PB85-196798
Determination of Toxic
Chemicals in Effluent from
Household Septic Tanks
Washington Univ.* Seattle
Prepared for

Environmental Protection Agency, Cincinnati, OH
Apr 85

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                                            EPA/600/2-85/050
                                            April  1985

  DETERMINATION OF TOXIC CHEMICALS IN         PBbb-   b  98
  EFFLUENT FROM HOUSEHOLD  SEPTIC TANKS
                   by
            Foppe B. DeWalle
              David Kalman
             Donald Norman
               John Sung

   Department of Environmental Health
        University of Washington
       Seattle, Washington  98195
               Gary Plews

Department of Social and Health Services
       Olympia, Washington  98504
         Cooperative Agreement
          Grant No.  R 806102
            Project Officer

            Ronald F.  Lewis
      Wastewater Research Division
  Water  Engineering Research  Laboratory
         Cincinnati, OH  45268
 WATER ENGINEERING RESEARCH LABORATORY
   OFFICE OF RESEARCH AND DEVELOPMENT
  U.S. ENVIRONMENTAL PROTECTION AGENCY
         CINCINNATI,  OH  45268

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                                    TECHNICAL REPORT DATA
                             (Pkase read/uUfiictioiit on the ttvtnc before coinptcrtiif
  I. REPORT NO.
   EPA/600/2-85/050
                               2.
                     3. RECIPIENT'S ACCESSION-NO.
                        PBS 5  196798 /AS
 4. TITLE AND SUBTITLE
   DETERMINATION OF  TOXIC CHEMICALS IN EFFLUENT FROM
   HOUSEHOLD SEPTIC  TANKS
                     5. REPORT DATE
                       April 1985
                     6. PERFORMING ORGANIZATION CODE
 7. AUTHOR(S)
   Foppe B DeWalle,  David A.  Kalman, Donald Norman,
   John Sung, and Gary  Plews
                    «. PERFORMING ORGANIZATION REPORT NO
 9. PERFORMING ORGANIZATION NAME AND ADDRESS
   Deaprtment of Environmental  Health
   University of Washington
   Seattle, Washington   98195
                     10. PROGRAM ELi.ME.NT NO.
                     11, CONTRACT/GSA.VT NO.


                           R806102
 12. SPONSORING AGENCY NAME AND ADDRESS
   Water Engineering Research Laboratory -
   Office of Research  and Development
   U.S. Environmental  Protection Agency
   Cincinnati, Ohio  45268
    - Cin. OH
13. TYPE OF RE?CRT AND PERIOD COVERED
   Final 10/78 - 9/82
                     4. SPONSORING ACeNCY CODE
                        EPA/600/14
 15. SUPPLEMENTARY NOTES
   Project Officer:  Ronald F.  Lewis
(513) 684-7644
 16. ASSTRACT
     The report   study  evaluated  the  presence  of  volatile   organics  in   raw
     domestic sewage  generated  In  a subdivision  and treated by a large  5-year-
     old community  septic  tank  that had  recently  been  cleaned  by  having  the
     solids removed  by  pumping just  prior to this  study.  Analysis  showed  the
     presence of  priority pollutants  in the raw  sewage.   Essentially  no  remov?I
     of these  compounds occurred   during  the  2-day  detention  in  the   septic
     tank.  The  priority  pollutants  generally showed  higher  levels  during  the
     weekend, probably reflecting leisure  activities and use of related
     chemicals  (paint thinners,  grease removers,  toilet bowl  cleaners,   etc.),
     than during  the  week  days.   Most of the  other  volatile  compounds were
     hydrocarbons, and  their   removal   by  the  septic  tank  generally  decreased
     with increasing  molecular weight.   Several  organic sulfur compounds
     showed substantial  increase as a  result  of  anaerobic degradation processes
     in the septic tank.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
       b.IDENTIFIERS/OPEN ENDED TERMS  jc. COSATI Field/Croup
 3. DISTRIBUTION STATEMENT

   Release to Public
       19. SECURITY C'.ASS (Tint Report)
        Unclassified
                                                                        21. NO. Of I'AGcS
                   34
                                              20. SECURITY CLASS iTIiit page/

                                                Unclassified
                                                                        ::. PRICE
EPA Form 2220-1 (»-73)
                                             i

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                                 DISCLAIMER
Although the information described in this document has been funded vnolly
or in part by the United States Environmental Protection Agency through
assistance agreement number R-806102 to the University of Washington,  it
has not been subjected to the Agency's required peer and administrative
review and therefore does not necessarily reflect the views of the Agency
and no official endorsement should be inferred.
                                       ii

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                                 FOREWORD
     The U. S. Environmental Protection Agency is charged by Congress with
protecting the Nation's land, air, and water systems.  Under a mandate of
national environmental laws, the agency strives to formulate and imple-
ment actions leading to a compatible balance between human activities and
the ability of natural systems to support and nurture life.  The Clean
Water Act, the Safe Drinking Water Act, and the Toxics Substances Control
Act are three of the major congressional laws that provide the framework
for restoring and maintaining the integrity of our Nation's water, for
preserving and enhancing the water we drink, and for protecting the
environment from toxic substances.  These laws direct the EPA to perform
research to define our environmental problems, measure the impacts, and
search for solutions.

