United Slates
Environmenta! Protection
Agency
Office o; Water
Regulations ana Standards
Washington, DC 20460
Water
                           Juns, 1985
Environmental Profs
and Hazard Indices
for Constituents
of Municipal Sludge;
Chromium

-------
                                 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,  landfilling,
incineration arid 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.

-------
                            TABLE OP CONTENTS


                                                                     Page

PREFACE 	   i

1.  INTRODUCTION	  1-1

2.  PRELIMINARY CONCLUSIONS FOR CHROMIUM IN MUNICIPAL SEWAGE
      SLUDGE	  2-1

    Landspreading and Distribution-and-Mark.eti.ng	  2-1

    Landfilling	  2-2

    Incineration	•	  2-2

    Ocean Disposal 	  2-2

3.  PRELIMINARY HAZARD INDICES FOR CHROMIUM IN MUNICIPAL SEWAGE
      SLUDGE	  3-1

    Landspreading and Distribution-and-Marketing 	  3-1

         Effect on soil concentration of chromium (Index 1) 	  3-1
         Effect on soil biota and predators of soil biota
           (Indices 2-3) 	  3-2
         Effect on plants and plant tissue
           concentration (Indices 4-6) 	  3-5
         Effect on herbivorous animals (Indices 7-8) 	  3-9
         Effect on humans (Indices 9-13) 	  3-12

    Landfilling	  3-20

         Index of groundwater concentration increment resulting
           from landfilled sludge (Index 1) 	  3-20
         Index of human toxicity resulting from
           groundwater contamination (Index 2)	  3-26

    Incineration	  3-28

         Index of air concentration increment resulting
           from incinerator emissions (Index 1) 	  3-28
         Index of human cancer risk resulting from
           inhalation of incinerator emissions
           (Index 2) 	  3-31

    Ocean Disposal 	  3-32
                                    11

-------
                            TABLE OP CONTENTS
                               (Continued)

                                                                     Page

4.  PRELIMINARY DATA PROFILE FOR CHROMIUM IN MUNICIPAL SEWAGE
      SLUDGE	  4~X

    Occurrence	•	•••  4
         Sludge 	  J"1
         Soil - Unpolluted 	  *~l
         Water - Unpolluted 	  4~2
         Air 	  4"4
         Food 	  4"4

    Human Effects 	  4~"5
         Ingestion 	    -
         Inhalation 	  4"6

    Plant Effects 	  4"8

         Phytotoxicity  	  4~8
         Uptake  	  4"8

    Domestic Animal and Wildlife Effects  	  4-8

         Toxicity 	  4~8
         Uptake  	  4"8

    Aquatic Life Effects	  4~8

         Toxicity 	  A~8
         Uptake  	  4"9

    Soil Biota Effects  	••••	  4"9

    Physicochemical Data  for  Estimating Fate  and  Transport  	  4-10

 5.  REFERENCES	• • • •	  5-I

 APPENDIX.   PRELIMINARY  HAZARD INDEX CALCULATIONS  FOR
    CHROMIUM  IN  MUNICIPAL SEWAGE  SLUDGE  	•	  A-l
                                    ill

-------
                                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.    Chromium (Cr)  was  initially identified  as  being of
potential concern when sludge  is landspread  (including  distribution and
marketing), placed  in  a  landfill,  or incinerated.*   This  profile  is a
compilation of information that  may be useful  in  determining  whether Cr
poses an actual hazard to human  health or the environment when sludge is
disposed of by these methods.
     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  •+• soil •» plant uptake •* animal uptake •*  human  toxicity).
The  values and   assumptions   employedin   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  landspreading and  distribution and marketing, landfilling,
and  incineration  practices are  included  in this  profile.   The calcula-
tion 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  (OWES)  to discuss  landspreading,  landfilling, incineration,
  and ocean disposal, respectively, of municipal sewage sludge.
                                   1-1

-------
                                SECTION 2

     PRELIMINARY CONCLUSIONS FOR CHROMIUM 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-AMD-MARKETING

     A.   Effect on Soil  Concentration of Chromium

         Landspreading of  sludge  is not expected to increase  the  soil
         concentration of  Cr  except  when   sludge containing a  typical
         concentration of  Cr  is  applied at a  high rate or  when  sludge
         containing a high concentration of Cr is applied at medium to
         high rates (see Index 1).

     B.   Effect on Soil  Biota and Predators of Soil Biota

         Conclusions concerning soil  biota  toxicity were not drawn due
         to lack of data (see  Index 2).  Landspreading  of  sludge  is not
         expected  to  pose  a  toxic hazard  due  to Cr  for predators  of
         soil biota (see Index 3).

     C.   Effect on Plants  and Plant Tissue  Concentration

         Landspreading  of   sludge  is  not  expected  to  produce  soil
         concentrations  of Cr  which  pose  a  phytotoxic  hazard  except
         possibly when sludge  containing a high  concentration of Cr  is
         applied at a high rate  (see Index 4).   The concentrations  of
         Cr  in tissues  of 'plants  in  the  animal  and  human  diet  are
         expected  to  increase above  background  levels  when sludge  is
         landspread;  these increases  may   be   substantial  when  sludge
         containing a high  concentration of Cr is  applied at  a high  rate
         (see  Index 5).   The substantial  increases   in  plant  tissue
         concentration of  Cr  predicted  when  high-Cr   sludge  is  land-
         spread at  a  high  rate may be  precluded  by phytotoxicity  (see
         Index 6).

     D.   Effect on Herbivorous Animals

         Landspreading of  sludge  is  not  expected  to   result  in plant
         tissue  concentrations  of Cr  that  pose  a  toxic  hazard  to
         animals consuming forage  crops  (see  Index  7).   Toxicity  to
         herbivorous  animals   through  direct  ingestion  of   sludge  or
         sludge-amended  soil  is not expected to  occur (see  Index 8).
                                   2-1

-------
     B.    Effect  on Humans

          Human  intake  of Cr through the  consumption of plants  grown  in
          sludge-amended  soil is  not expected  to pose  a  health  threat
          (see  Index  9).   A health threat  due  to Cr is not  expected  for
          humans   who  consume   animal   products  derived  from   animals
          feeding on  plants  grown in sludge-amended  soil (see  Index 10).
          Human   intake  of  Cr   through  consumption  of  animal  products
          derived from animals  which have  ingested sludge-amended  soil
          or  pure sludge  is  not expected  to pose  a health  threat  (see
          Index 11).    The direct  ingestion  of  sludge-amended  soil  or
          pure  sludge  by humans  is  likewise  not   expected  to  pose  a
          health  threat due  to  Cr (see  Index 12).  The aggregate  amount
          of  Cr  in the human diet resulting  from  landspreading of  sludge
          is  not  expected to  pose a health  threat  (see  Index  13).

 II.  LAHDPILLIMG

     Groundwater   concentration   of   Cr  at  the  well   are   expected   to
     increase above  background  concentrations when  sludge is landfilled;
     this  increase may be substantial at a disposal  site with  all  worst-
     case  conditions  (see Index 1).   Groundwater contamination  produced
     by  landfilled sludge is not expected  to pose a human health  threat
     due to Cr  (see Index 2).

III.  INCINEHATIOH

     Incineration of  sludge  is  expected  to  increase  air concentrations
     of  Cr above background  levels; this  increase may  be  substantial
     when   sludge containing a high concentration  of  Cr is incinerated  at
     a  high  feed  rate  (see  Index  1).    Inhalation  of  emissions  from
     sludge  incineration  is  expected to  increase the  human cancer  risk
     due   to   Cr  above  the   risk  posed   by  background    urban   air
     concentrations  of  Cr.    This   increase  in  cancer  risk   may  be
     substantial when  high-Cf sludge is  incinerated at a high feed rate
     (see  Index 2).

 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.
                                   2-2

-------
                                SECTION  3

                 PRELIMINARY HAZARD INDICES  FOR CHROMIUM
                       IN MUNICIPAL SEWAGE SLUDGE
I.   LANDSPREADING AND DISTRIBUTION-AND-MARKETING

     A.    Effect  on Soil  Concentration of Chromium

          1.    Index of Soil Concentration Increment (Index 1)

               a.   Explanation - Shows degree of  elevation of pollutant
                    concentration in  soil  to  which  sludge  is  applied.
                    Calculated  for  sludges  with  typical  (median  if
                    available) and worst  (95th  percentile  if available)
                    pollutant  concentrations,  respectively,  for  each of
                    four sludge  loadings.   Applications  (as  dry matter)
                    are chosen and explained as follows:

                      0 mt/ha  No sludge applied.   Shown  for all indices
                               for  purposes  of   comparison,   to  distin-
                               guish  hazard posed by  sludge  from  pre-
                               existing   hazard    posed  by   background
                               levels or other sources of the  pollutant.

                       5 mt/ha  Sustainable  yearly agronomic  application;
                               i.e.,   loading  typical  of   agricultural
                               practice,   supplying  ^50   kg  available
                               nitrogen per hectare.

                      50 mt/ha  Higher  application  as  may  be   used on
                               public  lands,  reclaimed  areas   or  home
                               gardens.

                     500  mt/ha Cumulative    loading   after   years   of
                               application.

               b.   Assumptions/Limitations - Assumes  pollutant is  dis-
                     tributed and retained within  the upper 15  cm of  soil
                     (i.e.,   the  plow  layer),  which has  an  approximate
                     mass  (dry matter) of 2 x 103  mt/ha.

               c.   Data Used and Rationale

                       i.  Sludge  concentration of pollutant  (SC)

                          Typical     230.1 Ug/g  DW
                          Worst      1499.7 Ug/g  DW

                          Hexavalent   Cr  (Cr  VI)  is  a  strong  oxidizing
                          agent  and  is  readily  reduced  to  trivalent  Cr
                          (Cr III)  in the  presence  of  organic  matter,
                          such as untreated  sewage (U.S.  EPA,  1978).   Cr
                                    3-1

-------
                   in  treated   sewage   sludge,   as  in  untreated
                   sewage,  is  assumed to be  in  sufficient contact
                   with  organic  matter  that the  remaining  hex-
                   avalent  Cr  is reduced  to  the  trivalent  form
                   (Cr III).   Therefore,  trivalent Cr  values are
                   used  in  calculating  hazard  indices  for   land-
                   spreading and landfilling.  However, hexavalent
                   Cr  values   are  used   in  calculating  hazard
                   indices  for  incineration  due  to the  high tem-
                   peratures   in  the  combustion  chamber.    The
                   typical  and  worst  sludge concentrations are the
                   median  and  95th percentile values statistically
                   derived  from  sludge  concentration  data  from a
                   survey   of  40  publicly-owned   treatment   works
                   (POTWs)  (U.S.  EPA,  1982).   (See  Section  4,
                   p. 4-1.)

               ii. Background concentration of pollutant in soil
                   (BS) =  100  ug/g DW

                   Allaway  (1968)  reported  a  mean of  100 ppm  Cr in
                   natural  soils ranging from 5  to  3000 ppm.  (See
                   Section  4,  p.  4-2.)

          d.    Index  1 Values

                                   Sludge Application Rate  (rot/ha)
                   Sludge
               Concentration       0        5       50        500
Typical
Worst
1
1
1.0
1.0
1.0
1.3
1.3
3.8
          e.   Value Interpretation -  Value  equals  factor by  which
               expected ' soil  concentration  exceeds  background  when
               sludge is  applied.   (A value  of 2 indicates  concen-
               tration  is  doubled;   a   value  of  0.5   indicates
               reduction  by one-half.)

          f.   Preliminary Conclusion  -  Landspreading  o£  sludge  is
               not expected  to increase  the  soil concentration  of
               Cr   except   when    sludge   containing   a   typical
               concentration  of  Cr is  applied at  a  high rate  or
               when sludge containing a high concentration of  Cr  is
               applied at medium to high  rates  (see  Index 1).

B.   Effect on Soil Biota and Predators of Soil Biota

     1.   Index of Soil Biota Toxicity (Index 2)

          a.   Explanation -  Compares pollutant  concentrations  in
               sludge-amended soil with soil concentration shown  to
               be toxic for some organism.
                              3-2

-------
b.   Assumptions/Limitations -  Assumes pollutant  form in
     sludge-amended  soil   is   equally  bioavailable  and
     toxic as form used in  study where toxic effects were
     demonstrated.

c.   Data Used and Rationale

       i. Index of soil concentration increment (Index 1)

          See Section 3, p.  3-2.

      ii. Background  concentration of  pollutant  in soil
          (BS) = 100 Ug/g DW

          See Section 3, p.  3-2.

     iii. Soil  concentration  toxic to  soil biota  (IB)  -
          Data not immediately available.

d.   Index 2  Values - Values  were not calculated  due to
     lack of data.

e.   Value Interpretation - Value equals  factor  by which
     expected soil  concentration exceeds  toxic concentra-
     tion.   Value >1  indicates a toxic hazard  may exist
     for soil biota.

f.   Preliminary  Conclusion -   Conclusion  was not  drawn
     because  index values could  not be calculated.

