#179_2016_0901_TS_FINAL

INSPECTION REPORT ROUTING SHEET
To be attached to all inspection reports in-house only.
Laboratory Cert. #: 179
Laboratory Name: City of Reidsville WWTP Laboratory
Inspection Type: Municipal Maintenance
Inspector
Name(s):
Tonia Springer,
Dana Satterwhite,
Gary Francies, and Todd Crawford
Inspection
Date:
August 9,
2016 and September 1,
2016
Date Report Completed:
Date Forwarded to Reviewer:
Reviewed by:
Date Review Completed:
Cover Letter to use:
Unit Supervisor/Chemist III:
Date Received:
Date Forwarded to Admin:
Date Mailed:
Special Mailing Instructions:
October 13, 2016
October 14, 2016
Beth Swanson
October 27, 2016
❑ Insp. Initial ❑ Insp. Reg.
❑ Insp. No Finding ❑ Insp. CP
❑ Corrected ® Insp. Reg. Delay
Todd Crawford
October 27, 2016
November 17, 2016
November 18, 2016

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Water Resources
ENVIRONMENTAL QUALJTY
November 18, 2016
179
Ms. Mitzy W. Fain
City of Reidsville WWTP Laboratory
407 Broad Street
Reidsville, NC 27320
PAT MCCRORY
DONALD R. VAN DER VAART
S. JAY ZIMMERMAN
Subject: North Carolina Wastewater/Groundwater Laboratory Certification (NC WW/GW LC)
Maintenance Inspection
Dear Ms. Fain:
Enclosed is a report for the inspection performed on August 9 and September 1, 2016 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.
Copies of the checklists completed during the inspection may be requested from this office. Thank you
for your cooperation during the inspection. Ifyouwish 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 Todd Crawford
Technical Assistance & Compliance Specialist
NC WW/GW Laboratory Certification Branch
Attachment
cc: Dana Satterwhite, Tonja Springer, Master File #179

LABORATORY NAME:
ADDRESS:
NPDES PERMIT #:
CERTIFICATE #:
DATE OF INSPECTION:
TYPE OF INSPECTION:
AUDITOR(S):
LOCAL PERSON(S) CONTACTED:
INTRODUCTION:
• • X ' • •
City of Reidsville WWTP Laboratory
407 Broad Street
Reidsville, NC 27320
NCO024881
179
August 9, 2016 and September 1, 2016
Municipal Maintenance
Tonja Springer, Todd Crawford, Gary Francies and Dana
Satterwhite
Mitzy Fain and Patrick McDonald
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. Benchsheets are well designed, easy to follow and concise. Records are well
organized and easy to retrieve. Staff was forthcoming and proactive to adopt necessary changes.
All required Proficiency Testing (PT) samples have been analyzed and the laboratory has fulfilled
its PT requirements for the 2016 PT calendar year.
Contracted analyses are performed by Meritech, Inc. (Certification # 165).
Current Approved Procedure documents for the analysis of the facility's currently certified Field
Parameter methods were provided at the time of the inspection.
The laboratory submitted their Quality Assurance (QA) and/or Standard Operating Procedures
(SOP) document(s) in advance of the inspection. Inspector's notes were sent via email. All the
SOPs will need to be revised. Although subsequent revisions were not requested to be
submitted, they must be completed by September 12, 2017.
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.

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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.
III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS:
Documentation
Recommendation: It is recommended to add a statement to the temperature logs that
temperatures are recorded with corrections applied.
Recommendation: It is recommended to document the calculation equation for Total Nitrogen on
the benchsheet and/or in the SOP/QAM.
Recommendation: It is recommended to document the conversion of psi to kPa on the autoclave
log and/or method required range in psi to show that Total Phosphorus method requirements,
which are in kPa, are being met.
Comment: Some temperature logs did not include thermometer identification. This is considered
supporting information to provide linkage to the annual NIST thermometer calibrations. The logs
include: the fecal coliform incubator Precision Scientific, Isotemp 6903 drying oven, True Bend
sample refrigerator and Fisherbrand Isotemp 3720 BOD incubator temperature daily log to. This is
considered pertinent information. North Carolina Administrative Code, 15A NCAC 2H .0805 (a) (7)
states: Each laboratory shall develop and maintain a document outlining the analytical quality
control practices used for the parameters included in their certification. Supporting records shall be
maintained as evidence that these practices are being effectively carried out. Acceptable corrective
action (i.e., updated temperature logs with thermometer serial numbers and identification which is
linked to the annual NIST thermometer verification calibration log) was performed by the laboratory
and approved by the auditor on September 1, 2016 during the second day of the inspection. No
further response is necessary for this Finding.
Comment: All units of measure were not included on the following logs and benchsheets: TSS
benchsheet, Total Phosphorus benchsheet, Precision Scientific fecal coliform incubator log,
Isotemp 6903 drying oven log, True Bend sample refrigerator log and Fisherbrand Isotemp 3720
BOD incubator log. This may not be a comprehensive list of locations of missing units of measure.
The laboratory needs to thoroughly review all benchsheets and logs to ensure compliance with this
requirement. North Carolina Administrative Code, 15 NCAC 2H .0805 (a) (7) (H), states: 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. Acceptable corrective action (i.e.,
updated logs and benchsheets with units added) was performed by the laboratory and approved