     The Water Engineering Research Laboratory is that component of EPA's
Research and Development program concerned with preventing, treating, and
managing municipal and industrial wastewater discharges; establishing
practices to control and remove contaminants from drinking water and to
prevent its deterioration during storage and distribution; and assessing
the nature and controllability of releases of toxic substances to the
air, water, and land from manufacturing processes and subsequent product
uses.  This publication is one of the products of that research and
provides a vital communication link between the researcher and tr.e user
community.

     The purpose of this project was to measure the presence of volatile
priority pollutants in domestic sewage as it enters a large comncaity
septic tank system and to evaluate the removal of these compounds in the
anaerobic septic tank by analyzing effluent samples collected froa the
distribution box as well as the sludge and scum found in the septic tank.

     This report is to bring this information to the attention of design
engineers and to researchers conducting work on the fate of priority
pollutants.
                                   Francis T. Mayo, Director
                                   Water Engineering Research Laboratory
                                   iii

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                                  ABSTRACT
The present  study  evaluated the presence  of  volatile organics  in  raw do-
mestic sewage generated  in  a subdivision and treated by a large 5-year-old
community septic tank  that  had recently been cleaned  by  having the solids
removed by pumping  just  prior  to  this  study.   Analysis showed the presence
or priority pollutants in the  raw  sewage.   Essentially no removal of these
compounds occurred  during  the 2-day  detention in  the  septic  tank.   The
priority pollutants  generally   showed  higher  levels  during  the week  end,
probably reflecting leisure  activities  and use  of related chemicals (paint
thinners, grease removers,  toilet bowl  cleaners, etc.) than during the week
days.  Most  of  the other volatile compounds were  hydrocarbons,  and their
removal by  the  septic tank generally  decreased with  increasing molecular
weight.  Several  organosulfur   compounds  showed substantial increase  as  a
result of anaerobic degradation processes  in the septic tank.

     This report  was  sbumitted  in  fulfillment  of  cooperative  agreement
R-806102 by  the University  of Washington, under  sponsorship  of  the  U.S.
Environmental Protection Agency.
                                      IV

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                                  CONTENTS
Disclaimer	ii
Foreword	iii
Abstract	iv
Concents ............................   v
Tables and Figures	  vi

        1.  Introduction 	   1
            Materials and Methods	   3
            Results and Discussion  	   5
              Flow measurements	   5
              Presence of trace organics  	   6

            Conclusion	10
            References	11
            Tables and Figures	12
            Appendix A.  Daily analyses   ....  	  23

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                             TABLES AND FIGURES
Number

  1

  2
Number
  2

  3

  4

  5

  6

  7

  8

  9


 10


 11
                       TABLES

                                                        Page

Occurrence of Volatlles in Septic Tank	12

Forward Search of Volatile Compounds in Septic Tank
(Sunday)	13



                       FIGURES

                                                        Page

Subdivision with community septic tank evaluated
in the present study	14

Community septic tank evaluated in the present study. .  14

Frequency distribution of water usage 	  15

Flow pattern at septic tank system	16

Normal frequency distribution of surrogate recovery . .  17

Daily variation of toluene	  18

Daily variation of dichloromethane  	  18

Daily variation of chloroform	19

Percentage of samples equal to or less than indicated
concentration (benzene, toluene, ethylbenzene)  ....  19

Percentage of samples equal to or less than indicated
concentration (dichloromethane, chloroform) 	  20

Percentage of samples equal to or less than indicated
concentration (bromomethane, tetrachloethene) 	  21

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                                   FIGURES

Number                                                              Page
 12         Reconstructed total ton current of the volatile organics
            in the influent and effluent of the septic tank ....  21

 13         Attenuation of volatile compounds during septic tank
            treatment	22

 14         Attenuation of volatile hydrocarbons during septic tank
            treatment	22
                                    vii

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Introduction



     On-site disposal of sewage is widely practiced in rural



areas and urban fringes.  However, it has received relatively



little attention from1regulatory agencies or research institutes,



For example, little comprehensive information is currently



available to document successes and failures of on-site disposal



systems and the resulting health implications.  The 1970 census



noted 403,910 septic tanks or cesspools and 14,464 other



individual systems such as aerobic or ponds in the State of



Washington, representing 34.7% of all housing units  (Bureau of



the Census, 1972).  A current survey in the State of Washington



also indicates the presence of more than 500 large on-site



systems serving hospitals, schools, restaurants and subdivisions



(DeWalle, 1981).  As the septic tank effluent is directly



returned to the soil through infiltration in the subsurface



drainfield, considerable public health concern exists in regard

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to groundwater contamination and pollution of drinking water



wells.  A recent study showed such widespread contamination in



major parts of central Pierce County south of Tacoma (DeWalle and



Schaff, 1980).



