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HomeMy WebLinkAbout#71_2023_1205_JMS_FINAL NC Department of Environmental Quality | Division of Water Resources | Laboratory Certification Branch 4405 Reedy Creek Road | 1623 Mail Service Center | Raleigh, North Carolina 27699-1623 March 5, 2024 71 Mr. Ronnie Hendrix Lower Creek WWTP Laboratory P.O. Box 958 Lenoir, NC 28645 Subject: North Carolina Wastewater/Groundwater Laboratory Certification Branch (NC WW/GW LCB) Maintenance Inspection Dear Mr. Hendrix: Enclosed is a report for the inspection performed on December 5, 2023, by Jason Smith. I apologize for the delay in getting this report to you. Where Finding(s) are cited in this report, a response is required. Within thirty days, please supply this office with a written item for item description of how these Finding(s) were corrected. Please describe the steps taken to prevent recurrence and include an implementation date for each corrective action. If the Finding(s) cited in the enclosed report are not corrected, enforcement actions may be recommended. For Certification maintenance, your laboratory must continue to carry out the requirements set forth in 15A NCAC 02H .0800. A copy of the laboratory’s Certified Parameter List at the time of the audit is attached. This list will not reflect any changes made during the audit. Copies of the checklists completed during the inspection may be requested from this office. Thank you for your cooperation during the inspection. If you have questions or need additional information, please contact me at (919) 745- 4368. Sincerely, Anna Ostendorff Technical Assistance & Compliance Specialist Division of Water Resources Attachment cc: Todd Crawford, Jason Smith, Master File #71 On-Site Inspection Report LABORATORY NAME: Lower Creek WWTP Laboratory NPDES PERMIT #: NC0023736, NC0023981 and NC0044164 ADDRESS: 1905 Broadland Road Lenoir, NC 28645 CERTIFICATE #: 71 DATE OF INSPECTION: December 5, 2023 TYPE OF INSPECTION: Municipal Maintenance AUDITOR(S): Jason Smith LOCAL PERSON(S) CONTACTED: Ronnie Hendrix, Elisa Triplett, Haden Land and Hailey Carlisle I.INTRODUCTION: This laboratory was inspected by a representative of the North Carolina Wastewater/Groundwater Laboratory Certification Branch (NC WW/GW LCB) to verify its compliance with the requirements of 15A NCAC 02H .0800 for the analysis of compliance monitoring samples. II.GENERAL COMMENTS: The laboratory is neat and well organized and has all the equipment necessary to perform the analyses. Staff were forthcoming and responded well to suggestions from the auditor. All required Proficiency Testing (PT) Samples have been analyzed for the 2023 PT Calendar Year and the graded results were 100% acceptable. The laboratory did not have Quality Assurance (QA) and/or Standard Operating Procedure (SOP) document(s) in place for all currently certified parameters. These documents must be submitted for review as specified in Finding A. Any time changes are made to laboratory procedures, Quality Assurance (QA) and/or Standard Operating Procedure (SOP) document(s) must be updated and relevant staff retrained. Staff must acknowledge that they have read and understand the changes as part of the documented training program. The same requirements apply when changes are made in response to Findings, Recommendations or Comments listed in this report, to ensure the methods are being performed as stated, references to methods are accurate, and the QA and/or SOP document(s) is in agreement with each approved practice, test, analysis, measurement, monitoring procedure or regulatory requirement being used in the laboratory. In some instances, the laboratory may need to create an SOP to document how new functions or policies will be implemented. Revisions to the existing SOPs, based on the Findings, Comments and Recommendations within this report must be submitted to this office by December 31, 2024. Page 2 #71 Lower Creek WWTP Laboratory The laboratory is reminded that SOPs are intended to describe procedures exactly as they are to be performed. Use of the word “should” is not appropriate when describing requirements (e.g., Quality Control (QC) frequency, acceptance criteria, etc.). Evaluate all SOPs for the proper use of the word “should”. Contracted analyses are performed by Meritech, Inc. (Certification #165) and Statesville Analytical Holdings, LLC (Certification #440). III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS: Documentation