NC0086819_FONSI and EA_20110801

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FINDING OF NO SIGNIFICANT IMPACT AND ENVIRONMENTAL ASSESSME T
BRUNSWICK COUNTY PUBLIC UTILITIES—NORTHEAST BRUNSWICK REGIONAL
WASTEWATER SYSTEM EXPANSION
Pursuant to the requirements of the North Carolina Environmental Policy Act(N.C.G.S. § 113A-1,et seq.),
an environmental assessment(EA)has been prepared by Brunswick County Public Utilities for the proposed
wastewater treatment plant(WWTP) expansion from its current discharge capacity of 1.65 million gallons
per day(MGD)to 2.475 MGD in Phase 1 and to 3.8 MGD in Phase 2. The wastewater collection system
will also be expanded:
Phase 1 Phase 2
• 3,300 linear feet(I.f.)of 12-inch force main • 1,20011 of 12-inch force main
• 3,10011 of 18-inch force main • 200 l.f. of 24-inch force main
• 1,500 l.f. of 12-inch force main • 2,70011 of 18-inch force main
These additions to the collection system will require upgrades to the Clairmont,Commerce,and Lincoln
School pump stations. Construction at the WWTP to allow for the Phase 1 expansion will include: influent
screen;equalization pump station and tank; aeration basin; clarifier; effluent filter;UV disinfection system;
effluent pump replacement;ATAD residuals treatment; and new 24-inch effluent discharge piping.
Construction at the WWTP to allow for the Phase 2 expansionwill include these new process components:
influent headworks, equalization storage tank; aeration basin; clarifier;effluent filter;UV disinfection;
effluent pump station; and residuals treatment.
Four alternatives were considered for wastewater treatment and disposal: 1)no action; 2)connection to an
existing WWTP; 3)expansion of the Northeast Brunswick Regional WWTP with effluent disposal by spray
irrigation; and 4)expansion of the Northeast Brunswick Regional WWTP with effluent disposal by surface
water discharge. Option 4 is the preferred alternative.
Direct impacts have been avoided and minimized to the extent practicable during project planning and
design. Noise levels will temporarily increase in the immediate vicinity of construction locations;however,
this impact will be temporary and occur only between the hours of 8AM and 6PM Monday through Friday.
Nuisance noise levels are not expected to increase or change adversely when the new expansion comes on-
line.Topography and soils will be directly impacted by grading activities;however,these alterations will not
result in permanent adverse impacts to the topography or soil. This project will not impact local flood
elevations. While immediate local air quality at the construction sites will be degraded by stirred dust,
limited open burning of cleared vegetation,and emissions from machinery, the expanded WWTP and
wastewater transmission infrastructure are not anticipated to significantly impact local air quality. Direct
impacts to streams and wetland areas from installation of the effluent discharge line and force mains will be
temporary as affected areas will be returned to their original slope and contour following construction. A
total of 11.25 forested acres will be cleared to allow the construction of Phases 1 and 2 of the WWTP
expansion, and an approximately 0.60 acres of forested area will be cleared for force main installation.
Proper erosion and sedimentation practices will be followed during construction to protect local water quality
as well as aquatic habitat and wildlife. Installation of the new effluent discharge line cannot occur between
Febru. 1 and J - 1 . ay.•• im.. I• •- ••e••• - :eon. There will not be any significant direct
negative impacts on existing land uses;prime or unique farmlands; groundwater;public lands,and scenic,
recreational and State natural areas;known archaeological or historical resources; shellfish or fish and their
habitats; or threatened or endangered species.
Secondary and cumulative environmental impacts(SCI)may result from this project and are outlined in the
EA. State and local programs to mitigate impacts in the project area,including flood damage prevention
ordinances, coastal stormwater rules,land use plans,and zoning ordinances,are described in detail within the
EA and include policies that promote orderly growth through proficient use of land and cost-effective
provision of sewer service. Therefore,the proposed project should not result in significant SCI.

•
Based on the findings of the EA,the impact avoidance/mitigation measures contained therein,and reviewed
by governmental agencies,the Division of Water Quality has concluded that the proposed project will not
result in significant impacts to the environment. This EA and FNSI are prerequisites for the issuance of
Division of Water Quality permits necessary for the project's construction. An Environmental Impact
Statement will not be prepared for this project. This FNSI completes the environmental review record,
which is available for inspection at the State Clearinghouse.
North Carolina Department of Environment and Natural Resources
Division of Water Quality
30 June 2011
• •

ATA
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins Dee Freeman
Governor Director Secretary
August 16,2011
T.Carter Hubard,P.E.
Project Manager
W.K.Dickson&Co.,Inc.
909 Market Street
Wilmington,NC 28401
SUBJECT: Brunswick County—Expansion of Northeast Brunswick WWTP
DWQ#14356;DENR#1553
SCH#: 11E43000329
Dear Carter:
On August 16,2011,the State Clearinghouse deemed the North Carolina Environmental Policy Act review on the above
project complete(see attached correspondence from the Clearinghouse). The attached comments should be taken into •
consideration during project development. It is now acceptable to proceed with your permit applications through the
Division of Water Quality for the proposed project. No further actions on the Environmental Assessment are required.
If there is anything I can assist you with,please do not hesitate to give me a call at(919) 807-6434.
Sincerely,
Hannah Stallings
SEPA Coordinator
•
Attachments: (SCH Sign Off Letter,FONSI)
Ecc: Melba McGee—DENR
Linda Willis—WiRO
Tom Belnick,Alan Clark,Jeff Maiming—DWQ
1617 Mail Service Center,Raleigh,North Carolina 27699-1617
Location:512 N.Salisbury St.Raleigh,North Carolina 27604 One
Phone:[phone] FAX:[phone] Customer Service:1-877-623-6748 NorthCarolina
Internet:veww.ncwaterquality.org �atura/Ij
An Equal Opportunity 1 Affirmative Action Employer

•
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North Carolina •
Department of .Administration
Beverly;Eaves.Perdue, Governor Moses Carey,Jr.,Secretary
August 16,:2011
Ms.Hannah Stallings
NCDENR,Water Quality
1617 Mail Service Center
Raleigh,NC 27699
Re: SCH File.#11-E-4300-.0329;EA/FONSI;Northeast Brunswick Regional Wastewater
System Expansion from current discharge capacity of 1.65 million gallons per day(MGD)
to 2.475 MGD in Phase 1 and 3:8 MGD in Phase 2
Dear Ms. Stallings;
The above referenced environmental impact information has beenreviewed through the State
Clearinghouse under the provisions of the North Carolina Environmental Policy Act.
Attached to-this letter are comments made in the review of this document. Because of the natureof the
comments,it has been determined that no further State Clearinghouse review action on your part,is
needed for compliance with the North Carolina Environmental Policy Act The attached comments
should be taken into consideration in project development.
Best regards.
Sincerely,
r
re',: -en
State Environmental Review Clearinghouse
Attachments
cc: Region 0
Mailing Address: Telephone: [phone] Location Address:
1301 Mail Service Center Fax[phone] 116 West Jones Street
Raleigh,NC 27699-1301 State Courier#51-01-00 Raleigh,North Carolina
e-mail state.clearinghouse©doa.nc.gov
An Equal Opportunity/Affirmative Action Employer
I

•
• NORTH CAROLINA CLEARINGHOUSE
DEPARTMENT od ki.,...otanstrioxou
INTERGOVERN*NTAII REVIEW
COUNTY: BRUNSWICK 502:WASTEWATER TREATMENT STATE NUMBER: 11,E-43.00-029
FACILITIES DATE RECEIVED.: 003012011
AGENCY RESPONSE .08/10/2011
REVIEW =MD: 0B/15/2011
CLEARINGHOUSE COORDINATOR
CC&PS - DIV OF EMERGENCY. MANAGEMENT
FLOODPLAIN MANAGEMENT PROGRAM
m80. 1 4719 f*S1
RALEIGH. NC At- 4- (5.\ •
REVIEW DISTRIBUTION
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CC&PS - DIV OF EMERGENCY MANAGEMENT 0
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DENR - COASTAL MGT
DENR LEGISLATIVE.AFFAIRS.
DEPT OF CULTURAL RESOURCES N
DEPT OF TRANSPORTATIONS.
PROJECT INFORMATION
APPLICANT: NCPENA,. Water Quality
TYPE.: State Envitontefital Policy ,.At
EnvirOnmefital AssesSment/Finding: of No Significant Imact
DEW: Northeast Brunswick Regional Wastewater System Expansion from current discharge
capacity of 1,-.65 million gallons per day (MGD) to 2.475 MOO in Phase 1 and .3.8
MGD in Phase 2
The attached project has been UbMittedto the. N. C. State ClearibgbdUSe for
intergovernmental review. Please review :and submit your respdhseby the above
indicated date to 1301 Mail Service Center, Raleigh NC 21699-1101.
If additional review time is needed, please contact this office at (919)807- 425.
1SARESULT OF THIS REVIEW THE. FOLLOWING IS: SOBMITTED: NQ COMMENT COMMENTS ATTACHED
SIGNED BY:
DATE: V Ij
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North Carolina Department of Crime Control and Public Safety
Division of Emergency.Management
Office of Geospatial and Technology Management
Beverly Eaves Perdue,Governor. IL Douglas Hoell,Jr:;Director
Reuben F..Young,Secretary
August 01,2011
ck
State Clearinghouse U61
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N.C.Department of Administration A.1
130:1 Mail Service Center � De- ,a
Raleigh,North Carolina 2769.9-1301 NSA.
Subject. Intergovernmental.Review State Number: 11,E-4300-0329
NE Brunswick Regional Wastewater SystemmFxpansion
As.requested by the North Carolina State.Clearinghouse,:the North"Carolina Department of
Crime Control,and,Public:.Safety Division..of Emergency Management Office of Geospatial
and Technology..Management (GTM) reviewed the proposed project listed above and offer
the following.comments:
1) The Town of Leland participates inthe National Flood Insurance Program and
enforces a Flood Damage:Prevention Ordinance that requires:a Floodplain
Development Permit be issued for-all AeveiOpinent located m the-SERA within their.
jurisdiction. The project crosses the:regulatory. floodway of Sturgeon Creek. The
Town of Leland's Flood Damage Prevention Ordinance and 44 CFR 60:3(d)(3).
requires a"no-rise"-certification or the preparation of a Conditional Letter of Map
Revision for any encroachment;in the regulatory floodway, Please ensure the
Floodplain Adrninistrator.reviews the proposed plans and issues a permit for the
proposed project.
2) The Town of Navassa and Brunswick County participate in the National Flood
Insurance Programand enforce a Flood Damage Prevention Ordinance that requires a
Floodplain Development.Permit be issued for all development Iocated in the SFHA
within their jurisdiction. The project encroaches within the regulatory floodway of the
Cape Fear River. Brunswick County's:Flood Damage Prevention.Ordinance Section
9.1.5.F and 44 CFR 60.3(d)(3)require a"no-rise"certification or the preparation of a
Conditional Letter of Map Revision for any encroachment into the regulatory
Mail: 4,.. _ Location:
4719Mail Service Center ,0% ._aMaww'r�.r F
[812 Tillery Place,Suite 105
Raleigh- Lett
Sh,NC 27699-4719 credited
� Raleigh,NC 27604
Telephone:[phone] a e � ''4".."1""""'•;-"-ter`- Far 919-715-0408
ea'oarLrr:trrcit;a..
Fmp,gsla�rad
www.NCCrlmeControl.org A NationallyAccredled Agency
An Equal Opportunity/Affirmative Action Employer

•
Page.2 of 2
August 01,2011.
floodway.: Please ensure the.Floodplain Administrator reviews the proposed:plansand
issues a permit-for the.proposed:project.
3) Brunswick:County's Flood:Damage.Prevention Ordinance and 44 CFR 60 3(ax4)(ii)
states all public utilities and facilities are to be located and constructed to-minimize or
eliminate flood damage: Please ensure.all utilities are elevated and/or protected to the
flood protection elevation noted in Brunswick.County's Ordinance:
Thank you for your cooperationand consideration. If you have anyquestionsconcerning the
above comments, please contact Dan Brubaker, P.E., CFM;,the NC NF1P Engineer at(919)
715-571:1 ext. 110;by email at dbrubaker@ncem:org or at the.address shown on thefooter of
this document
Sincerely,
1 1•"
et} Ash;P;E:,CFM.
,,Director
c: John Gerber,NF1P State Coordinator
Dan.Brubalcer,NF1P Engineer
•
Location: 1812 Tillery Place,Suite 105 • Raleigh,NC 27604•[phone]
An Equal Opporhutity/Affirmative Action Employer