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by the auditor on September 1, 2016 during the second day of the inspection. No further
response is necessary for this Finding.
A. Finding: The laboratory needs to increase the documentation of purchased materials,
consumable 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.
Comment: The following are examples of traceability issues observed. This list may not
be all inclusive.
® Date put in use, and occasionally the date prepared is not documented in the
standards and reagent log.
® Suspended Residue filter traceability information is not documented in a way to
provide linkage between the filters and the samples analyzed. Documenting lot
numbers on benchsheet would satisfy this requirement.
® Traceability is needed (e.g. date prepared or assign unique identifier) for
standards and QC on benchsheets to link them to the standard prep log for
Nitrite Nitrogen.
® Traceability is needed on the stock standardization, FAS standardization and
KMN04standardization worksheets for Nitrite Nitrogen.
® Traceability is needed (e.g. date prepared or assign unique identifier) for
standards, spikes and QC on benchsheet to link them to the standard prep log
for Total Phosphorus.
® The prep instruction for the Nitrite stock standard A concentration was incorrectly
documented as 100 mg/L instead of 250 mg/L on the Nitrite Nitrogen Standard
Concentrations sheet. It is documented correctly in the reagents section of the
SOP.
® Preparation of the 718 /imhos and 147 /imhos calibration standards is not
documented in the standards prep log for Conductivity.
Bacteria — Coliform Fecal — Standard Methods, 9222 D-1997 (MF) (Aqueous)
Comment: Sample bottle sterility was not verified. NC WW/GW LC Policy states: Minimally test
for sterility one sample bottle per batch sterilized in the laboratory, or at a set percentage such

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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. Notification of
acceptable corrective action (i.e. documentation of the sterility check on fecal sample bottles with a
statement, "the sterility check is performed on 1 fecal bottle per batch after sterilization of a batch of
fecal collection bottles is complete and documented", with an implementation date of September 1,
2016) was received by email on September 12, 2016 and November 8, 2016. No further
response is necessary for this Finding.
Comment: The incubator temperature is checked periodically throughout the day but only
documented in the morning. Standard Methods, 9020 B-2005. (4) (n) states: When incubator is in
use, monitor and record calibration -corrected temperature twice daily. Notification of acceptable
corrective action (i.e., a statement that the incubator temperature is now checked and documented
for the morning and afternoon with an implementation date of September 1, 2016) was received by
email on September 8, 2016. No further response is necessary for this Finding.
Comment: A culture positive plate was not analyzed weekly with each batch of purchased ready -
to -use media. NC WW/GW LC Policy states: A culture positive must be analyzed with each batch
of prepared media and once per week for purchased ready -to -use media. A sample volume that
yields a countable plate must be analyzed so that individual colonies may be verified to have
proper morphology (i.e., color, shape, size, surface appearance). Notification of acceptable
corrective action (i.e., a statement that a culture positive is now being analyzed weekly with an
implementation date of September 13, 2016) was received by email on September 21, 2016. No
further response is necessary for this Finding.
Comment: The laboratory is not documenting their use of heat indication tape. This is considered
pertinent information. Heat indicating tape used with all materials each sterilizing cycle is
documented on the bottles of dilution water and fecal collection bottles but it is not documented on
the autoclave log. North Carolina Administrative Code, 15A NCAC 2H .0805 (a) (7) (A) states: 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. 15A NCAC 2H .0805 (a) (7) states: Each laboratory
shall develop and maintain a document outlining the analytical quality control practices used for the
parameters included in their certification. Supporting records shall be maintained as evidence that
these_ practices are being effectively carried out. Notification of acceptable corrective action (i.e.,
a statement that heat indicating tape is used and being documented on the autoclave log for
fecal bottle sterilization with an implementation date of August 18, 2016) was received by email
on September 8, 2016. No further response is necessary for this Finding.
Comment: The time that the sample is filtered was not recorded on the benchsheet to show that
no more than 30 minutes passed before filters were placed into the incubator. North Carolina
Administrative Code, 15A NCAC 2H .0805 (a) (7) (A) states: 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. This is considered pertinent information. Notification of acceptable corrective
action (i.e. the benchsheet was updated to include analysis start time and time in the incubator
with an implementation date of September 1, 2016) was received by mail on September 12,
2016. No further response is necessary for this Finding.
Comment: Consumable materials used for the Fecal Coliform MF method are not properly tested
and no acceptance criteria has been established. Consumable testing was being conducted using
three positive samples. NC WW/GW LC policy states: When a new lot of culture medium, pads,
or membrane filters is to be used, a comparison of the current lot in use (reference lot) against the
new lot (test lot), be made. As a minimum, make single analyses on five positive samples. The
acceptance criterion outlined in SM 9020 B.5. (k) (2), (i) (2) and Q) — 2005 may be used or, per

