HomeMy WebLinkAbout#5228_2021_0226_MC_FINAL
September 10, 2021
5228
Mr. Mark Haver
Carolina Water Service Inc. - Charlotte Region
P.O. Box 240908
Charlotte, NC 28224-
Subject: North Carolina Wastewater/Groundwater Laboratory Certification (NC WW/GW
LC) Maintenance Inspection
Dear Mr. Haver:
Enclosed is a report for the inspection performed on February 26, 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 2H .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
On-Site Inspection Report
I. INTRODUCTION:
This laboratory was inspected by a representative of the North Carolina Wastewater/Groundwater Laboratory
Certification (NC WW/GW LC) program to verify its compliance with the requirements of 15A NCAC 02H
.0800 for the analysis of compliance monitoring samples.
II. GENERAL COMMENTS:
The inspection was performed remotely due to the coronavirus pandemic. The laboratory submitted
requested documentation and pictures of their consumables and instruments electronically. The inspection
was performed via phone and email.
Staff was forthcoming and responded well to suggestions from the auditor.
All required Proficiency Testing (PT) Samples for the 2021 PT Calendar Year have not yet been analyzed.
The laboratory is reminded that results must be received by this office directly from the vendor by September
30, 2021.
The laboratory submitted their Quality Assurance (QA) and/or Standard Operating Procedure (SOP)
document(s) in advance of the inspection. These documents were reviewed, and editorial and substantive
revision requirements and recommendations were made by this program outside of this formal report
process. Although subsequent revisions were not requested to be submitted, they must be completed by
February 28, 2022.
The laboratory is reminded that any time changes are made to laboratory procedures, the laboratory must
update the QA/SOP document(s) and inform relevant staff. Any changes made in response to the pre-
audit review or to Findings, Recommendations or Comments listed in this report must be incorporated to
insure the method is 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
LABORATORY NAME: Carolina Water Service, Inc. – Charlotte Region
NPDES PERMIT #:
NC0035041, NC0060461, NC0060755, NC0062383,
NC0064734, NC0071242, NC0084565, NC0086592,
NC0086606
ADDRESS: 7803 Idlewild Rd.
Indian Trail, NC 28079
CERTIFICATE #: 5228
DATE OF INSPECTION: February 26, 2021
TYPE OF INSPECTION: Field Commercial Maintenance
AUDITOR: Michael Cumbus
LOCAL PERSON(S) CONTACTED:
Brent Milliron
Page 3
#5228 Carolina Water Service, Inc. – Charlotte Region
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.
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”.
Contracted analyses are performed by K & W Laboratories (Certification #559) and Waypoint Analytical –
Charlotte (Certification #402).
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 standardize the laboratory benchsheet
template for all facilities, entering pertinent data such as site information and instrument information
prior to printing.
Recommendation: It is recommended that the laboratory combine the pH calibration log and the pH
benchsheet in order to reduce paperwork and aid in data review.
Recommendation: It is recommended that the laboratory reduce redundancy of where data is
recorded in order to facilitate data retrieval and review, and reduce the possibility of transcription
errors.
A. 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 of data corrections lacking date and/or initials were noted.
Multiple instances of data being obliterated by marking were also noted.
B. Finding: A temperature-measuring device (serial number 1245902) without a valid NIST
certificate or verification was used to analyze compliance samples.
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 (g) (1).
Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref:
15A NCAC 02H .0805 (g) (4).
Page 4
#5228 Carolina Water Service, Inc. – Charlotte Region
Requirement: All compliance temperature-measuring devices without a valid NIST certificate
must be checked initially and every 12 months against an NIST traceable temperature-
measuring device and the process documented. Documentation must include the serial
number of the device being checked. The serial number, stated accuracy and expiration date
of the NIST traceable temperature-measuring device used in the comparison must also be
documented. Verification data must be kept on file and be available for inspection for 5 years.
(NOTE: Vendors or other Certified laboratories may provide assistance in meeting this
requirement. When a vendor or other Certified laboratory provides this assistance, they must
provide a copy of their NIST Certificate or the serial number, accuracy and calibration
expiration date.) Ref: NC WW/GW LC Approved Procedure for the Analysis of Temperature.
