#94_2019_0129_AO_FINAL_REVISED

Inspection Report Revision History

Environmental Chemists, Inc. (Certification # 94)

Action Date Original Report Revision
11-8-2019
[Salinity – SM 2520 B-2011 (Aqueous)]

HHHH. Finding: Samples are not analyzed
within the 15-minute holding time.
Finding was removed from the report due to
new information received from EPA Region
IV 11-8-2019. Salinity hold time is now
enforced at 28 days rather than 15 minutes.

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INSPECTION REPORT ROUTING SHEET

To be attached to all inspection reports in-house only.

Laboratory Cert. #: 94
Laboratory Name: Environmental Chemists, Inc. (EnviroChem)
Inspection Type: Commercial Maintenance
Inspector Name(s): Anna Ostendorff, Beth Swanson, Todd Crawford, Dana Satterwhite, Tonja
Springer, Michael Cumbus, Tom Halvosa
Inspection Date: 1/29/2019 – 1/31/2019
Date Forwarded for Initial
Review: 8/2/2019
Initial Review by: Jason Smith
Date Initial Review
Completed: 8/9/2019
Cover Letter to use:
Insp. Initial
Insp. No Finding
Corrected
(to use: rt click, properties, check)
Insp. Reg
Insp. CP
Insp. Reg. Delay
Unit Supervisor/Chemist III: Beth Swanson
Date Received: 9/3/2019
Date Forwarded to Admin.: 10/25/2019
Date Mailed: 10/29/2019
Special Mailing Instructions: Send a copy to Paul Calamita with NC WQA, Mark Vander Borgh with NC DEQ
DWR, and Matthew McIver with UNCW (lab #638)

On-Site Inspection Report

LABORATORY NAME: Environmental Chemists, Inc. (EnviroChem)
ADDRESS: 6602 Windmill Way, Wilmington, NC 28405
CERTIFICATE #: 94
DATE OF INSPECTION: January 29, 2019 – January 31, 2019
TYPE OF INSPECTION: Commercial Maintenance
AUDITOR(S): Anna Ostendorff, Beth Swanson, Todd Crawford, Dana Satterwhite,
Tonja Springer, Michael Cumbus and Tom Halvosa
LOCAL PERSON(S) CONTACTED:
Ray Porter, Rhonda Stokes, Darrin Boswell, Jesse Williams, Denise
Stalvey, Eric McHorney, Sharon Clark, Zach Taneyhill, Amber Maready,
Rick Crowell, Melanie Drish and Zach Owen

I. INTRODUCTION:

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 compliance monitoring samples.

II. GENERAL COMMENTS:

The NC WW/GW LC Rules 15A NCAC 02H .0800 were revised and went into effect July 1, 2019
and must be fully implemented by December 31, 2019. The report references the older version of
the Rules that were in effect during the time of the inspection. All Rule references in the report are
still requirements in the revised Rules, but now may have a different reference citation and slight
wording changes. Furthermore, many of the policies referenced in this report are now included in
the revised Rules.

An on-site audit was requested by the laboratory to ensure they were compliant with current State
and Federal rules and regulations. However, the laboratory was not able to demonstrate successful
efforts in determining what the current regulations are. The audit did not include review of Metals
(EPA 200.7, EPA 200.8, SW-846 6010 D, and SW-846 6020 B) or Mercury (EPA 245.1 and SW-
846 7471 B) data due to time constraints. The facility was neat and staff were forthcoming and
receptive to adopting the necessary changes.

The laboratory has two satellite locations (Certification # 1 and # 628) with shorter parameter lists.
Any corrections implemented in response to this inspection should also be implemented at the
satellite laboratories for the applicable parameter methods.

The laboratory documentation was not well organized. There were several instances where the
incorrect SOP was provided to the auditors, an SOP could not be located, or there were multiple
versions of a benchsheet, leading to much confusion. The laboratory is advised to implement an
effective document control system to ensure the following requirements are met: 1. All copies of
SOPs and/or benchsheets are current; 2. Personnel have read the policies/procedures relevant to
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their job activities; 3. All SOPs/benchsheets have been authorized by the laboratory director or
designee before implementation; 4. SOPs are reviewed at least every two years; and 5. SOPs are
readily available for inspection by the State Laboratory.

There are several Findings that could give the perception of falsification of data, including manually
integrating standards differently than samples and analyzing matrix spikes that have not gone
through the appropriate preparation procedures (e.g., digestion, distillation, etc.).

All required Proficiency Testing (PT) Samples for the 2019 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, 2019.

The laboratory submitted their Quality Assurance (QA) and Standard Operating Procedure
(SOP) documents 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 September 1, 2020.

The laboratory is reminded that any time changes are made to laboratory procedures, the
laboratory must update the QA/SOP documents and inform relevant staff. Any changes made in
response to the pre-audit review or to Findings, Recommendations or Comments listed in this
report must be incorporated to insure the method is being performed as stated, references to
methods are accurate, and the QA and SOP documents are in agreement with each approved
practice, test, analysis, measurement, monitoring procedure or regulatory requirement being
used in the laboratory. In some instances, the laboratory may need to create an SOP to
document how new functions or policies will be implemented.

The laboratory is also reminded that SOPs are intended to describe procedures exactly as they
are to be performed. Use of the word “should” is not appropriate when describing requirements
(e.g., Quality Control (QC) frequency, acceptance criteria, etc.). Evaluate all SOPs for the proper
use of the word “should”.

Laboratory Fortified Matrix (LFM) and Laboratory Fortified Matrix Duplicate (LFMD) are also
known as Matrix Spike (MS) and Matrix Spike Duplicate (MSD) and may be used
interchangeably in this report.

Requirements that reference 15A NCAC 2H .0805 (a) (7) (A), stating “All analytical data pertinent
to each certified analysis must be filed in an orderly manner so as to be readily available for
inspection upon request”, are intended to be a requirement to document information pertinent to
reconstructing final results and demonstrating method compliance. Use of this requirement is not
intended to imply that existing records are not adequately maintained unless the Finding speaks
directly to that.

III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS:

General Laboratory

A. Finding for Immediate Response: The laboratory was not using a pH meter to determine
pH in the analyses of Ammonia (titrimetric method), BOD and Inorganic Phenols.

Requirement: Each laboratory requesting certification must contain or be equipped with
the glassware, chemicals, supplies and equipment required to perform all analytical
procedures included in their certification. Ref: 15A NCAC 02H .0805 (a) (6) (H).

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Requirement: Proceed as described in 4500-NH3 B using indicating boric acid solution as
absorbent for the distillate. Ref: Standard Methods, 4500 NH3 C-2011. (4) (a).

Requirement: If necessary, neutralize to approximately pH 7 with dilute acid or base, using
a pH meter. Ref: Standard Methods, 4500 NH3 B-2011. (4) (b).

Requirement: Check pH; if it is not between 6.0 and 8.0, adjust sample temperature to 20
± 3°C, then adjust pH to 7.0 to 7.2 using a solution of sulfuric acid (H2SO4) or sodium
hydroxide (NaOH) of such strength that the quantity of reagent does not dilute the sample
by more than 0.5%. Ref: Standard Methods, 5210 B-2011. (4) (b) (1).

Requirement: To sample and standards add 10 mL of buffer solution and mix. The pH
should be 10 ± 0.2. Ref: EPA method 420.1, Rev. 1978, Section 8.3.3.

Requirement: Apparatus: pH meter. Ref: EPA method 420.1, Rev. 1978, Section 6.2.

Comment: The laboratory was using pH strips with 1 S.U. increments to verify sample pH
as required in each method. However, the pH strips are not accurate enough to determine
the pH ranges specified in the reference methods. A Notice of Finding for Immediate
Response (NOFIR) was issued so the laboratory could obtain and implement use of a pH
meter more quickly than if waiting to first receive the inspection report to take corrective
action. A response due date of March 1, 2019 was negotiated with the laboratory.

Comment: Acceptable corrective action (i.e., pH meters were purchased for each of the
three analyses) was performed by the laboratory and supporting documentation (i.e.,
copies of the packing slips) was received February 21, 2019. No further response is
necessary for this Finding.

B. Finding: The laboratory is not verifying digital thermometers quarterly.

Requirement: Digital temperature-measuring devices and temperature-measuring devices
used in incubators must be verified at least quarterly (i.e., every 3 months) (or sooner if the
temperature-measuring device has been exposed to temperatures beyond the
manufacturer’s recommended range of use or other stresses) against a Reference
Temperature-Measuring Device with the appropriate accuracy and the process
documented. Ref: NC WW/GW LC Policy.

Comment: The policy referenced above has been promulgated in the newly revised NC
WW/GW LC rules.

Comment: The laboratory has been replacing all thermometers annually.

Comment: If the laboratory chooses to perform the temperature measuring-device
verifications in-house, an NIST Traceable temperature-measuring device will need to be
purchased to serve as the Reference Temperature-Measuring Device. It may only be used
to verify the calibration of other temperature-measuring devices and may not be used for
routine laboratory equipment measurements. Alternatively, a calibration company or other
third-party vendor may be used for this service.

C. Finding: Manufacturer expiration dates are sometimes exceeded.

Requirement: Adherence to manufacturer expiration dates is required.
Chemicals/reagents/ consumables exceeding the expiration date can no longer be
considered reliable. If the expiration is only listed as a month and year (with no specific day
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of the month), the last day of the month will be considered the actual date of expiration.
Monitor materials for changes in appearance or consistency. Any changes may indicate
potential contamination and the item should be discarded, even if the expiration date is not
exceeded. If no expiration date is given, the laboratory must have a policy for assigning an
expiration date. If no date received or expiration date can be determined, the item should
be discarded. Ref: NC WW/GW LC Policy.

Comment: The policy referenced above has been promulgated in the newly revised NC
WW/GW LC rules.

Comment: The following instances of expired chemicals in use were noted:
• 10N NaOH used to preserve samples expired April 2018.
• Na2B4O7•10H2O was expired

Documentation

Comment: There were instances in the Field Parameter logbooks where the analyst’s handwriting
was difficult to read, which could pose issues with data defensibility and/or transcription errors. The
revised Rule, 15A NCAC 2H .0805 (a)(7)(E), states that all analytical records shall be legible to all
parties. There is no consistent organization or clear documentation in the Field Parameter
logbooks.

Recommendation: It is recommended that the laboratory develop and implement a standardized
benchsheet or logbook for the Field Parameter personnel. This would assist personnel in
remembering to document all required elements for each analysis and improve the laboratory’s
overall data defensibility.

Recommendation: It is recommended the laboratory define terms and acronyms in the SOP for
consistent use across all benchsheets, spreadsheets and instrument data.

Recommendation: It is recommended that the laboratory add the formula used to calculate
sample results to the benchsheets. This is recommended in particular for, but not limited to, the
following parameter methods:
• Acidity – SM 2310 B-2011 (Aqueous)
• Alkalinity – SM 2320 B-2011 (Aqueous)
• Hardness, Total – 2340 C-2011 (Aqueous): for low hardness (less than 5 mg/L) samples

D. Finding: The laboratory Field Parameter logbooks are lacking pertinent data: Facility
name; Sample site (ID or location); Permit number; Collector’s/analyst’s name or initials;
and 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
2H .0805 (a) (7) (A).

Requirement: The following must be documented in indelible ink whenever sample
analysis is performed: Facility name, sample site (ID or location), and permit number;
Collector’s/analyst’s name or initials; Instrument identification (serial number preferred).
Ref: NC WW/GW LC Approved Procedure for the Analysis of Total Residual Chlorine (DPD
Colorimetric), 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.

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Comment: The Field Parameter logbooks document the client name, but it is not clear if it
is the facility name or a sample site. Sometimes “Effluent” is documented. Permit numbers
are not documented.

Comment: This Finding applies to Total Residual Chlorine, Dissolved Oxygen, pH and
Temperature.

E. Finding: The laboratory Field Parameter logbooks are lacking pertinent data for Dissolved
Oxygen (DO): Meter calibration and meter calibration time(s).

Requirement: 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: Meter calibration and meter calibration time(s). Ref: NC WW/GW
LC Approved Procedure for the Analysis of Dissolved Oxygen.

Requirement: The laboratory must document each time that a calibration is performed.
Calibration documentation must include the following, where applicable to the instrument
used and the type of calibration performed: elevation, temperature, barometric pressure (in
mmHg), salinity. After calibration, record the final DO reading in mg/L, the slope or %
efficiency. Ref: NC WW/GW LC Approved Procedure for the Analysis of Dissolved Oxygen.

F. Finding: The laboratory Field Parameter logbooks are lacking pertinent data for pH: meter
calibration and meter calibration time(s).

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: Meter calibration and meter calibration time(s). Ref: NC WW/GW
LC Approved Procedure for the Analysis of pH.

Comment: The laboratory is sometimes documenting 4, 7, and 10 S.U. buffers, but does
not label this as a meter calibration or calibration check buffer.

G. Finding: The laboratory Field Parameter logbooks are lacking pertinent data for TRC: Date
of most recent calibration curve generation or calibration curve verification.

Requirement: The following must be documented in indelible ink whenever sample
analysis is performed: Date of most recent calibration curve generation or calibration curve
verification. Ref: NC WW/GW LC Approved Procedure for the Analysis of Total Residual
Chlorine (DPD Colorimetric).

H. Finding: The laboratory Field Parameter logbooks are lacking pertinent data: Time of
sample analysis. Cited Previously on April 25, 2011 for Total Residual Chlorine.

Requirement: All analytical data pertinent to each certified analysis must be filed in an
orderly manner so as to be readily available for inspection upon request. Ref: 15A NCAC
2H .0805 (a) (7) (A).

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Requirement: The following must be documented in indelible ink whenever sample
analysis is performed: Date and time of sample analysis. Ref: NC WW/GW LC Approved
Procedure for the Analysis of Total Residual Chlorine (DPD Colorimetric), 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.

Comment: Time of sample analysis must be documented to verify the 15-minute holding
time is met. Only one time is documented and is not labeled as measured in-situ.

Comment: Temperature, DO and pH may be measured in-situ. If the sample is measured
in-situ, one time may be documented with a notation that the sample is measured in-situ.

I. 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 February 28, 2011.

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: The policy referenced above has been promulgated in the newly revised NC
WW/GW LC rules.