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the NC WW/GW Policy, it is acceptable to use your current acceptance criteria for fecal
duplicates. Acceptable corrective action (i.e., documentation of a consumable test with five positive
samples and acceptance criterion with a statement that the fecal coliform consumable testing is
performed with each new lot # of media and filters and that the practice will be continued going
forward with an implementation date of August 18, 2016) was performed by the laboratory and
approved by the auditor on September 1, 2016 during the second day of the inspection. No further
response is necessary for this Finding.
Comment: At the time of the inspection, we were unable to determine if the thermometer in the
fecal water bath was properly immersed. There was no paperwork available and the markings on
the thermometer were corroded so badly that it was difficult to determine if there was an immersion
line. User -Friendly Guidance on the Replacement of Mercury Thermometers,
baps://www.e a.gov/sites/production/file/2015-10/documents/nistuei riendly uide. document
states: Thermometers with no indicated depth are the total immersion type. When a partial -
immersion thermometer is used, the bottom of the thermometer up to the immersion line should
be exposed to the temperature being measured, with the remainder of the thermometer
exposed to ambient conditions. When a total immersion thermometer is used, the bulb and the
entire portion of the stem containing liquid, except for the last 1 cm, are exposed to the
temperature being measured. If the thermometer is not used in this manner, the thermometer
immersion is incorrect. Acceptable corrective action (i.e., a partial immersion thermometer was
purchased and is being used properly with an implementation date of August 30, 2016) was
performed by the laboratory and approved by the auditor on September 1, 2016 during the second
day of the inspection. No further response is necessary for this Finding.
Comment: The autoclave log did not include start and end time and the items being sterilized.
Standard Methods 9020 B-2005. (4) (h) states: Record items sterilized and sterilization
temperature along with total run-time (exposure to heat), actual time period at sterilization
temperature, set and actual pressure readings, and initials of responsible person for each cycle.
Acceptable corrective action (i.e., an updated log that includes space to document start and end
time and contents with an implementation date of September 2, 2016) was performed by the
laboratory and approved by the auditor on September 1, 2016 during the second day of the
inspection. No further response is necessary for this Finding.
B. Finding: Plate comparison counts are not being conducted.
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).
C. Finding: The laboratory is not monitoring the quality of the reagent water used in fecal
coliform analysis.
Requirement: Fecal coliform reagent water must be analyzed every twelve months to
ensure suitability. At a minimum, analyses must be performed for conductivity, TOC, Cd,
Cr, Cu, Pb, and Zn. Maximum Acceptable Limits are: Specific Conductance = < 2
pmhos/cm, TOC = < 1.0 mg/L, Heavy Metals, single element = < 0.05 mg/L and Heavy
Metals, Total of cited elements = < 0.10 mg/L. If these limits are not met, investigate and
correct or change water source. Ref: NC WW/GW LC Policy and Standard Methods 9020
B-2005. (5) (f).

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BOD —Standard Methods, 5210 B-2001 (Aqueous)
CBOD — Standard Methods, 5210 B-2001 (Aqueous)
Comment: A matrix spike is being analyzed. A spike is not required for this method.
Comment: BOD samples are analyzed for pretreatment only. CBOD are analyzed on the facility's
effluent.
Comment: Samples coming out of the refrigerator are being heated prior to analysis in the 104 °C
oven. This may adversely affect samples and is not recommended.
Recommendation: It is recommended to add a blanket statement to the benchsheet that all
samples except the blank and influent are seeded.
Recommendation: It is recommended that the method reference for preparation of the nutrients
not include the Standard Method edition number. The reagent prep log currently references SM
19th Ed. 5210 B-2001. The approval year is correct, but the 19th Edition reference is incorrect. All
the nutrients recipes are correct.
Recommendation: It is recommended that the benchsheet clearly label samples for either BOD
or CBOD. The benchsheet is labelled as BOD but includes samples for both BOD and CBOD.
Recommendation: Drift checks are performed initially, in the middle of the run and at the end.
They are documented on one line at the bottom of the benchsheet and it cannot be determined
when in the run the middle drift check is performed. It is recommended to clarify on the benchsheet
when the middle drift check is performed. This can be done by adding a note or by adding the drift
checks in the run log with the other samples instead of putting this information at the bottom of the
benchsheet.
D. Finding: Initial DOs are not always measured within 30 minutes of preparing dilutions.
Requirement: After preparing dilution, measure initial DO within 30 min. Ref: Standard
Methods, 5210 B-2001. (5) (g).
E. Finding: The dilution water blank acceptance criterion is incorrect.
Requirement: The DO uptake in 5 d must not be more than 0.20 mg/L and preferably
not more than 0.10 mg/L, before making seed corrections. Ref: Standard Methods,
5210 B-2001. (6) (c).
Comment: Blanks are documented to one decimal place (i.e., 0.2 mg/L) therefore it
cannot always be determined if it is within the 0.20 mg/L acceptance range. An
acceptance criterion of 0.2 mg/L is being used. Blanks need to documented to two
decimal places.
Nitrogen, NO3+NO2
F. Finding: Results are being reported for NO3+NO2 as N by adding NO3 results obtained
by EPA 352.1, 1971 and NO2 results obtained by SM 4500 NO2 B-2000. The
combination of results by these two methods is not an EPA approved method for
reporting NO3+NO2 as N.

