#11_2018_0228_TS_FINAL

Laboratory Cert. :
11
Laboratory Name:
Microbac Laboratories Inc.
Inspection Type:
Commercial Maintenance
Inspector Name(s):
Tonja Springer, Dana Satterwhite, Todd Crawford, Seth Swanson, Anna
Ostendorff and Tom Halvosa
Inspection Date:
February 27 and 28, 2018
Date Forwarded for Initial
July 10, 2018
Review:
Initial Review by:
Jason Smith
Date Initial Review
July 10, 2018
Completed:
❑ Insp. Initial ❑ Insp. Reg
Cover Letter to use:
❑Insp. No Finding ®Insp. CP
❑Corrected
(to use: rt ciic , properties, check) ®Insp. Reg. Delay
Unit Supervisor/Chemist III:
Todd Crawford
Date Received:
July 18, 2018
Date Forwarded to Admin.:
August 14, 2018
Date Mailed:
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Special Mailing Instructions:

WWte Pesou ces
FNVH;1j VF—r4T b_I, QUAL!"Y
August 15, 2018
11
Mr. James Williams
Microbac Laboratories Inc.
2592 Hope Mills Road
Fayetteville, NC 28306
ROY COOPER
MICHEAL S. REGAN
LINDA CULPEPPER
SUBJECT: North Carolina Wastewater/Groundwater Laboratory Certification (NC WW/GW LC)
Maintenance Inspection
Dear Mr. Williams:
Enclosed is a report for the inspection performed on February 27th and 28th, 2018 by Tonja Springer.
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 findings were corrected and include an implementation date for each corrective action.
We are concerned with the findings that were cited previously and not corrected. 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, Fayetteville Regional Office
Water Sciences Section
NC `'Nastewatert roundwater Laboratory Cent€ficatiort Branch
1823 r,2a Service e to'. Raleigh. Nosh Oa o na 2769u '623
a ion: F^-CU Reeo y C eek, Road, Raleiglr, Ncr f,, Carokna 276017
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CERTIFICATE :
Microbac Laboratories Inc.
2592 Hope Mills Road
Fayetteville, NC 28306
11
February 27 and 28, 2018
Commercial Maintenance
Tonja Springer, Dana Satterwhite, Todd Crawford, Beth Swanson, Anna
Ostendorff and Tom Halvosa
James Williams
This laboratory was inspected by representatives 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. Improvement
in documentation and traceability is needed. Approximately four months prior to the inspection, the
laboratory notified this program of an instance of analyst falsification of data. The analyst was
terminated and affected clients and the Fayetteville Regional Office were contacted and informed.
The laboratory has implemented annual ethics training, ethics refresher courses, and ethics
policies as well as other checks and balances systems to ensure data integrity.
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 July 2019.
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

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#11 Microbac Laboratories, Inc.
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". Define all acronyms in the SOPs and use consistently on all logs and
benchsheets. It is recommended the laboratory adopt a standardized format for SOPS to ensure
each has all the required elements. An SOP guidance document was provided at the time of the
inspection.
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.
Approved Procedure documents for the analysis of the facility's currently certified Field
Parameters were provided at the time of the inspection. A number of Findings were cited
regarding Field Parameter documentation. The laboratory is reminded that, in accordance with
15A NCAC 2H .0805 (a) (3) (C): 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.
III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS:
Documentation
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.
Recommendation: It is recommended to cross out or "Z out" unused portions of benchsheets.
Recommendation: It is recommended to revise the Conductivity benchsheet to clearly document
that the post calibration check is performed at the end of the analytical sequence to bracket
environmental sample measurements.
Recommendation: It is recommended to add a space to the Chain of Custody form to indicate
whether or not samples are for compliance monitoring.
A. 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. Cited previously on May 17, 2012.

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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.
® Anions IC (Cl-, F, S042 NO2 , NO3 , NO3 + NO2) — The true value of the
calibration standards is not documented.
® Anions IC (Cl-, F, S042-, NO2 , NO3 NO3 + NO2) — The preparation of the
calibration standards is not documented.
® Anions IC (Cl-, F, S042-, NO2 , NO3 NO3 + NO2) — The MS preparation is not
documented.
® Anions IC — The Nitrite Continuing Calibration Verification (CCV) standard is not
documented consistently in the Source Standard column of the "IC Standards and
Reagents Documentation Sheet".
® Anions IC (Cl-, F, S042-, NO2 , NO3 NO3 + NO2) — Traceability information is
needed to link the dry weight determination to the samples analyzed.
® Phenols — Traceability is needed for 1 +9 H3PO4, 1 +9 NaOH, CuSO4 and FAS.
® Phenols — The calibration standard preparation is not documented on the
benchsheet or in "Element". NOTE: While it appears, the standard was prepared
correctly, there was an error in the preparation instructions for the 250 pg/L
standard in the SOP, underscoring the importance of documenting the actual
preparation of standards.
® Phenol Distillation Log — Define acronyms (e.g., A = absent for C12)
® Metals Digestion Log — Traceability (e.g., lot #) is needed for the acids used during
digestion.
® Metals — The matrix spike preparation is not documented.
B. Finding: Some benchsheets and/or report summaries reference unapproved methods
and/or do not fully reference the approved methods.
Requirement: Laboratory Procedures. Analytical methods, sample preservation,
sample containers and sample holding times shall conform to those requirements found
in 40 CFR-136.3. Ref: 15A NCAC 2H .0805 (a) (1).
Comment: Following are examples where unapproved methods are referenced and/or
approved methods are not fully referenced. There may be other instances that were not
observed during the inspection.

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#11 Microbac Laboratories, Inc.
® Alkalinity benchsheet — References SM 2320 B-1997 instead of SM 2320 B-
2011.
® Anions instrument printouts — Reference method (EPA 300, Rev. 2.1, 1993) is
not documented.
® BOD/CBOD benchsheet — References SM 5210 B-2001 instead of SM 5210 B-
2011 (Hach 10360-2011, Rev. 1.2) LDO
® Conductivity benchsheet — References 20th Ed. 2510 B instead of SM 2510 B-
2011
® Hexavalent Chromium benchsheet — References SM 3500-Cr-B-2009 instead of
SM 3500-Cr-B-2011
® IDEXX Colilert® (24 hr.) (MPN) benchsheet — References 9223 B 21s' Edition
SM instead of SM 9223 B-2006
® Nitrogen, Ammonia benchsheet — References SM 4500 NH3 C-1997 instead of
SM 4500 NH3 C-2011.
® Nitrogen, Total Kjeldahl benchsheet — References SM 4500 N org C-1997
instead of SM 4500 N org C-2011. Also, need to add the quantitive method (i.e.,
SM 4500 Norg C-2011 [SM 4500 NH3 C-2011]).
® pH field benchsheet — References SM 20th Ed. 4500 H+B instead of SM 4500
H+B-2011.
® Settleable Residue field benchsheet — References SM 20th Ed. 2540 F instead of
SM 2540 F-2011.
® Turbidity benchsheet — References SM 20th Ed. 2130 B instead of SM 2130 B-
2011.
C. 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:
® MBAS benchsheet — Units of measure (i.e., mg/L) are not documented for Initial
Calibration Verification (ICV), CCV, MS, Duplicate and Check standard.
® Alkalinity benchsheet — Units of measure (i.e., mg/L) are not documented for QC
standard and Duplicate #1.
® Anions instrument printout — Units of measure (i.e., mg) are not documented for
the weight of non -aqueous samples analyzed.
® Dissolved Oxygen (DO) composition book designated for DO analysis — Units of
measure (i.e., mg/L) are not documented for DO measurements.
® BOD benchsheet — Units of measure are not documented for BOD dilution water
pH (i.e., S.U.) and temperature (i.e., °C), corrected DO column (i.e., mg/L), and
temperature (i.e., °C) during meter calibration.
® Phenol benchsheet — Units of measure are not documented for pH (i.e., S.U.),
adjusted pH (i.e., S.U.) and absorbance. (i.e., Au).
® Phenol benchsheet — The x-axis units (i.e., pg) are incorrect on the calibration
curve graph. The units should be pg/L.
® Metals Digestion Log- Units of measure are not documented for the digestion
temperature (i.e., °C).

