HomeMy WebLinkAbout#19_20201220Insp_Final
INSPECTION REPORT ROUTING SHEET
To be attached to all inspection reports in-house only.
Laboratory Cert. #: 19
Laboratory Name: Town of Morehead City WW Lab
Inspection Type: Municipal Maintenance
Inspector Name(s): Todd Crawford
Inspection Date: December 5, 2012
Date Report Completed: December 10, 2012
Date Forwarded to Reviewer: December 10, 2012
Reviewed by: Jason Smith
Date Review Completed: January 8, 2013
Cover Letter to use: Insp. Initial Insp. Reg.
Insp. No Finding Insp. CP
Corrected
Unit Supervisor: Dana Satterwhite
Date Received: January 14, 2013
Date Forwarded to Linda: February 12, 2013
Date Mailed: February 12, 2013
_____________________________________________________________________
On-Site Inspection Report
LABORATORY NAME: Town of Morehead City WW Lab
NPDES PERMIT # : NC002661
WATER QUALITY PERMIT # : WQ0006018; WQ0034842; WQ0022156
NC GENERAL PERMIT #: NCG110000
ADDRESS: 706 Arendell St.
Morehead City, NC 28557
CERTIFICATE #: 19
DATE OF INSPECTION: December 5, 2012
TYPE OF INSPECTION: Municipal Maintenance
AUDITOR(S): Todd Crawford
LOCAL PERSON(S) CONTACTED: Carl Dangerfield and Chad Sutton
I. INTRODUCTION:
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 was clean and well organized. The facility has all the equipment necessary to perform the
analyses. Proficiency Testing (PT) samples have been analyzed for all certified parameters for the 2012
proficiency testing calendar year.
The laboratory is reminded that any time changes are made to laboratory operations, the laboratory
must update the Quality Assurance (QA)/Standard Operating Procedure (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. Please submit updated SOPs to this office by April 30,
2013.
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 tim es,
and method modifications. The final rule may be found at:
http://water.epa.gov/scitech/methods/cwa/update_index.cfm. 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.
Page 2
#19 Town of Morehead City WW Lab
Contracted analyses are performed by Environmental Chemists, Inc. (Certification #94).
The requirements associated with Findings E, F, G, H, I, J, K, M, N, O, R, T, V, and W are new policies
that have been implemented by our program since the last inspection.
III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS:
General
Comment: The lab was analyzing samples for Vector Attraction Reduction (VAR) Option 6 and
reporting data without being certified. The North Carolina Administrative Code, 15A NCAC 2H .0804 (a)
states: Municipal and Industrial Laboratories are required to obtain certification for parameters which
will be reported to the State to comply with State surface water monitoring, groundwater, and
pretreatment Rules. An amendment form requesting certification for VAR Option 6 was completed
during the inspection and certification has been issued. No further response is necessary for this
finding.
Comment: The laboratory did not have a copy of Control of Pathogens and Vector Attraction in
Sewage Sludge nor a copy of SW -846 Method 9045D. The North Carolina Administrative Code, 15A
NCAC 2H .0805 (a) (6) (F) states: Each laboratory requesting certification must contain or be equipped
with the following: A copy of each approved analytical procedure being used in the laboratory. The
9045D method was printed out during the inspection. An internet link to Control of Pathogens and
Vector Attraction in Sewage Sludge was emailed to the lab the following day. No further response is
necessary for this finding.
A. Finding: The determination of sludge pH was not being performed according to SW -846 Method
9045D.
Requirement: Methods in the materials listed below shall be used to analyze samples of sewage
sludge. (4) Inorganic pollutants. ``Test Methods for Evaluating Solid Waste, Physical/Chemical
Methods'', EPA Publication SW -846, Second Edition (1982) with Updates I (April 1984) and II
(April 1985) and Third Edition (November 1986) with Revision I (December 1987). Second Edition
and Updates I and II are available from the National Technical Information Service, 5285 Port
Royal Road, Springfield, Virginia 22161 (PB-87-120-291). Third Edition and Revision I are
available from Superintendent of Documents, Government Printing Office, 941 North Capitol
Street, NE., Washington, DC 20002 (Document Number 955-001-00000-1). Ref: 40 CFR Part
503.8 (b) (4).
Requirement: To 20 g of waste sample in a 50-mL beaker, add 20 mL of reagent water, cover,
and continuously stir the suspension for 5 min. Additional dilutions are allowed if working with
hygroscopic wastes and salts or other problematic matrices. Ref: EPA SW -846 Test Methods for
Evaluating Solid Waste, Physical/Chemical Methods; 3rd Edition, Method 9045 D. Rev. 4,
November 2004, Section 7.3.1.
Comment: Samples were not being weighed.
B. Finding: pH readings are not taken at 25°C, or corrected to 25°C.
Requirement: pH should be measured in a slurry at 25°C. For more information on making a
slurry, see Section 10.7 [a more current version of this preparation is found in SW -846 Method
9045D]. Either sewage sludge samples may be taken and heated or cooled to 25°C or results can
be adjusted based on the ambient temperature where pH is measured and the following
calculation:
Page 3
#19 Town of Morehead City WW Lab
Correction Factor = 0.03 pH units X (Tmeas-25°C)
1.0°C
Actual pH = Measured pH +/- the Correction Factor
T = Temperature measured
Example of using the pH Correction Factor: If the measured pH is 12.304 at 30°C,
the actual pH can be calculated as follows:
Correction Factor = 0.03 x (30-25) = +0.15
Actual pH = 12.304 + 0.15 = 12.454
Ref: Control of Pathogens and Vector Attraction in Sewage Sludge, EPA/625/R-92/013, July
2003, Section 8.7, pg. 61.