Index of Soil Biota Predator Toxicity (Index 3)

a.   Explanation   -  Compares   pollutant   concentrations
     expected  in  tissues  of organisms  inhabiting sludge-
     amended  soil  with food  concentration  shown  to  be
     toxic to a predator on soil organisms.

b.   Assumptions/Limitations   -  Assumes   pollutant  form
     bioconcentrated  by soil  biota is  equivalent in cox-
     icity  to form used  to demonstrate toxic  effects in
     predator.  Effect  level  in predator may be estimated
     from that  in a different species.

c.   Data Used  and Rationale

       i. Index of soil concentration increment (Index 1)

          See Section 3, p. 3-2.

      ii. Background  concentration of  pollutant  in soil
          (BS)  =  100 Ug/g DW

          See Section 3, p. 3-2.
                    3-3

-------
iii. Uptake slope of  pollutant in soil  biota  (UB) =
     0.5 ug/g tissue DW (ug/g  soil DW)"1

     Helmke  et  al.  (1979)  measured  the  uptake  of
     metals in earthworms  from sewage sludge-amended
     plots and concluded  that  Cr is not taken  up to
     a  significant  degree; that  is,  the  Cr  concen-
     tration  in  the  soil  material  ingested  by  the
     earthworm is  nearly  equivalent  to  that in  the
     excreted cast and the concentration in  the worm
     body  is  virtually  unchanged by  sludge  applica-
     tion.   However,  since  a  predator  ingesting  an
     earthworm  also  ingests   the  soil  material  it
     contains, predator  Cr  intake  will  be  affected
     by  sludge  application.    Information  on  the
     relative dry  weight  of  earthworm  gut  contents
     alone and  total  weight  including  gut  contents
     is not immediately available.   If it  is  assumed
     that  gut  contents   constitute  50   percent  of
     total  dry weight,  then  an  uptake  factor  of
     0.5 Mg/g  tissue  DW  (yg/g  soil  DW)"1 would  be
     the  minimum  value  to  use, where  "tissue"  is
     understood to  be the total amount  ingested  by
     the predator.

 iv. Background concentration  in soil  biota (BB)  =
     50.5 ug/g DW

     In  the  study  described  above,  Helmke  et  al.
     (1979)   found  that   the   Cr   concentration  in
     worms,  after  correction  for  contamination  by
     casts, was approximately  1.0  yg/g  DW.   Follow-
     ing  the  above  assumption  that  the whole  worm is
     50  percent  soil  by  dry weight,  the  background
     concentration  in  worms  is  (BS  + 1.0 ug/g)/2  =
     50.5 ug/g DW.

  v. Feed  concentration  toxic  to   predator  (TR)  =
     2000 ug/g DW

     Data  presented by  MAS  (1980)  (see  Section  4,
     p. 4-15)  show  no  adverse  effects  of  Cr III
     ingestion  except   when   a  concentration   of
     2000 ug  Cr/g  feed   (assume   DW)   was   fed  to
     chickens  for  21 days.     This  exposure  level
     resulted  in  reduced  growth.    Lacking  data  on
     adverse  effect levels  for  Cr  III  in any  other
     species, the  value  of  2000 Ug/g DW  is used  as
     the  feed concentration  toxic   to   predators  of
     soil biota.
               3-4

-------
          d.    Index  3  Values

                                  Sludge Application Rate (mt/ha)
Sludge
Concentration
Typical
Worst
0
0.025
0.025
5
0.025
0.026
50
0.026
0.034
500
0.032
0.095
          e.    Value Interpretation -  Value equals factor  by which
               expected concentration  in  soil  biota  exceeds  that
               which is toxic  to predator.   Value >  1  indicates a
               toxic hazard may exist  for predators of  soil biota.

          f.    Preliminary Conclusion  -  Landspreading  of  sludge  is
               not expected  to pose a toxic  hazard due to  Cr for
               predators of soil biota.

C.   Effect on Plants and Plant Tissue Concentration

     1.   Index of Phytotoxicity (Index 4)

          a.    Explanation  - Compares  pollutant  concentrations  in
               sludge-amended  soil  with  the  lowest  soil concentra-
               tion shown to be toxic for some plant.

          b.   Assumptions/Limitations -  Assumes  pollutant  form  in
               sludge-amended   soil  is   equally  bioavailable  and
               toxic as form used  in  study where toxic effects were
               demonstrated.

          c.   Data Used and Rationale

                  i. Index of soil concentration  increment (Index  1)

                    See Section 3, p.  3-2.

                ii. Background  concentration  of pollutant,  in soil
                    (BS) =  100  Ug/g DW

                    See Section 3, p.  3-2.

               iii. Soil   concentration   toxic  to  plants   (TP)  =
                    200 Ug/g DW

                    200  Ug/g DW is the lowest soil concentration of
                    Cr at  which  an  adverse  effect  was  observed
                     (bean  plant) (Council  for Agricultural  Science
                    and  Technology  (CAST),  1976).   A 25%  yield
                    reduction  is  associated with  200  Ug/g  DW  Cr in
                     soil.   (See  Section 4,  p.  4-11.)
                              3-5

-------
d.   Index 4 Values

                        Sj.udge Application Rate  (mt/ha)
         Sludge
     Concentration        0         5       50       500
Typical
Worst
0.50
0.50
0.50
0.52
0.52
0.67
0.63
1.9
e.   Value Interpretation  - Value equals  factor by which
     soil concentration  exceeds phytotoxic concentration.
     Value >  1  indicates a  phytotoxic  hazard  may exist.

f.   Preliminary  Conclusion -  Landspreading  of sludge  is
     not  expected to  produce  soil  concentrations  of  Cr
     which pose a phytotoxic hazard  except possibly  when
     sludge  containing  a  high  concentration  of   Cr  is
     applied at a high rate.

Index  of Plant  Concentration  Increment  Caused by  Uptake
(Index 5)

a.   Explanation  -  Calculates  expected  tissue  concentra-
     tion  increment  in  plants  grown  in sludge-amended
     soil,  using  uptake  data  for  the  most  responsive
     plant " species  in  the  following  categories:     (1)
     plants  included  in  the  U.S.  human  diet; and   (2)
     plants  serving  as  animal feed.   Plants  used  vary
     according  to availability  of  data.

b.   Assumptions/Limitations  - • Assumes  a linear   uptake
     slope.   Neglects  the  effect of  time; i.e., cumula-'
     tive  loading over  several years  is  treated equiva-
     lently  to  single  application  of  the  same amount.
     The uptake  factor  chosen  for   the   animal diet  is
     assumed  to  be   representative  of  all crops  in  the
     animal  diet.  See  also  Index 6  for  consideration  of
     phytotoxicity.

c.   Data  Used  and Rationale

        i.  Index of  soil  concentration  increment (Index 1)

           See Section 3,  p. 3-2.

       ii.  Background  concentration  of  pollutant  in  soil
           (BS)  = 100  Ug/g DW

           See Section 3,  p. 3-2.
                     3-6

-------
    iii. Conversion  factor  between  soil  concentration
         and application rate (CO) =  2  kg/ha  (ug/g)"1

         Assumes  pollutant  is  distributed  and retained
         within  upper 15  cm of  soil  (i.e.  plow  layer)
         which  has an approximate  mass  (dry matter)  of
         2 x 103.

      iv. Uptake  slope of pollutant in plant tissue  (UP)

         Animal  diet:
         Fodder  rape   0.081  Ug/g tissue DW (kg/ha)'1

         Human diet:
         Onion         0.080 Ug/g tissue  DW  (kg/ha)"1

         The highest  uptake  values  for Cr in  sludge  were
         chosen   to   reflect   a   worst-case   scenario.
         Uptake  values for  Cr VI and other  compounds  of
         Cr  are not considered  analogous to Cr found  in
         sludge.  (See Section 4, pp. 4-13 and 4-14.)

       v. Background concentration in  plant tissue  (BP)

         Animal  diet:
         Fodder rape     2.6  ug/g DW

         Human diet:
         Onion          1.1  Ug/g DW

          The background  concentrations in plant  tissues
          are  the   control  tissue  concentrations   of  the
          same  plants  used   for uptake  values.     (See
          Section 4, pp.  4-13 and 4-14.)
d.   Index 5 Values
                                   Sludge Application
                                      Rate (mt/ha)

Diet
Animal

Human

Sludge
Concentration
Typical
Worst
Typical
Worst

0
1.
1.
1.
1.


0
0
0
0


1
1
1
1

5
.0
.2
.0
.5

50
1.
3.
1.
6.



500
2
2
5
0
2.
18
4.
42a
6

8

aValue exceeds  comparable  value  of  Index 6; therefore may
be precluded by phytotoxicity.

e.   Value  Interpretation  - Value equals  factor  by which
     plant  tissue concentration  is  expected  to  increase
     above  background when grown in sludge-amended soil.
                    3-7

-------
     f.   Preliminary Conclusion - The  concentrations  of Cr in
          tissues of  plants  in the  animal  and human  diet are
          expected  to increase  above  background  levels  when
          sludge  is   landspread;    these   increases  may  be
          substantial   when    sludge   containing    a    high
          concentration of Cr is applied at a high rate.

3.   Index  of  Plant  Concentration  Increment   Permitted  by
     Phytotoxicity (Index 6)

     a.   Explanation -  Compares  maximum plant  tissue concen-
          tration  associated  with  phytotoxicity  with  back-
          ground  concentration  in  same  plant  tissue.    The
          purpose is  to determine  whether  the  plant  concentra-
          tion  increments  calculated   in   Index  5   for  high
          applications are  truly  realistic,  or  whether  such
          increases  would be precluded by phytotoxicity.

     b.   Assumptions/Limitations  -  Assumes  that  tissue  con-
          centration will be  a consistent  indicator  of  phyto-
          toxicity.

     c.   Data Used and Rationale

            i. Maximum  plant   tissue concentration  associated
               with phytotoxicity (PP)

               Animal diet:
               Oat leaves    252 Ug/g DW

               Human diet:
               Onion          14 Ug/g DW

               Most  studies reporting  tissue concentrations of
               Cr associated  with  phytotoxicity give  data for
               vegetative  tissue  such  as  leaves  (see  Sec-
               tion 4, pp. 4-11  and  4-12).   Cr  concentrations
               may  be substantial  in  leaves:   30 Ug/g  DW was
               associated with 25% reduction in  yield of field
               beans,  and 252  Ug/g DW  with 41%  reduction in
               oat  leaves.    Neither  of  these  reductions  is
               great  enough  to preclude   the  possibility  of
               exposure  of  herbivorous  animals  to  these  con-
               centrations as  feed.   Since  a value for maximum
               tissue  concentration  in  fodder  rape  is  not
               available, oat  leaves  will  be used  to represent
               plants  in  the animal  diet.   The only informa-
               tion  immediately  available  on  the  maximum tis-
               sue  concentrations  observed in  human-consumed
               tissues is a  statement  (NAS,  1974)  that concen-
               trations  as  high  as   14  Ug/g  DW  have  been
               observed in fruits, vegetables, and grain with-
               out  evidence  of  harm.   Although  details  are
               lacking and  phytotoxicity was  not  observed, it
                         3-8

-------
               will  be  assumed  that  tissue  concentration  in
               onions will  not  exceed  14  Ug/g  DW.    (See  Sec-
               tion 4, p.  4-12.)

           ii. Background  concentration in plant tissue (BP)

               Animal diet:
               Oat leaves     1.0  ug/g DW

               Human diet:
               Onion         1.1  Ug/g DW

               A  background  concentration for  oat   leaves  was
               not immediately available.   However,  data  from
               Section  4, p. 4-13,  indicate  that   background
               concentrations in  corn and  wheat  leaf vary  from
               0.26 to  2.1 Ug/g  DW.   The  background in fodder
               rape was 2.6 Ug/g DW.   Based on  these values, a
               concentration of  1.0  Ug/g  DW is  chosen  for  oat
               leaves.  The  value  for  onion  is from  the  same
               study used  in  selecting an uptake value.   (See
               Section 4,  p.  4-14.)

     d.   Index 6 Values

              Plant              Index Value

              Oat leaves            252
              Onion                  13

     e.   Value   Interpretation  -"   Value   gives the  maximum
          factor  of  tissue  concentration   increment   (above
          background)  which  is   permitted  by  phytotoxicity.
          Value is compared  with values for the same  or simi-
          lar plant'  tissues  given  by  Index 5.   The lowest  of
          the two indices indicates  the maximal  increase which'
          can occur at any given  application rate.

     f.   Preliminary  Conclusion -  The substantial increases
          in  plant  tissue concentration  of  Cr  predicted  when
          high-Cr sludge  is  landspread at  a  high  rate  may  be
          precluded by phytotoxicity.

Effect on Herbivorous Animals

1.   Index of Animal  Toxicity Resulting from  Plant  Consumption
     (Index 7)

     a.   Explanation   -   Compares   pollutant   concentrations
          expected  in  plant  tissues  grown  in  sludge-amended
          soil  with  food  concentration  shown to be toxic  to
          wild or domestic herbivorous animals.  Does  not  con-
          sider  direct  contamination  of  forage  by  adhering
          sludge.
                         3-9

-------
b.   Assumptions/Limitations  -   Assumes   pollutant  form
     taken up by plants  is  equivalent  in  toxicity to form
     used to demonstrate  toxic  effects  in animal.  Uptake
     or  toxicity in  specific  plants  or  animals  may  be
     estimated from other species.

c.   Data Used and Rationale

       i. Index  of  plant  concentration  increment  caused
          by uptake (Index 5)

          Index  5  values  used  are  those  for  an  animal
          diet (see Section 3, p. 3-7).

      ii. Background concentration in  plant tissue (BP) =
          2.6 ug/g DW

          The background  concentration value  used  is for
          the  plant  chosen  for  the  animal  diet  (see
          Section 3, p. 3-7).

     iii. Peed concentration  toxic to  herbivorous animal
          (TA) = 2000 ug/g DW

          Chickens  ingesting  feed  containing  2000 Ug/g
          Cr III were  found  to  suffer  reduced growth over
          a 21-day  study  (NAS,  1980).   This value was the
          lowest  concentration  of   Cr  III   found  that
          resulted  in  an  adverse effect  in animals in the
          human  food chain.   (See Section 4,  p.  4-15.)

d.   Index 7 Values

                        Sludge Application Rate  ('mt/ha)
         Sludge
     Concentration        0         5       50        500

        Typical         0.0013    0.0013   0.0016   0.0034
        Worst  "       0.0013    0.0016   0.0041   0.024

e.   Value  Interpretation - Value equals  factor by  which
     expected  plant   tissue  concentration  exceeds  that
     which  is toxic to  animals.  Value  >  1  indicates a
     toxic hazard may  exist for  herbivorous animals.

f.   Preliminary Conclusion - Landspreading  of  sludge is
     not    expected   to    result   in    plant   tissue
     concentrations  of  Cr  that  pose  a  toxic  hazard  to
     animals  consuming forage crops.
                    3-10

-------
2.   Index of Animal  Tozicity Resulting  from Sludge Ingestion
     (Index 8)

     a.   Explanation -  Calculates  the amount  of  pollutant in
          a grazing animal's  diet resulting  from  sludge adhe-
          sion  to  forage  or  from  incidental  ingestion  of
          sludge-amended  soil  and   compares  this  with  the
          dietary toxic  threshold concentration for  a grazing
          animal .

     b.   Assumptions/Limitations  -  Assumes  that  sludge  is
          applied over  and  adheres  to growing  forage,  or that
          sludge  constitutes  5 percent  of  dry matter  in  the
          grazing animal's  diet, and that  pollutant  form in
          sludge  is   equally  bioavailable  and  toxic   as  form
          used to demonstrate  toxic effects.   Where  no sludge
          is  applied  (i.e.,  0 mt/ha),  assumes diet is 5 per-
          cent soil  as a basis for comparison.

     c.   Data Used and Rationale

            i. Sludge concentration of pollutant (SC)

               Typical     230.1  yg/g DW
               Worst      1499.7 ug/g DW

               See Section 3, p. 3-1.

           ii. Background  concentration  of  pollutant  in soil
               (BS) = 100 ug/g DW

               See Section 3, p. 3-2.

          iii. Fraction  of animal diet  assumed to  be soil (GS)
               Studies  of  sludge  adhesion  to  growing  forage
               following  applications  of  liquid or filter-cake
               sludge  show that when  3  to  6  mt/ha  of  sludge
               solids  is  applied,  clipped   forage  initially
               consists  of up to  30  percent  sludge  on  a dry-
               weight  basis  (Chaney and  Lloyd, 1979; Boswell,
               1975).   However, this  contamination diminishes
               gradually  with time  and growth,  and  generally
               is not  detected  in  the  following year's growth.
               For  example,  where  pastures  amended at  16 and
               32 mt/ha  were grazed throughout a growing sea-
               son  (168  days),  average sludge content  of for-
               age    was    only    2.14   and   4.75 percent,
               respectively  (Bertrand  et  al.,  1981).   It seems
               reasonable  to assume that animals  may  receive
               long-term  dietary  exposure to  5 percent  sludge
               if  maintained on a forage to   which  sludge  is
               regularly  applied.   This estimate  of  5  percent
                         3-11

-------
                   sludge  is used regardless  of application rate,
                   since  the above  studies did not  show  a clear
                   relationship  between application  rate  and  ini-
                   tial  contamination, and  since adhesion  is  not
                   cumulative yearly because of  die-back.

