TD367
.R37                                   OOD82003              DRAFT
1982y
Vol. 3
                             RCRA GUIDANCE DOCUMENT


                                 LAND TREATMENT        tC" ^ 
                                                                          'D
                     [to be  used with  Subpart M,  Part 264
                           of  the RCRA Regulations]
      U.S. Environmental Protection Agency
      fttgion 5, Library (PL-12J)
      r> West Jecfcson eoufevard, 12th ftp*
      C*kego,tt  60604-3590

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                         TABLE OF CONTENTS
                                                               Page

 A.   Purpose and Use	1

 B.   "Treatment" Demonstration  [264.272]	3

       I.  The Regulations

       2.  Guidance

       3.  Discussion

 C.   Design and Operating Requirements  [264.273]	9

      I.  Maximization of Treatment	9

          1.  The Regulations

          2.  Guidance

          3.  Discussion

     II.  Minimization of Run-off	18

          1.  The Regulations

          2.  Guidance

          3.  Discussion

    III.  Management of Collected Run-on/Run-off	23

          1.  The Regulations

          2.  Guidance

          3.  Discussion

     IV.  Wind Dispersal Control	27

          1.  The Regulations

          2.  Guidance

          3.  Discussion
Environments r-..-;  ,:{;n Agency

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                                                             Page




D.   Unsaturated Zone Monitoring [264.278]	32



    I.   Selection of "Principal Hazardous Constituents"	32




        1.   The Regulations



        2.   Guidance



        3.   Discussion



    II.  Monitoring Procedure	35




         1.  The Regulations



         2.  Guidance



         3.  Discussion




   III.  Evaluation and Response	48



         1.  The Regulations




         2.  Guidance



         3.  Discussion



E.   Closure and Post-Closure Care [264.280]	51




         1.  The Regulations



         2.  Guidance



         3.  Discussion



References	60



Appendix I

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A.   Purpose and Use



     Under the authority of Subtitle C of the Resource Conservation



and Recovery Act (RCRA), EPA has promulgated interim-final




regulations for the treatment and disposal of hazardous waste in



land treatment units (40 CFR Part 264).  This guidance




document presents land treatment unit design and operating



specifications which the Agency believes comply with the Treatment-



Demonstration Requirements (264.272), the Design and Operating




Requirements (264.273), the Unsaturated Zone Monitoring Requirements



(264.278) and the Closure and Post-Closure Requirements (264.280)



contained in these regulations.



     Section 264.272 requires the owner or operator to demonstrate



that hazardous constituents in the applied wastes can be completely



degraded, transformed, or immobilized in the treatment zone. The




data used for the treatment demonstration must be generated under



conditions similar to those present in the treatment zone of the



facility.




     Section 264.273 provides the design and many of the operating



requirements necessary at land treatment units.  It focuses



particularly on requirements which are designed to maximize



treatment of hazardous constituents within the treatment zone and



minimize the escape of these constituents to ground water,



surface water, and air.  Section 264.278 contains the unsaturated




zone monitoring requirements which are aimed at evaluating the



performance of the unit, while Section 264.280 delineates



the closure and post-closure care provisions.

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     The requirements in all of the Sections mentioned above




consist of performance-oriented statements and rules, and, as




a result, are also general in nature.  This provides maximum



flexibility to the owner or operator in locating, designing,



operating, and closing his unity.  However, while this approach




provides flexibility, it lacks certainty because the permitting



official must render a value judgment on the acceptability of




the particular design, operation, and closure specifications proposed



for each given unit.  As a result, there will be considerable



negotiation during permitting when this approach is used.




     To provide additional certainty to this permitting



process, this document identifies specific designs and operational



procedures which the Agency believes accomplish the performance



requirements in Sections 264.272, 264.273, 264.278, and 264.280.




Permit applicants who design, construct, operate, and close



their units in accordance with the specifications contained




herein will be considered in compliance with these Sections.



     The Agency wishes to emphasize that the specifications in



this document are guidance, not regulations.  EPA is not



requiring, and does not intend, that all land treatment units be



designed and operated in this way.  On the contrary, the Agency be-



lieves there are other designs and operating procedures which may be



acceptably used, depending on unit-specific factors. Detailed



discussions of various land treatment design and operational



approaches, including those recommended in this document,



are provided in the EPA technical resource document

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entitled Hazardous Waste Land Treatment (1).  Owners or operators



who wish to utilize a very different design or operation than



those recommended herein may do so by providing sufficient data



to the permitting official which demonstrates compliance with



the various performance requirements.




     This document is arranged according to the section of the



regulation to which it corresponds.  EPA is particularly interested




in information and suggestions concerning the usefulness of this




document, expansion of it, and the effectiveness of the guidance



in ensuring compliance with the performance requirements in the



regulations.  Those wishing to send technical information or




suggestions concerning this document should address them to:



Rod Jenkins, Chief, Land Disposal Branch, Office of Solid Waste



(WH-565E), U.S. Environmental Protection Agency, 401 M Street,




S.W., Washington, D.C. 20460.



B.   "Treatment" Demonstration [264.272]




     1.  The Regulations



     Section 264.272 states that the owner or operator must



demonstrate with literature, experimental and/or operating data,



that hazardous constituents in the applied wastes can be completely



degraded, transformed, or immobilized in the treatment zone of



the unit.  The demnstration must be based on conditions



similar to those in the treatment zone.  "Treatment zone" is



defined as the portion of the unsaturated zone below and including



the land surface in which the owner or operator intends to maintain



the conditions necessary for effective degradation, transformation,

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immobilization.  [The dimensions of this zone will be specified



in the permit.  Section 264.271 specifies that the maximum depth



of the treatment zone must be (a) no more than 1.5 meters




(5 feet) from the initial soil surface, and (b) more than one meter



(3 feet) above the seasonal high water table.]



     2.   Guidance




     a.   Comprehensive waste analysis data should be used to




identify hazardous constituents present in the waste in significant



concentrations.




     b.   A thorough literature search should be conducted on each



hazardous constituent present in the waste.  Available information



on (and factors affecting) the degradation, transformation,




immobilization, and toxicity of each hazardous constituent,



under conditions similar to those present in the treatment zone



of the facility, should be gathered.




     c.   If sufficient data to support the demonstration of



treatment is unavailable in the literature, the owner or operator



should conduct laboratory studies to examine the fate and effects



of hazardous constituents in the soil system and to determine



the impacts of various environmental factors or treatment processes.



Laboratory studies should include, at a minimum, studies addressing




degradation, transformation, mobility, and toxicity of hazardous



constituents.  The environmental factors that should be examined



include at least soil pH, temperature, and moisture.



     d.   Field pilot studies should be conducted to verify certain



laboratory results, discover any unforeseen potential environmental

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problems, and investigate interactions which cannot be adequately




assessed in the laboratory.



     e.  The owner or operators of existing (interim status)



units should consider the use of actual monitoring



data, in lieu of laboratory and field studies, to make the




treatment demonstration.  Such monitoring data should include



results from comprehensive soil core (including treatment zone)



soil pore-liquid, ground water, run-off, and air monitoring




generated over an extended period (i.e., several years)  of unit



operation.   This data should clearly demonstrate treatment with



no unacceptable release of hazardous constituents or hazardous



degradation products from the treatment zone.



     f.  All data used directly to support the treatment



demonstration should be generated under conditions which simulate




at least the following characteristics of the unit:



     (i)  characteristics of the land-treated waste;



    (ii)  characteristics of the treatment zone including the



soil texture, pH, cation exchange capacity, organic matter



content, moisture content, and depth of soil to the seasonal



high water table;



   (iii)  topography of the treatment zone including slope;



    (iv)  climate of the area including temperature, precipitation,



evaporation, and wind patterns; and




     (v)  operating practices including waste application method



and rate, tilling depth and frequency, and soil conditioning



practices (e.g., pH adjustment, fertilization, etc.).

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     3.  Discussion




     The treatment demonstration required under 264.272 can be



accomplished using information derived from published literature,



laboratory studies, field studies and/or actual land treatment unit




operation experience (i.e.,  monitoring results).   Successful demon-



strations will most often involve data obtained from several of the



above sources.




     A literature search on  each hazardous constituent in the



particular waste in question should first be conducted.   Information



in the published literature  may assist in the design of  laboratory



or field experiments, or significantly reduce or eliminate the



need for additional experimentation.    However, to completely



eliminate the need for additional testing, comprehensive literature




data on the degradation, transformation, mobility, and toxicity



of hazardous constituents under conditions similar to the treatment



zone must be clearly documented.  Such literature data must also



have been subjected to a thorough peer review.   However, the



Agency believes that for most land treated hazardous wastes, an



inadequate data base is available in  the literature to conclusively



predict the fate of particular hazardous constituents under



particular site-specific conditions.



     Therefore, a combination of laboratory and field studies



often will be necessary to provide the required treatability




data.  Laboratory studies may be used as rapid screening techniques



for examining, within a reasonable time frame,  the treatment of




hazardous constituents  in a soil system, and the effects of

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various environmental factors on this treatment.  These studies




should include tests directly addressing the degradation,



transformation, and mobility of the hazardous constituents in



the waste.  The Agency suggests the use of soil respirometry




tests and/or organic constituent analysis and characterization



studies conducted over time to examine hazardous constituent



degradation and transformation.  Soil thin-layer chromatography




tests or column leaching studies (using undisturbed soils



collected from the field) may be used to examine constituent



mobility.  Discussion of the advantages and disadvantages of



each of these tests, and specific procedures for completing




them are provided in Hazardous Waste Land Treatment (1).



     In addition, laboratory studies (and field studies)  should




evaluate the potential toxicity of hazardous constituents in the




waste to microbes and plants.  Prevention of microbial toxicity



is important to ensure successful biodegradation of degradable



waste constituents, while phytotoxicity must be limited in order



that an effective vegetative cover may be established.  Suggested



procedures for completing these studies are also provided by EPA's



technical resource document on land treatment (1).



     While laboratory tests provide valuable data,  the



extrapolation of this data to field conditions is often difficult



because of the complex interactions that occur in the field.



Therefore, the Agency believes that field studies usually will



be necessary to verify certain lab-generated results.   The extent



of verification required will depend on a number of factors

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including the variability in the laboratory test results, and




specific waste and land treatment unit characteristics.   The Regional



Administrator will determine the extent of field verification



necessary.




     Field pilot studies should be kept as small as possible.



Generally, plots should be no greater than 500 m^,  unless




specialized equipment requires additional room for waste application




or incorporation.  In general, waste application rates and treatment



zone conditions (e.g., pH maintenance) must be selected based on



the best available information obtained from the literature,



laboratory studies, and previous experience.