• .
• 101-1Z--.1.1 14:47 emum- T-089 F0001/0001 F-14Z
=MR CAROLINA STh! CLURZNaBoVsE
Dti•ARTidibri, OF ADMirATIITRATION s
INTERCOVERAMEICAL REVIEW •
COUNTY: BRUNSWICK Moa.:14ASTEWATER TREATMENT STATE KHMER: 1)-E-4300-0329
. rACILITIES
DATE RECEIVED: 0613.0/2011
AGENCY.RESPONSE t OH n.0/2.01.1.
. REVIEW.CLOSED: OW02014
CLEARINGHOUSE COORD REGION 0 ! .
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PROJECT. INHUMATION • /t
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APPLICANT: NCDENR, pater.-(43,a4;y• - c-4.2r•EnZin('
- :TYPE: State Environmental Policy Act
EnVironmental ASOSOMent/findingio ,00. SignificOn - /s100t
DESC: Northeast 8;UusWidk Rdgi0h0IMONt;&$0t SyNtsm_ Expansion fT0m current discharge
capacity 0f,1.66 million goIlon , per day (MGD): to 2'.!A75 MOD ill PhaSe 4 and 3,8
MGD in Phase 2
The attached project h3 been 4unaittadtb thd N. C. State Clearinghouse for
43)VVPv0rAmental review. P164.ge review and tubillityOuii-eopbbse by the aboyc
indicated date to 1301 mail Service Canter, RalCigh NO 2769.94301.
If additional roview time iq needed, please 006t.8.0t: this: offide dt (911311TI4z5,
AS A RESULT OF TRIS REVIEW THE FOLLOWING IS SUttaneDt 0 WO .COMMENT tomm =Amp
E- mg
SIGNED BY: 164&. eio .0.„.. ito.k ei:AV-4.9 DATE- 'ZAN \2..)2° \
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' . . NORTH CAROLINA STATE CLEARINGHOUSE
DEPARTMENT OF ADMINISTRATION
v INTERGOVEMMENTAL REVIEW
COUNTY: BRUNSWICK H02: WASTEWATER TREATMENT* STATE NUMBER: 11-E-4300-0329
FACILITIES DATE RECEIVED: 06/30/2011
AGENCY RESPONSE:.08/10/2011
REVIEW ctbsED: 08/15/2011
MS MELBA mc0EE .
CLEARINGHOUSE COORDINATOR'
DEER - COASTAL MGT t3131 1.2. . .
C/O ARCH DALE BLDG
RALEIGH NC4 ,
(t) ailli.
REVIEW rasTRitufzioN• • :"'--.., - ?On 45
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ct&ps - DIV OF EMERGENCY MANAGEMENT 4,
DEAR - COASTAL MGT V.!. .,..,
DEAR LEGISLATIVE AFFAIRS
IA
DEPT OF CULTURAL RESOURCES elisi g S
DEPT OF TRANSPORTATION
PROJECT INFORMATION
APPLICANT: NCDENR, Water Ouality
TYPE: State- EhvirOnmental POljOY' Aot
EnVironmental Ateessment/Finding of No Significant Impact
DESC: Northeast Brunswick- Regional Wastewater. System Expansion from current discharge
capacity of 1,65 million gallons per day (MGD) to 2.475 MGD in Phase 1 ands
MGD in Phase. -2
The attached project has been submitted to. the N. C. Stat,gi Clearinghouse for
intergovernmental review- Please review and submit your response by the above
indicated, date to 1301-Mail Service Center, Raleigh. NC 27699-1301.
If additional review time is needed, please contact this office at [phone].
AS A RESULT OF THIS REVIEW THE LLONING IS SUBMITTED: • NO COMMENT El COMMENTS ATTACHED
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. .
SIGNED BY: . - -' . _____ __--- ___Le7
. DATE:
1

. •
• NORTH CAROLINA STATE CLEARINGHOUSE •
DEPARTMENT OF ADM/NIETRATION
INTERGOVERNMENTAL REVIEW • 1
COUNTY: BRUNSWICK H02:WASTE '" • ..,r... STATE NUMBER: 11-E-4300-0329
FACIL IES:s. DATE RECEIVED:. 06/30/2(711
1 sa AGENCY RESPONSE: a8/1012613,
JUL 01 , t.,;. REVIEW CLOSED: 08/15/2011
'.. i:411 :
MS RENEE GLEDHILL-EARLEY
CLEARINGHOUSE COORDINATOR . HOTOCAORMONCORCE:
-et CR --Mil--
DEPT OF CULTURAL RESOURCES
STATE HISTORIC PRESERVATION OFFICE
MSC 4617 - ARCHIVES BUILDING
RALEIGH NC
7- V-64ICILLSLI
REVIEW DISTRIBUTION 6•V-j-m.
CAPE FEAR COG
CCLPS - DIV OF EMERGENCY MANAGEMENT
DENR - COASTAL MGT
DENR LEGISLATIVE AFFAIRS
DEPT OF CULTURAL RESOURCES
DEPT. .0. TRANSPORTATION
.p*coAcT iNvoNmAtica .
APPLICANT': NCDENR, Water Quality
TYPE: State Environmental Policy Act
Environmental Assessment/Finding of NO Significant Impact
DESC: Northeast Brunswick Regional Wastewater System Expansion from current discharge
capacity of 1.65 million 'clan:ohs per day (MGD) to 2.475 tab 'in Phase 1 and 3.8
MGD in Phase 2
The attached project has been submitted to the' N. C. State Clearinghouse for
intergovernmental review. Please review .and sUbrait your response by the above
indicated date to 1301 Mail Service Center, Raleigh NC .27 699-1:301.
If additional review time is needed, please contact this office at [phone].
AS A RESULT OF THIS REVIEW THE FOLLOWING IS *SUBMITTED: gCOMMENT ED COMMENTS ATTACHED
NO
SIGNED BY: ).011.auf)a- :if;:k.S11,61_ - DATE:
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Belnick, Tom
From: Carter Hubard[[e-mail]]
Sent: Tuesday, August 16,2011 5:05 PM
To: Belnick,Tom; Grzyb,Julie
Cc: [e-mail]
Subject: FW: SEPA Approval for Northeast Brunswick
Attachments: App Ietter.pdf
As requested I am forwarding the SEPA approval letter
T. Carter Hubard, P.E.
Project Manager
W.K. Dickson &Co., Inc.
909 Market Street
Wilmington, NC 28401
910-762-4200
F910-762-4201
www.WKDickson.com
From: Stallings, Hannah fmailto:[e-mail]
Sent:Tuesday,August 16, 2011 4:03 PM
To: Carter Hubard
Cc: Mcgee, Melba; Willis, Linda; Belnick,Tom; Clark,Alan; Manning, Jeff
Subject: SEPA Approval for Northeast Brunswick
Carter—
Please find the approval letter attached,along with correspondence from SCH and a copy of the FNSI. Please note that
SCH received comments that should be considered during project development.
This project may now proceed to permitting.
If you have any questions or concerns, please contact me.
Thank you.
Hannah
Hannah Stallings, DWQ's SEPA Coordinator
[phone]
Mailing address: 1617 Mail Service Center,Raleigh,NC 27699-1617
Physical location: 512 N.Salisbury Street,Raleigh,NC 27604
http://portal.ncdenr.org/web/waps/sePa
E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be
disclosed to third parties.
1

iodeii. 4kfQe 6Kim oa ,'411
DEVELOPMENT AND USE OF A THREE-DIMENSIONAL WATER QUALITY MODEL
TO PREDICT DISSOLVED OXYGEN CONCENTRATIONS IN THE LOWER
CAPE FEAR RIVER ESTUARY,NORTH CAROLINA
James D. Bowen, Solomon Negusse, J. Matthew Goodman, Benoit Duclaud,
Mathieu Robin, and Jesslyn Williams
Department of Civil and Environmental Engineering
William States Lee College of Engineering
University of North Carolina at Charlotte
Charlotte,NC 28223
•
The research on which this report is based was supported by funds provided by the North
Carolina General Assembly through the North Carolina Department of Environment and Natural
Resources.
October 2009

EXECUTIVE SUMMARY
An application of the three-dimensional water quality model EFDC (Environmental Fluid
Dynamics Code)was developed for the Lower Cape Fear River Estuary,North Carolina. The
model was used to investigate the effects of various organic matter and ammonia load reduction
scenarios on the dissolved oxygen concentrations within the estuary. The model region included
the tidally affected portions of the Cape Fear, Black, and Northeast Cape Fear Rivers near
Wilmington,North Carolina, and extended southward to the mouth of the Cape Fear River near
Southport, North Carolina.
The model's three-dimensional numerical grid had 1050 horizontal cells and eight
vertical layers. The average horizontal grid size was approximately 600 m; individual cell sizes
ranged from 100 to 1300 m. Cell water depths varied for river and estuary channel cells from 2.5
to 12.5 m. EFDC uses a"sigma" vertical grid so that the water depth within a horizontal cell
was subdivided into eight layers of uniform thicknesses. The model grid included 241 "marsh"
cells that were used to model the off-channel storage of wetlands adjoining the estuary. Flow
boundary conditions were utilized at the upstream riverine boundaries; a radiation-separation
boundary condition was used at the downstream open boundary. Model input data sets and
observed data sets used for calibration and confirmation, and model scenario testing were
developed using observed data gathered from various agencies. The period December 1,2003 to
December 31, 2004 was found to have sufficient data to create the necessary model data set for
calibration. An additional model data set using data from January 1 to December 31, 2005 was
used for model confirmation.
The model calibration period (January 1 —December 31, 2004) had streamflows that
were generally below average for the first half of the year, and generally above average for the
latter half of the year. After a storm in early May 2004, streamflows remained below average
until August. The remainder of 2004 and 2005 until the middle of April had streamflows that
were near historical average values. Flows through the summer of 2005 were generally below
average. Dissolved oxygen(DO)concentrations at two stations that were in the impaired region
and had continuous monitors installed in 2004 (Navassa and the Northeast Cape Fear at
Wilmington) showed summertime (April 1 —October 31)dissolved oxygen concentrations that
varied between 3 and 7.5 mg/L. At both of these sites the median DO concentration was below
4.5 mg/L and the 25th percentile DO concentration was below 4.1 mg/L. DO concentrations
were generally lower at the Northeast Cape Fear site, and at this site were generally lower near
the bottom of the water column.
Model calibration was performed separately on the hydrodynamic and water quality
submodels. Hydrodynamic model calibration relied heavily on a set of continuous in-situ water
level and water quality monitors that were deployed through the estuary. Hydrodynamic model
calibration consisted primarily of varying the location,width, and bottom roughnesses of shallow
model cells located adjacent to the river and estuary channels. The distribution of these"marsh"
cells utilized information on the location and lateral extent of saltwater marshes and wetland
forests adjoining the estuary. The calibrated hydrodynamic model matched well the attenuation
of the tidal amplitude signal from the estuary mouth to the upstream model boundaries. The
iv

s
model was also able to simulate to a reasonable extent the time histories of salinities
throughout the estuary.
The twenty-one state variable water quality model available in EFDC included multiple
dissolved and particulate organic carbon constituents, as well as organic and inorganic nutrients,
dissolved oxygen, and three phytoplankton constituents. To adequately characterize the various
organic matter decomposition rates of the riverine and wastewater inputs,both labile and
refractory dissolved organic matter constituents were used. The water quality model considered
inputs from the three riverine sources at the model boundaries, twenty wastewater point source
inputs within the estuary, and fourteen additional point sources that simulated other freshwater
inputs to the estuary from tidal creeks and wetlands. Over the three-year time period (2002-
2005) for which the freshwater and point source loadings were developed, approximately 10% of
the organic matter loading and 50% of the ammonia loading to the estuary came from the twenty
wastewater point sources that discharged directly to the estuary.
The dissolved oxygen model utilized a user specified sediment oxygen demand(SOD)
that could vary spatially and temporally. Both temporal and spatial variation in SOD was utilized
for the model. The temporally variable SOD that was used in this study was based upon an
analysis of the available monitoring data. Temporal variation was modeled according the
observed variation in measured SOD with changes in water temperature during the SOD
measurement. SOD values were then adjusted seasonally according to observed changes in
water temperature in the water body. During calibration it was determined that higher SOD
values should be used for the Northeast Cape Fear. The ratio between these higher SOD values
and the SOD values for remaining portion of the model region was determined during
calibration. Discharge and estuary monitoring data were used to quantify the loadings of organic
matter, nutrients, and dissolved oxygen to the estuary. As part of calibration SOD values were
varied to values above and below the average values from the monitoring program. The
calibrated value was found to be nearly identical to the corresponding value from the monitoring
program.
The calibrated model matched well time histories of observed dissolved oxygen
concentration. Model predictions were compared to over 5200 measured dissolved oxygen
concentrations collected at eighteen sites throughout the estuary. The mean model error was less
than 0.01 mg/L, and the root mean square error was 0.92 mg/L, which corresponded to 13.8%of
the mean value. The correlation r2 was 84.4%. This is an excellent degree of model fit for an
estuarine dissolved oxygen model. Time history comparisons were also made for other
important water quality constituents, such as nitrate+nitrite, orthophosphate,total nitrogen, and
chlorophyll. In each case the model acceptably simulated the spatial and temporal patterns in the
observed data set. A water quality model confirmation test run using input and calibration data
from 2005 showed a similar degree of fit between observed and predicted dissolved oxygen
concentrations. Based upon this work,the calibrated model is considered to be suitable for
conducting scenario tests on the effect of changes in organic matter and ammonia loadings on the
dissolved oxygen concentrations in the estuary.
A number of scenario tests were conducted to investigate the system's sensitivity to
loading changes and other possible changes in the water body. For each scenario, a model run
v

