United States Office of Water EPA-822-R-09-005
Environmental Protection Office of Science and Technology June 2008
Agency 4304T
Biennial Review of
40 CFR Part 503
As Required Under the
Clean Water Act
Section 405(d)(2)(C)
Reporting Period
2007 Biennial Review
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EPA-822-R-09-005
Biennial Review of 40 CFR Part 503
As Required Under the Clean Water Act Section 405(d)(2)(C)
Reporting Period Biennial Review 2007
U.S. Environmental Protection Agency
Office of Water
Office of Science and Technology
Health and Ecological Criteria Division
Ecological and Health Processes Branch
Washington, D.C.
April 2009
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NOTICE
This document has been reviewed in accordance with U.S. EPA policy and approved for
publication. This report was prepared with the support of Research Triangle Institute, and its
subcontractors, under the direction and review of the Office of Science and Technology.
Mention of trade names or commercial products does not constitute endorsement or
recommendation for use.
This document can be downloaded from EPA's website at:
http://www.epa.gov/waterscience/biosolids/
11
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EXECUTIVE SUMMARY
In 1993, the Environmental Protection Agency (EPA) promulgated regulations in 40 CFR
Part 503 as amended, setting numerical standards for certain metals in sewage sludge, requiring
vector attraction reduction (e.g., reducing birds, rodents and insects) for pathogens, and
establishing operational standards for emissions from sewage sludge incinerators. Section
405(d)(2)(C) of the Clean Water Act (CWA) states that EPA shall review the sewage sludge
regulations not less often than every two years for the purpose of identifying additional toxic
pollutants and promulgating regulations for such pollutants consistent with the requirements of
section 405(d).
In fulfilling this commitment for the 2007 Biennial Review Cycle, EPA collected and
reviewed publicly available information. The Agency searched databases with articles published
in English and in refereed journals for information on occurrence, fate and transport in the
environment, human health and ecological effects, as well as other relevant information for
pollutants that may occur in U.S. sewage sludge. If such data are available for pollutants that
may occur in sewage sludge, the agency is able to characterize the potential risk associated with
exposure to such pollutants when sewage sludge is applied to land as a fertilizer or soil
amendment, placed in a surface disposal site, or incinerated.
The data search identified 47 pollutants for which some data were available. However,
the available data are not sufficient at this time to allow the Agency to conduct exposure and
hazard assessments or determine what, if any, regulatory action may be needed. Therefore, at this
time EPA has not identified additional toxic pollutants for regulation under Section 405(d)(2)(C)
of the CWA.
in
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CONTENTS
Page
Notice ii
Executive Summary iii
Introduction 1
History of the Standards for the Use or Disposal of Sewage Sludge 1
Previous Biennial Reviews 5
2003 Biennial Review 5
2005 Biennial Review 6
2007 Biennial Review 7
Ecological Assessment 7
Human Health Assessment 7
Results of the 2007 Biennial Review 8
Additional Information 11
TABLES
1. Metals Regulated in 40 CFR 503 2
2. List of Pollutants Evaluated During BR 2007 with Human Health enchmarks 9
3. List of Pollutants for which Sufficient Data are Lacking 10
ATTACHMENT
Attachment A: Technical Memorandum:
Report on the Pollutants' Database and Suitability Attachment A-1
IV
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Introduction
This document summarizes the U.S. Environmental Protection Agency's (EPA) activities
related to the 2007 biennial review of pollutants pursuant to the Clean Water Act (CWA) Section
405(d)(2)(C). That section requires EPA to review existing sewage sludge regulations at least
every two years to identify additional pollutants for possible regulation. The biennial review
covered by this report summary - the 2007 Biennial Review - obtained biosolids-related
literature through October 2007. This document summarizes the analysis of that literature (a
Technical Memorandum contractor summary is included in Attachment A). In this document, we
use the term "biosolids" interchangeably with "sewage sludge," which is defined in the
regulations and used in the statute.
History of the Standards for Use or Disposal of Sewage Sludge
In Section 405 of the CWA, Congress set forth a comprehensive program designed to
reduce potential health and environmental risks associated with using or disposing of sewage
sludge. Under Section 405(d), EPA establishes numeric limits and management practices that
protect public health and the environment from the reasonably anticipated adverse effects of
chemical and microbial pollutants in sewage sludge. Section 405(d) prohibits any person from
using or disposing of sewage sludge from publicly owned treatment works (POTWs) or other
treatment works treating domestic sewage, unless the use or disposal complies with regulations
promulgated under section 405(d).
On February 19, 1993, EPA identified pollutants which, on the basis of available
information on their toxicity, persistence, concentration, mobility, or potential for exposure, were
present in sewage sludge in concentrations which may adversely affect public health or the
environment. At that time, the Agency promulgated regulations (58 FR 9248) - CFR 40 Part 503
Standards for the Use or Disposal of Sewage Sludge - specifying acceptable management
practices, numeric standards for ten metals (see Table 1) and operational standards for microbial
organisms.
The 1993 rule established requirements for the final use or disposal of sewage sludge
when it is: (1) applied to land as a fertilizer or soil amendment; (2) placed in a surface disposal
site, including sewage sludge-only landfills; or (3) incinerated. These requirements apply to
1
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publicly and privately owned treatment works that generate or treat domestic sewage sludge and
to anyone who uses or disposes of sewage sludge. The rule also requires monitoring, record
keeping, and reporting of specific information regarding sewage sludge management.
Table 1: Metals Regulated in 40 CFR 503
Metal
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Zinc
Land Application
X
X
X1
X
X
X
X1
X
X
X
Incineration
X
X
X
Surface Disposal
X
X
X
X
X
- Minor amendments published in 1994 and 1995 improved clarity and responded to the results
of judicial review resulting in changes in land application limits for chromium (deleted all limits)
and molybdenum (deleted limits in Tables 2, 3, and 4 of Section 503.13).
— Mercury emissions are regulated as limits to air emissions either by monitoring the exhaust air
from the incinerator or the ambient air around the incinerator. In either case, the concentration in
the air must meet the National Emission Standards for Hazardous Air Pollutants (NESHAPs, 40
CFR Part 61). Total hydrocarbons (THC) or carbon monoxide (CO) is monitored to represent all
organic compounds in the exhaust gas that are covered by the Part 503 Rule. See Subpart E,
Section 503.43 for other incineration requirements.
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Section 405(d)(2)(C) of the CWA also requires the Agency to review from time to time,
but not less often than every 2 years (i.e., biennial reviews), the regulations for the purpose of
identifying additional toxic pollutants and promulgating regulations for such pollutants (the
Agency uses the term pollutant as defined in the CWA). The purpose of reviewing information
on pollutants, or potential pollutants, is to assess the availability and sufficiency of the data to
conduct exposure and hazard assessments. Such exposure and hazard assessments, where
sufficient data exist, allow the Agency to determine the potential for harm to public health or the
environment following use or disposal of biosolids. To inform the exposure and hazard
assessments of pollutants in biosolids, EPA typically collects the following data:
• Toxicity to human and ecological receptors (e.g., toxicity defined in terms of reference
dose, reference concentrations, cancer slope factor, lethal dose, lethal concentration, or
chronic endpoints related to fecundity).
• Acceptable concentration data in sewage sludge. Both the ability to detect a given
pollutant in sewage sludge and the concentrations at which that pollutant is present are
highly dependent on the existence of acceptable analytical methods for that pollutant in
the sewage sludge matrix. Analytical methods for water, effluent, or soil may not
necessarily be appropriate for detecting pollutants in biosolids.
• Fate and transport data for pollutants that may be present in sewage sludge. These data
are necessary for assessing exposure. Chemical and physical properties that are
developed for a given pollutant in sewage sludge should generally include:
Parameter
Molecular weight
Solubility
Vapor pressure
Henry's law constant
Soil-water partitioning coefficient
Soil adsorption coefficient (Kd and Koc)
Degradation rates in various media
Log octanol-water partition coefficient (Log Kow)
Diffusivity in air
Diffusivity in water
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Air-to-plant transfer factor
Root uptake factor for above ground vegetation
Root concentration factor
Bioconcentration factors for animal products
The Agency evaluates the sufficiency of such data for pollutants having acceptable
analytical methods, source concentration values, human health benchmarks, and other pertinent
data for two general purposes:
1. To conduct sewage sludge exposure and hazard assessments for humans and the
environment.
2. To support potential rulemaking under 40 CFR Part 503.
EPA did not meet the timetable in section 405(d) for promulgating the first round of
regulations, and a citizen's suit was filed (Gearhardt v. Reilly (Civ. No. 89-6266-HO (D. Ore.))
to require EPA to fulfill this mandate. A consent decree was entered by the court in that case,
establishing schedules for two rounds1 of sewage sludge rules. To comply with the consent
decree, EPA was required to:
• Identify toxic pollutants in sewage sludge (not identified pursuant to 33 U.S.C.
Section 1345(d)(2)(A)(i) and (ii)) that may adversely affect public health and the
environment. In compliance, on February 19, 1993, EPA promulgated the first
rule codified at 40 CFR Part 503 (58 FR 9248) ("Round One").
• Sign a notice for publication proposing Round Two1 regulations no later than
December 15, 1999, and to sign a notice taking final action on the proposal no
later than December 2001. In compliance, on December 21, 2001 EPA published
in the Federal Register (66 FR 66228) its determination not to regulate dioxin and
~ The terms "Round One" and "Round Two" were used by the consent decree. EPA uses the
term "Biennial Review" to refer to subsequent reviews of Part 503 pursuant to Section 405(d) of
the CWA.
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dioxin-like compounds [i.e., poly chlorinated dibenzo-p-dioxins (PCDDs),
polychlorinated dibenzofurans (PCDFs), and dioxin-like coplanar
polychlorinated biphenyls (PCBs)] in sewage sludge that is incinerated or placed
in sludge landfills or containment ponds. EPA based its decision on an
evaluation of the risk of exposure for people most likely to be exposed to dioxin
from these sources. EPA concluded that existing regulations for incinerators,
landfills or containment ponds adequately protect human health and the
environment by limiting exposure to pollutants, including dioxins in sewage
sludge that is disposed of at a surface disposal site or incinerated in a sewage
sludge incinerator.
