NC0026921_Lab Certification Inspection_20071009

5203
Mr. Phillip Schroeder
Town of Parkton
PO Box 55
Parkton, NC 28371
• Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Coleen H. Sullins; Director
Division of Water Quality
DENR-Fkber 9, 2007
OCT 1:12007
DWQ
SUBJECT: Laboratory Certification Maintenance Inspection
Dear Mr. Schroeder:
Enclosed is a report for the inspection performed on September 12, 2007 by Ms. Tonja
Springer. Where finding(s) are cited in this report, .a response is required. Within thirty days of
receipt, please supply this office with a written item for item description of how these finding(s)
,were corrected. If the "finding(s) cited in the enclosed report are not corrected, enforcement
actions may be recommended. For certification maintenance, your laboratory must continue to
carry out the requirements set forth in 15A NCAC 2H .0800.
Copies of the checklists completed during the inspection may be requested from this
office. Thank you for your cooperation during the inspection. If you wish to obtain an electronic
copy of this report by email or if you have questions or need additional information, please
contact us at .919-733-3908.
Sincerely,
g�v Dana Satterwhite
Certification Unit Supervisor
Laboratory Section
Enclosure
cc: Tonja Springer
Fayetteville Regional Office
NorthCarolina
Naturally
North Carolina Division of Water Quality 1623 Mail Service Center Raleigh, NC 27699-1623 Phone [phone] Customer Service
Internet: www.dwglab.org Location: 4405 Reedy Creek Rd Raleigh, NC 27607 Fax [phone]
An Equal Opportunity/Affirmative Action Employer — 50% Recycled/10% Post Consumer Paper

On -Site Inspection Report
LABORATORY NAME: Town of Parkton
NPDES PERMIT #: NC0026921
ADDRESS: PO Box 55
Parkton, NC 28371
CERTIFICATE #: 5203
DATE OF INSPECTION: September 12, 2007
TYPE OF INSPECTION: Field Maintenance
AUDITOR(S): Tonja Springer
LOCAL PERSON(S) CONTACTED: Philip Schroeder
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:
Comment: At the time of the inspection, updated guidance documents were given for all the certified parameters,
along with a copy of new policies. The required documentation is listed at the bottom of each guidance document for
the field parameters.
Comment: The lab indicated during the time of the inspection that they will implement our example field sheet as
their own. An electronic copy was sent to the lab following the inspection.
Comment: The following findings: D, F, G, and H are new policies that have been implemented by our program
since the last inspection.
III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS:
Total Residual Chlorine - Standard Methods, 18th Edition, 4500 CI G
Comment: Values are reported on the DMR as <17,ug/L which is the permit limit. Per the Fayetteville
Regional office, the laboratory can continue to report as <17pg/L until an annual verification curve has
been analyzed. Once the curve has been done; the_lower`_reporting- limit will-be-thelowesCpoint-of the)
annual verification curve; Example: if -the -lowest pointt is 15 g/L, any values less:than. l-5 will -be -reported
as <15=Ng/L%
A. Finding: The internal calibration curve is not verified daily. The standards and samples are analyzed
under different programs.
Requirement: Verify frequently the accuracy of the curves or permanent standards by comparing with
standards prepared in the laboratory, using the same set of reagents, the same instrument, and the same
procedures as those used for analyzing samples. Even if permanent calibration curves or artificial
standards have been prepared accurately by the manufacturer, they may not be valid under conditions of
use. Ref: Standard Methods, 18th Edition — 1070D. page 1-28.
Requirement: Purchased "Gel- type" standards may be used for. daily calibration verification. Ref:
TECHNICAL ASSISTANCE FOR FIELD ANALYSIS OF TOTAL RESIDUAL CHLORINE.

