January 2009

Targeted National Sewage Sludge Survey

Sampling and Analysis Technical Report 

U.S. Environmental Protection Agency 

Office of Water (4301T) 

1200 Pennsylvania Avenue, NW 

Washington, DC 20460 

EPA-822-R-08-016 
TNSSS Sampling and Analysis Technical Report i January 2009

Acknowledgments and Disclaimer 

The Targeted National Sewage Sludge Survey was made possible by the assistance and 

cooperation of numerous staff working at each of the sewage treatment facilities involved. The 

staffs of the facilities contacted during the course of this survey were, without exception, 

knowledgeable, friendly, helpful, and deservedly proud of their efforts to protect the 

environment and serve their local constituencies. 

 This technical report has been reviewed and approved for publication by the Office of 

Science and Technology. This report was prepared with the support of Battelle Memorial 

Institute, Computer Sciences Corporation, and their subcontractors, under the direction and 

review of the Office of Science and Technology. EPA would like to thank the Alexandria 

Sanitation Authority, Alexandria, VA, who opened their doors and assisted EPA and contractor 

staff during hands-on training in sampling techniques in July 2006. 

Neither the United States government, nor any of its employees, contractors, 

subcontractors, or other employees makes any warranty, expressed or implied, or assumes any 

legal liability or responsibility for any third party’s use of, or the results of such use of, any 

information, apparatus, product, or process discussed in this report, or represents that its use by 

such a third party would not infringe on privately owned rights. 
TNSSS Sampling and Analysis Technical Report ii January 2009 
TNSSS Sampling and Analysis Technical Report iii January 2009 

Table of Contents 

Page

Acknowledgments and Disclaimer .................................................................................................. i 

Executive Summary ....................................................................................................................v 

Section 1 Background and Organization .......................................................................................1 

 1.1 Regulatory and Surveys History............................................................................1 

 1.2 Targeted National Sewage Sludge Survey ............................................................1 

 1.3 Content of this Report ...........................................................................................3 

Section 2 Survey Objective and Design.........................................................................................4

 2.1 Survey Objective ...................................................................................................4 

 2.2 Target Population ..................................................................................................4 

 2.3 Stratification ..........................................................................................................4 

 2.4 Facillity Selections ................................................................................................5 

Section 3 Sample Collection..........................................................................................................7 

 3.1 Training .................................................................................................................7

 3.2 Sample Collection .................................................................................................7 

 3.3 Site-specific Deviations.......................................................................................88 

 3.4 Representative Samples.........................................................................................9 

 3.5 Field Duplicates.....................................................................................................9 

 3.6 Sample Labeling and Tracking..........................................................................100 

 3.7 Packing and Shipping Samples to the Repository...............................................10 

 3.8 Storage and Shipments to Laboratories...............................................................11 

 3.9 Shipping Issues....................................................................................................12 

 3.10 Sampling Summary .............................................................................................13 

 3.11 Equipment Blanks ...............................................................................................13 

Section 4 Sample Analyses..........................................................................................................15 

 4.1 Analytes of Interest..............................................................................................15 

 4.2 Analytical Techniques.........................................................................................18 

 4.3 Laboratories.........................................................................................................18 

 4.4 Method Modifications .........................................................................................19 

 4.4.1 Ensuring Consistent Method Sensitivity ..................................................19 

 4.4.2 Anions in Sewage Sludge .......................................................................201 

 4.4.3 Modified GC/MS Procedures for Semivolatile Organics.........................21 

 4.4.4 PBDE Analyses ........................................................................................23 

 4.4.5 Pharmaceutical Analyses..........................................................................24 

 4.4.6 Steroid and Hormone Analyses ................................................................26 

 4.4.7 Focusing Quality Control on the Survey-specific Analytes of Interest....28 

Section 5 Data Review Procedures..............................................................................................29 

 5.1 General Review Procedures ................................................................................29 

 5.2 QC Acceptance Criteria.......................................................................................30 

 5.3 Data Qualifiers and Database ..............................................................................30 

 5.4 Data Review Findings .........................................................................................31 

 5.4.1 Reporting Limits.......................................................................................31 

 5.4.2 Calculation Errors.....................................................................................32 

 5.4.3 Blank Contamination................................................................................32 

 5.4.4 Extract Dilution ........................................................................................33 
TNSSS Sampling and Analysis Technical Report iv January 2009 

 5.4.5 Matrix Spikes............................................................................................34 

 5.4.6 Interferences .............................................................................................34 

 5.4.7 Recovery Issues ........................................................................................37 

 5.5 Revised Results for BDE-209 .............................................................................38 

Section 6 Survey Results .............................................................................................................39 

 6.1 Summary Results.................................................................................................39 

 6.2 Investigation of Results for Metals......................................................................42 

 6.3 Comparison of Metals Results to Current Standards ..........................................43 

 6.4 Analytical Completeness.....................................................................................43 

 6.5 Analytical Sensitivity ..........................................................................................44 

 6.6 Equipment Blank Evaluation...............................................................................47 

 6.6.1 Semivolatile Organics and PAHs .............................................................47 

 6.6.2 Metals .......................................................................................................48 

 6.6.3 PBDEs.......................................................................................................49 

 6.6.4 Anions.......................................................................................................49 

 6.7 Field Duplicate Results........................................................................................51 

 6.7.1 Anions.......................................................................................................52 

 6.7.2 Metals .......................................................................................................52 

 6.7.3 Semivolatile Organics and PAHs .............................................................53 

 6.7.4 PBDEs.......................................................................................................54 

 6.7.5 Pharmaceuticals ........................................................................................54 

 6.7.6 Steroids and Hormones.............................................................................56 

 6.7.7 Results in Liquid Samples ........................................................................58 

 6.8 Matrix Spike and Duplicate Results....................................................................59 

 6.8.1 Matrix Spike Results for Anions ..............................................................60 

 6.8.2 Duplicate Results for Anions....................................................................62 

 6.8.3 Matrix Spike Results for Metals...............................................................62 

 6.8.4 Duplicate Results for Metals ....................................................................65 

 6.8.5 MS/MSD Results for Organics.................................................................67 

 6.8.6 MS/MSD Results for PBDEs....................................................................69 

 6.8.7 Qualification of Sample Results based on MS/MSD Results...................70 

 6.8.8 Labeled Compound Recoveries for Isotope Dilution Methods ................71 

Section 7 References ..................................................................................................................72 

Appendix A Solids Leaching Procedure for Anions....................................................................73 

Appendix B Method Modifications for the PBDE Analyses.......................................................74 

Appendix C QC Acceptance Criteria...........................................................................................75 
TNSSS Sampling and Analysis Technical Report v January 2009 

Executive Summary 

 This Sampling and Analysis Technical Report (“Technical Report”) describes the 

sampling and analysis activities conducted by EPA in support of the Targeted National Sewage 

Sludge Survey (TNSSS). The TNSSS was designed to: 1) obtain updated occurrence 

information on nine analytes of potential concern, and 2) obtain occurrence information on a 

number of contaminants of emerging interest identified by EPA and the National Research 

Council (NRC). The objective of the survey was to obtain national estimates of the 

concentrations of these pollutants in sewage sludge for use in assessing if exposures may be 

occurring and whether those levels may be of concern. 

 Final sewage sludge is defined as the liquid, solid, or semi-solid residue generated during 

the treatment of domestic sewage, receiving secondary treatment or better, in a treatment works, 

which may include sewage sludge processed to meet land application standards. The publicly 

owned treatment works (POTWs) included in the survey were selected without consideration of 

their sewage sludge use or disposal practices. 

 

 For this survey, EPA focused its efforts on POTWs that treat more than one million 

gallons of wastewater per day (MGD). This group of facilities collectively generates 

approximately 94 percent of the wastewater flow in the nation. To be eligible for the survey, 

EPA also required that a POTW be located in the contiguous United States and employ 

secondary treatment or better. From the 3,337 POTWs that met the criteria, EPA statistically 

selected 74 facilities in 35 states for the survey and collected biosolids samples from those 

facilities. Whether the facility recycles the sewage sludge to land or disposes of it via 

incineration or surface disposal was not a consideration for selecting a facility for inclusion in 

the survey. By using statistical methods, the concentration measurements can be extrapolated to 

the entire population of 3,337 POTWs. 

 EPA collected samples between August 2006 and March 2007. EPA collected 84 

samples of sewage sludge from 74 facilities, one from each of 64 POTWs, as well as two 

samples at the remaining ten facilities (either because the facility had more than one treatment 

system and produced two types of final sewage sludge, or for quality assurance purposes. EPA 

conducted analysis of sewage sludge samples for 145 analytes, including four anions 

(nitrite/nitrate, fluoride, water-extractable phosphorus), 28 metals, four polycyclic aromatic 

hydrocarbons, two semi-volatiles, 11 flame retardants, 72 pharmaceuticals, and 25 steroids and 

hormones. 

 The survey used both well-established multi-laboratory validated EPA procedures as well 

as three analytical methods that were developed or updated for the survey. The two new 

methods are single-lab validated methods for pharmaceuticals (EPA Method 1694), and steroids 

and hormones (EPA Method 1698). The updated multi-lab validated method is for flame 

retardants (EPA Method 1614). 

 EPA took steps to ensure that the results were comparable across all of the facilities 

sampled. The percent solids in the various sewage sludge samples range from 0.14 to 94.9. To 

ensure comparability of results, all sample results are reported on a dry-weight basis. 
TNSSS Sampling and Analysis Technical Report vi January 2009 

 EPA subjected all of the analytical results generated by the laboratories to data review 

procedures. These procedures used review protocols to ensure that the results met EPA’s 

objectives for data quality. 

 This Technical Report includes the number of samples in which each analyte was 

reported, along with minimum and maximum measurements. Reported concentrations and 

frequency of detects are limited by the sensitivity of the analytical methods used. Some analytes 

were found in all 84 samples, while others were found in none or only a few of the sewage 

sludge samples. The minimum concentration is the lowest value reported as present in any 

sample. EPA did not report a minimum or maximum value for those analytes that were not 

detected (i.e., a situation that occurred for some of the pharmaceuticals, steroids and hormones). 

For these situations, EPA used “ND” to indicate that the minimum and maximum values were 

“not detected.” The maximum concentration is the highest value reported as present in any 

sample. 

 Briefly, the survey found: 

 The four anions were found in every sample. 

 27 metals were found in virtually every sample, with one metal (antimony) found in no 

less than 72 samples. 

 Of the six semivolatile organics and polycyclic aromatic hydrocarbons, four were found 

in at least 72 samples, one was found in 63 samples, and one was found in 39 samples. 

 Of the 72 pharmaceuticals, three (i.e., cyprofloxacin, diphenhydramine, and triclocarban)

were found in all 84 samples and nine were found in at least 80 of the samples. 

However, 15 pharmaceuticals were not found in any sample and 29 were found in fewer 

than three samples. 

 Of the 25 steroids and hormones, three steroids (i.e., campesterol, cholestanol, and 

coprostanol) were found in all 84 samples and six steroids were found in at least 80 of 

the samples. One hormone (i.e., 17α-ethynyl estradiol) was not found in any sample and 

five hormones were found in fewer than six samples. 

 All of the flame retardants except one (BDE-138) were found every sample or all but one 

sample. 

 It is not appropriate to speculate on the significance of the results until a proper 

evaluation has been completed and reviewed. EPA plans to evaluate the pollutants identified by 

the survey as being present in sewage sludge. As its first priority, using the survey information, 

EPA has begun assessing the nine pollutants identified from the 2003 biennial review as needing 

updated concentration information and molybdenum to determine whether additional action may 

be necessary. Later this year, EPA expects to initiate evaluations of other pollutants in the 

survey that may warrant further consideration. The evaluations will depend on the availability of 

data needed to conduct the evaluations.
TNSSS Sampling and Analysis Technical Report 1 January 2009

Section 1 

Background and Organization 

1.1 Regulatory and Surveys History 

 Sewage sludge is the solid, semisolid, or liquid organic material that results from the 

treatment of domestic wastewater by municipal wastewater treatment plants, also known as 

publicly owned treatment works (POTWs). The U.S. Environmental Protection Agency (EPA) 

uses the terms sewage sludge and biosolids interchangeably, but others often refer to biosolids as 

sewage sludge that has had additional processing for land application. 

 Section 405(d) of the Clean Water Act (CWA) requires that the EPA establish 

requirements for the use or disposal of sewage sludge. The Standards for the Use or Disposal of 

Sewage Sludge are found at Part 503 of Section 40 of the Code of Federal Regulations (40 CFR 

503, hereafter simply “Part 503”). 

These regulations establish numeric limits, management practices, and operational 

standards to protect public health and the environment. Sewage sludge is typically used by land 

applying to fertilize crops or reclaim mined lands, or disposed either by landfilling or surface 

disposing, or by incinerating. States may adopt additional or more stringent regulations for the 

use or disposal of biosolids. 

Additionally, Section 405(d) of the CWA requires EPA to review existing sewage sludge 

regulations at least every two years (i.e., biennial review). The purpose of such reviews is to 

identify additional toxic pollutants, and promulgate regulations, if needed, for those pollutants 

consistent with the requirements set forth in the CWA. 

1.2 Targeted National Sewage Sludge Survey 

 The Agency periodically conducts surveys to determine what may be present in sewage 

sludge. EPA has conducted three previous sewage sludge surveys: 1) a 40-city survey in 1982 to 

develop information on the fate and effects of priority pollutants in wastewater treatment plants 

and estimates of pollutant concentrations in sewage sludge; 2) a National Sewage Sludge Survey 

in 1988-1989 to gather information on sewage sludge use or disposal practices and to obtain 

updated information on the concentration of over 400 pollutants in the Nation’s sewage sludge; 

and 3) a National Sewage Sludge Survey in 2001 to obtain updated national estimates of dioxins 

and dioxin-like compounds in sewage sludge managed by land application. 

In conducting the 2003 biennial review (68 FR 75531), EPA identified 15 analytes that 

needed further evaluation. EPA subsequently reduced the list of analytes to nine based on a 

biosolids exposure and hazard assessment. EPA also determined it needed updated 

concentration data for more refined risk assessment and risk characterization of these nine 

pollutants (see Table 1). 
TNSSS Sampling and Analysis Technical Report 2 January 2009 

Table 1. 2003 Biennial Review Analytes Requiring 

Additional Information

Analyte Type 

Nitrate Anion 

Nitrite Anion 

Barium Metal 

Beryllium Metal 

Manganese Metal 

Silver Metal 

Fluoranthene PAH 

Pyrene PAH 

4-Chloroaniline Semivolatile organic 

Inclusion of pollutants in the TNSSS does not reflect a determination that their presence 

in sewage sludge adversely affects human health or the environment. Rather, EPA decided that 

updated or new concentration data were needed to assess exposure and help in evaluating 

whether levels of these pollutants in sewage sludge present environmental or human health 

concerns. 

 Given the national scope of the survey, EPA expanded the list of analytes to reflect the 

Agency’s interest in collecting concentration data for other pollutants. The expanded list 

included 24 additional metals that could be analyzed at little extra cost at the same time as the 

four metals (barium, beryllium, manganese, and silver) included in the list of nine pollutants 

above; molybdenum because of the Agency’s interest in determining the need for a revised 

numeric standard for it in land-applied biosolids; and other analytes because of their widespread 

incidence and use, as well as emerging concern. The latter category included:

 benzo(a)pyrene (found in coal tar, automobile exhaust fumes, tobacco and wood smoke, 

charbroiled food, and burnt toast); 

 2-methylnaphthalene (found in nonstructural caulking compounds and sealants, synthetic 

resins, rubber adhesives, and wall coverings); 

 bis (2-ethylhexyl) phthalate (widely used as a plasticizer in manufacturing of items such 

as cosmetics, toys, tools, and laboratory equipment); 

 fluoride (used in topical and systemic therapy for preventing tooth decay, as well as many 

other uses); 

 water-extractable phosphorus (correlated with phosphorus concentration in runoff from 

soils amended with manure and biosolids and an effective indicator of loss that may 

contribute to algae buildup in surface waters); 

 11 polybrominated diphenyl ethers (PBDEs). Four of the PBDEs were of most interest 

because of available human health information that may be useful for future risk 

evaluation efforts. PBDEs are used as flame retardants in a wide array of products, 

including building materials, electronics, furnishings, motor vehicles, plastics, 

polyurethane foams, and textiles; and 

 97 pharmaceuticals, steroids, and hormones because of broader emerging interest in these 

analytes. 

 
TNSSS Sampling and Analysis Technical Report 3 January 2009 

 EPA began sampling in August 2006, using the procedures described in Section 3, and 

completed sampling in March 2007. Analyses of survey samples were conducted as described in 

Section 4. 

1.3 Content of this Report 

 This report describes the design, sampling, and analysis activities for the TNSSS. The 

report addresses the following topics: 

 Survey Objective and Design 

 Sample Collection 

 Sample Analyses 

 Data Review Procedures 

 Survey Results 

 References 

 Appendices 
TNSSS Sampling and Analysis Technical Report 4 January 2009 

Section 2 

Survey Objective and Design

2.1 Survey Objective 

 The TNSSS was designed to: 1) obtain updated occurrence information on nine analytes 

of potential concern, and 2) obtain occurrence information on a number of contaminants of 

emerging interest identified by EPA and the National Research Council (NRC) that may be 

present in sewage sludge generated by POTWs. 

2.2 Target Population 

 For this survey, EPA focused its efforts on POTWs that treat more than one million 

gallons of wastewater per day (MGD). This group of facilities collectively generates 

approximately 94 percent of the wastewater flow in the nation. To be eligible for the survey, 

EPA also required that a POTW be located in the contiguous United States and employ 

secondary treatment or better. EPA selected POTWs meeting the criteria from information in the 

2004 Clean Water Needs Survey and the 2002 version of the Permit Compliance System. From 

the 3,337 POTWs that met the criteria in either data source, EPA used a stratified random 

sampling design to statistically select 74 facilities in 35 states for the survey and collected 

biosolids samples from those facilities. Whether the facility land applies the sewage sludge or 

disposes of it via incineration or surface disposal was not a consideration for selecting a facility 

for inclusion in the survey. By using statistical methods, the concentration measurements can be 

extrapolated to the entire population of 3,337 POTWs. 

2.3 Stratification 

 EPA selected POTWs for inclusion in the survey using a random sampling design 

stratified for flow. EPA divided the 3,337 facilities in the sample population into three 

categories, based on their design flow: 

 Flow rate of 1 to 10 MGD; 

 Flow rate of 10 to 100 MGD; and 

 Flow rate of greater than 100 MGD 

EPA then selected a proportionate number of POTWs from each of the above stratum at random. 

 POTWs with flow rates less than 1 MGD were not included in the survey. However, the 

combined flows of all such facilities represent less than 6% of the total flow of all POTWs 

nationwide. 
TNSSS Sampling and Analysis Technical Report 5 January 2009 

2.4 Facility Selections 

 EPA invited 80 POTWs to voluntarily participate in the survey. The initial written 

invitation was followed by a telephone call. These communications outlined the nature of the 

survey, the analytes of interest, and the timeframe for completion. EPA also assured each 

facility that samples sent to the laboratories for analysis would be submitted as “blind” samples, 

such that the results from any given sample could not be associated with a particular facility. 

 These communications identified facilities that did not meet the criteria for POTW 

selection in the peer-reviewed survey design and outlined above. Some POTWs provided only 

partial treatment of their wastewater, while others employed wastewater lagoons which do not 

typically produce sewage sludge, as defined, on a routine basis. Ultimately, EPA eliminated 

eleven POTWs and found five replacement POTWs. As a result, EPA selected 74 POTWs that 

met the stated criteria. The rationale for each replacement POTW is included in Table 2. 

Table 2. POTWs Selected for Sampling

Facility Name and Flow Group Flow Stratum City ST Status

Sugar Creek WWTP 1 <MGD <10 Alexander City AL

Replacement for Coley Creek; Sugar 

Creek is on the same system and 

completes the processing of Coley 

Creek’s partially-treated sewage 

sludge 

Aldridge Creek WWTP 1 <MGD <10 Huntsville AL Original selection 

Phoenix WWTP 10 <MGD <100 Phoenix AZ Original selection

Valley Sanitary District STP 1 <MGD <10 Indio CA Original selection

San Francisco > 100 MGD San Francisco CA Original selection

El Estero WWTP 1 <MGD <10 Santa Barbara CA Original selection

Santa Rosa 1 <MGD <10 Santa Rosa CA Original selection

Stockton Water Quality Plant > 100 MGD Stockton CA Original selection

Los Angeles County Sanitation District 10 <MGD <100 Whittier CA Original selection

Boulder WWTP 1 <MGD <10 Boulder CO Original selection

South Windsor 1 <MGD <10 South Windsor CT Original selection

Three Oaks WWTF 1 <MGD <10 Estero FL Original selection

Orange County Northwest WRF 1 <MGD <10 Orlando FL Original selection

Tampa 1 <MGD <10 Tampa FL Original selection

Albany 10 <MGD <100 Albany GA Original selection

Americus-Mill Creek 1 <MGD <10 Americus GA Original selection

Boone STP 1 <MGD <10 Boone IA Original selection

Calumet Water Reclamation Plant > 100 MGD Chicago IL

Replacement for MWRDGC North Side 

WWTP; Calumet is on the same 

system and completes the processing 

of North Side’s partially-treated 

sewage sludge 

Plainfield WWTP 1 <MGD <10 Plainfield IL Original selection

Lake County DPW, New Century STP 1 <MGD <10 Vernon Hills IL Original selection

Dupage County-Knollwood STP 1 <MGD <10 Wheaton IL Original selection

Blucher Poole WWTP 1 <MGD <10 Bloomington IN Original selection

William Ross Edwin WWTP 10 <MGD <100 Richmond IN Original selection

Parsons 1 <MGD <10 Parsons KS Original selection

Topeka 10 <MGD <100 Topeka KS Original selection

Mayfield WWTP 1 <MGD <10 Mayfield KY Original selection

Eunice 1 <MGD <10 Eunice LA Original selection

Jefferson Parish East Bank WWTP 1 <MGD <10 Marrero LA Original selection

Nantucket 1 <MGD <10 Nantucket MA Original selection

Salisbury 1 <MGD <10 Salisbury MD Original selection

Mechanic Falls Treatment Plant 1 <MGD <10 Mechanic Falls ME Original selection

Benton Harbor-St. Joseph WWTP 1 <MGD <10 St. Joseph MI Original selection

Wixom WTP 1 <MGD <10 Wixom MI Original selection

Festus Crystal City STP 1 <MGD <10 Crystal City MO Original selection

Elizabeth City WWTP 1 <MGD <10 Elizabeth City NC Original selection

Hillsborough WWTP 1 <MGD <10 Hillsborough NC Original selection
TNSSS Sampling and Analysis Technical Report 6 January 2009 

Table 2. POTWs Selected for Sampling

Facility Name and Flow Group Flow Stratum City ST Status

Beatrice 1 <MGD <10 Beatrice NE Original selection

Wildwood Lower WTF 10 <MGD <100 Cape May Court 

House NJ Original selection

Middlesex County Utility Authority WRC > 100 MGD Sayreville NJ Original selection

Verona TWP DPW 1 <MGD <10 Verona NJ Original selection

Buffalo > 100 MGD Buffalo NY Original selection

Canajoharie WWTP 1 <MGD <10 Canajoharie NY Original selection

Geneva A-C Marsh Creek STP 1 <MGD <10 Geneva NY Original selection

NYC DEP - Jamaica WPCP 10 <MGD <100 New York City NY Original selection

North Tonawanda STP 1 <MGD <10 North 

Tonawanda NY Original selection

Clermont County Commissioners 1 <MGD <10 Batavia OH Original selection

Bedford 1 <MGD <10 Bedford OH Original selection

Metropolitan Sewer District Little Miami 

WWTP 10 <MGD <100 Cincinnati OH Original selection

Northeast Ohio Regional Sewerage 

District Southerly WWTP > 100 MGD Cleveland OH

Replacement for Easterly; Southerly is 

on the same system and completes 

the processing of Easterly’s partiallytreated sewage sludge 

Delaware County Alum Creek WWTP 1 <MGD <10 Delaware OH Original selection

Mingo Junction STP 1 <MGD <10 Mingo Junction OH Original selection

Duncan Public Utilities Authority 1 <MGD <10 Duncan OK Original selection

City of Klamath Falls WWTF 1 <MGD <10 Klamath Falls OR Replacement for South Suburban 

Western Westmoreland Municipal 

Authority 1 <MGD <10 Irwin PA Original selection

Allegheny County Sanitary Authority 1 <MGD <10 Pittsburgh PA Original selection

Greater Pottsville Area Sewer Authority 1 <MGD <10 Pottsville PA Original selection

Punxsutawney 1 <MGD <10 Punxsutawney PA Original selection

South Kingstown WWTF 1 <MGD <10 Narragansett RI Original selection

Plum Island WWTP 10 <MGD <100 Charleston SC Original selection

Lawson Fork WTP 1 <MGD <10 Spartanburg SC Original selection

Elizabethton 1 <MGD <10 Elizabethton TN Original selection

Amarillo 10 <MGD <100 Amarillo TX Original selection

Dallas Southside WWTP > 100 MGD Dallas TX

Replacement for Dallas Central; 

Southside is on the same system and 

completes the processing of Dallas 

Central partially-treated sewage sludge 

Trinity River Authority of Texas 1 <MGD <10 Ellis County TX Original selection

Fredericksburg 1 <MGD <10 Fredericksburg TX Original selection

Odo J. Riedel Regional WWTP 1 <MGD <10 Schertz TX Original selection

Wagner Creek WWTP 1 <MGD <10 Texarkana TX Original selection

Tyler Southside WTP 1 <MGD <10 Tyler TX Original selection

Spanish Fork City Corporation 1 <MGD <10 Spanish Fork UT Original selection

Buena Vista 1 <MGD <10 Buena Vista VA Original selection

Everett City SVC Center MVD 10 <MGD <100 Everett WA Original selection; lagoon was sampled 

during dredging operations

Beaver Dam 1 <MGD <10 Beaver Dam WI Original selection

Elkins WWTP 1 <MGD <10 Elkins WV Original selection

Huntington 10 <MGD <100 Huntington WV Original selection

Facilities originally selected but not sampled 

Coley Creek WWTP Alexander City AL Partial treatment – replaced by Sugar 

Creek

City of Peoria, Beardsley WWTF Peoria AZ Partial treatment – dropped

Osceola Osceola AR Lagoon – dropped

Red Bluff WWTP Red Bluff CA Lagoon – dropped

MWRDGC North Side WRP Chicago IL Partial treatment – replaced by 

Calumet 

Water Valley Water Valley MS Lagoon – dropped

Northeast Ohio Regional S D Easterly 

WWTP Cleveland OH Partial treatment – replaced by Southerly

South Suburban Sanitary District Klamath Falls OR Lagoon – replaced by City of Klamath 

Falls 

Saluda Hampton SC Lagoon - dropped

Dallas Central WWTP Dallas TX Partial treatment – replaced by 

Southside 

Moses Lake WWTP Moses Lake WA Lagoon - dropped
TNSSS Sampling and Analysis Technical Report 7 January 2009 

Section 3 

Sample Collection 

EPA collected samples of the final treated sewage sludge at each of the 74 POTWs that 

ultimately participated in the TNSSS. EPA developed a sampling and analysis plan that was 

peer-reviewed and describes the sample collection procedures in detail. EPA revised the plan 

periodically during the survey to address the changing list of facilities and to add updated contact 

information for the laboratories that performed the analyses. As noted in Section 1.2, EPA 

sampled between August 2006 and March 2007. 

3.1 Training 

 Prior to the start of sampling, the biosolids samplers were trained by the contractor. The 

contractor, with assistance from the Alexandria Sanitation Authority, Alexandria, VA, provided 

the samplers with instructions on sampling techniques, sample point selection, required 

paperwork, sample packing, and shipping techniques. The samplers also toured the Alexandria 

Sanitation Authority to become familiar with typical sewage treatment processes. The tour 

included demonstrations and hands-on training in the collection of sewage sludge. 