                   Studies  of grazing  animals  indicate  that  soil
                   ingestion, ordinarily  <10 percent of dry  weight
                   of  diet, may  reach as  high  as  20  percent  for
                   cattle  and 30  percent  for sheep during  winter
                   months  when  forage  is  reduced   (Thornton  and
                   Abrams,   1983).     If   the   soil  were   sludge-
                   amended,  it  is  conceivable that up to 5  percent
                   sludge  may be ingested  in  this manner as well.
                   Therefore,  this  value   accounts  for  either  of
                   these  scenarios,  whether forage is harvested  or
                   grazed  in the field.

                iv. Feed  concentration toxic  to  herbivorous  animal
                   (TA) =  2000  ug/g  DW

                   See Section  3,  p. 3-10.

          d.    Index  8 Values

                                 Sludge Application  Rate  (mt/ha)
                   Sludge
               Concentration       0          5         50       500

                  Typical         0.0025    0.0058  0.0058    0.0058
                  Worst           0.0025    0.038    0.038     0.0058

          e.    Value  Interpretation -  Value equals factor by which
               expected  dietary concentration exceeds  toxic  concen-
               tration.    Value  >  1  indicates   a  toxic  hazard may
               exist  for  grazing animals.

          f.    Preliminary  Conclusion   -   Toxicity  to  herbivorous
               animals   through  direct   ingestion  of  sludge   or
               sludge-amended soil  is not  expected to occur.
E.   Effect on Humans
          Index of Human  Toxicity Resulting from  Plant  Consumption
          (Index 9)

          a.   Explanation -  Calculates  dietary intake  expected  to
               result  from  consumption  of  crops  grown  on  sludge-
               amended soil.   Compares dietary intake with  accept-
               able daily intake (ADI) of the pollutant.

          b.   Assumptions/Limitations - Assumes that all  crops  are
               grown on sludge-amended soil and that  all those con-
               sidered to be  affected take  up the pollutant  at  the
                             3-12

-------
same rate as  the  most  responsive plant(s) (as chosen
in Index 5).   Divides  possible variations in dietary
intake into  two  categories:    toddlers  (18 months to
3 years) and individuals over 3 years old.

Data Used and Rationale

  i. Index  of plant  concentration  increment  caused
     by uptake (Index 5)

     Index 5  values  used are those  for  a human diet
     (see Section 3, p. 3-7).

 ii. Background concentration  in plant  tissue (BP) =
     1.1 Ug/g DW

     The background  concentration value  used  is for
     the  plant   chosen   for   the  human  diet  (see
     Section 3, p. 3-7).

iii. Daily  human dietary intake  of affected  plant
     tissue (DT)

     Toddler     74.5 g/day
     Adult      205   g/day

     The intake  value  for adults is based  on  daily
     intake of crop  foods (excluding fruit)  by vege-
     tarians  (Ryan  et  al.,  1982);  vegetarians  were
     chosen  to  represent the worst  case.   The value
     for toddlers  is  based on the  FDA  Revised Total
     Diet  (Pennington,   1983)   and  food  groupings
     listed  by the  U.S. EPA  (1984a).    Dry weights
     for individual  food groups  were  estimated from
     composition  data  given  by   the  U.S. Department
     of  Agriculture  (USDA)   (1975).   These  values
     were    composited    to    estimated   dry-weight
     consumption of all non-fruit crops.

 iv. Average daily  human dietary intake of pollutant
     (DI)

     Toddler    22 ug/day
     Adult      65 Ug/day

     The adult  value is  the  average of  Cr  in  three
     diet studies  reported  by MAS  (1974).   No  value
     was  reported  for  toddlers.    The  value  for
     toddlers  is  assumed to  be  1/3  the value  of
     adults.  (See Section 4, p.  4-5.)
               3-13

-------
            v. Acceptable  daily  intake of  pollutant  (ADI) =
               111,000 Ug/day

               An  ADI of   111,000 Jig/day  was  derived  by  the
               U.S.  EPA  (1984b)  based  on  the  highest   no-
               observed-adverse-effects  level   (NOAEL)  in  a
               study on rats fed  a  diet containing Cr III.  An
               uncertainty  factor  of 1000 was  applied in cal-
               culating  the  human   ADI.     (See  Section  4,
               p. 4-6.)
     d.   Index 9 Values
                    Sludge
          Group   Concentration
                         0
       Sludge Application
          Rate (mt/ha)

          5        50     500
          Toddler   Typical
                    Worst
          Adult
          Typical
          Worst
0.00020 0.00023 0.00054 0.0030
0.00020 0.00057 0.0038  0.0303

0.00058 0.00068 0.0015  0.0083
0.00058 0.0016  0.011   0.083s
     f.
aValue  may   be  precluded   by   phytotoxicity;   see
Indices 5 and 6.

Value  Interpretation  -  Value equals  factor  by which
expected intake  exceeds  ADI.   Value  >  1  indicates  a
possible human  health threat.   Comparison  with  the
null  index  value at 0 mt/ha  indicates  the  degree to
which  any  hazard  is  due  to  sludge  application,  as
opposed to pre-existing dietary sources.

Preliminary  Conclusion - Human intake  of  Cr through
the  consumption  of  plants  grown  in sludge-amended
soil is not expected to pose a health threat.
2.   Index  of Human  Toxicity  Resulting  from Consumption  of
     Animal  Products  Derived  from Animals  Feeding on  Plants
     (Index 10)

     a.   Explanation   -  Calculates   human  dietary   intake
          expected  to   result   from   consumption   of   animal
          products  derived  from  domestic  animals  given  feed
          grown on  sludge-amended  soil (crop  or  pasture land)
          but  not  directly  contaminated  by  adhering  sludge.
          Compares expected intake with ADI.

     b.   Assumptions/Limitations  - Assumes   that  all  animal
          products  are  from animals receiving all  their  feed
          from sludge-amended soil.   The uptake  slope of  pol-
          lutant   in animal tissue  (UA)  used  is  assumed to  be
                        3-14

-------
representative of all  animal  tissue  comprised by the
daily human  dietary intake (DA) used.   Divides pos-
sible variations in dietary  intake  into two categor-
ies:     toddlers   (18  months  to   3   years)  and
individuals over 3  years old.

Data Used and Rationale

  i. Index  of plant  concentration  increment  caused
     by uptake (Index 5)

     Index  5 values  used are those  for  an  animal
     diet (see Section 3, p.  3-7).

 ii. Background concentration  in plant  tissue (BP) =
     2.6 ug/g DW

     The background concentration  value  used  is for
     the  plant  chosen  for  the  animal  diet  (see
     Section 3, p.  3-7).

iii. Uptake  slope of  pollutant in  animal tissue (UA)
     = 0 Mg/g tissue DW  (ug/g feed DW)'1

     In  the  only   study  immediately available  from
     which  uptake  slopes could  be  calculated  for
     consumed  animal  tissue,  beef  steers  grazed  on
     sludge-amended pasture   did not take  up  Cr  in
     kidney,  liver, or muscle  in  spite  of  a 3-fold
     increase in dietary  Cr  (Bertrand  et aL., 1981).
     (See Section 4, p. 4-17.)

 iv. Daily  human dietary  intake  of affected animal
     tissue  (DA)

     Toddler     51.1  g/day
     Adult      133 g/day

     The   intake   values   presented   which  comprise
     meat,  fish,  poultry  and eggs  are  derived from
     the FDA Revised  Total  Diet  (Pennington, 1983),
     food  groupings listed by U.S.  EPA (1984a), and
     food  consumption  data   listed  by  USDA (1975).
     Adult  intake   of  meats  is based on  males  25  to
     30  years of   age,  the   age-sex  group  with the
     highest daily  intake  (Pennington, 1983).

  v. Average  daily  human  dietary  intake of pollutant
     (DI)

     Toddler    22  Ug/day
     Adult      65  Ug/day

     See Section 3, p. 3-13.


               3-15

-------
          vi. Acceptable  daily  intake of  pollutant  (ADI)  =
              111,000 ug/day

              See Section 3,  p.  3-14.

    d.    Index  10 Values

                                       Sludge  Application
                                          Rate (mt/ha)
                     Sludge
          Group   Concentration   0       5      50       500

          Toddler   Typical    0.00020  0.00020  0.00020  0.00020
                    Worst      0.00020  0.00020  0.00020  0.00020

          Adult      Typical    0.00058  0.00058  0.00058  0.00058
                    Worst      0.00058  0.00058  0.00058  0.00058

    e.    Value  Interpretation - Same  as for Index 9.

    f.    Preliminary Conclusion -  A  health  threat  due  to Cr
          is  not  expected   for  humans  who  consume  animal
          products   derived  from  animals  feeding  on  plants
          grown  in sludge-amended soil.

3.   Index  of  Human Toxicity  Resulting  from Consumption of
    Animal  Products  Derived   from   Animals  Ingesting  Soil
     (Index 11)

     a.   Explanation  -   Calculates   human    dietary   intake
          expected  to result from consumption  of animal  prod-
          ucts   derived   from   grazing   animals   incidentally
          ingesting  sludge-amended  soil.    Compares  expected
          intake with ADI.

     b.   Assumptions/Limitations  -  Assumes   that  all  animal
          products   are  from  animals  grazing   sludge-amended
          soil,   and  that  all animal  products consumed take up
          the   pollutant  at  the  highest  rate  observed   for
          muscle  of any  commonly  consumed  species  or  at   the
          rate   observed  for  beef  liver  or  dairy  products
          (whichever is  higher).   Divides  possible  variations
          in  dietary  intake  into  two  categories:    toddlers
          (18 months to   3  years)  and individuals  over  three
          years old.

     c.   Data  Used and Rationale

             i.  Animal tissue =  Beef muscle

                See  Section 3,  p. 3-15.
                         3-16

-------
 ii. Background  concentration  of pollutant  in  soil
     (BS) =  100  jag/g DW

     See Section 3,  p.  3-2.

 iii. Sludge  concentration  of  pollutant  (SC)

     Typical      230.1  Ug/g  DW
     Worst       1499.7  ug/g  DW

     See Section 3,  p.  3-1.

 iv. Fraction  of animal diet assumed to be soil  (GS)
     =  5%

     See Section 3,  p.  3-11.

   v. Uptake  slope of pollutant in animal  tissue_jLUA)
     =  0 Ug/g  tissue DW (ug/g feed DW)~1

     See Section 3,  p.  3-15.

 vi. Daily  human  dietary intake  of affected  animal
     tissue  (DA)

     Toddler     51.1 g/day
     Adult       133    g/day

      See  Section 3,  p.  3-15.

 vii. Average daily  human  dietary  intake  of  pollutant
      (DI)

     Toddler    22 Ug/day
     Adult       65 Ug/day

      See  Section 3,  p.  3-13.

viii.  Acceptable  daily  intake  of pollutant  (ADI)  =
      111,000 Ug/day

      See  Section 3,  p.  3-14.
                3-17

-------
     d.   Index 11 Values

                                       Sludge Application
                                          Rate (mt/ha)
                     Sludge
          Group   Concentration  0       5      50       500

          Toddler   Typical   0.00020 0.00020 0.00020 0.00020
                    Worst     0.00020 0.00020 0.00020 0.00020

          Adult     Typical   0.00058 0.00058 0.00058 0.00058
                    Worst     0.00058 0.00058 0.00058 0.00058

     e.   Value Interpretation - Same as for Index 9.

     f.   Preliminary Conclusion  -  Human intake  of  Cr through
          consumption of  animal  products derived  from animals
          which  have  ingested  sludge-amended  soil  or  pure
          sludge, is not expected to pose a health threat.

A.   Index of Human Toxicity from Soil Ingestion (Index 12)

     a.   Explanation -  Calculates  the amount of  pollutant  in
          the  diet  of a  child who  ingests  soil  (pica  child)
          amended with sludge.  Compares this amount with RSI.

     b.   Assumptions/Limitations  -   Assumes   that   the  pica
          child  consumes  an  average  of  5  g/day of  sludge-
          amended  soil.    If  an  ADI  for  a  child  is  not
          available,  this index  assumes  that  the  ADI   for  a
          10 kg  child  is  the  same as  that  for a  70  kg  adult.
          It is  thus  assumed  that uncertainty  factors  used  in
          deriving  the  ADI provide  protection for  the  child,
          taking  into  account  the  smaller  body  size and  any
          other differences in sensitivity.

     c.   Data Used and Rationale

            i. Index of soil concentration increment (Index 1)

               See Section 3,  p. 3-2.

           ii. Sludge concentration of pollutant (SC)

               Typical     230.1 ug/g  DW
               Worst      1499.7 Ug/g  DW

               See Section 3,  p. 3-1.

          iii. Background  concentration of  pollutant in  soil
               (BS) = 100 ug/g DW

               See Section 3,  p. 3-2.
                         3-18

-------
     d.
Group
 iv. Assumed amount of soil in human diet (DS)

     Pica child   5    g/day
     Adult        0.02 g/day

     The  value  of  5  g/day  for  a  pica  child  is  a
     worst-case  estimate  employed   by   U.S.  EPA's
     Exposure  Assessment  Group  (U.S.  EPA,  1983a).
     The  value  of  0.02  g/day for  an  adult is  an
     estimate from U.S.  EPA (1984a).

  v. Average daily human dietary  intake  of pollutant
     (DI)

     Toddler    22 ug/day
     Adult      65 ug/day

     See Section 3, p. 3-13.

 vi. Acceptable  daily  intake  of pollutant  (ADI)  =
     111,000 Ug/day

     See Section 3, p. 3-14.