Comment: The following instances were noted where traceability documentation was
inadequate:
• Metals: Receipt log for reagents did not document the date opened / in use.
• Chlorine, Total Residual – Hach 10014 ULR (Aqueous): Field parameter logbooks
do not document any traceability for reagents.
• Chlorine, Total Residual – Hach 8167 HR (Aqueous): Field parameter logbooks do
not document any traceability for reagents.
• Color – SM 2120 B-2011 (Aqueous): Benchsheet needs traceability for standards
and QC elements.
• Cyanide – EPA 335.4, Rev. 1.0, (1993) (Aqueous): Benchsheet needs traceability
for standards and QC elements.
• Inorganic Phenols – EPA 420.1, Rev. 1978 (Aqueous): There is not a preparation
log for QC standards and reagents, nor is there a system of traceability.
• Oil & Grease – EPA 1664 Rev. B (Aqueous): Receipt log did not document the date
opened / in use for OPR and filters.
• Pesticides, Organochlorine – SW -846 8081 B (all matrices): The extraction log
needs traceability for solvent used.
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• pH – SM 4500 H+ B-2011 (Aqueous): Field parameter logbooks do not document
any traceability for reagents.
• pH – SW -846 9045 D (Non-Aqueous): Field parameter logbooks do not document
any traceability for reagents.
• Polychlorinated Biphenyls (PCBs) – SW -846 8082 A (all matrices): The extraction
log needs traceability for solvent used.

Recommendation: It is recommended that the laboratory assign a unique ID for linkage
from the data to preparation documentation.

J. Finding: Some SOPs, 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: The method reference was noted to be outdated or absent for the following
parameter methods:
• Acidity – SM 2310 B-2011 (Aqueous): benchsheet
• Alkalinity – SM 2320 B-2011 (Aqueous): benchsheet
• Base Neutral/Acid, Organics – SW -846 8270 E (Aqueous): prep method incorrectly
noted as 8270 on extraction log. Actually following SW -846 3541.
• Chlorine, Total Residual – Hach 10014 ULR (Aqueous): Field parameter logbooks
• Chlorine, Total Residual – Hach 8167 HR (Aqueous): Field parameter logbooks
• COD – SM 5220 D-2011 (Aqueous): benchsheet
• Color – SM 2120 B-2011 (Aqueous): benchsheet
• Cyanide – EPA 335.4, Rev. 1.0, 1993 (Total) (Aqueous): raw data (QA Tray Report)
• Dissolved Oxygen – SM 4500 O G-2011 (Aqueous): Field parameter logbooks
• Fluoride – SM 4500 F- C-2011 (Aqueous): benchsheet
• Hardness, Total – SM 2340 C-2011 (Aqueous): benchsheet
• Ignitability (Flashpoint) – SW -846 1010 A (Pensky-Martens) (Aqueous): benchsheet
• MBAS – SM 5540 C-2011 (Aqueous): benchsheet
• Nitrogen, Ammonia – SM 4500 D-2011 (Aqueous): benchsheet
• pH – SM 4500 H+ B-2011 (Aqueous): Field parameter logbooks
• Sulfide – SM 4500 S2- D-2011 (Aqueous): benchsheet
• Temperature – SM 2550 B-2010 (Aqueous): Field parameter logbooks

Recommendation: The list above is not comprehensive. It is recommended that the
laboratory check all benchsheets against the Certified Parameters Listing (CPL) to ensure
all benchsheets reflect the correct method reference.

K. Finding: 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: Units of measure were not documented or were inconsistently documented on
the following benchsheets and/or logs:
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• Acidity – SM 2310 B-2011 (Aqueous): Benchsheet was missing units in “Final pH”,
“NaOH vol”, and “True Value” column headers.
• Alkalinity – SM 2320 B-2011 (Aqueous): Benchsheet was missing units for “pH from
A”, “final pH”, and “Acid Vol” column headers.
• Chlorine, Total Residual – Hach 10014 ULR (Aqueous): Field parameter logbooks
• Chlorine, Total Residual – Hach 8167 HR (Aqueous): Field parameter logbooks
• Color – SM 2120 B-2011 (Aqueous): Benchsheet was missing units, Color Units
(CU)
• Dissolved Oxygen – SM 4500 O G-2011 (Aqueous): Field parameter logbooks
• Inorganic Phenols – EPA 420.1, Rev. 1978 (Aqueous): Benchsheet was missing
units for sample dilution volume and pH.
• MBAS – SM 5540 C-2011 (Aqueous): Benchsheet was missing units for
absorbance (nm).
• Oil & Grease – EPA 1664 Rev. B (Aqueous): Benchsheet was missing units for pH
and second weighing.
• Polychlorinated Biphenyls (PCBs) – SW -846 8082 A (Aqueous): Extraction batch
sheet was missing units for initial volume/mass and pH.
• pH – SM 4500 H+ B-2011 (Aqueous): Field parameter logbooks
• Sulfide – SM 4500 S2- D-2011 (Aqueous): Benchsheet was missing units for closing
Continuing Calibration Verification (CCV).
• Temperature logs for the drying ovens, BOD incubators and sample storage
refrigerators were missing consistent units of measure for Temperature (in the wet
lab in building 2)
• Temperature – SM 2550 B-2010 (Aqueous): Field parameter logbooks
• Chain of Custody (COC) forms were missing units of measure for temperatures of
sample at collection and upon receipt.

L. Finding: The preservative used is not consistently documented on the COC form.

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).

Comment: This Finding was noted for the following parameter methods:
• Inorganic Phenols – EPA 420.1, Rev. 1978 (Aqueous): The sample preservative
used for sample number 3244 was not check marked.

M. Finding: The laboratory is not always documenting the analysts’ initials on the
benchsheets and/or raw data.

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).

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).

Comment: Instances of this finding were noted for the following parameter methods:
• Cyanide – EPA 335.4, Rev. 1.0, 1993 (Total) (Aqueous)
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• Extractable Petroleum Hydrocarbons – MADEP, May 2004, Rev. 1.1 (Aqueous &
Non-Aqueous): extraction log
• Base Neutral/Acid, Organics – EPA 625.1 (Aqueous): extraction log
• Base Neutral/Acid, Organics – SW-846 8270E (Aqueous & Non-Aqueous):
extraction log

Recommendation: It is recommended that the laboratory maintain a log of all analysts’
signatures and initials.

N. Finding: The laboratory is not consistently documenting the post-distillation volume used
for analysis.

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).

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).

Comment: Instances of this finding were noted for the following parameter method:
• Cyanide – EPA 335.4, Rev. 1.0, 1993 (Total) (Aqueous)

Comment: The final sample volume of the distillate must be documented to determine if
the final results must be adjusted due to sample dilution or concentration.

O. Finding: The digestion log for Total Phosphorus and Total Kjeldahl Nitrogen (TKN) is
lacking pertinent information: initial sample volume, final sample volume and temperature.

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: Pipet 25.0 mL of sample, standard or blank in the digestor tube. Ref: EPA
Method 351.2, Rev. 2.0 (1993), Section 11.1.

Requirement: Place tubes in block digestor preheated to 160°C and maintain temperature
for one hour. Reset temperature to 380°C and continue to heat for one and one half hour.
(380°C MUST BE MAINTAINED FOR 30 MINUTES). Ref: EPA Method 351.2, Rev. 2.0
(1993), Sections 11.4. and 11.5.

Requirement: Use 50 mL or a suitable portion of thoroughly mixed sample. Ref: Standard
Methods, 4500 P B-2011. (5) (c).

Requirement: Boil gently on a preheated hot plate for 30 to 40 min or until a final volume of
10 mL is reached. Ref: Standard Methods, 4500 P B-2011. (5) (c).

Comment: This Finding applies to the following parameter methods:
• Nitrogen, Total Kjeldahl – EPA 351.2, Rev. 2.0, 1993 (Aqueous)
• Phosphorus, Total – SM 4500 P E-2011 (Aqueous)
• Phosphorus, Total – SM 4500 P F-2011 (Aqueous)
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P. Finding: The laboratory benchsheet does not clearly document the date and time in and
out of the oven for Residue samples.

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).

Comment: The analyst documents two times on each of the benchsheets, but it is not clear
that it is the time samples are placed in and removed from the drying ovens. This must be
clearly labeled on the benchsheet. The time Total Dissolved Residue samples are placed in
and removed from the 180 °C oven must also be documented.

Comment: This Finding applies to the following parameter methods:
• Residue, Dissolved – SM 2540 C-2011 (Aqueous)
• Residue, Suspended – SM 2540 D-2011 (Aqueous)
• Residue, Total – SM 2540 B-2011 (Aqueous)

Q. Finding: The use of heat-indicating tape is not always documented. This is considered
pertinent information.

Requirement: All analytical data pertinent to each certified analysis must be filed in an
orderly manner so as to be readily available for inspection upon request. Ref: 15A NCAC
2H .0805 (a) (7) (A).

Requirement: Use heat-indicating tape to identify supplies and materials that have been
sterilized. Ref: Standard Methods, 9020 B-2005. (4) (h).

Comment: Analysts state that heat-indicating tape is used with each sterilizing cycle. A
comment is sometimes added to the Autoclave Log that states the heat-indicating tape
turned color, but this is not consistently recorded.

R. Finding: The calibration standard concentrations used for comparison in the analysis of
Color is not documented. This is considered pertinent data.

Requirement: All analytical data pertinent to each certified analysis must be filed in an
orderly manner so as to be readily available for inspection upon request. Ref: 15 NCAC 2H
.0805 (a) (7) (A).

Requirement: Observe sample color by filling a matched Nessler tube to the 50-mL mark
with sample and comparing it with standards. Ref: Standard Methods, 2120 B-2011. (5) (c).

S. Finding: The laboratory benchsheet for Conductivity does not clearly identify which
standard(s) are used for calibration and which are used for calibration verification.

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: True value of the standard used for calibration; True value of the
calibration verification check standard. Ref: NC WW/GW LC Approved Procedure for the
Analysis of Specific Conductance (Conductivity).
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T. Finding: Error corrections are not always properly performed. Cited Previously on
February 28, 2011.

Requirement: All documentation errors must be corrected by drawing a single line through
the error so that the original entry remains legible. Entries shall not be obliterated by
erasures or markings. Wite-Out®, correction tape or similar products designed to obliterate
documentation are not to be used. Write the correction adjacent to the error. The correction
must be initialed by the responsible individual and the date of change documented. All data
and log entries must be written in indelible ink. Pencil entries are not acceptable. Ref: NC
WW/GW LC Policy.

Comment: The policy referenced above has been promulgated in the newly revised NC
WW/GW LC rules.

Comment: Several instances of error corrections were observed where the original entry
was struck through with a single line but was not initialed or dated.

U. Finding: Standard true values and/or evaluations of the acceptance criteria are not always
stated accurately.

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: This Finding was noted for Sulfate – EPA 300.0, Rev. 2.1, 1993 (Aqueous).
The "CCV1" analyzed at 12:21 on September 5, 2018 was listed as having a true value of
10 ppm. The observed concentration was 48.8688 ppm. An evaluation of 97.7 % recovery
was documented.

V. Finding: The laboratory was not documenting the instrument operating conditions for each
sample batch for all organic methods.

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: This Finding was noted for the following parameter methods:
• Pesticides, Organochlorine – SW -846 8081 B (Aqueous and Non-Aqueous)
• Pesticides, Organochlorine – EPA 608.3 (Aqueous)
• Polychlorinated Biphenyls (PCBs) – SW -846 8082 A (Aqueous, Non-Aqueous and
Oil)
• Polychlorinated Biphenyls (PCBs) – EPA 608.3 (Aqueous)

Proficiency Testing

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

Requirement: Each laboratory shall develop and maintain a document outlining the
analytical quality control practices used for the parameters included in their certification.
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Supporting records shall be maintained as evidence that these practices are being
effectively carried out. Ref: 15A NCAC 2H .0805 (a) (7).

Requirement: Laboratories must have a documented plan [this is usually detailed in the
laboratory’s Quality Assurance Manual or may be a separate Standard Operating
Procedure (SOP)] of how they intend to cover the applicable program requirements for
Proficiency Testing per their scope of accreditation. This plan shall cover any commercially
available PT Samples and any inter-laboratory organized studies, as applicable. The
laboratory must also be able to explain when PT Sample analysis is not possible for certain
methods and provide a description of what the laboratory is doing in lieu of Proficiency
Testing. This shall be detailed in the plan. The plan must also address the laboratory’s
process for submission of PT Sample results and related Corrective Action Reports
(CARs). Ref: Proficiency Testing Requirements, October 29, 2018, Revision 3.

Requirement: SOPs must address situations where the instructions from the Accredited
PT Provider for the preparation, analysis or result calculations would constitute a deviation
from the laboratory’s routine procedure. Examples of this may include how low-level PT
Samples will be analyzed, including concentration of the sample or adjustment of the
normality of a titrant. These instructions shall be followed when the concentration of a PT
Sample is below the range of their routine analytical method. Instructions shall also be
included in the laboratory’s SOP for how high-level PT Samples will be analyzed, including
preparation of multiple dilutions of the sample. These instructions will be followed when the
concentration of a PT Sample is above the range of their routine analytical method. Ref:
Proficiency Testing Requirements, October 29, 2018, Revision 3.

X. Finding: Additional QC beyond what is routine for Compliance Samples is being analyzed
with PT Samples.

Requirement: Laboratories are required to analyze an appropriate PT Sample by each
parameter method on the laboratory’s CPL. The same PT Sample may be analyzed by one
or more methods. Laboratories shall conduct the analyses in accordance with their routine
testing, calibration and reporting procedures, unless otherwise specified in the instructions
supplied by the Accredited PT Sample Provider. This means that they are to be logged in
and analyzed using the same staff, sample tracking systems, standard operating
procedures including the same equipment, reagents, calibration techniques, analytical
methods, preparatory techniques (e.g., digestions, distillations and extractions) and the
same quality control acceptance criteria. PT Samples shall not be analyzed with additional
quality control. They are not to be replicated beyond what is routine for Compliance Sample
analysis. Although, it may be routine to spike Compliance Samples, it is neither required,
nor recommended, for PT Samples. PT sample results from multiple analyses (when this is
the routine procedure) must be calculated in the same manner as routine Compliance
Samples. Ref: Proficiency Testing Requirements, October 29, 2018, Revision 3.

Comment: The TRC PT sample was duplicated and the first value was reported.
Compliance Samples for TRC are not routinely duplicated.

Quality Control

Comment: The revised Rule, 15A NCAC 02H .0805 (a) (7), now includes a requirement to
implement a formal process to review quality assurance documents and SOPs every two years.
Supporting records of the review dates and any revisions must be maintained.

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Comment: The revised Rule, 15A NCAC 02H .0805 (a) (7) (P), now includes a requirement for
laboratories to develop and implement a training program that includes documentation that staff
have read the laboratory quality assurance manual and applicable SOPs.

Comment: The laboratory performed MDL studies for Polychlorinated Biphenyls (PCBs) (SW-846
8082 A) and Organochlorine Pesticides (SW-846 8081 B) according to the outdated procedure.
MDL studies are not required for these methods. However, if the laboratory chooses to perform
MDL studies where the method does not require it, the laboratory should adhere to the updated
MDL procedure as written in Appendix B of the 2017 Method Update Rule of the 40 CFR Part 136.

Recommendation: It is recommended that the laboratory review all MDL studies for applicable
methods to ensure the updated MDL procedure has been implemented.

