NC0027103_Lab Inspection_20080204

Michael F. Easley, Govemor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
February 4, 2008
552
Ms. Rhonda Locklear
Town of Pembroke Wastewater Laboratory
P. O. Box 866
Pembroke, NC 28372-
SUBJECT: Laboratory Certification Maintenance Inspection
Dear Ms. Locklear :
Coleen H. Sullins, Director
Division of Water Quality
DENR-FRO
FEB 0 & 2008
DWQ
Enclosed is a report for the inspection performed on October 23, 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,
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 Pembroke Wastewater Laboratory
NPDES PERMIT #: NC0027103
ADDRESS: PO Box 866
Pembroke, NC 28372
CERTIFICATE #: 552
DATE OF INSPECTION: October 23, 2007
TYPE OF INSPECTION: Municipal Maintenance
AUDITOR(S): Tonja Springer
LOCAL PERSON(S) CONTACTED:. Rhonda Locklear and Karen Dial
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 staff is congratulated for doing an excellent job of implementing the laboratory certification program. The
laboratory is spacious and well equipped. All facilities and equipment are well maintained. Records are well kept.
Some further quality control procedures need to be implemented.
Comment: The following findings; A, B, and C, are new policies that have been implemented by our program since
the last inspection.
Comment: The laboratory has requested copies of the checklists. Copies of the checklists were sent in an email.
III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS:
- Standard Methods, 18th Edition, 4500 H+ B
A. Finding: The Automatic Temperature Compensator (ATC) has not been verified.
Requirement: The ATC must be verified annually (i.e., every twelve months) by analyzing a buffer at 25°
C (the temperature that pH values are compensated to) and a temperature(s) that bracket the temperature
ranges of the samples to be analyzed. This may require the analysis of a third temperature reading that is
> 25° C. Ref: North Carolina Wastewater/Groundwater Laboratory Certification (NC WW/GW LC) Policy
Statement February 2006. See the technical assistance document attached to report.
B. 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.
Total Residual Chlorine — Standard Methods, 18th Edition, 4500 CI G
C. Finding: The calibration time is not documented. This is considered pertinent information.

Requirement: Supporting records shall be maintained as evidence that these practices are being
effectively carried out. All analytical records must be available for a period of five years. Ref: 15A NCAC
2H .0805 (a) (7) and (a) (7) (G).
Fecal Coliform — Standard Methods, 18th Edition, 9222D (MF)
Comment: A culture positive is analyzed but the counts are TNTC.
Recommendation: Use sample or standard material that produces countable plates that better indicate the
viability of materials. A 20 to 60 colony per plate range is recommended, but not required.
D. Finding: No comparison test is conducted before a new lot of consumables are put into use.
Requirement: It is required that when a new lot of culture medium, pads, or membrane filters is to be
used, a comparison of the current lot in use (reference lot) against the new lot (test lot), be made. As a
minimum, make single analyses on five positive samples. Ref: Standard Methods, 18th Edition - Method
9020 B. 3d. (Page 9-7). See the technical assistance document attached to report.
E. Finding: The lab is analyzing a 100 mL sample but not reporting results from the 100 mL sample;
instead, counts from all dilutions yielding 20-60 colonies are averaged.
Requirement: If a 100 ml sample is analyzed and the counts are less than 60 colonies: report the total
number of colonies present on the 100 ml sample. If zero counts are obtained: report as <1/100 ml. (This is a
whole volume sample.) Ref: North Carolina Wastewater/Groundwater Laboratory Certification (NC
WW/GW LC) Fecal Coliform Reporting Guidance Document. A copy of the Fecal Coliform Reporting
Guidelines is attached to this report.
BOD — Standard Methods, 18th Edition, 5210B
Comment:. If all quality control requirements are not met, the data will still be reported and not rejected. The data
qualification should appear on the back of the Discharge Monitoring Report (DMR). It should document the
specific quality control failure, e.g., sample only depleted 1.95 mg/I. Also if appropriate, a statement, indicating that
these quality control failures do not make the data invalid, may be included.
Comment: The laboratory is analyzing a seeded blank with each analytical series but it is not prepared properly.
Recommendation: Add the same amount of seed as is used in sample analysis to a bottle of dilution water. The
actual depletion of the seed blank should be very close to value calculated from the seed control.
F. Finding: The seed correction is not calculated properly.
G. Finding: Seed corrections outside the acceptance criteria are being used to calculate the seed control.
Requirement: Determine BOD of the seeding material as for any other sample. To determine a sample
DO uptake subtract seed DO uptake from total DO uptake. The seed dilution used in calculating the seed
control must meet the "2" to "1" rule of a minimum DO usage of 2.0 mg/L, and a DO residual of 1 mg/L. The
DO uptake of the seeded dilution water should be between 0.6 and 1.0 mg/L. Average all seed controls
that meet the acceptance_ criteria. Ref: Standard Methods 18th Edition, Method 5210 B (4) (d) (2).
IV. PAPER TRAIL INVESTIGATION:
A paper trail was conducted. This consisted of comparing laboratory benchsheets to Discharge Monitoring
Reports (DMRs) submitted to the North Carolina Division of Water Quality. Data were reviewed for the months of
January, April and August of 2007. No 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 producequality
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 findings.
Report prepared by: Tonja Springer Date: January 17, 2008
Report reviewed by: David Livingston Date: January 25, 2008

