#115_2018_0131_TS_FINAL

To be attached to all inspection reports in-house only.
Laboratory Cert. #:
115
Laboratory Name:
Dunn Black River WWTP Lab.
Inspection Type:
Municipal Maintenance
Inspector Name(s):
Tonja Springer, Todd Crawford and Tom Halvosa
Inspection Date:
January 31, 2018
Date Forwarded for Initial
Review:
March 22, 2018
Initial Review by:
Anna Ostendorff
Date Initial Review
Completed:
March 28, 2018
Cover Letter to use:
❑ Insp. Initial
❑Insp. No Finding
❑Corrected
(tO Use: re click, Properties, heck)
❑ Insp. Reg
❑Insp. CP
®Insp. Reg. Delay
Unit Supervisor/Chemist III:
Todd Crawford
Date Received:
April 2, 2018
Date Forwarded to Admin.:
April 10, 2018
Date Mailed:
April 10, 2018
Special Mailing Instructions:

Water Resources
ENVIFONMEN'rAI- QUAL- T'Y
April 10, 2018
115
Ms. Tena Glover
Dunn Black River WWTP Lab
P.O. Box 1065
Dunn, NC 28335
ROY COOPER
MICHEAL S. REGAN
LINDA CULPEPPER
Subject: North Carolina Wastewater/Groundwater Laboratory Certification (NC WW/GW LC)
Maintenance Inspection
Dear Ms. Glover:
Enclosed is a report for the inspection performed on January 31, 2018 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 of receipt, 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 wish to obtain an
electronic copy of this report by email or if you have questions or need additional information, please
contact me at [phone] ext. 251.
Sincerely,
Todd Crawford
Technical Assistance & Compliance Specialist
NC WW/GW Laboratory Certification Branch
Attachment
cc: Dana Satterwhite
Tonja Springer
Water Sciences Section
NC WastewaterlGroundwater Laboratory Certification Branch
1G23 Mail Service Center, Raleigh, North Carolina 27699-1623
Location: 4405 Reedy Creek Road, Raleigh, North Carolina 27607
Phone: [phone] '. FAX [phone]
Internet: http:l/deQ,nc.govfabouVdivis€ons/water•resourceslwater-resources-datalwater-sciences-host_pAagel(aboratorvcertification-branch

LABORATORY NAME: Dunn Black River WWTP Lab
NPDES PERMIT #: NC0043176, NC0078955
WATER QUALITY PERMIT : WQ0006101
ADDRESS: 580 J.W. Edwards Lane
Dunn, NC 28334
CERTIFICATE : 115
DATE OF INSPECTION: January 31, 2018
TYPE OF INSPECTION: Municipal Maintenance
AUDITOR(S): Tonja Springer, Todd Crawford and Tom Halvosa
LOCAL PERSON(S) CONTACTED: Tena Glover, Donrie Dukes and Pam Gibbons
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 2H .0800 for the analysis of environmental samples.
II. GENERAL COMMENTS:
The facility is neat and well organized and has all the equipment necessary to perform the
analyses. Staff were forthcoming and proactive in adopting the necessary changes.
The following permits are under the certification of Dunn Black River WWTP Lab:
Dunn Black River WWTP Lab (NPDES #NC0043176) - Fecal Coliform, Total Residual
Chlorine (TRC), Dissolved Oxygen (DO), Ammonia, pH, Total Suspended Residue
(TSS), Temperature
City of Dunn (Water Quality #WQ0006101) — Vector Attraction Reduction (Option 1:
Reduction in Volatile Solids)
A.B. Uzzle WTP (NPDES #NC0078955) — TRC, Turbidity, TSS, pH
All required Proficiency Testing (PT) Samples for the 2018 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, 2018.
The laboratory submitted their Quality Assurance (QA) and/or Standard Operating Procedures
(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 January 2019.