     The development of the septic tank is credited to John Louis



Mouras who constructed a masonry tank in which sewage and rain-



water from a dwelling in Vesoul, France, were collected before



passing to a cesspool.  Absence of solids after twelve years of



operation led to its patent in 1881.  The first household septic



tank in the U.S. was constructed by Edward Philbrick of Boston,



Massachusetts, in 1883, and consisted of two round chamber tanks



(Metcalf, 1901).  Various types, shapes and arrangements have



been used since the earliest units with detention times ranging



from 2 hours in so-called "freshwater clarification tanks" in



Germany, to 20 days in large underground tanks in Poland, and



usually 24 hours in U.S. systems.  Walker and Driftmeier (1929)



noted decreasing solids removals when detention times increased



from 35 to 92' hours.  Weibel e_t al.  (1949) noted a leveling off



of the suspended solids (SS) removal beyond a detention time of



half a day, while the biochemical oxygen demand (BOD) removal



still showed stabilization after one day.  The low suspended



solids removal observed during the summer represents a typical



unloading of the sludge in which the generated gases carry the



solids out of the tank.  Additional  factors shown to be of



importance are sufficient depth to allow for sludge accumulation,



compartmentalization  to prevent short circuiting and use of



baffles to reduce sludge carry over.

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     In previously published studies only the efficiency of the
septic tank with respect to BOD, SS and grease removal was
evaluated while the trace organics present in domestic sewage and
in septic tank effluent were not measured.  The present study was
conducted to collect such data.  It was the purpose of the study
to measure the presence of volatile priority pollutants in
domestic sewage as it enters a large community septic tank
system.  The study also evaluated the removal of these compounds
in the anaerobic septic tank by analyzing effluent samples
collected from the distribution box.

Materials and Methods
     A community septic tank serving 97 homes in a subdivision
(Oakbrook 6) located south of Tacoma, Pierce County, Washington,
was used for this study.  The homes are located on four streets
served by a 200 mm (8 inch) gravity sewer which discharges into a
wetwell  (Figure 1).  A 10.1 L/s (160 gpm) submersible centrifugal
pump transports the waste to the septic tank.  The unit contains
84,935 litres (22,440 gallons) liquid volume in the first
compartment and 42,468 litres  (11,220 gallons) in the second
compartment (Figure 2).  The raw sewage sample was collected
through  the manhole from the inlet-T before the sewage mixed with
the contents of the first compartment.  The effluent sample was
collected from the distribution box located 4.57 meters (15 feet)
downstream  from the effluent-T.
     The sewage was collected  using an all glass/teflon custom-
made sampler.  The sewage was  drawn by suction through a  0.5  inch
                               3

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teflon intake line using a 100 ml glass syringe.  When the



syringe was in its drawn position, a teflon solenoid va.lve closed



the intake line and opened the discharge line.  When tf(e syringe



content was subsequently displaced, it flowed through the dis-



charge line to a collection device with a floating plunger to



prevent losses of volatile organics.  The septic tank effluent



was collected using a similar sampler drawing from below the



liquid surface in the distribution box.  The samples were col-



lected as 24 hour composites during a 7-day continuous period.



     The volatile organics were removed from the aqueous sample



with a purge and trap method  (Kalman, et al., 1980.  A modified



Hewlett/Packard 7675A Purge and Trap Sampler was used to purge



10 ml of liquid with nitrogen gas at a rate of 20 ml/min.  The



volatile organics that were stripped from the liquid were subse-



quently absorbed when the nitrogen passed through a Tenax GC



trap.  The trap was subsequently heated and the volatile organics



were back flushed and trapped in the initial 0.5 meter portion of



a  30 m fused silica WCOT column with SE-54, stationary phase



(J & W Scientific) chilled by liquid nitrogen.  After removal of



the cryotrap and flash heating of the column, the volatiles were



separated in the gas chromatograph (Model (3840A Hewlett/Packard,



Palo Alto, California) and detected by mass spectrometry



(Finnigan 4023, Finnigan, Sunnyvale.- California).  A computer



library system containing spectra of 30,000 compounds was used



for a spectral comparison with each detected compound.

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Results and Discussion



     a.  Flow measurements



     Flow data were obtained both from the water usage records of



the Lakewood Water District Company and from measurements in the



wetwell.  The water usage data show a baseline of 58.7 litres per



minute  (15.5 gallons per minute), which usage triples to 219.5



litres  per minute (58 gpra) during the summer months due to



extensive yard usage.  The frequency distribution of the flow



rates  (Figure 3) shows several maxima corresponding to usage in a



household with 1, 2, 3, 4, 5, 6, or 7 persons respectively.  The



median  household, having 3.2 persons, has a usage of 897 litres



per dav (237 gallons/day).  The usage ranges from 329.3 litres



per person per day  (87 gallons per person per day) for a one-



person  household to 242.2 litres per person per day (64 gallons



per person per day) for a seven-person household.



