There should be sufficient bench space for processing samples. Workbench space should be convenient to sink, water, gas, vacuum and electrical sources free from surges. Instruments should be properly grounded. For safety reasons, inorganic and organic facilities should be in separate rooms; organic analysis and sample extraction should also be separated to prevent cross contamination. The analytical and sample storage areas should be isolated from all potential portable equipment, sufficient floor and bench space for stationary equipment and areas for cleaning mater"are an sources of contamination. There should be sufficient storage space for the safe storage of chemicals, glasswa 3. Laboratory Equipment and Instrumentation The laboratory is to have the instruments and equipment needed to perform the approved methods for which certification has been requested. The checklist on pages 44 to 50 of this chapter provides more information on the necessary equipment. All instruments are to be properly maintained and calibrated. 4. General Laboratory Practices 4.I General 4.1.1 Chemicals/reagents: Chemicals and reagents used must meet any requirements specified in the methods If not specified, then"Analytical reagent grade"(AR)or American Chemical Society(ACS)grade chemicals or better should be used for analyses in certified laboratories. Consult the currently promulgated editions of standard Methods for the Examination of Water and Wastewater, part 1070 for more detailed information on reagent grades 4.2.1 Reagent water: The laboratory must have a source of reagent water having a resistance value of at least 0.5 megohms(conductivity less than 2.0 micromhos/cm) at 25C when required by the method. High quality water maintained by sealing it from the atmosphere. Quality checks to meet specifications above should be made and documented at planned intervals based on use. Individual analytical methods may specify additional requirements for the reagent water to be used. Inorganic methods require distilled or deionized water free of the analyte(s) of terest and trace metals methods require AsTM Type 1 water. first with tap water and then with reagent water. This cleaning procedure is sufficient for general analytical needs It is advantageous to maintain separate sets of suitably prepared glassware for the nitrate and mercury analyses due to the potential for contamination from the laboratory environment. Table Iv-I summarizes the cleaning procedures specified in the ePa methods 4.3 Organic Contaminants 4.3.1 Reagent water: Reagent water for organic analysis must adhere to any required QC specified in the methods Most methods specify the reagent water not contain analytes of interest above their respective method detection levels (MDLs). It may be necessary to treat water with activated carbon to eliminate all interferences. Reagent water requirements of individual methods must be followed 4.3.2 Glassware preparation: Glassware cleaning requirements specified in the methods must be followed Table IV-1 summarizes the cleaning procedures specified in the EPA method 4.4 Laboratory Safety customary safety practices as a part of good laboratory practices. Each laboratory is encouraged to have a safety, c While safety criteria are not an aspect of laboratory certification, laboratory personnel should apply general an as part of their standard operating procedure which includes personnel safety, training and protection. Where salp practices are required in an approved method (i.e, 515.1), they must be followed. See Standard Methods for the Examination of Water and Wastewater, part 1090 for a discussion of laboratory safety 4.5 Quality Assurance Laboratories should maintain current Quality Assurance Plans as described in Chapter 3. All laboratory activities
IV- 2 There should be sufficient bench space for processing samples. Workbench space should be convenient to sink, water, gas, vacuum and electrical sources free from surges. Instruments should be properly grounded. For safety reasons, inorganic and organic facilities should be in separate rooms; organic analysis and sample extraction should also be separated to prevent cross contamination. The analytical and sample storage areas should be isolated from all potential sources of contamination. There should be sufficient storage space for the safe storage of chemicals, glassware and portable equipment, sufficient floor and bench space for stationary equipment and areas for cleaning materials. 3. Laboratory Equipment and Instrumentation The laboratory is to have the instruments and equipment needed to perform the approved methods for which certification has been requested. The checklist on pages 44 to 50 of this chapter provides more information on the necessary equipment. All instruments are to be properly maintained and calibrated. 