1988 EPA Study -- Trace Organics and lnorganics in Distribution and Marketing Municipal Sludges
by: Rodger Baird and Sylva M. Gabrielian, the County Sanitary Districts of Los Angeles County,
Efforts to characterize major unknown organic components were limited to computer comparisons of
GC/MS peaks to the NBS mass spectral library. In none of the cases was a tentative identification made.
Manual review of those components with a high degree of fit with an NBS library compound (>8O%) allowed probable
compound class assignment for many peaks. Virtually all of the major components classified appeared to be aliphatics
or carboxylic acid type compounds. A majority of the sample extracts exhibited a hydrocarbon "hump" in the ion
chromatograms. The peaks reviewed, therefore, were superimposed on this background. As a result, a significant
portion of the major peaks were multi-component peaks whose identities remain completely unknown.
United States Health Effects
Environmental Protection Research Laboratory
Agency Research Triangle Park, NC 2771 I
Research and Development EPA60O/S1-88/001 Mar.1988
Project Summary
Trace Organics and lnorganics
in Distribution and Marketing
Municipal Sludges
Rodger Baird and Sylva M. Gabrielian
This project was undertaken to
complement a study of the
occurrence of pathogens in
distributed and marketed (D & M)
municipal sludge products. The
purpose was to provide a data base
of priority pollutant metals and
organics from sludges produced at
facilities in 26 cities across the U.S.
In addition, efforts were made to
characterize the major organic
components in sample extracts from
each city using GC/MS.
For two of the cities, where large
composting and marketing/
distribution operations were in place,
composites of weekly samples from
eight different sites were prepared.
Five to six composites from each of
these sites were prepared from eight
weekly samples collected at each
site. For the other 24 cities, 15 of
which had ongoing D & M operations,
less intensive analyses were carried
out for the survey: four monthly
samples from each site were
composited, and these 24
composites were analyzed with the
composite samples from the two
weekly-sampled cities.
Analytical methods were selected
prior to initiation of the project; they
followed standardized preparation,
cleanup, and analytical procedures.
Modifications were required in some
instances in order to deal with the
complicated sample matrix presented
by composted sludge. The
modifications for arsenic, selenium,
and thallium were successful in
dealing with the matrix. For extractable
organics, additional cleanup
methods are still required to achieve
suitable detection limits for some
components.
Of the 15 trace metals analyzed, all
but Be and TI were detected 100% of
the time in all 67 samples analyzed:
Be was at low but detectable
concentrations in 97% of the
samples, but TI was never detected.
The relative standard deviation of
individual metal concentrations for
each site where multiple composites
were analyzed was less than 30%. In
contrast, the range of metal
concentrations from site to site
varied up to two orders of magnitude
for some metals. Comparison of
these results with literature reports
of municipal sewage sludge
evaluations suggested that none of
the sludge products tested would be
classified as hazardous waste under
RCRA criteria. Comparison of the
analytical data to EPA proposed
criteria for D & M sludge products
indicate that copper may be a
problem in sludge from one city, and
that several D & M products across
the country may have a consistent
problem with lead.
Relatively few of the target organic
compounds were detected in any of
the samples. One phthalate (DEHP)
was detected in all samples. Some
two, three, and four-ring PAH, DDT
metabolites, phenol, and chlordane
were detected in several samples.
Sample matrix problems in the
pesticide analysis prevented a
complete survey by GC/EC. Six other
target compounds were detected in
one sample each. The PCB mixture,
Aroclor 1248, was detected in two
samples by GC/EC, but the
concentrations were too low to be
confirmed by GC/MS. The reported
levels did exceed the draft D & M
criteria, however.
The GC/MS characterization of
major organic components in 26
sludge extracts did not reveal any
"new" compounds. The i o n
chromatograms of most samples
were dominated by petroleum and
carboxylic acid-type compounds.
This Project Summary was
developed by EPA's Health Effects
Research Laboratory, Research
Triangle Park, NC, 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
The land application of municipal
wastewater treatment sludges is widely
practiced both as an economic treatment
or disposal method and to provide an
economic soil nutrient amendment for
agricultural use. Concerns over the
general disposal of sludge to land have
focused on several possible adverse
impacts from sludge-borne chemical
and microbial agents, including
phytotoxicity, domestic animal toxicity,
and human health. Human health issues
primarily emphasize pathogenic
microorganisms, and to a lesser extent,
trace metals and organics which might
enter the food chain via contamination of
drinking water, accumulation in and on
edible crops, or accumulation in animals
and animal products used for food.
Most studies of sludge products and
trace chemicals in sludge applied to land
have revolved around specific sludges
applied under controlled, planned
conditions, - either laboratory, pilot, or
full scale operations. Sludges used in
planned land applications are usually
stabilized via one or more treatments
such as digestion, chemical treatment,
dewatering, h e a t - d r y i n g , and
composting.
