plastic matrix.  The mixture is then  cooled to form a  rigid but
              deformable solid. Bitumen solidification is the most widely used of the thermoplastic
              techniques.

              Applications/Limitations

              Thermoplastic solidification involving the use of an asphalt binder is most suitable for
              heavy  metal  or electroplating  wastes.  Relative to  the cement solidification, the
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IMMOBILIZATION
              increase in volume is significantly less and the rate of leaching significantly lower.
              Also, thermoplastics are little affected by either water or microbial attack.

              There are a  number of waste  types  that  are  incompatible with  thermoplastic
              solidification.  Oxidizers such as perchlorates or nitrates can react with many of the
              solidification materials to cause an explosion. Some solvents and greases can cause
              asphalt materials to soften and never become rigid. Xylene and toluene diffuse quite
              rapidly through asphalt.  Salts that partially dehydrate at elevated temperatures can
              be a problem.  Sodium sulfate hydrate, for example, will lose some water during
              asphalt incorporation, and if the waste asphalt mix containing the partially dehydrated
              salt is soaked in water, the mass will swell and crack due to rehydration.  This can
              be avoided by eliminating easily dehydrated salts  or  coating the outside of the
              waste/asphalt mass with pure asphalt.  Chelating and complexing agents (cyanides
              and ammonium) can cause problems with containment of heavy metals (Cullinane and
              Jones, 1985).

              High equipment  and energy  costs  are  principal disadvantages of  thermoplastic
              solidification.   Another problem  is that the plasticity of the matrix-waste mixture
              generally  requires that  containers be provided for transportation and disposal of
              materials, which greatly increases the cost.

              Certain wastes, such as tetraborates and  iron  and aluminum salts, can cause
              premature solidification and plug  up the mixing machinery (USEPA, 1982b).

              Implementation Considerations

              Thermoplastic solidification requires specialty equipment and highly trained operators
              to heat and  mix  the wastes and solidifier.   The common range  of operating
              temperatures is 130°-230°C.  The energy intensity of the  operation is increased by
              the requirement that the wastes be thoroughly dried before solidification.

              Costs

              Cost data for thermoplastic solidification outside of the nuclear industry is not readily
              available.  Wernen and Pfleudern  Corporation has developed  an asphalt binder-based
              process called the Volume Reduction and Solidification  System;  solidification costs
              for nonradioactive materials are estimated at $20-$70 per ton.  This cost  includes
              secondary containment but not final transport and disposal (Doyle, 1980).
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IMMOBILIZATION

       Surface Microencapsulation

              General Description
              Surface encapsulation describes those methods that physically microencapsulate waste
              by sealing  them in an  organic  binder  or  resin.  Surface  encapsulation can be
              accomplished using a variety of approaches.  Three methods which  have been the
              subject of considerable research are described briefly below.

              One process developed by Environmental Protection Polymers involves the use of 1,2-
              polybutadiene and polyethylene to produce  a microencapsulated waste block  onto
              which a high-density polyethylene (HDPE) jacket is fused.  The 1,2-polybutadiene is
              mixed with  particulated waste which yields,  after  solvent evaporation, free-flowing,
              dry, resin-coated particulates.  The resulting polymers are  resistant to oxidative and
              hydrolytic degradation and to permeation by water. The next step involves formation
              of a block  of  the  polybutadiene/waste mixture.  Powdered,  HDPE  is grafted
              chemically onto  the polymer backbone to provide a final matrix with ductile qualities.
              Various  combinations of the  two resins (polybutadiene and polyethylene)  permit
              tailoring of the matrix's  mechanical properties without reduction of system stability
              when exposed to severe chemical stress.  In the  final step, a 1A-inch-thick  HDPE
              jacket is mechanically and chemically locked to the surface of the microencapsulated
              waste  (Lubowitz and Wiles, 1981).

              Another encapsulation method developed by Environmental Protection  Polymers
              involves a much simpler approach. Contaminated  soils or sludges are loaded  into an
              HDPE overpack.   A  portable  welding apparatus developed by Environmental
              Protection Polymers  is then used to spin weld  a  lid onto the container, thereby
              forming  a seam-free encapsulate.

              A third  surface  encapsulation method involves use of an organic binder  to seal  a
              cement-solidification mass.  United States Gypsum Company manufactures a product
              called Envirostone Cement, which is a special blend of high-grade polymer modified-
              gypsum  cement. Emulsifiers and ion-exchange resins may be added  along with the
              gypsum cement, which hydrates to form a free-standing mass.  A proprietary organic
              binder is used to seal the solidified mass (United  States Gypsum Co., 1982).  The
              process can be used to stabilize both organic and inorganic wastes. It has been shown
              to effectively immobilize waste oil present at concentrations as high as 36 volume
              percent (Clark,  Colombo, and Neilson, 1982). The volume of waste is smaller than
              that obtained with cement solidification alone.

              Applications/Limitations

              Current research shows that the major advantage of encapsulation processes is that the
              waste material is completely isolated  from leaching solutions.  These methods can be
              used for both organic  and  inorganic waste constituents.   However, each  of the
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IMMOBILIZATION

              available  encapsulation  processes  are  quite  unique and  the  feasibility  must  be
              determined on a case-specific basis.

              Other advantages  associated with hazardous waste  encapsulation include (USEPA,
              1982b):

              •       The  cubic and cylindrical encapsulates allow for efficient space use during
                     transport, storage, and disposal

              •       The  hazard of accidental spills during transport is eliminated

              •       Materials  used for encapsulation are commercially  available, very  stable
                     chemically, nonbiodegradable, mechanically tough, and flexible

              •       Encapsulated waste materials  can withstand the mechanical  and  chemical
                     stresses of a  wide range  of  disposal schemes (landfill, disposal  in  salt
                     formations, and  ocean disposal).

              The major disadvantages associated with encapsulation techniques include:

              •       Binding  resins  required   for  agglomeration/encapsulation  (HDPE  and
                     polybutadiene) are relatively expensive

              •       The  processes are  energy intensive and relatively costly

              •       Skilled labor is required to  operate molding  and fusing equipment.

              Costs

              Environmental  Protection Polymers  has   estimated   that  the   cost  of  the
              polybutadiene/HDPE microencapsulation  method  will be approximately $90/ton.
              Encapsulation in the seam-free HDPE overpack is approximately $50-$70 for an 80-
              gallon drum load (Lubowitz,  H., Environmental  Protection  Polymers, personal
              communication,October  13 and  14, 1983).

       Vitrification

              General Description

              Vitrification  of wastes  involves combining  the  wastes  with  molten glass at a
              temperature  of 1,350°C  or greater.  However, the encapsulation might be done at
              temperatures significantly below 1,350°C (a simple glass polymer such as boric acid
              can be poured at 850°C). This melt is  then cooled into a stable, noncrystalline solid
              (USEPA, 1982b).
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              Applications/Limitations
              This process is quite costly and has been restricted to radioactive or very highly toxic
              wastes.   To be  considered  for vitrification,  the wastes  should be either stable or
              totally destroyed at the process temperature.

              Of all the common solidification methods, vitrification offers the  greatest degree of
              containment.  Most resultant solids have an extremely low leach rate. Some glasses,
              such as borate-based glasses, have high leach rates and exhibit some water solubility.
              The  high energy demand and requirements  for specialized equipment and trained
              personnel greatly limit the use of this method.

              Implementation Considerations

              Vitrification of  wastes is an extremely  energy-intensive operation  and requires
              sophisticated machinery and highly trained personnel.

              Cost

              No cost information was available for vitrification.

              Technology Selection/Evaluation

              Evaluation of the technical feasibility and effectiveness of stabilization/solidification
              methods  must be determined on a case-by-case basis. Commercial firms specializing
              in these processes should be consulted whenever solidification/stabilization is being
              considered. Samples of the  solidified product will  need to be subjected to extensive
              leaching  tests  unless a reliable,  effective means of secondary containment is to be
              used. It should be noted that  secondary containment is recommended  with most of
              the previously described methods (except microencapsulation and glassification for
              some waste types). Similarly, where the end product is intended to be a  monolithic
              block, samples must be subjected to  compressive strength tests.

              Solidification/stabilization methods range from those that use simple,  safe, readily
              available equipment (cement and most silicate-based processes) to those that require
              highly  sophisticated,  costly,  and  specialized equipment (e.g.,  glassification and
              thermoplastic techniques). Use of these high technology processes should be limited
              to wastes that cannot be treated cost-effectively using any other methods.  Regardless
              of the simplicity of some of the equipment, professionals trained  in these processes
              should be consulted because formulations including proprietary additives are very
              waste specific.
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IMMOBILIZATION

       Immobilization

       Immobilization methods are designed to render contaminants insoluble and prevent leaching
       of the contaminants from the soil matrix and their movement from the area of contamination.
       Little is currently known about the effectiveness and reliability of immobilization techniques.

       Innovative Immobilization Technologies

       Immobilization methods that are currently being investigated include precipitation, chelation,
       and polymerization.

       Precipitation is the most promising method for immobilizing dissolved metals such as lead,
       cadmium, zinc, and iron.   Some forms of arsenic, chromium, mercury, and  some organic
       fatty acids can also be treated by precipitation (Huibregtse and Kastman, 1979).  All of the
       divalent metal  cations can be precipitated using sulfide, phosphate, hydroxide, or carbonate.
       However, the  solubility product  and the stability of the metal complexes vary.  Because of
       the  low solubility product of sulfides and the stability of the metal sulfide  over a broad pH
       range, sulfide  precipitation looks most promising.    The remaining  anions decrease in
       effectiveness in the following order: phosphate > hydroxide > carbonate.  Metal carbonates
       and hydroxides are stable only over a narrow pH range and the optimum pH range varies for
       different metals.  Precipitation of the metal as the metal phosphate may require very high
       concentrations of orthophosphate because calcium and other naturally occurring soil cations
       present in high concentrations will precipitate first.

       Sodium  sulfate used  in   conjunction  with   sodium  hydroxide   has  shown  widespread
       applicability for precipitation of metals.   Precipitation takes  place at a neutral or slightly
       alkaline pH. Resolubilization of sulfides is low.  Addition of sodium hydroxide minimizes
       the  formation of hydrogen sulfide gas by ensuring an  alkaline pH.  Experiments with sulfide
       precipitation of zinc indicate that a high residual of unreacted sulfide may remain in  solution.

       As with other in situ techniques, precipitation is most applicable to sites with sand or coarse
       silt  strata.   Disadvantages  include the injection of a potential groundwater  pollutant, the
       potential for formation  of  toxic  gases  (in the case of sulfide treatment),  the potential for
       clogging soil pore space, and the possibility of precipitate resolubilization.

       The use  of chelating  agents may also  be a very effective means  of immobilizing metals,
       although considerable research is needed in this area.  Depending  on the specific chelating
       agent,  stable metal  chelates may be highly mobile or may be strongly  sorbed to  the soil.
       Tetran is an example  of a chelating agent that is  strongly sorbed to  clay in soils (USEPA,
       1984a).

       A third method for immobilizing metals  applies specifically  to chromium and selenium.
       These metals can be present in the highly mobile, hexavalent state but can be reduced to less
       mobile Cr (III) and Se (IV) by addition of ferrous sulfate.  Arsenic exists  in soils  as either
       arsenate, As (V), or as arsenite,  As (III), the more toxic and soluble  form. Arsenic can be
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IMMOBILIZATION

       effectively immobilized by oxidizing As (III) to As (IV) and treating the As (IV) with ferrous
       sulfate to form highly insoluble FeAsO4.

       Polymerization  involves  injection  of a  catalyst into a  groundwater  plume  to  cause
       polymerization  of an organic monomer  (e.g., styrene, vinyl chloride,  isoprene, methyl
       methacrylate, and acrylonitrile).  The polymerization  reaction transforms the once fluid
       substance into a gel-like, nonmobile mass.  In situ polymerization is a technique most suited
       for groundwater  cleanup  following land spills or underground leaks of pure monomer.
       Applications for uncontrolled hazardous waste sites are very limited.  Major disadvantages
       include very limited application and difficulty of initiating sufficient contact of the catalyst
       with the dispersed monomer (Huibregtse and Kastman, 1979).  In situ polymerization was
       successfully performed  to remedy an acrylate monomer leak,  in which  4,200 gallons  of
       acrylate monomer leaked from a corroded underground pipeline into a glacial sand and gravel
       layer.  Soil  borings  indicated that as much as 90 percent of the monomer  had been
       polymerized by injection of a catalyst, activator,  and wetting agent (Williams, 1982).

       In situ treatment  of  a  leachate plume using precipitation  or polymerization  techniques
       probably has limited application.  Problems associated with these techniques include:

       •      Need  for numerous,  closely spaced injection wells even in coarse-grained deposits
              because  the  action   of precipitation or polymerization  will  lower  hydraulic
              conductivities near injection wells  and reduce treatment effectiveness

       •      Contaminants are not removed from the aquifer or some chemical reactions can  be
              reversed, allowing  contaminants to again migrate with groundwater flow

       •      Injection of a potential groundwater pollutant or the formation of toxic by-products.

       Therefore, prior to the application of an in situ precipitation or polymerization technique at
       a hazardous waste site,  thorough laboratory- and pilot-scale testing should be conducted to
       determine deleterious effects and ensure complete precipitation or polymerization of the
       chemical compounds.

       Solidification methods used for chemical soil consolidation can also immobilize contaminants.
       Solidification and stabilization techniques are assessed in terms of their applicability for in
       situ treatment of  landfilled wastes in  Guide to the Disposal  of Chemically Stabilized and
       Solidified Wastes  (USEPA,  1982).  The assessment concluded that most work with these
       techniques  has  not involved in situ  treatment.   Most techniques  are not  applicable  to
       hazardous waste  sites,  and  most of the techniques  involve a thorough mixing of  the
       solidifying agent and the waste (Truett, Holberger, and Sanning, 1982). Injection of silicate
       gel may be feasible to  immobilize subsurface contaminants, but may negatively impact
       groundwater quality (Truett, Holberger, and Sanning, 1982).
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IMMOBILIZATION

MONITORING

Wastestream characterization prior to selecting any treatment technology is essential. Also essential
is knowing the characteristics of these streams following treatment.  Therefore, sampling plans must
be prepared which will  identify  that a technology has  met its treatment objectives.   Because
solidification/stabilization treatments are designed to immobilize contaminants, it is important to test
the solidified product to determine whether wastes are indeed immobilized.  Therefore, representative
product samples must be collected.  These  samples are collected in cylindrical waxed cardboard or
PVC forms following a batch mix,  and then are allowed  to cure.   The length of curing time can
affect test results.  In the Chemfix process, a curing time  of 28 days was used prior to conducting
tests.

Tests performed to assess the effectiveness of solidification/stabilization treatments may be classified
as physical tests or chemical tests. Physical tests are performed to quantify  physical changes  to the
treated material and include such things as material bulk density  and moisture content.   Some
common physical tests include those listed in TABLE 1.  A more extensive list of physical and
chemical tests may be found in Stabilization/Solidification of CERCLA and RCRA Wastes  (EPA
document number 625/6-89/022).  The unconfined compressive strength of a solidified material is
considered to be satisfactory when  it  is a minimum of 50 psi according to USEPA OSWER Directive
No. 9437.00-2A.  Interpretation of results  from other physical tests have not been standardized.

Chemical tests are performed to evaluate the stability of the treated material within the environment.
Therefore, sample preparations that  specify leaching procedures can yield important data regarding
contaminant mobility. TABLE 2 shows several of the leaching procedures that are used to evaluate
contaminant mobility.  The Toxicity Characteristic Leaching  Procedure  (TCLP) was specified to
replace the Extraction Procedure Toxicity Test (EP Tox) as the criterion for defining whether a waste
is hazardous. The  intent was to use  a procedure that would yield "worst case" conditions for waste
leaching.  However, several studies  have shown that TCLP leaching of cement-based waste  forms
may not necessarily yield maximum  concentrations. Multiple extraction tests, such as the Monofill
Waste Extraction Procedure (MWEP) or the Multiple Extraction Procedure  (MEP), may  be needed
to assess maximum leachate concentrations under different pH conditions.

The short-term environmental impact of stabilizing most amenable  wastes  is small, but long-term
reliability is not well known. Leachate that may be produced as a result  of the curing process should
be collected and analyzed to determine the  necessity for treatment before disposal.  The  volume of
leachate is usually minimal. Gas monitoring, collection, and treatment may be necessary with wastes
containing ammonium ions or volatile organics. The alkalinity of cement drives off ammonium ions
as ammonia gas. The heat generated by the curing or setting of the stabilized product can drive off
organic volatiles.

Because the long-term effects of this technology have not been documented, site monitoring by means
of leachate collection and institutional  controls  may be warranted.
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IMMOBILIZATION
                                    APPENDIX I
       ADVANTAGES AND DISADVANTAGES OF CEMENTS AND POZZOLANS
                Advantages
               Disadvantages
  CEMENTS

  Inexpensive and plentiful raw materials.

  High strengths and low permeabilities are
  possible.

  Technology and equipment are commonplace.

  System is tolerant of most chemical
  variations.

  Dewatering is not necessary.
  POZZOLANS

  Very inexpensive raw materials.

  High strengths and low permeabilities are
  possible.

  Reactions are well understood.

  Dewatering is not necessary.
  Large quantities of cement often required.

  Ultimate leachability not guaranteed.


  Susceptible to borates, sulphates, and acids.
  Handling of lime can be difficult.

  Susceptible to acids, and sugars.


  Ultimate leachability not guaranteed.
Source: USEPA, 1980
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IMMOBILIZATION
                             APPENDIX II
TECHNOLOGY SUMMARY
Waste Type: Soils and Sludges
Technology: Stabilization/Solidification
Characteristics
Impacting Process
Feasibility
Sodium arsenate, berates,
phosphates, iodates, sulfide, and
carbohydrates
Sulfates
Volatile organics
Presence of leachable metals
Phenol concentration greater than
5%
Presence of coal or lignite
Organic content should be no
greater than 20-45 % by weight
when using cement-based
technologies
Semivolatile organics
> 10,000 ppm
PAHs
> 10,000 ppm
Wastes with less than 15% solids
Reason for Potential Impact
Retard setting and curing and weaken
strength of final product.
Retard setting and cause swelling and
sp ailing.
Volatiles not effectively immobilized.
Driven off by heat of reaction.
Sludges containing volatile organics can be
treated using a heated extruder/evaporator to
evaporate free water and VOCs and mixing
with asphalt. VOCs with flashpoint below
350°F, thermally unstable materials, solvents
in sufficient concentrations to soften the
asphalt, and highly reactive materials require
pretreatment.
Effectiveness of stabilization methods may
vary.
Results in marked decreases in compressive
strength
Coals and lignite can cause problems with
setting, curing, and strength of the end
product.
Organics interfere with bonding of waste
materials.
Organics interfere with bonding of waste
materials.
Large volumes of cement or other reagents
required, greatly increasing the volume and
weight of the end product. Waste may
require reconstitution with water to prepare
waste/reagent mix.
Data
Collection
Requirements
Bench-scale testing
Analysis for sulfate
Analysis for volatile
organics, bench-scale testing
Analysis for priority
pollutants, bench-scale
testing
Analysis for phenols
Core sampling with specific
analysis for coal
Analysis for volatile solids,
total organic carbon
Analysis for semivolatile
organics, PAHs
Analysis for total solids and
suspended solids
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IMMOBILIZATION
TECHNOLOGY SUMMARY
Waste Type: Soils and Sludges
Technology: Stabilization/Solidification
Characteristics
Impacting Process
Feasibility
Oil and grease should be < 10%
when using cement-based
technology
Fine particle size
Halides
Soluble salts of manganese, tin,
zinc, copper, and lead
Cyanides
>3,000ppm
Reason for Potential Impact
Weaken bonds between waste particles and
cement by coating the particles
Insoluble material passing through a No. 200
mesh sieve can delay setting and curing.
Small particles can also coat larger particles,
weakening bonds between particles and
cement or other reagents. Particle size < 14
inch in diameter not suitable.
May retard setting; easily leached.
Reduce physical strength of final product;
cause large variations in setting time; reduce
dimensional stability of the cured matrix,
thereby increasing teachability potential.
Cyanides interfere with bonding of waste
materials
Data
Collection
Requirements
Analysis for oil and grease
Soil particle size distribution
Analysis for total halides
Analysis for inorganic salts
Analysis for cyanides
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Section 13

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                              DISPOSAL OPTIONS
STUDENT PERFORMANCE OBJECTIVES:
At the conclusion of this unit, participants will be able to:
       •      Briefly describe  the federal regulations covering  hazardous waste  land
             disposal

       •      List at least two sources of information about EPA Land Disposal Restrictions

       •      Briefly describe the steps needed to complete a waste characterization record
             for shipping hazardous waste

       •      List at least three alternative hazardous waste disposal methods.
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                                                       /VOTES
          HOW DID WE GET
       WHERE WE ARE NOW ?
     • Resource Conservation and
       Recovery Act (RCRA) of 1976

     • Hazardous and Solid Waste
       Amendments (HSWA) of 1984
           LAND DISPOSAL
  •  EPA defined land disposal to include, but not
    be limited to, any placement of hazardous waste
    in:
      Landfills
      Surface impoundments
      Waste piles
      Injection wells
      Land treatment facilities
      Salt domes or salt bed formations
      Underground mines or caves
      Concrete vaults or bunkers intended for
       disposal purposes
  LANDMARK LAND DISPOSAL DATES
  • November 1986 - Spent solvents and dioxins

  • July 1987 - "California List" liquid wastes
      Cyanides
      Heavy metals
      Polychlorinated biphenyls (PCBs)
      Halogenated organic compounds (HOCs)
      Acids with pH ^ 2
5/93
Disposal Options
       page.1

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        NOTES
                                            LANDBANS
                                       • August 1988-First third

                                       • June 1989-Second third

                                       • May 1990-Third third
                                 DO YOU HAVE A HAZARDOUS WASTE?
                                 • Characteristic wastes (D001 - D043)
                                      Ignitable(DOOI)
                                      Corrosive (D002)
                                      Reactive (D003)
                                      Heavy metals (D004 - D011)
                                      Pesticides (D012-D017)
                                      Newly listed organics (D018 - D043)
                                 DO YOU HAVE A HAZARDOUS WASTE?
                                       Listed wastes
                                         Spent solvents (F001 - F005)
                                         Production by-products "K"
                                         Poisons "P"
                                         Unused products "U"
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                                                 NOTES
  DO YOU HAVE A HAZARDOUS WASTE?
    • Other listed wastes
        Metal treating or electroplating
           wastes (F006-F019)
        Wastes containing dioxin
           (F023, F026 - F028)
        Leachate (F039)
     TREATMENT STANDARDS



        • Concentration-based

        • Required technologies
      WASTEWATER VERSUS
         NONWASTEWATER

  • Wastewater definition
      Aqueous waste
      < i% total suspended solids (TSS)
      < 1% total organic carbon (TOC)

  • Nonwastewater definition
      Any waste of treatment residue
      not meeting the above definition
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                                                         Disposal Options
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         NOTES
                                       CONCENTRATION-BASED
                                        TREATMENT STANDARD
                                    • Based on Best Demonstrated Available
                                      Technology (BOAT)

                                    • Hazardous constituents in treatment
                                      residue

                                    • Technology example:
                                        Incinerator ash
                                        Incinerator scrubber water
                                     CONSTITUENT CONCENTRATIONS IN WASTES (CCW)
                                          Regulated Hazardous   Wastewaters   Nonwastewater
                                   Waste Code   Constituent     Cone, (mg/l)   Cone, (mg/l)
                                   F001-F005  1,1,2-Trichloroethane    0.03
                                   (Spent Solvents)

                                           Benzene          0.07
7.6


3.7
                                    TREATMENT STANDARD BASED ON
                                        REQUIRED TECHNOLOGIES
                                    • Treatment or disposal method specified
                                     for waste

                                    • Impossible, to establish concentration
                                     limits

                                    • Analytical results difficult to reproduce
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                                                          NOTES
         TECHNOLOGY-BASED STANDARDS
  Waste Code  Waste Description   Wastewaters  Nonwastewaters
          and/or Treatment             Technology
            Subdivision               Code
   F005    2-Ethoxyethanol  BIODGorlNCIN    INCIN


   K113    Toluenediamine  CARBN or INCIN  FSUBS or INCIN


   0002    Acid or alkaline     DEACT       DEACT
  TREATMENT STANDARD BASED ON
       REQUIRED TECHNOLOGIES
    •  Examples of available technologies
        Alkaline chlorination
        Carbon adsorption
        Fuel substitution
        Incineration
        Stabilization
      TREATMENT, STORAGE, AND
      DISPOSAL FACILITIES (TSD)

     • Treatments available
         Secure landfill
         Incineration
         Stabilization
         Deepwell injection
         Distillation (solvent recycling)
         Metals reclamation
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         NOTES
                                        TREATMENT, STORAGE, AND
                                        DISPOSAL FACILITIES (TSD)

                                    • Approval process
                                        Representative sample
                                        Profile sheet
                                        Analytical information
                                        Land disposal restriction (LDR) forms
                                        State  approval
                                        Approval fees
                                        Contract
                                        TREATMENT, STORAGE, AND
                                        DISPOSAL FACILITIES (TSD)
                                        Shipping requirements per HM-181
                                           Selection of carrier
                                           Manifest
                                           Labeling requirements
                                           Packaging requirements
                                           Notification & certification
                                        TREATMENT, STORAGE, AND
                                        DISPOSAL FACILITIES (TSD)

                                   •  Shipping containers for solids
                                        Roll-off boxes (bulk)
                                        Drums

                                   • Shipping containers for liquids and sludges
                                        Tankers (bulk)
                                        Vacuum tankers (bulk)
                                        Tote bins (200 - 300 gals.)
                                        Drums (steel, plastic)
Disposal Options
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                                                   /VOTES
      TREATMENT, STORAGE, AND
      DISPOSAL FACILITIES (TSD)
  • Special containers
      Lab-packs
      Burnable containers for incineration
      THESE STATES HAVE AT LEAST ONE
      HAZARDOUS WASTE INCINERATOR
     THESE STATES HAVE AT LEAST ONE
        HAZARDOUS WASTE LANDFILL
5/93
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                                DISPOSAL OPTIONS
       Offsite Disposal

              General Description

              This section describes the major factors that must be considered when selecting an
              offsite disposal facility and preparing wastes for offsite transport. Offsite disposal,
              as described in this section, includes landfilling and incineration.