Comment: From November 4, 2020 – November 10, 2020, Bradfield Farms measured
temperature for compliance purposes with their Reference Temperature-Measuring Device
(serial number #1245902). The calibration due date according to the manufacturer’s certificate
was September 12, 2015. No documentation regarding calibration or annual verification for
this thermometer was provided. The laboratory is reminded that Reference Temperature-
Measuring Devices are not to be used for anything other than verification of other temperature-
measuring devices.
C. Finding: The Reference Temperature-Measuring Device (serial number 1245902) used to
check other thermometers and/or temperature sensors was not recalibrated in accordance
with the manufacturer’s recalibration date.
Requirement: Reference Temperature-Measuring Devices shall meet National Institute of
Standards and Technology (NIST) specifications for accuracy and shall be recalibrated in
accordance with the manufacturer's recalibration date. If no recalibration date is given, the
Reference Temperature-Measuring Device shall be recalibrated every five years. Ref: 15A
NCAC 02H .0805 (g) (9) (A).
Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref:
15A NCAC 02H .0805 (g) (4).
Requirement: All NIST traceable temperature-measuring devices must have a stated
accuracy of at least ± 0.5°C and be within their expiration date. Ref: NC WW/GW LC Approved
Procedure for the Analysis of Temperature.
Comment: The Reference Temperature-Measuring Device (serial number 1245902)
certificate expired on September 12, 2015. This temperature-measuring device was used to
perform the verification of the compliance temperature-measuring devices for Hemby Acres
and Bradfield Farms in 2019.
D. Finding: Documentation of the compliance temperature-measuring device calibration
verification does not include the stated accuracy or the expiration date of the Reference
Temperature-Measuring Device used in the comparison. This is considered pertinent data.
Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref:
15A NCAC 02H .0805 (g) (4).
Requirement: All compliance temperature-measuring devices without a valid NIST certificate
must be checked initially and every 12 months against an NIST traceable temperature-
measuring device and the process documented. Documentation must include the serial
number of the device being checked. The serial number, stated accuracy and expiration date
of the NIST traceable temperature-measuring device used in the comparison must also be
documented. Verification data must be kept on file and be available for inspection for 5 years.
Page 5
#5228 Carolina Water Service, Inc. – Charlotte Region
(NOTE: Vendors or other Certified laboratories may provide assistance in meeting this
requirement. When a vendor or other Certified laboratory provides this assistance, they must
provide a copy of their NIST Certificate or the serial number, accuracy and calibration
expiration date.) Ref: NC WW/GW LC Approved Procedure for the Analysis of Temperature.
Requirement: All NIST traceable temperature-measuring devices must have a stated
accuracy of at least ± 0.5°C and be within their expiration date. Ref: NC WW/GW LC Approved
Procedure for the Analysis of Temperature.
Comment: This Finding applies to verifications performed by the laboratory as well as those
performed by K & W Laboratories (Certificate #559).
E. Finding: The laboratory benchsheet is sometimes lacking required documentation: Facility
name or permit number, sample site (ID or location), and 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; sample 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) (C) and (I).
Requirement: The following must be documented in indelible ink whenever sample analysis
is performed: Facility name or permit number. Ref: NC WW/GW LC Approved Procedure for
the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011).
Comment: The following documentation requirement deficiencies were noted but may not be
all inclusive:
• The April and November 2020 Total Residual Chlorine Logs for Abington are lacking
the site ID.
• The April and November 2020 laboratory benchsheets for pH and DO for Abington
are lacking the site ID.
• The April and November 2020 laboratory benchsheets for Bradfield Farms is lacking
the site ID.
• The September 2020 pH, dissolved oxygen and TRC laboratory benchsheets for The
Pointe/The Harbour are lacking the site ID.
• The November 2020 pH calibration log for The Pointe/The Harbour is lacking the site
ID.
• The April, September and November 2020 Hemby Acres laboratory benchsheets for
pH and TRC are lacking site ID.
• The September 2020 Queen’s Harbor laboratory benchsheets for pH and TRC
analysis are lacking site ID.
• The November 2020 Queen’s Harbor laboratory benchsheets for TRC and pH are
lacking facility name or permit number, site ID, and instrument ID.