was used to determine the predicted dissolved oxygen concentrations during the summer
period of 2004 (April 1 —October 31)within the state designated impaired region of the
estuary. Twice daily dissolved oxygen snapshots were recorded from all eight vertical layers at
eighteen sites within the impaired region. More than twenty separate model runs were made and
compared to the base case to determine how the dissolved oxygen concentrations might vary for
a particular scenario. These eight scenarios were examined:
1. Eliminating wastewater point source loadings
2. Reducing river, creek, and wetland loadings
3. Changing wastewater loadings for various values of sediment oxygen demand
4. Reducing river, creek, and wetland loadings and sediment oxygen demand
5. Eliminating ammonia inputs from wastewater point sources
6. Increasing wastewater inputs to maximum permitted values
7. Deepening of the navigation channel
8. Changing Brunswick County wastewater loadings
Four model runs were made to investigate the effect of completely turning off the
discharges from the wastewater treatment plants. These scenarios were run,not because the
pollutant removals used were considered achievable or advisable, but instead these scenarios
were run to investigate the system's sensitivity to WWTP loads. River, creek, and wetland
inputs were maintained at the base condition levels. It was assumed that organic matter and
ammonia concentrations in the wastewater inputs would be decreased to 0.0 mg/L. When all
WWTP loads were eliminated,the 10th percentile DO concentration increased by approximately
0.3 mg/L, from 4.3 to 4.5 mg/L. The median value DO concentration increased by about 0.10
mg/L, from 5.6 to 5.7 mg/L. Selectively turning off individual WWTP loads, as expected, had a
smaller effect. Turning off the International Paper WWTP had an effect that was roughly 2/3 of
that when all the plants were turned off. Turning off both Wilmington domestic wastewater
treatment plants had an effect that was roughly 1/3 of that when all discharges were turned off.
A fourth scenario considered eliminating the ammonia loading for all wastewater treatment
plants. This scenario increased the dissolved oxygen concentration by about 0.1 mg/L at the 10th
percentile level.
The impact of changing the loadings that entered the model region from rivers, creeks,
and wetlands were also investigated. Loading reductions of 30%, 50%, or 70% were assumed
for the three river inputs (Cape Fear, Black, and Northeast Cape Fear), and from the fourteen
creeks and wetland inputs in the estuary. To reduce the loadings, flows were maintained at the
observed levels, but concentrations were reduced by 30%, 50%, or 70%. Loadings for the
twenty wastewater point sources were maintained at the levels in the base case scenario. These
load reductions were found to have a significant impact on dissolved oxygen concentrations. At
the 10th percentile level, DO concentrations for the 30%, 50%, and 70% load reduction increased
by 0.20, 0.3, and 0.40 mg/L respectively, from 4.3 mg/I to either 4.5, 4.6 or 4.7 mg/L. Unlike the
other scenarios investigated, this level of increase in DO concentration was maintained at the
higher percentiles. In fact, the median DO concentration was increased to even a greater extent,
increasing from 5.6 to 5.85 mg/L for the 30% load reduction, and from 5.6 to 6.2 mg/L for the
70% load reduction scenario.
vi

Additional water quality model runs were conducted to investigate the sensitivity of the
results to the choice of model kinetic parameters. Because of its relative importance in
determining dissolved oxygen concentrations,the sensitivity analysis focused on the impact of
various choices for the sediment oxygen demand. During calibration it was found that this
parameter had a significant impact on dissolved oxygen concentrations in the estuary. In
addition to the calibrated SOD value (0.4 g/m2/d at 20° C), runs were made at a lower value (0.3
g/m2/d at 20° C)and a higher value (0.5 g/m2/d at 20° C). Model fit to the observed data set was
compared for these three cases. All three cases had similar correlation r2 values (83.4%, 83.4%,
and 84.5%),but on average the low SOD case overpredicted DO concentrations by 0.11 mg/L,
while the high SOD case underpredicted DO concentrations by a similar amount(0.09 mg/L).
The impact of turning off the organic matter and ammonia loadings from all wastewater
treatment plants was investigated for each of these three SOD cases. Each scenario produced a
very similar change in DO concentration when all point sources were turned off Even though
DO concentrations were changed with the different SOD cases, in each scenario,turning off the
sources increased DO concentrations by approximately 0.25 mg/L at the 10th percentile level. It
is expected that changes in other model parameters would have a similar result. Although
absolute concentrations are affected by changes in parameter values, relative changes in
concentration are less affected by changing parameter values.
An additional set of model runs were conducted to investigate the effect of reducing both
river loading of organic matter and sediment oxygen demand. Three pairs of model runs were
made that reduced river loading or river loading and SOD by 30%, 50%,and 70%,using the
methods described earlier. As expected, a larger effect was seen when both river loading and
SOD were reduced. A 30%reduction raised the 10th percentile DO concentration from 4.3 to 4.8
mg/L; a 50%reduction raised the 10th percentile DO concentration to 5.2 mg/L; a 70% reduction
raised the 10th percentile DO concentration to 5.4 mg/L. In this final case where both river load
and SOD were reduced by 70% from the base case, only about 1%of the model predicted DO
concentrations in the impaired region were less than the water quality standard value of 5.0
mg/L.
The impact of increasing all wastewater treatment plant loadings to the maximum
allowed by permit was also investigated. For cases where both the maximum concentration and
flow were specified,both these values were used in the scenario. In permits with only a load or
concentration limit, the existing flows were maintained,but concentrations were adjusted to
produce the permitted limit. Using these maximum permitted loadings decreased predicted
dissolved concentrations in the impaired region by approximately 0.1 mg/L. This level of
decrease was fairly uniform across the range of predicted concentrations.
The impact of deepening the navigation channel on predicted dissolved oxygen
concentrations in the estuary was also investigated. Model grid files were adjusted to match the
channel deepening plan developed by the Wilmington district of the US Army Corps of
Engineers that will deepen portions of the Cape Fear and Northeast Cape Fear Rivers. It was
found that this deepening would decrease dissolved oxygen concentrations by approximately 0.1
to 0.2 mg/L. The percentage of dissolved oxygen concentrations in the summertime in the
impaired region that would be below 5.0 mg/L would increase slightly with the channel
deepening from 32% to 34%.
vii

Three model scenarios considered the impact of changing the wastewater flow of a single
discharger(Brunswick County wastewater treatment plant). Based on the discharge monitoring
reports for the model period, the base condition had a time-averaged flow of 0.38 MGD. The
three scenarios tested had time-averaged flow of 1.65, 4.65 and 15 MGD. These scenarios
therefore represented the effect of changing the wastewater treatment flow by factors of 4.3,
12.1, and 39.1. Despite the relatively large changes in the assumed wastewater flow,there were
only very small differences in the predicted dissolved oxygen concentrations, for summertime
conditions in the impaired region. Across the entire range of dissolved oxygen concentrations,
the differences between the base case and each of the three scenarios were always less than 0.05
mg/L.
An analysis was performed to attribute the observed oxygen depletion within the estuary
to riverine loadings of degradable waste, wastewater discharges, and sediment oxygen demand.
It was found that for three sites in the impaired region during the summer, less than 10%of the
dissolved oxygen deficit was attributable to wastewater discharges. Riverine loadings and
sediment oxygen demand each contributed similar amounts to the remaining 90%of the deficit.
The report concludes with some recommendations as to additional development of the
model that seems justified. Both this model study and a previous effort demonstrated the
importance of benthic fluxes of oxygen. As this model used a prescribed sediment oxygen
demand, albeit one that varies temporally and spatially, further refinement of the sediment model
seems warranted. In addition, some additional work seems justified to separately consider the
effects of wetland and riverine loadings to dissolved oxygen conditions in the estuary.
viii

6.9 Effect of Changing Brunswick County Wastewater Loadings
Three model scenarios considered the impact of changing the wastewater flow of a single
discharger(Brunswick County wastewater treatment plant). Based on the discharge monitoring
reports for the model period(2003-2005), the base condition had a time-averaged flow of 0.38
MGD. The three alternate scenarios tested had time-averaged flows of 1.65, 4.65 and 15 MGD.
These scenarios therefore represented the effect of changing the wastewater treatment flow by
factors of 4.3, 12.1, and 39.1. In these alternate loading scenarios, each discharge flow was
increased by a constant factor. All concentrations were assumed to be constant. Thus the
wastewater loadings had identical patterns of time variation, but had time-averaged flows that
equaled the values given above. As for the other scenarios, twice daily dissolved oxygen
concentrations were collected and compared to the base case at eighteen sites within the impaired
region, from all eight layers of the model and from every day within the summertime period
(April 1 —October 31, 2004).
Despite the relatively large changes in the assumed wastewater flow,there were only
very small differences in the predicted dissolved oxygen concentrations, for summertime
conditions in the impaired region. Across the entire range of dissolved oxygen concentrations,
the differences between the base case and each of the three scenarios was always less than 0.05
mg/L(Figure 86). Thus there was essentially no effect of changing the wastewater flow. One
limitation of this analysis is the assumption that loading would increase solely by increasing the
flow. Since the organic matter concentrations were only slightly higher than the receiving
waters, it is not surprising that changing the loading by holding effluent concentrations constant
while increasing the flows had a very small effect on dissolved oxygen concentrations.
6-18

April through October Simulated Dissolved Oxygen Concentrations
in the Impaired Area,Lower Cape Fear River Estuary
1
- Base Case - -
BrCo., Q=1.7 MGD -
0.8 -
BrCo., Q=4.7 MGD
_ BrCo., Q=15 MGD , •
u "
0.6 - a e e a e ♦ , -
O"
L "
GI -
.r
•.r
• 0.4 - 4 1 4 i• • 4 O -
0.2 - -
0 I I I I I 1 I
3 3.5 4 4.5 5 5.5 6 6.5 7
Dissolved Oxygen (mg/L)
Figure 86.Percentile Plot of Model Predicted Dissolved Oxygen Concentrations During the
Summer 2004 for the Base Case and Three Brunswick County WWTP Loading
Scenarios. The y-axis indicates the fraction of values below the corresponding DO
concentration (mg/L) indicated on the x-axis.
6-19

6.10 Analysis of the Summer Dissolved Oxygen Deficit in the Impaired Region
One conclusion that results from the previous scenarios is that depressed summertime
dissolved oxygen concentrations in the Lower Cape Fear River Estuary can possibly be the result
from one or more processes. Sediment oxygen demand, water-column decomposition of organic
matter, or oxidation of ammonia can all result in dissolved oxygen depletion. Furthermore,there
are several sources of organic matter in the water column(e.g. wastewater point sources, riverine
inputs, inputs from creeks and rivers). An important consideration in the analysis of water
quality in the Lower Cape Fear River Estuary is the relative importance of these various sources
and processes to the dissolved oxygen concentrations in the impaired region of the Estuary.
To investigate the relative importance of these sources and processes, an analysis was
performed to quantitatively compare the rates of oxygen consumption in the water-column due to
riverine, estuarine, and wastewater sources, and to compare this consumption to sediment
oxygen demand. The analysis focused on three sites within the impaired region where
monitoring data were available: Cape Fear at Navassa(see Figure 6, Station NAV),Northeast
Cape Fear River at Wilmington(see Figure 7, USGS Station 02108690), and Cape Fear River at
Horseshoe Bend(see Figure 6, Station HB). Twice daily model predicted dissolved oxygen
concentration,temperature, and salinity values were recorded near the surface (layer 7 of 8) at
these three stations. Temperature and salinity values were used to calculate dissolved oxygen
saturation concentration(Chapra 1997), and then the DO concentrations were plotted as a
fraction of the DO saturation concentration(Figure 87) for a fourteen-month period beginning
December 1, 2003. At all three stations,the DO saturation fraction is highest during the winter
months and lowest during the summer months,probably as a result of temperature related
differences in the consumption rate of water-column dissolved oxygen. At all three stations DO
saturation percentages peak at about 90% in early March but then decline steady until August,
when DO saturation percentages are less than 60%at all three stations. Beginning in early April,
DO saturation values go below 70%at all stations, and do go back above 70%until late October
(Figure 87).
Clearly oxygen consumption and under-saturated DO concentrations are a persistent
feature during the summer at these three stations within the impaired region of the Lower Cape
Fear Estuary, but what is the relative importance of the processes that produce this under
saturation of dissolved oxygen in the water-column? To investigate this question, a first-order
sensitivity analysis was performed to determine the relative importance of these three processes:
1. Discharge of oxygen demanding wastes by the 20 wastewater treatment plants
that discharge directly to the estuary,
2. Discharge of oxygen demanding wastes by the three rivers in the basin(Cape
Fear, Black,Northeast Cape Fear) as well as the creek and wetlands areas that
discharge directly to the estuary, and
3. Sediment oxygen demand.
6-20

1 1 1 1 I I 1
DO spc at Nav -
DO spc at HB
0.9 ''l r. DO spc at NECF -
. li _
0.8 111 a . " o a... ....i o —
w � -
o
) 1
173. I i
V:
(4 0.7 _I .. I� —
O
Q ' t I -
II I -
0.6 . . \ 4 .. —
l'i .1
lir _
0.5 I I I I I I
12/1/03 2/1/04 4/1/04 6/1/04 8/1/04 10/1/04 12/1/04 2/1/05
Date
Figure 87. Model Predicted Dissolved Oxygen Concentrations in the Surface Waters as a
Percentage of Saturation Concentration at Two Cape Fear Locations (Navassa and
Horseshoe Bend) and one NE Cape Fear Station(Wilmington).
Three separate runs were made to determine the sensitivity of the time-averaged DO
concentration at the three test sites to changes in one of the processes listed above. In each run, a
prescribed relative change (e.g. 10%of the base case) in one of the loadings or the sediment
oxygen demand rate was made, while holding all other rates and parameters at the values set in
the base case. These three runs were then compared to the base case and the relatively
sensitivity of each process was determined by comparing the change in dissolved oxygen
6-21
I

concentration between the cases. The time-averaged mean oxygen depletion at each site was then
apportioned based upon the relative sensitivity of the three processes.
There were slight differences in the magnitudes of the oxygen depletion attributable to the
three different factors at the three different sites(Figure 88). In general,however, the dissolved
oxygen deficit caused by SOD and the river loadings of organic matter were significantly greater
than that caused by the WWTP loadings. Time averaged dissolved oxygen concentrations were
slightly different at the three sites, ranging from 5.65 mg/L at Navassa to 5.45 mg/L at the
Northeast Cape Fear at Wilmington site. At each site the time-averaged dissolved oxygen
saturation concentration was approximately 8.2 mg/L,thus each site had a time-averaged
dissolved oxygen depletion of approximately 2.7 mg/L. Of the three processes compared, the
wastewater treatment plant discharges had by far the smallest dissolved oxygen depletion effect.
At each wastewater treatment plants accounted for approximately 0.2 mg/L of the total dissolved
oxygen depletion. This amount of depletion represents approximately 7 to 9%of the total
depletion. Of the remaining DO depletion(approximately 2.5 mg/L, which is more than 90%of
the total),roughly similar amounts could be attributable to SOD or riverine loadings of organic
matter. The exception to this was the Northeast Cape Fear at Wilmington site,where more of the
depletion(56%vs. 37%)was due to the SOD. These findings are consistent with earlier
estimates of organic matter loading that show that rivers, creeks, and wetlands are the dominant
sources of oxygen demanding wastes to the estuary(e.g. see Figures 43,44, and 45).
6-22

