#173_08_2012_FINAL

INSPECTION REPORT ROUTING SHEET
To be attached to all inspection reports in-house only.
Laboratory Cert. #:
Laboratory Name:
Inspection Type:
Inspector Name(s):
Inspection Date:
Date Report Completed:
Date Forwarded to Reviewer:
Reviewed by:
Date Review Completed:
Cover Letter to use:
Unit Supervisor:
Date Received:
Date Forwarded to Linda:
Date Mailed:
#173
-Mooresville Rocky River WWTP Lab
Municipal Maintenance
Chet Whiting
August 30, 2012
September 14, 2012
September 14, 2012
Jason Smith
September 19, 2012
❑ Insp. Initial ❑ Insp. Reg.
❑ Insp. No Finding ❑ Insp. CP
x Corrected
Gary Francies
9/20/2012
9/244/2012
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Division of
Beverly Eaves Perdue
Governor
173
Mr. John Ritchie
Mooresville Rocky River WWTP Lab
P.O. Box 878
Mooresville, NC 28115
Charles Wakild, P. E.
Director
September 24, 2012
Dee Freeman
Secretary
SUBJECT: North Carolina Wastewater/Groundwater Laboratory Certification (NC WW/GW LC)
Maintenance Inspection
Dear Mr. Ritchie:
Enclosed is a report for the inspection performed on August 30, 2012 by Chet Whiting. Since
the finding(s) cited during the inspection were all corrected prior to the completion of the
enclosed report, a response is not required. The staff is commended for taking the initiative in
correcting the findings in such a timely manner. For certification maintenance, your laboratory
must continue to carry out the requirements set forth in 15A NCAC 2H .0800.
Copies of the checklists completed during the inspection may be requested from this office.
Thank you for your cooperation during the inspection. If you wish to obtain an electronic copy of
this report by electronic mail, or if you have questions or need additional information please
contact me at 828-296-4677.
Sincerely,
Gary Francies
Certification Unit Supervisor
Laboratory Section
CC: Chet Whiting
Master File
DENR DWO Laboratory Section NC Wastewater,Groundwater Laboratory Certification Branch
1623 Mail Service Center, Raleigh, North Carolina 27699-1623
Location: 4405 Reedy Creek Road. Raleigh, North Carolina 27607-6445
Phone: [phone] \ FAX: [phone]
Internet: wvvw.dwglab.org
One
Northfarolina
NodurallY
An Equal Opportunity \ Affirmative Action Employer

On -Site Inspection Report
LABORATORY NAME:
NPDES PERMIT #:
ADDRESS:
CERTIFICATE #:
DATE OF INSPECTION:
TYPE OF INSPECTION:
AUDITOR(S):
LOCAL PERSON(S) CONTACTED:
INTRODUCTION:
Mooresville Rocky River WWTP Lab
NCO046728
P.O. Box 878
Mooresville, NC 28115
173
August 30, 2012
Municipal Maintenance
Chet Whiting
John Ritchie and Whitney Munroe
This laboratory was inspected by a representative of the North Carolina Wastewater/Groundwater
Laboratory Certification (NC WW/GW LC) program to verify its compliance with the requirements of 15A
NCAC 2H .0800 for the analysis of environmental samples.
II. GENERAL COMMENTS:
The laboratory is reminded that any time changes are made to laboratory operations; the laboratory
must update the Quality Assurance (QA)/Standard Operating Procedures (SOP) document(s). Any
changes made in response to the Findings, Recommendations or Comments listed in this report must
be incorporated to insure the method is being performed as stated, references to methods are
accurate, and the QA and/or SOP document(s) is in agreement with approved practice and regulatory
requirements. In some instances, the laboratory may need to create a SOP to document how new
functions or policy will be implemented.
On May 18, 2012, EPA promulgated changes to the list of Clean Water Act (CWA) methods at 40 CFR
Part 136.3. This action, referred to as the Methods Update Rule (MUR) approves new methods, or
changes to existing methods, that affects over 100 EPA methods, Standard Methods, ASTM methods,
and other test procedures in Part 136 of Title 40 of the Code of Federal Regulations (CFR). The rule
also contains a number of clarifications relating to approved methods, sample preservation and holding
times, and method modifications. The final rule may be found at:
http://water.epa.gov/scitech/methods/cwa/update index.cfm. The North Carolina
Wastewater/Groundwater Laboratory Certification (NC WW/GW LC) program will be asking certified
laboratories to move toward implementation of the new rule with changes fully implemented by the end
of 2012. Each laboratory will need to review the MUR and evaluate its effect on current laboratory
practices. These changes must be made in the laboratory's Standard Operating Procedures and in
Quality Manuals, as well as any other place where the method is cited, e.g., reports, benchsheets,
logs, etc. During this transition period, inspection reports will refer to the methods employed at the
laboratory at the time of the inspection, but will reference the requirements in the most recently
approved version of the method. Any difficulties encountered with meeting the requirements of these
references by the date due may be addressed in the written corrective action response.
Per an e-mail communication on September 13, 2012 the Lab will submit updated SOP's by March 1,
2013.

