HomeMy WebLinkAbout#168 2010-final
INSPECTION REPORT ROUTING SHEET
To be attached to all inspection reports in-house only.
Laboratory Cert. #: 168
Laboratory Name: Mebane Bridge WWTP
Inspection Type: Municipal Maintenance
Inspector Name(s): Jeffrey R. Adams
Inspection Date: September 28, 2010
Date Report Completed: October 15, 2010
Date Forwarded to Reviewer: October 15, 2010
Reviewed by: Jason Smith
Date Review Completed: October 29, 2010________
Cover Letter to use: Insp. Initial X Insp. Reg. Insp. No Finding Insp. CP
Unit Supervisor: Dana Satterwhite
Date Received: November 8, 2010
Date Forwarded to Alberta: November 29, 2010
Date Mailed: November 29, 2010
_____________________________________________________________________
On-Site Inspection Report
LABORATORY NAME: Mebane Bridge WWTP
NPDES PERMIT #: NC0025071
ADDRESS: P.O. Box 70
Eden, NC 27288-0070
CERTIFICATE #: 168
DATE OF INSPECTION: September 28, 2010
TYPE OF INSPECTION: Municipal Maintenance
AUDITOR(S): Jeffrey R. Adams
LOCAL PERSON(S) CONTACTED: Melinda Ward and Rodney Johnson
I. INTRODUCTION:
This laboratory was inspected to verify its compliance with the requirements of 15A NCAC 2H .0800 for the
analysis of environmental samples.
II. GENERAL COMMENTS:
The laboratory was neat and equipment was well maintained. Records were maintained according to the
appropriate record retention schedules and were well organized; however, some quality control
procedures need to be implemented.
The laboratory was given a packet containing North Carolina Laboratory Certification quality control
requirements and policy changes during the inspection.
The laboratory presented the inspector with a letter from the NC Department of Environment and Natural
Resources, dated June 14, 2010, rescinding NPDES Permit Number NC0025151. This facility was routed
into their main discharge facility and its effluent is no longer being discharged directly into the natural water
stream.
Comment: The laboratory is currently decertified for Specific Conductance for failure to obtain
acceptable results on two consecutive proficiency testing samples. Prior to recertification, the lab must
complete an Amendment to Application form requesting recertification for this parameter and obtain two
consecutive acceptable proficiency testing results on blind samples provided by a NELAC-approved
vendor. Prior to analyzing the proficiency testing samples, the laboratory must follow the manufacturer’s
instructions for instrument calibration and must verify the operation of the Automatic Temperature
Compensator (ATC) on the meter(s) used for sample measurements and document these processes. A
copy of the ATC verification must be submitted to this office for review prior to issuance of
recertification.
Finding A is a new policy that has been implemented by our program since the last inspection.
Page 2
#168 Mebane Bridge WWTP
III. FINDINGS, REQUIREMENTS, COMMENTS AND RECOMMENDATIONS:
Documentation
A. Finding: The laboratory needs to increase the documentation of purchased materials and
reagents, as well as, documentation of standards and reagents prepared in the laboratory.
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: North
Carolina Wastewater/Groundwater Laboratory Certification Policy.
Dissolved Oxygen – Standard Methods, 18th Edition, 4500 O G
Comment: The Dissolved Oxygen (DO) probe storage well on the instrument was dirty and needed
cleaning. If the membrane is coated with oxygen consuming (e.g., bacteria) or oxygen evolving organisms
(e.g., algae), erroneous readings may occur. Ref: YSI Operators Manual pg. (7) (4.5) (2). YSI 1/07.
Recommendation: It is recommended that a light colored sponge be used in the storage chamber to
discern cleanliness. It is recommended the laboratory consult the owner’s manual for instructions on probe
storage and cleanliness.
Total Residual Chlorine – Standard Methods, 18th Edition, 4500 Cl G
B. Finding: The laboratory is not analyzing 5 standards when verifying the instrument’s
factory-set calibration.
Requirement: For colorimetric analyses, a series of five standards for a curve prepared
annually or three standards for curves established each day or standards as set forth in the
analytical procedure must be analyzed to establish a standard curve. The curve must be
updated as set forth in the standard procedures each time the slope changes by more than 10
percent at mid-range each time a new stock standard is prepared, or at least every twelve
months. Each analyst performing the analytical procedure must produce a standard curve. Ref:
15A NCAC 02H .0805 (a) (7) (I). A copy of the Annual 5 point Total Residual Chlorine
verification curve documentation must be submitted with the response to this report.
Comment: The instrument calibration is verified using 4 standards (32.6, 65.2, 130.4, and
260.8 µg/L).
Recommendation: Prepare a calibration curve using the following concentrations: 15, 20, 50, 200
and 400 µg/L, to bracket the expected concentrations of Proficiency Testing (PT) samples, as well
as, environmental samples.