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Recommendation: It is recommended to review all laboratory benchsheets to ensure
all proper units of measure are documented.
D. Finding: The laboratory does not check and document the pH of samples upon receipt to
verify chemical preservation.
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.
Comment: This finding was observed for Total Hardness, Cyanide and Metals by EPA
200.7.
E. Finding: The DO sample analysis time was not clearly documented.
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: Date and time of sample analysis to verify the 15-minute holding
time is met [Alternatively, one time may be documented for collection and analysis with the
notation that samples are measured in situ or immediately at the sample site.] Ref: NC
WW/GW LC Approved Procedure for the Analysis of Dissolved Oxygen.
Comment: Sometimes only one time was documented, with no statement that the sample
was analyzed in situ or on site.
Recommendation: It is recommended that a benchsheet be developed for DO. The DO
results are currently documented in a composition book, which sometimes does not have
all the pertinent information documented.
F. Finding: The Total Residual Chlorine (TRC) benchsheet was lacking pertinent data:
Sample analysis time, Daily Check Standard analysis time, True Value of the Daily Check
Standard and the Value Obtained for the Daily Check Standard.
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: Date and time of sample analysis to verify the 15-minute holding
time is met [Alternatively, one time may be documented for collection and analysis with
the notation that sample measured in situ or immediately at the sample site.], Daily
Check Standard analysis time, True value of the Daily Check Standards) and Value

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#11 Microbac Laboratories, Inc.
obtained for the Daily Check Standard(s) (verification of ± 10% recovery). Ref: NC
WW/GW LC Approved Procedure for the Analysis of Total Residual Chlorine.
Comment: The daily check standard is analyzed in the field but not documented on the
benchsheet.
G. Finding: The Field Parameter documentation is lacking pertinent data: Instrument
identification.
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 21-1.0805 (a) (7) (A).
Requirement: The following must be documented in indelible ink whenever sample
analysis is performed: Instrument identification (serial number preferred). Ref: NC
WW/GW LC Approved Procedure for the Analysis of Dissolved Oxygen, NC WW/GW
LC Approved Procedure for the Analysis of pH, 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: This Finding applies to DO, pH, Temperature and Conductivity.
H. Finding: The laboratory is not always documenting the initial sample volume or weight
and/or final digestion volume or weight. This is considered pertinent information.
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).
Requirement: All analytical data pertinent to each certified analysis must be filed in an
orderly manner so as to be readily available upon request. Ref: 15A NCAC 2H .0805 (a)
(7) (A)•
Comment: The documentation of the digestion process must include all information
necessary to provide historical reconstruction of final calculated sample results.
Comment: This Finding applies to metals and Total Phosphorus.
I. Finding: The volume of acid used during the sulfuric acid titrant standardization is not
being documented. This is considered pertinent data.
Requirement: Calculate normality:
Normality, N = A X B
53.00 X C
where:
A = g Na2CO3weighed into 1-L flask,
B = mL Na2CO3 solution taken for titration, and
C = mL acid used.
Ref: Standard Methods, 2320 B-2011 (3) (b).

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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
21-1.0805 (a) (7) (A).
Comment: The documentation of the sulfuric acid titrant standardization must include all
information necessary to provide historical reconstruction of final calculated result. The
titrant normality cannot be verified without knowing the volume of acid used.
Comment: This Finding applies to Ammonia by Standard Methods, 4500 NHs C-2011.
J. Finding: The TKN sulfuric acid titrant standardization process is not properly 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 02H .0805 (a) (7) (A).
Comment: Only the date and end results are documented. The documentation of the
titrant standardization process must include all information necessary to provide historical
reconstruction of final calculation sample results.
K. Finding: The dilution factor for the closing blank is documented incorrectly on the TKN
benchsheet.
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 .085 (a) (7).
Comment: On the benchsheet in the "Dilution Factor" column, a 2 instead of a 1 is
documented for the closing blank.
L. Finding: The drying time is not documented for Total Residue (TS). 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).
Requirement: Dry evaporated sample for at least 1 h. in an oven at 103 to 105°C, cool
dish in desiccator to balance temperature, and weigh. Ref: Standard Methods, 2540 B-
2011. (3) (b).
Quality Control
Comment: The laboratory policy for all parameters is to analyze duplicates at a frequency of
10%. North Carolina Administrative Code, 15A NCAC 2H .0805 (a) (7) (H), only requires a
frequency of 5% unless otherwise specified by the method. Residue methods require 10%
frequency. Duplicate analyses are not required for Field parameters.
Recommendation: In order to improve the quality of the data being reported, it is recommended
that the laboratory implement a more rigorous peer review system. Steps must be taken to

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#11 Microbac Laboratories, Inc.
minimize and correct errors in calculations, check documentation for completeness and apply
appropriate corrective actions when quality control limits are exceeded. Calculation error checks
may include but are not limited to the following: transcription errors, calculation errors, correct
application of dilution factors, appropriate reporting of dry weight versus wet weight, correct
application of conversion factors, etc. Whether a Laboratory Information Management System
(LIMS) or manual system is used to process laboratory data and generate analytical reports, the
review should include, at a minimum, a percentage of "raw data calculation verifications." The
data reviewer should recalculate reported results using instrument outputs (e.g., peak area or
absorbances) or recorded measurements (e.g., volume of titrant) for samples and standards,
along with sample -specific preparation information (e.g., dilutions, percent moisture). This can be
detailed in a data validation section of each standard operating procedure.
M. Finding: Precision (e.g., relative percent difference) and accuracy (e.g., percent recovery)
of QC results are not consistently calculated, evaluated and documented to demonstrate
the analytical process is in control and established acceptance criteria are met.
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: For Cyanide samples, the percent recovery of the Laboratory Control
Standard (LCS) and the relative percent difference (RPD) for the MSD are not always
calculated and documented.
Comment: For Metals samples, the percent recovery of the MS and the RPD of
duplicates are not calculated and documented.
Comment: For BOD samples, the percent recovery of the GGA and the blank results
are not evaluated against acceptance criteria and documented.
N. Finding: The laboratory is not qualifying data on client reports when sample collection,
hold times are exceeded and/or preservation requirements are not met. Cited previously
on May 17, 2012.
Requirement: At any time, a laboratory receives samples which do not meet sample
collection, holding time, or preservation requirements, the laboratory must notify the
sample collector or client and secure another sample if possible. If another sample
cannot be secured, the original sample may be analyzed but the results reported must
be qualified with the nature of the infraction(s) and the laboratory must notify the State
Laboratory about the infraction(s). The notification must include a statement indicating
corrective actions taken to prevent the problem for future samples. Ref: 15A NCAC 2H
.0805 (a) (7) (N).
Comment: The DO for samples K7K0673-01 and K71-0470-01 were out of hold time
and reported without a qualifier and the State Laboratory was not notified.
®. Finding: Maximum holding times for DO were routinely exceeded.
Requirement: Analyze within 15 minutes. Samples should be analyzed as soon as
possible after collection. The times listed are the maximum times that samples may be
held before the start of analysis and still be considered valid. Ref: Code of Federal

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#11 Microbac Laboratories, Inc.
Regulations, Title 40, Part 136; Federal Register Vol. 88, No. 165, August 28, 2017,
Table Il, Footnote 2.
Comment: DO samples are collected and brought back to the laboratory and analyzed
using the benchtop BOD (LDO) meter outside of hold time. It is not acceptable to routinely
analyze samples out of mandated maximum holding times even if the results are
appropriately qualified. The laboratory must take corrective action that will ensure the lab
is capable of analyzing all samples within the maximum holding time.
Recommendation: It is recommended that the lab acquire a meter capable of measuring
DO in the field.
P. Finding: The laboratory is not adjusting the sample concentration in the percent recovery
calculation when the spike solution 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 <_ 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 must be
adjusted by calculation. Ref: NC WW/GW LC Policy.
Comment: The samples reviewed for Oil & Grease were prepared with a spiking
solution volume that is between 1 and 2% of the total volume.
Comment: The samples reviewed for low -range COD are prepared with a spiking solution
volume that is 2.5% of the total volume.
Q. Finding: The volume of spike solution used in high -range COD MS preparation is >5% of
the total MS 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 <_ 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 must be
adjusted by calculation. Ref: NC WW/GW LC Policy.
Comment: The sample is diluted in the sample vial with 0.2 mLs of spike solution and 0.1
mLs of sample.
R. Finding: Spike recovery is not being calculated correctly when sample concentrations are
less than the reporting limit.
Requirement: If the sample concentration is below the reporting limit, use zero for
amount of target in the unspiked sample. Ref: North Carolina Wastewater/Groundwater
Laboratory Certification Matrix Spiking Policy and Technical Assistance.
Comment: The value from the instrument is used to calculate spike recovery instead of
zero.
S. Finding: The thermometer used in the fecal coliform incubator is not accurate to ± 0.1 °C.