A. Finding: The laboratory does not have QA/SOP documents for each certified parameter method nor a documented plan for PT procedures. Requirement: Each laboratory shall have a documented analytical quality assurance and quality control program. Each laboratory shall have a copy of each approved test, analysis, measurement, or monitoring procedure being used in the laboratory. Each laboratory shall develop documentation outlining the analytical quality control practices used for the Parameter Methods included in its Certification, including Standard Operating Procedures for each certified Parameter Method. Quality assurance, quality control, and Standard Operating Procedure documentation shall indicate the effective date of the document and be reviewed every two years and updated if changes in procedures are made. Each laboratory shall have a formal process to track and document review dates and any revisions made in all quality assurance, quality control, and Standard Operating Procedure documents. Supporting Records shall be maintained as evidence that these practices are implemented. The quality assurance, quality control, and Standard Operating Procedure documents shall be available for inspection by the State Laboratory. Ref: 15A NCAC 02H .0805 (a) (7). Requirement: Laboratories must have a documented plan [this is usually detailed in the laboratory’s Quality Assurance Manual or may be a separate Standard Operating Procedure (SOP)] of how they intend to cover the applicable program requirements for Proficiency Testing per their scope of accreditation. This plan shall cover any commercially available PT Samples and any inter-laboratory organized studies, as applicable. The plan must also address the laboratory’s process for submission of PT Sample results and related Corrective Action Reports (CARs). Ref: Proficiency Testing Requirements, January 1, 2023, Revision 6, Section 3.0. Comment: The laboratory does not have SOPs for Dissolved Oxygen (DO), Temperature, Vector Attraction Reduction: Option 7 and PT procedures. The SOPs for these parameters are required to be submitted with the report response. B. Finding: Error corrections are not dated. Cited previously on April 29, 2010. Requirement: All documentation errors shall be corrected by drawing a single line through the error so that the original entry remains legible. Entries shall not be obliterated by erasures or markings. Wite-Out®, correction tape, or similar products designed to obliterate documentation shall not to be used; instead, the correction shall be written adjacent to the error. The correction shall be initialed by the responsible individual and the date of change documented. Ref: 15A NCAC 02H .0805 (a) (7) (E). C. Finding: The Suspended Residue, Conductivity and Temperature benchsheets are lacking required documentation: the method or Standard Operating Procedure reference. Page 3 #71 Lower Creek WWTP Laboratory Requirement: All laboratories shall use printable laboratory benchsheets. Certified Data shall be traceable to the associated sample analyses and shall consist of: the method or Standard Operating Procedure. Each item shall be recorded each time that samples are analyzed. Ref: 15A NCAC 02H .0805 (a) (7) (F) (i). D. Finding: The pH, DO, Conductivity and Temperature benchsheets are lacking required documentation: the signature or initials of the analyst. Requirement: All laboratories shall use printable laboratory benchsheets. Certified Data shall be traceable to the associated sample analyses and shall consist of: the signature or initials of the analyst. Each item shall be recorded each time that samples are analyzed. Ref: 15A NCAC 02H .0805 (a) (7) (F) (v). E. Finding: The Conductivity benchsheet is lacking required documentation: the proper units of measure. Requirement: All laboratories shall use printable laboratory benchsheets. Certified Data shall be traceable to the associated sample analyses and shall consist of: proper units of measure. Each item shall be recorded each time that samples are analyzed. Ref: 15A NCAC 02H .0805 (a) (7) (F) (xii). F. Finding: The Total Residual Chlorine (TRC) benchsheet is lacking required documentation: Date of most recent TRC calibration curve verification. Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: The following must be documented in indelible ink whenever sample analysis is performed: Date of most recent calibration curve generation or calibration curve verification. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011). G. Finding: The laboratory is not documenting the temperature, barometric pressure and salinity values used to calibrate the DO meter. Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: The following must be documented in indelible ink whenever sample analysis is performed: Calibration variables (temperature, elevation or barometric pressure [in mmHg], and salinity). Ref: NC WW/GW LCB Approved Procedure for the Analysis of Dissolved Oxygen (DO). Requirement: Per NC WW/GW LC Branch policy, facilities may use the salinity default value of zero when calibrating the DO meter unless it is known or suspected that the salinity value of the samples being analyzed is > 9 ppt. In those situations, actual salinity values must be used. Regardless of which value is used, it must be documented. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Dissolved Oxygen (DO). H. Finding: The DO and pH benchsheets are lacking required documentation: meter calibration time. Page 4 #71 Lower Creek WWTP Laboratory Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts (a) (1) (A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: The following must be documented in indelible ink whenever sample analysis is performed: Meter calibration and/or verification date and time(s). Ref: NC WW/GW LCB Approved Procedure for the Analysis of Dissolved Oxygen (DO). Requirement: The following must be documented in indelible ink whenever sample analysis is performed: Meter calibration and meter calibration time(s). Ref: NC WW/GW LCB Approved Procedure for the Analysis of pH. I. Finding: The TRC benchsheet is lacking required documentation: Daily Check Standard analysis time(s). Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts (a) (1) (A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: The following must be documented in indelible ink whenever sample analysis is performed: Daily Check Standard analysis date and time(s). Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011). J. Finding: The laboratory benchsheets are lacking required documentation: the instrument identification. Requirement: All laboratories shall use printable laboratory benchsheets. Certified Data shall be traceable to the associated sample analyses and shall consist of: the instrument identification. Each item shall be recorded each time that samples are analyzed. Ref: 15A NCAC 02H .0805 (a) (7) (F) (iii). Proficiency Testing K. Finding: The laboratory is not documenting the preparation of PT Samples. Requirement: PT Samples received as ampules are diluted according to the Accredited PT Sample Provider’s instructions. It is important to remember to document the preparation of PT Samples in a traceable log or other traceable format. The diluted PT Sample then becomes a routine Compliance Sample and is added to a routine sample batch for analysis. No documentation is needed for whole volume PT Samples which require no preparation, however the instructions must be maintained. Ref: Proficiency Testing Requirements, January 1, 2023, Revision 6, Section 3.6. Comment: Dating and initialing the instruction sheet for each prepared PT Sample would satisfy the documentation requirement. L. Finding: The laboratory is not documenting PT Sample analyses in the same manner as routine Compliance Samples. Requirement: All PT Sample analyses must be recorded in the same daily analysis records (e.g., benchsheets) as for any Compliance Sample. This serves as the permanent laboratory record. Ref: Proficiency Testing Requirements, January 1, 2023, Revision 6, Section 3.6. Page 5 #71 Lower Creek WWTP Laboratory Requirement: The laboratory shall retain all records necessary to facilitate historical reconstruction of the analysis and reporting of analytical results for PT Samples. This means the laboratory must have available and retain for five years [pursuant to 15A NCAC 02H .0805 (a) (7) (E) and (g) (1)] all of the raw data, including benchsheets, instrument printouts and calibration data, for all PT Sample analyses and the associated QC analyses conducted by all Parameter Methods. Ref: Proficiency Testing Requirements, January 1, 2023, Revision 6, Section 4.0. Comment: This Finding applies to pH, TRC and Conductivity PT Samples. These results are only recorded on the PT vendor reporting form. M. Finding: PT Samples are not analyzed in the same manner as routine Compliance Samples. Requirement: Laboratories are required to analyze an appropriate PT Sample by each