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HomeMy WebLinkAbout#5716_2023_1108_TS_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 21, 2023 5716 Mr. Anthony Oscar Montero Cardinal Water Inc 700 Alamance Street Gibsonville, NC 27249 Subject: North Carolina Wastewater/Groundwater Laboratory Certification Branch (NC WW/GW LCB) Maintenance Inspection Dear Mr. Montero: Enclosed is a report for the inspection performed on November 8, 2023 by Tonja Springer. 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 (984) 220- 5439. Sincerely, Beth Swanson Technical Assistance & Compliance Specialist Division of Water Resources Attachment cc: Tonja Springer, Todd Crawford, #5716 On-Site Inspection Report LABORATORY NAME: Cardinal Water Inc. NPDES PERMIT #: NC0001384, NC0022691, NC0059251, NC0060259, NC0065358, NC0065412, NC0074446, NC0077135 and NC0077968 ADDRESS: 700 Alamance Street Gibsonville, NC 27249 CERTIFICATE #: 5716 DATE OF INSPECTION: November 8, 2023 TYPE OF INSPECTION: Field Commercial Initial AUDITOR: Tonja Springer LOCAL PERSON(S) CONTACTED: Anthony Montero 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. All required Proficiency Testing (PT) Samples have been analyzed and the laboratory has fulfilled its PT requirements for the 2023 PT Calendar Year. 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 SOP documents are 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 and a copy of the laboratory’s documented training program (see Finding A), 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 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 #5716 Cardinal Water Inc. 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. An amendment form was completed at the time of the inspection to change the Dissolved Oxygen (DO) method from SM 4500 O G-2016 (Aqueous) to Hach 10306 – 2011, Rev. 1.2 (Aqueous). An updated Certified Parameter Listing (CPL) was effective November 8, 2023. The laboratory records all compliance results electronically onto individually assigned iPads except for two permits that are handwritten, NC0022691 – Autumn Forest WWTP and NC0077968 – Reedy Fork Mobile Home Park. The laboratory was given a copy of the Electronic Signature and Data Storage Policy at the time of the inspection. The electronic records must be complete and in a form that does not allow alteration without detection. The system must use secure, computer-generated, time-stamped audit trails to automatically record the date and time of operator entries and actions that create, modify, or delete electronic records throughout the entire records retention period required by 15A NCAC 02H .0800 (i.e., 5 years). III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS: Documentation A. Finding: The laboratory is lacking a documented training program. Requirement: Each laboratory shall develop and implement a documented training program that includes the following: that staff have the education, training, experience, or demonstrated skills needed to generate quality control results within method-specified limits and that meet the requirements of these Rules; that staff have read the laboratory quality assurance manual or applicable Standard Operating Procedures; that staff have obtained acceptable results on Proficiency Testing Samples pursuant to Rule .0803(1) of this Section or other demonstrations of proficiency (e.g., side-by-side comparison with a trained analyst, acceptable results on a single-blind performance evaluation sample, an initial demonstration of capability study prescribed by the reference method). Ref: 15A NCAC 02H .0805 (g) (5). Comment: The laboratory’s training program is outlined in the analytical SOP’s but supporting documentation, including signatures and training dates, is not maintained. The documented training records must be submitted with the report response. B. Finding: Chemical containers are not dated when received and when opened. Requirement: Chemical containers shall be dated when received and when opened. Ref: 15A NCAC 02H .0805 (g) (7). C. 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: There were several instances of error corrections, including overwriting and obliteration of data. This Finding applies to the following permits: Page 3 #5716 Cardinal Water Inc. • NC0022691 – Autumn Forest WWTP • NC0077968 – Reedy Fork Mobile Home Park D. Finding: The laboratory is not documenting all traceability information for purchased materials, reagents and standards. Requirement: 15A NCAC 02H .0805 (a) (7) (K) and (g) (7) requires laboratories to have a documented system of traceability for the purchase, preparation, and use of all chemicals, reagents, standards, and consumables. That system must include documentation of the following information: Date received, Date Opened (in use), Vendor, Lot Number, and Expiration Date (where specified). Consumable materials such as pH buffers, lots of pre-made standards and/or media, solids and bacteria filters, etc. are included in this requirement. Ref: NC WW/GW LCB Traceability Documentation Requirements for Chemicals, Reagents, Standards and Consumables Policy (03/27/2020). Comment: Buffer lot numbers, vendor and expiration dates are documented on all pH benchsheets with the exception of NC0022691 (Autumn Forest WWTP). Only the vendor is documented on this benchsheet. There is no traceability information documented on the benchsheet for Total Residual Chlorine (TRC) DPD reagents. E. Finding: Sample collection time is not documented for TRC. Requirement: All laboratories shall use printable laboratory benchsheets. Certified Data shall be traceable to the associated sample analyses and shall consist of: the date and time of sample collection. Ref: 15A NCAC 02H .0805 (g) (2) (F). Comment: Only one time is documented for TRC. The sample collection time would be the time the grab sample is collected. The sample analysis time would be documented as the time when the DPD reagents are added. Space is provided to document the collection time for Total Residual Chlorine, but it is not being used. Comment: This Finding applies to all permits with TRC analyses. F. Finding: Only one time for sample collection and analysis is documented for Temperature, pH and DO without noting samples are analyzed in situ or immediately at the sampling site. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H 0805 (g) (4). Requirement: The following must be documented in indelible ink whenever sample analysis is performed: Date and time of sample collection; Date and time of sample analysis - Alternatively, one time may be documented for collection and analysis with the notation that samples are measured in situ or immediately at the sampling site (i.e., immediately following collection at a location as near to the collection point as possible). When this 'one time' option is used, state that the documented time is both collection and analysis time. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Temperature. Requirement: The following must be documented in indelible ink whenever sample analysis is performed: Date and time of sample collection; Date and time of sample analysis to verify the 15-minute holding time is met. Alternatively, one time may be documented for collection and analysis with the notation that samples are measured in situ or immediately at the sample site. Ref: NC WW/GW LCB Approved Procedure for the Analysis of pH and NC WW/GW LCB Approved Procedure for the Analysis of Dissolved Oxygen (DO). Page 4 #5716 Cardinal Water Inc. Comment: The benchsheet for NC0059251 – Quail Acres WWTP has only one time documented for collection and analysis without noting that collection and analysis times are the same. Recommendation: It is recommended that the collection time column be shaded for pH, DO and Temperature since samples are analyzed “in-situ” and only analysis time documented. G. Finding: The laboratory benchsheets are lacking required documentation: the quality control assessments for pH. 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 assessment. 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) (O). Comment: The acceptance criterion for the pH check standard is stated on the laboratory benchsheet, but assessment is not documented. There is no documentation showing the analyst assesses the pH values obtained against the acceptance range. Comment: A check box indicating that the acceptance criterion has been met would satisfy this requirement for the pH. No data was observed where the QC results were outside the acceptance criterion. H. Finding: The laboratory benchsheet for temperature 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: the proper units of measure. 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) (L). Comment: This Finding applies to compliance Temperature monitoring for all permits. The units are not documented on the column for “Eff Temp Daily”. Comment: A blanket statement can be added to the benchsheet to state what all the units are for each parameter. I. Finding: The laboratory benchsheet is lacking required documentation: the method or Standard Operating Procedure reference and 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 method or Standard Operating Procedure and instrument identification. 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) and (C). Comment: Neither the method reference nor the instrument identification are documented on the TRC benchsheet for the permits listed below. • NC0001384 – Riverside Furniture Gibsonville Warehouse WWTP • NC0022691 – Autumn Forest WWTP • NC0059251 – Quail Acres Mobile Home Park WWTP Page 5 #5716 Cardinal Water Inc. • NC0065412 – Pleasant Ridge WWTP • NC0074446 – Hilltop Mobile Home Park WWTP Comment: The instrument identification is not documented on the Temperature benchsheet for NC0059251 – Quail Acres Mobile Home Park WWTP. Comment: The requirement for documentation of instrument identification has been updated since the inspection was conducted. Going forward, the instrument identification must be a unique identifier, such as a serial number, not only a model name. J. Finding: The laboratory benchsheet is lacking required documentation: facility name or permit number and sample site (ID or location). Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H 0805 (g) (4). Requirement: The following must be documented in indelible ink whenever sample analysis is performed. Facility name or permit number, and sample site (ID or location). Ref: NC WW/GW LCB Approved Procedure for the Analysis of Dissolved Oxygen (DO), NC WW/GW LCB Approved Procedure for the Analysis of pH, NC WW/GW LCB Approved Procedure for the Analysis of Temperature and NC WW/LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G- 2011). Comment: This Finding applies to the following permits: • NC0022691 – Autumn Forest – Facility name or permit number is not documented on the benchsheets. Sample site is not documented on the TRC benchsheet. • NC0077968 – Reedy Fork Mobile Home Park – Sample site is not documented on the TRC benchsheet. K. Finding: All laboratory benchsheets are lacking required documentation: the sample collector and 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 sample collector and signature or initials of the analyst. 