4. General Laboratory Practices 4.1 General 4.1.1 Chemicals/reagents: Chemicals and reagents used must meet any requirements specified in the methods. If not specified, then "Analytical reagent grade" (AR) or American Chemical Society (ACS) grade chemicals or better should be used for analyses in certified laboratories. Consult the currently promulgated editions of Standard Methods for the Examination of Water and Wastewater, part 1070 for more detailed information on reagent grades. 4.2 Inorganic Contaminants 4.2.1 Reagent water: The laboratory must have a source of reagent water having a resistance value of at least 0.5 megohms (conductivity less than 2.0 micromhos/cm) at 25 C when required by the method. High quality water o meeting such specifications may be purchased from commercial suppliers. Quality of reagent water is best maintained by sealing it from the atmosphere. Quality checks to meet specifications above should be made and documented at planned intervals based on use. Individual analytical methods may specify additional requirements for the reagent water to be used. Inorganic methods require distilled or deionized water free of the analyte(s) of interest and trace metals methods require ASTM Type 1 water. 4.2.2 Glassware preparation: Glassware cleaning requirements specified in the methods must be followed. If no specifications are listed, then glassware should be washed in a warm detergent solution and thoroughly rinsed first with tap water and then with reagent water. This cleaning procedure is sufficient for general analytical needs. It is advantageous to maintain separate sets of suitably prepared glassware for the nitrate and mercury analyses due to the potential for contamination from the laboratory environment. Table IV-1 summarizes the cleaning procedures specified in the EPA methods. 4.3 Organic Contaminants 4.3.1 Reagent water: Reagent water for organic analysis must adhere to any required QC specified in the methods. Most methods specify the reagent water not contain analytes of interest above their respective method detection levels (MDLs). It may be necessary to treat water with activated carbon to eliminate all interferences. Reagent water requirements of individual methods must be followed. 4.3.2 Glassware preparation: Glassware cleaning requirements specified in the methods must be followed. Table IV-1 summarizes the cleaning procedures specified in the EPA methods. 4.4 Laboratory Safety While safety criteria are not an aspect of laboratory certification, laboratory personnel should apply general and customary safety practices as a part of good laboratory practices. Each laboratory is encouraged to have a safety plan as part of their standard operating procedure which includes personnel safety, training and protection. Where safety practices are required in an approved method (i.e., 515.1), they must be followed. See Standard Methods for the Examination of Water and Wastewater, part 1090 for a discussion of laboratory safety. 4.5 Quality Assurance Laboratories should maintain current Quality Assurance Plans as described in Chapter 3. All laboratory activities
including, but not limited to, sampling, test methods, instrument operation, data generation, data validation and corrective action procedures should be described in the Plan. Plans need to be read by all personnel 5. Analytical Methods 5.1 General A list of promulgated methods for inorganic and organic contaminants can be found in Tables IV-2 and Iv-3 respectively. Methods manuals should be available to applicable personnel. Other methods cannot be used for compliance samples unless approval has been granted by the agency by obtaining an Alternate Test Procedure approval. Allowed modification to the methods must be documented. Contact the appropriate certifying authority for the alternate test procedure process(see Chapter 3, p 10). Table Iv-4 lists the methods which must be used for the analysis of disinfectant residuals. Recommended methods for Secondary contaminants are listed in Table Iv-5 5.2 Analyses Approved by the state Measurements for turbidity, pH, temperature, disinfectant residual, calcium, orthophosphate, silica, alkalinity, and conductivity need not be made in certified laboratories, but may be performed by any persons acceptable to the State. However, approved methodology must) be used (Tables IV-2 to IV-5). The State should institute a quality assurance program to assure validity of data from these measurements 5.2.1 Turbidity standards: Sealed liquid secondary turbidity standards purchased from the instrument manufacturer or other sources should be calibrated against properly prepared and diluted formazin or styrene divinylbenzene polymer primary standards and revised values assigned at least every four months in order to monitor for any deterioration. This calibration should be documented. these standards should be replaced when they do lot fall within 15% of the initial assigned concentration of the standard. Solid turbidity standards composed of plastic, glass, or other materials are not reliable and should not be used 5.2.2 Residual chlorine standards: If visual comparison devices such as color wheels or sealed ampules are used for determining free chlorine