              Applications/Limitations

              Determining the  feasibility  of offsite  disposal requires  knowledge  of Resource
              Conservation Recovery Act (RCRA) regulations (40 CFR Parts 261-265) and other
              regulations developed by state governments.  RCRA manifest requirements, under 40
              CFR  Parts 262 and 263, must be complied with for all wastes that are  shipped
              offsite.  In  addition,  the waste generator  (or other responsible party, when the
              generator is unknown) must comply with RCRA manifest requirements under 40 CFR
              Parts 262 and 263, and the generator should  comply with applicable hazardous waste
              generator  requirements under 40  CFR  Part 262.  In addition, the  generator must
              comply with all applicable federal and state environmental and public health statutes.
              Under 40  CFR 264.12, RCRA storage and  disposal  facilities are required to notify
              the generator, in writing, that they are capable of managing the wastes.   The
              generator must keep a copy of this  written notification on file as part of the operating
              record.

       Offsite Landfilling

       Landfilling of hazardous materials is  becoming increasingly difficult and more expensive due
       to steadily growing regulatory control of  this technology.  Therefore,  wastes that are
       amenable to  treatment or incineration should be  segregated from  wastes for which no
       treatment alternative is known. Landfilling should usually be regarded as the least attractive
       alternative at a site cleanup  action.

       Landfilling costs are approximately  $240/ton for highly toxic wastes (e.g., high levels of
       chlorinated hydrocarbons), $120/ton for ignitable materials (40 CFR Part 264.312  must be
       complied with), $85/ton for most industrial sludges, and $40-$50/ton for municipal treatment
       sludges.

       Incineration

       The most important factors  that a treatment facility considers in determining the suitability
       of wastes for incineration include BTU content of the waste, viscosity, water content, halogen
       content and ash content.  Many incineration  facilities' permit conditions specify  a minimum
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       acceptable BTU content.  The minimum acceptable BTU is generally not less than about
       5,000 BTU/lb because  at this heating value, the  incineration  process  can often be  self
       sustaining and require no auxiliary fuel. High water content in a waste tends to reduce the
       heating value; therefore, many facilities will  specify a maximum allowable water content.
       Certain incinerators are not equipped to handle highly viscous or solid wastes, and this  may
       be yet another criterion that facilities use to accept or reject a waste load.

       EPA regulations (under RCRA) for hazardous waste incineration  require that paniculate
       emissions be no more than 180 mg/Nm3 and that hydrogen chloride removal efficiency from
       the exhaust gas be no less than 99 percent. Trial burns are conducted prior to issuance of
       a permit to determine the maximum ash and  chlorine content that  a waste can contain in
       order to meet these requirements.  Thus, the  facility is likely to have maximum  limits for
       halogen content and ash.  Incineration of PCBs  and low-level radioactive wastes requires
       special permits and there are only a limited number of facilities permitted to handle these
       wastes.
IMPLEMENTATION

       Preparation of Wastes for Offsite Treatment/Disposal

       Where drums or multiple impoundments are present, it is  often  most cost-effective to
       consolidate their contents in a tank truck.  Compatibility testing should be performed prior
       to bulking wastes for  offsite transport  to  ensure that  consolidation will  not result in
       incompatible waste reactions or in large volumes of waste that are unacceptable for offsite
       disposal.  Compatibility testing refers to simple, rapid, and cost-effective  testing procedures
       that  are  used to segregate  wastes into  broad categories.   By  identifying broad waste
       categories, compatible waste types can be safely bulked onsite without risk of fire, explosion,
       or release of toxic gases, and disposal options can be determined  without an  exhaustive
       analysis of each waste type.

       Compatibility testing protocols have been developed by a number of cleanup contractors and
       generators. Often, however, the procedures must be tailored to meet the testing requirements
       of prospective treatment/disposal facilities.  The Chemical Manufacturers Association (CMA,
       1982) has developed  a compatibility testing protocol that has been used at a number of sites.
       Based on the  CMA protocol, wastes  can be segregated  into the following  broad waste
       categories:

       •      Liquids

              - Radioactive
              - Peroxides and oxidizing agents
              - Reducing agents
              - Water-reactive compounds
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       •      Water insolubles

              - Low halogen, low PCB
              - Mixed halogen, high PCB
              - High halogen, low PCB

       •      Acids

              - Strong (pH < 2)
              - Weak (pH 7-12), with or without cyanides or sulfides

       •      Bases

              - Strong (pH > 12), with and without cyanides or sulfides
              - Weak (pH 7-12), with and without cyanides or sulfides

       •      Solids

              - Radioactive
              - Nonradioactive.

       Testing to determine gross halogen content is sometimes eliminated if all insoluble wastes are
       to be incinerated at a facility capable of handling chlorinated organics. However, testing for
       PCBs is required regardless of the need for testing other halogenated compounds.

       The CMA protocol also requires that small samples of wastes that are intended to be bulked
       are mixed  together.   Visual observations  are then made for precipitation, temperature
       changes, or phase separation.

       There are some differences between the CMA compatibility protocol and the protocol used
       by some cleanup contractors. One commonly used procedure is to conduct flammability and
       ignitability tests on a drum-by-drum or waste-by-waste basis for both liquid and solid drums.
       CMA, on the other hand, recommends that these  tests be performed on composite samples
       before bulking,  because these tests require more costly and time-consuming analysis (torch
       test and closed cup flame test).  Another common practice is to  conduct further testing  on
       samples from drums containing solids.  These tests may include  water  reactivity,  water
       solubility, pH, and the presence of oxidizers.  In general, the decision to perform these
       analyses on each waste rather than on a composite sample (prior to bulking) is made based
       on the number of drums and the types of wastes known to be present onsite.

       Hatayama et al.  (1980a, 1980b) have also provided guidance on waste incompatibilities that
       can be useful during the waste  consolidation process.  These researchers have developed a
       hazardous waste compatibility  protocol that allows the user to evaluate potential adverse
       reactions for binary combinations of hazardous  wastes.  Binary waste combinations are
       evaluated in terms of the  following adverse reactions:  heat generation  from a chemical
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DISPOSAL OPTIONS

       reaction, fire,  toxic gas  generation, flammable  gas generation,  explosion,  and violent
       polymerization  of a toxic substance.

       A  detailed  waste  analysis  is  generally  required  before a  waste  is  accepted by  a
       treatment/disposal  facility.  TABLE 1 specifies  the types of analyses that  are  typically
       required before a waste  can  be considered for  offsite  disposal at a particular facility.
       However, requirements  vary considerably depending  upon  the facility  permits,  state
       regulations, physical state of the  wastes, and the final disposal option that is selected.

       Onsite pretreatment of wastes may be required to make them acceptable for offsite transport
       or to meet the requirements of an incineration or disposal facility. For incineration or land
       disposal facilities, pretreatment will likely be limited to the  following:

       •      Acid-base neutralization (land disposal and incineration)

       •      Metal precipitation/solidification (land disposal)

       •      Hypochlorite oxidation of cyanide and sulfide (land disposal and incineration)

       •      Flash point reduction (land  disposal)

       •      Removal of free liquids by addition of soils, lime, fly ash, polymers, or other
              materials that remove free water (land disposal).

       Transportation

       The transportation of hazardous wastes is regulated by the U.S. Department of Transportation
       (DOT),  the Environmental Protection Agency, the states, and, in some instances, by local
       ordinances  and codes.   In  addition, more stringent  federal regulations also govern the
       transportation and disposal  of highly  toxic and  hazardous materials such  as PCBs and
       radioactive wastes.  Applicable DOT regulations include:

       •      Department of Transportation 49 CFR, Parts 172-179

       •      Department of Transportation 49 CFR, Part 2387 (46 FR 30974, 47073)

       •      Department of Transportation DOT-E 8876.

       The EPA regulations under RCRA (40 CFR Parts  262 and 263) adopt DOT regulations
       pertaining to labeling,  placarding,  packaging, and spill reporting.  These regulations also
       impose certain additional requirements for compliance with the manifest system and record-
       keeping.

       Vehicles for offsite transport of hazardous wastes must be DOT approved and must display
       the proper DOT placard.  Liquid wastes must be  hauled  in tanker trucks that meet certain
       requirements and specifications for the waste types.   Contaminated soils are hauled in box


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DISPOSAL OPTIONS

       trailers and drums in box trailers or flatbed trucks.  The trucks should be lined with plastic
       and/or absorbent materials.

       Before a vehicle is allowed to leave the site, it should be rinsed or scrubbed to remove
       contaminants.  Both bulk liquid containers and box trailers should be checked for proper
       placarding, cleanliness,  tractor-to-trailer hitch, and  excess  waste levels.   Bulk liquid
       containers should also be checked  for proper venting, closed  valve positions, and secured
       hatches.  Box trailers should be checked to ensure correct liner installation, secured cover
       tarpaulin, and locked  lift gate.
                                        TABLE 1
             POTENTIAL ANALYTICAL REQUIREMENTS FOR DISPOSAL
  Physical State
       Physical state at 70°F
       Number of layers
       Free liquids (percent by volume)
       pH
       Specific gravity
       Flash point
       Viscosity

  Waste Composition
       EP toxic metals (arsenic, barium, cadmium, chromium, lead, mercury, selenium, and
       silver)
       EP toxic pesticides (endrin, lindane, methoxychlor, toxophene, 2,4-D, 2,4,5-TP)
       Hydrocarbon composition (must account for 100 percent)
       Organochlorine
       Sulfur
       Cyanide
       PCB content

  Hazardous Characteristics
       Reactive (pyrophoric or shock sensitive)
       Explosive
       Water reactive
       Radioactive
       Ignitable
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       Selection/Evaluation Considerations

       Excavation and removal can almost totally eliminate the contamination at a site and the need
       for long-term monitoring.  Once excavation is begun, the time to achieve beneficial results
       can be short relative to such alternatives as in situ treatment, subsurface drains, and, in some
       instances, pumping.  Excavation and removal can be used in combination with almost any
       other remedial technologies.

       The biggest drawbacks with excavation, removal, and offsite disposal are  associated with
       worker safety, short-term impacts, cost, and institutional aspects. Where highly hazardous
       or toxic materials are present, excavation can pose a substantial risk to worker safety. Short-
       term  impacts such as fugitive dust emissions,  toxic gases,  and contaminated runoff  are
       frequently a major concern, although mitigative measures can be taken. Costs associated
       with offsite disposal are high and frequently result in exclusion of complete excavation and
       removal  as  a  cost-effective alternative.  The location  of a RCRA-approved landfill  or
       incinerator also has a substantial impact on cost.

       Implications of RCRA

       Subtitle C of RCRA  is designed  to provide comprehensive regulation of hazardous wastes.
       Intended  to protect the environment,  regulations under the act will place added  waste
       management responsibilities on organizations.  RCRA will affect the generation,  storage,
       treatment, transport,  and disposal of hazardous wastes.  These provisions are covered under
       Sections  3001 to 3010 of the act.  Hazardous wastes generated from spills and abandoned
       hazardous waste sites are affected as well.

       Code of  Federal Regulations

       Sections  3001-3010  of RCRA  provide the basis for regulations.    Hazardous  waste
       management is regulated under the Code of Federal Regulations (CFR), Title 40 - Protection
       of the Environment and  Parts 260 through 265 as follows:

       1.     Part 260:  Definitions &  General Provisions

       2.     Part 261:  Identification and Listing  of Hazardous Waste

       3.     Part 262:  Generation Standards (as Amended)

       4.     Part 263:  Transporter Standards (as Amended)

       5.     Part 264:  Facility Standards

       6.     Part 265:  Interim Status  Standards.
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       Regulatory Relationships

       40 CFR 260-265 relates to 40 CFR 122-125, Consolidated Permit Regulations administered
       by EPA and 49 CFR  100-199,  regulating materials transportation under the  Hazardous
       Materials Transportation Act (HMTA) administered by the DOT.

       1.      Consolidated Permit Regulations

              a.     Part 122:  Permit Requirements

              b.     Part 123:  State  Program Requirements

              c.     Part 124:  Procedures for Decision-makers

              d.     Part 125:  NPDES Amendment
             HMTA
             a.
    Part 172: Hazardous Materials & Communications
             b.     Pan 173:  Shippers General Requirements

             RCRA

             a.     The relationship between RCRA, the act, and the resulting
                    regulations can be seen in the following comparisons:

             b.     RCRA
                                        RCRA
SECTION

  (3001)


  (3002)



  (3003)
40 CFR

  261


  262



  263
                       SUBJECT
Contains criteria and listing of hazardous wastes.  Defines what
is considered to be hazardous for waste generators.

Lists standards and responsibilities applicable to generators of
hazardous wastes.  Covers recordkeeping, manifest system,  and
reporting requirements.

Lists standards applicable to transporters of hazardous wastes.
Includes recordkeeping, labeling, and coordination with DOT.
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                          15

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  (3004)         264,265
  (3005)
  (3006)
122, 124
  123
  (3007)
  (3008)
  (3009)
  (3010)       45 FR 12746
Lists design and operating standards applicable to owners and
operators  of hazardous  waste  treatment, storage, and  disposal
facilities (TSD).

Describes  the  permit  requirements  for  TSD  and   related
administrative requirements and procedures.

Gives individual states the responsibility of administering and
enforcing  the  act  by  briefly  outlining  the  requirements for
obtaining  authorization from  EPA and  retaining this authority
thereafter.

Provides inspection authority  to EPA and state officers for the
collection  of samples and filed information.  This section also
addresses the extent of confidentiality of information obtained.

Discusses the enforcement actions, civil and criminal penalties,
and fines exacted on violators of the act's requirements.  After an
unheeded 30-day allowance for corrective action, a violator may
be  assessed  a  $25,000  fine  for  each  day  of  continued
noncompliance. Knowingly violating the requirements of the act
can result in the same fine and/or imprisonment for up to one (1)
year upon conviction.

Sets up the EPA regulations as minimal requirements, causing the
states to align with the act.

Requires that  hazardous  waste generators,  transporters,  and
owners/operators of TSDs formally notify EPA of all hazardous
waste activities.   Federal agencies must also comply  with the
notification requirements.
       Transporter Standards

       40 CFR 263, Transporter Standards (as Amended) relate closely to 49 CFR Parts 100-199
       regulating materials transportation under the HMTA.  Specifically, 49 CFR 172, Hazardous
       Materials Table and Hazardous Materials Communications Regulations, along with 49 CFR
       173, Shippers - General Regulations for Shipments and Packaging, relate to 40 CFR 263.

       HMTA  regulations administered by  the  DOT  do not apply to federal,  state, or  local
       governments  carrying  hazardous materials  as  part  of a  governmental  function using
       governmental employees, facilities, and vehicles.  Also, HMTA highway transportation
       regulations generally apply only to interstate commerce; hence, intrastate hazardous material
       transportation by highway is not directly regulated. However, the EPA-administered RCRA
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                           16

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       transporter regulations do apply to (1) all governmental agencies, regardless of function, and
       (2) both interstate and intrastate commerce.

       Operations Under Regulations

       1.     Storage and classification

       2.     Site management

              a.      Sampling procedures

              b.      Chain of custody

              c.      Spill prevention

              d.      Water and air monitoring

       3.     Transportation

              a.      Containerization and handling

              b.      Labeling

              c.      Manifesting

              d.      Shipping

       4.     Ultimate Disposal

              a.      Onsite

              b.      Offsite
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HAZARDOUS AND SOLID WASTE AMENDMENTS OF 1984

EPA has drafted a rule to amend EPA's existing hazardous waste regulations to reflect the provisions
of the Hazardous and Solid Waste Amendments of 1984 (HSWA), which have immediate or short-
term effects on the regulated community.  The rule will be issued in interim final form and will
become effective immediately.  In the preamble to the rule, EPA invites public comment on the
regulatory amendments and on the issues raised by the amendments. The following is a summary
of the major regulatory changes:

        1.     Ban on placement of  noncontainerized liquid hazardous waste  and nonhazardous
              liquids in landfills.  The new regulations impose  an absolute ban on placement of
              bulk of noncontainerized liquid hazardous waste or hazardous waste containing free
              liquids in any permitted or interim status landfill effective May 8,  1985.  Effective
              November 8, 1985, placement of nonhazardous liquids in permitted or interim status
              landfills is banned. An owner or operator may obtain an exemption from the ban on
              nonhazardous liquids by demonstrating that  the only reasonably available disposal
              alternative for  such liquids is a landfill or unlined surface impoundment that  may
              already contain hazardous waste, and that disposal in the owner or operator's landfill
              will not present a risk of contamination to any underground source of drinking water.

        2.     Minimum  technological  requirement  for permitted and interim  status  facilities.
              Permits issued after November 8, 1984, for new landfills  and  surface impoundments
              must require two or more liners and a leachate collection system above (for landfills)
              and between the liners.   These  requirements may be necessary to protect human
              health and the environment.  Variances are available for monofills and for alternative
              designs.  Interim status landfills and surface impoundments, except for existing units,
              must also  meet  the new technological requirements with  respect to waste received
              beginning May 8,  1985. New interim status waste pile units must install single liners
              with a leachate collection  system above the liner.

        3.     Redefinition of "regulated unit" for purposes of  the groundwater  monitoring and
              response   program.    General  groundwater  monitoring and  corrective  action
              requirements of Subpart F of Part 264 apply at the time  of permitting to landfills,
              surface impoundments, waste piles, and land treatment units  that receive hazardous
              waste after July 16, 1982.  (The former cut-off date was January 26, 1983.)

        4.     Obligation to institute  corrective action at permitted facilities. Any permit issued
              after November 8, 1984, must require corrective action for all releases of hazardous
              waste or constituents from any solid waste management unit (including inactive units)
              regardless of when waste was placed at the unit.  When such  corrective action does
              not occur  before permitting, the permit issued to a facility containing solid waste
              management units must include  a schedule of compliance  and an  assurance of
              financial responsibility for completing  corrective action.
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        5.    Cleanup beyond a facility's property boundary.  The owner or  operator  of  a
              permitted facility must institute corrective action beyond the facility boundary where
              necessary to protect human health and the environment, unless the owner or operator
              shows that he or she  is unable to  obtain permission to undertake such action on
              adjacent property.

        6.    Elimination of the double-liner  variance  from the groundwater monitoring and
              response  program.   The  new  rule deletes the groundwater monitoring waiver
              formerly available to landfills,  surface impoundments, and waste piles that have  a
              double liner and are located entirely above the seasonal high water table.  The rule
              also deletes the groundwater monitoring waiver for waste piles that are located above
              the seasonal high water table and have periodic liner inspections.

        7.    Variance  from  groundwater monitoring for certain  engineered  structures.   A
              groundwater monitoring variance  is  available to an engineered structure that does not
              receive or contain liquid waste,  is designed and operated to exclude liquid from
              precipitation or other runoff, has  multiple leak detection systems built into the inner
              and outer layers of containment,  is  operated and maintained through the end of the
              post-closure period, and prevents  the migration of hazardous constituents beyond the
              outer layer of containment prior to the end of the post-closure care period.

        8.    Ban on disposal in certain salt dome  formations, caves, and underground mines.  The
              new rule bans placement of bulk  or noncontainerized liquid hazardous waste in salt
              dome formations, salt bed formations, underground mines, or caves in permitted
              facilities.   This  ban will remain in effect until EPA  is able to make a series of
              findings and issues a permit for the  facility.  In addition, interim status facilities are
              absolutely  prohibited from placing  any  hazardous waste in the four enumerated
              settings. This ban does not apply to the Department of Energy Waste Isolation Pilot
              Project in New Mexico.

        9.    Ban on use of materials mixed with  hazardous waste for dust suppression.  The new
              regulations prohibit the use of waste or used oil or other material that is contaminated
              with dioxin or any other hazardous waste (other than  a hazardous waste identified
              solely on the basis of ignitability) for dust suppression  or road treatment.