     It may be possible to demonstrate the treatment of hazardous



constituents in a particular waste based solely on previous land




treatment unit monitoring data.  This monitoring data, however, must



be comprehensive and clearly demonstrate degradation or transformation



of hazardous organic constituents within the treatment zone and



no unacceptable migration of any hazardous constituents to below



the treatment zone.



     Finally, any data, regardless of the source, which is used to



support the demonstration of treatment must be generated under



conditions similar to those present in the land treatment unit.



Specific unit characteristics the owner or operator should consider




are outlined in the guidance section above.  The Regional



Administrator may require the owner or operator to consider



additional characteristics which may be very important at a



specific unit.  With  regard to treatment zone characteristics,

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the Agency believes that the series classification will usually



adequately define the necessary similarities of soils; the soil



phase should also be considered in evaluating similarities in




surface soils.



C.  Design and Operating Requirements [264.273]



     I.  Maximization of Treatment  [264.273(a)]



     1.  The Regulations



     The performance standard delineated in 264.273(a) requires



owners and operators to design, construct,  operate, and maintain




the land treatment unit such that the treatment of hazardous



constituents by degradation, transformation, or immobilization,



is maximized within the treatment zone.




     2.  Guidance



     a)  A land treatment unit should be located,  designed,



and constructed so that the treatment zone  contains soils having



one or more of the following textures (USDA Classification):



loam, silt loam, sandy clay loam, sandy loam, silty clay loam,



or clay loam.




     b)  A land treatment unit should be designed  and located



so that the treatment zone does not contain karst  formations or



irregular terrain such as fissures, faults  or bedrock outcrops.



     c)  The owner or operator should carefully determine the



proper waste application rate based on data on the properties of




the land treated waste and on the characteristics  of the treatment



zone.  The selected waste application rate  must not exceed the




capacity of the treatment zone to degrade,  transform, or immobilize



hazardous constituents.



                                9

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     d)  The pH of all portions of the treatment zone should be



maintained at greater than or equal to 6.0 and less than or equal



to 8.0.



     e)  Measures that affect microbial and chemical reactions



(e.g., fertilization, tilling, moisture control) should be



carefully evaluated and optimized to enhance the effectiveness



of treatment processes.



     f)  All design and operating recommendations specified in



other sections of this document should be followed.



     3.  Discussion



     To meet the performance standard of Section 264.273(a),



each owner or operator should (a) properly locate,  design, and



construct the land treatment unit such that the treatment zone



contains soils suitable for land treatment, and (b) then operate



the unit so that treatment occurs within the defined (in the



facility permit) boundaries of this zone.



     Particular attention should be directed toward ensuring that



the treatment medium is adequate for the degradation, transformation,



or immobilization of the hazardous constituents of  the waste.



The Agency recognizes that different soil characteristics and



depths will be acceptable under different unit-specific



conditions.  Several general recommendations relating to soil



type, however, can be derived from experiences with currently



successful land treatment operations.



     Each particular type of soil has certain advantages and



disadvantages with regard to use in a land treatment system.
                                10

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Coarse textured soils (e.g., sand) will remain aerated while



fine soils (e.g., clay)  may often become reduced due to wetness.




The aeration state of the soil will play an important role in



determining how quickly, by what pathway, and in what form various



waste constituents will be degraded.  In general, most waste




constituents are more rapidly degraded under aerobic conditions.



While the aeration conditions of fine textured soils may be less



desirable, the generally higher sorptive capacity of these soils




may be very effective in immobilizing various ions.  The advantages



and disadvantages of various soil textures, as defined in the



1975 USDA soil classification system (2), are given in Table 1.



A more detailed discussion of each of the parameters in the




table is contained in Hazardous Waste Land Treatment (1).  In



general, hazardous waste land treatment units should not be




established on extremely deep sandy soils having hydraulic connection



to underlying aquifers,  due to the great potential for hazardous



constituents leaching to ground water.   Similarly, silty soils




which have a severe problem with crusting should not be selected



due to the extreme potential for erosive transport of hazardous



constituents.  Loam, silt loam, sandy clay loam, sandy loam,



silty clay loam, and clay loam soils generally provide the most



suitable medium for land treatment of hazardous wastes.   However,



in all cases, soils having these textures will have to be properly




managed (e.g., maintenance of pH and fertility) to maintain



their treatment capabilities.
                                11

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TABLE 1   SUITABILITY OF VARIOUS SOIL TEXTURES FOR LAND
          TREATMENT OF HAZARDOUS INDUSTRIAL- WASTES
Texture
      Advantages
    Disadvantages
sand
loamy sand
loam
silt loam
silt
 silty  clay
  Loam
 clay  loam
very rapid  infiltration
usually oxidized and .dry
low run-off potential
high  infiltration
low to medium  run-off
moderate  infiltration'
fair  oxidation
moderate  run-off  potential
generally accessible
good  CEC

moderate  infiltration
.fair  oxidation
moderate  run-off  potential
generally accessible
good  CEC

 low infiltration
 fair  to poor oxidation
good  CEC
good  available  water

medium-low percolation
 fair  structure
 high  CEC

 medium-low percolation
 good  structure
 med-poor  aeration
 high  CEC
 high  available  water
very low CEC
very high hydraulic
  conductivity rate
low available water
little soil structure

low CEC
moderate to high
  hydraulic conductivity
  rate
low to medium
  available water

fair structure
some crusting
high crusting potential
poor structure
high run-off
moderate  run-off
often wet
fair oxidation

med-low infiltration
med-high  run,-off
often wet

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'TABLE  i   (con't)
Texture
       Advantages
   Disadvantages
 clay
 sandy  clay
 sandy  clay
   loam
low percolation
high CEC
high available water
med-low percolation
med-high CEC
                      

med-high available water
good aeration
low infiltration
often massive structu:
high run-off
sometimes low aeratio

fair structure
moderate-high run-off

medium infiltration
 From:   K.W.  Brown  and  Assoc.,  Inc.   Hazardous Waste Land Treatment,
        U.S.EPA publication  SW-874,  Contract No.  68-03-2940,
        September,  1980 (1).
                                 13

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     In addition, special consideration in siting and designing a



land treatment unit should be given to avoiding karst formations



and broken or irregular terrain, such as bedrock outcrops, fissures,




and faults.  Such formations often provide direct passages to



ground water.



     Successful operation of a land treatment unit in compliance



with the 264.273(a) performance standard also depends upon properly




designing, operating, and constructing the unit such that the



treatment zone provides sufficient soil depth for treatment




of hazardous constituents sufficiently above the seasonal high



water table in order to minimize environmental impacts and optimize




treatment processes.   As mentioned earlier in this document,



Section 264.271 of the regulations specifies that the boundaries



of the unit's treatment zone will be defined in the facility



permit.  Treatment of hazardous constituents within these defined




treatment zone boundaries (i.e., the vertical and horizontal



dimensions) will then be the required goal of that unit.



Section 264.271 requires that the maximum depth of the treatment



zone must be 1.5 meters from the initial soil surface, or 1



meter above the seasonal high water table, whichever depth is



less.  The Agency believes this maximum limit provides adequate




soil medium for acceptable treatment.  The second part of this



requirement ensures a minimum buffer between the bottom of



the treatment zone and the seasonal high water table.  Additional



rationale for this standard is provided in the preamble to the



regulation.






                                14

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     Many operational controls are also .very important in ensuring



maximization of treatment within the treatment zone.   Waste



application rate is one of the most important factors determining



the success of a land treatment unit.   Overloading the system



can result in significant environmental impacts resulting from



hazardous constituent volatilization,  run-off, or leaching to



ground water.  The waste application rate should be carefully



determined so that the capacity of the soil to degrade, transform,



or immobilize hazardous constituents is not exceeded.  In determining



the proper application rate, the owner or operator should consider



the characteristics of the waste and of the unit, particularly



soil properties, hydrogeology, climate and type of vegetative



cover, if any.  Generally, one or only a few waste constituents



will limit application rates because of the constituent's concentratic



in the waste, or because the soil's assimilative capacity for



the constituent is very low.  Further discussion on determining



the application rate limiting constituents is provided in the



EPA technical resource document entitled Hazardous Waste Land



Treatment (1).



     Furthermore, because land treated wastes are often complex



mixtures of both inorganic and organic hazardous constituents,



the owner or operator should determine the application rate so that



adequate consideration is given not only to degradation and



transformation processes, but also to immobilization  processes.



For instance, the application rate must not inhibit the physical,



chemical, and biological processes essential to the degradation
                                15

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of organic constituents.  In addition, to attain treatment of



inorganics and persistent organics, the application rate must not



exceed the capacity of the treatment zone to immobilize these



constituents.  In assessing the treatment zone's immobilization



capacity, particular attention should be given to the cation



exchange capacity, pH, and organic matter content of the soil.




Laboratory and pilot scale studies, as well as existing information




in the literature, which reflect the conditions present in the land



treatment unit should be used in determining the assimilative (degra-




dation, transformation, and immobilization) capacity of the treatment



zone.  Some of this information should have been generated in the



treatment demonstration explained in Section B of this document.




Additional information on specific waste constituents can be



found in the literature (1, 3).



          Maintenance of a soil pH in the treatment zone in the



range of 6-8 generally provides optimum soil pH conditions for



degradation, transformation, and immobilization processes.  Data



has shown that the optimum soil pH for microorganisms lies in the



range of 6-8 (4,5,6); hence, waste biodegradation is greatest in



this pH range.  In addition, most heavy metals are much less



mobile in soil and less available to plants at pH levels greater




than 6.0 (7,8,9).  At pH levels greater than 8.0, however, the



mobility of certain metals increases, and the availability of



certain plant and microbial nutrients (e.g., phosphorus, iron)




decreases (4).  This condition leads to leaching hazards and



less than optimum biological treatment of wastes.  Maintenance
                                16

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of a neutral soil pH is a widely recommended practice for hazardous



and nonhazardous waste land treatment (6,10,11,12).



     While the Agency generally recommends a soil pH in the range



of 6-8, it recognizes that there are a few exceptions to this




general rule.  For instance, there are a limited number of



hazardous constituents (e.g., selenium)  which are more available



to plants in neutral pH soils than in acid soils.  Each owner or




operator should evaluate data on the mobility of the hazardous



constituents of the waste under various soil pH regimes prior to



land treating the waste.




