CATALOG DOCUMENTATION EMAP-ESTUARIES PROGRAM LEVEL DATABASE 1991 VIRGINIAN PROVINCE SEDIMENT CHEMISTRY TABLE OF CONTENTS 1. DATA SET IDENTIFICATION 2. INVESTIGATOR INFORMATION 3. DATA SET ABSTRACT 4. OBJECTIVES AND INTRODUCTION 5. DATA ACQUISITION AND PROCESSING METHODS 6. DATA MANIPULATIONS 7. DATA DESCRIPTION 8. GEOGRAPHIC AND SPATIAL INFORMATION 9. QUALITY CONTROL/QUALITY ASSURANCE 10. DATA ACCESS 11. REFERENCES 12. TABLE OF ACRONYMS 13. PERSONNEL INFORMATION 1. DATA SET IDENTIFICATION 1.1 Title of Catalog document EMAP-Estuaries Program Level Database 1991 Virginian Province Sediment Chemistry Data 1.2 Authors of the Catalog entry Charles Strobel, U.S. EPA NHEERL-AED Melissa M. Hughes, CSC 1.3 Catalog revision date 20 March 1996 1.4 Data set name vp91_sediment_chemistry_data.txt vp91_sediment_chemistry_qa_codes.txt vp90-93_sediment_analytes.txt 1.5 Task Group Estuaries 1.6 Data set identification code 00025 1.7 Version 001 1.8 Requested Acknowledgment These data were produced as part of the U.S. EPA's Environmental Monitoring and Assessment Program (EMAP). If you plan to publish these data in any way, EPA requires a standard statement for work it has supported: "Although the data described in this article has been funded wholly or in part by the U. S. Environmental Protection Agency through its EMAP-Estuaries Program, it has not been subjected to Agency review, and therefore does not necessarily reflect the views of the Agency and no official endorsement should be inferred." 2. INVESTIGATOR INFORMATION 2.1 Principal Investigator Darryl Keith U.S. Environmental Protection Agency NHEERL-AED 2.2 Investigation Participant-Sample Collection Charles J. Strobel U.S. Environmental Protection Agency NHEERL-AED 2.3 Principal Investigator-Sample Processing John Martinson U.S. Environmental Protection Agency Environmental Monitoring Systems Laboratory-Cincinnati 3. DATA SET ABSTRACT 3.1 Abstract of the Data Set The Sediment Chemistry data set presents a suite of chemical concentrations derived from analyses of a surface sediment sample collected at a station in the Virginian Province. Individual and summed analyte concentrations are presented. A code for each compound is given under ANALYTE. These include 18 inorganic, 57 organic, five organic concentration sums, Total Organic Carbon (TOC) and acid volatile sulfides (AVS). Concentrations are recorded in dry weight. Units are reported under a separate attribute: ug/g, ng/g, % or umoles/g. Quality Assurance/Quality Control issues are coded. Depending on the QA code, only a detection limit may be reported. 3.2 Keywords for the Data Set Contaminants, DDT, inorganic analytes, organic analytes, PAH, PCB, pesticides, QA Code, sediment, sediment chemistry, TOC and AVS 4. OBJECTIVES AND INTRODUCTION 4.1 Program Objective The Environmental Monitoring and Assessment Program (EMAP) was designed to periodically estimate the status and trends of the Nation's ecological resources on a regional basis. EMAP provides a strategy to identify and bound the extent, magnitude and location of environmental degradation and improvement on a regional scale based on station sites randomly located in estuaries. 4.2 Data Set Objective The objective of the Sediment Chemistry data set is to present the concentrations of a suite of analytes and compounds measured from an uncontaminated surface sediment sample collected at a station in the Virginian Province. The sample was an homogenate composed of several grabs. Only the randomly located Base Sampling Sites (BASE) are included in this data set. 4.3 Data Set Background Discussion The presence of contaminants in estuaries has been identified in both the scientific and popular press as a major problem contributing to degraded ecological resources and restricted harvest of fish and shellfish resources due to human health concerns. Reducing contaminant inputs and concentrations, therefore, is often a major focus of regulatory programs for estuaries. Contaminants include both inorganic (primarily metals) and organic forms originating from many sources, including atmospheric deposition, freshwater inputs, land runoff and point sources. These sources are poorly characterized, except in the most well-studied estuaries. Most contaminants that are potentially toxic to indigenous biological resources tend to bind to particles, which ultimately are deposited at the bottom of estuaries. This binding changes the form of contaminants and removes them from the water column; consequently, contaminants accumulate in estuarine sediments. Sediment contaminant concentrations were measured to aid in the interpretation of the spatial patterns observed in the condition of biological resources in the estuaries of the Virginian Province. EMAP monitoring efforts have focused on sediment contaminants rather than measurement of water column contaminants because concentrations of contaminants in sediments are less variable and the sediment integrates contaminant inputs to estuaries over time (i.e., months and years). Metals in the sediment are derived from anthropogenic sources or from the natural geochemical processes of weathering and erosion of the earth's crust. The difficulty arises in identifying which portion of the total metal content of the sediment was due to natural processes and which was due to human activities. Several methods can be used to determine whether measured metal concentrations in estuarine sediments represent anthropogenically-enriched or natural conditions. A further discussion can be found in one of the EMAP-VP statistical summaries. 