• The consent decree (as amended) required EPA to take final action on the land
application Round Two rulemaking from the original date of December 15, 2001,
to a new date of October 17, 2003. In compliance, on October 24, 2003 EPA
announced its final decision not to regulate dioxins in land-applied sewage
sludge, concluding that dioxins from land-applied sewage sludge do not pose a
significant risk to human health or the environment. (68 FR 61084).
Biennial Reviews
2003 Biennial Review
Consistent with the consent decree mentioned above, EPA agreed to publish a notice in
the Federal Register describing how the Agency intends to respond to the National Research
Council (NRC) report (http://www.epa.gov/waterscience/biosolids/nas/complete.pdf)
recommendations and to seek public comment on its planned response. EPA also agreed to
review publicly available information to identify additional toxic pollutants in sewage sludge and
to publish a notice and seek public comment on the results of the review. Fulfilling these
commitments, EPA published a notice in the Federal Register on December 31, 2003 (68 FR
75531).
For its 2003 Biennial Review, EPA assessed available data on chemical pollutants that
had been detected in sewage sludge and that had not been regulated or previously assessed. The
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Agency collected and reviewed publicly available information published between 1990 and 2003
on the occurrence of chemicals in sewage sludge; data on environmental properties such as
mobility and persistence; and available human health benchmarks (HHBs). Following this
review, EPA made preliminary determinations regarding sufficiency of information for
conducting an exposure and hazard-based screening assessment. That literature review identified
803 chemicals reported to occur in sewage sludge. Sufficient data for evaluation were available
for 40 of these 803 pollutants. EPA conducted a human health and an ecological hazard
screening assessment for these 40 pollutants. Of the 40 pollutants evaluated, EPA determined
that 15 pollutants presented a potential risk to human health and/or the environment. EPA further
reduced the 15 pollutants to nine pollutants based on an updated biosolids exposure and hazard
assessment. The results of EPA's review do not mean that EPA has concluded that these nine
pollutants in sewage sludge adversely affect human health or the environment. EPA will use the
results from the recently completed Targeted National Sewage Sludge Survey (TNSSS)
(www.epa.gov/waterscience/biosolids) to complete its risk evaluation for these 9 pollutants. EPA
will use that evaluation to inform what action, if any, to take under section 405(d) of the CWA.
2005 Biennial Review
For its 2005 Biennial Review, EPA again collected and reviewed publicly available
information. The Agency searched known databases and the published literature designed to
capture available information on occurrence, fate and transport in the environment, human health
or ecological effects, as well as other relevant information for pollutants that may occur in U.S.
sewage sludge. The data search identified 137 pollutants for which some data were available for
118 pollutants (Table 3; EPA-822-R-06-014), the available data were not sufficient to allow the
Agency to either conduct exposure and hazard assessments or determine what, if any, regulatory
action may be needed.
For the remaining 19 pollutants (Table 2; EPA-822-R-06-014), data are available to
enable EPA to evaluate exposure and hazard. This evaluation will use existing data, data
collected during the 2005 Biennial Review, and results from the recent Targeted National
Sewage Sludge Survey. When EPA evaluates potential risk for these pollutants, EPA will be able
to determine what, if any, regulatory action may be needed pursuant to Section 405(d) of the
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CWA. However, at this time EPA has not identified additional toxic pollutants for regulation
under Section 405(d)(2)(C) of the CWA.
2007 Biennial Review
The remainder of this document presents the 2007 Biennial Review. In conducting the
2007 Biennial Review, EPA again collected and reviewed publicly available information on
pollutants to evaluate potential harm to human health or the environment following use or
disposal of sewage sludge.
Ecological Assessment
EPA conducted a literature search from 2005 through October 2007. EPA searched
databases and the published literature to capture available information necessary for ecological
and environmental risk evaluations (e.g., occurrence, fate and transport in the environment, and
ecological effects) for pollutants in U.S. sewage sludge. The Agency used articles published in
English in peer-reviewed journals, databases such as ECOTOX, Aquatic Sciences and Fisheries
Abstracts, Biological Sciences Database, and the Environmental Sciences and Pollution
Management Database, as well as secondary sources of data for eco-toxicity benchmarks (e.g.,
the recent Ecological Soil Screening Level documentation for certain metals). The Agency
assessed whether data were sufficient to conduct an ecological exposure and hazard assessment.
Human Health Assessment
To conduct human health risk evaluations, EPA did a literature search from 2005 through
October 2007. EPA searched databases and the published literature, such as PubMed, TOXLINE,
and the Environmental Sciences and Pollution Management Database for information such as
occurrence, fate and transport in the environment, and human health for pollutants in U.S.
sewage sludge.
The Agency followed the same methodology as for the 2003 and 2005 Biennial Reviews
to determine whether the identified data were sufficient for proceeding with an exposure and
hazard screening assessment. This methodology involved identifying the pollutants for which
EPA peer-reviewed final human health benchmarks (HHBs) had been developed by the
Agency's Office of Pesticide Programs Programs (OPP) Reregi strati on Eligibility Decisions
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(REDs), or EPA's Office of Research and Development for Integrated Risk Information System
(IRIS) health assessments. For the biennial reviews, EPA does not include pollutants for which
the scientific basis of HHBs is being reassessed at the time of review. For future biennial
reviews, the Agency is re-evaluating its process of only relying solely on IRIS or OPP HHBs.
The goal is to be able to expand its sources of human health toxicity data and potentially evaluate
more pollutants.
Results of the 2007 Biennial Review
During the Agency's search of known databases and the open literature during the 2007
Biennial Review, the Agency collected and reviewed publicly available information for
pollutants listed in Tables 2 and 3. The Agency evaluated the availability and acceptability of
data addressing toxicity to human and ecological receptors, pollutant concentrations in sewage
sludge based on acceptable analytical methods, physical and chemical properties, and fate and
transport in the environment in order to be able to conduct an exposure and hazard assessment.
For its 2007 Biennial Review, EPA identified articles published since the 2005 Biennial
Review as potential sources of information on pollutants in biosolids. The Agency evaluated the
articles as potentially relevant sources containing new information that was not previously
available or evaluated for pollutants in a prior biennial review, as well as previously collected
information. Two criteria were established for selecting a pollutant for an exposure and hazard
evaluation if relevant data were available: 1) the pollutant has either an OPP or IRIS HHB and
that the HHB study was not undergoing reevaluation, and (2) the pollutant has nationally
representative or otherwise acceptable measured concentrations in U.S. sewage sludge based on
acceptable analytical methodology that can be used to detect and quantify such concentrations.
The Agency divided the list of pollutants identified into two major groups:
1. Pollutants that have not previously been evaluated but may have readily available
OPP or IRIS human health benchmarks (e.g., toxicity defined in terms of reference
dose, reference concentrations, or cancer slope factor). Table 2 lists seven
chemicals identified in the 2007 Biennial Review that have health benchmarks (not
necessarily limited to IRIS or OPP.
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Table 2. List of Pollutants Evaluated During 2007 Biennial Review
with Human Health Benchmarks
Constituent Name
Aluminum
Bisphenol A
Cobalt
Cresol, p- (4-methylphenol)
Phenanthrene
Phosphorus
Triclosan
CASRN
7429-90-5
80-05-7
7440-48-4
106-44-5
85-01-8
7723-14-0
3380-34-5
IRIS or OPP1
IRIS
IRIS
IRIS
OPP
Class
metal
plasticizer
metal
preservative
PAH
nutrient
disinfectant
I/ EPA's Integrated Risk Information System (IRIS) or EPA's Office of Pesticide Programs (OPP). If
neither IRIS nor OPP, the entry is blank
In spite of the fact that HHBs and other data exist for the seven pollutants listed in
Table 2, the available data were not sufficient at this time to allow the Agency to
conduct exposure and hazard assessments. Critical information gaps may include
source concentration, fate and transport in the environment, and ecological data.
2. Pollutants for which OPP or IRIS human health benchmarks were not available.
Table 3 lists pollutants (n=40) in sewage sludge for which the search did not
identify IRIS or OPP human health benchmarks. EPA's current process is that in
the absence of an IRIS or OPP human health benchmark, EPA will not conduct
human health risk evaluations, even if other data on exposure (e.g., fate and
transport in the environment) are available, because toxicity data for human
receptors are critical pieces of data.
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Table 3. List of Pollutants for which OPP or IRIS Human Health
Benchmark Data Are Lacking
Constituent Name
3 -beta-coprostanol
Acety 1-1, 1,3, 4,4,6-
hexamethyltetrahydronaphthalene, 7- (AHTN)
Amphetamine
Azithromycin
Beta-Sitosterol
Calcium
Carbamazepine
Cholesterol
Clarithromycin
Diphenhydramine
d-Limonene
Erythromycin
Fluoxetine
Galaxolide (HHCB)
Indole
Magnesium
Methamphetamine
Nitrogen
Nonylphenol monoethoxylate
Nonylphenol, 4- (para-)
Nonylphenol, dithoxy-total
Octylphenol, 4-tert-
Organic -nitrogen, NH4-N, NO3-N,
Potassium
Roxithromycin
Skatole
Stigmastanol
Tonalide (AHTN)
Triclocarban
Tylosin
Clostridium perfringens
Coliphage
Cryptosporidium parvum
E. Coli spp.
Endotoxin
Fecal coliform
Heterotrophic plate count
Salmonella spp.
Suffite -reducing Clostridia
total bacteria
CASRN
360-68-9
21145-77-7
300-62-9
83905-01-5
19044-06-5
7440-70-2
298-46-4
57-88-5
81103-11-9
58-73-1
5989-27-5
114-07-8
54910-89-3
1222-05-5
120-72-9
7439.95.4
537-46-2
7727-37-9
27986-36-3
84852-15-3
Not identified
140-66-9
14798-03-9
7440-09-7
80214-83-1
83-34-1
19466-47-8
21145-77-7
101-20-2
1401-69-0
Not applicable
Not applicable
Not applicable
Not applicable
Not applicable
Not applicable
Not applicable
Not applicable
Not applicable
Not applicable
Class
fecal steroid
fragrance
pharmaceutical
antibiotic
steroid
essential metal
pharmaceutical
steroid
antibiotic
pharmaceutical
fragrance
antibiotic
pharmaceutical
fragrance
fragrance
essential metal
pharmaceutical
nutrient
detergent metabolite
detergent metabolite
detergent metabolite
detergent metabolite
nutrient
essential metal
antibiotic
fecal indicator odor
steroid
fragrance
disinfectant
antibiotic
microbial agent
microbial indicator
microbial agent
microbial agent
microbial toxin
microbial indicator
heterotrophic microorganisms
microbial agent
microbial agent
microbial agent
10
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Consistent with the Agency's current process, the available data were not sufficient at
this time to allow the Agency to conduct exposure and hazard assessments. There are significant
data gaps for identified pollutants regarding environmental properties, human health and eco-
toxicity benchmarks, and acceptable concentration data in sewage sludge. Thus, EPA has not at
this time identified additional toxic pollutants during its 2007 Biennial Review for potential
regulation.