residual, the standards incorporated into such devices should be calibrated at least every six months. These calibrations need to be documented. Directions for preparing temporary and permanent type visual standards can be found in Method 4500-Cl-G, of the currently promulgated editions ofstandard methods for the Examination of water and Wastewater. By comparing standards and plotting such a comparison on graph paper, a correction factor can be derived and applied to future results obtained on the now calibrated apparatus 6. Sample Collection, Handling, and Preservation The manner in which samples are collected and handled is critical to obtaining valid data. It is important that a written sampling protocol with specific sampling instructions be available to and used by sample collectors and available for inspection by the certification officer.(Appendix A, Chain-of-Custody). 6.I Rej The laboratorys rejection criteria should be documented in writing in the laboratorys Qa Plan or in an SOP. The laboratory should reject any sample taken for compliance purposes which does not meet the criteria in 6.2 through 6.6 The laboratory must(141.23(a)(4)(i))notify the authority requesting the analyses and ask for a resample. If resampling is not possible and the sample is analyzed, the sample data should be clearly identified in the data package as being unusable for its intended purpose. In addition, the inadmissibility of these sample data need to be clearly communicated to all end data users 6.2 Sample Containers and Preservation The type of sample container and the required preservative for each inorganic and organic chemical contaminant are listed in Table IV-6. The laboratory must measure and record the temperature of the sample when it arrives when temperature preservation is required by the method. The use of blue ice"is discouraged because it generally does not maintain the temperature of the sample at 4C +2C or less. If blue ice is used, it should be frozen at the time of sampling, the sample should be chilled before packing, and special notice taken at sample receipt to be certain the required temperature (4C)has been maintained
IV- 3 including, but not limited to, sampling, test methods, instrument operation, data generation, data validation and corrective action procedures should be described in the Plan. Plans need to be read by all personnel. 5. Analytical Methods 5.1 General A list of promulgated methods for inorganic and organic contaminants can be found in Tables IV-2 and IV-3, respectively. Methods manuals should be available to applicable personnel. Other methods cannot be used for compliance samples unless approval has been granted by the Agency by obtaining an Alternate Test Procedure approval. Allowed modification to the methods must be documented. Contact the appropriate certifying authority for the alternate test procedure process (see Chapter 3, p 10). Table IV-4 lists the methods which must be used for the analysis of disinfectant residuals. Recommended methods for Secondary contaminants are listed in Table IV-5. 5.2 Analyses Approved by the State Measurements for turbidity, pH, temperature, disinfectant residual, calcium, orthophosphate, silica, alkalinity, and conductivity need not be made in certified laboratories, but may be performed by any persons acceptable to the State. However, approved methodology must) be used (Tables IV-2 to IV-5). The State should institute a quality assurance program to assure validity of data from these measurements. 5.2.1 Turbidity standards: Sealed liquid secondary turbidity standards purchased from the instrument manufacturer or other sources should be calibrated against properly prepared and diluted formazin or styrene divinylbenzene polymer primary standards and revised values assigned at least every four months in order to monitor for any deterioration. This calibration should be documented. These standards should be replaced when they do not fall within 15% of the initial assigned concentration of the standard. Solid turbidity standards composed of plastic, glass, or other materials are not reliable and should not be used. 5.2.2 Residual chlorine standards: If visual comparison devices such as color wheels or sealed ampules are used for determining free chlorine residual, the standards incorporated into such devices should be calibrated at least every six months. These calibrations need to be documented. Directions for preparing temporary and permanent type visual standards can be found in Method 4500-Cl-G, of the currently promulgated editions of Standard Methods for the Examination of Water and Wastewater. By comparing standards and plotting such a comparison on graph paper, a correction factor can be derived and applied to future results obtained on the now calibrated apparatus. 6. Sample Collection, Handling, and Preservation The manner in which samples are collected and handled is critical to obtaining valid data. It is important that a written sampling protocol with specific sampling instructions be available to and used by sample collectors and available for inspection by the certification officer. (Appendix A, Chain-of-Custody). 