Index 12 Values
    Sludge
 Concentration
Sludge Application
   Rate (mt/ha)

     5      50
       Pure
500   Sludge
Toddler      Typical    0.0047   0.0047  0.0048  0.0059  0.011
             Worst      0.0047   0.0048  0.0062  0.017   0.068

Adult        Typical    0.00060  0.00060 0.00060 0.00061 0.00063
             Worst      0.00060  0.00060 0.00061 0.00065 0.00086

     e.   Value Interpretation - Same as for Index 9.

     f.   Preliminary  Conclusion  -  The  direct  ingestion  of
          sludge-amended soil  or pure sludge by  humans  is not
          expected to pose a health threat due to Cr.

5.   Index of Aggregate Human Toxicity (Index 13)

     a.   Explanation  -  Calculates  the  aggregate  amount  of
          pollutant  in  the  human diet  resulting  from pathways
          described  in  Indices  9 to 12.  Compares  this  amount
          with ADI.

     b.   Assumptions/Limitations - As  described  for Indices 9
          to 12.
                         3-19

-------
                   Data  Used and Rationale - As described  for  Indices  9
                   to  12.
              d.    Index  13 Values
                              Sludge
                    Group Concentration
                             Sludge Application
                                Rate (mt/ha)

                               5      50       500
                    Toddler Typical
                           Worst

                    Adult   Typical
                           Worst
                    0.0047  0.0047  0.0052  0.0087
                    0.0047  0.0047  0.0099  0.0473

                    0.00060 0.00070 0.0015  0.0083
                    0.00060 0.0016  0.011   0.083a
               e.

               f.



II.  LANDFILLIMG
aValue may  be partially  precluded  by phytotoxicity;
see Indices 9 and 18.

Value Interpretation - Same as for Index 9.

Preliminary Conclusion  -  The aggregate  amount  of Cr
in  the  human  diet  resulting  from  landspreading of
sludge is not expected to pose a health threat.
     A.    Index of  Groundwater  Concentration Increment  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  Exposure  Assessment  Group  (EAG)
               model,  "Rapid Assessment of Potential Groundwater  Contam-
               ination Under -Emergency Response  Conditions" (U.S.  EPA,
               1983b).  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
                                  3-20

-------
         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
         the  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;  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

                   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),
                    1984).
                             3-21

-------
      (c) Volumetric water content (8)

          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
          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,  1984.

ii.  Site parameters

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

          Sikora   et   al.    (1982)   monitored   several
          landfills   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
          complete  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)
                          r
          Typical     5 m
          Worst       0 m

          Eight  landfills were  monitored  throughout  the
          United States  and  depths  to  groundwater below
          them  were  listed.   A typical  depth  of ground-
                    3-22

-------
         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    230.1 mg/kg DW
         Worst      1499.7 mg/kg DW

          See Section 3, p.  3-1.

     (b)  Degradation rate (u)  =  0 day"1

          The degradation rate  in the  unsaturated zone is
          assumed to be  zero for all inorganic chemicals
     (c)  Soil sorption coefficient

          Typical    56.5 mL/g
          Worst      16.8 mL/g
          K^  values were  obtained from  Gerritse  et  al.
          (1982) using  sandy  loam soil  (typical)  or sandy
          soil  (worst).  Values  shown are geometric means
          of  a  range  of  values  derived  using  sewage
          sludge  solution  phases  as  the  liquid  phase  in
          the adsorption experiments.
                    3-23

-------
b.   Saturated zone

     i.   Soil type and characteristics

          (a)  Soil type

               Typical    Silty sand
               Worst      Sand

               A silty  sand  having the values  of  aquifer por-
               osity and  hydraulic conductivity defined below
               represents a  typical aquifer material.   A more
               conductive medium such  as  sand  transports  the
               plume more readily  and  with less dispersion and
               therefore represents a reasonable worst case.

          (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  at  al.   (1982)  as presented
               in U.S. EPA (1983b).

          (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  (1983b).

      ii.  Site parameters

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

               Typical    0.001  (unitless)
               Worst      0.02   (unitless)
                         3-24

-------
         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).

     (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
         50 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   it  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  (W)  =  112.8  m

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

iii. Chemical-specific  parameters

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

         Degradation  is assumed  not  to  occur  in  the
         saturated  zone.
                   3-25

-------
               (b)   Background   concentration   of   pollutant   in
                    groundwater (BC) = 6.5 pg/L

                    A median  value,  6.5  Ug/L»  of the  range  (0  to
                    13  Ug/L)   of   well   water   concentrations   in
                    California was  chosen as a conservative  value
                    from the   standpoint  of  human  toxicity  (U.S.
                    EPA,  1983c).   (See Section 4, p. 4-3.)

               (c)   Soil sorption coefficient (Kj)  =  0 mL/g

                    Adsorption  is  assumed   to  be  zero   in   the
                    saturated  zone.

     4.    Index Values  - See Table 3-1.

     5.    Value  Interpretation  -  Value   equals  factor  by  which
          expected  groundwater concentration  of pollutant at   well
          exceeds   the  background  concentration  (a  value   of  2.0
          indicates the  concentration is  doubled,  a value  of  1.0
          indicates no  change).

     6.    Preliminary Conclusion — Groundwater  concentrations  of  Cr
          at  the  well   are  expected  to  increase  above  background
          concentrations when  sludge  is  landfilled;  this  increase
          may  be substantial at a disposal site  with  all  worst-case
          conditions.

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  increment  result-
               ing  from landfilled sludge  (Index 1)

               See  Table 3-1.

          b.    Background concentration of pollutant  in groundwater
               (BC) = 6.5 pg/L

               See  Section 3,  p.  3-26.
                             3-26

-------
Site Characteristics 1
Sludge concentration T
Unsaturated Zone
Soil type and charac- T
teristics"
Site parameters6 T
Saturated Zone
Soil type and charac- T
teristics^
u Site parameters^ T
i
tv)
^ Index 1 Value 2.0
Index 2 Value 0.00070
Condition of Analysisa»P»c
2345 6
W T T T T

T W NA T T

T T W T T

T T T W T

T T T T W

7.3 2.0 2.0 6.1 37
0.0013 0.00070 0.00070 0.0012 0.0048
7 8
W N

NA N

W N

W N

W N

1300 0
0.157 0.00058
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 (Pdry) and volumetric water content  (6).

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

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

SHydraulic gradient (i), distance from well to landfill (AH), and dispersivity coefficient (o).

-------
              c.   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.

              d.   Average daily human dietary intake of pollutant  (DI)
                   = 65 Ug/day

                   See Section 3, p. 3-13.

              e.   Acceptable   daily   intake   of   pollutant   (ADI)   =
                   111,000 Ug/day

                   See Section 3, p. 3-14.

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

         5.   Value  Interpretation  -  Value  equals  factor  by  which
              pollutant  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   -   Groundwater    contamination
              produced  by  landfilled sludge  is  not expected  to pose  a
              human health threat due to Cr.

III.  INCINERATION

     A.   Index   of   Air    Concentration   Increment   Resulting    from
         Incinerator Emissions (Index 1)

         1.   Explanation  -  Shows  the  degree  of   elevation  of  the
              pollutant  concentration   in the  air due to  the  incinera-
              tion of  sludge.   An input  sludge  with thermal properties
              defined  by the energy  parameter  (EP) was  analyzed using
              the BURN  model (CDM, 1984).  This model uses the thermo-
              dynamic  and  mass   balance  relationships  appropriate  for
              multiple  hearth  incinerators  to relate the  input sludge
              characteristics  to  the   stack gas parameters.   Dilution
              and dispersion of  these  stack gas  releases were described
              by  the  U.S.   EPA's Industrial  Source  Complex  Long-Term.
              (ISCLT)  dispersion  model  from  which  normalized  annual
              ground  level  concentrations   were  predicted (U.S.   EPA,
              1979a).   The  predicted   pollutant   concentration  can  then
              be  compared  to  a  ground  level   concentration  used  to
              assess risk.

         2.   Assumptions/Limitations  - The  fluidized  bed incinerator
              was  not  chosen  due  to a   paucity   of  available  data.
              Gradual plume  rise,  stack tip downwash,  and  building  wake
              effects   are  appropriate for describing  plume  behavior.
                                  3-28

-------
     Maximum  hourly  impact  values  can  be  translated  into
     annual average values.

3.   Data Used and Rationale

     a.   Coefficient to correct for mass and  time  units (C) =
          2.78 x 10~7 hr/sec x g/mg

     b.   Sludge feed rate (DS)

            i. Typical = 2660 kg/hr (dry solids input)

               A  feed  rate  of  2660  kg/hr DW  represents  an
               average  dewatered  sludge feed  rate  into  the
               furnace.  This  feed rate would serve  a  commun-
               ity of approximately 400,000  people.   This rate
               was incorporated  into  the U.S. EPA-ISCLT model
               based on the following input data:

                    EP = 360 Ib H20/mm BTU
                    Combustion zone temperature -  1400°F
                    Solids content - 28%
                    Stack height - 20 m
                    Exit gas velocity - 20 m/s
                    Exit gas temperature - 356.9°K (183°F)
                    Stack diameter - 0.60 m

           ii. Worst = 10,000 kg/hr (dry solids input)

               A  feed  rate  of  10,000  kg/hr  DW  represents  a
               higher  feed  rate and would  serve  a major U.S.
               city.  This rate  was  incorporated  into the U.S.
               EPA-ISCLT  model  based  on  the  following  input
               data:

                    EP = 392 Ib H20/mm BTU
                    Combustion zone temperature -  1400°F
                    Solids content - 26.62        y
                    Stack height - 10 m
                    Exit gas velocity - 10 m/s
                    Exit gas temperature - 313.8°K (105°F)
                    Stack diameter - 0.80 m

     c.   Sludge concentration of pollutant (SC)

          Typical     230.1 mg/kg DW
          Worst      1499-7 mg/kg DW

          See Section 3, p. 3-1.

     d.   Fraction of pollutant emitted through stack (FM)

          Typical    0.003 (unitless)
          Worst      0.006 (unitless)
                         3-29

-------
         Emission  estimates  may  vary  considerably  between
         sources;  therefore,  the values  used are based  on a
         U.S.  EPA  10-city  incineration  study  (Farrell  and
         Wall, 1981).  Where  data  were not available from the
         EPA  study,  a  more  recent  report  which  thoroughly
         researched heavy  metal emissions  was  utilized (CDM,
         1983).

    e.   Dispersion parameter for estimating maximum annual
         ground level concentration (DP)

         Typical    3.4  Ug/m3
         Worst      16.0  Ug/m3

         The  dispersion  parameter  is  derived  from  the  U.S.
         EPA-ISCLT  short-stack model.

    f.   Background concentration of  pollutant in urban
         air  (BA) = 0.010  ug/m3

         The  U.S.  EPA (1978)  reported that yearly averages of
         greater  than 0.010 Ug/m3 occurred  in  only  59 of  186
         urban  areas.   From  the  data immediately available,
         0.010  Ug/ro^  represents a conservative value from  the
         standpoint  of  human   toxicity.     (See  Section  4,
         p. 4-4.)

    Index  1 Values

                                              Sludge Feed
    Fraction  of                   '          Rate (kg/hr DW)a
    ^Pollutant Emitted   Sludge
    Through Stack     Concentration       0    2660   10,000
Typical
Typical
Worst
1.0
1.0
1.2
2.1
4.1
21.0
     Worst                Typical           1.0    1.3       7.1
                         Worst            1.0    3.3      41.0

     aThe typical  (3.4 Ug/m3) and worst (16.0  Ug/m3)    disper-
      sion  parameters will always correspond,  respectively,  to
      the typical (2660  kg/hr DW)  and worst (10,000 kg/hr DW)
      sludge feed rates.

5.   Value  Interpretation  -  Value  equals  factor by  which
     expected air concentration  exceeds  background levels due
     to incinerator  emissions.

6.   Preliminary  Conclusion   -   Incineration   of  sludge   is
     expected  to  increase  air   concentrations  of Cr  above
     background levels;  this  increase may be  substantial  when
     sludge   containing   a   high   concentration   of   Cr   is
     incinerated at  a high feed rate.


                         3-30

-------
B.   Index of Human Cancer Risk Resulting from Inhalation of
     Incinerator Emissions (Index 2)

     1.   Explanation - Shows the  increase  in  human intake expected
          to result from  the  incineration of  sludge.   Ground level
          concentrations  for  carcinogens  typically were  developed
          based upon assessments published  by  the  U.S.  EPA Carcino-
          gen Assessment Group  (CAG).   These ambient concentrations
          reflect  a dose  level  which,  for  a  lifetime  exposure,
          increases the risk of cancer by 10"^.

     2.   Assumptions/Limitations  -   The  exposed  population   is
          assumed  to  reside  within   the   impacted area  for   24
          hours/day.  A  respiratory volume of 20  m3/day  is  assumed
          over a 70-year lifetime.