Y. Finding: SOPs have not been developed and/or updated for all of the methods included on
the laboratory’s Certified Parameters Listing (CPL).

Requirement: Each laboratory shall develop and maintain a document outlining the
analytical quality control practices used for the parameters included in their certification.
Supporting records shall be maintained as evidence that these practices are being
effectively carried out. Ref: 15A NCAC 2H .0805 (a) (7).

Comment: The following parameter methods do not have an SOP:
• Bacteria, Coliform Fecal – SM 9221 C E-2006 (MPN) 24hr 503 (Non-Aqueous)
• Bacteria, Coliform Total – SM 9222 B-2006 (MF) (Aqueous)
• Leachate Procedure – SW -846 1311 Organics (Aqueous and Non-Aqueous)
• Leachate Procedure – SW -846 1312 Metals (Aqueous and Non-Aqueous)
• Leachate Procedure – SW -846 1312 Organics (Aqueous and Non-Aqueous)
• Mercury – SW -846 7471 B (Non-Aqueous)
• Nonhalogenated Volatile Organics – SM-846 8015 C (Aqueous and Non-Aqueous)
• Purgeable Aromatics – SW -846 8021 B (Aqueous and Non-Aqueous)
• Purgeable Halocarbons – SW -846 8021 B (Aqueous and Non-Aqueous)

Comment: Leachate procedures are no longer available for certification with the 15A
NCAC 02H .0800 Rule effective July 1, 2019. However, the laboratory must maintain an
SOP for extraction procedures.

Z. Finding: The laboratory does not have an SOP for manual integration.

Requirement: Each laboratory must develop a Standard Operating Procedure (SOP),
describing manual integration procedures. Alternatively, the laboratory may include manual
integration procedures in all applicable method SOPs. Ref: NC WW/GW LC Policy.

AA. Finding: The State Laboratory is not notified when samples are received out of
compliance.

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).

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Requirement: Fill the sample bottle just to overflowing in such a manner that no air
bubbles pass through the sample as the bottle is being filled. Seal the bottle so that no
air bubbles are entrapped in it. Ref: EPA Method 624.1, December 2014, Section 9.1.

Requirement: Fill sample bottle just to overflowing without passing air bubbles through
sample or trapping air bubbles in sealed bottle. Ref: Standard Methods, 6010 B-2011. (1).

Requirement: Fill an Imhoff cone to the 1-L mark with a well-mixed sample. Ref: Standard
Methods, 2540 F-2011 (3) (a).

Requirement: Aqueous samples should be collected in triplicate (or the number of vials
directed by the laboratory) without agitation and without headspace in contaminant-free 40
mL glass VOC vials with Teflon-lined septa screw caps. The Teflon liner must contact the
sample. Ref: MADEP, Method for the Determination of Volatile Petroleum Hydrocarbons
(VPH), February 2018, Rev. 2.1, Section 8.1.1.

Comment: The following instances were noted where non-compliant samples were
analyzed without notifying the State Laboratory:
• Purgeable, Organics – EPA Method 624.1 (Aqueous)
• Purgeable, Organics – SW -846 Method 8260 D (Aqueous)
• Purgeable, Organics – Standard Methods 6200 B-2011 (Aqueous)
• Residue, Settleable – Standard Methods, 2540 F-2011 (Aqueous)
• Sulfide – SM 4500 S2- D-2011 (Aqueous): Client report numbers 15064, 15144 and
15185 were received and analyzed out of hold time.
• Volatile Petroleum Hydrocarbons – MADEP, February 2018, Rev. 2.1 (Aqueous)

Comment: The laboratory analyzes and reports results for samples received for
Purgeable Organic compounds and Volatile Petroleum Hydrocarbons with 1/4", pea-
sized, air bubbles in Volatile Organic Compound (VOC) vials without qualification.
However, data from samples received with any air bubbles must be qualified and the
State Laboratory notified.

Comment: Settleable Residue is a method-defined parameter per the definition in the
Code of Federal Regulations, Part 136.6, Section (a) (5). This means that the method may
not be modified to reduce the sample volume per Section (b) (3).

BB. Finding: The laboratory is not calibrating mechanical volumetric liquid-dispensing devices
at least twice per year.

Requirement: Mechanical volumetric liquid-dispensing devices (e.g., fixed and adjustable
auto-pipettors, bottle-top dispensers, etc.) must be calibrated at least twice per year,
approximately six months apart. Each liquid-dispensing device must meet the
manufacturer’s statement of accuracy. For variable volume devices used at more than one
setting, check the accuracy at the maximum, middle and minimum values. Testing at more
than three volumes is optional. When a device capable of variable settings is dedicated to
dispense a single specific volume, calibration is required at that setting only. Ref: NC
WW/GW LC Policy.

Comment: The policy referenced above has been promulgated in the newly revised NC
WW/GW LC rules.

Comment: The laboratory was calibrating mechanical pipettors annually.

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CC. Finding: Precision (e.g., relative percent difference) and/or accuracy (e.g., percent
recovery) of QC results are not consistently calculated, evaluated or documented to
demonstrate the analytical process is in control and the 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: Following is a list of methods for which precision of QC results is not being
evaluated:
• Alkalinity – SM 2320 B-2011 (Aqueous)
• Nitrogen, Ammonia – SM 4500 NH3 C-2011 (Aqueous)
• Nitrogen, Ammonia – SM 4500 NH3 D-2011 (Aqueous)
• Chromium, Hexavalent – SM 3500 Cr B-2011 (Aqueous)
• Fluoride – SM 4500 F- C-2011 (Aqueous)
• Oil & Grease – SW -846 9071 B (Non-Aqueous)
• 1,2, Dibromoethane (EDB) – EPA 504.1 (Includes DBCP & TCP) (Aqueous)

Comment: Following is a list of methods for which accuracy of QC results is not being
evaluated:
• Alkalinity – SM 2320 B-2011 (Aqueous)
• Cyanide – EPA 335.4, Rev. 1.0, 1993 (Total) (Aqueous): CCV, LCS
• Nitrogen, Ammonia – EPA 350.1, Rev. 2.0, 1993 (Aqueous): CCV, Laboratory
Control Sample (LCS)
• Nitrogen, Ammonia – SM 4500 NH3 D-2011 (Aqueous): MSD
• Nitrite – EPA 353.2, Rev. 2.0, 1993 (Aqueous): CCV, LCS
• Nitrate + Nitrite – EPA 353.2, Rev. 2.0, 1993 (Aqueous): CCV, LCS
• Nitrogen, Total Kjeldahl – EPA 351.2, Rev. 2.0, 1993 (Aqueous): CCV, LCS
• Sulfate – EPA 300.0, Rev. 2.1, 1993 (Aqueous): Reporting limit standard (“Low
Std”) for the batch run February 9, 2018; MDL standard analyzed September 5,
2018.
• TPH Diesel Range, Organics – SW -846 8015 C (Aqueous & Non-Aqueous): MS for
batch run on February 12, 2018.

Comment: The precision of the LCS/LCSD was not evaluated for Volatile Petroleum
Hydrocarbons by MADEP, Feb 2018, Rev. 2.1 (Aqueous & Non-Aqueous).

Comment: The calibration standard back-calculation was not evaluated for
Orthophosphate by SM 4500 P E-2011 (Aqueous).

Comment: The results for the Continuing Calibration Blank (CCB) were not documented
for Total Kjeldahl Nitrogen by EPA 351.2, Rev. 2.0, 1993 (Aqueous).

DD. Finding: The laboratory is not always generating a 3-standard calibration curve daily or a
5-standard calibration curve every 12 months, where applicable.

Requirement: 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
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10 percent at mid-range, each time a new stock standard is prepared, or at least every
twelve months. Ref: 15A NCAC 2H .0805 (a) (7) (I).

Comment: This Finding was noted for the following parameter methods:
• Phosphate, Ortho – SM 4500 P E-2011 (Aqueous): prepared 12/2/2016 and
3/19/2018
• Phosphorus, Total – SM 4500 P E-2011 (Aqueous): last prepared 1/17/2017

EE. Finding: The laboratory is not analyzing an Initial Calibration Verification (ICV), where
required by the method.

Requirement: Calibration verification – The RF or calibration curve must be verified
immediately after calibration and at the beginning of each 12-hour shift, by analysis of a
standard at or near the concentration of the mid-point calibration standard (Section 7.2.1).
The standard(s) must be obtained from a second manufacturer or a manufacturer’s batch
prepared independently from the batch used for calibration. Traceability must be to a
national standard, when available. Include the surrogates (Section 6.8) in this solution. It is
necessary to verify calibration for the analytes of interest (Section 1.3) only. Ref: EPA
Method 625.1, Rev. 2.0, Section 7.3.

Requirement: There must be an ICAL of the GC/MS system as described in Sec. 11.3.
Prior to analyzing samples, verify the ICAL standards using a second source ICV standard,
if readily available (See Secs. 7.7.1 and 11.3.7). Ref: EPA SW-846 Test Methods for
Evaluating Solid Waste, Physical/Chemical Methods; 3rd Edition, Method 8270 E, Rev. 6,
June 2018, Section 9.3.2.

Comment: This Finding was noted for the following parameter methods:
• Base Neutral/Acid, Organics – EPA 625.1 (Aqueous)
• Base Neutral/Acid, Organics – SW -846 8270 E (Aqueous & Non-Aqueous)

FF. Finding: The laboratory is not always back-calculating calibration standards, where
required.

Requirement: Back calculate the concentration of each calibration point. 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).

Requirement: Calibration, especially when using linear regression models, has the
potential for a significant bias at the lower portion of the calibration curve. The lowest
calibration point should be recalculated (not reanalyzed) using the final calibration curve in
which this standard is used (i.e., re-fitting the response from the low concentration
calibration standard back into the curve). See Method 8000 for additional details. The
recalculated concentration of the low calibration point (especially where linear regression
fits are used) should be within ±50% of the standard's true concentration, and the
recalculated concentrations of any calibration standards above the LLOQ should be within
±30%. Ref: EPA SW-846 Test Methods for Evaluating Solid Waste, Physical/Chemical
Methods; 3rd Edition, Method 8270 E, Rev. 6, June 2018, Section 11.3.6.

Requirement: The NC WW/GW Laboratory Certification Branch must confirm that
analytical data is valid by reviewing the QA/QC data generated during the sampling and
analysis procedures when implementing SW-846 methods in order to be assured that
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scientifically sound decisions are made which will be protective of human health and the
environment. To promote consistency with the use of SW-846 methods and to assure
generation of data of known quality, the minimum recommended quality control
benchmarks in the methods will be considered the minimum QA/QC requirements. For
example, where a method states, “Documenting the effect of the matrix on target analyte
measurements should include the analysis of at least one matrix spike and one duplicate
unspiked samples or one matrix spike/matrix spike duplicate pair.”, the laboratory must
analyze at least one matrix spike and one duplicate unspiked sample or one matrix
spike/matrix spike duplicate pair. Laboratories may adopt more stringent QC acceptance
criteria for method performance but may not omit or use less stringent criteria than that
stated in SW-846 methods. Ref: NC WW/GW LC Policy.

Comment: The following instances where back calculation is required and was not
performed were noted:
• Sulfide – SM 4500 S2- D-2011 (Aqueous)
• Base Neutral/Acid, Organics – SW -846 8270 E (Aqueous)

GG. Finding: The laboratory is not always preparing the Laboratory Reagent Blank (LRB)
properly.

Requirement: Laboratory Reagent Blank (LRB) -- An aliquot of reagent water or other
blank matrices that are treated exactly as a sample including exposure to 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
351.2, Rev. 2.0, Section 3.6.

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).

Comment: The LRB was not being digested for the following parameter methods:
• Nitrogen, Total Kjeldahl – EPA 351.2, Rev. 2.0, 1993 (Aqueous)
• Phosphorus, Total – SM 4500 P E-2011 (Aqueous)
• Phosphorus, Total – SM 4500 P F-2011 (Aqueous)

Comment: The LRB did not include the preservative for the following parameter method:
• COD – SM 5220 D-2011 (Aqueous)

HH. Finding: The laboratory is not always preparing the Laboratory Fortified Blank (LFB)
properly.

Requirement: Laboratory Fortified Blank (LFB) -- 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 351.2, Rev. 2.0, Section 3.4.

Requirement: A laboratory-fortified blank [laboratory control standard (LCS)] is a reagent
water sample (with associated preservatives) to which a known concentration of the
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analyte(s) of interest has been added. Process the LFB through all sample preparation and
analysis steps. Ref: Standard Methods, 1020 B-2011. (6).

Comment: The LFB was not being digested for the following parameter methods:
• Nitrogen, Total Kjeldahl – EPA 351.2, Rev. 2.0, 1993 (Aqueous)
• Phosphorus, Total – SM 4500 P E-2011 (Aqueous)
• Phosphorus, Total – SM 4500 P F-2011 (Aqueous)

Comment: The LFB did not include the preservative for the following parameter method:
• COD – SM 5220 D-2011 (Aqueous)

II. Finding: The laboratory is not always analyzing a calibration blank and calibration
verification standard after every 10 samples for colorimetric and ion-selective electrode
methods.

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.

Comment: The policy referenced above has been promulgated in the newly revised NC
WW/GW LC rules. However, it is no longer required that the calibration verification standard
be mid-range.

Comment: Instances of this finding were noted in the data reviewed for the following
parameter methods:
• Nitrogen, Ammonia – SM 4500 NH3 D-2011 (Aqueous)
• Nitrogen, Total Kjeldahl – EPA 351.2, Rev. 2.0, 1993 (Aqueous)
• Phosphate, Ortho – SM 4500 P E-2011 (Aqueous)
• Phosphorus, Total – SM 4500 P E-2011 (Aqueous)

JJ. Finding: The Instrument Performance Check (IPC) standard is not at a mid-range
concentration, where required by the method.

Requirement: For all determinations the laboratory must analyze the IPC (a mid-range
check standard) and a calibration blank immediately following daily calibration, after every
10th sample (or more frequently, if required) and at the end of the sample run. Ref: EPA
Method 350.1, Rev. 2.0 (1993), Section 9.3.4.

Comment: The IPC may also be referred to as the CCV.

Comment: This Finding was noted for the following parameter method:
• Nitrogen, Ammonia – EPA 350.1, Rev. 2.0, 1993 (Aqueous)

KK. Finding: The laboratory is not always analyzing an LFM at the required frequency.

Requirement: The laboratory must add a known amount of analyte to a minimum of 10%
of the routine samples. Ref: EPA Method 350.1, Rev. 2.0, Section 9.4.1.

Requirement: The laboratory must add a known amount of analyte to a minimum of 10%
of the routine samples. Ref: EPA Method 353.2, Rev. 2.0, Section 9.4.1.
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Requirement: When appropriate for the analyte (Table 4020:I), 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:I and (2) (g).