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#115 Dunn Black River WV TP Lab
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 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 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".
Laboratory Fortified Matrix (LFM) and Laboratory Fortified Matrix Duplicate (LFMD) are also
known as Matrix Spike (MS) and Matrix Spike Duplicate (MSD) and may be used
interchangeably in this report.
Requirements that reference 15A NCAC 2H .0805 (a) (7) (A), stating "All analytical data pertinent
to each certified analysis must be filed in an orderly manner so as to be readily available for
inspection upon request", are intended to be a requirement to document information pertinent to
reconstructing final results and demonstrating method compliance. Use of this requirement is not
intended to imply that existing records are not adequately maintained unless the Finding speaks
directly to that.
Contracted analyses are performed by Environment 1, Inc. (Certification # 10).
Approved Procedure documents for the analysis of the facility's currently certified Field
Parameters were provided at the time of the inspection.
III. FINDINGS REQUIREMENTS COMMENTS AND RECOMMENDATIONS:
Supervisor Requirements
A. Finding: The supervisor does not visit the laboratory once each day of normal operations.
Requirement: All laboratory supervisors are subject to review by the State Laboratory.
One person may serve as supervisor of no more than two laboratories. The supervisor
shall provide personal and direct supervision of the technical personnel and be held
responsible for the proper performance and reporting of all analyses made for these
Rules. The supervisor must work in the laboratory or visit the laboratory once each day
of normal operations. If the supervisor is to be absent, the supervisor shall arrange for a
substitute capable of insuring the proper performance of all laboratory procedures,
however, the substitute supervisor cannot be in charge for more than six consecutive
weeks. Existing laboratory supervisors that do not meet the requirements of this Rule
may be accepted after review by the State Laboratory and meeting all other certification
requirements. Previous laboratory related performance will be considered when
reviewing the qualifications of a potential laboratory supervisor. Ref: 15A NCAC 2H
.0805 (a) (3) (C).
Comment: A.B. Uzzle WTP is not being visited each day of normal operations.

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#115 Dunn Black River WWTP Lab
Documentation
Comment: There were instances where the analyst's handwriting on the Dunn Black River
WWTP Lab data was difficult to read, (e.g., see Paper Trail Investigation section, transcription
errors on September 18 and 22, 2018) which could pose issues with data defensibility and/or
transcription errors.
Recommendation: It is recommended to add a statement to the laboratory equipment
temperature logs that temperatures are recorded with corrections applied. This will ensure all
personnel record measurements in the same manner.
B. Finding: Error corrections are not always properly performed.
Requirement: All documentation errors must 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. Write the correction adjacent
to the error. The correction must be initialed by the responsible individual and the date
of change documented. All data and log entries must be written in indelible ink. Pencil
entries are not acceptable. Ref: NC WW/GW LC Policy.
Comment: This was observed on data reviewed for A.B. Uzzle WTP.
C. Finding: The laboratory needs to increase the traceability documentation of purchased
materials and reagents, as well as documentation of standards and reagents prepared
in the laboratory.
Requirement: All chemicals, reagents, standards and consumables used by the
laboratory must have the following information documented: 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 LC Policy.
Requirement: Supporting records shall be maintained as evidence that these practices
are being effectively carried out. All analytical records must be available for a period of
five years. Ref: 15A NCAC 2H .0805 (a) (7) and (a) (7) (G).
Comment: Following are examples of traceability issues observed. There may be other
instances that were not observed during the inspection.
The receipt log for Dunn Black River WWTP Lab does not always include the
vendor name.
The purchased and pre -made standards log for Dunn Black River WWTP Lab
does not always include the expiration date.
The Chemical — Media Received Log for A.B. Uzzle WTP does not always
include date opened (in use) or the vendor.