F. Finding: The units of measure are not consistently documented on the benchsheets.
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. Ref: 15A NCAC 02H
.0805 (g) (2) (L).
Comment: The Total Residual Chlorine (TRC) benchsheets for Abington (NPDES permit #
NC0060461), Queens Harbor (NPDES permit # NC0062383) and Saddlewood (NPDES
Page 6
#5228 Carolina Water Service, Inc. – Charlotte Region
permit # NC0060755) instruct the analyst to circle one of two units of measure (i.e., µg/L or
mg/L), but this is not being done.
Comment: The pH calibration log for The Pointe/The Harbour (NPDES Permit numbers
NC0086592, NC0084565, NC0086606) lacks units for the post analysis check buffer.
G. 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). 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 are
included in this requirement. Ref: NC WW/GW LC Policy.
Comment: Only Hemby Acres and Bradfield Farms have a traceability log, according to a
phone interview. Of the logs submitted, only the pH buffers were documented. DPD powder
was not listed. It was discussed during the phone interview that if the materials are all stored
in a central place, that separate logs for each site would not be necessary. However, any
containers that reagents such as pH buffers are placed into for daily use in the field will need
accompanying traceability information.
Comment: The laboratory benchsheets for The Pointe and The Harbour list an incorrect lot
number for the gel-type standards being analyzed for TRC. This needs to be updated with the
correct lot number for the current set of standards being used.
H. Finding: The laboratory is not documenting the true value and percent recovery of TRC QC
standards on laboratory benchsheets.
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. Each item shall be recorded each time samples are analyzed. Ref: 15A NCAC
02H .0805 (g) (2) (O).
Requirement: The following must be documented in indelible ink whenever sample analysis
is performed: True Value of the Daily Check Standard and percent recovery. Ref: NC WW/GW
LC Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM
4500 Cl G-2011).
Comment: The true value of QC standards and percent recovery obtained must be
documented on the benchsheet and evaluated against established acceptance criteria to
demonstrate that the analyst was aware of any out-of-control situation. The corrective actions
taken must be documented. Any samples not meeting the acceptance criteria must be
reanalyzed, if possible. If this is not possible, the data must be flagged on the laboratory
reports as all QC requirements not met.
I. Finding: Sample analysis time is not consistently documented.
Requirement: All laboratories shall use printable laboratory benchsheets. Certified Data shall
be traceable to the associated sample analyses and shall consist of: the time of sample
analyses (when required to document a required holding time or when time-critical steps are
Page 7
#5228 Carolina Water Service, Inc. – Charlotte Region
imposed by the method, a federal regulation, or this Rule). Ref: 15A NCAC 02H .0805 (g) (2)
(G) and (g) (2) (H).
Comment: Some versions of the laboratory benchsheets have pH calibration logs separate
from the benchsheet where sample analysis is recorded. These sample analysis sheets often
do not record the sample analysis time, especially when multiple permitted sites are included
on the same benchsheet.
Comment: The laboratory benchsheet for Hemby Acres was lacking analysis time for TRC
on November 2 and 10, 2020.
J. Finding: Documentation does not demonstrate the gel-type standard was analyzed three
times to obtain an average concentration.
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 (g) (1).
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 LC Approved Procedure for the Analysis of Total Residual Chlorine (DPD
Colorimetric by SM 4500 Cl G-2011).
Comment: Data were reviewed for 8 evaluations of gel-type standards from 4 permitted sites.
Of these 8 evaluations, none were found to demonstrate that the gel-type standard had been
analyzed three times.
Comment: The laboratory is subcontracting this to K & W Laboratories (Certificate #559).
K. Finding: The laboratory is lacking a documented training program.
Requirement: Each laboratory shall develop and implement a documented training program
that includes documentation that: (i) staff have the education, training, experience, or
demonstrated skills needed to generate quality control results within method-specified limits
and meet the requirements of these Rules; (ii) staff have read the laboratory quality assurance
manual and applicable Standard Operating Procedures; and (iii) 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 method). Ref: 15A NCAC 02H .0805 (g) (5).
Proficiency Testing
L. 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
Page 8
#5228 Carolina Water Service, Inc. – Charlotte Region
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 PT Sample for Total Residual Chlorine was analyzed in duplicate in 2020.