     In an effort to maximize treatment, the owner and operator



should also carefully manage any other additional operational



measures, such as method of waste application, fertilization,



tilling method and frequency, and moisture control, which influence



the effectiveness of treatment processes.



     Finally, to ensure compliance with the Section 264.273(a)



performance standard, the owner or operator should follow the



additional guidance related to unit design, construction,



operation, and closure provided in other sections of this document.



Important sections include those pertaining to design and operating



conditions for minimizing run-off, wind dispersal control,



unsaturated zone monitoring, and closure and post-closure care




procedures.  Run-on and run-off management systems must also be



developed and implemented, as required in Sections 264.273(c) and



264.273(d) of the regulations, respectively.
                                17

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11  Minimization of Run-off [264.273(b)]



     1.  The Regulations




     Section 264.273(b) requires the owner or operator to



design, construct, operate, and maintain the treatment zone to




minimize run-off of hazardous constituents during the active



life of the land treatment unit.   [The regulations also



contain requirements pertaining to the control of run-off and run-




on.  Section 264.273(c) specifies that the owner or operator must



design, construct, operate and maintain a  run-on control system



to control flow onto or into the treatment zone during peak



discharge from at least a 25-year storm.  Under Section 264.273(d)



the owner or operator must design, construct, operate and maintain



a run-off management system to collect and control at least the



water volume resulting from a 24-hour, 25-year storm.  Guidance



related to run-on and run-off control systems is provided in



Hazardous Waste Land Treatment  (1).]




     2.  Guidance



     a) The treatment zone of the unit should not contain



soils  (or soil-waste mixtures) having very low infiltration rates.



     b)  The surface slope of the active portion of a land



treatment unit should be greater than 0.2  - 0.5 percent and less



than five percent.



     c)  Waste should not be applied to the treatment zone



when the surface of the zone is frozen  (less than or equal to 0C)



     d)  Waste should not be applied during rainy weather or




when the treatment zone is saturated.

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     e.  A vegetative cover should be established on the




treatment zone whenever practicable.



     3.  Discussion



     Run-off of hazardous constituents from land treatment



units may result in significant environmental contamination.



Therefore, the Agency believes that the goal of all land treatment



units should be to minimize the generation of run-off.  This



can be achieved through proper unit siting, design, and



construction, particularly with regard to soil characteristics



and slope, as well as through proper management of unit operation,




including the scheduling, method and rate of waste application. .



     Proper design of the treatment zone can greatly minimize run-



off potential.  The treatment zone should not be composed of



soils or soil-waste mixtures which have very low infiltration



rates.  (Infiltration is the entry of water into the soil, normally



measured as a rate having units of cm per sec.  or cm per hour.)



In addition, soils subj/sct to crusting should be avoided.  Soil



types recommended in Section C of this document generally provide



favorable infiltration properties.



     The slope of the treatment zone is one of the most important



factors influencing the degree and rate of hazardous constituent



run-off.  To minimize run-off, the surface slope of the active



portion should be less than 5 percent.  However, a minimum slope



of 0.2-0.5 percent is recommended to provide adequate surface



drainage and to minimize water and waste ponding.
                                19

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     Land treatment units may be equipped with terraces and



grass waterways to control the run-off of liquid and hazardous



constituents.  This is particularly essential when significant



areas are rendered barren for one or several seasons by repeated



waste applications, as might occur for a sludge-type waste.



Proper conservation terracing is also important if the waste is



applied to a continuously vegetated surface.  Terraces will slow



the flow of intensive storm water off the unit, allowing




optimal infiltration and putting less strain on retention basins.



Furthermore, by decreasing the slope length, less sediment will



erode from the slopes, and much less sediment will accumulate in



the retention structures.  The run-off quality will also be



improved prior to the run-off entering retention structures.



Information on the design of terraces Is provided in Hazardous




Waste Land Treatment (1).



     Proper management of unit operation also contributes



significantly to run-off control.  Particular attention should be



given to the timing of waste applications.  The Agency recommends



that waste applications be curtailed during periods when the



surface of the treatment zone is frozen, during rainy weather



and when the treatment zone is saturated.  These conditions not




only significantly increase the potential for run-off, but also



generally inhibit treatment processes, which are essential to the




success of a land treatment unit.



     The Agency believes that, in most cases, successful operation



of land treatment units will be limited to periods when
                                20

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surface soils are unfrozen.  The incorporation of wastes into



frozen soils usually cannot be effectively accomplished.  Kincannon



(12) found that at low temperatures (approximately 4.5C), congealing



and solidification of oily waste sludges was a severe problem.



Inadequate waste incorporation results in increased risk of



run-off, volatilization, or wind erosion, as well as reduced



waste exposure to biological and chemical treatment mechanisms.




     In addition, research data indicates that treatment processes



within a land treatment unit will be severely limited by low



temperatures.  Powell (14) found that potential waste decomposition




in Arctic regions may be less than 15% of that in the southern U.S..



According to Harris (15), microbial activity slows during the



cool seasons and practically ceases when soils are frozen.



Studies by Dibble and Bartha (5) found negligible microbial



activity at 5C, while Raymond et al (16) reported that results



from studies of two field locations showed little evidence of



degradation during the winter months.   As a result of poor mixing



and negligible degradation at low temperatures, waste applied



during the winter may cause significant run-off contamination



problems during the spring thaw.  Because of these problems,



existing land treatment units often discontinue or significantly



reduce waste application during the winter months (16, 17).



     EPA also recommends that the application of wastes be



curtailed during heavy, rainy weather and when the treatment



zone is saturated with water.  Rainy weather will obviously



increase the potential for contaminated run-off problems.
                                21

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Saturated soil conditions favor increased run-off,  as well as



accelerated migration of waste constituents through the treatment



zone due to dissolution or physical removal,  or as  a result of



anaerobic conditions (18).  Dissolution of waste constituents



will be a severe problem if the waste contains significant amounts



of water soluble substances such as the anions of carbonic,



sulfuric, hydrochloric, and nitric acids, and certain pesticides




such as carbaryl (18).   Anaerobic conditions  adversely affect



major (aerobic) degradation and immobilization processes,  and



increase the potential for odor problems (19, 20).   Aerobic



biodegradation of simple or complex organic material in soil is



commonly greatest at 50-70% of the soil water holding capacity



(5).  Inhibition is observed at lower values  due to inadequate



water, and at higher values due to the reduction in oxygen levels.




The solubility of most heavy metals is also increased under



more reducing conditions.



     Saturated soil conditions also usually cause practical



operational problems.  Plowing or tilling under these conditions



is usually very difficult.  Attempts at manipulating saturated



soil, or even wet soil, usually aggravate problems  because



plowing with heavy equipment often compacts soil and adversely




affects soil structure and porosity.  Loss of pore  space subsequently



enhances anaerobic conditions because pore spaces provide channels




through which oxygen diffuses into and through soils.



     Finally, vegetative cover should be established in the



treatment  zone whenever practicable.  Vegetation will assist in
                                22

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minimizing run-off of hazardous constituents.  Additional guidance



on vegetative covers is provided in Section C IV of this document.



     III.  Management of Collected Run-on/Run-off [264.273(e)]




     1.   The Regulations



     Section 264.273(e) specifies that collection and holding



facilities (e.g., tanks or basins) associated with run-on/run-



off control systems must be emptied or otherwise managed



expeditiously to maintain the capacity of the system.   If the



collected run-on/run-off is a hazardous waste as defined in



Part 261, it must be handled as such.



     Section 264.273(c) requires a run-on control system to




prevent flow onto the treatment zone during a peak discharge from



at least a 25-year storm, while Section 264.273(d) requires a run-off



management system to both control and collect run-off  from at least a




24-hour, 25-year storm.  Collection of run-on is not specifically



required by the regulations.  However, if a collection facility



is associated with the run-on control system, it must  be managed



such that the capacity of the system is maintained.   Collection



facilities will usually be associated only with run-off management



fac ilities.



     2.   Guidance



     a)   A comprehensive analysis of the collected run-on/ run-



off should be conducted to determine if it is "hazardous".



     b)   The following options should be evaluated for the




disposal or treatment of hazardous and non-hazardous run-on/



run-off liquid:
                                23

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         (i) Reapplication to the hazardous waste land treatment



    unit to enhance treatment processes,  promote growth of vegetation,



    or provide control of wind dispersal  of hazardous constituents;



         (ii) Solar evaporation;  and




         (iii) Disposal or treatment in a hazardous waste disposal or



    treatment unit, other than a  land treatment unit.



     c)  The following additional options should be evaluated for




the disposal or treatment of nonhazardous run-on/run-off liquid:



          (i) Treatment and disposal via  a wastewater treatment plant;



              and




          (ii) Direct discharge under a NPDES (National Pollutant



     Discharge Elimination System) permit.




     3.  Discussion



     There are several available  alternatives for rnanaging



collected run-on and run-off liquid.  The first step in evaluating



these treatment or disposal alternatives  is to determine the



characteristics of the collected  liquid.   If such liquid is



"hazardous", it must be treated or disposed of in a permitted



hazardous waste management unit.   If it is non-hazardous,



other alternatives are available.  Thus,  a complete analysis



of the collected liquid must be conducted.



     Hazardous (or nonhazardous)  collected liquid may be disposed




of through  (a) reapplication to the hazardous waste land treatment



unit,  (b) solar evaporation, or  (3) treatment or disposal in




a permitted hazardous waste management unit (other than a




land treatment unit).
                                24

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     Reapplication of the collected liquid to the land treatment



unit may be the most practicable means of run-on/run-off



liquid treatment and disposal.  This reapplied liquid may be used



to enhance microbial degradation of waste constituents, or



as an irrigation water source to promote vegetative crop growth.




In addition, the collected liquid may be used for surface



wetting in the control of wind dispersal of hazardous constituents.



     If reapplication systems are used, care must be taken not to




saturate the treatment zone and thus, inhibit treatment processes.



When sprinkler irrigation systems are used, the systems should be



designed to apply water at a rate lower than the infiltration



rate to minimize run-off.  The system should also be designed to



provide proper pressure at the nozzles to help spread the water



as uniformly as possible.  Also, if the run-on/run-off liquid



contains hazardous constituents, irrigation systems should be run



only during periods of low wind velocity to minimize wind dispersal



problems.  If the liquid contains significant levels of nutrients,




salts, or hazardous constituents, it will be necessary to keep a



record of water applications to monitor constituent accumulations.



