HomeMy WebLinkAboutNC0047597_Inspection_20220906
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September 6, 2022
Donald F. Greeley, Water Management Director
Durham County
101 City Hall Plaza
Durham, NC 27701-3329
Subject: Compliance Sampling Inspection
South Durham WRF
NPDES Permit No. NC0047597
Durham County
Dear Mr. Greeley:
On July 12, 2022, Jason Robinson and Cassidy Kurtz of the Division of Water Resources’ Raleigh Regional Office
(RRO) conducted a routine compliance sampling inspection of the subject facility. DWR staff met with Mr.
Charlie Cocker, Plant Superintendent and Operator in Responsible Charge (ORC) Mr. Jeremy Cartner, backup
Operator (bORC), and other Durham staff.
The NPDES Compliance inspection consisted of the following:
x Review of the NPDES permit
x Review of the owner/facility information
x Review of monitoring data and Electronic Discharge Monitoring Reports (eDMRs)
x Review of operator log books
x Observation and collection of wastewater samples for analysis
x Walk-thru inspection of the facility and observation of treatment units
Finding during the pre-inspection were as follows:
1. The most recent permit became effective on February 1, 2013 and expired on April 30, 2016. A
renewal application was received by the Division on October 30, 2015, but the permit has not been
reissued, and the old permit has instead been “administratively continued”. It is the inspectors
understanding that the delay in issuance of a new permit is a result of the status of the Jordan Lake
Nutrient Rules.
2. The facility is currently permitted to discharge up to 20.0 MGD into an unnamed tributary to New
Hope Creek in the Cape Fear River Basin, a WS-IV Nutrient Sensitive Water (NSW). Current flows
averaged approximately 9.3 MGD for the previous 12 months.
3. The facility is classified as a Grade IV Biological Water Pollution Control System.
4. Staff reviewed the Permit Contact Report generated by NCDWR’s Basinwide Information Management
System (BIMS).
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5. Mr. Charlie Cocker, the plant superintendent it the plants Operator in Responsible Charge (ORC), and
Mr. Jeremy Dirk Cartner is one of the backup Operators (bORC). There are numerous other bORCs for
this facility. All operators but one are WW-4 certified.
6. DWR last inspected this facility for NPDES compliance in July 2020. A pretreatment audit was
performed in September 2020.
7. The following monitoring violations have occurred since the last inspection:
a. Yearly Total Nitrogen Exceedance (2%) resulting in NOD-2022-LV-0012
b. Quarterly Monthly Mercury exceedance (135%) resulting in NOV-2022-LV-0247
Findings during the inspection were as follows:
8. The permit requires the permittee to monitor discharges at Outfall 001. This inspection included a
sampling inspection, so collection of both the effluent composite and grab samples was observed by
the inspectors. The composite bottle was mixed continuously while being poured into the smaller
sample bottles and each sample bottle was only filled a portion at a time before moving to the next
bottle, until all were filled, ensuring representative samples. Prior to the inspection, the ORC
questioned the different volumes of samples that were being requested by the inspector. The
volumes that were requested are determined by DWR’s Laboratory. The operator also questioned
the need for sampling TSS since there are “decades of data showing it’s not an issue”. Sampling
inspections require that all parameters in the facility’s permit are analyzed (within reason).
Samples were split with the inspector to bring to DWR’s lab for a separate analysis. The results
produced by DWR’s compared to those reported by the South Durham WRF on their Electronic
Discharge Report (eDMR)can be found in Appendix A. All results were comparable, with the
exception of fecal coliform, which was still well below the weekly/monthly limits (DWR: 44 CFU/100
mL vs. Durham: 10.7 #/100 ML)
9. Durham County has a Compliance Service Building where most parameters are analyzed (Certification
#176). The laboratory was not visited during this inspection.
10. As part of the inspection, the operator was asked to provide laboratory data for review, and it was
stated in an email prior to the inspection that lab data would need to be reviewed. Most of the lab
data was not available at the WRF, and the operator repeatedly questioned the request to review
lab data and that should be done as part of a separate lab inspection. The ORC told the DWR-
inspectors that lab data could be confirmed with a phone call to Durham’s lab. After a contentious
discussion, the inspector eventually suggested that Durham’s lab data could be provided to the
inspector via email after the inspection. Durham’s Laboratory staff later provided the inspector
with lab data for several specific parameters for specific dates in December 2021 and March 2022.
The data was compared to sampling results that were submitted by Durham on their electronic
Discharge Monitoring Reports (eDMRs) No discrepancies were found.
The review of a facility’s laboratory data that is used to complete eDMRs is a routine part of all
NPDES compliance inspections. It is recommended that the facility be given access to the lab data
electronically. Or at the least, the operator should ask the inspector what lab data is needed when
the facility’s next inspection is scheduled so hard copies can be available at the facility for review.
11. As required by North Carolina General Statute § 143-215.1C(a), a wastewater annual report for FY 2020-
2021 was available for review on the County’s website after the inspection.
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12. Daily operation log books were available for review. The books were detailed and complete.
13. A walk-thru of the facility was performed. The system treatment units are listed below:
AA. Mechanically cleaned bar screens – New Bar-Screens on-line since last inspection
B. Long channel grit chambers – New grit chambers on-line since last inspection.
C. Equalization Basin – Put on-line since last inspection. 2 million gallons.
D. Primary clarifiers
E. Aeration basins
F. Final clarifiers
G. Flocculation basins – Put in for metals, but never used.
H. Traveling bridge effluent sand filters – 29 cells in each, 3 of 4 online, one used for backwash
storage. Media changed last year
I. UV disinfection
J. Anaerobic digesters – 2 of 4 under construction
K. Aerobic digesters – No longer present.
L. Gravity belt thickener
M. Clarifier
N. Sand Drying Beds
O. Belt Filter Press
P. Back-up Generator (not listed in permit) – The facility has four generators that are tested
monthly by National Power Corporation.
If you have any questions regarding the report or any of the findings, please contact Jason Robinson at
Jason.Robinson@ncdenr.gov.
Sincerely,
Scott Vinson, Regional Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
Division of Water Resources, NCDEQ
ATTACHMENTS
x Appendix A: Effluent Sampling Results
x EPA Inspection Checklist
Cc: Raleigh Regional Office and Laserfiche
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Appendix A: Effluent Sampling Results for July 11/12 2022 (Composite started on 7/11 and
collected on 7/12)
Parameter Sample
Type
Measurement
Frequency
Facility’s
On-site
Laborator
y Results
DWR’s Lab
Results Permit Limit
BOD 5-day (Summer)
(mg/L)
Composite Twice/Week <2 2.6 7.5 (Weekly Avg)
5.0 (Monthly Avg)
Total Suspended Solids
(Residue Suspended in
Liquid) (mg/L)
Composite Daily <2.5 2.9 45.0 (Weekly Avg)
30.0 (Monthly Avg)
NH3 as N (Summer)
(mg/L)
Composite Daily <.05 .05 3.0 (Weekly Avg)
1.0 (Monthly Avg)
Fecal Coliform
(Geometric Mean)
Grab Daily 10.7 44 400 (Weekly Avg)
200 (Monthly Avg)
NO3-N + NO2-N (mg/L) Composite Weekly 3.4 3.3 Monitor & Report
TKN Composite Weekly 0.73 0.95 Monitor & Report
Total Nitrogen1 (mg/L) Composite Weekly 4.13 4.25 Monitor & Report
Total Phosphorus (mg/L) Composite Weekly .14 0.12 Monitor & Report
1Total N = NO2 & NO3 + TKN