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) (D) and (E). Comment: This Finding applies to all benchsheets. The column header is labelled as “OP Initials” for the pH and Temperature benchsheets and “Analyst” for TRC benchsheets. The DO benchsheet does not have a column for the sample collector or analyst. Comment: When applicable, a notation may be added to the benchsheet that the sample collector and analyst are the same. L. Finding: The laboratory is not documenting the barometric pressure and salinity values used to calibrate the DO meter. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). Requirement: The following must be documented in indelible ink whenever sample analysis is performed: Calibration variables (temperature, elevation or barometric pressure [in mmHg], Page 6 #5716 Cardinal Water Inc. 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). Comment: The Hach HQ30D multimeter has an internal barometer that automatically senses the barometric pressure. The barometric pressure is displayed on the calibration screen but this is not documented on the benchsheet. Comment: At the time of the inspection, there was no Salinity value included in the calibration screen. According to the instrument manual, the HQ30D meter has salinity correction turned off by default, thus it is not used in the calibration. The laboratory would need to include this information in the SOP and include a blanket statement on the benchsheet that salinity is zero. Comment: Temperature is the only calibration variable documented. Proficiency Testing M. Finding: The laboratory is not documenting PT Sample analyses. 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. 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: The laboratory’s current practice is to record the instrument reading directly into the PT Vendor’s electronic submission form. No record of the analysis is maintained. N. 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 Page 7 #5716 Cardinal Water Inc. 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: The laboratory was analyzing PT Samples multiple times and reporting an average of all the results. Compliance Samples are not analyzed in duplicate and the values of the pH cannot be arithmetically averaged. Sample duplicates are not a required QC element for Field Parameters. O. 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: This Finding applies to TRC. Comment: Dating and initialing the instruction sheet for each prepared PT Sample would satisfy the documentation requirement. P. Finding: PT Samples are not being distributed among all analysts from year to year. Requirement: Laboratories shall also ensure that, from year to year, PT Samples are equally distributed among personnel trained and qualified for the relevant tests and instrumentation (when more than one instrument is used for routine Compliance Sample analyses), that represents the routine operation of the work group at the time the PT Sample analysis is conducted. Ref: Proficiency Testing Requirements, January 1, 2023, Revision 6, Section 3.6. Quality Assurance/Quality Control Q. Finding: Chemicals and/or reagents are used beyond the expiration date. Requirement: Chemical containers shall be dated when received and when opened. Reagent containers shall be dated, identified, and initialed when prepared. Chemicals and reagents exceeding the expiration date shall not be used. Chemicals and reagents shall be assigned expiration dates by the laboratory if not given by the manufacturer. If the laboratory is unable to determine an expiration date for a chemical or reagent, a one-year time period from the date of receipt shall be the expiration date unless degradation is observed prior to this date. Ref: 15A NCAC 02H .0805 (g) (7). Comment: The pH 7.0 buffer documented on the NC0001384 (Riverside) and (NC0060259) Willow Oakes September 2023 benchsheets had an expiration date of October 2022. pH - Standard Methods, 4500 H+ B-2011 (Aqueous) R. Finding: The laboratory is not documenting the true value of all the calibration buffers. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). Page 8 #5716 Cardinal Water Inc. Requirement: The following must be documented in indelible ink whenever sample analysis is performed: True values of buffers used for calibration. Ref: NC WW/GW LCB Approved Procedure for the Analysis of pH. Comment: The pH meter is calibrated using 4.0, 7.0 and 10.0 S.U. buffers but the 7.0 S.U. buffer is not documented for the calibration. S. Finding: The laboratory is not using fresh aliquots of standard buffers to calibrate the pH meter each day. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). Requirement: A portion of the standard buffer is not to be used for more than one calibration. Discard any used buffer portions. Do not pour unused portions back into the original bottle. Ref: NC WW/GW LCB Approved Procedure for the Analysis of pH. Comment: A portion of the standard buffers are poured from the original bottles into separate containers that are used for a couple weeks before fresh buffers are poured. T. Finding: The laboratory is not analyzing a post-analysis check standard buffer when the meter is transported by vehicle to another location after calibration. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). 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. Comment: This Finding applies to all permits with pH monitoring requirements. Chlorine, Total Residual – Standard Methods, 4500 Cl G-2011 (Aqueous) U. Finding: The assigned true value of the gel-type check standard is not documented correctly on the benchsheet. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). Requirement: The following must be documented in indelible ink whenever sample analysis is performed: True values of the Daily Check Standard. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G- 2011). Comment: The incorrect assigned true value (i.e., 209 µg/L) is documented on the benchsheet instead of 200 µg/L. Comment: It appears this was not updated from the true value and range assigned during Page 9 #5716 Cardinal Water Inc. the gel verification on December 29, 2020. Comment: TRC is analyzed for the following permits: • NC0001384 – Riverside Furniture Gibsonville Warehouse WWTP • NC0022691 – Autumn Forest WWTP • NC0059251 – Quail Acres Mobile Home Park (MHP) • NC0060259 – Willow Oaks Mobile Home Park (MHP) • NC0065412 – Pleasant Ridge WWTP • NC0074446 – Hilltop Mobile Home Park WWTP V. Finding: The laboratory benchsheet is lacking required documentation. Date of most recent TRC calibration curve verification. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). 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). Comment: This Finding applies to all benchsheets that include TRC compliance sample analyses. W. Finding: The laboratory is not analyzing a Method Blank when using laboratory-prepared standards. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). Requirement: Method Blanks would be required when using laboratory-prepared standards [including Proficiency Testing (PT) Samples] and anytime sample dilutions are performed. Ref: NC WW/GW LC Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011). Requirement: The Method Blank is deionized or distilled water from the same source used to prepare the calibration verification standards or the PT Sample, and 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 verification standard concentration) or corrective action must be taken. Ref: NC WW/GW LC Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011). Comment: The prepared PT Sample is considered a laboratory-prepared standard. Dissolved Oxygen – Hach 10306 – 2011, Rev. 1.2 (Aqueous) Chlorine, Total Residual – Standard Methods, 4500 Cl G-2011 (Aqueous) X. Finding: The laboratory is not analyzing a post-analysis calibration verification when the meter is transported by vehicle to another location after calibration. Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref: 15A NCAC 02H .0805 (g) (4). Page 10 #5716 Cardinal Water Inc. 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 extended over an extended period of time. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Dissolved Oxygen (DO). 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 calibration verification be performed when samples are analyzed over an extended period of time. The value obtained for the Post-analysis Calibration Verification Standard must read within ±10% of the true value of the Post-analysis Calibration Verification 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: If the meter is recalibrated at each sample location before sample analysis, a post- analysis calibration verification is not required. Comment: This Finding applies to all permits that require TRC compliance monitoring. Comment: This Finding applies to the following permits that include DO compliance sample analysis: • NC0001384 – Riverside Furniture Gibsonville Warehouse WWTP • NC0022691 – Autumn Forest WWTP • NC0059251 – Quail Acres Mobile Home Park (MHP) • NC0074446 – Hilltop Mobile Home Park WWTP • NC0077135 – Hidden Valley WWTP • NC0065358 – Hidden Forest LLC Reporting Y. Finding: Qualified Data is not reported as such on the Discharge Monitoring Report (DMR). Requirement: Each certified Field Laboratory shall be in accordance with Paragraph (e) of this Rule. Ref: 15A NCAC 02H .0805 (g) (17). Requirement: Reported data associated with quality control failures, improper sample collection, holding time exceedances, or improper preservation shall be qualified as such. Ref: 15A NCAC 02H .0805 (e) (5). Comment: Data qualifiers from the contract laboratory reports are not transferred to the DMR. 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. Page 11 #5716 Cardinal Water Inc. Report prepared by: Tonja Springer Date: November 27, 2023 Report reviewed by: Michael Cumbus Date: November 28, 2023 Certificate Number:5716 Effective Date:1/1/2023 Expiration Date:12/31/2023 Lab Name:Cardinal Water Inc Address:700 Alamance Street Gibsonville, NC 27249 North Carolina Wastewater/Groundwater Laboratory Certification Certified Parameters Listing Date of Last Amendment:11/8/2023 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 CHLORINE, TOTAL RESIDUAL SM 4500 Cl G-2011 (Aqueous) DISSOLVED OXYGEN Hach 10360-2011, Rev. 1.2 (Aqueous) pH SM 4500 H+B-2011 (Aqueous) TEMPERATURE SM 2550 B-2010 (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.