     The land area needed for reapplication of collected run-on/



run-off will depend on the annual application rate and the annual



volume of collected run-on/run-off.  The annual application rate



will be determined either by some limiting constituent in the run-off




or by the hydraulic loading of the land.  The land area needed is



equal to the annual collected run-on/run-off volume divided by the



annual application rate.  If the application rate is set on the
                                25

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basis of hydraulic loading, care must be taken to allow for



chronic wet periods which will increase the volume and reduce the



application rate when compared to the average annual values.



Hydraulic loading and run-off models have been developed which



utilize long-term weather information.  Information regarding



these models can usually be obtained from local Soil Conservation



Service engineers or consulting firms.  The spatial requirements



for systems of this type often include preapplication holding



ponds that are used to empty run-off retention structures and



hold the liquid for future application to the land, to avoid



application on soil that is already saturated, frozen, or covered



with snow.



     Areas in the Western United States, where the moisture



deficit (evaporation minus precipitation) is greater than ten



inches, have a high potential for using evaporation for ultimate



disposal of collected liquid.  The area needed for evaporation



ponds is a function of the annual run-off volumes held in the



pond plus the moisture that falls on the pond divided by the



evaporation rate in inches per acre for the climatic area under



consideration.  The liquid may be sprayed in the air above the



pond to enhance evaporation if no volatile or aerosol hazard



will result.  The use of nozzles that form large droplets is



encouraged to help minimize spray drift and any aerosol effects.



     Another option for treatment or disposal of hazardous collected



liquid  is disposal in a permitted hazardous waste management



unit.   This option, however, is likely to be less economical



than the other alternatives suggested above.





                                26

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     Collected liquid which is found to be nonhazardous may be



treated or disposed of by two additional methods.   If the plant



or company owns and operates a wastewater treatment plant, the



run-on/run-off water can be pumped to the plant, treated, and



disposed via the wastewater treatment facility permit.   Care must



be taken to ensure that this added volume of water does not



overwhelm the treatment plant.  New facilities should have this



capacity designed into them.  Where the option of  using an existing



wastewater treatment facility is not a viable alternative, an



NPDES (National Pollutant Discharge Elimination System) permit



may be applied for.  This would allow direct discharge  of the run-



off liquid after collection if it meets the water  quality standards



specified in the NPDES permit.



IV.  Wind Dispersal Control [264.273(f) ]



     1.  The Regulations



     Section 264.273(f) states that if the treatment zone contains



particulate matter which may be subject to wind dispersal, the



owner or operator must manage the unit to control  the wind



dispersal.



     2.  Guidance



     a)  Waste applications should be planned to correspond



with periods of low wind velocity and atmospheric  stability.



     b)  The surface soil of the treatment zone should  be



stabilized through surface wetting with water or use of chemical soil



stabilizing agents.
                                27

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     c)  A vegetative cover should be established on the



treatment zone.




         d)   The effectiveness of natural or man-made wind barriers



for wind dispesal control should be evaluated in unit design.



     3.  Discussion



          Because large tracts of waste-treated land are often



exposed to wind erosion, wind dispersal of hazardous waste is  one



of the most important environmental concerns at hazardous waste



land treatment units.   The wind dispersal of hazardous




waste will be influenced by a number of factors including the



velocity and turbulence of the wind, the characteristics of the



surface soil-waste mixture (e.g., moisture content, texture),  and



the nature and orientation of cover vegetation.



     While wind velocity has a major influence, wind turbulence



probably has an even more significant impact.  This results from




wind-carried particles exerting a large impact on particles not yet



disengaged.



     Moisture content and texture of soils also significantly



influence the susceptibility of soil-waste particles to wind



erosion.  The greater the moisture content, the greater the wind



velocity needed to induce particle movement.  In addition,




moderately coarse particles (e.g., silt size) are more susceptible



to wind erosion than fine, less detachable particles (e.g.,




clay) or coarse, heavier, and less transportable particles (e.g.,



sand).   Soils having a higher organic matter content will also



provide greater potential for particle aggregation.






                                28

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      As a first step toward minimizing wind dispersal problems,



the Agency recommends that all waste applications be carefully



timed to avoid periods of excessive wind and atmospheric instability.



Waste application activities provide, in many cases, the most



significant opportunity for wind dispersal of hazardous constituents.



     Second, the surface soil of the treatment zone should be



stabilized through surface wetting with water or use of chemical



soil stabilizing agents.  Surface wetting with water is an




effective and economical means of increasing the resistance of



the soil-waste mixture to wind erosion by increasing the



cohesiveness of soil particles.  Numerous types of surface



irrigation systems, commonly used in agricultural operations, are



available for water application.  In certain cases, the waste



itself may provide the necessary moisture for limited periods of




time.  Additional water application, however, may be necessary



between waste applications.  Care should be taken to prevent



saturation of the treatment zone and inhibition of treatment



processes.



     Chemical soil stabilizing compounds may be used in lieu of,



or in combination with, surface wetting with water.  Many chemical



soil stabilizers, including organic polymers and other resin



emulsions, are currently available.  These compounds vary in



their effectiveness and cost.  Information on several chemical



soil stabilizers can be found in a recent report (21).   In evaluating



these compounds, special attention should be given not only to



the compound's effectiveness and cost, but also to its effect on
                                29

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plant emergence and growth, and waste treatment.   As in the case



of soil moisture, the waste itself may act as a stabilizer



against erosion.



     Third, a vegetative cover should be established on the



treatment zone between waste applications, whenever practicable.



However, the vegetative cover crop should not be  planted until



sufficient tilling and cultivation (when necessary) has allowed




adequate stabilization of the waste.   An effective vegetative



cover may eliminate the need for continuation of  surface soil



stabilization via water or chemical agents.   In addition to



controlling wind dispersal of particulates,  vegetation can minimize



run-off and water borne erosion by maximizing evapotranspiration



and infiltration, and can absorb excess nutrients such as nitrogen.



In situations where liquid hazardous wastes  are surface spread




by irrigation, or where wastes are subsurface injected, it may



be possible to maintain a continuous vegetative cover.  In instances



where solid hazardous wastes are surface spread only during the



warm season, a management schedule should be developed which will



allow enough time for the establishment of at least a temporary



cover crop after applications are complete.   In situations where



waste is treated year round, the active portion of the unit




should be subdivided into plots or rows, so  that the annual



application can be made within one or two short periods to given



plots or rows, followed by incorporation, surface contouring or



terracing as needed, and vegetation establishment on those plots



or rows.  To maximize wind dispersal control, the rows of vegetation
                                30

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(between nonvegetated rows) should run perpendicular to the



prevailing wind direction.



     Vegetation should be selected which is easily established




and maintained, and relatively tolerant of potentially phytotoxic



waste constituents, including organics, salts, metals, and excess



water where that is a factor.  Disease and insect resistance



should also be considered.  Information on the potential




phytotoxicity of various waste constituents has been reviewed by



several authors (1,3,7,22,23).



     Grasses are often a good choice for vegetation because they



are relatively tolerant of many toxic waste constituents, and



can usually easily be established from seed.  Perennial sod




crops native to the area are often the most desirable surface



cover, since they provide more protection against erosion, and a



longer period of active ground cover than annual grasses or



small grains.  The most suitable or desirable plant species for a



vegetative cover, however, will vary depending upon the season



and the region of the country.  Agronomists from the State



Agricultural Extension Service, USDA, or local university should



be consulted to provide information on varieties and cultural



practices best suited to the given region.  Additional information



on the selection of vegetative covers for land treatment units



is available from several sources (1,3,24).



     Regardless of the plant species selected, vegetation




establishment may require lime, fertilizer, the use of a mulch



and watering to ensure success.  Information on the specific
                                31

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cultural practices required for successful establishment in a



particular region can also be obtained from the area agronomists



mentioned above.




     Finally, each owner or operator should also evaluate the use



of natural (e.g., tree lines) or man-made (e.g., fences) wind



barriers in minimizing dispersal of hazardous waste.  Since such



barriers will only temporarily redirect the wind,  they will




often not be very effective at units having large  fields.



There may be instances,  however, particularly with small units,



when such measures may be effective and economically feasible.



     Land treatment units having wind dispersal control measures which



include waste application timing, and a combination of surface



soil stabilization with water chemical agents, and/or vegetative




cover will be considered in compliance with Section 264.273(f)  of



the RCRA regulations.   Wind barriers may also fulfill part or



all of the wind dispersal control requirements depending on



unit-specific considerations.  The acceptability of wind



barriers will be evaluated on a case-by-case basis.



D.   Unsaturated Zone Monitoring [264.278]



     I.  Selection of "Principal Hazardous Constituents"



     1.  The Regulations




     Section 264.278(a)  specifies that "principal  hazardous



constituents" (PHCs) may be designated for unsaturated zone



monitoring purposes in lieu of monitoring for all  hazardous



constituents.  "Principal hazardous constituents"  are



the most mobile hazardous constituents which are also
                                32

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relatively persistent and present in significant concentrations



in the waste.   "Principal hazardous constituents" may be specified



in the permit by the Regional Administrator only after a review of



data from waste analyses, literature reviews, laboratory tests,



and field studies submitted by the owner or operator.



     2.  Guidance



     a.  The owner or operator should submit comprehensive waste



analysis data which identifies the hazardous constituents present



in the waste and their concentrations.



     b.  The owner or operator should gather and submit available



data in the literature pertaining to the relative mobility and



persistence of the various hazardous constituents in the waste.



This data should adequately address the conditions present in



the land treatment unit.



     c.  The owner or operator should evaluate the data generated



in performing the treatment demonstration (see Section B of this



document) and extract any pertinent information related to the



relative mobility and persistence of the hazardous constituents.



     d.  Data gleaned from the literature and treatment demonstration:



should, if necessary, be  supplemented with additional laboratory



or field tests.



     3.  Discussion



     A hazardous constituent, to be designated as a "principal hazard<



constituent" (PHC), must  be one of the  most mobile hazardous



constituents present in the waste.  In  addition, consideration



will also be given to the concentration and persistence of the
                                33

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constituent; a highly mobile hazardous constituent which is



present in insignificant concentrations, or which is quickly



degraded, would be an unacceptable PHC.  The Regional Administrator




will usually elect to designate at least two PHCs because it is



likely, based on mobility, concentration, and persistence,  that



no single hazardous constituent will clearly represent the "best"




principal hazardous constituent.



     The use of PHCs allows the owner or operator to significantly



reduce the analytical burden associated with monitoring.  Thus,




the owner or operator should work closely with the Regional



Administrator in providing the necessary data to determine



acceptable PHCs.  It is important that the data meet quality



assurance criteria and allow a clear understanding of the relative



mobility and persistence of the various hazardous constituents



in the waste under conditions similar to those present in the



unit.  In evaluating literature data and designing experimental



tests, the owner or operater should consider the facility



characteristics outlined  in the Treatment Demonstration



(Section B).