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#11 Microbac Laboratories, Inc.
Requirement: Incubators with an incubation temperature tolerance of ± 0.2 °C must have
temperature measuring devices with a stated accuracy of ± 0.1 'C. Ref: NC WW/GW LC
Policy.
Comment: This Finding applies to the following thermometers: #491 in incubator #12 is
only accurate to ± 0.5°C and thermometer #272 in incubator #460 is only accurate to ± 0.5
°C.
T. Finding: The laboratory does not report results of all tests on the characteristics of the
effluent when duplicate sample analyses are performed. Cited previously on May 17,
2012.
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: When duplicates are analyzed, only the first replicate value is reported on
the basic client report. Both replicates are reported on the full QC report template or if
requested by the client.
Comment: In order to fulfill the requirement of the Rule, the laboratory must either
report the average of the results or include both results on the basic client report.
Proficiency Testing
U. 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 (e.g., pH), but it is recommended that the instructions be
maintained. Ref: Proficiency Testing Requirements, May 31, 2017, Revision 2.0.
Comment: The vendor instructions are retained for 5 years but are not dated and initialed.
Dating and initialing the instruction sheet for each prepared PT Sample would satisfy the
documentation requirement.
Anions (CI-, F-, SOa, NO2, NO3, NO3+NO2) — EPA 300.0, Rev. 2.1, 1993 (Aqueous)
Anions (Cl-, F-, SOa, N022 NO3, NO3+NO2) — EPA 300.0, Rev. 2.1, 1993 (Non -Aqueous)
Recommendation: It is recommended that the report coversheet include the true value for all
QC samples (e.g., CCVs).
Comment: The laboratory is working toward electronic data storage for Anion analysis. NCAC 2H
.0805 9 (a) (7) (G) states: All analytical records must be available for a period of 5 years.
Records which are stored only on electronic media must be maintained and supported in the
laboratory by all hardware and software necessary for immediate data retrieval and review.

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#11 Microbac Laboratories, Inc.
Also, see the NC WW/GW LC Policy for "Electronic Data Storage, Signature and Reporting", at
the end of this report.
Comment: The water dip was significantly interfering with the Fluoride peak on most of the data
reviewed; however, the laboratory recently implemented the use of concentrated eluent (10X) to
combat this and it has helped significantly.
V. Finding: The instrument's operating conditions are not printed with each set of data.
This is considered pertinent information.
Requirement: Establish ion chromatographic operating parameters equivalent to those
indicated in Tables 1A or 1 B. Ref: EPA Method 300.0, Rev. 2.1 (1993), Section 10.1.
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 02H .0805 (a) (7) (A).
W. Finding: The laboratory is not properly documenting required information regarding
manual integration.
Requirement: When manual integration is employed, the laboratory must clearly
identify manually integrated compounds, document the reason the manual integration
was performed, the date performed and who completed the work. A flag or qualifier
code may suffice for simple manual integrations. In addition, a hardcopy printout of the
data displaying the manual integration shall be included in the raw data package (i.e.,
both the original and manually integrated chromatograms, of similar scale, must be
present in the data package). All information necessary for the historical reconstruction
of data must be maintained by the lab. Additionally, the laboratory must employ a
systematic data validation procedure to check manual integrations to assure integrations
are technically sound and representative of the response. Ref: NC WW/GW LC Policy.
Comment: The following is not always documented or not documented in sufficient detail:
Reason for manual integration in sufficient detail such that the affected
peaks are identified and the action taken (e.g., baseline redrawn).
Not always retaining original integrated chromatograms (e.g., when the
baseline is adjusted).
Not having manual integrations reviewed and validated.
Recommendation: It is recommended that the laboratory include manual integration
examples specific to anion analysis (e.g., Fluoride integration when the water dip
interferes) in the manual integration SOP.
X. Finding: The analysis documentation does not reflect the appropriate form of the anion
(e.g., Nitrite as N, Nitrate as N) or the analytical column used. 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 02H .0805 (a) (7) (A).
Anions (Cl-, F-, SOa, NO2, NO3, NO3+NO2) — EPA 300.0, Rev. 2.1, 1993 (Non -Aqueous)

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#11 Microbac Laboratories, Inc.
Y. Finding: The laboratory is not extracting a Laboratory Fortified Blank (LFB) and
Laboratory Reagent Blank (LRB) with Non -Aqueous samples.
Requirement: An LFB is an aliquot of reagent water or other blank matrices to which
known quantities of the method analytes are added in the laboratory. The LFB is
analyzed exactly like a sample, and its purpose is to determine whether the
methodology is in control, and whether the laboratory is capable of making accurate and
precise measurements. Ref: EPA Method 300.0, Rev. 2.1 (1993), Section 3.5.
Requirement: The laboratory must analyze at least one LFB with each batch of
samples. Calculate accuracy as percent recovery (Section 9.4.2). If the recovery of any
analyte falls outside the required control limits of 90-110%, that analyte is judged out of
control, and the source of the problem should be identified and resolved before
continuing analyses. Ref: EPA Method 300.0, Rev. 2.1 (1993), Section 9.3.2.
Requirement: An LRB is an aliquot of reagent water or other blank matrices that are
treated exactly as a sample including exposure of all glassware, equipment, solvents,
reagents, internal standards, and surrogates that are used with other samples. The LRB
is used to determine if method analytes or other interferences are present in the
laboratory environment, the reagents, or the apparatus. Ref: EPA Method 300.0, Rev.
2.1 (1993), Section 3.7.
Requirement: The laboratory must analyze at least one LRB with each batch of
samples. Data produced are used to assess contamination from the laboratory
environment. Values that exceed the MDL indicate laboratory or reagent contamination
should be suspected and corrective actions must be taken before continuing the
analysis. Ref: EPA Method 300.0, Rev. 2.1 (1993), Section 9.3.1.
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.
Z. Finding: Non -aqueous sample results are not reported on a dry weight basis.
Requirement: The results of all soil sample analyses, performed to meet the
requirement of the Division of Environmental Management, must be reported on a dry
weight basis. Ref: "Analysis of Soil Samples", Memorandum, May 23, 1994. Division of
Environmental Management.
Bacteria — Coliform Fecal — Standard Methods, 9222 D-2006 (MF) (Aqueous)
Comment: The laboratory is monitoring the quality of the reagent water every 6 months. This is
only required every twelve months.
Comment: The prepared agar and media were being used beyond their expiration dates.
Standard Methods, 9222 D-2006 (1) (a) states: Refrigerate finished medium (preferably in
sealed plastic bags or other containers to reduce moisture loss) and discard unused broth after
96 h or unused agar after 2 weeks. Acceptable corrective action (i.e., agar and media are now
being discarded after 2 weeks and the LIMS has been programmed to alert staff by graying out
expired agar and media) was implemented on February 26, 2018 and corrected prior to the
inspection and approved by the auditor during the inspection. No further response is
necessary for this Corrected Finding.