C. Finding: The laboratory does not have an Analytical Quality Control Document or Standard
Operating Procedure (SOP) for the determination of pH according to SW -846 Method 9045D.
Requirement: Each laboratory shall develop and maintain a document outlining the analytical
quality control practices used for the parameters included in their certification. Supporting records
shall be maintained as evidence that these practices are being effectively carried out. Ref: 15A
NCAC 2H .0805 (a) (7).
Requirement: The laboratory must have an updated Quality Control/Standard Operating
Procedures document for the parameters included on the certificate attachment by April 30, 2013.
This must be submitted for review upon completion. A written response is required.
Quality Control
Comment: The mechanical pipettes that were purchased in August, 2012 will soon need to be
calibrated to satisfy the requirement that volumetric liquid-dispensing devices (e.g., fixed and
adjustable auto-pipettors, bottle-top dispensers, etc.) must be calibrated at least twice per year,
approximately six months apart and documented. Each liquid-dispensing device must meet the
manufacturer’s statement of accuracy.
D. Finding: SOPs do not include any acceptance criteria for duplicates.
Requirement: Each laboratory shall develop and maintain a document outlining the analytical
quality control practices used for the parameters included in their certification. Supporting
records shall be maintained as evidence that these practices are being effectively carried out.
Ref: 15A NCAC 2H .0805 (a) (7).
Documentation
E. Finding: The preparation of standards and reagents is not being documented.
Requirement: All chemicals, reagents, standards and consumables used by the laboratory
must have the following information documented: Date received, Date Opened (in use), Vendor,
Lot Number, and Expiration Date (where specified). A system (e.g., traceable identifiers) must
be in place that links standard/reagent preparation information to analytical batches in which the
solutions are used. Documentation of solution preparation must include the analyst’s initials,
date of preparation, the volume or weight of standard(s) used, the solvent and final volume of
Page 4
#19 Town of Morehead City WW Lab
the solution. This information as well as the vendor and/or manufacturer, lot number, and
expiration date must be retained for primary standards, chemicals, reagents, and materials
used for a period of five years. Consumable materials such as pH buffers, lots of pre-made
standards and/or media, solids and bacteria filters, etc. are included in this requirement. Ref:
NC WW/GW LC Policy.
F. Finding: The vendor and/or manufacturer is not consistently documented in the
chemical/material receipt logbook.
Requirement: All chemicals, reagents, standards and consumables used by the laboratory
must have the following information documented: Date received, Date Opened (in use), Vendor,
Lot Number, and Expiration Date (where specified). A system (e.g., traceable identifiers) must
be in place that links standard/reagent preparation information to analytical batches in which the
solutions are used. Documentation of solution preparation must include the analyst’s initials,
date of preparation, the volume or weight of standard(s) used, the solvent and final volume of
the solution. This information as well as the vendor and/or manufacturer, lot number, and
expiration date must be retained for primary standards, chemicals, reagents, and materials
used for a period of five years. Consumable materials such as pH buffers, lots of pre-made
standards and/or media, solids and bacteria filters, etc. are included in this requirement . Ref:
NC WW/GW LC Policy.
G. Finding: Purchased standards and reagents used in analyses are not sufficiently linked to the
manufacturer.
Requirement: All chemicals, reagents, standards and consumables used by the laboratory
must have the following information documented: Date received, Date Opened (in use), Vendor,
Lot Number, and Expiration Date (where specified). A system (e.g., traceable identifiers) must
be in place that links standard/reagent preparation information to analytical batches in which the
solutions are used. Documentation of solution preparation must include the analyst’s initials,
date of preparation, the volume or weight of standard(s) used, the solvent and final volume of
the solution. This information as well as the vendor and/or manufacturer, lot number, and
expiration date must be retained for primary standards, chemicals, reagents, and materials
used for a period of five years. Consumable materials such as pH buffers, lots of pre-made
standards and/or media, solids and bacteria filters, etc. are included in this requirement. Ref:
NC WW/GW LC Policy.
Comment: The receipt of purchased standards and reagents is documented in a logbook and
traceable identifiers (IDs) are assigned; however, traceable IDs are not used in the raw data to
unequivocally link calibration standards, quality control (QC) standards, spikes, etc. to analytical
batches.
Recommendation: It is recommended that traceable identifiers (IDs) be used in the raw data to
unequivocally link calibration standards, QC standards, spikes, etc. to the preparation and receipt
logs.
H. Finding: There is no language in the ammonia SOP that states that laboratory reagent blanks
must not exceed 50% of the reporting limit.
Requirement: Each laboratory shall develop and maintain a document outlining the analytical
quality control practices used for the parameters included in their certification. Supporting records
shall be maintained as evidence that these practices are being effectively carried out. Ref: 15A
NCAC 2H .0805 (a) (7).
Page 5
#19 Town of Morehead City WW Lab
Comment: The requirement for laboratory reagent blanks to not exceed 50% of the reporting
limit would also apply to Total Phosphorus. The laboratory was decertified for that parameter at
the time of the inspection and therefore there is no mention of that parameter in this report.
I. Finding: The laboratory does not have an Analytical Quality Control Document or Standard
Operating Procedure (SOP) for the calibration of mechanical volumetric liquid-dispensing devices
(e.g., fixed and adjustable auto-pipettors, bottle-top dispensers, etc.).