Demonstrations included how to collect a range of samples, from liquid to dewatered sewage 

sludge. 

3.2 Sample Collection 

 EPA began the sample collection process by identifying the number and nature of the 

types of sewage sludge produced at each facility. This effort took place during telephone 

conversations with the plant staff well in advance of sampling. Details were confirmed with 

plant staff upon gaining access to the final treated sewage sludge. Access to the treated sewage 

sludge was generally not difficult. However, in several instances, the samplers worked with 

plant staff to obtain samples from difficult locations where there might be safety concerns. Two 

facilities required that their personnel collect the actual samples. These instances are described 

in Section 3.3. 

 Grab samples were collected using sampling equipment appropriate to the type of sewage 

sludge (liquid or solid) and the analytes of interest. To avoid or minimize contamination from 

sampling equipment, plastic equipment was used to collect samples for analyses of metals and 

anions, and stainless steel equipment was used to collect samples for analyses of all the organics. 

 Liquid samples were collected as free-flowing materials from storage tanks, transfer 

lines, taps, and hoses. After purging any lines used to collect samples, liquid samples were 

collected directly into the final sample containers shown in Table 3. Where possible, plant staff 

turned on mixing equipment in any storage tanks prior to sampling so that the collected liquids 

were representative of the bulk sewage sludge. 

Solid samples included dewatered sewage sludge. These samples were collected from a 

belt press, filter press, drying bed, centrifuge, compost pile, or other source on site. The sampler 

collected small grab samples from multiple areas of any large piles, or multiple grabs from any 

continuous processes (e.g., belt press). Small grabs were composited in a large pre-cleaned 
TNSSS Sampling and Analysis Technical Report 8 January 2009 

container of appropriate construction, mixed well, and the mixed sample was transferred into the 

final sample containers (see Table 3). Several kilograms of material were collected for each type 

of treated sewage sludge and mixed. Any mixed material that remained after all the sample 

containers were filled was returned to the sewage sludge process for disposal. 

 Grabs of solid samples for anions and metals analyses were collected with a large precleaned plastic serving spoon and mixed in a pre-cleaned plastic wastebasket. Grab solid 

samples for organics analyses were collected using a pre-cleaned stainless steel scoop and mixed 

in a pre-cleaned stainless steel bowl (8 to 12 quarts). Separate sampling equipment was used for 

each facility and all equipment was cleaned prior to shipment to the facility. 

 Sample containers were purchased from commercial suppliers who provided certificates 

of analysis for common contaminants of interest (e.g., metals, semivolatile organics, pesticides, 

PCBs). The cleaning procedures applied by the vendors were presumed to be sufficient for the 

other analytes in the survey for which routine testing by the vendor was not performed. At least 

two containers of each type were used to prepare equipment blanks as an overall check on 

possible contamination (see the discussion of equipment blanks later in Section 3.11). Both the 

high density polyethylene (HDPE) and glass containers were wide-mouth designs, sealed with 

screw caps containing a polytetrafluorothylene (PTFE) lid liner. 

Table 3. Sample Containers for Solid and Liquid Sewage Sludge, by Analysis Fraction 

Analysis Fraction Solid Sample Container Liquid Sample Container 

Metals 500-mL wide-mouth HDPE 500-mL wide-mouth HDPE 

Polycyclic Aromatic Hydrocarbons (PAHs) 

and Semivolatiles (as one analytical 

fraction) 

500-mL wide-mouth glass 1000-mL wide-mouth glass 

Inorganic Anions 500-mL wide-mouth HDPE 500-mL wide-mouth HDPE 

Polybrominated Diphenyl Ether 

Congeners 500-mL wide-mouth glass 1000-mL wide-mouth glass 

Antibiotics and Drugs 500-mL wide-mouth glass 1000-mL wide-mouth glass 

Steroids and Hormones 500-mL wide-mouth glass 1000-mL wide-mouth glass 

Archive Samples - for use in the event of 

breakage, lab accident, or for future EPA 

studies 

2 500-mL wide-mouth HDPE and 

4 500-mL wide-mouth glass 

2 500-mL wide-mouth HDPE and 

4 1000-mL wide-mouth glass 

Total Containers per Sampling Point 12 12 

3.3 Site-specific Deviations 

 Site-specific conditions at two facilities required modifications to the equipment 

protocols. At one facility, the sewage sludge was discharged from a two-story tower with a belt 

press directly into a dump truck parked below. Access to the bed of the truck was not practical, 

even if the discharge was stopped temporarily. Therefore, the staff at this facility routinely 

collected samples in a polyethylene container mounted on the end of a length of PVC pipe. In 

the presence of the EPA-contractor sampler, the facility staff inserted the device into the 

discharge from an opening in the tower, collected a small grab sample, and pulled the device 

back through the opening. Successive grab samples were collected through that opening and 

quickly placed into either the stainless steel or plastic compositing containers held by the EPAcontactor sampler. The sampler carried the containers down from the tower, mixed the samples 

in the compositing containers as described above, and then placed the samples into the 

appropriate final containers. The total contact time of each grab sample with the polyethylene 

sampling device was on the order of 30 seconds. 
TNSSS Sampling and Analysis Technical Report 9 January 2009 

 At a second facility, sewage sludge was discharged into a roll-off dumpster body in a 

narrow building which allowed limited access. In the presence of the EPA sampler, one of the 

facility staff collected the sample in a 5-gallon plastic bucket lined with a trash bag. A stainless 

steel scoop was used to remove aliquots of sewage sludge from the center of the bucket and 

transfer the material to a stainless steel bowl. Once that portion was removed, a plastic spoon 

was used to transfer the sewage sludge to a plastic bowl. 

3.4 Representative Samples 

 The TNSSS was designed to collect sewage sludge samples that were representative of 

various types of sewage sludge. For bulk sewage sludge, collecting representative samples 

presented a challenge at some facilities. For example, at one facility that composted its final 

sewage sludge, samples were collected from one of the long piles of sewage sludge mixed with 

woods chips. The piles were upwards of 50 feet long and over 6 feet high, with sides sloping up 

at roughly a 45 degree angle. Samples were collected from the oldest sections of the rows at the 

facility to represent the length of the typical composting period at the facility, which ranges from 

one to six months, depending on the season. 

 Samples of biosolids materials were taken by digging into the side of the compost pile at 

roughly six points along its length, on both sides of the pile, a foot or more off the ground to 

avoid materials in contact with the concrete substrate. Materials removed from the pile often 

contained large chunks of wood or small branches. Because these materials would not fit into 

the sample containers, they were removed from the compositing containers before mixing the 

bulk sample. Once the bulk sample was well mixed, the samples were transferred to the final 

sample containers. This procedure was repeated twice: 1) for samples for the organic 

parameters, using stainless steel equipment and glass containers, and 2) for the metals and 

anions, using plastic equipment and containers. 

 At another facility which produced liquid sewage sludge, samples were collected from a 

catwalk atop a 1-million gallon storage tank. Sewage sludge was introduced into the tank by 

water cannon with a 4-inch diameter discharge nozzle. Plant personnel turned on the water 

cannon and throttled back the flow to a relative trickle and the sampler held each sample 

container in the edge of the stream until it was full. The containers were capped once they were 

full and wiped down before packing. Neither of these situations means that the samples were not 

representative or that the Agency can not rely on the results obtained. It simply points out the 

complexities and challenges with sampling sewage sludge generated by the variety of treatment 

processes and management options available nationally. 

3.5 Field Duplicates 

 The sampling plan called for collection of field duplicate samples at 10% of the facilities. 

A field duplicate sample is a second sample collected at the facility using similar procedures and 

equipment as the original sample for quality control purposes. The results of the field duplicate 

sample can be compared to the results of the original sample as a means of assessing the overall 

precision of the sampling and analysis processes. 
TNSSS Sampling and Analysis Technical Report 10 January 2009 

Note: The 10% frequency for field duplicates is a common, but arbitrary, choice designed to 

balance the cost of the additional samples against the desire to assess the precision of the 

sampling and analysis processes. 

 Eight facilities were originally selected for collection of field duplicates. This number 

was ultimately reduced to six because two of the facilities at which field duplicates were to be 

collected were dropped from the survey and not replaced (for reasons described in Section 2). 

 Separate EPA sample numbers were assigned to the field duplicates so they were not 

identifiable by the laboratories as duplicates. The results of the field duplicate analyses are 

discussed in Section 6. 

3.6 Sample Labeling and Tracking 

The EPA contract samplers labeled each container 

with a preprinted EPA Sample Number. An example label is 

shown at the right. The EPA sample number was specific to 

each sewage sludge sample at the facility. 

In addition to labeling each container, the samplers 

prepared an EPA Traffic Report that documented the origin of the samples. The sampler 

recorded the name of the facility, date of sampling, sampler’s name, and shipping airbill number 

on the traffic report. The numbers of sample containers of each type (e.g., four plastic and eight 

glass) that were collected were recorded. The traffic report prepared at the site allowed EPA to 

track shipments of samples to the EPA Sample Repository at Microbac Laboratories in 

Baltimore, MD. 

3.7 Packing and Shipping Samples to the Repository 

 The sample containers were packed for shipping using procedures described in the peerreviewed sampling and analysis plan. Each sample container was either encased in bubblewrap 

bag or layers of bubblewrap sheeting to prevent its movement during shipping. Samples were 

packed into sturdy plastic ice chests. All of the samples from a single site could be packed, with 

ice and bubblewrap, in one 48-quart ice chest, or two 28-quart ice chests, depending on 

availability. 

 The samplers purchased ice near each facility, or the POTW provided ice, and packaged 

it in one-gallon self-sealing plastic bags. Approximately one pound of ice was used for each 

sample container (e.g., four bags containing two pounds of ice each were used to cool eight 

samples in a 28-quart ice chest). To prevent leakage during shipping, each ice chest was lined 

with bubble wrap and two trash bags. Samples and ice were packed into the inner bag, and then 

tied or sealed shut with tape. Additional packing materials were placed around the inner bag, if 

needed, and the outer bag sealed shut. The completed traffic report was placed in a plastic bag 

and affixed to the underside of the lid of the ice chest with either tape or a plastic airbill pouch. 

 Each cooler was shut with a layer of duct tape placed horizontally across the seam 

between the ice chest and its lid. Packaging tape or filament tape was applied to the cooler 

vertically, one band near each end of the ice chest, to secure the lid. 

EPA Sample No. 68408

POTW Sewage sludge 

Date collected ___________ 

Sampler Initials ___________
TNSSS Sampling and Analysis Technical Report 11 January 2009 

 Ice chests were shipped overnight from full-service FedEx offices to the EPA Sample 

Repository. Samples collected from multiple facilities in a given day were shipped at the end of 

the day, or depending on the logistics, sent separately from different FedEx locations. Each 

sample shipment was tracked through the carrier’s web site and EPA confirmed receipt at the 

repository. 

 Over the course of the survey, samples from two facilities were hand carried to the 

repository in Baltimore, because the facilities were located nearby. These samples were packed 

in a similar fashion as those sent by FedEx, except that no airbills were prepared. 

3.8 Storage and Shipments to Laboratories 

 When samples arrived at the sample repository, the staff inspected the ice chests for 

external damage or leakage (none occurred) and placed them in one of two walk-in freezers 

dedicated to EPA samples and maintained at -11°C. Freezing at - 11°C reduces microbiological 

activity and the rates of any chemical reactions that might lead to changes in the sample. 

 To streamline the shipping logistics and manage both shipping and analytical costs, EPA 

shipped batches of 15 to 20 samples from the repository to the contract laboratories for analyses. 

EPA prepared new traffic reports that listed the samples in each shipment. Additional shipments 

were sent to the laboratories as more facilities were sampled. In all, six shipments were sent to 

the laboratory performing the analyses of metals, anions, and organics, with the last shipment 

being the two samples collected at the last facility. For the PBDEs, pharmaceuticals, and 

steroids and hormones analyses, more samples had been collected and stored at the repository by 

the time those analyses began. Ultimately, three shipments were made to the laboratory 

performing the PBDE analyses and three shipments were made to the laboratory performing the 

pharmaceuticals, steroids, and hormones analyses. 

 During the packing process prior to shipment, EPA examined the samples for signs of 

breakage, including cracked glass jars and cracked lids. Although some cracking and breakage 

did occur in jars or lids, as described below, it was observed that neither cross-contamination 

occurred due to frozen conditions nor were any samples lost or not available for analysis. 

 Only three incidents of breakage were observed and these containers were not shipped to 

laboratories, but were packaged in separate plastic bags and returned to the freezer. The jars may 

have cracked during freezing, as the cracked jars were all of the 1000-mL size used for liquid 

samples. While the samplers took care not to fill any of the jars to more than 90% of their 

capacity, the high water content of the liquid sewage sludge samples could lead to greater 

expansion during freezing. This may have resulted in a greater risk of breaking the 1000-mL 

glass jars than their 500-mL counterparts used for solid samples. 

 

 All samples sent from the repository were shipped frozen, with large quantities of ice 

added to all coolers. The laboratories inspected the samples on receipt and reported that all the 

coolers still contained ice. The laboratories also reported that a small number of samples (<15) 

were received with cracked lids or jars, which may have cracked during shipping. In each case, 

the laboratory transferred the sample to a suitable clean container or otherwise protected the 

contents, such that no samples were lost as a result of shipping. The laboratories stored the 
TNSSS Sampling and Analysis Technical Report 12 January 2009 

samples frozen until analysis. Each laboratory returned a copy of the traffic report, with the date 

and time of sample receipt documented on the form. 

 Methods for the analysis of pharmaceuticals, steroids, and hormones in sewage sludge 

were not available when sample collection began in August 2006. Therefore, samples were 

stored frozen (-11°C) until methods for these analytes were available. Except for the two 

samples collected from one plant in March 2007, all of the samples analyzed for 

pharmaceuticals, steroids, and hormones were stored frozen for 11 to 15 months. 

 For the purpose of this survey, EPA assumed that all the analytes of interest were stable 

in sewage sludge samples stored at -11°C. Because the analyses for metals involved the “total 

recoverable” concentrations (e.g., all of the metal that can be recovered during digestion with a 

strong acid), holding frozen samples for extended periods is not a concern because the metals 

will be recovered even if there were any residual microbiological or chemical activity in the 

frozen samples. For the anions and semivolatile organics, EPA also did not anticipate any 

substantive changes in the concentrations of these analytes during storage due to the relatively 

low storage temperature. 

 The samples analyzed for pharmaceuticals, steroids, and hormones were held in storage 

longer than any of the other samples. The stabilities of these analytes have not been studied by 

EPA. However, EPA began a holding time study of pharmaceuticals in aqueous samples and 

sewage sludge in late 2008 that may provide some data to assess the freezer storage stability of 

these analytes in the near future. 

3.9 Shipping Issues 

 EPA tracked each sample shipment through the carrier’s web site, or confirmed receipt 

by contacting the laboratory directly. Only two shipping problems occurred, a surprisingly small 

number, given the number of shipments involved. In one instance, the laboratory performing the 

metals and anions analyses was sent the incorrect number of sample containers, which was 

resolved. In a second instance, the airbills applied to two similar ice chests containing samples 

for different laboratories were switched and the wrong types of containers were sent to each 

laboratory. The error was discovered when the samples were received at each laboratory the 

next morning. Both laboratories kept the samples frozen until they were able to ship them to the 

intended recipient. 
TNSSS Sampling and Analysis Technical Report 13 January 2009 

3.10 Sampling Summary

 The overall scope of the sample collection effort is summarized in Table 4 below. 

Table 4. Summary Sampling Statistics 

People Travel Shipping 

A total of 12 samplers visited 74 

plants and collected 84 samples. 

This included 6 field duplicates 

and additional samples at 4 plants 

that produced 2 types of final 

sewage sludge. 

46 one-way airline 

flights 

More than 150 containers of sampling supplies and 

equipment were shipped to field locations during the 

survey. Over 3,100 pounds samples and ice packed in 

108 coolers were shipped to the EPA Sample 

Repository in Baltimore, MD, via FedEx. An additional 

4 coolers were hand delivered to the repository. 

Each sampler visited between 2 

and 14 plants and collected 12 

jars of sewage sludge per plant, 

for a total of 1,002 jars. 

12 samplers spent 

107 days on the 

road and drove over 

19,000 miles 

EPA shipped 427 jars to commercial labs for the 

analyses of metals, anions, organics, PBDEs, 

pharmaceuticals, steroids, and hormones. Samples 

from each site remain in an archive at the repository 

for possible future analyses. 

3.11 Equipment Blanks 

 All of the equipment that came into contact with samples during the collection process 

was made of stainless steel (for organics) or plastic (for metals and anions) and was used for only 

one facility to avoid potential cross-contamination between sites. Prior to sending equipment to 

the field, all of the stainless steel and plastic scoops, spoons, and bowls were washed thoroughly 

with a non-phosphate detergent, rinsed three times with tap water, rinsed once with reagent 

water, inverted and air dried. Once dry, stainless steel equipment was wrapped in aluminum foil 

and plastic equipment was sealed in plastic bags. No field cleaning of equipment was performed 

during the survey. Liquid samples were placed directly into appropriate containers, while solids 

samples were placed in appropriate containers using scoops and spoons. 

 There is no relevant clean solid “reference matrix” for sewage sludge that could be easily 

used to prepare equipment blanks for the variety of analytes in this survey. Therefore, 

equipment blanks were created as follows. Two sets of the relevant equipment were sent to each 

laboratory performing analyses of anions, metals, semivolatiles organics, and PBDEs (e.g., two 

stainless steel compositing bowls, two stainless steel scoops, and two glass jars for the organics). 

For the semivolatile organics and PBDEs, there were two styles of bowls, based on availability, 

and two sizes of glass jars (500-mL and 1000-mL wide-mouths). Because the glass jars were 

purchased with certificates of analysis for common organics, EPA did not anticipate any effect 

due to the jar size. Therefore, EPA assembled one blank using each style of stainless steel bowl 

and included one jar size with one style bowl and the other jar size with the other bowl. For the 

plastic equipment, EPA used only one style of plastic compositing bowl and one size high 

density polyethylene resin (HDPE) jar, so four identical sets of equipment were sent to the 

laboratory performing the metals and anions analyses (two sets for each class of analytes). 

Each laboratory used the equipment to prepare the equipment blank by rinsing each piece 

with the solvents or solutions used to prepare field samples. For organics, including PBDEs, the 

laboratories poured the same volumes of extraction solvents used for samples over the scoop into 

the bowl. The analyst carefully swirled the solvent in the bowl to contact the majority of the 

inner surface, and then poured it into the glass jar. For metals, the laboratory used the acidic 

sample digestion solution to contact all of the plastic materials. For the anions, the laboratory 

used reagent water to “extract” the samples in a similar fashion. The laboratory treated the 
TNSSS Sampling and Analysis Technical Report 14 January 2009 

solvent or solution as if it came from a nominal size field sample and the reported the results 

accordingly, on a dry-weight basis. 

 The results for these equipment blanks, or rinsates, represent worst-case estimates of the 

potential contributions of the equipment to the final sample results. The worst-case nature of the 

estimate reflects the fact that the samples were solids, and even with vigorous mixing during the 

compositing steps, not all of the surface area of the sample contacted the entire surface of the 

bowl. The samples themselves did not contain solvents, or acidic solutions, so the potential 

transfer of contaminants would be expected to be much less than using the sample preparation 

solutions. Finally, any contaminants that were transferred from the equipment would be 

associated with the bulk composite and the final sample sent to the laboratory was only a portion 

of the total material in the bowl. In practice, 6 to 8 liters of solid sewage sludge were 

composited to provide material to fill eight 500-mL glass jars, or partially fill eight 1000-mL 

jars, for the organics analyses. For the metals and anions, only four plastic 500-mL jars were 

filled. The remainder of the composited material was returned to the sewage sludge disposal 

process. 

 The results of the equipment blank analyses for the anions, metals, and semivolatile 

organics are discussed in detail in Section 6.6. Based on EPA’s experience with the semivolatile 

organic analytes of interest in the survey, and given the fact that EPA had exhausted the supply 

of one of the types of glass containers used to collect samples, EPA opted not to submit 

equipment blanks to the laboratory analyzing the pharmaceuticals, steroids, and hormones. 

There was no issue with organic compounds in general regarding contamination of equipment 

(e.g., through ambient air, equipment supplier, or laboratory contamination). Thus, the Agency 

does not believe that contamination with pharmaceuticals, steroids and hormones would have 

been an issue. 
TNSSS Sampling and Analysis Technical Report 15 January 2009 

Section 4 

Sample Analyses

4.1 Analytes of Interest 

 The TNSSS was designed to do two things: 1) obtain updated occurrence information on 

nine pollutants of potential concern, and 2) obtain occurrence information on a number of 

contaminants of emerging interest identified by EPA and the National Research Council (NRC). 

 As discussed in Section 1, EPA identified nine pollutants (shown in bold in Table 5) for 

further evaluation of occurrence in sewage sludge. This evaluation was based on an assessment 

of chemical pollutants for which EPA had adequate data (e.g., human health benchmark values, 

and information on fate and transport in the environment). 

 

 Given the national scope of the survey, EPA expanded the list of analytes to reflect the 

Agency’s interest in collecting concentration data for other chemicals (see Tables 5 and 6). The 

expanded list included 24 additional metals that could be analyzed at little extra cost at the same 

time as the four metals (barium, beryllium, manganese, and silver) included in the list of nine 

pollutants above; molybdenum because of the Agency’s interest in determining the need for a 

revised numeric standard for it in land-applied biosolids; and other analytes because of their 

widespread incidence and use and emerging concern. The latter category included: 

 benzo(a)pyrene (found in coal tar, automobile exhaust fumes, tobacco and wood 

smoke, charbroiled food, and burnt toast); 

 2-methylnaphthalene (found in nonstructural caulking compounds and sealants, 

synthetic resins, rubber adhesives, and wall coverings); 

 bis (2-ethylhexyl) phthalate (widely used as a plasticizer in manufacturing of items 

such as cosmetics, toys, tools, and laboratory equipment); 

 fluoride (used in topical and systemic therapy for preventing tooth decay, as well as 

many other uses); 

 water-extractable phosphorus (correlated with phosphorus concentration in runoff 

from soils amended with manure and biosolids and an indicator of loss that may 

contribute to algae buildup in surface waters); 

 11 polybrominated diphenyl ethers (PBDEs). Four of the PBDEs were of most 

interest because of available human health information that may be useful for future 

risk evaluation efforts. PBDEs are used as flame retardants in a wide array of 

products, including building materials, electronics, furnishings, motor vehicles, 

plastics, polyurethane foams, and textiles; and 

 97 pharmaceuticals, steroids, and hormones because of broader emerging interest in 

these analytes. 
TNSSS Sampling and Analysis Technical Report 16 January 2009 

Table 5. Primary Target Analytes for the TNSSS, by Analyte Class 

Analyte Class Analyte 

Aluminum Manganese 

Antimony Mercury* 

Arsenic* Molybdenum* 

Barium Nickel* 

Beryllium Phosphorus 

Boron Selenium* 

Cadmium* Silver 

Calcium Sodium 

Chromium* Thallium 

Cobalt Tin 

Copper* Titanium 

Iron Vanadium 

Lead* Yttrium 

Metals 

Magnesium Zinc* 

Polycyclic aromatic hydrocarbons Benzo(a)pyrene 2-Methylnaphthalene 

(PAHs) Fluoranthene Pyrene 

Other semivolatile organics bis (2-Ethylhexyl) phthalate 4-Chloroaniline 

Fluoride Water-extractable phosphorus Inorganic anions Nitrate Nitrite 

2,4,4'-TrBDE (BDE-28) 2,2',3,4,4',5'-HxBDE (BDE-138) 

2,2',4,4'-TeBDE (BDE-47) 2,2',4,4',5,5'-HxBDE (BDE-153) 

2,3',4,4'-TeBDE (BDE-66) 2,2',4,4',5',6-HxBDE (BDE-154) 

2,2',3,4,4'-PeBDE (BDE-85) 2,2',3,4,4',5',6-HpBDE (BDE-183) 

2,2',4,4',5-PeBDE (BDE-99) 2,2',3,3',4,4',5,5',6,6'-DeBDE 

(BDE-209)

Polybrominated diphenyl ethers 

(PBDEs), including the Tetra, Hexa, 

Penta, and Deca congeners 

2,2',4,4',6-PeBDE (BDE-100) 

The 9 pollutants in bold are those selected in the December 2003 Biennial Review 

* Metals currently regulated at 40 CFR 503 

 Among the other “new and emerging contaminants” of concern in the NRC report were 

various pharmaceuticals, steroids, and hormones for which several EPA organizations were 

developing methods at the time that the TNSSS was being planned. EPA included certain 

pharmaceuticals, steroids and hormones in the TNSSS for which analytical methods were 

developed. Given the time required to develop and test new methods, EPA proceeded with the 

sample collection effort for the TNSSS as described in Section 3, and stored samples for the 

analyses of these analytes of interest until such time as the new methods for these classes of 

compounds were more fully developed. The drugs, antibiotics, steroids, and hormones added to 

the TNSSS are shown in Table 6. 
TNSSS Sampling and Analysis Technical Report 17 January 2009 

Table 6. Pharmaceuticals, Steroids, and Hormones Included in the TNSSS 

Analyte Class Analyte 

Anhydrochlortetracycline Ofloxacin 

Anhydrotetracycline Ormetoprim 

Azithromycin Oxacillin 

Carbadox Oxolinic acid 

Cefotaxime Oxytetracycline 

Chlortetracycline Penicillin G 

Ciprofloxacin Penicillin V 

Clarithromycin Roxithromycin 

Clinafloxacin Sarafloxacin 

Cloxacillin Sulfachloropyridazine 

Demeclocycline Sulfadiazine 

Doxycycline Sulfadimethoxine 

Enrofloxacin Sulfamerazine 

4-Epianhydrochlortetracycline Sulfamethazine 

4-Epianhydrotetracycline Sulfamethizole 

4-Epichlortetracycline Sulfamethoxazole 

4-Epioxytetracycline Sulfanilamide 

4-Epitetracycline Sulfathiazole 

Erythromycin Tetracycline 

Flumequine Triclocarban 

Isochlortetracycline Triclosan 

Lincomycin Trimethoprim 

Lomefloxacin Tylosin 

Minocycline Virginiamycin 

Antibiotics and their degradation 

products, disinfectants, and other 

antimicrobials 

Norfloxacin 

1,7-Dimethylxanthine Diphenhydramine 

Acetaminophen Fluoxetine 

Albuterol Gemfibrozil 

Caffeine Ibuprofen 

Carbamazepine Metformin 

Cimetidine Miconazole 

Codeine Naproxen 

Cotinine Norgestimate 

Dehydronifedipine Ranitidine 

Digoxigenin Thiabendazole 

Digoxin Warfarin 

Other drugs 

Diltiazem 

Campesterol Epi-coprostanol 

Cholestanol Ergosterol 

Cholesterol β-Sitosterol 

Coprostanol β-Stigmastanol 

Steroids 

Desmosterol Stigmasterol 

Androstenedione Estriol 

Androsterone Estrone 

17α-Dihydroequilin 17α-Ethynyl estradiol 

Equilenin Norethindrone 

Equilin Norgestrel 

17α-Estradiol Progesterone 

17β-Estradiol Testosterone 

Hormones 

β-Estradiol-3-benzoate 
TNSSS Sampling and Analysis Technical Report 18 January 2009 

4.2 Analytical Techniques 

 Table 7 presents the analytical techniques applied to samples in the TNSSS. The target 

reporting limits in the table are based on a consensus of what might be achievable in a sewage 

sludge sample. The actual reporting limits achieved are discussed in Section 6.5. 