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#11 Microbac Laboratories, Inc.
Finding: The laboratory is using a partial immersion thermometer in the fecal incubator
improperly.
Requirement: 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. Ref:
"User -Friendly Guidance on the Replacement of Mercury Thermometers",
t JJ . rf v'� it r u t r r`r xc J Q c Clcf cu r 1r !uspr fri nolly,, u� f.
Comment: The thermometer in the 44.5°C water bath was submerged beyond the
immersion line and was resting on the bottom of the water bath incubator, which may
lead to errant readings. This was corrected during the audit; however, a corrective
action response and steps taken to prevent recurrence must be submitted with the
response to the report.
BB. Finding: The laboratory is not checking the pH of prepared media agar properly.
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 (1) (a).
Comment: A pH probe for solutions was inserted into the agar while still in the liquid
phase. The agar was allowed to solidify around the probe and then the observed pH was
documented. The proper technique would be to measure the pH after the agar has
solidified using a solid -surface pH probe.
CC. Finding: Consumable materials are not properly tested.
Requirement: Before a new lot of consumable materials are used for the Fecal Coliform
MF method, those materials must be tested and compared to those currently in use to
ensure they are reliable. Consumable materials included in this requirement are:
membrane filters and/or pads (often packaged together) and media. It is
recommended that only one consumable be tested at a time. At a minimum, make
single analyses on five positive samples that will yield 20-60 colonies for both the
current lot and the new lot. There are two options for determining acceptance of results:
Option 1: Follow the acceptance criteria described in Standard Methods 9020 B-2005.
(5) (0 (2) (a) and (b). Option 2: Compare the average colony count of each five -sample
set and evaluate against your routine sample duplicate acceptance criterion. Ref: NC
WW/GW LC Policy.
Comment: The consumables test is performed using four positive samples.
DD. Finding: Compliance sample results are not always calculated and reported correctly.
Requirement: Countable Membranes with 20-60 Blue Colonies: Calculate the fecal
coliform results from membrane filters within the ideal counting range of 20-60 blue
colonies using the general formula:

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#11 Microbac Laboratories, Inc.
Number of colonies counted x 100 = Fecal coliform colonies per 100 ml
volume of sample filtered in ml
If more than one filter (including a 100-mL sample volume) has a count in the acceptable
range, calculate the values in counts/100 mL for each filter in the countable range and
average.
Ref: NC WW/GW LC Policy
Requirement: Countable Membranes with less than 20 Blue Colonies: If all counts are
below the lower limit (20) of the ideal counting range:
(a) Select the count most nearly acceptable and compute the count using the general
formula. Report the count as an Estimated Count per 100 mL: or
(b) Total the counts on all filters and report as number per 100 mL. For example, if 50,
25, and 10 mL portions were examined and counts were 15, 6, and 0 coliform
colonies respectively, calculate results as follows and report the count as 25
colonies per 100 mL.
(15 + 6 + 0) counts x 100 = 25 colonies per 100 mL
50+25+10mL
Ref: NC WW/GW LC Policy
Comment: The laboratory is taking the colony count of the least diluted sample,
applying the dilution factor and reporting that value. Results were not calculated
correctly on the following data reviewed: July 10, 2017 reported 4 cfu/100mL, instead of
5 cfu/100mL, July 11, 2017 sample #K7G0252-01 reported 260 cfu/100mL instead of
282 cfu/100ml- and July 11, 2017 sample #K7G0252-02 reported 150 cfu/mL instead of
191 cfu/100mL.
Bacteria — Coliform Fecal — Standard Methods, 9221 C E-2006 (MPN) 24hr 503 (Non -
aqueous)
EE. Finding: The time samples are taken out of the 35°C incubator and put into the 44.5°C
incubator is not being documented.
Requirement: Incubate for 3 h at 35 ± 0.5°C. Transfer tubes to a water bath at 44.5 ±
020C and incubate for another 21 ± 2 h. Ref: Standard Methods 9221 C E-2006 (2) (b).
Requirement: 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)•
Comment: Only times into the 35°C incubator and out of the 44.5°C are documented.
This makes it impossible to tell exactly how long samples were in each incubator.
FF. Finding: The laboratory is using EC media with MUG.

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#11 Microbac Laboratories, Inc.
Requirement: EC medium: Preferably use a dehydrated, commercially available
medium. Ref: Standard Methods, 9221 E-2006 (1).
Comment: MUG is only used in conjunction with E. coli analysis.
GG. Finding: The sample is not being prepared properly.
Requirement: In a sterile dish weigh out 30.0 grams of well mixed sample. Transfer the
sample to a sterile blender. Use 270 ml of sterile buffered dilution water to rinse any
remaining sample into the blender. Cover and blend on high speed for two minutes. One
milliliter of this sample contains 0.10 g of the original sample. Ref: Control of Pathogens
and Vector Attraction in Sewage Sludge, EPA/625/R-92/013, (July 2003) Appendix F.
(1.1), solid samples (1).
Comment: The pH of the sample was being adjusted which is not required by this
method.
HH. Finding: The 350C incubator temperature tolerance is ±1 °C.
Requirement: Incubate for 3 h at 35 ± 0.5°C. Ref: Standard Methods, 9221 B. (2) (b)
(2) -2006.
Comment: This was observed in the SOP, on benchsheets and labels on the
incubators. The temperature log did not show any temperatures outside of 35 ± 0.5 °C.
H. Finding: Samples are not homogenized in a blender.
Requirement: Cover and blend on high speed for two minutes. Ref: Control of
Pathogens and Vector Attraction in Sewage Sludge, EPA/625/R-92/013, (July 2013)
Appendix F. (1.1), solid samples (1).
Comment: The laboratory is using a stir bar in a beaker.
Bacteria — Coliform Fecal — Standard Methods, 9221 C E-2006 (MPN) 24hr 503 (Non -
aqueous)
Bacteria — E. coli - IDEXX Colilert® (24 hr.) (MPN) (Aqueous)
JJ. 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).
Bacteria — E. soli - IDEXX Colilert® (24 hr.) (MPN) (Aqueous)
Comment: Most data reviewed did not appear to be compliance samples for Clean Water Act
(CWA) monitoring; however, that could not be determined definitively.
KK. Finding: The holding time was routinely exceeded.
Requirement: Coliform, total, fecal, and E. coli: Maximum holding time 8 hours. Ref:
Code of Federal Regulations, Title 40, Part 136, Table ll.

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#11 Microbac Laboratories, Inc.
Comment: Samples are routinely analyzed within a few hours of receipt but were
already out of holding time by the time they were received. The laboratory mistakenly
thought that the 30-hour holding time listed in 40 CFR 141.21 could be applied to CWA
samples. Therefore, they did not realize that the samples were being analyzed beyond
the holding time and would require qualification on the client report.
Comment: The following instances were observed:
® K7G0390 sample 1 was received 15
approximately 12 hours later.
® K8A0151 samples 1-7 were received
analyzed approximately 2 hours later.
® K7G0390 sample 1 was received around
approximately 5 hours later.
hours after sampling and analyzed
almost 20 hours after sampling and
19 hours after sampling and analyzed
® K8A0559 sample 1 was received around 20 hours after sampling and analyzed
approximately 5 hours later.
Recommendation: It is recommended to inform all affected clients of the 8-hour
holding time and notify them that their results should have been qualified.
BOD —Standard Methods, 5210 B-2011 (Aqueous)
CBOD — Standard Methods, 5210 B-2011 (Aqueous)
Comment: The analyst was not aware that the meter must be recalibrated if drift check is >0.2
mg/L. There were no instances of drift checks >0.2 mg/L in the data reviewed.
ILL. Finding: The laboratory does not prepare Sodium Sulfite daily.
Requirement: Sodium sulfite solution: This solution is not stable; prepare daily. Ref:
Standard Methods, 5210 B-2011. (3) (f).
Comment: The laboratory indicated on the completed checklist that the sodium sulfite
was "prepared and good for 3 days."
MM. Finding: Documentation does not demonstrate that the initial DO is measured within 30
minutes of sample preparation. This is considered pertinent data.
Requirement: After preparing dilution, measure initial DO within 30 min. Ref: Standard
Methods, 5210 B-2011. (5) (g).
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: 15 NCAC
2H .0805 (a) (7) (A).
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).
NN. Finding: The amount of seed added to GGA and samples is not documented.