     The  flow measurement at the wetwell consisted of determining



the interval between sequenced pump switch-on times.  By knowing



the holdup volume in the wetwell the flow rate during the day can



be calculated.  This resulted in an average calculated flow of



44.7 litres per minute (11.8 gpm) which  is 24% less than calcu-



lated  from the usage data, indicating that about a quarter of the



used water does not reach the septic tank and is lost through



evaporation  (clothes dryer, plant evapotranspiration, sewer  leaks,



etc.).   The highest discharge rates and  highest standard devi-



ation  were noted around  9 p.m.  (Figure 4).

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     b.  Presence of Trace Organics



     The efficiency of the volatile organic analysis (VGA) using



the purge and trap unit was evaluated using surrogate compounds



spiked at 20 ppb in the liquid before purging.  The results show



a median recovery of 91% for bromochloromethane, 90% for



1,4-dichlorobutane, and 82% for Dg-benzene (Figure 5).  The



standard deviations, however, were substantial at this low con-



centration level.



     The organics were measured in the samples during an



intensive week long monitoring followed by six additional



samplings, the last one occurring on January 23, 1982.  The



results are summarized in Table 1 and indicate that dichloro-



methane was found in all samples, followed by toluene in fre-



quency of detection.  These two compounds were also found in the



water collected from the 125-foot deep monitoring well located



adjacent to the drainfield.  The analysis during the week long



monitoring was initiated on Monday, September 22, and was ter-



minated on Sunday, September 28, 1980.  The volatile organic



fraction typically contained 40 to 50 compounds at a



concentration > 1 ppb.  However, only 5 were identified as



priority pollutants.  Appendix A has the daily data.



     Toluene was the most prevalent among the priority pollu-



tants, at an average concentration of 34.6 -vg/L in the raw



sewage, and 38.8 Mg/L in the effluent (Figure 6).  The toluene,



originating from cleaning solvents and paint thinners, reached



its maximum concentration of 47.8 pg/L in the influent-on Friday,



while the effluent reached a maximum  of 56.9 ug /L on Sunday.  The




                               6

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shift in the maximum toluene concentration by 2 days may be a



result of the detention time which was estimated at approximately



2 days.



     Dichloromethane likely originating from chlorinated tapwater



was present in the next highest concentration (Figure 7) and also



showed its highest level on Sunday.  However, no lag was detected



between effluent and influent.  Chloroform (Figure 8) showed its



maximum concentraion in the influent on Saturday, while the



effluent showed a second maximum on Sunday, representing a



one-day shift.  Tetrachloroethene was generally low during the



week but reached a maximum on Monday.  Benzene was detected only



on Wednesday.



     A log-normal frequency distribution graph of the aromatic



compounds (Figure 9) shows the presence of benzene only in the



scum and sludge layer.  Although benzene was not detected in the



influent, it was detected on two occasions in th effluent,



possibly due to discharge of solids from the scum or sludge



layer.  Toluene showed no removal in the septic tank and very



little accumulation  in the scum and sludge layer.  Low  removals



were also noted for  the chlorinated compounds (Figures  10, 11).



     The generally low removals of the volatile organics is fur-



ther reflected in Figure 12, showing the reconstructed  ion cur-



rent of all the compounds detected in this fraction.  A tabula-



tion of the 48 compounds (Table 2) shows that the majority are



hydrocarbons including both aliphatic and cyclic structures.



Several compounds reflect the presence of anaerobic degradation



processes occurring  in the sewerline or septic tank.  High

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concentrations were noted for 2-propanone, 2-ethyl-4-methyl-



1-pentanol and 4-methyl-2-propyl-l-pentanol/ all likely origi-



nating from anaerobic decomposition processes.  Large increases



were also noted for several biogenic organosulfur compounds such



as carbon disulfide, methanethiol (methylmercaptan), dimethyl



disulfide and dimethyl trisulfide.  The largest increase was



noted for methanethiol with small increases noted with larger



molecular weight compounds probably reflecting the greater



difficulty for bacteria to generate these larger compounds.  This



trend for alcohols, aldehydes, and organosulfur compounds is



reflected in Figure 13 where the effluent/influent ratio of each



compound generally decreases with increasing retention during the



chromatographic separation.  A larger retention time generally



reflects an increasing molecular weight.  The low molecular



weight alkylated benzenes show a significant removal, probably



due  to biodegradation, but the results show no removal for higher



molecular weight compounds.  The hydrocarbons (Figure 14) showed



the  highest removals at intermediate molecular weight and lower



removals at larger molecular weights, probably due to reduced



volatilization.  The increase noted for several of the low



molecular weight hydrocarbons may be a result of their formation



as  intermediates in the breakdown of larger molecular weight



hydrocarbons.