Table 7. Analytical Methods or Techniques 

Analyte Class Method or Technique 

Target Reporting 

Limit (dry weight) 

28 Metals, including mercury ICP/AES, ICP/MS, and CVAA 

(EPA Methods 200.7, 200.8, and 245.1) 3 to 4 mg/kg 

4 Polycyclic aromatic hydrocarbons 

(PAHs) and 2 semivolatiles (as one 

analytical fraction) 

GC/MS, with selected ion monitoring (SIM), after 

solvent extraction and gel permeation 

chromatography (GPC) cleanup 

(EPA SW-846 Method 8270C) 

100 to 300 μg/kg 

4 Inorganic anions, including waterextractable phosphorus (WEP) 

EPA Methods 340.2, 353.2, and 365.3, after 

leaching of the solid sample with reagent water 

with a study-specific protocol 

2 to 8 mg/kg 

11 PBDE Congeners* High resolution GC/MS, draft EPA Method 1614 5 to 200 ng/kg 

72 Pharmaceuticals 

High performance liquid chromatography (HPLC) 

with tandem MS/MS detection, using an early draft 

of EPA Method 1694† 

Not specified 

25 Steroids and hormones High resolution GC/MS, using an early draft of 

EPA Method 1698† Not specified

* The list of target PBDE analytes was limited to the following 11 PBDE congeners: 28, 47, 66, 85, 99, 100, 138, 153, 154, 183,

and 209, which include those identified in the method as being of potential environmental or public health significance. There are 

some differences between the specifics of the method and the procedures used for the TNSSS (see Section 4.4.4 of this report). 

† The laboratory solicitation and contract were issued prior to the December 2007 formal release of EPA Methods 1694 and 1698 

and as a result, there are some differences between the specifics of those methods and the procedures used for the TNSSS (see 

Sections 4.4.5 and 4.4.6 of this report). 

mg/kg = milligrams per kilogram μg/kg = micrograms per kilogram ng/kg = nanograms per kilogram 

 As indicated, the survey used both well-established multi-laboratory validated EPA 

procedures as well as three analytical methods that were developed or updated for the survey. 

The two new methods are single-lab validated methods for pharmaceuticals (EPA Method 1694), 

and steroids and hormones (EPA Method 1698). The updated multi-lab validated method is for 

flame retardants (EPA Method 1614). These three methods have not yet been promulgated at 40 

CFR Part 136 for compliance monitoring in CWA programs, including the analysis of sewage 

sludge. 

4.3 Laboratories 

 EPA awarded competitive-bid analytical contracts to the following commercial 

laboratories: 

 Columbia Analytical Services for the analyses of the metals, anions, and PAHs and 

semivolatile organics 

 Severn Trent Laboratories (now part of Test America) for the analyses of the PBDEs 

 Axys Analytical Services for the analyses of pharmaceuticals, steroids, and hormones. 
TNSSS Sampling and Analysis Technical Report 19 January 2009 

4.4 Method Modifications 

 From an analytical standpoint, sewage sludge is a challenging matrix. The concentrations 

of pollutants present in samples vary depending on the nature of the inputs to the treatment plant. 

In addition to the pollutants of interest, sewage sludge contains a number of other components 

that are potential interferences in the analyses of the pollutants of interest. These components 

include lipids and other naturally occurring materials, as well as materials that may be added to 

the sewage during processing (e.g., surfactants, ferric chloride, polymeric colloids, or lime). 

These components can manifest themselves as interferences at all stages of the analytical 

process, from sample preparation through the determinative analysis. 

 Another analytical challenge with a national survey of sewage sludge is that the various 

treatment process and disposal practices used nationwide lead to differences in the moisture 

content of the final sewage sludge sent for use or disposal. Some of the facilities from which 

samples were obtained in the TNSSS produce liquid final sewage sludge, while others produce 

solid sewage sludge. Among the sewage sludge that were pourable liquids, the percent solids 

(hereafter percent solids) content ranged from less than 1% to about 4%, across treatment plants. 

For the solids, the percent solids content ranged from 5% to 99%. These differences in the form 

(liquid vs. solid) of the sewage sludge and the range of moisture or solid contents have direct 

effects on the analyses of the samples. The differences also affect how the data for the survey 

can be interpreted. 

 Recognizing these challenges, EPA structured the laboratory subcontracts for the various 

analyses to achieve the most uniform results across facilities as practical. These modifications 

are described below. 

4.4.1 Ensuring Consistent Method Sensitivity 

 Many analytical methods applicable to biosolids instruct the laboratory to prepare a 

specific known weight of a solid material for analysis (e.g., some methods for organics specify 

using 30 g of sample). However, that sample aliquot may contain significant amounts of 

moisture. Those same methods may treat samples that are pourable liquids as if they contain 

little or no solids, and specify using a known volume, such as 1 L, for the analysis, although that 

volume may contain measurable solids as well. These differences in how liquid and solid 

samples are prepared and analyzed, as well as the differences in the amount of solids or moisture 

in the two types of samples, mean that any measure of method sensitivity (e.g., a reporting limit 

or a detection limit) will depend on the initial mass or volume chosen for analysis and its 

moisture content. 

 EPA considered these effects on sensitivity and comparability when it planned the 

TNSSS. EPA minimized the potential sensitivity differences by instructing the laboratories to 

determine the percentage of solids (percent solids) of each sample first, and then use that 

information to select a portion of the sample for the analysis that contains the method-specified 

sample weight or volume on a dry-weight basis. In addition, even when the laboratories 

prepared liquid samples using procedures designed for aqueous samples (e.g., liquid-liquid 

extraction with an organic solvent), they were instructed to report the results in weight/weight 

units (e.g., ng/kg, g/kg, or mg/kg) appropriate for the class of analyte, adjusted for the moisture 

content of the sample (e.g., 100% dry sample). 
TNSSS Sampling and Analysis Technical Report 20 January 2009 

 The laboratory that performed the analyses of the metals, anions, and PAH and 

semivolatile organics was instructed to determine the percent solids separately for each class of 

analytes. EPA examined the percent solids data from each class for the first 35 samples and 

determined that there was no statistically significant difference between the three measurements 

on each EPA sample (see Section 6.7.7). Nevertheless, in order to ensure the most consistent 

sensitivity across the survey, EPA instructed the laboratory to continue to determine percent 

solids on each sample for each class for the remainder of the project. 

4.4.2 Anions in Sewage Sludge 

 Methods for determining anions (e.g., nutrients) in sewage sludge samples require that 

the anions be dissolved in water and separated from the solid material. In planning the TNSSS, 

EPA considered several approaches to preparing the sewage sludge samples for the analysis of 

anions, including: 

 EPA Method 1685, Nitrate/Nitrite-N in Water and Biosolids by Automated Photometry, 

Draft January 2001; 

 EPA Method 1688, Total Kjeldahl Nitrogen in Water and Biosolids by Automated 

Colorimetry with Preliminary Semi-automatic Digestion, Draft January 2001; 

 A water extraction (or leaching) procedure developed at the Pennsylvania State 

University (Vadas, P. A. and Kleinman, P. J. A., 2006). 

 

 The two draft EPA methods cited above have only been validated in a single lab. Neither 

of these methods has been promulgated at 40 CFR Part 136 for compliance monitoring in CWA 

programs, nor for the analysis of sewage sludge samples. As a result, few, if any, laboratories 

routinely run samples using those draft methods. 

 The method developed at Pennsylvania State University was published in the literature 

and has been used by several mid-western states that regulate the application of manure and 

biosolids to agricultural lands. However, the authors only used that procedure for the analysis of 

phosphorus, and not the other anions. 

 After reviewing the Vadas and Kleinman leaching procedure, EPA concluded that the 

leachate was amenable to analyses of the anions of interest in the TNSSS by existing commonly 

used EPA methods that are approved at 40 CFR 136. Therefore, EPA decided to use the 

leaching procedure to prepare all of the sewage sludge samples and have the anion analyses 

performed using the following EPA methods: 

 Method 340.2, Fluoride, Potentiometric, Ion Selective Electrode, March 1983 

 Method 353.2, Nitrate-Nitrite, Colorimetric, Manual Cadmium Reduction, March 1983 

 Method 365.3, Phosphorus, All Forms, Colorimetric, Ascorbic Acid, Two Reagent, 

March 1983 

 
TNSSS Sampling and Analysis Technical Report 21 January 2009 

 Appendix A of this report provides the TNSSS-specific directions for the leaching 

procedure. Briefly, the procedure involves: 

 Determining the percent solids of the original sample using standard procedures 

 Weighing a sample aliquot equal to 0.5 g (dry weight) into a plastic bottle 

 Adding 100 mL of reagent water 

 Shaking the bottle on a shaker table for 60 minutes at 70 RPM 

 Centrifuging the mixture for 10 minutes at 2000 RPM 

 Filtering the sample by gravity through a Whatman #2 filter 

 Preserving the aqueous leachate sample by adding H2SO4 to pH <2 

 Analyzing the leachate sample within 48 hours (the holding time for nitrate/nitrite) 

 Reporting all results in mg/kg, based on the original 0.5-g sewage sludge sample weight. 

 The leaching procedure includes steps that will preserve the relative proportions of nitrate 

and nitrite after the sewage sludge sample is leached (e.g., acid preservation and analysis within 

48 hours). However, it is not possible to determine whether or not the leaching process itself 

resulted in oxidation of nitrite to nitrate, or vice versa. Therefore, EPA decided that nitrate and 

nitrite would be analyzed as the combined parameter nitrate/nitrite, using Method 353.2. This is 

approach is acceptable for determining better exposure scenarios for nitrate/nitrite during land 

applicable of biosolids. 

 In addition, the analytical approach for the survey included determining the element 

phosphorus (P) as part of the suite of metals. The water-extractable phosphorus (WEP) 

determined using the leaching procedure above is a useful predictor of the concentrations of 

phosphorus that might be available for runoff from land to which sewage sludge has been 

applied. The ratio of the two forms of phosphorus (WEP/P) is an indication of the proportion of 

the total phosphorus applied that may contribute to runoff. That ratio may be of interest to those 

states that regulate land application of sewage sludge. 

Note: The reader is cautioned about making comparisons between the anion results from this 

survey and data from other sources that may have used different procedures to leach the 

anions from the sample. EPA’s use of dry-weight reporting units may facilitate such 

comparisons, but other differences among leaching procedures may still influence the 

results. 

4.4.3 Modified GC/MS Procedures for Semivolatile Organics 

 Gas chromatography, coupled with mass spectrometric detection (GC/MS), is the 

backbone of the analytical methods for many organic pollutants, including the PAHs and 

semivolatile organics of interest in the TNSSS. The most common form of GC/MS analysis is 

known as “full scan” GC/MS and involves examining all of the mass fragments in a wide mass 

range that exit the GC column and reach the MS detector. A typical GC/MS method will scan a 

mass range from 35 to 450 atomic mass units (amu) once every second. The masses of any 

materials that exit the GC column in that range will be recorded and used to identify the 

pollutants of interest. 
TNSSS Sampling and Analysis Technical Report 22 January 2009 

 Some EPA GC/MS methods include several hundred target analytes, and while full-scan 

GC/MS is a powerful technique, it involves tradeoffs in sensitivity and selectivity in order to be 

applied to large number of analytes simultaneously. Full-scan GC/MS can also be subject to 

interferences from other materials in the sample that are not of interest. 

 Some of these “co-extracted” interferences include biolipids that can be removed from 

the sample extracts using established cleanup procedures. One such procedure is gel permeation 

chromatography (GPC), which segregates the relatively small pollutant molecules from the 

larger lipids and other interferences on the basis of molecular size. Based on our experience in 

two previous sewage sludge surveys, EPA required every sample extract analyzed for the PAHs 

and semivolatile organics be subjected to GPC cleanup before analysis. 

 When a GC/MS instrument is operated in full-scan mode, it scans the entire mass range 

very quickly and there is relatively little time to observe the results at any given mass within that 

range. This places some practical limits on the sensitivity of the procedure. However, those 

limitations can be overcome by using the technique known as selected ion monitoring (SIM). In 

SIM, the MS instrument only looks for a small subset of masses (ions) in the overall mass range. 

These masses are ones associated with the list of target analytes, and any other masses that exit 

the GC column are simply ignored. The ions that are ignored may be those associated with 

interferences, including biolipids, or those from analytes in a full-scan method that are not of 

interest for a given project. Because the MS can spend more time looking for fewer masses, the 

sensitivity of the instrument for those pollutants with those masses can increase 10-fold or more 

over that of a full-scan procedure. 

 EPA examined the results for the first 50 samples that were analyzed by full-scan GC/MS 

and found that for many of those samples, the reporting limits achieved by the laboratory were 

much higher than anticipated. In other words, analytes were reported as “not detected” at 

concentrations greater than the reporting limits desired for the survey. Many of the increased 

reporting limits were due to large amounts of interferences that remained in the sample extract 

even after GPC cleanup, which required dilution of the extract. The laboratory also diluted a 

smaller number of samples in order to get one or two target analytes (usually bis [2-Ethylhexyl] 

phthalate) within the instrument calibration range, resulting in a loss of sensitivity for other 

analytes present at much lower concentrations. 

 In response to these early findings, EPA required that the laboratory reanalyze the 

extracts for about 35 samples using a SIM procedure. That procedure included masses that 

represented the four PAHs and two semivolatile organics that are target analytes in the survey, as 

well as the surrogate compounds and internal standards used in the full-scan method. The 

masses used in the SIM procedure are shown in Table 8. Based on successful analyses of these 

extracts, the SIM procedure was the only GC/MS procedure employed for the analysis of the 

remaining samples in the survey.

Table 8. Selected Ion Monitoring Parameters for Organic Analytes 

Type Analyte Quantitation Mass Approximate Retention Time (min)* 

4-Chloroaniline 127 9.71 

2-Methylnaphthalene 142 10.49 

Fluoranthene 202 15.04 

Pyrene 202 15.32 

Target 

Analytes 

bis (2-Ethylhexyl) phthalate 149 16.61 
TNSSS Sampling and Analysis Technical Report 23 January 2009 

Table 8. Selected Ion Monitoring Parameters for Organic Analytes 

Type Analyte Quantitation Mass Approximate Retention Time (min)* 

Benzo(a)pyrene 252 18.12 

Nitrobenzene-d5 82 8.67 

Surrogates 2-Fluorobiphenyl 172 10.94 

p-Terphenyl-d14 244 15.49 

1,4-Dichlorobenzene-d4 152 7.90 

Naphthalene-d8 136 9.59 

Acenaphthene-d10 164 11.77 

Phenanthrene-d10 188 13.57 

Chyrsene-d12 240 16.63 

Internal 

Standards 

Perylene-d12 264 18.18 

*Retention times are specific to the GC column and operating conditions used for these samples. Retentions times on other 

columns or instruments will differ. These data are presented solely to illustrate the relationships among the target analytes,

surrogates, and internal standards. 

4.4.4 PBDE Analyses 

 The original plan for the survey was to analyze for all 209 of the PBDE congeners using 

the latest draft of EPA Method 1614, a high resolution GC/MS isotope dilution procedure. 

Method 1614 is a highly sensitive procedure that can determine PBDEs at the part per trillion 

(ng/kg) levels in solid samples. It employs at least five cleanup techniques, including GPC, to 

remove interferences from sample extracts. The method employs isotope dilution quantitation, 

in which PBDE congeners synthesized using only carbon 13 (13C), a stable (nonradioactive) 

isotope of carbon, are added to the sample prior to extract. These isotopically labeled congeners 

do not occur in nature and are used as internal standards to quantify the unlabeled PBDE 

congeners. Because the labeled congeners are carried through the entire sample preparation, 

cleanup, and analysis process, they can be used to correct for any loss of analytes during the 

overall analysis, providing a more accurate result for each unlabeled target analyte. For this 

reason, EPA uses isotope dilution in many of the 1600-series methods, including those for 

dioxins, furans, PCBs, and PBDEs. 

 

 Shortly after work began on the first batch of survey samples, the laboratory and EPA 

realized that additional efforts would be required to adequately determine PBDEs in sewage 

sludge. Ultimately, EPA agreed to permit the use of a range of modifications to the original plan 

to overcome as many analytical difficulties as practical in the time permitted for the TNSSS. 

Appendix B contains a detailed list of those modifications. The most significant modifications 

were: 

 Due to the high levels of some congeners and some interferences, the initial sample size 

was reduced from 10 g to 2 g for extraction, and ultimately to 0.2 g (dry weight). 

 Samples were not spiked with labeled congeners prior to extraction. 

 The sample extracts were concentrated to a final volume of 10 mL after extraction. 

 A 1-mL aliquot of the extract was removed for spiking and cleanup. 

 Labeled congeners were spiked into the 1-mL extract, which was then carried through the 

following cleanup steps described in the method: silica gel, GPC, and alumina. The 

remaining 9 mL of extract were retained in case dilutions or additional cleanups were 

required. 

 After cleanup, extracts were analyzed by HRGC/HRMS. 
TNSSS Sampling and Analysis Technical Report 24 January 2009 

 The list of target analytes was limited to the following 11 PBDE congeners: 28, 47, 66, 

85, 99, 100, 138, 153, 154, 183, and 209, which includes those identified in the method as 

being of potential environmental or public health significance. 

 Data were examined to determine if a larger sample size (greater than 0.2 g) was required 

to achieve the desired sensitivity, or if the extract required dilution to keep analytes 

within the calibration range. The latter was much more common. 

 If congeners were present above the upper limit of the calibration range, the laboratory 

evaluated whether or not the peaks had saturated the detector. If saturation did not occur, 

the results were reported, but flagged in the database as exceeding the calibration range. 

This approach reduced the dilutions that had to be analyzed for each sample to a practical 

number. 

 Because the labeled congeners are not spiked into the samples before extraction, matrix 

spike and matrix spike duplicate samples were prepared and analyzed periodically to 

provide an estimate of extraction efficiency. 

 Results for the 11 congeners were corrected for any losses of analytes that occur during 

the many cleanup steps, but this is not equivalent to the true isotope dilution quantitation 

procedure in the original method because it does not correct for the efficiency of the 

sample extraction procedures. 

 These steps were successful in overcoming challenges inherent in sewage sludge 

analyses, and produced useful data for the purposes of the TNSSS. However, these steps 

involved some trade-offs, most notably the loss of true recovery correction of isotope dilution 

quantitation and the degree to which the very small sample size represents the bulk material. 

4.4.5 Pharmaceutical Analyses 

 The analysis of the pharmaceuticals was performed using an early draft of EPA Method 

1694. EPA Method 1694 employs high performance liquid chromatography (HPLC) to separate 

the analytes of interest and tandem mass spectrometry (MS/MS) to detect them. HPLC (or 

simply LC) is a technique that allows the analysis of polar compounds in polar solvents. It has 

advantages over gas chromatographic (GC) methods for the pharmaceuticals because GC 

methods involve introducing the analytes into the instrumentation in a gaseous form and many of 

the pharmaceuticals are not easily volatilized. Some have boiling points that are above the 

operating temperatures of a GC system and others will break down when heated (i.e., they are 

“labile”). 

 Tandem mass spectrometry involves the use of two quadrapole mass spectrometers in 

series, with a collision cell between them, such that selected ions produced in the first MS unit 

are directed into the collision cell and further fragmented before being sent to the second MS for 

detection. The only ions passed through the collision cell are those selected by the instrument as 

representing the analytes of interest. These fragments, or “product” ions, are characteristic of the 

“precursor” compound and are used to positively identify the analyte in the presence of other 

analytes and potential interferences. The MS/MS detector can be operated in an ionization mode 

that produces positive ions from the analytes of interest, or in a mode that produces negative 

ions. The method for pharmaceuticals involves four analytical fractions, three of which operate 

in the positive ionization mode and one of which uses the negative ionization mode. As 

employed in this method, the tandem MS unit is operated at unit mass resolution (e.g., it can 

distinguish between masses that differ by one atomic mass unit). 
TNSSS Sampling and Analysis Technical Report 25 January 2009 

 The pharmaceuticals method employs solvent extraction procedures to isolate the 

analytes of interest from the sewage sludge samples. Many of the analytes are weak acids or 

weak bases that ionize in aqueous solutions, losing or gaining a proton from a water molecule. 

The extraction procedures in the pharmaceutical method involve adjusting the pH of the sample 

to provide more favorable conditions for isolating the analyte from the sample matrix. 

 An aliquot of each sewage sludge sample containing a consistent dry weight of solids is 

mixed with a phosphate buffer solution with a pH of 2. This pH adjustment causes the ionized 

acid forms of the analytes of interest to gain protons and become neutrally charged molecules 

that are less soluble in water than their ionized forms and more soluble in a polar organic solvent. 

 A suite of stable isotopically labeled standards (forms of the analytes that do not occur 

naturally) is spiked into the sample and the sample is further mixed. The analyst adds 

acetonitrile to the buffered sample, ultrasonically agitates the mixture for 30 minutes, and 

centrifuges the solution to separate the solvent extract from the solids. After decanting and 

collecting the acetonitrile, the analyst performs a second extraction of the solids with fresh 

aqueous buffered acetonitrile, and a third extraction using acetonitrile alone. All three acid 

extracts are combined for cleanup. 

 The base extraction is conducted in a similar fashion, using a second aliquot of the 

original sample, but the pH of the sample is adjusted to 10 with an ammonium hydroxide 

solution. Three extractions are performed, two with aqueous buffered acetonitrile and a third 

extraction with acetonitrile alone. All three base extracts are combined for cleanup. 

 The combined acid extract is concentrated to remove the acetonitrile and prepared for 

cleanup by adding disodium EDTA and diluting the solution to 200 mL with reagent water. The 

aqueous solution is processed through a solid-phase extraction (SPE) cartridge, which traps the 

analytes of interest. Potential interferences are removed by eluting the cartridge with reagent 

water and discarding that eluant. The analytes of interest are eluted from the cartridge with 

methanol, followed by 1:1 acetone:methanol. The eluant is evaporated to near dryness, 

reconstituted in methanol, spiked with the method-specified internal standards, and brought to a 

final volume of 4 mL with a 0.1% formic acid buffer solution. 

 The base extract is subjected to a similar SPE cleanup procedure, but the cartridge is 

eluted with methanol, followed by 2% formic acid in methanol. The combined eluant is 

evaporated to near dryness, reconstituted in methanol, spiked with the method-specified internal 

standards, and brought to a final volume of 4 mL with a 0.1% formic acid buffer solution. 

 Four separate LC/MS/MS analyses are performed for the pharmaceuticals: three on the 

acid extract and one on the base extract. Separate chromatographic conditions are associated 

with each of the four fractions. The LC/MS/MS instrument is operated in the multiple reaction 

monitoring (MRM) mode, which monitors a series of precursor/product ion transitions that are 

characteristic of each target analyte. 

 The labeled analytes spiked into the sample prior to extraction are used to perform 

isotope dilution quantitation for all of the target analytes that have labeled analogs. For those 

target analytes for which labeled analogs are not readily available, quantitation is performed 

using the labeled analog of a similar compound in that fraction. As a result, all of the target 
TNSSS Sampling and Analysis Technical Report 26 January 2009 

analyte concentrations are corrected for the recovery of the labeled analogs, thus accounting for 

extraction efficiencies and losses during cleanup. 

 The approach to ensuring more consistent method sensitivity described in Section 4.4.1 

of this report was applied to the pharmaceutical analyses as well. 

4.4.6 Steroid and Hormone Analyses 

 The analysis of the steroids and hormones was performed using an early draft of EPA 

Method 1698. EPA Method 1698 employs GC to separate the analytes of interest and high 

resolution mass spectrometry (HRMS) to detect them. As employed in this method, the mass 

spectrometer achieves a resolution of at least 5,000. The target analytes in the method have 

molecular weights that range from about 100 to 500, such that the MS can distinguish between 

analytes with molecular weights that differ by 0.02 to 0.1 atomic mass units, and identify them in 

the presence of potential interferences. 

 The steroids and hormones method also employs solvent extraction procedures to isolate 

the analytes from the sewage sludge samples. An aliquot of each solid sample containing a 

consistent dry weight of solids is spiked with a suite of stable isotopically labeled standards. The 

sewage sludge samples that are firm solids are extracted in a Soxhlet extractor with 60:40 

acetone:hexane. The extract is split into two portions, with 1/25th of the extract used for steroids 

analysis and the other 24/25th used for the hormones analysis. This split ratio is used to 

compensate for the fact that the steroids and their interferences are present at higher levels in the 

samples than the hormones. 

 The sewage sludge samples that are pourable liquids are extracted using a liquid-liquid 

solvent extraction with methylene chloride. The extracts of these samples also are split into two 

portions, with a split ratio of 1:99, for the steroids and hormones respectively. 

 For both forms of sewage sludge (liquid and solid), the separate extract portions are 

subjected to cleanup using a layered alumina-Florisil (LAF) column. Following cleanup, each 

sample extract is concentrated to approximately 0.1 mL and the extract solvent is exchanged to 

pyridine. 

 In order to be amenable to GC analysis, the steroids and hormones are converted to 

compounds that are more volatile than their native forms. Both the steroids and hormones are 

derivatized to their trimethyl-silyl ethers using N,O-bis(trimethylsilyl) trifluoroacetamide with 

trimethylchlorosilane (BSTFA:TMCS). The derivatized extracts are concentrated and spiked 

with the method-specified internal standards and the final extract volume is adjusted to 500 μL. 

 Separate GC/HRMS analyses are performed for the steroids and for the hormones, using 

the same chromatographic conditions for each analytical fraction, but running the two fractions 

at different dilutions. The GC/HRMS instrument is operated at a mass resolution of at least 

5,000, and at least two exact masses are monitored for each target analyte. 

 As with the pharmaceuticals method, the labeled analytes spiked into the sample prior to 

extraction are used to perform isotope dilution quantitation for all of the target analytes that have 

labeled analogs. For those target analytes for which labeled analogs are not readily available, 
TNSSS Sampling and Analysis Technical Report 27 January 2009 

quantitation is performed using the labeled analog of a similar compound in that fraction. As a 

result, all of the target analyte concentrations are corrected for the recovery of the labeled 

analogs, thus accounting for extraction efficiencies and losses during cleanup. 

 EPA worked with the laboratory to adjust the procedures for the steroids and hormones to 

address problems encountered early in the survey. In particular, the laboratory modified one of 

the cleanup procedures. As written, the steroids and hormones method involves solvent 

extraction of the sample and processes that extract through a layered alumina-Florisil (LAF) 

cleanup column before splitting the extract into two unequal portions (1/25 and 24/25) for 

analyses of steroids and hormones, respectively. However, some of the steroids and hormones 

are present in both extract portions and during the early part of the survey, the high levels of 

steroids were creating analytical challenges during the analysis of the hormones fraction. 

 The laboratory proposed a solution to the problem that involved modifying the order in 

which the extract was subjected to cleanup and split into two portions. Instead of running the 

entire extract through the LAF column and then splitting it into two unequal portions, the raw 

extracts were split first and then run through separate LAF cleanups, one for steroids and one for 

hormones. The LAF cleanup for the steroids was run as described in the original procedure. 

 The laboratory modified the LAF procedure for the hormones to remove most of the 

steroids from the hormone fraction. The steroids were eluted from the LAF column with 

methylene chloride and that eluant was discarded. The hormones then were eluted from the 

column with methanol, as described in the original procedure. 

 The laboratory tested the method modifications prior to starting analyses of the survey 

samples by extracting large samples of sewage sludge from another source (e.g., not a TNSSS 

sample), spiking the extracts with the hormones of interest to ensure that they were present, and 

splitting each extract into two portions. One of the portions was run through the LAF column as 

described in the method. The other portion was subjected to the modified LAF procedure. Both 

extract portions were analyzed for hormones by GC/HRMS and the results were compared. The 

change to the LAF procedure dramatically reduced the levels of steroids that remained in the 

hormone fraction, and improved the results for the hormones. 

