The laboratory shall use support equipment only for its intended purpose, and it shall keep that equipment in working order by routine and preventive maintenance.
When support equipment leaves the direct control of the laboratory for maintenance or for any other reason, the laboratory shall ensure that the function and calibration status of that equipment is checked or demonstrated to be in working order before the equipment is returned to service.
Calibration and verification of support equipment. NR 149.44(3)(a)(a)
The laboratory shall calibrate or verify all support equipment within that equipment's range of use using available reference materials traceable to NIST. When reference materials traceable to NIST are not commercially available, the laboratory shall use materials of a quality that will ensure the accuracy of the calibrated or verified support equipment for its intended use.
The acceptability criteria for these calibration or verification checks shall be established by the methods, or in the absence, department guidance.
NR 149.44 Note
Department guidance can be found on the Wisconsin department of natural resources laboratory accreditation program website.
The laboratory shall establish a procedure for calibrating or verifying the calibration of support equipment which shall include all the following elements:
Procedures for utilization of correction factors when there is a bias.
Evaluation criteria used which defensibly documents the continued accuracy of the equipment.
Procedures for addressing equipment which fails to meet calibration or verification requirements.
Minimum verification frequencies include all the following:
Annually: devices used to measure atmospheric pressure and temperature.
Quarterly: mechanical and automatic volumetric dispensing devices, including pipettes.
Monthly: balances, with one weight in the expected range of use. Balance weights shall be all the following:
Traceable to NIST and of class 2 quality or better. Certified for accuracy every five years by a metrology service outside the laboratory. Alternatively, new weights of class 2 quality or better, traceable to NIST, shall be purchased for use. Weight recertification shall be performed sooner than every five years if balance checks performed using these weights suggest that a change in the certified weights has occurred.
NR 149.44 Note
Weights that are currently NIST traceable may be used to verify other weights.
Each day of use: when specific temperatures are required by method, regulation, or covered program, the operating temperature of the equipment used to control temperatures shall be checked and documented.
All the following are exempt from accuracy verification under this section:
The laboratory shall use personnel properly trained to operate analytical instruments. Instructions on the use and maintenance of equipment shall be available to instrument operators.
The laboratory shall properly maintain, inspect, and clean all instruments. The laboratory shall establish procedures for the maintenance of analytical instruments to prevent contamination or deterioration that may affect reported results.
The laboratory shall remove from service all analytical instruments that give suspect results or that have been shown to be defective or outside of performance specifications.
When analytical instruments leave the direct control of the laboratory for maintenance or for any other reason, the laboratory shall ensure that the instruments are functional and that a new initial calibration has passed to demonstrate that the instruments are in satisfactory working order before returned to service.
NR 149.44 History
History: CR 17-046: cr. Register February 2021 No. 782, eff. 6-29-21. NR 149.442(1)(1)
Sample acceptance policy and sample handling procedures. NR 149.442(1)(a)
The laboratory shall have and follow a written policy that clearly outlines the conditions under which samples will be accepted or rejected for analysis or under which associated reported results will be qualified.
NR 149.442 Note
Section NR 149.47 (4)
provides rejection criteria.
The laboratory shall receive drinking water samples in a secure manner so that the integrity of the sample is maintained.
When samples received do not conform to the descriptions provided by a collector or do not conform to sample acceptance requirements, the laboratory shall consult with the collector or client to determine the proper processing or disposition of the samples.
The laboratory shall place a unique identification code on a sample container as a durable label. The unique identification code shall be used as a link to associate samples with the complete sample history, including treatment and analysis, while in the laboratory's possession.
A laboratory shall follow the sample preservation procedures and holding times required by state and federal regulations.
NR 149.442 Note
Sample preservation procedures and holding times are given in 40 CFR Part 136
, 40 CFR Part 141
, NR 219, SW-846 “Test Methods for Evaluating Solid Waste” and may be specified in the methods.
NR 149.442 Note
Links to 40 CFR Part 136
, 40 CFR Part 141
, NR 219, and SW-846 can be found on the Wisconsin department of natural resources laboratory accreditation program website.
The laboratory shall measure and document the sample temperature at the time of receipt when temperature preservation is required.
The laboratory shall consider any sample requiring preservation at ≤
6 ºC to be preserved if the sample is received at a temperature greater than its freezing point to 6 ºC. When samples are received on the same day that they were collected, the samples may not yet have reached the appropriate temperature by the time they arrived at the laboratory. These samples may be considered acceptable, without the need to qualify the data, if all the following apply:
Samples were received at the laboratory on ice. “Blue ice” packs may not be considered as received on ice.