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#11 Microbac Laboratories, Inc.
Requirement: Always record the exact volume of seed suspension added to each bottle.
Ref: Standard Methods, 5210 C-2011. (5) (d).
00. Finding: The laboratory is not calculating the RPD of duplicates properly.
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: All dilutions including the non -duplicated dilution results are used in calculating
the RPD. (i.e., 2 averages are calculated using all dilution bottle results; one with the first
duplicate and remaining bottles and the other with the second duplicate and remaining
bottles). The two averages are then used to get the % RPD. Instead, the RPD must be
calculated and evaluated for just the dilution that is duplicated to monitor precision rather
than agreement of the analytical measurements.
COD — Standard Methods, 5220 D-2011 (Aqueous)
Recommendation: It is recommended that the acceptance criterion for the blanks be
documented on the benchsheet.
PP. Finding: Quantitation at 1 to 2 times the Method Reporting Limit (MRL) is not verified at
least quarterly.
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 a
level 1 to 2 times the MRL. Ref: Standard Methods, 5020 B-2010. (1) (c).
QQ. Finding: Preservative is not being added to reagent blanks or LFBs.
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. The reagent blank is used to determine
whether, and how much, reagents and the preparative analytical steps contribute to
measurement uncertainty. Ref: Standard Methods, 1020 B-2011. (5).
Requirement: A laboratory fortified blank [laboratory control standard (LCS)] is a
reagent water sample (with associated preservatives) to which a known concentration of
the analyte(s) of interest has been added. An LFB is used to evaluate laboratory
performance and analyte recovery in a blank matrix. Ref: Standard Methods, 1020 B-
2011. (6).
RR. Finding: The calibration verification standard analyzed initially, after every tenth sample
and at the end of the sample group is not mid -range for the low range curve.
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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#11 Microbac Laboratories, Inc.
Comment: Standard concentrations verified annually for the low -range curve are 10, 50
and 150 mg/L and the daily calibration verification standard for the low -range curve
concentration is 100 mg/L.
SS. Finding: The laboratory acceptance criterion for calibration verification standard
recoveries exceeds the maximum allowable difference of <_ 5 % of the true value.
Requirement: Prepare calibration curve for each new lot of tubes or ampules or when
standards prepared in ¶ a above differ by z 5 % from calibration curve. Ref: Standard
Methods, 5220 D-2011. (4) (c).
Comment: The recovery acceptance criterion for the high -range curve was already 95-
105% so this Finding applies to the low -range curve only.
TT. Finding: The laboratory acceptance criterion being used exceeded the method
requirement of ±15% recovery.
Requirement: If the LRB is not prepared from a second source to confirm method
accuracy, (unless the method specifies otherwise) the laboratory must also verify the
accuracy of its standard preparation by analyzing a mid -level second -source calibration
standard whenever a new initial calibration curve is prepared. Results must agree within
15% unless otherwise specified in the method. Ref: Standard Method, 5020 B-2011. (2)
(b).
Comment: The second source QC standard acceptance criterion is 5 20% difference.
UU. Finding: The laboratory is not analyzing five standards when verifying the instrument's
factory set calibration.
Requirement: For analytical Procedures requiring analysis of a series of standards, the
concentrations of these standards must bracket the concentration of the samples
analyzed. One of the standards must have a concentration equal to the laboratory's lower
reporting concentration for the parameter involved. For metals by AA or ICP, a series of
three standards must be analyzed with each group of samples. For colorimetric analyses,
a series of five standards for a curve prepared annually or three standards for curves
established each day or standards as set forth in the analytical procedure must be
analyzed to establish a standard curve. The curve must be updated as set forth in the
standard procedures, each time the slope changes by more than 10 percent at midrange,
each time a new stock standard is prepared, or at least every twelve months. Each analyst
performing the analytical procedure must produce a standard curve. Ref: 15A NCAC 2H
.0805 (a) (7) (1).
Requirement: Prepare at least five standards from potassium hydrogen phthalate solution
with COD equivalents to cover each concentration range. Ref: Standard Methods 5220 D-
2011 (4) (c).
Comment: The instrument's factory -set calibration is verified annually with three
standards instead of five.
W. Finding: A calibration verification curve is not prepared for each new lot of tubes.

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#11 Microbac Laboratories, Inc.
Requirement: Prepare calibration curve for each new lot of tubes or ampules or when
standards prepared in ¶ a above differ by z 5 % from calibration curve. Ref: Standard
Methods, 5220 D-2011. (4) (c).
Conductivity — Standard Methods, 2510 E-2011 (Aqueous)
Finding: The Automatic Temperature Compensator (ATC) has not been verified.
Requirement: The Automatic Temperature Compensator (ATC) must be verified prior
to initial use and annually (i.e., 12 months) thereafter at two temperatures by analyzing a
standard or sample at 250C (i.e., the temperature to which conductivity values are
reported) and a temperature(s) that brackets the temperature ranges of the
environmental samples routinely analyzed. This may require the analysis of a third
temperature reading that is > 25°C. As the temperature increases or decreases, the
value of the conductivity standard or sample must be within ±10% of the true value of
the standard or ±10% of the value of the sample at 25°C. If not, corrective action must
be taken. Ref: NC WW/GW LC Approved Procedure for the Analysis of Specific
Conductance (Conductivity). Cited previously on May 17, 2012.
Comment: A temperature verification was being done instead of an ATC check.
Total Cyanide — EPA Method 335.4, Rev. 1.0, 1993 (Aqueous)
Recommendation: It is recommended that the laboratory obtain a copy of Standard Practice for
Sampling, Preservation and Mitigating interferences in Water Samples for Analysis of Cyanide,
ASTM D7365-09a.
Comment: Unless the method specifies otherwise, sodium arsenite is the preferred reducing
agent. Ascorbic acid can also be used; however, analysis must be performed within 24 hours to
avoid cyanide degradation unless the holding time has been determined as described in
Practice D4841 and Section 8.3.2. Ref: ASTM Method D7365-09a, Section 8.3.9.1.
XX. Finding: The State Laboratory is not notified when samples do not meet preservation
requirements.
Requirement: At any time a laboratory receives samples which do not meet samples
collection, holding time, or preservation requirements, the laboratory must notify the
samples collector or client and secure another sample if possible. If another sample
cannot be secured, the original sample may be analyzed but the results reported must
be qualified with the nature of the infraction(s) and the laboratory must notify the State
Laboratory about the infraction(s). The notification must include a statement indicating
corrective actions taken to prevent the problem for future samples. Ref: 15A NCAC 2H
.0805 (a) (7) (N).
Recommendation: It is recommended that the laboratory send out an information sheet
to clients on Cyanide interferences and their mitigation.
Comment: It appears the clients are not checking for oxidizers or sulfide. The laboratory
checks the sample with chlorine strips upon receipt but treatment and verification of
effectiveness must be performed in the field and the process documented. Results must
be qualified if documentation is not provided.

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#11 Microbac Laboratories, Inc.
YY. Finding: The laboratory acceptance criterion for the calibration verification standard
exceeds the maximum allowable difference of ± 10%.
Requirement: Analysis of the IPC solution and calibration blank immediately following
calibration must verify that the instrument is within ±10% of calibration. Subsequent
analyses of the IPC solution must verify the calibration is still within ±10%. If the
calibration cannot be verified within the specified limits, reanalyze the IPC solution. If the
second analysis of the IPC solution confirms calibration to be outside the limits, sample
analysis must be discontinued, the cause determined and/or in the case of drift the
instrument recalibrated. All samples following the last acceptable IPC solution must be
reanalyzed. The analysis data of the calibration blank and IPC solution must be kept on
file with the sample analyses data. Ref: EPA Method 335.4, Rev. 1.0 (1993), Section
9.3.4.
Comment: The laboratory is using a recovery acceptance criterion for the ICV and CCV
(i.e., IPC) of 80-120%.
Comment: The data reviewed met the 90-110% recovery acceptance criterion.
Hardness, Total — Standard Methods, 2340 C-2011 (Aqueous)
Comment: The laboratory had not analyzed any compliance samples during the previous 12
months, therefore; PT data was reviewed during the inspection.
Comment: When preserving samples, the method blank and LFB must have preservative
added.
Comment: The laboratory must subtract the volume of EDTA used for the blank when
analyzing samples below 5 mg/L, but not for samples above that concentration.
Metals — EPA Method 200.7, Rev. 4.4, 1994 (Aqueous)
Comment: The reporting limits (RL) are being set at <3 times the Method Detection Limit (MDL).
Some of the RLs and MDLs are almost the same (e.g., Lead MDL 0.0027 and RL 0.0030). It is
recommended to re-evaluate the RL in terms of the blank, a standard analyzed at the RL and the
calculated MDL.
ZZ. Finding: The laboratory is not maintaining the proportionality of reagents when using a
reduced sample volume.
Requirement: For the determination of total recoverable analytes in aqueous samples
(other than drinking water with <1 NTU turbidity), transfer a 100 mL (±1 mL) aliquot from a
well mixed, acid preserved sample to a 250 mL Griffin beaker (Sections 1.2, 1.3, 1.6, 1.7,
1.8, and 1.9). (When necessary, smaller sample aliquot volumes may be used.) Ref: EPA
Method 200.7, Rev. 4.4 (1994), Section 11.2.2.
Requirement: Add 2 mL (1+1) nitric acid and 1.0 mL of (1+1) hydrochloric acid to the
beaker containing the measured volume of sample. Ref: EPA Method 200.7, Rev. 4.4
(1994), Section 11.2.3.
Comment: The laboratory uses 1 mL of concentrated nitric acid and 0.5 mL of
concentrated hydrochloric acid for Aqueous samples and 2 mL of concentrated nitric acid