Requirement: Each laboratory shall develop and maintain a document outlining the analytical
quality control practices used for the parameters included in their certification. Supporting records
shall be maintained as evidence that these practices are being effectively carried out. Ref: 15A
NCAC 2H .0805 (a) (7).
Recommendation: It is recommended that the calibration take into account the temperature of
the water and the pressure in the room. The average weight of at least five aliquots should then
be compared to the theoretical weight, determined by use of the Z factor, and have a maximum
percent difference of 2%.
Proficiency Testing
J. Finding: The preparation of Proficiency Testing (PT) samples is not documented.
Requirement: PT samples received as ampules must be diluted according to the PT provider’s
instructions. The preparation of PT samples must be documented in a traceable log or other
traceable format. The diluted PT sample becomes a routine environmental sample and is added
to a routine sample batch for analysis. Ref: Proficiency Testing Requirements, February 20,
2012, Revision 1.2.
K. Finding: The laboratory is not documenting all Proficiency Testing (PT) sample analyses in the
same manner as environmental samples.
Requirement: All PT sample analyses must be recorded in the daily analysis records as for any
environmental sample. This serves as the permanent laboratory record. Ref: Proficiency Testing
Requirements, February 20, 2012, Revision 1.2.
Comment: The analysis of PT samples is designed to evaluate the entire process used to
routinely report environmental analytical results; therefore, PT samples must be analyzed and the
process documented in the same manner as environmental samples.
Comment: BOD PT samples were documented in the same manner as environmental samples.
Temperature – Standard Methods, 2550 B - 2000
L. Finding: The temperature sensing device on the Dissolved Oxygen meter used to obtain
reported temperature values has never been checked against a NIST traceable thermometer.
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. To
check a thermometer or the temperature sensor of a meter, read the temperature of the
thermometer/meter against a NIST certified or NIST traceable thermometer and record the two
temperatures. The calibration must be performed at a temperature that corresponds to the
temperature used by the incubator, refrigerator, freezer, etc. In the case of temperature
measuring devices used to perform variable temperature readings the calibration must be
Page 6
#19 Town of Morehead City WW Lab
performed at a temperature range that approximates the range of the samples. The
thermometer/meter readings must be less than or equal to 1ºC from the NIST certified or NIST
traceable thermometer reading. The documentation must include the serial number of the NIST
certified thermometer or NIST traceable thermometer that was used in the comparison. Also
make any corrections to the data and document any correction that applies (even if zero) on both
the thermometer/meter and on a separate sheet to be filed. Ref: NC WW/GW LC Policy.
Comment: The portion of the requirement regarding corrections to the data is new.
pH – Standard Methods, 4500 H+ B - 2000
Comment: A check of the pH meter’s Automatic Temperature Compensator (ATC) is no longer required.
Ammonia Nitrogen – Standard Methods, 4500 NH3 D - 1997
Comment: Distillation of samples is no longer required for the electrode method.
M. Finding: Blanks are documented as being less than the reporting limit, making it impossible to
determine whether or not the requirement for the blank to be less than 50% of the reporting limit is
being met.
Requirement: For analyses requiring a calibration curve, the concentration of method and
reagent blanks must not exceed 50% of the reporting limit, unless otherwise specified by the
reference method. Ref: NC WW/GW LC Policy.
Requirement: Each laboratory shall develop and maintain a document outlining the analytical
quality control practices used for the parameters included in their certification. Supporting
records shall be maintained as evidence that these practices are being effectively carried out .
Ref: 15A NCAC 2H .0805 (a) (7).
N. Finding: A calibration blank and calibration verification standard (mid-range) are not analyzed
at the end of the sample group and/or after every tenth sample.
Requirement: 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.). Ref: NC WW/GW LC Policy based upon Standard Methods, 20th Edition, 1020 B. (10) (c),
3020 B. (2) (b), and 4020 B. (2).
Requirement: For analyses requiring a calibration curve, the concentration of method and
reagent blanks must not exceed 50% of the reporting limit, unless otherwise specified by the
reference method. Ref: NC WW/GW LC Policy.
Comment: The calibration verification standard must be prepared from the calibration stock
standard solution.
O. Finding: A second source standard is not analyzed.
Requirement: When a standard curve is manually prepared (as opposed to a factory-set
calibration), it is required to analyze one known standard in addition to calibration standards
each day samples are analyzed to document accuracy. This standard must be prepared from
Page 7
#19 Town of Morehead City WW Lab
materials obtained from a source independent from the one used for preparing the calibration
standards (often referred to as a second source standard or external reference standard). A
second source standard may be:
• a quality control standard obtained from a vendor,
• a standard prepared from primary standards obtained from a second vendor, or
• a standard made from primary standards from the same vendor but from a
different lot number (i.e., an independent lot) as those used to make the
calibration standards.
Second source standards must be evaluated using one of the following: vendor supplied
criteria, method-defined acceptance criteria, in-house calculated acceptance limits that are
statistically-derived from historical data based on three standard deviations from the mean in
the detectable range or other statistically viable evaluation criterion. If the results fall outside of
acceptance limits, the analysis is out of control. The analysis must be terminated and the
problem corrected prior to sample analysis. Ref: NC WW/GW LC Policy based upon 15A
NCAC 2H .0805 (a) (7) (B), (a) (7) (F), and Standard Methods, 20th Edition, 1020 B. (2) and (5).