     3.   Data Used and Rationale

          a.   Index of  air  concentration  increment resulting  from
               incinerator emissions (Index 1)

               See Section 3,  p. 3-30.

          b.   Background concentration  of  pollutant  in  urban  air
               (BA) = 0.010 Ug/m3

               See Section 3,  p. 3-30.

          c.   Cancer potency =41 (mg/kg/day)^

               The  Carcinogen  Assessment  Group  (CAG)  of  U.S.  EPA
               has  carried out  a quantitative assessment  of  cancer
               risk for inhaled Cr.  Although  this risk estimate is
               not  specific  as  to  the  form  inhaled,   the  estimate
               "is  to  be  used  only  in conjunction with  those  Cr
               compounds evaluated  by  the CAG to  be carcinogenic";
               that is  hexavalent  Cr  compounds  (U.S.   EPA,  1983c).
               Cr  in incinerator emissions  is  assumed   to  be  in  the
               hexavalent form  due  to  the high temperatures  in  the
               combustion  chamber.   This  assumption constitutes  a
               conservative  approach  where   definitive   data   are
               lacking.  Therefore, Cr  emissions from sludge  incin-
               erators are assumed  to  be carcinogenic.   Based on  a
               value of  1.7  x  10~6 mg/day established  by the U.S.
               EPA  (1980), a- cancer potency of 41  (mg/kg/day)"1  was
               derived   by  adjusting   to   continual    inhalation
               exposure (U.S.  EPA,  1983c).

          d.   Exposure criterion (EC) = 8.5 x 10"^ ug/m3

               A  lifetime  exposure level  which  would  result in  a
               10~°  cancer  risk  was   selected   as  ground   level
               concentration   against   which  incinerator   emissions
               are  compared.   The risk  estimates  developed   by  CAG
                             3-31

-------
                   are  defined  as the  lifetime  incremental cancer  risk
                   in  a  hypothetical  population  exposed  continuously
                   throughout    their    lifetime    to    the    stated
                   concentration   of  the  carcinogenic   agent.     The
                   exposure criterion is calculated using  the  following
                   formula:

                        c-r -  10"6 x 103 ug/mg x 70 kg
                        £U -                — - r~ —
                             Cancer  potency x  20  mj/day

         4.   Index 2 Values

                                                        Sludge  Feed
              Fraction of                             Rate  (kg/hr DW)a
              Pollutant Emitted    Sludge
              Through Stack     Concentration     0      2660   10,000


              Typical             Typical         120     140      480
                                  Worst           120  '   250     2500

              Worst               Typical         120     160      840
                                  Worst           120     380     4800
              aThe typical (3.4 lig/m)  and  worst  (16.0  Ug/m-)    disper-
               sion  parameters  will always  correspond, respectively,  to
               the typical  (2660  kg/hr DW) and  worst (10,000 kg/hr  DW)
               sludge feed rates.

          5.   Value.  Interpretation -  Value >  1  indicates  a potential
              increase  in  cancer  risk of  >  10~6   (1  per  1,000,000).
              Comparison  with  the  null  index  value  at  0 kg/hr   DW
              indicates the  degree to  which any hazard is due to  sludge
              incineration,   as   opposed   to   background   urban   air
              concentration.

          6.   Preliminary  Conclusion  -  Inhalation  of  emissions from
              sludge  incineration  is   expected  to  increase  the  human
              cancer risk  due to  Cr above  the  risk posed by  background
              urban  air  concentrations of  Cr.   This increase in  cancer
              risk   may   be   substantial   when   high-Cr   sludge   is
              incinerated at  a high feed rate.

IV.  OCEAN DISPOSAL

     Based on the recommendations of the  experts  at  the OWES 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.
                                  3-32

-------
                              SECTION 4

  PRELIMINARY DATA PROFILE FOR CHROMIUM IN MUNICIPAL SEWAGE SLUDGE


I. OCCURRENCE

   A.   Sludge

        1.   Frequency of Detection

             Assumed  100% because of the ubiquitous
             nature of Cr
        2.   Concentration

             Range   22  to 33,000 pg/g DW
             Mean    2031  Ug/g DW
             Median  380 Ug/g DW

             Median            230.1 Ug/g DW
             95th percentile  1499.7 ug/g DW
             Median 1320 ug/g DW
               95%  14,000 ug/g DW
               94%   4925 ug/g DW

             Chicago, XL
               4200 ug/g DW
             Southern CA
               <40 to 600 ug/g DW
             Oklahoma
               trace levels to 600 ug/g DW
             Indiana
               50 to 19,600 Ug/g DW

             Incinerated sludge ash 5280 ug/g
   B.   Soil - Unpolluted

        1.   Frequency of Detection

             Virtually 100%
Page, 1974
(p. 11)
Values statis-
tically
derived from
sludge concen-
tration data
presented in
U.S. EPA, 1982

Furr et al.,
1976a (p. 684)
Page, 1974
(p. 15)
U.S. EPA,
1983c
(p. 3-29)
                                 4-1

-------
    2.   Concentration

         64% of U.S. soils in 25 to 85 ppm range


         Most soils  <300  ppm
         Median     100 ppm
         Range      5 to 3000 ppm

         5 to 1500  ppm
         Mean 43 ppm  {Canadian  soils)
U.S. Soils
     Range 1 to 1000 ppm

Selected U.S. median concentrations!
14 to 70 ppm

Missouri - Median 71 ppm

Natural soils
Range      5 to 3000 ppm
Mean      40 ppm

10 to 6000 kg/ha
Typical level  200 kg/ha

Minnesota soils
     Range   14 to 111 Ug/g
     Median  36" ug/g
     Mean    43 ug/g

5.0 to  1000  ppm
C.   Water - Unpolluted

     1.   Frequency of Detection

          386 of 1577


     2.   Concentration

          a.   Freshwater

               Range 0.1 to 6 ppb
               Median 1 ppb
                                           U.S. EPA, 1978
                                           (p. 226)

                                           U.S. EPA, 1978
                                           (p. 226)

                                           Allaway, 1968
                                           (p. 241)

                                           Gary, 1982
                                           (p. 51)

                                           Gary, 1982
                                           (p. 51)
                                                    U.S. EPA,  1983c
                                                    (p. 3-30)
                                                     U.S.  EPA,  1983c
                                                     NAS,  1974
                                                     (p. 85)

                                                     Page,  1974
                                                     (p. 71)
                                                     Pierce  et  al.,
                                                     L982  (p. 418)
                                                     Yopp et  al.,
                                                     1974 (p.  89)
                                           Page, 1974
                                           (p. 25)
                                           Gary, 1982
                                           (p. 53)
                              4-2

-------
     North American rivers:
          58 yg/L

     Range 0 to 112 ppb
     Average 9.7 ppb
     Range 1 to 112
     U.S.  surface water mean con-
     centration (based on 1577
     samples) 9.7 Ug/L
b.   Seawater
     Mean 0.3 ppb
     Range 0.2 to 50 ppb
     0.5
     0.04 to 0.07 ppb
     Surface seawater
          0.02 to 0.14 ppb Cr III
          0.28 to 0.36 ppb Cr VI

     Drinking Water

     Range 0 to 79 ppb
     Average 2.3 ppb

     Maximum permissible Cr
     concentration in public water
     supplies 0.05 ppm

     Tap water (3834 U.S. cities)
     0.4 to 8 ppb
     0,43 Ug/L as Cr

     Average 10 Ug/L


     Groundwater

     <10 ug/L uncontaminated
     well (New York);
     0 to 13 Ug/L well water
     (California); 5 to 38 Ug/L
     in Illinois River
     600 Ug/L contaminated well
     (Mew York.)
Hem, 1970

U.S. EPA, 1978


U.S. EPA, 1980

U.S. EPA, 1980
(p. A-2)
Gary, 1982
(p. 53)

Hem, 1970
(p. 11)

U.S. EPA,
1978 (p. 236)
U.S. EPA,
1978 (p. 240)
U.S. EPA,
1978 (p. 236)

U.S. EPA,
1978 (p. 247)
U.S. EPA,
1983c
(p.  2-2)

Hem, 1970

U.S. EPA,
1980
(p. C-6)
U.S. EPA,
1983c (p. 3-25)
                    4-3

-------
D.   Air
     1.   Frequency of Detection

          Most is in the form of particulate
          in the atmosphere

          Ambient air concentration
            1.785 x 10~2 ug/m3  Cr  III

          Urban-rural range
            0.0052 to 0.1568 Ug/m3

          Traces to 0.02 Ug/m3  as  Cr
          No naturally occurring gaseous  forms.
          However, Cr is associated with
          particulate matter or aerosol mist
          (as in plating or cooling towers).

          National Air Sampling Network 1964 gave
          a national average of 0.015  Ug/m3
          with maximum of 0.350 Ug/m3
      2.
Concentration
                Urban
                Yearly  averages
                  Ranges  = below detection level  to
                  0.120 Ug/m3
                  Only  59 of  186 urban cities
                  exceeded 0.010 Ug/ro3
                  yearly'averages

                Rural

                Usually below detection limits


                Mean of 5.3  +  3.0  pg/m3  at
                South Pole with a range of 2.5
                to 10 pg/m3
 B.   Pood

      1.   Total Average Intake

           50 to 100 Ug/day


           100 to 280
                                          U.S. EPA,
                                          1978 (p. 3)

                                          ACGIH,  1983
                                           U.S. EPA,
                                           1983c  (p.  2-2)

                                           NAS, 1974
                                           (p.  85)

                                           Gary,  1982
                                           (p.  55)
                                           U.S.  EPA,
                                           1979b (p.  213)
                                           U.S. EPA,
                                           1978 (p. 267)
                                           U.S. EPA,
                                           1980 (p. C-8)

                                           U.S. EPA,
                                           1978
                                           (p. 225)
                                           U.S. EPA,
                                           1980 (p. C-6)

                                           NAS, 1974
                               4-4

-------
               5 to 115 Ug/day in food
               78 Ug/day institutional diet

               52 lag/day institutional diet
               78 yg/day institutional diet
               65 yg/day student diet

               Total all media intake = 100 yg/day/
               individual;  80 yg from food

          2.   Concentration

               Cherry/fruit 0.032 ppra DW
               Corn/grain 0.48 ppm DW
               Pear/whole fruit 0.03 ppm DW
               Potato/tuber 0.002 ppm DW

               Pear/whole fruit 0.44 mg/kg
               Potato 0.15  mg/kg
               Average for  all foods 0.175 to
               0.472 mg/kg  institutional diet
               80 yg/day Cr intake/individual

II.  HUMAN EFFECTS

     A.   Ingestion

          1.   Carcinogenicity

               a.   Qualitative Assessment

                    The oral Carcinogenicity of Cr VI
                    and Cr  III has never been
                    demonstrated.

                    Existing oral Carcinogenicity data
                    for Cr  III is negative and recent
                    data indicate that in the presence
                    of gastric juice, Cr VI is reduced
                    to Cr III.

                    0.5 mg/m-* threshold limit value
                    Cr III


               b.   Potency

                    Not applicable.

               c.   Effects

                    Not applicable.
U.S. EPA,
1978 (p. 165)

NAS, 1974
(p. 28)
U.S. EPA,
1978 (p. 267)
U.S. EPA,
1978 (p. 84)
U.S. EPA,
1978
(pp. 265 to
(267)
U.S. EPA,
1980 (p. C-32)
U.S. EPA,
1980 (p. C-33)
ACGIH, 1983 in
U.S. EPA,
1984b
                                   4-5

-------
    2.   Chronic Toxicity

         a.   ADI

              Cr VI     = 0.175  mg/day/man
          b.
Cr III

Effects
                         = 111  mg/day/man
               Hypersensitivity,  respiratory
               effects.

     3.    Absorption Factor

          <12 Cr*3
          3  to  6%  Cr+6

          0.1%  to  1.2%  trivalent  Cr salts
          absorbed

     4.    Existing Regulations

          Domestic water supply 50 Ug/L total Cr
          Drinking water  50 yg/L total Cr VI
          Livestock water  1000 Ug/L Cr VI

          Ambient  water quality criteria for
          protection of human health
          59,000 pg/L Cr III
              83 Ug/L Cr VI

B.   Inhalation

     1.    Carcinogenic!ty

          a.   Qualitative Assessment

               Using the IARC classification
               scheme,  Cr falls in Group 1,
               meaning there is decisive evi-
               dence for carcinogenicity in
               humans.

               It is presumed that all forms
               of Cr VI are carcinogenic;
               Cr III is less studied but is
               considered less likely to be
               carcinogenic.
U.S. EPA, 1980
(p. C-34)

U.S. EPA,
1984b
                                      U.S. EPA,
                                      1984b
                                      Tandon, 1982
                                      (p. 218)

                                      U.S. EPA,
                                      1978 (p. 143)
                                      U.S. EPA, 1980
                                      (p. C-31)
                                      U.S. EPA,
                                      1983c (p. 8-4)
                                      U.S. EPA,
                                      1983c
                                      (p. 7-84)
                              4-6

-------
     Potency

     Cr VI (lung cancer) cancer potency
     = 41 (mg/kg/day)'1

     CAG estimated lifetime cancer risk
     due to constant exposure to air
     containing 1 jag/m^ of
     hexavalent Cr to be 1.2 x 10~2

     Cancer potency = 41  (mg/kg/day)~^
     Effects

     Lung tumors in chromate industry
     workers
     Mutagenicity - mutagenic and cell
     transforming of chromates
Chronic Toxicity

a.   Inhalation Threshold or MPIH

     Cr VI oral  50 Ug/L total Cr
                 0.175 mg/day/man ADI

b.   Effects

     Respiratory effects, hyper-
     sensitivity.

Absorption Factor

Airborne Cr exposure 0.2 ug/day for
each individual

Existing Regulations

NIOSH  1  ug/m3  Cr  VI  recommended
       maximum workplace concentration
       airborne

NIOSH  1  Ug/m3  Cr  VI  (insoluble)
       is carcinogenic
       25  Ug/m3 Cr III  noncarcino-
       genic (soluble); time weighted
U.S. EPA,
1983c

U.S. EPA,
1983c (p.
2-9)
U.S. EPA,
1983c (p.
7-79)
U.S. EPA,
1983c (p.
2-9)

U.S. EPA,
1980
(p. C-22)
U.S. EPA,
1980
U.S. EPA,
1978 (p. 267)
U.S. EPA,
1978
(p. 188)

U.S. EPA,
1978 (p. 188)
                    4-7

-------
                    average exposure, 10-hr workday,
                    40-hr workweek
                    50  Ug/m^ Cr III noncarcino-
                    genic; 15-min.  sample

             Permissible maximum  concentration
             Chromic and chromous salts  0.5 mg/nH
             Metal  and  soluble  salts 1.0 mg/nH

   III. PLANT EFFECTS

   A.   Phytotoxicity

        See  Table  4-1.

        Moderately toxic


   B.   Uptake

        See  Table  4-2.


        Plant  background  concentration
        0.2  to  1.0 pg/g

IV. DOMESTIC ANIMAL AND WILDLIFE EFFECTS

    A.   Toxicity

         3000 ppm Cr as an oxide in cattle and sheep
         feed (NOAEL)
         1000 ppm Cr as a chloride in chickens (NOEL)
         100 ppm Cr as  K2Cr°4 or  Na2CrC>4 in chicks
         (NOAEL)

         See Table 4-3.'

    B.   Uptake

         See Table 4-4.