Automatic Temperature Compensator (ATC) Check Procedure for pH meter:
The following must be performed on an annual (i.e., 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 less 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 or NIST traceable thermometer and record the two temperatures. The thermometer/meter
readings must be less than or equal to 1°C from the NIST or NIST traceable 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 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 traceable
thermometers used for temperature measurement must be recalibrated in accordance with the manufacturer's
recalibration date. If no recalibration date is given, the NIST certified or traceable thermometer must be
recalibrated on a periodic basis not to exceed five years. Ref: 15A NCAC 2H .0805 (a) (7) (0) and NC WW/GW
LC Policy (2006).

Testing of Consumable Materials for Fecal Coliform MF Method
Standard Methods requires that before a new lot of consumable materials are used for the Fecal
Coliform MF method, those materials be tested to ensure they are reliable. North Carolina policy
requires the testing of the following consumable materials before they can be used for sample
analyses: membrane filters and/or pads (often packaged together) and media. Test only one
consumable at a time.
REQUIREMENT: It is required that when a new lot of culture medium, pads, or membrane filters is to
be used, a comparison, of the current lot in use (reference lot) against the new lot (test lot), be made.
As a minimum, make single analyses on five positive samples. Ref: Standard Methods, 18th Edition -
Method 9020 B.3d. (page 9-7).
The following is provided as guidance in performing the required testing. Let's say you got a new batch
of membrane filters in. We will call the currently used filters lot #1 and the new filters lot #2.
1. Select a culture positive sample.
What you want is something that will yield 20-60 colonies when a reasonable sample volume is filtered.
This may be a stream sample or a sample taken somewhere within the waste treatment plant. If the
concentration is high enough that greater than 60 colonies are obtained when 1 mL is filtered then the
solution is too strong and must be diluted. Any time a sample is diluted be sure it is done with the
BUFFERED dilution water used for rinsing the, funnels.
2. Test the culture positive to determine the appropriate volume to use.
When collecting the culture positive sample do not think about it as a sample. You do not have to be
concerned with a sterile sample bottle or 6 hour hold time. Collect enough sample so that you have
plenty to work with, probably more than your normal fecal bottle holds. Set a series of dilutions using
the currently used materials, in this example filter lot #1. Do not use the materials you want to prove
are OK at this point. All you are trying to do is to determine the volume of sample that will yield 20-60
colonies. Put the rest of the sample in the refrigerator. For example:
Volume used Colonies obtained on lot #1 filters
50 ml TNTC
, 25 ml 138
10 ml 50
5 m1 22
1 ml 4
Based on this preliminary testing it appears that a 10 ml volume would probably be appropriate to use
and will yield the desired 20-60 colonies. Remember when you do the actual consumable test, the
culture positive sample will be 24 hours old and the results you obtain may be lower than the initial
results yielded, but not so significantly lower as to change your dilution choice. It is better to have your
initial results on the high side of the 20-60 range for this reason. In this example the 5 ml volume would
probably be too low and would likely yield less than 20 colonies the next day.
3. Perform the consumable test
Once you determine the appropriate volume, in this case 10 mis, take the remaining culture positive
sample from the refrigerator, bring to room temperature and set five 10 ml plates with the currently
used filters, lot #1, and five 10 ml plates with the new filters, lot #2.
4. Determine acceptability of new material.
For example:

Lot #1-current filters
10 ml
10m1
10 ml
10 ml
10 ml
Lot #2-new filters
10 ml
10m1
10 ml
10 ml
10 ml
Colonies obtained on lot #1 filters
48
45
50
44
43
Average: 46
Colonies obtained on lot #2 filters
40
45
38
46
37
Average: 41
When determining the acceptability of the new material, compare the average of the five replicatesfor
lot #1 to the average of the five replicates for lot #2; that is 46 vs. 41 colonies. The recommended
acceptance criteria would be your current acceptance criteria used for your Fecal Coliform duplicates.
If the test and reference materials check within what you have determined is acceptable for duplicates
of samples, the test material would be considered acceptable to use. This may be a calculated
acceptance criteria based on 3 times the standard deviation of the mean or a set value like 20% RPD.
No matter how you determine your duplicate acceptance criteria make sure you use colony counts
not final calculated values in doing this. Other factors to consider when determining if a new material
is suitable include:
Are the colonies obtained typical, that is normal looking blue colonies?
Are the colonies evenly distributed across the membrane surface?
Are there an unusual number of non typical colonies present?
Is there a pattern to the colony recoveries? For example are all the plates
significantly lower in counts than the reference lot?
It is recommended that new consumables be .tested as soon as possible
problems if the materials are not acceptable. Once you determine that the new
to use; you may begin to do so. Document the date the new lot # is put into use.
Revised 2/06
for the test materials
after receipt to avoid
material is acceptable