Parameter Method and in each associated matrix on the laboratory’s CPL. The same PT Sample may be analyzed by one or more methods. Laboratories shall conduct the analyses in accordance with their routine testing, calibration and reporting procedures, unless otherwise specified in the instructions supplied by the Accredited PT Sample Provider. This means that they are to be logged in and analyzed using the same staff, sample tracking systems, standard operating procedures including the same equipment, reagents, calibration techniques, analytical methods, preparatory techniques (e.g., digestions, distillations and extractions) and the same quality control acceptance criteria. PT Samples shall not be analyzed with additional quality control. They are not to be replicated beyond what is routine for Compliance Sample analysis. Although, it may be routine to spike Compliance Samples, it is neither required, nor recommended, for PT Samples. PT sample results from multiple analyses (when this is the routine procedure) must be calculated in the same manner as routine Compliance Samples. Ref: Proficiency Testing Requirements, January 1, 2023, Revision 6, Section 3.6. Comment: Field parameter PT Samples are not being analyzed by staff that routinely analyze Compliance Samples. Also, the PT Sample for pH is analyzed using a laboratory pH meter rather than the field meter that is used for Compliance Samples. Quality Assurance/Quality Control N. Finding: Precision (e.g., relative percent difference) and accuracy (e.g., percent recovery) of QC results are not calculated, evaluated and documented. Requirement: Unless specified by the method or this Rule, each laboratory shall establish performance acceptance criteria for all quality control analyses. Each laboratory shall calculate and document the precision and accuracy of all quality control analyses with each sample set. When the method of choice specifies performance acceptance criteria for precision and accuracy, and the laboratory chooses to develop laboratory-specific limits, the laboratory-specific limits shall not be less stringent than the criteria stated in the approved method. Ref: 15A NCAC 02H .0805 (a) (7) (A). Requirement: All laboratories shall use printable laboratory benchsheets. Certified Data shall be traceable to the associated sample analyses and shall consist of: the quality control assessments. Ref: 15A NCAC 02H .0805 (a) (7) (F) (xv). Comment: The purpose of calculating and documenting QC is to demonstrate whether the analytical process is in control and the established acceptance criteria are met or whether corrective action must be taken. Page 6 #71 Lower Creek WWTP Laboratory O. Finding: Laboratory temperature-measuring devices are not verified at the temperature of use. Requirement: Excluding digital, incubator, and infrared temperature-measuring devices, all non-Reference Temperature-Measuring Devices shall be verified at the temperature of use every 12 months against a Reference Temperature-Measuring Device and their accuracy shall be corrected. Ref: 15A NCAC 02H .0805 (a) (7) (N) (ii). Requirement: Digital temperature-measuring devices and temperature-measuring devices used in incubators shall be verified at the temperature of use every three months against a Reference Temperature-Measuring Device and their accuracy shall be corrected. Ref: 15A NCAC 02H .0805 (a) (7) (N) (iii). Comment: All thermometers were verified at room temperature. P. Finding: Laboratory temperature-measuring device readings are not corrected. Requirement: Excluding digital, incubator, and infrared temperature-measuring devices, all non-Reference Temperature-Measuring Devices shall be verified at the temperature of use every 12 months against a Reference Temperature-Measuring Device and their accuracy shall be corrected. Ref: 15A NCAC 02H .0805 (a) (7) (N) (ii). Requirement: Digital temperature-measuring devices and temperature-measuring devices used in incubators shall be verified at the temperature of use every three months against a Reference Temperature-Measuring Device and their accuracy shall be corrected. Ref: 15A NCAC 02H .0805 (a) (7) (N) (iii). Q. Finding: Laboratory temperature-measuring devices are not labeled with their respective correction factors. Requirement: Document any correction that applies (e.g., add 0.2 °C, subtract 0.3 °C, or if no correction needed; 0.0 °C) on both the temperature-measuring device and in a format that can be retained for a minimum of five