M. 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.
N. 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 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: The laboratory benchsheet for the 2020 PT Sample lists a value different from the
value submitted to the PT vendor. The value on the benchsheet is the same as the Assigned
Value, as stated on the PT report. It may appear to a third-party observer that the benchsheet
was filled out after the PT report was made public and back-dated.
O. Finding: The laboratory does not have a documented plan for PT procedures.
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
Page 9
#5228 Carolina Water Service, Inc. – Charlotte Region
shall be maintained as evidence that these practices are implemented. Ref: 15A NCAC 02H
.0805 (g) (4).
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 laboratory must also
be able to explain when PT Sample analysis is not possible for certain methods and provide
a description of what the laboratory is doing in lieu of Proficiency Testing. This shall be detailed
in the plan. 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, February 19, 2020, Revision 5, Section 3.0.
QA/QC
P. Finding: Accuracy of QC results are not consistently 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: For the month of November 2020, the TRC analysis for Saddlewood used a gel-
type standard (Lot #A8087) with an assigned true value of 206 µg/L, as noted in the verification
performed on November 12, 2020 by K & W Laboratories. However, the laboratory
benchsheet lists an outdated lot number (#AR807A) and acceptance range (162-198 µg/L).
Therefore, it appears that the acceptance criteria for the November data were not met and
due to the lack of quality control assessment, no corrective action (i.e., determining that the
gel-type standard and values had not been updated) was performed. Applying the correct gel-
type standard assigned value demonstrates that the acceptance criteria was actually met. The
fact that the observed value of the standard and the acceptance range were handwritten each
time and the observed value was not within the acceptance range should have been obvious
to the analyst. It is concerning that this did not seem to be the case based on lack of corrective
action.
Recommendation: It is recommended that the laboratory institute a system of peer review.
Q. Finding: An inconsistency was noted between the SOP and laboratory practice as follows:
Personnel were not following procedures as stated in the Laboratory’s SOP.
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
Page 10
#5228 Carolina Water Service, Inc. – Charlotte Region
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 SOP for TRC states “Analyze duplicate samples once per week”.
The laboratory SOP for pH states “A duplicate sample (split sample) will be analyzed per batch
of 20 samples or less.” Duplicates are not being analyzed for either parameter.
Recommendation: Duplicates are not a required QC element for Field Parameters. It is
recommended that the SOPs be updated to remove the duplicate requirement.
Reporting
R. Finding: The laboratory does not report results of all tests on the characteristics of the effluent
when multiple sample analyses are performed.
Requirement: The results of all tests on the characteristics of the effluent, including but not
limited to NPDES permit monitoring requirements, shall be reported on the monthly report
forms. Ref: 15A NCAC 2B .0506 (b) (3) (J).
Comment: The laboratory subcontracted Saddlewood’s BOD analyses for November 2020
to both K & W Laboratories and Waypoint Analytical. The laboratory did not report both sets
of data. The laboratory may choose to either average the values or report the value that is
closest to the bounds of the permit limit in the daily cell and report the other value in the
comment section.
Comment: The laboratory records sample temperatures during analysis of pH and DO for
Riverpointe, Bradfield Farms, Hemby Acres and Saddlewood WWTP. Only the reading from
the DO meter is reported. The laboratory may choose to either average the values or report
the value that is closest to the bounds of the permit limit in the daily cell and report the other
value in the comment section.
Chlorine, Total Residual – Standard Methods, 4500 Cl G-2011
S. Finding: The laboratory does not appear to be waiting the minimum 3-minute development
time after adding the color reagents before starting analysis.
Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref:
15A NCAC 02H .0805 (g) (4).
Requirement: Daily Sample Analysis Procedure:
• Add DPD/buffer within 15 minutes of collection
• Wait 3 - 6 minutes
• Read sample result
• Document required information
Ref: NC WW/GW LC Approved Procedure for the Analysis of Total Residual Chlorine (DPD
Colorimetric by SM 4500 Cl G-2011).
Requirement: Some examples of the allowed types of changes, provided the requirements
of this section are met include: (xiii) The use of prepackaged reagents. As such, the proper
procedure for using the packaged reagents would then be determined by the manufacturer’s
instructions. Ref: Code of Federal Regulations, Title 40, Part 136; Federal Register Vol. 77,
No. 97, May 18, 2012; 136.6. (b) (4).