March 25, 2003
FECAL COLIFORM REPORTING
The following criteria are to be used in obtaining and reporting fecal coliform data:
Standard Methods suggests analyzing samples by filtering three different volumes (diluted or undiluted)
depending on the,bacterial density. Each laboratory must filter multiple dilutions of the sample in order to obtain plates
containing 20 to 60 fecal coliform colonies. It is strongly recommended that sampling containers of at least 250 ml be
used in order to collect sufficient volume to meet method criteria. See Standard Methods 16th, 19th or 20th Edition 9222D,
and EPA Microbiological Methods for Monitoring the Environment Part IIC and Part IIIC. The rules for calculating values
are given in Standard Methods 9222 D.3, 9222 B.6, and EPA Micro Methods, Part IIC 3.6 and Part IIIC 2.7. The following
is a compilation of these rules to be used in calculating the fecal coliform count per 100 ml of sample for compliance
with NC/ENR/DWQ Laboratory Certification.
ALL RESULTS MUST BE REPORTED IN WHOLE NUMBERS.
(1)
Countable Membranes with 20-60 Blue Colonies: Calculate the fecal coliform results from membrane filters
within the ideal counting range of 20-60 blue colonies using the general formula:
Number of colonies counted x 100 = Fecal coliform colonies per 100 ml
volume of sample filtered in ml
If more than one filter has a count in the acceptable range, calculate the values in counts/100 ml and average.
If a 100 ml sample is analyzed and the counts are less than 60 colonies: report the total number of colonies
present on the 100m1 sample. If zero counts are obtained: report as <1/100 ml. (This is a whole volume sample)
(2) Countable Membranes with less than 20 Blue Colonies: If all counts are below the lower limit (20) of the ideal
counting range:
(a) Select the count most nearly acceptable and compute the count using the general formula. Report the count
as an Estimated Count per 100 ml: or
(b) Total the counts on all filters and report as number per 100 ml. For example if 50, 25, and 10 ml portions
were examined and counts were 15, 6, and 0 coliform colonies respectively, calculate results as follows and
report the count as 25 colonies per 100 ml.
(3)
(15 + 6 + 0) counts x 100 = 25 colonies per 100 ml
50 + 25 + 10 ml
Membranes with No Colonies: If counts from all filters are zero, report the count for the fecal coliform as a less
than (<) value. Calculate the number of colonies per 100 ml that would have been reported if there had been
one colony on the filter representing the largest filtration volume. For example, sample volumes of 25, 10 and 2
ml produced colony counts of 0, 0 and 0, respectively. The count would be reported as <4 colonies per 100 ml.
<1 counts x 100 = <4 colonies per 100 ml
25 ml
(4) Countable Membranes with more than 60 Colonies: If all filter counts are above the upper limit (60), but
countable, calculate the count from the smallest volume filtered and report as a greater than (>) value. For
example, if 10, 5, and 1 ml portions of samples were examined and counts were TNTC, 310, and 95 coliform
colonies respectively, calculate results as follows and report the count as >9500 colonies/100 ml.
>95 counts x 100.= >9500 colonies per 100 ml
1 ml
Uncountable Membranes: For uncountable filters with more than 60 colonies or "Too numerous to Count"
(TNTC), use 60 colonies as the basis of calculation with the smallest filtration volume and report as a greater
than value. For example, sample volumes of 10, 1.0 and 0.1 ml all produced too many colonies to show
separated colonies and the laboratory bench sheet showed TNTC. The count would be reported as >60,000
colonies per 100 ml.
(5)
>60 counts x 100 = >60,000 colonies per 100 ml
0.1 ml
(6) If the Filters for a sample have counts of both >60 and <20, but none in the 20-60 range: Use all countable filters
and calculate as in (2) (b) above.

(7)
Abnormalities: The above rules are to be used except when an abnormality occurs in the analysis of a sample.
When abnormalities occur, analysts must use their best judgment in selecting the proper value to report.
Geometric Mean: Find the log of the values and add them together and then average. Get the antilog. Anything with a
less than number is a 1. If greater than number, use the absolute number.