P. Finding: The laboratory is not documenting the percent recovery of the calibration verification
and/or laboratory control standards on the benchsheet.
Requirement: The quality control results obtained must be documented on the benchsheet and
evaluated against established acceptance criteria to demonstrate that the analyst was aware of
any out-of-control situation. The corrective actions taken must be documented. Any samples
not meeting the acceptance criteria must be reanalyzed, if possible. If this is not possible, the
data must be flagged on the laboratory reports and Discharge Monitoring Reports (DMRs) as all
quality control requirements not met. Ref: 15A NCAC 2H .0805 (a) (7) and 15A NCAC 2H .0805
(a) (F).
Requirement: Each laboratory shall develop and maintain a document outlining the analytical
quality control practices used for the parameters included in their certification. Supporting
records shall be maintained as evidence that these practices are being effectively carried out.
Ref: 15A NCAC 2H .0805 (a) (7).
Ammonia Nitrogen – Standard Methods, 4500 NH3 D - 1997
Residue Suspended – Standard Methods, 2540 D - 1997
Q. Finding: The Relative Percent Difference (RPD) is not being calculated and documented for
duplicates.
Requirement: The quality control results obtained must be documented on the benchsheet and
evaluated against established acceptance criteria to demonstrate that the analyst was aware of
any out-of-control situation. The corrective actions taken must be documented. Any samples
not meeting the acceptance criteria must be reanalyzed, if possible. If this is not possible, the
data must be flagged on the laboratory reports and Discharge Monitoring Reports (DMRs) as all
quality control requirements not met. Ref: 15A NCAC 2H .0805 (a) (7) and 15A NCAC 2H .0805
(a) (F).
Requirement: Each laboratory shall develop and maintain a document outlining the analytical
quality control practices used for the parameters included in their certification. Supporting
records shall be maintained as evidence that these practices are being effectively carried out.
Ref: 15A NCAC 2H .0805 (a) (7).
Page 8
#19 Town of Morehead City WW Lab
Residue Suspended – Standard Methods, 2540 D - 1997
R. Finding: Filters are not weighed to constant weight prior to sample analysis, nor is a dry filter
blank analyzed with each set of samples.
Requirement: 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. Ref: NC WW/GW LC Policy based upon Standard Methods 20th Edition 2540 D. (3)
(a).
S. Finding: Samples are not dried to constant weight nor are the times in and out of the oven
documented in such a way as to demonstrate adherence to the acceptable drying time
established by the drying time study.
Requirement: 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. Ref: North Carolina Wastewater/Groundwater
Laboratory Certification Policy based on Standard Methods 20th Edition, 2540 D. (3) (c), 2540 B.
(3) (b), and 2540 C. (3) (d).
Comment: North Carolina allows for an annual drying study in lieu of the requirement above to
repeat the drying cycle for every sample. A random full set of samples should be used for the
drying study. The repeated drying time in the oven should be at least 1 hour long. The time
used for the annual drying study is the minimum time that samples are to be dried until a new
drying study is performed.
Comment: The time that the analysis began and the time that the cooled samples were weighed
is documented. This is not sufficient to show how long the samples were actually being dried at
the proper temperature.
T. Finding: The laboratory is not basing the reporting limit on the minimum weight gain required
by the method.
Requirement: 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 required 2.5 mg, the value must be reported as less than the
appropriate value based upon the volume used. Ref: NC WW/GW LC Policy based upon
Standard Methods, 20th and 21st Editions, 2540 D. (3) (b).
Comment: For example, if 500 mL of sample is analyzed and < 2.5 mg of dried residue is
obtained, the value reported would be < 5 mg/L.
U. Finding: No acceptance criteria have been established to evaluate the precision of sample
duplicate analyses.
Page 9
#19 Town of Morehead City WW Lab
Requirement: 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. Ref:
15A NCAC 2H .0805 (a) (7) (F).
Comment: 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-B] x 100 = 2[4 mg/L - 2 mg/L] 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.
BOD – Standard Method, 5210 B – 2001
Comment: Be aware that the NC WW/GW LC program is not yet, but will be soon enforcing the
following two requirements and they should be implemented and included your SOP revision:
Requirement: Using the dilution water prepared as in ¶ 5a, make at least three dilutions of
prepared sample estimated to produce a residual DO of at least 1.0 mg/L and a DO uptake of
at least 2.0 mg/L after 5-d incubation. Five dilutions are recommended if experience with a
particular sample does not produce at least three bottles having acceptable minimum DO
depletions and residual limits (¶ 6a). Ref: Standard Methods, 5210 B-2001. (5) (c).
Requirement: Add sufficient amounts of standard glucose-glutamic acid solution (¶ 3h) to give
3.0 mg glucose/L and 3.0 mg glutamic acid/L in each of three test bottles (20 mL GGA
solution/L seeded dilution water or 6.0 mL/300-mL bottle). The resulting average BOD for the
three bottles, after correction for dilution and seeding, must fall into the range of 198 ± 30.5
mg/L. Ref: Standard Methods, 5210 B-2001. (6) (b).
V. Finding: Extra nutrient, mineral, and buffer solutions are not added to the Biochemical Oxygen
Demand (BOD) bottles containing more than 67% (i.e., > 201 mL) sample.
Requirement: 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 (0.30 mL/300-mL bottle) or use commercially-prepared
solutions designed to dose the appropriate bottle size. Ref: Standard Methods, 5210 B-2001,
(5) (c) (2).