     The present study has important implications  for assessing



the  environmental  impact of septic tanks.  As little removal of



the  volatile priority pollutants.is observed, these  compounds



will be discharged through the subsurface drainfield and may




                                8

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enter the groundwater.  Volatilization is a removal mechanism in



the septic tank, tmtc this mechanism will not be effective in the



presence of a thick scum layer and during subsurface drainage and



migration.  Some biodegradation of several organosulfurs and



hydrocarbons will likely occur during soil migration, especially



since aerobic conditions generally prevail.  The chlorinated



organics and most of the branched or cyclic hydrocarbons,



however, are less likely to be degraded by bacterial action, and



are expected to migrate considerable distances in the soil.  A



related study by DeWalle and Chian (1981) noted substantial



migration of low molecular weight chlorinated solvents away from



a  landfill in Delaware.

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Conclusion



     The present study evaluated the presence of volatile



organics in raw domestic sewage generated in a subdivision and



treated by a large 5-year-old community septic tank that had



recently been cleaned by having the solids removed by pumping



just prior to this study.  Analysis showed the presence of



priority pollutants in the raw sewage which compounds showed



essentially no removal during the 2-day detention in the septic



tank.  The priority pollutants generally showed higher levels in



the week end, probably reflecting leisure activities and use of



related chemicals  (paint thinners, grease removers, toilet bowl



cleaners, etc.).   Most of the other volatile compounds were



hydrocarbons, and  their removal by the septic tank generally



decreased with increasing molecular weight.  Several organosulfur



compounds showed substantial increase as a result of anaerobic



degradation processes in the septic tank.
                                10

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                        REFERENCES
Bureau of the Census.  Housing characteristics for states,
cities and counties, Volume I, Part 49.  Washington.  45
Government Printing Office, Washington, D.C., 1972.

DeWalle, F. B.  Failure analysis of large septic tank
systems.  Jour. Envir. Engin. Div. ASCE 107:229, 1981.

DeWalle, F. B., and Schaff, R. M.  Groundwater pollution by
septic tank drainfields.  Jour. Envir. Engin. Div. ASCE
K)6/.631, 1980.

DeWalle, F. B., and Chian, E. S. K.  Detection of trace
organics in well water near a solid waste landfill.  Jour.
Amer. Water Works Assoc. 7_3:206, 1981.

Kalman, D. A., Dills R., Perera C., and DeWalle, F.  On
column cryogenic trapping of sorbed organics for
determination by capillary gas chromatography.  Anal.
Chemistry 52:1992, 1980.

Metcalf, L.  The antecedents of the septic tank.  Trans.
Amer. Soc. Civil Engin. 5_, 1901.

Walker, H. B., and Driftmeier, R. H.  Studies of the septic
tank method of sewage disposal for isolated homes.  Agr.
Engin. 10^:256, 1929.

Weibel, S. R., e_t al.  Studies on household sewage disposal
systems, Vol. I.  Public Health Service, Cincinnati, 1949.
                           11

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Table 1.  Occurrence of Volatiles in Septic Tank
Compound
Dichlorone thane
Chloroform
Trichlorofluorcme thane
Bromcme thane
1,1, 2- tr ichloroethane
Trichloroe thane
1,1, 1-tr ichloroethane
1 , 3-dichloropropene
Benzene
Chlorobenzene
Toluene
Ethylbenzene
Tap
n=2
100%
0
0
0
0
0
0
0
0
0
0
0
Influent
n=13
100%
62
0
0
0
8
0
8
0
0
85
15
Effluent
n=13
100%
62
0
15
8
8
8
0
15
0
85
23
Scun
n=2
100%
0
50
100
8
50
0
0
100
0
50
100
Sludge
n=2
100%
0
0
50
0
0
0
0
50
50
0
100
Well
n=l
100%
0
0
0
0
0
0
0
0
0
100
0
                       12

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               Table 2.  Forward Search of Volatile Conpounds in
                              Septic Tank (Sunday)

