NC0027103_Lab Inspection_20021209

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Michael F. Easley, Governor ,-
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E. Director
Division of Water Quality
December 9, 2002
552
Ms. Rhonda Locklear
Town of Pembroke Wastewater Laboratory
P. O. Box 866
Pembroke, NC 28372-
SUBJECT: Laboratory Certification Maintenance Inspection
Dear Ms. Locklear:
'DEC I 0 2002
Enclosed is a report for the inspection performed on November 25, 2002 by Mr. Frederick L.
Bone. Where deficiencies are cited in this report, a response is required as well as for all lettered
comments and/or recommendations. Within thirty days of receipt, please supply this office with a
written item for item description of how these deficiencies, comments and/or recommendations were
corrected. If the deficiencies cited in the enclosed report are not corrected, enforcement actions will
be recommended. For certification maintenance, your laboratory must continue to carry out the
requirements set forth in 15A NCAC for 2H .0800.
Copies of the checklists completed during the inspection may be requested from this office.
Thank you for your cooperation during the inspection. Please contact us at 919-733-3908, if you have
questions or need additional information.
Sincerely,
G2�tne4
WM�
James W. Meyer
Laboratory Section
Enclosure
cc: Frederick L. Bone
Fayetteville Regional Office
NCDNR
Laboratory Section N. C. Division of Water Quality 1623 Mail Service Center Raleigh, NC 27699-1623
[phone] Fax: [phone] Internet: dwglab.org Customer Service 1-800-623-7748

On -Site Inspection' Report
LABORATORY NAME: Pembroke VWVfP
ADDRESS: P.O. Box 866
Pembroke, NC 28372
CERTIFICATE NO: 552
DATE OF INSPECTION: November 25, 2002
TYPE OF INSPECTION: Maintenance
EVALUATOR: Frederick L. Bone
LOCAL PERSON(S) CONTACTED: Rhonda Locklear
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 is spacious and well equipped. All facilities and equipment are well maintained. Records
.are well kept and most data looked good. Some further quality control procedures need to be
implemented.
III. DEFICIENCIES, RECOMMENDATIONS, REQUIREMENTS, AND COMMENTS:
General:
A. COMMENT: The laboratory is reporting all preservation check data as "0".
REQUIREMENT: All data must be reported as less than the lowest standard concentration
demonstrated by the laboratory. In the case of preservation checks, the data should be reported as
less than the detection limit of the test method used. Residual chlorine preservation checks should be
documented as < 0.5 mg/L when tested with KI paper.
Dissolved Oxygen:
B. COMMENT: The influent sample taken for dissolved oxygen is not measured immediately upon
sample collection, but is transported to the laboratory fo.r analysis. Effluent samples are measured
immediately.
REQUIREMENT: All dissolved oxygen measurements must be taken immediately at the site of
collection. Ref: 40CFR Ch.1(7-1-95) p. 644 table II.
RESIDUAL CHLORINE:
C. COMMENT: The recovery of the lower reporting limit standard in two out of three analytical curves
reviewed did not demonstrate acceptable recovery limits. The laboratory is reporting a detection limit

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of 0.2 mg/L. The low reporting limit concentration recovered for each of the three curves is as follows:
0.3 mg /L, 0.4mg/L and 0.2 mg/L.
REQUIREMENT: The recovery of the low reporting standard must be within three times the standard
deviation of the true value or the 99 percent confidence interval. The low standard must therefore be
within approximately 25% of the true value. The laboratory must reanalyze the analytical curve and
demonstrate the capability of accurately achieving the detection limit standard.
Note: The analytical curve used by the laboratory is from 0.2 mg /L to 2.0 mg/L. The laboratory may
consider shortening the analytical curve range used for residual chlorine analysis. By decreasing the
total overall linear range, the laboratory should be able to increase the sensitivity in the lower range of
the analytical curve. This increased sensitivity will lead to better recoveries of the detection limit
standard.
D. COMMENT: The laboratory is analyzing a DI water blank daily, but does not perform a reagent
blank each analysis day.
RECOMMENDATION: The laboratory should zero their instrument with the DI water blank. The
laboratory should then analyze the reagent blank in which the DPD colorimetric reagents are added to
the DI water. ,This will allow the laboratory to determine any interferences caused by laboratory
contamination or reagent interference.
Total Suspended Solids and Total Solids:
E. COMMENT: The laboratory does not record the time and date that the samples were placed info the
oven and time and date that the samples were removed from the oven on the bench sheet for the
drying time verification study.
REQUIREMENT: Dry evaporated sample for at least 1 hour 'in an oven at 103 the 105°C, cool in
desiccator to balance temperature, and weigh. Repeat cycle of drying, cooling, desiccation, and
weighing until a constant weight is obtained, or until weight change is less than 4% of previous weight
or 0.5 mg, whichever is less. Ref: Standard Methods 18th Edition 2540 B Total Solids at 103=105° C
section (3) b p2-54.
IV: PAPER TRAIL INVESTIGATION:
This consisted of comparing data reported on DMR's submitted to this Division with the values obtained
on laboratory bench worksheets. Data reviewed for the months of January, July, and September 2002
indicated no problems in proper data reporting.
V. CONCLUSIONS:
Correcting the above cited comments and implementing the recommendations should help them to
produce quality data and meet certification requirements. Please respond to all lettered Comments
cited in this report.
Report prepared by: Frederick L. Bone Date: November 26, 2002

Town of Pembroke
Wastewater Laboratory
Town of Pembroke
P.O. Box 868
Pembroke NC, 28372
Phone: [phone]
Fax: [phone]
Corrective Action -Response
Laboratory Name: Pembroke WWTP
Address: P.O. Box 866
Pembroke, NC 28372
Certificate No: 552
DM; �1 nI�lL11: O
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REPORTED BY: Rhonda Hagan
Locklear

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DENR FA I r_ ILL E REGIONAL OFFICI
I. GENERAL DEFICIENCIES, RECOMMENDATIONS, REQUIREMENTS, AND
COMMENTS:
GENERAL:
A. COMMENT: The laboratory is reporting all preservation check
data as "0".
Correction: We are currently documenting residual chlorine
preservation checks as < 0.5 mg/1 when tested with KI
paper.
DISSOLVED OXYGEN:
B. COMMENT: The influent sample taken for dissolved oxygen is
not measured immediately upon sample collection, but is
transported to the laboratory for analysis. Effluent samples are
measured immediately.
Correction: The laboratory does not measure dissolved
oxygen at the influent , only effluent dissolved oxygen.
RESIDUAL CHLORINE:
C. COMMENT: The recovery of the lower reporting limit standard in
two out of three analytical curves reviewed did not demonstrated
acceptable recovery limits. The laboratory is reporting a detection
limit of 0.2 mg/I. The low reporting limit concentration recovered
for each of the three curves is as follows: 0.3 mg/I, 0.4 mg/I and
0.2 mg/I.
Correction: The laboratory is creating new calibration
curves.
D. COMMENT: The laboratory is analyzing a DI water blank daily,
but does not perform a reagent blank each analysis day.
Correction: The laboratory is currently preparing a analysis
blank daily.
TOTAL SUSPENDED SOLIDS AND TOTAL SOLIDS
E. COMMENT: The Laboratory does not record the time and date that
the samples were placed into the oven and time and date that the
samples were removed from the oven on the bench sheet for the
drying time verification study.
Correction: The laboratory has modified drying time
verification bench sheet to reflect all times.
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