The Agency will continue to assess the availability of sufficient information for these and
other pollutants during subsequent biennial reviews pursuant to Section 405(d)(2)(C) of the
CWA. In addition, the Agency is evaluating its process for how future biennial reviews will be
conducted. For example, for future biennial reviews, the Agency is re-evaluating its process of
only relying solely on IRIS or OPP HHBs.
Additional Information
For more information about EPA's Biosolids program, contact Rick Stevens in the Health
and Ecological Criteria Division, 1200 Pennsylvania Avenue, N.W., Washington, DC 20460
(telephone: 202-566-1135 ore-mail: stevens.rick@epa.gov).
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Attachment A
Technical Memorandum
Report on Pollutants' Database and Suitability
Attachment A -1
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Technical Memorandum
Report on Pollutants' Database and Suitability
U.S. Environmental Protection Agency
Office of Water
1200 Pennsylvania Avenue, NW
Washington, DC 20460
October 2007
Attachment A - 2
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Introduction
This technical memorandum constitutes a deliverable under EPA Contract 68-C-04-006,
Task 2, Work Assignment 3-04. The purpose of this task is to identify additional chemical and
microbial pollutants in U.S. sewage sludge and provide EPA with information on the suitability
for modeling and potential rulemaking for these pollutants.
Data Search
The search for new data was primarily based on the strategy developed under previous
work assignments (e.g., Contract 68-C-04-006, Work Assignments #B-20 and 1-20); results from
bibliographic databases were limited to articles published in English in refereed journals. The
bibliographic databases included PubMed, Toxline, Aquatic Sciences and Fisheries Abstracts,
Biological Sciences Database, and the Environmental Sciences and Pollution Management
Database. Publications from March 2005 to October 2007 were sought. The data search key
words included:
Topic/Keyword: Sewage sludge, biosolids, pollutants, toxicants, pathogens,
microbial, Salmonella, treated sewage, sludge treatment, sewage
treatment, land application, farm, agriculture, soil.
Based on previous literature searches (e.g., Biennial Review 2005), EPA did not uncover
many new articles or publications with significant new data. Using this search strategy, we
identified 97 articles as potential sources of information on chemical and microbial pollutants in
biosolids. As this was fewer articles than anticipated, we expanded our search and identified 50
additional potentially useful studies. We also incorporated results from the pharmaceuticals and
personal care products (PPCPs) literature search (from Work Assignments #2-43 and 3-43) into
the biennial review effort (in summary so as to not duplicate work between these ongoing tasks);
however only 1 study was identified to contain data on concentrations in biosolids within the
time period sought.
From these articles, we identified the 36 articles shown in Attachment 1 as potential
sources of information on chemical and microbial pollutants in biosolids (abstracts are included
where available). Many studies were off-topic or addressed pollutants that have been previously
modeled; these studies were omitted from consideration and are not included in Attachment 1.
Topics of excluded studies included concentration data in other media (e.g., wastewater effluent,
surface waters, and soil), non-U.S. data, not municipal waste (e.g., industrial, agricultural), the
lack of analytical measurement techniques in biosolids, and the lack of information concerning
toxicity in aquatic and invertebrate organisms. The Agency divided the list of pollutants
identified in these articles into two major groups:
1. Pollutants that have not previously been modeled but have readily available health
benchmarks.
2. Pollutants that have been identified in recent studies on biosolids for which health
benchmarks were not identified in a major reference.
A - 3
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Identification of Additional Pollutants in U.S. Sewage Sludge
Pollutants with Health Benchmarks
Table 1 lists the chemicals (n=7) with health benchmarks (not limited to IRIS or OPP)
that fit the following criteria: (1) identified in a previous National Sewage Sludge Survey, (2) not
currently on EPA's list of potential candidates for addition to the Part 503 standards, and (3) not
previously regulated or evaluated for sewage sludge. The chemicals are also identified by analyte
groups defined by similarity in structure as well as typical uses when appropriate.
Table 1. List of Pollutants with Health Benchmarks
Constituent Name
Aluminum
Bisphenol A
Cobalt
Cresol, p- (4-methylphenol)
Phenanthrene
Phosphorus
Triclosan
CASRN
7429-90-5
80-05-7
7440-48-4
106-44-5
85-01-8
7723-14-0
3380-34-5
IRIS/OPP?
IRIS
IRIS
Class
metal
other
metal
other
PAH
metal
pharmaceutical
Pollutants without Health Benchmarks
Table 2 lists additional pollutants of concern (e.g., pharmaceuticals) in sewage sludge
that do not have human health benchmarks available, according to our search.
A - 4
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Table 2. List of Pollutants without Health Benchmarks
Constituent Name
3 -beta-coprostanol
Acety 1-1, 1,3, 4,4,6-
hexamethyltetrahydronaphthalene, 7-
(AHTN)
Amphetamine
Azithroymcin
Beta-Sitosterol
Calcium
Carbamazepine
Cholesterol
Clarithromycin
Diphenhydramine
d-Limonene
Erythromycin
Fluoxetine
Galaxolide (HHCB)
Indole
Magnesium
Methamphetamine
Nitrogen
Nonylphenol monoethoxylate
Nonylphenol, 4- (para-)
Nonyphenol, dithoxy-total
Octylphenol, 4-tert-
Organic -nitrogen, NH4-N, NO3-N,
Potassium
Roxithromycin
Skatole
Stigmastanol
Tonalide (AHTN)
Triclocarban
Tylosin
Clostridium perfringens
Coliphage
Cryptosporidium parvum
E. coli
Endotoxin
Fecal coliform
HPC bacteria
Salmonella
Sulfite-reducing Clostridia
total bacteria
CASRN
21145-77-7
300-62-9
83905-01-5
7440-70-2
298-46-4
57-88-5
81103-11-9
58-73-1
5989-27-5
114-07-8
54910-89-3
1222-05-5
120-72-9
7439-95-4
537.46-2
7727-37-9
27986-36-3
104-40-5
140-66-9
14798-03-9
7440-09-7
80214-83-1
83-34-1
19466-47-8
21145-77-7
101-20-2
1401-69-0
Class
sterol
odor
pharmaceutical
pharmaceutical
pharmaceutical
metal
pharmaceutical
pharmaceutical
pharmaceutical
pharmaceutical
solvent
pharmaceutical
pharmaceutical
musk
scent
metal
pharmaceutical
nutrient
NP/AE/APE
NP/AE/APE
NP/AE/APE
NP/AE/APE
nutrient
metal
pharmaceutical
odor
pharmaceutical
odor
pharmaceutical
pharmaceutical
microbial
microbial
microbial
microbial
microbial
microbial
microbial
microbial
microbial
microbial
Allaciiincnl A - 5
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Attachment 1
Potential Sources of Information on Pollutants in Biosolids
Atalay, A; Bronick, C; Pao, S; et al. (2007) Nutrient and microbial dynamics in biosolids
amended soils following rainfall simulation. Soil Sed Contam 16(2):209-219.
Abstract: Municipal waste treatment plants are mandated by U.S.EPA to treat domestic
wastewater prior to releasing it to receiving streams. The dewatering and high
temperature drying processes at the plant are considered effective in reducing microbial
contaminants in the waste. The resulting solid material (biosolid) is rich in nutrients that
may serve as a value-added product for plant growth. In this study, we examined the
nutrient value of biosolids, their potential biological and chemical risks that could result
from surface application to two Mid-Atlantic soils: Bojac (coarse-loamy, mixed, thermic
Typic Hapludult) and Cullen (clayey, mixed, thermic Typic Hapludult). Soils were placed
on tilt beds and packed to their respective bulk density. Biosolids were added at a rate of
2.24 Mg/ha equivalent and mixed with the top 5 cm of the soil bed. Simulated rain was
applied at a rate of 65 mm h super(-l) for 45 minutes. Surface runoff and percolation
water were collected and analyzedfor elemental content, Escherichia coli (E. coli) and
total coliform bacteria. Among the nutrient elements of concern (P, Zn, Mn, and Cu) in
biosolids, none were found to be higher than the specified EPA limits. The concentration
of P was highest in runoff and percolation water from beds packed with Bojac and
biosolids. The combined effects of high clay (35%), Al (1.14%), and Fe (5.11%) in
Cullen increased its P-adsorbing capacity. Low levels of E. coli and other coliform
bacteria were present in samples from biosolids-treated beds packed with Cullen.
Microbial counts in runoff and percolation samples varied with soil type; in some
instances they were ten-fold higher in Bojac than in Cullen. The results obtained in this
study suggest that surface runoff from land applications of biosolids might contribute to
microbial contamination of receiving waters near agricultural fields.
Brooks, JP; Tanner, BD; Josephson, KL; et al. (2005) A national study on the residential impact
of biological aerosols from the land application of biosolids. J Appl Microbiol 99(2): 310-322.
Abstract: The purpose of this study was to evaluate the community risk of infection from
bioaerosols to residents living near biosolids land application sites. METHODS AND
RESULTS: Approximately 350 aerosol samples from 10 sites located throughout the
USA were collected via the use of six SKC Biosamplers. Downwind aerosol samples
from biosolids loading, unloading, land application and background operations were
collected from all sites. All samples were analysed for the presence of HPC bacteria, total
coliform bacteria, Escherichia coli, Clostridium perfringens, coliphage, enteroviruses,
hepatitis A virus and norovirus. Total coliforms, E. coli, C. perfringens and coliphage
were not detected with great frequency from any sites, however, biosolids loading
operations resulted in the largest concentrations of these aerosolized microbial indicators.
Microbial risk analyses were conducted on loading and land application operations and
their subsequent residential exposures determined. CONCLUSIONS: The greatest annual
risks of infection occurred during loading operations, and resulted in a 4 x 10(-4) chance
of infection from inhalation of coxsackievirus A21. Land application of biosolids resulted
in risks that were <2 x 10(-4) from inhalation of coxsackievirus A21. Overall bioaerosol
exposure from biosolids operations poses little community risk based on this study.
