United States
Environmental Protection
Agency
Municipal Environmental
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-84-101 Sept. 1984
SER& Project Summary
Characterization of Soil Disposal
System Leachates
Mason Tomson, Carol Curran, J.M. King, Helen Wang, Joe Dauchy, Virginia
Gordy, and C.H. Ward
Groundwater samples from ten septic
tank systems around the country were
sampled and analyzed for inorganic
ions, bacteria, viruses, and chromato-
graphable trace-level organics (C-TLO's).
Generally, wastewater effluent samples
were taken from the distribution box at
each site and put into the soil adsorption
field. Groundwater at the site was then
collected and analyzed. The study
primarily emphasizes the C-TLO's, 22
of which were targeted for quantitation
as a result of previous studies. The 22
compounds include chloroform, trichlo-
roethylene, toluene, dichlorobenzenes,
naphthalene, skatole, p(1,1,3,3-tetra-
methylbutyl) phenol, benzophenone,
and bis (2-ethylhexyl) phthalate. Several
are priority pollutants. Concentrations
of the 22 target compounds varied from
a high of ~ 300 fjg/L in the distribution
boxes to a high of ~ 15 fjg/L in the
groundwater wells. Typical concentra-
tions in the distribution boxes and
groundwater samples were <1 ;ug/L
and <0.1 fjg/L. respectively, indicating
>90% removal of C-TLO's within 9 m
(30 ft) or so.
This Project Summary was developed
by EPA's Municipal Environmental
Research Laboratory, Cincinnati. Ohio,
to announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
Very little is known about the fate of
chromatographable trace level organics
(C-TLO's) such as chlorinated hydrocar-
bons, aromatics, or phthalate esters in
groundwater below septic tank systems.
Many of these compounds are either
solvents or synthesized organics. Often
these compounds are chosen by industry
for their stability and resistance to
degradation.
The overall objective of this research
has been to determine (1) whether
potentially harmful C-TLO's are being
systematically added to groundwater by
septic tank systems, (2) which compounds
or classes of compounds are present at
what concentration levels, and (3) to what
extent they might migrate in the subsur-
face. Domestic septic tank systems were
the primary focus, but larger systems
used by several homes were studied
where possible. Ten systems were
sampled (Figure 1). Speonk, New York,
and Cisco Grove, California, were parti-
cularly well suited for study and produced
the most definitive information on the
potential migration of C-TLO's in ground-
water beneath septic tanks. C-TLO data
from each system are presented in the
report, but emphasis was placed on the
Speonk and Cisco Grove systems.
Methods
Chromatographable Trace
Level Organics
C-TLO's were analyzed using well
documeted procedures of separation,
concentration, and chromatography.
Generally, 5 to 20 L of water were slowly
(—30 ml/min) pumped through a Teflon*
resin column containing 8 ml of XAD-2
amberlite macroreticular resin. The resin
columns were then capped and stored on
ice in a bag containing activated charcoal
"Mention of trade names or commercial products
does not constitute endorsement or recommenda-
tion for use.
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10
Stellacoom
Stinson
Beach
Speonk
Percent of
households using
septic tanks
Over 35 percent
5 Penwaugh
6 Aldine
7 Pear/and
9 Southern Bible College
'/////A 25 to 35 percent
Less than 25 percent
Figure 1.
Distribution of onsitewastewater systems by state and sampling locations for C-TLO
analysis in this study.
for shipment to the labortory at Rice
University for workup. The C-TLO's were
stripped from the resin column with
about 40 ml of methylene chloride. The
resulting solution was then concentrated
by evaporation to either 1.0 or 0.1 ml.
Generally, a gas chromatographic (GC)
trace was obtained the same day the
sample was concentrated. GC spectra
were recorded on an integrating compu-
ter. Several portions (approximately 10/uL
each) of each sample were then put into
surface deactivated melting point tubes
and the ends were melted closed. These
small samples were either stored at
-40°C for later examination or used for gas
chromatographic/mass spectrometer
(GC/MS) analysis. Through preliminary
research and previous experience, a suite
of 22 compounds was chosen for quanti-
tation on the GC/MS by reverse-ion
search against a prepared standard. An
internal spike of Da-naphthalene was
added to each sample.
Resin column blanks were taken on each
field trip and treated the same as the
sample resin column exceptthat no water
was passed through them. They were
returned to the laboratory, treated as the
other samples, and analyzed by both GC
and GC/MS. If a target compound
appeared in the blank at any detectable
concentration, it was noted in the
reported data, and less importance was
given to the compound in all subsequent
interpretation.
COD, TOO and Inorganic
Analyses
The following analyses were generally
performed on each water sample in the
field except as noted: total and free Clz,
conductivity, chloride, fluoride, iron,
sulfate, sulfide, hardness, alkalinity, pH,
NlVN, N03~N, N02~N, inorganic and
organic phosphate, COD, TOC, and DO.
