Definitions

As used in 310 CMR 42.00, the following terms shall have the meanings stated: Ambient Water refers to any fresh, marine, or estuarine surface water used for recreation, propagation of fish, shellfish, or wildlife, agriculture, industry, or navigation. Analyst means a chemist, microbiologist or technician who actually performs a test. Analytical Batch means a group of up to 20 samples to be analyzed for chemical or radiochemical parameters, or a group of up to ten samples to be analyzed for microbiological parameters, that behave similarly with respect to the testing procedures being employed and that are processed as a unit. For quality control purposes, if the number of samples in a group to be analyzed for chemical or radiochemical parameters is greater than 20, then each group of 20 or fewer samples will be handled as a separate batch. If the number of samples in a group to be analyzed for microbiology parameters is greater than ten, then each group of ten or fewer samples will be handled as a separate batch. (Mass. Register #1419 6/12/20) Category means an analyte or group of analytes for which certification is offered. Certification Officer means the person or persons designated by the Department to inspect and evaluate environmental laboratories for compliance with the criteria set forth in 310 CMR 42.00. Certified Thermometer means a thermometer that has documentation showing that it has been compared against a National Institute of Standards and Technology thermometer for the temperature range in which it is to be used. Check Standard means a solution of one or more analytes that is used to check laboratory performance. It is prepared from a source of reagents different from those used to prepare the stock standards and primary dilution standard solutions. Department means the Department of Environmental Protection of the Commonwealth of Massachusetts. Discipline means a scientific area of expertise for testing (e.g., microbiology, chemistry, radiochemistry). EPA means the United States Environmental Protection Agency. Field Reagent Blank means reagent water or analyte-free solvent placed in a sample container in the laboratory, taken to the sampling site and returned to the laboratory unopened. It is treated as a sample in all respects, including exposure to sampling site conditions, storage, preservation and all analytical procedures. Holding Time means the maximum amount of time a sample may be held from collection to analysis or, where applicable, from collection to extraction (sample holding time) or the maximum amount of time a sample extract may be held from extraction to analysis (sample extract holding time). Instrumentation Analyst means an analyst who operates an instrument including, but not limited to, an atomic absorption spectrophotometer, ion chromatograph (IC), gas chromatograph, liquid chromatograph (LC), gas chromatograph/mass spectrometer (GC/MS), inductively coupled plasma-atomic emission spectrometer (ICP), ICP/MS, or LC/MS. Laboratory Fortified Blank means an aliquot of reagent water to which known quantities of the method analytes are added in the laboratory. The laboratory fortified blank is analyzed exactly as a sample. Its purpose is to determine whether the methodology is in control, and whether the laboratory is capable of making accurate measurements at the required method detection limit. Laboratory Fortified Sample Matrix means an aliquot of an environmental sample to which known quantities of the method analytes are added in the laboratory. The laboratory fortified sample matrix is analyzed exactly as a sample. Its purpose is to determine whether the sample matrix contributes bias to the analytical results. The background concentrations of the analytes in the sample matrix must be determined in a separate aliquot and the measured values in the laboratory fortified sample matrix corrected by background concentrations. Laboratory Reagent Blank means an aliquot of reagent water that is treated exactly as a sample including exposure to all glassware, equipment, solvents, reagents, internal standards, and surrogates that are used with other samples. The laboratory reagent blank is used to determine if method analytes or other interferences are present in the laboratory environment, the reagents, or the apparatus. Matrix means the substrate of a test sample (e.g., potable water, non-potable water). Maximum Contaminant Level means the maximum permissible level of a contaminant in water that is delivered to any user of a public water system. Maximum Residual Disinfectant Level means a level of a disinfectant added for water treatment that may not be exceeded at the consumer’s tap without an unacceptable possibility of adverse health effects pursuant to the Department’s Drinking Water Program. Method Detection Limit means the minimum concentration of substance that can be identified, measured, and reported with 99% confidence that the analyte concentration is greater than zero and is determined from analysis of a sample in a given matrix containing the analyte. The method detection limit refers to samples that have been processed through all the steps of an established analytical procedure. Minimum Reporting Level means the minimum concentration that can be reported as a quantitated value for a target analyte in a sample following analysis. Person means an individual, corporation, company, association, trust, partnership, the Commonwealth, a municipality, district or other subdivision or body politic of the Commonwealth, and any department, agency or instrumentality of the United States. Primary Dilution Standard Solution means a solution of several analytes prepared in the laboratory from stock standard solutions and diluted as needed to prepare calibration solutions and other needed analyte solutions. Proficiency Test (PT) Samples mean samples that contain known amounts of analytes and are obtained from the Department or from a third party acceptable to the Department. The composition of the sample is unknown to the laboratory performing the analysis. The PT sample is used to evaluate the ability of the laboratory and of the individual analyst to produce accurate and precise results within specified acceptance criteria. PT samples may be single blind (i.e., the laboratory/analyst knows that the sample is a PT sample), or double blind (i.e., the PT sample appears to be a routine sample so the laboratory/analyst is unaware that the sample is a PT sample). Proficiency Testing means a program in which proficiency test samples are used to evaluate the analytical performance of a laboratory. Signature means any mark, such as initials, printed or handwritten name, or equivalent electronic documentation made by a person to signify his or her responsibility for the performance of an action such as a measurement or the authentication of documentation produced internal to the laboratory analytical process. The signature must represent a unique person who can be identified with a specific action in the laboratory. Source Water means untreated water from streams, rivers, lakes, or underground aquifers that is used to supply private wells and public drinking water. Stock Standard Solution means a concentrated solution containing a single certified standard that is a method analyte, or a concentrated solution of a single analyte prepared in the laboratory with an assayed reference compound. Surrogate Analyte means a pure analyte(s), which is extremely unlikely to be found in any sample, and which is added to a sample aliquot in known amount(s) before extraction and is measured with the same procedures used to measure other sample components. Valid Data means analytical data that are: (a) technically sound (i.e., generated in accordance with good laboratory practices and meeting the quality control criteria of approved analytical methods); and (b) legally defensible (i.e., the laboratory’s compliance with quality control criteria designed to assure the accuracy of the analysis is completely and accurately documented).