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SIGNIFICANCE AND IMPACT OF THE STUDY: This study evaluated the overall
incidence of aerosolized micro-organisms from the land application of biosolids and
subsequently determined that microbial risks of infection were low for residents close to
biosolids application sites.
Brooks, JP; Tanner, BD; Gerba, CP; et al. (2006) The measurement of aerosolized endotoxin
from land application of Class B biosolids in Southeast Arizona. Can J Microbiol 52(2): 150-
156.
Abstract: The purpose of this study was to determine aerosolized endotoxin
concentrations downwind of a biosolids land application site. Aerosol samples were
collected from biosolids land application sites, tractor operation, and an aeration basin
located within an open-air wastewater treatment plant. Aerosolized endotoxin above
background concentrations was detected from all sites, at levels ranging from below
detection up to 1800 EU m-3 of air. Biosolids loading operations resulted in the greatest
concentrations of endotoxin (mean 344 EU m-3). As downwind (perpendicular to wind
vector) distance increased from sources (2-200 m), levels of endotoxin decreased to near
background (without biosolids application) concentrations. Overall, the detected levels of
aerosolized endotoxin were within past proposed aerosolized endotoxin limits (250-2000
EU m-3) by other occupational exposure studies. Occasionally, peak concentrations were
found to be above these limits. Sites in which soil was being aerosolized resulted in
greater concentrations of endotoxin with or without biosolids, which suggested that the
majority of endotoxin may in fact be of soil origin. This study evaluated the presence of
aerosolized endotoxin from the land application of biosolids and showed that these levels
were within ranges for concern suggested by other studies and that this area of research
needs further investigation.
Brooks, J; Gerba, C; Pepper, I. (2007) Diversity of aerosolized bacteria during land application
of biosolids. J Appl Microbiol 103(5): 1779-1790.
Abstract: The purpose of this study was to determine the diversity of bacterial
communities associated with bioaerosols generated during land application of biosolids
using 16S ribosomal RNA (16S rRNA) PCR. Methods and Results: Anaerobically
digested Class B biosolids were land applied to an agricultural site located in South
Central Arizona. Aerosol samples were collected downwind of the biosolids operations
and were collected via the use of SKC Biosamplers and subsequently extracted for the
presence of bacterial community DNA. All DNA was amplified using 16S rRNA
primers, cloned and sequenced. All sequences were aligned and phylogenetic trees were
developed to generate community profiles. The majority of aerosolized bacterial clone
sequences belonged to the Actinobacteria and alpha- and beta-proteobacterial taxa.
Aerosol samples collected downwind of soil aerosolization produced similar profiles.
These profiles differed from upwind and background samples. Conclusions: No one clone
sequence isolated from the aerosol samples could be solely attributed to biosolids; on the
contrary, the majority appeared to have arisen from soil. Significance and Impact of the
Study: This study demonstrates that in dry, arid climates the majority of aerosols
associated with biosolids land application appear to be associated with the onsite soil.
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Buyuksonmez, F; Sekeroglu, S. (2005) Presence of pharmaceuticals and personal care products
(PPCPs) in biosolids and their degradation during composting. Journal of Residuals Science &
Technology 2(1):31-40.
Abstract: The presence of pharmaceuticals and personal care product (PPCPs) in
biosolids generated during municipal wastewater treatment (WWTP) was monitored
weekly for 19 weeks. Biosolids samples obtained from a local WWTP were subjected to
extraction with Soxhlet(R) apparatus for 24 hours. The extracts were concentrated and
analyzed with a gas chromatograph-mass spectrometer. There were 18 compounds
representing a wide range of origins identified in biosolids including phthalate esters,
ibuprofen and galaxolide. Phthalate esters were the most frequently detected compounds;
and 4-nonyl phenol was the most concentrated chemical at 210 mg/kg-dry weight basis.
The efficacy of the composting process to degrade the 10 of the PPCP compounds was
also investigated with and without spiking biosolids. Biosolids were amended with straw,
and composted for up to 45 days using a laboratory-scale composting system. The lowest
degradation rate was observed for 50.11% for octyl-4-methoxy cinnamate (OM) and the
highest was 99.73% for butylated hydroxyl toluene (BHT). For all tested compounds
except for unspiked OM, degradation efficiencies surpassed 85% at the end of the 45
days of composting study. The results of this study confirm the presence of various
organic contaminants originated from personal care products in biosolids, and suggest
that composting could be an effective treatment alternative for biosolids.
Campo, NCD; Pepper, IL; Gerba, CP. (2007) Assessment of Salmonella typhimurium growth in
Class A biosolids and soil/biosolid mixtures. Journal of Residuals Science & Technology
4(2):83-88.
Abstract: The potential of Salmonella typhimurium regrowth in Class A biosolid pellets
and compost after land application was assessed. Mixtures of soil, soil plus biosolids, and
biosolids were inoculated with two different concentrations and monitored during a
period of 20 days. No Salmonella growth occurred in any of the soil/biosolid mixtures
regardless of inoculum size or moisture content. No growth occurred in any of the
biosolids with a moisture content of 20% except the pellets from Texas when inoculated
with 10,000 colony forming units/g. Growth of Salmonella did occur in all of the Class A
products under saturated conditions. Under all moisture conditions indigenous microflora
increased in numbers in the biosolids, soil and biosolid/soil mixtures. In conclusion, these
results suggest that while regrowth of Salmonella in biosolids may occur under saturated
conditions it does not occur after Class A biosolids land application at typical agronomic
rates.
Chetochine, AS; Brusseau, ML; Gerba, CP; et al. (2006) Leaching of phage from Class B
biosolids and potential transport through soil. Appl Environ Microbiol 72(1):665-671.
Abstract: The objective of this study was to investigate leaching and transport of viruses,
specifically those of an indigenous coliphage host specific to Escherichia coli ATTC
15597 (i.e., MS-2), from a biosolid-soil matrix. Serial extractions of 2% and 7% (solids)
class B biosolid matrices were performed to determine the number of phage present in the
biosolids and to evaluate their general leaching potential. Significant concentrations of
coliphage were removed from the biosolids for each sequential extraction, indicating that
many phage remained associated with the solid phase. The fact that phage was associated
with or attached to solid particles appeared to influence the potential for release and
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subsequent transport of phage under saturated-flow conditions, which was examined in a
series of column experiments. The results indicated that less than 8% of the indigenous
coliphage initially present in the biosolids leached out of the biosolid-soil matrix. A
fraction of this was subsequently transported through the sandy porous medium with
minimal retention. The minimal retention observed for the indigenous phage, once
released from the biosolids, was consistent with the results of control experiments
conducted to examine MS-2 transport through the porous medium.
Choi, CY; Grabau, MR; O'Shaughnessy, SA; et al. (2005) Pathogen reduction in biosolids for
land application. Journal of Residuals Science & Technology 2(3):159-171.
Abstract: Fecal coliforms or Salmonella criteria have to be met, regardless of which of
the six recognized alternatives for achieving Class A pathogen reduction criteria per 40
CFR Part 503 are utilized. Therefore, solar inactivation of fecal coliforms and Salmonella
spp. from Class B to Class A levels were evaluated in biosolids drying beds as a function
of three treatments: no tilling (control), moderate tilling (twice per week), and intensive
tilling (five (5) to six (6) times per week). Experiments were conducted in both summer
and winter periods to study seasonal variability. During the 21-day summer drying
experiment, total solids in the control bed increased from 30.1% to 41.6%. Total solids in
the two tilled beds increased from 30.1% to approximately 90%. Fecal coliforms
drastically decreased from 7.7 x 10(8) MPN/g dry weight to less than 3.0 MPN/g in all
beds. Detected Salmonella spp. decreased from 38.6 MPN/4g to less than 3.0 MPN/4g in
all beds. Based on fecal coliform criteria, the control, moderately tilled, and intensively
tilled drying beds achieved Class A standards within 15, 5, and 7 days, respectively;
based on Salmonella spp. criteria, the beds achieved Class A standards within 7, 3, and 5
days, respectively. Fecal coliform inactivation rates increased as a function of tilling
intensity during the hot and and season. However, during the winter experiment (which
lasted for 89 days), fecal coliform levels never declined below 1.0 x 10(3) MPN/g. After
41 days, the levels of Salmonella spp. declined below 3.0 MPN/4g in the control and
moderately tilled beds. After 85 days, Salmonella spp. levels in the intensively tilled bed
fell below 3.0 MPN/4g. These studies indicate that tilling significantly increases drying
bed efficiency and pathogen inactivation during hot, dry periods. However, during cold
and wet winter seasons, tilling provides limited measurable benefits. The seasonal studies
suggest that the best management practice associated with the drying and disinfection of
biosolids in open solar drying beds is to till during hot and and months and leave
biosolids untreated during cold, wet seasons.
Ciparis, S; Hale, RC. (2005) Bioavailability of polybrominated diphenyl ether flame retardants in
biosolids and spiked sediment to the aquatic oligochaete, Lumbriculus variegatus. Environ
Toxicol Chem (4):916-925.
Abstract: Polybrominated diphenyl ether (PBDE) flame retardants have become
distributed ubiquitously in the environment. High concentrations have been reported in
U.S. sewage sludge (biosolids). The burgeoning practice of land-applying biosolids as
fertilizer creates an avenue for reintroduction of PBDEs to surface waters and aquatic
sediments. Bioavailability of biosolids- and sediment-associated PBDEs was assessed
using the freshwater oligochaete, Lumbriculus variegatus. Oligochaetes were exposed to
composted biosolids (1,600 ng/g total PBDEs) and artificial sediment spiked with penta-
and deca-brominated diphenyl ether (BDE) formulations (1,300 ng/g total PBDEs).
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Uptake (28-d exposure) and depuration (21 d) of eight congeners were studied.
Polybrominated diphenyl ethers in both substrates were bioavailable, but
bioaccumulation was 5 to 10 times greater from spiked artificial sediment. The congeners
BDE 47 and BDE 99 were the most prevalent congeners in oligochaetes after exposure.
Congener BDE 47 was more bioaccumulative, possibly due to the threefold greater
depuration rate of BDE 99. Bioaccumulation of penta- and hexa-brominated congeners
appeared to be affected more strongly by substitution pattern than degree of bromination.