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Requirement: Ref: Code of Federal Regulations, Title 40, Part 136; Federal Register
Vol. 77, No. 97, May 18, 2012. Table IB.
Comment: The laboratory is not certified for the combined method NO3+NO2 as N.
Comment: The laboratories NPDES permit has expired and is in the process of being
reviewed. The permit states to report results by Nitrate plus Nitrate Total (as N).
Recommendation: It is recommended that the laboratory contact the regional office to
ask if the laboratory can report NO2 and NO3 individually on the DMR rather than
reporting the combination (NO2 + NOs) as stated on the permit.
Nitrogen, Nitrite — Standard Methods, 4500-NO2- B-2000 (Aqueous)
G. Finding: A method blank is not filtered when samples are filtered due to the presence of
turbidity.
Requirement: A reagent blank (method blank) consists of reagent water (see Section
1080) and all reagents (including preservatives) that normally are in contact with a sample
during the entire analytical procedure. Ref: Standard Methods, 1020 B-2011. (5).
Phosphorus, Total — Standard Methods, 4500 P E-1999 (Aqueous)
Nitrogen, Nitrite — Standard Methods, 4500-NO2- B-2000 (Aqueous)
H. Finding: Calibration standards are not back calculated.
Requirement: Back calculate the concentration of each calibration point. The back -
calculated and true concentrations should agree within ± 10%. Ref: Standard Methods,
4020 B-2009. (2) (a).
Comment: Acceptance criteria will need to be established. The method says they should
agree within ±10%, however, a wider acceptance range may be needed for the lowest
concentration standard. Be aware that the acceptance criteria need to be set at values
where it won't weaken confidence in the data.
Finding: Quantitation at 1 to 2 times the Method Reporting Limit (MRL) was not verified
initially and at least quarterly thereafter.
Requirement: Verify quantitation at the MRL initially and at least quarterly (preferably
daily) by analyzing a QC sample (subjected to all sample -preparation steps) spiked at
level 1 to 2 times the MRL. A successful verification meets the method's or laboratory's
accuracy requirements at the MRL. Laboratories must define acceptance criteria for the
operational range — including the MRL — in their QA documentation. Ref: Standard
Methods, 4020 B-2009. (1) (c).
J. Finding: A calibration blank is not analyzed initially.
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.

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Phosphorus, Total — Standard Methods, 4500 P E-1999 (Aqueous)
Nitrogen, Nitrate — EPA 352.1, 1971 (Aqueous)
Comment: The scale on both axes of the graph for the calibration curve is not uniform. The scale
shows one block between 0 and 0.1. The scale then shows two blocks for each 0.1 increment
beyond that. However, the reported data does not appear to be affected since the portion of the
scale that is off is below the reporting limit (i.e., 0.1 mg/L).
Recommendation: It is recommended to use Excel or calculated linear regression instead of
graph paper for improved accuracy.
Nitrogen, Nitrate — EPA 352.1, 1971 (Aqueous)
K. Finding: Matrix spike recoveries are not properly calculated.
Requirement: If the spike solution volume constitutes >1% of the total sample volume,
the sample concentration or spike concentration must be adjusted by calculation. Ref:
North Carolina Wastewater/Groundwater Laboratory Certification Matrix Spiking Policy
and Technical Assistance document.
Comment: The dilution was not factored in the calculated spike recovery. 1.0 mL of 10
mg/L N08 standard is added to 20 mL of the effluent sample for a total volume of 21 mL,
which means the spike solution volume was 5% of the total spiked sample volume. See
option 2 in the Matrix Spiking Policy and Technical Assistance document attached to the
end this report for further guidance.
Phosphorus, Total — Standard Methods, 4500 P E-1999
Recommendation: The laboratory is using 155 mLs of concentrated H2SO4 to prepare Sulfuric
Acid Digestion Solution instead of 150 mL as prescribed by the currently approved method. It is
unlikely that this negligible difference will affect the results. Despite this, we recommend the
laboratory start using 150 mLs of H2SO4 concentrated as stated in the method.
Comment: An improper reagent was used to prepare the Antimony Potassium Tartrate solution.
A trihydrate form of Antimony Potassium Tartrate (i.e., C8H4K2O12Sb2 ® 31-12O) is being used to
make the Antimony Potassium Tartrate solution instead of the form prescribed by the method (i.e.,
K(SbO)C4H4O8 e Y2 H2O). Standard Methods, 4500 P-E -1999. (3) (b) states: Dissolve 1.3715 g
K(SbO)C4n4O6 e Y2 H2O in 400 mL distilled water in a 500-mL volumetric flask and dilute to volume.
Notification of acceptable corrective action (i.e., a statement that a correct form of Antimony
Potassium Tartrate has been put into use August 11, 2016) was received by email on September
1, 2016. No further response is necessary for this Finding.
Comment: The spectrophotometer was zeroed using a digested blank. Standard Methods, 4500-P
E-1999 (5) (c) states: Use a distilled water blank with the combined reagents to make photometric
readings for the calibration curve. Standard Methods, 4500-P E-1999. (4) (a) states: After at least
10 min. but no more than 30 min. measure absorbance of each sample at 880 nm, using regent
blank as the reference solution. Notification of acceptable corrective action (i.e., updated
benchsheet that included a statement, "zero spec. with Cal. Blank made with DI water and
combined reagents added" with an implementation date of August 23, 2016) was received by email
on October 5, 2016. No further response is necessary for this Finding.
Comment: The Method Blank (digested), which the laboratory was calling a digested blank
standard, was not evaluated against the required acceptance criteria. Standard Method, 4020 B-
2009. (2) (d) states: Include at least one MB daily or with each batch of 20 or fewer sample,