Comment: This Finding was noted for the following parameter methods:
• Nitrogen, Ammonia – EPA 350.1, Rev. 2.0, 1993 (Aqueous): 5% of samples were
spiked
• Nitrite – EPA 353.2, Rev. 2.0, 1993 (Aqueous): 5% of samples were spiked
• Nitrate + Nitrite – EPA 353.2, Rev. 2.0, 1993 (Aqueous): 5% of samples were
spiked
• Nitrogen, Total Kjeldahl – SM 4500 Norg B-2011 (SM 4500 NH3 C-2011) (Aqueous):
samples spiked at an inconsistent frequency

LL. Finding: The laboratory is not rotating the range of spike concentrations.

Requirement: 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%. Ideally, the new concentration should be at or below the midpoint of the
calibration curve, and for maximum accuracy, the spike should approximately double the
sample's original concentration. If necessary, dilute the spiked sample to bring the
measurement within the calibration curve. Also, rotate the range of spike concentrations to
verify performance at various levels. Ref: Standard Methods, 4020 B-2011. (2) (g).

Requirement: 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%. Ideally, the new concentration should be at or below the midpoint of the
calibration curve, and for maximum accuracy, the spike should approximately double the
sample’s original concentration. If necessary, dilute the spike sample to bring the
measurement within the calibration curve. Also, rotate the range of spike concentrations to
verify performance at various levels. Ref: Standard Methods, 5020 B-2010, Table 5020:I
and (2) (g).

Comment: The following instances were noted where the spike concentration was not
varied:
• Nitrogen, Ammonia – SM 4500 NH3 C-2011 (Aqueous)
• Nitrogen, Ammonia – SM 4500 NH3 D-2011 (Aqueous)
• Organic Carbon, Dissolved – SM 5310 B-2011 (Combustion) (Aqueous)
• Organic Carbon, Total – SM 5310 B-2011 (Combustion) (Aqueous)
• Phosphate, Ortho – SM 4500 P E-2011 (Aqueous)
• Phosphorus, Total – SM 4500 P F-2011 (Aqueous)

MM. Finding: The laboratory is not always preparing the LFM correctly.

Requirement: 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%. Ideally, the new concentration should be at or below the midpoint of the
calibration curve, and for maximum accuracy, the spike should approximately double the
sample’s original concentration. If necessary, dilute the spiked sample to bring the
measurement within the calibration curve. Also, rotate the range of spike concentrations to
verify performance at various levels. Ref: Standard Methods, 4020 B-2011. (2) (g).
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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.

Requirement: 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. Ref: NC WW/GW
LC Policy.

Requirement: A Post Digestion Spike (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. Ref: NC WW/GW LC Policy.

Requirement: The laboratory must add a known amount of analyte to a minimum of 10%
of the routine samples. In each case the LFM aliquot must be a duplicate of the aliquot
used for sample analysis. The analyte concentration must be high enough to be detected
above the original sample and should not be less than four times the MDL. The added
analyte concentration should be the same as that used in the laboratory fortified blank. Ref:
EPA Method 350.1, Rev. 2.0 (1993), Section 9.4.1.

Requirement: The LFM is analyzed exactly like a sample, and its purpose is to determine
whether the sample matrix contributes bias to the analytical results. Ref: EPA Method
335.4, Revision 1.0 (1993), Section 3.5.

Comment: The laboratory is preparing the LFM with a spike solution volume greater than
5% of the total LFM volume for the following parameter methods:
• Nitrogen, Ammonia – SM 4500 NH3 C-2011 (Aqueous)
• Nitrogen, Ammonia – SM 4500 NH3 D-2011 (Aqueous)
• Nitrogen, Total Kjeldahl – EPA 351.2, Rev. 2.0, 1993 (Aqueous)

Comment: The laboratory is diluting samples prior to the addition of the spike solution for
the following parameter methods:
• Purgeable, Organics – EPA 624.1 (Aqueous)
• Purgeable, Organics – SW -846 8260 D (Aqueous)
• Purgeable, Organics – SM 6200 B-2011 (Aqueous)

Comment: The laboratory is performing a 40x dilution prior to spiking the samples for the
analysis of Purgeable Organics. Diluting the sample prior to spiking can dilute out any
interference that the spiking procedure is designed to detect.

Comment: The laboratory is analyzing the sample and then adding the spike solution on
top to analyze again as the LFM for the following parameter methods:
• Nitrogen, Total Kjeldahl – EPA 351.2, Rev. 2.0, 1993 (Aqueous)
• Phosphorus, Total – SM 4500 P F-2011 (Aqueous)

Comment: The laboratory is adding the spike solution to samples after distillation for the
following parameter methods:
• Cyanide – EPA 335.4, Rev. 1.0, 1993 (Total) (Aqueous)
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NN. Finding: The laboratory is not calculating the MS percent recovery properly.

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.

Requirement: If the sample concentration is below the reporting limit, use zero for amount
of target in the unspiked sample. Ref: NC WW/GW LC Policy.

Comment: The laboratory is not applying the sample volume dilution factor in the percent
recovery calculation when the spike volume is greater than 1% of the total sample volume.

Comment: The laboratory is not using zero for the amount of target in the unspiked sample
when the value is less than the reporting limit.

OO. Finding: The laboratory is not analyzing an LFMD where required in the method.

Requirement: When appropriate for the analyte (Table 4020:I), 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:I and (2) (g).

Comment: This applies to the following parameter methods:
• Nitrogen, Total Kjeldahl – SM 4500 Norg B-2011 (SM 4500 NH3 C-2011) (Aqueous)
• Phosphate, Ortho – SM 4500 P E-2011 (Aqueous)
• Phosphorus, Total – SM 4500 P E-2011 (Aqueous)
• Phosphorus, Total – SM 4500 P F-2011 (Aqueous)
• Sulfide – SM 4500 S2- D-2011 (Aqueous)

Comment: The laboratory is analyzing sample duplicates rather than an LFMD. An LFMD
is required for these methods.

PP. 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: This was observed for the following parameter methods:
• Chlorinated Acid Herbicides – SW -846 8151 A (Aqueous & Non-Aqueous)
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• Extractable Petroleum Hydrocarbons – MADEP, May 2004, Rev. 1.1 (Aqueous &
Non-Aqueous)
• Pesticides, Organochlorine – SW -846 8081 A (Aqueous & Non-Aqueous)
• Sulfate – EPA 300.0, Rev. 2.1, 1993 (Aqueous)

Reporting

QQ. Finding: Data that does not meet all QC requirements is not always qualified on the client
report.

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 policy referenced above has been promulgated in the newly revised NC
WW/GW LC rules.

Comment: The following instances were noted where QC failures occurred, but the data
was not qualified on the client report:
• Base Neutral/Acid, Organics – SW -846 8270 E (Aqueous): Sample ID 17-49018 not
qualified for MS/MSD exceedance.
• Base Neutral/Acid, Organics – EPA 625.1 and SW-846 8270 E (Aqueous): Data is
not qualified when Surrogate recoveries exceed acceptance criteria.
• Inorganic Phenols – EPA 420.1, Rev. 1978 (Aqueous): Sample number 3244
duplicate precision exceeded acceptance criterion.
• MBAS – SM 5540 C-2011 (Aqueous): Sample ID 18-04897. MS exceeded
acceptance criterion.
• Nitrogen, Total Kjeldahl – EPA 351.2, Rev. 2.0, 1993 (Aqueous): Sample IDs 18-
17082, 18-17111 and 18-17185. CCV exceeded acceptance criterion
• Purgeable Halocarbons – EPA 601 / SM 6200 C-2011 (Aqueous): Sample ID 18-
18690. MS and CCV exceeded acceptance criteria.
• Oil & Grease – EPA 1664 Rev. B (Aqueous): Sample number 3533. MS recoveries
exceeded acceptance criterion.
• TPH Diesel Range, Organics – SW -846 8015 C (Non-Aqueous): Report number
18-01377. Final CCV exceeded acceptance criterion.

RR. Finding: The laboratory is analyzing samples and reporting data without North Carolina
Wastewater/Groundwater Laboratory Certification.

Requirement: Commercial laboratories are required to obtain certification for parameters
which will be reported by the client to comply with State surface water monitoring,
groundwater, and pretreatment Rules. Ref: 15A NCAC 2H .0804 (a).

Comment: The following instances of samples analyzed without certification were noted:
• Cyanide – EPA 335.4, Rev. 1.0, 1993 (Total) (Non-Aqueous): Appears a solid or
sludge sample was analyzed for the Town of Morehead City. Currently only certified
for the Aqueous matrix.
• Nitrogen, Total Kjeldahl – SM 4500 Norg B-2011 (SM 4500 NH3 C-2011) (Non-
Aqueous): Non-Aqueous samples were analyzed. Currently only certified for the
Aqueous matrix.
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• Sulfide – SM 4500 S2- D-2011 (Non-Aqueous): Non-Aqueous samples were
analyzed in the same batch as Aqueous samples. Currently only certified for the
Aqueous matrix.

Comment: Certification for Non-Aqueous matrices is distinct and separate from Aqueous
matrices. If the laboratory needs to add Non-Aqueous methods to their CPL, a formal
request must be made.

SS. Finding: The laboratory does not report results of all tests on the characteristics of the
effluent when duplicate sample analyses are performed.

Requirement: The results of all tests on the characteristics of the effluent, including but not
limited to NPDES permit monitoring requirements, shall be reported on the monthly report
forms. Ref: 15A NCAC 2B .0506 (b) (3) (J).

Comment: This Finding was noted for the following parameter method:
• Inorganic Phenols – EPA 420.1, Rev. 1978 (Aqueous)

Comment: The laboratory may either report both values from the sample and sample
duplicate or the values may be averaged. If sample duplicates are performed for pH, both
values must be reported. The averaging of pH sample results is not permitted.

TT. Finding: Values for pH were reported that exceed the method specified accuracy of 0.1
units.

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

Comment: The laboratory was reporting sample results to two decimal places.

Acidity – Standard Methods, 2310 B-2011 (Aqueous)

Recommendation: It is recommended that initial pH be added to the benchsheet.

Recommendation: It is recommended that the end time be removed from the benchsheet since it
is not necessary nor being used.

Alkalinity – Standard Methods, 2320 B-2011 (Aqueous)

Comment: The laboratory is currently analyzing a MS/MSD. This is not required per the method.
The laboratory may eliminate the MS and analyze a sample duplicate. However, if the laboratory
continues to analyze a MS/MSD, the percent recovery of the MS and MSD will need to be
evaluated.

Recommendation: It is recommended that the beginning and end times be removed from the
benchsheet since they are not required documentation items nor are they being used.

Recommendation: It is recommended that the laboratory vary the concentration of the LFB to
cover the range from the midpoint to the lower part of the calibration curve, including the reporting
limit.
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Comment: The laboratory denotes the LFB as LCS on the benchsheet.

Bacteria – Coliform Fecal – Standard Methods, 9222 D-2006 (MF) (Aqueous)

UU. Finding: Samples are not always incubated for 24 ± 2 hours.

Requirement: Incubate for 24 ± 2 h at 44.5 ± 0.2°C. Ref: Standard Methods, 9222 D-2006.
(2) (d).

Comment: In the data reviewed, a few instances were observed in February 2018 where
samples were removed from the incubator after 20.5 and 21 hours.

VV. Finding: Consumable materials used for the Fecal Coliform MF method 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)
(f) (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. Please
obtain (i.e., purchase or borrow) a new lot of media and perform the consumable
testing on your current media and submit the results of this study with your
response to this report.

Comment: New lots of consumable materials are tested prior to use with commercially
prepared QC samples and evaluated against the vendor specified acceptance criteria. Five
plates are evaluated for each new lot of media, filters and pads. This is documented and
kept on file. Performing a side-by-side comparison of the old and new lots ensures the new
materials do not adversely affect bacterial growth.

WW. Finding: Plate comparison counts are not being performed.

Requirement: For routine performance evaluation, repeat counts on one or more positive
samples at least monthly, record results, and compare the counts with those of other
analysts testing the same samples. Replicate counts for the same analyst should agree
within 5% (within analyst repeatability of counting) and those between analysts should
agree within 10% (between analysts’ reproducibility of counting). If they do not agree,
initiate investigation and any necessary corrective action. Ref: Standard Methods, 9020 B-
2005. (9) (a).

Bacteria – Coliform Fecal – IDEXX Colilert-18® (MPN) (Aqueous)
Bacteria – E. Coli – IDEXX Colilert-18® (MPN) (Aqueous)
Bacteria – Enterococci – IDEXX Enterolert® (MPN) (Aqueous)

XX. Finding: Duplicate analyses were not performed.

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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).

Comment: Duplicate analyses were implemented beginning January 21, 2019.

Comment: It is recommended the laboratory use the 95% Confidence Interval Table
provided by email on February 1, 2019 to evaluate duplicates.

Chlorine, Total Residual – Hach 10014 ULR (Aqueous)
Chlorine, Total Residual – Hach 8167 HR (Aqueous)

YY. Finding: The Factory-set Calibration Curve is not verified with a Daily Check Standard
each day that samples are analyzed.

Requirement: When an annual five-standard Factory-set Calibration Curve verification is
used, the laboratory must check the calibration curve each analysis day. To do this, the
laboratory must zero the instrument with a Calibration Blank and analyze a Daily Check
Standard (gel-type standards are most widely used for these purposes). The value
obtained for the Daily Check Standard must read within 10% of the true value of the Daily
Check Standard. If the obtained value is outside of the ±10% range, corrective action must
be taken. Ref: NC WW/GW LC Approved Procedure for the Analysis of Total Residual
Chlorine (DPD Colorimetric).

Comment: A liquid standard must be prepared and analyzed to verify the meter calibration
when using the Hach 10014 method. A gel standard may be used to verify the meter
calibration when using the Hach 8167 method.

COD – Standard Methods, 5220 D-2011 (Aqueous)

ZZ. Finding: The laboratory is not analyzing an LFM.

Requirement: When appropriate for the analyte (Table 5020:I), 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,
5020 B-2010, Table 5020:I and (2) (g).

Color – Standard Methods, 2120 B-2011 (PtCo) (Aqueous)

AAA. Finding: Samples are not stored at ≤6 °C.

Requirement: Cool, ≤6 °C. Ref: Code of Federal Regulations, Title 40, Part 136; Federal
Register Vol. 82, No. 165, August 28, 2017; Table II.

BBB. Finding: The sample pH is not checked.

Requirement: Check sample pH. If outside the range of 4 to 10, preferably adjust sample
to pH 7 and note the adjustment. Ref: Standard Methods, 2120 B-2011. (5) (b).

Comment: Calibration of the pH meter must be documented, if used. Alternatively, pH
strips may be used.

CCC. Finding: Sample duplicates are not analyzed at the required frequency.
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Requirement: Analyze every tenth sample in duplicate (i.e., duplicating the entire
procedure) to assess method precision. Ref: Standard Methods, 2120 B-2011. (7) (b).

