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Addendum 2 Quality Control Requirements for Laboratories Performing .Microbiological Testing In addition to the quality control requirements outlined in Chapter 5 of the NELAC Standards, the following quality control measures shall be implemented for this Agreement. Note: "Sample" refers to samples that have been either collected or analyzed under the terms of this Agreement. 1 . All microbiological analyses must conform to the requirements for facilities, personnel qualifications, equipment specifications and quality control measures discussed in AWWA Standard Methods, section 9020 (all acceptable editions) 2 . Holding Times — Any sample that exceeds the holding time specified in 40 CFR Part 136 (for non-potable water) or 40 CFR Part 141 (for drinking water compliance) must be appropriately qualified with a "Q" . The holding begins with the sample collection date and time and ends with the date and time of the placement of the processed sample into or on the applicable growth medium. a. For non-potable water, the maximum transport time to the laboratory is 6 hours and samples should be processed within 2 hours of receipt at the laboratory. For purposes of contractual services and to determine compliance with this requirement, the Department will allow no greater than, 6 hours from time of collection to the time of receipt by the laboratory AND no greater than 8 hours from time of collection to the placement of the processed sample into or on the applicable growth medium b. All samples that are either received after 6 hours OR placed into or on growth medium after 8 hours will be considered outside of holding time and must be qualified with a "Q" qualifier. (i) All samples that exceed the method-specified incubation period (range of minimum to maximum) shall be qualified with a "J" qualifier. c. For drinking water compliance, the time from sample collection to placement of the processed sample into or on the applicable growth medium may not exceed 30 hours. ( i) All samples that are processed after 30 hours will be considered outside of holding time and must be qualified with a "Q" qualifier. (ii) All samples that exceed the method-specified incubation period (range of minimum to maximum hours) shall be qualified with a "J" qualifier. d. In order to evaluate the holding time for each sample, the following information shall be documented. ( 1 ) Date and time of sample collection (2) Date and time of laboratory receipt of the sample (3 ) Date and time the analysis begins — (The time at which the sample is placed in or on the appropriate media for incubation) . (4) Date and time incubation begins (5 ) Date and time analysis ends - The date and time incubation ends and plates/tubes are read. 3 . Dilutions for membrane filter analysis - In order to achieve the recommended range of target organisms (20 — 60 colony forming units (CFU) for fecal coliform, enterococci and fecal streptococcus or 20 — 80 for total coliforms and E .coli), multiple dilutions of a sample must be run. While the general history of a sample site may be well known, the water will be influenced by many environmental factors at any one time. a. A minimum of 3 dilutions will be run for each sample analysis (except blanks). The three dilution volumes may vary according to the range of expected values or an understanding of the environmental conditions at the time of sampling. Waters of a higher quality (low microbial density) may benefit from a dilution series of 100 mL, 50 mL, and 25 mL of sample volume, whereas, lower quality waters (high microbial density) might require only 10 mL, 1 .0 mL, and 0 . 1 mL . Use a 100 mL dilution for all blanks ( including field and equipment blanks). Table 1 provides suggested volumes for varying water sources and has been adapted from Table 9222 : I11, Standard Methods, 20'' Edition, and can be used for microbiological samples : REMAINDER OF PAGE INTENTIONALLY LEFT BLANK Revision Date: 02/09 DEP Agreement No. G0353, Attachment J, Page 9 of 14