#649_2022_0802_TLH_FINAL

NC Department of Environmental Quality | Division of Water Resources | Laboratory Certification Branch
4405 Reedy Creek Road | 1623 Mail Service Center | Raleigh, North Carolina 27699-1623
919-733-3908

August 31, 2022

649
Mr. Gene Reed
Town of Williamston WWTP
P.O. Box 506
Williamston, NC 27892

Subject: North Carolina Wastewater/Groundwater Laboratory Certification Branch (NC
WW/GW LCB) Maintenance Inspection

Dear Mr. Reed:

Enclosed is a report for the inspection performed on August 2, 2022 by Thomas Halvosa. Where
Finding(s) are cited in this report, a response is required. Within thirty days, please supply this
office with a written item for item description of how these Finding(s) were corrected. Please
describe the steps taken to prevent recurrence and include an implementation date for each
corrective action. 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 02H .0800.

A copy of the laboratory’s Certified Parameter List at the time of the audit is attached. This list will
not reflect any changes made during the audit. Copies of the checklists completed during the
inspection may be requested from this office. Thank you for your cooperation during the
inspection. If you have questions or need additional information, please contact me at (919) 733-
3908 Ext. 259.

Sincerely,

Beth Swanson
Technical Assistance & Compliance Specialist
Division of Water Resources

Attachment
cc: Tom Halvosa, Todd Crawford, #649

On-Site Inspection Report

LABORATORY NAME: Town of Williamston WWTP
NPDES PERMIT #: NC0020044
ADDRESS: 1801 Willow Drive
Williamston, NC 27892
CERTIFICATE #: 649
DATE OF INSPECTION: August 2, 2022
TYPE OF INSPECTION: Municipal Maintenance
AUDITOR: Tom Halvosa

LOCAL PERSON(S) CONTACTED:

Gene Reed and Billie Jo Cooper

I. INTRODUCTION:

This laboratory was inspected by a representative of the North Carolina Wastewater/Groundwater Laboratory
Certification Branch (NC WW/GW LCB) to verify its compliance with the requirements of 15A NCAC 02H
.0800 for the analysis of compliance monitoring samples.

II. GENERAL COMMENTS:

The facility is neat and well organized and has all the equipment necessary to perform the analyses.
Laboratory personnel communicate well with each other and coordinate sample analyses effectively to
manage workload and holding times. Staff was forthcoming and responded well to suggestions from the
auditor.

All required Proficiency Testing (PT) Samples have been analyzed for the 2022 PT Calendar Year and the
graded results were 100% acceptable.

The laboratory is reminded that any time changes are made to laboratory procedures, QA/SOP
document(s) must be updated and relevant staff retrained. Staff must acknowledge that they have read
and understand the changes as part of the documented training program. The same requirements apply
when changes are made in response to Findings, Recommendations or Comments listed in this report, to
ensure the methods are being performed as stated, references to methods are accurate, and the QA
and/or SOP document(s) is 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.
Revisions to the SOPs, based on the Findings, Comments and Recommendations within this
report must be submitted to this office by March 1, 2023.

The laboratory is also reminded that SOPs are required to be reviewed at least every two years and are
intended to describe procedures exactly as they are to be performed. Use of the word “should” is not
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# 649 Town of Williamston WWTP

appropriate when describing requirements (e.g., Quality Control (QC) frequency, acceptance criteria, etc.).
Evaluate all SOPs for the proper use of the word “should”.

Contracted analyses are performed by Environment 1, Inc. (Certification # 10).

Approved Procedure documents for the analysis of the facility’s currently certified Field Parameters were
provided at the time of the inspection.

III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS:

Documentation

A. Finding: Error corrections are not properly performed.

Requirement: All documentation errors shall 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 shall not to be used; instead, the correction shall be written adjacent to the
error. The correction shall be initialed by the responsible individual and the date of change
documented. Ref: 15A NCAC 02H .0805 (a) (7) (E).

Comment: The laboratory does not write the date of change on the correction and there were
several instances of write-overs.

B. Finding: The Total Residual Chlorine (TRC) and pH laboratory benchsheets are lacking
required documentation: all quality control assessments.

Requirement: All laboratories shall use printable laboratory benchsheets. Certified Data shall
be traceable to the associated sample analyses and shall consist of: all quality control
assessments. Each item shall be recorded each time that samples are analyzed. Ref: 15A
NCAC 02H .0805 (a) (7) (F) (xv).