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#11 Microbac Laboratories, Inc.
and 1 mL of concentrated hydrochloric acid for Non -Aqueous samples in a 50-mL sample
volume.
Finding: A standard is not analyzed at the concentration of the lower reporting limit for all
elements.
Requirement: For analytical Procedures requiring analysis of a series of standards, the
concentrations of these standards must bracket the concentration of the samples
analyzed. One of the standards must have a concentration equal to the laboratory's lower
reporting concentration for the parameter involved. Ref: 15A NCAC 2H .0805 (a) (7) (1).
Comment: The lab is analyzing a multipoint curve for each element (generally, 0, 0.001,
0.003, 0.05, 0.250, 1.0, 5.0, 10, 20 ppm) but the lab is not analyzing a standard equal to
the lower reporting limit concentrations for all elements (e.g., the lower reporting limit for
Cu is 0.005 ppm).
Nitrogen, Ammonia — Standard Methods, 4500 NH3 C-2011 (Aqueous)
Recommendation: It is recommended to delete the column on the benchsheet that states that all
samples are at a pH > 11. This appears to be a holdover from when the benchsheet was used for
the ion -selective electrode method.
Recommendation: It is recommended that the LFB concentration be expressed as 30 mg/L and
the volume analyzed as 100 mL, instead of a concentration of 100 mg/L with a volume of 3 mL
analyzed.
BBB. Finding: The sample pH is not being adjusted to 9.5 S.U. using a pH meter.
Requirement: Add 25 mL borate buffer solution and adjust to pH 9.5 with 6N NaOH using
a PH meter. Ref: Standard Methods, 4500 NH3 B-2011 (4) (b).
Comment: The pH adjustment is being made using pH paper. The concentration of
ammonia in the sample is determined by the volume of titrant required to adjust the pH
from 9.5 S.U. to the end -point. Having the initial pH right at 9.5 S.U. is critical to an
accurate measurement. Therefore, pH paper is not allowed.
Nitrogen, Ammonia — Standard Methods, 4500 NH3 G-2011 (Aqueous)
CCC. Finding: The laboratory is not evaluating the recoveries of the back -calculated standards.
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).
Requirement: The back -calculated and true concentrations should agree within ± 10%,
unless different criteria are specified in an individual method. At the lower limit of the
operational range, acceptance criteria are usually wider. Such criteria must be defined in
the laboratory's QA plan. Ref: Standard Methods, 4020 B-2011. (2) (a).
Comment: The standards were automatically back -calculated by SEAL software.
However, the recoveries were not being evaluated against any acceptance criteria. The

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#11 Microbac Laboratories, Inc.
data showed that recoveries were not always within 10% of the true value, which it
should be for concentrations above the lower limit of the operational range.
Nitrogen, Total Kieldahl — Standard Methods, 4500 N-org C-2011 (Standard Methods,
4500 NH3 C-2011) (Aqueous)
Recommendation: The printed results summary sheets do not indicate which sample was
spiked or which sample was duplicated. This information is designated on the primary
worksheet by superscript numbers but doesn't show on the printed results report. It is
recommended that this be viewable on the printed results report as well.
®®®. Finding: Corrections are not applied to the final results.
Requirement: Carry a blank through all steps of the procedure and apply the necessary
corrections to the results. Ref: Standard Methods, 4500 NH3 C-2011. (4) (d).
Comment: The formula on the benchsheet shows to subtract the blank, however this is
not being done. If there is a hit in the blank, the run is discarded and samples are
reanalyzed.
Nitrogen, Total Kieldahl — Standard Methods, 4500 N-org C-2011 (Standard Methods,
4500 NH3 C-2011) (Aqueous)
Nitrogen, Ammonia — Standard Methods, 4500 NH3 C-2011 (Aqueous)
EEE. Finding: Rounding off by dropping insignificant digits is not being performed properly.
Requirement: Round off by dropping digits that are not significant. If the digit 6, 7, 8, or
9 is dropped, increase preceding digit by one unit; if the digit 0, 1, 2, 3, or 4 is dropped,
do not alter preceding digit. If the digit 5 is dropped, round off preceding digit to the
nearest even number: thus 2.25 becomes 2.2 and 2.35 becomes 2.4. Ref: Standard
Methods, 1050 B-2006. (2).
Comment: The sulfuric acid titrant normality used in the final result calculation is being
expressed to 5 significant figures. Since the volume dispensed by the burette, which
would be the limiting factor in determining the number of significant figures used to
express the determined normality, is being measured in 0.05 ml increments, the titrant
normality needs to be expressed to only 2 decimal places. The number of significant
figures in the normality has a measurable impact on the final result of the sample:
Nitrogen, Total Kieldahl — Standard Methods, 4500 N-org C-2011 (Standard Methods,
4500 NH3 C-2011) (Aqueous)
Nitrogen, Ammonia — Standard Methods, 4500 NH3 C-2011 (Aqueous)
Nitrogen, Ammonia — Standard Methods, 4500 NH3 G-2011 (Aqueous)
FFF. Finding: The distillation apparatus is not steamed out and verified to show no trace of
ammonia prior to each sample distillation.
Requirement: Add 500 ml water and 20 ml borate buffer, adjust pH to 9.5 with 6N
NaOH solution, and add to distillation flask. Add a few glass beads or boiling chips and
use this mixture to steam out the distillation apparatus until distillate shows no traces of
ammonia. To minimize contamination, leave distillation apparatus assembled after
steaming out and until just before starting sample distillation. Ref: Standard Methods,
4500-NH3 B-2011. (4) (a).

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#11 Microbac Laboratories, Inc.
Comment: The distillation apparatus is being cleaned with laboratory glassware
detergent. The distillation apparatus is steamed out with a blank and the blank is
analyzed for carryover after every tenth samples. Blanks are also analyzed after
samples suspected of carryover but this is not documented.
Comment: The method implies steaming out after every sample. The laboratory only
has the capacity to distill one sample at a time.
GGG. Finding: The 4% Boric acid solution is being prepared incorrectly.
Requirement: Dissolve 20 g H2BO3 in water, add 10 mL mixed indicator solution and
dilute to 1 L. Prepare monthly. Ref: Standard Methods, 4500 N NH3 C-2011. (3) (a) and
(b).
Comment: The laboratory is adding 41.67 g of 11-1213O3 to 1 L, instead of 20 grams to 1 L.
Nitrogen, Ammonia — Standard Methods, 4500 NH3 C-2011 (Aqueous)
Nitrogen, Ammonia — Standard Methods, 4500 NH3 G-2011 (Aqueous)
Nitrogen, Total Kieldahl — Standard Methods, 4500 Worg C-2011 (Standard Methods, 4500
NH3 C-2011) (Aqueous)
Inorganic Phenols — EPA Method 420.1, Rev. (1978) (Aqueous)
Phosphorus, Total — Standard Methods, 4500 P F-2011 (Aqueous)
HHH. Finding: The laboratory is not analyzing an LFMD.
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: The laboratory analyzes a sample duplicate. Analysis of the LFMD, at the
required frequency, is acceptable to satisfy the sample duplicate requirement listed in
North Carolina Administrative Code, 15A NCAC 2H .0805 (a) (7) (C).
Oil & Grease — EPA Method 1664 Rev. B (Aqueous)
III. Finding: The preservative is not verified properly.
Requirement: Dip a glass stirring rod into the well mixed sample. Withdraw the stirring
rod and allow a drop of the sample to fall on or touch the pH paper. Rinse the stirring
rod with a small portion of n-hexane that will be used for extraction (to ensure that no
extractable material is lost on the stirring rod). Ref: EPA Method 1664, Rev. B, Sections
11.2.1.1, 11.2.1.2, 11.2.1.3.
Comment: The laboratory is verifying the preservation by dipping the pH paper into a
drop of sample on the cap. Additionally, since the SPE method does not include the
sample bottle cap, rinse the cap and glass rod into the sample after checking the pH
using the glass rod.