6.1 Rejection of Samples The laboratory’s rejection criteria should be documented in writing in the laboratory’s QA Plan or in an SOP. The laboratory should reject any sample taken for compliance purposes which does not meet the criteria in 6.2 through 6.6. The laboratory must (141.23(a)(4)(i))notify the authority requesting the analyses and ask for a resample. If resampling is not possible and the sample is analyzed, the sample data should be clearly identified in the data package as being unusable for its intended purpose. In addition, the inadmissibility of these sample data need to be clearly communicated to all end data users. 6.2 Sample Containers and Preservation The type of sample container and the required preservative for each inorganic and organic chemical contaminant are listed in Table IV-6. The laboratory must measure and record the temperature of the sample when it arrives when temperature preservation is required by the method. The use of "blue ice" is discouraged because it generally does not maintain the temperature of the sample at 4°C ±2°C or less. If blue ice is used, it should be frozen at the time of sampling, the sample should be chilled before packing, and special notice taken at sample receipt to be certain the required temperature (4°C) has been maintained
6.3 Maximum Holding Times Samples must be analyzed within the maximum holding times required by the method. These are listed in Table Iv-6 6.4 Sample Collection and Transport There must be strict adherence to correct sampling procedures, sample handling, complete identification of the sample, and prompt transfer of the sample to the laboratory when required by the method. When the laboratory is not responsible for sample collection and transport, it must verify that the paperwork, preservatives, containers and holding times are correct as required by the methods or reject the sample. The rejection criteria should(EPa Order 5360. 1)be documented 6.5 Sample Collector The sample collector should be trained in sampling procedures and have complete written sampling instructions(SOPs) for each type of sample to be collected. The samplers are to be able to demonstrate proper sampling technique 6.6 Sample Report Form The sample collection report form should contain, at a minimum, the ID, location, date and time of collection, collector's name, preservative added and shipping requirements, container and volume, sample type, analysis, and any special remarks concerning the sample. Indelible ink should be used 6.7 Sample Com positing If samples are composited, the compositing must (40 CFR 141.23, 24)be done in the laboratory. Samples may only be composited if the laboratory detection limit is adequate for the number of samples being composited (up to a maximum of five). For example, for inorganic samples, composite samples from a maximum of five samples are allowed if the detection limit of the method used for analysis is less than one-fifth the MCL. If the concentration of any inorganic chemical in the composite is greater than or equal to one-fifth of the MCL, then a followup sample must be taken within 14 days at each sampling point included in the composite. These samples must be analyzed for the contaminants which exceeded one-fifth the mCl in the composite sample. [CFR 144.23 (a)(4)] Compositing of VOCs is not recommended. 7. Quality Control 7.1 General Requirements 7.1.1 Availability of QA Documents: The laboratory's Qa plan and appropriate Standard Operating Procedures (SOPs) should be readily available to the analysts and for inspection by auditors. (see Chapter Ill,s discussion of Quality Assurance). 7.1.2 Availability of QC Information: All quality control information should be readily available for inspection by auditors 7.1.3 Balances and weights: Balance range should be appropriate for the application for which it is to be used Drinking water chemistry laboratories should use balances that weigh to at least 0.0001 g. The balances should be calibrated at least annually with ASTM Type l, Class I or 2 weights. (ASTM, 1916 Race St, Philadelphia, PA 19103) This may be done by laboratory personnel or under contract by a manufacturer's representative. We strongly recommend that laboratories have a contract to calibrate balances due to the expense of the calibration weights, and to outside QC check of the weights and balances. Weights meeting ASTM Type I, Class I or 2 specifications should be recertified at least every five years or if there is reason to believe damage(corrosion nicks)has occurred. Each day the mechanical or digital balance is used, a verification should be performed. The verification consists of a check of a reference mass at approximately the same nominal mass to be determined. Verifications should be done each weighing session unless it can be shown that fluctuations in the environment do not affect the calibration. Weights meeting ASTM Type 1 specifications may be used. These should be calibrated annually against the reference weights at time of balance calibration. The checks and their frequency should be as prescribed in the laboratory s QA Plan. A record of all checks should be kept and be available for inspection
