United States
Environmental Protection
Agency
Office of Water
Regulations and Standards
Washington, DC 20460
Water
                           June, 1985
Environmental Profiles
and Hazard Indices
for Constituents
of Municipal Sludge:
2,4-Dichlorophenoxyacetic
Acid

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I

                                PREFACE
     This document is one of a series of preliminary assessments dealing
with chemicals  of potential  concern  in municipal  sewage  sludge.    The
purpose of these documents is to:   (a)  summarize  the  available  data  for
the  constituents  of  potential  concern,  (b)  identify  the  key  environ-
mental  pathways  for  each constituent  related to a reuse  and  disposal
option  (based on hazard  indices), and  (c) evaluate  the  conditions  under
which such a pollutant  may pose  a hazard.   Each document provides a sci-
entific basis  for  making an  initial  determination  of whether  a pollu-
tant, at levels currently observed in  sludges, poses  a  likely hazard to
human health  or the  environment when  sludge  is  disposed  of  by any of
several methods.   These  methods  include landspreading on food  chain or
nonfood chain  crops,  distribution  and marketing  programs,  Landf illing,
incineration and ocean  disposal.

     These documents  are intended to serve as a rapid screening tool to
narrow an initial list  of pollutants  to those  of  concern.   If  a  signifi-
cant hazard  is  indicated  by this preliminary analysis,  a more  detailed
assessment will  be  undertaken  to  better quantify  the  risk  from  this
chemical and to derive criteria  if  warranted.   If a hazard is  shown to
be unlikely, no further assessment will be conducted  at  this  time;  how-
ever, a  reassessment will  be conducted after  initial  regulations  are
finalized.  In no  case, however, will  criteria be derived  solely on  the
basis of information  presented in this document.

                              n
                              Constitution Ave NW
                           Washington DC 20004
                              202-566-0556
                        Repository Material
                       Permanent Collection

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                            TABLE OP CONTENTS


                                                                     Page

PREFACE 	   i

1.  INTRODUCTION	  1-1

2.  PRELIMINARY CONCLUSIONS FOR 2,4-DICHLOROPHENOXYACETIC ACID
      IN MUNICIPAL SEWAGE SLUDGE 	  2-1

    Landspreading and Distribution-and-Marketing 	  2-1

    Landfilling 	  2-1

    Incineration 	  2-1

    Ocean Disposal 	  2-1

3.  PRELIMINARY HAZARD INDICES FOR 2,4-DICHLOROPHENOXYACETIC
      ACID IN MUNICIPAL SEWAGE SLUDGE 	  3-1

    Landspreading and Distribution-and-Marketing 	  3-1

    Landf illing 	.  3-1

         Index of groundwater concentration resulting
           from landfilled sludge (Index 1) 	  3-1
         Index of human toxicity resulting from
           groundwater contamination (Index 2) 	  3-8

    Incineration 	  3-9

    Ocean Disposal 	  3-9

4.  PRELIMINARY DATA PROFILE FOR 2,4-DICHLOROPHENOXYACETIC
      ACID IN MUNICIPAL SEWAGE SLUDGE 	  4-1

    Occurrence 	  4-1

         Sludge 	  4-1
         Soil - Unpolluted 	  4-1
         Water - Unpolluted 	  4-2
         Air 	  4-2
         Food 	  4-3

    Human Effects 	  4-3

         Ingestion 	  4-3
         Inhalation 	  4-4
                                   11

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                            TABLE OP CONTENTS
                               (Continued)

                                                                     Page

    Plane Effects 	  4-5

         Phytotoxicity 	  4-5
         Uptake 	  4-5

    Domestic Animal and Wildlife Effects 	  4-5

         Toxicity	  4-5
         Uptake 	  4-5

    Aquatic Life Effects 	  4-5

    Soil Biota Effects 	  4-5

         Toxicity 	  4-5
         Uptake 	  4-6

    Physicochemical Data for Estimating Fate and Transport 	  4-6

5.  REFERENCES	  5-1

APPENDIX.  PRELIMINARY HAZARD INDEX CALCULATIONS FOR
    2,4-DICHLOROPHENOXYACETIC ACID IN MUNICIPAL SEWAGE
    SLUDGE 	  A-l
                                   111

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                                SECTION 1

                               INTRODUCTION
     This  preliminary  data  profile  is  one  of  a   series  of  profiles
dealing  with  chemical  pollutants  potentially of  concern  in  municipal
sewage  sludges.    2,4-Dichlorophenoxyacetic acid  (2,4-D) was  initially
identified as  being  of potential  concern when  sludge  is  placed  in a
landfill.*   This  profile  is a  compilation of  information  that  may be
useful  in determining  whether  2,4-D  poses an  actual  hazard  to human
health or the environment when sludge is disposed of by this method.
     The  focus   of this  document  is  the calculation   of  "preliminary
hazard  indices"  for  selected  potential exposure  pathways,  as  shown in
Section  3.   Each  index illustrates  the hazard  that could  result from
movement  of  a  pollutant by  a  given  pathway  to cause  a  given  effect
(e.g., sludge * groundwater *  human toxicity).   The values  and assump-
tions  employed   in  these  calculations   tend  to  represent  a  reasonable
"worst  case"; analysis  of  error  or  uncertainty  has been  conducted to a
limited degree.  The  resulting value in most  cases  is  indexed to unity;
i.e.,  values  >1  may indicate  a  potential hazard,  depending  upon  the
assumptions of the calculation.
     The data used  for  index calculation have  been selected  or estimated
based  on  information  presented  in  the  "preliminary  data  profile",
Section 4.  Information in  the profile is  based  on  a compilation of the
recent  literature.    An  attempt has been  made  to  fill   out  the profile
outline  to the  greatest extent possible.   However,  since this  is a pre-
liminary analysis, the literature has not been exhaustively perused.
     The  "preliminary conclusions" drawn  from each  index  in  Section 3
are  summarized  in  Section  2.    The preliminary  hazard   indices  will  be
used as  a  screening tool to determine*which pollutants  and  pathways may
pose a  hazard.   Where a potential hazard  is  indicated  by interpretation
of  these  indices,  further analysis  will  include a  more  detailed exami-
nation  of potential  risks  as  well  as  an examination  of site-specific
factors.   These  more  rigorous  evaluations may  change  the preliminary
conclusions  presented  in  Section  2,  which are based  on  a  reasonable
"worst case" analysis.
     The  preliminary  hazard   indices  for   selected   exposure  routes
pertinent  to  landfilling practices  are included  in  this profile.   The
calculation formulae  for these  indices  are shown in the  Appendix.   The
indices are rounded to two significant figures.
* Listings  were determined  by  a series  of  expert  workshops  convened
  during  March-May,  1984  by   the  Office   of   Water   Regulations  and
  Standards  (OWRS)  to discuss landspreading,  landfilling,  incineration,
  and ocean disposal, respectively, of municipal  sewage  sludge.
                                   1-1

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                                SECTION 2

        PRELIMINARY  CONCLUSIONS  FOR  2,4-DICHLOROPHENOXYACETIC  ACID
                        IN MUNICIPAL SEWAGE  SLUDGE
     The  following  preliminary  conclusions  have  been  derived  from the
calculation of  "preliminary hazard  indices",  which  represent  conserva-
tive or  "worst  case" analyses  of  hazard.   The  indices and  their basis
and  interpretation  are  explained   in  Section  3.    Their  calculation
formulae are shown in the Appendix.