 As noted in Section 4.2, the target analyte list for the TNSSS was based on a variety of 

factors, but was not driven by lists of analytes in any individual methods. EPA had included 

Mestranol as a target analyte in early versions of the survey plan for the TNSSS. However, 

Desogestrel was never listed as a target analyte for the survey. Therefore, this modification to 

the LAF cleanup procedure sacrificed one hormone in favor of improvements for all the other 

target hormones. Given the difficulties inherent in sewage sludge analyses, EPA judged this to 

be a reasonable compromise. 
TNSSS Sampling and Analysis Technical Report 28 January 2009 

4.4.7 Focusing Quality Control on the Survey-specific Analytes of Interest 

 Because the analytes of interest for the TNSSS often are a very limited subset of the total 

number of analytes listed in some of the relevant methods, EPA did not require the laboratories 

to consider those other analytes in either preparing or evaluating the quality control operations 

associated with these samples. For example, EPA only required the laboratory to spike the 

analytes of interest for this survey into such QC samples as matrix spike/matrix spike duplicates 

and ongoing precision and recovery (OPR) samples, not all the analytes that may be listed in a 

given method. Alternatively, if the laboratory chose to use spiking solutions that contained 

additional analytes beyond those in Tables 5 and 6, EPA did not require them to assess the 

results for those non-survey target analytes or take corrective actions if those non-survey 

analytes failed to meet the acceptance criteria. 

 This approach allowed the laboratories to focus their efforts on the survey-specific 

analytes of interest in the face of the analytical challenges presented by sewage sludge matrices. 

It also allowed EPA to control the costs for the analyses to some degree by eliminating 

reanalyses related to potential QC failures associated with non-target analytes. It also reduced 

the costs for EPA’s data review efforts described in Section 5. 
TNSSS Sampling and Analysis Technical Report 29 January 2009 

Section 5 

Data Review Procedures 

5.1 General Review Procedures 

 EPA assessed the results for all of the samples analyzed during the survey using wellestablished procedures described in this section. The analysis involved in the TNSSS was 

complex and a number of analytical challenges were faced. Biosolids is one of the most 

challenging environmental matrices known due to the high solids content and matrix 

interferences present. When conducting analyses in sewage sludge matrices it is expected that 

some results will have to be qualified to accurately reflect the uncertainty of the values. 

 EPA subjected all laboratory results to a comprehensive review for completeness and 

compliance with project and method specifications to ensure that the data met the objectives of 

the survey. A multi-stage review process was used and designed to identify and correct data 

deficiencies as early as possible and maximize the amount of usable data generated. 

 Trained staff reviewed the data using established review process designed to identify and 

correct data deficiencies as early as possible and maximize the amount of usable data generated 

during the TNSSS. EPA encoded the data quality information gathered during the review in the 

final results database using a series of qualifiers and reasons. EPA did not exclude data unless a 

result was flawed such that no reasonable use could be made of it. The four stages of the review 

process are described below. 

 In the first stage of the data review process, EPA performed a data completeness check. 

Specifically, EPA evaluated elements in the laboratory submission to verify that results for 

specified samples were provided, that data were reported in the correct format, and that relevant 

information, such as preparation and analysis logs, was included in the data package. EPA 

initiated corrective action procedures to resolve any deficiencies identified. 

 The second stage of the data review process focused on an instrument performance 

check. EPA verified that calibrations, calibration verifications, standards, and calibration blanks 

were analyzed at the appropriate frequency and met method or survey performance 

specifications. Corrective action procedures were initiated to resolve any deficiencies identified. 

 The third stage of the data review process focused on a laboratory performance check. 

EPA verified that the laboratory correctly performed the required analytical procedures and was 

able to demonstrate a high level of precision and accuracy. During this stage, EPA evaluated 

quality control (QC) elements such as the ongoing precision and recovery (OPR) tests, method 

blanks, and other QC operations. Again, corrective action procedures were initiated to resolve 

any deficiencies identified. 

 
TNSSS Sampling and Analysis Technical Report 30 January 2009 

 In the fourth stage of the data review process, EPA examined method/matrix performance 

data to discern whether any QC failures resulted from laboratory performance or difficulties with 

the method or sample matrix. EPA evaluated labeled compound and surrogate spike results and 

other performance data. The reviewers also verified that proper sample dilutions were performed 

and that necessary sample cleanup steps were taken. As with previous steps, corrective action 

procedures were initiated with the laboratory to resolve any deficiencies identified. 

 

 The objective of the data review process was to document the quality of all of the data in 

the TNSSS and identify any limitations that might affect their end use. The EPA database on the 

mainframe contains data qualifiers applied to results from the TNSSS, individually, and by 

analyte class. 

5.2 QC Acceptance Criteria 

 As noted in Section 4, the analytes of interest for this survey were subject to quality 

control. Appendix C presents a summary of the QC acceptance criteria for all of the analyte 

classes. 

 The laboratory performing the analyses for the anions, metals, PAHs and semivolatiles 

used its own in-house limits routinely applied to soil samples (as opposed to aqueous samples), 

except as noted in Appendix C. The laboratory prepared liquid sewage sludge samples using 

procedures applicable to aqueous samples (e.g., a liquid-liquid solvent extraction procedure for 

the organics) and the laboratory ran an aqueous laboratory control sample (LCS) and applied 

acceptance limits appropriate to that set of procedures. The laboratory derived their acceptance 

limits for solid samples from historical data for sewage sludge samples. Given the difficulties 

evident in the analyses of the sewage sludge samples, one might expect that statistically derived 

acceptance criteria for sewage sludge samples would differ from those for soil samples. 

Therefore, recoveries falling slightly outside of the limits for soil are not necessarily fatal flaws 

in these analyses. However, for the sake of transparency, EPA noted all recovery problems in 

the database. 

 The laboratory performing the analysis of the PBDEs using draft EPA Method 1614 

employed the default acceptance limits in the draft method. 

 The methods used for the pharmaceutical, steroid, and hormone analyses include QC 

acceptance criteria. The acceptance criteria include statistically derived limits that are based on 

data from a single laboratory. As a result, the acceptance limits for some QC operations are 

fairly wide (e.g., 5 – 200% for labeled compound recoveries). The laboratory that performed the 

pharmaceutical, steroid, and hormone analyses for the TNSSS was also the laboratory that 

helped EPA develop these methods. Therefore, EPA believes that the use of the singlelaboratory specifications is a reasonable approach. 

5.3 Data Qualifiers and Database 

 After reviewing each data package, the reviewers and the database development staff 

created an analytical database in MS Access that contained all field sample results from the 

survey. Appendix D of this report contains a table with the data applied to the results during the 

review process for TNSSS pollutants and entered into the database. 
TNSSS Sampling and Analysis Technical Report 31 January 2009 

 At intervals during development and upon completion of the database, EPA performed 

various checks to verify the accuracy of the database, including checks for consistent analyte 

names, CAS numbers, and data qualifier flags. After completing the review of the results for 

each analytical fraction, EPA uploaded the data from an Access database to the EPA mainframe 

using standardized procedures. The final database for the survey includes all of the qualifiers 

that were applied to the individual sample results. 

Note: Except for the “exclude” qualifier in the database, the presence of data qualifiers is not 

intended to suggest that data are not useable. Rather, the qualifiers are designed to 

caution the user about an aspect of the data that does not meet the acceptance criteria 

originally established for the project.

5.4 Data Review Findings 

 The data review process was crucial in identifying the sensitivity issues associated with 

the full-scan GC/MS analyses discussed in Section 4. By examining the first sets of sample 

results shortly after they were delivered by the laboratory, EPA was able to take corrective action 

and instituted the use of selected ion monitoring for all PAH analyses in the survey to achieve 

the needed analytical sensitivity. 

 The data review process uncovered only a few other issues with data quality. Typical 

issues included: 

 Reporting unit issues 

 Calculation errors for specific samples 

 Blank contamination 

 Extract dilution issues 

 Matrix spike issues 

 Interference issues 

 Recovery issues 

Specific examples of these issues are presented in Section 5.4.1 to 5.4.7. 

5.4.1 Reporting Limits 

 As expected, some samples with low percent solids were prepared and analyzed as 

aqueous samples. However, when reporting the results for the earliest such samples, the 

laboratory performing the metals analyses provided results in the weight/volume units typically 

applied to aqueous samples. When contacted by the data reviewers regarding this error, the 

laboratory revised these results and reported them on the basis of the dry weight of solids in the 

samples, as originally requested. 

 
TNSSS Sampling and Analysis Technical Report 32 January 2009 

 The laboratory analyzing the pharmaceuticals, steroids, and hormones reported all the 

sample results on a dry-weight basis, as required, including those samples that were pourable 

liquids. However, the laboratory used reporting units of nanograms per gram (ng/g), instead of 

the method-specified units of nanograms per kilogram (ng/kg). This error was discovered during 

the early stages of the review of these data. However, because the units of ng/g are equivalent to 

μg/kg, after consulting the laboratory and considering the concentrations of the analytes in the 

samples, EPA decided to accept the numerical results in ng/g (e.g., EPA kept the numbers 

reported by the lab), but changed the units in the EPA database to μg/kg (i.e., 100 ng/g is equal 

to 100 μg/kg). 

5.4.2 Calculation Errors 

 EPA noted that the fluoride results for two sewage sludge samples appeared to be much 

higher than any other results for this analyte. EPA contacted the laboratory and asked them to 

check these two results. The laboratory reported that the raw data for these two results were off 

by two orders of magnitude, due to a transcription error. The laboratory corrected the error and 

resubmitted the results for those two samples. The corrected results were included in the survey 

database. 

5.4.3 Blank Contamination 

 EPA examined the results for each analyte in every sample and compared the results to 

the concentrations of analytes found in each of the method blanks associated with each batch of 

samples. For all of the analyte classes, the concentrations of the analytes found in the method 

blanks were generally well below the concentrations in the field samples. 

 In some cases, there were low levels of analytes in some method blanks. For all of the 

analytes in the TNSSS, EPA used a common approach to evaluating blank contamination known 

simply as “the 5x and 10x rules.” Under routine circumstances, EPA qualified a field sample 

result if the concentration of an analyte was not at least 10 times the amount found in the blank. 

The rationale for the 10x rule is that under the worst of circumstances, in which the material 

found in the blank is coming from a source within the laboratory, the amount in the blank would 

only represent 10% of the amount in the field sample, and that small contribution is likely within 

the overall measurement error. If the amount in the sample is between 5x and 10x the amount in 

the blank, EPA normally will qualify the sample result as a maximum value because the potential 

contribution from the laboratory could be as high as 20%. Below 5x the amount in the blank, 

EPA considered the field sample result to be a non-detect at the nominal reporting limit. 

 The method blanks for the steroids and hormones presented greater challenges. Three of 

the steroid and hormone analytes, Cholesterol, Stigmasterol, and β-Sitosterol, were frequently 

found in the method blanks, and a fourth analyte, Progesterone, was occasionally found in those 

blanks. During the course of the survey, the laboratory determined that the steroids were 

adhering to the glassware used to prepare samples, perhaps originating from an earlier sewage 

sludge sample prepared in the same glassware. Although the laboratory took steps to improve its 

glassware cleaning procedures to prevent such “carryover,” they were not able to completely 

eliminate the occurrence of some target analytes in the method blanks. 
TNSSS Sampling and Analysis Technical Report 33 January 2009 

 Therefore, EPA flagged the steroids and hormones results, where applicable. Normally, 

EPA evaluates results for samples that have been diluted for analysis by multiplying the blank 

result (which is usually not diluted) by the dilution factor for the sample. For example, if a 

sample extract is diluted by a factor of 50 to bring one or more target analytes within the 

calibration range of the instrument, EPA will multiply the concentration of an analyte found in 

the blank by that dilution factor of 50 before comparing the blank and the field sample results. 

That approach represents a worst-case assumption that the contaminant may be present in the 

solvent used to extract the samples, thus using more of that solvent to dilute the extract would 

add more of the contaminant. 

 In the case of the steroids and hormones, the laboratory checked its reagent water and 

extraction solvents and found no such contamination. As noted above, the laboratory surmised 

that the material in the blanks was being transferred from the surface of the glassware used to 

prepare the blank, but it originated from an earlier sample processed with the same glassware. 

Thus, the amount, or concentration, found in the blank may represent the material that the sample 

extract might pick up from similar glassware, but there would be no likely contribution from the 

solvents themselves, and thus no need to consider the dilution factors of the samples. The 

dilution factors for samples in thus survey often were quite high. 

 Even after instituting this minor change to the data review procedures, there were still 24 

instances in which the levels in the blank led EPA to consider the results for one or more of the 

steroids to be a non-detect. These 24 instances represented 14 field samples, with 1 to 3 analytes 

affected in each of those samples. In many cases, the original result for the field sample was not 

only less than 5x the blank results it was actually 2x to 3x lower than the amount found in the 

blank. Of the 14 affected samples, 5 were in the first batch of 12 samples analyzed and reported. 

The 6 subsequent batches of samples had lower levels of these analytes in the blanks, with 2 

batches having no samples set to non-detects and 2 more batches with only 1 difficult analyte. 

These improved blank results are evidence of the effectiveness of the revised glassware cleaning 

procedures instituted by the laboratory. 

5.4.4 Extract Dilution 

 Surrogate compounds were added to each sample for the semivolatile and PAH analysis 

as a measure of sample extraction efficiency. However, if the sample contained large amounts of 

the target analytes, the laboratory often had to dilute the sample extract to bring the results for 

that analyte within the instrument’s calibration range. If the dilution factor was high enough, the 

surrogates may have been present in the diluted extract at such low levels that they could not be 

detected. Without measurable results for the surrogate, EPA could not evaluate the efficiency of 

the extraction procedures for that sample. 

 An important part of the data review process was to ensure that results for a given sample 

included those where the surrogates could be measured as well as results where all of the 

analytes were within the calibration range. This often requires that the laboratory provide results 

from multiple analyses of the sample at different dilution factors. EPA worked with the 

laboratory analyzing the semivolatiles and PAHs to obtain data from as many analyses as 

practical and minimize situations in which only the most dilute analysis (without observable 

surrogates) was provided. However, the exceptionally high levels of bis (2-Ethylhexyl) 
TNSSS Sampling and Analysis Technical Report 34 January 2009 

phthalate in some samples made the situation more difficult. EPA flagged in the database any 

samples in which the surrogates were diluted out. 

5.4.5 Matrix Spikes 

 Due to the often high and variable levels of many analytes in the samples, some of the 

MS/MSD samples were spiked at levels too low to provide useful recovery data. This issue 

occurred frequently for the anions, metals, semivolatile organics and PAHs. It also was an issue 

for the PBDE analyses when EPA added matrix spike analyses to those analyses to make up for 

the method modifications that eliminated the use of true isotope dilution quantitation (see 

Section 4.4.4). Matrix spike samples were not required for the pharmaceutical, steroid, and 

hormone analyses because those methods use isotope dilution quantitation and therefore provide 

a sample-specific recovery correction of every analyte. 

 The difficulty in generating useful matrix spike results was exacerbated by the different 

approaches to calculating MS/MSD recovery provided in different methods. EPA initially 

qualified the results for samples associated with “under spiked” MS/MSD samples as estimates. 

However, EPA recalculated the recoveries of the spiked analytes using an alternative equation 

designed to address this issue (see Section 6.7) and the bias and precision of the recalculated 

results were further evaluated. 

5.4.6 Interferences 

 All of the methods used in the TNSSS included some form of identification criteria for 

the analytes of interest. These criteria included absorption or emission wavelengths, retention 

times, and mass spectrometric criteria. The GC/HRMS method for the steroids and hormones 

involves monitoring two characteristic ions for each analyte. As with other many EPA 

GC/HRMS methods (e.g., Method 1613B, 1614, and 1668A), the responses for both of those 

ions are used to quantify the concentration of the analyte in the sample, using an approach called 

dual-ion quantitation. 

 The method for the steroids and hormones stipulates that the ratio of the abundances of 

the two ions must be within a certain percentage of the theoretical ratio for the analyte. The 

theoretical ratio is determined from natural abundances of the exact masses of all of the 

component elements that make up both of the ions monitored for the analyte. The acceptance 

criterion in the method for the steroids and hormones is a ± 30% window around the theoretical 

ion abundance ratio for the analyte. 

 The purpose of this criterion is to ensure that the analytes of interest are adequately 

separated from one another and from any potential interfering compounds. As described in the 

method, if the ion abundance ratio is not met, the analyte cannot be positively identified. The 

method instructs the analyst to note any instances where both ions from the analyte are present, 

but the ion abundance ratio acceptance criterion is not met. This approach to reporting results 

allow the data users to decide how best to use the data. 

 
TNSSS Sampling and Analysis Technical Report 35 January 2009 

 The most likely reason that the ion abundance ratio does not meet the acceptance 

criterion is that there is a positive interference for one of the two ions monitored. That positive 

interference increases the response for that ion, affecting the ion abundance ratio (IAR). Because 

the areas (abundances) for the peaks representing the two ions are added together to calculate the 

concentration of the analyte, the positive interference translates into a higher reported 

concentration for the analyte of interest. Thus, the reported result is an estimated maximum 

possible concentration (EMPC) for the analyte. 

 There were 129 instances of EMPCs in the steroid and hormone results out of the total of 

2100 results, or about 6% of all steroid and hormone results. In all, 76 of the 84 survey samples 

had one or more analytes qualified as an EMPC, and 17 of the 25 analytes were affected. The 

frequencies at which EMPCs were reported are shown in Table 9. In some instances, the 

observed ion abundance ratio was only marginally outside of the method acceptance limits, and 

in other instances, the differences were much greater. 

Table 9. Frequency of Estimated Maximum Possible Concentrations (EMPCs) 

Analyte # of EMPCs Reported Analyte # of EMPCs Reported 

Campesterol 50 Androstenedione 3 

Estrone 21 β-Stigmastanol 3 

Testosterone 11 Equilin 3 

Stigmasterol 10 17 α-Dihydroequilin 1 

Ergosterol 6 Androsterone 1 

Desmosterol 5 β-Estradiol 3-benzoate 1 

β-Sitosterol 4 Equilenin 1 

Norethindrone 4 Progesterone 1 

Norgestrel 4 

 The affected analytes include both steroids and hormones, and therefore represent 

separate analytical runs in the method. 

 

 The degree to which the reported results for an EMPC exceed the actual concentration 

cannot be determined exactly because a number of factors are involved, including the effect of 

the interferences and the fact that the results are quantified by isotope dilution. In order to place 

some bounds on the likely effects, EPA examined the survey results for Testosterone in detail. 

The 11 EMPCs for Testosterone have reported concentrations that range from 34.8 to 2040 

μg/kg. The reported ion abundance ratios for these 11 Testosterone results ranged from 0.01 to 

2.34, with the laboratory’s QC acceptance limits for the ratio being 2.38 to 4.42. The lowest ion 

abundance ratio (0.01) was associated with the highest reported result (2040 μg/kg), but there is 

no apparent relationship between the other ratios and results. 

 Although the actual areas of the two peaks monitored for each analyte are presented in 

the hard copy raw data provided by the laboratory, these peak areas are not readily accessible in 

the electronic data. Rather than retrieving several hundred peak areas (2 peaks for each of 129 

EMPCs) from the raw data, entering them into a spreadsheet, and checking for data entry errors, 

EPA took an alternative approach. 

 Although the actual peak areas were not in an accessible electronic format, EPA had the 

ion abundance ratios themselves in the database. In order to investigate the likely effects of the 

interferences, EPA arbitrarily assigned the area of the first peak a value of 10,000 area counts. 
TNSSS Sampling and Analysis Technical Report 36 January 2009 

Using the reported ion abundance ratios, we calculated the corresponding area of the second 

peak. As described in the method, the concentration of an analyte is calculated from the sum of 

the areas of both peaks, so we summed the two “dummy” areas for each sample result. EPA also 

calculated the area of the second peak using the theoretical ion abundance ratio for the analyte 

and summed those two areas. Since the sample concentration is proportional to the sum of the 

areas, we compared the two calculated sums to determine a factor that could be used to convert 

the reported result to the result that might have been calculated without the positive interferences 

that affected the ion abundance ratio. The results for the 11 EMPCs for Testosterone are shown 

in Table 10. 

Table 10. Potential Effects of Ion Abundance Ratio on Reported Concentrations of 

Testosterone 

Sample 

Dummy 

Abundance 

Mass 1 

Reported 

IAR 

Dummy 

Abundance 

Mass 2 

Sum of 

Dummy 

Masses 

Ratio of Sum from 

Reported IAR to that 

from Theoretical IAR 

Reported 

Conc. 

Adjusted 

Conc. 

1 10,000 0.01 1,000,000 1,010,000 0.012813046 2040 26.1 

2 10,000 0.27 37,037 47,037 0.275127374 97.9 26.9 

3 10,000 0.54 18,519 28,519 0.453781513 238 108 

4 10,000 0.55 18,182 28,182 0.459203036 701 322 

5 10,000 0.68 14,706 24,706 0.523809524 46.9 24.6 

6 10,000 1.2 8,333 18,333 0.705882353 65.7 46.4 

7 10,000 1.22 8,197 18,197 0.711181770 42.3 30.1 

8 10,000 1.4 7,143 17,143 0.754901961 122 92.1 

9 10,000 1.99 5,025 15,025 0.861302380 238 205 

10 10,000 2.04 4,902 14,902 0.868421053 34.8 30.2 

11 10,000 2.34 4,274 14,274 0.906657274 67.3 61.0 

 The results in Table 10 are sorted by the reported ion abundance ratios. For ease of 

discussion, the samples addressed in this table were numbered 1 to 11, in order of reported ion 

abundance ratio. The sample numbers have no other significance. As can be seen for Sample 1, 

the potential implications of the ion abundance ratio could be dramatic. However, for many of 

the other samples, the effects are far less apparent. The reported concentrations already include 

the recovery correction inherent in isotope dilution, so the adjusted concentrations include the 

same degree of correction. 

 EPA performed similar calculations for the 50 reported EMPCs for Campesterol. 

Because none of the observed ion abundance ratios were as far from the theoretical ratio for this 

analyte, the overall effects on the reported results were smaller. The applicable conversion 

factors for Campesterol range from 0.173 to 0.907, meaning that the results for this analyte might 

be reduced by factors from 1.1 to 6. Given the time required, EPA did not perform these 

calculations for all the other analytes in which EMPC results were reported by the laboratory. 

Note: The adjusted concentrations shown in Table 10 illustrate the potential change to the 

reported results. However, the calculations shown assume that the ion abundance ratio 

problem is the result of a simple positive interference in one of the two ions for the 

analyte. The actual cause may be more complicated. Therefore, EPA included the 

original results reported by the laboratory in the survey database, not the adjusted 

concentrations described above. EPA flagged each result in the database that did not 

meet the method-specified ion abundance ratio as an “EMPC.” 
TNSSS Sampling and Analysis Technical Report 37 January 2009 

5.4.7 Recovery Issues 

 Three other analytical issues were noted that had significant potential effects on the 

survey data for the pharmaceuticals, steroids, and hormones. EPA identified each such instance 

in the EPA database with the qualifier EXCLUDE to prevent those results from being used to 

determine the national estimates of the concentrations of pollutants in biosolids. 

 Two of those issues involved recoveries of the isotopically labeled analytes used to 

perform isotope dilution quantitation. The third issue involved the “internal standards” added to 

the sample extracts immediately prior to instrumental analyses and used to measure the 

recoveries of the labeled analytes. 

 There were 27 instances where EPA excluded pharmaceutical results from the database, 

involving 15 analytes. For 13 of those analytes, EPA excluded the results for 3 samples because 

the labeled compounds for those analytes were not recovered from the samples. These were not 

simply instances of lower than expected recoveries of the labeled compounds, but rather, no 

recovery at all (zero). The inability to recover the labeled compound spiked into the sample 

suggests a significant analytical problem beyond the routine analytical challenges presented by 

sewage sludge samples. All three samples were extracted on the same date and analyzed 

together several days later. 

 There were two instances where the results for the analyte Fluoxetine were excluded 

because the labeled compound for this analyte was not recovered from those samples. 

 The remaining 12 results were excluded for the analyte Minocycline. All 12 instances 

came from the same extraction batch and were excluded because the laboratory did not recover 

the native (unlabeled) analyte in the laboratory control sample (LCS, also known as an ongoing 

precision and recovery sample, or OPR) that was prepared at the same time as this batch of 12 

samples. The laboratory did not report numerical results for Minocycline in these 12 samples 

and flagged all of the Minocycline results with an “NQ” flag in the database, indicating that the 

laboratory was not able to quantify the analyte. 

 There were 65 instances of steroid and hormone results being excluded from the 

database, involving 14 analytes. In 42 of those instances, involving 7 analytes, the data were 

excluded because the laboratory found only trace levels (e.g., extremely low) of the internal 

standard, Pyrene-d10, added to the sample extract immediately before analysis and used to 

measure the recovery of the labeled compounds added to the sample before extraction. Trace 

levels of the internal standard occurred in 6 samples analyzed in the same batch, suggesting a 

possible problem with the addition of the internal standard (e.g., the automated injection of the 

internal standard may have failed or been incomplete). 

 The remaining 23 excluded results involved 7 other analytes where there was no recovery 

of the labeled compound in the same 6 samples. In these cases, the issue was not simply that the 

recovery could not be measured because of the very low level of the internal standard present, 

but rather that there was no measurable signal for the labeled compound itself. 
TNSSS Sampling and Analysis Technical Report 38 January 2009 

5.5 Revised Results for BDE-209 

 In March 2008, the laboratory that performed the PBDE analyses in 2007 prepared a new 

set of calibration standards for the PBDEs, compared the responses of the new standards to data 

from the standards used for the TNSSS analyses, and found that the results for one of the target 

congeners (BDE-209) were markedly different. The laboratory also compared the results to a 

standard from a second source and found similar differences, ultimately tracing the difference to 

a vial of the original BDE-209 standard that was mislabeled by the manufacturer. 

 After discussions with the laboratory, EPA decided that the BDE-209 results could be 

recalculated based on the responses in the single-point calibration verification standard analyzed 

with each batch of samples and that this recalculation would mathematically adjust the results to 

a more accurate value. This verification standard was prepared from a separate source from the 

initial calibration standards and was not affected by labeling error. The laboratory recalculated 

the BDE-209 results for all 84 field samples and the 2 equipment blanks and resubmitted the 

corrected data in late May 2008. The resubmitted BDE-209 results were reviewed and uploaded 

to the survey database on the EPA mainframe. 
TNSSS Sampling and Analysis Technical Report 39 January 2009 

Section 6 

Survey Results

6.1 Summary Results 

 Table 11 provides a summary of the results for all 84 samples in the first phase (i.e., all 

analytes excluding pharmaceuticals, steroids, and hormones) of the survey, listing the number of 

samples in which each analyte was reported, along with the minimum and maximum 

concentrations. Tables 12 and 13 provide the results for the pharmaceuticals and steroids and 

hormones, respectively. All sample results are reported on a dry-weight basis, based on the 

percent solids in the original sample. The percent solids in the various sewage sludge samples 

range from 0.14 to 94.9. The units for pollutants vary with the class of analyte, as shown. This 

summary includes the results for the six field duplicate samples and the four POTWs that 

generate more than one type of sewage sludge. The minimum concentration is the lowest value 

reported as present in any sample. EPA did not report a minimum or maximum value for those 

analytes that were not detected. That situation only occurred for some of the pharmaceuticals, 

steroids and hormones, and EPA used “NA” to indicate that the minimum and maximum values 

were “not applicable.” 