Uptake of BDE 209, the dominant congener in deca-BDE, was minimal. Accumulation of
certain PBDE congeners from biosolids and sediments by benthos provides a pathway for
transfer to higher trophic levels, and congener discrimination may increase with each
trophic transfer.
Cogger, CG; Forge, TA; Neilsen, GH. (2006) Biosolids recycling: Nitrogen management and
soil ecology. Canadian Journal of Soil Science 86(4):613-620.
Abstract: Biosolids are municipal wastewater treatment solids that meet regulatory
standards for land application. Most biosolids are a rich source of N, P, and
micronutrients. Although the use of biosolids on food crops remains controversial in the
public eye, decades of research have led to the development of regulations for the safe
and beneficial use of biosolids in agriculture. Emerging areas of research include
biosolids in commercial and home horticulture, the fate of pathogens and organics in
biosolids, the use of biosolids in the remediation of contaminated sites, and biosolids
effects on soil ecology. Nutrient management remains the most critical day-to-day issue
for land application of biosolids. Recent research on plant-available nitrogen (PAN) in
biosolids has found that N availability is similar over a range of biosolids processing
types, and that growing-season climate is a key factor affecting available N. Regionally
based predictions of PAN have been developed for the United States, and could be
extended into Canada. Relatively little is known about the effects of biosolids
applications on soil ecology, but soil nematodes offer an opportunity to evaluate the
structure and function of the soil ecosystem following biosolids applications. We have
studied responses of nematode communities to application of municipal biosolids and
composts, in forage production systems and orchards. Both types of amendments
increased the abundance of enrichment opportunists, for up to 3 yr after single
applications. These data on the persistence of increased enrichment opportunists have
provided insight into the longevity of amendment-induced enhancement of biological
activity and nutrient cycling. Cumulative biosolids applications of 90 Mg ha(-l) have
caused reductions in abundance of pollutant-sensitive Dorylaimida. The extent to which
this change is the result of metal or nutrient loading is unclear and deserves more detailed
study.
Das KC, XK. (2007) Transformation of 4-nonylphenol isomers during biosolids composting.
Chemosphere Sept 6 Epub ahead of print.
Abstract: 4-Nonylphenol, a degradation intermediate of commercial surfactant and
known endocrine disrupter, has been frequently detected at levels up to several thousand
mugl(-l) in surface waters and up to several hundred mgkg(-l) (dry weight) in soil and
sediment samples. Large quantities of 4-NP can be quickly sorbed by the organic rich
solid phase during wastewater treatment and are concentrated in biosolids, a possible
major source for 4-NP in the environment. Microbial transformation in culture studies
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followed different mechanisms for different 4-NP isomers, which have different
estrogenic activity. Composting is a process of solid matrix transformation where
biological activity is enhanced by process control. This approach has been used
successfully in remediation of contaminated soils and sludges. In this study, the
transformation kinetics of 4-NP and its isomers were characterized during biosolids
composting. Five distinctive 4-NP isomer groups with structures relative to alpha- and
beta-carbons of the alkyl chain were identified in biosolids. Composting biosolids mixed
with wood shaving at a dry weight percentage ratio of 43:57 (C:N ratio of 65:1) removed
80% of the total 4-NP within two weeks. At this biosolids/wood shaving ratio (B:WS),
the transformation of total 4-NP and its isomers followed second-order kinetic. Higher
B:WS ratios yielded significantly slower 4-NP transformation which followed first-order
kinetic. Isomers with alpha-methyl-alpha-propyl structure transformed significantly
slower than those with less branched tertiary alpha-carbon and those with secondary
alpha-carbon, suggesting isomer-specific degradation of 4-NP during biosolids
composting.
Elliott, HA; Brandt, RC; O'Connor, GA. (2005) Runoff phosphorus losses from surface-applied
biosolids. J Environ Qual 34(5): 1632-1639.
Abstract: Runoff losses of dissolved and particulate phosphorus (P) may occur when
rainfall interacts with manures and biosolids spread on the soil surface. This study
compared P levels in runoff losses from soils amended with several P sources, including
10 different biosolids and dairy manure (untreated and treated with Fe or Al salts).
Simulated rainfall (71 mm h(-l)) was applied until 30 min of runoff was collected from
soil boxes (100 x 20 x 5 cm) to which the P sources were surfaced applied. Materials
were applied to achieve a common plant available nitrogen (PAN) rate of 134 kg PAN
ha(-l), resulting in total P loading rates from 122 (dairy manure) to 555 (Syracuse N-Viro
biosolids) kg P ha(-l). Two biosolids produced via biological phosphorus removal (BPR)
wastewater treatment resulted in the highest total dissolved phosphorus (13-21.5 mg TDP
L(-l)) and total phosphorus (18-27.5 mg TP L(-l)) concentrations in runoff, followed by
untreated dairy manure that had statistically (p = 0.05) higher TDP (8.5 mg L(-l)) and TP
(10.9 mg L(-l)) than seven of the eight other biosolids. The TDP and TP in runoff from
six biosolids did not differ significantly from unamended control (0.03 mg TDP L(-l);
0.95 mg TP L(-l)). Highest runoff TDP was associated with P sources low in Al and Fe.
Amending dairy manure with Al and Fe salts at 1:1 metal-to-P molar ratio reduced runoff
TP to control levels. Runoff TDP and TP were not positively correlated to TP application
rate unless modified by a weighting factor reflecting the relative solubility of the P
source. This suggests site assessment indices should account for the differential solubility
of the applied P source to accurately predict the risk of P loss from the wide variety of
biosolids materials routinely land applied.
Harrison, EZ; Oakes, SR; Hysell, M; et al. (2006) Organic chemicals in sewage sludges. Sci
Total Environ 367(2-3):481-497.
Abstract: Sewage sludges are residues resulting from the treatment of wastewater
released from various sources including homes, industries, medical facilities, street runoff
and businesses. Sewage sludges contain nutrients and organic matter that can provide soil
benefits and are widely used as soil amendments. They also, however, contain
contaminants including metals, pathogens, and organic pollutants. Although current
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regulations require pathogen reduction and periodic monitoring for some metals prior to
land application, there is no requirement to test sewage sludges for the presence of
organic chemicals in the U. S. To help fill the gaps in knowledge regarding the presence
and concentration of organic chemicals in sewage sludges, the peer-reviewed literature
and official governmental reports were examined. Data were found for 516 organic
compounds which were grouped into 15 classes. Concentrations were compared to EPA
risk-based soil screening limits (SSLs) where available. For 6 of the 15 classes of
chemicals identified, there were no SSLs. For the 79 reported chemicals which had SSLs,
the maximum reported concentration of 86% exceeded at least one SSL. Eighty-three
percent of the 516 chemicals were not on the EPA established list of priority pollutants
and 80% were not on the EPA's list of target compounds. Thus analyses targeting these
lists will detect only a small fraction of the organic chemicals in sludges. Analysis of the
reported data shows that more data has been collected for certain chemical classes such as
pesticides, PAHs and PCBs than for others that may pose greater risk such as
nitrosamines. The concentration in soil resulting from land application of sludge will be a
function of initial concentration in the sludge and soil, the rate of application,
management practices and losses. Even for chemicals that degrade readily, if present in
high concentrations and applied repeatedly, the soil concentrations may be significantly
elevated. The results of this work reinforce the need for a survey of organic chemical
contaminants in sewage sludges and for further assessment of the risks they pose.
Heidler JC; Sapkota A; Halden R. (2006) Partitioning, persistence, and accumulation in digested
sludge of the topical antiseptic triclocarban during wastewater treatment. Environ Sci Technol
40:3634-3639.
Abstract: The topical antiseptic agent triclocarban (TCC) is a common additive in many
antimicrobial household consumables, including soaps and other personal care products.
Long-term usage of the mass-produced compound and a lack of understanding of its fate
during sewage treatment motivated the present mass balance analysis conducted at a
typical U.S. activated sludge wastewater treatment plant featuring a design capacity of
680 million liters per day. Using automated samplers and grab sampling, the mass of
TCC contained in influent, effluent, and digested sludge was monitored by isotope
dilution liquid chromatography (tandem) mass spectrometry. The average mass of TCC
(mean (standard deviation) entering and exiting the plant in influent (6.1 ( 2.0 ig/L) and
effluent (0.17 ( 0.03 ig/L) was 3737(694 and 127(6 g/d, respectively, indicating an
aqueous-phase removal efficiency of 97 (1%. Tertiary treatment by chlorination and
sand filtration provided no detectable benefit to the overall removal. Due to strong
sorption of TCC to wastewater parti culate matter (78 (11% sorbed), the majority of the
TCC mass was sequestered into sludge in the primary and secondary clarifiers of the
plant. Anaerobic digestion for 19 days did not promote TCC transformation, resulting in
an accumulation of the antiseptic compound in dewatered, digested municipal sludge to
levels of 51 ( 15 mg/kg dry weight (2815 (917 g/d). In addition to the biocide mass
passing through the plant contained in the effluent (3 ( 1%), 76 (30% of the TCC input
entering the plant underwent no net transformation and instead partitioned into and
accumulated in municipal sludge. Based on the rate of beneficial reuse of sludge
produced by this facility (95%), which exceeds the national average (63%), study results
suggest that approximately three-quarters of the mass of TCC disposed of by consumers
in the sewershed of the plant ultimately is released into the environment by application of
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municipal sludge (biosolids) on land used in part for agriculture.
Ippolito, JA; Barbarick, KA; Norvell, KL. (2007) Biosolids impact soil phosphorus
accountability, fractionation, and potential environmental risk. J Environ Qual 36(3):764-772.
Abstract: Biosolids land application rates are typically based on crop N requirements but
can lead to soil P accumulation. The Littleton/Englewood, Colorado, wastewater
treatment facility has supported biosolids beneficial-use on a dryland wheat-fallow
agroecosystem site since 1982, with observable soil P concentration increases as biyearly
repeated biosolids applications increased from 0, 6.7, 13, 27, to 40 Mg ha(-l). The final
study year was 2003, after which P accountability, fractionation, and potential
environmental risk were assessed. Between 93 and 128% of biosolids-P added was
accounted for when considering conventional tillage soil displacement, grain removal,
and soil adsorption. The Fe-P fraction dominated all soil surface P fractions, likely due to
an increase in amorphous Fe-oxide because Fe2(SO4)3 was added at the wastewater
treatment facility inflow for digester H2S reduction. The Ca-P phase dominated all soil
subsurface P fractions due to calcareous soil conditions. A combination of conventional
tillage, drought from 1999 to 2003, and repeated and increasing biosolids application
rates may have forced soil surface microorganism dormancy, reduction, or mortality;
thus, biomass P reduction was evident. Subsurface biomass P was greater than surface
biomass, possibly due to protection against environmental and anthropogenic variables or
to increased dissolved organic carbon inputs. Even given years of biosolids application,
the soil surface had the ability to sorb additional P as determined by shaking the soil in an
excessive P solution. Biosolids-application regulations based on the Colorado Phosphorus
Index would not impede current site practices. Proper monitoring, management, and
addition of other best management practices are needed for continued assurance that P
movement off-site does not become a major issue.
