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Water Resources--Office of Water Quality
3.53 x 10-11
3.53 x 10-8
|pound per squar inch|
Temperature: Water and air temperature are given in degrees Celsius (°C), which can be converted to degrees Fahrenheit (°F) by use of the following equation: °F = 1.8 (°C) + 32
Accuracy: The degree of agreement of a measured value with the true or expected value (from Taylor, 1987).
Analyte (target analyte): "Substances being determined in an analysis" (from Bennett, 1986). The term target analyte is used in this report to refer to any chemical or biological substance for which concentrations in a sample will be determined. The definition for target analyte does not include field-measured parameters such as temperature, specific electrical conductance, pH, dissolved oxygen, Eh, alkalinity, color, or turbidity.
Bias: Systematic error inherent in a method or caused by some artifact or idiosyncrasy of the sample measurement, collection, or processing system. The error can be positive (indicating contamination) or negative (indicating loss of analyte concentration) (from Taylor, 1987).
Contaminant: Biological or chemical substances added to the medium of concern, commonly through human activity.
Contamination (of water): Change of ambient water composition by the addition of biological or chemical substances as a result of human activity or natural processes. Addition of such substances can be detrimental to the quality of the water resource.
Data-quality requirements: The subset of data-quality objectives pertaining specifically to the analytical detection level for concentrations of target analytes and the variability allowable to fulfill the scientific objectives of the study.
Quality Assurance (QA): The systematic management of data-collection systems by using prescribed guidelines and criteria for implementing technically approved methods and policies. Quality assurance incorporates a comprehensive plan that outlines the overall process for providing a product or service that will satisfy the given requirements for quality.
Quality Control (QC): The specific operational techniques and activities used to obtain the required quality of data. Quality control consists of the application of technical procedures to achieve prescribed standards of performance and to document the quality of collected data. Quality-control data are used to identify and evaluate any corrective actions necessary to improve performance or data interpretation to acceptable levels.
Trace element(s): For the purpose of this report and to maintain consistency with common usage, the term trace element(s) is used to refer to metal and nonmetal inorganic elements such as arsenic, antimony, selenium, and tellurium that usually are present in natural surface-water and ground-water systems in concentrations less than 1 mg/L (modified from Hem, 1985). Common usage of this term, as defined above, is inexact and not rigorous with respect to aqueous chemistry.
|lb/in2||pounds per square inch|
|mg/L||milligram per liter|
|µg/L||microgram per liter (equivalent to parts per billion (ppb))|
|mL/min||milliliters per minute|
|ng/L||nanogram per liter|
|ng/µL||nanogram per microliter|
|ppb||parts per billion (see µg/L)|
|ANC||acid neutralizing capacity|
|ASR||Analytical Services Request|
|DIC||dissolved inorganic carbon|
|DOC||dissolved organic carbon|
|FA||filtered, acidified sample|
|FAR||filtered, acidified sample for analyses of selected radiochemicals|
|FCA||filtered, chilled, acidified sample|
|FCC||filtered, chilled sample|
|FU||filtered, untreated sample|
|GCC||glass, chilled sample for analysis of nonvolatile organic compounds|
|GC/MS||gas chromatograph/mass spectrophotometer|
|IBW||inorganic-grade blank water (water with certified analysis of trace elements and other inorganic constituents and used for blank QC samples for analysis of inorganic constituents)|
|MBAS||methylene blue active substances|
|NAWQA||National Water-Quality Assessment Program|
|NFM||National Field Manual for the Collection of Water-Quality Data|
|NPDES||National Pollutant Discharge Elimination System|
|NWQL||National Water Quality Laboratory of the USGS|
|OWQ||Office of Water Quality of the USGS|
|PBW||pesticide-grade blank water (water certified free of pesticide compounds)|
|QW||quality of water, or water quality|
|QWSU||Quality of Water Service Unit, USGS, Ocala, Florida|
|RA||raw, acidified sample|
|RAH||raw, acidified sample for analysis of antimony, arsenic, and (or) selenium|
|RAM||raw, acidified sample for analysis of mercury|
|RCB||raw, chilled sample|
|RU||raw, untreated sample|
|RUR||raw, untreated sample for analysis of selected radiochemicals|
|RUS||raw, untreated sample for analysis of stable isotopes|
|SOC||suspended organic carbon|
|TOC||total organic carbon|
|URL||Uniform Resource Locator|
|USEPA||U.S. Environmental Protection Agency|
|USGS||U.S. Geological Survey|
|VBW||volatile-organic-compounds-grade blank water (water certified free of VOCs)|
|VOC||volatile organic compounds|
|WCA||raw, chilled, acidified nutrient sample|
|13 C/12C||carbon-13/carbon-12 isotope ratio|
|2 H/1H||deuterium/protium isotope ratio|
|3 H/3He||tritium/helium-3 isotope ratio|
|HNO3K2Cr2O7||nitric acid/potassium dichromate|
|15 N/14N||nitrogen-15/nitrogen-14 isotope ratio|
|18 O/16O||oxygen-18/oxygen-16 isotope ratio|
|34 S/32S||sulfur-34/sulfur-32 isotope ratio|
Selected References and Internal Documents
Return to 5.6--Contents Page
Return to Chapter A5 Contents Page
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