HomeMy WebLinkAboutWhite Oak Addendum TMDL Final
Addendum to the White Oak River TMDL
for Impaired Segments in the
White Oak River Watershed,
North Carolina
August, 2012
[Waterbody IDs: 20-21,20-22, 20-23, 20-23-1, 20-23-2, 20-23-3, 20-24, 20-26, 20-26-1, 20-27,
20-28, 20-29, 20-29-1, 20-29-1-1, 20-29-2, 20-29-2-1]
White Oak River Basin
Submitted by:
NC Department of Environment and Natural Resources
Division of Water Quality
1617 Mail Service Center
Raleigh NC 27699-1617
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Addendum to the White Oak River TMDL
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Introduction
The North Carolina Division of Water Quality (DWQ) developed a Total Daily Maximum Load (TMDL) for
the White Oak River in 2010 to address fecal coliform impairments. The TMDL was approved by EPA
Region 4 on September 8, 2010.
This addendum to the White Oak River TMDL is to address additional assessment units on the 303(d)
list for fecal coliform impairments within shellfish growing areas in the White Oak River watershed.
These assessment units are primarily tidal creeks that drain to the White Oak River and were first
included on the 303(d) list in 2002. The impaired waters and associated assessment units (AUs) are
shown below:
Waterbody Name [Assessment Unit] Description
Water
Quality
Classification
Acres
Pitts Creek (Hargetts Creek): [20-21] From Source to White Oak River SA; HQW 1.8
Cales Creek: [20-22] From source to White Oak River SA; HQW 7.2
Hadnot Creek: [20-23] From source to White Oak River SA; HQW 43.4
Schoolhouse Branch: [20-23-1] From source to Hadnot Creek SA; HQW 4.2
Steep Hill Branch: [20-23-2] From source to Hadnot Creek SA; HQW 4.8
Caleb Branch (City Weeks Branch):
[20-23-3] From source to Hadnot Creek SA; HQW 7.1
Godfry Branch: [20-24] From source to White Oak River SA; HQW 3.4
Holland Mill Creek: [20-26] From source to White Oak River SA; HQW 29.1
Cartwheel Branch: [20-26-1] From source to Holland Mill Creek SA; HQW 4.3
Hampton Bay: [20-27] Entire Bay SA; HQW 82.1
Stevens Creek: [20-28] From source to White Oak River SA; HQW 6.9
Pettiford Creek Bay: [20-29] Entire Bay SA; HQW 239.3
Pettiford Creek: [20-29-1] From source to Pettiford Creek Bay SA; HQW 41.6
Mill Creek (Pettiford Creek) [20-29-1-1] From source to Pettiford Creek SA; HQW 4.8
Starkey Creek: [20-29-2] From source to Pettiford Creek Bay SA; HQW 31.4
Mullet Gut: [20-29-2-1] From source to Starkey Creek SA; HQW 1.6
Area Description
The White Oak River is a 42-mile long blackwater river located along the central North Carolina coast.
The watershed encompasses portions of Jones, Carteret, Craven, and Onslow counties and covers 273
square miles. The river begins to widen approximately nine miles before flowing into Bouge Sound;
here the river classification changes from class C,HQW to class SA,HQW. This point marks the northern
boundary of the Division of Marine Fisheries Shellfish Sanitation and Recreational Water Quality
Shellfish Growing Area D-3 which extends south to Bogue Sound. The addendum waters are shown in
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green in the southern portion of the watershed on Figure 1. This area has seen continued residential
development in recent years. Oyster and clam production are good throughout the area, however all
of the shellfish beds in the White Oak River Watershed areas are prohibited, or conditionally closed or
open, due to high fecal coliform levels (NC DMF, 2010). The dominant tide in this region is the lunar
semi-diurnal (M2) tide with a mean tidal range of 3.11 ft based on the NOAA station at Beaufort, NC.
Figure 1 - White Oak River Watershed
Documentation of Impairment
The sixteen addendum assessment units in the White Oak River Watershed are listed in Category 5 of
the North Carolina Integrated Report. These restricted shellfish harvesting areas are identified as areas
in this basin that do not meet their designated uses. Waters within this classification, according to 15A
NCAC 02B.0221 (Tidal Salt Water Quality Standards for Class SA Waters), must meet the following
water quality standard in order to meet their designated use: “Organisms of coliform group: fecal
coliform group not to exceed a median MF of 14/100 ml and not more than 10 percent of the samples
shall exceed an MF count of 43/100 ml in those areas most probably exposed to fecal contamination
during the most unfavorable hydrographic and pollution conditions.” In addition, for the approval of
shellfish growing areas “the median fecal coliform Most Probable Number (MPN) or the geometric
Addendum to the White Oak River TMDL
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mean MPN of water shall not exceed 14 per 100 milliliters, and not more than 10 percent of the
samples shall exceed a fecal coliform MPN of 43 per 100 milliliters (per five tube decimal dilution) in
those portions of areas most probably exposed to fecal contamination during most unfavorable
hydrographic conditions”(15A NCAC 18A .0431 Standards for an Approved Shellfish Growing Area). In
addition “a minimum of the 30 most recent randomly collected samples from each sample station shall
be used to calculate the median or geometric mean and 90th percentile to determine compliance with
this standard” (NSSP, 2009).