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Town of Parkton
Comment: The lab was reading all 3 gel standards each analysis day as a verification check. The gels
were being read on program 80 instead of program 86. The gel standard and samples must be read on
program 86.
B. Finding: The spectrophotometer has not had its internal calibration curve verified across the range of the
meter with five standards. (See Attachment for Guidance on the Curve and Gel standards)
Requirement: A verification of the internal calibration curve must be performed at least annually (i.e., every
twelve months). This is performed by verifying the readings of five standards. The concentrations of the five
standards must bracket the concentration of the samples analyzed. One of the standards must have a
concentration equal to or below the lower reporting concentration. It is recommended that the values
obtained not vary by more than 10% of the known value for standards greater than 50 µg/L and 25% of the
true value for standards less than 50 µg/L. If the stored program readings vary by more than the above
acceptance criteria, the stored calibration program should not be used for quantitation until troubleshooting is
carried out to determine and correct the source of error. Ref: Standard Methods, 18th Edition - Method 4500-
CI G., Method 1020B Quality Control (5) page 1-5. (Please submit a copy of the curve with the report
reply)
Recommendation: It is recommended that the calibration curve be in a range of 15pg/L — 400pg/L.
C. Finding: The gel standard used, as a mid -range check was not initially verified.
Requirement: The value supplied with the gel standard is an estimated value within a range. The true
value must be determined for each instrument and program. The true (assigned) values must be verified
at a minimum of every 12 months. Ref: Manufacturer's Instructions and TECHNICAL ASSISTANCE FOR
FIELD ANALYSIS OF TOTAL RESIDUAL CHLORINE
Comment: At the time of the inspection, the gel standard was read on program 86 and an assigned value
of 188pg/L was assigned until the verification curve is analyzed. Once the verification curve is analyzed,
the gel standard will need to be verified against the curve and a new value assigned.
D. Finding: The time the daily check , standard is analyzed is not documented. This is considered
pertinent information.
Requirement: Data pertinent to each analysis must be maintained for five years. Certified data must
consist of date collected, time collected, samples site, sample collector, and sample analysis time..
The field bench sheets must provide a space for the signature of the analyst, and proper units of
measure for all analyses; Ref: 15A NCAC 2H .0805 (g) (1).
Total Residual Chlorine - Standard Methods, 18th Edition, 4500 CI G
pH - Standard Methods, 18th Edition, 4500 H+ B
DO - Standard Methods, 18th Edition, 4500 0 G
E. Finding: The collection and analysis time is documented as one time for all analyses.
Requirement: Certified data must consist of date collected, time collected, sample site, sample
collector, and sample analysis time. Ref: 15A NCAC 2H .0805 (a) (g) (1).
Comment: A collection and analysis time must be documented for each individual analysis unless the
samples are analyzed in situ at the sampling point.
pH - Standard Methods, 18th Edition, 4500 H+ B
DO - Standard Methods, 18th Edition, 4500 0 G
Temperature - Standard Methods, 18th Edition, 2550B
F. Finding: The temperature sensing device on the meters has not been calibrated against a NIST certified
or NIST traceable thermometer.

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Town of Parkton
Requirement: The temperature sensor must be calibrated annually even if it is not being used to report
temperature. (See Attachment for Procedure) Please send a copy to our office with your reply.
Comment: The pH meter is used to -analyze the effluent temperature.
pH - Standard Methods, 18th Edition, 4500 H+ B
G. Finding: The verification of the accuracy of the pH meter automatic temperature compensation (ATC)
function was not conducted annually. (See the Attachment for the Procedure) Please send a copy to our
office with your reply.
Requirement: Verify the accuracy of the pH meter temperature compensation at least annually (i.e., every
12 months). Ref: NC WW/GW Lab Certification policy
H. Finding: The temperature at which pH is measured is not documented.
Requirement: Always report temperature at which pH is measured. Ref: Standard Methods 18th.Edition
4500-H+B (1) (b).
Comment: The temperature documented off the meter in the laboratory is not to be reported as the
effluent reported temperature.
Finding: The check buffer is not being documented. This is considered pertinent information.
Requirement: The laboratory must calibrate the pH meter with at least two buffers and read a third
buffer below pH 10, approximately 3 pH units different from the second buffer and the reading should be
within 0.1 pH units from the expected value. Ref: Standard methods 18th Edition 4500-H B (4) (a) p4-
68.
Requirement: Data pertinent to each analysis must be maintained for five years. Certified data must
consist of date collected, time collected, samples site, sample collector, and sample analysis time. The
field bench sheets must provide a space for the signature of the analyst, and proper units of measure for
all analyses. Ref: 15A NCAC 2H .0805 (g) (1).
Temperature - Standard Methods, 18th Edition, 2550B
J. Finding: Samples are collected and brought back to the lab and analyzed on the pH meter.
Requirement: All temperature measures must be taken immediately i.e., at the site of collection. The
Federal Register states the maximum holding time as "analyzed" which is defined by our program as "in
situ". Ref: 40CFR Vol. 72, March 12, 2007 Table II.
Recommendation: It is recommended that the DO field meter be used to analyze the samples "in situ".
DO - Standard Methods, 18th Edition, 4500 0 G
K. Finding: The calibration is not documented, nor is the calibration time. This is considered pertinent
information.
Requirement: Data pertinent to each analysis must be maintained for five years. Certified data must
consist of date collected, time collected, samples site, sample collector, and sample analysis time. The
field bench sheets must provide a space for the signature of the analyst, and proper units of measure for
all analyses. Ref: 15A NCAC 2H .0805 (g) (1).
Comment: The adjusted air calibration value is the reading that would be documented for the calibration.
This reading is displayed once the meter has completed calibration. The mode can be switched between
% and mg/L. If the value is in % press the mode button to display the reading in mg/L.