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whichever is more frequent. Any constituent(s) recovered must generally be less than or equal to
one-half the reporting level (unless the method specifies otherwise). This may include re -analyzing
the sample batch. North Carolina Wastewater/Groundwater Laboratory Certification Policy
states: The concentration of Method Blanks (MB) and Continuing Calibration Blanks (CCB)
must not exceed 50% of the reporting limit standard concentration. Notification of acceptable
corrective action (i.e., updated benchsheet that includes analysis of a Method Blank with an
acceptance criterion of <_ % PQL with an implementation date of November 15, 2016) was
received by email on November 15, 2016. No further response is necessary for this Finding.
Comment: The benchsheet references the incorrect method code. North Carolina Administrative
Code 15A NCAC 2H .0805 (a) (1) states: Laboratory Procedures. Analytical methods, sample
preservation, sample containers and sample holding times shall conform to those requirements
found in 40 CFR-136.3... The benchsheet referenced Standard Methods, 4500-P E-1997.
Acceptable corrective action (i.e., updated benchsheet with the correct method code, Standard
Methods 4500-P E-1999, with an implementation date of August 23, 2016) was performed by the
laboratory and approved by the auditor on September 1, 2016 during the second day of the
inspection. No further response is necessary for this Finding.
L. Finding: Phenolphthalein is not added prior to digestion to determine if sample pH
adjustment is needed.
Requirement: Add 0.05 mL (1 drop) phenolphthalein indicator solution. If a red color
develops add H2SO4 solution dropwise to just discharge the color. Then add 1 mL H2SO4
solution and either 0.4 g solid (NH4)252O8 or 0.5 g solid K2S2O8. Ref: Standard Methods,
4500-P B -1999. (5) (c).
Comment: 1 mL of digestion acid solution is being added to all samples, blanks and
standards and then 0.4 g of solid ammonium peroxydisulfate is added to each bottle prior to
digestion but the initial pH check with phenolphthalein and adjustment is not performed.
M. Finding: The laboratory is using 10N (equivalent to 10M) NaOH during the persulfate
digestion.
Requirement: Sodium hydroxide, NaOH, 1N. Ref: Standard Methods, 4500-P B-1999. (5)
(c).
N. Finding: The laboratory is adding 0.5 grams of ammonia persulfate prior to digestion.
Requirement: Then add 1 mL H2SO4 solution and either 0.4 q solid (NH4)252O8 or 0.5 g
solid K2S2O8. Ref: Standard Methods, 4500-P B-1999. (5) (c).
O. Finding: The calibration curve graph does not include a label for the x-axis. This is
considered pertinent information.
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).

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Nitrogen, Ammonia — Standard Methods, 4500 NH3 D-1997 (Aqueous)
Nitrogen, Total Kjeldahl — Standard Methods, 4500 NORG C-1997 (SM 4500 NH3 D-1997)
(Aqueous)
Recommendation: It is recommended to add a check box to the benchsheet to document that
the sample pH is adjusted to >11 during the analysis instead of documenting the color of the pH
range from the pH strip box.
Comment: The calibration curve and samples were being graphed on regular graph paper instead
of semilogarithmic graph paper. Standard Methods, 4500 NH3 D-1997. (3) (c) states: Using
semilogarithmic graph paper, plot ammonia concentration in milligrams NH3-N per liter on the log
axis vs. potential in millivolts on the linear axis starting with the lowest concentration at the bottom
of the scale. If the electrode is functioning properly a tenfold change of NH3-N concentration
produces a potential change of about 59 mv. Notification of acceptable corrective action (i.e., a
statement that they are now plotting on semilogarithmic paper and reporting results in mg/L directly
from the curve with an implementation date of October 7, 2016) was received by email on October
7, 2016. No further response is necessary for this Finding.
P. Finding: The sample volume is not documented.
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 21-1.0805 (a) (7) (H).
Q. Finding: The blank acceptance criterion is not properly evaluated.
Requirement: For analyses requiring a calibration curve, the concentration of reagent,
method and calibration blanks must not exceed 50% of the reporting limit or as otherwise
specified by the reference method. Ref: NC WW/GW LC Policy.
Requirement: Each laboratory shall develop and maintain a document outlining the
analytical quality control practices used for the parameters included in their certification.
Supporting records shall be maintained as evidence that these practices are being
effectively carried out. Ref: 15A NCAC 2H .0805 (a) (7).
Comment: The precision and accuracy of QC results must be documented and evaluated
against the prescribed acceptance criteria to demonstrate that the analytical process is in
control. Any samples associated with QC not meeting the criteria must be reanalyzed if
possible. If this is not possible, the data must be flagged on the laboratory reports and
Discharge Monitoring Reports (DMR) as all quality control requirements not met and giving
a brief description of the QC exceedance that occurred.
Comment: Blank values were being documented on benchsheets as < 0.10 mg/L, which is
the reporting level. This does not allow for proper evaluation against the required
acceptance criterion.
Nitrogen, Total Kjeldahl — Standard Methods, 4500 NoRc C-1997 (SM 4500 NH3 D-1997)
R. Finding: Borate buffer is not being used to steam out the distillation apparatus.
Requirement: Equipment preparation: Add 500 mL water and 20 mL borate buffer, adjust
pH to 9.5 with 6N NaOH solution, and add to a distillation flask. Add a few glass beads or