 V. AQUATIC LIFE EFFECTS

    A.   Toxicity

         1.   Freshwater

              Freshwater aquatic  organisms should
              not  be affected unacceptably if  the
              four-day  average  concentration of
              acid-soluble Cr VI  does not exceed
              11 Ug/L  more  than once every  three
              years on  the average  and  if the  one-
U.S. EPA,
1980
(p. C-31)
Allaway, 1968
(p. 241)
Allaway,  1968
(p. 241)

Allaway,  1968
(p. 241)
 NAS,  1980
 (p.  147)
 U.S. EPA, 1985
                                   4-8

-------
               hour average concentration does not
               exceed 16 Ug/L more than once
               every three years on the average.
               Freshwater aquatic organisms should
               not be affected unacceptably if at
               water hardnesses of 50, 100, and
               200 mg/L as CaC03, the four-day
               average concentrations of acid-
               soluble Cr III do not exceed
               120, 210, and 370 Ug/L, respectively,
               and the one-hour average concentrations
               do not exceed 980, 1700, and
               3100 Ug/L, respectively.

          2.   Saltwater

               No saltwater criterion can be derived      U.S.  EPA,  1985
               for Cr III, but 10,300 ug/L is the
               EC50 for eastern oyster embryos, whereas
               50,400 Ug/L did not affect a poly-
               chaete worm in a life-cycle test.

     B.   Uptake

          Passive uptake in rainbow trout                 U.S.  EPA,  1978
                                                          (p.  109)

          Bioconcentration Factor (BCF)                   U.S.  EPA,  1980
                                                          (p.  C-7)
               Cr VI     in fish muscle  <1
                         Blue mussel     192
                         Oyster          125
               Cr III    Soft shell clam 153
                         Blue mussel      86
                         Oyster          116

          Weighted average BCF for edible portions        U.S.  EPA,  1980
          of all freshwater and estuarine aquatic         (p.  C-8)
          organisms = 16

VI.  SOIL BIOTA EFFECTS

     Data not immediately available.
                                   4-9

-------
VII. PHYSICOCHEMICAL DATA FOR ESTIMATING PATE AND TRANSPORT

     Atomic weight:  51.996                               CRC Handbook of
     Melting point:  1857 + 20°C                          Chemistry and
     Boiling point:  2672°C                               Physics,
                                                          64 Ed. (p. B85)
     Cr is slightly soluble in dilute
     H2S04 or dilute HC1 but is
     insoluble in water.

     Soil partition coefficient (K,j) mL/g
          Sandy soil          16.8                        Gerritse
          Sandy loam soil     56.5                        et al., 1982
                                                          (p. 359 to 364)
                                   4-10

-------
                                                       TABLE 4-1.  PHYTOTOXICITY OF CHROMIUM
Plant/tissue
Soybeans

Soybeans/ tops
Soybeans/ roots
Bean/leaf


Bean/root
Corn



Corn


Oats

Field Bean/leaf

Tomato/leaf
Corn/leaf
Chemical
Form Applied
Cr VI

Cr VI
Cr VI
Cr VI
Cr VI

Cr VI
Cr VI
-sludge (pot)
Cr VI
-sludge (pot)
Cr III
Cr2(SO«)3
-sludge
Cr VI
Cr VI
Crb

Crb
Sludge (field)
Soil
pU
NRC

NR
NR
NR
NR

NR

NR

NR


5.5
NR
NR
NR

NR
NR
Control
Tissue
Concentration
(ug/g DW)
NR

NR
NR
NR
NR

NR

NR

NR


NR
NR
NR
NR

NR
0.4
Experimental
Soil
Concentrat iona
(Ug/g DW)
0-5

0.5
1.0
0.01
0.1-1

0.2

80

320


320
5
10
200

NR
NR
Experimental
Application
Rate
(kg/ha)
NR

NR
NR
NR
NR

NR

NR

NR


NR
NR
NR
NR

NR
135, 270, 530
Experimental
Tissue
Concentration
(ug/g DW)
NR

NR
NR
NR
NR

NR

NR

NR


NR
NR
NR
30

5
0.4, 0.4, 0.5
Effect References
Decreased uptake U.S. EPA, 1978
of nutrients (p. 97)
Decreased growth
Decreased growth
Dry weight reduction
Chlorosis; greatest
weight reduction
Decrease in dry weight

87Z weight decrease

97Z weight decrease


50Z reduced yield
Diffuse leaf chlorosis
Chlorotic and stunted
25Z reduction in CAST, 1976
yield (p. 25 and 46)
Yield reduction
No increase cone.
Corn/grain
(anaerobic)

Sludge (field)  NR
(anaerobic)
NR
135,  270,  530   <0.1
due to application
rate
No increase cone.
due to application
rate

-------
                                                                       TABLE 4-1  (continued)
NJ
Chemical Soil
Plant/tissue Form Applied pit
Corn/leaf

Corn/leaf
Corn/stover
Plants
Corn
Tobacco/leaves


Tobacco/roots

Corn/leaves
Pruits, vegetables,
grain
Oat/leaves





Soybean/leaves


Corn/leaves

Sludge (field)

Sludge (field)
Sludge (field
Cr VI
Chromic sulfate
Natural
high-Cr soil

same as above
same as above
Cr°
Natural
high-Cr soil
Cr&

CrD

Cr°

Crb


Cr°

NR

NR
NR
NR
NR
NR

NR
NR
NR
NR
NR

NR

NR

NR

NR


NR

Control
Tissue
Concentration
(Ug/g DW)
1 . 2 ppm

1.5
1.0
1.1-1.9
NR
NR

NR
NR
NR
NR
NR

NR

NR

NR

NR


NR

Experimental Experimental
Soil Application
Concentration8 Rate
(Ug/g DW) (kg/ha)
NR

NR
NR
8.4-71
5
NR

NR
NR
NR
NR
NR

NR

NH

NR

NR


NR

350-700

416-833
416-833
NR
NR
NR

NR
NR
NR
NR
NR

NR

NR

NR

NR


NR

Experimental
Tissue
Concentration
(MB/g DW) Effect
1.3-1.2

1.2
1.2

-------
TABLE 4-2.  UPTAKE Of CHROMIUM BY PLANTS
Plant/tissue
Corn/tops
Corn/leaf
Corn/leaf
Corn/tops
Wheat/grain
Wheat /stem
Wheat/leaf
Alfalfa
Buckwheat /whole
plant
Swiss chard
Potato/cortex
Potato/cortex
Fodder rape
Chemical Form
Applied
Sludge (A) (pot)
Sludge (B) (pot)
Sludge & Na2Cr207(CrVI)
Sludge & Na2Cr207(CrVI)
Sludge & Cr2(S04)3(CrIII
Sludge (field)
Sludge (field)
Sludge (field)
(anaerobic)
Sludge (pot)
(anaerobic-amended)
Cr(OH)3 (CrllD(pot)
Cr(OH)3 (CrlllHpot)
CR(Otl)3 (CrllD(pot)
Cr(OH)3 (CrllD(pot)
Cr(OH)3 (CrllD(pot)
Sludge (field)
(anaerobic)
Sludge (field)
(liquid)
Sludge (field)
(anaerobically digested,
Sludge
Soil
pll
NRC
NR
5.5
7.0
) 5.5
NR
NR
NR
6.8
5.6
5.6
5.6
5.6
5.6
5.5 - 6.5
4.5 - 4.9
NR
liquid)
NR
Range (and Nfl) of
Application Rates
(kg/ha)
68-1360 ppm
3-50 ppm
5-320
5-320
5.320
0-700
0-B33
0-530 (4)
0-3340 (4)
0-12,000 (6)d
0-12,000 (6)d
0-12,000 (6)d
0-12,000 (6)d
0-12,000 (6)d
0-282 (2)
0-0.28 (2)
0-605 (2)
0-18.5 (2)
Control Tissue
Concentration,
(ug/g DU)
2.1
2.1
1.6
0.5
1.6
1.2
1.5
0.4
<3.0
0.011
0.029
0.258
0.101
0.211
1.0
1.0
1.36
2.6
Uptake*3
Slope
-4.15 x 10-4
-0.0195
0.171
0.178
0.00431
0
NR
0.000193
0.010
0.15 x 10~6
12 x 10'6
39 x 10'6
10 x 10~6
26 x 10~6
0.0004
0.0
0.0014
0.081
References
U.S. EPA, 1978 (p. 76)
CAST, 1976 (p. 47)
CAST, 1976 (p. 46)
Cunningham et al., 1975
Carey, 1982 (p. 58)




Furr et al., 1976a
(p. 87)
Naylor and Mondy, 1984
(p. 9)
Page, 1974 (p. 45)

-------
                                                              Table 4-2.  (continued)
Plant/tissue
Bean/edible
Cabbage/edible
Carrot/edible
Millet/edible
Onion/edible
Potato/edible
Tomato/edible
Chemical form
Applied
Sludge (pot)
(air dried)
Sludge (pot)
(air dried)
Sludge (pot)
(air dried)
Sludge (pot)
(air dried)
Sludge (pot)
(air dired)
Sludge (pot)
(air dired)
Sludge (pot)
(air dired)
Range (and Na) of Control Tissue
Soil Application Rates Concentration Uptake^
pH (kg/ha) (Ug/g DW) Slope References
5 3 - 7.1 0-60 (2) 3.5 0 Furr et al., 1976b
(p. 761)
5.3 - 7.1 0-60 (2) 0.2 0.055
5.3 - 7.1 0-60 (2) 0.1 0.005
5.3 - 7.1 0-60 (2) , 0.3 0
5.3 - 7.1 0-60 (2) 1.1 0.080
5.3 - 7.1 0-60 (2) 0.07 0.00067
5.3 - 7.1 0-60 (2) 0.01 0.00033
a N - Number of application rates.
D Uptake slope = y/x!  y = MB/8 tissue DM; x = kg/ha applied.
c NR = Not reported.
d Application rate calculated from soil  concentration,  assuming 1 pg/g - 2 kg/ha.

-------
                      TABLE 4-3.   TOX1CITY OP CHROMIUM TO DOMESTIC ANIMALS  AND WILDLIFE
Species (N)a
Chicken (24)
Chicken (52)
Chicken
Chicken


Rat (50)
Rat

Rat (16)




Rat (20)




Rat
Chemical Form
Fed
CrClj (CrIIl)
Na2CrO« (CrVI)
Na2CrO^ (CrVI)
CrCl3 (CrIIl)


Cr(CH3COO)3
KjCrO^ (CrVI)

K2CrO^ (CrVI)




K2Cr04 (CrVI)



CrCl3 (CrIIl)
Chromium III
Feed
Concentration
(Mg/g)
3
30
100
500
1000
2000
NR
NR
NR
NR
NR
NR
NR
NR
NR



NK
276
Water
Concentration
(mg/L)
NRb
NR
NR
NK
NR
NR
5
300
500
0.45
2.2
4.5
7.7
11
25



25
NR
Daily
Intake
(mg/kg BW)
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR



NR
NR
Duration
of Study
27 days
32 days
32 days
21 days
21 days
21 days
Life-term
180 days
180 days
1 year
1 year
1 year
1 year
1 year
1 year



1 year
140 days
Effect* References
No adverse effects NAS, 1980
No adverse effects
No adverse effects
No adverse effects
No adverse effects
Reduced growth
No adverse effects
No adverse effects
No adverse effects
No adverse effects
No adverse effects
No adverse effects .
Increased Cr in tissues
Increased Cr in tissues
Decreased water intake;
concentrated in tissue 9 times
more than Cr III but no toxic
signs
No adverse effects
No adverse effects
nicotinic acid
complex

-------
                                                                Table  4-3   (continued)
Species (N)a
House (SO)
House (54)
House (62)
Mouse
Dog, cat,
rabbit

-C- Young rats
i
t— >
a*
Dogs
Feed Water Daily
Chemical Form Concentration Concentration Intake
Fed  (mg/L) (mg/kg BW)
Cr(CH3COO)3 (Crlll)
Cr(VI)
Cr(CH3COO)3 (CrIII)
Cr(VI)
K2Cr20; (CrVI)

K2Cr(>4 (CrVI)
K2Cr04 (CrVI)


K2Cr04 (CrVI)
NR
NR
NR
NR
NR

NR
1.2 mg/g


2.8-5.7 g
5
5
5
10
NR

NR
NR


NR
NR
NR
NR
NR
1.9-5.5 mg/kg

body wt/day
NR


NR
Duration
of Study
Life-term
Life-term
Life-term
Life-term
29-685 days

29-685 days
Daily


Daily
Effects References
No adverse effects HAS, 1980
Reduced growth
No adverse effects
Increased Cr in tissues
None harmful NAS, 1974

None harmful
Maximum nontoxic U.S. EPA, 1978
effect

Fatal in 3 months
8 N =• Number of animals in study.
b NR - Not reported.

-------
                                            TABLE  4-4.   UPTAKE OP  CHROMIUM BY  DOMESTIC  ANIMALS  AND WILDLIFE


Chemical
Species Form Fed
Guinea pigs Swiss chard grown
on sludge/soil
Beef steers Sludge-amended
pasture grass
i
Range
of Feed Tissue
Concentration
(tig/g DU)
1.0, 1.1, 1.1
2.68 - 9.56



Tissue
Analyzed
Liver
Muscle
Kidney
Liver
Muscle


Control Tissue
Concentration
(Mg/g DW)a
1.3,1.9,1.1
• 1.8,2.6,3.4
0.73d
0.73d
0.73d



Uptake6
Slope References
NCC Purr et al., 1976a (p. 88)
NCC
-0.003d Bert rand et al . , 1981 (p. 149)
0
0

 • When tissue concentrations were reported as  wet  weight,  unless  otherwise  indicated  a  moisture  content  of  77Z was  assumed  for  kidney,  70Z  for
   liver,  and 72Z for muscle.
• b Uptake  slope * y/xi  y = Mg/g animal tissue  DU;  x = Mg/g feed DM.
 c Not calculated because change in feed concentration not  considered  significant.
 d Tissue  feed weight.

-------
                                SECTION 5

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

Allaway, W. H.   1968.   Agronomic  Controls  Over the Environmental Cycling
     of Trace  Elements.   In;  Norma A.  G.  (ed.),  Advances  in Agronomy.
     Vol. 80.  Academic Press, New York, NY.

American  Conference  of  Governmental  and  Industrial  Hygienists.   1983.
     In:  Technical Resources  Document  for  Public Comments.   Methods for
     Prediction  of   Leachate   Plume  Migration   and   Mixing.    Draft.
     Municipal Environmental Research Laboratory,  Cincinnati, OH.