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#115 Dunn Black River WWTP Lab
Recommendation: It is recommended that all logs be reviewed for traceability to
ensure all required documentation is included.
D. Finding: The units of measure are not consistently documented on benchsheets.
Requirement: All laboratories must use printed laboratory bench worksheets that include
a space to enter the signature or initials of the analyst, date of analyses, sample
identification, volume of sample analyzed, value from the measurement system, factor and
final value to be reported and each item must be recorded each time samples are
analyzed. Ref: 15A NCAC 2H .0805 (a) (7) (H).
Comment: Following are examples of where units were lacking. There may be other
instances that were not observed during the inspection,
A.B. Uzzle WTP - Units of measure for reported results are not documented on the
pH calibration log (i.e., S.U.), TSS Oven Temperature Logs (i.e., °C), Effluent
Worksheet (i.e., pH - S.U., Total Residual Chlorine - mg/L, Ammonia- mg/L, Total
Suspended Residue - mg/L, Total Nitrogen - mg/L, Total Phosphorus — mg/L,
Manganese - ug/L, Copper — ug/L, Fluoride - ug/L, Aluminum - mg/L.)
A.B. Uzzle WTP - The column header for Turbidity shows the units but does not
identify the parameter. Dunn Black River WWTP Lab — Units of measure are not
documented on the Total Suspended Residue benchsheet for the column header
labeled "difference value" (i.e., mg/L)
Dunn Black River WWTP Lab — Units of measure are not documented on the
Operators Daily Lab Worksheet for the pH calibration buffers and reported
results (i.e., S.U.)
Recommendation: It is recommended that all laboratory benchsheets be reviewed to
ensure all proper units of measure are documented.
E. Finding: The Field Parameter benchsheets were lacking pertinent data: instrument
identification and permit number.
Requirement: All analytical data pertinent to each certified analysis must be filed in an
orderly manner so as to be readily available for inspection upon request. Ref: 15A
NCAC 2H .0805 (a) (7) (A).
Requirement: The following must be documented in indelible ink whenever sample
analysis is performed: Facility name, sample site (ID or location), and permit number;
instrument identification (serial number preferred). Ref: NC WW/GW LC Approved
Procedure for the Analysis of Total Residual Chlorine, NC WW/GW LC Approved
Procedure for the Analysis of Dissolved Oxygen, NC WW/GW LC Approved Procedure
for the Analysis of pH, and NC WW/GW LC Approved Procedure for the Analysis of
Temperature.
Comments: The benchsheets for all permits were missing instrument identification and
associated permit numbers.
F. Finding: The benchsheet was lacking pertinent data: Signature or initials of the analyst.
Requirement: All laboratories must use printed laboratory bench worksheets that
include a space to enter the signature or initials of the analyst, date of analyses, sample

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#115 Dunn Black River WWTP Lab
identification, volume of sample analyzed, value from the measurement system, factor
and final volume to be reported and each item must be recorded each time samples are
analyzed. Ref: 15A NCAC 2H .0805 (a) (7) (H).
Comment: The benchsheet for A.B. Uzzle WTP did not include the signature or initials
of the analyst.
G. Finding: The benchsheet was lacking pertinent data: Method reference.
Requirement: The following must be documented in indelible ink whenever sample
analysis is performed: Method reference. Ref: NC WW/GW LC Approved Procedure for
the Analysis of pH and NC WW/GW LC Approved Procedure for the Analysis of Total
Residual Chlorine.
Comment: The A.B. Uzzle WTP benchsheet did not have method references for pH
(i.e., SM 4500 H+B-2011), Total Residual Chlorine (i.e., SM 4500 Cl G-2011), Total
Suspended Residue (i.e., SM 2540 D-2011) and Turbidity (i.e., SM 2130 B-2011).
Quality Control
Comment: Sample duplicates are not a required quality control element for Field Parameters
(i.e., Conductivity, Dissolved Oxygen, pH, Settleable Residue, Temperature and TRC). The
laboratory is currently analyzing duplicates for pH, DO and TRC samples.
Analysis and Reporting
Comment: The laboratory was analyzing samples and reporting data for Vector Attraction
Reduction (Option 1: Reduction in Volatile Solids) without North Carolina
Wastewater/Groundwater Laboratory Certification. North Carolina Administrative Code, 15A
NCAC 2H .0804 (a) states: Municipal and Industrial Laboratories are required to obtain
certification for parameters which will be reported to the State to comply with State surface water
monitoring, groundwater and pretreatment Rules. The laboratory obtained certification for this
method effective March 20, 2018. No further response is necessary for this Finding.
H. Finding: The laboratory does not report results of all tests on the characteristics of the
effluent when duplicate sample analyses are performed.
Requirement: Municipal and Industrial Laboratories are required to obtain certification for
parameters which will be reported by the client to comply with State surface water
monitoring, groundwater, and pretreatment Rules. Ref: 15A NCAC 2H .0804 (a).
Comment: Dunn Black River WWTP Lab analyzes a duplicate for pH and only the first
value is reported on the DMR.
Proficiency Testing
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, May 31, 2017, Revision 2.0.