Comment: Dilution water prepared as normal with nutrient, mineral, and buffer solutions would
still be used in the BOD bottles. For the bottles containing more than 67% sample, extra
nutrient, mineral, and buffer solutions would be added in addition to the dilution water.
Page 10
#19 Town of Morehead City WW Lab
Recommendation: Rather than pipetting 0.30 mL of each reagent into the BOD bottle, it is
recommended that commercially prepared nutrient buffer pillows for 300 mL bottles be used.
Enterococci - Enterolert® IDEXX
W. Finding: The Quanti-Tray® sealer is not checked monthly for leaks.
Requirement: If the Quanti-Tray® or Quanti-Tray®/2000 test is used, the sealer must be
checked monthly by adding a dye (e.g., bromcresol purple) to a water blank. If dye is observed
outside the wells, either perform maintenance or use another sealer. Ref: NC WW/GW LC
Policy.
IV. PAPER TRAIL INVESTIGATION:
The paper trail consisted of comparing laboratory benchsheets and contract lab reports to Discharge
Monitoring Reports (DMRs) submitted to the North Carolina Division of Water Quality. Data were
reviewed for July, August and October, 2012. The following errors were noted:
Date Parameter Location Value on Benchsheet
*Contract Lab Data Value on DMR
07/17/12 Total Nitrogen Effluent *9.0 mg/L 8.37 mg/L
08/08/12 Enterococci Effluent No Value 1.5 MPN
08/09/12 Enterococci Effluent 1.5 MPN No Value
It was also noted that values with a “less than” sign were reported in the “average” field on the DMR.
When calculating an arithmetic mean, you may consider a "less than" value as equal to zero.
Therefore, if all monthly values are “less than” values, the monthly arithmetic average would be “zero”.
Please see the attached documents (i.e., NC DWQ NPDES Permitting Guidance for DMR Calculations
and Directions for Completing Monthly Discharge Monitoring Reports) for additional guidance.
In order to avoid questions of legality, it is recommended that you contact the appropriate Regional
Office for guidance as to whether an amended Discharge Monitoring Report will be required. A copy of
this report will be made available to the Regional Office.
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
its assistance during the inspection and data review process. Please respond to all findings.
Report prepared by: Todd Crawford Date: December 10, 2012
Report reviewed by: Jason Smith Date: January 8, 2013
NC DWQ NPDES Permitting Guidance for DMR Calculations
Averages
Data “averages” recorded on DMRs should produce the arithmetic mean for all parameters with the exception of
Fecal Coliform. The average for Fecal Coliform should be calculated as the geometric mean of the values.
Arithmetic Mean
This is the simple, common averaging of a series of numbers. You add a group of numbers together to get the
sum. Then you divide the sum by the number of values you added to get the sum. The r esult is the arithmetic
mean or average of the series of numbers.
Example:
5.30
6.21
4.00
5.25
+ 8.72
______________
29.48
29.48 / 5 = 5.896 (round off to 5.90 = average)
This calculation is used for averaging of all parameters except for Fecal Coliform (code number 31616).
Geometric Mean
There are two ways to go about calculating the geometric mean. The two procedures are really just different ways
of doing the same thing and either way yields the same result, but both require the use of a scientific calculator.
Calculators adequate for performing such operations as the geometric mean can probably be purchased for less
than $15.00. With the calculator, follow these steps:
PROCEDURE 1 (we think this is the easier of the two)
1. Multiply all the data values together.
2. Take the "nth" root of the product of the multiplication, where "n" is the number of values multiplied. In other
words, if you multiply 4 values and get a result, take the 4th root of the product. This is the geometric mean.
To do this on the calculator, get the product of multiplication, then press (1) the "INV" key, (2) the "yx" key, and (3)
the "nth" root number. Labeling of keys and functions will vary with different brands of calculators. Consult your
calculator’s user’s manual for the specific procedure to perform these functions.
Example: (Using as data the numbers: 50, 100, 150 and 200)
50 x 100 x 150 x 200 = 150,000,000 (1.5x108)
4th root of 150,000,000 = 111 (rounded from 110.66819 - value on calculator)
use only whole numbers when reporting fecal coliform back to top
PROCEDURE 2
1. Add together the base 10 logarithms for the data values.
2. Divide the sum by the number of values added.
3. Take the antilog of the result of step 2. This will again be the geom etric mean.
To do this on the calculator, key the data value and press the "log" key. Then press "+" and repeat for all values.
After the last logarithm is entered, press "=" to get the sum. Divide by the number of values that were added.
Press the "INV"key and then press the "log" key.
Example: (again, using 50, 100, 150 and 200 as data values)
Base 10 logarithm of: 50 is 1.69897
100 is 2.0
150 is 2.1760913
200 is + 2.30103
Sum = 8.1760913
8.1760613 / 4 = 2.0440228
Antilog of 2.0440228 = 111 (rounded from 110.66819 - value on calculator)
* Calculation may be performed in the same manner (although calculation values will be different) using natural
logarithms (lnx).
Use of "Less Than" Values
Complications may arise in calculations when dealing with testing results showing values of less than a minimum
detection level for the testing method. Current Division policy gives permittees the benefit of doubt all the way to
the lowest levels when performing calculations using such "less than" values. When calculating an arithmetic
mean, you may consider a "less than" value as equal to zero. For the calculation of a geometric mean, a "less
than" value may be considered to be equal to one. Remember, this procedure pertains only to the calculation of an
average. You must report individual data values on the DMR exactly as reported to you by your laboratory. If you
are doing calculations with "less than" (<) values, here is how they should be handled:
a) Calculating an arithmetic mean
In calculating the arithmetic mean, "less than" values may be considered to equal zero (0). If all results for a
particular parameter during the month are "less than," the average for the month would be zero. The maximum
and minimum, however, should be recorded as the "less than" values.