4.4 Summary of Data Set Parameters The organic and inorganic compound concentrations measured included: 15 major and trace elements, 24 individual Poly-Aromatic Hydrocarbon (PAH) compounds, the pesticide DDT and its metabolites, 9 pesticides other than DDT, 18 individual Poly-Chlorinated Biphenyl (PCB) congeners, mono-, di- and tri-butyltin (MBT, DBT, TBT), Total Organic Carbon (TOC) and acid volatile sulfides (AVS). This suite of analytes is the same as that measured in the National Oceanic and Atmospheric Administration's (NOAA) National Status and Trends (NS&T) program. Values in this data set include individual inorganic and organic compound concentrations and concentrations summed for several major groups: total PAHs, Low and High Molecular Weight PAHs, PCBs and DDTs. Concentrations of all sediment chemistry analytes are reported on a dry weight basis. 5.0 DATA ACQUISITION AND PROCESSING METHODS 5.1 Data Acquisition 5.1.1 Sampling Objective Collect sediment samples suitable for the analysis of organic and inorganic compounds, TOC and AVS. One sediment sample was expected to be collected at each station. 5.1.2 Sample Collection Methods Summary The grab sampler was lowered through the water column such that travel through the last 5 meters was no faster than 1 m/sec. The grab penetrated the sediment by gravity releasing a trigger allowing the jaws to close. When the grab was pulled from the sediment using the winch, the jaws closed, encapsulating the sediment sample. The chance of sampling the exact same location twice was minimized. After three grabs were taken, the boat was moved five meters downstream by letting out the appropriate length of anchor line. Stainless steel utensils were used to remove the top two cm of sediment from a grab. The sediment was removed to a stainless steel bowl and placed in a cooler of ice to remain cold, but unfrozen. The grab sampler was rinsed and re-deployed. This procedure was repeated until approximately 3,000 cc of sediment was collected. The sediment was mixed by hand until thoroughly homogenized, and aliquots were placed immediately into pre-cleaned glass jars (for organics) or plastic containers (for inorganics and AVS). The samples were immediately stored on ice following collection. The remainder of the sediment was split between grain size and sediment toxicity samples. 5.1.3 Beginning Sampling Date 22 July 1991 5.1.4 Ending Sampling Date 13 September 1991 5.1.5 Platform Sampling was conducted from 8 m (24 ft), twin-engine Chesapeake style work boats. 5.1.6 Sampling Equipment A 1/25 m2, Kynar-coated stainless steel, Young-modified Van Veen Grab sampler was used to collect sediments. This grab sampled an area of 440 cm2 and a maximum depth of penetration in the sediment of 10 cm. 5.1.7 Manufacturer of Sampling Equipment Young's Welding, Sandwich, MA 5.1.8 Key Variables This data set does not contain any values which were measured at the time of collection. 5.1.9 Sampling Method Calibration The sampling gear does not require any calibration. It required inspection for deformities incurred due to mishandling or impact on rocky substrates. 5.1.10 Sample Collection Quality Control Field technicians were trained to follow Standard Operating Procedures to insure the collection of representative, uncontaminated and high quality samples. QA/QC measures were taken in the field to avoid or reduce contamination and insure the collection of representative samples. These included: use of stainless steel instruments, thorough cleaning of the sampler between grabs, use of pre-cleaned containers for sediment storage and ensuring that engines were shut down when a sample was exposed to the air. A successful grab had relatively level, intact sediment over the entire area of the grab and a sediment depth of 7-10 centimeters. Unacceptable grabs included those: containing no sediments, which were partially filled or had shelly substrates or grossly slumped surfaces. Grabs completely filled to the top, where the sediment was oozing out of the hinged top, were also unacceptable. 5.1.11 Sample Collection Method Reference Strobel, C. J. and S. C. Schimmel. 1991. Environmental Monitoring and Assessment Program Near Coastal Component: 1991 Virginian Province Field Operations and Safety Manual. U.S. Environmental Protection Agency, Office of Research and Development, NHEERL-AED, Narragansett, RI. June 1991. 5.1.12 Sample Collection Method Deviations None 5.2 Data Preparation and Sample Processing 5.2.1 Sample Processing Objective Process uncontaminated sediment samples for characterization of contaminants. 