Most of the parameters were measured
using a portable Hach kit. COD was
measured in the field using a portable
heating block and premixed ampules.
TOC samples were stored on ice in low-
head-space, screw-cap vials until analysis
in the laboratory in a TOC analyzer.
Microbiological and Soil
Analyses
Total coliforms, fecal coliforms, and
fecal streptococci were determined either
by local personnel at each site or by the
Houston Public Health Service. For virus
analysis, 18.9 L (5 gal) of wastewater or
378.5 L (100 gal) of groundwater was
passed through either a positively charged
Cuno Virosorb Filter Cartridge (Type 1-
MDS) or a negatively charged Filterite
filter in the field. The analyses for viruses
were performed by Dr. C.P. Gerba at the
Baylor College of Medicine, Houston,
Texas, by procedures that he and his staff
had developed. All soil analyses were
performed by Harris Labs, Lincoln,
Nebraska.
Results
The complete report presents a separate
evaluation for each site. Generally
included in the report for each site are (1)
a site description and history, (2) a site
map or diagram of the septic tank/leachate
field system, (3) a table presenting the
physical, inorganic, and microbiological
analyses, (4) GC traces from samples
taken from the septic tank effluent
distribution box, monitoring wells, and
groundwater or lakes, and (5) a table
presenting the concentrations found for
any of the 22 C-TLO's targeted for
quantitation by reverse-ion search from
these samples used for the GC traces. A
discussion is presented for each site
relating the variety of compounds, the
amount of wastewater, and the movement
of the compounds through the leachate
field with the local uses of water, soil
types, and adsorption of compounds.
The last section of the report presents a
more general discussion and summary of
C-TLO's found in the septic/tank leachate
fields. Most of the 22 target compounds
are in common use m a normal household.
The major uses and water solubility of
these compounds are listed in Table 1.
Numerous additional C-TLO's were also
identified by the GC/MS/data system. A
partial list of additional compounds
identified in the Speonk, New York,
groundwater is reproduced in Table 2
along with a list of wells in which each
compound was identified. Because of the
method used, there is a rather high
degree of certainty about the identity of
most of these compounds. Several
additional compounds such as methyl-
naphthalene or some of the bicyclo
compounds might be added from this list
to the basic 22 in future studies.
Conclusions
1. Many domestic septic tank efflu-
ents contain more than a hundred C-
TLO's in the fjg/L range with potential
impact on the groundwater. Many of
these can be accounted for by products
used in a normal household.
2. In sandy soils, significant C-TLO
compounds may be detected up to 61 m
(200 ft) away from the leach field, even
though removals for the initital concen-
trations added to the leach field were
>90%. A short distance in the leach field
(about 15 m) is probably not sufficient for
significant C-TLO removal.
3. C-TLO's may travel only a few
meters in heavy clay soils.
4. Several classes of C-TLO's together
account for most C-TLO's that persist in
groundwater:
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Table 1. Major Uses of C-TLO's Targeted for Study
Compound Water Solubility fmg/L)
Major Uses
1 Chloroform
2 Carbon tetrachloride
3 Trichloroethylene
4 Toluene
5 Tetrachloroethylene
6 Chlorobenzene
7 m-Xylene
8 Bromobenzene
9 m-Dicholorobenzene
10 p-Dichlorobenzene
11 o-Dichlorobenzene
12 Acethophenone
13 Naphthalene
14 Skatole
15 o-Phenylphenol
16 Diethylphthalate
17 2(Methylthio)benzothiazole
18 (1,1,3,3-Tetramethyl-
butyl)phenol
19 Benzophenone
20 Butylbenzene sulfonamide
21 Dibutylphthalate
22 bis(2-£thylhexy/)phthalate
7950 _ Solvent, cleaning agent,
fire extinguishers,
rubber industry
800 Solvent, fire extinguisher,
cleaning clothes, insect-
icide, manufacture of
organic chemicals
1470 Solvent, degreasing, dry
cleaning, manufacture
of organic chemicals
470 Solvent, manufacture of
organic chemicals, dyes,
explosives
483,400,200 Degreasing metals, solvent
448 Manufacture of organics,
solvent
Solvent, manufacture of
dyes, etc,
446 Organic synthesis, solvent,
additive to motor oils
79 Solvent, manufacture of dyes,
organic synthesis
79 Insecticidal fumigant
154 Insecticidal fumigant
5420 Perfumery, catalyst in
syntheses
31.7 Raw ingredient in organic
sytheses
Occurs in feces, beet root,
and coal tar
700 Pesticide, rubber industry
7040,1000 Solvent, fixative for perfumes
Fungicide, pesticide
preparations
Surfactant
148 Perfumery, soaps, manufacture
of drugs and insecticides
Plasticizer
4.5 Insect repellent
0.4 Vacuum pumps
a. Chlorinaterd hydrocarbons
b. Plasticizers
c. Antioxidants
d. Aromatic solvents
e. Bicycle compounds such as borneol
5. Both viruses and coliforms are
generally removed after groundwater
passes through 10 to 20 m (32 to 64 ft) of
sandy soil or through an even thinner
layer of clay.