Page 11
#5228 Carolina Water Service, Inc. – Charlotte Region
Requirement: For successful testing, especially in treated effluents, strict adherence to the
development time is necessary. Three to six minutes of development time are sufficient to
resolve all chloramine forms without significant error from competing reactions. Ref: Hach
Company, “Current Technology of Chlorine Analysis for Water and Wastewater”, 2002.
Comment: Some, but not all, benchsheets have a box that may be checked when the 3-
minute color development time requirement has been met. Documenting the 3-minute color
development time is not required. However, having a space on the benchsheet for
documentation that is not consistently filled out gives the perception that the required color
development time is not being observed.
T. Finding: The laboratory is not evaluating whether the Factory-set Calibration Curve
Verification standards are within the acceptable recovery range.
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 LC Approved Procedure for the Analysis of Total Residual Chlorine
(DPD Colorimetric by SM 4500 Cl G-2011).
Comment: The laboratory verification performed on October 15, 2019 did not pass the lowest
standard recovery criteria for the Queen’s Harbor TRC meter (serial number 1179277). The
laboratory submitted a passing calibration verification which was performed on January 12,
2021.
U. Finding: The laboratory is not consistently 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 LC Approved Procedure for the
Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-2011).
Comment: The spectrophotometer for Queen’s Harbor (serial number 1179277) had a
verification performed on October 15, 2019. The next verification was performed on
January 12, 2021.
V. Finding: The laboratory failed to perform corrective action when the verification of the TRC
meter at Queen’s Harbor was outside the recovery acceptance criteria.
Page 12
#5228 Carolina Water Service, Inc. – Charlotte Region
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).
Requirement: If the factory-set readings vary by more than the stated acceptance criteria,
the stored calibration program must not be used for compliance monitoring until
troubleshooting is carried out to determine and correct the source of error. Ref: NC WW/GW
LC Approved Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM
4500 Cl G-2011).
Comment: Possible corrective actions include: re-zeroing the meter; ensuring glassware is
clean and not scratched; preparing fresh calibration standards; having the meter serviced, etc.
Comment: The Queen’s Harbor spectrophotometer (serial number 1179277) continued to be
used after failing a low-level standard verification in 2019. The 10 µg/L standard had 130%
recovery in 2019. The spectrophotometer passed the most recent curve verification in January
2021, with the 10 µg/L standard having a recovery of 80%.
W. Finding: The Factory-set Calibration Curve is not consistently verified 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 calibration 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 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 LC Approved Procedure for the Analysis of Total Residual Chlorine (DPD
Colorimetric by SM 4500 Cl G-2011).
Comment: The Hemby Acres spectrophotometer (serial number 1154192) was not verified
with a Daily Check Standard on November 2 and 10, 2020.
X. Finding: Values less than the established reporting limit are being reported on the DMR.
Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref:
15A NCAC 02H .0805 (g) (4).
Requirement: For all calibration options, the range of standard concentrations must bracket
the permitted discharge limit concentration, the range of sample concentrations to be analyzed
and anticipated PT Sample concentrations. One of the standards must have a concentration
less than the permitted Daily Maximum Limit. The lower reporting limit concentration is equal
to the lowest standard concentration. Sample concentrations that are less than the lower
reporting limit must be reported as a less-than value. Ref: NC WW/GW LC Approved
Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric by SM 4500 Cl G-
2011).
Page 13
#5228 Carolina Water Service, Inc. – Charlotte Region
Comment: The laboratory established a lower reporting limit of 10 µg/L for Queen’s Harbor
by verifying that concentration against the latest calibration curve. Values with concentrations
less than that must be reported as < 10 µg/L on the DMR. The laboratory recorded and
reported a value of 2 µg/L on April 13, 2020.
Dissolved Oxygen – Standard Methods, 4500 O G-2011 (Aqueous)
Recommendation: It is recommended that the laboratory remove the “in situ” language from
Comment 2 on the Saddlewood benchsheet since the time sampled and time analyzed for November
2020 were different.
Y. Finding: Documentation of the calibration variables for the DO meter does not include all
pertinent data.