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#115 Dunn Black River VWVfP Lab
Comment: The PT sample analyses are documented on the PT vendor report form. This
form is filed and kept for 5 years.
J. Finding: PT Samples have not been distributed among all analysts and instruments
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, May 31, 2017,
Revision 2.0.
Comment: A.B. Uzzle WTP analyzes Turbidity, TRC, pH and Suspended Residue but
PT Samples are only analyzed by the analyst at Dunn Black River WWTP Lab.
K. Finding: The laboratory is not analyzing PT Samples in the same manner as routine
Compliance Samples.
Requirement: As specified in 15 NCAC 2H .0800, in order to meet the minimum
standards for Certification, laboratories must use acceptable analytical methods. The
acceptable methods are those defined or referenced in the current State and federal
regulations for the environmental matrix being tested. All samples, (including PT
Samples) that are, or that may, be used for Certification purposes, must be analyzed
using approved methods only. All PT Samples are to be analyzed and the results
reported in a manner consistent with the routine analysis and reporting requirements of
Compliance Samples. Laboratories must document any exceptions. 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,
May 31, 2017, Revision 2.0.
Comment: The laboratory was analyzing PT Samples multiple times and reporting an
average of all results. Compliance Samples are not analyzed and reported in this
manner.
Bacteria — Coliform Fecal — Standard Methods, 9222 D-1997 (MF) (Aqueous)
L. Finding: Sample bottle sterility is not verified at the required frequency.
Requirement: Minimally test for sterility one sample bottle per batch sterilized in the
laboratory, or at a set percentage such as 1 to 4%. This is performed by adding sterile
dilution/rinse water to the bottle after sterilization and then subsequently analyzing it as
a sample. Document results. If sample bottles or bags are purchased pre -sterilized,
verification of sterilization is not required if the laboratory maintains copies of the
Certificate of Analysis from the vendor. Ref: NC WW/GW LC Policy.
Comment: The laboratory is cleaning one batch of bottles per week but only testing one
bottle per month.
M. Finding: The laboratory is not checking the pH of prepared media agar properly.

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#115 Dunn Black River WWTP Lab
Requirement: Rehydrate product in 1 L water containing 10 mL 1 % rosolic acid in 0.2 N
NaOH. Heat to near boiling, promptly remove the heat, and cool below 50 'C. If agar is
used, dispense 5- to 7-mL quantities to 50 x 12-mm petri plates and let solidify. Final pH
should be 7.4 ± 0.2. Ref: Standard Methods, 9222 D-2006,
Comment: The pH of the solidified agar can be measured using a pH electrode for solid
and semi -solid samples.
N. Finding: Plate comparison counts are not being performed.
Requirement: For routine performance evaluation, repeat counts on one or more
positive samples at least monthly, record results, and compare the counts with those of
other analysts testing the same samples. Replicate counts for the same analyst should
agree within 5% (within analyst repeatability of counting) and those between analysts
should agree within 10% (between analysts reproducibility of counting). If they do not
agree, initiate investigation and any necessary corrective action. Ref: Standard
Methods, 9020 B-2005. (9) (a).
Comment: The following procedure will meet this requirement. The primary analyst will
recount one plate monthly and compare the two values and any auxiliary analysts will
count the same plate twice comparing the two values and compare the values with the
main analyst. If any comparisons do not agree with the established criteria, retraining may
be necessary. All counts must be documented.
Comment: Plates are read one time by a single analyst.
O. Finding: The laboratory is not monitoring the quality of the reagent water.
Requirement: At a minimum, reagent water used to prepare buffered dilution/rinse water
or media must be analyzed at least every twelve months for the following parameters:
Specific Conductance, Total Organic Carbon, Cadmium, Chromium, Copper, Nickel, Lead,
and Zinc.
Maximum Acceptable Limits are:
Total Organic Carbon < 1.0 mg/L
Specific Conductance < 2 pmhos/cm
Heavy Metals, single element < 0.05 mg/L
Heavy Metals, Total of cited elements < 0.10 mg/L
If the facility is using vendor purchased dilution/rinse water this testing is not required as
long as the Certificate of Analysis from the manufacturer meets these requirements and is
kept on file. Ref: NC WW/GW LC Policy.
Nitrogen, Ammonia — Standard Methods, 4500 NH3 D-2011 (Aqueous)
Recommendation: It is recommended to add preservative to the second source standard so that
it also satisfies the Laboratory Fortified Blank (LFB) requirement.
P. Finding: The laboratory does not document the pH of samples upon receipt to verify
preservation.