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#11 Microbac Laboratories, Inc.
Residue, Dissolved — Standard Methods, 2540 C-2011 (Aqueous)
Residue, Suspended — Standard Methods, 2540 D-2011 (Aqueous)
JJJ. Finding: The laboratory is not always 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
more than 10 min are required to complete filtration, increase filter size or decrease
sample volume. Ref: Standard Methods, 2540 C-2011. (3) (b).
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. If more
than 10 min are required to complete filtration, increase filter size or decrease sample
volume. Ref: Standard Methods, 2540 D-2011 (3) (b).
Comment: On September 1, 2017 three TDS samples did not achieve the minimum
required weight gain of 2.5 mg using 50 mLs of sample.
Comment: For Suspended Residue, elevated reporting limit results are not being
reported when sample volumes of less than 1 liter are used. It appears the analyst is
transferring values from "concentration" column. The "report value" and "report limit"
columns have the correct values. Sample K8A0015-01 was reported as 2.62 mg/L but
should have been <3.13 mg/L. Sample K7G0047-01 was reported as 1.39 mg/L but less
than 1 liter was filtered.
Comment: For Suspended Residue, when less than a liter is filtered and less than 2.5
mg of residue is obtained, the sample result must be adjusted accordingly.
KKK. Finding: Data qualifiers are not being transferred to the client report. Cited previously
on May 17, 2012.
Requirement: When quality control (QC) failures occur, the laboratory must attempt to
determine the source of the problem and must apply corrective action. Part of the
corrective action is notification to the end user. If data qualifiers are used to qualify
samples not meeting QC requirements, the data may not be useable for the intended
purposes. It is the responsibility of the laboratory to provide the client or end -user of the
data with sufficient information to determine the usability of the qualified data. Ref: NC
WW/GW LC Policy.
Comment: The qualifier for duplicates exceeding the acceptance criterion for sample
K7H1345-03 was not documented on the client report.
Comment: If filtration of 1 liter is not possible, the reporting limit must be adjusted based
on the sample volume used and results must be qualified.
Residue, Suspended — Standard Methods, 2540 D-2011 (Aqueous)
LLL. Finding: The daily drying time is less than the time used for the initial verification study
drying cycle.
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

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#11 Microbac Laboratories, Inc.
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.
Comment: The annual drying time verification study was performed for 2 hours and 30
minutes but samples are dried for 1 hour.
MMM. Finding: The oven temperature is not adjusted to approximately 98 °C for evaporation of
samples.
Requirement: When evaporating in a drying oven, lower temperature to approximately 2
°C below boiling to prevent splattering. Ref: Standard Methods, 2540 B-2011. (3) (b).
Comment: The Total Residue benchsheet states temperatures between 103-1050C are
used for evaporation. The drying time needs to be documented on the benchsheet.
NNN. Finding: The samples are not weighed to constant weight, nor is an annual multiple
weighing study to verify the adequacy of the drying time, performed.
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.
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: 15 NCAC
21-1.0805 (a) (7) (A).
Total Cyanide — EPA Method 335.4, Rev. 1.0, 1993 (Aqueous)
Inorganic Phenols — EPA Method 420.1, Rev. (1978) (Aqueous)
Recommendation: It is recommended to document on the printed summary results sheets the
sample that was spiked and duplicated. This is designated on the preliminary worksheet by
subscript numbers.
000. Finding: The laboratory is not always documenting the initial sample volume and/or final
distillation volume. This is considered pertinent information.
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).

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#11 Microbac Laboratories, Inc.
Requirement: All analytical data pertinent to each certified analysis must be filed in an
orderly manner so as to be readily available upon request. Ref: 15A NCAC 2H .0805 (a)
(7) (A).
Comment: For Cyanide, the distillation log on January 31, 2018 only documented the
sample number. The documentation of the distillation process must include all
information necessary to provide historical reconstruction of final calculated sample
results. There were no distillation logs for July 14, 2017 and September 12, 2017 for any
of the methods.
Recommendation: It is recommended to coat sample vials with the same layer of silicone oil
as standard vials, to keep them comparable.
PPP. Finding: Results are not reported with the proper significant figures based on the
sample range.
Requirement: Report turbidity readings as follows:
Turbidity Range
Report to the nearest
0-1.0
0.05
1-10
0.1
10-40
1
40-100
5
100-400
10
400-1000
50
>1000
100
Ref: Standard Methods, 2130 B-2011 (5).
Comment: Results in the 1-10 NTU range are reported to two decimal places.
IV. PAPER TRAIL INVESTIGATION:
The paper trail consisted of comparing original records (e.g., laboratory benchsheets, logbooks,
etc.) and client reports. Fecal (MPN) data were reviewed for July 14, 2017, September 13, 2017,
January 25, 2018 and January 29, 2018. BOD data was reviewed for K860364-01 and K8A0069-
01. Cyanide data were reviewed for July 6, 2017, July 14, 2017, September 12, 2017, September
19, 2017, January 11, 2018 and January 19, 2018. IC data was reviewed for July 7, 2017,
September 12, 2017, January 3, 2018, January 5, 2018 and January 26, 2018. Phenol data was
reviewed for K7D0869-01 (TransMontaigne Inc. Roswell GA). Ammonia SM 4500 NI -is C-2011 for
July 7, 2017, July 10, 2018, September 1, 2017, September 6, 2017, January 10, 2018 and
January 12, 2018. Ammonia SM 4500 NH3 G-2011 data was reviewed for July 10, 2017, July 24,
2017, September 6, 2017, September 8, 2017 and January 8, 2018 and January 18, 2018. TKN
data was reviewed for July 5, 2017, July 11, 2017, September 8, 2017, September 13, 2017,
January 2, 2018 and January 8, 2018. Turbidity data was reviewed for July 6, 2017, July 13, 2017,
September 6, 2017, September 8, 2017, January 8, 2018 and January 18, 2018. Metals data was
reviewed for January 8, 2018. The following errors were noted: E. coli results for K7G0390,
K8A0151, K7G0390 and K8A0559 were reported without a qualifier indicating that they were
analyzed out of holding time (See Finding KK), Fecal Coliform (MF) data was calculated
incorrectly (See Finding DID) and Suspended Residue results were not calculated correctly (See
Finding JJJ.

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#11 Microbac Laboratories, Inc.
We are concerned with the Findings that were cited previously and not corrected.
Laboratory Decertification Ref: 15A NCAC 2H .0807 (a) (1), (13) and (14):
A laboratory may be decertified for any or all parameters for up to one year for any or all of the
following infractions:
(1) Failing to maintain the facilities, or records, or personnel, or equipment, or quality control
program as set forth in the application, and these Rules; or
(13) Failing to respond to requests for information by the date due; or
(14) Failing to comply with any other terms, conditions, or requirements of this Section or of a
Laboratory certification.
Correcting the above -cited Finding(s) and implementing the Recommendation(s) will help this
laboratory to produce quality data and meet Certification requirements. The inspector would like
to thank the staff for its 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: July 10, 2018
Report reviewed by: Jason Smith Date: July 10, 2018