TMDL Reductions
The 2010 White Oak River TMDL (http://tinyurl.com/8qcc83c) requires a 75.2% reduction from
nonpoint sources and from the North Carolina Department of Transportation. These reductions apply
to the entire White Oak River Watershed, including the addendum assessment units, with the
exception of the watersheds addressed separately in the 2009 Southeast White Oak River Embayments
TMDL (NC DWQ, 2009).
Figure 2 shows assessment units covered in the 2009 Southeast White Oak River Embayments TMDL
(Pink), assessment units from the 2010 White Oak River TMDL (Orange), and the addendum
assessment units to the White Oak River TMDL are shown in Green.
Full implementation of the 2010 White Oak River TMDL and achievement of the fecal coliform loading
reduction target of 75.2% is expected to achieve water quality standards in the addendum waters.
DWQ may reevaluate the need for individual TMDLs for the addendum waters if the required
reductions are determined to be insufficient.
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Figure 2 - Assessment Units
Public Participation
The 2010 White Oak River TMDL was public noticed on the North Carolina Modeling and TMDL website
on July 12, 2010. The TMDL was also public noticed on July 14, 2010 through the North Carolina Water
Resources Research Institute email list-serve. In Addition, the TMDL was public noticed in the relevant
counties through a local newspaper (Carteret County News-Times) on July 16, 2010.
A draft of this addendum to the White Oak River TMDL was publicly noticed through various means,
including electronic notification of the draft addendum to the DWQ Modeling and TMDL Unit’s listserv.
The addendum to the White Oak River TMDL was also noticed on the DWQ Modeling and TMDL Unit
website and on the DWQ event calendar during the comment period. The public comment period
lasted from June, 25 through July 26, 2012. A copy of the public notice is included in Appendix A.
DWQ received five public comments from the NCDOT on the addendum to the White Oak River TMDL.
The comments and DWQ responses are included in Appendix B.
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References
NC DMF, 2010. Report of Sanitary Survey, Growing Area D-3, White Oak River Area. NC Division of
Marine Fisheries Shellfish Sanitation and Recreational Water Quality. June, 2010.
NC DWQ, 2009. Total Maximum Daily Loads for Fecal Coliform for Embayments in Southeast White Oak
River, North Carolina. April, 2009.
http://portal.ncdenr.org/c/document_library/get_file?uuid=e134c8a7-1b6a-446b-b7eb-
713788f14ab6&groupId=38364
NSSP, 2009. National Shellfish Sanitation Program Guide for the control of Molluscan Shellfish 2009,
Section II, Chapter IV.02 (Bacteriological Standards). US Food and Drug Administration, 2007. Website:
http://www.fda.gov/Food/FoodSafety/Product-
SpecificInformation/Seafood/FederalStatePrograms/NationalShellfishSanitationProgram/ucm046988.ht
m
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Appendix A – Public Notification of Addendum to the White Oak River TMDL
Addendum to the White Oak River TMDL
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Appendix B – Public Comments Response Summary
Addendum to the White Oak River TMDL
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Addendum to the White Oak River TMDL
Public Comment Responsiveness Summary
July, 2012
The public comment period extended from June 25, 2012 through July 26, 2012. Comments
were received from the North Carolina Department of Transportation. These comments with the
NC Division of Water Quality responses are provided in the Responsiveness Summary presented
below.
Response: This document is an addendum to the 2010 White Oak River TMDL Report and is not
intended to be a revision of the report. This addendum will accompany the 2010 White Oak River
TMDL report in the future.
Response: The NC Division of Marine Fisheries (DMF) Shellfish Sanitation Program uses
monitoring data primarily from sampling locations in the White Oak River, along with shoreline
surveys, to determine the condition of shellfish growing areas. The DMF data is summarized in
Appendix A of the 2010 White Oak River TMDL report.
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Response: The sentence in the Addendum Report prior to sentence mentioned in this comment
states, “Full implementation of the 2010 White Oak River TMDL and achievement of the fecal
coliform loading reduction target of 75.2% is expected to achieve water quality standards in the
addendum waters.”
The ambient monitoring station P6400000 compliance point and subsequent assessment units in
the 2010 White Oak River TMDL report received a TMDL of 1.34E+11 cfu/day. When the
TMDL is fully implemented and the TMDL is achieved, fecal coliform bacteria levels in all
assessment units in the watershed should be in compliance with water quality standards. If the
TMDL is met and some assessment units are still impaired then those assessment units will
receive a new TMDL.
Response: Your assumption is correct.
Response: Figure 2 and Appendix A have been removed from the document. Land cover and
source assessment information for the White Oak River watershed is documented in the 2010
White Oak River TMDL document. Figure 3 (now Figure 2) has been updated to label each of
the 16 assessment units.