Volatile Compounds (rcg/L)                   Scan    Influent   Scan    Effluent

Methane, dichlorcdifluoro                   1380      0.64      —      < 0.7
Methanethiol                                 —     < 0.7      1395     128
2-Propanone                                 1407     18.2      1410      70.3
Methane, thiobis                            1415     23.0      1418      84.4
Unknown hydrocarbon                         1419      2.0      1421       4.2
Carbon disulfide + dichloromethane          1422      4.2      1424      10.0
C? hydrocarbon                              1536     13.0      1527      13.6
H6xane, 3-methyl                            1558      8.1       —      < 0.7
Heptane                                     1612      6.2       —      < 0.7
Disulfide, dimethyl                         1754     11.6      1729      29.7
Benzene, methyl                             1842     74.4      1825      16.7
Hexane, 2,5-dimethyl                        1843     14.9       —      < 0.7
Heptane, 3-methyl                           1875      5.3       —      < 0.7
Cyclohexane, 1,3-dimethyl, cis              1883      5.3       —      < 0.7
Cyclohexane, 1,3-dimethyl, trans            1890      1.2       —      < 0.7
Cyclohexane, l-ethyl-2-methyl               1971      1.0       —      < 0.7
Heptane, 2.4-dimethyl                       2009     15.3       —      < 0.7
CIQ cyclic hydrocarbon                       —     < 0.7      2770       3.3
PeKtane, 2,2,3,4-tetratvethyl                2947      9.7       —      < 0.7
Trisulfide, dimethyl                        2960     11.4      2941      12.7
Heptane, 6,6-dimethyl-2-methylene           2997      6.2       —      < 0.7
Hexane, 2,2,5,5-tetramethyl                 3000      8.0       —      < 0.7
Branched C,0 hydrocarbon                    3044      3.7       —      < 0.7
Nonene, 4,eVs-trimethyl                     3074      3.4       —      < 0.7
Hexane, 3,3,4-trimethyl                     3091      3.2       —      < 0.7
Hexane, 2,4-dimethyl                        3124      8.3       —      < 0.7
Benzene, 1,4-dichloro                       3149     16.7      3134      11.5
Pentane, 2,2,3-trimethyl                    3157      2.5       —      < 0.7
C,0 cyclic hydrocarbon                      3179      7.2      3168      25.1
Benzene, l-methyl-4 (1-methylethyl)         3211     15.4      3205      71.6
Heptane, 2,2,4,6,6-pentamethyl              3221     17.1      3212       7.2
Cyclohexane, l-methyl-4-(l-methylethenyl)   3229    126        3221     107
C1n hydrocarbon  "                           3238      3.6       —      < 0.7
Hexane, 2,2,5-trimethyl                     3240      7.2      3231      15.5
Hexane, 3,3-dimethyl                        3252     38.7      3242      21.7
Hexane, 2,2,3-triroethyl                     3326     45.8      3318      24.7
1,4-cyclonexadiene,
    l-methyl-4 (1-methylethyl)               3346      3.9       —      < 0.7
Butane 2,2,3-trimethyl                      3349      3.9       —      < 0.7
1-pentanol, 2-ethyl-4-methyl                3367     21.2      3362      13.6
Pentane, 2,3,4-trimethyl                    3408     11.9      3402       7.6
Pentane, 2,2,4,4-tetramethyl                3415      4.0      3410       1.8
Cyclohexane,1-methy1-4-(1-methylethylidene  3453      9.2      3449      15.7
1 pentanol, 4-methyl-2-propyl               3500     13.5      3497      10.0
Hexane 2,2,3-trimethyl                      3583      5.9      3579       3.4
Cyclonexane (1-methylethyl)                  —     < 0.7      3606       1.9
Bicycloneptane 3,7,7-triraethyl              3650      5.3      3652      41.6
Heptane, 5-ethyl-2-methyl                   3717      5.7      3714      37.7
Benzene, 1,2,3-trichloro                     —     < 0.7      3745       2.7

           Total                                    623                 793

                                     13

-------
                            RtSERVt
                                      . |  i .
                                          RESERVE
                                        Jl  DRATNFrriO
^-J

5"—
• Ite
, W
U
t...-

' V
rsl
«
~(
-d
Jl_

S'l
r
ft
i«
^
i


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u
Iu4





»*W





*«••
f t.





*t»'
tl
«




•"•
N
|


«. '-t. r-
" " A.
J---J •

Figure  I.   Subdivision  with community  septic  tank  evaluated in
                              the present study.


                                                       (To provide the reader with
                                                       complete information, these
                                                       reduced engineering drawings are
                                                       Included.  These are the best
                                                       copies available; we regret that
                                                       portions are undecipherable.)
                         \
              I. i
                                                                  f?V
                       FOR 97RESIOEKCES
                       48 HOUR DETENTION TIME
.LK
•':. T
... LJ
140 GALLONS)
I ME







42.
("

-------
                         OF KS1DCNCES AT GIVEN RCURATE
                 NEDIAN FLOW  897 LITRES/HOUSE.
                 £237 GALLON/HOUSE.DAY)
                                          1  PERSON - 329 LITRES/PERSON.DAY
                                          (87 GALlOtl/PERSON.OAY)
                     2 PERSONS -
                  ~306 LITRES/PERSON.DAY
                  ' (81 GALLON/PERSON.DAY)

                  -_3 PERSONS -
                   284 LITRES/PERSON.DAY
                  (75 GALLON/PERSON.DAY)

                          _  4 PERSOKS-
                        tTRES/PERSON.OAY
      5 PERSONS-  (» WU-ON/PERSON.DAY)
 253  LITRES/PERSON.DAY
(67 GALLON/PERSON.DAY)
                        -6 PERSONS-250 LITRES/PERSON.DAY
                         (U GALLON/PERSON.DAY)
        i -*-7 PERSONS-242 LITRES/PERSON.DAY
             (64 GALLON/PERSON.DAY)
          4.4X OF HOUSEHOLDS  1893-4436 LITRES /DAY  (SCO - 1172  GALLONS PER DAY)
Figure  3.    Frequency  distribution  of  water  usage.
                                    15

-------
  100
        AVERAGE OF 8 DAILY MtASUKKNTS
S  SO
5
a
                      «T«LL MEASUREMENT 44.7 LPK (11.8 GPM)