Bertrand,  J.  E.,  M.  C.  Lutrick, G.  T. Edds,  and R.  L. West.   1981.
     Metal  Residues  in Tissues,  Animal Performance and Carcass Quality
     with Beef Steers  Grazing  Pensacola Bahiagrass Pastures Treated with
     Liquid Digested Sludge.  J.  Ani. Sci.  1981.   53:1.

Boswell,  F. C.    1975.    Municipal  Sewage  Sludge and  Selected Element
     Applications  to   Soil:    Effect  on Soil and  Fescue.   J. Environ.
     Qual.  4(2):267-273.

Camp  Dresser  and  McKee,  Inc.   1983.    New  York  City  Special  Permit
     Application  Ocean  Disposal  of  Sewage  Sludge.    City  of  New York
     Department of Environmental  Protection.

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

Gary,  E.  E.   1982.    Chromium   in Air,  Soil  and Natural Waters.   In:
     Biological  and  Environmental  Aspects  of  Chromium.    S.  Langard
      (ed'.),  Elsevier  Biomedical Press,  New  York,  NY.

Chaney,  R.  L.,  and  C.  A.  Lloyd.   1979.   Adherence  of Spray-Applied
     Liquid Digested   Sewage  Sludge to  Tall  Fescue.   J. Environ. Qual.
      1979.   8(3):407-411.

Council  for Agricultural  Science and  Technology.   1976.  Application  of
      Sewage Sludge to Cropland:  Appraisal  of Potential  Hazards  of the
      Heavy Metals  to  Plants and Animals. Ames,  IA.

CRC Handbook of Chemistry and  Physics.   64th Edition  (1983-1984).   R.C.
      Weast  (ed.),  CRC Press,  Inc.,  Boca Raton,  FL.

Cunningham, J. D., J.  A.  Ryan,   and D. R. Keeney.  1975.  Phytotoxicity
      in and  Metal Uptake from  Soil  Treated  with Metal-Amended  Sewage
      Sludge.   J.  Environ. Qual.  4(4):455-460.
                                    5-1

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

Farrell, J. B., and H. Wall.   1981.   Air Pollutional Discharges from Ten
     Sewage Sludge Incinerators.  Draft  Review Copy.  U.S. Environmental
     Protection Agency.  Cincinnati, OH.  February.

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

Furr, A. K., A.  W.  Lawrence,  and S. S.  long.   1976a.   Multi-Element and
     Chlorinated  Hydrocarbon   Analysis   of  Municipal  Sewage   Sludges  of
     American Cities.  Environ. Sci. & Technol. 10(7):683-687.

Furr, A. K., W.  C.  Kelly,  C.  A. Bache,  W.  H.  Gutenmann,  and  D. H. Lisk.
     1976b.  Multi-Element Absorption  by Crops Grown  on Ithaca Sludge-
     Amended Soil.  Bull. Environ. Contam. Toxicol.  16:756-763.

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

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

Helmke, P. A., W.  P.  Robarge,  R.  L.  Korotev,  and  P.  J. Schomberg.  1979.
     Effects of  Soil-Applied  Sewage  Sludge on Concentrations  of  Elements
     in Earthworms.  J. Environ.  Qual.  8:322-327.

Hem,   J.   D.      1970.     Study  and   Interpretation   of  the   Chemical
     Characteristics   of   Natural  Water.     EPA 600/52-83-113.    U.S.
     Government Printing Office.  Washington, D.C.

National  Academy of  Sciences.   1974.   Chromium.     National  Research
     Council Committee on  Medical  and  Biologic  Effects  of  Atmospheric
     Pollutants.  National Academy of Sciences, Washington, D.C.

National  Academy of  Sciences.   1980.    Mineral  Tolerance  of  Domestic
     Animals.    National  Academy  of Sciences,  Subcommittee   on Mineral
     Toxicity in Animals, Washington, D.C.

Naylor,  L.  M.,  and  N.  I.  Mondy.   1984.  Metals  and PCBs  in  Potatoes
     Grown  in Sludge-Amended  Soils.  ASAE Technical Paper No.  NAR 84-211.
     For  presentation at  1984 North Atlantic  Regional  Meeting.   Amer.
     Soc. Agric. Eng., St. Joseph, MI.

Page,  A.  L.   1974.  Fate  and  Effects  of Trace Elements in Sewage Sludge
     When  Applied  to  Agricultural  Lands.    EPA  570/2-74-005.    U.S.
     Environmental Protection  Agency, Cincinnati, OH.

Pennington, J. A.  T.   1983.   Revision of the Total Diet  Study  Food Lists
     and Diets.  J. Am. Diet.  Assoc. 82:166-173.
                                   5-2

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

Pierce, F. J., R.  H.  Dowdy,  and D. F. Grigal.   1982.   Concentrations of
     Six Trace Metals  in  Some Major Minnesota Soil  Series.   J. Environ.
     Qual. 2(3).

Ryan, J. A.,  H.  R. Pahren,  J.  B.  Lucas.   1982.   Controlling Cadmium in
     the  Human  Food  Chain:    A  Review  and  Rationale  Based  on  Health
     Effects.  Environ Res.  28:251.

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.

Tandon, S.  K.   1982.   Organic Toxicity  of  Chromium  in Animals.   In;
     Biological   and  Environmental   Aspects   of   Chromium.    S.  Langard
     (ed.), Elsevier Biomedical Press.

Thornton,  I., and  P.  Abrams.   1983.   Soil Ingestion - A Major  Pathway of
     Heavy Metals  into  Livestock  Grazing  Contaminated  Land.   Sci.   Total
     Environ. 28:287-294.

U.S.   Department   of   Agriculture.     1975.      Composition   of  Foods.
     Agricultural Handbook No. 8.

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.     1978.     Reviews   of   the
     Environmental  Effects  of Pollutants:  III.   Chromium.   EPA 600/1-
     78-023,  U.S. Environmental  Protection   Agency,  Cincinnati,  OH,  or
     ORNL/EIS-80, Oak Ridge National Laboratory, Oak Ridge, TN.

U.S. Environmental Protection  Agency.   1979a.  Industrial Source Complex
     (ISC)  Dispersion  Model  User  Guide.    EPA  450/4-79-30.   Vol.  1.
     Office  of  Air  Quality  Planning and  Standards,   Research Triangle
     Park, NC.  December.

U.S.  Environmental Protection Agency.   1979b.   Air  Quality  Data  for
     Metals   1976  from   the  National  Air    Surveillance  Networks.
     EPA 600/4-79-054.  Environmental  Monitoring  and Support Laboratory,
     Research Triangle Park, NC.

U.S.  Environmental Protection Agency.    1980.    Ambient Water  Quality
     Criteria  for  Chromium.    EPA  440/5-80-035.    U.S.  Environmental
     Protection  Agency.   Office  of  Water   Regulations  and  Standards.
     Washington,  D.C.
                                   5-3

-------
U.S.  Environmental  Protection   Agency.     1982.     Fate   of  Priority
     Pollutants  in  Publicly-Owned  Treatment  Works.    Vol.    I.    EPA
     440/1-82-303.   U.S.    Environmental  Protection  Agency.    Effluent
     Guidelines Division, Washington,  D.C.

U.S.  Environmental  Protection  Agency.  1983a.    Assessment  of  Human
     Exposure  to  Arsenic:     Tacoma,   Washington.    Internal  Document.
     OHEA-E-075-U.    Office  of  Health  and  Environmental  Assessment,
     Washington, D.C.  July 19.

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

U.S.  Environmental  Protection   Agency.     1983c.     Health  Assessment
     Document for  Chromium.   External Review Draft.   EPA 600/8-83-014A.
     U.S.  Environmental Protection  Agency.  Research Triangle Park, NC.
U.S. Environmental Protection  Agency.   1984a.  Air  Quality Criteria for
     Lead.   External Review  Draft.    EPA 600/8-83-028B.   Environmental
     Criteria  and   Assessment  Office,  Research   Triangle   Park,   NC.
     September.

U.S. Environmental Protection  Agency.   1984b.   Health Effects Assessment
     for Trivalent Chromium.  Program Office Draft.  ECAO-CIN-H035.

U.S. Environmental Protection  Agency.   1985.   Water  Quality Criteria for
     Chromium.  Unpublished.

Yopp, J.  H.,  W.  F.  Schmid, and R.  W. Hoist.   1974.   Determination of
     Maximum  Permissible  Levels  of  Selected  Chemicals That  Exert  Toxic
     Effects  on Plants  of Economic Importance  in  Illinois.   PB-237 654.
     U.S.  Department  of   Commerce.     National   Technical  Information
     Service.
                                   5-4

-------
                                APPENDIX

           PRELIMINARY HAZARD INDEX CALCULATIONS  FOR  CHROMIUM
                       IN MUNICIPAL SEWAGE SLUDGE
I.   LANDSPREADING AND DISTRIBUTION-AND-MARKETING

     A.   Effect on Soil Concentration of Chromium

          1.   Index of Soil Concentration Increment (Index 1)

               a.   Formula

                          ,  _ (SC x AR) •*• (BS x MS)
                          l	BS (AR + MS)	

                    where:

                         SC  = Sludge    concentration    of     pollutant
                              (Ug/g DW)
                         AR  = Sludge application rate (mt  DW/ha)
                         BS  = Background  concentration  of  pollutant  in
                              soil (ug/g DW)
                         MS  = 2000 mt  DW/ha  =  Assumed  mass  of  soil  in
                              upper 15 cm

               b.   Sample calculation

              - (230.1 ug/g DW x 5 mt/ha) + (100 Ug/g DW x 2000 mt/ha)
                        100  ug/g DW (5 mt/ha + 2000 mt/ha)

     B.   Effect on Soil Biota and Predators of Soil Biota

          1.   Index of Soil Biota Toxicity (Index 2)

               a.   Formula

                              Ii  x BS
                    Index 2  = ——


                    where:

                    II = Index 1  = Index of soil  concentration increment
                         (unitless)
                    BS = Background  concentration  of pollutant  in  soil
                         (Ug/g DW)
                    TB = Soil  concentration  toxic  to  soil biota  (ug/g
                         DW)

               b.   Sample  calculation - Values  were not  calculated due
                    to lack  of data.
                                  A-l

-------
    2.   Index of Soil Biota Predator Toxicity (Index 3)


         a.   Formula

                         (II -  1)(BS x UB) + BB
              Index 3 = 	™-	


              where:

                   II = Index   1  =  Index  of  soil  concentration
                        increment (unitiess)
                   BS = Background  concentration  of pollutant  in
                        soil (ug/g DW)
                   UB = Uptake  slope of  pollutant  in  soil  biota
                        (Ug/g  tissue DW [ug/g soil DW]'1)
                   BB = Background   concentration  in  soil  biota
                         (Ug/g  DW)
                   TR = Feed concentration  toxic  to predator (yg/g
                        DW)


          b.    Sample calculation

               0.02525 =  [(1.003244-1) (100  ug/g  DW x 0.5

                       Ug/g DW  [ug/g soil DW]'1)  +  50.5 ug/g  DW] *


                      2000 Ug/g DW

C.   Effect on Plants  and Plant Tissue Concentration

     1.   Index of Phytotoxicity (Index  4)


          a.   Formula

                        ' II x BS
               Index 4 = ——	


               where:

                    !]_• = Index  1  =  Index  of  soil  concentration
                         increment (unitless)
                    BS = Background  concentration  of  pollutant  in
                         soil (Ug/g DW)
                    TP = Soil  concentration  toxic  to  plants  (ug/g
                         DW)

          b.   Sample calculation


         n <;niA9-> - 1-003244 x  100 Ug/g DW
         0.501622 -      20Q  ug/g DW
                              A-2

-------
2.   Index of  Plant Concentration  Increment  Caused by  Uptake
     (Index 5)

     a .   Formula

                    (Ii - 1) x BS
          Index 5 = — = - x CO x UP + 1
                         BP

          where:

               Ij = Index  1  =  Index  of  soil  concentration
                    increment (unitless)
               BS = Background  concentration  of  pollutant  in
                    soil (ug/g DW)
               CO = 2  kg/ha   (ug/g)~*  =  Conversion   factor
                    between soil concentration  and  application
                    rate
               UP = Uptake  slope of pollutant in plant  tissue
                    (Ug/g tissue DW [kg/ha]"1)
               BP = Background  concentration  in  plant  tissue
                    (Ug/g DW)

     b.   Sample calculation

     i ninoi™   (1.Q0324A-1) x 100 Ug/g  DW      2 kg/ha
     1.0202126 -                              x
            0.081 Ug/g tissue
          X      kg/ha          i

3.   Index  of  Plant  Concentration   Increment   Permitted  by
     Phytotoxicity (Index 6)

     a.   Formula

                    PP
          Index 6 = ~
          where:
               PP = Maximum    plant    tissue    concentration
                    associated with phytotoxicity (ug/g DW)
               BP = Background  concentration  in  plant  tissue
                    (Ug/g DW)
     b.   Sample calculation
                252 ug/g DW
                1.0 Ug/g DW
                         A-3

-------
C.   Effect on Herbivorous Animals

     1.   Index of Animal Toxicity Resulting  from Plant Consumption
          (Index 7)

          a.   Formula

                         I5 x BP
               Index 7 =
                           TA
               where:
                    I5 = Index  5  =  Index  of  plant  concentration
                         increment caused by uptake (unitless)
                    BP = Background  concentration  in plant  tissue
                         (Ug/g  DW)
                    TA = Feed   concentration  toxic   to  herbivorous
                         animal (ug/g
           b.    Sample  calculation
                           1.0202126 x 2.6 Ug/g DW
                0.001.3  -      2000 ug/g DW

           Index of Animal  Toxicity Resulting from Sludge  Ingestion
           (Index 8)
                Formula
                                  BS x GS
                If AR = 0,   I8 = — ^ -
                                  SC x GS
                if AR * o,   i8 = —  —
                where:
                     AR = Sludge application rate (mt DW/ha)
                     SC = Sludge     concentration     of    pollutant
                          (Ug/g  DW)
                     BS = Background  concentration  of  pollutant  in
                          soil (ug/g  DW)
                     GS = Fraction  of animal  diet  assumed to be soil
                          (unitless)
                     TA = Feed   concentration   toxic  to  herbivorous
                          animal  (ug/g
            b.    Sample  calculation
                                     100 ug/g DW x 0.05
                 If  AR = 0, 0.0025 =   2000  Ug/g DW
                                        230.1 Ug/g DW x O.Q5
                 If  AR * 0, 0.0057525 =      200Q ug/g DW
                                A-4