Table 11. Summary of Results for Metals, Anions, Organics, and PBDEs 

Observed Dry-weight Concentration 

Class Analyte Units # Detects Minimum Maximum 

Solids Percent Solids % 84 0.43 93.5 

Fluoride 84 7.6 234 

Nitrate/Nitrite 84 1.6 6,120 

Water-extractable phosphorus 

mg/kg 

84 11.0 9,550 Anions 

WEP ratio unitless 84 0.00065 0.33920 

Aluminum 84 1400 57,300 

Antimony 72 0.45 26.6 

Arsenic* 84 1.18 49.2 

Barium 84 75.1 3,460 

Beryllium 83 0.04 2.3 

Boron 80 5.70 204.0 

Cadmium* 84 0.21 11.8 

Calcium 84 9,480 311,000 

Chromium* 84 6.74 1160 

Cobalt 84 0.87 290 

Copper* 84 115 2,580 

Iron 84 1,575 299,000 

Lead* 84 5.81 450 

Magnesium 84 696 18,400 

Manganese 84 34.8 14,900 

Mercury* 84 0.17 8.3 

Molybdenum* 84 2.51 132 

Nickel 84 7.44 526 

Phosphorus 84 2,620 118,000 

Selenium* 84 1.10 24.7 

Silver 84 1.94 856 

Sodium 84 154 26,600 

Thallium 80 0.02 1.7 

Tin 78 7.50 522 

Titanium 83 18.50 7,020 

Vanadium 84 2.04 617 

Yttrium 84 0.70 26.3 

Metals 

Zinc* 

mg/kg 

84 216 8,550 
TNSSS Sampling and Analysis Technical Report 40 January 2009 

Table 11. Summary of Results for Metals, Anions, Organics, and PBDEs 

Observed Dry-weight Concentration 

Class Analyte Units # Detects Minimum Maximum 

4-Chloroaniline 63 51 5,900 

2-Methylnaphthalene 39 10 4,600 

Fluoranthene 77 45 12,000 

Pyrene 72 44 14,000 

bis (2-Ethylhexyl) phthalate 84 657 310,000 

Organics 

(PAHs and 

Semivolatiles) 

Benzo(a)pyrene 

g/kg 

64 63 4,500 

BDE-28 84 2,200 160,000 

BDE-47 84 73,000 5,000,000 

BDE-66 84 1,800 110,000 

BDE-85 84 3,200 150,000 

BDE-99 84 64,000 4,000,000 

BDE-100 84 13,000 1,100,000 

BDE-138 56 1,900 40,000 

BDE-153 84 9,100 410,000 

BDE-154 84 7,700 440,000 

BDE-183 84 2,100 120,000 

PBDEs 

BDE-209 

ng/kg 

83 150,000 17,000,000 

* Metals currently regulated at 40 CFR 503 

Table 12. Summary of Results for Pharmaceuticals 

Observed Dry-weight Concentration 

Analyte Units # Detects Minimum Maximum 

Percent Solids % 84 0.14 94.9 

Acetaminophen 2 1,120 1,300 

Albuterol 1 23.2 23.2 

Anhydrochlortetracycline 1 125 125 

Anhydrotetracycline 52 94.3 1,960 

Azithromycin 80 10.2 6,530 

Caffeine 39 65.1 1,110 

Carbadox 0 NA NA 

Carbamazepine 80 8.74 6,030 

Cefotaxime 0 NA NA 

Chlortetracycline 1 1,010 1,010 

Cimetidine 74 7.59 9,780 

Ciprofloxacin 84 74.5 47,500 

Clarithromycin 45 8.68 617 

Clinafloxacin 0 NA NA 

Cloxacillin 0 NA NA 

Codeine 20 9.59 328 

Cotinine 39 11.4 690 

Dehydronifedipine 19 3.48 24.6 

Demeclocycline 3 96 200 

Digoxigenin 0 NA NA 

Digoxin 0 NA NA 

1,7-Dimethylxanthine 4 1,130 9,580 

Diltiazem 69 1.39 225 

Diphenhydramine 84 36.7 5,730 

Doxycycline 76 50.8 5,090 

Enrofloxacin 14 12.1 66 

4-Epianhydrochlortetracycline 0 NA NA 

4-Epianhydrotetracycline 31 126 2,160 

4-Epichlortetracycline 1 974 974 

4-Epioxytetracycline 8 35.7 54.9 

4-Epitetracycline 80 47.2 4,380 

Erythromycin-total 77 3.1 180 

Flumequine 0 NA NA 

Fluoxetine 

μg/kg 

79 12.4 3,130 

Gemfibrozil μg/kg 76 12.1 2,650 
TNSSS Sampling and Analysis Technical Report 41 January 2009 

Table 12. Summary of Results for Pharmaceuticals 

Observed Dry-weight Concentration 

Analyte Units # Detects Minimum Maximum 

Ibuprofen 54 99.5 11,900 

Isochlortetracycline 1 3,140 3,140 

Lincomycin 3 13.9 33.4 

Lomefloxacin 2 33.3 39.8 

Metformin 6 550 1,160 

Miconazole 80 14.2 9,210 

Minocycline 32 351 8,650 

Naproxen 44 20.9 1,020 

Norfloxacin 29 99.3 1,290 

Norgestimate 0 NA NA 

Ofloxacin 83 73.9 58,100 

Ormetoprim 1 5.91 5.91 

Oxacillin 0 NA NA 

Oxolinic Acid 1 39.4 39.4 

Oxytetracycline 29 18.6 467 

Penicillin G 0 NA NA 

Penicillin V 0 NA NA 

Ranitidine 46 3.83 2,250 

Roxithromycin 3 14.3 22.8 

Sarafloxacin 2 179 1,980 

Sulfachloropyridazine 2 35.9 58.7 

Sulfadiazine 3 22.9 140 

Sulfadimethoxine 5 3.58 62.2 

Sulfamerazine 1 5.61 5.61 

Sulfamethazine 2 21.5 23.2 

Sulfamethizole 0 NA NA 

Sulfamethoxazole 30 3.91 651 

Sulfanilamide 8 191 15,600 

Sulfathiazole 1 21 21 

Tetracycline 81 38.3 5,270 

Thiabendazole 58 8.42 239 

Triclocarban 84 187 441,000 

Triclosan 79 430 133,000 

Trimethoprim 24 12.4 204 

Tylosin 0 NA NA 

Virginiamycin 15 43.5 469 

Warfarin 0 NA NA 

NA = Not applicable, because the analyte was not reported in any sample 

Table 13. Summary of Results for Steroids and Hormones 

Observed Dry-weight Concentration 

Analyte Units # Detects Minimum Maximum 

Percent Solids % 84 0.14 94.9 

Androstenedione 32 108 1,520 

Androsterone 50 21.3 1,030 

Campesterol 84 2,840 524,000 

Cholestanol 84 3,860 4,590,000 

Cholesterol 81 18,700 5,390,000 

Coprostanol 84 7,720 43,700,000 

Desmosterol 58 2,730 94,400 

17 α-Dihydroequilin 1 98.4 98.4 

Epicoprostanol 83 868 6,030,000 

Equilenin 1 60.6 60.6 

Equilin 

μg/kg 

15 22.3 107 

Ergosterol 53 4,530 91,900 

17 α-Estradiol 

μg/kg 

5 16.1 48.8 
TNSSS Sampling and Analysis Technical Report 42 January 2009 

Table 13. Summary of Results for Steroids and Hormones 

Observed Dry-weight Concentration 

Analyte Units # Detects Minimum Maximum 

17 β-Estradiol 11 22 355 

β-Estradiol 3-benzoate 18 30.2 1850 

17 α-Ethinyl-estradiol 0 NA NA 

Estriol 18 7.56 232 

Estrone 60 26.7 965 

Norethindrone 5 21 1,360 

Norgestrel 4 43.8 1,300 

Progesterone 19 143 1,290 

β-Sitosterol 73 24,400 1,640,000 

β-Stigmastanol 83 3,440 1,330,000 

Stigmasterol 76 11,000 806,000 

Testosterone 17 30.8 2,040 

NA = Not applicable, because the analyte was not reported in any sample 

6.2 Investigation of Results for Metals 

 After compiling the results from the first phase of the survey, EPA investigated the 

potential causes for the maximum results for calcium, iron, phosphorus, and silver. By 

reviewing the sampler’s field notes and ultimately contacting the POTWs by telephone, EPA 

found that: 

 The maximum result for calcium (311,000 mg/kg) was for a sample of Class A sewage 

sludge produced by a process known as advanced alkaline stabilization with subsequent 

drying. The alkaline stabilization process involves addition of large amounts of lime 

(calcium carbonate) to the material. The final sewage sludge is sold as a soil amendment. 

 The maximum concentrations of iron (299,000 mg/kg) and elemental phosphorus 

(118,000 mg/kg) occurred in the same sample. The facility from which this sample was 

collected adds ferric chloride during its wastewater treatment process to reduce the level 

of phosphorus in its effluent discharge. This treatment step results in high levels of iron 

and phosphorus in the sewage sludge from this plant. 

 The maximum result for silver (856 mg/kg) occurred in a sewage sludge sample from a 

POTW that employs a “complete mix activated sewage sludge process” and disposes of 

its sewage sludge by incineration. There are two major industrial dischargers to this 

POTW, but neither employs silver. The plant is not aware of any other instances of high 

silver results in their sewage sludge. There were no apparent calculation or transcription 

errors. The laboratory noted that this result was determined by ICP/MS, and when the 

laboratory re-examined its result for the ICP/AES analysis of the same sample, silver was 

present in that analysis at about 900 mg/kg, thus seemingly confirming the ICP/MS 

results. 
TNSSS Sampling and Analysis Technical Report 43 January 2009 

6.3 Comparison of Metals Results to Current Standards 

 As noted in Section 1 of this report, the sewage sludge regulations at Part 503 include 

standards for land application of nine metals. These standards are based on the dry-weight 

concentrations. Table 14 illustrates the maximum results from this survey for the nine metals. 

Table 14. Comparison of Survey Maximums to Existing Regulatory Limits 

Dry-Weight Concentration in mg/kg 

Pollutant Land application ceiling Survey Maximum

Number of TNSSS Results 

Over Ceiling

Arsenic 75 49.2 0

Cadmium 85 11.8 0

Copper 4,300 2,580 0

Lead 840 450 0

Mercury 57 8.3 0

Molybdenum 75 132 2

Nickel 420 526 3

Selenium 100 24.7 0

Zinc 7,500 8,550 1

 Maximum results that exceed the land application ceiling are shown in bold.

Note: It is critical to note that the selection of facilities to be sampled in this survey was not

based on whether they managed their sewage sludge by land application, nor was a goal 

of this survey to assess compliance. In fact, a number of the facilities disposed of their 

sewage sludge by incineration or placement in a landfill, and those facilities need not 

meet the ceiling concentrations shown in Table 14. 

 As shown in bold in Table 14, three metals had observed concentrations in this survey 

that exceeded the land application ceiling concentrations (molybdenum, nickel, and zinc). The 

maximum observed concentrations for all other regulated metals were below the land application 

ceiling concentrations. 

 Five samples in this survey, collected from four facilities, contained metals that exceeded 

the land application limits (two of those samples were a pair of field duplicates collected from 

one facility). One sample exceeded the limits for both molybdenum and nickel. Of the four 

facilities involved, one incinerates its sewage sludge on site and the other three send their sewage 

sludge to landfills. None of the facilities that actually dispose of their sewage sludge by land 

application exceeded the limits. 

6.4 Analytical Completeness 

 “Completeness” is a quality assurance measure of the number of samples collected 

compared to the number of useable results produced. Although the laboratories experienced a 

number of difficulties with the samples from this survey and not all of the results met all of the 

acceptance criteria in the applicable analytical methods, laboratories made acceptable efforts to 

overcome these challenges and adequately document any QC issues encountered. In all cases 

laboratories provided acceptable documentation for every sample in the survey. 
TNSSS Sampling and Analysis Technical Report 44 January 2009 

6.5 Analytical Sensitivity 

 As noted earlier in this report, the two previous national sewage sludge surveys 

experienced analytical sensitivity challenges for some analytes. This was largely due to the coextracted interferences present in the challenging matrix and the wide variation in the solids 

content of treated sewage sludge disposed of nationwide. EPA designed the TNSSS for practical 

analytical sensitivity, taking the steps outlined in Section 4 to ensure that the results were directly 

comparable across facilities in the survey. 

 Table 7 lists the target reporting limits for all classes of analytes in the survey. Those 

targets were based on EPA’s decision of what was practical in sewage sludge. The anions were 

found in every sample and all but six metals were found in the 100 percent of the survey samples 

(see Table 11). Thus, sensitivity is not a concern. Therefore, the focus of analytical sensitivity is 

on the actual reporting limits for the other analyte classes and on the metals that were not found 

in every sample (i.e., antimony, beryllium, boron, thallium, tin, and titanium). Table 15 provides 

a comparison of those target limits with the actual reporting limits. 

Table 15. Analytical Sensitivity 

Analyte Class Target Reporting Limit (dry weight) Actual Reporting Limit for Non Detects 

Antimony 0.05 mg/kg

Beryllium 0.02 mg/kg

Boron 5 mg/kg

Thallium 0.02 mg/kg

Tin 5 mg/kg

Metals 3 to 4 mg/kg 

Titanium 2 mg/kg

4-Chloroaniline 

2-Methylnaphthalene 

Fluoranthene 

Pyrene 

Benzo(a)pyrene 

10 μg/kg

(by SIM)

PAHs and 

semivolatiles 100 to 300 μg/kg 

bis (2-Ethylhexyl) phthalate NA

PBDEs 5 to 200 ng/kg BDE 138 5000 ng/kg

Anions 2 to 8 mg/kg All anions detected in all samples NA

NA = Not applicable, analyte reported in all samples in the survey 

 As can be seen in Table 15, the laboratories not only met, but far exceeded, the majority 

of the sensitivity targets. The reporting limits for boron and tin were only slightly higher than 

the target range. Four of the six samples in which tin was not reported include situations where 

the results for tin in the samples and their associated method blank differed by less than a factor 

of five. As part of the data review process described in Section 5, the tin results were reset in 

those four samples to non-detects at the nominal reporting level. 

 Bis (2-Ethylhexyl) phthalate is a common laboratory contaminant and EPA reviewed the 

results for all of the method blanks to ensure that the laboratory was not the source of the bis (2-

Ethylhexyl) phthalate in the samples. Although the laboratory reported bis (2-Ethylhexyl) 

phthalate in many of the method blanks for organics, the levels in the samples are two to four 

orders of magnitude higher than the levels in the blanks, indicating that sensitivity was not an 

issue. 

 The reporting limits for the other five organics were well below the target range using the 

selected ion monitoring modifications described in Section 4. The full-scan GC/MS results 
TNSSS Sampling and Analysis Technical Report 45 January 2009 

included in the database are for samples in which the majority of the analytes were present above 

the original target reporting limits in Table 11, thus sensitivity was not an issue for those 

samples. 

 All of the PBDE congeners except BDE-138 and BDE-209 were detected in all of the 

survey samples, often at high levels relative to the calibration range of the method. There was 

only one non-detect for BDE-209. BDE-138 was not detected in 30 of the survey samples with 

the reporting limit of 5,000 ng/kg. That reporting limit is significantly higher than the original 

target, but reflects the need to adjust the sample size and extract dilution to accommodate the 

very high levels of the other congeners that the laboratory reported in the survey samples, which 

were often 10 to 20 times higher than the BDE-138 concentrations. Therefore, sensitivity was 

not a significant issue for the PBDE analyses.

 Because the methods for the pharmaceuticals, steroids, and hormones were under 

development at the time the TNSSS began, EPA did not set any goals for sensitivity for these 

analytes. The reporting limits are based on the “Minimum Levels” in the methods, which were 

not optimized for the analysis of sewage sludge samples, but apply to all solid matrices. The 

Minimum Level is the concentration in the sample that is equivalent to the concentration of the 

lowest calibration standard analyzed by the laboratory. When used as a reporting limit, that 

value is adjusted for the nominal sample size and the moisture content of the sample (i.e., it is a 

dry-weight concentration). The advantage of the approach used for the TNSSS to ensure 

consistent sensitivity is that the reporting limit for each analyte was the essentially the same for 

all the samples, regardless of the moisture content of the original sample. 

 The Minimum Levels for the 72 pharmaceuticals vary by analyte, and range from 2 μg/kg 

for analytes such as Albuterol, Digoxin, and Erythromycin, to 1,000 μg/kg for 1,7-Dimethylxanthine. The Minimum Levels for the steroids and hormones ranged from 21 μg/kg for 

Testosterone, to 2,500 μg/kg for Cholesterol. Table 16 presents the Minimum Levels for the 

pharmaceuticals and Table 17 presents the Minimum Levels for the steroids and hormones. 
TNSSS Sampling and Analysis Technical Report 46 January 2009 

Table 16. Minimum Levels for the Pharmaceuticals

Minimum Level μg/kg (dry-weight) 

2 4 10 20 

Albuterol 

Digoxin 

Diltiazem 

Erythromycin-total 

Roxithromycin 

Sulfadimethoxine 

Cimetidine 

Dehydronifedipine 

Diphenhydramine 

Ormetoprim 

Oxolinic Acid 

Ranitidine 

Sulfamerazine 

Sulfamethazine 

Sulfamethizole 

Sulfamethoxazole 

Azithromycin 

Carbadox 

Carbamazepine 

Clarithromycin 

Cotinine 

Flumequine 

Fluoxetine 

Gemfibrozil 

Miconazole 

Ofloxacin 

Sulfachloropyridazine 

Sulfadiazine 

Sulfathiazole 

Thiabendazole 

Trimethoprim 

Warfarin 

Cloxacillin 

Codeine 

Enrofloxacin 

Lincomycin 

Lomefloxacin 

Naproxen 

Norgestimate 

Oxacillin 

Penicillin G 

Triclocarban 

Minimum Level μg/kg (dry-weight) 

40 100 400 1,000 

Ciprofloxacin* 

4-Epioxytetracycline 

4-Epitetracycline 

Cefotaxime 

Chlortetracycline 

Clinafloxacin 

Doxycycline 

Isochlortetracycline 

Oxytetracycline 

Penicillin V 

Tetracycline 

Tylosin 

Sarafloxacin† 

4-Epianhydrotetracycline 

4-Epichlortetracycline 

Anhydrochlortetracycline 

Anhydrotetracycline 

Caffeine 

Demeclocycline 

Digoxigenin 

Ibuprofen 

Norfloxacin 

Sulfanilamide 

Metformin▲

4-Epianhydrochlortetracycline 

Acetaminophen 

Minocycline 

Triclosan 

1,7-Dimethylxanthine 

There were 3 analytes with unique MLs. They were grouped with other analytes in this table for simplicity. The actual MLs are

shown below. 

* Actual ML = 35 μg/kg 

† Actual ML = 91 μg/kg 

▲ Actual ML = 200 μg/kg

Table 17. Minimum Levels for the Steroids and Hormones 

Minimum Level μg/kg (dry-weight) 

21 42 104 

17 α-Dihydroequilin 

17 α-Estradiol 

17 α-Ethinyl-estradiol 

17 β-Estradiol 

Androsterone 

Equilenin 

Equilin 

Estriol 

Estrone 

Norethindrone 

Testosterone 

β-Estradiol 3-benzoate 

Norgestrel Androstenedione 

Progesterone 

Minimum Level μg/kg (dry-weight)

500 1,500 2,500 

Campesterol 

Cholestanol 

Coprostanol 

Epicoprostanol 

Stigmasterol 

β-Sitosterol 

β-Stigmastanol 

Cholesterol 

Desmosterol 

Ergosterol 
TNSSS Sampling and Analysis Technical Report 47 January 2009 

 There were 15 pharmaceuticals and 1 hormone that were not detected in any sample. 

EPA examined the supporting QC data, such as the OPR samples and labeled compound 

recoveries, looking for indications of methodological issues. 

 There were several pharmaceutical analytes that exhibited occasional low recoveries in 

an OPR aliquot, no recoveries in an OPR aliquot, or low labeled compound recoveries in a 

sample. For example, 1,7-Dimethylxanthine was only found in 4 samples, and there were 12 

samples (prepared in one batch) that were associated with an OPR aliquot with low recovery of 

this analyte. The other 72 samples were analyzed in 6 other batches associated with acceptable 

OPR recoveries for 1,7-Dimethylxanthine. 

 There were 13 results for Warfarin where the sample exhibited low labeled compound 

recovery and EPA qualified the non-detect results for the analyte. There were no issues with 

labeled compound recoveries or OPR recoveries for Warfarin in the other 71 samples in the 

survey. Therefore, EPA does not believe that the fact that Warfarin was not detected in any 

sample is an indication of a methodological challenge (i.e., that the method did not work). 

Rather, it may be related to method sensitivity or breakdown of this analyte during sewage 

treatment. 

 For the steroids and hormones, 17 α-Ethinyl-Estradiol was the one analyte that was not 

reported in any sample. EPA noted four instances where the labeled compound associated with 

this analyte was not recovered at all, leading EPA to exclude those four non-detect results from 

the survey database. In three other instances, EPA noted that the recovery of the labeled 

compound was low, but there was some recovery. However, EPA did not note OPR issues for 

this analyte, which suggests that in those specific samples there may be issues associated with 

the specific biosolids samples being analyzed rather than pervasive analytical problems. 

6.6 Equipment Blank Evaluation 

 Equipment blanks were prepared as described in Section 3.11 in each of the laboratories 

that analyzed sewage sludge samples in the first phase of the TNSSS. Equipment blanks were 

prepared for anions, metals, semivolatile organics and PAHs, and PBDEs. Equipment blanks 

were not prepared for the pharmaceuticals, steroids, and hormones in the second phase of the 

TNSSS. 

 EPA evaluated the results for the equipment blanks by comparing them to their 

associated method blanks and to the sample results. This was done to determine if any analytes 

of concern were present at levels that might affect EPA’s use of the data. 

6.6.1 Semivolatile Organics and PAHs 

 For semivolatile organics and PAHs, the laboratory reported only one target analyte in 

either equipment blank, BEHP, at a concentration of 10 g/kg, based on a nominal 10-g sample 

weight. However, BEHP is a common laboratory contaminant and the method blank associated 

with both equipment blanks was reported to contain 11 g/kg. In addition, all of the field sample 

results for BEHP were orders of magnitude higher than either the method blank or equipment 

blank results, ranging from 657 to 310,000 g/kg. Therefore, there is no evidence that the 

compositing equipment contributed BEHP to any of the field samples. 
TNSSS Sampling and Analysis Technical Report 48 January 2009 

6.6.2 Metals 

 The laboratory reported low concentrations of eight elements in the two equipment 

blanks. Table 18 presents the results for the two equipment blanks. The reported concentrations 

are based on the nominal 1-g dry-weight aliquot used for the field samples. The laboratory 

reported all other metals as non-detects in the two equipment blanks. 

 The concentrations of some of the metals in the equipment blanks exceeded the 

concentrations in the associated method blank, although in some instances only marginally. For 

example, the laboratory reported nickel in the method blank at 0.05 mg/kg, and at 0.1 mg/kg in 

one equipment blank, but nickel was not detected in the other equipment blank. The laboratory 

reported lead in one equipment blank at 0.03 mg/kg, which is only marginally above the 

laboratory’s reported detection limit of 0.02 mg/kg for lead, and lead was not detected in the 

other equipment blank. Therefore, the equipment blank results are not unexpected, or of 

significant concern. 

Table 18. Equipment Blank Metal Results 

Concentration (mg/kg) 

Analyte Equipment Blank 1 Equipment Blank 2 

Barium 27.2 27.9 

Calcium 26.9 22.3 

Copper 1.33 1.56 

Lead 0.03 ND 

Magnesium 2.8 2.1 

Manganese 0.07 ND 

Nickel 0.1 ND 

Zinc 3.3 6.7 

ND = not detected 

 The concentrations in the field samples generally were several orders of magnitude 

higher than those in the equipment blanks (see Table 11). However, EPA took a conservative 

approach to evaluating the potential impact of the equipment blanks. EPA compared the results 

for each analyte in each of the solid samples against the results for both equipment blanks and 

flagged in the database any solid sample result that was not at least five times higher than the 

result in either of the two equipment blanks. 

 Barium was the only metal analyte affected, with the results in four solid sewage sludge 

samples less than five times the results in the equipment blanks (27.2 and 27.9 mg/kg, 

respectively). Those results are shown in Table 19. The value of 5 is a multiplier that is often 

used for the evaluation of blanks. It indicates that the amount of contaminant in the equipment 

blank might account for 20% or more of a given field sample result. 

Table 19. Comparison of Sample Results and Equipment Blank Results for Barium 

Ratio of Sample Result to Equipment Blank Result 

Sample Result (mg/kg Sample/Equipment Blank 1 Sample/Equipment Blank 2 

68320 128 4.7 4.6 

68343 75.1 2.8 2.7 

68344 78.6 2.9 2.8 

68393 134 4.9 4.8 
TNSSS Sampling and Analysis Technical Report 49 January 2009 

 The fact that the results for these four samples are less than five times the equipment 

blank results is not clear evidence that any portion of the barium in the samples was actually 

derived from the sampling equipment. As noted in Section 3, equipment blanks for solids are 

conceptually different than those for aqueous samples and sampling equipment. In the 2001 

NSSS, equipment blanks were prepared by placing wet sand in the compositing bowls used for 

collecting samples. Aliquots of the sand had been analyzed for dioxins, furans, and PCBs and 

the sand was found to be free of these analytes, so it could be mixed with reagent water to 

simulate wet sewage sludge. Equipment blanks prepared in that manner in the 2001 survey 

demonstrated that the stainless steel equipment used to collect samples did not contribute any 

dioxins, furans, or PCBs. 

 In this survey, sand could not be used for equipment blanks because it contains metals. 

No readily available solid reference material is free of metals and resembles sewage sludge, so it 

was not practical to prepare equipment blanks for solids that mimic the way that the sample 

comes in contact with the sampling equipment. 

6.6.3 PBDEs 

 The laboratory did not detect any of the PBDE congeners in the two equipment blanks 

above their nominal reporting limits. The reporting limits for these blanks ranged from about 

100 ng/kg to 20,000 ng/kg, for the various congeners, based on a nominal sample size of 10 g. 

However, because the sample size for the field samples was reduced to 0.2 g, EPA examined the 

equipment blank in greater detail. In addition to using reporting limits that were based on the 

low-point of the instrument calibration, the laboratory estimated the signal-to-noise based 

detection limits for each analyte in each sample. Those estimated detection limits were markedly 

lower than the nominal reporting limits (e.g., 1 ng/kg versus 100 ng/kg). The low levels of 

PBDEs detected in the equipment blanks were similar to those reported in the method blanks, 

indicating that the sampling equipment did not contribute additional PBDEs to the samples. 

6.6.4 Anions 

 The equipment blanks for the anions analysis contained low levels of fluoride and 

nitrate/nitrite. The results for both analytes in both equipment blanks were below the 

laboratory’s reporting limits, but above their detection limits, and the laboratory reported the 

results as “estimated.” Neither analyte was detected in the method blanks associated with the 

equipment blanks or the field samples. Table 20 presents the results for the anions in the two 

equipment blanks. 

Table 20. Equipment Blank Anion Results 

Concentration (mg/kg) 

Analyte Equipment Blank 1 Equipment Blank 2 

Nitrate/Nitrite 5.2 1.9 

Fluoride 11 18 

 
TNSSS Sampling and Analysis Technical Report 50 January 2009 

 The equipment blank results for water-extractable nitrate/nitrite are two to five times 

lower than the laboratory’s nominal reporting limit. The concentration of water-extractable 

nitrate/nitrite in the field samples ranges from 1.6 mg/kg to more than 6,100 mg/kg. Of 41 

sewage sludge samples that contained less than 10 mg/kg of nitrate/nitrite, 29 of those are solid 

samples that came in contact with the plastic sampling equipment. However, the other 12 

samples with less than 10 mg/kg nitrate/nitrite are liquid sewage sludge that was never in contact 

with the equipment. Because of this, EPA concluded that nitrate/nitrite levels observed in blanks 

were acceptable for the purposes of this report. 