                      WATER METER READING 58.7 LPM 05.s GPM)


                      UNACCOUNTED  24J
                                                                                             20
                                                                                             10
                               NOON
                                          Tt« OF DAY
                                                                       12 MIDNIGHT
                 Figure  4.    Flow  pattern  at  septic  tank  system.
                                            16

-------
                 zoo
                 150
               £
               UJ


               S
                  100
                  SO
 JO U6/L SWING UYU



O BWWOiLOROCTXAJtt



A M-OICHIOROBUTAM



O 06-BEKZEKE
                            I
                                     I
                                                I
                    J       10       JO     50    70        90       98



                    PERC£NTAG£ OF SAMPLES WITH LESS THAN CORRESPONDING RECOVERY
Figure 5.   Normal  frequency  distribution  of  surrogate  recovery
                                      17

-------
    sc
    40
    10
                          TOLUENE
                          O RAW SEWAGE
                          A SEPTIC TANK EFFLUENT
     1
     Non
 2
Tue
 3
Ued
 4
Thurj
 5
Frl
 7
Sun
     Figure  6.  Daily  variation of  toluene.
                          O  RAW SEWAGE
                             SEPTIC TANK EFFLUENT
     Non    Tut    Ued     Thur
                                            Sun
Figure  7.  Daily  variation of  dichlororaethane,
                         18

-------
                            CHlOKOftXW

                            O  «AU SUAGE

                               SEPTIC TAHJC EFRUDIT
                                                             Sun
                     (ton     Tut    «eO    Thurs



                 Figure  8.   Daily  variation of chloroform.
               BEHZENE
  1000
   100
3  '"

s


5
»—
K
UJ
^**  10
§  '
  0.1 -
  0.01
       TOLUENE





O TAP (UEU HATER)



O St'TIC TANK IHFLUENT



A EFFLUEUT


A SCUM LAYER


• SLUDGE


D ORAINFIELO WELL
                                                                  ETHYLS EXZENE
           20
                 SO
                        80
                              95 S
                                     20
                                            SO
                                                  80
                                                        9S S
                                                               20
                                                                      SO
                                                                             80
  Figure  9.   Percentage of  samples equal  to  or  less  than indicated

                                   concentration.
                                        19

-------
         s
         i
         t~
         §
            1000 —
             100
              10
             1.0
              0.1
             0.01
                     D1OU.OKWETHANC
    CHLOftOFOW


• TAP (UULUATER)


O SEPTIC TAtIK IKFLUEKT


& EFFLUENT


A SCUM


• SLUDGE


D DRMNFIELO WELL
                5     ZO      so     80    95 5    20      SO     80     95
Figure  10.   Percentage of  samples  equal  to or  less than  indicated
                                 concentration.
                                    20

-------
           1000
           100
            10
        §
        i
        X
        UJ
        g  1.0
           0.1
           0.01
                    tHONONCTHMtf
                               TETRACH.OHOETHENE


                            • TAP {WELL HATER)

                            O SEPTIC TAX* INFLUENT

                            A EFFLUENT

                            A SO* LAYER

                            • SLUDGE

                            Q  DRAINFIELD HELL
                               80
                                    95 S
                                                SO
                                                      80
Figure 11.   Percentage of  samples  equal  to or  less than indicated
                              concentration.



a




1 	
E si; » T?T«L
j| EFFLUENT •
1 I1' » . 1. H
«[' • ,. . . J-^J— ^
Jv
r
jJlvJiXjkiu

-UL
Figure 12.
Reconstructed total  ion current  of the  volatile
               organics in  the
 influent  and effluent of  the septic tank.

                   21

-------
             1000
             100
          o
          i   10
          »~
          X
             0.1
             0.01
O SanjR COMPOUNDS
A SENZENC COTOUNOS
O ALCOHOLS
                                    10
                                                         20
Figure 13.   Attenuation of  volatile  compounds  during  septic  tank
                                treatment.
             100
              10
              0.1
             0.01
                       O HYDROCARBONS


                                    10
Figure  14.  Attenuation of volatile hydrocarbons  during  septic
                            tank  treatment.
                                 22

-------
                                                     APPENDIX A



                                                 DAILY ANALYSES  (pg/L)
<
c
PURGIABUS
1. M«lh«ne, bronj-
2. Htthtne, IrtcMorofluoro-

(•wthrlenechlorldt)
4. tthenc,t.2-dlcMoro-
5. Cth«n«. l,l-dlchlort>-
6. Chloroform
7. Totutni
8. tthene, tftr«chloro-
9. Btnienc, chloro-
10. Benjtne, tthyl-
11. Methane, Irlbromo-
12. Clh«r>e. 1.1.1-
Trlchloro-
13. Ben^ne
14. Prop«ne.l .2-
01 hloro-
1S. tthc. c.trkMoro-
16. 1-Proprne.l .3-
dlchloroU)-
17. tlh«nf .1.1.2-
Irlchloro-
18. 1 .«-
fM ^
CV C

14.8
4 8



5.3
24.1












r* 3
cv c
V* 3


44.4



0.9
31.9












IN*
IN*
"I


1.0




0,7












0. C
4V V
V> 3
3 C
1 VZ






34 9










0.79/

0. C







22.2












zi
+* «J
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V» 3






0.82
38.1










J.S7

c\ c
V tl
tn 3







32.9





O.IB






ex c




















0. C
£5
i a





-/0.3
8.5/
SJj?