     Because the selection of a principal hazardous constituent



will be very waste- and facility-specific, the Agency cannot define




a precise selection and testing protocol.  The Regional Administrator



will determine the exact  type and extent of data needed to support



the selection of one or more principal hazardous constituents for



a particular waste at a specific unit.
                                34

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     II.   Monitoring Procedure



          1.  The Regulations



              Section 264.278 requires that all land treatment



units have an unsaturated zone monitoring program that is



capable of determining whether hazardous constituents have migrated



below the treatment zone.  The monitoring program must include



momh soil-core and soil-pore liquid monitoring.  Monitoring




for hazardous constituents must be performed on a background



plot (until background levels are established) and immediately



below the treatment zone (active portion).  The number, location,




and depth of soil-core and soil-pore liquid samples taken must



allow an accurate indication of the quality of soil-pore liquid



and soil below the treatment zone and in the background area.




The frequency and timing of soil-core and soil-pore liquid



sampling must be based on the frequency, time and rate of waste



application, proximity of the treatment zone to ground water,



soil permeability, and amount of precipitation.   The Regional



Administrator will specify in the facility permit the sampling



and analytical procedures to be used.   The owner or operator



must also determine if statistical increases in hazardous



constituents (or PHCs) have occurred below the treatment zone.



     [Ground-water monitoring is also required at hazardous waste




land treatment units.  Requirements pertaining to ground-



water monitoring are provided under Subpart F of Part 264.



Run-off or air emission monitoring is not specifically required



at land treatment units under the Part 264 regulations.]
                                35

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     2.  Guidance




          a)  Soil-core monitoring - Background




              Background concentrations of principal hazardous



constituents should be established using the following procedure.




             (i)  Take at least eight randomly selected soil



cores for each soil series present in the treatment zone from



similar soils where waste has not been applied.  The cores should




penetrate to a depth below the treatment zone but no greater than



15 centimeters (6 inches) below the treatment zone.



             (ii)  After taking each soil core, backfill the core



hole with soil.




            (iii)  Obtain one sample from each soil-core portion



taken below the treatment zone.




            (iv)  Composite the soil-core samples from each soil



series to form a minimum of four composite samples for each soil



series (i.e., randomly composite two soil-core samples to form a




composite sample; since eight core samples per soil series were



taken, a total of four composite samples will be formed).



          (v)  Preserve and ship the composite samples according



to procedures specified in Test Methods for Evaluating Solid



Waste. (25).



          (vi)  Analyze each composite sample for the principal




hazardous constituents according to the methods included in




Test Methods for Evaluating Solid Waste (25).



          (vii)  For each soil series, a background arithmetic



mean and variance for each principal hazardous constituent should



be determined by pooling all composite sample measurements.



                                36

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         b)   Soil core monitoring - Active Portion



         (i)  The owner or operator should take at least six



randomly selected soil cores per uniform area, semi-annually.



However, if a uniform area is greater than 5 hectares (12 acres),



at least two randomly selected soil cores per 1.5 hectares (4



acres) should be taken semi-annually.  The cores should penetrate




to a depth below the treatment zone but no greater than 15 centimeter




(6 inches) below the treatment zone.



         (ii)  After taking each soil core, backfill each core



hole with native soil or other material that will prevent direct




passage of waste constituents to below the treatment zone.



         (iii)  The pH of the treatment zone in each uniform



area should be determined using the following procedure:



     (A)  Obtain one representative sample from each soil-core



portion taken within the treatment zone.



     (B)  Composite the soil-core samples from each uniform area



to form a minimum of three composite samples for each uniform



area.  However, if a uniform area is greater than 5 hectares



(12 acres),  a minimum of one composite sample per 1.5 hectares



(4 acres) should be formed.



     (C)  Preserve and ship the composite samples according



to procedures provided in Test Methods for Evaluating Solid




Waste (25).



     (D)  Determine the pH of each composite sample according  to



the method included in Test Methods for Evaluating Solid Waste




(25).
                                37

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    (iv)  The concentrations of principle hazardous constituents



below the treatment zone in each uniform area should be determined



using the following procedure:



     (A)  Obtain one sample from each soil-core portion taken



below the treatment zone.




     (B)  Composite the soil-core samples from each uniform area



to form a minimum of three composite samples for each uniform



area.  However, if a uniform area is greater than 5 hectares




(12 acres), a minimum of one composite sample per 1.5 hectares



(4 acres) should be formed.




     (C)  Preserve and ship each composite sample according



to procedures provided in Test Methods for Evaluating Solid



Waste (25).



     (D) Analyze each composite sample for the principal hazardous




constituents according to the methods included in Test Methods



for Evaluating Solid Waste (25).



     (E)  For each uniform area, an arithmetic mean and variance



for each principal hazardous constituent should be determined by



pooling all composite measurements.



     c)   Soil-pore liquid monitoring - Background



     Background concentrations of principal hazardous constituents




should be established using the following procedure.



     (i)  For each soil series present in the treatment zone,




install two soil-pore liquid monitoring devices at randomly



selected  locations (see Appendix I) in similar soils where waste



has not been applied.  The sample collecting portions of the
                                38

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monitoring devices should be placed at a depth no greater than



30 centimeters (12 inches) below the actual treatment zone used



at the unit.



     (ii)  Collect and analyze samples from each of the soil-pore



liquid monitoring devices on at least a quarterly basis for at



least one year.  If liquid is not present at a regularly scheduled




sampling event, a sample should be collected as soon as liquid




is present.



     (iii)  Sample preservation and shipment should be done in



accordance with the procedures provided in Test Methods for




Evaluating Solid Waste (25).



     (iv)  Samples should be analyzed for the principal hazardous



constituents according to the methods included in Test Methods




for Evaluating Solid Waste (25).




     (v)  For each soil series, a background arithmetic mean



and variance for each principal hazardous constituent should be



determined by pooling all measurements.



     d)  Soil Pore-liquid Monitoring - Active Portion



     (i)  The owner or operator should install three soil-pore



liquid monitoring devices at randomly selected locations (see



Appendix I) per uniform area, but no less than one device per 1.5 hec



tares  (4 acres).  The sample collecting portion of the monitoring



device should be placed at a depth no greater than 30 centimeters



(12 inches) below the treatment zone.



     (ii)  Samples from each of the soil-pore liquid monitoring




devices should be collected and analyzed at least quarterly unless
                                39

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the wastes are applied very infrequently.   If liquid is not




present at a regularly scheduled sampling  event, the monitoring




device should be checked within 24 hours of each following significant



waste application or rainfall event, and a sample drawn when



sufficient liquid is present.



     (iii)  Samples should be preserved and shipped according to



procedures provided in Test Methods for Evaluating Solid Waste (25).




     (iv)  Samples should be analyzed for the principal hazardous



constituents according to methods included in Test Methods for



Evaluating Solid Waste (25).




     (v)  For each uniform area, an arithmetic mean and variance



for each principal hazardous constituent should be determined by



pooling all measurements.



     3.  Discussion




          The above guidance provides specific procedural protocols



for soil-core and soil-pore liquid monitoring in both background




plots and in the active portion of the unit.   Guidance on the



installation of and equipment needs for these monitoring systems



is provided elsewhere (1, 26, 27).  Guidance on ground-water



monitoring at hazardous waste disposal facilities is currently



being developed.



     Although the regulations specify that the number of samples,




and the frequency and timing of unsaturated zone sampling must



be based upon a number of unit-specific factors, the guidance



delineated above provides the minimum elements of what the Agency



considers acceptable unsaturated zone monitoring protocols.  EPA
                                40

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has attempted to develop soil-core and soil-pore liquid



monitoring protocols which would not only minimize sampling and



analytical costs, but also assure statistically reliable results.



To accomplish this, the Agency incorporated, in both monitoring



protocols, the essential elements of random sampling in given




"uniform areas" and sample compositing.



     Soil characteristics, waste type, and waste application




rate are all important factors in determining the environmental



impact of a particular land treatment unit or part of a



unit on the environment.  Therefore, areas of the land treatment



unit within which these characteristics are similar (i.e., uniform



areas) should be sampled as a single monitoring unit.   As used



in the recommended protocols, a uniform area is an area of the




active portion of a land treatment unit which is composed of




soils of the same soil series (as defined in the 1975 USDA soil



classification system: Reference 24) and to which similar wastes



or waste mixtures are applied at similar application rates.  If,




however, the texture of the surface soil differs significantly



among soils of the same series classification,  the phase classificatic



of the soil should be considered in defining "uniform areas".   A



certified professional soil scientist should be consulted in



designating uniform areas.



     In addition, EPA recommends that the location of soil-core



sampling or soil-pore liquid monitoring devices within a given



uniform area be randomly selected.  Random selection of samples



ensures a more accurate representation of conditions within a
                                41

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given uniform area.  Procedures for randomly selecting sampling



locations are provided in Appendix I of this document.



     Finally, the protocols specify that within a given uniform



area, samples should be composited to form a minimum number of




composite samples for analysis.  The Agency believes that



compositing is an effective mechanism to increase statistical



reliability and to reduce analysis costs.




     The soil-core and soil-pore liquid monitoring protocols for



both the active portion of the unit and a background area



[i.e., some other area where waste has not been applied and which




has soil characteristics similar to those present in the active



portion; for the purposes of this guidance, similar soil



characteristics means soils of the same soil series (and similar




surface soil texture)] are provided.  Active portion samples




must be collected from uniform areas which are selected based



upon the soil series, waste type and application rate.  The



appropriate background area is an untreated area having soil of



the same soil series.  The determination of the appropriate



background area is based solely on soil series; waste type and



application rates are irrelevant in background area selection.



It is important that uniform areas and associated background



areas be selected under the supervision of a certified professional




soil scientist.



     The Agency realizes that the owners or operators of certain



units will have background data on hazardous constituents



(in soil and soil-pore liquid) generated during the interim status
                                42

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period.  This information may be submitted to the Regional



Administrator to fulfill some or all of the Part 264 requirements



related to the establishment of background values.   This background



information should have been obtained using procedures which at



least generally conform with the guidance provided in this




document.   The Regional Administrator will determine the validity



of the background data generated during the interim status period,



and the extent to which this data will fulfill the final Part 264




requirements.