 Fluoride is added to drinking water by many municipal water systems for its dental decay 

prevention benefits. It also is present in toothpastes and mouthwashes that are rinsed down the 

drain after use. Fluoride is soluble in water, which is, in fact, the basis of the analytical results 

for this survey, as the samples were leached with reagent water as described in Appendix A, and 

the leachate was analyzed for all of the anions. Figure 2 is a plot of the fluoride concentrations 

versus the percent solids in each survey sample. 

 Water is removed from sewage sludge by a variety of means, including several types of 

presses, centrifugation, and air drying. Given the solubility of fluoride, one would expect that 

water removed by mechanical means such as presses and centrifugation would take some portion 

of fluoride with it, leaving the solids with lower concentrations then at the start of the water 

removal process. 

Figure 2. Plot of Fluoride Concentration versus Percent Solids 

 
TNSSS Sampling and Analysis Technical Report 51 January 2009 

As can be seen in Figure 2, there is an inverse relationship between solids and fluoride in these 

samples, with most of the highest fluoride concentrations in the samples with the lowest solids 

contents. 

Note: All of the fluoride results are reported on a dry-weight basis in this survey, so the results 

are directly comparable across samples with different percent solids. 

 The presence of fluoride in the two equipment blanks may indicate that the reagent water 

rinse did not remove some of the fluoride in the tap water used to wash the equipment. As with 

the nitrate/nitrite results, the amounts of fluoride reported in the two equipment blanks are 2 to 4 

times lower than the laboratory’s reporting limits. EPA treated the fluoride results in the field 

samples in the same fashion described above for nitrate/nitrite, flagging any results in solid 

samples less than five times the higher equipment blank result as an estimate, but retained the 

data in the database. A total of 62 fluoride results for solid samples were flagged in the database. 

However, there also were 12 liquid samples with fluoride concentrations in that same range of up 

to five times the higher equipment blank result. These samples never contacted the sampling 

equipment, so the fluoride in them cannot be attributed to the equipment. 

 

 As noted in Section 3, the sampler mixed a large quantity of sewage sludge in each 

plastic bowl, and only placed a portion of that material in jars for analysis. The moisture in the 

original sewage sludge samples was not free flowing for the solid samples, thus it would not 

contact the surfaces of the equipment in the same way that the reagent water used to prepare the 

anions equipment blank did. EPA does not believe that the qualifiers applied to these results 

significantly compromise data usability. 

6.7 Field Duplicate Results 

 As part of the quality assurance effort, EPA collected field duplicate samples to assess 

the overall precision of the sampling and analysis approach for the survey. Of the 80 facilities 

originally selected for sampling, 8 were chosen at random for collection of a field duplicate. As 

described in Section 3, two of those facilities were not sampled and not replaced, and one other 

field duplicate was collected at a different plant than originally planned. 

 The tables in this section present the relative percent differences (RPDs) between the two 

results in each of the six pairs of field duplicate samples, for each analytical class. The RPD is 

used as the measure of precision because both results from the pair are measured concentrations 

and there is no “true” concentration to be used in the comparison. The formula for RPD is 

shown below where Result 1 and Result 2 represent the concentrations reported in the two 

samples in each pair. The vertical bars in the numerator indicate it is the absolute value of the 

difference, and the factor of 100 converts the value to a percentage. 

 In cases where both of the results in a field duplicate pair were non-detects, there was 

little point in comparing the sample-specific reporting limits. EPA indicated these instances with 

ND, for “not detected.” When only one of the results in a field duplicate pair was a non-detect, 

EPA did not calculate the RPD and indicated these instances with NC, for “not calculated.” 

100

2

2)Result1(Result

2Result1Result

RPD 



 
TNSSS Sampling and Analysis Technical Report 52 January 2009 

 EPA did not establish a formal acceptance limit for the RPD of field duplicates in this 

project. However, 50% is often used as a default limit that reflects the sum of the anticipated 

analytical variability and the variability in the sample collection process. 

6.7.1 Anions 

 Table 21 summarizes the field duplicate results for the anions. The majority of the RPD 

values for the anions are less than 20%, and are well within the expected variability of 

laboratory duplicate analyses. Using the default limit of 50% for field duplicates, the 16 of 24 

observed RPD values in Table 21 that are below 20% indicate better than anticipated results for 

these QC samples. 

Table 21. Comparison of Field Duplicate Results for Anions 

Relative Percent Difference (%) 

Analyte Pair 1 Pair 2 Pair 3 Pair 4 Pair 5 Pair 6 

Fluoride 11.9 18.3 8.0 35.1 8.1 3.6 

Nitrate/Nitrite 19.0 17.1 16.1 15.7 2.2 36.2 

Water-Extractable Phosphorus 84.3 26.0 33.4 39.5 9.0 20.5 

Total Solids 8.1 0.2 0.8 58.7 0.9 1.0 

 The RPD values above 20% occur primarily for the water-extractable phosphorus (WEP) 

and most of the analytes in Pair 4. The WEP results are more variable than those for fluoride or 

nitrate/nitrite. All three analytes are extracted from the sewage sludge at the same time using the 

same leaching procedure. The WEP differences between some of the duplicate pairs may simply 

be due to variability. 

 Field duplicate Pair 4 exhibited large RPD values for the anions and all other analytes 

(see Tables 21 – 26). EPA examined the sample collection information and found that this was a 

liquid sewage sludge collected from a large storage tank. Because of safety concerns at the 

facility, the sampler observed as one of the facility staff opened a series of valves, flushed liquid 

sewage sludge through the piping, and collected each aliquot of the first sample, then collected 

the second sample. The percent solids results for these two samples are 1.85% and 1.01% in the 

aliquots use for the anions analyses. However, the percent solids in the aliquots used for the 

metals analyses are 4.27% and 1.01%, while the aliquots for the organics are 0.61% and 3.2% 

respectively. These data for total solids suggest that liquid sewage sludge was not particularly 

homogeneous and the sampling procedures used for this facility did not result in true duplicate 

samples. 

6.7.2 Metals 

 Table 22 presents the field duplicate results for the metals. The majority of the RPD 

values for the metals (125 of 174) are less than 20%, and 135 RPD values are less than 30%. As 

with the anions, results for field duplicate Pair 4 are markedly higher than the other five pairs. 
TNSSS Sampling and Analysis Technical Report 53 January 2009 

Table 22. Comparison of Field Duplicate Results for Metals 

Relative Percent Difference (%) 

Analyte Pair 1 Pair 2 Pair 3 Pair 4 Pair 5 Pair 6 

Aluminum 0.0 1.3 4.2 100.5 7.7 0.7 

Antimony ND 3.6 3.0 97.5 19.3 2.3 

Arsenic 6.2 0.0 4.5 109.2 30.8 7.3 

Barium 4.1 59.8 4.6 100.7 10.8 1.5 

Beryllium 0.0 3.6 0.0 83.3 25.0 7.4 

Boron 13.7 2.9 1.6 115.1 12.6 0.1 

Cadmium 7.1 1.7 3.7 106.1 31.5 7.3 

Calcium 4.3 1.9 2.5 112.2 11.2 1.5 

Chromium 7.5 6.8 27.9 120.3 29.4 0.9 

Cobalt 2.7 0.2 4.6 110.4 22.4 9.1 

Copper 3.4 1.7 5.4 100.7 10.3 2.9 

Iron 4.7 3.6 2.5 106.5 9.6 0.6 

Lead 7.1 0.6 3.9 105.4 30.5 8.5 

Magnesium 10.5 0.7 4.9 112.5 8.5 1.2 

Manganese 4.8 5.4 3.1 105.8 12.1 1.0 

Mercury 25.6 95.3 2.7 89.5 11.8 7.1 

Molybdenum 9.1 5.0 0.5 112.6 31.2 8.4 

Nickel 5.1 3.3 4.3 107.9 27.7 11.4 

Phosphorus 4.7 0.6 4.3 106.1 11.0 0.6 

Selenium 2.7 1.1 12.5 118.7 31.3 9.8 

Silver 5.0 1.8 10.2 95.4 8.8 16.9 

Sodium 1.6 41.8 4.2 121.6 5.2 3.2 

Thallium 6.1 3.1 0.0 112.5 41.4 0.0 

Tin 6.6 0.5 ND 94.1 9.3 23.5 

Titanium 9.9 3.9 27.2 96.8 4.6 16.2 

Vanadium 8.3 4.1 3.6 100.7 28.6 8.7 

Yttrium 8.1 1.6 4.3 107.5 28.0 8.2 

Zinc 4.6 1.6 5.4 106.5 10.7 1.5 

Total Solids 0.4 1.2 0.4 123.5 2.7 1.0 

ND = not detected in either sample in the duplicate pair 

6.7.3 Semivolatile Organics and PAHs 

 Table 23 presents the field duplicate results for the semivolatile organics and PAHs. A 

total of 29 of 42 RPDs are less than 20% and 31 of 42 RPDs are less than 50%. The issues with 

Pair 4 are apparent in the organics data as well (see Section 6.7.7). 

Table 23. Comparison of Field Duplicate Results for Semivolatile Organics and PAHs 

Relative Percent Difference (%) 

Analyte Pair 1 Pair 2 Pair 3 Pair 4 Pair 5 Pair 6 

2-Methylnaphthalene 12.7 36.6 ND ND ND 17.1 

4-Chloroaniline NC 7.4 8.0 41.8 12.7 5.0 

Benzo(a)pyrene 2.4 3.1 ND 143.9 8.7 17.0 

bis (2-Ethylhexyl) phthalate 16.7 3.6 0.0 157.8 15.9 10.8 

Fluoranthene 16.7 0.0 0.0 144.3 2.1 14.2 

Pyrene 0.0 6.9 ND 128.9 5.7 8.9 

Total Solids 1.2 4.3 1.2 136.0 10.6 1.0 

ND = not detected in either sample in the duplicate pair 

NC = not detected in one sample in the duplicate pair and therefore RPD was not calculated 
TNSSS Sampling and Analysis Technical Report 54 January 2009 

6.7.4 PBDEs 

 Table 24 presents the field duplicate results for the PBDEs. A total of 36 of 72 RPD 

values are less than 20% and 58 of 72 are less than 40%. Field duplicate Pair 4 exhibits higher 

RPD values than then other five pairs, but the differences are not as marked as for the other 

analyte classes. It is possible that the difference may be a reflection of the smaller sample size 

used for the PBDE analyses compared to the other classes. Due to the concentrations of PBDEs 

in biosolids, which can interfere with analysis, the laboratory extracted just 0.2 g of the sewage 

sludge, compared to samples of up to 10 g for other samples and analytes. Extracting a smaller 

sample eliminated the need for repeated dilution of the sample, resulted in fewer burdens to (i.e., 

didn’t overwhelm) the laboratory equipment, and made quantitation possible. 

Table 24. Comparison of Field Duplicate Results for PBDEs 

Relative Percent Difference (%) 

Analyte Pair 1 Pair 2 Pair 3 Pair 4 Pair 5 Pair 6 

BDE-28 19.6 16.7 11.2 42.4 21.9 19.4 

BDE-47 16.7 22.2 9.1 35.3 26.3 9.5 

BDE-66 28.0 10.0 6.5 25.6 2.7 14.6 

BDE-85 45.3 25.6 2.3 40.0 30.8 20.2 

BDE-99 17.4 15.1 19.0 48.6 27.8 1.0 

BDE-100 14.7 22.2 9.5 48.6 34.2 14.6 

BDE-138 NC 34.3 ND 44.6 ND 8.0 

BDE-153 18.2 15.4 11.1 45.0 27.9 8.7 

BDE-154 21.1 15.0 13.3 45.1 28.6 10.5 

BDE-183 16.9 18.2 10.3 46.2 28.6 19.4 

BDE-209 33.0 32.7 4.9 44.7 41.9 25.0 

Total Solids 4.6 7.1 2.5 38.9 28.2 0.0 

ND = not detected in either sample in the duplicate pair 

NC = not detected in one sample in the duplicate pair and therefore RPD was not calculated 

6.7.5 Pharmaceuticals 

 Table 25 presents the field duplicate results for the pharmaceuticals. As noted earlier, in 

cases where both of the results in a field duplicate pair were non-detects, EPA indicated these 

instances with ND, for “not detected.” There are 270 instances of NDs for the pharmaceuticals. 

 When only one of the results in a field duplicate pair was a non-detect, EPA did not 

calculate the RPD and indicated these instances with NC, for “not calculated.” There were 18 

instances of NCs for the pharmaceuticals. In Table 25, bold is used to indicate all of the RPD 

values that exceeded 50%.

Table 25. Comparison of Field Duplicate Results for Pharmaceuticals 

Relative Percent Difference (%) 

Analyte Pair 1 Pair 2 Pair 3 Pair 4 Pair 5 Pair 6 

Acetaminophen ND ND ND ND ND ND 

Albuterol ND ND ND NC ND ND 

Anhydrochlortetracycline ND ND ND ND ND ND 

Anhydrotetracycline 13.9 NC 11.2 31.8 22.6 15.3 

Azithromycin 14.8 9.4 9.38 50.9 25.6 18.9 

Caffeine ND ND 3.71 72.4 21.4 ND 

Carbadox ND ND ND ND ND ND 

Carbamazepine 18.4 6.0 9.32 38.2 11.1 19.7 

Cefotaxime ND ND ND ND ND ND 
TNSSS Sampling and Analysis Technical Report 55 January 2009 

Table 25. Comparison of Field Duplicate Results for Pharmaceuticals 

Relative Percent Difference (%) 

Analyte Pair 1 Pair 2 Pair 3 Pair 4 Pair 5 Pair 6 

Chlortetracycline ND ND ND ND ND ND 

Cimetidine 3.6 34.4 73.1 116 24.5 17.0 

Ciprofloxacin 38.4 5.5 0.54 50.7 2.0 5.5 

Clarithromycin ND ND 20.6 19.0 ND 6.4 

Clinafloxacin ND ND ND ND ND ND 

Cloxacillin ND ND ND ND ND ND 

Codeine ND ND ND 39.4 NC ND 

Cotinine ND 10 10.5 NC 27.3 19 

Dehydronifedipine ND ND 27.8 27.3 ND ND 

Demeclocycline ND ND ND ND ND ND 

Digoxigenin ND ND ND ND ND ND 

Digoxin ND ND ND ND ND ND 

Diltiazem NC 34.1 50.5 32.9 46.4 2.96 

1,7-Dimethylxanthine ND ND ND ND ND ND 

Diphenhydramine 22.0 0.8 11.9 15.8 29.5 6.23 

Doxycycline 48.1 27.4 15.7 17.4 15.8 4.55 

Enrofloxacin ND ND ND 18.9 7.2 ND 

4-Epianhydrochlortetracycline ND ND ND ND ND ND 

4-Epianhydrotetracycline ND NC 2.5 36.3 35.0 5.30 

4-Epichlortetracycline ND ND ND ND ND ND 

4-Epioxytetracycline ND ND ND ND ND NC 

4-Epitetracycline 37.6 27.8 24.4 55.2 3.24 18.2 

Erythromycin-total 51.7 44.1 2.25 32.5 138 22.2 

Flumequine ND ND ND ND ND ND 

Fluoxetine 25.5 10.1 40.3 47.9 7.5 18.5 

Gemfibrozil 3.4 13.1 7.8 71.1 4.7 2.6 

Ibuprofen ND 2.2 14.2 119.1 3.0 0 

Isochlortetracycline ND ND ND ND ND ND 

Lincomycin ND ND ND ND NC ND 

Lomefloxacin ND ND ND ND ND ND 

Metformin ND ND ND ND ND ND 

Miconazole 5.7 1.80 ND 2.3 187 33.8 

Minocycline ND ND 9.2 ND 5.1 6.2 

Naproxen ND 12.0 11.8 68.5 15.5 NC 

Norfloxacin ND ND 18.2 59.2 1.8 ND 

Norgestimate ND ND ND ND ND ND 

Ofloxacin 15.9 16.5 3.9 29.0 11.2 12.3 

Ormetoprim ND ND ND ND ND ND 

Oxacillin ND ND ND ND ND ND 

Oxolinic acid ND ND ND ND ND ND 

Oxytetracycline ND NC ND ND NC 9.04 

Penicillin G ND ND ND ND ND ND 

Penicillin V ND ND ND ND ND ND 

Ranitidine ND ND NC 121.5 2.1 ND 

Roxithromycin ND ND 4.03 ND ND ND 

Sarafloxacin ND ND ND ND ND ND 

Sulfachloropyridazine ND ND ND NC ND ND 

Sulfadiazine ND ND ND ND ND ND 

Sulfadimethoxine ND ND ND NC ND ND 

Sulfamerazine ND ND ND ND ND ND 

Sulfamethazine ND ND ND ND ND ND 

Sulfamethizole ND ND ND ND ND ND 

Sulfamethoxazole ND ND ND 56.3 ND ND 

Sulfanilamide ND ND ND ND ND ND 
TNSSS Sampling and Analysis Technical Report 56 January 2009 

Table 25. Comparison of Field Duplicate Results for Pharmaceuticals 

Relative Percent Difference (%) 

Analyte Pair 1 Pair 2 Pair 3 Pair 4 Pair 5 Pair 6 

Sulfathiazole ND ND ND ND ND ND 

Tetracycline 15.2 1.6 5.09 2.3 0.52 13.1 

Thiabendazole ND ND 20 0.8 0.30 0.49 

Triclocarban 6.1 10.2 0 13.2 7.31 5.90 

Triclosan 5.7 12.4 37.3 38.3 26.9 41.0 

Trimethoprim ND ND 30.8 ND ND NC 

Tylosin ND ND ND ND ND ND 

Virginiamycin ND 22.1 NC ND NC ND 

Warfarin NC ND ND ND ND ND 

Total Solids 1.7 4.0 2.84 88.0 6.21 3.54 

ND = Not detected in both samples in the pair 

NC = Not calculated because one of the results was a non-detect 

RPD values greater than 50% are shown in bold. 

 

 EPA calculated 143 RPD values for the pharmaceuticals, not including those for the total 

solids in each sample. Of the 143 RPDs, 16 exceeded 50%, although some only marginally (e.g., 

50.5, 50.7, and 50.9%). Of the 16 values greater than 50%, 11 occurred in Field Duplicate Pair 

4. As discussed above, EPA believes that the RPD values in Pair 4 reflect differences in the two 

samples of liquid sewage sludge collected at that facility, with the RPD for the total solids at 

88%. 

 Many of the 270 instances where an analyte was not detected in either sample in the field 

duplicate pair are a function of the low frequency at which some of the pharmaceuticals were 

detected. For example, as shown in Table 12, Acetaminophen was only detected in 2 of the 84 

survey samples. Therefore, its frequency of occurrence was only 2.38%. The chance that a field 

duplicate sample would be collected at any of the 74 POTWs in the survey was 8.1% (6 out of 74 

plants). The likelihood of detecting Acetaminophen in both samples in a field duplicate pair is 

on the order of 0.2% (e.g., 2.38% x 8.1%). Therefore, the fact that Acetaminophen is listed as 

ND in Table 25 for all 6 field duplicate pairs is not surprising. 

 In contrast, Ciprofloxacin was reported in all 84 samples from the survey, including the 6 

field duplicate samples. Therefore, EPA was able to calculate an RPD value for each field 

duplicate pair in Table 25. Except for field duplicate Pair 4, the RPDs for Ciprofloxacin indicate 

good precision (four of the RPD values are less than 6%). 

6.7.6 Steroids and Hormones 

 Table 26 presents the field duplicate results for the steroids and hormones. 
TNSSS Sampling and Analysis Technical Report 57 January 2009 

Table 26. Comparison of Field Duplicate Results for Steroids and Hormones 

Relative Percent Difference (%) 

Analyte Pair 1 Pair 2 Pair 3 Pair 4 Pair 5 Pair 6 

Androstenedione ND 9.7 ND ND 83.3 

Androsterone ND ND 3.4 ND NC 28.8 

Campesterol 0 10.4 5.1 88.9 96.6 17.1 

Cholestanol 11.1 9.3 6.2 97.0 32.8 7.2 

Cholesterol 0.0 3.4 2.5 99.4 48.0 3.7 

Coprostanol 13.4 14.5 3.8 110.4 39.8 13.6 

Desmosterol 20.0 3.2 14.8 96.7 9.0 23.1 

17 α-Dihydroequilin ND ND ND NC ND ND 

Epicoprostanol 17.3 38.4 13.4 109.7 32.8 5.6 

Equilenin ND ND ND ND ND ND 

Equilin ND ND 13.4 ND ND 5.7 

Ergosterol 38.4 ND 33.6 93.8 24.4 43.0 

17 α-Estradiol ND ND ND ND NC ND 

17 β-Estradiol ND ND ND 119.5 27.5 ND 

β-Estradiol 3-benzoate ND ND ND 88.3 ND ND 

17 α-Ethinyl-estradiol ND ND ND ND ND ND 

Estriol ND ND 90.0 NC 21.0 NC 

Estrone ND 8.3 3.1 0.6 4.5 

Norethindrone ND ND ND ND ND ND 

Norgestrel ND ND ND ND ND ND 

Progesterone ND 20.5 ND ND ND 65.9 

β-Sitosterol 38.7 8.8 16.2 87.4 44.4 3.2 

β-Stigmastanol 39.0 3.8 14.3 87.0 33.1 30.6 

Stigmasterol 25.5 5.1 34.5 83.6 61.0 2.5 

Testosterone ND ND ND ND ND NC 

Total Solids 1.7 4.0 2.8 88 6.2 3.5 

ND = Not detected in both samples in the pair 

NC = Not calculated because one of the results was a non-detect 

RPD values greater than 50% are shown in bold. 

 There were 6 instances of NCs for the steroids and hormones. For the steroids and 

hormones, EPA calculated 74 RPD values, not including those for the total solids in each sample. 

Of those 74 RPDs, 17 exceeded 50%. There were 70 instances where EPA did not calculate an 

RPD value because both results for the analyte were non-detects (listed as ND in Table 26). As 

discussed for the pharmaceuticals, the prevalence of the ND entries in Table 26 is largely a 

function of the frequency of occurrence of the analytes across all samples. For example, 

Norgestrel was only reported in 4 of 84 samples from the survey (4.76%), yielding a very low 

likelihood it would be found in both samples from a field duplicate pair. The occurrence of 

Cholesterol in 81 of 84 samples is not surprising, given that it is excreted by humans. That high 

frequency of occurrence enabled us to calculate an RPD value for all 6 field duplicate pairs. 

 Of the 17 RPD values for steroids and hormones greater than 50%, 12 occurred in Field 

Duplicate Pair 4. EPA believes that the RPD values reflect differences in the two samples of 

liquid sewage sludge collected at that facility. The differences are evident in the total solids 

contents of each sample, where the RPD is 88%. 
TNSSS Sampling and Analysis Technical Report 58 January 2009 

6.7.7 Results in Liquid Samples

 The results for all classes of analytes support EPA’s conclusion that the sampling 

procedures were appropriate and effective in collecting sewage sludge for the TNSSS. The 

exception was for the facility from which Field Duplicate Pair 4 was collected. EPA believes 

that the variability of the field duplicate results for Pair 4 is not typical of the variability observed 

for the other liquid samples in the survey, but may reflect site-specific conditions. 

 Given the variability of the results for Field Duplicate Pair 4 shown in the tables above, 

EPA examined the results for those two samples in greater detail, comparing the two samples 

from that one site to the liquid sewage sludge samples from other sites. EPA examined the 

percent solids data from the anions, metals, and semivolatile organics analyses for all 19 liquid 

sewage sludge samples collected during the survey. Because the results for the PBDEs, 

pharmaceuticals, steroids, and hormones were delivered later in the TNSSS effort, EPA did not 

include them in this more detailed analysis of liquid sample results. 

 EPA examined the percent solids results generated during analyses of the anions, metals, 

and semivolatile organics in all 19 liquid sewage sludge samples (19 samples x 3 classes = 57 

measurements in all). Based on the observed distribution of results, the data were transformed 

by taking the natural log of the results and subjecting them to an F-test. The null hypothesis was 

that the three aliquots from each of the two samples in Pair 4 did not have significantly different 

variances from the variances of the three aliquots in each of the other liquid samples, indicating 

that they came from the same population. Table 27 presents the log-transformed percent solids 

data for all 19 liquid sewage sludge samples. 

Table 27. Log-transformed Percent Solids Data for Liquid Sewage Sludge 

Samples 

Natural Log of % Solids 

Liquid Sample Anions Metals Organics Variance of Logs 

1 1.284 1.747 0.425 0.450 

2 3.795 3.773 3.795 0.000 

3 0.560 0.560 1.621 0.376 

4 4.126 4.126 4.126 0.000 

5 1.543 0.270 1.085 0.416 

6 0.482 0.482 1.456 0.316 

7 - FD 0.615 1.452 -0.494 0.953 

8 - FD 0.010 0.010 1.163 0.443 

9 2.434 2.407 2.477 0.001 

10 2.425 2.434 2.370 0.001 

11 1.677 1.128 0.920 0.153 

12 -0.844 -0.693 -0.942 0.016 

13 0.293 0.647 0.604 0.037 

14 0.815 0.658 0.888 0.014 

15 0.182 0.182 0.191 0.000 

16 -0.673 -0.844 -0.892 0.013 

17 0.270 0.207 0.182 0.002 

18 2.072 1.991 1.652 0.049 

19 0.788 -0.041 0.775 0.226 

FD = Field duplicate pair 

 
TNSSS Sampling and Analysis Technical Report 59 January 2009 

 Table 28 presents the results of the F-test. The pooled within-sample variance (the 

standard deviation squared) is markedly greater for the two field duplicate samples, compared to 

the remaining liquid sewage sludge samples in the survey. The F-ratio in Table 28 is greater 

than the critical value of F, leading to the conclusion that the variances in the percent solids 

results for the field duplicate samples are greater than would be expected by chance from 

samples in a single population. 

Table 28. F-test Results for Field Duplicates and Other Liquid Samples 

Pooled Variance (field duplicates) 0.698 

Pooled Variance (non-field duplicates) 0.122 

F-ratio 5.731 

F-critical 2.650 

p-value 0.001229 

 Therefore, the variability exhibited by the field duplicate results for Pair 4 is not typical 

of the variability that is apparent for the other liquid samples in the survey. The results for Pair 4 

are not an indication that the sampling procedures used for the survey are inappropriate for liquid 

samples. Rather, the results for Pair 4 may reflect site-specific conditions. However, both sets 

of results for all of the field duplicate pairs, including Pair 4, are included in the survey database. 

6.8 Matrix Spike and Duplicate Results 

 Matrix spike (MS) samples and matrix spike duplicate (MSD) samples, or matrix spike 

samples and unspiked duplicate (DUP) samples, were prepared with batches of field samples 

analyzed for the anions, metals, semivolatile organics and PAHs, and the PBDEs analyzed as 

described in Section 4 without isotope dilution quantitation. These QC samples served to 

demonstrate the applicability of the methods to the matrices in question, e.g., liquid and solid 

sewage sludge. The use of an MSD versus a DUP is generally called out in the method, with 

MS/MSD pairs being the norm in methods for organics, and MS and DUP samples being the 

norm in methods for metals and other inorganic such as anions. The results for those analyses 

are discussed below by analyte class. Appendix C presents the QC acceptance limits used by the 

laboratories. 

 Because the methods used for the pharmaceuticals, steroids, and hormones use isotope 

dilution quantitation, those methods do not require that separate MS/MSD samples be analyzed. 

Rather, the recoveries of the isotopically labeled analytes spiked into every sample are monitored 

and used to correct the results for the target analytes. 

 The MS/MSD results for the TNSSS are discussed in the subsections that follow, by 

analyte class. The labeled compound recoveries for the isotope dilution methods are discussed in 

Section 6.8.8. 
TNSSS Sampling and Analysis Technical Report 60 January 2009 

6.8.1 Matrix Spike Results for Anions 

 The laboratory prepared eight sets of matrix spike samples for the anion analyses. Table 

29 presents the results in terms of the percent recovery of each analyte spiked into the sample. 