       10.    Manifest and destination requirements for small quantity generators.  Small quantity
              generators generating  between  100  and  1,000 kilograms of hazardous waste per
              calendar month must either (1) treat, store, or dispose of such waste at a facility with
              interim status or a RCRA permit;  (2) treat, store, or dispose of such waste at  a
              facility authorized by a state to manage municipal or industrial solid waste; (3) store
              no more than 1,000 kilograms of the waste onsite; or (4) recycle the waste.  These
              requirements remain in effect until EPA promulgates  new standards applicable to
              small quantity generators or until  March 31, 1986, whichever occurs first.  No later
              than August 7, 1985, hazardous waste shipped offsite by  a small quantity generator
              must be accompanied by a copy of the EPA Uniform Hazardous Waste Manifest.
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       11.    Variance from preconstruction ban.  Current regulations prohibit the construction of
              new hazardous waste management facilities without a finally effective RCRA permit.
              The new rule exempts from this ban any facility for the incineration of PCBs that has
              an EPA approval under TSCA.

       12.    Permit life.  Any permit  for a treatment, storage, or disposal facility must be for a
              fixed term, not to exceed 10 years. Each permit for a  land disposal facility must be
              reviewed 5 years after the date of issuance or reissuance and must be modified where
              necessary to comply with applicable requirements or to protect human health and the
              environment.

       13.    Authority to add conditions.  In deciding whether to issue a permit,  EPA must
              consider adding additional requirements, beyond those contained in EPA regulations,
              where necessary to protect human health and the environment.

       14.    Extension of interim  status  to newly regulated  units.  A facility may  qualify for
              interim  status if it is in existence on the effective date of a statutory or regulatory
              change under RCRA that requires the facility to have a permit (e.g., a facility which
              treats, stores, or disposes of newly listed hazardous wastes). The facility must also
              comply  with the other prerequisites specified in the statute (e.g., submission of a Part
              A application) to  actually obtain interim status.

       15.    Loss of interim status. Interim status terminates automatically  for any facility that
              fails to submit a Part B application by a specified deadline.  Land disposal facilities
              must also certify  compliance with applicable groundwater monitoring and financial
              responsibility requirements.  Application deadlines are November 8, 1985, for land
              disposal facilities, November 8, 1986, for incinerators, and November 8, 1988, for
              all other facilities.

       16.    Ban on  hazardous waste in  certain cement kilns.   Any cement kiln located in an
              incorporated city  with a population greater than 500,000 many not burn hazardous
              waste, or any fuel containing a hazardous waste, unless the cement kiln complies with
              RCRA regulations applicable to incinerators.  The ban is effective until EPA develops
              substantive standards for  cement kilns burning hazardous waste.

       17.    Labeling of hazardous waste fuels.  Beginning  February 6, 1985, any person who
              produces, distributes,  or markets fuel produced  from hazardous waste or containing
              hazardous waste must include a warning label on the invoice or  bill of sale.  The
              regulations provide exemptions from the labeling requirement for hazardous waste-
              derived  petroleum coke and  for two types of hazardous waste-derived  fuels from
              petroleum refining operations.

       18.    Clarification of household waste exclusion. A resource recovery facility recovering
              energy from burning  municipal waste is not considered to be managing hazardous
              waste as long as the facility (1) receives and burns only household waste and non-
              hazardous solid waste from other sources and (2) does not accept hazardous wastes.


5/93                                        20

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DISPOSAL OPTIONS

       19.    Exposure information and health assessments.  Beginning August 8, 1985, Part 8
              permit applications for surface impoundments and landfills must be accompanied by
              information on the potential for the public to be exposed to hazardous wastes through
              releases related to the unit.  Owners or operators who submitted Part B applications
              prior  to November 8, 1984,  must submit the required exposure  information  by
              August 8, 1985.

       20.    Additional  criteria and procedures  for delisting petitions.   In evaluating a delisting
              petition, EPA must consider factors including additional constituents other than those
              for which the waste was listed if the Administrator has a reasonable basis to believe
              that such additional factors could cause the waste to be a hazardous waste.  Delisting
              petitions must include sufficient information for this determination.  The rule also
              eliminates EPA's procedure for granting temporary exclusions without notice  and
              comment.

       21.    Research and development permits.  EPA is authorized to issue permits for research,
              development, and demonstration treatment activities for which permit standards have
              not been established  in the regulations.  Permits may be issued independent of the
              substantive standards  in Parts 264  and 265.  EPA may waive or modify its basic
              permitting procedures in order to expedite permitting. Permits are issued for 1 year
              and may be renewed 3 times.

       22.    Extension of interim authorization  for state programs.   Interim authorization under
              RCRA now ends on January 26, 1986.

       23.    Requirement  that  state  programs  ensure  public  availability  of  information.
              Information obtained by  authorized states  regarding  facilities  and sites for the
              management of hazardous waste must be made available to the public  in substantially
              the same manner as would be the case if EPA were carrying out the RCRA program
              in the state.

       24.    Requirements  effective in authorized  states prior to state  authorization.   Any
              requirements or prohibition imposed by HSWA takes effect on the same date in both
              authorized  and  nonauthorized states.   The Administrator will carry  out  such
              requirements directly in an authorized state until the state is granted authorization to
              do so.  A state  or local requirement that is more stringent than a requirement in the
              new rule will remain in effect.

       25.    Moving target  provision.   Under  EPA's current regulations, EPA may base its
              decision to authorize a state's program on the federal program in effect 1 year prior
              to submission of the state's application.  HSWA specifically endorses this approach.
              For purposes of the new provisions addressed by the codification rule, the "effective
              date" under the moving target rule is the date and codification rule that appears in the
              Federal Register.
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DISPOSAL OPTIONS

       26.    Conforming amendments to  state  authorization regulations.   The codification rule
              adds several new provisions to EPA's regulatory program. States may begin to seek
              authorization to implement those provisions in lieu of the federal program.  EPA's
              state authorization rules will be modified, as needed, to provide requirements for state
              programs that parallel the new requirements.

       27.    Recordkeeping for hazardous waste exports. Any person exporting hazardous waste
              must file with EPA, no later than March 1 of each year, a report summarizing types,
              quantities, frequency, and ultimate  destination of all hazardous waste exported during
              the previous year.

       28.    Waste minimization certification and reporting  requirements.  Effective September
              1, 1985, a generator (except for a  small quantity generator) must sign a certification
              in the Uniform Hazardous Waste Manifest Form that the generator has a program to
              minimize the amount and toxicity  of wastes  generated and  that the generator's
              proposed treatment, storage, or disposal method  minimizes the threat to human health
              and the environment.   Generators must submit information regarding such waste
              minimization efforts in their biennial report to EPA.  Effective September 1, 1985,
              any permittee who treats, stores,  or disposes of hazardous  waste on the premises
              where the waste was generated must provide a certification in the written operating
              record regarding efforts taken to minimize the amount and toxicity of the generated
              wastes.

       29.    Requirements for new underground storage tanks.  Effective May 7,  1985, the new
              rule prohibits the installation of any new underground storage tank unless the tank (1)
              will prevent releases due to corrosion or structural failure for the operational life of
              the tank, (2) is cathodically protected against corrosion, constructed of noncorrosive
              material, or designed to prevent releases, and (3) is constructed of material that is
              compatible  with the substances stored.  An exemption from the corrosion protection
              requirement is available for tanks that are installed in  soils  with a resistivity  of
              12,000  ohm/cm  or more.   These requirements  remain in  effect until  EPA
              promulgates standards for new tanks.
5/93                                        22

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DISPOSAL OPTIONS
                             APPENDIX I
TABLE 1
LAND DISPOSAL RESTRICTIONS REGULATIONS1
Date
May 28, 1986
November 7, 1986
June 4, 1987
July 8, 1987
July 26, 1988
August 16, 1988
February 27, 1989
May 2, 1989
June 14, 1989
June 23, 1989
September 6, 1989
June 1, 1990
June 13, 1990
January 31, 1991
Federal Register2
51 FR 19305
51 FR 40636
52 FR 21014
52 FR 25787
53 FR 28118
53 FR 30908
54 FR 18266
54 FR 18837
54 FR 25422
54 FR 26647
54 FR 36970
55 FR 22683
55 FR 23935
56 FR 3876
Contents
Provides implementation schedule
Solvents and dioxins rule
Corrections to November 7, 1986 rule
"California List Wastes" (halogenated wastes,
certain metal-bearing wastes, polychlorinated
biphenyls [PCBs], and cyanide and corrosive
wastes)
Underground Injection Control (UIC): Solvents
and Dioxins
UIC: California List and some "First Third"
wastes (specific F, K, P, and U hazardous waste
codes)3
Amendment to schedule for multi-source leachate
Amendments to "First Third" rule
UIC: "Second Third" wastes (see §148.15)
"Second Third" wastes (see §268.11)
Corrections to August 17, 1988, and May 2, 1989,
"First Third" rules
"Third Third" wastes and characteristic wastes
(D001-D017)(see§268.12)
Corrections to September 6, 1989, rule
"Third Third" and characteristic wastes technical
correction notice
1 LDR regulations promulgated as of January 1991 are summarized in this document.
2 Federal Register (FR) citations (e.g., 51 FR 19305) are read Volume 51, Federal Register,
page number 19305.
*" Hazardous waste code will be used throughout this document to reference hazardous waste
numbers identified in 40 CFR §261.20-§261.24 and §261.33.
4 Notations such as §268.10, appearing in this document, refer to the section of Title 40 of
the Code of Federal Regulations (CFR) in which information pertaining to the specific
subject matter can be found.
5/93
23

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DISPOSAL OPTIONS

GLOSSARY OF TERMS

California List:  Effective July 8, 1987, this rulemaking prohibited disposal (except by deep well
injection) of California List wastes. California List wastes are liquid and nonliquid hazardous wastes
containing HOCs above 1,000 ppm, liquid hazardous wastes containing PCBs above 50 ppm, certain
toxic metals above specified statutory concentrations, or corrosive liquid wastes that have a pH level
below  2.   This list is based on  regulations developed by the California Department of Health
Services.

Certification:  A written  statement of professional opinion and intent signed by an  authorized
representative that acknowledges an owner or operator's compliance with applicable land disposal
restriction requirements.  Certifications are required for treatment surface impoundment exemption
requests, applications for case-by-case extensions to an effective date, no-migration petitions,  and
waste analysis and recordkeeping provisions  applicable to any person who generates, treats, stores,
or disposes of  hazardous wastes.   The  information referenced by the certification must be true,
accurate, and complete.  There are significant penalties for submitting false information, including
fines and imprisonment.

Extraction Procedure Toxicity Test: The Extraction Procedure Toxicity Test (EP Tox Test) is used
to determine the toxicity characteristic of a waste.   It is now  being replaced by the TCLP.

Facility:  A facility is defined as all contiguous land and structures (or other appurtenances)  and
improvements on the land used for treating, storing, or disposing of hazardous waste. A facility may
consist of several  treatment, storage, or disposal  operational  units (e.g.,  one or more landfills,
surface impoundments, or combinations  of them).

First Third Rule:  Effective August 8, 1988, this rule prohibited the land disposal of 62 wastes and
set restrictions on 121 others.  It regulates some of the F-coded wastes such as bath solutions from
electroplating processes, some of the K-coded wastes such as  acetonitrile production wastes,  and
some of the P- and U-coded wastes that are discarded commercial chemical products such as
formaldehyde.

Hazardous and Solid Waste Amendments (HSWA): Amendment to RCRA in 1984. It minimizes
nation's reliance on land disposal of hazardous waste by, among other  things, requiring EPA to
evaluate all listed and characteristic hazardous wastes according to a strict schedule to determine
which wastes should be restricted  from land  disposal.

Hazardous Waste:  Waste that because of  its quantity, concentration, or physical, chemical, or
infectious characteristics may cause, or  significantly contribute to, an increase in mortality or an
increase in serious irreversible or incapacitating reversible illness, or pose a substantial present or
potential hazard to human health or the environment when improperly treated, stored, transported,
disposed of, or otherwise managed.

Hazardous Waste Code:  The number assigned by EPA to each hazardous waste listed in 40 CFR
Part 162, Subpart D, and to each characteristic waste identified in 40 CFR Part 261, Subpart C.
5/93                                        24

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DISPOSAL OPTIONS

Lab Pack Wastes:  A lab pack waste is an overpack container, usually a steel or fiber drum,
containing small quantities of chemicals of the same hazardous class.

Land Disposal Restrictions:  Prohibits the land disposal of hazardous wastes into or on the land
unless EPA finds that it will not endanger human health and the environment.  EPA must develop
levels or methods of treatment that substantially diminish the toxicity of the waste or the likelihood
that hazardous constituents will migrate from the waste that must be met before the waste is land
disposed.  Strict statutory deadlines were imposed on EPA to regulate the land disposal of specific
hazardous wastes, concentrating first on the most harmful.  EPA has met  all of the  Congressionally
mandated dates.

Notification: When restricted wastes are being  shipped offsite for treatment, storage, and disposal
or are managed  onsite, EPA  has established a tracking system that requires that notifications and
certifications  be sent to the receiving  facility or, if applicable,  to EPA or  the appropriate  EPA
representative.  These requirements are outlined in 40 CFR §268.7.

Prohibition Levels:   Treatment standards  that when exceeded trigger statutory  land disposal
prohibitions on  certain wastes.   These levels  were established by the  California  List rule that
Congress  incorporated into the 1984 amendments to  RCRA.

Resource Conservation and Recovery Act (RCRA): The Resource Conservation and Recovery Act
of 1976 regulates hazardous waste generation, storage, transportation, treatment, and disposal.  This
act was  amended on November 8, 1984. The 1984 amendments (HSWA) significantly expanded the
scope and requirements of RCRA.

Second Third Rule:  Effective  June  8, 1989, this rule established  treatment standards for 67
additional wastes and for the F-coded wastes not addressed in the first third rulemaking.  Besides
specifying BDAT treatment standards, this  rule expressed treatment  standards as concentrations
measured in the treatment residues or required specific treatment methods (such as incineration) for
some wastes.

Solvents and Dioxins Rule:  Effective November 7, 1986, this rule prohibited further land disposal
(except by deep well injection) of spent  solvent wastes with EPA hazardous waste codes F001-F005
and dioxin wastes with hazardous waste codes F020-F023 and F026-F028.  The rule also requires
that these wastes be treated prior to land disposal.

Subtitle C Facility:  Solid waste regulated under Subtitle C of RCRA are hazardous and are directed
to Subtitle C disposal facilities.  These facilities  fall into three general categories:  landfills, surface
impoundments, and land treatment facilities.

Subtitle D Facility:  Solid waste regulated under Subtitle D of RCRA are primarily nonhazardous
and are directed to Subtitle D disposal  facilities. These facilities fall  into four general categories:
landfills, surface impoundments, land application facilities, and waste piles.
5/93                                        25

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DISPOSAL OPTIONS

Third  Third  Rule:  Effective  May 8, 1990,  this fifth and  final  rulemaking pursuant to the
Congressionally mandated dates set treatment standards and imposed restrictions on 344 listed wastes
and all characteristic wastes.  Two-thirds of the listed wastes have treatment standards expressed as
concentrations in the treated wastes,  whereas  the  remaining  wastes have treatment standards
expressed as specific technologies.

Tolling Agreement:  A tolling agreement is a contract between a small quantity generator and a
recycling facility that arranges for collection and reclamation of a specified waste and for redelivery
of regenerated material at a specified frequency.

Toxicity Characteristic Leaching Procedure  (TCLP):   Promulgated in the November 7,  1986,
solvents and dioxins rule, this testing procedure was specifically initiated for evaluation of solvent-
and dioxin-containing  wastes.  EPA requires that when a waste extract is tested, the TCLP is used
to determine whether a waste requires treatment.  Additionally, the TCLP is used to determine
whether a waste  is hazardous and serves as a monitoring technique to determine whether a treated
waste meets the applicable waste extract treatment standard.
5/93                                        26

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Section 14

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                       ALTERNATIVE TREATMENTS
STUDENT PERFORMANCE OBJECTIVES:








At the conclusion of this section, participants will be able to:








      •      Briefly describe the reverse osmosis process




      •      Briefly describe the ultraviolet oxidation process




      •      Briefly describe the thermal desorption process




      •      Briefly describe the dehalogenation process




      •      Briefly describe the in situ vitrification process.
5/93

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                                                  NOTES
    ALTERNATIVE TREATMENTS
          •  Reverse osmosis
          •  Ultraviolet oxidation
          •  Thermal desorption
          •  Dehalogenation
          •  Vitrification
        REVERSE OSMOSIS
           ADVANTAGES
  • Selective ion removal
  • Large volumes of liquid waste can be
    treated
  • Volume of waste for final disposal is low
  • Ion recovery is possible
        REVERSE OSMOSIS
         DISADVANTAGES
    Non-destructive, waste disposal required
    pH and temperature range limited
    Chlorine intolerance
5/93
Alternative Treatments
          page 1

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         NOTES

                                                   Osmosis
                                                     Osmotic
                                                     Pressure

                                                    Semipermeable
                                                      Membrane
                                               Reverse Osmosis
                                       SIMPLIFIED REVERSE OSMOSIS UNIT
                                                           Concentrated
                                                           Waste Water
Alternative Treatments
page 2
5/93

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                                                             NOTES
           REVERSE OSMOSIS UNIT
    Contaminated
      Water
                                     Treated
                                     Water
                Semipermeable
                 Membrane
                            Concentrated
                            Waste Water
          REVERSE OSMOSIS SYSTEM

Storage
Tank

NaOH
V




Clarifier
^^^x-"
REVERSE OSMOSIS
COST
FLOW RATE
(gpm )
25
50
100
CAP. COST
($)
69,000
126.000
235,000
O & M COST
( $/yr )
30,000
41 ,000
76,000
5/93
                                                                  Alternative Treatments
                                                                              page 3

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         NOTES
                                       UV RADIATION/OXIDATION
                                     Transformation of O.or H2 O2 to highly
                                     reactive (OH) radicals

                                     Initial attack of the target organics by UV
                                     light

                                     Applicable to waste streams
EFFECTS
Control
UV
UV / H2O2
Og/HjO,,
UV/03
UV / O3 / H2O2
Concentration
OF UV - 03
CH3CI2
100
42
17
21
16
7.6
- mg/l
-Hp2
CH3OH
75
75
75
-
31
1.2
                                           UV OXIDATION SYSTEM
03
v^3


UV
Lamps -.

*pY —
&



0
-~~-,
o
o

0
O
•^
0
0
o


0
C
k
0
o

0
o
o
0
>
O


0
O
0
O
a
o
0
0

j
O
)
0
O
0


Q
0
0
o<
o
o
0
0
0
o
i
0
9
0


o
C
o
0
o
0°
o

9
0
O
o


o

O
o
0
oo o 0- o~ OO o°
Alternative Treatments
page 4
5/93

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                                                             NOTES
         TREATMENT COSTS
     Ozone @ 0.06/Kwh     0.119
     H202@0.75/lb         0.118
     UV including power and   0.133
      annual lamp replacement
     0 & M cost            0.440
     Capital amortization     0.290

     Total treatment costs     $0.75/1000 gal
        Flow rate: 210 gpm
        Influent cone.: 5500 ug/l TCE
        Effluent cone.: 1 ug/l TCE
  LOW TEMPERATURE DESORPTION
 	ADVANTAGES	
    • Removes high percent of volatile organics
    • Less expensive than incineration
    • Contaminated soil returned to location
    • Able to process 120-180 tons/day
    • Will process volatile organics, semi-volatiles,
      PCBs, and volatile metals (Hg and Pb)
  LOW TEMPERATURE DESORPTION
 	DISADVANTAGES	
  • Not a destruction technology
  • Process only works if the soil contains < 10% total
    organics
  • Technology only applicable to soil within the pH range
    of 5-11
  • Additional costs are incurred for carbon regeneration
    and/or carbon disposal
  • Process cannot be used on soils with high moisture
   - contents
5/53
Alternative Treatments
            page 5

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        NOTES
                                Chemical Waste Management, Inc.
                                 X* TRAX: Process Flow
                                       Diagram
                                       DEHALOGENATION
                                          ADVANTAGES
                                  Toxicity reduction of target compound
                                  Mobility of treatment unit
                                  Short residence time
                                  Cost effective
                                       DEHALOGENATION
                                        DISADVANTAGES
                                   • Limited to halogenated compounds
                                   • Residuals
                                   • Formation of explosive gases
                                       Methyl sulfide
                                       Chloroacetylene
                                   • Severe corrosion problems
Alternative Treatments
page 6
5/93

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                                                        NOTES
         Dehalogenation Flow Diagram
       Nitrogen
                                 -To *mo«ph.r.
                                   Furttnt
                                  > TrHtmen!
                                   olOfl-SIU
  Containing PCBl
  or CJoiIni
            VITRIFICATION
      DESIGN SPECIFICATIONS

      • Maximum and minimum area treated

      • Fluxing material added

      • Full-scale operation
          In situ vitrification processes 4 to 6
            tons/hour
          0.3 to 0.5 kwh/pound of soil
          Dual phase system requires 1.9
            Mw/phase
           VITRIFICATION
            ADVANTAGES
      Waste is fixed in a solid glass
      monolith
         Obsidian

      Limited mobility of contaminants
5/93
Alternative Treatments
           page 7

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        NOTES
                                         VITRIFICATION
                                       DISADVANTAGES
                                     • Not a destruction technology
                                     • Possibility of leaching
                                     • Limited number of vendors
                                     • High energy consumption
                                     • Backfill required
                                     IN SITU VITRIFICATION
                                 APPLICATION & EVALUATION
                                     • Geosafe Corporation
                                     • Inorganics and organics
                                     • Soil matrix
                                     • Cost data
                                          $250-350 per ton
Alternative Treatments
page 8
5/93

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                         ALTERNATIVE TREATMENTS
THE QUEST FOR ALTERNATIVE TECHNOLOGIES

When Superfund was launched, land disposal was the most common method of handling hazardous
waste.  Land disposal entailed immobilizing hazardous waste in a specially prepared pit, landfill, or
surface impoundment. Though cost-effective in the short run, it often led, through leaks and other
defects, to extremely expensive long-term environmental problems.

By the time the Resource Conservation and Recovery Act was reauthorized in 1984, opinion had
shifted dramatically in the direction of more permanent methods of handling hazardous waste.  The
Superfund Amendments and Reauthorization Act of 1986 (SARA) continues the pendulum swing in
that direction.

SARA requires EPA, to the maximum extent practicable, to select  remedial actions that create
permanent solutions and, in doing so, to make use of alternative or resource recovery technologies.
The least preferred remedial method is to  transport untreated Superfund wastes to landfills.

Even before the passage of SARA, Superfund was making use of alternatives to land disposal.
Thermal destruction technology has been used in approximately 50 percent of all Superfund removal
actions.  It is currently planned for use  in approximately 40 percent of all Superfund remedial
actions.  Various forms of chemical and physical treatment are  included in current plans for
approximately 70 percent of remedial actions.

The  leading technologies under consideration as alternatives  to land  disposal can be categorized
according to whether they destroy, immobilize, or separate the waste.

       Waste Destruction Technology

       "Destroying" hazardous waste means getting rid of most of it.  Some harmful residues may
       still be left behind, however, and these must be properly disposed of.