▪ WWTP deficit
O SOD deficit
El Riv Load Def,
10 El Avg. Conc.
.•
8
• •
6 —
a.)
-•••
CIJ
4 -
•
2 —
-••
• -----
0
CF at Nay CF at HB NECF at Wilm.
Location
Figure 88. Bar Graphs of Summer Season (April through October) Time-Averaged Model
Predicted Dissolved Oxygen Concentrations (green) and the Dissolved Oxygen
Deficit Caused by Wastewater Treatment Plants (black) Riverine Discharges (blue),
and Sediment Oxygen Demand(pink) at Two Cape Fear Locations (Navassa and
Horseshoe Bend) and one NE Cape Fear Station (Wilmington).
6-23

7. SUMMARY,DISCUSSION,AND CONCLUSIONS
The three-dimensional water quality model EFDC(Environmental Fluid Dynamics Code)
was applied to simulate hydrodynamic and water conditions for the Lower Cape Fear River
Estuary,North Carolina. The model region included the tidally affected portions of the Cape
Fear, Black, and Northeast Cape Fear Rivers near Wilmington,North Carolina, and extended
southward to the mouth of the Cape Fear River near Southport, North Carolina. A multi-agency
monitoring program was used to gather the necessary data to run and calibrate the model. A
fourteen-month period from November 2003 until January 2005 was used for model calibration.
The model was created in such a way so that it separately accounted for the oxygen demanding
loadings to the estuary from the three major rivers, tidal creeks and fringing wetlands within the
estuary, wastewater treatment plant discharges, and sediment oxygen demand within the estuary.
A phased multi-objective calibration procedure was implemented that sought to maximize the
model's fit to multiple water quality constituents. The calibration phasing was accomplished in
such a way that recognized the primary importance of dissolved oxygen prediction. The
calibrated model simulated well the temporal and spatial patterns of dissolved oxygen
concentration within the estuary. Model confirmation testing was performed for a twelve-month
period from January 2005 to January 2006. The model's ability to simulate dissolved oxygen
during the confirmation run was similar to that for the calibration period.
The model was used to investigate the effects of various organic matter and ammonia
load reduction scenarios on the dissolved oxygen concentrations within the estuary. Various
scenarios investigated the system response to reductions in wastewater and watershed loadings.
Of the three primary constituents that contribute to oxygen depletion,only ammonia had a load
that was contributed primarily from the wastewater sources. For organic matter loadings, the
majority of the load was contributed by the incoming rivers and local tidal creeks and wetlands
discharging directly to the estuary. Reducing these watershed loads had a significant impact on
the dissolved concentrations within the estuary. Despite the sensitivity of the system to changes
in these loadings, elimination of violations of the water quality standard for dissolved oxygen(5
mg/L)would require a 70% reduction both in riverine loadings but also a similar reduction in
sediment oxygen demand.
Reducing wastewater loads generally had a smaller,but still noticeable impact on
dissolved oxygen concentrations. Generally the magnitude of the increase in dissolved oxygen
concentration followed the relative importance of the discharge to the overall loading to the
estuary. An additional scenario tested the degree to which parameter variation, in this case
sediment oxygen demand, could change the system's sensitivity to load reductions. This case
demonstrated that the change in DO concentrations for a particular load reduction did not vary
appreciably as the SOD used by the model was changed. Other scenarios investigated the
system's sensitivity,with regard to dissolved oxygen concentrations to changes in the estuary
that might result from dredging of the navigation channel or increases in wastewater treatment
plant loadings up to the maximum permitted values. These two scenarios had a relatively minor
effect on dissolved oxygen concentrations.
7-1

The model was designed to allow for relatively simple specification of additional
scenarios. The results of the scenario tests, strategic choices made in creating the model, and
results from previous modeling work on the estuary(e.g. Tetra Tech 2001), indicate that further
refinement of the benthic flux model is justified. Both this study and the previous modeling
effort demonstrate the significance of benthic fluxes to the overall dissolved oxygen budget.
While special efforts were undertaken to rationally specify the temporal and spatial variation in
SOD,the method by which benthic fluxes are prescribed rather than predicted from a sediment
diagenesis model does limit the predictive ability of this model. For instance, it was recognized
that reductions in river loading would probably also reduce sediment oxygen demand in the long-
term,but with the prescribed SOD there was no way to predict the magnitude of the changes in
SOD, or the time scale of those changes. Also,the monitoring data indicated that spatial
differences in SOD probably exist within the estuary,but the DO monitoring data alone don't
provide sufficient information to rationally prescribe the spatial variation in sediment quality.
The results of the analysis are qualitatively similar to that of the previous modeling study
(Tetra Tech 2001),despite the conceptual differences in the two models. Both models indicate
the importance of the wetland areas within the estuary, even though conceptualization of this
portion of the water body differs between the two models. The previous model only considered
the wetlands to be a sink of dissolved oxygen; consideration of organic matter loadings from
these areas was not considered. In the model described here,the tidal creeks and wetlands were
considered sinks of dissolved oxygen as well as a source of organic matter and freshwater. In the
previous modeling work the "marsh effect"was estimated by completely removing these cells
from the model,which had both water quality and circulation effects. In the modeling work
described here, the effects of the wetlands were lumped together with that of the major rivers that
drain to the estuary. These effects were quantified by varying the loadings from the all of the
riverine and non-point sources, and then observing the resulting effects on dissolved oxygen
concentrations within the estuary. With the analysis done this way, it is not possible to
distinguish between the effect caused by the riverine sources and that from the wetlands and tidal
creeks. One good aspect of this model, however, is that a scenario that looks separately at the
effects of the rivers and the wetlands could be easily formulated and may be warranted in the
future.
It is hoped that the model will be used as a tool for the rational water quality management
of the system. The model was created with the objective of considering all sources of oxygen
demanding waste to the estuary. A second objective was to quantify these sources in such way
so that additional scenario testing would not be overly burdensome. Considering the complexity
of the system, the importance of the natural resource,and the importance of the economy
supported by the estuary's resources, further analysis in the future using this model seems
warranted.
7-2

'eimil Ft(' NCTO ? tJi' 67w/
l
Belnick, Tom N.&wN w+cK wi re - r`€ V i S ed SEM ert
From: Belnick, Tom
Sent: Friday, June 24, 2011 5:37 PM
To: Stallings, Hannah
Cc: Grzyb,Grzyb, No4� rf s EPA fce,v{) fowl
Julie
Subject: NE Brunswick EA
ani peorMa+�4 / ceedi 4o N i'd€3
DWQ# 14356 pP/MtN')Yj h/IVA. erf�ir1.11JM
NPDES Permit# NC0086819 t J �f
NE Brunswick SEPA EA u n/h �� LJ ll+�in Gatti S 4 047(0r
WK Dickson Response Comments dated 6/2/2011 (�31.�Jui /4 i'a'ri 5,JIi).
r4/
Hannah- I have no further comments on this SEPA document. &AY !/
Julie-comments are due to Hannah by 6/27, but I think you will be out. I've left the document in your inbox in case you
want to review the consultant responses.
Tom Belnick
Supervisor, Complex NPDES Permitting Unit
NC DENR/Division of Water Quality
1617 Mail Service Center, Raleigh, NC 27699-1617
(919)-807-6390;fax [phone]
E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be
disclosed to third parties.
•
1

WK
DICI<SON
community infrastructure consultants
June 2, 2011
Ms. Hannah Stallings
NC Division of Water Quality — Planning Section
1617 Mail Service Center
Raleigh, North Carolina 2 7699-1 61 7
RE: Northeast Brunswick Regional Wastewater System Expansion
Brunswick County, North Carolina
WKD Project Number 80465.00.RA
Dear Ms. Stallings:
This letter is in response to design review comments and letter dated May 17, 2011. Original
comments have been noted, followed by our response in bold.
Comment: 1. (NPDES) The facility received speculative limits for a proposed expansion in a
DWQ letter dated May 13, 2009. Since that time, DWQ has gathered
information that has altered what we believe the Cape Fear River can support
over the 20-year planning horizon for this facility. Changes to these speculative
limits include the following:
a. Flow Limits: The applicant has requested speculative limits for several
design flows. Based on the current SEPA proposal, the facility is
planning a phased expansion to 2.475 MGD and 3.8 MGD.
b. Total Suspended Solids (TSS) Limits: The discharge is to Primary
Nursery Area (PNA) waters, which is subject to High Quality Water
requirements per 15A NCAC 26.0224. For expanding discharges, TSS
limits of 10 mg/I (monthly average) and 15 mg/I (daily maximum) must
be implemented for PNAs.
c. Nutrient Limits: Although nutrient limitations (TN and TP) were
originally included in the 2009 speculative letter, there is insufficient
data to support such limits at this time.
Please update the proposed WWTP design and EA to reflect these changes.
Response: We acknowledge the changes to the speculative limits and have revised the
Environmental documents and will include the total suspended solids limit in
the design of the filtration process.
Comment: 2. (NPDES and CG&L) Reclaimed Water Use: Per the January 18, 2011, letter
sent from DWQ to County Manager Marty Lawing (attached), it is expected that
the County construct and operate reclaimed water facilities at its Northeast
Brunswick WWTP. These reclaimed water facilities are being coordinated

1
Ms. Hannah Stallings
June 2, 2011
Page 2
through DWQ's Construction Grants and Loans Section, separate from the
current project.
Response: The County has submitted a reuse plan to Construction Grants and Loans
Section and begun to implement portions of the plan.
Comment: 3. (NPDES) Information presented on pages 6 and 12 about possible infiltration
raises questions that warrant further explanation. While such a system would
normally anticipate about a 10% consumptive loss, it is experiencing greater
than a 40% loss: In the evaluation of loss for July through September 2009, the
WWTP anticipated receiving approximately 2.147 MGD; however, the actual
average flow was only 1.007 MGD. This indicates a possible problem with
effluent leaving the collection system through exfiltration. DWQ is concerned
that there is approximately 1 MGD of potentially untreated effluent that is
unaccounted for.
a. Has the County performed any studies to determine where exfiltration is
occurring? Please explain how the difference in the 2.147 and
1.007 MGD occurs. Is the loss contributing to oxygen consumption in
the lower Cape Fear River system?
b. Is the loss due to consumptive use? Sometimes high consumptive losses
are due to customers on septic systems. Could the County determine
how many non-sewer customers in the system are contributing flow to
the WWTP and how much unaccounted-for water those systems
product? Vardry Austin (919-715-5422, [e-mail])with
the Division of Water Resources can provide the number of septic
customers and unaccounted-for water reported in the local water supply
plans by the relevant systems.
c. Also, the County could discuss water conservation measures to reduce
the use of potable water and consider water audits to check for leaks.
Response: There is no prevailing evidence of significant exfiltration in the collection
systems or transmission system. Approximately 900 residences(189,000 gpd)
are water customers that are not connected to the sewer system.
From review of the water records in the service area, it is apparent that
irrigation significantly impacts the consumptive loss from April through
October. The average water consumption for the year is 1.8 MGD with 1.14
MGD sewer flow. The pattern of water usage increases in April through
October by 21 percent to 2.18 MGD while the sewer usage decreases 10
percent to 1.03 MGD.The pattern for November through March represents
increased sewer(15 percent)as expected in the wet period and significant
decrease in water consumption (-22 percent). As the sewer flow increases as
expected in wet weather season but is not influenced by water consumption,

Ms. Hannah Stallings
June 2, 2011
Page 3
the data supports irrigation as the cause of the high consumptive loss rather
than exfiltration. See attached summary of meter records and graph for
March 2009 through February 2010.
Comment: 4. (NPDES) Page 13, Future Industrial Flow: The EA states the projected industrial
flow includes the planned industrial park and industrial reserve (10% of the
design wastewater flows). How much projected industrial flow was specifically
allotted to the planned industrial park or is that flow included in the 10%
industrial reserve volume?
Response: The industrial park flow is included in the 10% industrial reserve volume. The
projected flow from the planned industrial park is not available.
Comment: 4A. (NPDES) Also, DWQ wants to make certain that the County is aware that
because the estuary is impaired for DO, turbidity, low pH, and copper, nutrient 7
limitations on the proposed discharge may become an issue to address since •
nutrient levels affect the chlorophyll a concentrations, which could adversely ` ¢l�
4)
affect DO levels in the estuary. �It
Response: The County will abide by permit limits per regulatory requirements.
Comment: 5. (US Fish and Wildlife) Continuous monitoring of the waters of the Cape Fear
River will need to be conducted to detect dissolved oxygen levels (especially in
summer months when high temperatures depress dissolved oxygen) as well as
test for nutrients and contaminants as required.
Response: The Cape Fear River is tidally influenced at the Northeast Brunswick WWTP
outfall and north of the outfall. Continuous monitoring of water quality data
from both 'upstream'and 'downstream' is appropriate to create an accurate
representation of the area's water quality conditions and trends. DWQ has
ambient water quality monitoring station locations upstream and downstream
of the outfall. See the attached figure which indicates:two stations within
two miles of the outfall(B9050000 and B9050025), seven additional stations
within five miles(B9020000, B9740000, B903000089050100, B9670000,
B9720000,and B9790000),and eight additional stations within ten miles
(B9013000, B9580000, B9800000, B9820000, B8465000, B9580000,
B9795000, and B9800000). Data collected at these stations should be
sufficient to determine if changes in the Cape Fear River's water quality are
related to the NE Brunswick WWTP's capacity expansion.
Comment: 6. (US Fish and Wildlife) We recommend that existing maintained right-of-ways
be utilized for this project to the maximum extent possible.

