Loading...
HomeMy WebLinkAbout#5451_2021_1215_MC_FINAL February 25, 2022 5451 Ms. Heather Auman Denton Water Treatment Plant P.O. Box 306 Denton, NC 27239 Subject: North Carolina Wastewater/Groundwater Laboratory Certification Branch (NC WW/GW LCB) Maintenance Inspection Dear Ms. Auman: Enclosed is a report for the inspection performed on December 15, 2021 by Michael Cumbus. 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 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) 733- 3908 Ext. 259. Sincerely, Beth Swanson Technical Assistance & Compliance Specialist Division of Water Resources Attachment cc: Todd Crawford, Michael Cumbus, File #5451 On-Site Inspection Report LABORATORY NAME: Denton WTP NPDES PERMIT #: NC0082949 ADDRESS: 3049 Bringle Ferry Rd Denton, NC 27239 CERTIFICATE #: 5451 DATE OF INSPECTION: December 15, 2021 TYPE OF INSPECTION: Field Municipal Maintenance AUDITOR(S): Michael Cumbus LOCAL PERSON(S) CONTACTED: Heather Auman and Jeff Isley 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 facility 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 2021 PT Calendar Year and the graded results were 100% acceptable. The laboratory is reminded that any time changes are made to laboratory procedures, QA/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 SOPs, based on the Findings, Comments and Recommendations within this report must be submitted to this office by May 31, 2022. Your auditor may suggest an order of priority based on the severity and quantity of findings. The laboratory is also reminded that SOPs are required to be reviewed at least every two years and 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”. Page 2 #5451 Denton WTP Contracted analyses are performed by Meritech, Inc. (Certification # 165). Approved Procedure documents for the analysis of the facility’s currently certified Field Parameters were provided at the time of the inspection. III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS: Documentation A. Finding: The laboratory is not using indelible ink for documentation purposes. Requirement: All manual data and log entries shall be written in indelible ink. Ref: 15A NCAC 02H .0805 (g) (1). Comment: The laboratory was using a pencil to record data and log entries. B. Finding: Error corrections are not properly performed. 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 are 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 (g) (1). Comment: Multiple instances were noted of error corrections lacking the date and the initials of the analyst. C. Finding: The laboratory benchsheet is lacking required documentation: the method reference, the laboratory identification, the instrument identification, the date and time of sample analysis, sample identification, the proper units of measure and the quality control assessments. 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; the laboratory identification; the instrument identification; the date of sample analyses; the time of sample analyses (when required to document a required holding time or when time-critical steps are imposed by the method, a federal regulation, or this Rule); sample identification; the proper units of measure; the quality control assessments. Each item shall be recorded each time samples are analyzed. Analyses shall conform to methodologies found in Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (2) (A) (B) (C) (G) (H) (I) (L) and (O). Comment: Benchsheets lack units of measure for pH and TRC. Comment: Benchsheets lack the method reference for TRC. Comment: The laboratory benchsheets prior to December 2021 contained a single analysis time for pH and TRC. It was unclear to which parameter that time applied. Page 3 #5451 Denton WTP Proficiency Testing Comment: The laboratory currently only has one analyst. If the laboratory hires additional laboratory personnel, the PT Samples must be rotated among all qualified personnel from year to year. D. Finding: PT Samples are not being analyzed in the same manner as routine Compliance Samples. Requirement: Laboratories are required to analyze an appropriate PT Sample by each parameter method 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, February 19, 2020, Revision 5, Section 3.6. Comment: The laboratory is averaging the results of multiple analyses for PT Samples, but only analyzing Compliance Samples once. Duplicates are not a required quality control element for Field parameters. E. Finding: Additional QC beyond what is routine for Compliance Samples is being analyzed with PT Samples. Requirement: Laboratories are required to analyze an appropriate PT Sample by each parameter method 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, February 19, 2020, Revision 5, Section 3.6. Comment: Laboratories must not analyze additional standards with known concentrations along with PT Samples with unknown concentrations, as this is not the routine testing protocol for Compliance Samples. This is not to say that they cannot be used for troubleshooting purposes before analyzing a remedial PT Sample on a separate day. This would be considered part of the corrective action plan. F. Finding: The laboratory is not documenting PT Sample analyses in the same manner as routine Compliance Samples. Page 4 #5451 Denton WTP Requirement: All PT Sample analyses must be recorded in the daily analysis records as for any Compliance Sample. This serves as the permanent laboratory record. Ref: Proficiency Testing Requirements, February 19, 2020, Revision 5, Section 3.6. 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, February 19, 2020, Revision 5, Section 4.0. Comment: Documentation for the analysis of PT Samples was lacking sample identification, date and time of sample analysis, the laboratory identification; the instrument identification, the method or SOP reference and the proper units of measure. G. 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, February 19, 2020, Revision 5, Section 3.6. Comment: Dating and initialing the instruction sheet for each prepared PT Sample would satisfy the documentation requirement. Reporting H. Finding: The laboratory is not reporting all data in units of measure as specified in the permit. Requirement: All data must be documented and reported in units of measure as specified in the permit (e.g., mg/L for regular level or µg/L for low level). Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G- 2011). Comment: The permit requires units of µg/L for TRC, which are the units of measure used in the laboratory. DMRs for the months of March through October 2021 listed the units of measure for TRC as mg/L instead of µg/L with no conversion factor applied to the numerical result. Recommendation: It is recommended that the laboratory implement a peer review system to prevent transcription errors. pH – Standard Methods, 4500 H+ B-2011 (Aqueous) I. Finding for Immediate Response: The laboratory is not analyzing a check standard buffer after calibration and prior to sample analysis. Page 5 #5451 Denton WTP Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). Requirement: Instruments are to be calibrated according to the manufacturer’s calibration procedure prior to analysis of samples each day compliance monitoring is performed. Calibration must include at least two buffers. The meter calibration must be verified with a third standard buffer solution (i.e., check buffer) prior to sample analysis. Ref: NC WW/GW LCB Approved Procedure for the Analysis of pH. Comment: During data review, it was noted that the laboratory was not analyzing a check standard buffer, nor was it part of their normal procedure. Due to this fact, a Notice of Finding for Immediate Response was issued. A response time of 48 hours was negotiated with the analyst. The laboratory submitted a benchsheet with 2 days of calibrations of the pH meter with acceptable calibration curve checks on December 18, 2021. No further response is required for this Finding. Chlorine, Total Residual – Standard Methods, 4500 Cl G-2011 (Aqueous) J. Finding for Immediate Response: The laboratory is not verifying the instrument’s Factory- set Calibration Curve every 12 months. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). Requirement: Annual Factory-set Calibration Curve Verification: This type of calibration curve verification must be performed initially, at least every 12 months and any time the instrument optics are serviced. Zero the instrument with a Calibration Blank and then analyze a Method Blank and a series of five standards (do not use gel or sealed liquid standards for this purpose). 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: During the inspection, it was noted that the laboratory was not verifying the factory- set calibration curve every 12 months. Since the lack of a calibration curve verification has the potential to severely impact the validity of the data, a Notice of Finding for Immediate Response was issued. A response date of January 5, 2022 was negotiated with the analyst and the laboratory agreed to submit a copy of the contract lab verification as the Corrective Action. A passing calibration curve verification was received by this office on December 29, 2021. A Corrective Action Response describing how this deadline will be kept up with in the future is required to complete this Finding. K. Finding for Immediate Response: The Factory-set Calibration Curve is not checked with a Daily Check Standard each day that samples are analyzed. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). Requirement: When an annual five-standard Factory-set Calibration Curve verification is used, the laboratory must check the curve each analysis day. To do this, the laboratory must zero the instrument with a Calibration Blank and analyze a Daily Check Standard (gel-type standards are most widely used for these purposes). The value obtained for the Daily Check Page 6 #5451 Denton WTP Standard must read within ±10% of the true value of the Daily Check Standard for standards ≥50 μg/L and within ±25% of its true value for standards <50 μg/L. If the obtained value is outside of the acceptance limits, corrective action must be taken. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011). Comment: During the inspection, it was noted that the laboratory was not analyzing a Daily Check Standard. Since the lack of a calibration curve daily check has the potential to severely impact the validity of the data, a Notice of Finding for Immediate Response was issued. The inspector and analyst were able to locate a Gel-Type Standard that could be used for this purpose. A response date of January 5, 2022 was negotiated with the analyst. The laboratory agreed to submit a copy of the Gel-Type Standard true value assignment and an updated benchsheet showing the acceptance range and true value of the standard, as well as actual data demonstrating that the standard is in use as the Corrective Action. A copy of the Daily Check Standard Log with two days of Acceptable recoveries was received by this office on December 29, 2021. The laboratory also submitted data from December 30, 2021 demonstrating the Daily Check Standard has been put into use. No further response is required for this Finding. IV. PAPER TRAIL INVESTIGATION: The paper trail consisted of comparing original records (e.g., laboratory benchsheets, logbooks, etc.) and contract laboratory reports to DMRs submitted to the North Carolina Division of Water Resources. Data were reviewed for Denton WTP (NPDES permit # NC0082949) for June, July and November 2021. The following errors were noted: Date Parameter Location Value on Benchsheet Value on DMR 06/01/2021 Chlorine, Total Residual Effluent < 15 µg/L < 15 mg/L 06/09/2021 Chlorine, Total Residual Effluent < 15 µg/L < 15 mg/L 06/16/2021 Chlorine, Total Residual Effluent < 15 µg/L < 15 mg/L 06/22/2021 Chlorine, Total Residual Effluent < 15 µg/L < 15 mg/L 06/30/2021 Chlorine, Total Residual Effluent < 15 µg/L < 15 mg/L 07/02/2021 Chlorine, Total Residual Effluent < 15 µg/L < 15 mg/L 07/08/2021 Chlorine, Total Residual Effluent < 15 µg/L < 15 mg/L 07/14/2021 Chlorine, Total Residual Effluent < 15 µg/L < 15 mg/L 07/20/2021 Chlorine, Total Residual Effluent < 15 µg/L < 15 mg/L 07/28/2021 Chlorine, Total Residual Effluent < 15 µg/L < 15 mg/L It was noted during additional DMR review that all TRC data for the months of March through October 2021 was reported in units of mg/L, as noted in Finding H above. All reported values for TRC during these months were “less than” so the monthly averages were all reported as zero. To avoid questions of legality, it is recommended that you contact the appropriate Regional Office for guidance as to whether amended DMRs will be required. A copy of this report will be made available to the Regional Office. Page 7 #5451 Denton WTP V. CONCLUSIONS: Correcting the above-cited Findings and implementing the Recommendations 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 all Findings and include supporting documentation, implementation dates and steps taken to prevent recurrence for each corrective action. Report prepared by: Michael Cumbus Date: January 10, 2022 Report reviewed by: Jason Smith Date: January 12, 2022 Certificate Number:5451 Effective Date:1/1/2021 Expiration Date:12/31/2021 Lab Name:Denton Water Treatment Plant Address:3049 Bringle Ferry Rd Denton, NC 27239 North Carolina Wastewater/Groundwater Laboratory Certification Certified Parameters Listing Date of Last Amendment: 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 CHLORINE, TOTAL RESIDUAL SM 4500 Cl G-2011 (Aqueous) pH SM 4500 H+B-2011 (Aqueous) 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.