#5016_2023_0208_MC_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

March 10, 2023

5016
Ms. Madeline McIntyre
Lowes Company Iredell Distribution
711 Tomlin Mill Rd.
Statesville, NC 28625-

Subject: North Carolina Wastewater/Groundwater Laboratory Certification Branch (NC
WW/GW LCB) Maintenance Inspection

Dear Ms. McIntyre:

Enclosed is a report for the inspection performed on February 8, 2023 by Michael Cumbus. 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: Michael Cumbus, Todd Crawford, #5016

On-Site Inspection Report

LABORATORY NAME: Lowes Company Iredell Distribution
NPDES PERMIT #: NC0085120
ADDRESS: 711 Tomlin Mill Rd.
Statesville, NC 28625
CERTIFICATE #: 5016
DATE OF INSPECTION: February 8, 2023
TYPE OF INSPECTION: Field Industrial Maintenance
AUDITOR(S): Michael Cumbus

LOCAL PERSON(S) CONTACTED:

Madeline McIntyre and Willie Gregory

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. The
staff were forthcoming and responded well to suggestions from the auditor.

All required Proficiency Testing (PT) Samples have been analyzed for the 2022 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 August 31, 2023.

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”.

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Contracted analyses are performed by Statesville Analytical Holdings LLC (Certification # 440).

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: The pH calibration log includes a column for “temp/slope” with units of Celsius
but the column is used to document the slope of the pH meter calibration. This is not required to be
documented. It is recommended that the laboratory either change the column heading to “slope” and
replace Celsius with the units for slope or remove the column entirely.

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).

B. Finding: The laboratory is not documenting all traceability information for purchased pH
buffers.

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). A system (e.g., traceable identifiers) must be in place that
links standard/reagent preparation information to analytical batches in which the solutions are
used. Documentation of solution preparation must include the analyst’s initials, date of
preparation, the volume or weight of standard(s) used, the solvent and final volume of the
solution. This information as well as the vendor and/or manufacturer, lot number, and
expiration date must be retained for primary standards, chemicals, reagents, and materials
used for a period of five years. 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.

Comment: Dates received and opened were written on the pH buffer bottles, as required.
While this can provide a traceability link to analyses while the chemicals are still in use, that
link is lost once the bottles are discarded.

C. Finding: The laboratory benchsheet is lacking required documentation: the method or
Standard Operating Procedure reference; the instrument identification; the sample collector;
the date and time of sample collection and 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 method or Standard
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Operating Procedure; the instrument identification; the sample collector; the date and time of
sample collection and 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) (A) (C) (D) (F) and (L).

Comment: The calibration log for the pH meter is lacking units of measure. The units of
measure for temperature are improperly listed as “©” rather than " °C”.

D. Finding: Error corrections are not always 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: Several instances were noted where the error correction was lacking the date that
the change was made. Several instances were also noted where the error correction was
written over the original result. An instance of obliteration was noted on the July 2022 ORC
sign-in sheet.

Proficiency Testing

Comment: The laboratory has seen frequent personnel changes and PT samples have been rotated,
as required, due to these changes. Now that the staffing has become more stabilized, the laboratory
is reminded that PT samples must continue to be rotated from year to year among all personnel who
may be analyzing compliance samples.

E. Finding: The laboratory does not have a documented plan for PT procedures.

Requirement: 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.

F. Finding: The laboratory is not documenting PT Sample analyses.

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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.

G. 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 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: 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.

Quality Assurance/Quality Control

H. Finding: SOPs have not been developed for the methods included on the laboratory’s
Certified Parameters Listing (CPL).

Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. A
copy of each analytical method or Approved Procedure and Standard Operating Procedure
shall be available to each analyst and available for review upon request by the State
Laboratory. Standard Operating Procedure documentation shall state the effective date of the
document and shall 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 Standard Operating Procedure documents. Supporting Records
shall be maintained as evidence that these practices are implemented. Ref: 15A NCAC 02H
.0805 (g) (4).

Comment: The laboratory must have a QC/SOP document for the parameters included on
their CPL by August 31, 2023. This must be submitted for review upon completion. SOP
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templates have been developed and are available for download on the NC WW/GW LCB
website.

pH – Standard Methods, 4500 H+ B-2011 (Aqueous)

I. Finding: QC results for the pH check standard buffer are not being evaluated to demonstrate
the analytical process is in control and the established acceptance criteria are met.

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 (g) (2) (O).

Requirement: If quality control results fall outside established limits or indicate an analytical
problem, the laboratory shall identify the Root Cause of the failure. The problem shall be
resolved through corrective action, the corrective action process documented, and any
samples involved shall be reanalyzed, if possible. If the sample cannot be reanalyzed, or if
the quality control results continue to fall outside established limits or indicate an analytical
problem, the results shall be qualified as such. Ref: 15A NCAC 02H .0805 (g) (8).

Comment: No data were examined where the pH QC results were not within the established
acceptance criteria of ± 0.1 S.U.

J. Finding: Values were reported that exceed the method specified accuracy of 0.1 units.

Requirement: By careful use of a laboratory pH meter with good electrodes, a precision of
±0.02 unit and an accuracy of ±0.05 unit can be achieved. However, ± 0.1 pH unit represents
the limit of accuracy under normal conditions, especially for measurement of water and poorly
buffered solutions. For this reason, report pH values to the nearest 0.1 pH unit. Ref: Standard
Methods, 4500 H+ B-2011. (6).

Comment: Per PT Vendor instructions, the PT Sample results should be reported to two
decimal places, which is an exception to the requirement for Compliance Samples.

Recommendation: The laboratory currently reports pH sample results to two decimal places.
It is recommended that the laboratory continue to measure and document sample results on
the benchsheet to two decimal places, and to round to the nearest 0.1 S.U. when reporting
results on the DMR.

Temperature – Standard Methods, 2550 B-2010 (Aqueous)

Comment: Temperature is being reported to 0.1°C on the DMR.

Recommendation: Unless greater precision is required by the permit or data receiving agency, it is
recommended that all temperatures reported for compliance monitoring, be reported in whole
numbers as recommended by the DWR’s Precision in Discharge Monitoring Reports document.

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 Lowes Company Iredell Distribution (NPDES permit # NC0085120) for December 2021
through November 2022. No transcription errors were observed. The facility appears to be doing a good
job of accurately transcribing data.

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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: February 15, 2023
Report reviewed by: Tom Halvosa Date: February 15, 2023

Certificate Number:5016
Effective Date:1/1/2022
Expiration Date:12/31/2022
Lab Name:Lowes Company Iredell Distribution
Address:711 Tomlin Mill Rd.
Statesville, NC 28625-
North Carolina Wastewater/Groundwater Laboratory Certification
Certified Parameters Listing
Date of Last Amendment:11/16/2021
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
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.