Ms. Hannah Stallings
June 2, 2011
Page 4
Response: The transmission system force main design and construction will utilize
existing easements and maintained right-of way to the maxim extent possible.
Comment: 7. (Natural Heritage Program) The Natural Heritage Program has several records
of rare species, significant natural communities, significant natural heritage
areas, and conservation/managed areas either at or close to the project area.
One of the proposed project sites (Phase I — Proposed 3,100 LF of 18" FM)
crosses Sturgeon Creek. Much of the Sturgeon Creek floodplain here (both west
and east) is identified by our Program as the Sturgeon Creek Tidal Wetlands
natural area, of Regional significance (see enclosed map). Several other
proposed construction sites lie close to the State significant Brunswick
River/Cape Fear River Marshes natural area (see map). This is a very large site
that lies just east of the existing WWTP, as well as just east of several projects in
the vicinity of the US 17/74/76 bridge and causeway at Eagle Island.
Response: EA Section D6 revised as follows: as shown in a map provided by the NC
Natural Heritage program and summarized in their review of the 7 March
2011 EA(Appendix H), "The Natural Heritage Program has several records of
rare species, significant natural communities,significant natural heritage
areas,and conservation/managed areas either at or close to the project area,"
including the Sturgeon Creek Tidal Wetlands natural area of Regional
significance and the Brunswick River/Cape Fear River Marshes natural area of
State significance.
Section D13.3 revised as follows• While potential habitat for several
protected species exists, none were observed within or adjacent to the
proposed Phase 1, Phase 2, or transmission system construction areas. A
known element occurrence of shortnose sturgeon exists in the reach of the
Cape Fear River into which the existing outfall discharges,as does an
American alligator element occurrence(see NHP-provided map in Appendix
H).
Comment: 8. (Natural Heritage Program) The Federally Endangered shortnose sturgeon
(Acipenser brevirostrum) and the State Threatened American alligator (Alligator
mississippiensis) occur in the Cape Fear and Brunswick Rivers just east of the
project area. Because of the presence of rare animal species in the waters near
the project area and the crossing of the Sturgeon Creek floodplain/estuary, it is
extremely important that proper sedimentation control be in place during the
construction phases to avoid impact to these natural resources.
Response: EA Section F10.1:To minimize direct impacts to water
resources during project construction, an approved erosion and sedimentation
control plan will be included in the project's final design plans. Ongoing on-

Ms. Hannah Stallings
June 2, 2011
Page 5
site construction inspections will ensure that construction contractors are
following these DENR-approved plans. Permanent stormwater control and
treatment will comply with General Permit NCG110000.
To mitigate secondary and cumulative impacts to water resources the
Participants have enforceable protections(complete language is contained in
Appendix l's DVD):
Comment: 9. (Division of Coastal Management) Wetlands: The EA identifies wetlands
within the project area as "Palustrine forested, Palustrine-shrub and Estuarine
sub-tidal wetlands". Section E.4 of the EA notes that"Temporary wetland
impacts total approximately 0.961 acres and include Palustrine forested,
Palustrine-shrub and Estuarine sub-tidal wetlands". Section E.4 also notes that
there will some direct impacts to "wetlands". However, the type of wetlands to
be impacted is unstated. Along this line, the graphics in the EA do not
distinguish wetlands by their type. We request, for regulatory reasons, that the
EA differentiate wetlands into Section 404 wetlands and "coastal wetlands" to
clarify the nature of wetland impacts. The term "coastal wetlands" is defined in
15A NCAC 07H.0205. We encourage the EA to include a table and graphic
identifying the Section 404 wetlands and "coastal wetlands"and the project's
effect on each of these wetland types.
Response: Table 18 and Figures 3a, 3b, 7a, 7b, 11a,and 11b were modified:
Table 18. Wetland Impacts Total Wetland Impacts
(acres)
Wetland-Type Impact Type Phase I Phase II
WC-Coastal Temporary 0.057
WD-Coastal Temporary 0.291
WE-Coastal Temporary 0.045 0.559
WF-Coastal Temporary 0.066
*as noted above, following a preliminary Jurisdictional Determination,
impacts to Wetland WA were removed from EA Section E.4 and Table 18.
Comment: 10A. (Division of Coastal Management) Mitigation: The EA in some sections of the
EA implies that mitigation is not necessary. While the preceding assertion may
be valid, we would urge caution and clarification in its use. Specifically, if a
permit does not require mitigation that does not mean that the project
proponent cannot offer mitigation to offset adverse impacts. If a project
proponent is not offering to provide mitigation for adverse impacts, it should be
clearly stated.

Ms. Hannah Stallings
June 2, 2011
Page 6
Response: Section F.4... Because no permanent wetland impacts are anticipated,
mitigation is unlikely to be required, pursuant to USACE Nationwide Permit
12. Additionally,adherence to site-specific erosion and sediment control
plans will avoid accidental deposition of erosive material into wetlands and
waters adjacent to construction sites.
Should permit-specific mitigation be required, it shall be provided.
Comment: 10B. (Division of Coastal Management) Section F.4 of the EA makes the statement
that "Permanent direct impacts to wetlands will be well below the threshold
that requires mitigation, pursuant to USACE Nationwide Permit 12." The
preceding statement should not be used to imply that mitigation is something
that is not necessary. The project proponent can offer mitigation. Furthermore,
there is a possibility that other required permits may result in a mitigation
requirement.
Response: Section F.4... Because no permanent wetland impacts are anticipated,
mitigation is unlikely to be required, pursuant to USACE Nationwide Permit
12. Additionally,adherence to site-specific erosion and sediment control
plans will avoid accidental deposition of erosive material into wetlands and
waters adjacent to construction sites.
Should permit-specific mitigation be required, it shall be provided.
Comment: 11. (Division of Coastal Management) Water Resources: Section D.10 of the EA
notes that portions of the Cape Fear River and the Brunswick River are
"impaired" for aquatic life. Section E.10 of the EA, however, did not examine
whether the proposed project would or would not have an effect on the
"impaired" status. However, Section E.12 of the EA does make the assertion
that the discharged water will be higher quality and that this would be
beneficial to aquatic life. We request that the EA make an assessment on
whether the proposed project would have an effect on the "impaired" status.
(We do recognize that there are a variety of factors, besides the proposed
project itself, that would affect the designation of"impaired".)
Response: EA Section E.10.1 revised as follows:
As noted in the Speculative Limits letter,Preliminary results shows(sic]that
the lower dissolved oxygen levels are not significantly affected by the
discharge from Northeast Brunswick County's present outfall. The speculative
limits' higher dissolved oxygen requirements are anticipated to improve the
site's existing conditions.

Ms. Hannah Stallings
June 2, 2011
Page 7
Additionally, Development and Use of a Three Dimensional Water Quality
Model to Predict Dissolved Oxygen Concentrations in the Lower Cape Fear
River Estuary, North Carolina(2009)determined that:
The three scenarios tested had time-averaged flow of 1.65, 4.65 and 15
MGD...Despite the relatively large changes in the assumed wastewater flow,
there were only very small differences in the predicted dissolved Oxygen
concentrations, for summertime conditions in the impaired region. Across the
entire range of dissolved oxygen concentrations, the differences between the
base case and each of the three scenarios were always less than 0.05 mg/L.
An analysis was performed to attribute the observed depletion within the
estuary to riverine loadings of degradable waste, wastewater discharges, and
sediment oxygen demand. It was found that for three sites in the impaired
region during the summer, less than 10% of the dissolved oxygen deficit was
attributable to wastewater discharges. Riverine loadings and sediment oxygen
demand each contributed similar amounts to the remaining 90% of the deficit.
Therefore,the regional WWTP expansion in accordance with the Speculative
Limits, will accommodate new development without further impairment of
the dissolved oxygen level in the Cape Fear River from the wastewater
discharges. Additionally,the removal of failing septic systems within the
service area will increase removal of BOD, nutrients,and fecal coliform
loadings not accounted for in the Speculative Limits.
Note:the DO modeling report's Executive Summary is attached to this
response.
Comment: 12. (Division of Coastal Management) Outstanding Resource Waters:
Section D.10 of the EA does not imply the presence of"Outstanding Resource
Waters" as occurring within the study area. Section F.10 has a review of
permitting requirement related to the presence of"Outstanding Resource
Waters". Assuming that the study area does not contain any "Outstanding
Resource Waters" it would appear that the narrative in Section F.10 would be
unnecessary. We would encourage a review of the EA to assure that it focuses
on the relevant environmental topics raised by the proposed project.
Response: The reference in EA Section F.10.1 that summarized the Coastal Stormwater
Rules'Outstanding Resource Waters development restrictions was removed.

Ms. Hannah Stallings
June 2,2011
Page 8
Above we have summarized the agency review comments received,as well as our responses thereto,
some of which are contained within the body of the revised EA(also enclosed)
Sincerely,
W.K.Dickson&Co., Inc.
T. Carter Hubard, P.E.
Project Manager
4r1h/ar
Senior Environmental Scientist
/pb
Enclosures
cc: Brunswick County Utilities Director,Jerry Pierce, PE

•
Northeast Brunswick Service Area Water Consumption by Meter Records
H2GO Brunswick
Lanvale RR H2G0 Navassa Navassa Industrial Total Water NEB H2GO WWTP Consumptive
Date NW H2GO Lanva (2) Grayson Quality Davis Retail Consumption WWTP WWTP Total Loss
Gal/Mo. Gal/Mo. Gal/Mo. Gal/Mo. Gal/Mo. Gal/Mo. Gal/Mo. GPD GPD GPD GPD
Mar-09 2,764,440 16,205,000 20,468,000 131,340 1,870,760 0 619,850 1,502,121 1,032,100 192,000 1,224,100 19%
Apr-09 2,934,270 18,482,000 24,404,000 126,270 1,673,250 0 399,750 1,714,984 1,124,100 192,000 1,316,100 23%
May-09 3,651,630 22,130,000 31,021,000 472,420 1,970,860 0 485,880 2,133,278 1,027,400 192,000 1,219,400 43%
Jun-09 4,566,180 24,556,000 35,736,000 1,388,690 2,297,310 0 444,110 2,463,868 955,500 192,000 1,147,500 53%
Jul-09 2,209,150 22,129,000 40,562,000 768,220 2,098,290 0 416,910 2,435,128 1,019,300 192,000 1,211,300 50%
Aug-09 3,219,480 17,836,000 34,057,000 607,820 2,101,930 0 358,900 2,077,898 1,011,700 192,000 1,203,700 42%
Sep-09 3,270,100 17,733,000 35,047,000 531,970 2,190,800 0 314,560 2,110,265 989,100 192,000 1,181,100 44%
Oct-09 3,079,360 35,713,000 24,779,000 493,340 1,548,930 17,850 261,720 2,353,329 1,061,900 192,000 1,253,900 47%
Nov-09 2,982,800 14,424,000 18,059,000 317,220 1,470,620 8,870 258,520 1,340,037 1,188,650 192,000 1,380,650 -3%
Dec-09 4,686,640 13,176,000 23,013,000 331,130 1,888,870 11,040 281,170 1,549,566 1,415,200 192,000 1,607,200 -4%
Jan-10 3,871,570 11,507,000 20,321,000 366,130 2,548,510 9,000 280,500 1,389,418 1,405,800 192,000 1,597,800 -15%
Feb-10 3,169,410 10,522,000 19,288,000 405,370 2,022,580 8,640 451,010 1,280,965 1,485,394 192,000_ 1,677,394 -31%
Average 3,367,086_ 18,701,083 27,229,583 494,993 1,973,559 11,080 381,073 1,862,571 1,143,012 192,000 1,335,012 22%
November-March 3,494,972 13,166,800 20,229,800 310,238 1,960,268 11,080 378,210 1,412,421 1,305,429 192,000 1,497,429 -7%
April-October 3,275,739 22,654,143 32,229,429 626,961 1,983,053 NA 383,119 2,184,107 1,027,000 192000 1,219,000 43%
Notes:
Data includes water and sewer data for the Northeast Brunswick Service Area and H2GO service area.
The water consumption pattern indicates I/I gain of 3%in Winter months with 52%increase in irrigation months
Grayson meter had 3 times the average flow in June 2009
Highlighted indicates above average/expected