IV- 4 6.3 Maximum Holding Times Samples must be analyzed within the maximum holding times required by the method. These are listed in Table IV-6. 6.4 Sample Collection and Transport There must be strict adherence to correct sampling procedures, sample handling, complete identification of the sample, and prompt transfer of the sample to the laboratory when required by the method. When the laboratory is not responsible for sample collection and transport, it must verify that the paperwork, preservatives, containers and holding times are correct as required by the methods or reject the sample. The rejection criteria should (EPA Order 5360.1) be documented in writing. 6.5 Sample Collector The sample collector should be trained in sampling procedures and have complete written sampling instructions (SOPs) for each type of sample to be collected. The samplers are to be able to demonstrate proper sampling technique. 6.6 Sample Report Form The sample collection report form should contain, at a minimum, the ID, location, date and time of collection, collector's name, preservative added and shipping requirements, container and volume, sample type, analysis, and any special remarks concerning the sample. Indelible ink should be used. 6.7 Sample Compositing If samples are composited, the compositing must (40 CFR 141.23,24) be done in the laboratory. Samples may only be composited if the laboratory detection limit is adequate for the number of samples being composited (up to a maximum of five). For example, for inorganic samples, composite samples from a maximum of five samples are allowed if the detection limit of the method used for analysis is less than one-fifth the MCL. If the concentration of any inorganic chemical in the composite is greater than or equal to one-fifth of the MCL, then a followup sample must be taken within 14 days at each sampling point included in the composite. These samples must be analyzed for the contaminants which exceeded one-fifth the MCL in the composite sample. [CFR 144.23(a)(4)] Compositing of VOCs is not recommended. 7. Quality Control 7.1 General Requirements 7.1.1 Availability of QA Documents: The laboratory's QA plan and appropriate Standard Operating Procedures (SOPs) should be readily available to the analysts and for inspection by auditors. (see Chapter III's discussion of Quality Assurance). 7.1.2 Availability of QC Information: All quality control information should be readily available for inspection by auditors. 7.1.3 Balances and Weights: Balance range should be appropriate for the application for which it is to be used. Drinking water chemistry laboratories should use balances that weigh to at least 0.0001 g. The balances should be calibrated at least annually with ASTM Type I, Class 1 or 2 weights. (ASTM, 1916 Race St., Philadelphia, PA 19103) This may be done by laboratory personnel or under contract by a manufacturer's representative. We strongly recommend that laboratories have a contract to calibrate balances due to the expense of the calibration weights, and to serve as an outside QC check of the weights and balances. Weights meeting ASTM Type I, Class 1 or 2 specifications should be recertified at least every five years or if there is reason to believe damage (corrosion, nicks) has occurred. Each day the mechanical or digital balance is used, a verification should be performed. The verification consists of a check of a reference mass at approximately the same nominal mass to be determined. Verifications should be done each weighing session unless it can be shown that fluctuations in the environment do not affect the calibration. Weights meeting ASTM Type 1 specifications may be used. These should be calibrated annually against the reference weights at time of balance calibration. The checks and their frequency should be as prescribed in the laboratory's QA Plan. A record of all checks should be kept and be available for inspection
7.1.4 Color Standards: Wavelength settings on spectrophotometers should be verified at least annually with color standards. The specific checks and their frequency should be as prescribed in the laboratory 's Qa documents. a record of these checks should be kept as prescribed in the laboratorys Qa documents and be available fo 7.1.5 Temperature Measuring Devices Liquid bearing thermometers such as mercury or alcohol thermometers need to be traceable to NIST calibration and verified at least annually and whenever the thermometer has been exposed to temperature extremes. The correction factor should be indicated on the thermometer and the date the thermometer was calibrated and the calibration factor should be kept as prescribed in the laboratorys QA documents and be available for inspection. The nist thermometer should be recalibrated at