       Thermal Treatment

       The most common type of thermal treatment heats waste over a flame-powered incinerator.
       Currently, if waste at a Superfund site is to be burned, it is usually removed from the site
       and taken to the incinerator.  In  the  future,  EPA will  make  greater use  of mobile
       incinerators, which can be moved  from one site to another as needed.

       Various types of flame-free thermal treatments are now being developed to destroy hazardous
       waste, including fluidized bed treatment, infrared treatment, plasma arc, and pyrolysis.
5/93

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ALTERNATIVE TREATMENTS

       Neutralization

       Certain types of hazardous waste can be "neutralized."  For example, an acid can be added
       to an excessively alkaline waste, or a base can be added to an overly acidic waste.

       Waste Immobilization Technology

       Immobilizing a waste puts it into a solid form that is easier to handle and less likely to enter
       the surrounding environment. It is useful for dealing with wastes, such as heavy metals, that
       cannot be destroyed.  Once a waste has been immobilized,  the material resulting from the
       immobilization process must be properly disposed of.

       Fixation and Solidification

       Two popular methods of immobilizing waste are fixation and solidification.  Engineers and
       scientists mix materials such as  fly ash or cement into hazardous waste.  This either "fixes"
       hazardous particles, in the sense of immobilizing them or making them chemically inert, or
       "solidifies" them into a solid mass.  Solidified waste is sometimes made into solid blocks that
       can be stored more easily than a liquid.

       Waste Separation Technology

       Waste  separation entails either separating one hazardous waste from another, or separating
       hazardous waste from a nonhazardous  material that it  has  contaminated.  Sometimes this
       separation is achieved by changing the waste from one form (solid, liquid, gas) to another.
       Regardless of the way it is achieved, separation results in end products that can be adaptable
       to recycling.

       Air Stripping and Steam Stripping

       Air stripping is sometimes used to remove volatile chemicals from water.  Volatile chemicals,
       which have a tendency to vaporize easily, can be forced out of liquid when air passes through
       the liquid.  Steam stripping works on the  same general principle, except that it uses heated
       air to raise the temperature of the liquid and force out volatile chemicals ordinary air would
       not.

       It  should be noted that  the mixture of air and chemicals that results  from air  and steam
       stripping is still hazardous and must be further treated before release.

       An interesting  variation on this technology is now being used at the Verona Well Field site
       in Michigan to remove volatile organic  chemicals from the soil above an aquifer. Another
       promising variant is landfill gas  extraction, in which vacuum wells are used to remove gases
       from soil.
5/93                                        10

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ALTERNATIVE TREATMENTS

       Carbon Adsorption

       Carbon adsorption tanks contain particles of carbon that have been specially activated to treat
       hazardous chemicals  in gaseous and  liquid hazardous waste.   The  carbon chemically
       combines with the waste or catches hazardous particles just  as  a fine  wire mesh  catches
       grains of sand.  Contaminated carbon must then be disposed of or cleaned and reused.

       Precipitation

       Precipitation involves adding special materials to a liquid waste.  These bind to hazardous
       chemicals and cause them  to precipitate  out of the liquid and form large particles called
       "floe."  Floe that settles can be separated as sludge; floe that remains suspended can be
       filtered.

       Soil Washing and Flushing

       Soil  containing easily dissolved chemicals  can sometimes be  cleaned by  soil  washing.
       Cleaning liquid, added at the top of a tank of contaminated soil, picks up waste as it passes
       through the soil.  The contaminant-laden cleaning liquid must be further treated or properly
       disposed of.

       Soil flushing works  on the same principle, except that it occurs in the ground rather than in
       a tank.  Soil is purified when cleaning liquid is passed through it; each time the liquid passes
       through, it is collected by pipes or wells located at the base of the contaminated area.

       Removing Obstacles to Innovation

       While  alternative technologies may  be currently available,  there  are  often  serious
       impediments to their use at Superfund sites.  These include certain factors that EPA cannot
       control, such as  economic and marketplace  uncertainties.  One major uncertainty is  the
       degree to which the public will accept a particular means of handling  hazardous waste. This
       has been a special problem in the case of incineration.

       There  are other  steps  EPA can take  to create a  climate more receptive  to alternative
       technologies.  EPA  is moving ahead with them.

       For example, EPA is setting up  a quicker  and more flexible method for selecting contractors
       to clean up Superfund sites  and  to determine  how Superfund wastes may be treated.   EPA's
       Office of Solid Waste is also working to streamline the Superfund Permitting process to give
       high  priority to issuing permits  for alternative treatment technologies.

       A new provision of SARA also fosters the use of alternative technologies by giving EPA the
       authority, under certain circumstances, to assume liability for contractor efforts  to  test or
       demonstrate alternative technologies.
5/93                                         11

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ALTERNATIVE TREATMENTS

       In addition, a  Superfund Innovative  Technology Evaluation (SITE)  program has  been
       established to demonstrate new and innovative technologies.  Starting in the summer of 1987,
       such technologies will be tested on real wastes in full-scale.situations  at Superfund sites.

       The results of these tests will generate vital cost and performance data, making it easier for
       new  technologies to  compete in  the real world.  EPA has also developed  a program to
       communicate SITE data to appropriate offices within Superfund.

       What Lies Ahead

       Congress, EPA, and the U.S. public are seeking reliable, long-term solutions to the problem
       of managing Superfund sites.  Land disposal is no longer a preferred remedy, but it will take
       some time for alternative technologies to develop sufficient capacity to fill the gap.

       During the years ahead,  alternative technologies will  be  substituted for landfilling at  an
       increasing number of Superfund sites.  EPA is doing everything possible to hasten the day
       when enough  safe and reliable  remedies exist to  ensure that Superfund cleanups are
       permanent.

       Reverse Osmosis

              General Description

              Osmosis is the spontaneous  flow of solvent (e.g., water) from a  dilute  solution
              through a semipermeable membrane (impurities or solute permeates at a much slower
              rate) to a more concentrated solution. Reverse osmosis is the application of sufficient
              pressure to the concentrated solution to overcome the osmotic pressure and force the
              net flow of water through the membrane toward the dilute phase.  This allows the
              concentration  of solute (impurities) to  be built up in a circulating system on one side
              of the membrane while relatively pure water is transported through the membrane.
              Ions  and small molecules in true  solution can be separated from water by this
              technique.

              The basic components of a reverse osmosis unit are  the membrane, a membrane
              support structure, a containing vessel, and a high-pressure pump.  The membrane and
              membrane support structure are the most critical elements.  FIGURE 1 illustrates the
              principle of reverse osmosis.

              Applications/Limitations

              Reverse osmosis is used to reduce  the concentrations of dissolved solids, both organic
              and inorganic. In treatment of hazardous waste contaminated streams, use of reverse
              osmosis would be primarily limited to polishing low flow streams containing highly
              toxic contaminants.  In general, good removal can be expected for high molecular
              weight organics and charged  anions and cations. Multivalent  ions are treated more
              effectively than are univalent ions.  Recent advances in membrane technology have


5/93                                        12

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ALTERNATIVE TREATMENTS
           made it possible to remove such low molecular weight organics as alcohols, ketones,
           amines, and aldehydes (Gooding, 1985). TABLE 1 shows removal results obtained
           during testing of a mobile reverse osmosis unit  using two favorable membrane
           materials (Whittaker, 1984).
                          PRESSURE VESSEL
  FEED
 HIGH-PRESSURE

     PUMP
                  CONCENTRATED
                     SOLUTION
       DILUTE

     SOLUTION
PERMEATE
    REGULATING
        VALVE
          SEMIPERMEABLE
              MEMBRANE
                              CONCENTRATE
                                FIGURE 1
                           REVERSE OSMOSIS
5/93
13

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ALTERNATIVE TREATMENTS
TABLE 1
RESULTS OF PILOT-SCALE TESTING OF A REVERSE OSMOSIS UNIT




Chemical
Dichloromethane
Acetone
1,1-Dichloroethene
Tetrahydrofuran
Diethyl ether
Chloroform
1 ,2-Dichloroethane
1 , 1 , 1-Trichloroethane
Trichloroethene
Benzene
Bromoform
Hexane


Feed
Concentration
(ppb)
406
110
34
17,890
210
270'
99
659
24'
539
12'
10'

Percent
Concentration
in
Concentrate
203
355
795
467
439
567
415
651
346
491
633
704
Percent removed in permeate

Polyether-
polysulphone
membrane
58
84
99
98
97
98
92
99.8
99
99
99.1
99.8
Polyester/
amide
polysulphone
membrane
52
76
95
89
89
92
85
97
99
99
98
97
1 No standard available; concentration estimated.
Source: Whittaker, 1984
              Reverse osmosis units are subject  to  chemical  attack, fouling,  and plugging.
              Pretreatment requirements  can be extensive.  Wastewater  must be pretreated to
              remove  oxidizing  materials  such as  iron  and  manganese  salts,  to filter  out
              particulates, adjust pH to a range of 4.0-7.5, and  to remove oil, grease, and other
              film forms  (DeRenzo, 1978).  The  growth of slimy biomass on  the membrane
              surface, or the presence of organic macromolecules, may also foul the membrane.
              This organic fouling can  be minimized by  prechlorination, addition of biocides,
              and/or pretreatment with activated carbon (Ghassemi, Yu, and Quinlivan, 1981).

              Design Considerations

              The most critical design consideration applicable to  reverse osmosis technology is the
              design of the semipermeable membrane.  In addition to allowing the achievement of
              the required degree of separation at an economic flux level under ideal conditions,
              the membrane must be incorporated into an operating system that satisfies the
              following practical requirements (Conway and Ross,  1980):
5/93
14

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ALTERNATIVE TREATMENTS
              •      Minimum concentration polarization (i.e., ratio of impurity concentration at
                     the membrane surface to that in the bulk stream)

              •      High packing density (i.e., membrane surface area per unit volume of the
                     pressure module)

              •      Ability to handle any paniculate impurities (by proliferation if necessary)

              •      Adequate support for  the membrane and other  physical features such as
                     effectiveness of seals, ease of membrane replacement, and ease of cleaning.

              Membranes are usually fabricated in flat sheets or tubular forms and are assembled
              into modules.  The most common  materials used are cellulose acetate and other
              polymers such as polyamides  and polyether-polysulphone.  There are three basic
              module designs:  tubular, hollow fiber, and spiral wound.  These  are illustrated in
              FIGURES 2a, 2b, and 2c.  Each type of membrane module has its own advantages
              and limitations. The tubular module provides the largest flow channel and allows for
              turbulent fluid flow regime; thus, it is least susceptible  to plugging  by suspended
              solids and has the highest flux.  However, because of its small area to volume ratio,
              the total product recovered per module is small.  The cost of a tubular module is
              approximately  5 times that for the  other modules for an equivalent  rate of water
              recovery, and  the total space  requirements is about  3-5 times  that  for the spiral
              wound system  (Ghassemi, Yu  and Quinlivan, 1981).

              A  hollow fiber  membrane is constructed  of polyamide polymers  and cellulose
              triacetate by Dupont and Dow, respectively.  The polyamide membrane permits a
              wider operating pH range than cellulose acetate, which  is  commonly used for the
              construction of spiral wound and tubular membranes.  The flow channel and the flux
              are about an order of magnitude lower than the other configurations.  This small flux,
              however, is compensated for by the large surface area  to volume ratio, with the total
              product water per module being close to that obtainable with spiral  wound modules.
              However, because of the small size of the channels (about 0.004 in.) and the laminar
              fluid flow regime within the channels, this module is susceptible to plugging and may
              require  extensive  pretreatment to  protect the  membrane (Ghassemi,  Yu,  and
              Quinlivan, 1981).
5/93                                        15

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ALTERNATIVE TREATMENTS
              CASING
                  \
S3>-
                                     WATER
                                     PLOW
              MEMBRANE
                        FIGURE 2a
                    TUBULAR MEMBRANE
          ROLL TO    ,
          ASSEMBLE ,-',
    FEED SIDE
    SPACER
                          FEED FLOW
                 V
                PERMEATE FLOW
                (AFTER PASSAGE
                THROUGH MEMBRANE)
  PERMEATE OUT
PERMEATE SIDE BACKING
MATERIAL WITH MEMBRANE ON
EACH SIDE AND GLUED ABOUND
EDGES AMD TO CENTER TUBE
                        FIGURE 2b
                   HOLLOW FIBER MODULE
5/93
    16

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ALTERNATIVE TREATMENTS
                 CONCtXTKATE
                 OUTLET
FLOW
                                                 OPEN END
                                                 OF FIBERS
                            EPOXY
                           TUBE SHEET
                                                                POROUS
                                                                BACK-UP DISC
                                                                       ,SNAP KING
                                                                       PERMEATE
            END PLATE     FIBER
                                   SHELL
          POROUS FEED       V    /      iTC
           DISTRIBUTOR   "0" RING  END PVATE
              TUBE       SEAL
                                      FIGURE 2c
                              SPIRAL WOUND MODULE
Source: Ghassemi, Yu, and Quinlivan, 1984
             The reverse osmosis unit being tested by Environment Canada can handle flow up to
             11,000 gpd and costs approximately $60,000. Membranes vary considerably in cost.
             The Toray and DSI membranes discussed in TABLE 1 for example, cost $360 and
             $915, respectively (Whittaker et. al., 1985).

             The spiral wound module consists of an envelope of flat sheet membranes rolled
             around a permeate collector tube.  This configuration provides for a higher flux and
             greater resistance to fouling than the hollow fiber modules. It is also less expensive
             and occupies less space than a tubular module (Ghassemi, Yu, and Quinlivan, 1981).

             Technology Selection/Evaluation

             Reverse osmosis is an effective treatment technology for removal of dissolved solids
             presuming appropriate pretreatment  has  been performed  for  suspended solids
             removal, pH adjustments, and removal of oxidizers, oil, and grease.  Because  the
             process is so susceptible to fouling and plugging, on-line monitors may be required
             to monitor pH,  suspended solids,  and other parameters on a  continuous basis.
             Reverse osmosis has not been widely used for treatment of hazardous wastes. A flow
             diagram FIGURE 3 for a reverse osmosis unit at the PAS site in Oswego, NY is
             shown.
5/93
          17

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In-ground storage
      tank
    200,0001
     Static mixer

               02. micron
               cartridge
                 filters
  5 micron
cartridge filters
      RO feed tank
      Cap. 2,000 1
Reaction tank
  Cap. 8001
                                                       Sludge: to disposal
                                                           RO system
                                      02 micron
                                      cartridge
                                        filters
                                                                    PC
                                                                    2
                                                                                                 >
                                                                                                 H
                                FIGURES
                 PRETREATMENT SYSTEM UTILIZED FOR
  THE PHASE II ENGINEERING STUDIES AT THE PAS SITE IN OSWEGO, NY

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ALTERNATIVE TREATMENTS
              Reverse osmosis will not reliably treat wastes with a high organic content, because
              the membrane may dissolve in the waste.  Lower levels of organic compounds may
              also be detrimental to the unit's reliability, because biological growth may form on
              a membrane that is fed an influent containing biodegradable organics.

              The fact that reverse osmosis units can be operated in series or in parallel provides
              some  flexibility in dealing with increased flow rates or concentration of dissolved
              species.

              Memtek Corporation of Ontario, Canada has developed a mobile reverse osmosis unit
              for Environmental Canada.  The unit, which is capable of handling low flows  of
              about 10 gpm, is currently being tested for various types of spills (Whittaker, 1984).

              The volume of the reject generated by osmosis is about  10-25 percent of the feed
              volume.  Provisions must be made to treat this potentially hazardous waste.

              Costs

              Costs for various sizes of reverse osmosis units are presented in TABLE 2.  The
              construction costs include housing, tanks, piping, membranes, flow meters, cartridge
              filters, acid and polyphosphate feed equipment, and cleanup equipment.  These costs
              are based on influent total dissolved solids concentrations of less than 10,000 ppm.

              The operation and maintenance costs include electricity for the high-pressure feed
              pumps (450 psi operating pressure), building utilities, routine periodic repair, routine
              cleaning, and membrane replacement every  3 years.  Operation and maintenance
              costs do not include costs for pretreatment chemicals because of the extreme usage
              rate variability between plants.
TABLE 2
REVERSE OSMOSIS COST
Flow Rate (gpm)
25
50
100
Cap. Cost ($)
69,000
126,000
235,000
O&M Cost ($/yr)
30,000
41,000
76,000
5/93
19

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ALTERNATIVE TREATMENTS

       Freeze Crystallization

       Freeze crystallization is the general separation process used to remove pure components from
       solutions  by crystallizing the materials to be removed.  This process has been used for
       applications as diverse as organic  chemical refining and  fruit juice concentration.  It  is
       especially suited for treating hazardous wastes.  The process can be used in  site remediation
       activities, including treating contaminated soils, where it can be used to recover valuable by-
       products  from RCRA and other  industrial wastestreams.   The basis for this process's
       usefulness in mixed (hazardous and radioactive) wastes is also discussed.

       Freeze Technologies Corporation  has built a  mobile, site remediation  prototype  of a
       commercial plant  to  demonstrate the  field  remediation  aspects of this  technology.  The
       capacity of the unit is nominally 10 gpm of ice production from a leachate or groundwater,
       at 90-percent water recovery. It is contained in two modules that are transported on standard
       low-boy trailers and requires less than 1 week to set up.

       Freeze crystallization has several advantages for remediation and waste recovery applications.
       First,  it is a very  efficient volume  reduction process, producing a concentrate that has no
       additional chemicals added to it.  If disposal in a hazardous waste landfill or incinerator
       destruction is required, these costs will be substantially reduced.  When a large fraction of
       the solvent (usually water) is removed from a waste, the remaining impurities often begin to
       crystallize as well; they are often  sufficiently  pure to have by-product value for  resale.
       Processing costs with freezing are generally low, ranging from $.03 to $.15 for 40 and 5
       gpm plants, respectively.

       Freeze Process Description

       The basic operation  involved  in freeze crystallization  is the production of crystals by
       removing  heat from a solution.  Crystals produced in this manner invariably have very high
       purities.  Once small, uniform crystals have been produced, they must be washed to remove
       adhering brine.  The brine is recycled to the crystallizer,  so that as much  solvent as desired
       can be recovered.  The pure crystals are usually melted in a heat-pump cycle, which  further
       improves  the energy efficiency of the process.

       When one or more of the solutes exceeds its solubility additional crystal forms are produced,
       but they are formed separately  from each  other and from the solvent crystals.  Because in
       most waste applications the solvent  is water, and ice is always less dense than the solution
       and the solutes are usually more dense, it is easy to separate these crystals  by gravity.

       A freeze crystallization process is then composed of the following components, as illustrated
       in the process flow diagram of FIGURE 4:

       •      A  CRYSTALLIZER, where heat is removed to lower the temperature of the material
              to  the freezing temperature of the solution (usually crystallizing the  solvent first)
5/93                                         20

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ALTERNATIVE TREATMENTS
  MELT
                                                                   HEAT
                                                                 REJECTION
                                                                 CONDENSER
        U-'
        HEAT
      REJECTION
     COMPRESSOR
                                                   txj	>- CONCENTRATE
                                                          OUTLET
                                    FIGURE 4
                      FREEZE PROCESS FLOW SCHEMATIC
             A EUTECTIC SEPARATOR to segregate the crystals of solvent and solute into
             different streams, so that each can be recovered in pure forms

             CRYSTAL SEPARATOR/WASHERS that function to remove the crystals from the
             mother liquor in which they are slurried, and to wash adhering brine to very low
             levels so that the recovered crystals have high purity
5/93
21

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ALTERNATIVE TREATMENTS

       •     A HEAT-PUMP REFRIGERATION CYCLE to remove refrigerant vapor from the
             crystallizer and compress it so that it will condense and give up its heat to melt the
             purified crystals

       •     HEAT EXCHANGERS to recover heat from the cold effluent streams, improving the
             heat efficiency of the process

       •     DECANTERS and STRIPPERS are required in some processes to remove volatile
             materials and/or refrigerant from the effluent streams before discharge

       •     UTILITIES, CONTROLS, ELECTRICAL SWITCH GEAR, PUMPS and PIPING
             to implement the freeze process in a continuous, closed system.

       The design, operating characteristics, capabilities, and limitations are determined largely by
       the type  of crystallizer that is used, of which there are three basic choices:

       1.     INDIRECT CONTACT, using a scraped surface or similar heat exchanger that will
             crystallize by removing heat through the heat transfer surface.

       2.     TRIPLE POINT crystallizers  use the solvent as the refrigerant at its triple  point
             (where solid, liquid,  and vapor phases are all in equilibrium).  For instance, with
             aqueous systems, the triple point occurs at less than 3  mm Hg absolute pressure at
             30°F or below.

       3.     SECONDARY REFRIGERANT freezing uses an  immiscible refrigerant that is
             injected directly into  the process fluid and evaporates at several hundred  to several
             thousand times the vapor pressure of the solvent.

       The third option offers a number of advantages in treating hazardous wastes, resulting in a
       less expensive process that is inherently capable of producing higher quality effluents and
       effecting a greater reduction  of the final volume.

       10 gpm  Remediation Prototype

       The freeze  crystallization process that has been accepted into EPA's SITE Program is a
       secondary refrigerant process. A prototype commercial remediation plant has been designed
       and built for that program.  The capacity of the plant is a nominal 10 gpm of ice produced
       from an  aqueous wastestream with a freezing point of 20°F.

       The plant contained all of the components described in a typical freeze crystallization process
       above,   including  the  crystallizer,  eutectic  separator,  crystal  separator/washer,  heat
       exchangers, heat pump (pen cycle screw compressor), decanters and strippers, and ancillary
       utility related systems.
5/93                                       22

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ALTERNATIVE TREATMENTS
       The  plant  was  designed for ultimate  transportability,  using  modular  design concepts
       developed by  Applied Engineering Co., Orangeburg, South  Carolina, the acknowledged
       leader in this field.  The plant was contained in two modules designed for transport on the
       back of low-boy trailers.  Each measures approximately 50 ft 1 in. by 13 ft by 11.5 ft. They
       were picked off upon arrival at the site by a standard road crane, and one was placed on top
       of the other.  The 3 electrical and 30 flanged-piping interconnections take about a day to
       complete.

       The plant is totally self-contained except for electrical supply,  containing instrument  air,
       cooling water, electrical distribution, and electrical heating components. It has a distributed
       digital processor that  is programmed to operate without  attendance, using on-line  quality
       sensors to evaluate process efficiencies and discern any operating problems, recycling effluent
       for reprocessing if warranted. Cost summary results show three different size units.  The
       greater the flow rate, the more economical the system will be to operate (TABLE 3).
TABLE 3
FREEZE CRYSTALLIZATION COST SUMMARY
Cost Component
Amortization, 5-year SLD
Labor
Electricity
Supplies, chemicals, etc.
Maintenance
TOTALS
Cost at Plant Size, $/Gal.
5 gpm
$.08
.04
.008
.010
.007
.145
10,gpm
$.05
.02
.0075
.0075
.005
.09
40 gpm
$ .015
.005
.006
.005
.004
.035
5/93
23

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ALTERNATIVE TREATMENTS

       SITE Demonstration Program - Stringfellow NPL

       The FTC Direct Contact Secondary Refrigerant Freeze Crystallization Process was accepted
       by EPA's Office of Research & Development,  SITE Program, into the third phase of their
       program, when first proposed  by Freeze Technologies.  A program with the State  of
       California, Department of Health Services, Alternative Technologies Office, was already in
       place, and the selection of the Stringfellow NPL site had been agreed to with the state.