When sample temperature measurements are required, the laboratory shall record any of the following:
The laboratory shall verify the pH of each bottle received for samples requiring chemical preservation to a specific pH requirement under this section. Bottles not received at the proper pH may be adjusted at the laboratory provided that the methods allow preservation upon receipt and the lab retains documentation of its actions.
NR 149.442 Note
pH verification is only required from the bottle that is analyzed.
Sample receipt documentation.
The laboratory shall document the receipt and condition of all samples in chronological hard copy or electronic records. The records may be maintained in any format that retains all the following information:
The identity of the client or entity submitting samples, or the project associated with the received samples.
The times of sample collection for samples to be analyzed for tests with holding times expressed in hours.
The unique sample identification code assigned by the laboratory.
Documentation of sample preservation status and other sample conditions on receipt for all sample containers analyzed for those tests for which it is appropriate.
An unequivocal link between the sample identification code assigned by the laboratory and the field collection identification code assigned by the collector.
The requested analyses, unless the laboratory collects and analyzes its own samples and analyses are directed by permit.
The reference to requested test methods when the collector or sample originator specifies the methods.
Any comments resulting from the inspection undertaken to determine whether samples meet the policy in sub. (2)
The laboratory shall have procedures and appropriate facilities for avoiding deterioration, contamination, loss, or damage of samples during storage.
The laboratory shall store samples requiring thermal preservations at ≤
C at temperatures from greater than the samples' freezing point to 6 o
The laboratory shall store samples separately from all standards, reagents, food, and other potentially contaminating sources. Samples shall be stored in areas that prevent or minimize cross-contamination.
The laboratory shall store sample extracts, digestates, leachates, or concentrates resulting from any initial preparatory step as specified in this subsection.
NR 149.442 History
History: CR 17-046: cr. Register February 2021 No. 782, eff. 6-29-21. NR 149.444
Initial instrument calibration requirements. NR 149.444(1)(a)(a)
The laboratory shall calibrate or verify the calibration of all analytical instruments before the instruments are used to provide any quantitative results.
Once a calibration model is selected, a calibration function is established, and an initial calibration is finalized, a laboratory may not change the model or calibration function after samples have been analyzed without performing another initial calibration.
The laboratory shall perform an initial calibration if any of the following apply:
A second consecutive (immediate) CCV standard is performed under the same conditions and it also fails and the corrective action taken does not result in two consecutive passing CCV standards.
The laboratory shall retain all the raw data necessary to reconstruct or reproduce calibration functions associated with initial calibrations.
For colorimetric technologies, the laboratory may not use a method blank to zero the instrument.
NR 149.444 Note
For colorimetric technologies other than those based on inverse chemistries, the instrument is to be zeroed with the matrix of interest which is generally reagent water.
The laboratory may not utilize pre-programmed initial calibrations, provided by the instrument manufacturer, for compliance testing.
The laboratory shall include or reference the details of initial instrument calibration procedures including algorithms, any required equations, and acceptance criteria in the method standard operating procedure.
When required by method, the laboratory shall process each calibration standard in the same manner as samples.
Point-to-point calibrations are not allowed unless otherwise specified in this chapter.
Minimum number of standards.
To establish calibration, the laboratory shall select the number of nonzero standard concentrations that is appropriate for the calibration model selected and the expected range of concentrations. If a method requires analyzing more than three standards to establish a linear calibration, and the laboratory chooses to narrow the calibration range of the determination to no more than two orders of magnitude, the laboratory may use 3 standards to generate the initial calibration. The minimum number of nonzero standard concentrations selected to establish calibration shall be three except for all the following:
Dissolved oxygen meters, for which the minimum shall be one. Dissolved oxygen meters shall be calibrated against water-saturated air or air-saturated water at a known temperature and pressure. Alternatively, calibration may be performed using an iodometric method.
Conductivity meters, for which the minimum shall be one. Conductivity meters shall be calibrated by verifying the cell constant or adjusting the meter based on the analysis of a potassium chloride standard solution.
Inductively coupled plasma emission spectrophotometers and inductively coupled plasma mass spectrometers, for which the minimum number shall be one.
Quadratic calibration models, for which the minimum shall be five.