Comment: Sample duplicates must be analyzed with each batch of 10 or fewer samples.

DDD. Finding: Sample results are not reported as Apparent CU when samples are not filtered.

Requirement: If samples are not filtered, report data as Apparent CU. Ref: Standard
Methods, 2120 B-2011. (6) (b).

EEE. Finding: Sample pH is not being reported with the results.

Requirement: Report sample pH. Ref: Standard Methods, 2120 B-2011. (6) (c).

Conductivity – EPA 120.1, Rev. 1982 (Aqueous)

Comment: The laboratory is currently analyzing a blank with each sample batch. This is not
required.

Comment: The laboratory is currently analyzing sample duplicates. Sample duplicates are not
required for Field Parameters.

Recommendation: It is recommended that the “*sample temp to 0.1°C” be removed from the
benchsheet since it is not required to document sample temperature for the analysis of
Conductivity and the meter is equipped with an Automatic Temperature Compensator (ATC).

FFF. Finding: The Automatic Temperature Compensator (ATC) was not verified prior to initial
use and every 12 months thereafter.

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 25°C (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).

GGG. Finding: Samples are being diluted.

Requirement: Conductivity samples must not be diluted. Ref: NC WW/GW LC Approved
Procedure for the Analysis of Specific Conductance (Conductivity).

Cyanide – EPA 335.4, Rev. 1.0, 1993 (Total) (Aqueous)

Comment: It is not clear from the raw data or the SOP which standards are distilled and which are
not. This needs to be clearly identified and defined in the SOP and on laboratory benchsheets.

Comment: If sulfamic acid must be added for nitrate or nitrite interference, a MB and LFB must
also be treated with sulfamic acid.

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Recommendation: It is recommended that the laboratory obtain a copy of the ASTM D7365-09a
method, which addresses mitigating interferences in water samples for the analysis of Cyanide.
Table II of 40 CFR Part 136 footnotes 5 and 6 refer specifically to this document.

HHH. Finding: The Method Detection Limit (MDL) does not support the current reporting level.

Requirement: The method detection limit (MDL) is defined as the minimum measured
concentration of a substance that can be reported with 99% confidence that the measured
concentration is distinguishable from method blank results. Ref: Code of Federal
Regulations, Title 40, Part 136; Federal Register Vol. 82, No. 165, August 28, 2017;
Appendix B–Definition and Procedure for the Determination of the Method Detection Limit–
Revision 2.

Comment: The study performed 12/10/2018 determined the MDL to be 0.0066 mg/L. The
reporting level is 0.005 mg/L. The laboratory must either elevate the reporting level above
the MDL or repeat the MDL study with results determined to be less than the reporting
level.

III. Finding: The Stock Cyanide Solution is not standardized.

Requirement: Stock Cyanide Solution: Dissolve 2.51 g of KCN (CASRN-151-50-8) and 2 g
KOH (CASRN-1310-58-3) in 900 mL of reagent water. Standardize with 0.0192 N AgNO3
(Section 7.9). Dilute to appropriate concentration so that 1 mL = 1 mg CN. Ref: EPA
Method 335.4, Revision 1.0 (1993), Section 7.10.

Comment: The Stock Cyanide Solution must be standardized after preparation. It must
also be re-standardized prior to preparing new intermediate standards, regardless of
whether the Stock Cyanide Solution is purchased or prepared in house.

JJJ. Finding: Calibration standards are not analyzed in order of decreasing concentration.

Requirement: Place appropriate standards in the sampler in order of decreasing
concentration and perform analysis. Ref: EPA Method 335.4, Revision 1.0 (1993), Section
10.5.

KKK. Finding: The laboratory does not have a mechanism in place for reducing the holding time
to 24 hours when ascorbic acid is added to samples.

Requirement: Sampling, preservation and mitigating interferences in water samples for
analysis of cyanide are described in ASTM D7365-09a. Ref: Code of Federal Regulations,
Title 40, Part 136; Federal Register Vol. 82, No. 165, August 28, 2017; Table II, Footnote 6.

Requirement: 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.

Comment: The laboratory did not have a copy of the ASTM Method D7365-09a on file.

Inorganic Phenols – EPA 420.1, Rev. 1978 (Aqueous)

LLL. Finding: The laboratory was not performing all required QC elements.

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Requirement: If the method lacks QA/QC procedures, the permittee/laboratory has the
following options to comply with the QA/QC requirements: (c)(1) Incorporate the following
twelve quality control elements, where applicable, into the laboratory’s documented
standard operating procedure (SOP) for performing compliance analyses when using an
approved Part 136 method when the method lacks such QA/QC procedures. One or more
of the twelve QC elements may not apply to a given method and may be omitted if a written
rationale is provided indicating why the element(s) is/are inappropriate for a specific
method. (i) Demonstration of Capability (DOC); (ii) Method Detection Limit (MDL); (v) Matrix
spike (MS) and matrix spike duplicate (MSD), or laboratory fortified matrix (LFM) and LFM
duplicate, may be used for suspected matrix interference problems to assess precision.
Ref: Code of Federal Regulations, Title 40, Part 136; Federal Register Vol. 77, No. 97, May
18, 2012; 136.7. (c) (1).

Comment: The EPA 420.1, Rev. 1978 method does not contain any QC procedures.
Therefore, the twelve QC elements outlined in 40 CFR Part 136.7 must be included. The
laboratory was lacking a Demonstration of Capability, a Method Detection Limit study and
an MSD.

Comment: The laboratory was analyzing an MS and sample duplicate. However, when
using this method, an MSD is required per 40 CFR Part 136.7, so a sample duplicate may
not be used in its place to demonstrate precision.

MMM. Finding: The laboratory was not calibrating with the method specified number of
standards.

Requirement: Using working solution B (7.8), prepare the following standards. Standards
may be prepared by pipetting the required volumes into the separatory funnels and diluting
to 500 mL with distilled water.
Ref: EPA Method 420.1, Rev. 1978, Section 8.3.1.

Comment: The laboratory was preparing a 3-standard calibration curve each analysis day.
However, since Inorganic Phenols is a method-defined parameter, the calibration
procedure must be followed as written.

MBAS – Standard Methods, 5540 C-2011 (Aqueous)

Comment: While the method requires samples to be rocked vigorously, the laboratory is cautioned
to not shake samples so hard during extraction so as to cause emulsion formation or foam.

Recommendation: It is recommended that the laboratory only document the calibration standard
values on the benchsheet that are actually used.

NNN. Finding: The laboratory is not documenting the molecular weight of LAS in the reagent log
book or on the benchsheet.

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Requirement: Report results in terms of a suitable standard calibration curve, for example
“0.65 mg MBAS/L (calculated as LAS, mol. wt. 318”). Plot a calibration curve of absorbance
vs. micrograms LAS taken, specifying the molecular weight of the LAS used. Ref: Standard
Methods, 5540 C-2011. (1) (d) and (4) (a).

OOO. Finding: Sample results were not reported in terms of LAS molecular weight.

Requirement: Report as “MBAS, calculated as LAS, mol wt _____.” Ref: Standard
Methods, 5540 C-2011. (5).

PPP. Finding: The laboratory is not pre-extracting the glass wool.

Requirement: Glass wool: Pre-extract with CHCl3 to remove interferences. Ref: Standard
Methods, 5540 C-2011. (3) (k).

QQQ. Finding: The laboratory is not rinsing the delivery tube between extractions.

Requirement: Draw off CHCl3 layer into a second separatory funnel. Rinse delivery tube of
first separatory funnel with a small amount of CHCl3. Repeat extraction two additional
times, using 10 mL CHCl3 each time. If blue color in water phase becomes faint or
disappears, discard and repeat, using a smaller sample. Ref: Standard Methods, 5540 C-
2011. (4) (d) (3).

RRR. Finding: The laboratory is not rinsing funnels and glass wool after second extraction of the
wash solution.

Requirement: Combine all CHCl3 extracts in the second separatory funnel. Add 50 mL was
solution and shake vigorously for 30 s. Emulsions do not form at this stage. Let settle, swirl,
and draw off CHCl3 layer through a funnel containing a plug of glass wool into a 100-mL
volumetric flask; filtrate must be clear. Extract wash solution twice with 10 mL CHCl3 each
and add to flask through the glass wool. Rinse glass wool and funnel with CHCl3. Collect
washings in volumetric flask, dilute to mark with CHCl3, and mix well. Ref: Standard
Methods, 5540 C-2011. (4) (d) (4).

SSS. Finding: The laboratory is not calibrating with at least five standards.

Requirement: Prepare an initial calibration curve consisting of at least five standards
covering the referenced (5540C.1f) or desired concentration range. Ref: SM 5540 C-2011.
(4) (a).

Comment: The laboratory is calibrating with three standards. However, since MBAS is a
method-defined parameter, the calibration procedure must be followed as written.

TTT. Finding: The laboratory is not using the method-specified acceptance criterion for
evaluating the reporting limit standard.

Requirement: Provided that linearity is demonstrated over the range of interest (r = 0.995
or better) run daily check standards at the reporting limit and a concentration above the
expected samples’ concentration. Check standard results should be within 25% of original
value at the reporting limit and 10% of original value for all others. Otherwise, prepare a
new calibration curve. Ref: SM 5540 C-2011. (4) (a).

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Comment: The laboratory is using an acceptance criterion of 30% to evaluate the reporting
limit standard. No instances of the reporting limit standard exceeding 25% were noted in
the data reviewed.

UUU. Finding: The method blank and LFB are not treated in the same manner as samples when
interferences are mitigated.

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. Process the LFB through all sample preparation and
analysis steps. Ref: Standard Methods, 1020 B-2011. (6).

Nitrogen, Ammonia – Standard Methods, 4500 NH3 C-2011 (Aqueous)
Nitrogen, Ammonia – Standard Methods, 4500 NH3 D-2011 (Aqueous)
Nitrogen, Ammonia – EPA 350.1, Rev. 2.0, 1993 (Aqueous)

VVV. Finding: Samples are not checked for Total Residual Chlorine upon receipt at the
laboratory.

Requirement: Residual Chlorine reacts with ammonia; remove by sample pretreatment. If
a sample is likely to contain residual chlorine, immediately upon collection, treat with
dechlorinating agent as in 4500-NH3.B.3d. Ref: SM 4500 NH3 A-2011 (2).

Requirement: Sample preparation: Remove the residual chorine in the sample by adding
dechlorinating agent (Section 7.5) equivalent to the chlorine residual. Ref: EPA Method
350.1, Rev. 2.0, Section 11.2.

Requirement: Except where noted in this Table II and the method for the parameter,
preserve each grab sample within 15 minutes of collection. For a composite sample
collected with an automated sample (e.g., using a 24-hour composite sample; see 40 CFR
122.21 (g)(7)(i) or 40 CFR Part 403, Appendix E), refrigerate the sample at ≤6°C during
collection unless specified otherwise in this Table II or in the method(s). For a composite
sample to be split into separate aliquots for preservation and/or analysis, maintain the
sample at ≤6°C, unless specified otherwise in this Table II or in the method(s), until
collection, splitting, and preservation is completed. Add the preservative to the sample
container prior to sample collection when the preservative will not compromise the integrity
of a grab sample, a composite sample, or aliquot split from a composite sample within 15
minutes of collection. If a composite measurement is required but a composite sample
would compromise sample integrity, individual grab samples must be collected at
prescribed time intervals (e.g., 4 samples over the course of a day, at 6-hour intervals). Ref:
Code of Federal Regulations, Title 40, Part 136; Federal Register Vol. 88, No. 165, August
28, 2017; Table II, Footnote 2.

Requirement: A record of date collected, time collected, sample collector, and use of
proper preservatives must be maintained. 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
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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: Samples for analysis of Ammonia by Titration (SM 4500 NH3 C-2011) are
checked for chlorine at the bench prior to analysis. However, this must be done at the time
of collection or upon receipt at the laboratory.

Comment: If samples are received with a detectable amount of chlorine (i.e., >0.5 mg/L),
the laboratory must notify the client to recollect the sample, if possible. If recollection is not
possible and the sample is analyzed, the results must be reported with qualification and the
State Laboratory must be notified, per 15A NCAC 02H .0800.

Nitrogen, Ammonia – Standard Methods, 4500 NH3 C-2011 (Aqueous)

Recommendation: It is recommended that the laboratory include the titrant standardization date
on the benchsheet.

WWW. Finding: The laboratory is not steaming out the distillation apparatus properly for cleaning.

Requirement: Add 500 mL water and 20 mL borate buffer, adjust pH to 9.5 with 6N NaOH
solution, and add to a distillation flask. Add a few glass beads or boiling chips and use this
moisture to steam out the distillation apparatus until distillate shows no traces of ammonia.
Ref: 4500 NH3 B-2011 (4) (a).

Comment: The laboratory is not adding borate buffer or NaOH when steaming out the
distillation apparatus.

Nitrogen, Ammonia – Standard Methods, 4500 NH3 D-2011 (Aqueous)

Comment: The benchsheet did not document QC evaluations prior to May 2018.

Recommendation: It is recommended that the acceptance criterion for the meter calibration slope
be listed on the benchsheet.

XXX. Finding: The laboratory is adding 10N NaOH before immersing the electrode.

Requirement: Do not add NaOH solution before immersing electrode, because ammonia
may be lost from a basic solution. Ref: SM 4500 NH3 D-2011 (4) (b).

Comment: This Finding applies to both samples and standards.

Nitrogen, NO3 + NO2 – EPA 353.2, Rev. 2.0, 1993 (Aqueous)

Recommendation: It is recommended that the laboratory compare at least one nitrite standard to
a nitrate standard of the same concentration to verify the efficiency of the reduction column per
EPA Method 353.2, Section 10.1.

Nitrogen, Total Kjeldahl – Standard Methods, 4500 Norg B-2011 (Standard Methods, 4500
NH3 C-2011) (Aqueous)

Recommendation: It is recommended that the laboratory digest and analyze an organic nitrogen
standard with each TKN analysis to determine and verify digestion efficiency and accuracy. The
following glutamic acid standard is an acceptable option (with any required adjustment for
analytical range):
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Weigh 1.0503 grams of dried glutamic acid.
Bring to volume with deionized H2O in a 1000 ml volumetric flask.
Add 1 ml of concentrated H2SO4 for preservation.

This solution yields 100 mg/L of organic nitrogen. 10 mg/L is recommended as a mid-range level
for each set of analyses. Establish acceptance limits based upon three standard deviations of the
mean concentration of a minimum of 25 measurements. The laboratory may adopt a default
acceptance criterion until sufficient data points are collected to calculate historical control limits.

Oil & Grease – EPA 1664 Rev. B (Aqueous)

Recommendation: It is recommended that the acceptance criteria for the weight checks be added
to the benchsheet.

Recommendation: It is recommended that the OPR lot number be added to the benchsheet.