       The goals of the SITE program are, among other things, to demonstrate applicability of a
       technology on as general a wastestream as can be found and  to develop the  best economic
       and performance  criteria that  can be projected  from test results.  Freeze  Technologies
       proposed that testing could be performed with either a 0.5 gpm portable pilot plant or with
       a 10 gpm prototype remediation plant, designed specifically for Superfund work.  The groups
       involved in the demonstration of this technology concurred unanimously that the larger plant
       is a better vehicle for accomplishing the goals of the program.

       The current  schedule will have the equipment at the Stringfellow NPL  site in late July and
       installed and ready to operate in early August.  The SITE tests  and sampling program will
       occur over a 2- to 3- week schedule in August, with a public visitors day on Sunday, August
       16, 1989.   Further testing for reliability and  longer-term performance confirmation will
       continue into  September and  the  plant will be  removed from  the  site by the end  of
       September, after appropriate decontamination.

       This demonstration program is designed to have minimal impact  on the host site, a condition
       that is paramount in the planning at the EPA Regional level and with local communities. The
       freeze equipment will be fit in as a "black-box" in the pipeline that carries wastes from the
       NPL site to the onsite pretreatment plant.  We will intercept the wastes between the collection
       wells and the pretreatment plant, process the wastes, then recombine them for transfer to the
       pretreatment plant.  The residence time  in the freeze crystallization plant, including storage
       before and after the actual freeze processing equipment, will be 72 hours.

       Because the  freeze  process operates in closed  vessels,  with  recycling of refrigerants and
       wastes at temperatures  well below  ambient, there  are no emissions from the process.  An
       option exists at Stringfellow for treating the concentrated effluent for metals  recovery,  for
       organic  by-product extraction, or by solidifying the concentrate for subsequent landfilling.
       The by-product recovery is an attractive option because  it eliminates a  large  volume that is
       now landfilled. TABLE 4 shows the analysis of the feed and melt.
5/93                                        24

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ALTERNATIVE TREATMENTS
TABLE 4
STRINGFELLOW LEACHATE ANALYSES

Component
pH
Conductivity, mS/cm
Dissolved Organic Carbon
p-CBSA
Volatile halocarbons
Volatile ketones
Na
Total heavy metals
Al
Cd
Cr(6+)
Cu
Fe
Mg
S04

NO3
Concentration, mg/1
Feed
3.5
39
1125
1670
9.7
14.
820
3385
1650
2.5
85
9
335
1160
16,200
335
320
Melt
6.5
0.02
<1
<1
< 0.010
< 0.010
<1
<5
<1
<0.010
<0.010
<0.010
<1
<1
<5
<1
<1
       Waste Treatment with Bv-Product Reclamation

       Remediation offers some opportunities for by-product recovery, but more frequently these
       applications occur in on-going RCRA generation facilities.  The following discussion covers
       generic conditions that favor freeze crystallization treatment and how other unit processes can
       be used with freezing to offer a complete remediation or by-product recovery process train.
       In addition,  a few recent applications that have been reviewed and tested  using freeze
       crystallization will also be discussed.

       Generic Application Considerations

       Freeze crystallization works by making pure crystals from water, or other components, in
       a waste solution.  The waste must be in liquid form, so contaminated soils are treated by first
       washing the  impurity  out of the  soil  into a wash solvent  (usually water).   In the case of
5/93
25

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ALTERNATIVE TREATMENTS

       aqueous-based wastes, the crystal that is produced is ice, and all impurities are excluded and
       remain in the concentrated liquid portion. The process is effective in removing water from
       these wastes, thereby reducing the volume that must be dealt with.

       Because crystallization  excludes all impurities  from  the  ice,  all impurities  are equally
       removed.  The freeze process is capable of treating wastes with heavy metals, all types of
       dissolved organics, and radioactive materials. All impurities are reduced in concentration
       in the effluent bv a factor of about 10.000.

       Freeze crystallization is not the answer for all  applications.  The information in FIGURE 5
       indicates the conditions that favor its use over alternative treatment technologies.  The chart
       demonstrates that  freezing becomes more economically and technically competitive as the
       waste becomes more concentrated and more  complex.  For instance,  wastes with heavy
       metals  require concentrations  of 1,000-10,000 mg/1 to be economically recoverable  with
       freezing.   Aqueous streams require organic concentrations of 3-7  wt-%  before it is more
       economical to treat with freeze crystallization  than by conventional means.  Yet, when the
       waste contains both organics and heavy metals,  freeze crystallation becomes more economical
       than multiprocess treatment trains using conventional technologies at between 0.5 and 1.5 wt-
       % total contaminants.
1
N
C
R
E
A
5
E
D
C
0
N
C
E
N
T
R
A
s,
N1
'
TYPE OF CONTAMINANT
VOLATILE HEAVY
ORGANICS ORGANICS
SALTS

STRIPPING

CARBON ADSORPTION

BIOLOGICAL & CHEMICAL
OXIDATION

R

HEAVY
METALS

ION EXCHANGE



ELECTRODIALYS1S

EVERSE OSMOSIS


EVAPORATION

FREEZE CRYSTALLIZATION




                                       FIGURE 5
                        TECHNOLOGY COMPARISON CHART
5/93
26

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ALTERNATIVE TREATMENTS

       UV Radiation. Ozone. Hydrogen Peroxide

       This section provides an overview of the Ultrox technology and a description of the treatment
       system equipment, support equipment, and utility requirements.  Detailed descriptions of the
       Ultrox treatment technology are present in the Demonstration Plan (PRC,  1989).

              Process Description

              The use of oxidants such as ozone, hydrogen peroxide, and ultraviolet (UV) radiation
              to destroy organic contaminants present in groundwater is gaining considerable
              attention, mainly because the oxidants destroy the contaminants instead of transferring
              them to  another phase.   Alternative  treatments, such as air  stripping,  granular
              activated carbon (GAC) adsorption, and reverse osmosis, require additional treatment.

              Ultrox  International  developed a technology  that uses  three  oxidants:    ozone,
              hydrogen peroxide, and UV  radiation.  The  Ultrox  technology is best suited for
              destroying dissolved organic contaminants, including  chlorinated hydrocarbons and
              aromatic compounds, in water with low suspended solids levels.  This  technology is
              currently  treating contaminated groundwater  at  facilities located  in Kansas City,
              Missouri; Nashua, New Hampshire; and Muskegon, Michigan. Groundwater at these
              sites is contaminated  with trichloroethylene, tetrachloroethylene, vinyl  chloride,
              pentachlorophenol, phenol, and various other organics.   The design  flow rates of
              these facilities are in the range of 20 to 210 gpm.

              Process Chemistry

              Processes in which ozone is  used in combination with hydrogen  peroxide  or UV
              radiation may be categorized as catalytic processes. These processes accelerate ozone
              decomposition, thereby  increasing the  hydroxyl  radical  (OH~) concentration and
              promoting the oxidation rate of the  compounds of interest.  Specifically, hydrogen
              peroxide, hydroxide ion,  UV radiation,  and some transition  metal  ions such as
              ferrous iron (Fe2+) have been found to initiate ozone decomposition and accelerate
              the oxidation of refractory organics  via the free radical reaction pathway.  Natural
              water components such as carbonate ions, bicarbonate ions, cyanide  ions, nitrite ions,
              and several other species that consume oxidants  act as  free radical scavengers and
              effectively consume hydroxyl radicals.

              The ozone-hydrogen process is affected by the molar ratio of the oxidants used. For
              example, the expected stoichiometry for hydroxyl radical formation from ozone and
              hydrogen peroxide is two, as  shown in  the following equation:

                               H2O2  + 203 ** 2 OH" + 3 O2
5/93                                        27

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ALTERNATIVE TREATMENTS
              In the treatment of water containing trichloroethylene and tetrachloroethylene, Aieta
              et al. (1988) observed maximum removals at a molar ratio of 2 or a 2.86 weight ratio
              of ozone to hydrogen peroxide, which agrees with the expected stoichiometry. The
              removals were significantly less when the molar ratio was not 2.  Although in this
              case the expected stoichiometry for pure water agreed with the molar ratio at which
              optimum removal was observed, several factors may influence the molar ratio (Aieta
              et al., 1988). These factors are summarized below:

              •      Hydrogen peroxide can  act  as  a  free radical  scavenger itself,  thereby
                     decreasing the hydroxyl radical concentration if it is present in excess

              •      Ozone can directly react with hydroxyl radicals, consuming both ozone and
                     hydroxyl radicals

              •      Ozone and hydroxyl radicals may be consumed by other constituents, known
                     as scavengers, of the water to be treated.

              In the ozone-UV process,  the UV photolysis  of  ozone in water yields hydrogen
              peroxide rather than two hydroxyl radicals.  Thus, the ozone-UV process resembles
              the ozone-hydrogen peroxide process, but offers the additional advantage that  direct
              photolysis and photosynthesized processes also  decompose organic substrates.

              The Ultrox process, therefore, can be viewed as a catalytic ozonation process and the
              oxidation of contaminants is likely to occur  either by direct reaction of the oxidants
              added or by reaction of the hydroxyl radicals with the contaminants. The optimum
              proportion of the  oxidants  for maximum removals  cannot be predetermined; rather,
              the proportion must be experimentally  determined for each  wastestream.   The
              following section identifies specific factors that influence the  effectiveness of the
              Ultrox technology in treating the groundwater at the LB&D site.

              Factors Affecting the Ultrox Technology

              The factors that affect the Ultrox technology can be grouped into three categories:

              1.     Performance evaluation parameters

              2.     Operating parameters

              3.     Miscellaneous parameters.

              The performance  evaluation parameters of the Ultrox technology at the LB&D site
              under specified conditions were specific chemical constituents.  These constituents are
              volatile organic compounds (VOCs), semivolatile organics, polychlorinated biphenyls
              (PCBs),  and pesticides.  The influent concentrations of these constituents can
              significantly influence the treatment efficiency of the technology.
5/93                                        28

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ALTERNATIVE TREATMENTS
              Operating parameters  are those parameters that were  manually varied during the
              treatment  process  to  achieve  a desired degree of treatment efficiency.    Such
              parameters included hydraulic retention time, ozone dose, hydrogen peroxide dose,
              UV radiation intensity, and influent pH level.

              Because the Ultrox technology is  an oxidation process and  is intended for the
              destruction of organic contaminants, any other species  present in the contaminated
              water that consume oxidants were viewed as an additional load for the system. These
              species, called scavengers, include anions such as carbonates, bicarbonates, sulfides,
              nitrites, bromides,  and cyanides.  Also,  metals present in reduced states, such as
              trivalent chromium (Cr3*), ferrous iron (Fe2"1"), and several others, are likely to be
              oxidized.  In addition, physical characteristics of the influent,  such as temperature
              and pH, also influence the Ultrox process.

              Treatment System Equipment

              The treatment system used to demonstrate the Ultrox process is shown in FIGURE
              6.  This system (Model PM-150) uses UV radiation, ozone, and hydrogen peroxide
              to  oxidize the modules designed for transport with either a flatbed truck or in an
              enclosed trailer.  The major components of the system include the following:

              •      UV radiation/oxidation  reactor module

              •      Ozone generator module

              •      Hydrogen peroxide feed system

              •      Catalytic ozone decomposer unit.
5/93                                        29

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ALTERNATIVE TREATMENTS
                                                                nn-
                                                                   I  I  U_ E«ii.~>t
                                                                          tio..o>
                                   FIGURE 6
                      ULTROX SYSTEM FLOW DIAGRAM
            An  isometric view of the Ultrox system is  given in  FIGURE 7.  The  UV
            radiation/oxidation reactor used  for this demonstration has a wet volume of  150
            gallons and is 3 ft by 1.5 ft by 5.5 ft.  The reactor is divided by 5 vertical baffles
            into 6 chambers and contains 24 UV lamps  (65 watts each) in quartz sheaths.  These
            lamps are installed vertically and are evenly distributed throughout the reactor (four
            lamps per chamber). Each chamber also has one sparger that covers the width of the
            reactor.  These spargers provide  a supply of uniformly diffused ozone gas from the
            base of the reactor into the treated groundwater.
5/93
                                      30

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                                                                     W.TWOX
                                                                UV/OXJO»TX)M REACTOR
                                                                                 TH6ATEO
                                                                                 EfTVUEHT
                                                                                 TOOtSCMAflCE
All
                                         FIGURE 7
                          ISOMETRIC VIEW OF ULTROX SYSTEM

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ALTERNATIVE TREATMENTS
              The ozone generator requires  compressed air as a source of oxygen for onsite
              generation of ozone.  The air compressor operates in association with an air dryer,
              which removes moisture.  In addition, a water cooler recirculates cooling water
              supplied to the ozone generator.

              The hydrogen  peroxide  feed system  introduces a predetermined  concentration of
              hydrogen peroxide to the reactor via an  influent feed line.   Commercial-grade
              hydrogen peroxide of known concentration (about 35 percent) was purchased from
              a chemical supplier and diluted with distilled water to the appropriate concentration.
              An in-line static mixer disperses the hydrogen peroxide from the feed tank into the
              groundwater as groundwater is pumped through the influent feed line.

              The catalytic ozone decomposer unit (Ultrox Model 3014 FF ozone decomposer)
              catalytically  decomposes ozone to oxygen using a nickel  catalyst.  The ozone
              decomposer  (Decompozon) unit can accommodate flows of up to 10 standard cubic
              feet per minute.  The unit is rated to decompose ozone concentrations ranging from
              1 to 20,000 ppm (by weight) to less than 0.1 ppm.

              During the demonstration operation, contaminated groundwater came in contact first
              with hydrogen  peroxide as it flowed through the influent line to the reactor.  It then
              came in contact with UV radiation and ozone  while it flowed through the reactor at
              a specified rate to achieve  the desired hydraulic retention time.   The hydrogen
              peroxide dose was controlled by varying the ratio of the hydrogen peroxide feed flow
              rate to the influent contaminated water flow  rate.  Similarly, the ozone dose was
              controlled by varying the ration of the ozone gas flow rate to the contaminated water
              flow rate and,  also, the  ozone  feed gas concentration.   The treatment system was
              designed  so  that ozone present in  the off-gas from the reactor could be destroyed
              using a catalyst by the Decompozon unit.  Treated groundwater effluent was pumped
              from the reactor to a storage tank.

              Treatment System Support Equipment

              Typically, support equipment is needed depending on the site logistics, required
              operating procedures, and equipment limitations.  Submersible discharge pumps may
              be needed to bring groundwater from the source to the Ultrox system.  In addition,
              a submersible pump is commonly needed to pump the effluent from a small capacity
              container to a storage tank. As discussed previously, an air compressor is frequently
              used to generate ozone from air.  However, in some applications an alternative air
              source is used, such as compressed air or oxygen cylinders.

              For the  demonstration,  two  collapsible  bladder tanks  were used  to  store  site
              groundwater in order to  reduce VOC losses.  The treated water was pumped from
              an effluent collection tank to an effluent storage tank in all test runs.  The combined
              effluent from all the runs was stored in the  storage tanks  until  the effluent was
              analyzed  and found to be acceptable for discharge into Coyote  Creek,  a nearby
              watercourse.
5/93                                        32

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ALTERNATIVE TREATMENTS

              Utility Requirements

              Utilities required for the Ultrox system demonstration included water, electricity, and
              telephone service.

              •      Water - Tap water was required for the Ultrox process and for equipment and
                     personnel decontamination.  During operation, the Ultrox system required
                     less than 3.5 gpm of cooling water.  A recirculating chiller enabled reuse of
                     cooling water.  Water used for equipment and personnel decontamination was
                     provided using existing site pipelines.

              •      Electricity - Electricity was required to operate the Ultrox system, the office
                     trailer, and the laboratory equipment. The Ultrox system required 480-volt,
                     3-phase electrical service. Also, 110-volt, single-phase power was needed for
                     lighting the field trailer and operating the onsite laboratory equipment.

       Oxygen Enhanced Incineration

              Technology Description and Explanation of Developers Claim

              The Pyretron Thermal Destruction System is designed for application to a rotary kiln
              incinerator.  It consists of two burners,  one installed in the primary combustion
              chamber (kiln) and one installed in the afterburner;  valve trains for supplying these
              burners with controllable flows of auxiliary fuel, oxygen, and air; a  computerized
              process control system; an oxygen supply system; and a kiln water injection system.
              A schematic of the system is shown in FIGURE 8. The Pyretron burners use a
              parallel combustion approach based on the independent introduction of two distinct
              oxidizers to each burner, each of which has significant differences in oxygen content.
              In most situations, as demonstrated in this test program, one of the two  oxidizers will
              be pure oxygen, whereas the second oxidizer will be air and/or oxygen-enriched air.
5/93                                     33

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VO
OJ
r
rf
    i
                Afterburner Pyretron burner
                Transfer
                duct
                  Ash
                  pit
                            Afterburner
                                                     r
                                                      r
                                           Kiln Pyretron
                                           burner
Measured
process
parameters
                                                                                            i
n
r*
o
9

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ALTERNATIVE TREATMENTS
              The burner is designed to provide a pyrolytic combustion zone where fuel is mixed
              with pure oxygen under substoichiometric conditions.  This pyrolytic zone, which is
              located inside  the flame envelope, is used to provide high  flame luminosity and
              stability.   A second combustion stage is established by secondary oxidizing gas,
              typically air or oxygen-enriched air.  The secondary oxidizing gas is directed toward
              the pyrolytic flame  core from the area surrounding the core inside a water-cooled
              burner chamber.  The  resulting oxidation of the fuel stream from both inside and
              outside directions results in rapid oxidation and expansion of the combustion products
              before they leave the burner tunnel, thus providing a high-velocity, highly turbulent
              flame that serves to  enhance oxygen mass transfer inside the incineration chambers.

              The system uses a  programmable logic controller to effect process  control.  The
              control system is based on a process  control algorithm that is designed to maintain
              both process temperature and excess  oxygen levels.  This control algorithm allows
              preset responses to process deviations (discussed below) by changing the amount of
              nitrogen-containing combustion air introduced into the incineration process. Nitrogen
              occupies a major fraction of a conventional combustion chamber volume and likewise
              represents a sink for a major  fraction of the burner heat input.   In the Pyretron
              system, the amount of nitrogen can be controlled by varying the ratio of the two
              oxygen sources (air  and oxygen) delivered to the burners.

              When the combustion system of a conventional kiln and afterburner uses only air to
              supply combustion  oxygen, the only process parameter that can be controlled to
              maintain the desired operating temperatures is the auxiliary fuel heat input introduced
              by the burners.  When the Pyretron  system is used, an additional process control
              parameter exists, namely the percent of oxygen in the combustion air supplied to the
              burners. With the Pyretron system it is possible to replace 50 percent of the amount
              of combustion  oxygen available for organic contaminant destruction without  adding
              additional  diluent nitrogen.  Combustion gas temperatures  can be maintained with a
              lower auxiliary fuel heat input because the combustion gas heat sink represented by
              the additional nitrogen is removed.   In addition, combustion gas residence time is
              increased because the diluent nitrogen is removed from the combustion gas volume.

              Dedicated carbon monoxide (CO) and oxygen analyzers are used in addition to stack
              gas analyzers to supply the computerized control system information on the measured
              levels of CO and excess oxygen in the exhaust gases from the primary combustion
              chamber.  When the levels of CO and/or excess oxygen deviate from a level deemed
              appropriate for the given composition and feed volume of the waste, the system can
              initiate a preprogrammed firing schedule in the primary and afterburner chambers to
              bring the  process back to the desired operating conditions  through an  automatic
              increase in the oxygen feed  rates,  with or without a simultaneous reduction in
              combustion air supply.

              In a typical application, the control algorithm increases the flow rate of  oxygen to
              both the kiln and afterburner burners when one of three events occur:
5/93                                        35

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ALTERNATIVE TREATMENTS
              •      A batch  waste change  event with  a predetermined  and preset (in the
                     algorithm) subsequent time lapse

              •      Kiln exit CO levels exceed a predetermined and preset level

              •      Kiln exit 02 levels decrease below a predetermined and preset level.

              A baseline oxygen flow rate to each burner is also preset,  as in the increased level
              to which oxygen  flow  is increased following one of the other above events.  When
              one of the three events occurs,  oxygen flow rates are increased from the baseline
              levels to the preset higher levels and held at these levels for preset period of time.
              After this time period, oxygen flow rates are returned to baseline levels provided no
              triggering condition still exists (e.g., sustained high CO or low
              Burner air flow rates  are typically controlled to maintain a preset ratio of air to
              auxiliary fuel. Thus, air flow rates increase and decrease with corresponding changes
              in auxiliary fuel  feed  rates.   Fuel feed rates, in turn, are varied in response to
              combustor (kiln, afterburner) temperature variations.  The control system varies fuel
              flow rates to maintain combustor temperatures at their set points.  Preset changes in
              air flow rates accompanying the oxygen flow rate changes can be incorporated over
              and above the preset air/fuel ratio if desired.  This additional air flow rate control is
              optional:

              ACI proposes that three major advantages will result from application of the system
              to a rotary kiln incinerator:

              •      The  Pyretron system will be capable of reducing the magnitude of transient
                     high levels of CO, unburned hydrocarbon, and soot ("puffs") that can occur
                     with repeated batch charging of a high heat content waste to a rotary kiln

              •      The  Pyretron system  will allow increased waste feed rate to the kiln while
                     still  achieving  the hazardous  waste  incinerator performance  standards for
                     POHC destruction and removal efficiency (DRE) and paniculate emissions

              •      The  Pyretron system is more economical than conventional incineration.

              The basis for the first claim is as follows.  Rotary kiln incinerators are unique in that
              they are  designed to allow at least a portion of the waste load to be  introduced or
              charged to the system in a batch, rather than continuous, mode.  For organic, heating
              value-containing wastes,  a portion of the heat input to the system is correspondingly
              introduced in a batch mode.  Typically, waste containerized in cardboard, plastic, or
              punctured steel drums  is  charged to the kiln at established intervals.  Upon entry to
              the kiln, the waste containers are heated until they rupture  or burn.  This then
              exposes the waste contents to the  hot kiln environment.   Volatile  organic  material
              then rapidly vaporizes  and reacts with available oxygen in the  combustion gas.
5/93                                         36

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ALTERNATIVE TREATMENTS
              However, if the devolatilization of organic material is more rapid than the rate at
              which combustion oxygen can be supplied to the kiln, incomplete combustion can
              result.  This can lead to a puff of incompletely destroyed organic material exiting the
              kiln. In most instances, this puff will be destroyed in the system's afterburner.  In
              fact, afterburners are included in rotary kiln incinerator systems for this very reason.
              However, if the puff is of sufficient magnitude, insufficient excess oxygen and/or
              residence time may exist in the afterburner to allow its complete destruction.