least every five years or whenever the thermometer has been exposed to temperature extremes Digital thermometers, thermocouples and other similar electronic temperature measuring devices should be calibrated at least quarterly. The date the thermometer was calibrated and the calibration factor should be kept prescribed in the laboratorys Qa documents and be available for inspection When an infrared detection device is used to measure the temperature of samples, the device should be verified at least every six months using a NISt certified thermometer over the full temperature range that the Ir thermometer will be used. This would include ambient (20-30%C), iced(4 C)and frozen(0 to-5C). Each day of use a single check of the IR should be made by checking the temperature of a bottle of water at the temperature of interest that contains a calibrated thermometer. Agreement between the two should be within 0.5C, or the device should be calibrated 7.1.6 Traceability of calibration: Calibrations of all measurement devices need to be traceable to national standards whenever applicable 7. 2 Specific Requirem ents: The follo wing are required for each analyte for which a laboratory is certified 7.2.1 Proficiency Testing(PT) Samples: In order to receive and maintain full certification for an analyte, the laboratory must(40CFR 141 23(k)(3(i), 141.24(h)(17)(i)(A)and 141.89(a)(1)(i))analyze PT samples(if available) acceptable to the Certifying Authority at least once every 12 months for each analyte and by each method used to analyze compliance samples. Results from analysis of the Pt sample must be within the acceptable limits established by U.S. EPA. These acceptance limits are listed in Table Iv-10, "MCl and Profeciency Testing Sample Acceptance Criteria in the CFR, Primary and Secondary Drinking Water Regulations [S 1.23(k)(3)(ii)and 141.24(f(17) and(19)]. The laboratory should document the corrective actions taken when a PT sample is analyzed unsuccessfully. A copy of this documentation should be available for review by the certification officer. A make up PT sample must be successfully analyzed. If problems arise, the appropriate action to be taken is pecified in Chapter ll, Implementation of Certification Program Excluding vinyl chloride, the laboratory may be certified for all voCs if they successfully analyze at least 80% of the regulated VOCs(141.24(17)(D(i)(B). The intention of this regulation is to allow some flexibility for random misses because the voC methods include 20 regulated analytes. A laboratory should not be certified or an analyte which it fails repeatedly. This 80% rule "for VOCs has recently been made more difficult to interpret since some Pt providers are including THMs in the same vial as the VOCs. The 80%Rule does not pply to the THMs. The Stage I Disinfection By Products(DBP)Rule, which became effective in January 2002, regulates the sum of five haloacetic acids(HAA5): monochloroacetic acid, dichloroacetic acid trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. Laboratories are certified for hAA5, but successful analyses f the HAa Pt samples are based on the results for the individual compounds. The 80% Rule applies to the HAASS, so if four of the 5 HAASs are successfully analyzed the laboratory may be certified for HAA5. As before, a laboratory should not be certified if the same analyte is failed repeatedly
IV- 5 7.1.4 Color Standards: Wavelength settings on spectrophotometers should be verified at least annually with color standards. The specific checks and their frequency should be as prescribed in the laboratory’s QA documents. A record of these checks should be kept as prescribed in the laboratory’s QA documents and be available for inspection. 7.1.5 Temperature Measuring Devices Liquid bearing thermometers such as mercury or alcohol thermometers need to be traceable to NIST calibration and verified at least annually and whenever the thermometer has been exposed to temperature extremes. The correction factor should be indicated on the thermometer and the date the thermometer was calibrated and the calibration factor should be kept as prescribed in the laboratory’s QA documents and be available for inspection. The NIST thermometer should be recalibrated at least every five years or whenever the thermometer has been exposed to temperature extremes. Digital thermometers, thermocouples and other similar electronic temperature measuring devices should be calibrated at least quarterly. The date the thermometer was calibrated and the calibration factor should be kept as prescribed in the laboratory’s QA documents and be available for inspection. When an infrared detection device is used to measure the temperature of samples, the device should be verified at least every six months using a NIST certified thermometer over the full temperature range that the IR thermometer will be used. This would include ambient (20-30°C), iced (4°C) and frozen (0 to -5°C). Each day of use a single check of the IR should be made by checking the temperature of a bottle of water at the temperature of interest that contains a calibrated thermometer. Agreement between the two should be within 0.5°C, or the device should be recalibrated. 