  I. LANDSPREADING AND DISTRIBUTION-AND-MARKETINC

     Based on  the recommendations of  the experts  at the OWRS  meetings
     (April-May,  1984),  an assessment of  this reuse/disposal option is
     not being  conducted  at  this time.   The U.S.  EPA reserves  the right
     to conduct such an assessment  for this option in the future.

 II. LANDPILLING

     Landfilled sludge  will  produce  a maximum groundwater  concentration
     of  2,4-D  at  the well  which varies  over  three  orders of  magnitude
     depending  upon  the  soil  type,   site  parameters,  and  chemical-
     specific parameters  (see  Index  1).   The  2,4-D  groundwater  contami-
     nation produced  by  landfilled  sludge  is not   expected  to  pose  a
     human health  risk under  any  of the  site conditions analyzed  (see
     Index 2).

III. INCINERATION

     Based on  the recommendations of  the experts  at the OWRS  meetings
     (April-May,  1984),  an assessment of  this reuse/disposal option is
     not being  conducted  at  this time.   The U.S.  EPA reserves  the right
     to conduct such an assessment  for this option in the future.

 IV. OCEAN DISPOSAL

     Based on  the recommendations of  the experts  at the OWRS  meetings
     (April-May,  1984),  an assessment of  this reuse/disposal option is
     not being  conducted  at  this time.   The U.S..  EPA reserves  the right
     to conduct such an assessment  for this option in the future.
                                   2-1

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                               SECTION 3

     PRELIMINARY HAZARD INDICES FOR 2,4-DICHLOROPHENOXYACETIC ACID
                       IN MUNICIPAL  SEWAGE  SLUDGE
 I. LAMDSPREADING AND DISTRIBUTION-AND-MARKETING

    Based on  the recommendations  of  the experts  at the  OURS  meetings
    (April-May,  1984),  an assessment of  this reuse/disposal option is
    not being  conducted  at  this  time.   The U.S. EPA reserves  the right
    to conduct an assessment for this option in the future.

II. LANDFILLING

    A.   Index  of  Groundwater Concentration  Resulting  from Landfilled
         Sludge (Index 1)

         1.   Explanation -  Calculates  groundwater  contamination which
              could occur  in a potable  aquifer  in  the  landfill  vicin-
              ity.   Uses  U.S. EPA's  Exposure  Assessment  Group (EAG)
              model, "Rapid  Assessment of  Potential  Groundwater Contam-
              ination  Under  Emergency Response  Conditions"  (U.S.  EPA,
              1983).   Treats landfill  leachate as a  pulse input, i.e.,
              the application  of  a constant  source  concentration for a
              short time period relative to the  time frame of the anal-
              ysis.   In  order  to predict  pollutant movement  in soils
              and groundwater, parameters  regarding  transport  and fate,
              and boundary  or  source conditions are  evaluated.   Trans-
              port  parameters  include  the   interstitial  pore  water
              velocity  and  dispersion  coefficient.    Pollutant  fate
              parameters  include  the degradation/decay  coefficient  and
              retardation factor.   Retardation is primarily a  function
              of  the  adsorption  process,  which  is  characterized by a
              linear,  equilibrium  partition  coefficient  representing
              the  ratio  of  adsorbed  and solution pollutant concentra-
              tions.   This  partition coefficient, along  with  soil  bulk
              density  and  volumetric  water content,  are  used  to calcu-
              late  the  retardation  factor.    A  computer  program  (in
              FORTRAN) was  developed to  facilitate  computation  of  the
              analytical  solution.  The  program  predicts pollutant  con-
              centration as  a  function of  time and location in  both the
              unsaturated  and saturated  zone.    Separate computations
              and parameter  estimates  are  required for  each zone.   The
              prediction  requires  evaluations  of  four  dimensionless
               input  values  and   subsequent  evaluation  of  the  result,
              through use of the computer program.

         2.   Assumptions/Limitations -  Conservatively  assumes  that  the
              pollutant  is   100  percent  mobilized in  the  leachate  and
               that  all  leachate  leaks out  of the landfill  in  a finite
              period and  undiluted by precipitation.   Assumes  that  all
               soil  and aquifer properties  are homogeneous and isotropic
               throughout each  zone;  steady, uniform  flow occurs only in
                                  3-1

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          Che  vertical  direction  throughout  the  unsaturated  zone,
          and  only  in  the  horizontal  (longitudinal)  plane  in  the
          saturated zone; pollutant  movement  is considered  only in
          direction of groundwater flow  for the  saturated zone;  all
          pollutants  exist  in concentrations  that do  not  signifi-
          cantly affect  water movement; for organic  chemicals,  the
          background  concentration  in the  soil  profile  or  aquifer
          prior to  release  from the  source  is assumed to  be zero;
          the pollutant source is a  pulse  input; no  dilution of  the
          plume occurs  by  recharge  from  outside  the  source  area;
          the  leachate   is  undiluted  by  aquifer  flow within  the
          saturated zone;  concentration  in  the  saturated   zone  is
          attenuated only by dispersion.

3.   Data Used and Rationale

     a.   Unsaturated zone

          i.   Soil type and characteristics

               (a)  Soil type

                    Typical     Sandy loam
                    Worst      Sandy

                    These two  soil  types  were  used  by Gerritse  et
                    al.   (1982)  to  measure partitioning of  elements
                    between   soil  and   a  sewage  sludge  solution
                    phase.   They are used  here  since  these  parti-
                    tioning  measurements (i.e., K^ values)  are con-
                    sidered   Che  best  available   for  analysis   of
                    metal transport  from  landfilled  sludge.    The
                    same soil types are  also used  for  nonmetals  for
                    convenience and consistency of  analysis.

               (b)  Dry bulk density

                    Typical     1.53  g/mL
                    Worst      1.925  g/mL

                    Bulk density is the  dry. mass per unit volume  of
                    the  medium (soil), i.e., neglecting the  mass  of
                    the  water  (Camp  Dresser  and McKee, Inc.  (CDM),
                    1984a).

               (c)  Volumetric water content (9)

                    Typical     0.195  (unitless)
                    Worst      0.133  (unitless)

                    The  volumetric water content   is  the  volume  of
                    water  in  a  given   volume  of  media,   usually
                    expressed as a fraction or percent.   It  depends
                    on properties of  the media and  the water flux
                              3-2

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          estimated by infiltration  or  net  recharge.   The
          volumetric water content  is  used  in calculating
          the water movement  through the unsaturated zone
          (pore  water   velocity)   and   the   retardation
          coefficient.  Values obtained from CDM, 1984a.

     (d)  Fraction of organic carbon (foc)

          Typical    0.005  (unitless)
          Worst      0.0001 (unitless)

          Organic content  of  soils   is  described  in terms
          of percent organic  carbon, which  is required in
          the  estimation  of  partition  coefficient,  Kj.
          Values,  obtained  from R.  Griffin  (1984)  are
          representative values  for  subsurface soils.

ii.  Site parameters

     (a)  Landfill leaching time (LT) = 5 years

          Sikora et  al.   (1982)  monitored  several  sludge
          entrenchment sites  throughout  the United  States
          and estimated time  of  landfill  leaching  to  be 4
          or 5 years.  Other  types  of  landfills  may leach
          for longer periods  of  time; however,  the  use of
          a value  for  entrenchment   sites is  conservative
          because   it   results    in   a  higher   leachate
          generation rate.