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. In addition, if a MS duplicate is analyzed, the laboratory may choose to follow the method
defined acceptance criteria or develop statistically valid acceptance criteria that are not 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
following will apply.
No. of Target Analytes Requirement
1-10 Spike All
11-20 Minimum of 10 or 80%, whichever is greater
>20 Minimum of 16
Add a concentration that is at least 10 times the MRL, less than or equal to the mid -point of the calibration curve,
or method specified level to selected samples. Preferably use the same concentration as for the LFB to allow
analysts to separate the matrix's effect from laboratory's performance.
The concentration of the spiked samples must be bracketed by the calibration range. If the spiked sample result is
over the calibration range, the spiked sample must be diluted and re -analyzed. It is not acceptable to dilute the
sample first and then add the spike solution so as not to affect bias attributed to matrix.
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 <_ 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 must be adjusted by calculation.
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.)
Parameters Excluded from MS Requirements (All Field Parameters are exempt)
Acidity
Alkalinity
Bacteriological Parameters -
AII
BOD/CBOD
Chlorophyll a
Color — ADM
Color - PtCo
Conductivity
Dissolved Oxygen
Free Available Chlorine
Hardness — Titration
Ignitability
Paint Filter Test
Residues — All
pH
Salinity
Sulfite
Temperature
Total Residual Chlorine
Turbidity
Vector Attraction Reduction
(All Options)

Matrix Spike Technical Assistance
When spiking with multi -component standards and a subset is used, it is recommended that the spiking
compounds be periodically rotated to include all compounds of interest.
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 - Spike volume is greater than 1% of the total spiked sample volume. 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 Option 1 spike recovery is as follows:
%R= A*—Bx100
D
The general equation for Option 2 spike recovery is as follows:
%R= A*—(BXC)xlOO
D
Where:
(A) The spiked sample result
(B) Unspiked sample result
(C) % sample expressed as a decimal (sample volume used divided by final volume)
(D) Theoretical spike concentration
Note: If the spike sample is diluted, you must apply the dilution factor to the spiked sample result before
calculating the percent recovery. See Option 2, Example 3.
*Note: If the sample concentration is below the reporting limit, use zero for amount of target in the
unspiked sample.
To apply these general equations 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 1:
0.5 mL of a 1000 mg/L standard spike added to 100 mL of sample has a theoretical value of 5.0
mg/L.
(A) The spiked sample result is 5.1 mg/L
(B) If the unspiked sample result is 0.5 mg/L
(D) Theoretical value is 5.0 mg/L

The Percent Recovery = spiked sample result (A) — unspiked sample result (B) divided by
theoretical value (C) X 100; or
5.1 — 0.5 X 100 = 92% recovery A — B X 100 = Percent recovery
5.0 D
Option 1, Example 2:
If the spike sample is diluted, you must apply the dilution factor to the spiked sample result before
calculating the percent recovery.
1 mL of spike (concentration 250 mg/L) brought to 100 mL with sample the theoretical MS value is
2.5 mg/L. The spiked sample yielded approximately 3.1 mg/L, which is outside the upper limit of
the calibration curve, so a 2X dilution was performed on the spiked sample.
(A) The diluted spiked sample result is 1.6 mg/L. After applying the 2X dilution factor, the
spiked sample result is 3.2 mg/L (i.e., 2 x 1.6 mg/L = 3.2 mg/L).
(B) If the unspiked sample result is 0.5 mg/L
(D) Theoretical value is 2.5 mg/L
The Percent Recovery = spiked sample result (A) — unspiked sample result (B) divided by
theoretical value (D) X 100; or
3.2 — 0.5 X 100 = 108% recovery A — B X 100 = Percent recovery
2.5 D
Option 2 - Spike volume is greater than 1% of the total spiked sample volume. In this case the sample
concentration must be adjusted.
Option 2 Example 1:
5 mL of spike (concentration 50 mg/L) brought to 100 mL with sample the theoretical MS value is
2.5 mg/L.
(A) The spiked sample result is 3.1 mg/L
(B) If the unspiked sample result is 0.5 mg/L
(C) % sample is 0.95 (sample volume used (95) divided by final volume (100))
(D) Theoretical value is 2.5 mg/L
The Percent Recovery = spiked sample result (A) — (unspiked sample result (B) x % sample (C))
divided by theoretical value (D) X 100; or
3.1 — (0.5 x 0.95) X 100 = 105% recovery A — B x C X 100 = Percent recovery
2.5 D
Option 2 Example 2: Larger spike volume 10 mL of spike (concentration 50 mg/L) brought to 250
mL with sample the theoretical MS value is 2.0 mg/L.
(A) The spiked sample result is 2.6
(B) If the unspiked sample result is 0.5 mg/L
(C) % sample is 0.96 (sample volume used (240) divided by final volume (250))
(D) Theoretical value is 2.0 mg/L
The Percent Recovery = spiked sample result (A) — (unspiked sample result (B) x % sample (C))
divided by theoretical value (D) X 100; or
2.6 — (0.5 x 0.96) X 100 = 106% recovery A — (B x C) X 100 = Percent recovery
2.0 D

Option 2, Example 3:
If the spike sample is diluted, you must apply the dilution factor to the spiked sample result before
calculating the percent recovery.
5 mL of spike (concentration 50 mg/L) brought to 100 mL with sample the theoretical MS value is
2.5 mg/L. The spiked sample yielded 3.1 mg/L, which is outside the upper limit of the calibration
curve, so a 2X dilution was performed on the spiked sample.
(A) The diluted spiked sample result is 1.6 mg/L. After applying the 2X dilution factor, the
spiked sample result is 3.2 mg/L (i.e., 2 x 1.6 mg/L = 3.2 mg/L).
(B) If the unspiked sample result is 0.5 mg/L
(C) % sample is 0.95 (sample volume used (95) divided by final volume (100))
(D) Theoretical value is 2.5 mg/L
The Percent Recovery = spiked sample result (A) — (unspiked sample result (B) x % sample (C))
divided by theoretical value (D) X 100 or
3.2 — (0.5 x 0.95) X 100 = 109% recovery A — (B x C) X 100 = Percent recovery
2.5 D
Corrective Action/Qualifications for S/MSD
Spike accuracy is usually based on a range of percent recovery (e.g., 80-120%). Spike duplicate precision
is usually based on Relative Percent Difference (RPD). Refer to the method of choice for specific
acceptance criteria for accuracy and precision until the laboratory develops or adopts statistically valid,
laboratory -specific performance criteria. If a MS is out of established limits for either precision or accuracy,
and the LCS (and other quality control) 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.
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.
Multi -component Method Spike Requirements — Quick Reference
The following provides a quick reference for the spike component requirements for multi -component
methods.
® Standard Methods 6020B requires spiking all analytes of interest.
® SW-846 8000D requires spiking all analytes of interest.
® SW-846 9056A does not specify, so since there are 1-10 target analytes, all target analytes must
be spiked per this policy.
® For the EPA methods, including 608.3, 624.1, 625.1, 504.1 and 1653 all target analytes of interest
must be spiked. Exception: EPA Method 1650 requires spiking only with 2,4,6-Trichlorophenol.

Electronic Data Storage, Signature and Reporting Policy (04/09/2010)
Electronic records must be complete and in a form that does not allow alteration without
detection. The lab must insure that the complete records, including related support data, can be
maintained in a secure and accessible form on the pre-existing system or migrated to a new
system without modification, as needed, throughout the required retention period (5 years per
15A NCAC .0800). The system must use secure, computer -generated, time -stamped audit
trails to automatically record the date and time of operator entries and actions that create,
modify, or delete electronic records. Audit trails must also be maintained throughout the
required record -retention period and must be readily available for review. Audit trails must track
the old and new records when a change is made and these changes must not obscure
previously recorded information.
The system must ensure that any record bearing an electronic signature contains the name of
the signatory, the date and time of the signature, and information that explains the meaning
affixed to the signature (e.g., review, approval, responsibility, authorship, etc.). The electronic
signature must be unique to that individual at the time the signature is created and he or she
must be uniquely entitled to use it. Electronic signatures must be protected so that any
signature that has been affixed to a record cannot be changed, detached, copied or otherwise
compromised so as to falsify an electronic record. Electronic signatures must be included in
readable format on the electronic record and subsequent printouts, where applicable.
In addition, it is recommended that users sign an electronic signature agreement to properly
use and protect their, electronic signature attesting:
® They agree to protect the signature from use by anyone except themselves and
to confirm system security with third parties where necessary.
® They assert that the contents of the documents or records are both truthful and
accurate.
® They understand and agree they will be held legally bound, obligated or
responsible by their use of their electronic signature as they would with any
handwritten signature.
® They agree never to delegate the use of their electronic signature or make it
available to anyone else.
® They agree to report any compromise to the security of their electronic signature
within a defined reasonable period of time.
® When authorization to an electronic signature is revoked, the holder will be
notified.

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