-------
E.   Effect on Humans

     1.   Index  of   Human  Toxicity  Risk   Resulting  from  Plant
          Consumption (Index 9)

          a.   Formula

                         [(I5 - 1) BP x DT] + DI
               Index 9 = 	
                                     ADI

               where:

                    15 = Index  5   =   Index  of  plant  concentration
                         increment caused by uptake (unitless)
                    BP - Background  concentration  in  plant  tissue
                         (Ug/g DW)
                    DT = Daily  human  dietary  intake  of  affected
                         plant~~trissue (g/day DW)
                    DI = Average  daily  human  dietary   intake   of
                         pollutant (ug/day)
                   ADI = Acceptable   daily    intake   of   pollutant
                         (Ug/day)

          b.   Sample  calculation (toddler)

0 000233 - K1-0471855 - 1) x 1.1  ug/g DW x 74.5 a/day] + 22 ug/dav
                              111,000 Ug/day

     2.   Index  of  Human  Toxicity  Resulting  from  Consumption  of
          Animal  Products  Derived from  Animals  Feeding on  Plants
          (Index  10)

          a.   Formula

                          [(15 - 1) BP x UA x DA]  «• DI
               Index 10  = —->	_	


               where:

                   15 = Index  5  =  Index  of  plant   concentration
                         increment  caused  by uptake  (unitless)
                   BP = Background   concentration  in  plant  tissue
                         (Ug/g DW)
                   UA = Uptake  slope of pollutant in animal  tissue
                         (Ug/g tissue DW [ug/g feed DW]"1)
                   DA = Daily  human dietary  intake  of   affected
                         animal  tissue (g/day  DW)
                   DI = Average  daily   human  dietary  intake  of
                         pollutant  (ug/day)
                  ADI = Acceptable   daily   intake   of   pollutant
                         (Ug/day)
                             A-5

-------
                       b.    Sample calculation (toddler)

01982 =

12-1) x 2.6 ug/g DW x  0.0  Ue/e tissuefug/g feed]"1 x 51.1 g/dayl + 22 Ug/day
	~111,000 Ug/day

                  3.    Index of  Human Toxicity  Risk Resulting from  Consumption
                       of Animal  Products Derived from  Animals  Ingesting  Soil
                       (Index 11)

                       a.   Formula
                                          T „    n    (BS x GS x UA x  DA) * DI
                            If AR = 0,    Index 11  =  	£j^	

                                   ,       T J         (SC x GS x UA x DA)  +  DI
                            If AR ^ 0,    Index 11  =  	—	


                            where;

                                 AR = Sludge application rate  (mt DW/ha)
                                 BS = Background  concentration of  pollutant  in
                                      soil (Ug/g DW)
                                  SC = Sludge     concentration    of     pollutant
                                      (Ug/g DW)
                                  GS = Fraction of  animal  diet assumed to be soil
                                      (unitless)
                                  UA = Uptake  slope of  pollutant in animal tissue
                                      (Ug/g tissue DW  [ug/g feed  DW"1]
                                  DA = Average   daily  human  dietary  intake  of
                                      affected animal  tissue (g/day DW)
                                  DI = Average   daily  human  dietary  intake  of
                                      pollutant  (ug/day)
                                ADI = Acceptable   daily   intake   of   pollutant
                                      •(Ug/day)

                  b.    Sample  calculation (toddler)

         0.000198  =

  LI ue/g DW x 0.05 x  0.0 Ug/g tissue fug/g feedl"1 x  51.1 g/day DW)  f 22  Ug/day
  	111,000  Ug/day

                  4.    Index  of  Human  Toxicity  Resulting   from  Soil  Ingestion
                        (Index 12)

                        a.   Formula

                                        (II x  BS x DS) + DI
                             Index 12 = 	
                                                     r  .    10    (SC x PS) * DI
                             Pure sludge ingestion:  Index  iz  -        ADI
                                            A-6

-------
            where:

                II  = Index  1  =  Index  of   soil   concentration
                      increment (unitless)
                SC  = Sludge    concentration    of     pollutant
                      (Ug/g DW)
                BS  = Background  concentration  of  pollutant  in
                      soil (ug/g DW)
                DS  = Assumed  amount  of  soil  in  human   diet
                      (g/day)
                DI  = Average daily  dietary  intake of  pollutant
                      (Ug/day)
                ADI  = Acceptable   daily  intake   of   pollutant
                      (Ug/day)

       b.   Sample calculation (toddler)

n ._,,._,   (1.003244 x 100 Ug/g DW x 5 g soil/day) + 22 Ug/day
0-0047173 = 	111,000 yg/day	

            Pure sludge:

         . nin«.,,,  _ (230.1 Ug/g DW x 5 g soil/day) + 22 Ug/day
         0.0105631 -            111,000 yg/day

  5.   Index of Aggregate Human Toxicity (Index 13)

       a.   Formula

                                                  3DI
            Index 13 = I9 + IIQ +  111 + I12 ~    ADI

            where:

                   19 = Index  9   =  Index  of   human   toxicity
                        resulting    from    plant    consumption
                        (unitless)
                      = Index  10   =  Index   of   human   toxicity
                        resulting   from   consumption  of  animal
                        products derived  from  animals feeding on
                        plants (unitless)
                      ~ Index  H   =  Index   of   human   toxicity
                        resulting   from   consumption  of  animal
                        products  derived  from animals  ingesting
                        soil (unitless)
                  Il2 = In(iex  12   =  Index   of   human   toxicity
                        resulting from soil ingestion (unitless)
                   DI = Average    daily    dietary   intake    of
                        pollutant (ug/day)
                  ADI = Acceptable  daily  intake  of   pollutant
                        (yg/day)
                           A-7

-------
             b.    Sample calculation (toddler)


0.0047514 = (0.0002333 + 0.000198 + 0.000198 + 0.004717) -


   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,
             t0,  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 estimates initial dilution in the aquifer to
             give  the initial  concentration,  C0, for  the  saturated  zone
             assessment.   (Conditions  for  B,  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  unsaturated zone  except  for  the definition  of
             certain parameters  and choice of parameter  values.   The maxi-
             mum  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(Ai)  erfc(A2)  +  exp^)  erfc(B2)] = P
-------
    and where for the unsaturated zone:

         C0 = SC x CF = Initial leachate concentration  (ug/L)
         SC = Sludge concentration of pollutant (mg/kg DW)
         CF = 250 kg sludge solids/m3 leachate =

              PS x 103
              1 - PS

         PS = Percent  solids   (by  weight) of  landfilled  sludge
              202
          t = Time (years)
         X  = h = Depth to groundwater  (m)
         D* = a x V* (m2/year)
          a = Dispersivity coefficient  (m)

         V* = —2—  (m/year)
              0 x R
          Q = Leachate generation rate  (m/year)
          0 = Volumetric water content  (unitless)

          R = 1 + P(iry x Kd =  Retardation factor  (unitless)
                     0
       Pdry = Dry bulk density (g/mL)
         Kd = Soil sorption coefficient  (mL/g)

         H* =
                R                    ,
           U  = Degradation  rate  (day  -1)

    and where for  the  saturated zone:

          C0  = Initial   concentration of  pollutant  in  aquifer  as
               determined by Equation 2  (jjg/L)
           t  = Time (years)
           Y  = AS, = Distance from well to landfill (m)
          D*  = a x V* (m2/year)
           Ct  = Dispersivity coefficient  (m)

          V*  = ^ x  L (m/year)
          V    0 x  R
           K  = Hydraulic conductivity of the aquifer  (m/day)
           i  = Average  hydraulic gradient between  landfill and  well
               (unitless)
           0  = Aquifer  porosity (unitless)

           R  = 1 +  Pdr? x Kd = Retardation factor = 1 (unitless)

               since Kd is  assumed  to  be  zero  for the  saturated
               zone

C.  Equation  2.  Linkage Assessment
                          Q x W	
          C0  = cu x 365 [(K  x  i)  t 0] x B
                              A-9

-------
     where:

          C0  =  Initial  concentration of  pollutant  in the  saturated
               zone  as  determined by Equation 1 (yg/L)
          Cu  =  Maximum   pulse  concentration  from   the   unsaturated
               zone  (pg/L)
          Q  =  Leachate generation rate (m/year)
          W  =  Width of landfill (m)
          K  =  Hydraulic conductivity of the aquifer (m/day)
          i  =  Average  hydraulic gradient between  landfill and  well
               (unitless)
           	-^—:	TTT	    and  B  > 2
                 —     K  x  i  x  365              —

D.  Equation  3.  Pulse Assessment
          C(X?t) = P(x,t)  for  0  < t < t0
             Co


          C(x?t)   P t
             "O

     where:
                                     o
Cr
          t0  (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:

                        • •*     C dt] -t-  Cu

                   >t)  = —LXj—i as determined by Equation 1
                           co
E.   Equation  4.   Index  of   Groundwater Concentration   Increment
     Resulting from Landfilled Sludge (Index 1)

     1.   Formula

                     Cmav  "*" BC
          Index 1 =
                        BC

          where:
               cmax = Maximum  concentration  of pollutant  at  well -
                      Maximum  of C(A2,,t)  calculated  in  Equation 1
                      (Wg/L)
                 BC = Background   concentration  of   pollutant  in
                      groundwater  (pg/L)
                              A-10

-------
         2.   Sample Calculation

                  *   6.26 ug/L +• 6.5
                             6.5 ug/L

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

         1.   Formula

                         [(I I  -  1) BC x AC]  + DI
              Index 2 =	


              where:

                    II -  Index  1  = Index  of  groundwater  concentration
                         increment  resulting  from landfilled sludge
                    BC =  Background   concentration    of    pollutant    in
                         groundwater (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

         n  0006qa - K1.96  -  1)  x  6.5 US/L * 2 L/dav] + 65 US/day
         0.000698 -            111,000 Ug/day

III.  INCINERATION


     A.   Index  of Air Concentration Increment Resulting  from Incinerator
         Emissions  (Index 1)

         1.   Formula

                       (C x PS x SC x FM x DP) + BA
             Index  1 = 	££—


             where:

                   C = Coefficient   to correct  for  mass  and time  units
                       (hr/sec x  g/mg)
                  DS = Sludge feed  rate (kg/hr DW)
                  SC = Sludge concentration of pollutant (mg/kg DW)
                  FM = Fraction  of   pollutant   emitted   through   stack
                       (unitless)
                  DP = Dispersion   parameter   for    estimating   maximum
                       annual ground level concentration (yg/m3)
                  BA = Background  concentration  of  pollutant  in  urban
                       air (ug/m3)

-------
                  2.   Sample Calculation

         1.1735574 =

78  x 10~7 hr/sec  x g/mg x  2660 kg/hr DW  x  230.1  mg/kg DW x 0.003 x 3.4  yg/m3)  +

                  0.010 yg/m3] -fr 0.010  yg/m3

             B.  Index  of   Human   Cancer  Risk  Resulting  from  Inhalation   of
                 Incinerator Emissions  (Index 2)

                 1.  Formula

                                [(!]_  - 1)  x BA]  + BA
                     Index  2 = 	
                                          EC
                     where:

                        II  =  Index  1  =  Index of air concentration increment
                             resulting  from incinerator emissions
                             (unitless)
                        BA  =  Background concentration of pollutant in
                             urban  air  (yg/m-3)
                        EC  =  Exposure criterion (yg/m3)

                  2.  Sample  Calculation


                               - Kl.1735574  -  1)  x  0.01  Ug/m31  * 0.01  Ug/m3
                               —                     c     •>
                                            8.5 x  10"5 Ug/mJ
         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-12

-------
TABLE A-l.  INPUT DATA VARYING IN LANDFILL ANALYSIS AND RESULT FOR EACH CONDITION
Condition of Analysis
Input Data
Sludge concentration of pollutant, SC (Hg/g DM)
Unsaturated zone
Soil type and characteristics
Dry bulk, density, Pjry (g/mL)
Volumetric water content, 6 (unitleas)
Soil sorption coefficient, Kj (mL/g)
Site parameters
Leachate generation rate, Q (m/year)
Depth to groundwater, h (m)
Disperflivity coefficient, a (m)
Saturated zone
Soil type and characteristics
Aquifer porosity, 0 (unitless)
Hydraulic conductivity of the aquifer,
K (m/day)
Site parameters
Hydraulic gradient, i (unitless)
Distance from well to landfill, At (m)
Dispersivity coefficient, a (m)
1

230.1

1.53
0.195
56.5

0.8
5
0.5


0.44
0.86

0.001
100
10
2
•
1499.7

1.53
0.195
56.5

0.8
5
0.5


0.44
0.86

0.001
100
10
3

230.1

1.925
0.133
16.8

0.8
5
0.5


0.44
0.86

0.001
100
10
4 5

230.1 230.1

NAb 1.53
NA 0.195
NA 56.5

1.6 0.8
0 5
NA 0.5


0.44 0.389
0.86 A. 04

0.001 0.001
100 100
10 10
6

230.1

1.53
0.195
56.5

0.8
5
0.5


0.44
0.86

0.02
50
5
7

1499.7

NA
NA
NA

1.6
0
NA


0.389
4.04

0.02
50
5
8
N«


N
N
N

N
N


N
N

H
N
N

-------
                                                             TABLE A-l.   (continued)
 I
>-•
4>
Condition of Analyst!
Results
Unsaturated zone assessment (Equations 1 and 3)
Initial leachate concentration, Co (|Jg/L)
Peak concentration, Cu (pg/L)
Pulse duration, t0 (years)
Linkage assessment (Equation 2)
Aquifer thickness, B (m)
Initial concentration in saturated zone, C0
(Mg/L)
1

57500
591
486

126
591
2

375000
3850
486

126
3850
3

57500
1580
182

126
1580
4

57500
57500
5.00

253
57500
5

57500
591
486

23.8
591
6

57500
591
486

6.32
591
7

375000
375000
5.00

2.38
375000
8

N
N
N

N
N
Saturated zone assessment (Equations 1 and 3)

  Maximum well concentration, Cmax (pg/L)             6.26          40.8

Index of groundwater concentration increment
  resulting from landfilled sludge,
  Index 1 (unitless) (Equation 4)                     1.96          7.28

Index of human toxicity resulting
  from groundwater contamination, Index 2
  (unitless) (Equation 5)                           0.000698     0.00132
    6.26
    1.06
6.26
1.96
33.3
                               6.12
236
             37.4
8680      N
                                                         1340     0
0.000698      0.000698      0.00118
                       0.00484     0.157  0.000586
*H  = Null condition, where no landfill exists; no value is used.
"NA = Not applicable for this condition.

-------