Recommendation: It is recommended that the values obtained not vary by more than 10% of the
known value for standard concentrations greater than or equal to 50 µg/L, and not vary by more
Page 3
#168 Mebane Bridge WWTP
than 25% of the known value for standard concentrations less than 50 µg/L. If they do, the
instrument may require servicing by a commercial vendor.
C. Finding: The calibration verification standard concentrations do not bracket Proficiency Testing
sample concentrations.
Requirement: For analytical procedures requiring analysis of a series of standards, the
concentrations of these standards must bracket the concentration of the samples analyzed. Ref:
15A NCAC 02H .0805 (a) (7) (I).
Requirement: The analysis of proficiency testing (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.
Ref: North Carolina Wastewater/Groundwater Laboratory Certification Policy.
For example, for colorimetric (DPD) procedures, Total Residual Chlorine (TRC) PT samples must
be analyzed on the same spectrophotometric program (i.e., the sample wavelength) using the
same procedure that is used for sample analysis. There are two options for achieving this:
1. If a regular level TRC performance evaluation sample is analyzed, it must be diluted to the
verified range of the low level curve. The reported result must then be calculated using the
dilution factor and the TRC value obtained.
2. Since the dilution factor in option 1 may introduce error, it is recommended that the low
level TRC sample be analyzed. These are currently available from many approved
vendors. This sample should be within the range of your verified curve on the low level
program.
D. Finding: Results of <10 µg/L are being routinely reported if the sample result is below 28 µg/L,
even though the calibration curve is only verified down to 32.6 µg/L. 32.6 µg/L is above the
laboratories permit compliance limit of 28 µg/L.
Requirement: For analytical procedures requiring analysis of a series of standards, the
concentrations of these standards must bracket the concentration of the samples analyzed. One
of the standards must have a concentration equal to the laboratory’s lower reporting concentration
for the parameter involved. Ref: 15A NCAC 02H .0805 (a) (7) (I).
Temperature – Standard Methods, 18th Edition, 2550 B
E. Finding: The temperature measurements reported on Discharge Monitoring Reports (DMRs) are
analyzed out of hold time.
Requirement: All temperature measurements must be taken immediately at the site of
collection. Ref: Code of Federal Regulations, Title 40, Part 136; Federal Register Vol. 72, No.
47, March 12, 2007; Table II.
Comment: The analyst was measuring the temperature at the effluent stream and in the
laboratory, but was recording the laboratory obtained values on the DMRs. Therefore, the
values recorded on the DMRs were out of hold time. The timeline involved appeared to be all of
2010 up until the inspection performed on September 28, 2010.
Page 4
#168 Mebane Bridge WWTP
Recommendation: It was recommended that the supervisor review prior months back through
2009 and to notify the appropriate DWQ Regional Office for guidance as to whether amended
Discharge Monitoring Reports will be required.
Total Suspended Solids – Standard Methods, 18th Edition, 2540 D
Comment: A minimum dried residue weight gain of 1 mg is used to determine the reporting limit.
North Carolina Wastewater/Groundwater Laboratory Certification Policy states: The minimum reporting
value is established at 2.5 mg/L when 1000 mL of sample is analyzed. The minimum weight gain
allowed by any approved method is 2.5 mg. 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.
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. This reporting error was corrected prior to the inspection. All TSS data
reported on the DMR’s after May 01, 2010 were reported with the new PQL of < 2.5 mg/L. No further
response is necessary for this finding.
F. Finding: The laboratory is not performing a quarterly Quality Control (QC) check.
Requirement: Excluding oil and grease, all residue parameters, leachate extractions, residual
chlorine, and coliform, analyze one known standard in addition to calibration standards each
day samples are analyzed to document accuracy. Analyze one suspended residue, one
dissolved residue, one residual chlorine and one oil and grease quarterly. For residual chlorine,
all calibration standards required by the approved procedure in use and by EPA must be
analyzed. Ref: 15A NCAC 02H .0805 (a) (7) (B).
Recommendation: It is recommended that the laboratory purchase a commercially prepared
QC sample from a vendor or prepare an ash type QC sample in the laboratory.
IV. PAPER TRAIL INVESTIGATION:
The paper trail consisted of comparing benchsheets and contract lab reports to Discharge Monitoring
Reports (DMRs) submitted to the North Carolina Division of Water Quality. Data were reviewed
for Mebane Bridge WWTP (NPDES permit #NC0025071) for March, May and July, 2010. The following
error was noted.
Date Parameter Location Value on Benchsheet Value on DMR
5/05/10 Total Suspended
Residue
Effluent < 2.5 mg/L < 6.3 mg/L
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 forwarded to the Regional Office.
Page 5
#168 Mebane Bridge WWTP
V. CONCLUSIONS:
Correcting the above-cited findings and implementing the recommendation(s) 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: Jeffrey R. Adams Date: October 15, 2010
Report reviewed by: Jason Smith Date: October 29, 2010