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boiling chips and use this mixture to steam out the distillation apparatus until distillate
shows no traces of ammonia. Ref: Standard Methods, 4500 NH3 B- 1997, Rev. 2011. (4)
(a).
Comment: The laboratory is steaming out the distillation apparatus with three 300mLs of
DI H20.
S. Finding: The distillation and digestion are not documented. This is considered pertinent
information.
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).
Nitrogen, Ammonia — Standard Methods, 4500 NH3 D-1997 (Aqueous)
T. Finding: The laboratory is not analyzing an 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: SM 4020 B-2009, Rev.
2011, Table 4020: 1 and (2) (g).
Comment: The laboratory is analyzing one LFMD a month.
Conductivity —Standard Methods, 2510 B-1997 (Aqueous)
Recommendation: It is recommended to document the conductivity readings both before and
after adjusting for temperature.
Comment: The incorrect value was documented for the calibration standard on the benchsheet.
The value documented was 1413 pmhos/cm instead of 1412 Nmhos/cm. The NC WW/GW LC
Approved Procedure for the Analysis of Specific Conductance (Conductivity) document states:
The following must be documented in indelible ink whenever sample analysis is performed: True
value of the standard used for calibration. Acceptable corrective action (i.e., updated benchsheet
which included the correct calibration standard value of 1412 Nmhos/cm with an implementation
date of August 11, 2016) was performed by the laboratory and approved by the auditor on
September 1, 2016 during the second day of the inspection. No further response is necessary
for this Finding.
Comment: A verification check standard is not being analyzed. The NC WW/GW LC Approved
Procedure for the Analysis of Specific Conductance (Conductivity) document states: Analyze and
document a calibration verification check standard prior to environmental sample analysis. It is
recommended that this standard value bracket (may be higher or lower than the calibration
standard, as applicable) the expected range of sample values measured. The value obtained for
the calibration verification check standard must read within 10% of the true value of the
calibration verification check standard. If the obtained value is outside of the ±10% range,
corrective action must be taken. Acceptable corrective action (i.e., updated benchsheet which
included a calibration verification check standard with an implementation date of August 11,
2016) was performed by the laboratory and approved by the auditor on September 1, 2016
during the second day of the inspection. No further response is necessary for this Finding.

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Temperature — Standard Methods, 2550 B-2000 (Aqueous)
Conductivity —Standard Methods, 2510 B-1997 (Aqueous)
U. Finding: The laboratory benchsheet was lacking pertinent data: Instrument
identification.
Requirement: The following must be documented in indelible ink whenever sample
analysis is performed: Instrument Identification. Ref: NC WW/GW LC Approved
Procedure for the Analysis of Temperature and NC WW/GW LC Approved Procedure for
the Analysis of Specific Conductance (Conductivity).
Comment: The thermometer used was not identified on the benchsheet or the daily
grab temperature log.
Conductivity —Standard Methods, 2510 B-1997 (Aqueous)
Chlorine, Total Residual — Standard Methods, 4500 CI G-2000 (Aqueous)
V. Finding: Stock standards and reagents prepared in the lab are not assigned expiration
dates.
Requirement: Adherence to manufacturer expiration dates is required.
Chem icals/reagents/consumables exceeding the expiration date can no longer be
considered reliable. If the expiration is only listed as a month and year (with no specific day
of the month), the last day of the month will be considered the actual date of expiration.
Monitor materials for changes in appearance or consistency. Any changes may indicate
potential contamination and the item should be discarded, even if the expiration date is not
exceeded. If no expiration date is given, the laboratory must have a policy for assigning an
expiration date. If no date received or expiration date can be determined, the item should
be discarded. Ref: NC WW/GW LC Policy.
Chlorine, Total Residual — Standard Methods, 4500 CI G-2000 (Aqueous)
Comment: The instrument was zeroed with a reagent blank. The NC WW/GW Approved
Procedure for the Analysis of Total Residual Chlorine document states: For colorimetric
analyses, a calibration blank must be analyzed each day to zero the instrument prior to analyzing
any standards, samples or the reagent blank. A calibration blank is a volume of reagent water of
the same matrix as the calibration standards, but without the target analyte and without DPD. A
sealed standard (e.g., gel) blank may also be used for this purpose. Notification of acceptable
corrective action (i.e., a statement that the instrument is zeroed with unreacted DI water with an
implementation date of September 8, 2016) was received by email on September 9, 2016. No
further response is necessary for this Finding.
Comment: The reagent blank was used as a point in the calibration curve along with 5 non-
zero standards. The NC WW/GW Approved Procedure for the Analysis of Total Residual
Chlorine document states: Analyze a calibration blank to zero the instrument and then analyzed
a series of five standards (do not use gel or sealed liquid standards for this purpose). The curve
verification must check 5 concentrations (not counting the blank) that bracket the range of the
sample concentrations to be analyzed. Notification of acceptable corrective action (i.e., updated
calibration curve that does not include the reagent blank as a point in the calibration with an
implementation date of September 8, 2016) was received by email on September 9, 2016. No
further response is necessary for this Finding.
Comment: The reagent blank was not properly evaluated. The reagent blank was used to zero
the instrument before being analyzed. Zeroing with the reagent blank biases the subsequent