5.2.2 Sample Processing Methods Summary Upon receipt at the laboratory, the samples were frozen pending analysis. The frozen sediment samples were thawed and thoroughly homogenized prior to analysis. Separate aliquots of the homogenized sediment were removed. The aliquots were processed for several types of chemical analyses. These included: inorganic analyses (major and trace elements; butyltins (MBT, TBT and DBT); organic analyses (PAHs, PCBs and pesticides) and acid volatile sulfides (AVS). INORGANIC Analysis of the sediment for major and trace elements involved a total digestion (i.e., complete dissolution) of the sediment matrix. For the metals Ag, Al, Cr, Cu, Fe, Mn, Ni, Pb and Zn, the total digestion was accomplished using HF/HNO3 in an open beaker on a hot plate, followed by instrumental analyses using inductively-coupled plasma-atomic emission spectrometry (ICP-AES). For the metals, As, Cd, Sb, Se and Sn, a microwave digestion using HNO3/HCl in a closed teflon-lined pressure vessel was followed by analysis using Zeeman-corrected, stabilized temperature graphite furnace atomic absorption (GFAA). Mercury (Hg) was analyzed by cold vapor atomic absorption spectrometry. Sediment concentrations of butyltin compounds were determined using high resolution gas chromatography and flame photometric detection. ORGANIC The analysis of organic contaminants involved extraction and cleanup followed by instrumental analysis. This included the following basic steps: Soxhlet extraction, extract drying using sodium sulfate, extract concentration using Kuderna-Danish apparatus, removal of elemental sulfur with activated copper, removal of organic interferents with gel permeation chromatography (GPC) and/or alumina. Following extraction and cleanup, PAH compounds were analyzed using gas chromatography/mass spectrometry (GC/MS). The pesticides and PCB congeners were analyzed using gas chromatography/electron capture detection (GC/ECD) with second column confirmation. OTHER CONSTITUENTS The concentration of total organic carbon (TOC) in each sediment sample was determined by ultraviolet light-promoted persulfate oxidation. Acid volatile sulfides (AVS) were measured using a sulfide ion-specific electrode following reaction of the sediment with hydrochloric acid and subsequent trapping of the evolved hydrogen sulfide in solution. 5.2.3 Sample Processing Method Calibration For the 1991 sediment analyses, a Standard or Certified Reference Material (SRM or CRM) typically was used as the Laboratory Control Material (LCM). SRMs and CRMs have known or "certified" concentrations of the analytes being measured and therefore, are useful for assessing both accuracy and precision. The 1991 QA Plan required the laboratory's percent recovery (relative to the certified concentration in the reference material) to fall within the range of 80 to 120 % for each inorganic analyte and 70 to 130 % for each organic analyte. If the laboratory consistently failed to meet these accuracy goals for the CRM or SRM, the values reported for the failed analytes were considered to be suspect and were flagged. 5.2.4 Sample Processing Quality Control Each laboratory was required to analyze the following quality control (QC) samples along with every batch or "set" of field chemistry samples: laboratory reagent blank, calibration check standards, laboratory fortified sample matrix, laboratory duplicate and Laboratory Control Material (LCM). Results for these QC samples had to fall within certain pre-established control limits for the analysis of a batch of samples to be considered acceptable. 5.2.5 Sample Processing Method Reference Not Available 6. DATA MANIPULATIONS 6.1 Name of New or Modified Values TOT_PCB, TOT_PAH, PAH_LMW, PAH_HMW, TOT_DDT and TOT_ANAL 6.2 Data Manipulation Description 6.2.1 TOT_PCB, TOT_PAH, PAH_LMW, PAH_HMW, TOT_DDT Summary values were calculated for groups of organic analytes. The values under a summed analyte are the sum of the concentrations of a specific set of compounds. 6.2.2 TOT_ANAL The number of analytes under TOT_ANAL include only those with a concentration. 6.3 Data Manipulation Examples The following groups must be summed in order to have consistency across Provinces: 6.3.1 Total Poly-aromatic Hydrocarbons TOT_PAH = sum of concentrations of biphenyl, fluorene, 1-methylnaphthalene, 2-methylnaphthalene, naphthalene, 2,6-dimethylnaphthalene, acenaphthene, phenanthrene, anthracene, acenaphthlyene, 2,3,5-trimethylnaphthalene, 1-methylphenanthrene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b,k)fluoranthene or individual compounds, ideno(1,2,3-c,d)pyrene, benzo(g,h,i)perylene, perylene, benzo(a)pyrene, benzo(e)pyrene and dibenz(a,h)anthracene. 6.3.2 Low Molecular Weight PAHs PAH_LMW = sum of concentrations of biphenyl, fluorene, 1-methylnaphthalene, 2-methylnaphthalene, naphthalene, 2,6-dimethylnaphthalene, anthracene, acenaphthlyene, 2,3,5-trimethylnaphthalene. 