     The background soil-core monitoring protocol recommends a



minimum of eight soil cores from each background area.  Background




soil cores should penetrate to the same depth as the cores taken



from the active portion.  (Soil cores from the active portion



should be taken at a depth below the depth of the treatment zone




but no deeper than 15 centimeters (6 inches)  below the treatment



zone depth.)   The limit on the depth of the soil cores enables a



valid and accurate comparison of the levels of principal hazardous




constituents immediately below the treatment zone (active portion)



to background levels at the same depth.  One sample should be



taken from each soil core portion taken below the depth of the



treatment zone.  These samples should then be composited to



form at least four composite samples for analysis of principal



hazardous constituents.  The Agency believes that four samples




are the minimum number of samples necessary to ensure the



establishment of accurate background data.  The arithmetic mean



and variance for each principal hazardous constituent should then
                                43

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be determined by pooling all composite sample measurements from



each background area representing a specific soil series.




     The soil-core monitoring protocol for the active portion of



a land treatment unit is similar to the background protocol



with the following exceptions: (a) soil cores are collected from



uniform areas; (b) a minimum of six soil cores per sampling area




(uniform area) is recommended; and (c) sampling within the treatment



zone is recommended for the determination of soil pH, and (d)




monitoring frequency is semi-annual, rather than a one-time event.



Sampling from uniform areas is included for the active portion



to allow the selection of sampling areas to be based not only on



soil series, but also on waste type and application rates.  The



active portion protocol also specifies that if a given uniform



area is greater than 5 hectares (12 acres), at least two randomly




selected soil cores per 1.5 hectares (4 acres) should be taken



semi-annually.  This provision is included to ensure that an



adequate number of cores are taken from very large uniform areas.



     A minimum of six cores (which are composited to form three



samples for analysis) per sampling area is suggested for the



active portion, rather than eight (as in background), in order



to minimize the burden of the active portion sampling and analysis.



Active portion monitoring must be carried out throughout the



unit operating life, closure, and post-closure, whereas




background monitorng is a one-time event.



     Finally, it  is recommended in the soil-core monitoring protocol



for the active portion that the pH of the treatment zone in each uniform
                                44

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area be determined by taking a representative sample from each



soil-core portion within the treatment zone.   A "representative



sample" of soil within the treatment zone may be obtained by



collecting subsamples from each 30 cm (12 inch) depth interval




(within the treatment zone), and then compositing and mixing



these subsamples to form a composite sample.



     The regulations only require analysis for principal hazardous




constituents be conducted on soil-core samples taken below the



treatment zone.  However, analysis for these constituents of



samples taken within the treatment zone may provide important



information on the success of degradation and transformation, if




such mechanisms are used to attain treatment.  All analyses



should be conducted according to the methods provided in Test




Methods for Evaluating Solid Waste (25).



     A specific protocol for soil-pore liquid monitoring (background



and active portion) is also provided in this guidance.   Background




areas are selected according to the same criteria (i.e., soil



series) as specified for soil-core monitoring.  In order to



minimize costs and to adequately account for changes in soil-pore



liquid quality over time, the Agency is recommending that background



levels be established using quarterly monitoring of two soil-



pore monitoring devices per soil series over a period of one



year.  The sample collection portions of the background soil-



pore liquid monitoring devices should be placed at the  depth



corresponding to the depth of active portion devices (i.e., no




greater than 30 cm below treatment zone).
                                45

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     Although the elements of the protocol for soil-pore liquid



monitoring on the active portion of the unit are generally



similar to those for soil-core monitoring on the active portion,



there are several notable differences.   First, only one half as



many soil-pore liquid monitoring devices are specified per unit of



area in order to limit the costs associated with installation of



numerous monitoring devices.  Second, compositing of soil-pore



liquid samples is not recommended because only the minimum number



of samples are specified in the protocol to minimize the cost of



lysimeter installation and management.   If the number of samples



is significantly increased, compositing of samples may be



considered.   Third, the maximum depth for sampling below the



treatment zone is somewhat greater than that provided for soil



core samples (30 centimeters instead of 15 centimeters).  This



provides flexibility to the owner or operator for site-specific



variations in the installation of soil-pore liquid monitoring



devices.



     Finally, the frequency for the sampling and analysis of



soil-pore liquid is greater than that for soil cores (i.e.,



quarterly versus semi-annually).  This is because information



on fast-moving principal hazardous constituents is needed on a



more frequent basis.  The Agency believes that at least quarterly



sampling and analysis is necessary for soil-pore liquid monitoring



at units at which waste is applied on a relatively frequent



basis  (i.e., at least 3 times per year).  More frequent sampling



may be necessary, for example, at units located in areas
                                46

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with highly permeable soils or high rainfall, or at which wastes



are applied very frequently.  The timing of sampling should be



geared to the waste application schedule as much as possible.



     At land treatment units at which wastes are applied



infrequently (i.e., only once or twice a year), quarterly sampling



and analysis of soil-pore liquid may be unnecessary.  Because




soil-pore liquid is instituted primarily to detect fast-moving princi-




pal hazardous constituents, monitoring for these constituents many



months after waste application would be useless.  The Agency believes



that if fast-moving principal hazardous constituents are to migrate out



of the treatment zone, they will migrate at least within 90 days follow-



ing waste application (assuming normal climatic conditions).  There-




fore, owners or operators of land treatment units at which wastes



are applied infrequently may monitor soil-pore liquid less




frequently (semi-annually or annually).  The Regional Administrator



will determine the frequency of sampling and analysis necessary



based on the frequency and rate of waste application, and on the



characteristics of the waste and unit treatment zone.



     If sufficient liquid is not present in the soil-pore liquid



monitoring devices during a scheduled sampling, the owner or operator



should obtain a sample immediately after liquid is present.  Following




an unsuccessful sampling, the owner or operator should check the



monitoring devices for liquid within 24 hours following any significant



rainfall or waste application event.



     Existing land treatment units covered under the interim



status regulations, promulgated on May 19, 1980, were required to
                                47

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have implemented unsaturated zone monitoring systems,  including



soil-pore liquid monitoring devices.   EPA realizes that many of



these devices were not installed according to the exact specifications



(e.g., located randomly in "uniform"  areas)  provided in this guidance.



The Regional Administrator will evaluate the design and location



of these existing systems and determine the  extent of  system



modification necessary.  In many cases, the  Agency believes no



relocation or modification will be necessary; in certain cases,



however, additional devices will have to be  installed.



     Finally, although the Part 264 regulations do not  require



run-off or air emission monitoring, the Agency believes that such



monitoring is good management practice at all hazardous waste land



treatment units.  At least periodic monitoring of run-off



quality will be necessary during the  active  life to determine the



management and ultimate disposal of collected run-off.   For



example, if the collected run-off is  a hazardous waste, it must



be treated or disposed of in a permitted hazardous waste management



unit.  (See Section C III of this document for a discussion



of management of collected run-off.)   In addition, periodic air



monitoring should be conducted to evaluate the success  of controls



geared toward minimizing wind dispersal and  volatilization of



hazardous constituents.



Ill.  Evaluation and Response



     1.  The Regulations



          Under Section 264.278(f), the owner or operator must



compare the results for each hazardous constituent (or  PHC)
                                48

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obtained in soil-core and soil-pore liquid monitoring, to



its respective background value to determine if statistically



significant increases have occurred.  Section 264.278(g) specifies



that if statistically significant increases are observed, the



owner or operator must notify the Regional Administrator of this



finding within 7 days.  The owner or operator must then, within



90 days, submit to the Regional Administrator a request for




permit modification to incorporate modifications to unit



operations which will maximize treatment of hazardous



constituents within the treatment zone.



     Under Section 264.278(h), however, the owner or operator



may demonstrate that a source other than the regulated unit



caused the increase or that the increase resulted from error in



sampling, analysis or evaluation.  In making this demonstration,




the owner or operator must (1) within 7 days notify the Regional



Administrator in writing that he intends to make a demonstration,




(2) within 90 days, submit a report to the Regional Administrator demon-



strating that a source other than the regulated land treatment unit



caused the increase or that the increase resulted from error in samplinc



analysis or evaluation, (3) within 90 days, submit to the Regional Ad-



ministrator an application for a permit modification to make any appro-



priate changes to the unsaturated zone monitoring program at the unit,



and (4) continue to monitor in accordance with the established



unsaturated zone monitoring program.



     2.  Guidance



     a)   If statistically significant increases in
                                49

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hazardous constituents (or PHCs)  are observed,  the following



modifications to unit operations  should be considered to



maximize treatment within the treatment zone:



     (i)  modifications of waste  characteristics;



    (ii)  reduction of waste application rate;



   (iii)  modification in method  or timing of  waste application;



    (iv)  cessation of the application of one  or more particular



wastes at the unit;



     (v)  modifications to treatment zone cultivation or management



practices; and



    (vi)  modification of characteristics of the treatment zone,



particularly soil pH or organic matter.



     3.  Discussion



     Hazardous constituent movement to below the treatment zone



may result from improper unit design,  operation, or location.



Problems related to unit design and operation  can often be



corrected, while serious problems resulting from poor unit



siting are more difficult to rectify.   Certain locational



"imperfections" may be compensated for through careful unit



design, construction, and operation.



     If statistically significant increases of hazardous



constituents are detected below the treatment  zone via unsaturated



zone monitoring, the owner or operator should  closely evaluate



the unit's operation, design and  location to determine the



source of the problem.   The characteristics of the waste should



be evaluated for possible effects on treatment effectiveness.
                                50

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The rate, method, and timing of waste application should be



examined.  Management of the treatment zone including maintenance



of physical, chemical and biological characteristics necessary



for effective treatment, should also be reevaluated.  Soil pH



and organic matter content of the treatment zone are two important




parameters which should be assessed.  Finally, the owner or



operator should determine if the design or location of the unit




is causing failure of the system.  Topographic, hydrogeologic,



pedalogic and climatic factors all play a role in determining



the success of the .Land treatment system.  In certain cases, the



necessary unit modifications will be very minor, while in




other cases they will be major.  Numerous unit-specific



factors must be considered to make this determination.  The



Regional Administrator will make the final determination of the




modifications necessary based on the seriousness of the problem.



     In order to make the demonstration provided for under 264.278(h),



the owner or operator should carefully investigate activities



occurring near the unit to confirm the source of the



contamination, and also closely examine the procedures used in



completing unsaturated zone monitoring.  Resampling of the unit



may be required to determine errors in sampling, analysis, or



evaluation.  The exact elements of the demonstration will be



determined on a case-by-case basis.