3.S/-






.n/

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1. C
fe. *-






0.1
47.8










J.9

** **
VI 3
iT«-
U. UJ







38.4












0. C







32.1










2.7

W» 3






0.4
48.9










79

CX C






1.9
25. J










4 ,

Su. Stot. 28
Effluent (UW






1.0
56.9










0.7
~
vt|


0.18




M.5
0.47

0.01




0.03

0.13

—
W» 3


0.37




44.9
0.17

0.03








~
S3
Ck C
VI 3
3 C







71,4
0.44

0.30








~
S3
ss
VI 3
•s
—





26.9
0.31

0.34








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3 *-







49.1


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0.12
0.04

0.31

I—
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C4 «l
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0.01





(3.2
0.13

1.7


1.1

0.15



ro
CO

-------
APPENDIX A (continued)





  DAILY ANALYSES (pg/L)
,
PVRCCABUS
1. Mtlhinf, bromo-
2. Mtthine, Irlchlororiuoro-
3. M{lb«nt, dlchloro
(««thrl«n«hlorld«)
4. lthcnc,t,2-4lcMoro-
S. (thine, 1,1-dlchloro-
6. Chloroform
7. Toluene
fl. tthene, ttlrichloro-
9. Bcniene, chloro-
10. Benjene, ethyl-
11. Helhjne, trlbromo-
12. tthjne. 1.1.1-
Trlchloro-
13. Beniene
14. Propane .1,2*
OlcMoro- '
IS. Uhfne.lrlchloro-
16'. 1 -Propf ne .1,3-
dlchloro(I)-
17. HMnf. 1,1,2-
tr Ichloco-
It. 1 ,<-dlchlorobtn-
o
r Ji^
u c
* *»
O 3
^"i
5?. 3

1.7

0.3S
3.0
19,1
1.2



O.S6






t-
r* ^*
15
U
« *
O o*
,•3
V> VI
lisa

3S(.3






u.a








f-*
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i-
0 i.
V
• fc»
^3


O.d



O.JI










-
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"!•!
»rt K-


0.7?















t-
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• **
C C
^;
.c
J!i


0.7?



5,6











H-
— O
C C
i* V
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54.4

0.74



11.2











»-
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u c
2S
• s-
^i


4.1
o.eo
4.2
1.7









0.34


J.
fM O
US
25
• %.
^w
0.40

1.4
1.2

0.84





O..ZJ
0.28





: E
» s
fM*-»
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•?x
• i
^^


(9,9















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•M'*-
C C
4* «
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• <%.
5£


so.;


IO.S
19.7
0.011










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as
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C C
•* t»
"> D
Ji'5


«.2


2.1



0.0'








~p
e t»
• 3
3 if
VI W


7997






1,9


16,5





^ h-
«*< *—
O
ft
• »
^^
134

231





?»,!
11,}


ISM




	
O
St.
^!
^'5


1S3



Q.H


,0)5




























-------
APPENDIX A (continued)





 DAILY ANALYSES (pg/L)
<
<
BASE-NEUTRAL EXIRACTA8LES
1. 1 ,4-Dichlorobenjene
2. Nitrobenzene
3. Acenaphthylene
ro 4. Di-N-Buthylphthalat*
 3
• *-
^£



10.2
136




1.1



3.4
OD
CM
*-» *>
ex c
«V 4V
4/> D
»*»-
3 *-
vn uj



33.5
t?8




8.3

0.2.

14.4
09
CM
*>
a.
«» *•
»yi CT»
13
» 3
3 —
»X» »XI
16S



3004

18S9


297
6S23



. *«»
u c
4b 4V
a 3
j?!!



12.4
168




20.6

0.59

17
r^*
. **
0 C
«l «
O 3
3 «-
l/t t*J









141.7




r-

O 3
* **.
3 C
l/t —




123




21.55



14.6
. «j
c c
«J H
1 3
• Iw
3 *•-
4/t UJ




444




33.1



?4.6

C C
•« «l
•-> 3
• u.
3 »-
\n u«



32.0
74.2
1.9

21.8

30.9



6.6
^
CM
C
«
• 3
3 O
>n
607.4
52.8


37.2

1590.;
67.1


2057

107. 1

 (7»
T3
• 3
3 •—
*n w^

9.6



50.6
18.2
3.6

12.9
26.6



*
rs« i.
•/
. *j
c «
» 31
O
3 V
 »



7.9
11.0


0.6

1.2(


2.2


-------