6.3.3 High Molecular Weight PAHs PAH_HMW = sum of concentrations of fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b,k)fluoranthene or individual compounds, ideno(1,2,3-c,d)pyrene, benzo(g,h,i)perylene, perylene, benzo(a)pyrene, benzo(e)pyrene and dibenz(a,h)anthracene, acenaphthene, phenanthrene and 1-methylphenanthrene. 6.3.4 Total DDT TOT_DDT = sum of concentrations of OPDDE, OPDDD, OPDDT, PPDDE, PPDDD, PPDDT. 6.3.5 Total Polychlorinated Biphenyls TOT_PCB = sum of concentrations of the following PCB congeners: 8, 18, 28, 52, 44, 66, 101, 118, 153, 105, 138, 187, 128, 180, 170, 195, 206 and 209. 7. DATA DESCRIPTION 7.1 Description of Parameters Parameter Data Parameter # SAS Name Type Len Format Label ----------------------------------------------------------------- 1 STA_NAME Char 8 8. The Station Identifier 2 VST_DATE Num 8 YYMMDD6. The Date the Sample was Collected 3 ANALYTE Char 8 8. Analyte Code 4 CONC Num 8 13.6 Conc. of Analyte (dry wt.) 5 CHMUNITS Char 15 12. Concentration Units 6 QA_CODE Char 15 15. Quality Assurance Code for Data 7 TOT_ANAL Num 8 3. Analytes (#) Included in Summed Conc. 8 DETLIMIT Num 8 13.6 Method Detection Limit for Analyte 9. ANAL_CAT Char 15 15. General Category for Group of Analytes 7.1.6 Precision to which values are reported The sediment chemistry concentrations presented are in a format of 6 decimal places. This format is necessary because some concentrations are in ug/g and some concentrations are in ng/g. However, the concentrations are only valid FOR THREE SIGNIFICANT FIGURES (not necessarily three decimal places), i.e., 345.67 ug/g is 346 ug/g but 0.00235 ng/g remains as 0.00235 ng/g. 7.1.7 Minimum Value in Data Set by Analyte ANALYTE Minmum Value ACENTHE 0.08 ACENTHY 0.04 AG 0.01 AL 1760.00 ALDRIN 0.23 ANTHRA 0.07 AS 0.77 AVS 0.04 BENANTH 3.65 BENAPY 0.11 BENEPY 0.12 BENZOFL 1.17 BENZOP 0.06 BIPHENYL 1.43 CD 0.03 CHRYSENE 1.44 CISCHL 0.24 CR 1.88 CU 0.49 DBT 2.43 DDT_TOT 0.00 DIBENZ 0.07 DIELDRIN 0.25 DIMETH 1.34 FE 653.00 FLUORANT 1.25 FLUORENE 1.80 HEPTACHL 0.24 HEPTAEPO 0.20 HEXACHL 0.28 HG 0.00 INDENO 0.30 LINDANE 0.46 MBT 4.86 MENAP1 0.86 MENAP2 1.71 MEPHEN1 0.93 MIREX 0.23 MN 11.60 NAPH 0.96 NI 1.79 OPDDD 0.10 OPDDE 0.10 OPDDT 0.10 PAH_HMW 1.77 PAH_LMW 1.15 PAH_TOT 3.21 PB 2.17 PCB101 0.24 PCB105 0.13 PCB118 0.20 PCB128 0.23 PCB138 0.21 PCB153 0.2580 PCB170 0.2200 PCB18 0.2440 PCB180 0.2260 PCB187 0.2220 PCB195 0.1920 PCB206 0.2130 PCB209 0.2380 PCB28 0.2240 PCB44 0.2120 PCB52 0.2740 PCB66 0.2300 PCB8 0.2240 PCB_TOT 0.0000 PERYLENE 0.2220 PHENANTH 0.5350 PPDDD 0.1000 PPDDE 0.2200 PPDDT 0.1000 PYRENE 0.0514 SB 0.0534 SE 0.1170 SN 0.1290 TBT 2.9800 TNONCHL 0.2140 TOC 0.0650 TRIMETH 0.3790 ZN 3.6600 7.1.8 Maximum Value in Data Set by Analyte ANALYTE Maximum Value ACENTHE 2960.00 ACENTHY 186.00 AG 9.69 AL 89300.00 ALDRIN 1.82 ANTHRA 6510.00 AS 34.90 AVS 156.00 BENANTH 10000.00 BENAPY 6040.00 BENEPY 3950.00 BENZOFL 11300.00 BENZOP 3780.00 BIPHENYL 240.00 CD 6.58 CHRYSENE 9770.00 CISCHL 7.32 CR 174.00 CU 263.00 DBT 50.30 DDT_TOT 124.00 DIBENZ 342.00 DIELDRIN 4.56 DIMETH 399.00 FE 54500.00 FLUORANT 22900.00 FLUORENE 3180.00 HEPTACHL 3.19 HEPTAEPO 0.96 HEXACHL 3.21 HG 1.96 INDENO 4080.00 LINDANE 0.46 MBT 73.30 MENAP1 386.00 MENAP2 459.00 MEPHEN1 2100.00 MIREX 0.62 MN 6430.00 NAPH 488.00 NI 70.10 OPDDD 13.10 OPDDE 12.90 OPDDT 12.70 PAH_HMW 132000.00 PAH_LMW 8280.00 PAH_TOT 141000.00 PB 323.00 PCB101 53.20 PCB105 34.80 PCB118 55.70 PCB128 8.94 PCB138 42.20 PCB153 31.10 PCB170 7.82 PCB18 50.70 PCB180 17.90 PCB187 14.30 PCB195 5.12 PCB206 10.30 PCB209 18.20 PCB28 346.00 PCB44 72.60 PCB52 107.00 PCB66 152.00 PCB8 35.40 PCB_TOT 1040.00 PERYLENE 2020.00 PHENANTH 25500.00 PPDDD 32.90 PPDDE 30.80 PPDDT 33.30 PYRENE 24600.00 SB 49.10 SE 1.76 SN 27.00 TBT 98.40 TNONCHL 3.83 TOC 3.98 TRIMETH 518.00 ZN 484.00 7.2 Data Record Example 7.2.1 Column Names for Example Records STA_NAME VST_DATE ANALYTE CONC CHMUNITS QA_CODE TOT_ANAL DETLIMIT ANAL_CAT 7.2.2 Example Data Records 1. VA91-261 910803 AS 1.680000 ug/g . . METAL 2. VA91-261 910803 ALDRIN . ng/g CH-A,CH-C . 0.250000 PESTICIDE 3. VA91-261 910803 AVS 0.115000 umoles/g CH-C . . AVS 8. GEOGRAPHIC AND SPATIAL INFORMATION 8.1 Minimum Longitude -77 Degrees 18 Minutes 58.80 Decimal Seconds 8.2 Maximum Longitude -70 Degrees 01 Minutes 00.00 Decimal Seconds 8.3 Minimum Latitude 36 Degrees 56 Minutes 24.60 Decimal Seconds 8.4 Maximum Latitude 42 Degrees 08 Minutes 00.00 Decimal Seconds 8.5 Name of area or region Virginian Province Stations were located in estuaries along the East Coast of the United States from Cape Cod, Massachusetts, to Cape Henry, Virginia, at the mouth of the Chesapeake Bay. The area includes the District of Columbia and the States of Virginia, Maryland, New Jersey, Delaware, Pennsylvania, New York, Connecticut, Rhode Island and Massachusetts. 9. QUALITY CONTROL AND QUALITY ASSURANCE Because of the complexity and importance of sediment contaminant data, EMAP has expended a tremendous effort in the Quality Assurance of these data as is reflected in the detail provided in this section. 