YYY. Finding: The Practical Quantitation Limit (PQL) is not being adjusted when less than 1L of
sample is being analyzed.

Requirement: Determine the original sample volume (Vs) in liters by filling the sample
bottle to the mark with water and measuring the volume of water in a 1- to 2-L graduated
cylinder. If the sample weight was used (Section 11.1.4), weigh the empty bottle and cap
and determine Vs by difference, assuming a sample density of 1.00. Ref: EPA method
1664 Rev. B, Section 11.4.5.

Requirement: n-Hexane extractable material–Calculate the concentration of HEM (“oil and
grease”) in the sample per the following equation: HEM (mg/L) = (Wh in mg) / (Vs in L)
where:

Wh = Weight of extractable material from Section 11.4.4.1 (mg)
Vs = Sample volume from Section 11.4.5 (L).

Ref: EPA Method 1664, Rev. B, Section 12.1.

Comment: This was noted for samples in client reports 18-37105 and 18-36490.

ZZZ. Finding: Sample results are not reported to the correct number of significant figures.

Requirement: Report results to three significant figures for HEM and SGT-HEM found at or
above 10 mg/L, and report results to two significant figures for HEM and SGT-HEM found
below 10 mg/L. Ref. EPA Method 1664, Rev. B, Section 12.3.

Requirement: Samples–Report results for HEM and SGT-HEM found below the ML as <
5.0 mg/L, or as required by the permitting authority or permit. Ref. EPA Method 1664, Rev.
B, Section 12.3.1.

Comment: Results found at or above 10 mg/L are reported to four significant figures.
Results found below 5 mg/L are reported as <5 mg/L, rather than <5.0 mg/L as required.

pH – Standard Methods, 4500 H+ B-2011 (Aqueous)
pH – SW-846 9045 D (Aqueous)

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AAAA. Finding: The laboratory is not analyzing a check standard after calibration and prior to
sample analysis for samples analyzed in the field.

Requirement: Instruments are to be calibrated according to the manufacturer’s calibration
procedure prior to analysis of samples each day compliance monitoring is performed.
Calibration must include at least two buffers. The meter calibration must be verified with a
third standard buffer solution (i.e., check buffer) prior to sample analysis. Ref: NC WW/GW
LC Approved Procedure for the Analysis of pH.

Phosphate, Ortho – Standard Methods, 4500 P E-2011 (Aqueous)

BBBB. Finding: Samples are not filtered within 15 minutes of collection.

Requirement: The immediate filtration requirement in orthophosphate measurement is to
assess the dissolved or bio-available form of orthophoshorus (i.e., that which passes
through a 0.45-micron filter), hence the requirement to filter the sample immediately upon
collection (i.e., within 15 minutes of collection). Ref: Code of Federal Regulations, Title 40,
Part 136; Federal Register Vol. 82, No. 165, August 28, 2017; Table II, Footnote 24.

Residue, Dissolved 180 C – Standard Methods, 2540 C-2011 (Aqueous)
Residue, Suspended – Standard Methods, 2540 D-2011 (Aqueous)
Residue, Total – Standard Methods, 2540 B-2011 (Aqueous)

CCCC. Finding: The laboratory is not notifying the State Laboratory when less than one liter of
sample is provided for analysis and the minimum weight gain of 2.5 mg is not achieved
when the entire sample volume is analyzed.

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: Residues are considered a method-defined parameter per the definition in the
Code of Federal Regulations, Part 136.6, Section (a) (5). This means that the method may
not be modified to reduce the sample volume per Section (b) (3).

Comment: No instances of samples gaining less than the 2.5 mg minimum were observed
for Dissolved Residue or Total Residue in the data reviewed. There were instances
observed in the Suspended Residue data where samples neither gained the minimum 2.5
mg nor was 1 L of sample provided.

DDDD. Finding: The laboratory is not always analyzing 10% of samples in duplicate each day
analyses are performed.

Requirement: Analyze at least 10% of all samples in duplicate. Ref: Standard Methods,
2540 D-2011. (3) (c).

EEEE. Finding: Data is not qualified when less than 2.5 mg of dried residue is obtained and less
than 1 L of sample is used.

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
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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).

Requirement: Choose sample volume to yield between 2.5 and 200 mg dried residue. If
volume filtered fails to meet minimum yield, increase sample volume up to 1 L. Ref:
Standard Methods, 2540 D-2011 (3) (b).

Comment: This Finding was noted only when less than 1 L of sample was provided.

Residue, Dissolved 180 C – Standard Methods, 2540 C-2011 (Aqueous)
Residue, Total – Standard Methods, 2540 B-2011 (Aqueous)

FFFF. Finding: The samples are not weighed to constant weight, nor is an annual drying 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.

Comment: North Carolina currently allows for an annual drying study in lieu of the
requirement above to repeat the drying cycle for every sample. A random full set of
samples should be used for the drying study. The repeated drying time in the oven should
be at least 1 hour long. The time used for the annual drying study is the minimum time that
samples are to be dried until a new drying study is performed.

Comment: Effective January 1, 2021, NC WW/GW LC will no longer allow drying studies
or dry filter blanks to substitute for drying and weighing to a constant weight. Prior to
filtering samples, all filters will have to be washed and dried to a constant weight (within 0.5
mg of the prior weight). All filters after filtering samples will also have to be dried and
weighed to a constant weight (within 0.5 mg of the prior weight).

Residue, Total – Standard Methods, 2540 B-2011 (Aqueous)

GGGG. Finding: A quarterly check standard is not being analyzed.

Requirement: Analyze one suspended residue, one dissolved residue, one residual
chlorine and one oil and grease standard quarterly. Ref: 15A NCAC 2H .0805 (a) (7) (B).

Comment: The revised Rule increases the frequency of analyzing a check standard to
monthly for Total Suspended Residue, Total Dissolved Residue and Total Residue. The
laboratory must implement the requirements of the revised Rule by January 1, 2020.

Sulfate – EPA 300.0, Rev. 2.1, 1993 (Aqueous)

HHHH. Finding: The IPC is not always analyzed immediately after calibration.

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Requirement: For all determinations the laboratory must analyze the IPC (a mid-range
check standard) and a calibration blank immediately following daily calibration, after every
tenth sample (or more frequently, if required) and at the end of the sample run. Analysis of
the IPC solution and calibration blank immediately following calibration must verify that the
instrument is within ±10% of calibration. Ref: EPA Method 300.0, Rev. 2.1 (1993), Section
9.3.4.

Comment: The laboratory only analyzes a mid-range standard on days when held curves
are used.

IIII. Finding: The laboratory was not always drawing the baseline correctly during manual
integration.

Requirement: Under no circumstances will manual integration be performed solely for the
purpose of meeting quality control criteria, nor is it to be used as a substitute for proper
sample preparation (e.g., cleanup), proper instrument optimization or maintenance on the
chromatographic system. Corrective actions, with regard to the instrumentation for
computer software, must be taken if manual integrations become common for an analysis
or an instrument that normally uses automated peak integration. Examples of inappropriate
manual integration may include the following:

• Peak trimming, shaving or clipping
• Peak enhancement
• Baseline elevated above the signal
• Baseline dropped below the signal
• Improper peak identification
• Selectively adjusting integration events
• Insufficient sensitivity

Ref: NC WW/GW LC Policy.

Comment: The manual integrations of the MDL4 and MDL5 chromatograms analyzed
February 9, 2018 did not draw the baseline at the proper level, which resulted in peak
shaving.

1,2, Dibromoethane (EDB) – EPA Method 504.1, Revision 1.1, 1995 (Aqueous)

Comment: It is the laboratory’s standard practice to only analyze trip blanks if the associated
samples contain the analyte of interest at a concentration above the reporting limit.

Recommendation: It is recommended that the CCV be evaluated as a percent recovery. The
CCV is being evaluated as percent difference from the true value. All other standards are
evaluated as a percent recovery.

JJJJ. Finding: The concentration of the LFB is not 0.25 µg/L.

Requirement: The laboratory must demonstrate that the measurement system is in control
by analyzing an LFBs of the analytes at 0.25 µg/L concentration level. Ref: EPA Method
504.1, Rev 1.1 (1995), Section 9.3.

Comment: The laboratory analyzes an LFB at a concentration of 0.10 µg/L.

Base Neutral/Acid, Organics – EPA 625.1 (Aqueous)
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Base Neutral/Acid, Organics – SW-846 8270 E (Aqueous)

Recommendation: It is recommended that the laboratory, at regular time intervals, manually re-
evaluate all control limits for acceptability. Limits for QC items should not be so narrow as to be
unachievable, nor should they be so broad as to be meaningless. The laboratory’s QA Plan and
SOPs should clearly designate review and updates at defined intervals, as well as documentation
detailing any aberrations.

KKKK. Finding: The laboratory is not evaluating peak tailing.

Requirement: Calculate peak tailing factors for benzidine and pentachlorophenol.
Calculation of the tailing factor is illustrated in Figure 1. The tailing factor for benzidine and
pentachlorophenol must be used for analyses of all standards, blanks, and samples. Ref:
EPA Method 625.1, Section 7.2.1.1.

Requirement: Benzidine and pentachlorophenol should be present at their normal
responses, and should not exceed a tailing factor of 2 given by the following equation:
where the peak is defined as follows (see Figure 1 for a full-page version of this image with
additional information): AB is the line segment from the center to point A; AC is width at
10% height; BC is the line segment from the center to point C; DE is the height of peak and
B is the height at 10% of DE. This equation compares the width of the back half of the peak
to the width of the front half of the peak at 10% of the height. Ref: EPA SW-846 Test
Methods for Evaluating Solid Waste, Physical/Chemical Methods; 3rd Edition, Method 8270
E. Rev. 6, June 2018, Section 11.3.1.3.
Comment: Degradation and tailing factor checks are performed to verify injection port
inertness and are important when the target list includes a broad range of compounds,
especially reactive phenols and pesticides.

Extractable Petroleum Hydrocarbons – MADEP, May 2004, Rev. 1.1 (Aqueous & Non-
Aqueous)

Comment: It is unclear from the data reviewed whether the area of the surrogates is subtracted
from the area of the target ranges and whether the surrogates are being integrated valley-to-valley.

LLLL. Finding: The laboratory is not storing the silica gel cartridges in a properly maintained
desiccator.

Requirement: Silica gel is hygroscopic. Unused cartridges readily absorb moisture from
ambient air if not properly sealed. To preclude moisture adsorption, which adversely effects
cartridge performance, unused cartridges must be stored in a properly-maintained
desiccator prior to use. Ref: MADEP, Method for the Determination of Extractable
Petroleum Hydrocarbons (EPH), May 2004, Rev. 1.1, Section 7.1.5.

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Requirement: Unsealed silica gel/cartridges must be stored in a properly-maintained
desiccator to avoid inadvertent adsorption of ambient moisture. Silica gel that has been
exposed to moisture may perform erratically resulting in poor performance manifested by
naphthalene/2-methylnaphthalene and fractionation surrogate breakthrough. Ref: MADEP,
Method for the Determination of Extractable Petroleum Hydrocarbons (EPH), May 2004,
Rev. 1.1, Section 9.2.2.

Comment: The silica gel cartridges were being stored in a cabinet.

MMMM. Finding for Immediate Response: The laboratory is not evaluating breakthrough
of naphthalene or 2-methylnaphthalene in the LCS and LCSD.

Requirement: Because of their weakly polar nature, naphthalene and substituted
naphthalenes readily mobilize into the aliphatic extract if excessive amounts of hexane are
used to elute the silica gel cartridge/column. Because these compounds constitute a
significant percentage of the water-soluble fraction of fuel oils, this occurrence is especially
problematic in the analysis of water samples. For this reason, the method requires the
evaluation of the aliphatic fraction for the presence of naphthalene and 2-
methylnaphthalene in the LCS/LCSD pair on a batch basis. The fractionation surrogate, 2-
bromonaphthalene, is used to monitor sample-specific fractionation efficiency. Ref:
MADEP, Method for the Determination of Extractable Petroleum Hydrocarbons (EPH), May
2004, Rev. 1.1, Section 4.7.

Requirement: Each sample (field and QC sample) must be evaluated for potential
breakthrough on a sample-specific basis by evaluating the % recovery of the fractionation
surrogate (2-bromonaphthalene) and on a batch basis by quantifying naphthalene and 2-
methylnaphthalene in both the aliphatic and aromatic fractions of the LCS and LCSD. If
either the concentration of naphthalene or 2-methylnaphthalene in the aliphatic fraction
exceeds 5% of the total concentration for naphthalene or 2-methylnaphthalene in the LCS
or LCSD, fractionation must be repeated on all archived batch extracts. If the fractionation
surrogate recovery is outside the 40-140% limits, then fractionation must be repeated on
the archived extract of the affected sample. Ref: MADEP, Method for the Determination of
Extractable Petroleum Hydrocarbons (EPH), May 2004, Rev. 1.1, Section 10.4.2.

Comment: The data packages reviewed do not list quantified results for any individual
compounds other than the surrogates and target hydrocarbon ranges. Breakthrough was
noted in the LCS/LCSD on January 7, 2019, August 23, 2018 and March 5, 2018.

Comment: Acceptable corrective action (i.e., the SOP was updated to include language
that the LCS/LCSD must be evaluated with each batch for breakthrough by quantifying
naphthalene and 2-methylnaphthalene in both the aliphatic and aromatic fractions) was
performed by the laboratory and supporting documentation (i.e., the revised SOP and
copies of a data package with naphthalene and 2-methylnaphthalene quantified and
evaluated in the LCS and LCSD) was received February 21, 2019. No further response is
necessary for this Finding.

NNNN. Finding: The laboratory was not performing a fractionation check on each lot of silica gel
cartridges.

Requirement: The Fractionation Check Solution described in Section 7.8 must be used to
evaluate each new lot of silica gel/cartridges to re-establish the optimum volume of hexane
elutriate. See Appendix 5, Section 5.0 for optimization specifications. Ref: MADEP, Method
for the Determination of Extractable Petroleum Hydrocarbons (EPH), May 2004, Rev. 1.1,
Section 9.2.3.4.
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Requirement: A fractionation check solution is prepared containing 14 alkanes and 17
PAHs at a nominal concentration of 200 ng/µL of each constituent. The Fractionation
Check Solution must be used to evaluate the fractionation efficiency of each new lot of
silica gel / cartridges as described in Appendix 5, Section 5.0, and establish the optimum
hexane volume required to efficiently elute aliphatic hydrocarbons while not allowing
significant aromatic hydrocarbon breakthrough. For each analyte contained in the
fractionation check solution, excluding n-none, the Percent Recovery (see Appendix 5,
Equation 5-4) must be between 40 and 140%. A 30% Recovery is acceptable for n-nonane.
Ref: MADEP, Method for the Determination of Extractable Petroleum Hydrocarbons (EPH),
May 2004, Rev. 1.1, Section 10.4.3.7.