              In conventional incineration systems, the only way to ensure that sufficient oxygen
              exists in the kiln to allow complete waste oxidation is to increase the air flow rate to
              the kiln. This can be accomplished either by steadily firing the kiln burner at higher
              excess  air than  needed to burn the burner fuel or by  increasing the air flow rate in
              anticipation of or in response to a puff.  In either instance, an increased air flow rate
              adds both increased oxygen  for waste combustion and  increased nitrogen.  The
              increased diluent nitrogen flow  is detrimental to complete waste destruction for two
              reasons. Its presence in the combustion gas volume decreases kiln combustion gas
              residence time,  and, because the nitrogen must be heated, it decreases combustion gas
              temperature.

              In contrast, the Pyretron system offers the  capability to increase the amount of
              oxygen in the combustion process in anticipation of or in response to a puff while not
              adding diluent nitrogen. Thus, kiln temperature can be more easily maintained and
              additional oxygen needed for waste puff destruction can be introduced with far less
              an effect on combustion gas volume,  hence combustion gas residence time, than
              possible with air alone.  This  extra oxygen, without diluent nitrogen, is available for
              waste puff oxidation.  With this additional kiln condition  control flexibility, the
              magnitude of transient puffs  should  be reduced as compared to similar operating
              conditions with conventional incineration.

              The basis for the second claim, that the Pyretron System  will allow increased waste
              feed rate in a given kiln system, follows from the basis of the first claim.  The
              maximum feed  rate of a high organic content waste in a conventional incinerator is
              determined by the onset of transient  puffs that survive the afterburner.  When this
              occurs, waste constituent destruction is  less than complete and eventually falls below
              the regulation mandated 99.99 percent hazardous constituent DRE.

              The discussion  supporting the first claim noted that because the additional oxygen to
              support waste combustion would be supplied without diluent nitrogen in the Pyretron
              system, incineration residence times would be greater for a given waste and auxiliary
              fuel  feed  rate.    Therefore, incineration destruction efficiency  would be  greater.
              Thus, a feed rate that produced unacceptable  transient  puffs  under conventional
              incineration would not do so with the Pyretron system. Correspondingly, the onset
              of unacceptable transient puffs under Pyretron operation would occur at a higher
              waste feed rate.  Thus, acceptable operation at higher waste feed rate (or throughput)
              should be possible with the Pyretron  system.
5/93                                         37

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ALTERNATIVE TREATMENTS

              The Pyretron system uses oxygen for a portion of the waste oxidant (instead of air).
              Therefore,  a given set of incineration temperatures can  be maintained  with less
              auxiliary fuel feed than is possible with conventional incineration.   Less diluent
              nitrogen is fed, thereby obviating the need to heat it  to  combustion temperature.
              Thus auxiliary fuel use per unit of treated waste is less for the Pyretron system than
              for conventional incineration.

              In addition, if higher waste feed rates can be employed in a given combustor with the
              Pyretron system, then the treatment time required per unit of waste is decreased.
              This affords further operating cost savings as well as capital recovery cost savings
              per unit of waste treated.

              The test program discussed here was specifically  designed to evaluate the first two
              of the above claims and to establish needed data to evaluate the third.

       Dehalogenation

              Technology Description

              The alkaline metal hydroxide/polyethylene glycol (APEG) dehalogenation technology
              uses a glycolate reagent generated from an* alkaline metal hydroxide and a glycol to
              remove halogens (e.g., chlorine, bromine,  and fluorine) from halogenated aromatic
              organic  compounds in a batch reactor.  KPEG (potassium hydroxide/polyethylene
              glycol) is the most commonly used type of APEG  reagent.  Potassium hydroxide, or
              sodium hydroxide/tetra-ethylene glycol (ATEG), is another variation of the reagent.
              APEG processes involve heating and physical mixing of contaminated soils, sludges,
              or liquids with the chemical reagents. During the reaction, water vapor and volatile
              organics are removed and condensed.  Carbon filters^re used to trap volatile organic
              compounds that are not condensed in the vapor.   The treated residue is rinsed to
              remove  reactor by-products and reagent and then dewatered before disposal.  The
              process results in treated soil and wash water.

              Application

              •      Selected by EPA  for cleanup at three  Superfund  sites:  Wide Beach, New
                     York; Re-Solve,  Massachusetts; and  Sol Lynn,  Texas.  None  of these
                     cleanups has been completed.

              •      Approved  by EPA's  Office  of Toxic  Substances  to treat PCBs  under the
                     Toxic Substances Control Act.
5/93                                        38

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ALTERNATIVE TREATMENTS

              Technology Strengths

              •      Greater public acceptance than for incineration.

              •      Reduces the toxicity of halogenated organic compounds, particularly
                     dioxins and furans, PCBs, and certain chlorinated pesticides in soils,
                     sludges, sediments, and liquids.

              •      Has successfully treated contaminant concentrations of PCBs reported
                     as high as 45,000 ppm to less than 2 ppm.

              •      Uses standard reactor  equipment to mix/heat soil and reagents.

              •      Energy requirements are moderate, and operation and maintenance
                     costs are relatively low.

              Technology Limitations

              •      Most effective with aromatic halides when APEG and KPEG reagents
                     are used,  although ATEG reportedly works with aliphatic halides.
                     The presence of other pollutants, such as metals and other organics,
                     can interfere with the process.

              •      Wastewater will be generated from the  residual washing process.
                     Treatment may include chemical oxidation,  biodegradation,  carbon
                     adsorption, or precipitation.

              •      Engineering controls, such as a lined and bermed treatment area and
                     carbon filters  on gas effluent stacks may be necessary to guard against
                     releases to the environment.

              Waste Characteristics Affecting Performance

              •      Treatability studies are necessary to help determine the residence time
                     in the  reactor.  The  treatment process is  affected  by  the type of
                     contaminant;  initial and desired  final  concentrations;  pH; water
                     content; and humic and clay content of soils (TABLE 5).

              •      The  ability to recover and recycle reagents is  key to  determining
                     process cost-effectiveness.

              •      Although  individual batch  units may have limited capacity,  several
                     may be operated in parallel for a large-scale remediation.
5/93                                        39

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ALTERNATIVE TREATMENTS
                                        TABLE 5
                              WASTE CHARACTERISTIC
  Waste Type:
  Technology:
Soils and Sludges
Glycolate Dechlorination
        Characteristics
      Impacting Process
          Feasibility
               Reason for Potential Impact
           Data
         Collection
       Requirements
  Elevated Concentrations of
  chlorinated organics
               Concentrations greater than
               5% require excessive
               volumes of reagent (low ppm
               is optimum).
Analysis for priority
pollutants
  Presence of:
    •  Aliphatic organics
    •  Inorganics
    •  Metals
               Reagent effective only with
               aromatic halides (PCBs),
               dioxins, chlorophenols, and
               chlorobenzenes.
Analysis for priority
pollutants
  High moisture content
               Water may require excessive
               volumes of reagent.
Soil moisture content
  LowpH(<2)
               Process operates under highly
               alkaline conditions.
pH testing
  Presence of other alkaline
  reactive
               Aluminum and possible other
               metals that react under highly
               alkaline conditions may
               increase amount of reagent
               required by competing for the
               KPEG.  The reaction may
               also produce hydrogen gas.
Metals analysis
  High humic content in soil
               Increases reaction time. Clay
               and sandy soils as well as
               high organic content soils can
               be treated with increased
               reaction time.
Organic content in soil
Source:  Technology Screening Guide for Treatment of Soils and Sludges EPA/540/2-88/004
5/93
                                           40

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ALTERNATIVE TREATMENTS

BASE-CATALYZED DECOMPOSITION (BCD)

BCD  is another technology  for removing chlorine molecules from contaminants such as PCBs,
dioxins, and pentachlorophenols.  The EPA and the U.S. Navy are conducting extensive research
on this new technology.  Like the KPEG process, BCD requires the addition of a reagent to the
contaminated soils and heating of the material for the reaction.  But because the reagent is not a
glycol reagent, it is significantly less expensive than the  KPEG reagent.

Laboratory research indicates that the BCD process is appropriate for PCBs, pentachlorophenol,
dioxins, and chlorinated pesticides with a very high destruction/removal rate. It also appears to work
well on all types of soils. Because this  technology has not been widely applied, it is difficult to
predict what difficulties will arise at future sites.  To be effective, it requires the soil to be screened
or ground. In 1991, the U.S. Navy will  be applying BCD at a site in Guam.


       In Situ Vitrification

       Technology Description

       In situ vitrification (ISV)  uses electrical power  to  heat and melt  contaminated soils  and
       sludges to form a stable glass and crystalline structure with very low leaching characteristics.
       ISV (FIGURE 9) uses a square array of four electrodes inserted into the ground to establish
       a current in the soil. This heats the soil to a range of 1,600 to 2,000°C, well above a typical
       soil's melting  point.   As the melt is generated downward  from  the surface,  organic
       contaminants are destroyed by pyrolysis. The pyrolized products then migrate to the surfaces
       of the vitrified zone, where they combust in the presence of oxygen. Nonvolatile inorganic
       contaminants are dissolved and incorporated into  the melt.  The resulting product is devoid
       of residual organics.   A vacuum hood placed over the area collects  off-gases, which are
       treated before being released into the atmosphere.
5/93                                        41

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ALTERNATIVE TREATMENTS
   SdU containing oroanlcs
   and Inorganics
   Extrem* heat
   (-1600-2000eQ
    In Situ
Vitrification
Vttrtfledsoll
Treated oflgasei
Spent activated cortxjn
Scrubber water from APC
                                     FIGURE 9
                             IN SITU VITRIFICATION
      Application
             To date, only engineering and pilot-scale tests have been conducted on  ISV of
             hazardous wastes.   Full-scale remediation  of hazardous  waste  is expected to
             commence in 1991.

             A large-scale test has been conducted at Hanford, Washington, on mixed radioactive
             and chemical wastes containing chromium.

             Only one vendor is licensed by the U.S. Department of Energy to perform ISV.

             ISV has been selected for evaluation under the SITE program.
5/93
       42

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ALTERNATIVE TREATMENTS

       •      Two EPA regions have selected ISV to treat contaminated soils at three Superfund
              sites contaminated with PCBs, heavy metals, organics, pesticides, and low-level
              dioxins.

       •      Currently  there  is  a  difference of  opinion concerning  the fate  of organic
              contaminants.  The issue concerns the completeness of destruction and the possibility
              that organic vapors  may migrate away from the soil mass that is being vitrified.

       Technology Strengths

       •      Has the potential to destroy, remove, or immobilize all contaminant  groups.

       •      Successfully tested for the treatment of radioactive and hazardous wastes.

       •      Produces a stable crystalline structure encapsulating the residual inorganic waste with
              long-term durability.

       Technology Limitations

       •      Requires off-gas  collection and treatment, as well as disposal of spent activated
              carbon, scrubber  water, and other waste  materials  from the air pollution control
              equipment that may be hazardous.

       •      May require backfilling with clean soil because volume can decrease  20-40 percent.

       •      Only one licensed vendor for commercial applications.

       •      High electrical energy consumption.

       Waste Characteristics Affecting Performance

       •      Soil moisture, which  must be driven off before melting occurs, can have a major
              effect on cost.

       •      A second major factor affecting cost is the price of electricity.

       •      The capability of the system depends on two factors: (1) the capabilities of the power
              supply and (2) the capacity of the off-gas system.

       •      The two factors that affect the ability of the power supply system are the presence
              of groundwater and  buried metals. Vitrification can take place in saturated soils with
              low permeabilities if the melting rate is greater than the rate of recharge.

       •      Miscellaneous buried  metal, such as drums, should have little or no effect on the
              ability  to  process a site.  A conduction path that could lead to shorting between
              electrodes should  be avoided.


5/93                                        43

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ALTERNATIVE TREATMENTS
              The off-gas system should maintain a negative pressure to prevent any release of
              contamination.  Gas can be released from relatively short transient events such as the
              release of entrapped air from  intrusions into void spaces, penetration of a drum
              containing combustible material, and intrusion into areas containing solid or liquid
              combustible materials.

              Treatability tests should focus on performance requirements for the off-gas treatment
              system and the type and quantity of secondary waste generated.  Almost all soils can
              be  vitrified,  and this is generally not a serious  consideration during treatability
              testing.

              TABLE 6 identifies additional characteristics impacting in situ vitrification feasibility.
5/93                                         44

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ALTERNATIVE TREATMENTS
TABLE 6
WASTE CHARACTERISTICS
Waste Type: Soils and Sludges
Technology: In Situ Vitrification
Characteristics
Impacting Process
Feasibility
Presence of groundwater
and soil permeability less
than 1 x 10'$ cm/sec
Buried metals (drums)
occupying over 90% of
linear distance between
electrodes
Loosely packed rubbish,
buried coal
Combustible liquids*
(9,600 Ib/yd of depth or
7wt%)
Combustible packages*
(1.2 yd3 or 32 ft3)
Volatile metal content
and depth
Combustible liquids
Void volumes
Reason for Potential Impact
Severity limits economic practicality
because much energy will be
expended in driving off water.
Buried metals can result in a
conductive path that would lead to
electrical shorting between electrodes.
May start underground fire.
Time-ordered limits to the capacity of
the off-gas system to contain
combustion gas. Not cumulative
capacity.
Time-ordered limits to the capacity of
the off-gas system to contain
combustion gas. Not cumulative
capacity.
Retention of volatile metals in melt is
reduced as surface is approached.
Clean soil may be placed on top to
increase depth to which off-gas
treatment may be relied on.
9,600 Ib/yd of depth or 7% by
weight.
5-6 ydj or 152 ft3.
Data Collection
Requirements
Percolation test/water
table mapping
Site mapping
Site mapping
Site mapping, analysis
for priority pollutants,
feasibility testing
Site mapping, analysis
for priority pollutants,
feasibility testing
Site mapping analysis
for Cd, Pb, Hg, As


* Concentration limits are generic in nature; individual applications need to be reviewed in
detail.
Source:  Technology Screening Guide for Treatment of Soils and Sludges, EPA/540/2-88/004
5/93
45

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ALTERNATIVE TREATMENTS

       Thermal  Desorption

             Technology Description
             Thermal desorption technologies consist of a wide variety of processes that vaporize
             volatile and semivolatile organics from soil  or  sludge.   After desorption, the
             volatilized organics may be subsequently treated in an afterburner, or condensed for
             reuse or destruction in am incinerator.  Air pollution control (APC) equipment may
             be  used to treat  the exhaust gas by removing acid gas  (scrubber),  dust  and
             parti9ulates (cyclone, baghouse, or venturi), and residual organics (activated carbon
             adsorption unite). Although there are no generally  accepted definitions for grouping
             the different types  of thermal desorption, the following four terms may be used to
             describe the different processes:

             •      Low-temperature direct-fired desorber

             •      Low-temperature indirect-fired desorber'

             •      Oxygen-free thermal processors

             •      In situ  steam extraction
   Soils containing organics
   Heat(300°F-1200eF)
  Thermal
Desorption
Treated residual
Recovered contaminants
Water from ARC'
Treated offgases
Partlculate control dust
Spent carbon *
* D*p«r>clrtg on toehnoiogy
5/93
       46

-------
ALTERNATIVE TREATMENTS

              Low-Temperature Direct-Fired Desorber

              Direct fired systems use a fuel burner as a heat source which fires directly into the
              primary soil heating chamber.  These units operate at temperatures of less than SOOT
              and are generally applicable to the treatment of nonchlorinated  organics.  Exhaust
              gasses  from the rotating cylinder pass through a  dust collection system  prior to
              secondary combustion.  OH Materials, Inc. operates a low-temperature direct-fired
              desorber.

              Low-Temperature Indirect-Fired Desorber

              Indirectly heated systems use a heat transfer medium such as hot oil or an  external
              flame.  Heat may be transferred through metal surfaces to the waste or by externally
              heated  air.  Indirect heating results in greater control and lower volume of exhaust
              gas.  A low gas flow results in a low loading for the exhaust gas treatment and air
              pollution control systems.  This facilitates the use of more sophisticated emission
              control  equipment and the potential for treatment of chlorinated  hydrocarbons.
              Desorbed  organics  may be  condensed  an/or  removed  by  carbon adsorption.
              Examples of vendors for this technology include Canonie Environmental and Weston
              Services, Inc.   Canonie Environmental has a  low-temperature thermal  aeration
              system, which consists of a rotating dryer that heats incoming air from 300°F to
              600°F by an external flame. The system forces heated air countercurrent to  the flow
              of soils in a rotary drum dryer.   Weston Services has a low-temperature thermal
              stripping process, which uses a hollow  screw mixer that is filled with hot oil to heat
              the soil to approximately 450°F.

              Oxygen-Free Thermal Processors

              These processors operate with indirect heating at  higher temperatures (>600°F).
              They process soils and sludges in an  oxygen-free environment that  prevents
              oxidation/combustion and may  be used to treat  PCBs.  Two examples of  this
              technology are  Chemical Waste Management's X'TRAX System  and SoilTech's
              AOSTRA  Taciuk Processor.  Both processes recover contaminants for subsequent
              recycling or destruction.  The X*TRAX System uses a nitrogen atmosphere to keep
              the process oxygen free.  Waste is treated in an indirectly heated rotating  dryer at
              temperatures ranging from 600°F to 900°F.  The volatilized organics are carried to
              a gas treatment system that condenses  and recovers the contaminants.  The Taciuk
              process consists of a preheating chamber that operated at 300°F to 400°F, followed
              by a primary pyrolysis zone that operated at 1,100°F to 1,200°F.  Hydrocarbons are
              desorbed and then recovered in a condenser.

              In Situ Steam Extraction

              This process  uses hollow-stem drills to inject steam and hot air into the  ground.
              Volatile organics are stripped form  the soil (or groundwater)  and collected in  a
              shroud   at the  surface.   The  technology is  especially applicable  for  volatile


5/93                                        47

-------
ALTERNATIVE TREATMENTS
              contamination near the surface.  Toxic Treatments (USA) has used their unit to treat
              soil at a Superfund site.  Steam (at 450°F) and hot air (at 300°F) are injected through
              counter-rotating drills up to 30 feet in depth.  Volatile contaminants and water vapor
              are collected and removed from the off-gas stream by condensation

                     Application

                     •      Currently selected for 12 Superfund sites. Several variations on the
                            technology  exist.

                     •      See  article  on status of  thermal  remediation in the Incineration
                            chapter.

                     •      Operating at lower  temperatures, these processes use less fuel  than
                            incineration.

                     •      Decontaminated soil still retains some organics and soil properties (it
                            is not an ash).

                     Waste Characteristics Affecting Performance

                     •      Temperature and residence time are the primary factors affecting
                            performance.

                     •      Wastes with high moisture content significantly increase fuel use.

                     •      Fine  silt  and  clay may result in  greater  dust  loading  to the
                            downstream air pollution control equipment.
5/93                                        48

-------
VO
                                                          TABLE 7
                     STRENGTHS AND LIMITATIONS OF FOUR THERMAL DESORPTION PROCESSES
                                                                                                                              H
               Process;: Type
               Strengths
         Limitations
    Low-Temperature Direct-Fired
Relatively simple
Technology consists of primary combustion,
dust collection, and afterburner
Low cost
Appropriate for nonchlorinated hydrocarbons
Limited applicability
High exhaust gas flow rate
Likely to be considered same as an
incinerator by the public
    Low-Temperature Indirect-Fired
Low exhaust gas flow allows more
sophisticated air emission control equipment
Low air flow limits paniculate carryover
from primary chamber
May be used for chlorinated hydrocarbons
Afterburner not necessarily required;
condensed or adsorbed gases may be
removed offsite
Lack of direct combustion minimizes
formation of products of incomplete
combustion (PICs)
Operation at lower temperatures
may limit applicability to volatile
organics
    Oxygen-Free Thermal
Potential use on PCB waste
Hydrocarbons may be collected for offsite
destruction or reuse
Closed systems eliminate exhaust gases
Lower capacity and higher cost
than low-temperature direct- and
indirect-fired units
    In Situ Steam Extraction
May be used for volatile contamination near
the surface (where vacuum extraction is not
effective
Although not generally applicable
for semivolatiles, some removal
may take place

-------
ALTERNATIVE TREATMENTS
                                       TABLE 8
                             WASTE CHARACTERISTICS

  Waste Type:  Soils and Sludges
  Technology:  Low-Temperature Thermal Stripping
      Characteristics
     Impacting Process
         Feasibility
    Reason for Potential Impact
    Data Collection
     Requirements
  Presence of:
  •  Metals
  •  Inorganics
  •  Less volatile organics
Some processes effective only for
highly volatile organics (Henry's Law
Constant >3 x 10'3 atm-mVmole).
X*TRAX System can treat organics
with boiling points up to  about 800°F
Analysis for priority
pollutants
  pH
Corrosive effect on system
components
pH analysis
  Presence of mercury (Hg)
Boiling point of mercury (356°C)
close to operating temperature for
process (100°C to 300°C)
Analysis for mercury
  Unfavorable soil
  characteristics:
  •  High percent of clay
     or silt

  •  Tightly aggregated
     soil or hardpan

  •  Rocky soil or glacial
     till

  •  High moisture content
Fugitive dust emissions during
handling

Incomplete devolatilization during
heating

Rock fragments interfere with
processing

High energy input required.
Dewatering may be required as
pretreatment.
Grain size analysis


Soil sampling and
mapping

Soil mapping


Soil moisture content
Source: Technology Screening Guide for Treatment of Soils and Sludges, EPA/540/2-88/004
5/93
               50

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           United States       Office of Emergency and      Environmental
           Environmental Protection   Remedial Response         Response
           Agency          Emergency Response Division    Team
xvEPA
Treatment Technologies
for Superfund
           Workbook

-------
      TREATMENT TECHNOLOGIES FOR SUPERFUND (165.3)




                          WORKBOOK



                           CONTENTS










COMMONLY USED ACRONYMS IN HAZARDOUS WASTE MANAGEMENT  	1-4
CLASS PROBLEMS:






     Bulking Hazardous Waste	5-26






     Nampa, Idaho	27-32






     Houston, Missouri - PCP Incident	33-38






     Sydney Mines Waste Disposal Site	39-49

-------
     COMMONLY USED ACRONYMS IN HAZARDOUS WASTE MANAGEMENT
AA
ACGIH
AIHA
ANSI
ARAR
ARCS
ATSDR
BOAT
BM
BOD
CAA
CAG
CBD
CDC
CERCLA
CERCLIS
CERI
CFR
CHEMTREC
CHRIS
CMA
COD
COE
CRS
CWA
DE
DOA
DOD
DOE
DQI
DOJ
DOL
DOT
DQO
Assistant Administrator (EPA)
American Conference of Governmental Industrial Hygienists
American Industrial Hygiene Association
American National Standards Institute
Applicable or Relevant and Appropriate Requirement
Alternative Remedial Contracting Strategy
Agency for Toxic Substances and Disease Registry
Best Demonstrated Available Technology
Bureau of Mines
Biochemical Oxygen Demand
Clean Air Act
Cancer Assessment Group
Commerce Business Daily
Center for Disease Control
Comprehensive Environmental Response, Compensation, and Liability Act
CERCLA Information System
Center for Environmental Research Information
Code of Federal Regulations
Chemical Transportation Emergency Center
Chemical Hazard Response Information System
Chemical Manufacturers Association
Chemical Oxygen Demand
Corps of Engineers
Congressional Research Services
Clean Water Act
Destruction Efficiency
Department of Agriculture
Department of Defense
Department of Energy
Department of the Interior
Department of Justice
Department of Labor
Department of Transportation
Data Quality Objectives
5/93
                     1