9.1 Measurement Quality Objectives Measurement Quality Objectives (MQOs) for the 1991 Virginian Province sediment chemistry analyses were defined in the 1991 Virginian Province Quality Assurance Project Plan (Valente and Schoenherr, 1991). This plan required each laboratory to analyze the following quality control (QC) samples along with every batch or "set" of field chemistry samples: laboratory reagent blank, calibration check standards, laboratory fortified sample matrix, laboratory duplicate, and Laboratory Control Material (LCM). Results for these QC samples had to fall within certain pre-established control limits. 9.2 Quality Assurance/Quality Control Methods If results for these QC samples did not fall within certain pre-established control limits, the analysis of a batch of samples was not considered acceptable. These and other quality control issues are coded in four data qualifier codes or "flags" used in the 1991 Virginian Province sediment chemistry data set: CH-A CODE The "CH-A" code indicates that an analyte was not detected. When the "CH-A" code is used, the concentration field is left blank and the detection limit for the analyte in that particular sample is reported under the method detection limit (DETLIMIT). CH-B CODE It is sometimes possible for a laboratory to detect an analyte and report its concentration at a level which is below the calculated method detection limit for the sample. In these situations, the analyst is confident that the analyte was present in the sample, but there is a high degree of uncertainty in the reported concentration. The "CH-B" code is used to flag reported values which are below the calculated method detection limit for the sample. Such values are considered estimates only and should be used with discretion. CH-C CODE The "SC-C" code is applied in situations where the laboratory failed to meet required control limits for one or more of the quality control samples analyzed along with each sample batch. In such situations, there is reason to believe that the concentrations reported for an analyte or group of analytes may not accurately reflect the actual concentrations present in the samples. Values flagged with the "SC-C" code therefore are considered estimates only and should be used with discretion. It is important to note that values flagged with the SC-C code ARE included in the TOTALs. Excluding analytes would result in an artificially lowered concentration. CH-D CODE In 1991, the laboratory used gas chromatography/electronic capture detection (GC/ECD) with dual column confirmation for the analysis of PCB congeners and chlorinated pesticides in the sediment samples. All values reported in the database for the PCBs and pesticides represent "confirmed" results (i.e., the analyte was detected and could be quantified on both the primary and secondary columns). In situations where an analyte was detected on one column, but was not confirmed on the second column, the result was treated as a "not detect" (i.e., the CH-A code is used to flag the result in the database). In general, for all reported PCB congeners except PCB 195, the rate of confirmation was between 95% to 100% (PCB 195 rate of confirmation was 87%). The rate of confirmation exceeded 90% for all the chlorinated pesticides except the following: heptachlor (59%), heptachlor epoxide (57%), mirex (82%), p,p DDT (65%), and o,p DDT (72%). Close inspection of the "confirmed" results for the DDT-series compounds revealed a number of instances where there was a significant discrepancy in the amount detected on the two GC/ECD columns (i.e., greater than a factor of 3 difference). In these instances, it is difficult to ascertain which amount is more accurate (i.e., which is the "right" answer). A decision was made to take a "conservative" approach and report the lower of the two values in the database, and to flag these values using the "CH-D" code. The SC-D code has the following meaning: "Analyses were conducted using GC/ECD with dual column confirmation. Quantification on the two columns differed by more than a factor of three, and the lower of the two results is reported." Values which are not flagged with the CH-B, CH-C or CH-D codes are considered valid and useful for most assessment purposes. 9.3 Quality Assessment Results Results of QC sample analyses are stored in the EMAP-Estuaries Virginian Province database and are available upon request. In the following sections, these results are summarized, and the data flags associated with the 1991 Virginian Province sediment chemistry analyses are explained. 