Table 29. Matrix Spike Recoveries for Anions in Sewage Sludge 

Matrix Spike Recovery (%) 

Analyte MS1 MS2 MS3 MS4 MS5 MS6 MS7 MS8 

Fluoride 93 74 66 82 93 60 68 77 

Nitrate/Nitrite 98 101 103 95 100 90 101 96 

Water-Extractable Phosphorus -24 88 75 102 90 95 80 95 

 The laboratory’s acceptance limits for matrix spike recoveries were 75 - 125%, and 18 of 

24 recoveries in Table 29 met those limits. The laboratory reported the recovery of WEP in MS3 

as 74.8%, before rounding. That value is only marginally out of the specification, and rounds to 

75%, the lower limit of the laboratory’s acceptance range. 

 The laboratory reported the recovery of WEP in one matrix spike (MS1) as -24%. 

Negative recoveries are not physically possible and the reported recovery is a function of the 

manner in which it is calculated. Although most recent published EPA methods explicitly 

include example calculations for QC parameters such as recovery, some older analytical methods 

do not. EPA Methods 340.2, 353.2, and 365.3, used for the anion analyses, are among those 

methods without example calculations. In the absence of project-specific requirements, the 

laboratory performing the anions analyses relied on formulae from the SW-846 methods manual 

from EPA’s Office of Solid Waste. Chapter One of the manual includes definitions of a number 

of commonly used terms and provides the equation for the calculation of recovery shown below: 

where: 

%R = percent recovery 

xs = measured value for spiked sample 

xu = measured value for unspiked sample 

K = known value for the spike in the sample 

 This same basic formula appears in many individual EPA methods. The remainder of 

this report refers to this equation as the “traditional approach” to calculating recovery. As 

written, K is often interpreted as the amount of material spiked into the sample. That 

interpretation ignores any “background” concentration of the analyte in the unspiked sample. In 

practice, the equation produces recoveries that appear reasonable and generally meet 

expectations in those samples where the background concentration of the analyte is either very 

low, or where the amount spiked into the sample is much greater than the background amount. 

However, the laboratory calculates negative recoveries any time the result in the spiked sample is 

less than that in the unspiked sample, even if that is a function of inhomogeneity in the original 

sample. Given the Law of Conservation Mass, whereby matter cannot be created or destroyed, 

negative recoveries are physically impossible. 

 

K

) ux s (x100 %R  
TNSSS Sampling and Analysis Technical Report 61 January 2009 

 Laboratories commonly prepare MS samples without extensive knowledge of the 

background levels of any target analytes in specific samples. Therefore, a laboratory may 

blindly spike an amount that is similar to that already in the sample and the equation above will 

perform poorly. 

 Given the frequency at which negative and unrealistic recoveries are reported using the 

equation above, EPA developed an alternative calculation that considers the result found in the 

matrix spike sample in comparison to what was found in the unspiked sample plus the amount 

spiked. The alternative equation is as follows: 

where: 

%R = percent recovery 

Cs = measured value for spiked sample 

Cu = measured value for unspiked sample 

Cn = nominal spike added to the sample 

 Eliminating the subtraction operation in the numerator of the equations prevents the 

occurrence of any negative values. Moving the concentration of the unspiked sample to the 

denominator more effectively addresses the issue of the “background” concentration. 

 In the case of the first MS sample in Table 29, the water-extractable phosphorus result in 

the MS sample (271 mg/kg) was less than the result in the unspiked sample (317 mg/kg), despite 

adding 189 mg/kg of phosphorus, leading to a negative recovery (-24.3%) using the traditional 

approach, as follows: 

(100 x (271 - 317))/189 = -4600/189 = -24.3% 

Using the alternative equation above and the same laboratory results, the recovery in the matrix 

spike is calculated as: 

100 x (271/(317 + 189) = 27100/506 = 53.6% 

While the recovery of 53.6% is still below the acceptance limits used by the laboratory, it is a 

more rational expression of the results in this sample. 

 The alternative equation increased the recovery of WEP dramatically in this example. 

However, it did not cause the recoveries that already appear reasonable to exceed the acceptance 

limits when they did not otherwise do so. For example, Table 29 lists the recovery of 

nitrate/nitrite in MS3 as 103%. This value is rounded down from 103.3652% determined via the 

traditional calculation. Using the alternative equation, the recovery is 103.3466%, a trivial 

difference that is removed when the results are rounded to the nearest whole percentage. Given 

this trivial difference, EPA did not recalculate every recovery reported by the laboratory, but 

focused this discussion on the negative recoveries alone. 

100x

Cu Cn

%R Cs

 
TNSSS Sampling and Analysis Technical Report 62 January 2009 

6.8.2 Duplicate Results for Anions 

 The laboratory prepared eight sets of duplicate sample analyses for anions. Table 30 

presents the results shown in terms of the relative percent difference (RPD) for each analyte in 

the sample. Although the laboratory used acceptance limits expressed to the nearest whole 

percentage, Table 30 presents the RPDs to one decimal place to illustrate the small differences 

between many of the duplicate pair results. 

Table 30. Duplicate Precision for Anions in Sewage Sludge 

Relative Percent Difference (%) 

Analyte Dup 1 Dup 2 Dup 3 Dup 4 Dup 5 Dup 6 Dup 7 Dup 8 

Fluoride 0.9 2.7 4.5 14.6 5.4 12.2 0.4 14.6 

Nitrate/Nitrite 3.6 0.0 23.0 17.1 2.2 8.3 6.9 10.7 

Water-extractable Phosphorus 6.1 5.2 18.8 4.6 9.4 6.8 4.1 11.1 

 The laboratory’s acceptance limit for precision (RPD) is 20% and all but one result in 

Table 30 met that limit. The highest RPD value reported by the laboratory was 23.0% for 

nitrate/nitrite in Duplicate 3. This RPD was only slightly outside of the 20% limit. 

 Except as discussed above, the recovery data in Table 29 and the precision data in Table 

30 demonstrate that the methods were generally accurate and precise when applied to sewage 

sludge samples. 

6.8.3 Matrix Spike Results for Metals 

 The laboratory prepared 15 sets of matrix spike samples for the metals analyses. Table 

31 presents the matrix spike recoveries in three parts (Tables 31A, 31B, and 31C), rounded to 

one-tenth of a percent, to illustrate some of the smaller differences. 

 Because calcium and magnesium are common components of soils and occur at levels 

that vary widely, the laboratory did not spike these two metals into solid samples, and they do 

not appear in Table 31. However, calcium and magnesium also are not major metals of concern 

in this survey. 

 The laboratory analyzed mercury separately from any other metals. Therefore, the results 

for mercury appear at the bottom of the table because the laboratory prepared only 9 matrix spike 

samples for mercury and did not necessarily use the same field samples for the mercury matrix 

spike analyses as for the other metals. 

 During the survey, as the laboratory gained experience with the sewage sludge samples, 

they adjusted the amounts of some metals spiked into each matrix spike sample in an effort to 

account for the background concentrations. For example, for aluminum, the spiking 

concentrations ranged from about 400 mg/kg to about 3200 mg/kg, while copper spiking levels 

ranged from about 40 mg/kg to 4000 mg/kg. These adjustments to the spiking levels were not 

always successful in addressing recovery issues. 

 
TNSSS Sampling and Analysis Technical Report 63 January 2009 

 Aluminum and iron presented problems with reported recoveries. The laboratory also 

reported negative recoveries for phosphorus, again a function of the assumption that the 

background concentrations are much lower than the spiking levels. Therefore, Table 31 includes 

the recoveries reported by the laboratory using the traditional calculation from the methods (in 

the MS# columns) along with the alternative calculation described above (in the ALT# columns). 

Using the alternative calculation, all of the negative recoveries reported by the laboratory 

become positive values. In addition, many of the very high recoveries (e.g., over 250%) are 

greatly reduced in magnitude. 

Table 31A. Matrix Spike Recoveries for Metals in Sewage Sludge, Calculated in the Traditional 

Fashion and with an Alternative Equation 

Recovery (%) 

Analyte MS1 ALT1 MS2 ALT2 MS3 ALT3 MS4 ALT4 MS5 ALT5 

Aluminum 177.7 102.4 334.5 104.2 68.8 98.5 400 114.9 443.9 107.9 

Antimony 44.3 45.7 41.1 43.7 75.7 75.7 41.5 42.0 46.4 47.4 

Arsenic 102.0 101.8 102.0 101.7 101.5 101.4 111.1 110.6 101.6 101.5 

Barium 99.2 99.7 98.8 99.5 101.9 101.0 96.3 98.2 117.5 105.7 

Beryllium 108.7 108.3 99.7 99.7 102.3 102.3 112.4 112.0 101.2 101.2 

Boron 105.1 103.5 106.5 105.9 110.6 108.4 110.6 108.9 103.7 103.0 

Cadmium 110.7 105.9 117.4 108.6 112.9 111.5 121.8 119.6 110.7 107.9 

Chromium 93.9 98.8 113.7 105.0 110.5 106.9 118.8 110.5 118.1 102.4 

Cobalt 101.1 101.0 102.9 102.7 107.6 107.3 116.3 115.7 115.7 104.0 

Copper 83.2 98.5 59.7 96.7 79.5 97.9 40.0 95.2 173.3 104.7 

Iron -203.0 98.0 1543.8 111.3 -71.4 96.5 265.0 103.4 156.2 100.8 

Lead 111.3 104.4 108.3 103.0 111.1 108.6 118.9 113.6 109.5 105.7 

Manganese 78.2 97.9 135.9 108.1 91.7 99.7 81.0 95.1 101.3 100.4 

Molybdenum 103.0 102.6 108.7 105.7 111.5 110.0 110.3 110.0 107.5 106.9 

Nickel 101.7 101.3 105.5 103.8 105.6 105.1 118.3 114.7 102.5 102.2 

Phosphorus -101.5 96.9 -123.5 91.2 -203.9 90.1 -46.0 91.7 -41.8 96.0 

Selenium 102.3 102.0 101.4 101.3 102.8 102.6 112.9 112.2 103.5 103.2 

Silver 68.0 90.7 93.8 98.2 103.3 101.4 83.1 92.3 101.8 101.1 

Thallium 104.8 104.7 106.2 106.2 107.4 107.4 108.9 108.8 108.4 108.4 

Tin 96.6 96.8 95.4 95.9 95.6 95.9 91.3 91.6 81.1 82.6 

Titanium 47.3 57.7 29.4 43.2 16.3 21.9 55.5 61.1 10.8 14.8 

Vanadium 101.4 101.0 105.9 104.3 107.3 106.4 117.7 115.1 101.4 101.3 

Yttrium 102.2 101.8 102.4 101.9 106.0 105.6 119.6 115.5 103.7 102.7 

Zinc 50.8 97.1 41.2 96.6 99.9 100.0 72.0 94.1 125.3 101.9 

Mercury 106.0 101.3 76.0 97.0 110.8 104.1 106.6 103.2 62.5 94.4 

Table 31B. Matrix Spike Recoveries for Metals in Sewage Sludge, Calculated in the Traditional 

Fashion and with an Alternative Equation 

Recovery (%) 

Analyte MS6 ALT6 MS7 ALT7 MS8 ALT8 MS9 ALT9 MS10 ALT10 

Aluminum 236.2 104.3 194.9 104.3 653.0 353.7 202.0 103.2 485.0 325.1 

Antimony 72.4 72.9 74.8 75.8 69.1 69.4 47.9 49.1 74.3 74.5 

Arsenic 103.0 102.8 102.8 102.7 140.3 137.8 100.3 100.2 119.1 118.5 

Barium 103.7 101.8 107.8 104.2 119.5 118.8 92.6 96.9 103.0 102.9 

Beryllium 93.0 93.1 95.6 95.8 98.7 98.7 117.5 116.7 100.9 100.9 

Boron 105.7 104.8 102.6 101.9 119.5 119.1 103.4 102.3 127.0 126.3 

Cadmium 110.3 108.8 107.2 106.3 119.9 119.3 111.8 109.0 107.7 107.6 

Chromium 93.5 96.7 100.0 100.0 116.9 116.3 88.6 96.6 184.4 171.2 

Cobalt 102.4 102.3 102.3 102.2 118.8 118.2 99.6 99.6 110.3 110.2 

Copper 111.3 101.1 182.6 103.6 216.4 191.8 38.4 93.6 304.4 247.3 

Iron 94.7 99.8 1167.5 103.9 2126 465.7 -1312.7 92.5 250.4 214.3 

Lead 107.2 105.7 110.1 108.8 329.8 263.9 131.2 113.6 166.5 157.6 

Manganese 98.8 99.5 99.3 99.7 206.4 186.1 10.1 93.7 102.7 102.6 

Molybdenum 109.6 108.4 108.2 107.3 101.9 101.8 100.6 100.5 107.1 106.7 

Nickel 100.3 100.3 99.8 99.8 150.0 145.0 103.2 102.4 184.9 171.3 
TNSSS Sampling and Analysis Technical Report 64 January 2009 

Table 31B. Matrix Spike Recoveries for Metals in Sewage Sludge, Calculated in the Traditional 

Fashion and with an Alternative Equation 

Recovery (%) 

Analyte MS6 ALT6 MS7 ALT7 MS8 ALT8 MS9 ALT9 MS10 ALT10 

Phosphorus -63.0 96.5 243.4 102.0 360.6 263.5 -282.7 91.1 320.6 238.4 

Selenium 103.4 103.1 101.7 101.6 111.7 111.3 101.8 101.7 114.4 113.6 

Silver 56.8 85.1 33.4 84.0 95.8 96.0 67.7 87.3 114.2 112.1 

Thallium 105.9 105.9 105.7 105.7 108.9 108.9 104.7 104.7 103.9 103.9 

Tin 92.5 93.1 85.4 86.1 94.0 94.0 99.7 99.7 83.6 83.6 

Titanium 13.7 20.7 22.5 29.5 91.0 91.0 85.0 90.8 79.0 79.0 

Vanadium 98.9 99.0 115.8 106.7 169.7 162.1 109.6 105.8 139.8 136.8 

Yttrium 101.9 101.7 99.7 99.8 140.0 137.4 107.0 105.6 100.1 100.1 

Zinc 95.7 99.5 109.4 101.1 230.8 201.3 92.0 92.2 160.4 153.4 

Mercury 236.7 145.5 116.2 115.6 124.9 109.0 91.4 94.4 -- -- 

Table 31C. Matrix Spike Recoveries for Metals in Sewage Sludge, Calculated in the Traditional 

Fashion and with an Alternative Equation 

Recovery (%) 

Analyte MS11 ALT11 MS12 ALT12 MS13 ALT13 MS14 ALT14 MS15 ALT15 

Aluminum 229.9 184.4 500.0 108.6 -395.9 75.8 301.9 107.3 147.5 101.9 

Antimony 77.7 77.7 55.9 56.7 75.2 75.6 54.7 56.1 85.1 85.4 

Arsenic 101.2 101.2 95.9 96.1 69.7 70.5 -8.2 56.4 105.8 105.6 

Barium 107.7 107.6 95.2 98.0 47.7 82.3 115.1 103.5 120.7 108.8 

Beryllium 101.4 101.4 100.1 100.1 94.5 94.5 91.9 92.6 109.4 109.2 

Boron 119.5 118.4 100.1 100.1 88.7 90.7 99.8 99.8 111.6 106.8 

Cadmium 104.4 104.4 108.7 107.4 101.9 101.7 55.5 76.9 114.1 111.9 

Chromium 105.3 105.3 102.8 101.6 77.4 87.6 118.9 108.7 130.0 104.7 

Cobalt 103.5 103.5 100.9 100.9 95.8 96.0 102.5 102.3 108.2 107.8 

Copper 155.8 153.7 62.1 97.8 -204.1 74.7 181.8 104.0 178 105.9 

Iron 505.6 224.6 250 102.6 -1573.6 77.4 1209.8 109.4 599.9 103.2 

Lead 100.0 100.0 108.9 106.0 62.2 82.6 120.5 107.6 114.9 109.8 

Manganese 100.3 100.3 92.1 99.1 0.0 89.0 178.0 104.1 124.0 105.9 

Molybdenum 105.3 105.3 108.8 107.2 99.3 99.3 -40.9 50.9 112.9 110.5 

Nickel 105.0 105.0 102.8 102.3 91.0 92.3 104.7 103.8 116.2 109.5 

Phosphorus 384.0 169.0 -80.2 96.2 -142.0 76.9 105.9 100.6 260.0 102.3 

Selenium 100.3 100.3 93.1 93.5 91.8 92.2 -98.2 38.9 107.8 107.3 

Silver 90.9 91.8 94.5 97.2 41.0 79.4 79.2 93.5 91.0 97.4 

Thallium 99.4 99.4 104.5 104.5 101.0 101.0 95.4 95.6 111.6 111.6 

Tin 90.2 90.3 88.9 90.0 91.8 92.2 84.0 84.3 99.4 99.4 

Titanium 90.5 90.8 35.7 51.4 23.9 26.8 27.0 28.3 40.8 47.7 

Vanadium 100.9 100.9 109.1 108.1 92.6 93.7 102.5 101.9 106.9 105.0 

Yttrium 100.0 100.0 107.8 106.9 108.2 106.2 89.1 91.2 104.8 104.4 

Zinc 461.3 237.9 86.1 98.5 -106.1 77.7 181.8 104.9 138.0 103.8 

 Using either calculation, many of the metals exhibited a small positive bias. A total of 12 

the 25 spiked metals have mean traditional recoveries between 101% and 115%, while 14 of 25 

metals have mean alternative recoveries in the same range. Five metals exhibited a slight 

negative bias using the traditional calculation, with mean recoveries ranging from 80% to 97%. 

 Antimony, phosphorus, and titanium exhibited mean traditional recoveries below 70%. 

The alternative calculation dramatically altered the mean recovery of phosphorus, raising it from 

39% to 120%, by virtue of eliminating the large number of negative values in the traditional 

calculation. 

 
TNSSS Sampling and Analysis Technical Report 65 January 2009 

 The mean recovery of titanium was only 43% in these 15 matrix spike samples, with only 

four values in the acceptable range. Similarly, the mean recovery of antimony was 62% in these 

15 matrix spike samples, with only five values in the acceptable range. Neither titanium nor 

antimony is among the nine pollutants initially selected for this survey (see Section 1), nor one of 

the metals that currently has a regulatory standard in sewage sludge. 

6.8.4 Duplicate Results for Metals 

 Over the course of the survey, the laboratory analyzed 15 samples for metals in duplicate, 

to assess analytical precision. Table 32 presents the results for those duplicate analyses. The 

laboratory prepared and analyzed only seven duplicates for mercury, and as with the matrix spike 

results, not necessarily using the same field samples as for the other metals. The exception is for 

Duplicate 8, where the results for mercury are from the same sample as for all the other metals. 

Table 32 is divided into several parts. The vast majority of the RPD values are less than the 

acceptance limit of 30%. The exceptions are almost exclusively in Duplicates 8, 10, and 11. All 

three of these samples were liquid sewage sludge. 

Table 32A. Duplicate Precision for Metals in Sewage Sludge 

Relative Percent Difference (%) 

Analyte Dup1 Dup2 Dup3 Dup4 Dup5 Dup6 Dup7 Dup8 

Aluminum 14.4 6.2 0.7 13.6 3.1 8.1 1.4 142.1 

Antimony 8.3 4.5 ND 21.9 18.8 10.0 6.8 146.3 

Arsenic 2.5 0.0 8.6 6.8 3.2 10.0 4.4 145.0 

Barium 2.3 0.8 3.1 1.4 1.7 5.8 1.4 140.3 

Beryllium 6.3 0.0 8.0 18.2 3.8 4.4 5.4 141.9 

Boron 13.8 2.8 6.5 13.9 5.0 6.1 4.2 141.4 

Cadmium 1.3 4.8 3.4 5.2 0.6 3.1 6.4 151.0 

Calcium 1.2 3.9 0.7 17.1 1.8 6.1 1.1 139.0 

Chromium 0.7 2.2 4.7 13.6 3.8 8.0 5.0 140.0 

Cobalt 0.4 2.4 4.3 10.1 4.7 5.3 9.3 144.4 

Copper 3.2 3.0 2.6 2.1 0.7 5.5 0.9 138.1 

Iron 0.7 5.4 1.5 7.3 1.4 7.5 0.9 140.9 

Lead 3.9 4.0 3.7 0.5 0.5 1.6 7.2 150.7 

Magnesium 4.3 8.5 0.7 27.3 4.3 6.6 1.4 140.6 

Manganese 2.3 6.2 1.8 3.2 1.2 5.6 1.9 141.0 

Molybdenum 1.2 4.2 3.3 14.1 0.9 16.2 5.0 134.1 

Nickel 1.2 2.3 4.3 2.9 3.7 9.3 5.5 143.6 

Phosphorus 1.6 0.0 2.8 2.4 0.6 5.9 1.2 141.1 

Selenium 3.6 3.4 2.6 3.3 1.8 9.1 2.8 141.0 

Silver 12.4 7.6 2.1 1.7 1.5 8.0 15.9 139.5 

Sodium 1.0 10.4 3.3 2.0 2.0 4.4 1.0 134.1 

Thallium 0.0 0.0 0.0 22.2 4.0 2.9 4.3 167.0 

Tin 1.0 2.3 3.3 9.1 0.7 2.1 5.8 ND 

Titanium 51.1 22.5 1.4 18.2 4.3 1.2 1.0 142.5 

Vanadium 1.1 3.2 4.1 2.9 6.6 3.1 11.9 148.9 

Yttrium 0.0 3.8 3.5 6.1 2.6 3.7 4.3 149.4 

Zinc 3.2 0.6 0.8 0.5 0.8 5.9 1.3 141.1 

Mercury 17.5 2.5 28.7 14.1 5.8 29.9 -- 136.1 
TNSSS Sampling and Analysis Technical Report 66 January 2009 

Table 32B. Duplicate Precision for Metals in Sewage Sludge 

Relative Percent Difference (%) 

Analyte Dup9 Dup10 Dup11 Dup12 Dup13 Dup14 Dup15

Aluminum 5.0 148.3 94.0 7.4 20.4 2.5 0.1 

Antimony 20.5 97.6 30.9 6.3 21.9 11.2 10.7 

Arsenic 1.8 89.8 41.7 0.4 7.7 18.8 7.3 

Barium 3.2 147.9 43.6 0.2 21.8 3.5 2.3 

Beryllium 6.2 81.1 ND 0.0 15.2 30.9 0.0 

Boron 8.7 135.6 71.2 8.3 11.5 3.5 0.7 

Cadmium 2.5 105.9 38.9 1.2 17.5 33.1 11.6 

Calcium 3.1 140.0 82.1 0.4 24.6 2.7 2.4 

Chromium 2.9 83.9 43.1 4.3 23.9 1.6 1.9 

Cobalt 2.2 98.0 17.8 0.0 27.0 1.8 9.5 

Copper 1.9 148.2 44.9 0.3 23.1 1.2 2.1 

Iron 3.0 144.6 91.8 4.4 19.8 0.6 1.3 

Lead 2.3 89.9 43.6 1.9 28.9 5.0 8.8 

Magnesium 3.4 129.8 51.1 3.7 19.1 0.8 1.6 

Manganese 2.3 144.9 87.6 0.7 13.5 2.3 2.3 

Molybdenum 1.9 91.2 48.0 4.2 6.1 46.0 6.0 

Nickel 0.6 89.6 38.2 0.4 32.5 7.9 11.2 

Phosphorus 2.4 137.7 63.4 0.9 11.3 1.5 2.0 

Selenium 0.0 63.9 50.0 1.3 2.2 45.2 8.6 

Silver 2.7 118.2 36.5 0.0 26.8 2.5 4.6 

Sodium 1.9 122.4 5.5 1.3 21.3 2.4 1.3 

Thallium 2.2 66.7 ND 8.0 6.5 43.7 0.0 

Tin 6.2 ND 48.4 1.3 21.0 7.6 9.1 

Titanium 12.6 ND 68.5 55.3 11.1 1.0 4.4 

Vanadium 7.3 89.8 53.1 2.6 20.4 1.1 10.5 

Yttrium 2.4 84.3 46.9 5.7 2.4 32.7 8.2 

Zinc 1.7 148.8 94.5 0.1 19.9 2.2 1.6 

Mercury -- -- -- 8.6 18.9 -- -- 

 The differences apparent in the three liquid sewage sludge samples in Table 32 

(duplicates 8, 10, and 11) cannot be attributed to differences between the percent solids results in 

different containers, as was suggested for the field duplicate samples earlier. Each of these 

duplicates was prepared at the laboratory from the single 500-mL HDPE container of sewage 

sludge from the particular POTW. 

 The laboratory homogenized each sample before removing the two aliquots (the original 

sample and the duplicate), but those procedures may not have been entirely adequate for samples 

with very low solids contents, or the samples may have settled between collection of the two 

aliquots. In addition, the laboratory only measured the percent solids of each sample once, for 

the original aliquot. Therefore, if the duplicate aliquot used for the metals analysis had slightly 

different solids content than that of the original sample aliquot, this would not be known or 

reflected in the dry-weight results in this survey. 

 EPA does not include laboratory duplicate analyses in a survey database, since that would 

provide two results for each sample chosen for this laboratory QC test. Therefore, while the 

RPD values in Table 32 may be useful in diagnosing laboratory issues, they do not influence the 

survey data EPA may use. 
TNSSS Sampling and Analysis Technical Report 67 January 2009 

6.8.5 MS/MSD Results for Organics 

 Organic contaminants such as the PAHs and semivolatiles of interest in this survey are 

generally less common in environmental samples. Therefore, most methods for organics specify 

using MS and MSD samples as the means of assessing the applicability of the method to the 

matrix of interest, rather than a single MS sample and a duplicate sample analysis. The 

advantage of spiking the analytes into both QC samples is that it avoids the difficulty of 

comparing non-detect results to assess precision. If the laboratory only analyzes an unspiked 

duplicate sample and a compound is not found, there is no numerical result that can be compared 

to the original sample result, which may also be a non-detect. While one can compare reporting 

limits for non-detects, those limits may differ for legitimate reasons that do not reflect analytical 

precision. 

 The laboratory prepared and analyzed seven sets of MS/MSD samples for the organics in 

this survey. They prepared some of the MS/MSD samples in conjunction with the full-scan 

GC/MS analyses and prepared others, later in the survey, with the selected ion monitoring (SIM) 

analyses. Five of the seven MS/MSD pairs were solid samples and two were liquid samples. 

The laboratory employed separate acceptance limits for samples analyzed as liquids versus those 

analyzed as solids. The results of all seven sets are summarized in Table 33. 

Table 33. MS and MSD Recovery and Precision for Organics 

MS/MSD 1 (solid) MS/MSD 2 (solid) MS/MSD 3 (solid) 

Analyte

MS 

Rec 

MSD 

Rec RPD 

MS 

Rec 

MSD 

Rec RPD 

MS 

Rec 

MSD 

Rec RPD 

2-Methylnaphthalene 55 60 9 19 11 56 120 143 18 

4-Chloroaniline 89 98 10 -480 -503 5 671 685 2 

Benzo(a)pyrene 104 112 7 -641 -589 9 131 115 14 

bis (2-Ethylhexyl) 

phthalate 149 226 41 -8024 -9476 17 -7160 -4296 50 

Fluoranthene 62 63 3 -2101 -1980 6 93 105 12 

Pyrene 51 61 17 -613 -754 21 105 146 32 

MS/MSD 4 (liquid) MS/MSD 5 (liquid) MS/MSD 6 (solid) 

MS 

Rec 

MSD 

Rec RPD 

MS 

Rec 

MSD 

Rec RPD 

MS 

Rec 

MSD 

Rec RPD 

2-Methylnaphthalene 62 67 9 99 108 8 109 110 1 

4-Chloroaniline 66 80 19 97 95 2 75 85 12 

Benzo(a)pyrene 67 80 18 169 94 58 117 120 3 

bis (2-Ethylhexyl) 

phthalate -72 16 314 -1362 -275 133 267 416 44 

Fluoranthene 43 44 2 290 119 84 124 135 8 

Pyrene 57 66 15 278 100 94 123 141 14 

MS/MSD 7 (solid) 

MS 

Rec 

MSD 

Rec RPD 

2-Methylnaphthalene 92 97 5 

4-Chloroaniline 53 57 7 

Benzo(a)pyrene 83 95 14 

bis (2-Ethylhexyl) 

phthalate 4622 4785 4 

Fluoranthene 78 97 22 

Pyrene 77 91 17 

 
TNSSS Sampling and Analysis Technical Report 68 January 2009 

 The recoveries in Table 33 exhibit some of the same issues as for the anions and metals, 

including large negative recoveries for some analytes, particularly bis(2-Ethylhexyl) phthalate. 