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#173 Mooresville Rocky River WWTP Lab
Quality Control
Comment: The laboratory was not calculating and documenting duplicate and spike recoveries. 15A
NCAC 2H .0805 (a) (7) (F) states: "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."
In order to meet this criterion the results obtained must be documented on the bench sheet and
evaluated against the acceptance criteria to demonstrate that the analyst was aware of any out -of -
control situation and the corrective action that was taken. Any samples not meeting the criteria must be
reanalyzed if possible. If this is not possible, the data must be flagged on the laboratory reports and
Discharge Monitoring Reports (DMR) as all quality control requirements not met. Demonstration of
acceptable corrective action (i.e. a revised benchsheet with Q.0 and applicable acceptance ranges
documented) was received by e-mail September 7, 2012. No further response is necessary for this
finding.
General Laboratory
Comment: Multiple instances of overwriting were observed. NCWW/GLC Policy states: 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. Demonstration of acceptable corrective action (i.e. a revised benchsheet with instructions
not to overwrite) was received by e-mail September 7, 2012. No further response is necessary for
this finding.
Total Suspended Solids — Standard Methods, 20th Edition, 2540 D
Recommendation: 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-Bl x 100 = 2f4 mg/L - 2 mg/1-1 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.
Comment: The laboratory was using a minimum dried residue weight gain of 1 mq to determine the
reporting limit. NC WW/GW LC Policy based upon Standard Methods, 20th and 21' Editions, 2540 D.
(3) (b) states: 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

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#173 Mooresville Rocky River WWTP Lab
required 2.5 mg, the value must be reported as less than the appropriate value based upon the volume
used. This requirement is a new policy that has been implemented by our program since the last
inspection. Demonstration of acceptable corrective action (i.e. a revised benchsheet documenting the
minimum weight gain) was received by e-mail September 7, 2012. No further response is necessary
for this finding.
Comment: Samples were not weighed to constant weight, nor had an annual multiple weighing study, to
verify the adequacy of the drying time, been performed within the last twelve months. NC WW/GW LC
Certification Policy based on Standard Methods, 20th Edition, 2540 D. (3) (c), 2540 B. (3) (b), and 2540 C.
(3) (d). 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. Acceptable corrective action (i.e. a study
documenting a 1 hour drying time) was performed during the inspection on August 30, 2012. No
further response is necessary for this finding.
Comment: Filters were not weighed to constant weight prior to sample analysis, nor is a dry filter blank
analyzed with each set of samples. North Carolina Wastewater/Groundwater Laboratory Certification
Policy based upon Standard Methods 20th Edition 2540 D. (3) (a) states: 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. This requirement is a new policy that has been implemented by our program
since the last inspection. Notification of corrective action (i.e. implementation of a dry blank for constant
weight) was received by e-mail on September 7, 2012. No further response is necessary for this
finding
Biochemical Oxygen Demand — Standard Methods, 20th Edition, 5210 B
Comment: Extra nutrient, mineral, and buffer solutions were not added to the sample bottles
containing more than 67% sample. Standard Methods, 5210 B-2001, (5) (c) (2) states: When a bottle
contains more than 67% of the sample after dilution, nutrients may be limited in the diluted sample and,
subsequently, reduce biological activity. In such samples, add the nutrient, mineral, and buffer
solutions (3a through e) directly to individual BOD bottles at a rate of 1 mL/L (0.33 mL/300-mL bottle)
or use commercially -prepared solutions designed to dose the appropriate bottle size. This requirement
is a new policy that has been implemented by our program since the last inspection. Demonstration of
acceptable corrective action (i.e. a revised benchsheet documenting the addition of nutrients to bottles
containing more than 201 mL of sample) was received by e-mail on September 7, 2012. No further
response is necessary for this finding
Ammonia Nitrogen — Standard Methods, 20th Edition, 4500 NH3 F
Comment: Samples were checked to verify that the pH was > 11 Standard Units (S.U.), however this
was not documented. The North Carolina Administrative Code, 15A NCAC 2H .0805 (a) (7) (A) states: All
analytical data pertinent to each certified analysis must be filed in an orderly manner so as to be readily
available for inspection upon request. This requirement is a new policy that has been implemented by
our program since the last inspection. Demonstration of acceptable corrective action (i.e. a revised
benchsheet documenting that the pH is elevated to > 11 S.U.) was received by e-mail September 7,
2012. No further response is necessary for this finding.

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#173 Mooresville Rocky River WWTP Lab
Comment: The laboratory was not analyzing a blank at the end of the sample run. NC WW/GW LC
Policy based upon Standard Methods, 20th Edition, 1020 B. (10) (c), 3020 B. (2) (b), and 4020 B. (2)
states: 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.). Notification of corrective action (i.e.
sample runs will end with a mid -range standard and blank) was received by e-mail on September 7,
2012. No further response is necessary for this finding
IV. PAPER TRAIL INVESTIGATION:
The paper trail consisted of comparing laboratory bench sheet and contract lab reports to Discharge
Monitoring Reports (DMRs) submitted to the North Carolina Division of Water Quality. Data were
reviewed for Mooresville Rocky River WWTP (NPDES permit #NC0046728) for April, May and June,
2012. No transcription errors were detected. The facility appears to be doing a good job of accurately
transcribing data
V. CONCLUSIONS:
All findings noted during the inspection were adequately addressed prior to the completion of this
report. The inspector would like to thank the staff for its assistance during the inspection and data review
process. No response is required.
Report prepared by: Chet Whiting Date: September 14, 2012
Report reviewed by: Jason Smith Date: September 19, 2012