     (b)  Leachate generation rate (Q)

          Typical    0.8 m/year
          Worst      1.6 m/year

          It   is   conservatively   assumed    that   sludge
          leachate enters  the unsaturated  zone  undiluted
          by  precipitation or  other recharge,  that  the
          total  volume  of liquid in  the   sludge  leaches
          out of the  landfill,  and  that leaching  is  com-
          plete in 5 years.   Landfilled  sludge  is  assumed
          to be 20 percent solids' by volume,  and  depth of
          sludge in  the  landfill  is 5 m  in  the  typical
          case  and  10 m  in   the  worst  case.    Thus,  the
          initial  depth   of   liquid  is  4  and  8 m,   and
          average yearly  leachate generation  is  0.8  and
          1.6 m, respectively.

     (c)  Depth to groundwater (h)

          Typical    5 m
          Worst      0 m
                    3-3

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          Eight  landfills  were  monitored throughout  the
          United States  and depths  to groundwater  below
          them were  listed.   A  typical depth  to  ground-
          water  of  5 m  was  observed  (U.S.  EPA,  1977).
          For the  worst  case,  a value  of 0 m  is  used to
          represent the situation where the  bottom of the
          landfill  is occasionally or  regularly below the
          water table.   The  depth to groundwater  must be
          estimated  in  order to  evaluate the  likelihood
          that pollutants  moving through  the  unsaturated
          soil will reach the groundwater.

     (d)  Dispersivity coefficient (a)

          Typical    0.5  m
          Worst      Not  applicable

          The dispersion  process  is  exceedingly  complex
          and difficult  to quantify,  especially  for  the
          unsaturated zone.   It  is  sometimes  ignored  in
          the unsaturated  zone,  with  the reasoning  that
          pore water  velocities  are  usually  large enough
          so  that   pollutant  transport   by   convection,
          i.e.,  water movement,  is paramount.   As a  rule
          of  thumb,   dispersivity  may  be  set  equal  to
          10 percent  of  the  distance  measurement  of  the
          analysis   (Gelhar  and   Axness,   1981).     Thus,
          based on  depth to groundwater listed  above,  the
          value for the  typical  case  is 0.5 and that  for
          the worst  case  does  not apply since  leachate
          moves directly  to the  unsaturated zone.

iii. Chemical-specific parameters

     (a)  Sludge concentration of pollutant (SC)

          Typical    4.64 mg/kg  DW
          Worst      7.16 mg/kg  DW

          Of  over   200  publicly-owned   treatment  works
          (POTWs) surveyed in the United  States, analyses
          for 2,4-D  were  conducted only  at  two Phoenix,
          Arizona plants  (COM,  1984b).  The mean and  max-
          imum concentrations of  2,4-D in  the  sludge  at
          these  two  POTWs is  used  for  the  typical  and
          worst  concentration,   respectively.    Although
          these  concentrations   may   be  biased   due   to
          unique local conditions, they were used  because
          they are the  only specific  values  available.
          (See Section 4,  p.  4-1.)
                    3-4

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          (b)  Soil half-life of pollutant (tp = 135 days

               The  value   selected   represents   the   longest
               (worst-case)  half-life  for  2,4-D reported  in a
               study  which  compared  degradation  rates  under
               aerobic and  anaerobic  conditions  (Liu et  al.,
               1981).   (See  Section 4,  p.  4-6.)

          (c)  Degradation rate (p) = 5.13 x 10"3 day'1

               The unsaturated  zone can serve as  an effective
               medium  for  reducing   pollutant   concentration
               through a  variety  of   chemical  and  biological
               decay  mechanisms  which  transform or  attenuate
               the pollutant.  While these decay processes are
               usually complex,  they  are  approximated here  by
               a  first-order  rate constant.   The  degradation
               rate is calculated using the following formula:
           (d) Organic  carbon  partition  coefficient  (Koc)  -
               20 mL/g

               The  organic  carbon  partition  coefficient  is
               multiplied  by   the   percent   organic   carbon
               concent  of  soil  (foc)  to  derive  a  partition
               coefficient  (K
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     (b)   Aquifer porosity (0)

          Typical    0.44   (unitless)
          Worst       0.389 (unitless)

          Porosity is that portion of the  total  volume  of
          soil  that is made  up  of voids (air) and  water.
          Values   corresponding  to  the  above  soil  types
          are from  Pettyjohn et  al.  (1982) as  presented
          in U.S. EPA (1983).

     (c)   Hydraulic conductivity of the  aquifer (K)

          Typical    0.86  m/day
          Worst       4.04  m/day

          The hydraulic conductivity (or permeability)  of
          the aquifer is needed to estimate  flow velocity
          based  on Darcy's Equation.   It  is a measure  of
          the volume  of  liquid  that  can  flow  through  a
          unit  area or media with time; values  can  range
          over  nine orders of  magnitude depending on  the
          nature   of  the  media.   Heterogenous  conditions
          produce  large  spatial  variation  in  hydraulic
          conductivity,  making   estimation  of  a  single
          effective  value  extremely  difficult.    Values
          used  are  from   Freeze  and   Cherry   (1979)   as
          presented in U.S.  EPA  (1983).

     (d)   Fraction of organic carbon (foc)  =
          0.0 (unitless)

          Organic  carbon  content, and  therefore adsorp-
          tion,  is assumed to be 0 in the  saturated  zone.

ii.  Site parameters

     (a)   Average hydraulic  gradient between landfill  and
          well  (i)

          Typical    0.001  (unitless)
          Worst       0.02   (unitless)

          The hydraulic  gradient  is  the  slope  of  the
          water   table  in  an unconfined aquifer,  or  the
          piezometric  surface   for a   confined   aquifer.
          The  hydraulic   gradient  must   be    known   to
          determine   the   magnitude  and   direction   of
          groundwater flow.  As gradient  increases, dis-
          persion  is  reduced.    Estimates  of typical  and
          high  gradient values  were  provided by Donigian
          (1985).
                   .3-6

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          (b)  Distance from well to landfill (A&)

               Typical    100 m
               Worst       50 m

               This   distance   is  the   distance  between   a
               landfill and  any  functioning public or  private
               water supply or livestock water supply.

          (c)  Dispersivity coefficient (a)

               Typical    10 m
               Worst       5 m

               These  values  are  10 percent  of  the  distance
               from well  to landfill  (AH), which  is  100  and
               SO m,  respectively,  for  typical  and   worst
               conditions.

          (d)  Minimum thickness  of saturated zone (B) = 2 m

               The  minimum  aquifer  thickness  represents  the
               assumed  thickness  due   to   preexisting  flow;
               i.e., in the absence of leachate.  It  is termed
               the  minimum  thickness  because  in the  vicinity
               of  the site  ic  may  be  increased  by  leachate
               infiltration  from the  site.    A value  of  2 m
               represents    a  worst   case   assumption   that
               preexisting flow  is  very limited and  therefore
               dilution of  the  plume  entering  the  saturated
               zone is negligible.

          (e)  Width of landfill  (U) =  112.8 m

               The  landfill   is  arbitrarily  assumed   to   be
               circular with an area of 10,000 m^.

     iii. Chemical-specific parameters

          (a)  Degradation rate (u) = 0 day'1

               Degradation  is  assumed  not  to  occur  in  the
               saturated zone.