Example: (using 10, 15, 20 and <5 as data values)
10
15
20
+ 0 (<5)
_________________
45
45 / 4 = 11.25 (round off to 11
b) Calculating a geometric mean
In calculating the geometric mean, all "less than" values may be considere d to equal one (1). This is due to the
nature of the calculation; zeros may not be used in the calculation of the geometric mean. If all testing results for
Fecal Coliform during a particular month came back as "less than" values, the geometric mean for the month
would be one (1). The maximum and minimum for the month, however, should be recorded as the "less than"
values.
Example: (using Procedure 1 noted above and 10, 15, 20 and <5 as data)
10
15
20
x 1 (<5)
_________________
3000
4th root of 3000 = 7.400828 (record on DMR as 7)
If these procedures are followed, there is never an instance when a "less than" value should be reported as a
monthly average. Using these procedures, a discreet value can always be obtained for either the arithmetic o r
geometric mean. We (the compliance staff) realize that this policy does not necessarily represent good chemistry,
but it allows for a standard practice in dealing with this type of data.
Please note that it is a requirement of your permit that you utilize testing methods that can evaluate the discharge
to levels low enough so as to demonstrate compliance with permit limits. For example, if you are required to
monitor for a parameter with a limit of 50 m g/L, you must utilize a test that can analyze to at least that level. If
current laboratory technology will not allow for a parameter to be analyzed to the permit limit, you must utilize the
best available method for that parameter. If the analyses using that method show no detection of the parameter in
question, you will be considered in compliance. Questions regarding laboratory methods and practices can be
answered by the staff of the Division of Water Quality’s Laboratory Section, by calling (919) 733-3908.
Use of "Greater Than" Values
Such values are only expected (infrequently) in the reporting of Fecal Coliform and (even less frequently) BOD. It
is a violation of reporting rules to report a Fecal Coliform value of "Too Numerous To Count" (TNTC). For fecal
coliform, "greater than" (> ##,###) values denote at least one, and possibly all volumes of the evaluated sample
yielded results outside the method range for accurate counting of the colonies of bacteria (or TNTC). Laboratories
should perform enough dilutions to the sample to produce a discreet number as the result of testing. If a "greater
than" value is reported, the numeric portion of the value should be sufficiently high so as to make the facility aware
of the extent of any problems with disinfection.
For both fecal coliform and BOD, the generation of a "greater than" value usually occurs when characteristics of
the effluent differ from what is normally discharged. If laboratories "set up" the test procedures based upon normal
conditions, they may not have the capacity to get an accurate measurement of higher fecal coliform or BOD
concentrations, hence the reported "greater than" value. If you are suspicious or aware of conditions at your plant
that cause you to believe effluent pollutant concentrations are beyond their normal levels, you should inform your
laboratory of your concern so modifications to testing procedures can be made.
For calculation purposes only, when you report a "greater than" value, the numeric portion of the value must be
used to calculate the average (arithmetic or geometric mean). The actual result of testing must be reported in the
daily cell on the DMR.
Conversion from mg/L to lbs/day
Some permits have parameters limited in units of pounds per day (lbs/day). Laboratories report the concentrations
(such as mg/L) of sample characteristics as a result of testing. They cannot report the daily load in lbs/day
because that total is dependent upon the amount of flow carrying a known concentration. But if the concentration
of a pollutant and the daily flow from the facility are known, the daily load in lbs/day can be calculated:
Multiply the concentration (in mg/L) x daily flow (in MGD) x 8.34 (a constant). This formula will yield the result in
units of lbs/day. You must be certain to use data values with the noted units of measurement to get the proper
result from this particular formula. Other units of measurement (like m g/L or GPD) may be used, but you will need
to modify the constant (which is a composite number representing all the unit conversions).
Estimated Results
“Estimated” results should be reported as the number with the “estimated” qualifier. When averaging results with
estimated values, use the estimated number and report the average as “estimated”.
Example: (using 10, 15, 20 and e5 as data values)
10
15
20
+ 5 (e5)
_________________
50
50 / 4 = 12.5 Round the result to 12 and report as “estimated”
* Remember when rounding numbers that end 5, to round off the preceding digit to the nearest even number: thus
2.25 becomes 2.2 and 2.35 becomes 2.4, as described in Standard Methods 1050 B. (2)
DIRECTIONS FOR COMPLETING MONTHLY DISCHARGE MONITORING REPORTS
Revised 3/2009
(Forms MR-1, MR-1.1, MR-2 & MR-3)
I: FACILITY INFORMATION
1. NPDES Permit No. Operator In Responsible Charge
2. Discharge No. Grade
3. Facility Name Certified Laboratory
4. Class Person(s) Collecting Samples
5. County Signature Of Operator In Responsible Charge
II: DATA REPORTING
1. Operator Arrival Time Units of Measurement
2. Operator Time On Site Additional Parameters
3. ORC on Site? Average, Maximum, Minimum
4. Data Sample Type
5. Flow Monthly Limit
6. Parameter Codes
III: FACILITY STATUS INFORMATION
1. Status Information
2. Signature of Permittee
IV: STREAM MONITORING INFORMATION
1. Stream
2. Location
V: GENERAL
1. Submitting Reports Calculations
2. Appearance Enforcement
3. Order of Report Forms Number of Reports
4. Multiple Submittals Permits for Other Program Areas
5. Toxicity Reporting Corrected or Amended Reports
6. Contacts
I. FACILITY INFORMATION
1. NPDES Permit No. - Number issued by the Division of Water Quality consisting of
the letters "NC" followed by a seven digit number. Information from non-discharge
facilities should not be reported on the MR series of forms.