The full report was submitted in partial
fulfillment of Cooperative Agreement CR
806931 by Rice University under the
sponsorship of the U.S. Environmental
Protection Agency.
Table 2.
Compounds Identified by Reverse Ion Search in Water Samples from the Speonk, New
York. Site
Compound Class
Sample or Well Number
I. Alkyl-aromatics
Benzene
Ca-Benzene
Ct-Benzene
(2,2-Dimethoxyethyl)benzene
a-Ethylbenzenemethanol
Ct-phenol
Ci -Naphthalene
1,1 '-oxybis(benzene)
Ca-Napthalene
(1,V-Biphenyl)-2-o1
Methylbezoate
Cz-Napththalene
(2-hydroxy-4-methoxy-
phenyljphenylmethanone
Toluene
Xylene
Acetophenone
Naphthalene
o-Phenylphenol
(1.1.3.3.-Tetramethylbutyl)phenol
Benzophenone
0,13
D, 1,9, 10, 13
D. 1.9. 13
9.13
13
D,9, 10, 13
D, 1.9, 10, 13. 15, 16
10,13
D.1,9,10,13,15,16
D
1,15,16
15
D.1,10,13,15,16
D. 1,9. 13. 15, 16
13, 15, 16
D, 1.9. 10, 13, 15, 16
D.9. 10. 13
D,9, 10, 13
D.9. 10. 13
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Table 2. (continued)
Compound Class
Sample or Well Number
Butylbenzene sulfonamide
Skatole
II. Alkanes
Ca
Cio
Cn
Ct-cyclohexanol
Ct-cyclohexanone
Ctester of 2-mi thylpropanoic acid
C,4
C,6
C,e
hexatriacontane
11 -Decyldocosane
pentacosane
Ce
/, 1 -Diethoxyethane
1,1 '-Oxybisdecane
III. Sulfur-Containing
Isothiazole
Benzothiazole
Dimethyldisulfide
Sa
Dethyldisulfide
2(Methylthio)benzothiazole
IV. Bicyclo-compounds
1 -Methyl-4-(isopropyl)- 7-oxa-
bicyclo[2.2. 1 \heptane
1,3,3- Trimethylbicyclo[2.2.1 ]-
heptan-2-one
1,3,3-Trimethylbicyclo(2.2. /]-
heptan-2-ol
1,7,7- Trimethylbicyclo[2.2.1}-
heptan-2-one
1,3,3- Trimethyl-2-oxa-bicyclo
[2.2.2]octane
2,6,6-Trimethylbicyclo[3.1.7]-
heptane
cis-p-menthan-4-ol
2,2-Dimethyl-3-methylenebicyclo-
[2.2.1]heptane
V. Chlorinated hydrocarbons
Chloroform
Trichloroethylene
Carbon tetrachloride
Tetrachloroethylene
Chlorobenzene
(Bromobenzene)
a-Chlorotoluene
Dichlorobenzene
VI. Phthalate Esters
Diethyl phthalate
Dibutylphthalate
bis(2-Ethylhexyl)phthalate
D,9,10,13
D.9.10
D, 1,13.15.16
D, 1,10.13,15,16
13,15.16
D.9,13
13
13
13,15
1,13,15,16
1,13.16
1.13
1.13.15,16
13.15
D. 1,9,10.15,16
9
9
13
13
D.1
D
1
D.9,10.13,15,16
13
13
13
13
D.9,10
10
9
D.9
D, 1,9.10.13,15.16
D.9,13,15.16
1,10.16
D. 1,9.10,13,15.16
D.I
D
D. 1,9.10.13,15.16
D, 1,9,10,13,15,16
D. 1.9,10,13,15,16
D, 1,9.10,13,15,16
*USGPO: 1984-759-102-10662
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Mason Tomson, Carol Curran. J. M. King. Helen Wang, Joe Dauchy, Virginia
Gordy, and C. H. Ward are with Rice University, Houston, TX 77251.
Ronald F. Lewis and Marion P. Scalf are the EPA Project Officers (see below).
The complete report, entitled "Characterization of Soil Disposal System
Leachates," (Order No. PB84-196 229; Cost: $11.50, subject to change) will be
available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, MA 22161
Telephone: 703-487-4650
The EPA Project Officers can be contacted at:
Municipal Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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