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],
and salinity). Ref: NC WW/GW LC Approved Procedure for the Analysis of Dissolved Oxygen
(DO).
Comment: The SOP states that the salinity is input as zero. This must be documented on the
benchsheet.
Comment: The DO calibration log for The Pointe and The Harbour lists elevation as 800 ft.
However, DO calibration logs for the other permitted sites do not include an elevation.
Z. Finding: When analyses are performed at multiple sample sites, the laboratory is not
calibrating at each sample site or performing a Post-Analysis Calibration Verification at the
end of the run.
Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref:
15A NCAC 02H .0805 (g) (4).
Requirement: When performing analyses at multiple sample sites, the meter must be
calibrated at each sample site prior to analysis or a post-analysis calibration verification must
be performed at the end of the run, regardless of meter type. 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 LC Approved
Procedure for the Analysis of Dissolved Oxygen (DO).
pH – Standard Methods, 4500 H+ B-2011 (Aqueous)
Comment: The temperature sensor is being verified on the pH meters. If the laboratory does not use
pH meters for temperature compliance monitoring, then this does not need to be performed. NC
WW/GW LC does not require Automatic Temperature Compensation probe checks for pH analyses.
AA. Finding: The instrument is not being calibrated prior to analysis of samples each day
compliance monitoring is performed.
Page 14
#5228 Carolina Water Service, Inc. – Charlotte Region
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. Ref: NC
WW/GW LC Approved Procedure for the Analysis of pH.
Comment: The pH meter at Hemby Acres is calibrated on a weekly basis. However, pH
analyses usually occur more frequently. Data from April, September and November, 2020
show 16 instances where the pH meter was not calibrated prior to sample analysis.
BB. Finding: Values are being 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.
Comment: The laboratory reported a pH of 6.17 S.U. for Hemby Acres Effluent on April 28,
2020.
Temperature – Standard Methods, 2550 B-2010 (Aqueous)
Recommendation: It is recommended that the laboratory report temperatures in whole numbers.
CC. Finding: The annual temperature-measuring device check procedure is not consistently
performed correctly.
Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref:
15A NCAC 02H .0805 (g) (4).
Requirement: To check a compliance temperature-measuring device, compare readings at
two temperatures that bracket the range of compliance samples routinely analyzed against a
National Institute of Standards and Technology (NIST) traceable temperature-measuring
device and record all four readings. The readings from both devices must agree within 0.5 ºC.
Ref: NC WW/GW LC Approved Procedure for the Analysis of Temperature. Please submit
an updated temperature verification for each applicable compliance temperature-
measuring device bracketing the range of compliance samples analyzed with the
report reply.
Comment: The Saddlewood DO meter, which is used for compliance monitoring purposes,
was verified at a single temperature in 2019, but was correctly verified in 2020. The
verifications were performed by K & W Laboratories (Certificate #559).
Comment: The laboratory verified the temperature measuring device for Bradfield Farms
and Hemby Acres at a single temperature in 2019. The DO meter for Bradfield Farms was
verified by the laboratory at a single temperature in 2020. The Pointe’s temperature
measuring device was verified at a single temperature by K & W Laboratories in 2019 and
2020. The temperature-sensing device check of the Hemby Acres pH meter performed by
K&W Laboratories in 2019 did not bracket the upper range of the compliance sample
Page 15
#5228 Carolina Water Service, Inc. – Charlotte Region
temperatures routinely encountered. The highest temperature checked was 21°C and
routine compliance temperatures in July 2020 exceeded 25°C. The DO meter for Bradfield
Farms, also used for compliance monitoring, was verified by K & W Laboratories at two
temperatures on November 17, 2020, but data from April 28, 2020 shows a temperature of
10.2°C, which is below the lower verified temperature of 13.5°C.
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 Hemby Acres WWTP (NPDES permit # NC0035041), Abington WWTP (NPDES permit
# NC0060461), Queen’s Harbor WWTP (NPDES permit # NC0062383), Bradfield Farms WWTP (NPDES
permit # NC0064734), Riverpointe WWTP (NPDES permit # NC0071242), Saddlewood WWTP (NPDES
permit # NC0060755), The Pointe Well #1 WTP (NPDES permit # NC0086592), The Harbour Well #4
WTP (NPDES permit # NC0086606) for April, September and November 2020. The following errors were
noted:
Date Parameter Location
Value on
Benchsheet
*Contract
Laboratory Data
Value on DMR
11/17/2020 Temperature Abington
Downstream 18.9°C 18.5°C
11/19/2020 pH Abington
Effluent 7.3 S.U. 7.5 S.U.