The EPA published a process design
manual, "Land Application of Municipal
Sludge" (l), setting guidelines for
projects and reviewing existing
information and data bases. In a separate
report, EPA identified approximately 50
individual metals and organics of
probable concern in different disposal
management options (2). These options
included: landspreading and
distribution/marketing (agricultural);
landfilling; incineration; and ocean
disposal.
In a separate but obviously related
issue, the "Domestic Sewage Study" (3)
addressed concerns over the industrial
disposal of toxic wastes into municipal
treatment systems and the domestic
sewage and sludge exclusion from
RCRA. This study proposed a list of 165
chemicals for analysis in municipal
treatment systems. As part of a
cooperative study (4) between the
Association of Municipal Sewage
Agencies (AMSA) and EPA, 18 sludges
were evaluated using the "Toxicity
C h ar ac t e r i s t i c Leach i n g P roc e d u re "
(TCLP). A wide range of sludge types
was included in that study, and although
none exceeded the proposed TCLP
limits for hazardous wastes, some were
close to the proposed limits (5). The EPA
is currently in the process of issuing
regulations for sludge management, and
draft criteria were made available to
AMSA in mid-1987.
Although there is much data to be
found in the literature for metals, there is
comparatively less available for trace
organics, and in either case, little recent
data on composted D & M sludges are
available. The project reported herein
was undertaken to address two goals:
1. provide a data base of 15 trace
metals and 121 toxic organic
compounds in stabilized sludge
products from 26 cities which
are distributed and marketed for
various land application uses.
2. characterize selected sludge
extracts from each city for nontarget
organic chemicals which
might predominate in individual
sludges.
Experimental Procedures
The following is a brief discussion of
the analytical procedures employed and
some of their limits relevant to data
interpretation. Few problems arose in the
acid digestion and ICP or AA analyses of
Ba, Be, Cd, Cr, Cu, Pb, Mn, Ni, Ag, Zn,
or Hg following guidelines in the EPA
Methods SW 846 procedures.. For the
graphite furnace AA analysis for TI,
however, Smith-Hieftje background
correction was required. For As, Se, and
Sb analyses by hydride generation AA
methods, 6.5 N hydrochloric acid was
required to minimize the transition metal
inhibition of the hydride generation step.
Graphite furnace analyses of As and Se
were precluded due to severe
background interferences.
The volatile organics were analyzed
by purge and trap methods using
capillary gas chromatography/electrolytic
conductivity/photoionization detectors,
following guidelines set forth in EPA
methods SW 846. While these
techniques were suitable for the target
compounds in the composted sludge
matrix, a number of unidentifiable
components were detected by the
photoionization detector. It is unlikely that
these unknowns were present in the
extracts used for GUMS characterizations
described below.
Initial efforts to analyze for pesticides
and PCBs by capillary GC with electron
capture detector met with mixed success.
Sample extract fractions had to be
treated with KOH, mercury, and sulfuric
acid in addition to silica gel cleanup;
each of these fractions required dual
column analyses before and after the
chemical treatment. This tedious process
was successful, in some instances, in
yielding data. More often than not,
however, interferences remained. GC/EC
was abandoned in favor of GC/MS after
15 samples were analyzed.
The GC/MS procedures followed the
extraction and GPC cleanup methods
described in EPA Methods SW 846. Most
of these samples had been processed,
and many of the analyses completed
prior to availability of the draft D & M
sludge criteria. Therefore, in many
samples, the complex organic matrix in
extracts from most sites interfered with
the instruments' ability to detect several
of the target compounds at levels low
enough to be interpreted relevant to the
proposed D & M criteria. Although
experiments are being continued in an
effort to improve relative detection limits
in these matrices, results were not
available for this report.
Efforts to characterize major unknown
organic components were limited to
computer comparisons of GC/MS peaks
to the NBS mass spectral library. In none
of the cases was a tentative identification
made. Manual review of those
components with a high degree of fit with
an NBS library compound (>8O%)
allowed probable compound class
assignment for many peaks. Virtually all
of the major components classified
appeared to be aliphatics or carboxylic
acid type compounds. A majority of the
sample extracts exhibited a hydrocarbon
"hump" in the ion chromatograms. The
peaks reviewed, therefore, were
superimposed on this background. As a
result, a significant portion of the major
peaks were multi-component peaks
whose identities remain completely
unknown.