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COMMONLY USED ACRONYMS IN HAZARDOUS WASTE MANAGEMENT CONT'D
ORE          -      Destruction and Removal Efficiency
EERU         -      Environmental Emergency Response Unit
EPTC         -      Extraction Procedure Toxicity Characteristics
EPA          -      Environmental Protection Agency
ERCS         -      Emergency Response Cleanup System
ERT          -      Environmental Response Team
FCO          -      Federal Coordinating Officer
FEMA         -      Federal Emergency Management Agency
FIFRA         -      Federal Insecticide, Fungicide, and Rodenticide Act
FIT           -      Field Investigation Team
FS            -      Feasibility Study
GAC          -      Granular Activated Carbon
GWA         -      Ground Water Act of 1987
HA           -      Health Assessment
HC           -      Hydrocarbon
HHS          -      Department of Health and Human Services
HRS          -      Hazard Ranking System
HSWA         -      Hazardous and Solid Waste Amendments (to RCRA, 1984)
IFB           -      Invitation for Bids
IUPAC        -      International Union of Pure and Applied Chemists
LUST         -      Leaking Underground Storage Tank
MCL         -      Maximum Contaminant Level
MCLG         -      Maximum Contaminant Level Goal
MSHA         -      Mine Safety and Health Administration
MSW         -      Municipal Solid Waste
NAS          -      National Academy of Sciences
NEAR         -      Nonbinding Preliminary Allocation of Responsibility
NCP          -      National Oil and Hazardous Substances Pollution Contingency Plan
NFPA         -      National Fire Protection Association
NIPSH        -      National Institute of Occupational Safety and Health
NOAA         -      National Oceanic and Atmospheric Administration
NPDES        -      National Pollutant Discharge Elimination System
NPL          -      National Priority List
NRC          -      National Regulatory Commission or National Response Center

5/93                                     2

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COMMONLY USED ACRONYMS IN HAZARDOUS WASTE MANAGEMENT CONT'D
NRT
NSF
NTIS
OERR
OHMTADS
O&M
ORD
OSC
OSHA
OSWER
OTA
PA
PAAT
PAC
PAH
PCDD
PCB
PCDF
PCP
PIAT
PIC
PM
POHC
POM
POTW
PRP
QA/QC
RA
RBC
RCRA
RD
RD&D
REMFIT
RFP
National Response Team
National Science Foundation
National Technical Information System
Office of Emergency and Remedial Response
Oil and Hazardous Materials Technical Assistance Data System
Operation and Maintenance
Office of Research and Development
On-Scene Coordinator
Occupational Safety and Health Administration
Office of Solid Waste and Emergency Response
Office of Technology Assessment
Preliminary Assessment
Public Affairs Assistance Team
Powdered Activated Carbon
Polycyclic Aromatic Hydrocarbons
Polychlorinated Dibenzo-p-dioxin
Polychlorinated Biphenyl
Polychlorinated Dibenzofuran
Pentachlorophenol
Public Information Assistance Team
Product of Incomplete Combustion
Project Manager
Principle Organic Hazardous Constituent
Polycyclic Organic Matter
Publicly  Owned Treatment Works
Potentially Responsible Party
Quality Assurance/Quality Control
Remedial Action or Regional Administrator
Rotating Biological Contactor
Resource Conservation and Recovery Act
Remedial Design
Research Development and Demonstration
Field Investigation Team for EPA Remedial Actions
Request for Proposal
5/93

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COMMONLY USED ACRONYMS IN HAZARDOUS WASTE MANAGEMENT CONT'D
RI/FS         -      Remedial Investigation/Feasibility Study
RO           -      Reverse Osmosis
ROD          -      Record of Decision
RPM          -      Regional Project Manager
RQ           -      Reportable Quantity
RRC          -      Regional Response Center
RRT          -      Regional Response Team
SARA         -      Superfund Amendments and Reauthorization Act
SITE          -      Superfund Innovative Technology Evaluation
SQG          -      Small Quantity Generator
SSC          -      Scientific Support Coordinator
SWDA        -      Solid Waste Disposal Act
TAT          -      Technical Assistance Team
TCLP         -      Toxicity Characteristic Leaching Procedure
T&E          -      Test and Evaluation Facility
TOC          -      Total Organic Carbon
TSCA         -      Toxic Substances Control Act
TSDF         -      Treatment, Storage, and Disposal Facility
TUHC         -      Total Unburned Hydrocarbons
USCG         -      United States Coast Guard
USGS         -      United States Geological Survey
VOC          -      Volatile Organic Chemical or Volatile Organic Compound
5/93

-------
CLASS PROBLEM:  BULKING HAZARDOUS WASTE
THE SITUATION:

A site that contains a minimum of 700 drums has been found in southwest Ohio.  The land is owned
by the Hamilton County Park District.  Representatives of the park district have stated that the site
is relatively inaccessible and they have no idea how the drums got there.

You have been assigned to remove the drums and dispose of them properly.  Furthermore, because
the  cost of removal must be minimized, you are to determine which drums you may safely bulk.

You started by preparing  the  site, staging the drums, and sampling each container.  You assigned
a field chemist the task of field categorization.  The results of the chemist's work can be found on
the  following pages.
ANSWER THE FOLLOWING QUESTIONS:

              1.     Which of the drums may be bulked safely? Why?

              2.     What other information may be helpful for you to complete
                    your job?

              3.     What are your major concerns about the bulking operation?
5/93

-------
                    HAZARDOUS WASTE CATEGORIES
            Drum ff_
            Drum #_
            Drum #_
            Drum #_
            Drum #
                              GROUP #1
                                TYPE:
Drum #_
Drum #_
Drum#_
Drum #_
Drum #
Drum #
Drum #
Drum #
Drum #
Drum #
GROUP #2
TYPE:
Drum #
Drum#
Drum#
Drum #
Drum #


Drum #
Drum #
Drum ti
Drum #
Drum #
GROUP #3
TYPE:
Drum #
Drum #
Drum #
Drum #
Drum #

5/93

-------
                    HAZARDOUS WASTE CATEGORIES
Drum #
Drum #
Drum #
Drum #
Drum #
GROUP #4
TYPE:
Drum #
Drum #
Drum #
Drum #
Drum #


Drum #
Drum ft
Drum #
Drum #
Drum #
GROUP #5
TYPE:
Drum #
Drum #
Drum #
Drum #
Drum #


            Drum#_
            Drum ti_
            Drum #_
            Drum #_
            Drum #
                              GROUP #6
                                TYPE:
Drum #_
Drum #_
Drum #_
Drum #_
Drum #
5/93

-------
                  HAZARDOUS WASTE CATEGORIES
Drum #
Drum #
Drum ft
Drum #
Drum #
GROUP #7
TYPE:
Drum #
Drum#
Drum #
Drum #
Drum #


Drum #
Drum #
Drum #
Drum #
Drum #
GROUP #8
TYPE:
Drum #
Drum #
Drum #
Drum #
Drum #

          DISCREPANCIES:
5/93

-------
                  HAZARDOUS WASTE CATEGORIES
          COMMENTS:
5/93

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FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
Drum Number:	       	  	  	
Drum Type and Condition:  £5 &AL.   C.H
Markings or Labels:
              Drum Location:
 5.
 7.
 8.
Drum Volume:
Drum Color	
Comments:	
                                     6.
                                           Solid Heel:
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:    A/6
Head Space PIP:  2OOO
pH:	£
Water Solubility:.
Specific Gravity:
Water Reactivity:
Flash Point:
                  ZOO °f
.Acid Solubility:  A/£.
Beilstein:.
Cyanide:_
Other:
           A/I.
                                     12.   ORP:
                                     15.   Density Gradient:
                                     19.
                                     21.
                                     23.
                                           Base Solubility :
                                           PCB:
                                            Sulfide:
5/93
                           11

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FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
Drum Number:_	
Drum Type and Condition: S5GAL    (Ltl
Markings or Labels:.
                                                       Poof
              Drum Location:
                         A
 5.
 7.
 8.
Drum Volume:.
Drum Color	
Comments:	
6.
                                           Solid Heel:
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:   ^
Head Space PIP:  /£
pH:	
                         -A/0  &AAIA/G-
Water Solubility:_
Specific Gravity:     /	
Water Reactivity:    A/O
Flash Point:   > ZOO V
Acid Solubility:
Beilstein:    A/ K,
Cyanide:   A/
Other:
                                     12.    ORP:    3%Q
                                     15.    Density Gradient:
                                     19.    Base Solubility:  M £.
                                     21.    PCB:_
                                     23.    Sulfide:
5/93
                          12

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
Drum Number:.
Drum Type and Condition
Markings or Labels.
              Drum Location:
                                                       */O A/f
 5.
 7.
 8.
Drum Volume:.
Drum Color	
Comments:	
                                     6.
                                           Solid Heel:
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:
Head Space PID:.
pH:	i
                   A/fe
                  A/O
                   /
Water Solubility:.
Specific Gravity:,
Water Reactivity:.
Flash Point:    > ZOO °f
Acid Solubility:
Beilstein:    A/ ^.
Cyanide:_
Other:
                                     12.    ORP:  
-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
 5.
 7.
 8.
Drum Number:
Drum Type and Condition:
Markings or Labels:   /.c
              Drum Location:
Drum Volume:.	
Drum Color     &AC.Z
Comments:	
                                     r  OZ.L  "
                                     6.
                                           Solid Heel:
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:    /OO
Head Space PIP:   2.OOQ
pH:	13.	
Water Solubility:_
Specific Gravity :_JI
Water Reactivity:_
Flash Point:   >HOr
Acid Solubility:  A/O
Beilstein:.
Cyanide:_
Other:
          A/1.
                                     12.    ORP:
                                     15.    Density Gradient:.
                                     19.
                                     21.
                                     23.
                                           Base Solubility:  A/0
                                           PCB:   A/- &.
Sulfide:
5/93
                          14

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
 5.
 7.
 8.
Drum Number:	
Drum Type and Condition: /2./Jsrz(L
Markings or Labels:.
                                               S &AL
             Drum Location:
Drum Volume:.
Drum Color	
Comments:	
                        A
                                    AXUH  /Saw
                                    6.
      Solid Heel:
                                        Z5
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:
Head Space PID:
pH:	/
Water Solubility:.
Specific Gravity:.
Water Reactivity:
Flash Point:
Acid Solubility:.
Beilstein:	
Cyanide:	
Other:	
                   Jfa
                  V&S
              A//g.
                                    12.    ORP:
                                    15.   Density Gradient:  A/OA/C
19.    Base Solubility:  A/ A?.
21.    PCB:	
23.    Sulfide:
5/93
                          15

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
Drum Number:
Drum Type and Condition: Oti   £5 &AL
Markings or Labels:
              Drum Location:
                                          4*JA
                          A
 5.
 7.
 8.
Drum Volume:.
Drum Color	
Comments:	
6.
                                            Solid Heel:
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
              :    V5 %
Head Space CGI
Head Space PIP:    2OOO
pH: _ ^.y
Water Solubility:
Specific Gravity:
                   /
Acid Solubility:_
Beilstein:    AJ.
Cyanide:	
Other:	
                                     12.    ORP:   A//.
15.    Density Gradient:  A/.
Water Reactivity:
Flash Point:   <  HO* f     > lOQ'F
                                     19.    Base Solubility:  A/0
                                     21.    PCB:	
                                     23.    Sulfide:
5/93
                           16

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
Drum Number:	
Drum Type and Condition:
Markings or Labels:   A/QA/C
                                               &AL
                              &A&A&C.C
              Drum Location:
                            A
 5.
 7.
 8.
Drum Volume:.
Drum Color	
Comments:	
               35-
6.
Solid Heel:
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:.
Head Space PIP:
oH:
Water Solubility:
Specific Gravity:   /
                           A&0\/^
Water Reactivity:
Flash Point:      > 2OO °-r
Acid Solubility:
Beilstein:	
Cyanide:	
Other:	
                                     12.    ORP:  V/O
                                     15.    Density Gradient:
                                     19.    Base Solubility:.
                                     21.    PCB:_
                                     23.    Sulfide:
5/93
                           17

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
 5.
 7.
 8.
Drum Number:	 _
Drum Type and Condition:
Markings or Labels:   (jO£*.OSZ. l/€
                                             55 fi-AL
             Drum Location:
                                                      XT
Drum Volume:.
Drum Color	
Comments:	
                                    6.    Solid Heel:  A/QA/C
 9.
10.
n.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:.
Head Space PIP:
pH:__/V
                  
-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
Drum Number:
Drum Type and Condition:  £t-1 65  &AL
Markings or Labels:
              Drum Location:
 5.
 7.
 8.
Drum Volume:    35
Drum Color	
Comments:	
                                     6.     Solid Heel:  A>6?A/£
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:   /OO
Head Space PIP:
pH:
Water Solubility:	
Specific Gravity:    /	
Water Reactivity:   A/QA/£
Flash Point:    < /GO °f
Acid Solubility:
Beilstein:	
Cyanide:	
Other:	
                                     12.    ORP:  3?O
                                     15.    Density Gradient:  M?A/£
                                     19.    Base Solubility:
                                     21.    PCB:	
                                     23.    Sulfide:
5/93
                           19

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
 5.
 7.
 8.
Drum Number:	
Drum Type and Condition:  I//  &OOA   55  GrtL.
Markings or Labels:.
Drum Location:
Drum Volume:
Drum Color	
Comments:
                                       A
                                     6.     Solid Heel:_/UW£
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:   < /
Head Space PIP:   2.OOO
PH:        7Q	
Water Solubility:   A/3	
Specific Gravity:  ^ /	
Water Reactivity:     AA &
Flash Point:      > ZOO °f
Acid Solubility:
Beilstein:	
Cyanide:	
Other:	
                                     12.    ORP:    3ZO
                                     15.    Density Gradient:
                                     19.    Base Solubility:
                                     21.    PCB:	
                                     23.    Sulfide:
5/93
                           20

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
Drum Number:.
Drum Type and Condition: 55 &AL
Markings or Labels:
                                             CM
              Drum Location:
 5.
 7.
 8.
Drum Volume:
Drum Color	
Comments:
                                            Solid Heel:
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:
Head Space PID:
PH:         ?-
                   i
Water Solubility:,
Specific Gravity:_
Water Reactivity:.
Flash Point:     > 2JOO *f
Acid Solubility:.
Beilstein:     // K. •
Cyanide:	
Other:	
                                      12.    ORP:
                                      15.    Density Gradient:
                                      19.
                                      21.
                                      23.
                                            Base Solubility:
                                            PCS:
                                            Sulfide:
5/93
                                         21

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
Drum Number:	
Drum Type and Condition:  55 CrAL
Markings or Labels:.
              Drum Location:
                             A
                                           /&*€
 5.
 7.
 8.
Drum Volume:.
Drum Color	
Comments:	
6.
                                            Solid Heel:
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:   /OP*?*
Head Space PIP:   2QOO
pH:         7. /
Water Solubility:	
Specific Gravity:    '
                                     12.    ORP:  3XO
                                     15.    Density Gradient:  A/OA/£
Water Reactivity:
Flash Point:   > IQP 'f    
-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
 5.
 7.
 8.
Drum Number:
Drum Type and Condition:^/ 65/j
Markings or Labels:  A/OM&
              Drum Location:
                            /O
Drum Volume:.
Drum Color	
Comments:	
                                            Solid Heel:
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:
Head Space PIP:
pH: _ ^
                  < / n
Water Solubility:   A/0
Specific Gravity:	'
Water Reactivity:	
Flash Point:     > ZOO °r
Acid Solubility:
Beilstein:	
Cyanide:	
Other:	
                                     12.    ORP:
                                     15.    Density Gradient:
                                     19.    Base Solubility:
                                     21.    PCB:	
                                     23.    Sulfide:
5/93
                           23

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
 5.
 7.
 8.
Drum Number:   //A/003
Drum Type and Condition: 5*5 CrAL 3T&C.L CH
Markings or Labels:
              Drum Location:
Drum Volume:
Drum Color
Comments:
                                     6.     Solid Heel:  A/Ofi/6.
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:  &O A
Head Space PIP:  2-OOO
pH:	6-O	
Water Solubility:
Specific Gravity:
                  A/O
Water Reactivity:_
Flash Point:    >/OO °:
Acid Solubility:  A/O
Beilstein:	
Cyanide:	
Other:	
                                     12.    ORP:
                                     15.    Density Gradient:
                                         *f
19.
21.
23.
                                           Base Solubility:   A/Q
                                           PCB:
                                           Sulfide:
5/93
                          24

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
 5.
 7.
 8.
Drum Number:,
Drum Type and Condition:
Markings or Labels:  /Jo/J£
                                ID
              Drum Location:
Drum Volume:.
Drum Color	
Comments:	
/
                                     6.     Solid Heel:  A/QA/t.
                                         SotrA
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:   < /
Head Space PIP:  A/*fJ6
pH:    /ff5o6AA  g £.Z
Water Solubility:.
Specific Gravity:    /
Water Reactivity:  A/0
Flash Point:
Acid Solubility:
Beilstein:_
Cyanide:_
Other:
            ///e
                                     12.    ORP:
                                     15.    Density Gradient:
           19.    Base Solubility:
           21.    PCB:	
           23.    Sulfide:
5/93
                          25

-------
FIELD ANALYSIS WORKSHEET
 1.
 2.
 3.
Drum Number:
               ANfoo I
                                3O &AL   SrGC.t
Drum Type and Condition:.
Markings or Labels.  AetQMTAHX*lATl*lGr
_^	AS-Z	
              Drum Location:
 5.
 7.
 8.
Drum Volume:.
Drum Color	
Comments:	
                                    6.
                                          Solid Heel:
 9.
10.
11.
13.
14.
16.
17.
18.
20.
22.
24.
Head Space CGI:   ^ >
Head Space PIP:    3
pH:  /^^A/. - 5.5"
Water Solubility:
Specific Gravity:
                  /
Water Reactivity:
Flash Point:
Acid Solubility:  //<<•
Beilstein:	
Cyanide:	
Other:	
                                    12.    ORP:
                                                  72^7
                                    15.    Density Gradient:
                                    19.
                                    21.
                                    23.
                                          Base Solubility: A/A-
                                          PCS:        A/1-
                                          Sulfide:
                                                     A//.
5/93
                          26

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CLASS PROBLEM:  NAMPA, IDAHO

THE SITUATION:

The aquifer underlying the city of Nampa, Idaho, has been contaminated with a light petroleum-type
material for a number of years. During certain times of the year, the water table is close to the
ground surface, causing these materials to collect in basement sumps and fumes to permeate buildings
in the downtown area.

Using the information supplied,  design a simple groundwater study that will determine:

               1.     Direction of groundwater flow.

               2.     The estimated extent  of contamination by the petroleum
                      materials.

               3.     The possible source.
THE APPROACH:

Plot on the accompanying map the height of the water column in each well (see TABLE 1 for well
data).  Establish a few equipotential surface  lines.  Assuming that the groundwater will flow in
pathways at right angles to these equipotential lines, determine general flow direction.  (The result
is a very simplified flow net.)

Well data in TABLE 1 will also provide information concerning observed contamination at each well
point. Using this information, estimate the extent of contamination and draw a rough outline on the
map of the plume.

After  establishing the location of the contamination and the possible source or sources,  prepare a
general approach to recovery.

       1.     What are the treatment concerns for the water recovered with the oil?

       2.     What are discharge considerations for this wastewater?

       3.     What kind of simple treatments might be applicable to render this wastewater
              suitable for discharge?

       4.     Are there any wastewater or oil storage difficulties?
5/93                                       27

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CLASS PROBLEM: NAMPA, IDAHO

ABBREVIATIONS USED ON MAP:      A    -     Trumbull Oil
                                  B    -     Town Pump
                                  C    -     Sinclair
                                  D    -     Chevron
                                  E    -     Union
                                  F    -     Fleetway
                                  G    -     Ace Oil
5/93                                28

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CLASS PROBLEM: NAMPA, IDAHO
TABLE 1
DATA ON TEST WELLS
Well Number
Water Column Elevations (ft)
Comments

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
2,474.77
2,474.34
2,473.74
2,473.50
2,473.44
2,473.19
2,473.95
2,474,24
2,475.64
2,475.27
2,475.33
2,474.94
2,475.53
2,476.05
2,476.03
2,477.60
2,478.44
2,477.58
2,476.83
2,476.55
2,477.06
2,477.98
2,477.68
2,477.70
2,475.78
Nothing observed
Nothing observed
HNU down hole 160
HNU down hole 150
HNU down hole 6
HNU down hole 6
HNU down hole 130
HNU down hole 130
Nothing observed
HNU down hole 150
HNU down hole 120
Nothing observed
Nothing observed
HNU in mud 200
Nothing observed
HNU down hole 8
Nothing observed
Nothing observed
HNU down hole 100
Nothing observed
Oily
Nothing observed
Nothing observed
Nothing observed
Running water
5/93
29

-------
CLASS PROBLEM:  NAMPA, IDAHO
TABLE 1
DATA ON TEST WELLS
Well Number
Water Column Elevations (ft)
Comments

26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
51
2,474.27
2,475.40
2,474.64
2,473.80
2,473.40
2,473.06
2,473.23
2,472.36
2,472.36
2,472.56
2,472.90
2,473.08
2,472.18
2,472.99
2,472.36
2,471.43
2,472.66
2,472.51
2,471.89
2,472.16
2,479.00
2,479.86
2,481.75
2,478.09
2,471.34
Nothing observed
HNU down hole 15
Nothing observed
Nothing observed
Nothing observed
HNU down hole 120
Nothing observed
Nothing observed
HNU down hole 50
HNU down hole 50
HNU in mud 200
Nothing observed
Black stained sand
Oily sand
Nothing observed
Nothing observed
Black stained sand
Nothing observed
Nothing observed
HNU in mud 50
Nothing observed
Nothing observed
Nothing observed
Nothing observed
Nothing observed
5/93
30

-------
CLASS PROBLEM: NAMPA, IDAHO
                              TABLE 1
                        DATA ON TEST WELLS
  Well Number
Water Column Elevations (ft)
Comments
52
S7
S8
Nl
N2
N3
N4
N5
N6
N7
N8
N9
N10
Nil
2,473.77
2,474.36
2,471.99
2,470.34
2,470.16
2,467.31
2,467.70
2,467.44
2,467.47
2,467.45
2,467.00
2,468.35
2,467.07
2,465.00
Nothing observed
Nothing observed
Nothing observed
Nothing observed
HNU down hole 15
HNU down hole 6
Nothing observed
Nothing observed
Nothing observed
Nothing observed
HNU down hole 100
Nothing observed
Nothing observed
Nothing observed
5/93
                  31

-------
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INDIAN  CREEK
                                 NAMPA,  IDAHO

-------
CLASS PROBLEM:  HOUSTON, MISSOURI - PCP INCIDENT
INCIDENT:

An aboveground storage tank collapsed from its supports, causing breach of the tank and subsequent
discharge of a large amount of oil containing a high concentration of pentachlorophenol (PCP).
LOCATION:

Houston Chemical Co., two and one-half miles south of Houston, Missouri.