Total Water Consumption
2,400,000 --WWTP Total
2,200,000
2,000,000 - - — - —
AVG. Water Consumption
1,800,000 -
1,600,000
Nov.-March AVG.Water Consumption
1,400,000 — — —
1,200,000
1,000,000
0 0 0 0 0 0 0 0 0 0
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Ambient Water Quality Monitoring Stations
DICI<SON ®Mlles Brunswick Regional WWTP Service Area
1 inch equals 2 miles Lower Cape Fear River Basin

DEVELOPMENT AND USE OF A THREE-DIMENSIONAL WATER QUALITY MODEL
TO PREDICT DISSOLVED OXYGEN CONCENTRATIONS IN THE LOWER
CAPE FEAR RIVER ESTUARY,NORTH CAROLINA
James D. Bowen, Solomon Negusse,J. Matthew Goodman, Benoit Duclaud,
Mathieu Robin, and Jesslyn Williams
Department of Civil and Environmental Engineering
William States Lee College of Engineering
University of North Carolina at Charlotte
Charlotte,NC 28223
The research on which this report is based was supported by funds provided by the North
Carolina General Assembly through the North Carolina Department of Environment and Natural
Resources.
October 2009

TABLE OF CONTENTS
EXECUTIVE SUMMARY iv
LIST OF FIGURES viii
LIST OF TABLES xiii
1. INTRODUCTION 1-1
1.1 Background 1-1
1.2 Study Objectives 1-2
1.3 Organization of the Study Report 1-3
2. MODEL SETUP 2-1
2.1 Model Description 2-1
2.2 Description of the Lower Cape Fear River Basin 2-3
2.3 Previous Modeling of the Cape Fear River Estuary 2-5
2.4 Model Grid and Bathymetry 2-6
2.5 Monitoring Data Used for Model Setup and Calibration 2-11
3. SPECIFICATION OF MODEL INPUT FILES 3-1
3.1 Riverine and Wetland Inputs 3-1
3.1.1 Flow Specification 3-1
3.1.2 Temperature and Concentration Specification 3-5
3.2 Point Source Inputs 3-8
3.2.1 Flow Specification 3-8
3.2.2 Temperature and Concentration Specification 3-8
3.3 Downstream Boundary Inputs 3-15
3.3.1 Water Surface Elevation Specification 3-15
3.3.2 Temperature and Concentration Specification 3-17
3.4 Benthic Inputs 3-18
3.5 Meteorological Inputs 3-18
4. CALIBRATION 4-1
4.1 Description of the Calibration Time Period 4-1
4.2 Hydrodynamic Model Calibration 4-2
4.2.1 Modeled and Observed Water Surface Elevations 4-4
4.2.2 Modeled and Observed Salinities 4-22
4.3 Temperature Model Calibration 4-30
4.4 Water Quality Model Calibration 4-38
5. MODEL EVALUATION 5-1
5.1 Model Confirmation 5-1
5.2 Sensitivity Testing 5-15
ii

6. SCENARIO TESTING 6-1
6.1 Description of Base and Scenario Cases 6-1
6.2 Effect of Eliminating Wastewater Point Source Loadings 6-1
6.3 Effect of Reducing River, Creek,and Wetland Loadings 6-4
6.4 Effect of Changing Sediment Oxygen Demand 6-6
6.5 Cumulative Effect of Lower Sediment Oxygen Demand and Reduced Loadings from
Rivers, Creeks, and Wetlands 6-8
6.6 Effect of Eliminating Ammonia Inputs from Wastewater Point Sources 6-10
6.7 Effect of Increasing Wastewater Inputs to Maximum Permitted Values 6-12
6.8 Effect of Deepening of the Navigation Channel 6-16
6.9 Effect of Changing Brunswick County Wastewater Loadings 6-18
6.10 Analysis of the Summer Time-Averaged Dissolved Oxygen Deficit in the Impaired
Region 6-20
7. SUMMARY, DISCUSSION, AND CONCLUSIONS 7-1
8. REFERENCES 8-1
Appendix A. Conversion Matrices Used to Create WQPSL.INP Appendix A 1
Appendix B. Grid Files CELL.INP, DXDY.INP, LXLY.INP Appendix B 1
Appendix C. EFDC Control File EFDC.INP for base case run Appendix C 1
Appendix D. EFDC Water Quality Control File,WQ3DWC.INP Appendix D 1
Appendix E. EFDC Benthic Flux Input File, benflux_tser.inp Appendix E 1
iii

EXECUTIVE SUMMARY
An application of the three-dimensional water quality model EFDC (Environmental Fluid
Dynamics Code)was developed for the Lower Cape Fear River Estuary,North Carolina. The
model was used to investigate the effects of various organic matter and ammonia load reduction
scenarios on the dissolved oxygen concentrations within the estuary. The model region included
the tidally affected portions of the Cape Fear, Black,and Northeast Cape Fear Rivers near
Wilmington,North Carolina,and extended southward to the mouth of the Cape Fear River near
Southport,North Carolina.
The model's three-dimensional numerical grid had 1050 horizontal cells and eight
vertical layers. The average horizontal grid size was approximately 600 m; individual cell sizes
ranged from 100 to 1300 m. Cell water depths varied for river and estuary channel cells from 2.5
to 12.5 m. EFDC uses a"sigma"vertical grid so that the water depth within a horizontal cell
was subdivided into eight layers of uniform thicknesses. The model grid included 241 "marsh"
cells that were used to model the off-channel storage of wetlands adjoining the estuary. Flow
boundary conditions were utilized at the upstream riverine boundaries; a radiation-separation
boundary condition was used at the downstream open boundary. Model input data sets and
observed data sets used for calibration and confirmation, and model scenario testing were
developed using observed data gathered from various agencies. The period December 1,2003 to
December 31,2004 was found to have sufficient data to create the necessary model data set for
calibration. An additional model data set using data from January 1 to December 31, 2005 was
used for model confirmation.
The model calibration period(January 1 —December 31, 2004)had streamflows that
were generally below average for the first half of the year, and generally above average for the
latter half of the year. After a storm in early May 2004, streamflows remained below average
until August. The remainder of 2004 and 2005 until the middle of April had streamflows that
were near historical average values. Flows through the summer of 2005 were generally below
average. Dissolved oxygen(DO)concentrations at two stations that were in the impaired region
and had continuous monitors installed in 2004(Navassa and the Northeast Cape Fear at
Wilmington) showed summertime(April 1 —October 31)dissolved oxygen concentrations that
varied between 3 and 7.5 mg/L. At both of these sites the median DO concentration was below
4.5 mg/L and the 25th percentile DO concentration was below 4.1 mg/L. DO concentrations
were generally lower at the Northeast Cape Fear site, and at this site were generally lower near
the bottom of the water column.
Model calibration was performed separately on the hydrodynamic and water quality
submodels. Hydrodynamic model calibration relied heavily on a set of continuous in-situ water
level and water quality monitors that were deployed through the estuary. Hydrodynamic model
calibration consisted primarily of varying the location, width, and bottom roughnesses of shallow
model cells located adjacent to the river and estuary channels. The distribution of these"marsh"
cells utilized information on the location and lateral extent of saltwater marshes and wetland
forests adjoining the estuary. The calibrated hydrodynamic model matched well the attenuation
of the tidal amplitude signal from the estuary mouth to the upstream model boundaries. The
iv

model was also able to simulate to a reasonable extent the time histories of salinities
throughout the estuary.
The twenty-one state variable water quality model available in EFDC included multiple
dissolved and particulate organic carbon constituents, as well as organic and inorganic nutrients,
dissolved oxygen,and three phytoplankton constituents. To adequately characterize the various
organic matter decomposition rates of the riverine and wastewater inputs,both labile and
refractory dissolved organic matter constituents were used. The water quality model considered
inputs from the three riverine sources at the model boundaries,twenty wastewater point source
inputs within the estuary, and fourteen additional point sources that simulated other freshwater
inputs to the estuary from tidal creeks and wetlands. Over the three-year time period(2002-
2005) for which the freshwater and point source loadings were developed,approximately 10%of
the organic matter loading and 50%of the ammonia loading to the estuary came from the twenty
wastewater point sources that discharged directly to the estuary.
The dissolved oxygen model utilized a user specified sediment oxygen demand(SOD)
that could vary spatially and temporally. Both temporal and spatial variation in SOD was utilized
for the model. The temporally variable SOD that was used in this study was based upon an
analysis of the available monitoring data. Temporal variation was modeled according the
observed variation in measured SOD with changes in water temperature during the SOD
measurement. SOD values were then adjusted seasonally according to observed changes in
water temperature in the water body. During calibration it was determined that higher SOD
values should be used for the Northeast Cape Fear. The ratio between these higher SOD values
and the SOD values for remaining portion of the model region was determined during
calibration. Discharge and estuary monitoring data were used to quantify the loadings of organic
matter,nutrients,and dissolved oxygen to the estuary. As part of calibration SOD values were
varied to values above and below the average values from the monitoring program. The
calibrated value was found to be nearly identical to the corresponding value from the monitoring
program.
The calibrated model matched well time histories of observed dissolved oxygen
concentration. Model predictions were compared to over 5200 measured dissolved oxygen
concentrations collected at eighteen sites throughout the estuary. The mean model error was less
than 0.01 mg/L, and the root mean square error was 0.92 mg/L,which corresponded to 13.8%of
the mean value. The correlation r2 was 84.4%. This is an excellent degree of model fit for an
estuarine dissolved oxygen model. Time history comparisons were also made for other
important water quality constituents, such as nitrate+nitrite,orthophosphate,total nitrogen,and
chlorophyll. In each case the model acceptably simulated the spatial and temporal patterns in the
observed data set. A water quality model confirmation test run using input and calibration data
from 2005 showed a similar degree of fit between observed and predicted dissolved oxygen
concentrations. Based upon this work,the calibrated model is considered to be suitable for
conducting scenario tests on the effect of changes in organic matter and ammonia loadings on the
dissolved oxygen concentrations in the estuary.
A number of scenario tests were conducted to investigate the system's sensitivity to
loading changes and other possible changes in the water body. For each scenario,a model run
v

was used to determine the predicted dissolved oxygen concentrations during the summer
period of 2004(April 1 —October 31) within the state designated impaired region of the
estuary. Twice daily dissolved oxygen snapshots were recorded from all eight vertical layers at
eighteen sites within the impaired region. More than twenty separate model runs were made and
compared to the base case to determine how the dissolved oxygen concentrations might vary for
a particular scenario. These eight scenarios were examined:
1. Eliminating wastewater point source loadings
2. Reducing river,creek, and wetland loadings
3. Changing wastewater loadings for various values of sediment oxygen demand
4. Reducing river,creek, and wetland loadings and sediment oxygen demand
5. Eliminating ammonia inputs from wastewater point sources
6. Increasing wastewater inputs to maximum permitted values
7. Deepening of the navigation channel
8. Changing Brunswick County wastewater loadings
Four model runs were made to investigate the effect of completely turning off the
discharges from the wastewater treatment plants. These scenarios were run,not because the
pollutant removals used were considered achievable or advisable,but instead these scenarios
were run to investigate the system's sensitivity to WWTP loads. River,creek,and wetland
inputs were maintained at the base condition levels. It was assumed that organic matter and
ammonia concentrations in the wastewater inputs would be decreased to 0.0 mg/L. When all
WWTP loads were eliminated, the 10th percentile DO concentration increased by approximately
0.3 mg/L, from 4.3 to 4.5 mg/L. The median value DO concentration increased by about 0.10
mg/L, from 5.6 to 5.7 mg/L. Selectively turning off individual WWTP loads, as expected, had a
smaller effect. Turning off the International Paper WWTP had an effect that was roughly 2/3 of
that when all the plants were turned off. Turning off both Wilmington domestic wastewater
treatment plants had an effect that was roughly 1/3 of that when all discharges were turned off.
A fourth scenario considered eliminating the ammonia loading for all wastewater treatment
plants. This scenario increased the dissolved oxygen concentration by about 0.1 mg/L at the 10`h
percentile level.
The impact of changing the loadings that entered the model region from rivers,creeks,
and wetlands were also investigated. Loading reductions of 30%, 50%, or 70%were assumed
for the three river inputs(Cape Fear, Black, and Northeast Cape Fear), and from the fourteen
creeks and wetland inputs in the estuary. To reduce the loadings, flows were maintained at the
observed levels,but concentrations were reduced by 30%, 50%,or 70%. Loadings for the
twenty wastewater point sources were maintained at the levels in the base case scenario. These
load reductions were found to have a significant impact on dissolved oxygen concentrations. At
the 10`h percentile level, DO concentrations for the 30%, 50%,and 70%load reduction increased
by 0.20,0.3,and 0.40 mg/L respectively, from 4.3 mg/1 to either 4.5,4.6 or 4.7 mg/L. Unlike the
other scenarios investigated, this level of increase in DO concentration was maintained at the
higher percentiles. In fact, the median DO concentration was increased to even a greater extent,
increasing from 5.6 to 5.85 mg/L for the 30% load reduction,and from 5.6 to 6.2 mg/L for the
70% load reduction scenario.
vi