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#179 City of Reidsville WWTP Laboratory
analysis of the reagent blank by already telling the meter that its value is zero. The NC WW/GW
Approved Procedure for the Analysis of Total Residual Chlorine document states: A reagent
blank is made from the same laboratory water source used to make quality control and/or
calibration standards with DPD. The concentration of reagent blanks must not exceed 50% of
the reporting limit (i.e., the lowest calibration or calibration verification standard concentration),
unless otherwise specified by the reference method, or corrective action must be taken.
Notification of acceptable corrective action (i.e., updated calibration curve that includes a
statement that the reagent blank must be s Y2 concentration of MRL Standard. with an
implementation date of September 8, 2016) was received by email on September 9, 2016. No
further response is necessary for this Finding.
IV. PAPER TRAIL INVESTIGATION:
The paper trail consisted of comparing original records (e.g., laboratory benchsheets, logbooks,
etc.) and contract lab reports to Discharge Monitoring Reports (DMRs) submitted to the North
Carolina Division of Water Resources. The following data were reviewed for City of Reidsville
WWTP Laboratory (NPDES permit # NC0024881): Field parameter data from January, April and
June 2016; TSS data for April 5 and 7, 2016 and June 1 and 7, 2016; BOD and CBOD data for
January 4 and 8, 2016 and July 14, 2016. No transcription errors were detected. The facility
appears to be doing a good job of accurately transcribing data.
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 and implementation dates
for each corrective action.
Report prepared by: Tonja Springer Date: October 13, 2016
Report reviewed by: Beth Swanson Date: October 19, 2016

North Carolina Wastewater/Groundwater Laboratory Certification
Matrix Spiking Policy and Technical Assistance (05/11/2012)
Policy Statement
Unless the referenced method states a greater frequency, spike 5% of samples on a monthly basis.
Laboratories analyzing less than 20 samples per month must analyze at least one matrix spike (MS) each
month samples are analyzed. If MS results are out of control, the results must be qualified or the
laboratory must take corrective action to rectify the effect, use another method, or employ the method of
standard additions. When the method of choice specifies MS performance acceptance criteria for
accuracy, and the laboratory chooses to develop statistically valid, laboratory -specific limits, the
laboratory -generated limits cannot be less stringent than the criteria stated in the approved method.
When spiking with multi -component standards, if the method does not specify the spiking components,
the Laboratory Control Spike (LCS) and MS must contain all analytes that are reported.
If the unspiked sample result is in the top 40% of the calibration range, the sample should be diluted and
the MS prepared using the diluted sample. The recovery of the MS samples must be bracketed by the
calibration range.
The volume of spike solution used in MS preparation must in all cases be <_ 10% of the total MS volume. It
is preferable that the spike solution constitutes <_ 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 volume constitutes >1% of the total sample volume, the sample concentration or
spike concentration must be adjusted by calculation.
Technical Assistance
Spike Preparation
The spike concentration may be set at either 5 to 50 times the Method Detection Limit (as determined by
the Method Detection Limit or MDL study) for the analyte, or at 1 to 10 times the ambient level (average
concentration) of the analyte in samples. There are several options for preparing spikes, for example:
Option 1 (Recommended - easiest) - If the spike solution volume is equal to 1% or less of the
total sample volume, direct subtraction of the unspiked sample is allowed. When the volume of
the standard solution spiked into a sample or a sample extract is less than 1 % of the total volume
then the final concentration need not be adjusted (e.g., 10 pL of spike solution added to a 1 mL
final extract results in only a negligible 1% change in the final extract volume).
Option 2 - Adjust spike solution to a known volume with sample. In this case the sample
concentration must be adjusted. When the volume of spike solution exceeds 1% of the total MS
volume the sample concentration must be adjusted prior to determining spike recovery.
The general equation for spike recovery is as follows:
% R = amt. of target in spiked sample — amt. of target in unspiked sample
(conc. or mass) (conc. or mass) x 100
amt. of target spiked into the sample
(conc. or mass)
To apply this to the sample preparation schemes described above, refer to the following examples.