2. Discharge No. - Three-digit number which corresponds to the effluent pipe for which
the data are being reported (i.e., 001, 002, 003, etc.). Numbers are found within the
NPDES permit.
3. Facility Name - Name of the facility as it appears on the NPDES permit.
4. Class - The class of the facility as designated by the Water Pollution Control System
Operators Certification Commission. The rating will be either 0, I, II, III or IV. You
should enter the water quality classification of the receiving stream in this space.
Revised 3/2009
5. County - County in which the discharge outfall is located.
6. Operator In Responsible Charge -The printed name of the certified WWTP operator
designated as operator in responsible charge. Unrated (class 0) facilities do not require an
operator in responsible charge.
7. Grade - Certificate grade of the operator in responsible charge as awarded by the
Water Pollution Control System Operators Certification Commission.
8. Certified Laboratory - Name of the certified laboratory (-ies) performing analyses (if
applicable).
9. Person(s) Collecting Samples - Printed name of the individual who collected the
sample for which the data was reported. In the case of several individuals, please specify
as a group name, such as "operators" or "staff," etc.
10. Signature Of Operator In Responsible Charge - Dated signature of the operator in
responsible charge. Each month’s report must include an original signature in ink. Copies
are not acceptable.
II. DATA REPORTING
1. Operator Arrival Time -Record the time of arrival of a certified operator using a
2400 clock value. If the facility is staffed by operators 24 hours a day, record the arrival
time of the 1st shift operator.
2. Operator Time On Site - Record the number of hours spent by certified operators at
the facility. If the facility is staffed on all three shifts, enter "24." If more than one
operator is on duty at the same time, this value is not the sum of all hours worked by the
operators, but the total number of hours the facility was staffed.
3. ORC On Site? - Record yes (Y) or no (N) as to whether the designated ORC visited
the site on that date. If the designated backup operator served as ORC on a particular day,
record "B" in this column for that date. It is also appropriate to record "H" in the cell if
the date is a legal holiday.
4. Data - Enter the analytical results for each sample under the appropriate parameter
code in the row that corresponds to the day upon which the sample was taken. Please note
that Flow should always be reported as a decimal number (do not use scientific notation)
in units of millions of gallons per day (MGD), unless the permit states otherwise.
5. Parameter Codes - Codes for the more commonly monitored parameters can be found
on the back of form MR-1 or MR-1.1. A complete list of parameter codes can be found
on the NPDES website.
6. Units of Measurement - All data values must be accompanied by corresponding units
of measurement, noted at the top of the data column for the particular parameter. If your
permit contains a numeric limit for any parameter, then the reporting units must be the
same units of measurement of that limit. If your reporting units are other than those on
Revised 3/2009
the pre-printed form, the printed units should be marked out and the reporting units be
clearly designated at the top of the column.
7. Additional Parameters - Enter the appropriate parameter code, name of the parameter
and units of measurement in the space provided.
8. Average, Maximum, Minimum - Enter the average, maximum and minimum values
for the results recorded in the data column. Please note no average is to be calculated for
pH. Any average for Fecal Coliform is to be calculated as a geometric mean. If you are
uncertain about how to calculate the geometric mean, please contact your local DWQ
Regional Office or a member of the NPDES Compliance/Enforcement Unit staff at (919)
807-6300. If only one value is reported for a parameter during the reporting month, that
value should be reported as the average, maximum and minimum.
9. Sample Type - Enter the sample description in each column for which data is being
reported. Enter the letter "C" for composite or the letter "G" for grab.
10. Monthly Limit - Enter the monthly limit for each parameter as found in the current
NPDES permit, Special Order by Consent or Judicial Order by Consent.
III. FACILITY STATUS INFORMATION
1. Facility Status - Mark the appropriate box to show whether facility was compliant or
noncompliant with regard to permit, SOC or JOC requirements. If noncompliant, use the
comment section to explain in detail the course of action taken or to be taken to achieve
compliance.
2. Signature of Permittee - Record the name of the permittee or his or her authorized
agent (printed or typed), the dated signature of that person and a mailing address and
phone number at which he or she may be reached during working hours. If someone other
than the permittee is to be the signatory, the requirement noted by the double asterisk
"**" must be met. Also record the expiration date of the current permit in this section.
While this is not on the form, you may also wish to provide an e-mail address in this
space that can provide the Division with another avenue of communication.
IV. STREAM MONITORING INFORMATION
1. Stream - Name of the stream from which the upstream or downstream monitoring
samples are taken.
2. Location - Location of the site on the stream from which the sample was taken. This
may be recorded as a distance (e.g. "100 feet upstream of outfall") or a specific location
(e.g. "S.R. 1111").
V. GENERAL
1. Submitting Reports - An original and one copy of each month’s monitoring report is
required to be submitted to the Division of Water Quality’s Central Files office (address
Revised 3/2009
listed on form MR-1) and must be received by the Division within thirty (30) days after
the end of the month for which the report is made.
