Brominated Diphenyl Ether Results from EPA’s Targeted National Sewage Sludge Survey Harry McCarty, CSC and Rick Stevens, USEPA

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Background Sewage sludge is also known as “biosolids” Defined in USEPA regulations as a solid, semi-solid, or liquid residue generated during treatment of domestic sewage in a treatment works (40 CFR 503) By definition, it does not include residuals from treatment of industrial wastewater

Regulatory History In the U.S., the Clean Water Act places limits on the pollutants in effluent discharges Historically, the limits began with 126 “priority pollutants,” which include metals and common organic chemicals There are over 16,000 publicly owned treatment works (POTWs) in the U.S., and every plant is subject to Federal, State, and sometimes local, regulations on its effluent discharge and its sludge Separate regulations exist for effluents discharged from industrial wastewater treatment facilities

New and Emerging Contaminants EPA continues to investigate additional pollutants, including various “new and emerging” contaminants Among those “new and emerging” contaminants are the polybrominated diphenyl ethers (PBDEs) that are used as flame retardants in various products Other new contaminants of interest include drugs, steroids, hormones, and other personal- care products, collectively called PPCPs

National Sewage Sludge Surveys EPA has conducted 3 national surveys: – , examining over 400 pollutants (organics and metals) in samples from 174 POTWs –2001, examining PCDDs, PCDFs, and 12 “toxic” PCB congeners in samples from 94 POTWs – , examining selected metals, anions, semivolatile organics, and other contaminants in samples from 74 POTWs Each survey designed to obtain unbiased national estimates of pollutant concentrations in final sludge products

Sludge Surveys (cont.) survey lead to the 1992 numerical limits on 10 metals in sewage sludge managed through land application, surface disposal, and incineration 2001 survey lead to the conclusion that: “neither numerical limitations nor requirements for management practices are currently needed to protect human health and the environment from reasonably anticipated adverse effects from dioxin and dioxin-like compounds in land-applied sewage sludge”

Sludge Survey Designed to provide data for a small set of anions, metals, and semivolatile organics for which new human health benchmark data are available Expanded to include additional contaminants, including the PBDEs and PPCPs

Target POTW Population Plant existed in 2002 or 2004 Flow rate ≥1 million gallons per day (MGD) Employs at least secondary treatment Produces a final treated biosolid product Not known to employ a pond or lagoon as the final stage of treatment, and Located in the contiguous United States

Target POTWs (cont.) 16,255 POTWs nationwide 3337 POTWs that meet the definition of the target population EPA selected a national sample of 80 POTWs from the 3,337 facilities in the target population Random sampling design stratified for flow

Stratification by Flow 1 to 10 MGD, representing approximately 75% of the POTWs nationwide 10 to 100 MGD, representing approximately 15% of the POTWs nationwide >100 MGD, representing approximately 10% of the POTWs nationwide

National Coverage – POTWs in 37 States

Sample Collection CSC staff sampled at 73 POTWs between August and December 2006 Sampling delayed at 1 POTW until April 2007, due to repairs 6 POTWs in the original 80 were not sampled: –Did not produce a final sludge product (partial treatment only), or –Used a lagoon that was not yet mature

Sample Collection (cont.) 74 POTWs and 78 sludges in total –Collected samples of two products at each of 4 POTWs (multiple treatment lines) –Also collected field duplicate samples at 6 POTWs, as a check on sampling procedures At each plant, CSC collected –4 500-mL wide mouth HDPE jars (for anions and metals analyses) and –8 500-mL or 1-L wide-mouth glass jars (for organics, including PBDEs)

Sample Shipment Given logistics of shipping samples from 74 sites to multiple labs, all samples were sent to an EPA Sample Repository in Baltimore, MD, and stored frozen Once sites were sampled, batches of frozen samples were shipped to 3 contract labs, and a group of collaborators including 2 EPA labs and 3 university labs Only the 3 contract labs, 1 EPA lab, and 1 university lab received every sample

Sampling Summary 12 samplers 107 days of travel 46 one-way airline flights 19,419 miles driven 1,002 jars of sludge collected Over 300 coolers shipped one way Over 500 jars of sludge shipped to 8 labs

PBDE Analysis Samples for PBDE analyses were held frozen for about 1 year before being shipped to lab Used EPA Method 1614, a high resolution GC/MS procedure employing isotope dilution Originally targeted the 45 PBDE congeners or coeluting congener pairs listed in the method Due to the complexity of the matrix and concentrations present, scaled back to 11 congeners

11 Target Congeners BDE-028BDE-099BDE-154 BDE-047BDE-100BDE-183 BDE-066BDE-138BDE-209 BDE-085BDE-153 Yellow indicates the 8 congeners identified in the method as being of potential environmental or public health significance (4th Annual Workshop on Brominated Flame Retardants in the Environment, June 2002)

Sludge is a “challenging” matrix!