E.  Closure and Post-Closure Care [264.280]




     1.  The Regulations



     The regulations specify that, during the closure period, the
                                51

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owner or operator must continue all operations necessary to maximize



degradation, transformation, or immobilization of hazardous




constituents within the treatment zone except to the extent that



such operations are inconsistent with the vegetative cover requirement




specified in Section 264.280(a)(8).  These operations are simply



extensions of those required under 264.273(a).   The closure



requirements also specifically require (a) minimization of run-off,




(b) maintenance of run-on control and run-off management systems,



(c) control of wind dispersal of hazardous waste, (d) food-chain



crop growth restrictions,  (e)  continuation of unsaturated zone




monitoring, and (f) establishment of vegetative cover at such time



that the cover will not substantially impede degradation, transformation,




or immobilization of hazardous constituents within the treatment zone.




Soil-pore liquid monitoring may be terminated 90 days after the



last waste application.



     The post-closure care requirements state that the owner or



operator must (a) continue all operations necessary to enhance



degradation and transformation, and sustain immobilization of



hazardous constituents, (b) maintain the vegetative cover,



(c)  maintain run-on control and run-off management systems,



(d) control wind dispersal of hazardous waste,(e) assure that the



growth of food chain crops complies with 264.276, and (f) continue



unsaturated zone monitoring (except soil-pore liquid monitoring



which may be terminated 90 days after last waste application).



     An owner or operator may be exempted from the vegetative



cover requirement under closure, and all of the post-closure care
                                52

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requirements if he demonstrates to the Regional Administrator



that the entire treatment zone contains no statistically significant



increases in hazardous constituents over background.  In addition,



Subpart F of the regulations states that if the above successful




demonstration is made and if the unsaturated zone monitoring



(264.278) has not shown statistically significant increases of




hazardous constituents (or PHCs) over background below the treatment




zone at any time during the active life of the unit, then the



the owner or operator is exempt from ground-water monitoring during




the post-closure period.



     Owners or operators of land treatment faciities must also



comply with the general closure requirements provided under



Subpart G.  These requirements address the closure performance



standard (264.111), the closure plan (264.112), time allowed




for closure (264.113), disposal or decontamination of equipment



(264.114), certification of closure (264.115), post-closure care



period (264.117), post-closure plan (264.118), and notices



(264.119 and 264.120).



     2.  Guidance



     (a)  To meet the above closure and post-closure care requirements



under 264.280 the owner or operator should follow the applicable



recommendations provided in Section C of this document.



     (b)  Unsaturated zone monitoring during the closure care



period should be carried out in accordance with the protocol



outlined in Section D of this document.
                                53

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     (c)   In enhancing degradation and transformation,  and in




sustaining the immobilization of hazardous constituents during



the post-closure care period, the owner or operator should,



at a minimum, consider the effects of soil pH,  soil moisture



content,  nutrient levels, and physical, chemical,  or biological



disturbances of the treatment zone.




     (d)   Unsaturated zone monitoring during the post-closure care




period should be carried out in accordance with the protocol outlined



in Section D of this document except that the minimum frequency



of sampling should follow a geometrically progressive schedule




(i.e., 1/2, 1, 2, 4, 8, 16 and 30 years after the  post-closure care



period begins).  If not already terminated during  the closure period,



soil-pore liquid monitoring may be terminated 90 days after the



last waste application.




     (e)   To demonstrate that the entire treatment zone contains



no statistically significant increases in hazardous constituents



over background, the owner or operator should use  the following



procedure:



     i.  Background



     A.  Take at least eight randomly selected (see Appendix I)



soil cores for each soil series present in the treatment zone from




similar soils where waste has not been applied.  The soil cores



must penetrate to a depth equal to the depth of the treatment zone.




     B.  From each soil core, obtain one sample of every 30



centimeter (12 inch) depth increment so that the sample increments




correspond for all soil cores within a soil series.
                                 54

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     C.  Composite all soil-core samples for each depth increment



of a soil series, to form at least four composite samples (for



each depth increment of a soil series) for analysis.  Analyze each



composite sample for the hazardous constituents of the waste according




to methods provided in Test Methods for Evaluating Solid Waste (25).



     (D)  For each depth increment in each soil series, a background




arithmetic mean and variance for each hazardous constituent




should be determined by pooling all measurements.



     i i.  Active Portion



     (A)  Take at least six randomly selected soil cores per




uniform area.  However, if a uniform area is greater than (12



acres) at least two randomly selected soil cores per 1.5 hectares



(4 acres) should be taken.  The soil cores must penetrate to the




bottom of the treatment zone.



     (B)  From each soil core, obtain one sample of every 30



centimeter (12 inch) depth increment, so that the sample increments




correspond for all soil cores within a uniform area.



     (C)  Composite all soil-core samples for each depth increment



of a uniform area to form a minimum of three composite samples



(for each depth increment of a uniform area).  However, if a



uniform area is greater than 5 hectares (12 acres), the minimum



for each depth increment is one composite sample per 1.5 hectares




(4 acres) .



     (D)  Analyze each composite sample for the hazardous




constituents of the waste according to methods provided in



Test Methods for Evaluating Solid Waste (25).
                                55

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     (E)  For each depth increment in each uniform area, an



arithmetic mean and variance for each hazardous constituent




should be determined by pooling all measurements.



     iii.  Comparison




     Compare the arithmetic mean results for each hazardous



constituent determined in paragraph (e)(ii)(E)  of this Section to



its respective background arithmetic mean determined in paragraph




(e)(i)(D) of this Section, using the statistical test or procedure



specified in the facility permit to determine statistically



significant changes.




     3.   Discussion



     "Closure" of a land treatment unit begins  after the last



load of waste is accepted for treatment.  The initial phases of



closure include management practices which are  simply extensions




of those carried out during active unit operation.  All practices



designed to maximize the degradation, transformation, and immobilization




of hazardous constituents must be continued throughout the closure



period,  except those practices that will prevent the establishment



of a vegetative cover (after sufficient treatment has occurred).



Such activities (e.g., tilling of soil) must be terminated when the



establishment of the vegetative cover commences according to the




provisions specified in Section 264.280(a)(8).



     In addition, unsaturated zone monitoring should be continued



as specified in Section D of this document.  Soil pore liquid



monitoring may be terminated 90 days after the  last waste




application.
                                56

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     During the closure period, the owner or operator must also



establish a vegetative cover over the closed portion of the



unit.  This vegetative cover must not be established until



sufficient treatment has occurred so that the termination of




certain management practices (e.g., tilling) and the establishment



of a vegetative cover will not substantially impede treatment




processes.  This vegetative cover must be capable of sustaining




growth without requiring extensive maintenance (e.g., frequent



fertilization, liming, watering).  Specific guidance on potential




vegetative covers is contained in Hazardous Waste Land Treatment (1).



     The Agency recognizes that degradation and transformation



processes at land treatment units are, in many cases, long



term processes.  Complete degradation and transformation of certain




degradable waste constituents may take several years.  The




accomplishment of sufficient treatment (after which certain



active treatment management activities may be reduced and a



vegetative cover established), however, usually may be possible



within a shorter time frame.  Therefore, during the closure period,



the Agency requires the completion of certain active practices



(e.g., tilling) which promote sufficient treatment and allow



establishment of a vegetative cover.  The Agency does believe



that, in general, sufficient treatment will have been achieved



when it is determined that certain active treatment management



activities (e.g., tilling) are no longer necessary to maintain



continued degradation of residual organic constituents, and




continued effective immobilization of inorganic constituents.






                                57

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Also, the vegetative cover must not be established until it is



determined that the cover will not substantially inhibit degradation,



transformation, or immobilization of hazardous constituents.



Results from unsaturated zone monitoring,  treatment zone analyses,




and data on run-off liquid quality, should be used in judging the



degree of treatment achieved.



     The Agency believes that, in many cases, the closure activities




at land treatment units (i.e., sufficient  treatment (via tilling, etc.)



and establishment of vegetative cover) may be accomplished within



180 days (as specified in Subpart G), assuming the last waste




applications occur at the early stages of  closure.  Additional



time, however, may be required by a number of other land treatment



units due to one or more factors.




     The post-closure care requirements include activities for



enhancing and sustaining treatment, and precautions for managing



and monitoring for unacceptable releases (e.g., run-on/run-off



controls, unsaturated zone monitoring).  Therefore, treatment



may be completed during the post-closure care period without



increased environmental risk.  Soil pH, soil moisture content,



nutrient levels, and significant physical, chemical, or biological



disturbances of the treatment zone may all play a major role in




enhancing sustaining the degradation, transformation and



immobilization of hazardous constituents.    These factors should



be carefully examined and corrected periodically, if necessary,



throughout the post-closure care period to ensure maintenance of




treatment processes.
                                58

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     Soil-core monitoring during the post-closure care period should



continue as recommended in Section H of this document, except



that the frequency of monitoring may follow a progressive geometric



schedule of 1/2, 1, 2, 4, 8, 16, and 30 years after post-closure care




begins.  The reduced frequency of this monitoring is suggested



because EPA believes that the risk of hazardous constituent



migration will be reduced over time in closed land treatment




units where waste applications have ceased and treatment is




nearing completion.



     Soil-pore liquid monitoring during the closure and post-




closure care periods will only have to continue for 90 days after the



last waste application.  Thus, depending on when wastes are applied



during the closure period, soil-pore liquid monitoring may or may



not have to be conducted during the post-closure care period.  At




least two sampling events should occur during that 90 days



following the last waste application.




     Finally, the Agency has provided a sampling protocol for use



in demonstrating that the entire treatment zone contains no



statistically significant increases in hazardous constituents



over background.  This soil-core monitoring protocol differs from



the one provided in Section D of this document in that samples



are taken of various depth increments within the treatment zone,



rather than just below the treatment zone.  Samples from respective



depths within each uniform area may be composited to form a



minimum of four samples for analysis.  Background and active-




portion samples at each depth should then be compared using an



appropriate statistical procedure.



                                  59

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     If a successful demonstration is made  under 264.280(d),  the



owner or operator is not required to establish a vegetative  cover



or comply with the post-closure care requirements.   However,  the



Agency still believes that it is good management practice  to



establish a vegetative cover, even if hazardous constituents are



not present, in order to minimize soil erosion.
                                60

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                          References
1.    Brown, K.W.  and Assoc.,  Inc., Hazardous Waste Land Treatment,
     U.S.  EPA publication, SW-874, Contract No.  68-03-2940 (9/80).

2.    Soil  Survey Staff, Soil  Conservation Service, USDA, Soil
     Taxonomy; A Basic System of Soil Classification for Making
     and Interpreting Soil Surveys, Agriculture Handbook No.  436,
     U.S.  Government Printing Office, Washington, DC, 12/75.