11/24/2020 pH Abington
Effluent 6.3 S.U. 7.3 S.U.
4/14/2020 pH Queen’s Harbor
Effluent 7 S.U. 7.1 S.U.
11/10/2020
Temperature Queen’s Harbor
Effluent 20.5°C 20.6°C
11/18/2020 Chlorine, Total
Residual
Queen’s Harbor
Effluent <10 µg/L Not Reported
4/30/2020 Temperature RiverPointe
Effluent 26.5°C Not Reported
4/30/2020 Dissolved Oxygen RiverPointe
Effluent 6.4 mg/L Not Reported
4/28/2020 Temperature Hemby Acres
Upstream 15.1°C 15.5°C
4/28/2020 Temperature Hemby Acres
Downstream 15.5°C 15.1°C
4/26/2020 pH Hemby Acres
Effluent 6.7 S.U. Not Reported
11/3/2020 BOD Saddlewood
Effluent 2.1 mg/L* 2 mg/L
11/10/2020 BOD Saddlewood
Effluent <2 mg/L* 2 mg/L
11/19/2020 BOD Saddlewood
Effluent 2.8 mg/L* 2.4 mg/L
11/24/2020 BOD Saddlewood
Effluent 3.3 mg/L* 2.6 mg/L
Page 16
#5228 Carolina Water Service, Inc. – Charlotte Region
4/13/2020 Dissolved Oxygen Bradfield Farms
Effluent 7.54 mg/L 7.51 mg/L
4/28/2020 Temperature Bradfield Farms
Effluent 10.2°C 20.2°C
11/02/2020 Dissolved Oxygen Bradfield Farms
Effluent 7.74 mg/L Not Reported
11/06/2020 Temperature Bradfield Farms
Effluent 19.4°C 19.1°C
11/13/2020 Temperature Bradfield Farms
Effluent 21.9°C 21°C
11/23/2020 Temperature Bradfield Farms
Effluent 19.8°C 19°C
11/23/2020 Dissolved Oxygen Bradfield Farms
Effluent 19.8 mg/L Not Reported
11/24/2020 Dissolved Oxygen Bradfield Farms
Effluent 19.2 mg/L 5.89 mg/L
11/25/2020 Dissolved Oxygen Bradfield Farms
Effluent 20.5 mg/L 6.21 mg/L
11/26/2020 Dissolved Oxygen Bradfield Farms
Effluent 20.6 mg/L 6.21 mg/L
11/27/2020 Dissolved Oxygen Bradfield Farms
Effluent 20.9 mg/L 6.51 mg/L
11/30/2020 Dissolved Oxygen Bradfield Farms
Effluent 19.9 mg/L 5.17 mg/L
To avoid a possible monitoring frequency violation, it is recommended that you contact the appropriate
Regional Office for guidance as to whether an amended DMR(s) will be required. A copy of this report will
be made available to the Regional Office.
To avoid questions of legality, it is recommended that you submit an amended report(s) to your client(s).
A copy of this report will be made available to the Regional Office.
V. CONCLUSIONS:
We are concerned about the number of Findings, transcription errors and apparent lack of QA/QC
oversight. It is strongly recommended that the laboratory institute a practice of periodic internal audits,
and/or review of a certain percentage of the data, for each permitted site in order to ensure a high standard
of quality data and increased legal defensibility.
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: May 10, 2021
Report reviewed by: Tonja Springer Date: May 11, 2021
Certificate Number:5228
Effective Date:1/1/2021
Expiration Date:12/31/2021
Lab Name:Carolina Water Service Inc. - Charlotte Region
Address:7803 Idlewild Rd
Indian Trail, NC 28079
North Carolina Wastewater/Groundwater Laboratory Certification
Certified Parameters Listing
Date of Last Amendment:4/17/2018
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
SM 4500 O G-2011 (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.