Additional water quality model runs were conducted to investigate the sensitivity of the
results to the choice of model kinetic parameters. Because of its relative importance in
determining dissolved oxygen concentrations,the sensitivity analysis focused on the impact of
various choices for the sediment oxygen demand. During calibration it was found that this
parameter had a significant impact on dissolved oxygen concentrations in the estuary. In
addition to the calibrated SOD value(0.4 g/m2/d at 20° C), runs were made at a lower value(0.3
g/m2/d at 20° C)and a higher value(0.5 g/m2/d at 20° C). Model fit to the observed data set was
compared for these three cases. All three cases had similar correlation r2 values(83.4%, 83.4%,
and 84.5%),but on average the low SOD case overpredicted DO concentrations by 0.11 mg/L,
while the high SOD case underpredicted DO concentrations by a similar amount(0.09 mg/L).
The impact of turning off the organic matter and ammonia loadings from all wastewater
treatment plants was investigated for each of these three SOD cases. Each scenario produced a
very similar change in DO concentration when all point sources were turned off. Even though
DO concentrations were changed with the different SOD cases, in each scenario,turning off the
sources increased DO concentrations by approximately 0.25 mg/L at the 10t percentile level. It
is expected that changes in other model parameters would have a similar result. Although
absolute concentrations are affected by changes in parameter values, relative changes in
concentration are less affected by changing parameter values.
An additional set of model runs were conducted to investigate the effect of reducing both
river loading of organic matter and sediment oxygen demand. Three pairs of model runs were
made that reduced river loading or river loading and SOD by 30%, 50%, and 70%, using the
methods described earlier. As expected, a larger effect was seen when both river loading and
SOD were reduced. A 30%reduction raised the 10`h percentile DO concentration from 4.3 to 4.8
mg/L; a 50%reduction raised the 10`h percentile DO concentration to 5.2 mg/L; a 70%reduction
raised the 10`h percentile DO concentration to 5.4 mg/L. In this final case where both river load
and SOD were reduced by 70% from the base case, only about 1%of the model predicted DO
concentrations in the impaired region were less than the water quality standard value of 5.0
mg/L.
The impact of increasing all wastewater treatment plant loadings to the maximum
allowed by permit was also investigated. For cases where both the maximum concentration and
flow were specified,both these values were used in the scenario. In permits with only a load or
concentration limit, the existing flows were maintained,but concentrations were adjusted to
produce the permitted limit. Using these maximum permitted loadings decreased predicted
dissolved concentrations in the impaired region by approximately 0.1 mg/L. This level of
decrease was fairly uniform across the range of predicted concentrations.
The impact of deepening the navigation channel on predicted dissolved oxygen
concentrations in the estuary was also investigated. Model grid files were adjusted to match the
channel deepening plan developed by the Wilmington district of the US Army Corps of
Engineers that will deepen portions of the Cape Fear and Northeast Cape Fear Rivers. It was
found that this deepening would decrease dissolved oxygen concentrations by approximately 0.1
to 0.2 mg/L. The percentage of dissolved oxygen concentrations in the summertime in the
impaired region that would be below 5.0 mg/L would increase slightly with the channel
deepening from 32%to 34%.
vii

Three model scenarios considered the impact of changing the wastewater flow of a single
discharger(Brunswick County wastewater treatment plant). Based on the discharge monitoring
reports for the model period,the base condition had a time-averaged flow of 0.38 MGD. The
three scenarios tested had time-averaged flow of 1.65, 4.65 and 15 MGD. These scenarios
therefore represented the effect of changing the wastewater treatment flow by factors of 4.3,
12.1,and 39.1. Despite the relatively large changes in the assumed wastewater flow,there were
only very small differences in the predicted dissolved oxygen concentrations, for summertime
conditions in the impaired region. Across the entire range of dissolved oxygen concentrations,
the differences between the base case and each of the three scenarios were always less than 0.05
mg/L.
An analysis was performed to attribute the observed oxygen depletion within the estuary
to riverine loadings of degradable waste,wastewater discharges, and sediment oxygen demand.
It was found that for three sites in the impaired region during the summer, less than 10%of the
dissolved oxygen deficit was attributable to wastewater discharges. Riverine loadings and
sediment oxygen demand each contributed similar amounts to the remaining 90%of the deficit.
The report concludes with some recommendations as to additional development of the
model that seems justified. Both this model study and a previous effort demonstrated the
importance of benthic fluxes of oxygen. As this model used a prescribed sediment oxygen
demand, albeit one that varies temporally and spatially, further refinement of the sediment model
seems warranted. In addition, some additional work seems justified to separately consider the
effects of wetland and riverine loadings to dissolved oxygen conditions in the estuary.
viii

ENVIRONMENTAL ASSESSMENT
NORTHEAST BRUNSWICK REGIONAL WASTEWATER SYSTEM
BRUNSWICK COUNTY, NORTH CAROLINA
7 March 2011
Revised: 2 June 2011
Lead Agency Contact:
Hannah Stallings
N.C. Division of Water Quality
Planning Section
1617 Mail Service Center
Raleigh, NC 27699-1617
919-807-6434
Brunswick County Public Utilities: Project Engineer:
Jerry Pierce, PE Carter Hubard, PE
20 Referendum Drive NE WK Dickson & Co., Inc.
PO Box 249 909 Market Street
Bolivia, NC 28422 Wilmington, NC 28401
910-253-2657 919-762-4200
EA Prepared by:
Ward Marotti
WK Dickson & Co., Inc.
720 Corporate Center Dr.
Raleigh, NC 27607
919-782-0495
Project 80465.00.RA

,
TABLE OF CONTENTS
A. PROJECT DESCRIPTION 5
A.1. Existing Systems and Conditions 5
A.2. Proposed WWTP, Treated Wastewater Outfall, and Transmission System Expansion 8
A.3. Project Service Area 9
B. NEED 9
C. ALTERNATIVES ANALYSIS 14
C.1. Alternative 1 — No Action 14
C.2. Alternative 2—Connection to an Existing Regional WWTP 14
C.3. Alternative 3 —Treatment at the Northeast Brunswick WWTP and Disposal by Spray
Irrigation 15
C.4. Alternative 4—Treatment at the Northeast Brunswick WWTP and Disposal by Surface Water
Discharge 17
C.5. Conclusions and Recommendations 18
D. EXISTING ENVIRONMENTAL CHARACTARISTICS OF THE PROJECT AREA 19
D.1. Topography and Geology 19
D.2. Soils 19
D. 3. Land Use 24
D.4. Wetlands 25
D.5. Prime and Unique Farmland 26
D.6. Public Lands and Scenic, Recreational, and State Natural Areas 26
D.7. Areas of Archaeological or Historical Value 27
D.8. Air Quality 27
D.9. Noise Levels 28
D.10. Water Resources 28
D.10.1. Surface Water Resources 28
D.10.2 Groundwater Resourses 30
D.11. Forestry Resources 30
D.12. Shellfish or Fish and Their Habitats 31
D.13. Wildlife, Natural Vegetation and Protected Species 31
D.13.1. Wildlife 31
D.13.2. Natural Vegetation 31
D.13.3. Protected Species 33
E. Predicted Environmental Effects of Project 36
E.1. Topography 36
E.2. Soils 36
E.3. Land Use 37
E.4. Wetlands 37
E. 5. Prime and Unique Farmland 38
E.6. Public Lands and Scenic, Recreational, and State Natural Areas 38
E.7. Areas of Archaeological or Historical Value 38
E.8. Air Quality 38
E.9. Noise Levels 39
E.10. Water Resources 39
E.10.1 Surface Water Resources 39
E.10.2 Groundwater Resources 40
2

E.11. Forestry Resources 41
E.12. Shellfish or Fish and Their Habitats 41
E.13. Wildlife, Natural Vegetation and Protected Species 42
E.14. Introduction of Toxic Substances 42
F. Mitigative Measures 42
F.1. Topography 43
F.2. Soils 45
F.3. Land Use 45
F.4. Wetlands 46
F.5. Prime and Unique Farmland 46
F.6. Public Lands and Scenic, Recreational, and State Natural Areas 46
F.7. Areas of Archaeological or Historical Value 46
F.8. Air Quality 46
F.9. Noise Levels 47
F.10. Water Resources 47
F.10.1 Surface Water Resources 47
F.10.2 Groundwater Resources 56
F.11. Forestry Resources 56
F.12. Shellfish or Fish and Their Habitats 56
F.13. Wildlife, Natural Vegetation and Protected Species 56
F.14. Introduction of Toxic Substances 56
G. Maps
Figure 1. Service Area Boundary
Figure 2. Existing Wastewater Transmission System
Figure 3. Proposed Improvements
Figure 4. Service Area-USGS Topographic Quadrangles
Figure 5. FEMA Floodplains
Figure 6. NRCS Soils
Figure 7. WWTP Zoning
Figure 8. Service Area Zoning
Figure 9. Land Use/Land Cover
Figure 10. NWI Wetlands
Figure 11. Wetland Delineation Boundaries
Figure 12. DWQ Surface Water Use Classifications
H. References
3

Tables:
Table 1. Existing Effluent Limitations(NC0086819)
Table 2. Northeast Brunswick Regional Wastewater Treatment Plant Existing Lines
Table 3. Participants'Current and Phase 1 Allocation
Table 4. Historical Population
Table 5. Population Projection
Table 6. Flow Projections
Table 7. Estimated Cost for Expansion of the West Brunswick Regional Water Reclamation Facility
Table 8. Land Area for Alternative 3 Application Sites
Table 9. Estimated Cost for Alternative 3
Table 10. Estimated Cost for Alternative 4
Table 11. Alternative Cost Summary
Table 12. Soil Series Characteristics
Table 13. Service Area Zoning
Table 14. DAQ 2008 Air Quality Monitoring Data from New Hanover County
Table 15. DWQ Surface Water Use Classifications (service Area)
Table 16. Protected Plant Species in Brunswick County
Table 17. Protected Animal Species in Brunswick County
Table 18. Wetland Impacts
Table 19. Existing Effluent Limitations vs. Speculative Limitations
Appendices:
Appendix A. Speculative Limits Letter
Appendix B. Reclaimed Water Use-Correspondence
Appendix C. Water Consumption and Wastewater Plant Flow
Appendix D. Northeast Brunswick Regional Wastewater Project Sewer Service Agreement
Appendix E. Technical Memorandum— Northeast Area Wastewater Modeling and Evaluations
Appendix F. Engineering Alternatives Analysis— Northeast Brunswick Regional Partners—
Wastewater Treatment Plant Expansion
Appendix G. Public Meeting—Affidavit of Publication and Sign In Sheet
Appendix H. Inter-agency Scoping and EA Review— Letter, Comments, Comment Summaries, and
Responses
Appendix I. Local Ordinances and Land Use Plans
4

A. PROJECT DESCRIPTION
A.1. Existing Systems and Conditions
The Northeast Brunswick Regional Wastewater Treatment Plant(WI/VIP) is located at 10480
Royster Road in Navassa, North Carolina. The WWTP has a National Pollutant Discharge and
Elimination System (NPDES) permitted discharge (NC0086819) capacity of 1.65 million gallons per
day(GPD). The existing facility includes preliminary treatment, biological treatment,filtration,
disinfection, and residuals treatment. The current facility average daily flow is 1.11 million GPD,
which is 67 percent of the design capacity. The treatment facility receives flow directly from the
towns of Leland and Navassa, as well as the City of Northwest,the Town of Sandy Creek, and
portions of unincorporated Brunswick County (Participants). Additionally, the NE Brunswick
Regional WWTP receives flow from Brunswick Regional Water and Sewer (H2GO, formerly North
Brunswick Sanitary District, also a Participant), which serves the Town of Belville and portions of
the Town of Leland. The treatment facility discharges tertiary treated effluent into the Cape Fear
River at a discharge point 1,100 feet east of the WWTP(Figure 1) with the following effluent
limitations.
The Cape Fear River is classified as Class C, impaired for dissolved oxygen, at the point of
discharge. According to the North Carolina Division of Water Quality (DWQ), modeling of the
dissolved oxygen levels in the lower Cape Fear indicate that the dissolved oxygen levels are not
significantly affected by the discharge from the Northeast Brunswick WWTP present outfall. DWQ
has issued speculative limits for a proposed expansion of this facility(Appendix A).
The WWTP's original permit included a reuse force main with planned spray irrigation at
the Magnolia Greens golf course, as well as possible industrial reclaimed water applications. The
Magnolia Greens Golf Course has an irrigation system supplied by groundwater and stormwater.
The existing golf course was planned for reclaimed water but does not have adequate setbacks
from storage ponds to be suitable for compliance with current reclaimed water regulations NCAC
15A 2T Section .0900. The golf course owner has declined to accept and use reclaimed water
(Appendix B).
Table 1. Existing Effluent Limitations(NC0086819)
Effluent Characteristics Limits*
Monthly Weekly Daily
Average Average Maximum
Flow 1.65 MGD
BOD, 5-day, 20° C 5.0 mg/L 7.5 mg/L
(April 1 —October 31)
BOD, 5-day, 20° C 10.0 mg/L 15.0 mg/L
(November 1 -March 31)
Total Suspended Solids 30.0mg/L 45.0 mg/L
NH3 as N 1.0 mg/L 1 3.0 mg/L
(April 1 —October 31)
NH3 as N 2.0 mg/L 6.0 mg/L
(November 1-March 31)
5