7.1.6 Traceability of Calibration: Calibrations of all measurement devices need to be traceable to national standards whenever applicable. 7.2 Specific Requirements: The following are required for each analyte for which a laboratory is certified: 7.2.1 Proficiency Testing (PT) Samples: In order to receive and maintain full certification for an analyte, the laboratory must (40CFR 141.23(k)(3)(i),141.24(h)(17)(i)(A) and 141.89(a)(1)(i)) analyze PT samples (if available) acceptable to the Certifying Authority at least once every 12 months for each analyte and by each method used to analyze compliance samples. Results from analysis of the PT sample must be within the acceptable limits established by U.S. EPA. These acceptance limits are listed in Table IV-10, “MCL and Profeciency Testing Sample Acceptance Criteria in the CFR, Primary and Secondary Drinking Water Regulations [§141.23(k)(3)(ii) and 141.24(f)(17) and (19)].” The laboratory should document the corrective actions taken when a PT sample is analyzed unsuccessfully. A copy of this documentation should be available for review by the certification officer. A make up PT sample must be successfully analyzed. If problems arise, the appropriate action to be taken is specified in Chapter III, Implementation of Certification Program. Excluding vinyl chloride, the laboratory may be certified for all VOCs if they successfully analyze at least 80% of the regulated VOCs (141.24(17)(f)(i)(B). The intention of this regulation is to allow some flexibility for random misses because the VOC methods include 20 regulated analytes. A laboratory should not be certified for an analyte which it fails repeatedly. This “80% rule” for VOCs has recently been made more difficult to interpret since some PT providers are including THMs in the same vial as the VOCs. The 80% Rule does not apply to the THMs. The Stage 1 Disinfection By Products (DBP) Rule, which became effective in January 2002, regulates the sum of five haloacetic acids (HAA5): monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. Laboratories are certified for HAA5, but successful analyses of the HAA PT samples are based on the results for the individual compounds. The 80% Rule applies to the HAA5s, so if four of the 5 HAA5s are successfully analyzed, the laboratory may be certified for HAA5. As before, a laboratory should not be certified if the same analyte is failed repeatedly
The DBP Rule also changed the way the trihalomethanes (THMs): chloroform, dichlorobromomethane, chlorodibromomethane and bromoform Pts are evaluated. Laboratories are still certified for total THMs but under the DBP Rule, each THM concentration must (141. 13 1(b)(2) be reported, evaluated and passed dividually to pass the PT sample. The DBP Rule also states that if a laboratory fails one ThM, it cannot be PT sample to be certified to analyze compliance monitoring samples for total trihalomethane Q certified for TTHMs, but must (141.131()(2)analyze another PT sample and pass all four of the ThMs in a The following table summarizes the 80% Rule Analyte(s) PT Success Requirement Vinyl Chlorid 80%1 4 THMS 5 HAASs A lab should not maintain certification for analyte(s)which it repeatedly fails 7.2.2 Quality Control Samples: At least once each quarter, the laboratory should analyze a quality control sample for the analytes they are determining in that quarter. The sample should be prepared from a source other than that from which their working standards are prepared. The sample should be in the same concentration range as the drinking water calibration curve. If errors exceed limits required in the methods, corrective action nust be taken and documented, and a follow-up quality control sample analyzed as soon as possible to demonstrate the problem has been corrected. 7.2.3 Calibration Curve: Calibration requirements in the methods must be followed. If there are no calibration requirements in the method, the following are guidelines to be used. At the beginning of each day that samples are to be analyzed, a calibration curve covering the sample concentration range and all target analytes should be generated according to the approved SoP. Depending on concentration ranges, the curve should be composed of three or more points. Field measurements(e. g pH and chlorine residual)need to be made on instruments which have been properly calibrated as specified in the method or instrument manual and checked each day of use. The less precise the measurement, the greater the number of concentrations which should be included in the calibration curve 7. 