BACKGROUND:

A representative of the Cairo Treating Plant of Houston Chemical Co. in Houston, Missouri, called
the EPA Regional Office at 8:30 a.m.', June 18, 1979, to report a four-day-old spill of an estimated
15,000 gallons of oil and pentachlorophenol (5-percent PCP by volume). This PCP/oil mixture is
used by the Cairo Plant as a preservative in a wood treatment process.  The initial  spiller's report
stated that the material had been contained by a dike and was being removed by a pump truck. The
spiller reported no problem with the cleanup and no potential for the product to enter drinking water
supplies.

At approximately 4:30 p.m., June 18, a Missouri conservation commission agent called the regional
spill  line and reported that  an  estimated 90 percent of the spilled product had escaped  the plant
containment structures and had been temporarily caught in a small farm pond, a tributary  to Hog
Creek and Big Piney River.  The pond reportedly was covered with a layer of PCP/oil and had very
little freeboard to prevent discharge if rain, which was predicted, occurred.

The threat of heavy rains and subsequent contamination of public drinking water supply (Big Piney
River) mandated immediate action.  On June  19,  representatives of the U.S.  Environmental
Protection Agency; U.S. Coast Guard; Occupational Safety and Health Administration; U.S. Food
and Drug Administration; U.S.  Army Corps of Engineers; Missouri Department of Health, Natural
Resources, Conservation, and Highways; and a commercial cleanup contractor met in Houston to
determine the  course of action to be followed  to alleviate the  threat to public health  and the
environment.

An early morning investigation  revealed that the large storage tank (21,300 gallons) collapsed after
being filled to capacity from a nearby mixing plant (see map).  The west (front) end of the tank
struck the ground, and the drain valve and pipe sheared off, causing continuous  discharge.  Total
spillage was estimated at 15,000 gallons.  The PCP/oil ran down a dirt driveway.  Some of the
materials filled the holding pit behind the mixing facility and overflowed through a drain pipe and


5/93                                       33

-------
CLASS PROBLEM: HOUSTON, MISSOURI - PCP INCIDENT
into a drainage ditch. The remainder of the mixture ran down the drive into the same drainage ditch.
The PCP/oil ran down the ditch, through a culvert, under a side road, then through a culvert under
U.S. Route 63 into a water  catch basin.  The material then traveled underground approximately 75
feet, leaching into a small pond (7/10 of an  acre, approximately 250 feet long, 122 feet wide, and
6 Vi feet deep). At the time of the investigation, the pond was covered with a Vi-inch  layer of
PCP/oil.  Under high water conditions, the water  overflows the pond at the  northeast corner
spillway, draining  into Hog Creek, then to the Big  Piney  River.  Further studies provided the
following information:

       •       There was a total fish  kill in the pond

       •       The tank was located in an undiked area, at the top of the ridge to the west

       •       The pond is at a 20-foot-lower elevation than the spill site

       •       The well located just south of the mixing facility was fouled by the PCP/oil

       •       There are a number of residential wells in the vicinity

       •       Pond temperature is 68°F.

Representatives of the Missouri Department of Conservation and the U.S. Fish and Wildlife Service
recommended a treatment level of 10 ppb in order to restore conditions  for aquatic life.
TASK:

       1.       Develop a control and cleanup plan for this situation.

       2.       Using the information provided in the scenario and supplemental fact sheet,
               solve the following problems:

               a.     Determine the volume in gallons of water in the pond.

               b.     Determine the volume in gallons of spilled material on the
                     pond surface.

               c.     Determine the percentage of the spilled material collected
                     on the surface of the pond.
5/93                                        34

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CLASS PROBLEM:  HOUSTON, MISSOURI - PCP INCIDENT
               d.     Determine the amount of PCP, in grams, in the pond water.
                     What assumptions, if any, must you make?

               e.     Under laboratory conditions it has been determined that one
                     brand of activated carbon has an adsorption capacity of 40
                     mg/g carbon.  How much of this carbon is required to
                     remove  all the PCP in the pond water?  (Calculate the
                     maximum that can be dissolved under optimum conditions.)

CONVERSION FACTORS:

                                  1.06 quarts = 1 liter

                                 1 gallon = 0.1337cu. ft.

                                 2.2 pounds =  1 kilogram

                       Solubility of PCP in water = 14 mg/1 @'68°F.



SUPPLEMENTARY FACT SHEET:

A report of a  "Penta" spill in Houston, Missouri, was received on the EPA  Action Line in the
Kansas City office.  The information was immediately  given to the emergency response section.

Phenol is a compound produced from coal tar and is used in making explosives and synthetic resins.
It is a strong corrosive poison.  Pentachlorophenol is produced by mixing phenol with chlorine. It
is used as a wood preservative to lengthen the life of structural wood products.  Its sodium salts are
widely used as pesticides.

EPA was concerned about the chemical getting into drinking water supplies because ingestion causes
lung, liver, and kidney damage.

EPA became  involved  when conversations with the  spiller and a  Missouri  conservation  agent
revealed that the actions taken by the spiller were inadequate to protect public health.

The Regional Response Team was activated to evaluate the situation and determine whether a federal
cleanup would  be necessary to protect public health and environmental resources.

The Regional Response Team is composed of representatives from federal and state agencies who
can contribute to the identification of hazards and cleanup actions.


5/93                                       35

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CLASS PROBLEM: HOUSTON, MISSOURI - PCP INCIDENT
Federal and state involvement is recommended for spills from 10 pounds up.

The contaminated soil must be removed because the chemical will remain toxic for an indefinite
period of time.

The contaminated soil will be disposed of at Bob's Home Service Landfill in Wright City, Missouri.
This is (was) an approved permitted landfill.

If the spiller had provided for onsite spill retention, the cost of the cleanup would have amounted
to approximately $5,000. Without such precautions, the estimated cleanup is $500,000.
5/93                                     36

-------
vo
UJ
               North
                                                                          Mtxina bld£.  \Storage

                                                                                          tank   v. 15,000 f>al

                                                                                            	1  '
                                                                                            o	I «-







                                                                                        'cylindrical

                                                                                       storage  tank

                                                                                       21,300 gal-
                                     to Houston,

                                     Missouri

                                     1.5 miles
Water catch basin

(man-made)
                                                                         Dry drainage  ditch
                                                                   old U.S.  63
                                                                                                                 O
                                                                                    oo
                                                                                    V)


                                                                                    8
                                                                                    O
                                                                                    W
                                                                                    g
                                                                                    2
                                                                                    C/3

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                                                                                                                 o
                                                                                                                 2:
                                                                                                                 n
                                     MAP FOR HOUSTON, MISSOURI - PCP INCIDENT

-------
CLASS PROBLEM:  SYDNEY MINES WASTE DISPOSAL SITE
HISTORY:

The site is located in Hillsborough County, Florida, on land that was stripmined for phosphate ore
during the 1930s and  1950s, and then abandoned.  Hillsborough County leased the site in 1973 as
a permitted solid waste disposal facility and constructed a sludge pond for disposal of grease trap,
septic waste, and waste oil.  A second pond was added in  1979 to separate the disposal of septic
waste from oil waste.  These two surface impoundments are the primary disposal facilities onsite.
The septic waste pond occupies 6,070 square meters (1.5 acres); the smaller oil waste pond covers
2,430 square meters (0.6 acres).  The disposal area of concern covers approximately 10 acres in a
mining area of over 100 acres.

The county ceased waste disposal activities at the site  in November 1981 and retained  a consultant
in June  1982 to  assist  in filing  a  site  closure application  with  the Florida Department of
Environmental Regulation.  Previous site investigations and additional intensive sampling indicated
toxic organics were present in the  disposal ponds and  the perched  groundwater table below the
ponds. The consultant was  retained  to provide engineering design and construction management for
remedial activities.

The waste disposal ponds are located above an  area  that was mined  twice and reclaimed by
backfilling with  phosphatic clay wastes called slimes.   Perimeter retention dikes  were constructed
during mining operations to form clay, slime-settling  ponds.  The highly impermeable slimes are
covered with tailing sands from 1 to 6 meters (20 feet) deep.  A perched water table recharged by
rainfall has developed in the sand tailings, as shown in the figure below.  This perched water table
is not used for water supply.  It is separated from the Floridian aquifer, which lies  approximately
90 meters (300 feet) below  land surface, by the clay slimes and the natural clay strata that underlie
the  clay slimes.

The disturbed, rather than natural, geological setting of the waste disposal ponds has created unique
circumstances of contaminant migration.  The perched water table has no  outlet  for groundwater
flow, except  during rainy periods when a rising  water table allows flow into the northern settling
pond dike wall.

Surface cleanup is the most complex portion of the Sydney Mine site closure. Waste disposal pond
contents, including oil, sludges, and contaminated bottom sands, must be treated and/or disposed of
in an acceptable  and cost-efficient manner.

The septic waste pond covers approximately 1.5 acres, is 200 feet wide by 300 feet long, and is 10
feet deep in tailing sands 20 feet thick. Because of drought conditions, free liquids have evaporated,
leaving concentrated toxic organic sludge nearly  5  feet deep.  Sampling of pond contents (EP Tox
and  heavy metals  and pesticides) showed wastes  to  be within  RCRA toxicity  limits.   Oil
contamination is visible in  the sand.  Lateral seepage is limited to 1 foot and vertical seepage  is
approximately 5  feet.


5/93                                        39

-------
CLASS PROBLEM: SYDNEY MINES WASTE DISPOSAL SITE
             Perched
           Water Table
            Contaminant                Septic Wastes
                 Flow                         Pond
                   \       Oil  Waste  Pond        I
                                   /  /-	N    1
         Clay  Slimes
 /'  /   / Unmiried  Impermeable Layer
.'S'S.tfst'     •
                                                                   -^
The oil disposal pond is deeper than the septic waste pond and extends almost into the clay slimes.
The pond is 150 feet wide, 175 feet long, and 18 feet deep. There are waxes, emulsified oils, VOC-
contaminated waters, and floating oils in the pond with an estimated 2 feet of sludge in the bottom.
Liquids (including the sludge) are 10 feet deep in the pond. Lateral seepage is limited to 1 foot and
vertical seepage extends to the clay slimes.
INSTRUCTIONS PART I:

      1.       Estimate the volume of sands and sludges to be excavated.

              a.     Use a depth of 20 feet for the tailing sands.

              b.     The septic  pond is empty of water but contains 2 feet of
                    sludge.
5/93
                           40

-------
CLASS PROBLEM:  SYDNEY MINES WASTE DISPOSAL SITE
               c.     The oil pond contains liquids, floating product, and 2 feet
                      of sludge.  Liquids will go to a separator.  The  separator
                      process will generate 2 tons of sludge that will subsequently
                      be disposed of with the solids.

               d.     Use a lateral  seepage distance of 1  foot.

               e.     Vertical seepage can be estimated to extend 5 feet.

       2.       Using a soil density  of 118  pounds per cubic foot, calculate the tonnage of
               excavated soil.

       3.       Determine the cost of treatment and disposal for the following alternatives:

               a.     Excavation costs for all alternatives

                                   can dig 1,200 cu. yds. per day
                                   costs $1,970 per day
               b.     Landfilling
                                   costs per ton shipping $75.00
                                   cost per ton placement $100.00
                                   analysis costs $30,000
                                   continued responsibility
               c.     Stabilization and in situ placement
                                   costs per ton $150.00
                                   analysis cost $20,000
                                   continued monitoring, extra costs
                                   continued responsibility
               d.     Incineration onsite
                                   cost per ton $190.00
                                   includes ash disposal and setup.

       4.       Based on cost and other concerns, select a treatment method(s).
5/93                                        41

-------
CLASS PROBLEM:  SYDNEY MINES WASTE DISPOSAL SITE
A 10-acre area surrounding the waste ponds is isolated by the construction of a slurry trench cutoff
wall.  The total depth of tailing sands  is 20 feet, but the saturated thickness is only 10 feet.  The
ultimate porosity or volume of voids to total volume is 0.40.
INSTRUCTIONS PART II:

       1.       Using the saturated volume and the porosity, calculate water content.

       2.       There are 40 pumps providing an average of 6 gpm to an equalization tank
               of 200,000 gal. Calculate detention time in the tank  (volume/flow rate =
               time).

The  following pages contain information of the groundwater  contaminant  constituents,  chemical
information, a list of conditions concerning treatment, and four treatment descriptions. Construction
costs, operation and maintenance costs per unit, and efficiencies are provided for each.

       3.       Using efficiencies, select a treatment unit or units to  treat the groundwater
               wastestream to the specified discharge limits.

                      1 ppb volatile organics or detection limits
                      10 ppb extractable organics or detection limits
                      design of each unit has been preselected

       4.       Calculate the annual cost of treatment.

                      spread construction costs over 5 years.
                      flow rate is 200,000 gpd (5 years of treatment)
                      cost analysis is greatly simplified and not demonstrative of
                      a complete cost-benefit analysis
CONDITIONS:

       1.       Treatment units in packet were selected to meet the ARARs in general sense.

       2.       Unit design features such as size, retention time, overflow rates, and other
               parameters were preselected.  Design of the units themselves would be an
               effort beyond the scope of this course.



5/93                                       42

-------
CLASS PROBLEM: SYDNEY MINES WASTE DISPOSAL SITE
       3.       Cost  factors  were calculated  using  averages and  only  gross  costs are
               provided for  simplicity.  Actual cost-benefit comparisons are much more
               complex and would be too time-consuming for the course.

       4.       All removal efficiencies were arbitrarily selected from averages and would
               not necessarily hold true for a specific wastestream.

       5.       The selection of appropriate treatment systems is much more complex than
               is possible to simulate in detail within the time constraints of this  course.
               However, every effort has been made to provide a problem that covers the
               most important aspects of the process.
INFLUENT FLOW RATE
200,000 GPD
DISCHARGE LIMITS
1 ppb volatile organics and
10 ppb extractable organics and pesticides or detection
limits
DURATION OF TREATMENT
Five years estimated duration would naturally vary for
different treatment  systems, but the time has been
established   for  the  problem   set  to  simplify
comparisons.
5/93
  43

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CLASS PROBLEM:  SYDNEY MINES WASTE DISPOSAL SITE
DISCHARGE WILL BE THROUGH AN ONSITE IRRIGATION SYSTEM

Irrigation will  be over the site, providing a flush of the contaminated  area.  Concentrations of
contaminants in the influent will decrease as treatment progresses.  This decreasing load would make
it necessary to design considerable flexibility of treatment into each unit. For our purposes, assume
that the design of each unit takes this need into account.

       1.       Only construction and operation and maintenance costs will be considered.
               Salvage, depreciation, replacement, and interest costs will be ignored.

       2.       Suspended solids content in the groundwater wastestream is 20 ppm.

       3.       The solids in the oil pond waste will require removal.  Oil pond waters after
               oil/water separation will be  included in  the  water treatment  system.
               Approximately 2 tons of sludge will  be generated.

       4.       Design concentrations will be provided in a table and will represent the total
               wastestream to be treated.

       5.       Discharge limits on all  compounds are one ppb, and 10 ppb or  detection
               limits.

       6.       Units provided in the packet can meet necessary regulations in operation, if
               not alone, then in combination with another  in the packet.

                              DESIGN CONCENTRATIONS
                           Benzene                          100 ng/\
                           Carbon Tetrachloride              100 /xg/1
                           Chloroform                      <20/*g/l
                           1,1-Dichloroethane                  25 /ig/1
                           1,2-Dichloroethane                  50 /ig/1
                           1,1-Dichloroethene                 200 /ig/1
                           rra/w-l,2-Dichloroethene            30 /ig/1
                           Methylene Chloride               1000 /ig/1
                           1,1,1-Trichloroethane               50 /ig/1
                           Trichloroethylene                 100 /ig/1
                           Toluene                          500 /ig/1
                           Vinyl  Chloride                     50 /ig/1
                           Pentachlorophenol                 250 /ig/1
                           2,4-D                             50 /*g/l
                           2,4,5-TP                           30 /ig/1
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CLASS PROBLEM: SYDNEY MINES WASTE DISPOSAL SITE
VOLATILE ORGANICS:
BENZENE
CARBON TETRACHLORIDE
CHLOROFORM
1,1-DICHLOROETHANE
1,2-DICHLOROETHANE
1,1 -DICHLOROETHENE
solubility - l,780mg/l
Henry's Law constant - .00559 atm-m3/mole
adsorption - 76 mg compound/g carbon
biodegradation - degradable

solubility - 800 mg/1
Henry's Law constant - 0.0241 atm-m3/mole
adsorption - 76 mg compound/g carbon
biodegradation - refractory/nondegradable

solubility - 8,000 mg/1
Henry's Law constant - 0.00278 atm-mVmole
adsorption - 1.6 mg compound/g carbon
biodegradation - refractory to nondegradable

solubility - 5,500 mg/1
Henry's Law constant - 0.00431 atm-mVmole
adsorption -
biodegradation - degradable

solubility - 8,520 mg/1
Henry's Law constant - 0.000978 atm-mVmole
adsorption -
biodegradation - degradable

solubility - 2,250 mg/1
Henry's Law constant - 0.0340 atm-m3/mole
adsorption -
biodegradation - degradable
TRANS-1.2-DICHLOROETHANE  solubility - 6,300 mg/1
                               Henry's Law constant - 0.00656 atm-mVmole
                               adsorption -
                               biodegradation - degradable
METHYLENE CHLORIDE
solubility - 20,000 mg/1
Henry's Law constant - 0.00203 atm-m3/mole
adsorption -  2.7 mg compound/g carbon
biodegradation - degradable
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CLASS PROBLEM: SYDNEY MINES WASTE DISPOSAL SITE
1,1,1 -TRICHLOROETHANE
TRICHLOROETHYLENE
TOLUENE
VINYL CHLORIDE
solubility - 4,400 mg/1
Henry's Law constant - 0.0144 atm-m3/mole
adsorption -  155 mg compound/g carbon
biodegradation - degradable

solubility - 1,100 mg/1
Henry's Law constant - 0.0091 atm-nWmole
adsorption -  140 mg compound/g carbon
biodegradation - refractory

solubility - 515 mg/1
Henry's Law constant - 0.00637 atm-nWmole
adsorption -  147 mg compound/g carbon
biodegradation - degradable

solubility - 1.1 mg/1
Henry's Law constant - 0.0891 atm-nWmole
adsorption -  trace
biodegradation - refractory
EXTRACTABLE ORGANICS:
PENTACHLOROPHENOL
solubility - 14 mg/1
biodegradation - degradable
PESTICIDES AND PCBs:

2,4-D



2,4,5-TP
solubility - 890 mg/1
biodegradation - degradable
adsorption - trace

solubility - 278 mg/1
biodegradation - refractory
adsorption - trace
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        46

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CLASS PROBLEM:  SYDNEY MINES WASTE DISPOSAL SITE
CONSTRUCTION COSTS

Air stripping unit:  $50,000

Steam stripping unit:  $75,000

Carbon adsorption unit:  $50,000

Rotating biological contactor unit:  $60,000

Oil/water separation unit: $15,000 includes solids removal

Units are sized to accommodate 200,000 gpd which is the design flow rate of our system.

Costs are generic and may not reflect actual system costs in an area.



OIL/WATER SEPARATION

Oil pond is separated into free oils, sludges, and an  aqueous portion.  Using NaOH, alum and a
polymer, solids are flocced and settled from the aqueous portion after which they are passed through
a filter unit and pumped to the equalization tank in the groundwater treatment system. Free oil and
the hydroxide sludges are to be incinerated.

Cost per 1,000 gallons:  $0.03

Concentration of contaminants is included in design concentrations for groundwater treatment system.

In actual  practice, such additions to the groundwater would be a major increase in load over the
period the pond wastes are treated.  The shock of the load can be dampened by dilution  in the
equalization tank.
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CLASS PROBLEM: SYDNEY MINES WASTE DISPOSAL SITE
AIR STRIPPING

Limits:  Compounds with a Henry's Law constant greater than 0.003 atm-m3/mole.

Efficiency:  Removal to 98 percent, lower efficiencies for compounds out of limits.

Cost per 1,000 gallons:  $0.04 exclusive of vapor treatment.

Design  features such as tower fabrication, media selection,  and air to water ratio have been
optimized for the problem.



STEAM STRIPPING

Limits:  Organic compounds
        Henry's Law constant of 0.0004 atm-m3/mole or greater
        Vapor treatment unnecessary

Efficiency:  99 percent

Cost per 1,000 gallons:  $0.80

Unit design features  optimized as part of problem.



CARBON ADSORPTION

Limits:  Low solubility (less than 1 or 2 percent)
        Nonpolar
        Adsorptive capacity 50 mg/g carbon
        Concentration below 1 percent
        Suspended solids less than 50 ppm
        Oil and grease less than 10 ppm

Efficiency:  Varies with wastestream for the purpose of this exercise.  If the compound meets the
constraints in the limits listed above, the removal rate will  be 90 percent.   Do not consider
regeneration for the exercise.

Cost per 1,000 gallons:  $0.25 if used primary unit
                      $0.05 if used as a polish unit


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CLASS PROBLEM: SYDNEY MINES WASTE DISPOSAL SITE
BIOLOGICAL TREATMENT

Limits: Compound degradable
       Nontoxic concentrations
       BOD greater than 50 mg/1

Efficiency: Degradable compound removal 95 percent
          Refractory compound removal 30 percent

Cost per 1,000 gallons: $0.03

Unit is an RBC and has been sized for the problem.  Removal rates of refractory compounds are
arbitrarily selected at 30 percent for the problem.
CALCULATIONS
               PART 1:

      A.      Volume to be excavated

      B.      Weight of excavated sands

      C.      Disposal cost totals

      D.      Disposal method selected
                   PART 2:

          A.      Water content

          B.      Retention time of equalization
                  tank

          C.      Treatment unit selection

          D.      Annual cost of treatment
5/93
49

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     SOURCES FOR U.S. ENVIRONMENTAL PROTECTION AGENCY DOCUMENTS
Center for Environmental Research Information (CERT) (no charge for documents)

       Center for Environmental Research Information (CERI)
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      Public Information Center (PIC)
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      PM-211B
      401 M Street,  S.W.
      Washington, D.C. 20460
      (202) 382-2080             FTS 8-382-2080
Superfund Docket and Information Center (SDIC)

      U.S. Environmental Protection Agency
      Superfund Docket and Information Center (SDIC)
      OS-245
      401 M Street, S.W.
      Washington, D.C. 20460
      (202) 260-6940             FTS 8-382-6940
National Technical Information Services (NTIS) (cost varies)

      National Technical Information Services (NTIS)
      U.S. Department of Commerce
      5285 Port Royal Road
      Springfield, VA 22161
      (703) 487-4650             l-800-553-NTIS(6847)
Superintendent of Documents

      Government Printing Office
      (202) 783-3238
5/93

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