Spike Preparation Examples
Option 1 - If the spike solution volume is equal to 1% or less of the total sample volume, direct
subtraction of the unspiked sample is allowed.
Option 1 Example:
0.5 mis of a 1000 mg/L standard spike added to 100 mis of sample has a theoretical value of 5
mg/L.
(A) The spiked sample recovery is 5.1 mg/L
(B) If the unspiked sample result is 0.5 mg/L
(C) Theoretical value is 5.0 mg/L
The Percent Recovery = spiked sample recovery (A) — unspiked sample result (B) divided by
theoretical value (C) X 100 or
5.1 — 0.5 X 100 = 92% recovery
5.0
A — B X 100 = Percent recovery
C
Option 2 - Adjust spike solution to a known volume with sample. In this case the sample concentration
must be adjusted.
Option 2 Example 1:
10 mis of spike (concentration 50 mg/L) brought to 100 mis with sample the theoretical MS value is
5 mg/L.
(A) The spiked sample recovery is 5.1
A If the unspiked sample result is 0.5 mg/L
(C) % sample is 0.90 (sample volume used (90) divided by final volume (100))
(D) Theoretical value is 5.0 mg/L
The Percent Recovery = spiked sample recovery (A) — (unspiked sample result (B) x % sample
(C)) divided by theoretical value (D) X 100 or
5.1 — (0.5 x 0.9) X 100 = 93% recovery A — (B x C) X 100 = Percent recovery
5.0 D
Option 2 Example 2: Larger spike volume
25 mis of spike (concentration 50 mg/L) brought to 250 mis with sample the theoretical MS value
is 5 mg/L.
(A) The spiked sample recovery is 5.6
(B) If the unspiked sample result is 0.5 mg/L
(C) % sample is 0.90 (sample volume used (225) divided by final volume (250))
(D) Theoretical value is 5.0 mg/L
The Percent Recovery = spiked sample recovery (A) — (unspiked sample result (B) x % sample
(C)) divided by theoretical value (D) X 100 or
5.6 — (0.5 x 0.9) X 100 = 103% recovery A — (B x C) X 100 = Percent recovery
5.0 D

Corrective Action/Qualifications for MS
Spike accuracy is usually based on a range of percent recovery (e.g., 80-120%). Refer to the method of
choice for specific acceptance criteria for the matrix spikes until the laboratory develops or adopts
statistically valid, laboratory -specific performance criteria for accuracy. If a MS fails, and the LCS is
acceptable, qualify the data for the MS sample. Repeated failures for a specific matrix may require use of
an alternate method or method of standard addition. Base the sample batch acceptance on the results of
the LCS analyses (and other quality control results) rather than the MS alone, because the matrix of the
spiked sample may interfere with the method performance. If a MS and the associated LCS fail, re -
prepare and reanalyze affected samples.
Post Digestion Spikes (PDS)
Post Digestion Spikes (PDS) are used for some analyses (e.g., metals) to assess the ability of a method
to successfully recover target analytes from an actual sample matrix after the digestion process has been
performed. The PDS results are used with MS results to evaluate matrix interferences. The MS and PDS
should be prepared from the same environmental sample. A PDS is not to be analyzed in place of a MS.
Post Digestion Spikes must be reported as post -digested and must not be misrepresented as pre-
digested spikes. (Exception: TCLP and SPLP samples are always spiked post digestion.)
Corrective Action/Qualifications for Post Digestion Spikes
In general, if the MS recovery for an analyte does not fall within the quality control acceptance range but
the PDS recovery is acceptable, then a matrix affect (associated with the preparatory process) should be
suspected and the unspiked sample results must be qualified on the basis of the matrix spike recovery.
However, when historical data for the effect does not exist, the laboratory would normally be expected to
perform a second digestion and reanalysis of the MS to confirm the result. The result would be confirmed
if the MS recoveries and PDS recoveries for both sets of analyses were similar in magnitude and bias.
When both the MS recovery and PDS recovery for a particular analyte falls outside of quality control
acceptance range in the same manner (i.e., the PDS and MS failures are of similar magnitude and the
direction of bias is the same), confirmatory analyses are unnecessary but the data must be qualified.
Parameters Excluded from MS Requirements
Acidity
BOD/C BOD
Chlorophyll
Color — ADMI
Conductivity
Ignitability
Paint Filter Test
pH
Salinity
Total Residual Chlorine
Alkalinity
Aquatic Humic Substances
All Bacteriological Parameters
Color - PtCo
Dissolved Oxygen
All Residues
Turbidity
Temperature
Sulfite
Vector Attraction Reduction (All Options)
(Field Laboratories and Field Setting analyses are exempt.)