Abstract:
This dataset contains oil chemistry data from the Deepwater Horizon (DWH) accident collected cooperatively by BP and the agencies, including agencies that serve as DWH natural resource damage trustees (Trustees). This report provides additional context for the oil chemistry dataset, including information about the collection, analysis, and organization of the data. This data posting differs from other recently published datasets relating to the Gulf of Mexico in several respects: This oil chemistry dataset focuses on information related to petroleum-related chemical constituents in oil samples and other matrices collected during studies focused primarily on the sampling of oil. Chemical compounds that are not present in Mississippi Canyon lease block 252 (MC252) oil (such as polychlorinated biphenyls, pesticides, and halogenated volatiles) are not included in this dataset. This dataset includes data from independent studies performed by BP consultants. BP has been working to produce and organize these independent data, and has engaged outside consultants to perform quality assurance and quality control (QA/QC) checks. As a result, these data have not previously been publicly accessible. This dataset combines results from 24 NRDA studies and 20 Response studies to create a unified data file. Before posting, extensive work was done independently by BP contractors to verify some aspects of the posted data (e.g., positional coordinates and field data). The chemical parameters provided in this data posting include: Parent and alkylated polycyclic aromatic hydrocarbons (PAHs) Saturated hydrocarbons (SHC) Total petroleum hydrocarbons (TPH), including parameters reported as total extractable material (TEM) and total extractable hydrocarbon (TEH) Benzene, toluene, ethylbenzene, and xylenes (BTEX) and other volatile hydrocarbons classified as paraffins, isoparaffins, aromatics, naphthenes, and olefins (PIANO) Geochemical biomarkers (sterane and triterpane), where available Dispersant markers Metals Total organic carbon. The chemical analyte lists are generally consistent between studies for the standard PAH, SHC, and BTEX compounds. However, portions of the dataset also include analysis of the extended PIANO volatile hydrocarbon list, TPH, or geochemical biomarkers. Additionally, NRDA PAH analyses include an extended list of PAHs (parent and alkylated PAHs) and non-PAH compounds (decalins, benzothiophenes, naphthobenzothiophenes, and related chemicals) that were not included in all of the Response analyses. This dataset includes data associated with natural field samples for oil and other sample matrices, along with the associated field-collected quality control samples, such as field replicates, equipment blanks, field blanks, and trip blanks. Laboratory duplicate sample data are provided, where available. MC252 control oils associated with chemistry analyses are part of a separate data posting (see Version History). No other laboratory quality control samples (e.g., laboratory blanks or spike samples) are included in this data posting. In addition to the detailed data file, a cross-tab summary version of these data is also provided (OilChemistry_O-05v01-01_xTab.zip) in Excel format. Results for each sample are presented in a single row with individual chemicals in columns. In addition, a summed concentration for total PAHs is included as “PAH50 Sum” and was calculated using 50 individual PAH results. This summary is provided to enable researchers to access this large data set in a more manageable format. A sample summary table in excel format is provided to summarize the number of analytical results for each parameter type for each sample.