Comment: The TRC benchsheet lacks the acceptance criterion for the daily check standard
and the pH benchsheet lacks the acceptance criterion for the check standard buffer.

C. Finding: The laboratory benchsheet is lacking required documentation: Date of most recent
TRC calibration curve verification.

Requirement: The State Laboratory may develop Approved Procedures for Field Parameters
based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this
Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F).

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 LCB Approved Procedure for the Analysis of Total Residual Chlorine (DPD
Colorimetric by Hach 10014 ULR).

D. Finding: The unit of measure for barometric pressure (mm Hg) is not documented on the
Dissolved Oxygen (DO) benchsheet.

Requirement: All laboratories shall use printable laboratory benchsheets. Certified Data shall
be traceable to the associated sample analyses and shall consist of: the proper units of
measure. Each item shall be recorded each time samples are analyzed. Ref: 15A NCAC 02H
.0805 (a) (7) (F) (xii).
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# 649 Town of Williamston WWTP

E. Finding: The Reference Temperature-Measuring Device used to verify the laboratory
temperature-measuring devices is not NIST traceable.

Requirement: Laboratory procedures shall comply with Subparagraph (a)(1) of this Rule. Ref:
15A NCAC 02H .0805 (g) (4).

Requirement: All compliance temperature-measuring devices without an NIST traceable
certificate, or with an expired NIST traceable certificate, must be verified against a Reference
Temperature-Measuring Device and the process documented initially and every 12 months.
Ref: NC WW/GW LCB Approved Procedure for the Analysis of Temperature.

Requirement: A Reference Temperature-Measuring Device is an NIST traceable
temperature-measuring device used only to verify the calibration of other temperature-
measuring devices (i.e., limited use only). This device must be able to distinguish
temperature changes of 0.1°C and equilibrate rapidly. It must be recalibrated in accordance
with the manufacturer’s recalibration date (not to exceed five years). If no recalibration date
is given, the Reference Temperature-Measuring Device must be recalibrated, at a
minimum, every five years. A new certificate of traceability must be issued and maintained
for inspection upon request. Recalibrate sooner if the device has been exposed to
temperatures beyond the manufacturer’s recommended range of use. Ref: NC WW/GW
Temperature Measuring-Devices used for Laboratory Operations LCB Policy.

Requirement: The Reference Temperature-Measuring Device used to verify the
calibration of any device used in a microbiological incubator must have a stated accuracy
of at least ± 0.1°C. The Reference Temperature-Measuring Device used to verify the
calibration of any device used in a BOD incubator must have a stated accuracy of at least
± 0.3°C. The Reference Temperature-Measuring Device used to verify the calibrations of
any device used in laboratory equipment; other than incubators, must have a stated
accuracy of at least ± 0.5°C. Ref: NC WW/GW LCB Temperature Measuring-Devices used
for Laboratory Operations Policy.

Comment: The laboratory has an Ertco Model 1011-3 thermometer capable of reading 0.1
°C increments, however, no NIST certificate or recalibration documentation could be produced
to show the stated accuracy or expiration date of calibration. The thermometer is being verified
yearly by Environment 1, Inc.; however, this does not result in the issuance of a certificate of
traceability to NIST standards, so it is not considered a valid calibration.

Chlorine, Total Residual – Hach 10014 ULR (Aqueous)

F. Finding: The laboratory is not analyzing a Reagent Blank.

Requirement: The State Laboratory may develop Approved Procedures for Field Parameters
based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this
Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F).

Requirement: Reagent Blank: Deionized or Distilled water, from the same source used to
make calibration and calibration verification standards, to which 1.0 mL of Blanking Reagent
is added. The Blanking Reagent removes chlorine and chloramines from the water. It is then
analyzed like a sample (i.e., with DPD/buffer added). The concentration of the reagent blank
must not exceed 5 μg/L. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total
Residual Chlorine (DPD Colorimetric by Hach 10014 ULR).

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# 649 Town of Williamston WWTP

Requirement: The Reagent Blank value must be determined each analysis day and must be
< 5 μg/L. The Reagent Blank value must be subtracted from the Method Blank and all sample
and standard results. Ref: NC WW/GW LCB Approved Procedure for the Analysis of Total
Residual Chlorine (DPD Colorimetric by Hach 10014 ULR).

Dissolved Oxygen – Standard Methods, 4500 O G-2016 (Aqueous)

G. Finding: The laboratory is using the default salinity value of zero without determining whether
the salinity of the samples is ≤ 9ppt.