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#115 Dunn Black River WWTP Lab
Requirement: A record of date collected, time collected, sample collector, and use of
proper preservatives must be maintained. Each sample must clearly indicate the State
of North Carolina collection site on all record transcriptions. Ref: 15 NCAC 2H .0805 (a)
(7) (M)•
Requirement: Basic documentation requirements to verify that sample preservation and
hold time requirements are met include: Preservation status; temperature and chemical
preservative(s) used (i.e., name of preservative, pH<2, pH>9, etc., where pH is not
adequately adjusted document the measured pH). Ref: NC WW/GW LC Policy.
Q. Finding: The laboratory is not documenting that the sample pH was adjusted to >11
S.U. during analysis. This is considered pertinent data.
Requirement: All analytical data pertinent to each certified analysis must be filed in an
orderly manner so as to be readily available for inspection upon request. Ref: North
Carolina Administrative Code, 15A NCAC 2H .0805 (a) (7) (A).
Requirement: Add a sufficient volume of 10N NaOH solution (1 mL usually is sufficient)
to raise pH above 11. Ref: Standard Methods, 4500 NH3 D-2011. (4) (e) and (4) (b).
Comment: The pH of the sample is displayed along with the Ammonia concentration and
the analyst visually confirms it is greater than 11 S.U., but the pH is not documented.
R. Finding: The laboratory is not analyzing a Method Blank (MB).
Requirement: Include at least one MB daily or with each batch of 20 or fewer samples,
whichever is more frequent. Ref: Standard Methods, 4020 B-2011. (2) (d) and Table
4020:1.
Requirement: A reagent blank (method blank) consists of reagent water (see Section
1080) and all reagents (including preservatives) that are normally in contact with a
sample during the entire analytical procedure. Ref: Standard Methods, 1020 B-2011.
(5).
S. Finding: The laboratory is not analyzing an LFM/LFMD at the required frequency.
Requirement: When appropriate for the analyte (Table 4020:1), include at least one
LFM/LFMD daily or with each batch of 20 or fewer samples. To prepare an LFM, add a
known concentration of analytes (ideally from a second source) to a randomly selected
routine sample without increasing its volume by more than 5%. Ref: Standard Methods,
4020 B-2011, Table 4020:1 and (2) (g).
Comment: An LFM/LFMD is analyzed once per month. The monitoring frequency is 5
times per week.
T. Finding: The laboratory is not adjusting the sample concentration in the percent recovery
calculation when the spike volume is >1% of the total sample volume.
Requirement: The volume of spike solution used in MS preparation must in all cases be
<- 5% of the total MS volume. It is preferable that the spike solution constitutes s 1 % of
the total MS volume so that the MS can be considered a whole volume sample with no
adjustment (i.e., volume correction) by calculation necessary. If the spike solution