Study-Specific Modifications Reduce sample size from 10 g to 0.2 g, dry weight (to stay within calibration range) Extract samples before adding labeled compounds (to avoid diluting them out) Concentrate extract to 10-mL volume and take only 1 mL through silica gel, GPC, and alumina cleanups (to avoid overloading) Spike that 1 mL with labeled compounds (to compensate for losses during cleanup) Retain the other 9 mL for dilutions or more cleanups, if needed

Potential Ramifications Reduced sample size could affect sensitivity Concern about representativeness of aliquot analyzed Extraction efficiency not accounted for by isotope dilution, so added matrix spike samples (MS/MSD pair) with each extraction batch

Analytical Reality Sensitivity generally was not an issue –9 of 11 congeners reported in all 84 samples –BDE-209 detected in 83 samples –BDE-138 only detected in 56 samples –Many samples required significant dilutions to bring results within calibration range Representativeness of a 0.2-g sample is a concern, but probably no more so than a 1-L jar versus a 1-million gallon tank or a 100-foot long pile

Analytical Reality (cont.) MS/MSD analyses –Recovery calculations affected by high background concentrations in some samples –Calculation problem not unique to PBDEs, or to this study CSC performed alternative recovery calculations –Eliminated any chance of negative recoveries –Revised recoveries range from 52 to 172% –Revised RPDs range from 0 to 58%

Results (with apologies to Dick Orkin and Chickenman)

They’re everywhere!

Keep in mind

Summary Data AnalyteCount Concentration (µg/kg, dry weight) MinimumMaximumMean1Mean2 BDE BDE , BDE BDE BDE , BDE , Mean1 is the simple arithmetic average of all detected results (n=84) Mean2 uses the average result for each pair of field duplicate samples at 6 plants (n=78)

Summary Data (cont.) AnalyteCount Concentration (µg/kg, dry weight) MinimumMaximumMean1Mean2 BDE BDE BDE BDE BDE ,5001,737 1,617 % solids Mean1 is the simple arithmetic average of all detected results (n=84) Mean2 uses the average result for each pair of field duplicate samples at 6 plants (n=78)

Percentile Concentrations Analyte Percentile Concentration (µg/kg, dry weight) 99th98th95th90th50th BDE BDE-0472,6502,2121,6891, BDE BDE BDE-0992,6972,2481,7131, BDE

Percentile Concentrations Analyte Percentile Concentration (µg/kg, dry weight) 99th98th95th90th50th BDE BDE BDE BDE BDE-2097,5156,0434,3643,2691,178 BDE-138 only reported in 56 samples, BDE-209 only reported in 77 samples, all others reported in all 78 samples

Preliminary Data Analyses Examined correlations between pairs of congeners and with % solids and performed an analysis of variance (ANOVA) with the flow stratum No strong correlations with % solids for any congener (r values range from to -0.10) No apparent effects of flow stratum

BDE-209 by Stratum

Preliminary Analyses (cont.) Good correlations between congeners within the same level of bromination –All r values >0.9 –Except for those involving BDE 138, for which there were more non-detects Correlations between congeners in adjacent levels of bromination are lower, with r values generally between 0.8 and 0.9 for the tri- through hexa-BDEs

Preliminary Analyses (cont.) Correlations between hexa and either hepta or deca congeners are much lower ( r values range from 0.57 to 0.64) Correlation of hepta and deca congeners is only 0.67 Deca is not well correlated with any other congeners (r values range from 0.46 to 0.67) Deca results similar across strata

Example Correlation Plot

Possible Implications Different sources for the congeners BDE-209 may be coming from a separate source Results may reflect changes in flame retardant formulations over time, mediated by human body burdens and excretion rates

Contacts For questions about this presentation, contact: Harry McCarty Computer Sciences Corporation For questions about the Targeted National Sewage Sludge Survey, contact: Rick Stevens USEPA National Biosolids Coordinator