Requirement: The State Laboratory may develop Approved Procedures for Field Parameters
based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this
Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F).

Requirement: Per NC WW/GW LC Branch policy, facilities may use the Salinity default value
of zero when calibrating the DO meter unless it is known or suspected that the Salinity value
of the samples being analyzed is > 9 ppt. In those situations, actual Salinity values must be
used. Regardless of which value is used, it must be documented. Ref: NC WW/GW LCB
Approved Procedure for the Analysis of Dissolved Oxygen (DO).

Requirement: Since the effect on oxygen solubility is < 0.5 mg/L when Salinity values are ≤
9.0 ppt and sample temperatures are above 11 °C, all facilities may use the DO meter
calibration default Salinity value of zero, unless it is known or suspected that the Salinity value
of the samples being analyzed is > 9.0 ppt. Ref: NC WW/GW LCB Dissolved Oxygen (DO)
Meter Calibration Policy.

Temperature – Standard Methods, 2550 B-2010 (Aqueous)

H. Finding: The compliance temperature-measuring device is not checked at two temperatures
that bracket the range of observed sample temperatures.

Requirement: The State Laboratory may develop Approved Procedures for Field Parameters
based upon the methods in any of the sources referenced in Parts(a)(1)(A) through (F) of this
Rule. Ref: 15A NCAC 02H .0805 (a) (1) (F).

Requirement: To check a compliance temperature-measuring device, compare readings at
two temperatures that bracket the range of compliance samples routinely analyzed against a
National Institute of Standards and Technology (NIST) traceable temperature-measuring
device and record all four readings. The readings from both devices must agree within 0.5 ºC.
If they do not, the device may not be used for temperature compliance monitoring. Ref: NC
WW/GW LCB Approved Procedure for the Analysis of Temperature.

Comment: The compliance temperature-measuring device is checked at only one
temperature.

IV. PAPER TRAIL INVESTIGATION:

The paper trail consisted of comparing original records (e.g., laboratory benchsheets, logbooks, etc.) and
contract laboratory reports to DMRs submitted to the North Carolina Division of Water Resources. Data
were reviewed for Town of Williamston WWTP (NPDES permit # NC0020044) for July 2021, January and
May 2022. The following errors were noted:

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# 649 Town of Williamston WWTP

Date Parameter Location
Value on
Benchsheet

Value on DMR

7/13/2021 Temperature Effluent 25.8 ºC 25 ºC
7/14/2021 Temperature Effluent 26.3 ºC 25 ºC
7/15/2021 Temperature Effluent 26.0 ºC 25 ºC
5/4/2022 Dissolved Oxygen Effluent 7.59 mg/L 7.4 mg/L

To avoid questions of legality, it is recommended that you contact the appropriate Regional Office for
guidance as to whether an amended DMR(s) will be required. A copy of this report will be made available to
the Regional Office

V. CONCLUSIONS:

Correcting the above-cited Findings will help this laboratory to produce quality data and meet Certification
requirements. The inspector would like to thank the staff for their 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: Tom Halvosa Date: August 3, 2022
Report reviewed by: Michael Cumbus Date: August 12, 2022

Certificate Number:649
Effective Date:1/1/2022
Expiration Date:12/31/2022
Lab Name:Town of Williamston WWTP
Address:1801 Willow Drive
Williamston, NC 27892
North Carolina Wastewater/Groundwater Laboratory Certification
Certified Parameters Listing
Date of Last Amendment:9/21/2021
The above named laboratory, having duly met the requirements of 15A NCAC 2H.0800, is hereby certified for the measurement of the parameters listed below.
CERTIFIED PARAMETERS
INORGANIC
BACTERIA - COLIFORM FECAL
IDEXX Colilert ®18 (MPN) (Aqueous)
CHLORINE, TOTAL RESIDUAL
Hach 10014 ULR (Aqueous)
DISSOLVED OXYGEN
SM 4500 O G-2016 (Aqueous)
pH
SM 4500 H+B-2011 (Aqueous)
RESIDUE, SUSPENDED
SM 2540 D-2015 (Aqueous)
TEMPERATURE
SM 2550 B-2010 (Aqueous)
This certification requires maintance of an acceptable quality assurance program, use of approved methodology, and satisfactory performance on evaluation samples. Laboratories are subject to civil penalties and/or decertification for infraction
as set forth in 15A NCAC 2H.0807.