Conclusions
All of the municipal sludge products
analyzed from 26 cities contained
measurable levels of heavy metals;
concentrations ranged over two orders of
magnitude between sites. Based upon
comparisons with reported evaluations of
municipal sludges in the literature, it is
unlikely that any of the distributed and
marketed sludge products tested in this
study would be classified as hazardous
waste. However, in comparing measured
concentrations with EPA-proposed D &
M sludge criteria, copper ( > 1100 mg/kg)
and lead ( > 200 mg/kg) concentrations
from several sites appeared to be high
enough to consistently exceed these
criteria for land use.
Volatile priority pollutant organics
were rarely detected; toluene was found
at 86 ug/kg in one sample and p-dichlorobenzene
at 110 ug/kg in another.
Hence this group of compounds appears
to have little significance in sludge
products. Few samples contained
detectable amounts of any of the
extractable priority pollutant organics.
Chlordane, DDT metabolites, and two to
four-ring PAH were frequently
detected, but incidence was clearly site
specific. Of these, Pyrene was detected
18 times, ranging from 0.4 to 4.4 mg/kg.
Bis-(2-ethylhexyl)phthalate was
detected in all 67 samples tested ranging
from 1.9 to 130 mg/kg.
Phenol was found three times; di-nbutylphthalate,
2-nitropheno1, Nnitrosodimethylamine
were found once each. Aroclor 1248 was detected twice.
Where analytical detection limits were
sufficient to address the proposed D & M
criteria, the only organic which exceeded
these guidelines was the Aroclor mixture.
In general, the priority pollutant organics
do not appear to be cause for concern in
these types of products, but site specific
evaluations appear to be
warranted based on the scatter of data
among the sampling sites.
No new toxic organics were identified
in GC/MS characterizations of the major
organic components in samples from
each city. The preponderance of the
materials appeared to belong to aliphatic
and carboxylic acid classes of
compounds. A majority of the sites
contained molecular profiles suggesting
a high petroleum contribution.
The molecular complexity of many of
the sludges presented matrix problems
which inhibited detection limits for the
standardized extraction, cleanup, and
analytical methods used. The resulting
detection limits were not sufficient to
address the proposed D & M sludge
criteria levels for at least five of the
organics on that list in the majority of
samples analyzed.
Recommendations
This project was initiated prior to
availability of draft criteria for use of D &
M sludge products, and completed
before final recommendation of the
criteria. Therefore, once D & M sludge
product criteria are finalized, data
developed in this survey should again be
reviewed.
Where existing survey data are found
to be insufficient for comparison to the
finalized criteria due to analytical matrix
problems and poor detection limits, sites
should be re-surveyed. Compounds
which appear to be candidates at this
time include toxaphene, benzo(a)pyrene,
hexachlorobenzene, heptachlor, and
aldrin/dieldrin. In addition, molybdenum
was not analyzed in this study, but
appears on the draft criteria list.
Appropriate modifications of existing
GC/MS analytical techniques, including
more comprehensive fractionation:
cleanup steps, must be developed to
accomplish these tasks.
Since data indicate the probability of
site-specific problems, (e.g., copper,
lead, PCB) in terms of D & M land use
criteria, monitoring programs are needed
to better define the extent of the
apparent problems at these sites.
References
1. Land Application of Municipal
Sludge - Process Design Manual
Cincinnati, OH. 1983
2. Summary of Environmental Profiles
and Hazard Indices for Constituents
of Municipal Sludge: Methods and
Results. U.S. EPA Office of Water
Regulations and Standards,
Washington, D.C. 1985.
3. Report to Congress on the Discharge
of Hazardous Wastes to
Publicly Owned Treatment Works,
Office of Water Regulations and
Standards, Washington, D.C 1986.
4. Walker, J. M., Cooperative Testing
of Municipal Sewage Sludges by
Toxicity Characteristic Leaching
Procedure and Compositional
Analysis, Draft Report, Residuals
Management Branch WH-595, U.S.
EPA office of Municipal Pollution
Control, Washington, D.C. 1987.
EPA-62511-83-016. U.S. EPA,
EPA 530-SW-86-004, U.S. EPA
3
Rodger Baird and Sylva M. Gabrielian are with the County Sanitary Districts of
Los Angeles County, Whittier, CA 90601
W. Emile Coleman is the €PA Project Officer (see below).
The complete report, entitled “Trace Organics and lnorganics in Distribution
and Marketing Municipal Sludges, “ (Order No. PB 88- 160 585lAS; Cost:
$25.95, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22 16 1
Telephone: 703-487-4650
Health Effects Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
The €PA Project Officer can be contacted at:
United States
Environmental Protection Information
Agency Cincinnati OH 45268
Center for Environmental Research
Official Business
Penalty for Private Use $300
* U.S. GOVERNMENT PRINTING OFFICE: 198a548-013/870~6
5. Federal Register, 51, 21648 (June 13, 1986) 40 CFR Parts 261, 271,and 302.