years. Routine temperature measurements must be documented with any applicable correction factor applied. Ref: NC WW/GW LCB Temperature Measuring-Devices used for Laboratory Operations Policy (08/30/2021). R. Finding: Digital temperature-measuring devices and temperature-measuring devices used in incubators are not verified against a Reference Temperature-Measuring Device at least every three months. Requirement: Digital temperature-measuring devices and temperature-measuring devices used in incubators shall be verified at the temperature of use every three months against a Reference Temperature-Measuring Device and their accuracy shall be corrected. Ref: 15A NCAC 02H .0805 (a) (7) (N) (iii). Bacteria – Coliform Fecal – Standard Methods, 9222 D-2015 (MF) (Aqueous) S. Finding: Culture positive plates are not analyzed with each batch of prepared media. Requirement: For each lot of medium received, each laboratory-prepared batch of medium, and each lot of commercially prepared medium, verify appropriate response by testing with known positive and negative control cultures for the organism(s) under test. See Table 9020:VI for examples of test cultures. Record results. Ref: Standard Methods, 9020 B-2015. (9) (b). Page 7 #71 Lower Creek WWTP Laboratory Requirement: A culture positive must be analyzed with each batch of prepared media and once per week for purchased ready-to-use media. A sample volume that yields a countable plate must be analyzed so that individual colonies may be verified to have proper morphology (i.e. color, shape, size, surface appearance). Ref: NC WW/GW LCB Fecal Coliform Membrane Filter Culture Positive Policy (09/22/2016). T. Finding: Sample results are not always calculated and reported correctly. Requirement: Countable Membranes with less than 20 Blue Colonies: If all counts are below the lower limit (20) of the ideal counting range: (a) Select the count most nearly acceptable and compute the count using the general formula. Report the count as an Estimated Count per 100 ml: or (b) Total the counts on all filters and report as number per 100 ml. For example, if 50, 25, and 10 ml portions were examined, and counts were 15, 6, and 0 coliform colonies respectively, calculate results as follows and report the count as 25 colonies per 100 ml. (15 + 6 + 0) counts x 100 = 25 colonies per 100 ml 50 + 25 + 10 ml Ref: NC WW/GW LCB Fecal Coliform Reporting Policy (5/23/2019). Comment: When all counts are below 20, the laboratory calculates the fecal coliform colonies per 100 mL for each filter and then averages those results. Recommendation: When all countable membrane filters have less than 20 blue colonies, it is recommended that the reported result be calculated by the formula in (b) above because (a) requires the results to be reported as estimated, but (b) does not. U. Finding: The time sample filtration begins is not recorded on the benchsheet to show that no more than 30 minutes has passed before filters are placed into the incubator. This is considered pertinent data. Requirement: All analytical records, including original observations and information necessary to facilitate historical reconstruction of the calculated results, shall be maintained for five years. All analytical data and records pertinent to each certified analysis shall be available for inspection upon request. Ref: 15A NCAC 02H .0805 (a) (7) (E). Requirement: Place all prepared cultures in the water bath within 30 min after filtration. Ref: Standard Methods, 9222 D-2015. (3) (d). V. Finding: The incubator temperature is checked twice per day, but the times are not documented to show that they are at least four hours apart. This is considered pertinent data. Requirement: All analytical records, including original observations and information necessary to facilitate historical reconstruction of the calculated results, shall be maintained for five years. All analytical data and records pertinent to each certified analysis shall be available for inspection upon request. Ref: 15A NCAC 02H .0805 (a) (7) (E). Requirement: When incubator is in use (i.e., samples are being incubated), monitor and record corrected temperature twice daily separated by 4 h. Ref: Standard Methods, 9020 B- 2015. (4) (n). Page 8 #71 Lower Creek WWTP Laboratory BOD – Standard Methods, 5210 B-2016 (Aqueous) W. Finding: Documentation does not demonstrate that the initial DO for BOD analysis is measured within 30 minutes of sample preparation. This is considered pertinent