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Town of Parkton
L. Finding: Samples are collected and brought back to the lab and analyzed'.
Requirement: Temperature changes quickly; pH may change significantly in a matter of minutes;
dissolved gases (e.g., oxygen, carbon dioxide) may be lost. Determine temperature, pH, and
dissolved gases in the field. Ref: Standard Methods, 18 h Edition, 1060 C.
Recommendation: While the Federal Register states the maximum holding time for Dissolved Oxygen is
"within 15 minutes", it is recommended that the field DO meter be used to analyze the sample "in situ'.
Footnote 4 of 40 CFR Part 136 Table II explains that "some samples may not be stable for the maximum
time period given in the table. A permittee or monitoring laboratory is obligated to hold the sample for a
shorter time if it knows that a shorter time is necessary to maintain sample stability."
IV. PAPER TRAIL INVESTIGATION:
A paper trail was conducted. This consisted of comparing field testing records to Discharge Monitoring Reports
(DMRs) submitted to the North Carolina Division of Water Quality. Data werereviewed for the months of February
and May of 2007. The following error was noted:
Date
May 1, 2007
Parameter
Temperature
Location
Effluent
Value on Benchsheet
19°C
Value on DMR
18°C
Comment: The Fayetteville Regional office has requested that the correction be done onsite and initialed. No
amended report is needed.
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 their assistance in the
inspection and data review process. Please respond to all lettered findings.
Report prepared by: Tonja Springer Date: September 17, 2007
Report reviewed by: Tony Hatcher Date: September 17, 2007

Total Residual Chlorine Annual Verification Curve (Required every 12 months):
Every 12 months a 5 point calibration curve must be analyzed. If a lab has a pocket colorimeter the curve should not
go any lower than 100 µg/L (.100mg/L). The meter is not sensitive below 100 µg/L. If a facility has a permit limit of 28
µg/L, it is recommended that the lowest point of the verification curve start at 25 µg/L. It is recommended that the
curve be no lower than you have to, such as a limit of 17 µg/L, the lowest point be 15 µg/L. The highest point of the
curve should be high enough so that the daily check standard falls about mid -point of the curve. For example if a gel
standard in the 180 µg/L (0.18mg/L) is read the highest point of the curve would be about 300pg/L or 400 pg/L. A
curve for a facility with a permit limit of 28 µg/L would look something like this: 25 µg/L, 50 µg/L, 150 µg/L, 250 µg /L,
and 400 µg/L. It is recommended that the values obtained not vary by more than 10% of the known value for
standard concentrations greater than 50 µg/L and 25% of the true value for standard concentrations less than 50
µg/L.
Gel Standards Verification: (Required every 12 months (Field Labs Only)
In order to Use the gel standards past the manufacturer's expiration date, the gels must be verified annually against
the annually verification curve. If a contract lab is doing the verification curve for a facility, the field lab would need to
bring both the instrument and the gel standards to the contract lab. The contract lab will read the field facility's gel
standards like a sample after the annual verification .curve is analyzed. The values obtained from the gel standards
will be the true value for the gels until the curve is analyzed in 12 months. If more than one instrument is used for
testing, the gels will need to be read on each instrument and obtained values assigned to each instrument. The gels
are instrument specific. The values will change from instrument to instrument. The gels are also program specific
and should be measured on the same program as the samples. The contract lab should document all the information
such as the stock standard information (lot numbers, etc) and how the curve was made. The correlation coefficient
for the curve should be documented. The gel standard documentation should include the assigned value and the
obtained values, along with the lot number of the gel standard.
Automatic Temperature Compensator (ATC) Check Procedure for pH meter:
The following must be performed on an annual (Le., 12 month) basis:
1. Pour an adequate amount of buffer into a beaker or other container and analyze at 25° C. Document the
temperature and pH value.
2. Lower the temperature of the buffer by placing the container in cool water or a refrigerator to Tess than the
lowest anticipated sample temperature and analyze. Document the temperature and pH value.
3. If samples greater than 25° C are to be analyzed, perform the following additional step: Place the container in
warm water, or a water bath and raise the temperature above 25° C to greater than the highest anticipated
sample temperature and analyze. Document the temperature and pH value.
As the temperature increases or decreases, the value of the buffer must be within ± 0.1 S.U. of the true value of the
buffer.
Comment: Anticipated temperatures can be obtained from a review of the Discharge Monitoring Reports (DMRs)
from the peak summer and winter months. Historical data should provide a reasonably accurate estimation of ranges
that will bracket the expected sample temperatures.
Temperature Sensor Check Procedure:
To check a thermometer or the temperature sensor of a meter, read the temperature of the thermometer/meter
against a NIST thermometer and record the two temperatures. The thermometer/meter readings must be less
than or equal to 1°C from the NIST thermometer reading. REQUIRED for certified data. (NC WW/GW LC
Policy). In the documentation include the serial number and manufacturer of the NIST thermometer or NIST
traceable thermometer that was used in the comparison. Also document any correction that applies (even if zero)
on both the thermometer/meter and on a separate sheet to be filed.
Recommendation: Use a NIST calibrated thermometer that approximates the temperature range on each
thermometer used with an incubator, refrigerator, or freezer. You may borrow such a thermometer, but keep a copy
of the traceable to NIST certificate on file to show the inspector.
Requirement: All thermometers and temperature measuring devices must be checked every 12 months against
a NIST certified or NIST traceable thermometer and the process documented. NIST certified or NIST traceable
thermometers used for temperature measurement mustbe recalibrated in accordance with the manufacturer's
recalibration date. If no recalibration date is given, the NIST certified or NIST traceable thermometer must be
recalibrated on a periodic basis to not exceed five years. Ref: Technical Assistance for Field Analysis for
Temperature.