          (b)  Background    concentration   of   pollutant   in
               groundwater (BC) = 0 Ug/L

               It  is  assumed that no  pollutant  exists in  the
               soil profile  or aquifer  prior  to release  from
               the source.

4.   Index Values - See Table 3-1.
                         3-7

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     S.   Value Interpretation  -  Value equals  the  maximum expected
          groundwater concentration  of pollutant,  in Ug/L,  at the
          well.

     6.   Preliminary Conclusion - Landfilled  sludge will produce a
          maximum  groundwater concentration  of 2,4-D  at  the  well
          which  varies  over  three  orders  of magnitude  dependi-ng
          upon  the  soil  type,   site  parameters,  and  chemical-
          specific parameters.

B.   Index   of    Human    Toxicity   Resulting   from   Groundwater
     Contamination (Index 2)

     1.   Explanation  -   Calculates   human   exposure  which  could
          result from groundwater  contamination.   Compares exposure
          with acceptable daily intake (ADI) of pollutant.

     2.   Assumptions/Limitations  -  Assumes  long-term exposure  to
          maximum concentration at well at a rate of 2 L/day.

     3.   Data Used and Rationale

          a.   Index  of  groundwater   concentration resulting  from
               landfilled sludge (Index 1)

               See Section 3,  p. 3-10.

          b.   Average human  consumption of  drinking water  (AC)  =
               2 L/day

               The value  of  2  L/day  is  a  standard  value  used  by
               U.S. EPA in most risk assessment studies.

          c.   Average daily human dietary  intake  of pollutant  (DI)
               = 2.81 Mg/day

               Although no  2,4-D residues  were reported  in  market
               basket  surveys  from  FY75  to  FY78   (Food  and  Drug
               Administration   (FDA),   1979),   a  worst-case  average
               daily human dietary intake was  calculated  with prior
               food  concentration  data  (Johnson  and Manske,  1976;
               Manske and Johnson, 1975) and  average  daily consump-
               tion data for adults (FDA,  1980).   The concentration
               of  2,4-D reported  for  potatoes and  leafy  vegetables
               was multiplied by the  respective average  daily adult
               consumption  (159 g/day potatoes and 58 g/day  leafy
               vegetables;  FDA,   1980) and  summed  to  obtain  the
               total  average  daily human  dietary  intake of  2,4-D
               reported above.  (See  Section 4, p.  4-3).
                              3-8

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               d.   Acceptable  daily   intake   of   pollutant   (ADI)   =
                    8750 Ug/day

                    Using an  uncertainty  factor of  100,  the  U.S.  EPA
                    (1982)  calculated  an  ADI  of 0.125  mg/kg/day  (see
                    Section   4,  p.  4-4).    Assuming  the  average  adult
                    weights  70 kg (U.S.  EPA,  1982),  the  value given was
                    calculated by multiplying 0.125 mg/kg/day by  70  kg
                    and converting mg to Ug (1000 Ug/mg).

          4.   Index 2 Values -  See  Table 3-1.

          5.   Value Interpretation -  Value  equals  factor by  which pol-
               lutant intake exceeds ADI.  Value  >1  indicates  a possible
               human  health  threat.    Comparison with   the  null  index
               value indicates the  degree  to  which  any hazard  is  due  to
               landfill  disposal,   as   opposed  to   preexisting  dietary
               sources.

          6.   Preliminary Conclusion - The 2,4-D groundwater  contamina-
               tion  produced  by  landfilled   sludge  is not  expected  to
               pose a human  health risk under any of the  site  conditions
               analyzed.

III. INCINERATION

     Based on  the  recommendations  of  the experts at  the OWRS  meetings
     (April-May,  1984),  an  assessment  of  this  reuse/disposal  option  is
     not being conducted at this  time.   The  U.S. EPA reserves  the  right
     to conduct such an assessment for  this option in the  future.

 IV. OCEAN DISPOSAL

     Based on  the  recommendations  of  the experts at  the OWRS  meetings
     (April-May,  1984),  an  assessment  of  this  reuse/disposal  option  is
     not being conducted at this  time.   The  U.S. EPA reserves  the  right
     to conduct such an assessment for  this option in the  future.
                                   3-9

-------
               TABLE 3-1.  INDEX OP CROUNDWATER CONCENTRATION  RESULTING  FROM  LANDFILLED  SLUDGE  (INDEX 1)  AND

                           INDEX OF HUMAN TOXICITY RESULTING FROM  GROUNDUATER CONTAMINATION  (INDEX 2)
I
->
o
Site Characteristics
Sludge concentration
Unsaturated Zone
Soil type and charac-
teristics^
Site parameters6
Saturated Zone
Soil type and charac-
teristics^
Site parameters^
Index 1 Value (ug/L)
Index 2 Value
1
T
T
T
T
T
0.0186
3.3x10-4
2
U
T
T
T
T
0.0287
3.3,10-4
3
T
W
T
T
T
0.0321
3.3x10-4
Condition of
4
T
NA
U
T
T
0.1261
3.5x10-4
AnalysisaDc
5
T
T
T
W
T
0.0987
3.4x10-4
6
T
T
T
T
U
0.7435
4.9x10-4
7
W
NA
U
W
U
41.43
9.8xlO-3
8
N
N
N
N
N
0
3.2x10-4
    aT = Typical values used; W = worst-case values used; N = null condition, where no landfill exists, used as

     basis for comparison; NA = not applicable for this condition.


    "Index values for combinations other than those shown may be calculated using the formulae in the Appendix.


    cSee Table A-l in Appendix for parameter values used.


    "Dry bulk density (P(jry) volumetric water content (6), and fraction of organic carbon (foc).


    eLeachate generation rate (Q), depth to groundwater (h), and dispersivity coefficient (a).


    'Aquifer porosity (0) and hydraulic conductivity of the aquifer (K).


    ^Hydraulic gradient (i), distance from well to landfill (AS,), and dispersivity coefficient  (a).

-------
                              SECTION 4

     PRELIMINARY DATA PROFILE FOR 2,4-DICHLOROPHENOXYACETIC ACID
                      IN MUNICIPAL SEWAGE  SLUDGE
I. OCCURRENCE

   2,4-D was introduced as a plant growth-regulator   MAS, 1977
   in 1942.  It is registered in the United States    (p. 493)
   as an herbicide for control of broadleaf plants
   and as a plant growth-regulator.  Domestic use is
   estimated at 40 to 50 million Ibs/yr, approxi-
   mately 84% of which is used agriculturally and
   about 16Z non-agriculturally (mainly for forest
   brush control).

   A.  Sludge

       1.  Frequency of Detection

           Data not immediately available.

       2.  Concentration

           Concentrations in sludges from five        Jones and Lee,
           sludge sources in Chicago were <1000       1977 (p. 52)
           Mg/L.

           In 4 composite samples from two Phoenix,    CDM, 1984b
           Arizona treatment plants, 2,4-D ranged     (pp. 43-56)
           from 2.12 to 7.16 mg/kg DW with a mean
           of 4.64 mg/kg DW.

   B.  Soil - Unpolluted

       1.  Frequency of Detection

           Out of 188 samples from soils where        U.S. EPA,
           2,4-D had been applied, 1.6Z contained     1981 (p. 7-6)
           2,4-D residues (1969).

