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HomeMy WebLinkAbout#267_2023_1102_TLH_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 919-733-3908 December 6, 2023 267 Ms. Stefania Marroquin Town of Apex Middle Creek WWTP Laboratory P.O. Box 250 Apex, NC 27539 Subject: North Carolina Wastewater/Groundwater Laboratory Certification Branch (NC WW/GW LCB) Maintenance Inspection Dear Ms. Marroquin: Enclosed is a report for the inspection performed on November 2, 2023 by Tom Halvosa and Jill Puff. 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) 733- 3908 Ext. 259. Sincerely, Beth Swanson Technical Assistance & Compliance Specialist Division of Water Resources Attachment cc: Todd Crawford, Tom Halvosa, #267 On-Site Inspection Report LABORATORY NAME: Town of Apex Middle Creek WWTP Laboratory NPDES PERMIT #: NC0064050 ADDRESS: 300 Pristine Waters Dr. Apex, NC 27502 CERTIFICATE #: 267 DATE OF INSPECTION: November 2, 2023 TYPE OF INSPECTION: Municipal Maintenance AUDITOR(S): Tom Halvosa and Jill Puff LOCAL PERSON(S) CONTACTED: Stefania Marroquin and Tony Giles I. INTRODUCTION: This laboratory was inspected by representatives 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 2023 PT Calendar Year and the graded results were 100% acceptable. 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 SOPs, based on the Findings, Comments and Recommendations within this report must be submitted to this office by March 31, 2024. 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”. Page 2 #267 Town of Apex Middle Creek WWTP Laboratory Laboratory Fortified Matrix (LFM) and Laboratory Fortified Matrix Duplicate (LFMD) are also known as Matrix Spike (MS) and Matrix Spike Duplicate (MSD) and may be used interchangeably in this report. Contracted analyses are performed by Waypoint Analytical - Greenville (Certification #10). 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 Recommendation: It is recommended that the laboratory add their name to the sample receipt log and standards and reagents prep log. A. Finding: The laboratory is not documenting the salinity value used to calibrate the Dissolved Oxygen (DO) meter. Requirement: All analytical records, including original observations and information necessary to facilitate historical reconstruction of the calculated results, shall be maintained for five years. Ref: 15A NCAC 02H .0805 (a) (7) (E). Requirement: Determination of Initial DO: Use the Azide modification of the iodometric method (Section 4500-O.C), membrane-electrode method (Section 4500-O.G), or optical- probe method (Section 4500-O.H) to determine initial DO on all sample dilutions, dilution water blanks, and, where appropriate, seed controls. Ref: Standard Methods, 5210 B-2016. (5) (g). Requirement: Calibrate probe in accordance with manufacturer's instructions to obtain the guaranteed precision and accuracy. Ref: Standard Methods, 4500 O H-2016. (4). 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). Comment: This finding applies to both the DO and BOD parameter methods. A revision to your SOP indicating that the salinity of the samples is ≤ 9 ppt and so the default concentration of 0 ppt is used along with a blanket statement on the benchsheet that salinity is programmed as 0 ppt would be sufficient. Quality Assurance/Quality Control B. Finding: Thermometers in the BOD and fecal coliform incubators are not verified against a Reference Temperature-Measuring Device (TMD) 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). Page 3 #267 Town of Apex Middle Creek WWTP Laboratory Comment: The temperatures were verified once each quarter, but some were more than three months apart. C. Finding: For chemicals/reagents/consumables that do not have an expiration date, the laboratory has not established a policy for assigning expiration dates. Requirement: When commercially prepared chemicals, reagents, standards and consumables have expiration dates listed as a month and year (with no specific day of the month), the last day of the month will be considered the actual date of expiration. If no expiration date is given by the manufacturer, the laboratory must use their policy for assigning one. If the laboratory is unable to determine an expiration date for a chemical, reagent or standard a one-year time period from the date of receipt shall be the expiration date unless degradation is observed prior to this date. If neither a date received nor an expiration date can be determined, the item must not be used. If the method does not specify an expiration date, chemicals, reagents and standards prepared in the laboratory for use with that method must be assigned an expiration date according to the laboratory’s policy for doing so. Monitor materials for changes in appearance or consistency. Any changes may indicate potential contamination or degradation, and therefore, the item must not be used, even if the manufacturer’s or laboratory’s expiration date has not been exceeded. Laboratory-assigned expiration dates may be re-evaluated based on performance and recovery data and