Iranpour, R; Cox, FtH. (2006) Recurrence of fecal coliforms and Salmonella species in biosolids
following thermophilic anaerobic digestion. Water Environ Res 78(9): 1005-1012.
Abstact: The U.S. Environmental Protection Agency (U.S. EPA) Part 503 Biosolids Rule
requires the fecal coliform (indicator) or Salmonella species (pathogen) density
requirements for Class A biosolids to be met at the last point of plant control (truck-
loading facility and/or farm for land application). The three Southern Californian
wastewater treatment plants in this study produced biosolids by thermophilic anaerobic
digestion and all met the Class A limits for both fecal coliforms and Salmonella sp. in the
digester outflow biosolids. At two plants, however, a recurrence of fecal coliforms was
observed in postdigestion biosolids, which caused exceedance of the Class A limit for
fecal coliforms at the truck-loading facility and farm for land application. Comparison of
observations at the three plants and further laboratory tests indicated that the recurrence
of fecal coliforms can possibly be related to the following combination of factors: (1)
incomplete destruction of fecal coliforms during thermophilic anaerobic digestion, (2)
contamination of Class A biosolids with fecal coliforms from external sources during
postdigestion, (3) a large drop of the postdigestion biosolids temperature to below the
maximum for fecal coliform growth, (4) an unknown effect of biosolids dewatering in
centrifuges. At Hyperion Treatment Plant (City of Los Angeles, California), fecal
coliform recurrence could be prevented by the following: (1) complete conversion to
thermophilic operation to exclude contamination by mesophilically digested biosolids
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and (2) insulation and electrical heat-tracing of postdigestion train for maintaining a high
biosolids temperature in postdigestion.
Jolis, D. (2006) Regrowth of fecal coliforms in class A biosolids. Water Environ Res 78(4):442-
445.
Abstract: Eight types of Class A biosolids were tested for fecal coliform (FC) reactivation
and/or regrowth at 20, 35, and 50 degree C for 21 days. Growth of FC did not occur at 20
or 50 degree C, but it was observed in two samples incubated at 35 degree C after a lag
period of 48 hours. In undigested biosolids, final FC concentration exceeded 10 super(4)
MPN/g, whereas in thermophilically digested biosolids, the final FC concentration
remained below 10 super(3) MPN/g, as FC regrowth may have been affected by the
presence of the anaerobic bacterial consortium responsible for the digestion process.
Fecal-coliform reactivation and regrowth within treatment plant operations seem unlikely
but can occur in land application of biosolids.
Jones-Lepp, TL; Stevens, R. (2007) Pharmaceuticals and personal care products in
biosolids/sewage sludge: the interface between analytical chemistry and regulation. Anal
Bioanal Chem 387(4): 1173-1183.
Abstract: Modern sanitary practices result in large volumes of human waste, as well as
domestic and industrial sewage, being collected and treated at common collection points,
wastewater treatment plants (WWTPs). In recognition of the growing use of sewage
sludge as fertilizers and soil amendments, and the scarcity of current data regarding the
chemical constituents in sewage sludge, the US National Research Council (NRC) in
2002 produced a report on sewage sludge. Among the NRC's recommendations was the
need for investigating the occurrence of pharmaceuticals and personal care products
(PPCPs) in sewage sludge. PPCPs are a diverse array of non-regulated contaminants that
had not been studied in previous sewage sludge surveys but which are likely to be
present. The focus of this paper will be to review the current analytical methodologies
available for investigating whether pharmaceuticals are present in WWTP-produced
sewage sludge, to summarize current regulatory practices regarding sewage sludge, and
to report on the presence of pharmaceuticals in sewage sludge.
Kaleta A; Ferdig M; Buchberger W. (2006) Semi quantitative determination of residues of
amphetamine in sewage sludge samples. Journal of Separation Science 29(11): 1662-1666.
Abstract: A procedure based on HPLC and mass spectrometric detection has been
developed for screening of residues of the illicit drug amphetamine in sewage sludge.
Sample pretreatment consisted in extraction by 50 mM formic acid and methanol (80 : 20
v/v), followed by adjustment of the pH to 10 and preconcentration by SPE at
poly(divinylbenzene)-N-vinylpyrrolidone. HPLC separation of the extract was done on a
CIS RP with a mixture of 50 mM formic acid and methanol (80 : 20 v/v) as mobile
phase. The mass spectrometer was operated in the MS2 and MS3 mode using the
transition from m/z 136 to 119 and from m/z 119 to 91. Due to the complex matrix,
ionization suppression effects as well as shifts in the sensitivity of the detector within a
series of runs could not be fully excluded. Therefore, quantitation was done by standard
addition together with external standards, so that semi quantitative results could be
obtained down to concentrations of 2 g/kg sewage sludge. Samples taken from various
municipal sewage treatment plants indicate that amphetamine residues are ubiquitous in
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urban areas.
Kelly, JJ; Favila, E; Hundal, LS; et al. (2007) Assessment of soil microbial communities in
surface applied mixtures of Illinois River sediments and biosolids. Applied Soil Ecology 36(2-
3):176-183.
Abstract: Restoration of the Illinois River and its backwater lakes involves the dredging
of millions of cubic meters of sediment, and the relocation of this dredged sediment is a
significant challenge. Beneficial use of sediment as landscaping soil on brownfields, strip
mines, highway borders and other areas is a potential use for large quantities of this
material, as sediments have desirable soil characteristics, including a favorable texture for
plant growth and good water holding capacity. The addition of biosolids to Illinois River
sediments has the potential to increase the organic and nutrient content of the sediments
and thus to make these sediments more useful for the reclamation of damaged soils. The
goal of the current study was to assess the impacts of biosolids additions on the
physical/chemical characteristics and microbial communities of surface applied river
sediments. Field plots containing various sediment/biosolids mixture were established
and examined 1 year after application. Results indicated that biosolids addition had
significant positive effects on soil organic carbon, total Kjeldahl nitrogen, total
phosphorous, and microbial biomass and activity. In addition, the sediment/biosolids
mixtures showed lower salinity and lower concentrations of copper, lead and zinc than
the pure biosolids. PLFA analysis revealed that biosolids addition resulted in shifts in
microbial community composition, with relative increases in Gram negative bacteria and
relative decreases in Gram positive bacteria, fungi, and actinomycetes. These data
suggest that a mixture of sediment and biosolids is preferable to either sediment or
biosolids alone, (c) 2007 Elsevier B.V. All rights reserved
Kinney, CA; Furlong, ET; Zaugg, SD; et al. (2006) Survey of organic wastewater contaminants
in biosolids destined for land application. Environ Sci Technol 40(23):7207-7215.
Abstract: In this study, the presence, composition, and concentrations of organic
wastewater contaminants (OWCs) were determined in solid materials produced during
wastewater treatment. This study was undertaken to evaluate the potential of these solids,
collectively referred to as biosolids, as a source of OWCs to soil and water in contact
with soil. Nine different biosolids products, produced by municipal wastewater treatment
plants in seven different states, were analyzed for 87 different OWCs. Fifty-five of the
OWCs were detected in at least one biosolids product. The 87 different OWCs represent
a diverse cross section of emerging organic contaminants that enter wastewater treatment
plants and may be discharged without being completely metabolized or degraded. A
minimum of 30 and a maximum of 45 OWCs were detected in any one biosolid. The
biosolids used in this study are produced by several production methods, and the plants
they originate from have differing population demographics, yet the percent composition
of total OWC content, and of the most common OWCs, typically did not vary greatly
between the biosolids tested. The summed OWC content ranged from 64 to 1811 mg/kg
dry weight. Six biosolids were collected twice, 3-18 months apart, and the total OWC
content of each biosolids varied by less than a factor of 2. These results indicate that the
biosolids investigated in this study have OWC compositions and concentrations that are
more similar than different and that biosolids are highly enriched in OWCs (as mass-
normalized concentrations) when compared to effluents or effluent-impacted water.
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These results demonstrate the need to better describe the composition and fate of OWCs
in biosolids since about 50% of biosolids are land applied and thus become a potentially
ubiquitous nonpoint source of OWCs into the environment.
Lee, LS; Carmosini, N; Sassman, SA; et al. (2007) Agricultural contributions of antimicrobials
and hormones on soil and water quality. Advances in Agronomy, Vol 93 93:1-68.
Abstract: Detection of many emerging chemicals of concern, including antimicrobials
and steroid hormones, in the environment has increased in the past decade with the
advancement of analytical techniques. There are several potential sources of these inputs,
including municipal wastewater discharge, municipal biosolids, pharmaceutical
production, and agriculture-related activities. However, the heavy use of antibiotics in the
livestock industry and the dramatic shift in recent years toward more highly concentrated
animal feeding operations (C AFOs), thus a concomitant increase in the volume of animal
wastes per unit of land, has drawn attention to the role of animal waste-borne
antimicrobials, antibiotic-resistant bacteria, and steroid hormones on ecosystem and
human health. Antimicrobials, although frequently detected, are typically present in water
at concentrations in orders of magnitude below what would be considered inhibitory to
most biota. Most antibiotics have a high affinity for soil and sediment, thus residual soil
concentrations are usually much higher than noted in water but still often below
concentrations of concern. The focal point with antibiotic use in animal production is the
development of antibiotic-resistant bacteria. Although there is a growing body of
evidence of the presence of numerous antibiotic-resistant genes in animal wastes, in soils
where wastes are land applied, and in water bodies receiving runoff from manure-
amended fields or discharges from aquacultures, conclusive evidence of animal-derived
antibiotic-resistant pathogens compromising human health is lacking. In contrast to
antibiotics, hormones and related chemicals can cause significant biological responses at
very low concentrations. CAFO discharges will include a variety of estrogens, natural
and synthetic androgens and progesterones, and phytoestrogens associated with animal
feed. Measurable concentrations of many of these hormones have been detected in soil,
and ground and surface waters receiving runoff from fields fertilized with animal manure
and downstream from farm animal operations. Overall, hormones appear to be
moderately to highly sorbed and to dissipate quickly in an aerobic soil environment, but
quantitative information on hormone persistence in manure-applied fields and subsequent
effects of hormone loads from CAFOs to the aquatic environment is lacking. Research
directed toward evaluating the facilitated transport processes with regards to
antimicrobial and hormone inputs from manure-amended fields is in its infancy. With the
advances in analytical techniques and what has already been learned with regards to
transport of nutrients (nitrogen, phosphorus, and carbon) and pesticides from agricultural
fields, a reasonable evaluation of CAFOs and associated activities (land application of
animal wastes) should be forthcoming in the next decade. Meanwhile, implementation of
management practices that optimize reduction in already regulated nutrient releases from
CAFOs should also help to minimize the release of antimicrobials and hormones.