9.3.1 Major and trace element analyses (except mercury) For the analysis of major and trace elements by ICP-AES and GFAA, the laboratory generally met the pre-established acceptability criteria (control limits) for the QC samples (e.g., calibration check samples, laboratory reagent blanks, matrix spikes, and Laboratory Control Materials). For the ICP-AES analyses, which included the metals Al, Cr, Cu, Fe, Mn, Ni, Pb, and Zn, a total of 13 analytical sets or "batches" of samples were analyzed. The Certified Reference Material (CRM) "BCSS-1" (Estuarine Sediment, issued by the National Research Council of Canada) was analyzed along with every batch as the Laboratory Control Material. With the exception of Cr and Pb, the average percent recovery of each metal (relative to the certified concentration in BCSS-1) was within the acceptability range of 80% to 120% (Table 9-1). The average percent recovery for Cr was slightly lower than acceptable, and the average percent recovery for Pb was slightly higher than acceptable. These results suggest that Cr may have been consistently "under-recovered" and Pb may have been consistently "over-recovered" in the actual samples. Therefore, all reported values for these two metals were qualified with the SC-C code in the database. The GFAA analyses included the metals Ag, As, Cd, Sb, Se, and Sn; a total of 19 analytical sets or "batches" of samples were analyzed. The CRM BCSS-1 also was analyzed along with every sample batch as the Laboratory Control Material. Average CRM percent recoveries for all metals fell within the acceptability range of 80% to 120% (Table 9-1), and no results were flagged in the database. The CRM BCSS-1 does not have a "certified" value for silver, making it difficult to assess laboratory accuracy and precision for this metal. ---------------------------------------------------------------- Table 9-1. Summary results for CRM BCSS-1 (Estuarine Sediment) used as a set control for the 1991 EMAP-Estuaries sediment inorganic analyses. ---------------------------------------------------------------- ICP-AES METALS (n = 13 analysis sets or "batches"): Element Average1 Stdv2 C.V.3 Min.4 Max.5 ------------------------------------------------------------------ Al 95 6.2 6.5 87 109 Cr 70 2.0 2.8 66 73 Cu 105 3.0 2.8 99 110 Fe 95 2.9 3.0 91 100 Mn 93 2.9 3.1 87 97 Ni 91 2.4 2.7 86 94 Pb 122 26.5 21.7 81 185 Zn 89 1.5 1.7 87 91 GFAA METALS (n = 19 analysis sets): Element Average1 Stdv2 C.V.3 Min.4 Max.5 ------------------------------------------------------------------- Ag na na na na na As 94 9.0 9.6 76 114 Cd 91 23.6 26.1 39 157 Sb 98 15.4 15.6 78 137 Se 111 32.5 29.3 50 189 Sn 111 14.9 13.4 66 135 ---------------------------------------------------------------------- 1 Average percent recovery relative to the SRM certified value. 2 Standard deviation of the percent recovery values. 3 Coefficient of variation of the percent recovery values. 4 Minimum percent recovery for n analysis sets 5 Maximum percent recovery for n analysis sets 9.3.2 Organic analyses In general, results for reagent blanks and calibration check samples analyzed with each batch of samples fell within control limits and serve to verify that sample contamination did not occur and that all instruments were calibrated properly throughout the analytical runs. Average recoveries of compounds in matrix spike samples generally fell within control limits, although these recoveries tended to be highly variable between different batches. This in part reflects the fact that the spiked samples were chosen at random and sometimes had high "background" concentrations of the spiked analytes. In these cases it was difficult for the laboratory to accurately recover the spiked amount relative to the high background, resulting in zero percent recovery in some samples. Furthermore, it is difficult to evaluate laboratory performance solely on the basis of matrix spike results because it is often equivocal whether low recoveries are due to flawed methodology, poor technique, or a true matrix interference. Given the above limitations on using the matrix spike results to assess the overall quality of the 1991 organics data, great emphasis was placed on the Laboratory Control Material results. For both the PAH and PCB/pesticide analyses, SRM 1941 (Organics in Marine Sediment, issued by the National Institute of Standards and Technology) was analyzed as the Laboratory Control Material along with each batch of field samples. For most of the individual PAH compounds and PCB congeners with "known" concentrations in SRM 1941 (this includes both "certified" and "non-certified" values), the average percent recovery achieved by the laboratory (based on n = 14 batches for PAHs and n = 15 batches for PCB/pesticides) generally fell within the control limit range of 70% to 130% (Tables 9-2 and 9-3). Whenever the laboratory failed to achieve these average recovery rates for a particular compound, all the results in the 1991 database for that compound were flagged with the "SC-C" code to indicate the potential inaccuracy inferred from the SRM analysis. It is important to note that the 70% to 130% recovery criteria only applies to compounds having SRM concentrations greater than 10 times the laboratory's detection limit. When compounds occur at concentrations less than about 10 times the detection limit, a greater amount of analytical uncertainty is expected and the normal control limit "acceptability" criteria do not apply. Based on the above, the results for the following organic compounds were flagged with the "SC-C" code in the 1991 database: PCB 101, PCB 138, PCB 153, PCB 18, PCB 187, acenaphthlylene, chrysene, 1-methylphenanthrene, and naphthalene. In addition, although the average