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#115 Dunn Black River WVVfP Lab
volume constitutes >1 % of the total sample volume, the sample concentration must be
adjusted by calculation. Ref: NC WW/GW LC Policy.
Comment: The laboratory was using 10% spike solution per total volume to prepare the
LFM/LFMD.
U. Finding: A calibration blank and calibration verification standard (mid -range) are not
analyzed at the end of the sample group.
Requirement: The calibration blank and calibration verification standard (mid -range)
must be analyzed initially (i.e., prior to sample analysis), after every tenth sample and at
the end of each sample group to check for carry over and calibration drift. If either fall
outside established quality control acceptance criteria, corrective action must be taken
(e.g., repeating sample determinations since the last acceptable calibration verification,
repeating the initial calibration, etc.). Ref: NC WW/GW LC Policy.
Turbidity — Standard Methods, 2130 B-2011 (Aqueous)
V. Finding: Duplicate analyses are not performed.
Requirement: Analyze five percent of all samples in duplicate to document precision.
Laboratories analyzing less than 20 samples per month must analyze at least one
duplicate each month samples are analyzed. Ref: 15A NCAC 2H .0805 (a) (7) (C).
W. Finding: The volume of sample analyzed is not documented on the benchsheet.
Requirement: All laboratories must use printed laboratory bench worksheets that
include a space to enter the signature or initials of the analyst, date of analyses, sample
identification, volume of sample analyzed, value from the measurement system, factor
and final value to be reported and each item must be recorded each time samples are
analyzed. The date and time BOD and coliform samples are removed from the incubator
must be included on the laboratory worksheet. Ref: 15A NCAC 2H .0805 (a) (7) (H).
Residue, Suspended — Standard Methods, 2540 D-2011 (Aqueous)
X. Finding: The laboratory is not analyzing a volume of sample to yield a minimum of 2.5
mg dried residue.
Requirement: Choose sample volume to yield between 2.5 and 200 mg dried residue.
If volume filtered fails to meet minimum yield, increase sample volume up to 1 L. Ref:
Standard Methods, 2540 D-1997 (3) (b).
Comment: Dunn Black River WWTP Lab always filters 500 mL. The minimum required
residue weight gain was not achieved for any sample in the data reviewed.
Comment: A.B. Uzzle WTP always filters 100 mL. The minimum required residue
weight gain was not achieved for any sample in the data reviewed.
Comment: The range of measurement for Suspended Residue is determined by the
optimum solids loading on the filter, which can be controlled by adjusting the volume of
sample filtered. The method -defined reporting limit for Suspended Residue is 2.5 mg/L
when filtering 1 L of sample. This sample volume may not be necessary to demonstrate
compliance with regulatory limits; however, it is not acceptable to routinely report less-

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#115 Dunn Black River WVVfP Lab
than results using a reporting limit greater than 2.5 mg/L. A copy of this report will be
shared with the regional office.
Recommendation: It is recommended the laboratories increase the sample volume to
the maximum allowed volume of 1 L.
Y. Finding: Neither facility is basing the reporting limit on the minimum weight gain
required by the method.
Requirement: The minimum weight gain allowed by any approved method is 2.5 mg.
Choose sample volume to yield between 2.5 and 200 mg dried residue. This establishes
a minimum reporting value of 2.5 mg/L when 1000 mL of sample is analyzed. If
complete filtration takes more than 10 minutes increase filter diameter or decrease
sample volume. In instances where the weight gain is less than the required 2.5 mg, the
value must be reported as less than the appropriate value based upon the volume used.
Ref: NC WW/GW LC Policy.
Comment: On September 7, 2017 and on December 7, 2017, samples analyzed by
Dunn Black River WWTP Lab yielded a residue weight below 2.5 mg (i.e., 1.3 mg in
each case) and the results were reported as 2.6 mg/L. Since the laboratory only
analyzed 500 ml of sample, the reporting limit would have been 5.0 mg/L; therefore, the
results should have been reported as <5.0 mg/L.
Z. Finding: Influent samples are not weighed to constant weight, nor is an annual drying
study to verify the adequacy of the drying time, performed for Dunn Black River WWTP
Lab.
Requirement: Constant weights must be documented. The approved methods require
the following: "Repeat the cycle of drying, cooling, desiccating, and weighing until a
constant weight is obtained or until the weight change is less than 4% of the previous
weight or 0.5 mg, whichever is less." In lieu of this, an annual study documenting the
time required to dry representative samples to a constant weight may be performed.
Verify minimum daily drying time is greater than or equal to the time used for the initial
verification study drying cycle. Drying cycles must be a minimum 1 hour for verification.
Ref: NC WW/GW LC Policy.
Temperature —Standard Methods, 2550 B-2010(Aqueous)
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 Precision in Discharge Monitoring Reports document found
here: http://portal.ncdenr.or /c/document librar /giet file?uuid=1407b370-e848-4550-9f4b-
21 a2f05b95e4&groupld=38364
Chlorine, Total Residual — Standard Methods, 4500 Cl G-2011 (Aqueous)
AA. Finding: The laboratory did not verify the instrument's factory -set calibration curve prior
to initial use and every 12 months thereafter.
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 Reagent Blank and a series of five standards (do not use gel or sealed liquid