           No 2,4-D detected in soil samples          U.S. EPA,
           from the corn belt in 1970.                1981 (p. 7-7)

           2,4-D detected in 20% of soil samples       U.S. EPA,
           from wheat fields in 1969.                 1981 (p. 7-7)

       2.  Concentration

           In 1.6% of 188 soil samples from 2,4-D     U.S. EPA,
           application sites, 2,4-D had a mean        1981 (p. 7-7)
           concentration of  <0.01 ug/g (1969).
                                 4-1

-------
        In 20% of soil samples from wheat fields   U.S. EPA,  1981
        in 1969, 2,4-D was detected with a         (p. 7-7)
        maximum value of 0.2 yg/g DU.

C.  Hater - Unpolluted

    1.  Frequency of Detection

        No detectable 2,4-D found in monthly       U.S. EPA,  1981
        water-suspended samples from 11 rivers     (p. 7-5)
        in the western United States in 1965-66.

        2,4-D detected in 14 out of 20 stations    U.S. EPA,  1981
        on 19 rivers in 1967-68.                   (p. 7-5)

        No measurable levels of 2,4-D detected     U.S. EPA,  1981
        in Texas surface waters in 1970.           (p. 7-6)

    2.  Concentration

        a.  Freshwater

            In a two-year study of 19 western      U.S. EPA,  1981
            U.S. rivers, the highest 2,4-D con-    (p. 7-5)
            centration found was 0.35 Ug/L in
            the James River at Huron, SD, in 1968.

            The highest concentration of 2,4-D     U.S. EPA,  1981
            detected in a three-year study (1968-  (p. 7-6)
            1971) of 19 western U.S. streams was
            0.97 ug/L.

        b.  Seawater

            Data not immediately available.

        c.  Drinking Water

            Data not immediately available.

D.  Air

    1.  Frequency of Detection

        In a one-year monitoring study of air      U.S. EPA,  1981
        in 16 U.S. cities, three samples           (p. 7-4)
        contained detectable 2,4-D levels.

        The isopropyl ester of 2,4-D was found     U.S. EPA,  1981
        in 20 out of 22 samples of air in north-   (p. 7-1)
        eastern Oregon in 1962.  In eastern
        Washington, 2,4-D esters were present
        in 60 to 70% of the samples.
                              4-2

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        2.  Concentration
                 Urban

                 In  a one-year monitoring  study  of
                 air in  16 U.S.  cities,  three  samples
                 contained 2,4-D as  follows:
                 Jordan,  NY
                 Rome,  NY
                 Salt Lake City,  UT
0.00115 Mg/m3
0.00154 pg/m3
0.004   yg/m3
             b.   Rural
                 Out  of  434  samples  from Oregon  and
                 Washington  in  1962  to  1964,  the
                 concentration  range for most 2,4-D
                 esters  was  from  trace  levels to 5.12
                 yg/m3.
     B.   Pood
         1.   Total  Average Intake

             In market  basket  surveys  from FY75  co
             FY78,  no 2,4-D residues were  reported.

             Total  diet samples  detailing  residues
             in infant  and toddler food  and tap  water
             (1974-75)  did not contain any detectable
             2,4-D  residues.

         2.   Concentration

             2,4-D  occurred in 1 out of  30 composite
             potato samples in 1972-73 at  a level
             of 0.014 Mg/g.

             2,4-D  occurred in 1 out of  35 composite
             leafy  vegetable samples in  1971-72
             at a level of 0.01  Ug/g.

II.  HUMAN EFFECTS

     A.  Ingestion

         1.   Carcinogenicity

             a.  Qualitative Assessment

                 No conclusive evidence  of
                 2,4-D carcinogenicity exists
                 when administered orally  to
                 animals.
                 U.S. EPA, 1981
                 (p. 7-5)
                 U.S. EPA, 1981
                 (p. 7-2)
                 FDA, 1979
                 U.S. EPA, 1981
                 (p. 7-10)
                 Johnson and
                 Manske, 1976
                 Manske and
                 Johnson, 1975
                 (p. 100)
                 NAS, 1977
                 U.S. EPA, 1982
                                   4-3

-------
        b.  Potency

            Not derived.

        c.  Effects

            No carcinogenic effects demonstrated.

    2.  Chronic Toxicity

        a.  ADI

            0.3 mg/kg/day
            0.0125 mg/kg/day - safety factor of
              1000 used.
            0.125 mg/kg/day - safety factor of
              100 used (or 8.75 mg/man/day)

        b.  Effects

            Fibrillary twitching,  muscular
            paralysis, hemoglobinuria,
            myoglobinuria, general hyporeflexia.

    3.  Absorption Factor

        75 to 90 percent  absorption of ingested
        2,4-D.


    4.  Existing Regulations

        Quality criteria  for a domestic water
        supply set for 2,4-D at 0.1 mg/L

B.  Inhalation

    1.  Carcinogenicity

        Data not immediately available.

    2.  Chronic Tozicity

        Data not assessed since no evaluation of
        incineration was  performed.

    3.  Absorption Factor

        Data not immediately available.
FAO/WHO cited in
NAS, 1977
U.S. EPA, 1982
NAS, 1977
Kohli et al.,
1974, cited in
U.S. EPA, 1980
U.S. EPA, 1976
                              4-4

-------
         4.  Existing Regulations

             10 mg/m3    Time weighted average
             20 mg/n)3    Short-term exposure limit

III. PLANT EFFECTS

     A.  Phytotoxicity

         See Table 4-1.

         When combined with captan or dichlone,
         2,4-D exhibited synergistic phytotoxicity
         on cucumbers but not on oats.

         Applications of 2,4-D resulted
         in poor germination and malformed foot tips
         in cotton plants and reduced germination of
         poinsetta.

     B.  Uptake

         Data not immediately available.

 IV. DOMESTIC ANIMAL AND WILDLIFE EFFECTS

     A.  Toxicity

         See Table 4-2.

     B.  Uptake

         Data not immediately available.

  V. AQUATIC LIFE EFFECTS

     Data not immediately available.

 VI. SOIL BIOTA EFFECTS

     A.  Tozicity

         See Table 4-3.

         Gram positive and aerobic bacteria were
         inhibited at lower concentrations than gram
         negative and anaerobic bacteria.

         Very high levels of 2,4-D cause  inhibition
         of nitrification and ammonification.
ACGIH,  1983
Nash and Harris,
1973 (p. 495)
NAS, 1968  (p. 6)
Newman and
Downing, 1958
(p. 352)

Newman and
Downing, 1958
(p. 352)
                                   4-5

-------
     B.  Uptake

         Data not immediately available.

VII. PHYSICOCHEMICAL DATA FOR ESTIMATING FATE AND TRANSPORT

     Persistence of 2,4-D in soils has been reported    Liu et al., 1981
     to be between 4 weeks and 3 years.                 (p. 788)

     Under aerobic conditions, half-lives of 2,4-D      Liu et al., 1981
     were 1.8 to 3.1 days.  Under anaerobic conditions, (p. 792)
     half-lives were 69 to 135 days.

     For low application rates (<100 Ug/g)  2,4-D        Ou et al., 1978
     degradation is favored by moisture and soil        (p. 246)
     organic matter.

