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INSPECTION REPORT ROUTING SHEET
To be attached to all inspection reports in-house only.
Laboratory Cert. #: 178
Laboratory Name: City of Rockingham WWTP
Inspection Type: Municipal Maintenance
Inspector Name(s): Tonja Springer
Inspection Date: May 25, 2011
Date Report Completed: June 6, 2011
Date Forwarded to Reviewer: June 30, 2011
Reviewed by: Todd Crawford
Date Review Completed: July 1, 2011
Cover Letter to use: ___ Insp. Initial X Insp. Reg. Insp. No Finding Insp. CP
Unit Supervisor: Dana Satterwhite
Date Received: July 1, 2011
Date Forwarded to Alberta: July 13, 2011
Date Mailed: July 13, 2011
_____________________________________________________________________
On-Site Inspection Report
LABORATORY NAME: City of Rockingham WWTP
NPDES Permit #: NC0020427
ADDRESS: 514 Rockingham Road
Rockingham, NC 28379
CERTIFICATE #: 178
DATE OF INSPECTION: May 25, 2011
TYPE OF INSPECTION: Municipal Maintenance
AUDITOR(S): Tonja Springer and Chet Whiting
LOCAL PERSON(S) CONTACTED: Larry Cobler
I. INTRODUCTION:
This laboratory was inspected to verify its compliance with the requirements of 15A NCAC 2H .0800 for
the analysis of environmental samples.
II. GENERAL COMMENTS:
The laboratory was well equipped, neatly organized and clean.
Findings B, D, G, H, K, and L are new policies that have been implemented by our program since the last
inspection.
III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS:
Documentation
Comment: Temperature corrections were not posted on the DO meter, pH meters and the refrigerator.
North Carolina Wastewater/Groundwater Laboratory Certification Policy states: Document any
correction that applies (even if zero) on both the thermometer and meter and on a separate sheet to be
filed. Temperature corrections were posted at time of inspection. This adequately addresses this
finding. This requirement is a new policy that has been implemented by our program since the last
inspection. No further response is necessary for this finding.
A. Finding: The use of Wite-Out®, as well as, several instances of writing over a number as a
means of error correction, and corrections without dates and initials were observed.
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. T he 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: North Carolina
Wastewater/Groundwater Laboratory Certification Policy.
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B. Finding: Proficiency Testing (PT) samples were not documented in the same manner as
routine environmental samples.
Requirement: The analysis of PT samples is designed to evaluate the entire process used to
routinely report environmental analytical results; therefore, PT samples must be analyzed and
the process documented in the same manner as environmental samples. Ref: North Carolina
Wastewater/Groundwater Laboratory Certification Policy.
General Quality Control
C. Finding: No acceptance criteria have been established to evaluate the precision of sample
duplicate analyses.
Requirement: Any time quality control results indicate an analytical problem, the problem must
be resolved and any samples involved must be rerun if the holding time has not expired. Ref:
15A NCAC 2H .0805 (a) (7) (F).
Comment: For low level results, using a default Relative Percent Difference (RPD) may not
provide an adequate evaluation of precision of samples. An example is Total Suspended Solids
(TSS) results below 10 mg/L. In this example, TSS results yielding 4 mg/L for the parent
sample and 2 mg/L for the duplicate is a reasonable difference in raw sample concentrations;
however, the RPD presents a different picture. The RPD is calculated as follows:
RPD = 2[A-B] x 100 = 2[4 mg/L - 2 mg/L] x 100 = 66% (RPD)
A+B 4 mg/L + 2 mg/L
The RPD looks excessive, yet an examination of the raw results indicates good precision. In
such cases, we recommend a two-tiered evaluation system (i.e., using one acceptance criterion
for low concentration samples and another acceptance criterion for high concentration
samples). For example, the TSS duplicate acceptance criterion for sample concentrations
below 10 mg/L might be set at a maximum 3 mg/L absolute difference and the TSS duplicate
acceptance criterion for sample concentrations equal to 10 mg/L or higher might be set at a
maximum default RPD of 20%. Please contact this office if you need additional guidance in
establishing duplicate acceptance criteria.
D. Finding: The reagent log does not include all the pertinent information required and there is no
system for tracing standards and reagents used in a particular analysis.
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:
North Carolina Wastewater/Groundwater Laboratory Certification Policy.
Comment: Guidance materials for documenting traceability of purchased and prepared
standards and reagents were provided to the laboratory at the time of the inspection.