3.    Overcash, M.R.  and D. Pal, Design of Land Treatment Systems
     for Industrial  Wastes -  Theory and Practices.  Ann Arbor
     Science, Ann Arbor, Michigan, 1978.

4.    Brady, N.C., The Nature  and Properties of Soils - 8th Ed.
     McMillan Publ.  Co., N.Y., 1974.

5.    Dibble, J.T. and R. Bartha, "Effect  of Environmental
     Parameters on Biodegradation of Oil  Sludge,"  App. Env.
     Microbiology 37: 729-38, 1979.

6.    SCS Engineers,   Land Cultivation of  Industrial Wastes
     and Municipal Solid Wastes;  State of the Art Study.
     Volume I.  Contract No.  68-01-2435,  U.S.  Environmental
     Protection Agency, August, 1978.

7.    Page, A.L.,  Fate and Effects of Trace Elements in Sewage
     Sludge When Applied to Agricultural  Lands.    A Literature
     Review Study.   EPA-670/2-74-005, U.S. Environmental
     Protection Agency, January 1974.

8.    Dowdy, R.H., and W.E. Larson.  "The  Availability of
     Sludge-born Metals to Various Vegetable Crops."  J. of
     Env.Quality 4:  278-282,  1975.

9.    Chaney, R.L., P.T. Hundemann, W.T. Palmer,  R.J. Small,
     M.C.White and A.M. Decker,  "Plant Accumulation of Heavy
     Metals and Phytotoxicity Resulting from Utilization of
     Sewage Sludge and Sludge Composts on Cropland," pp 86-97.  In
     Proc. Nat'l Conf, Composting Municipal Residues and Sludges.
     Information Transfer Inc., Rockville, Md.,  1978.

10.  Huddleston,  R.L., "Treatment of Oily Wastes by Land
     Farming," Presented at the RSMA Meeting,  "Disposal of
     Industrial and  Oily Sludges by Land  Cultivaton," Houston,
     Texas, January  18-19, 1978.
11,
CONCAWE, Sludge Farming:  A Technique for the Disposal of Oily
Refinery Wastes, Report No. 3/80, 1980.
                                61

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12.   U.S.  Environmental Protection Agency,  "Principles and
     Design Criteria for Sewage Sludge Application on
     Agricultural Land.", Chapter 9 in Sludge Treatment and
     Disposal - Vol. 2., 1978.

13.   Kincannon, C.B., Oily Waste Disposal by Soil Cultivation
     Process.,  EPA - R2-72-100, U.S.  EPA, 12/72.

14.   Rowell, Michael J.,  "Land Cultivation in Cold Regions"
     In:  Disposal of Industrial and Oily Sludges by Land
     Cultivation, Resource Systems &  Mgmt Assoc., 1980.

15.   Harris, J.O., "Petroleum Wastes  in Soil"  In: Land
     Application of Waste Materials,   Soil Conservation
     Society of America, Akeny, Iowa, 1976.

16.   Raymond, R.L., J.O. Hudson, and  J.W. Jamison, "Oil
     Degradation in Soil."  Applied and Environmental
     Microbiology, 31:4  522-535, 1976.

17.   Lewis, R.S., Sludge Farming of Refinery Wastes as Practiced
     at Exxon's Bayway Refinery and Chemical Plant.  Presented
     at the National Conference on Disposal of Residues on Land,
     St.  Louis, Missouri, Sept. 13-16, 1976.

18.   Fuller, W.H., Movement of Selected Metals, Asbestos,
     and  Cyanide in Soil;  Applications to Waste Disposal.
     EPA  - 600/2-77-020, U.S. EPA, April, 1977.

19.   Lytle, Paul E., Site Visit:  Gulf Coast Waste Disposal
     Authority, Houston, Texas; Trip  report. U.S. EPA, Office
     of Solid Waste, Wash., D.C., Jan. 1, 1978.

20.   Lennon, James V., Site Visit:  IT Corporations,  Martines,
     Calif., Trip Report, U.S.  EPA, Office of Solid Waste,
     Washington, D.C., Oct. 24, 197.   Slide Presentation.

21.   Versar, Inc.  Technical Assistance in the Coal BAT Review-II;
     Special Report; Revegetation of  Coal Strip Mines, U.S.EPA
     Contract No. 68-01-5149, November 26, 1979.

22.   Allaway, W.H. Agronomic Control  over Environmental Cycling
     of Trace Elements. Adv. Agron. 20:235-274, 1968.

23.   Chaney, R.L. and P.M. Giordano.   Microelements as related to
     plant deficiencies at toxicities. pp 234-279.  In: L.F. Elliott
     and  R.J. Stevenson (ed.) Soils for Management of Organic Wastes
     and  Waste Waters. American Socity of Agronomy, Madison, WI. , 1977.

24.   Lutton, R.J. Evaluating Cover Systems for Solid and Hazardous
     Waste.  U.S. EPA publication no. SW-867.  EPA-IAG-D7-01097, 9/80.

25.   U.S.  Environmental Protection Agency, Test Methods for
     Evaluating Solid Waste, Publication No. SW-846,  1982.
                                 62

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26.   Wilson, L.G.,  Monitoring in the Vadose Zone; A Review of
       Technical Element and Methods, EPA-600/7-80-134, Contract
       No.  V-0591-NALX, 6/80.

27.   Fenn,  D.,  E.  Cocozza, 0. Braids, B. Yare, and P. Roux,
       Manual  for Ground Water Monitoring at Solid Waste Disposal
       Facilities,   EPA publication SW-611, Contract. No. 68-01-3210
       12/80.
                                63

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                            Appendix I



                         Random Sampling








     If n units are to be selected from the population, a simple



random sample is defined as a sample obtained in such a manner




that each possible combination of n units has an equal chance of



being selected (1).  In practice, each unit is selected separately,



randomly, and independently of any units previously drawn.  For



unsaturated zone monitoring, each unit to be included in the



"sample" is either a volume of soil (soil core)  or a volume of



liquid (soil-pore liquid).




     It is convenient to spot the field location for soil-coring



and soil-pore liquid devices by selecting random distances on a



coordinate system and using the intersection of the two random




distances as the location at which a soil core should be taken or



a soil-pore liquid monitoring device installed.   This system



works well for fields of both regular and irregular shape, since




the points outside the area of interest are merely discarded, and



only the points inside the area are used in the sample.



     The location, within a given uniform area of a land treatment unit



(i.e., active portion monitoring), at which a soil core should be



taken or a soil-pore liquid monitoring device installed should be



determined using the following procedure:




     (1)  Divide the land treatment unit into uniform areas,




as defined in Section H of this document.  A certified professional



soil scientist should be consulted in completing this step;
                               1-1

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      (2)  Map each uniform  area by  establishing  two base lines at

 right angles to each other  which  intersect  at  an arbitrarily

 selected origin, for example,  the southwest corner.  Each baseline

 should extend to the boundary  of  the  uniform area.

      (3)  Establish a scale  interval  along  each  base line.   The

 units of this scale may be  feet,  yards,  miles, or other units

 depending on the size of  the uniform  area.   Both base lines must

 have the same scale.

      (4)  Draw two random numbers from  a random  numbers table

 (usually available in any basic statistics  book).   Use these

 numbers to locate one point  along each  of the  base lines.

      (5)  Locate the intersection of  two lines drawn perpendicular

 to these two base line points.  This  intersection represents one

 randomly selected location  for collection of one soil core, or

 for installation of one soil-pore liquid device.  If this location

 at the intersection is outside the  uniform  area, disregard and

 repeat the above procedure.

      (6)  For soil-core monitoring,  repeat  the above procedure as

 many times as necessary to  obtain six soil  coring locations within

 each uniform area of the  land  treatment unit.  If a uniform area is

 greater than twelve acres,  repeat the above procedure as necessary

 to provide at least two soil coring  locations  per four acres.

 [If the same location is  selected twice, disregard the second

 selection and repeat as necessary to  obtain different locations]

 This procedure for randomly selecting soil  coring locations must

 be repeated at each sampling event  (i.e., semi-annually).


U,$. Environmental Protection A*nc
Htgion 5, Library (PL-12J)   9|. -._       1-2
77 West Jackson Boulevard,
Chicago, IL 60604-3590

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                           DATE DUE.
     (7)  For soil-pore liquid monitoring, repeat the above



procedure as many times as necessary to obtain three locations for



installation of soil-pore liquid monitoring devices within each



uniform area.  In addition, there should be no less than one



soil-pore liquid monitoring device (location) per four acres of




uniform area.  Monitoring at these same randomly selected locations




will continue throughout land treatment unit life (i.e., devices do



not have to be relocated at every sampling event).




     One point should be made regarding randomly locating soil-



pore liquid monitoring devices according to the procedure specified



above.   In many cases, this procedure will result in the selection



of a sampling location situated in the middle of the active



portion.  In order to prevent operational inconvenience and



sampling bias, the monitoring system should be designed and




installed so that the above-ground portion of the device is



located at least 10 meters from the sampling location.  If the



above-ground portion of the device is located immediately above



the sampling device, the sampling location will often be avoided



because of operational difficulties.   Thus, samples collected at



this location will be biased and not representative of the treated



area.



     Locations for monitoring on background areas should be randomly



determined using the following procedure:




     (1)  Consult a certified professional soil scientist in



determining an acceptable background area.  The background area



must have characteristics (i.e., at least soil series classification)
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similar to those present in the uniform area of the land treatment

unit it is representing.

     (2)  Map an arbitrarily selected portion of the background

area by establishing two base lines at right angles to each other

which intersect at an arbitrarily selected origin.

     (3)  Complete steps 3, 4, and 5 as defined above.

     (4)  For soil-core monitoring, repeat this procedure as

necessary to obtain eight soil coring locations within each

background area.

     (5)  For soil-pore liquid monitoring, repeat the above

procedure as necessary to obtain two locations for soil-pore liquid

monitoring devices within each background area.


                            Referencees

(1)  Petersen, R.G., and L.D. Calvin.  Sampling.  In Methods of
       Soil Analysis, Part 1^, Physical and Mineralogical Properties,
       Including Statistics of Measurement and Sampling.  C.A. Black, ed,
       American Society of Agronomy, Inc., 1965.  p. 57-59.

(2)  N.C-118.  Sampling and Analysis of Soils, Plants, Waste Waters
       and Sludges: Suggested Standardization and Methodology.  N.C.
       Regional Publication 230.  Kansas State University Agricultural
       Experiment Station, 1975.
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