     Bacteria are the major organisms responsible       Ou et al., 1978
     for 2,4-D degradation in soils, and                (p. 246)
     low soil pH will significantly reduce 2,4-D
     degradation rates.

     Solubility:  540 mg/L at 20C (in water)           MAS, 1977
                                                        (p. 493)

     2,4-D is chemically stable, but its esters         NAS, 1977
     are rapidly hydrolyzed to the free acid.           (p. 493)

     From Che available data, 2,4-D does not appear     U.S. EPA, 1981
     to be persistent in the environment.  2,4-D is     (p. 1-1)
     rapidly photolytically degraded in both air and
     water and does not sorb significantly to soils
     or sediments.

     Molecular weight:  221.04                          U.S. EPA, 1981
     Melting point:     104-141C                       (p. 3-2)
     Boiling point:     106C
     Density:           1.57 at 30C
     Formula:
                                   4-6

-------
                                            TABLE 4-1.  PHYTOTOXICITY OP 2,4-DICHLOROPHENOXYACETIC ACID
Plant/tissue
Tomato

Kidney beans
I Laeenana sp.
>j
Pea seedlings
Wheat seedlings

Chemical Form
Appl ted
2,4-D

NH4 2,4-D
2,4-D
2,4-D
2,4-D

Growth
Medium
soil

soil
soil
paper
petri dish

Experimental
Concentration"
(mg/L)
5-300

66-1000
500
1.5-50
0.01-100

Effects
Stem bending, increased
cell division adventi-
tious roots, parthenocarpy
Stomatal closure
Reduction of chlorophyll
a and b
tumor-like formations in
radicle and hypocotyl
21-98Z reduction in root
growth
19-71Z reduction in shoot
growth
References
U.S. EPA, 19B1 (Table 9-1)




U.S. EPA, 1981 (Table 9-15)

a Solution concentration to soil  or to germination  substrate  (paper).

-------
                              TABLE 4-2.  TOXICITY OF 2,4-DICHLOROPHENOXYACETIC ACID TO DOMESTIC ANIMALS AND WILDLIFE
Species
Cattle
Cattle
Sheep
Chickens
.p-
i Pheasant
CO
Quail
Mule Deer
Dog
Rat
Rat
Chemical Form
Fed
2,4-D
2,4-D
2,4-D
2,4-D
2,4-D
2,4-D
2,4-D
2,4-D
2,4-D
2,4-D
2,4-D
2,4-D
Peed
Concentration
(ug/g)
2,000
NRa
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
Daily Intake
(mg/kg)
NR
<10
300-300
900
NR
668
400-800
8
100
20
30
300
Duration
of Study
28 days
106 doses
9 doses
28 days
single dose
21 days
single dose
single does
single does
NH
NH
18-49 days
4 weeks
4 weeks
Effects
Anorexia and weight loss
Normal post mortem
Lethal
Anorexia and weight loss
LDjQ. No adverse effects
LD50
LD50
LD50
No adverse effects
LD50
75Z mortality
No effect
Gastrointestinal
irritation
References
U.S. EPA, 1981
(Table 10-1)
U.S. EPA, 1981
(Table 10-1)
U.S. EPA, 1981
(Table 10-1)
U.S. EPA, 1981
(Table 10-1)
Tucker and Crabtree,
1970 (p. 40)
Tucker and Crabtree,
1970 (p. 40)
Tucker and Crabtree,
1970 (p. 40)
HAS, 1977 (p. 496)
HAS, 1977 (p. 496)
aNR = Not reported.

-------
                                       TABLE 4-3.  TOXICITY Of 2,4-DICHLOROPHENOXYACETIC ACID TO SOIL BIOTA
Chemical Form
Species Applied
Breeder earthworms 2,4-D
Nematodes 2,4-D
Coccinellid beetles 2,4-D
vo Soil bacteria 2,4-D
Soil fungi 2,4-D
Rhizobium 2,4-D
Soil microbes 2,4-D
Soil microbes 2,4-D
Soil
Type
lab
lab
NRa
Thornton's
Medium
aoi 1
soil
sandy loam
loam
Soil
Concentration
(UB/B)
0.1-1000b
100C
~
125
100
2
10-200
10-200
Application
Rate
(kg/ha) Effects
0.1-100 no effect,
at 1000 ug/g
100Z mortality
LD50
1.68 Sluggish behavior
Inhibited soil bac-
teria at pH 5.6
but not at pH 6.4
 Increased fungi
population
Inhibited some species
No inhibition of
electron transport
system
Significantly inhibited
electron transport
system at all levels
References
U.S. EPA, 1981
(p. 11-9)
U.S. EPA, 1981
(p. 11-9)
Pimentel and Goodman,
1974 (p. 42)
Newman and Downing,
1958 (p. 352)


Trevors and Starodub,
1983 (p. 596)

a NR - Not reported.
b In solution - immersed for 2 hours.
c In solution - immersed for 48 hours.

-------
                                SECTION 5

                                REFERENCES
Abramowitz,  M.,  and  I.  A.  Stegun.    1972.    Handbook  of  Mathematical
     Functions.  Dover Publications, New York, NY.

American  Conference  of  Governmental   Industrial  Hygienists.    1983.
     Threshold Limit  Values  for Chemical  Substances  and Physical Agents
     in the  Work  Environment  with Intended Changes  for  1983-84.   Second
     Printing.  Cincinnati, OH.  93 pp.

Camp Dresser  and  McKee,  Inc.   1984a.   Development  of  Methodologies for
     Evaluating Permissible  Contaminant  Levels  in  Municipal  Wastewater
     Sludges.   Draft.  Office  of  Water Regulations  and Standards,  U.S.
     Environmental Protection Agency, Washington, D.C.

Camp Dresser  and  McKee, Inc.   1984b.   A  Comparison  of  Studies of Toxic
     Substances  in  POTW Sludges.    Prepared  for  the   U.S.   EPA  Under
     Contract No. 68-01-6403.  Annandale,  VA.  August.

Donigian, A.  S.   1985.   Personal  Communication.   Anderson-Nichols & Co.,
     Inc., Palo Alto, CA.  May.

Food  and  Drug  Administration.    1979.    Compliance  Program   Report  of
     Findings  FY78  Total  Diet  Studies-Adult   (7305-003).     Bureau  of
     Foods, Washington, D.C.

Food  and  Drug  Administration.    1980.    Compliance  Program   Report  of
     Findings FY77 Total  Diet  Studies-Adult  (7320.73).   Bureau of Foods,
     Washington, D.C.

Freeze,  R.  A.,  and  J.  A. Cherry.   1979.   Groundwater.  Prentice-Hall,
     Inc., Englewood  Cliffs, NJ.

Gelhar,  L.  W.,   and G.  J.  Axness.    1981.    Stochastic  Analysis  of
     Macrodispersion  in 3-Dimensionally Heterogeneous Aquifers.   Report
     No. H-8.   Hydrologic  Research  Program,  New  Mexico  Institute  of
     Mining and Technology, Soccorro, NM.

Gerritse, R.  G.,  R.  Vriesema,  J.  W. Dalenberg, 'and  H. P. DeRoos.  1982.
     Effects  of  Sewage Sludge  on  Trace Element  Mobility in  Soils.   J.
     Environ. Qual. 2:359-363.

Griffin,  R.   A.    1984.    Personal  Communication  to U.S.  Environmental
     Protection   Agency,   ECAO  -   Cincinnati,   OH.     Illinois  State
     Geological Survey.