Recommendation: It is recommended that fractionation efficiency be evaluated on a more
frequent basis for large lots (> 500 units) as different mesh sizes and cartridge weights
could exist. This helps to ensure consistent performance.

OOOO. Finding: The laboratory is not using the required amount of hexane to exchange
solvents during extraction.

Requirement: Exchange the methylene chloride with hexane by adding 50 mL of hexane
to the top of the Snyder column. Concentrate the extract to less than 10 mL, as described
in Section 9.1.1.10, raising the temperature of the water bath, if necessary, to maintain
proper distillation. Ref: MADEP, Method for the Determination of Extractable Petroleum
Hydrocarbons (EPH), May 2004, Rev. 1.1, Section 9.1.1.11.

Comment: The laboratory is using less hexane to meet the time requirement for sample
concentration within 10 to 20 minutes as specified in Section 9.1.1.10. However, it is the
volume of solvent which is critical, rather than the time of sample concentration.

PPPP. Finding: The laboratory is not documenting the volume of hexane elutriate used during
fractionation.

Requirement: The amount of hexane used during fractionation is critical. Excessive
hexane – as little as 0.5 mL – can cause significant elution of lighter aromatics into the
aliphatic fraction. Insufficient hexane will cause low recoveries of the aliphatic fraction. The
volume of the hexane fractionation elutriate should not exceed 20 mL. Ref: MADEP,
Method for the Determination of Extractable Petroleum Hydrocarbons (EPH), May 2004,
Rev. 1.1, Section 9.2.3.3.

QQQQ. Finding: The laboratory is not adequately resolving n-nonane from the solvent
peak on the lowest calibration standard.

Requirement: The n-nonane (n-C9) peak must be adequately resolved from the solvent
front of the chromatographic run. Ref: MADEP, Method for the Determination of Extractable
Petroleum Hydrocarbons (EPH), May 2004, Rev. 1.1, Section 10.1.3.

Comment: The n-nonane peak is adequately resolved in the solvent peak of the remaining
calibration standards.

Pesticides, Organochlorine – EPA 608.3 (Aqueous)
Polychlorinated Biphenyls (PCBs) – EPA 608.3 (Aqueous)

RRRR. Finding: The laboratory is not meeting the MDL requirements specified in the method.

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Requirement: The laboratory must also establish MDLs for the analytes of interest using
the MDL procedure at 40 CFR part 136, appendix B. The laboratory’s MDLs must be equal
to or lower than those listed in Tables 1 or 2, or lower than one-third the regulatory
compliance limit, whichever is greater. For MDLs not listed in Tables 1 or 2, the laboratory
must determine the MDLs using the MDL procedure at 40 CFR part 136, appendix B under
the same conditions used to determine the MDLs for the analytes listed in Tables 1 and 2.
When analyzing the PCBs as Aroclors, it is only necessary to establish an MDL for one of
the multi-component analytes (e.g., PCB 1254), or the mixture of Aroclors 1016 and 1260
may be used to establish MDLs for all of the Aroclors. Similarly, MDLs for other multi-
component analytes (e.g. Chlordanes) may be determined using only one of the major
components. Ref: EPA Method 608.3, Section 8.2.

Comment: Meeting the MDL requirements specified in Tables 1 and 2 is required for
NPDES compliance samples.

SSSS. Finding: The minimum level (ML) concentration exceeds the requirements as specified in
the method for some analytes.

Requirement: The term “minimum level” refers to either the sample concentration
equivalent to the lowest calibration point in a method or a multiple of the method detection
limit (MDL), whichever is higher. Minimum levels may be obtained in several ways: They
may be published in a method; they may be based on the lowest acceptable calibration
point used by a laboratory; or they may be calculated by multiplying the MDL in a method,
or the MDL determined by a laboratory, by a factor of 3. For the purposes of NPDES
compliance monitoring, EPA considers the following terms to be synonymous: “quantitation
limit,” “reporting limit,” and “minimum level.” Ref: EPA Method 608.3, Section 23.2.

Requirement: Prepare calibration standards for the single-component analytes of interest
and surrogates at a minimum of three concentration levels (five are suggested) by adding
appropriate volumes of one or more stock standards to volumetric flasks. One of the
calibration standards should be at a concentration at or below the ML specified in Table 1,
or 2, or as specified by a regulatory/control authority or in a permit. The ML value may be
rounded to a whole number that is more convenient for preparing the standard, but must
not exceed the ML value listed in Tables 1 or 2 for those analytes which list ML values.
Alternatively, the laboratory may establish an ML for each analyte based on the
concentration of the lowest calibration standard in a series of standards produced by the
laboratory or obtained from a commercial vendor, again, provided that the ML does not
exceed the ML in Table 1 and 2, and provided that the resulting calibration meets the
acceptance criteria in Section 7.5.2 based on the RSD, RSE, or R2. Ref: EPA Method
608.3, Section 6.8.2.1.

TTTT. Finding: Sodium sulfate is not rinsed with methylene chloride.

Requirement: Sodium sulfate, reagent grade, granular anhydrous (Baker or equivalent),
rinsed with methylene chloride, baked in a shallow tray at 450 °C for 1 hour minimum,
cooled in a desiccator, and stored in a pre-cleaned glass bottle with screw cap which
prevents moisture from entering. If, after heating, the sodium sulfate develops a noticeable
grayish cast (due to the presence of carbon in the crystal matrix), that batch of reagent is
not suitable for used and should be discarded. Extraction with methylene chloride (as
opposed to simple rinsing) and baking at a lower temperature may produce sodium sulfate
suitable for use. Ref: EPA Method 608.3, Section 6.3.

UUUU. Finding: The laboratory is not calibrating with at least three standard concentrations for
PCBs or Toxaphene.
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Requirement: A standard containing a mixture of Aroclor 1016 and Aroclor 1260 will
include many of the peaks represented in the other Aroclor mixtures. As a result, a multi-
point initial calibration employing a mixture of Aroclors 1016 and 1260 at three to five
concentrations should be sufficient to demonstrate the linearity of the detector response
without the necessity of performing multi-point initial calibrations for each of the seven
Aroclors. In addition, such a mixture can be used as a standard to demonstrate that a
sample does not contain peaks that represent any one of the Aroclors. This standard can
also be used to determine the concentrations of either Aroclor 1016 or Aroclor 1260, should
they be present in a sample.

Therefore, prepare a minimum of three calibration standards containing equal
concentrations of both Aroclor 1016 and Aroclor 1260 by dilution of the stock standard with
isooctane or hexane. The concentrations should correspond to the expected range of
concentrations found in real samples and should bracket the linear range of the detector.
Ref: EPA Method 608.3, Section 6.8.2.2.1.

Requirement: For Toxaphene, prepare a minimum of three calibration standards
containing Toxaphene by dilution of the stock standard with isooctane or hexane. The
concentrations should correspond to the expected range of concentrations found in real
samples and should bracket the linear range of the detector. Ref: EPA Method 608.3,
Section 6.8.2.2.3.

Comment: The laboratory was calibrating with one concentration for PCBs and
Toxaphene.

VVVV. Finding: A single standard of the remaining five Aroclors not used for calibration is not
being analyzed.

Requirement: Single standards of each of the other five Aroclors are required to aid the
analyst in pattern recognition. Assuming that the Aroclor 1016/1260 standards described in
Section 6.8.2.2.1 have been used to demonstrate the linearity of the detector, these single
standards of the remaining five Aroclors also may be used to determine the calibration
factor for each Aroclor. Prepare a standard for each of the other Aroclors. The
concentrations should generally correspond to the mid-point of the linear range of the
detector, but lower concentrations may be employed at the discretion of the analyst based
on project requirements. Ref: EPA Method 608.3, Section 6.8.2.2.2.

WWWW. Finding: The laboratory is not using the acceptance criterion for the CCV for all
target analytes as specified in the method.

Requirement: The working calibration curve, CF, or RF must be verified immediately after
calibration and at the beginning and end of each 24-hour shift by the analysis of a mid-level
calibration standard. The calibration verification standard(s) must be obtained from a
second manufacturer or a manufacturer’s batch prepared independently from the batch
used for calibration (Section 6.8.4). Requirements for calibration verification are given in
Section 13.6 and Table 4. Ref: EPA Method 608.3, Section 7.8.

Requirement: For each analyte or for coeluting analytes, compare the concentration with
the limits for calibration verification in Table 4. For coeluting analytes, use the coeluting
analyte with the least restrictive specification (the widest range). For analytes in Table 2 not
listed in Table 4, QC acceptance criteria must be developed by the laboratory. Ref: EPA
Method 608.3, Section 13.6.2.

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Requirement: A laboratory may develop its own performance criteria (as QC acceptance
criteria), provided such criteria are as or more restrictive than the criteria in this method.
Ref: EPA Method 608.3, Section 8.1.

Comment: The laboratory was using an acceptance criterion of 70-130% for the CCV for
all target analytes. The acceptance criteria listed in Table 4 are more restrictive for the
majority of analytes.

XXXX. Finding: The DDT and Endrin decomposition (breakdown) solution is not prepared and
injected at the mass specified in the method.

Requirement: Prepare a solution containing endrin at a concentration of 50 ng/mL and
4,4’-DDT at a concentration of 100 ng/mL, in isooctane or hexane. A 1-µL injection of this
standard will contain 50 picograms (pg) of endrin and 100 pg of DDT. The concentration of
the solution may be adjusted by the laboratory to accommodate other injection volumes
such that the same masses of the two analytes are introduced into the instrument. Ref:
EPA Method 608.3, Section 6.8.7.

Pesticides, Organochlorine – EPA 608.3 (Aqueous)

YYYY. Finding: Sample pH is not checked upon receipt at the laboratory.

Requirement: Cool, ≤6 °C, pH 5-915. Ref: Code of Federal Regulations, Title 40, Part 136;
Federal Register Vol. 82, No. 165, August 28, 2017; Table II.

Requirement: The pH adjustment may be performed upon receipt at the laboratory and
may be omitted if the samples are extracted within 72 hours of collection. For the analysis
of aldrin, add 0.008% Na2S2O3. Ref: Code of Federal Regulations, Title 40, Part 136;
Federal Register Vol. 82, No. 165, August 28, 2017; Table II, Footnote 15.

Comment: Sample pH is checked at the bench. However, sample holding time is reduced
to 72 hours if not within pH 5-9 S.U. and if not adjusted upon receipt at the laboratory.
There were no instances in the data reviewed where sample pH exceeded 5-9 S.U.

Pesticides, Organochlorine – SW-846 8081 B (Aqueous)

ZZZZ. Finding: The laboratory is not treating aqueous samples that have residual chlorine with
sodium thiosulfate.

Requirement: Add 3 mL 10% sodium thiosulfate solution per gallon (or 0.008%). Addition
of sodium thiosulfate solution to sample container may be performed in the laboratory prior
to field use. Cool to 0-6°C. Ref: EPA SW-846 Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods, 3rd Edition, Chapter Four, Rev. 5, October 2012, Table 4-1.

Requirement: The NC WW/GW Laboratory Certification Branch must confirm that
analytical data is valid by reviewing the QA/QC data generated during the sampling and
analysis procedures when implementing SW-846 methods in order to be assured that
scientifically sound decisions are made which will be protective of human health and the
environment. To promote consistency with the use of SW-846 methods and to assure
generation of data of known quality, the minimum recommended quality control
benchmarks in the methods will be considered the minimum QA/QC requirements. Ref: NC
WW/GW LC Policy.

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Requirement: Dechlorination agents used at the time of sampling must be documented to
have been effective upon receipt in the laboratory. A variety of field testing kits are
considered to be adequate for most chlorine interference checks and a maximum detection
limit of 0.5 mg/L is allowed. Ref: NC WW/GW LC Policy.

Comment: Once the laboratory begins treating samples with sodium thiosulfate, it will be
required to document the dechlorination was effective.

Comment: Additional chlorine checks are not required for sites that have been
characterized as chlorine-free and documented as such.

Pesticides, Organochlorine – SW-846 8081 B (Non-Aqueous)

Recommendation: It is recommended that the Sulfur Cleanup method, SW -846 3660 B be
implemented for sediment samples as suggested in SW-846 8081 B, Section 4.5.

Pesticides, Organochlorine – SW-846 8081 B (Aqueous & Non-Aqueous)

AAAAA. Finding: The laboratory did not assign an appropriate acceptance criterion for
evaluating the LCS.

Requirement: Consult Method 8000 for information on developing acceptance criteria for
the LCS. Ref: EPA SW-846 Test Methods for Evaluating Solid Waste, Physical/Chemical
Methods; 3rd Edition, Method 8081 B. Rev. 2, February 2007, Section 9.6.2.

Requirement: Many methods may not contain recommended acceptance criteria for LCS
results. The laboratory should use 70 - 130% as interim acceptance criteria for recoveries
of spiked analytes, until in-house LCS limits are developed (Sec. 9.6). Where in-house
limits have been developed for matrix spike percent recoveries, the LCS results should be
similar to or tighter than those limits, as the LCS is prepared in a clean matrix. Ref: EPA
SW -846 Test Methods for Evaluating Solid Waste, Physical/Chemical Methods; 3rd Edition,
Method 8000 D. Rev. 5, March 2018, Section 9.4.4.

Requirement: The NC WW/GW Laboratory Certification Branch must confirm that
analytical data is valid by reviewing the QA/QC data generated during the sampling and
analysis procedures when implementing SW-846 methods in order to be assured that
scientifically sound decisions are made which will be protective of human health and the
environment. To promote consistency with the use of SW-846 methods and to assure
generation of data of known quality, the minimum recommended quality control
benchmarks in the methods will be considered the minimum QA/QC requirements. For
example, where a method states, “Documenting the effect of the matrix on target analyte
measurements should include the analysis of at least one matrix spike and one duplicate
unspiked samples or one matrix spike/matrix spike duplicate pair.”, the laboratory must
analyze at least one matrix spike and one duplicate unspiked sample or one matrix
spike/matrix spike duplicate pair. Laboratories may adopt more stringent QC acceptance
criteria for method performance but may not omit or use less stringent criteria than that
stated in SW-846 methods. Ref: NC WW/GW LC Policy.

Comment: The laboratory was using old in-house generated limits for the LCS but
implemented an acceptance criterion of 60-140% recovery in December 2018 based on the
QC Acceptance Criteria listed in EPA 608.3 Table 4.

BBBBB. Finding: The MS and LCS do not contain all the target analytes.

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Requirement: The solution used to fortify a sample and/or an LCS should contain all of the
target analytes and their concentration level should be determined as described in Secs.
9.4.1 and 9.4.2. Ref: EPA SW-846 Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods; 3rd Edition, Method 8000 D. Rev. 5, March 2018, Section
9.4.2.