McBride, MB; Barrett, KA; Kim, B; et al. (2006) Cadmium sorption in soils 25 years after
amendment with sewage sludge. Soil Science 171(l):21-28.
Abstract: Long-term changes in the solubility and bioavailability of heavy metals in soils,
accumulated as the result of waste application, cannot be predicted without knowledge of
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the nature of metal retention in these soils. To test the theory that Fe- and Al-rich mineral
phases in sewage sludge-amended soils can act as long-term sinks for heavy metals, soils
were sampled from two field sites, each with a similar history of multi-year application of
either high-Fe, high-Al, or high-Ca sludge (similar to 25 years earlier) but with different
textural characteristics. These soils were amended with Cd in the form of CdC12 in the
laboratory to determine Cd solubility as a function of total added Cd over the range of 0
to 20 mg/kg. The slopes of these linear solubility functions, used to determine the
strength of Cd sorption, revealed that the high-Fe and high-Al sludge amendments did not
improve the soils' affinity for Cd at either site. The high-Al sludge treatment decreased
the affinity for Cd in the more coarse-textured soil. The high-Ca sludge amendment,
conversely, increased the affinity, for Cd, probably a result of the higher soil pH that has
persisted since the sludge application. The results suggest that sludge Fe and Al may not
be effective in binding Cd in all soils of humid temperate climates.
Mohillo, S; Montgomery, A; Fuman, D; et al. (2006) Detection of Cryptosporidium parvum
oocysts in sediment and biosolids by immunomagnetic separation. Water Environ Res
78(9):1013-1016.
Abstract: A method for the detection of Cryptosporidium parvum oocysts in sediment and
wastewater biosolids has been developed using immunomagnetic separation kits that
were designed for use with water. This method requires no pretreatment of the sediment
or biosolids samples before the commercial kit application. Oocyst recovery efficiencies
from sediment and biosolids using the modified Dynal (Lake Success, New York) and
Crypto-Scan commercial methods (Immucell Corporation, Portland, Maine) ranged from
20 to 60%. While the sensitivity of the method is dependent on the amount of sediment
processed and the equivalent volume examined under the microscope, it was able to
detect 0.48 oocysts per gram dry weight sediment. Using this method, Cryptosporidium
parvum oocysts were found at levels as high as 97 oocysts/g of primary biosolids and at
levels up to 4 oocysts/g in polluted sediment.
Montgomery, MB; Ohno, T; Griffin, TS; et al. (2005) Phosphorus mineralization and availability
in soil amended with biosolids and animal manures. Biological Agriculture & Horticulture
22(4):321-334.
Abstract: Land spreading of biosolids (sewage sludge) and animal manures on
agricultural soils is a means of disposal that is both environmentally and economically
attractive. As with any soil amendment, there is potential for adverse impact from the
land application of these materials. Applying biosolid or manure to meet crop N
requirements can often result in excessive P application. A greenhouse bioassay study
was conducted to evaluate bioavailable P from biosolid and manure amendments and to
determine the effectiveness of the modified Morgan soil test (pH 4.8, 1.25 M ammonium
acetate) and an in situ anion exchange membrane resin P soil test (P (InSitu)) to estimate
plant-available P in the amended soil. The effects of biosolid stabilization processes on P
availability were investigated by using lime stabilized (LSB), composted (CB),
anaerobically digested (ADB) and unstabilized (UB) biosolids. The three animal manures
studied were: dairy (DM), poultry (PM), and swine (SM). Triple super phosphate (TSP)
served as an inorganic reference. Cumulative net P uptake by ryegrass (Lolium perenne
L.) was highest for DM and SM, intermediate for PM, LSB, UB and TSP, and lowest for
CB and ADB. Soil test P levels measured by the Morgan and P-AEM Methods were
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highly correlated (r = 0.88, p = 0.01). The P uptake by ryegrass (Lolium perenne L.)
agreed well with predicted P availability, indicating that both the modified Morgan soil
test and in situ exchange resin methods are appropriate for determining P availability in
biosolid- and manure-amended agricultural soils.
Osemwengie, LI. (2006) Determination of synthetic musk compounds in sewage biosolids by gas
chromatography/mass spectrometry. J Environ Monit (9):897-903.
Abstract: A review of sewage sludge regulations and land application practices by the
United States National Research Council (2002) recommended development of improved
analytical techniques to adequately identify and quantify new chemical contaminants,
such as synthetic musk compounds in Class A sewage sludge (i.e., biosolids). This
prompted the development of a rugged analytical method using gas chromatography
coupled to mass spectrometry to detect this group of organic pollutants in biosolids. In
this paper, the term "biosolids" is used interchangeably with "sewage sludge", which is
defined in the regulations and used in the statue (Clean Water Act). Samples of Class A
biosolids obtained from sewage treatment plants in Los Angeles, California, the City of
Las Vegas, Nevada, and also in the form of a commercial fertilizer, were extracted using
pressurized liquid extraction technique, subjected to gel permeation chromatography
cleanup, and analyzed by GC/MS using the selected ion monitoring mode. The method
developed has the potential to detect synthetic musk compounds in complex matrices,
may provide accurate data useful in human health and environmental risk assessment,
and may be useful in determining the efficacy of municipal sewage treatment plants for
removing synthetic musk compounds.
Paez-Rubio, T; Ramarui, A; Sommer, J; et al. (2007) Emission rates and characterization of
aerosols produced during the spreading of dewatered class B biosolids. Environ Sci Technol
41(10):3537-3544.
Abstract: This study measured aerosol emission rates produced during the spreading of
dewatered class B biosolids onto agricultural land. Rates were determined in multiple
independent experimental runs by characterizing both the source aerosol plume geometry
and aerosol concentrations of PM10, total bacteria, heterotrophic plate count bacteria
(HPC), two types of biosolids indicator bacteria, endotoxin, and airborne biosolids
regulated metals. These components were also measured in the bulk biosolids to allow for
correlating bulk biosolids concentrations with aerosol emission rates and to produce
reconstructed aerosol concentrations. The average emission rates and associated standard
deviation for biosolids PM10, total bacteria, HPC, total coliforms, sulfite-reducing
Clostridia, endotoxin, and total biosolids regulated metals were 10.1 +/- 8.0 (mg/s), 1.98
+/- 1.41 x 10(9) (no./s), 9.0 +/- 11.2 x 10(7) (CFU/s), 4.9 +/- 2.2 x 10(3) (CFU/s), 6.8 +/-
3.8 x 10(3) (CFU/s), 2.1 +/- 1.8 x 10(4) (EU/s), and 36.9 +/- 31.8 (mu g/s) respectively.
Based on the land application rates of spreaders used in this study, an estimated 7.6 +/-
6.3 mg of biosolids were aerosolized for every 1 kg (dry weight) applied to land.
Scanning electron microscopy particle size distribution analysis of the aerosols revealed
that greater than 99% of the emitted particles were less than 10 mu m and particle size
distributions had geometric mean diameters and standard deviations near 1.1 +/- 0.97 mu
m. The demonstrated correlations of bulk biosolids concentrations with aerosol emission
rates, and the reconstruction of aerosol concentration based on PM10 and bulk biosolids
concentration provide a more fundamental, bulk biosolids-based approach for extending
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biosolids aerosol exposure assessment to different land application scenarios and a
broader range of toxins and pathogens.
Paez-Rubio, T; Xin, H; Anderson, J; et al. (2006) Particulate matter composition and emission
rates from the disk incorporation of class B biosolids into soil. Atmos Environ 40:7034-7045.
Abstract: Biosolids contain metal, synthetic organic compound, endotoxin, and pathogen
concentrations that are greater than concentrations in the agricultural soils to which they
are applied. Once applied, biosolids are incorporated into soils by disking and the
aerosols produced during this process may pose an airborne toxicological and infectious
health hazard to biosolids workers and nearby residents. Field studies at a Central
Arizona biosolids land application site were conducted to characterize the physical,
chemical, and biological content of the aerosols produced during biosolids disking and
the content of bulk biosolids and soils from which the aerosols emanate. Arrayed
samplers were used to estimate the vertical source aerosol concentration profile to enable
plume height and associated source emission rate calculations. Source aerosol
concentrations and calculated emission rates reveal that disking is a substantial source of
biosolids-derived aerosols. The biosolids emission rate during disking ranged from 9.91
to 27.25 mg s super(-l) and was greater than previously measured emission rates
produced during the spreading of dewatered biosolids or the spraying of liquid biosolids.
Adding biosolids to dry soils increased the moisture content and reduced the total PM
sub(10) emissions produced during disking by at least three times. The combination of
bulk biosolids and aerosol measurements along with PM sub(10) concentrations provides
a framework for estimating aerosol concentrations and emission rates by reconstruction.
This framework serves to eliminate the difficulty and inherent limitations associated with
monitoring low aerosol concentrations of toxic compounds and pathogens, and can
promote an increased understanding of the associated biosolids aerosol health risks to
workers and nearby residents.
Pepper, LL; Brooks, JP; Gerba, CP. (2006) Pathogens in biosolids. Advances in Agronomy
90:1-41.