Hassett, J.  J., W. L. Banwart,  and  R.  A.  Griffin.   1983.  Correlation of
     Compound  with  Sorption  Characteristics  of  Non-polar  Compounds  by
     Soils and  Sediments:  Concepts and  Limitations.   Chapter 15.   In:
     Francis, C.  W.  and  I. Auerbach  (eds.).   The  Environment and Solid
     Waste   Characterization,   Treatment   and Disposal.      Butterwork
     Publishers, Boston, MA.

                                   5-1

-------
Johnson,  R.,  and  D.  Manske.   1976.   Pesticide Residues  in Total  Diet
     Samples  (IX).  Pest. Monit. J.  9(4):157-159.

Jones,  A., and  G.  F.  Lee.    1977.'    In;    Risk Assessment  and  Health
     Effects  of Land  Application of  Municipal  Wastewater  and  Sludges.
     Sagik, B.,  and C.   Sorber,  (eds).   Center for Applied Technology,
     University of Texas at  San Antonio,   p.  52.

Lui,  D.,  W.  M.  Strachan,  K.  Thomson,  and  K.   Kwasniewska.     1981.
     Determination  of  the  Biodegradability of Organic  Compounds.    Env.
     Sci.  & Tech.  15(7):788-793.

Manske,  D.,  and R.  Johnson.   197S.   Pesticide Residues  in Total  Diet
     Samples  (VIII).  Pest.  Monit. J. 9(2):94-105.

Nash,  R., and  W.   Harris.    1973.    Screening for  Phytotoxic  Pesticide
     Interactions.  J. Env.  Qual. 2(4):493-497.

National  Academy of  Sciences.   1968.  Effects of Pesticides on Fruit and
     Vegetable  Physiology.    Vol. 6  of  Principles  of  Plant  and  Animal
     Pest  Control.  Publication 1968.

National   Academy  of  Sciences.    1977.     Drinking Water   and  Health.
     National  Research  Council  Safe  Drinking  Water  Committee,   NAS,
     Washington, D.C.

Newman,  A., and  C. Downing.  1958.   Herbicides  and  the  Soil.  J.  Agric.
     Food  Chem. 6(5):352-3.

Ou,  L.,  D. F. Rothwell, U.  B.  Wheeler, and J. M. Davidson.   1978.  The
     Effect   of  High  2,4-D Concentration  of   Degradation  and   Carbon
     Dioxide  Evolution in Soils.  J.  Env. Qual.  7(2):241-246.

Pettyjohn, W.  A.,  D. C. Kent,  T.  A. Prickett, H. E. LeCrand,  and F. E.
     Witz.    1982.    Methods  for   the  Prediction  of  Leachate  Plume
     Migration  and Mixing.   U.S.  EPA Municipal  Environmental Research
     Laboratory, Cincinnati, OH.

Pimentel,  D.,   and  N.   Goodman.     1974.    Environmental  Impact  of
     Pesticides. In;   Khan, M., (ed.).   Survival in Toxic Environments.
     Academic Press, NY.

Sikora,  L. J., W.  D.  Burge and  J.  E.  Jones.   1982.   Monitoring of  a
     Municipal  Sludge  Entrenchment  Site.   J. Environ.  Qual.  2(2):321-
     325.

Trevors,  J.,   and  M.  Starodub.   1983.    Effect of  2,4-D  on Electron
     Transport System  (ETS)  Activity and  Respiration in  Soil.  Bull  Env.
     Contarn.  Toxicol. 31:595-598.

Tucker,  R., and  D. Crabtree.   1970.   Handbook of Toxicity of Pesticides
     to  Wildlife.   Bureau  of Sport  Fisheries  and  Wildlife.   Res.  Pub.
     No.  84.
                                   5-2

-------
U.S.  Environmental  Protection Agency.    1976.    Quality Criteria  for
     Water.  Washington, D.C.

U.S.  Environmental  Protection Agency.   1977.   Environmental Assessment
     of  Subsurface Disposal  of  Municipal  Wastewater  Sludge:   Interim
     Report.     EPA/530/SW-547.      Municipal   Environmental   Research
     Laboratory, Cincinnati, OH.

U.S.  Environmental  Protection Agency.   1980.   2,4-Dichlorophenoxyacetic
     Acid  (2,4-D):  Hazard  Profile.    Revised  by  Environmental  Criteria
     and  Assessment Office,  Cincinnati, OH.    Prepared  by   Center  for
     Chemical Hazard Assessment,  Syracuse Research  Corp.,  Syracuse,  NY.
     14 pp.

U.S. Environmental  Protection Agency.   1981.   Criteria Document  for 2,4-
     Dichlorophenoxyacetic  Acid.     SRC TR-81-S86.     Cincinnati,   OH.
     Prepared by Syracuse Research Corporation, Syracuse, NY.

U.S.  Environmental  Protection Agency.   1982.   Draft  Interim Criterion
     Statement:      Chlorophenoxy  Herbicides.     Ambient  Water   Quality
     Criterion  for the  Protection  of Human  Health.   Internal  Review
     Draft CIN-82-D005.  Prepared for Criteria Standards Division Office
     of  Water  Regulation  and  Standards.   Environmental  Criteria  and
     Assessment  Office, Cincinnati,  OH.  44  pp.

U.S.  Environmental  Protection Agency.    1983.    Rapid  Assessment  of
     Potential   Groundwater   Contamination   Under   Emergency   Response
     Conditions.  EPA 600/8-83-030.
                                   5-3

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                               APPENDIX

  PRELIMINARY HAZARD INDEX CALCULATIONS FOR 2,4-DICHLOROPHENOXYACETIC
                    ACID IN MUNICIPAL SEWAGE SLUDGE
 I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING

    Based on  the recommendations of  the experts  at  the OURS  meetings
    (April-May,   1984),  an  assessment of  this  reuse/disposal option is
    not being conducted at  this  time.   The U.S. EPA  reserves  the right
    to conduct such an assessment for this option in the future.

II. LANDFILLING

    A.  Procedure

        Using Equation  1,  several  values of  C/CO for the  unsaturated
        zone  are calculated  corresponding  to  increasing values of  t
        until equilibrium  is  reached.   Assuming  a  5-year pulse  input
        from the landfill, Equation  3  is employed to estimate  the con-
        centration vs. time data at the water  table.  The concentration
        vs.  time curve is then transformed into a  square  pulse  having a
        constant  concentration  equal  to  the  peak  concentration,  Cu,
        from the  unsaturated  zone,  and a duration,  to, chosen  so that
        the  total  areas under-the  curve and  the pulse  are equal,  as
        illustrated in Equation  3.   This square  pulse  is then  used as
        the  input  to  the  linkage  assessment,  Equation  2,  which  esti-
        mates initial dilution in the  aquifer  to give  the initial con-
        centration, C0, for the saturated zone assessment.   (Conditions
        for  B,  minimum thickness  of unsaturated  zone,  have  been  set
        such that dilution is actually negligible.)   The  saturated zone
        assessment procedure is nearly identical to that  for the unsat-
        urated zone except for the definition of certain  parameters  and
        choice of  parameter  values.   The maximum concentration  at  the
        well,  Cmax,  is used  to  calculate  the  index  values  given  in
        Equations 4 and 5.