percent recovery for ideno(1,2,3-c,d)pyrene was within limits (98%), all results for this compound were flagged with the SC-C code because the recoveries between batches exhibited relatively high variability (35% coefficient of variation). Although the average SRM percent recoveries for the compounds dieldrin, heptachlor epoxide and PCB 195 also were outside the acceptability range of 70% to 130% (Table 9-3), these compounds occur in the SRM at concentrations less than 10 times the laboratory's detection limit. Therefore, the acceptability criteria do not apply. In addition to the above, due to analytical difficulties, all 1991 pesticide results have been assigned the SC-C code and are considered estimates. ---------------------------------------------------------------- Table 9-2. Results for SRM 1941 (Organics in Marine Sediment) used as the set control (Laboratory Control Material) for the 1991 sediment PAH analyses (n = 14 analysis sets or "batches"). ---------------------------------------------------------------- Compound1 Average2 Stdv3 C.V.4 Min5 Max6 ---------------------------------------------------------------- Acenaphthene 111 23.2 20.9 67 137 Acenaphthlylene 41 10.6 25.9 27 61 Anthracene 95 26.4 27.7 59 142 Benz(a)anthracene 92 28.2 30.5 54 165 Benzo(a)pyrene 77 15.1 19.7 52 106 Benzo(e)pyrene 101 22.4 22.2 61 138 Benzo(b+k)fluoranthene 121 25.4 21.0 87 174 Benzo(g,h,i)perylene 105 21.1 20.1 64 141 Biphenyl 103 22.7 22.1 63 138 Chrysene 145 30.4 21.0 94 196 2,6-dimethylnaphthalene 113 24.2 21.3 70 145 Fluoranthene 93 20.2 21.7 64 134 Fluorene 105 32.3 30.7 62 179 Ideno(1,2,3-c,d)pyrene 98 34.1 34.7 21 150 1-methylnaphthalene 99 27.8 28.2 59 158 2-methylnaphthalene 109 33.6 30.8 53 158 1-methylphenanthrene 138 50.5 36.5 64 247 Naphthalene 69 27.3 39.5 8 126 Perylene 72 15.2 21.1 47 96 Phenanthrene 111 27.2 24.4 76 160 Pyrene 96 23.9 24.9 56 134 ---------------------------------------------------------------- 1 Listed compounds include those having both "certified" and "non-certified" concentrations in SRM 1941. 2 Average percent recovery relative to the SRM value. 3 Standard deviation of the percent recovery values. 4 Coefficient of variation of the percent recovery values. 5 Minimum percent recovery for 14 analysis sets 6 Maximum percent recovery for 14 analysis sets Table 9-3. Results for SRM 1941 (Organics in Marine Sediment) used as the set control (Laboratory Control Material) for the 1991 sediment PCB/pesticide analyses (n = 15 analysis sets or "batches"). ---------------------------------------------------------------- Compound1 Average2 Stdv3 C.V.4 Min5 Max6 ---------------------------------------------------------------- PCB 18 32 10.0 31.2 20 50 PCB 28 77 11.7 15.2 58 95 PCB 52 102 14.1 13.8 85 122 PCB 66 87 12.8 14.7 68 104 PCB 101 68 10.4 15.2 48 86 PCB 118 93 28.0 29.9 58 170 PCB 153 66 5.2 7.9 55 76 PCB 105 128 19.1 15.0 99 165 PCB 138 68 5.5 8.1 60 77 PCB 187 64 7.7 11.9 52 84 PCB 180 96 9.9 10.3 80 110 PCB 170 75 6.4 8.6 68 89 PCB 195* 142 29.8 20.8 108 199 PCB 206* 76 10.4 13.7 62 92 PCB 209 82 9.7 11.8 69 98 Dieldrin* 143 29.3 20.6 85 182 Heptachlor epoxide* 139 27.3 19.6 99 184 cis-Chlordane* 96 12.7 13.3 71 122 trans-Nonachlor* 89 15.3 17.2 72 127 4,4'-DDE 91 9.5 10.5 75 109 4,4'-DDD 80 9.0 11.2 64 98 4,4'-DDT* 102 22.6 22.2 62 128 ---------------------------------------------------------------- 1 SRM 1941 only lists "non-certified" or informational values for this group of PCB congeners and pesticides (* = concentration in the SRM is less than 10 times the target detection limit). 2 Average percent recovery relative to the SRM value. 3 Standard deviation of the percent recovery values. 4 Coefficient of variation of the percent recovery values. 5 Minimum percent recovery for 22 analysis sets 6 Maximum percent recovery for 22 analysis sets 9.3.3 Mercury analyses For the 1991 mercury analyses, the Certified Reference Material BEST-1 (issued by the National Research Council of Canada) was analyzed along with every sample batch as the Laboratory Control Material (n = 9 sample batches). The average percent recovery of 92% for mercury in this reference material fell well within the acceptability range of 80% to 120%. In addition, an average percent recovery of 104% was achieved for the matrix spike samples analyzed in each batch. Overall, these results indicate acceptable accuracy for the mercury analyses, and no "SC-C" codes were used to qualify the data. The 1991 mercury results were deemed acceptable for use without qualification. 9.3.4 Total Organic Carbon analyses All QC results for the analysis of total organic carbon in the 1991 sediment samples fell within required control limits. The Certified Reference Material PACS-1 (issued by the National Research Council of Canada) was utilized as the Laboratory Control Material. The certified concentration of total carbon in this reference material is 3.69% (percent dry weight). The average percent recovery achieved by the laboratory for n = 11 batches of TOC samples (i.e., 11 separate analyses of CRM PACS-1) was 94.1%, with all values falling within the range 88% to 99%. Since the PACS-1 certified concentration includes both organic carbon and a very small fraction of inorganic carbon, the laboratory's percent recovery values for organic carbon are expected to be below 100%. Based on the good overall percent recovery of organic carbon in the Certified Reference Material, the 1991 sediment TOC data were deemed acceptable for use without qualification. 