Abstract: The world population of 6.8 billion people produces sewage. In the developed
world most of this is treated by the activated sludge process, which results in large
volumes of sludge or biosolids being produced (NRC, 2002). These result in millions of
tons of biosolids produced each year in the United States, which must either be disposed
of or recycled in some manner. Land application has been seen as the most economical
and beneficial way of handling biosolids. Biosolids that result from municipal wastewater
treatment processes contain organic matter and nutrients that, when properly treated and
applied to farmland, can improve the productivity of soils or enhance re-vegetation of
disturbed ecosystems. However, besides the documented benefits of land application,
there are also potential hazards, which have caused the public response to the practice to
be mixed. Here we review one of the potential hazards associated with biosolids and its
land application, namely human pathogens associated with biosolids. (c) 2006, Elsevier
Inc
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Filial, SD. (2007) Bioaerosols from land-applied biosolids: Issues and needs. Water Environ Res
79(3):270-278.
Abstract: Bioaerosols are a vehicle for the dissemination of human and animal pathogens.
Because of land-filling costs and the ban on ocean dumping of municipal biosolids, land
application of biosolids and animal manure is increasing all over the globe. There is no
doubt that the creation, generation, and disposal of human and animal wastes increases
the aerosolization potential of a wide variety of microbial pathogens and related
pollutants. In an attempt to address public health issues associated with the land
application of municipal biosolids, the U.S. National Research Council (Washington,
D.C.) published a report on this issue in 2002. This paper focuses on the current
information and technology gaps related to estimating the public health risks associated
with bioaerosols during the land application of biosolids.
Schwab, AP; Lewis, K; Banks, MK. (2006) Biosolids-amended soils: Part II. Chemical lability
as a measure of contaminant bioaccessability. Water Environ Res 78(11):2231-2243.
Abstract: Biosolids recycling by amending agricultural soils has increased significantly
over the last few decades. The presence of contaminants in small, bioavailable quantities
has generated concerns about health threats resulting from accumulation of potential
toxins in the food chain. In this study, land application of biosolids was evaluated for
environmental risk. Chemical lability tests for metals were used for the test soils and
included analyses for water soluble, exchangeable, and metals extractable by the
physiologically based extraction test. Chemical extractions detected slight increases in
labile metal concentrations for many of the treated soils, particularly those receiving
long-term applications of 5 years or more. Significantly higher metal concentrations were
observed in the soils that had been exposed to biosolids before the U.S. Environmental
Protection Agency (Washington, D.C.) 503 Rule (U.S. EPA, 2004) was implemented.
Shober, AL; Hesterberg, DL; Sims, JT; et al. (2006) Characterization of phosphorus species in
biosolids and manures using XANES spectroscopy. J Environ Qual 35(6): 1983-1993.
Abstract: Identification of the chemical P species in biosolids or manures will improve
our understanding of the long-term potential for P loss when these materials are land
applied. The objectives of this study were to determine the P species in dairy manures,
poultry litters, and biosolids using X-ray absorption near-edge structure (XANES)
spectroscopy and to determine if chemical fractionation techniques can provide useful
information when interpreted based on the results of more definitive P speciation studies.
Our XANES fitting results indicated that the predominant forms of P in organic P sources
included hydroxylapatite, PO(4) sorbed to Al hydroxides, and phytic acid in lime-
stabilized biosolids and manures; hydroxylapatite, PO(4) sorbed on ferrihydrite, and
phytic acid in lime- and Fe-treated biosolids; and PO(4) sorbed on ferrihydrite,
hydroxylapatite, beta-tricalcium phosphate (beta-TCP), and often PO(4) sorbed to Al
hydroxides in Fe-treated and digested biosolids. Strong relationships existed between the
proportions of XANES PO(4) sorbed to Al hydroxides and NH(4)C1- + NH(4)F-
extractable P, XANES PO(4) sorbed to ferrihydrite + phytic acid and NaOH-extractable
P, and XANES hydroxylapatite + beta-TCP and dithionite-citrate-bicarbonate (DCB)- +
H(2)SO(4)-extractable P (r(2) = 0.67 [P = 0.01], 0.78 [P = 0.01], and 0.89 [P = 0.001],
respectively). Our XANES fitting results can be used to make predictions about long-
term solubility of P when biosolids and manures are land applied. Fractionation
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techniques indicate that there are differences in the forms of P in these materials but
should be interpreted based on P speciation data obtained using more advanced analytical
tools.
Sullivan, TS; Stromberger, ME; Paschke, MW. (2006) Parallel shifts in plant and soil microbial
communities in response to biosolids in a semi-arid grassland. Soil Biology & Biochemistry
38(3):449-459.
Abstract: Approximately 70,150 dry Mg of biosolids from over 450 wastewater treatment
facilities are applied to the semi-arid rangelands of Colorado every year. Research on
semi-arid grassland responses to biosolids has become vital to better understand
ecosystem dynamics and develop effective biosolids management strategies. The
objectives of this study were to determine the long-term (similar to 12 years) effects of a
single biosolids application, and the short-term ( similar to 2 years) effects of a repeated
application, on plant and microbial community structure in a semi-arid grassland soil.
Specific attention was paid to arbuscular mycorrhizal fungi (AMF) and linkages between
shifts in plant and soil microbial community structures. Biosolids were surface applied to
experimental plots once in 1991 (long-term plots) and again to short-term plots in 2002 at
rates of 0, 2.5, 5, 10, 21, or 30 Mg ha(-l). Vegetation (species richness and above-ground
biomass), soil chemistry (pH, EC, total C, total N, and extractable P, NO3-N, and NH4-
N), and soil microbial community structure [ester-linked fatty acid methyl esters (EL-
FAMEs)], were characterized to assess impacts of biosolids on the ecosystem. Soil
chemistry was significantly affected and shifts in both soil microbial and plant
community structure were observed with treatment. In both years, the EL-FAME
biomarker for AMF decreased with increasing application rate of biosolids; principal
components analysis of EL-FAME data yielded shifts in the structure of the microbial
communities with treatment primarily related to the relative abundance of the AMF
specific biomarker. Significant (p <= 0.05) correlations existed among biomarkers for
Gram-negative and Gram-positive bacteria, AMF and specific soil chemical parameters
and individual plant species' biomass. The AMF biomarker was positively correlated with
biomass of the dominant native grass species blue grama (Bouteloua gracilis [Willd. ex
Kunth] Lagasca. ex Griffiths) and was negatively correlated with western wheatgrass
(Agropyron smithii Rydb.) biomass. This study demonstrated that applications of
biosolids at relatively low rates can have significant long-term effects on soil chemistry,
soil microbial community structure, and plant community species richness and structure
in the semi-arid grasslands of northern Colorado. Reduced AMF and parallel shifts in the
soil microbial community structure and the plant community structure require further
investigation to determine precisely the sequence of influence and resulting ecosystem
dynamics, (c) 2005 Elsevier Ltd. All rights reserved
Sullivan, TS; Stromberger, ME; Paschke, MW; et al. (2006) Long-term impacts of infrequent
biosolids applications on chemical and microbial properties of a semi-arid rangeland soil.
Biology and Fertility of Soils 42(3):258-266.
Abstract: A plot study was conducted to quantify long-term (> 12 years) impacts of a
single biosolids application, and short-term impacts (< 2 years) of a repeated application,
on semi-arid rangeland soil chemical and microbial parameters. In 2003 and 2004, plots
which had received 0, 2.5, 5, 10, 21, or 30 Mg biosolids ha(-l) once in 1991 (long-term
plots), or again in 2002 ( short-term plots), were sampled and analyzed for soil chemical
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parameters, microbial biovolumes, C and N mineralization activities, Biolog EcoPlate
substrate utilization potential, and plant productivity and tissue quality. Repeated
applications temporarily exacerbated differences in soil chemical properties among
treatments, but after 2 years, soil chemistry trends were similar between short-term and
long-term plots. Soils which received a repeated application of 21 or 30 Mg biosolids
ha(-l) had greater bacterial biovolumes and C and N mineralization activities. Biosolids-
amended soil communities also utilized Biolog substrates more quickly compared to
communities from control plots. Plant biomass increased, whereas plant diversity and
plant C/N ratio decreased with increasing application rate for both short-and long-term
plots. Infrequent biosolids application had positive ecosystem effects in terms of site
management objectives, with relatively low extractable metal levels in soil and greater
plant biomass and tissue quality despite reduced species richness.
Zaleski, KJ; Josephson, KL; Gerba, CP; et al. (2005) Potential regrowth and recolonization of
salmonellae and indicators in biosolids and biosolid-amended soil. Appl Environ Microbiol
71(7):3701-3708.
Abstract: This study evaluated the potential for conversion of Class B to Class A
biosolids with respect to salmonellae and fecal coliforms during solar drying in concrete
lined drying beds. Anaerobically (8% solids) and aerobically (2% solids) digested Class
B biosolids were pumped into field-scale drying beds, and microbial populations and
environmental conditions were monitored. Numbers of fecal coliforms and salmonellae
decreased as temperature and rate of desiccation increased. After 3 to 4 weeks, Class A
requirements were achieved in both biosolids for the pathogens and the indicators.
However, following rainfall events, significant increase in numbers was observed for
both fecal coliforms and salmonellae. In laboratory studies, regrowth of fecal coliforms
was observed in both biosolids and biosolid-amended soil, but the regrowth of
salmonellae observed in the concrete-lined drying beds did not occur. These laboratory
studies demonstrated that pathogens decreased in numbers when soil was amended with
biosolids. Based on serotyping, the increased numbers of salmonellae seen in the concrete
lined drying beds following rainfall events was most likely due to recolonization due to
contamination from fecal matter introduced by animals and not from regrowth of
salmonellae indigenous to biosolids. Overall, we conclude that the use of concrete-lined
beds created a situation in which moisture added as rainfall accumulated in the beds,
promoting the growth of fecal coliforms and salmonellae added from external sources.
Zaleski, KJ; Josephson, KL; Gerba, CP; et al. (2005) Survival, growth, and regrowth of enteric
indicator and pathogenic bacteria in biosolids, compost, soil, and land applied biosolids. Journal
of Residuals Science & Technology 2(l):49-63.
Abstract: In the U.S. approximately 60% of all biosolids are currently land applied.
Although it is known that bacteria in biosolids normally decrease to low or non-
detectable levels following treatment, a major concern is that regrowth of pathogens may
occur. Specifically the question arises: "Does regrowth occur following reintroduction or
recolonization of pathogens after land application or during storage under favorable
conditions?" The following paper reviews available information on survival and potential
regrowth of pathogenic and indicator bacteria in biosolids, compost, soil, and land
applied biosolids. Based on the literature, a conceptual framework is provided to explain
the phenomenon of "regrowth."
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