The laboratory adjusted the amounts of the analytes spiked into samples over the course of the 

survey. However, the within-sample variability affected many of the recoveries, resulting in 

some negative recovery values. Therefore, EPA recalculated the MS/MSD recoveries and RPDs 

using the alternative recovery equation described earlier. Table 34 presents the recalculated 

results, rounded to one-tenth of a percent, to illustrate some of the smaller differences. 

Table 34. Alternative MS and MSD Recovery and Precision for Organics 

MS/MSD 1 (solid) MS/MSD 2 (solid) MS/MSD 3 (solid) 

Analyte

MS 

Rec 

MSD 

Rec RPD 

MS 

Rec 

MSD 

Rec RPD 

MS 

Rec 

MSD 

Rec RPD 

2-Methylnaphthalene 66.6 70.4 5.5 67.6 64.2 5.2 109.7 120.8 9.6 

4-Chloroaniline 94.1 99.1 5.2 41.3 38.9 6.0 670.6 685.0 2.1 

Benzo(a)pyrene 104.0 111.7 7.1 61.3 64.0 4.3 113.0 106.0 6.4 

bis (2-Ethylhexyl) 

phthalate 112.3 131.6 15.8 71.7 66.7 7.2 82.2 89.2 8.2 

Fluoranthene 76.1 77.1 1.3 40.3 43.6 7.9 98.6 101.0 2.4 

Pyrene 71.1 76.8 7.7 70.8 65.0 8.5 101.1 110.0 8.4 

MS/MSD 4 (liquid) MS/MSD 5 (liquid) MS/MSD 6 (solid) 

MS 

Rec 

MSD 

Rec RPD 

MS 

Rec 

MSD 

Rec RPD 

MS 

Rec 

MSD 

Rec RPD 

2-Methylnaphthalene 63.1 68.5 8.2 99.3 107.6 8.0 108.9 109.9 0.9 

4-Chloroaniline 78.5 87.2 10.5 98.3 97.4 0.9 89.6 93.8 4.6 

Benzo(a)pyrene 74.8 84.5 12.2 142.1 96.0 38.7 114.8 117.4 2.2 

bis (2-Ethylhexyl) 

phthalate 73.9 87.3 16.6 68.1 91.8 29.6 115.3 129.0 11.2 

Fluoranthene 69.1 69.6 0.7 183.3 108.3 51.4 114.1 120.6 5.5 

Pyrene 70.3 76.7 8.7 171 99.9 52.5 114.6 126.1 9.6 

MS/MSD 7 (solid) 

MS 

Rec 

MSD 

Rec RPD 

2-Methylnaphthalene 92.5 97.3 5.1 

4-Chloroaniline 91.2 91.9 0.8 

Benzo(a)pyrene 90.0 97.2 7.7 

bis (2-Ethylhexyl) 

phthalate 526.1 541.5 2.9 

Fluoranthene 88.3 98.6 11.0 

Pyrene 88.0 95.3 8.0 

 As Table 34 illustrates, all of the negative recovery values are eliminated and the 

exceptionally large negative and positive recoveries for bis (2-Ethylhexyl) phthalate were 

reduced as well. With the notable exceptions of 4-chloroaniline in MS/MSD 3 and bis (2-

Ethylhexyl) phthalate in MS/MSD 7, the recoveries range from 39% to 183%. 

 A total of 74 out of 84 recoveries are less than 125% and 70 of 84 recoveries are in the 

range of 70% to 130%. Only 4 recoveries are below 50%. A total of 38 of 42 RPD values are 

less than 20%, with the other 4 RPDs between 30% and 53%. These alternative recovery data 

demonstrate that the analytical methods employed for this survey exhibit precision and bias 

within expected norms for the analysis of organics. 
TNSSS Sampling and Analysis Technical Report 69 January 2009 

6.8.6 MS/MSD Results for PBDEs 

 The laboratory performed the PBDE analyses using EPA Method 1614, which normally 

employs isotope dilution quantitation of the analytes of interest. Because every sample is spiked 

with the labeled compounds and their recoveries are measured in every sample, isotope dilution 

methods do not require the analysis of MS/MSD aliquots to assess bias. However, as noted in 

Section 4, the survey involved a number of modifications to the published method in order to 

overcome analytical challenges presented by the sewage sludge samples. One of these 

modifications was that the laboratory did not spike the labeled compounds into the sample before 

extraction, but rather spiked the raw sample extracts. Using this modification, the laboratory was 

able to successfully analyze the survey samples, but their data on labeled compound recovery 

does not include an assessment of extraction efficiency. Therefore, in conjunction with that 

modification, the laboratory agreed to prepare MS/MSD aliquots with each batch of field 

samples analyzed by the modified procedure. Ultimately, four sets of MS/MSD analyses were 

performed. Table 35 summarizes the MS/MSD results for the PBDEs. 

Table 35. MS/MSD Recovery and Precision for PBDEs 

MS/MSD 1 MS/MSD 2 

Analyte MS Rec MSD Rec RPD MS Rec MSD Rec RPD 

BDE-28 91 128 19 61 54 4.5 

BDE-47 0 3430 0 0 0 0 

BDE-66 0 197 0 26 0 0 

BDE-85 102 202 23 44 18 7.1 

BDE-99 0 1750 0 0 0 0 

BDE-100 146 547 23 0 0 0 

BDE-138 144 180 15 104 91 7.4 

BDE-153 91 256 22 0 0 0 

BDE-154 95 224 20 0 0 0 

BDE-183 104 123 8.7 54 35 9.8 

BDE-209 171 2910 18 0 0 0 

MS/MSD 3 MS/MSD 4

MS Rec MSD Rec RPD MS Rec MSD Rec RPD 

BDE-28 99 100 1.8 91 60 35 

BDE-47 215 121 5.4 298 0 0 

BDE-66 98 98 1 107 69 35 

BDE-85 102 105 3.2 113 61 41 

BDE-99 172 116 3.6 315 0 0 

BDE-100 118 98 5.1 128 2.9 51 

BDE-138 141 94 20 123 84 34 

BDE-153 94 102 4.4 106 36 45 

BDE-154 96 101 3.5 105 40 44 

BDE-183 106 98 3.8 88 58 34 

BDE-209 261 143 8.7 291 179 28 

The laboratory reported recoveries as zero (0) any time the calculated recovery was 

negative, and reported the RPD as 0 when either of the recovery values was reported 

as 0. 

As noted in Table 35, the laboratory’s reporting practices included substituting zero (0) 

for any calculated negative recoveries, as well as for the RPD when either recovery value in the 

MS/MSD pair is reported as 0. There are 16 negative recoveries reported as 0 for first 2 

MS/MSD pairs and only 2 negative recoveries for the last 2 MS/MSD pairs. This is because the 

laboratory increased their spiking levels for the later analyses. There are also a number of 

reported recoveries well over 100%, ranging as high as 3430% in one case. 
TNSSS Sampling and Analysis Technical Report 70 January 2009 

 Given these recoveries and RPDs, EPA performed the alternative calculations described 

in Sections 6.7.1 to 6.7.5 for the PBDE data. Those alternative recoveries and RPDs are shown 

in Table 36, rounded to one-tenth of a percent, to illustrate some of the smaller differences. 

Table 36. Alternative MS/MSD Recovery and Precision for PBDEs 

MS/MSD 1 MS/MSD 2 

Analyte MS Rec MSD Rec RPD MS Rec MSD Rec RPD 

BDE-28 95.7 116.1 19.3 81.5 51.7 44.8 

BDE-47 96.2 126.0 26.8 89.0 77.3 14.1 

BDE-66 72.3 124.7 53.2 82.9 76.5 8.1 

BDE-85 100.3 126.4 23.0 88.3 82.1 7.2 

BDE-99 94.3 121.2 24.9 84.1 78.0 7.6 

BDE-100 103.1 129.9 23.0 83.8 71.7 15.5 

BDE-138 127.0 148.4 15.5 101.9 94.6 7.5 

BDE-153 98.7 123.8 22.6 84.5 76.8 9.6 

BDE-154 98.6 120.5 20.0 85.7 77.6 9.9 

BDE-183 101.8 111.5 9.1 78.4 71.4 9.4 

BDE-209 99.9 120.4 18.6 94.0 79.5 16.7 

MS/MSD 3 MS/MSD 4

MS Rec MSD Rec RPD MS Rec MSD Rec RPD 

BDE-28 99.5 99.5 0.0 91.8 64.5 35.0 

BDE-47 107.2 101.6 5.4 120.8 68.7 55.0 

BDE-66 98.5 98.1 0.5 106.2 74.1 35.5 

BDE-85 101.3 103.3 2.0 109.0 72.1 40.8 

BDE-99 104.1 100.4 3.6 121.3 66.5 58.4 

BDE-100 104.2 98.6 5.6 110.0 65.3 51.1 

BDE-138 136.7 164.4 18.4 121.1 86.1 33.8 

BDE-153 96.8 100.3 3.5 103.0 65.5 44.5 

BDE-154 99.3 101.7 2.4 102.2 65.2 44.2 

BDE-183 103.8 98.8 5.0 89.3 63.3 34.1 

BDE-209 111.9 102.6 8.7 172.4 130.1 27.9 

 Using the alternative calculations, all 18 of the negative values originally reported by the 

laboratory as “0” were eliminated. The recalculated recoveries range from 52% to 172%. The 

laboratory employed acceptance limits of 50-150% for MS/MSD recoveries, and all but the one 

recalculated recovery of 172.4% fall within that range. The calculated RPD values range from 

0% to 58.4%. Only three recalculated RPD values were above the laboratory’s acceptance limit 

of 50%. 

 As with the other analytical classes, these alternative recovery data demonstrate that the 

analytical methods employed for this survey exhibit precision and bias within expected norms 

for the analysis of PBDEs. 

6.8.7 Qualification of Sample Results based on MS/MSD Results 

 During review of the sample results, EPA qualified any MS/MSD results reported by the 

laboratory that fell outside of the relevant acceptance limits. Those data qualifiers were carried 

over into the results database. However, the results of the alternative calculations shown in 

Section 6.7 for all classes of analytes demonstrate that the shortcomings in MS/MSD recoveries 

and precision are largely a function of the calculations in many EPA methods. 

 
TNSSS Sampling and Analysis Technical Report 71 January 2009 

 Therefore, while retaining the data qualifiers that indicate that the recoveries and/or RPD 

reported by the laboratories fell outside of the acceptance limits, EPA also added a qualifier to 

affected samples to indicate that the alternative calculations suggest that method performance in 

the sewage sludge matrix is not an immediate concern. This new qualifier is “ACAP,” for 

“Alternative Calculation indicates Acceptable Performance,” as stated in the database. 

6.8.8 Labeled Compound Recoveries for Isotope Dilution Methods 

 As noted elsewhere in this report, EPA’s isotope dilution methods spike labeled analogs 

of the target analytes into each sample and monitor the recoveries of those labeled compounds as 

a measure of method performance. Therefore, EPA’s isotope dilution methods do not require 

that the laboratory prepare separate matrix spike samples. Rather than assessing extraction 

efficiency and other aspects of method performance on 5% of the samples (i.e., 1 out of every 20 

samples is used to create an MS/MSD pair), the isotope dilution methods generate extraction 

efficiency data on 100% of the samples, and use those data to correct the final results for each 

analyte for the recovery of its labeled compound. 

 During the data review process, EPA checked the recovery of every labeled compound in 

every field sample and QC samples against the method acceptance criteria for that analyte. 

When the labeled recovery fell outside of the acceptance criteria, EPA flagged in the database 

the sample results for the associated unlabeled analytes. 
TNSSS Sampling and Analysis Technical Report 72 January 2009 

Section 7 

References

NRC, 2002. Biosolids Applied To Land: Advancing Standards And Practices, National Research 

Council of the National Academies. July 2002. 

USEPA, 2003. United States Federal Register. 68 FR 75531. Wednesday December 31, 2003, 

pp. 75531-75552. 

Vadas, P. A. and Kleinman, P. J. A., 2006. Effect of Methodology in Estimating and Interpreting 

Water-Extractable Phosphorus in Animal Manures, J. Environ. Qual., 35: 1151-159. 
TNSSS Sampling and Analysis Technical Report 73 January 2009 

Appendix A 

Solids Leaching Procedure for Anions 

1. Using the percent solids determined by drying an aliquot of the sample of known weight 

overnight at 103 - 105°C and reweighing, weigh out a sample aliquot equal to 0.5 g dry 

weight in a 200- or 250-mL wide-mouth (screw-top) plastic bottle. 

2. Add reagent water until the total mixture mass is 100.5 g. The resultant solids:solution ratio 

is 0.5 g solids:100-mL solution, or 1:200. 

3. Seal bottles with screw top caps and place in a standard laboratory shaker set at 70 

revolutions per minute for 60 minutes. 

4. Upon completion of agitation, centrifuge sealed bottles at 2000 rpm for 10 minutes. 

5. Gravity filter the concentrate from step 4 using Whitman #2 filter paper. (Suggest 150-mm 

circular filters folded and placed in simple plastic lab funnels.) 

6. Adjust the pH of the filtrate to pH<2 with H2SO4 to preserve the nitrate/nitrite in the filtrate 

and store at 4°C until analysis. 

7. The holding time for nitrate/nitrite is 48 hours, so samples must be analyzed for all three 

analytes within 48 hours of preservation. 

8. All sample results will be reported in mg/kg on the basis of the original 0.5-g sludge sample. 

Adapted from Vadas, P. A. and Kleinman, P. J. A., 2006. 
TNSSS Sampling and Analysis Technical Report 74 January 2009 

Appendix B 

Method Modifications for the PBDE Analyses 

 The following table summarizes the modifications made to the sample preparation and 

analysis procedures described in EPA Method 1614 for the analysis of the PBDEs. EPA and the 

laboratory instituted these modifications to address the interferences present in extracts of the 

samples, and the relatively high levels of some PBDEs in the samples. 

 

 The table provides a reference to the relevant section of the draft method, the original 

method specification, and the revised approach employed for this survey. 

Method Section Topic Original Method Specification Revised Approach 

11.5.1 Sample size 10 g dry weight As little as 0.2 g dry weight 

11.5.2 Spiking labeled 

standards 

Spike into sample before extraction Spike sample extract before 

cleanup 

12.6 Macroconcentration 

of extract 

3 – 4 mL 10 mL 

13 Cleanups May use GPC, silica gel, alumina, 

or Florisil, if needed. 

Must use silica gel, GPC, and 

alumina, in that order 

13.2.3 GPC cleanup Process 5 mL of extract Process 1 mL of the 10 mL extract 

1.1.1 and 17 Target analytes All 209 possible BDE congeners Only 11 congeners: 

 BDE-28 

 BDE-47 

 BDE-66 

 BDE-85 

 BDE-99 

 BDE-100 

 BDE-138 

 BDE-153 

 BDE-154 

 BDE-183 

 BDE-209 

17.1 Isotope dilution 

quantitation 

11 congeners determined by true 

isotope dilution, and the remaining 

congeners by internal standard. 

The internal standards are the 

labeled congeners for other PBDEs 

that are added to the samples 

before extraction. 

11 congeners quantified using 

labeled standards for 8 of those 11 

congeners, all spiked into the 

extract before cleanup. All results 

are corrected for losses during the 

cleanup steps, but not for initial 

extraction efficiency. 

17.1 Matrix spike 

samples 

Not used, due to isotope dilution Added periodic MS/MSD to 

provide data on extraction 

efficiency 

17.5 Calibration range All results must be within the 

calibration range, or must be 

diluted to bring them within range 

Results for some congeners like 

BDE-209 flagged “E” in the 

database if above the calibration 

range but not high enough to 

saturate the detector system. 
TNSSS Sampling and Analysis Technical Report 75 January 2009 

Appendix C 

QC Acceptance Criteria 

QC Acceptance Criteria for the Targeted National Sewage Sludge Survey 

Analytical Fraction QC Parameter Analyte Acceptance Limits (%) 

Fluoride 85-115 

LCS Phosphorus 85-115 

Nitrate/Nitrite 90-110 

MS Recovery All analytes 75-125 

Anions 

Duplicate Precision (RPD) All analytes 20 

Aluminum 58-142 

Antimony 12-223 

Arsenic 77-123 

Barium 82-118 

Beryllium 77-122 

Boron 56-144 

Cadmium 80-121 

Calcium 79-121 

Chromium 78-121 

Cobalt 80-120 

Copper 82-118 

Iron 50-150 

Lead 79-121 

Magnesium 77-123 

Manganese 80-120 

Mercury 60-123 

Molybdenum 72-128 

Nickel 81-119 

Phosphorus NA 

Selenium 76-124 

Silver 61-139 

Sodium 56-145 

Thallium 76-124 

Tin NA 

Titanium 40-160 

Vanadium 76-124 

Yttrium NA 

LCS for solid samples 

Zinc 79-120 

LCS for liquid samples All metals 85 -115 

All metals, except as noted 

below 

70-130 

Mercury 60-128 

Tin 50-150 

MS/MSD Recovery 

Titanium 50-150 

Metals 

MS/MSD Precision (RPD) All metals 30 

4-Chloroaniline 39-95 

2-Methylnaphthalene 12-159 

Fluoranthene 47-139 

Pyrene 52-129 

bis (2-Ethylhexyl) phthalate 39-174 

LCS 

Benzo(a)pyrene 49-144 

4-Chloroaniline 10-104 

2-Methylnaphthalene 39-116 

Fluoranthene 49-130 

Pyrene 58-110 

bis (2-Ethylhexyl) phthalate 53-172 

Organics 

MS/MSD Recovery for solid 

samples 

Benzo(a)pyrene 50-126 

NA = Not applicable. The commercial reference material used for the LCS does not have certified values for these analytes. 
TNSSS Sampling and Analysis Technical Report 76 January 2009 

QC Acceptance Criteria for the 2006–2007 Targeted National Sewage Sludge Survey 

Analytical Fraction QC Parameter Analyte Acceptance Limits (%) 

4-Chloroaniline 10-62 

2-Methylnaphthalene 10-109 

Fluoranthene 10-150 

Pyrene 10-136 

bis (2-Ethylhexyl) phthalate 10-150 

MS/MSD Recovery for liquid 

samples 

Benzo(a)pyrene 10-152 

MS/MSD Precision (RPD) All analytes, all matrix types 40 

Nitrobenzene-d5 35-128 

2-Fluorobiphenyl 43-133 

Organics 

Surrogate Recovery 

p-Terphenyl-d14 49-137 

LCS All analytes 25-150 

Labeled Compound All, except as shown below 25-150 

Recovery 13C-BDE-209 20-200 

MS/MSD Recovery All analytes 50-150 

PBDEs 

MS/MSD Precision (RPD) All analytes 50 

QC Acceptance Criteria for Pharmaceuticals for the 

Targeted National Sewage Sludge Survey 

Analyte VER (%) OPR (%) 

Acid-Extractable Fraction - Positive Electrospray Ionization

Acetaminophen 70 -130 50 -120 

Azithromycin 70 -130 33 -120 

Caffeine 70 -130 50 -124 

Carbadox 70 -130 33 - 144 

Carbamazepine 70 -130 21 - 137 

Cefotaxime 70 -130 8 - 186 

Ciprofloxacin 70 -130 50 - 120 

Clarithromycin 70 -130 8 - 154 

Clinafloxacin 70 -130 5 - 200 

Cloxacillin 70 -130 5 - 200 

Codeine 70 -130 34 - 129 

Cotinine 70 -130 50 - 124 

Dehydronifedipine 70 -130 42 - 120 

Digoxigenin 70 -130 8 - 183 

Digoxin 70 -130 5 - 148 

Diltiazem 70 -130 11 - 120 

1,7-Dimethylxanthine 70 -130 50 - 138 

Diphenhydramine 70 -130 48 - 120 

Enrofloxacin 70 -130 50 - 125 

Erythromycin 70 -130 50 - 158 

Flumequine 70 -130 36 - 200 

Fluoxetine 70 -130 49 - 125 

Lincomycin 70 -130 5 - 120 

Lomefloxacin 70 -130 17 - 120 

Miconazole 70 -130 27 - 120 

Norfloxacin 70 -130 50 - 135 

Norgestimate 70 -130 36 - 120 

Ofloxacin 70 -130 50 - 200 

Ormetoprim 70 -130 50 - 120 

Oxacillin 70 -130 5 - 200 
TNSSS Sampling and Analysis Technical Report 77 January 2009 

QC Acceptance Criteria for Pharmaceuticals for the 

Targeted National Sewage Sludge Survey 

Analyte VER (%) OPR (%) 

Oxolinic Acid 70 -130 42 - 124 

Penicillin G 70 -130 5 - 200 

Penicillin V 70 -130 5 - 200 

Roxithromycin 70 -130 38 - 120 

Sarafloxacin 70 -130 17 - 200 

Sulfachloropyridazine 70 -130 50 - 200 

Sulfadiazine 70 -130 5 - 200 

Sulfadimethoxine 70 -130 50 - 120 

Sulfamerazine 70 -130 50 - 148 

Sulfamethazine 70 -130 50 - 142 

Sulfamethizole 70 -130 50 - 120 

Sulfamethoxazole 70 -130 50 - 120 

Sulfanilamide 70 -130 5 - 189 

Sulfathiazole 70 -130 41 - 120 

Thiabendazole 70 -130 50 - 120 

Trimethoprim 70 -130 50 - 126 

Tylosin 70 -130 16 - 149 

Virginiamycin 70 -130 5 - 189 

Tetracyclines

Anhydrochlortetracycline 70 -130 50 - 135 

Anhydrotetracycline 70 -130 7 - 141 

Chlortetracycline 70 -130 45 - 172 

Demeclocycline 70 -130 5 - 200 

Doxycycline 70 -130 22 - 166 

4-Epianhydrochlortetracycline 70 -130 18 - 120 

4-Epianhydrotetracycline 70 -130 5 - 200 

4-Epichlortetracycline 70 -130 40 - 150 

4-Epioxytetracycline 70 -130 50 - 142 

4-Epitetracycline 70 -130 50 - 173 

Isochlortetracycline 70 -130 5 - 200 

Minocycline 70 -130 5 - 176 

Oxytetracyclin 70 -130 50 - 183 

Tetracycline 70 -130 50 - 155 

Acid-Extractable Fraction - Negative Electrospray Ionization

Gemfibrozil 70 -130 50 - 120 

Ibuprofen 70 -130 50 - 120 

Naproxen 70 -130 50 - 120 

Triclocarban 70 -130 50 - 120 

Triclosan 70 -130 50 - 120 

Warfarin 70 -130 50 - 120 

Base-Extractable Fraction - Positive Electrospray Ionization

Albuterol 70 -130 50 - 133 

Cimetidine 70 -130 5 - 120 

Metformin 70 -130 50 - 149 

Ranitidine 70 -130 24 - 160 
TNSSS Sampling and Analysis Technical Report 78 January 2009 

QC Acceptance Criteria for Pharmaceutical Labeled Compounds for 

the Targeted National Sewage Sludge Survey 

Analyte VER (%) OPR (%) Recovery in Samples (%) 

Acid-Extractable Fraction - Positive Electrospray Ionization 13C2-

15N-Acetaminophen 70 -130 5 - 200 19 - 200 13C3-Caffeine 70 -130 5 - 200 31 - 200 13C3-

15N-Ciprofloxacin 70 -130 5 - 200 37 - 181 

Cotinine-d3 70 -130 5 - 120 5 - 145 13C2-Erythromycin 70 -130 50 - 120 23 - 120 

Fluoxetine-d5 70 -130 50 - 126 40 - 148 13C6-Sulfamethazine 70 -130 5 - 157 12 - 120 13C6-Sulfamethoxazole 70 -130 50 - 146 40 - 129 

Thiabendazole-d6 

A

 70 -130 50 - 146 32 - 140 13C3-Trimethoprim 70 -130 50 - 177 50 - 172 

Tetracyclines 

Thiabendazole-d6 

A

 70 -130 50 - 120 30 - 132 

Acid-Extractable Fraction - Negative Electrospray Ionization 

Gemfibrozil-d6 70 -130 38 - 122 21 - 123 13C3-Ibuprofen 70 -130 28 - 122 29 - 127 13C-Naproxen-d3 70 -130 34 - 131 14 - 132 13C6-Triclocarban 70 -130 5 - 172 5 - 147 13C12-Triclosan 70 -130 5 - 168 5 - 153 

Warfarin-d5 70 -130 50 - 177 50 - 200 

Base-Extractable Fraction - Positive Electrospray Ionization 

Albuterol-d3 70 -130 35 - 121 39 - 141 

Metformin-d6 70 -130 5 - 141 5 - 200 

A Thiabendazole-d6 is used as a labeled analog in both the tetracyclines and the acid 

extractable-positive electrospray fractions, with separate acceptance criteria. 
TNSSS Sampling and Analysis Technical Report 79 January 2009 

QC Acceptance Criteria for Steroids and Hormones for 

the Targeted National Sewage Sludge Survey

Analyte VER (%) OPR (%) 

Androstenedione 70 - 130 5 - 200 

Androsterone 70 - 130 50 - 121 

Campesterol 70 - 130 40 - 200 

Cholestanol 70 - 130 50 - 164 

Cholesterol 70 - 130 5 - 200 

Coprostanol 70 - 130 34 - 200 

Desmosterol 70 - 130 5 - 200 

17α-Dihydroequilin 70 - 130 45 - 151 

Epicoprostanol 70 - 130 50 - 197 

Equilenin 70 - 130 5 - 200 

Equilin 65 - 135 5 - 200 

Ergosterol 50 - 150 5 - 200 

17α-Estradiol 70 - 130 50 - 120 

17α-Ethinyl estradiol 70 - 130 50 - 123 

17β-Estradiol 70 - 130 50 - 176 

β-Estradiol-3-benzoate 70 - 130 5 - 189 

Estriol 70 - 130 5 - 193 

Estrone 70 - 130 50 - 173 

Norethindrone 70 - 130 45 - 200 

Norgestrel 70 - 130 46 - 200 

Progesterone 70 - 130 5 - 200 

β-Sitosterol 70 - 130 5 - 200 

β-Stigmastanol 70 - 130 29 - 200 

Stigmasterol 70 - 130 50 - 200 

Testosterone 70 - 130 50 - 136 

QC Acceptance Criteria for Steroid and Hormone Labeled Compounds 

for the Targeted National Sewage Sludge Survey 

Analyte VER (%) OPR (%) Recovery in Samples (%) 

Cholesterol-d7 70 - 130 50 - 120 50 - 120 

17α-Ethinyl estradiol-d4 70 - 130 50 - 120 50 - 120 

17β-Estradiol-d4 70 - 130 50 - 120 29 - 132 

Norethindrone-d6 70 - 130 37 - 120 12 - 120 

Norgestrel-d6 70 - 130 36 - 120 7 - 120 

Progesterone-d9 70 - 130 5 - 200 5 - 200