9.3.5 Butyltin analyses Data users are cautioned that there are deficiencies in the 1991 sediment data set for butyltin compounds which might limit or preclude the use of these data. The laboratory's failure to detect the butyltin compounds of interest (TBT, DBT, MBT) in the majority of samples analyzed suggests a potential deficiency resulting from the method detection limits for the individual analytes. The MDLs established by the laboratory were 5 ng/g dry weight for both TBT and DBT, and 12 ng/g dry weight for MBT. Assuming these MDL's are valid, it is probable that contamination by butyltin compounds may be more widespread than indicated by these data. It should be noted at this point that all butyltin results are reported as ng tin/g dry sediment. Appropriate multipliers must be applied to convert to nanograms of the ion per gram of sediment if that is the desired unit of measurement. The Certified Reference Material PACS-1 (issued by the National Research Council of Canada) was utilized as the Laboratory Control Material for these analyses. Average percent recoveries relative to the certified value for n = 12 analysis sets were 79% for TBT, 89% for DBT and 115% for MBT. The percent recovery value for TBT falls slightly outside the acceptable accuracy limits of 80% to 120% and indicates that TBT may have been consistently under-recovered in this reference material. Average percent recoveries for matrix spike samples (98% for TBT, 66% for DBT and 70% for MBT) suggest the laboratory attained better accuracy for TBT than the SRM results indicate. Given these inconsistencies in the QC data, all values reported for TBT in samples where this compound was detected are considered estimates (SC-C code) and should be used with discretion. 10. DATA ACCESS 10.1 Data Access Procedures A Data Request Package can be requested from a contact under Section 10.3. Data can be downloaded from the WWW site. 10.2 Data Access Restrictions Data can only be accessed from the WWW site. 10.3 Data Access Contact Persons John Paul, Ph.D. U.S. EPA NHEERL-AED (401) 782-3037 (Tel.) (401) 782-3030 (FAX) paul.john@epamail.epa.gov Data Librarian EMAP-Estuaries U.S. EPA NHEERL-AED (401) 782-3184 (Tel.) (401) 782-3030 (FAX) hughes.melissa@epamail.epa.gov 10.4 Data Set Format Data files are space-delimited. Species lists are comma-delimited. The ASCII data files can be opened with most spreadsheets, word processors, or text editors. Windows Notepad is not recommended; instead, use Windows WordPad. 10.5 Information Concerning Anonymous FTP Not accessible 10.6 Information Concerning WWW Data can be downloaded from the WWW. 10.7 EMAP CD-ROM Containing the Data Set Data not available on CD-ROM. 10.8 Data Integrity Checks File Name Size (bytes) # Records vp91_sediment_chemistry_data.txt 723,218 7940 vp91_sediment_chemistry_qa_codes.txt 981 5 vp90-93_sediment_analytes.txt 3,886 855 11. REFERENCES Holland, A. F., ed. 1990. Near Coastal Program Plan for 1990: Estuaries. EPA 600/4-90/033. U. S. Environmental Protection Agency, Office of Research and Development, NHEERL-AED, Narragansett, RI. Strobel, C. J. and S. C. Schimmel. 1991. Environmental Monitoring and Assessment Program Near Coastal Component: 1991 Virginian Province Field Operations and Safety Manual. U.S. Environmental Protection Agency, Office of Research and Development, NHEERL-AED, Narragansett, RI. June 1991. Valente, R. M. and J. R. Schoenherr. 1991. EMAP-Near Coastal 1991 Virginian Province Quality Assurance Project Plan. U.S. Environmental Protection Agency, Office of Research and Development, NHEERL-AED, Narragansett, RI. July 1991. 12. LIST OF ACRONYMS 13. PERSONNEL INFORMATION Virginian Province Manager Darryl Keith U.S. Environmental Protection Agency NHEERL-AED 27 Tarzwell Drive Narragansett, RI 02882-1197 (401)782-3135 (Tel.) (401)782-3030 (FAX) keith.darryl@epamail.epa.gov Virginian Province QA Officer Charles J. Strobel U.S. Environmental Protection Agency NHEERL-AED 27 Tarzwell Drive Narragansett, RI 02882-1197 (401)782-3180 (Tel.) (401)782-3030 (FAX) strobel.charlie @epamail.epa.gov Sample Processing Contact John Martinson U.S. Environmental Protection Agency Environmental Monitoring Systems Laboratory 26 W. Martin Luther King Drive Cincinnati, OH 45268 (513)569-7286 (Tel.) John Paul, Ph.D. U.S. Environmental Protection Agency NHEERL-AED 27 Tarzwell Drive Narragansett, RI 02882-1197 (401) 782-3037 (Tel.) (401) 782-3030 (FAX) paul.john@epamail.epa.gov Data Librarian, EMAP-Estuaries Melissa M. Hughes CSC U.S. EPA NHEERL-AED 27 Tarzwell Drive Narragansett, RI 02882-1197 (401) 782-3184 (Tel.) (401) 782-3030 (FAX) hughes.melissa@epamail.epa.gov