Data Parameters and Units:
concentrations of: BTEX/PIANO (99 compounds) benzene, toluene, ethylbenzenes and xylenes/paraffins, isoparafins, aromatics, naphthenes, or olefins; PAH/aPAH (64 compounds) polynuclear aromatic hydrocarbons/alkylated polynuclear aromatic hydrocarbons; SHC (37 compounds) saturated hydrocarbon compounds; TPH (5 types) total petroleum hydrocarbons; Biomarkers (101 compounds); Dispersants (6 compounds); Metals (24 metals) (mg/kg); Solids (1 analyte); Moisture (1 analyte) (PCT = percent); TOC (1 analyte) Total Organic Carbon (mg/Kg); Other PAH (14 compounds) Other Polynuclear aromatic hydrocarbons; Data Publication Date = Date published on BP website gulfsciencedata.bp.com (DD-MMM-YY); Study Reference Number = Reference number assigned by BP to provide a link between data and associated work plans and study descriptions; Study Name = The study name used by the original investigator or NOAA; Harmonized Study Name = A BP assigned name to a group of related sample collection efforts; Location or Station ID = A name given to the location where samples were collected. Not all samples have an assigned value.; Interpretive Sample ID = The identifier given to represent a unique combination of location, date and time, and depth; Sample Date = The date on which the sample was collected (M/DD/YYYY or DD-MMM-YY); Sample Time = The time at which the sample was collected; Latitude = North latitude in decimal degrees where sample was collected; Longitude = The west longitude in decimal degrees where the sample was collected; Spatial Zone = Short code descriptor to indicate high level location of a sample. Seven zones assigned where LA = Louisiana, MS = Mississippi, AL = Alabama, TX = Texas, FL = Florida, Wellhead = within 10 nautical miles of wellhead , Federal = Federal waters outside wellhead area; Upper Depth = The upper depth of the sample in the water column ; Lower Depth = The lower depth of the sample in the water column; Depth Unit = The units for sample upper and lower depth (cm, m); Field Fraction = Indicates whether the dissolved, particulate, or total sample was submitted for analysis; Sample Type = Indicates whether the sample was a normal sample or a QC sample; Field Matrix = The most general description of the substance collected for analysis (aqueous, biota- plant and other, liquid, oil, oil/non-aqueous, sediment, solid - earthen, solid - non-earthen, tissue, unknown, water); Field Sample Material = The most specific description of the substance collected for analysis; Field Data Verification Status = Summary of the field data verification process. Valid entries: not started, underway, complete; Field Data Verification Result = Summary of the field data verification result for samples that have a Field Data Verification Status of "complete"; Analytical Sample ID = The client sample identifier given to a portion of the interpretive sample, or to the whole interpretive sample, when submitted to a laboratory for analysis. There may be one or several analytical sample IDs for each interpretive sample ID; Lab = The name of the laboratory generating the anaytical chemistry data; Laboratory Sample ID = The internal laboratory sample identifier; ASR Number = Analytical Service Request number of Analytical Request Form number associated with a data set. Not all samples have an ASR or related number; SDG = Sample Delivery Group. A lab generated number for a batch of samples processed together; Lab Matrix = The most general description of the substance or fraction of the sample that is analyzed (oil, sediment, solid (non-specific), unknown, water); Lab Material = The most specific description of the substance or fraction that is analyzed; Parameter Type = The basic group to which the chemical belongs: PAH, SHC, TPH, PIANO, biomarkers, dispersants, and others; Chemical Name = The name of the chemical analyzed; Chemical Code = A standardized system specific code to uniquely identify each chemical or analyte; Chemical Type = Indicates whether the chemical is a target analyte or an added standard (e.g. surrogates); Concentration - NDs at MDL = The reported concentration of the chemical in the sample or the detection limit for non-detect results; Concentration - NDs at zero = The reported concentration in the sample or a zero value for non-detects; Unit = The units of the associated concentration value (mg/Kg, ug/Kg, ug/L, ng, ug, ng/Samp, ug/Samp) Final Qualifiers = The data qualifiers that should be used with the concentration value for data analysis and interpretation. This column may contain a packed string of the qualifiers: "U", "J", "R", "T", and "F" which are defined in the AQAP; Validation Qualifiers = Data qualifiers applied by the data validation firm; Lab Qualifiers = The data qualifiers originaly applied by the analytical laboratory; Nondetect Flag = Indicates whether or not the analyte was detected in a sample; Validation Level = The type and amount of data validation performed; see AQAP for a descritpion of the validation levels used; Reporting Limit = The laboratory determined reporting limit concentration associated with each chemical result; Method Detection Limit = The laboratory determined method detection limit associated with each chemical result; Measurement Basis = Indicates whether a concentration value is expressed in terms of the wet weight or dry weight of the environmental medium; Lab Fraction = Indicates whether the sample was filtered in the laboratory prior to analysis to obtain the dissolved fraction. This field does not capture informatino related to field filtration; Preparation Method = Method used to prepare the sample for analysis; Analytical Method = Method used to produce the measured concentration as reported by the laboratory; Base Analytical Method = A generalization of the analytical method, standardized across laboratory specific variations in the specific analytical method to aid the data user with categorizing samples by analysis type; Lab Replicate = Code to distinguish multiple measureents when all other identifying attributes are identical; Dilution Factor = The factor by which the sample was diluted for analysis; Date Extracted = The date that the sample was extracted at the laboratory (M/DD/YYYY); Date Analyzed = The date that the sample was analyzed to produce the reported concentration (M/DD/YYYY);
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