new expiration dates assigned at that time. Manufacturer-assigned expiration dates may not be extended. Ref: NC WW/GW LCB Chemical, Reagent, Standard and Consumables Expiration Date Policy (04/21/2022). Comment: The sulfuric acid bottle did not have an expiration date. BOD – Standard Methods, 5210 B-2016 (Aqueous) Recommendation: The laboratory’s SOP states, “Samples not analyzed within 2 hours of collection are stored at ≤ 6°C”. It is recommended that the laboratory change this language to “If samples are not thermally preserved at ≤ 6°C within 15 minutes after collection, they must be analyzed within two hours”. Dissolved Oxygen – Hach 10360-2011, Rev. 1.2 (Aqueous) Comment: The laboratory is calculating the theoretical DO immediately after calibration. This step is not required. Nitrogen, Ammonia – Standard Methods, 4500 NH3 D-2011 (Aqueous) Recommendation: The laboratory analyzes a mid-point 50 mg/L laboratory-fortified blank (LFB) with every run but does not vary the concentration over time. It is recommended that the laboratory vary LFB concentrations to cover the range from the midpoint to the lower part of calibration curve, including the reporting limit. Recommendation: The laboratory is not rotating the range of the LFM spike concentrations. It is recommended that the laboratory rotate the range of spike concentrations to verify performance at various levels. Also, the concentration of the LFM spike should be the same as that of the LFB when rotating spike concentrations. D. Finding: The laboratory is not randomly selecting samples to fortify. Requirement: As a minimum, include one duplicate sample or one LFM duplicate with each sample set (batch) or on a 5% basis, whichever is more frequent, and process it independently Page 4 #267 Town of Apex Middle Creek WWTP Laboratory through the entire sample preparation and analysis. Ref: Standard Methods, 4020 B-2014. (8) and Table 4020:I. Requirement: Duplicate samples are analyzed randomly to assess precision on an ongoing basis. If an analyte is rarely detected in a matrix type, use an LFM duplicate. An LFM duplicate is a second portion of the sample described in 1020B.7 to which a known amount of the analyte(s) of interest is added before sample preparation. If sufficient sample volume is collected, this second portion of sample is added and processed in the same way as the LFM. If there is not enough sample for an LFM duplicate, then use a portion of an alternate sample (duplicate) to gather data on precision. As a minimum, include one duplicate sample or one LFM duplicate with each sample set (batch) or on a 5% basis, whichever is more frequent, and process it independently through the entire sample preparation and analysis. Evaluate LFM duplicate results for precision and accuracy (precision alone for duplicate samples). Ref: Standard Methods, 1020 B-2014. (8). Comment: The laboratory routinely spikes the Influent sample, because the values of the plant effluent are less than 1 mg/L. Nitrogen, Total Kjeldahl - SM 4500 Norg B-2011 (SM 4500 NH3 C-2011) (Aqueous) Comment: Standards and spikes are being analyzed at different volumes than the blank and samples. This has a minimal effect on the recovery calculations. pH – Standard Methods, 4500 H+ B-2011 (Aqueous) Comment: The laboratory analyzes a second-source pH check buffer in addition to the required check buffer. This is not required. Recommendation: The laboratory includes a sentence on their benchsheet that describes the process for calibration. It is recommended that the lab include a check box to signify that the calibration was performed according to their requirements. Temperature – Standard Methods, 2550 B-2010 (Aqueous) E. 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 agree within 0.5ºC. If they do 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 checks the DO meter, which is used as the TMD, at one temperature. Page 5 #267 Town of Apex Middle Creek WWTP Laboratory IV. 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: Tom Halvosa Date: November 16, 2023 Report reviewed by: Michael Cumbus Date: November 17, 2023 Certificate Number:267 Effective Date:1/1/2023 Expiration Date:12/31/2023 Lab Name:Town of Apex Middle Creek WWTP Laboratory Address:300 Pristine Waters Dr. Apex, NC 27502 North Carolina Wastewater/Groundwater Laboratory Certification Certified Parameters Listing Date of Last Amendment:1/19/2023 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 IDEXX Colilert ®18 (MPN) (Aqueous) BOD SM 5210 B-2016 (Aqueous) COD Hach 8000 (Aqueous) DISSOLVED OXYGEN Hach 10360-2011, Rev. 1.2 (Aqueous) SM 4500 O G-2016 (Aqueous) NITROGEN, AMMONIA SM 4500 NH3 D-2011 (Aqueous) NITROGEN, NO3 + NO2 SM 4500 NO3ˉ E-2016 (Aqueous) NITROGEN, TOTAL KJELDAHL SM 4500 Norg B-2011 (SM 4500 NH3 C-2011) (Aqueous) pH SM 4500 H+B-2011 (Aqueous) PHOSPHORUS, TOTAL Hach 10210 TNT (Aqueous) RESIDUE, SUSPENDED SM 2540 D-2015 (Aqueous) RESIDUE, TOTAL SM 2540 B-2015 (Aqueous) TEMPERATURE SM 2550 B-2010 (Aqueous) TURBIDITY SM 2130 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.