Requirement: The NC WW/GW Laboratory Certification Branch must confirm that
analytical data is valid by reviewing the QA/QC data generated during the sampling and
analysis procedures when implementing SW-846 methods in order to be assured that
scientifically sound decisions are made which will be protective of human health and the
environment. To promote consistency with the use of SW-846 methods and to assure
generation of data of known quality, the minimum recommended quality control
benchmarks in the methods will be considered the minimum QA/QC requirements. For
example, where a method states, “Documenting the effect of the matrix on target analyte
measurements should include the analysis of at least one matrix spike and one duplicate
unspiked samples or one matrix spike/matrix spike duplicate pair.”, the laboratory must
analyze at least one matrix spike and one duplicate unspiked sample or one matrix
spike/matrix spike duplicate pair. Laboratories may adopt more stringent QC acceptance
criteria for method performance but may not omit or use less stringent criteria than that
stated in SW-846 methods. Ref: NC WW/GW LC Policy.

Pesticides, Organochlorine – SW-846 8081 B (Aqueous & Non-Aqueous)
Polychlorinated Biphenyls (PCBs) – SW-846 8082 A (Aqueous, Non-Aqueous & Oil)

CCCCC. Finding: The laboratory was not analyzing a second source standard after each
initial calibration.

Requirement: When a standard curve is manually prepared (as opposed to a factory-set
calibration), it is required to analyze one known standard in addition to calibration standards
each day samples are analyzed to document accuracy. This standard must be prepared
from materials obtained from a source independent from the one used for preparing the
calibration standards (often referred to as a second source standard or external reference
standard). A second source standard may be:

• a quality control standard obtained from a vendor,
• a standard prepared from primary standards obtained from a second vendor, or
• a standard made from primary standards from the same vendor but from a different lot
number (i.e., an independent lot) as those used to make the calibration standards.

Laboratory control standards are evaluated to assess whether the lab is in control of the
processes involved in the preparation and analysis of specific tests. Laboratory control
standards must be similar in composition to the environmental samples. They must contain
known concentrations of all analytes of interest and undergo the same preparatory and
determinative procedures as the environmental samples.

Second source standards must be evaluated using one of the following: vendor supplied
criteria, method-defined acceptance criteria, in-house calculated acceptance limits that are
statistically-derived from historical data based on three standard deviations from the mean
in the detectable range or other statistically viable evaluation criterion. If the results fall
outside of acceptance limits, the analysis is out of control. The analysis must be terminated
and the problem corrected prior to sample analysis. Ref: NC WW/GW LC Policy.

Comment: The policy referenced above has been promulgated in the newly revised NC
WW/GW LC rules.
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Comment: The laboratory began analyzing a second source LCS in January 2019.

Polychlorinated Biphenyls (PCBs) – SW-846 8082 A (Aqueous, Non-Aqueous & Oil)

DDDDD. Finding: A single standard of the remaining five Aroclors not used for calibration is
not being analyzed.

Requirement: Single standards of each of the other five Aroclors are required to aid the
analyst in pattern recognition. Assuming that the Aroclor 1016/1260 standards described in
Sec. 7.7.1 have been used to demonstrate the linearity of the detector, these single
standards of the remaining five Aroclors also may be used to determine the calibration
factor for each Aroclor when a linear calibration model through the origin is chosen (see
Sec. 11.4). Prepare a standard for each of the other Aroclors. The concentrations should
generally correspond to the mid-point of the linear range of the detector, but lower
concentrations may be employed at the discretion of the analyst based on project
requirements. Ref: EPA SW-846 Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods; 3rd Edition, Method 8082 A. Rev. 1, February 2007, Section
7.7.2.

EEEEE. Finding: The laboratory is not evaluating the MS/MSD recovery or precision
against the appropriate acceptance criteria.

Requirement: When a method is initially established in a laboratory, the LCS limits may be
applied to the matrix spikes until the laboratory has sufficient data (a minimum of 20 or
more MS/MSD samples of the same matrix) to generate their own statistical limits. These
data should be used as the basis for determining MS/MSD precision and bias limits.
Alternatively, acceptance criteria based on historical LCS data may continue to be used for
evaluating bias in matrix spike recovery and may be more sensitive to matrix effects than
acceptance limits based on MS/MSD data. It is generally preferable to use statistically
calculated MS/MSD, rather than LCS recovery limits once sufficient data points have been
collected (i.e., ≥20 MS/MSD samples). See Secs. 9.6.1 – 9.6.3 for calculating in-house
performance criteria for LCS, MS/MSD and surrogate recoveries. Ref: EPA SW-846 Test
Methods for Evaluating Solid Waste, Physical/Chemical Methods; 3rd Edition, Method 8000
D. Rev. 5, March 2018, Section 9.4.4.2.

Requirement: Many methods may not contain recommended acceptance criteria for LCS
results. The laboratory should use 70-130% as interim acceptance criteria for recoveries of
spiked analytes, until in-house LCS limits are developed (Sec. 9.6). Where in-house limits
have been developed for matrix spike percent recoveries, the LCS results should be similar
to or tighter than those limits, as the LCS is prepared in a clean matrix. Ref: EPA SW-846
Test Methods for Evaluating Solid Waste, Physical/Chemical Methods; 3rd Edition, Method
8000 D. Rev. 5, March 2018, Section 9.4.4.

Comment: The laboratory was evaluating MS recoveries against a 50-150% recovery
criterion and MSD precision against 40% RPD criterion. In-house limits had not been
established as prescribed in 9.6.1 – 9.6.3.

Purgeable, Aromatics – EPA Method 602 (Aqueous)
Purgeable, Aromatics – Standard Methods 6200 C-2011 (Aqueous)
Purgeable, Halocarbons – EPA Method 601 (Aqueous)
Purgeable, Halocarbons – Standard Methods 6200 C-2011 (Aqueous)

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Comment: Samples are being analyzed by EPA Method 601, EPA Method 602 and Standard
Method 6200 C-2011 in combined analytical runs. As such, the most stringent QC between the
methods must be adhered to.

Comment: The QC batch report does not display the MSD percent recoveries nor the MS/MSD
RPD acceptance criterion; making it appear as though these QC elements are not being evaluated.

FFFFF. Finding: The laboratory is not always analyzing a CCV after every 10 samples.

Requirement: Perform continuing calibration every 10 samples for GC analysis, every 20
samples for GC/MS analysis, or every 12 h, whichever is more frequent. Ref: Standard
Methods, 6200 C-2011. (6) and Standard Methods, 6200 A-2011. (5) (b) (2).

Comment: Analytical run 051118 had 14 samples between CCVs.

GGGGG. Finding: The laboratory is not varying the concentration of the CCV across the
calibration range.

Requirement: Vary actual concentration of continuing calibration standard over calibration
range, with a minimum concentration greater than two times the reporting limit. Ref:
Standard Methods, 6200 C-2011. (6) and Standard Methods, 6200 A-2011. (5) (b) (2).

Comment: The laboratory refers to the CCV as the LFB. Varying the LFB concentration
is also required in the laboratory’s SOP.

Purgeable, Organics – EPA Method 624.1 (Aqueous)
Purgeable, Organics – SW-846 Method 8260 D (Aqueous & Non-Aqueous)
Purgeable, Organics – Standard Methods 6200 B-2011 (Aqueous)

HHHHH. Finding: Calibration working standards are being used beyond their expiration
dates.

Requirement: Aqueous calibration standards can be stored up to 24 h if held in sealed
vials with zero headspace. Otherwise, discard within 1 h. Ref: Standard Methods, 6200 B-
2011. (3) (j).

TPH Diesel Range, Organics – SW-846 8015 C (Aqueous & Non-Aqueous)

Comment: It was unclear from the data reviewed whether the surrogate was being subtracted out
during quantitation.

IIIII. Finding: The laboratory is not verifying the retention time for each analyte and surrogate
each 12-hour work shift.

Requirement: The initial calibration and retention times need to be verified at the
beginning of each 12-hr work shift, at a minimum. When individual target analytes are
being analyzed, verification is accomplished by the analysis of one or more calibration
standards (normally mid-concentration, but a concentration at or near the action level
may be more appropriate) that contain all of the target analytes and surrogates. When
petroleum hydrocarbons are being analyzed, verification is accomplished by the
measurement of the fuel standard and the hydrocarbon retention time standard. Ref:
EPA SW-846 Test Methods for Evaluating Solid Waste, Physical/Chemical Methods; 3rd
Edition, Method 8015 C, Rev. 3, February 2007, Section 11.5.1.

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JJJJJ. Finding: The laboratory is not always analyzing all required QC elements with each
sample batch.

Requirement: The initial calibration and retention times need to be verified at the
beginning of each 12-hr work shift, at a minimum. When individual target analytes are
being analyzed, verification is accomplished by the analysis of one or more calibration
standards (normally mid-concentration, but a concentration at or near the action level
may be more appropriate) that contain all of the target analytes and surrogates. When
petroleum hydrocarbons are being analyzed, verification is accomplished by the
measurement of the fuel standard and the hydrocarbon retention time standard. Ref:
EPA SW-846 Test Methods for Evaluating Solid Waste, Physical/Chemical Methods; 3rd
Edition, Method 8015 C, Rev. 3, February 2007, Section 11.5.1.

Requirement: Samples are analyzed in a set referred to as an analytical sequence. The
sequence begins with calibration verification followed by sample extract analyses.
Additional analyses of the verification standard(s) throughout a 12-hr shift are strongly
recommended, especially for samples that contain visible concentrations of oily material. A
verification standard is also necessary at the end of a set (unless internal standard
calibration is used). Ref: EPA SW-846 Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods; 3rd Edition, Method 8015 C, Rev. 3, February 2007, Section
11.6.1

Requirement: Documenting the effect of the matrix should include the analysis of at least
one matrix spike and one duplicate unspiked sample or one matrix spike/matrix spike
duplicate pair. The decision on whether to prepare and analyze duplicate samples or a
matrix spike/matrix spike duplicate must be based on a knowledge of the samples in the
sample batch. If samples are expected to contain target analytes, then laboratories may
use one matrix spike and a duplicate analysis of an unspiked field sample. If samples are
not expected to contain target analytes, laboratories should use a matrix spike and matrix
spike duplicate pair. Ref: EPA SW-846 Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods; 3rd Edition, Method 8015 C. Rev. 3, February 2007, Section
9.6.1.

Comment: The sample batch analyzed on July 11, 2018 lacked an ICV, CCV, LFM and
LFMD.

Volatile Petroleum Hydrocarbons – MADEP, February 2018, Rev. 2.1 (Aqueous & Non-
Aqueous)

Recommendation: It is recommended that the laboratory prepare the LCS and MS at a mid-range
concentration. In correspondence with MADEP, they stated this was the intent of the language in
method sections 10.2.6 and 10.3.2.

Recommendation: It is recommended that the laboratory prepare samples and QC standards to
have the surrogate at a mid-range concentration. In correspondence with MADEP, they stated this
was the intent of the language in method section 7.5.1.
KKKKK. Finding: The laboratory is not preserving samples to pH ≥ 11.0 S.U. when
analyzing with a heated purge temperature.

Requirement: Samples analyzed with heated purge temperature: Samples must be
treated to a pH of 11.0 or greater at the time of collection. This can be accomplished by
adding 0.40 to 0.44 grams of trisodium phosphate dodecahydrate (TSP) to a 40-mL sample
vial prior to collection. Samples must be cooled to 0-6°C immediately after collection. Ref:
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MADEP, Method for the Determination of Volatile Petroleum Hydrocarbons (VPH),
February 2018, Rev. 2.1, Section 8.1.1.

Comment: The method considers a heated purge to be any purge temperature greater
than ambient (i.e., 25 °C). The laboratory is using a purge temperature of 35 °C. This is
considered a significant modification, as stated in Section 11.3.1.

LLLLL. Finding: The laboratory is not always reanalyzing samples when QC elements fail.

Requirement: If any of the performance standards specified in Section 10.2 are not met,
the cause of the nonconformance must be identified and corrected before any additional
samples may be analyzed. Any samples run between the last QC samples that met the
criteria and those that are fallen out must be reanalyzed, as noted in Section 10.2. These
QC samples include the Continuing Calibration Standard, LMB, LCS, and LCSD. If this is
not possible, the data must be reported as suspect. Ref: MADEP, Method for the
Determination of Volatile Petroleum Hydrocarbons (VPH), February 2018, Rev. 2.1, Section
10.4.

Requirement: See Section 10.2.6 for corrective actions associated with recoveries outside
of acceptance limits. Ref: MADEP, Method for the Determination of Volatile Petroleum
Hydrocarbons (VPH), February 2018, Rev. 2.1, Section 10.2.7.

Requirement: If the recoveries are low and outside of the acceptance limits, reanalyze the
LCS and associated samples. If still outside of the acceptance limits, recalibrate.
If the recoveries are high and outside of the acceptance limits and the affected compound
was detected in the associated samples, reanalyze the LCS and the associated samples. If
recoveries are still outside of the acceptance limits, recalibrate.
If the recoveries are high and sample results were nondetect, data can be reported without
qualification; however, the high recoveries should be noted in the laboratory narrative. Ref:
MADEP, Method for the Determination of Volatile Petroleum Hydrocarbons (VPH),
February 2018, Rev. 2.1, Section 10.2.6.

Comment: In the sample batch analyzed January 18-19, 2019, the second LCS/LCSD
exceeded the acceptance criterion and the analytical batch was not reanalyzed.

IV. PAPER TRAIL INVESTIGATION:

The paper trail consisted of comparing original records (e.g., laboratory benchsheets, logbooks,
etc.) and client reports. Color data were reviewed for February 21, 2018, May 9, 2018, August 31,
2018 and November 16, 2018. Cyanide data were reviewed for February 7, 2018, February 16,
2018, February 27, 2018, May 18, 2018, May 22, 2018, September 7, 2018 and November 7,
2018. Inorganic Phenol data were reviewed for February 1, 2018, May 3, 2018, May 17, 2018, May
31, 2018, September 6, 2018, September 27, 2018 and November 15, 2018. MBAS data were
reviewed for February 9, 2018, February 16, 2018, February 23, 2018, May 4, 2018, May 11, 2018,
May 18, 2018, September 7, 2018, September 28, 2018 and November 16, 2018. Organochlorine
Pesticide data was reviewed for January 15, 2019.

V. CONCLUSIONS:
We are concerned about the number of Findings, the severity of Findings and the Findings that
were cited previously. For these reasons, the accuracy and legal defensibility of the data may be
uncertain. A follow-up audit will be scheduled after the laboratory’s corrective action response has
been approved.
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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 Findings and implementing the Recommendations will help this
laboratory to produce quality data and meet Certification requirements . The inspector would like
to thank the staff for its assistance during the inspection and data review process. Please
respond to all Findings and include supporting documentation, implementation dates
and steps taken to prevent recurrence for each corrective action.

Report prepared by: Anna Ostendorff Date: August 2, 2019
Report reviewed by: Jason Smith Date: August 9, 2019