2.4 Calibration Check: The calibration for some methods is so time-consuming that 7.2.3 is impractical on a daily basis. Where the determinative time is extensive such as Methods 508/508.1, 515.1, 524.2, 525.2 etc and the instrument is very stable, the calibration curve should be initially developed as specified in 7.2.3 Thereafter, each day analyses are performed, this curve should be verified by analysis of at least one standard for each of the target analytes at the expected concentration range. This verification should be done at both the beginning and end of the analyses. All checks must be within the control limits required in the method or the system is to be recalibrated as specified in 7. 2.3. The concentration of the check standard should vary from day to day across the range of analyte concentrations being measured For some methods an initial conditioning injection is to be made to deactivate active sites that may have developed overnight. Depending on the method, the blank may be appropriate for this. Specific calibration requirements in the methods must be followed if different than the above It is recommended that a calibration standard of one component of a multicomponent analyte(PCBs, toxaphene or chlordane)also be analyzed each day or work shift. By rotating the analyte chosen, continuing calibration data can be obtained on all the multicomponent analytes over a period of one to two weeks. If a positive for a multcomponent analyte is found in a sample, a calibration check for that analyte should be performed as soon as possible ⅣV-6
IV- 6 The DBP Rule also changed the way the trihalomethanes (THMs): chloroform, dichlorobromomethane, chlorodibromomethane and bromoform PTs are evaluated. Laboratories are still certified for total THMs but under the DBP Rule, each THM concentration must (141.131(b)(2) be reported, evaluated and passed individually to pass the PT sample. The DBP Rule also states that if a laboratory fails one THM, it cannot be certified for TTHMs, but must (141.131(b)(2)analyze another PT sample and pass all four of the THMs in a PT sample to be certified to analyze compliance monitoring samples for total trihalomethanes. The following table summarizes the 80% Rule. Analyte(s) PT Success Requirement Vinyl Chloride 100% 20 VOCs 80% 1 4 THMs 100% 5 HAA5s 80% 1 A lab should not maintain certification for analyte(s) which it repeatedly fails. 1 7.2.2 Quality Control Samples: At least once each quarter, the laboratory should analyze a quality control sample for the analytes they are determining in that quarter. The sample should be prepared from a source other than that from which their working standards are prepared. The sample should be in the same concentration range as the drinking water calibration curve. If errors exceed limits required in the methods, corrective action must be taken and documented, and a follow-up quality control sample analyzed as soon as possible to demonstrate the problem has been corrected. 7.2.3 Calibration Curve: Calibration requirements in the methods must be followed. If there are no calibration requirements in the method, the following are guidelines to be used. At the beginning of each day that samples are to be analyzed, a calibration curve covering the sample concentration range and all target analytes should be generated according to the approved SOP. Depending on concentration ranges, the curve should be composed of three or more points. Field measurements (e.g. pH and chlorine residual) need to be made on instruments which have been properly calibrated as specified in the method or instrument manual and checked each day of use. The less precise the measurement, the greater the number of concentrations which should be included in the calibration curve. 7.2.4 Calibration Check: The calibration for some methods is so time-consuming that 7.2.3 is impractical on a daily basis. Where the determinative time is extensive such as Methods 508/508.1, 515.1, 524.2, 525.2, etc. and the instrument is very stable, the calibration curve should be initially developed as specified in 7.2.3. Thereafter, each day analyses are performed, this curve should be verified by analysis of at least one standard for each of the target analytes at the expected concentration range. This verification should be done at both the beginning and end of the analyses. All checks must be within the control limits required in the method or the system is to be recalibrated as specified in 7.2.3. The concentration of the check standard should vary from day to day across the range of analyte concentrations being measured. For some methods an initial conditioning injection is to be made to deactivate active sites that may have developed overnight. Depending on the method, the blank may be appropriate for this. Specific calibration requirements in the methods must be followed if different than the above. It is recommended that a calibration standard of one component of a multicomponent analyte (PCBs, toxaphene or chlordane) also be analyzed each day or work shift. By rotating the analyte chosen, continuing calibration data can be obtained on all the multicomponent analytes over a period of one to two weeks. If a positive for a multcomponent analyte is found in a sample, a calibration check for that analyte should be performed as soon as possible