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#115 Dunn Black River VWVfP Lab
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 pg/L and must not vary by more than 25% from the known value for standard
concentrations less than 50 pg/L. Ref: NC WW/GW LC Approved Procedure for the
Analysis of Total Residual Chlorine.
Comment: The lab did not have any documentation to. show that the instrument's
factory -set calibration curve had ever been verified. This Finding applies only to A.B.
Uzzle WTP.
BB. Finding: The Factory -set Calibration Curve is not verified with a Daily Check Standard
each day that samples are analyzed.
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. If the obtained value is outside of the ±10% range, corrective
action must be taken. Ref: NC WW/GW LC Approved Procedure for the Analysis of
Total Residual Chlorine.
Comment: The lab did not have any documentation to show that a daily check
standard was being analyzed each analysis day. This Finding applies only to A.B. Uzzle
WTP.
Dissolved Oxygen — Standard Methods, 4500 O G-201 1 (Aqueous)
Temperature —Standard Methods, 2550 B-2010 (Aqueous)
CC. Finding: Only one time for sample collection and analysis was documented without noting
samples are analyzed in situ.
Requirement: 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). Ref: NC WW/GW LC Approved Procedure for the Analysis of Temperature.
Comment: When this `one time' option is used, state that the documented time is both
collection and analysis time.
Comment: On the benchsheet for Dunn Black River WWTP Lab only "time" is
documented.
pH — Standard Methods, 4500 H+ B-2011 (Aqueous)
DD. 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: This was observed on the data reviewed for Dunn Black River WWTP Lab.

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#115 Dunn Black River VVVVTP Lab
EE. Finding: The measured values for compliance samples are not bracketed with calibration
and check standard buffers.
Requirement: Instrument calibration: In each case follow manufacturer's instructions
for pH meter -and for storage and preparation of electrodes in use. Ref: Standard
Methods, 4500 H+ B-2011. (4) (a).
Requirement: Instruments are to be calibrated according to the manufacturer's
calibration procedure prior to analysis of samples each day compliance monitoring is
performed. Calibration must include at least two buffers. The meter calibration must be
verified with a third standard buffer solution (i.e., check buffer) prior to sample analysis.
The calibration and check standard buffers must bracket the range of the samples being
analyzed. Ref: NC WW/GW LC Approved Procedure for the Analysis of pH.
Comment: The meter is calibrated with the 4.0 and 7.0 S.U. buffers and then the 4.0
and 7.0 S.U. buffers are read back as check standard buffers. Some of the compliance
samples have pH results that are above the 7.0 S.U. buffer.
Comment: This was observed on the pH calibration log for A.B. Uzzle WTP.
IV. PAPER TRAIL INVESTIGATION:
The paper trail consisted of comparing original records (e.g., laboratory benchsheets, logbooks,
etc.) and contract lab reports to electronic Discharge Monitoring Reports (eDMRs) submitted to
the North Carolina Division of Water Resources. Data were reviewed for Dunn Black River
WWTP Lab (NPDES permit # NC0043176) for July, September and December 2017. The
following errors were noted:
Value on Benchsheet
Date
Parameter
Location
Value on eDMR
*Contract Lab
9/12/2017
Mercury
Effluent
*0.953 ng/L
Reported on wrong
date; 9/11/2017
9/18/2017
Dissolved
Oxygen
Effluent
5.98 mg/L
5.93 mg/L
9/22/2017
Dissolved
Oxygen
Effluent
7.09 mg/L
7.04 mg/L
Total Nitrogen
*TKN + Nitrate/Nitrite =
*0.97
12/5/2017
(TN)
Effluent
+ 0.64 = 1.61
1.29 mg/L
mg/L
The TN is being calculated by adding the contract lab results for Ammonia (0.32 mg/L) + TKN
(0.97 mg/L) instead of adding the TKN (0.97 mg/L) + Nitrate/Nitrite Nitrogen (0.64 mg/L) results.
To avoid questions of legality, it is recommended that you contact the appropriate Regional
Office for guidance as to whether amended eDMRs will be required. A copy of this report will
be made available to the Regional Office.

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#115 Dunn Black River WWTP Lab
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: Tonja Springer Date: March 20, 2018
Report reviewed by: Anna Ostendorff Date: March 28, 2018

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