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E. Finding: There was no documentation for the National Institute of Standards and Technology
(NIST) traceable digital thermometer to show when the calibration was due.
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: All thermometers must meet National Institute of Standards and Technology
(NIST) specifications for accuracy or checked, at a minimum annually, against a NIST traceable
thermometer and proper corrections made. Ref: 15A NCAC 2H .0805 (a) (7) (O).
Requirement: Obtain a NIST traceable thermometer with a current calibration certificate and
repeat the temperature checks on all thermometers as well as the sensor checks on the DO
and pH meters. Send copies of the calibration documentation for the NIST thermometer,
the laboratory thermometers and the DO and pH meter sensors with your response to
this report.
Comment: You may have trouble getting your NIST thermometer re-certified. As part of an
initiative to reduce the use of mercury in products, EPA is working with stakeholder s to reduce
the use of mercury-containing non-fever thermometers in industrial and commercial settings.
The National Institute of Standards and Technology (NIST), which is working with EPA on this
effort, announced on February 2, 2011 that it will no longer calibrate mercury-in-glass
thermometers for traceability purposes beginning on March 1, 2011. Other vendors may follow
this lead. Additional information on the phase-out of mercury-filled thermometers and selecting
alternatives to mercury-filled thermometers can be found on the following EPA website:
http://www.epa.gov/hg/thermometer.htm.
F. Finding: Standard Operating Procedures (SOPs) have not been updated with current quality
control requirements for all of the parameters included on the laboratory’s certificate
attachment.
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.
The quality control document shall be available for inspection by the State Laborat ory. Ref: 15A
NCAC 2H .0805 (a) (7). Submit the updated SOPs for review by November 25, 2011. A
written response is required.
Total Residual Chlorine – Standard Methods, 18th Edition, 4500 Cl G
Recommendation: It is recommended that the laboratory consider switching to another source of
standard material for Total Residual Chlorine (TRC) internal curve verification and mid-range standard.
Range standards may be less accurate especially where large dilution factors are involved. It is
recommended that potassium permanganate standards be used. They are less prone to degradation
and more economical.
Recommendation: It is recommended that the laboratory verify the internal calibration using the
concentrations: 25, 35, 50, 200, 400 µg/L. This will verify the analytical range used to measure
Proficiency Testing (PT) samples as well as environmental samples. The current curve range is 28,
56, 112, 224, 448 µg/L.
Comment: A second source standard is no longer required if a factory set calibration curve is being
used.
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G. Finding: A calibration blank and/or calibration verification standard (mid-range) are not
analyzed at the end of the sample group.
Requirement: The calibration blank and calibration verification standard (mid-range) must be
analyzed initially (i.e., prior to sample analysis), after every tenth sample and at the end of each
sample group to check for carry over and calibration drift. If either fall outside established
quality control acceptance criteria, corrective action must be taken (e.g., repeating sample
determinations since the last acceptable calibration verification, repeating the initial calibration,
etc.). Ref: North Carolina Wastewater/Groundwater Laboratory Certification Policy based upon
Standard Methods, 20th Edition, 1020 B. (10) (c), 3020 B. (2) (b), and 4020 B. (2).
H. Finding: The auto-pipette has not been calibrated.
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 and documented. Each liquid-dispensing device must meet the manufacturer’s
statement of accuracy. Ref: North Carolina Wastewater/Groundwater Laboratory Certification
Policy.
Comment: A minimum of 5 aliquots dispensed from the pipette should be weighed and
averaged in order to determine the volume dispensed. Guidance information was provided at
the time of the inspection.
Comment: The auto-pipette is only used for the liquid chlorine standards. If the laboratory
switches to the potassium permanganate solution and uses the Class A glass pipettes to make
the annual verification standards and the daily check standard, then this pipette will no longer
be needed.
I. Finding: The preparation of the calibration standards are only documented on the standard
bottle.
Requirement: All analytical records must be available for a period of five years. Ref: 15A
NCAC 2H .0805 (a) (7) (g).
pH – Standard Methods, 18th Edition, 4500 H+ B
Comment: Verification of the pH meter Automatic Temperature Compensator (ATC) is no longer
required.
pH – Standard Methods, 18th Edition, 4500 H+ B
DO – Standard Methods, 18th Edition, 4500 O G
J. Finding: Calibration time is not documented. This is considered pertinent information.
Requirement: All analytical data pertinent to each certified analysis must be filed in an orderly
manner so as to be readily available for inspection upon request. Ref: 15A NCAC 2H .0805 (a)
(7) (A).