2. Appearance - Forms must be completed in ink. Please make all entries on forms
legible. All information other than signatures must be printed or typed. If you fill out
forms by hand, please make sure the originals are completed in ink and that all entries are
legible. Copies of the original report must also be readable and must include a
reproduction of the backside of the effluent reporting form containing the permittee’s
certification. If you utilize a computer-generated report, you must also ensure that the
report is legible and that proper copies are made. DWQ will notify if you are the user of
a form that is deemed deficient and will advise you of what modifications need to be
made.
3. Calculations
(a) Averages. All averages are to be calculated as the arithmetic mean of the
recorded values with the exception of that of Fecal Coliform, which is to be
calculated as a geometric mean. If you are uncertain about how to calculate the
geometric mean, please contact your local DWQ Regional Office or a member of
the NPDES Compliance/Enforcement Unit staff at (919) 807-6300.
(b) Use of "less than" values. For calculation purposes only, recorded values of
less than a detectable limit (< #.##) may be considered to equal zero (0) for all
parameters except Fecal Coliform, for which values of "less than" may be
considered to be equal to one (1). Values of results which are less than a
detectable limit should be reported in the daily cells using the "less than" symbol
(<) and the detectable limit used during the testing (or the value with appropriate
unit conversion). Please note there is never a case when an average would need to
be recorded along with a "less than" symbol.
(c) Use of "greater than" values. Such values are only expected (and then only
infrequently) in the reporting of Fecal Coliform and BOD. If a "greater than"
value is reported, the numeric portion of the value should be sufficiently high so
as to make the facility aware of the extent of any problems with treatment
efficiency. Upon receipt of "greater than" testing results, a facility should consult
its laboratory to see if changes in testing procedure need to be made in order to
get discreet values from the analysis. For calculation purposes only, the numeric
portion of the value must be used to calculate either an arithmetic or geometric
mean.
4. Enforcement - Failure to comply with any of the requirements listed above may result
in the facility being issued a Notice of Violation or being subject to other appropriate
enforcement action.
5. Order of Report Forms - DMR submittals typically include the results of monitoring
of the facility’s effluent, its influent and its receiving stream. It is requested that for any
DMR, the report be bound with the Effluent page(s) (DWQ form MR-1 or MR-1.1) on
top, followed by the Influent page (form MR-2, if influent monitoring is required) and
finally the Upstream/Downstream page (form MR-3).
6. Number of Reports - You are required to submit the original and one copy of the
report to DWQ. Each copy should be a discreet report for the month, put together in the
order described above.
7. Multiple Submittals - School systems and contract operations, please take note of this
request. If you submit reports for multiple permits within one mailing, please bind
together the submittals (original and one copy) for the various facilities. Please do not
segregate the reports into any other type of organization (e.g., binding together all
effluent or stream monitoring pages). To do so will cause reports to be taken apart and
placed together properly, which slows processing and introduces opportunity for mistakes
to be made. If you send many DMRs in one envelope, it is advisable that you send a
summary sheet along with the DMRs that lists what reports are contained in the package.
8. Permits for Other Program Areas - Please note that this discussion pertains to
submittal of DMRs required of NPDES permittees (point source discharge pipes to
streams). You may have permits for activities in other program areas such as DWQ’s non
discharge program (wastewater spray irrigation or land application of residuals) or the
Division of Environmental Health’s public water supply program (drinking water). Please
consult those permits for instructions for their submittal. It is not advisable to submit any
other reports along with your DMR submittals.
9. Toxicity Reporting - Some permittees will have monitoring requirements for Toxicity
within their permits. Please be aware that this parameter has a dual reporting requirement.
Results of toxicity testing should be reported on DMR forms, but the toxicity testing
results forms must be submitted to the Aquatic Toxicity Unit at the address listed below.
Aquatic Toxicology Unit
DWQ Environmental Sciences Branch
1621 Mail Service Center Raleigh, NC 27699-1621
10. Corrected or Amended Reports - In the event that you omit or erroneously report
data on a DMR, the information should be updated with the submittal of an amended
report. To best handle the amended data, the following procedure is recommended:
1. Regenerate or make a copy from your files of the DMR previously submitted to
DWQ.
2. Make changes to the individual data points on the form, including updated
summary information.
3. Initial and highlight changes to the original submittal.
4. At the top of the reporting page, write very conspicuously: "Amended Report" or
"Corrected Report."
5. Provide a short cover page describing the changes to the DMR or note changes in
the comment area on the back of the MR-1 form.
Use of this procedure will be a great help to DWQ’s data entry staff. Without
specifically identifying changes on the DMR, each data point must be evaluated
between the original and amended reports to ensure the values in our database are
correct. Calling attention to just those values that are changed both speeds up our
processes and decreases the possibility for errors to be made.
Revised 3/2009
11. Contacts - DWQ deals with a tremendous number of permitted entities that may be
experiencing their own changes involving administration and personnel. In dealing with
NPDES permit matters, DWQ must deal with only one representative of the permitted
facility (someone with authority to see that changes are made at the facility if they are
necessary) in order to be effective. You are encouraged to keep DWQ informed of any
updates as to the person responsible for the permit, addresses or phone numbers in order
to facilitate the best possible communication between our two organizations. This can be
done by sending an e-mail to our Unit or by using the back of the MR-1 form under the
permittee certification section. Regulations regarding who may be deemed responsible
for a permit and who may sign as the "permittee" on the DMR can be found
(respectively) in the North Carolina Administrative Code in sections 15A NCAC 2H
.106(e) and 15A NCAC 2B .0506 (b) (2).