    B.  Equation 1:  Transport Assessment
     C(y.t) i  [exp(AL)  erfc(A2)  * exp(B1) erfc(B2>]
      Co

         Requires  evaluations  of   four  dimensionless  input  values  and
         subsequent  evaluation  of . the  result.    Exp(A^)  denotes  the
         exponential    of   A],   e ^,   where   erfc(A2)   denotes    the
         complimentary  error function  of  A2.   Erfc(A2) produces values
         between 0.0 and  2.0  (Abramowitz  and Stegun,  1972).

         where:
             Al - X_ [V* - (V*2 + 4D* x
             Al  2D*
                                 A-l

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          Y -  t  (V*2 *  AD*" x
     A2 =        (4D* x  t)

     B.  *_  [V*  +  (V*2 + 4D* x
     Dl
        _ Y +  t  (V*2 + AD*  x  U*)*
     82 "        (4D* x t)
and where for the unsaturated zone:

     C0 = SC x CF = Initial leachate concentration  (pg/L)
     SC = Sludge concentration of pollutant (mg/kg DW)
     CF = 250 kg sludge solids/in-* leachate =

          PS x 103
          1 - PS

     PS = Percent  solids  (by  weight)  of  Landf illed  sludge
          20Z
      t = Time (years)
     X  = h = Depth to groundwater (m)
     D* = a x V*  (m2/year)
      a = Dispersivity coefficient (m)

     V* =  9  (m/year)
          0 x R
      Q = Leachate generation rate (m/year)
      6 = Volumetric water content (unitless)
      R = 1 +  lll x KJ = Retardation factor (unitless)
                0
   P
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           0 = Aquifer porosity (unitless)
           R = 1 +  drv x Kd = Retardation factor = 1 (unitless)

               since K 	9 *  " *          and B > 2
                      K x i x 365             
    Equation 3.  Pulse Assessment
                   P(X,t)  for  0  <. t <. t
                       ,t)  - P(x,t - t0) for t > t(
          to  (for  unsaturated zone)  =  LT =  Landfill  leaching time
          (years)

          t0  (for  saturated  zone) = Pulse  duration  at  the  water
          table (x = h) as determined by  the  following equation:
               tn =  [   /   C dt]  * C
          P(XC)  =    i    as determined by Equation 1
                      co
                              A-3

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     E.    Equation 4.   Index of Groundvater Concentration  Resulting
          from Landfilled Sludge (Index 1)

          1.    Formula

               Index 1 = Cmax

               where:

                         = Maximum concentration of  pollutant at well  =
                           maximum of  C(A,t)  calculated  in Equation  1
                           (Ug/D

          2.    Sample  Calculation

               0.0186  Ug/L = 0.0186 Ug/L

     P.    Equation  5.     Index   of  Human   Toxicity  Resulting   from
          Groundwater  Contamination (Index 2)

          1.    Formula

                          (Ii x AC) + DI
               Index 2 =


               where:

                    Ij = Index   1  =  Index of  groundwater  concentration
                         resulting from Landfilled  sludge (ug/L)
                    AC = Average  human  consumption   of   drinking  water
                         (L/day)
                    DI = Average daily human dietary  intake  of  pollutant
                         (Ug/day)
                   ADI = Acceptable daily intake of pollutant (ug/day)

          2.    Sample  Calculation

               ,  ,,A   in-4 - (0.0186 Ug/L x 2 L/day) + 2.81 Ug/day
               3'25* * 10   "            8750  Ug/day

III. INCINERATION

     Based on  the recommendations of  the experts  at  the OWRS  meetings
     (April-May,   1984),  an  assessment of  this  reuse/disposal option  is
     not  being conducted at  this  time.   The U.S. EPA reserves  the  right
     to conduct such an assessment for this option  in the future.

 IV. OCEAN DISPOSAL

     Based on  the recommendations of  the experts  at  the OWRS  meetings
     (April-May,   1984),  an  assessment of  this  reuse/disposal option  is
     not  being conducted at  this  time.   The U.S. EPA reserves  the  right
     to conduct such an assessment for this option  in the future.
                                  A-4

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                                    TABLE A-l.  INPUT DATA VARYING IN LANDFILL ANALYSIS  AND RESULT  FOR  EACH CONDITION
>
Condition of Analysis
Input Data
Sludge concentration of pollutant, SC (pg/g DU)
Unsaturated zone
Soil type and characteristics
Dry bulk density, Pdry (g/mL)
Volumetric water content, 6 (unitless)
Fraction of organic carbon, foc (unitless)
Site parameters
Leachate generation rate, Q (m/year)
Depth to grounduater, h (m)
Dispersivity coefficient, a (m)
Saturated zone
Soil type and characteristics
Aquifer porosity, 0 (unitleae)
Hydraulic conductivity of the aquifer,
K (m/day)
Site parameters
Hydraulic gradient, i (unitless)
Distance from well to landfill, A 8. (m)
Dispersivity coefficient, a (m)
1
4.64


1.53
0.195
0.005

0.8
5
0.5


0.44
0.86

0.001
100
10
2
7.16


1.53
0.195
0.005

0.8
5
0.5


p. 44
0.86

0.001
100
10
3
4.64


1.925
0.133
0.0001

0.8
5
0.5


0.44
0.86

0.001
100
10
4 5
4.64 4.64


NA 1.53
NA 0.195
NA 0.005

1.6 0.8
0 5
NA 0.5


0.44 0.389
0.86 4.04

0.001 0.001
100 100
10 10
6
4.64


1.53
0.195
0.005

0.8
5
0.5


0.44
0.86

0.02
SO
5
7 B
7.16 N"


NA N
NA N
NA N

1.6 N
0 N
NA N


0.389 N
4.04 N

0.02 N
50 N
5 M

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                                                            TABLE A-l.  (continued)
Condition of Analysis
Results
Unsaturated zone assessment (Equations 1 and 3)
Initial leachate concentration, C0 (iig/L)
Peak concentration, Cu (|ig/L)
Pulse duration, to (years)
Linkage assessment (Equation 2)
Aquifer thickness, B (a)
Initial concentration in saturated zone, C0
(UB/D
1

1160
170.8
5.001

126.0
171.0
2

1790
263.6
5.001

126.0
264.0 .
3

1160
295.0
4.999

126.0
295.0
4

1160
1160
5.000

253.0
1160
5

1160
170.8
5.001

23.80
171.0
6

1160
170.8
S.001

6.320
171.0
7

1790
1790
5.000

2.380
1790
8

N
N
N

N
N
Saturated zone assessment (Equations 1 and 3)

  Maximum uell concentration,  Cmax (lig/L)

Index of groundwater concentration resulting
  from landfilled sludge. Index 1 (|ig/L)
  (Equation 4)

Index of human toxicity resulting from
  groundwater contamination, Index 2
  (unitless) (Equation 5)
    0.0186
    0.0186
                 0.0287
                 0.0287
0.0003254   0.0003277
0.0321
                              0.0321
                         0.0003285
                                            0.1261
                                            0.1261
                                       0.00035
                           0.0987
                                                         0.0987
                                                    0.0003437
                                                                      0.7435
                                                                      0.7435
                                                                                 41.43
                                                                                 41.43
                                   0.0004911   0.009791  0.0003211
aN  - Null condition, where no landfill exists;  no value is used.
bNA = Not applicable for this condition.

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