DO – Standard Methods, 18th Edition, 4500 O G
Comment: Units were not documented on the benchsheet. The North Carolina Administrative Code,
15A NCAC 2H .0805 (a) (7) (H) states: All laboratories must use printed laboratory bench worksheets
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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. Units were
documented on the benchsheet at the time of the inspection. No further response is necessary for
this finding.
Residue, Suspended – Standard Methods, 18th Edition, 2540 D
K. Finding: The laboratory is using an incorrect reporting limit.
Requirement: The minimum weight gain allowed by any approved method is 2.5 mg. Choose
sample volume to yield between 2.5 and 200 mg dried residue. This establishes a minimum
reporting value of 2.5 mg/L when 1000 mL of sample is analyzed. If complete filtration takes
more than 10 minutes increase filter diameter or decrease sample volume. In instances where
the weight gain is less than the required 2.5 mg, the value must be reported as less than the
appropriate value based upon the volume used. Ref: North Carolina Wastewater/Groundwater
Laboratory Certification Policy based upon Standard Methods, 20th and 21st Editions, 2540 D.
(3) (b).
Comment: For example, if 500 mL of sample is analyzed and < 2.5 mg of dried residue is
obtained, the value reported would be < 5 mg/L.
Recommendation: It is recommended that the laboratory increase the sample volume to one
that can still be filtered in less than 10 minutes and yield the required 2.5 mg of dried residue.
L. Finding: Filters are not weighed to constant weight prior to sample analysis, nor is a dry filter
blank is not analyzed with each set of samples.
Requirement: If pre-prepared filters are not used, the method requires that filters must be
weighed to a constant weight after washing. Repeat cycle of drying, cooling, desiccating, and
weighing until a constant weight is obtained or until weight change is less than 4% of the previous
weighing or 0.5 mg, whichever is less. In lieu of this process, it is acceptable to analyze a single
daily dry filter blank to fulfill the method requirement of drying all filters to a constant weight prior to
analysis. Ref: North Carolina Wastewater/Groundwater Laboratory Certification Policy based
upon Standard Methods 20th Edition 2540 D. (3) (a).
Coliform, Fecal – Standard Methods, 18th Edition, 9222 D (MF)
Comment: Sample analysis should begin immediately, preferably within 2 hours of collection. The
maximum transport time to the laboratory is 6 hours, and samples should be processed within 2 hours
of receipt at the laboratory. Ref: Code of Federal Reg ulations, Title 40, Part 136.3; Federal Register
Vol. 72, No 47, March 26, 2007; Table II, Footnote 22.
M. Finding: The pH of the prepared fecal coliform media is not documented to show that it is
within method specifications (i.e., pH 7.4).
Requirement: Final pH should be 7.4. Ref: Standard Methods, 18th Edition, 9222 D (1) (a).
Requirement: Supporting records shall be maintained as evidence that these practices are
being effectively carried out. The quality control document shall be available for inspection by
the State Laboratory. Ref: 15A NCAC 2H .0805 (a) (7).
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Recommendation: It is recommended that a small amount of the media be poured out to check
the pH.
N. Finding: No comparison test is conducted before a new lot of media and filters are put into
use.
Requirement: When a new lot of culture medium, membrane filters or a new source of
reagent-grade water is to be used, make comparison tests of the current lot in use (reference
lot) against the new lot (test lot). As a minimum, make single analyses on five positive samples.
Ref: Standard Methods, 18th Edition, 9020 B. (3) (d).
Recommendation: It is recommended that the laboratory obtain some fecal plates from
another municipality which has been verified as suitable and perform a comparison against their
own media currently in use.
Recommendation: It is recommended that the comparison tests be performed with a culture
positive sample that will yield the desired 20 to 60 colonies. The culture positive sample should
be analyzed the day prior to the comparison testing to determine the appropriate dilution to
yield 20 – 60 colonies.
IV. PAPER TRAIL INVESTIGATION:
The paper trail consisted of comparing field testing records and contract lab reports to
Discharge Monitoring Reports (DMRs) submitted to the North Carolina Division of Water
Quality. Data were reviewed for City of Rockingham WWTP (NPDES permit #NC0020427) for
January, February and March 2011. No transcription errors were detected. The facility appears
to be doing a good job of accurately transcribing data.
V. CONCLUSIONS:
Correcting the above-cited findings and implementing the recommendations will help this lab 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.
Report prepared by: Tonja Springer Date: June 6, 2011
Report reviewed by: Todd Crawford Date: July 1, 2011