data. Requirement: All analytical records, including original observations and information necessary to facilitate historical reconstruction of the calculated results, shall be maintained for five years. All analytical data and records pertinent to each certified analysis shall be available for inspection upon request. Ref: 15A NCAC 02H .0805 (a) (7) (E). Requirement: After preparing dilution, measure initial DO within 30 min. Ref: Standard Methods, 5210 B-2016. (5) (g). X. Finding: Calculated results of sample dilutions are not being evaluated to ensure < 30% difference between high and low values. Requirement: Identify results in the test reports when any of the following QC conditions occur: test replicates show >30% difference between highest and lowest values. Ref: Standard Methods, 5210 B-2016. (7) (b). Chlorine, Total Residual – Standard Methods, 4500 Cl G-2011 (Aqueous) Y. Finding: The annual Factory-set Calibration curve verifications did not pass the individual standard recovery criteria. Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: The calibration standard values obtained must not vary by more than ±10% from the known value for standard concentrations greater than or equal to 50 μg/L and must not vary by more than ±25% from the known value for standard concentrations less than 50 μg/L. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011). Comment: The laboratory evaluated the curves by the correlation coefficient rather than the percent recovery of the standards. Comment: The laboratory submitted acceptable curve verifications on January 17, 2024. Z. Finding: The laboratory did not properly assign a true value to the gel-type standard prior to initial use. Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: To assign a true value to the gel-type or sealed liquid standard: 1. Zero the instrument with the calibration blank. 2. Read and record gel standard values. 3. Repeat steps 1 and 2 at least two more times. 4. Assign the average value as the true value. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011). Page 9 #71 Lower Creek WWTP Laboratory Requirement: Purchased “gel-type” or sealed liquid standards may be used only for daily calibration curve verifications. These standards must have a true value assigned initially and every 12 months thereafter. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011). Comment: The laboratory used a true value of 189 µg/L based on the manufacturer’s documentation which may not be accurate for this application. AA. Finding: The laboratory is not analyzing a Method Blank when required. Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: Method Blank: Deionized or Distilled water, from the same source used to make calibration and calibration verification standards, that is analyzed like a sample (i.e., with DPD/buffer added). The concentration of the Method Blank must not exceed 50% of the reporting limit (i.e., the lowest calibration or calibration verification standard concentration), unless otherwise specified by the reference method, or corrective action must be taken. Method Blanks are required when using laboratory-prepared standards [including Proficiency Testing (PT) Samples] and anytime sample dilutions are performed. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011). Conductivity – Standard Methods, 2510 B-2011 (Aqueous) BB. Finding: The Automatic Temperature Compensator (ATC) was not verified prior to initial use and every 12 months thereafter. Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: The Automatic Temperature Compensator (ATC) must be verified prior to initial use and annually (i.e., 12 months) thereafter at two temperatures by analyzing a standard or sample at 25 °C (i.e., the temperature to which conductivity values are reported) and a temperature(s) that brackets the temperature ranges of the compliance samples routinely analyzed. This may require the analysis of a third temperature reading that is > 25 °C. As the temperature increases or decreases, the value of the conductivity standard or sample must be within ±10% of the true value of the standard or ±10% of the value of the sample at 25 °C. If not, corrective action must be taken. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Specific Conductance (Conductivity). CC. Finding: The acceptance criterion for the calibration verification check standard is ±25%, which exceeds the allowable acceptance of ±10%. Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts (a) (1) (A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: The value obtained for the calibration verification check standard must read within 10% of the true value of the calibration verification check standard. If the obtained value Page 10 #71 Lower Creek WWTP Laboratory is outside of the ±10% range, corrective action must be taken. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Specific Conductance (Conductivity). Comment: In the data reviewed, the following standards were not within 10% of the true value and unacceptable: • November 16, 2023 o The initial 25.0 µmhos/cm standard was 22.1 µmhos/cm (88% recovery) o The initial 250 µmhos/cm standard was 212 µmhos/cm (85% recovery) o The final 250 µmhos/cm standard was 215 µmhos/cm (86% recovery) • December 1, 2023 o The initial 25.0 µmhos/cm standard was 30.1 µmhos/cm (120% recovery) o The final 25.0 µmhos/cm standard was 30.5 µmhos/cm (122% recovery) o The initial 250 µmhos/cm standard was 278 µmhos/cm (111% recovery) Dissolved Oxygen – Hach 10360-2011, Rev. 1.2 (Aqueous) pH – Standard Methods, 4500 H+ B-2011 (Aqueous) DD. Finding: The laboratory is not calibrating prior to analysis at each sample site or performing a post-analysis calibration verification when the pH or DO meter is transported by vehicle to another location after calibration. Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: A post-analysis calibration verification must be performed at the end of the run any time the meter is transported by vehicle to another location after calibration. It is recommended that a mid-day check standard buffer be analyzed when samples are analyzed over an extended period of time. The post-analysis check standard buffer(s) must read within ±0.1 S.U. or corrective actions must be taken. If recalibration is necessary, all samples analyzed since the last acceptable calibration verification must be reanalyzed, if possible. If samples cannot be reanalyzed, the data must be qualified. Ref: NC WW/GW LCB Approved Procedure for the Analysis of pH. Requirement: A post-analysis calibration verification must be performed at the end of the run any time the meter is transported by vehicle to another location after calibration. The calculated theoretical DO value must verify the meter reading within ±0.5 mg/L. If the meter verification does not read within ±0.5 mg/L of the theoretical DO, corrective action must be taken. If the meter is not calibrated at each sample site, it is recommended that a mid-day calibration be performed when samples are analyzed over an extended period of time. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Dissolved Oxygen (DO). Dissolved Oxygen – Hach 10360-2011, Rev. 1.2 (Aqueous) pH – Standard Methods, 4500 H+ B-2011 (Aqueous) Temperature – Standard Methods, 2550 B-2010 (Aqueous) EE. Finding: The laboratory is not always analyzing samples in such a manner to prevent contamination or error. Requirement: Each laboratory requesting Certification shall be maintained so as to ensure the security and integrity of samples. Samples shall be analyzed in such a manner that contamination or error will not be introduced. Ref: 15A NCAC 02H .0805 (a) (6). Page 11 #71 Lower Creek WWTP Laboratory Comment: The thermometer, pH electrode and DO electrode used for field analyses are not rinsed between sample analyses to prevent contamination. Residue, Suspended – Standard Methods, 2540 D-2015 (Aqueous) FF. Finding: The laboratory is not checking and documenting the temperature each time samples are being placed into and removed from the drying oven. Requirement: The date, time and temperature must be documented each time samples are placed into and removed from a drying oven. Ref: NC WW/GW LCB Residue Oven Temperature Documentation Policy (07/30/2021). Temperature – Standard Methods, 2550 B-2010 (Aqueous) GG. Finding: The compliance temperature-measuring device is not checked at two temperatures that bracket the range of observed sample temperatures. Requirement: The State Laboratory may develop Approved Procedures for Field Parameters based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F). Requirement: To check a compliance temperature-measuring device, compare readings at two temperatures that bracket the range of compliance samples routinely analyzed against a Reference Temperature-Measuring Device and record all four readings. The readings from both devices must be ≤ 0.5ºC. If they are not, the device may not be used for temperature compliance monitoring. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Temperature. Comment: The laboratory only checked the device at room temperature. Vector Attraction Reduction: Option 7 – Moisture Reduction Without Solids Comment: Per the Code of Federal Regulations, Title 40, Part 503.8 (b) (7), Standard Methods 2540 G is the analytical method for Vector Attraction Reduction: Option 7 – Moisture Reduction Without Solids. The laboratory was using an automatic moisture analyzer to analyze for percent solids. It includes a built-in balance and a halogen heater that dries the sample until the weight stabilizes and calculates the percent moisture. However, due to the design of the instrument, it is not possible to verify the temperature or the internal thermometer. Due to this, after the inspection the laboratory began analyzing the samples using the laboratory balance and Suspended Residue oven, both of which have been verified to meet the method requirements. HH. Finding: Samples are analyzed in aluminum weighing dishes. Requirement: Sample dishes: Dishes of approximately 90-mm dia and 100-mL capacity made of one of the following materials: 1) Porcelain, 2) Platinum, 3) High-silica glass (may react with highly alkaline samples), or 4) Other material shown to be resistant to the sample matrix and weight stable at the required evaporation and drying temperatures. Aluminum is NOT appropriate for this purpose. Ref: Standard Methods, 2540 G-2015. (2) and Standard Methods, 2540 B-2015. (2) (a). Page 12 #71 Lower Creek WWTP Laboratory II. Finding: The weighing dishes are not properly prepared and stored. Requirement: If only measuring total solids, heat dish for ≥1 h in a 103–105°C oven. Cool in desiccator to ambient temperature and weigh. Store in desiccator or 103–105°C oven until needed. Ref: Standard Methods, 2540 G-2015. (3) (a) (1). JJ. Finding: Samples are not correctly analyzed. Requirement: Transfer approximately 25–50 g to a prepared evaporating dish and weigh. Then, place in a 103–105°C oven for ≥1 h, cool to ambient temperature in a desiccator, and weigh. Repeat cycle (drying, cooling, desiccating, and weighing) until weight change is <50 mg. Ref: Standard Methods, 2540 G-2015. (3) (a) (2) (b). Comment: The automatic moisture analyzer heats approximately 1 g of sample until it determines that it has reached a constant weight. The heating time is <1 hour and the sample is not cooled to ambient temperature before weighing and the constant weight is not properly demonstrated. KK. Finding: Duplicate analyses are not performed. Requirement: Analyze ≥5% of all samples in duplicate or at least one duplicate sample with each batch of ≤20 samples. Ref: Standard Methods, 2020 B-2017. Table II and Standard Methods, 2540 A-2015 (5). IV. CONCLUSIONS: Correcting the above-cited Findings and implementing the Recommendation will help this laboratory to produce quality data and meet Certification requirements. The inspector would like to thank the staff for their assistance during the inspection and data review process. Please respond to the Findings and include supporting documentation, implementation dates and steps taken to prevent recurrence for each corrective action. Report prepared by: Jason Smith Date: January 3, 2024 Report reviewed by: Jill Puff Date: January 5, 2024 Certificate Number:71 Effective Date:1/1/2023 Expiration Date:12/31/2023 Lab Name:Lower Creek WWTP Laboratory Address:1905 Broadland Road Lenoir, NC 28645- North Carolina Wastewater/Groundwater Laboratory Certification Certified Parameters Listing Date of Last Amendment:8/13/2021 The above named laboratory, having duly met the requirements of 15A NCAC 2H.0800, is hereby certified for the measurement of the parameters listed below. CERTIFIED PARAMETERS INORGANIC BACTERIA - COLIFORM FECAL SM 9222 D-2015 (MF) (Aqueous) BOD SM 5210 B-2016 (Aqueous) CHLORINE, TOTAL RESIDUAL SM 4500 Cl G-2011 (Aqueous) CONDUCTIVITY SM 2510 B-2011 (Aqueous) DISSOLVED OXYGEN Hach 10360-2011, Rev. 1.2 (Aqueous) SM 4500 O G-2016 (Aqueous) pH SM 4500 H+B-2011 (Aqueous) RESIDUE, SUSPENDED SM 2540 D-2015 (Aqueous) TEMPERATURE SM 2550 B-2010 (Aqueous) VECTOR ATTRACTION REDUCTION: OPTION 7 Moisture Reduction without Solids This certification requires maintance of an acceptable quality assurance program, use of approved methodology, and satisfactory performance on evaluation samples. Laboratories are subject to civil penalties and/or decertification for infractions as set forth in 15A NCAC 2H.0807.