Table 1. Existing Effluent Limitations(NC0086819)
Effluent Characteristics Limits*
Monthly Weekly Daily
Average Average Maximum
Total Residual Chlorine 28 pg/L
Fecal Coliform 200/100 mL 400/100 mL
(geometric mean)
Enterococci 35/100 ml
pH 6.0-9.0 standard units
*from 16 January 2007 correspondence, limits valid through 30 November
2011
Current Flow:
The average daily flow at the Northeast Brunswick Regional WWTP in 2009 was 1.11 GPD.
The peak month flow over the same period was 1.452 MGD in December. This flow at the
Northeast Brunswick Regional WWTP includes up to 0.173 MDG of diversion flow from the Belville
WWTP service area. The Belville WWTP(NPDES Permit NC0075540) is owned and operated by
H2GO.
The Bellville WWTP uses the contact stabilization process, has a 0.4 MGD treatment
capacity, and is permitted to discharge up to 0.8 MGD of effluent into the Brunswick River. The
Bellville WWTP operates at approximately 0.192 MGD with 0.173 MGD pumped to the Northeast
Brunswick Regional WWTP. The diversion of flow from the H2GO service area is to assist with
treatment performance of the Bellville WWTP. H2GO has plans to replace the current Belville
WWTP with a new 0.4 MGD WWTP. Flow from this service area that will exceed the capacity of
the Belville 0.4 MGD WWTP in the 20-year period will be diverted to the Northeast Brunswick
Regional WWTP. Therefore, H2GO service area future flows are included in the Northeast
Brunswick Regional WWTP flow projection.
Water consumption data was reviewed to quantify wastewater volume(Appendix C). Water
consumption data for the Participants includes residential, commercial,and industrial users. Water
consumption minus 10 percent of loss is typically considered as the wastewater flow potential. The
Participants'water consumption data, however, does not correlate well with the actual WWTP flows
as the water consumption averages 40 percent higher than wastewater plant flow. The disparity of
water use to actual WWTP flow is greatest in the summer months, which indicates that irrigation
contributes to the consumptive loss. In most of the service area, irrigation is not metered. Also,the
water consumption data includes water customers in the service area served by master municipal
water meters without sewer service available.
Inflow of the system was analyzed based on flow into the Northeast Brunswick WWTP after a
rainfall event on December 25, 2009,of 2.14 inches preceded by five days of little or no
precipitation. Average influent preceding the event was 1.344 MGD. On the day of the rainfall
event, influent was 1.511 MGD. Resulting inflow,therefore, was 0.167 MGD. Based on industrial
flows and population of the service area, inflow per capita was not excessive at 8 GPD per capita.
Infiltration of the system was evaluated by comparing the three wettest months'wastewater
treatment plant flows to expected flows by water consumption. For the months July through
September 2009, average flow was 1.007 MGD. Water billing records for the same period was
2.386 MGD. Standard 10 percent consumption rate is normally applied to the water consumption to
6

estimate expected wastewater flows. However, in this case, the water consumption expected flow is
2.147 MGD which does not correlate with WWTP inflow.
The water consumption data indicates that irrigation and other losses are influencing the
water consumption. Approximately 900 residences (189,000 gpd) are water customers that are not
connected to the sewer system. From review of the water records in the service area, it is apparent
that irrigation significantly impacts the consumptive loss from April through October. The average
water consumption for the year is 1.8 MGD with 1.14 MGD sewer flow. The pattern of water
usage increases in April through October by 21 percent to 2.18 MGD while the sewer usage
decreases 10 percent to 1.03 MGD. The pattern for November through March represents increased
sewer (15 percent) as expected in the wet period and significant decrease in water consumption (-
22 percent). As the sewer flow increases as expected in wet weather season but is not influenced
by water consumption, the data supports irrigation as the cause of the high consumptive loss rather
than exfiltration. See attached summary of meter records and graph for March 2009 through
February 2010 in Appendix F.
Because the actual wastewater flow in this wet period (1.007 MGD) is below both the
average annual flow(1.111 MGD) and the expected wastewater flow, there is no significant
infiltration in the system.
The Participants are actively tracking and pursuing inflow and infiltration reduction to reduce
operating costs. H2GO completed a sanitary sewer evaluation study(SSES) in 2010. Brunswick
County monitors flows and cleans and TVs the collection system. Navassa's Public Works director is
actively working on collection system repair to reduce Ill. Leland has evaluated parts of the gravity
system, installed sewer guards, and has slip-lined areas known to be leaking.
The Northeast Brunswick Regional Wastewater Treatment Plant's transmission system
includes 27.04 miles of force main, 14 pump stations,and 5.75 miles of reuse effluent lines(Figure 2
and Table 2).
Table 2. Northeast Brunswick Regional
Wastewater Transmission System
Diameter Use
Use (in) Length (ft) Length
(mi)
Force Main 3 7,642
4 2,917
6 4,511
8 36,102 27,04
10 53,568
12 24,961
14 1,274
16 11,796
Effluent 8 26,147 5.75
16 4,236
Total 173,155 32.79
7

A.2. Proposed WWTP, Treated Wastewater Outfall, and Transmission System Expansion
The proposed Phase 1 WVVTP expansion will increase the current WWTP's treatment
capacity by 0.825 MGD, from 1.65 MGD (NPDES Permit NC0086819)to 2.475 MGD.
The Phase 1 project will include new:
• Influent screen
• Equalization pump station and tank
• Aeration basin
• Clarifier
• Effluent filter
• UV disinfection system
• Effluent pump replacement
• ATAD residuals treatment
• Parallel effluent line
Effluent piping to the outfall will require approximately 200 feet of existing piping to be
replaced with 24-inch discharge pipe.
When the Phase 1 expansion's 2.475 MGD capacity approaches 70 percent utilization, the
Phase 2 design will begin. The Phase 2 expansion will increase capacity from 2.475 MGD to 3.8
MGD, with a separate treatment facility located on the adjacent County-owned parcel to the west of
the existing plant property. Phase 2 will include the following additional new process components:
• Influent headworks
• Equalization storage tank
• Aeration basin
• Clarifier
• Effluent filter
• UV disinfection
• Effluent pump station
• Residuals treatment
The Participants' 20-year flow projections necessitate WWTP expansion. The Participants'
flow allocations are as follows:
Table 3. Participants'Current Allocations
Participant Current
Brunswick County 6.1%
Town of Leland 45.3%
Town of Navassa 6.4%
City of Northwest 9.1%
H2GO 33.2%
Total (MGD) 1.65
Effluent piping to the outfall will require approximately 200 feet of existing piping within the
existing Brunswick County easement to be replaced with 24-inch discharge pipe. The new outfall
8

piping will accommodate both Phase 1 and Phase 2 discharge.
Additionally, to convey future projected flows, the following transmission system
improvements are planned (Figures 3a-3b):
Phase 1
• 3,300 linear feet of 12-inch force main
• 3,100 linear feet of 18-inch force main
• 1,500 linear feet of 12-inch force main
Phase 2
• 1,200 linear feet of 12-inch force main
• 200 linear feet of 24-incch force main
• 2,700 linear feet of 18-inch force main
The transmission system improvements for Phase I and Phase II will also include the
expansion of the Clairmont pump station. The Clairmont pump station expansion will include
increasing the wetwell capacity by 115 square feet, replacing the 75 horsepower pumps with 85
horsepower pumps, installing variable frequency drives to operate the new pumps. The construction
activities will be within the existing pump station site. The existing Clairmont pump station capacity
will be expanded from 475 gallons per minute to a maximum of 1,650 gpm.
The force main upgrades(Figure 3a)will provide increased force main capacity for future
upgrades of the Commerce and Lincoln School pump stations. Expansion of the pump stations will
include increasing pumping capacity and wetwell storage capacity. Based on the flow projections
the upgrades to these pump stations will increase the pumping capacity to 1,745 gpm in the subject
force main. The wetwell expansion and pump station upgrades will be within the existing pump
station sites.
Other transmission system improvements will be needed to convey wastewater to the
WWTP, but the routes and construction timing have not been finalized.
A.3. Project Service Area
The Northeast Brunswick Regional Wastewater Treatment Plant's service area is
approximately 169 square miles and serves most of northeast Brunswick County, including portions
of Navassa, Leland, Belville, Northwest, and Sandy Creek. It is bound to the north and northeast by
Pender County; to the northwest by Columbus County; to the southwest and south by
unincorporated portions of Brunswick County;to the southeast by unincorporated portions of
Brunswick County and portions of Belville and Leland; and to the east by the Brunswick River(Figure
1). The service area was established to provide regional wastewater treatment to un-served areas or
areas with package treatment facilities and operates under a sewer service agreement(Appendix D).
B. NEED
The Northeast Brunswick WWTP needs to be expanded to eliminate septic tanks in the
service area and to accommodate the rapid residential and commercial development that has
occurred since 2000,which has outpaced the treatment plant's capacity. Currently,the majority of
the residential and commercial properties that are outside of the municipalities in the service area use
septic tank systems for waste disposal. Expanding the WWTP will provide the capacity to serve
unsewered areas and eliminate the existing septic systems.
9

The growth rate in Brunswick County and the Northeast Brunswick Regional Wastewater
System service area exceeded original population expectations for the 2000 to 2009 time period.
The rapid growth is attributable to the region's affordable housing, desirable living conditions, and
proximity to beaches and metropolitan areas. Leland, Navassa, and Belville (all in the service area)
were three top growth municipalities in North Carolina from 2000 to 2009. Brunswick County, as a
whole, also grew rapidly at greater than 46 percent from 2000 to 2009.
Table 4-Historical Population
Census State Municipality Data
Service Area Municipalities 2000 2009
Leland 1,938 13,408
Navassa 479 1,973
Northwest 671 882
Belville 284 1,488
Sandy Creek 246 304
Municipality Total 3,618 18,055
Brunswick County Total 73,141 107,127
Growth rates of the service area municipalities and the County are available from the North
Carolina Office of State Planning. The growth in the project service area during the past 10 years was
due in part to annexation of unincorporated areas. The unincorporated areas do not have defined
population boundaries.
To evaluate the service area population, W. K. Dickson has evaluated the population of the
service area by census tract. The 2000 census tract data for the Northeast Brunswick Service Area
indicates a 2000 population of 16,698. The total of the census data presented for the municipalities
in Table 4 indicates 3,618 people in 2000. Census 2000 data indicates 13,080 in the unincorporated
areas of the service area.
As the area beyond the municipal limits includes new development and unincorporated
areas,the population from the 2000 census data can be used as a baseline to apply growth
projections. The 2009 service area population was estimated by the relation of the service area to
the County population projection. The service area population relation to the total County
population from the 2000 census is 22.6 percent. Applying 22.6 percent factor to the County
population estimate of 107,127 results in a service area population of 24,253 for 2009.
The North Carolina Office of State Planning estimates that the Brunswick County population
will be 173,314 in 2030. Using the planned flows from the participant's current permitted
developments and estimated correlating population,the service area population for the Northeast
Brunswick Regional WWTP is estimated to be 49,877,which is an increase of 24,775 people over
the 20-year period. Because wastewater flows will depend on actual growth in the area, projections
presented herein will need to be periodically revisited and adjusted accordingly.
A comparison of the Office of State Planning estimates for County growth rate and service area
projected growth rate is shown in Table 5.
10

Table 5-Population Projection
Brunswick Project Area Service
County OSP County Estimated Area
Year Population' Growth' Growth' Population
2000 73,756 NA NA 16,698
2009 107,127 4.13% 4.13% 24,253
2010 110,279 2.94% 3.50% 25,102
2011 113,430 2.86% 3.50% 25,980
2012 116,583 2.78% 3.50% 26,890
2013 119,733 2.70% 3.00% 27,696
2014 122,885 2.63% 3.00% 28,527
2015 126,039 2.57% 3.00% 29,383
2016 129,189 2.50% 2.00% 29,971
2017 132,341 2.44% 2.00% 30,570
2018 135,491 2.38% 2.00% 31,182
2019 138,645 2.33% 2.00% 31,805
2020 141,797 2.27% 2.00% 32,441
2021 144,947 2.22% 2.50% 33,252
2022 148,100 2.18% 3.00% 34,250
2023 151,251 2.13% 4.00% 35,620
2024 154,404 2.08% 4.00% 37,045
2025 157,557 2.04% 4.00% 38,527
2026 160,707 2.00% 5.00% 40,453
2027 163,859 1.96% 5.00% 42,476
2028 167,011 1.92% 5.50% 44,812
2029 170,163 1.89% 5.50% 47,276
2030 173,314 1.85% 5.50% 49,877
1 Ref-http://www.osbm.state.nc.us/ncosbm/facts_and_figures/
2 Annual County Growth Rate from OSP data
3Annual Growth Estimated from Participant Planning Projections
Municipal Flow Projection
The municipal flow projection is based on the Division of Water Quality, National Pollution
Discharge Elimination System section, EAA Guidance Document method that includes current flows,
future residential,future commercial,and future industrial flows.
Current Flow:
The flow at the Northeast Brunswick WWTP from the WWTP metering data over the period
February 2009 to January 2010 was 1.111 MGD. The peak month flow over the same period was
1.452 MGD in December. The flow at the Northeast Brunswick WWTP included 0.173 MGD of
diversion flow from the Belville WWTP service area.
11

The Belville WWTP(NPDES Permit NC0075540), which is owned and operated by H2GO,
uses the contact stabilization process, has a 0.4 MGD treatment capacity,and is permitted to
discharge up to 0.8 MGD of effluent into the Brunswick River. The Belville WWTP operates at
approximately 0.192 MGD with 0.173 MGD pumped to the Northeast Brunswick Regional WWTP.
The diversion of flow from the Belville facility service area is to assist with treatment performance of
the Belville WWTP. H2GO has plans to replace the current facility with a new 0.4 MGD WWTP.
Flow from this service area that will exceed the capacity of the Belville 0.4 MGD WWTP will be
diverted to the Northeast Brunswick Regional WWTP in the future. Therefore, H2GO service area
future flows are included in the Northeast Brunswick Regional WWTP flow projection.
Water consumption data was also reviewed for the same period to quantify wastewater
volume(see Appendix E). Water consumption data for the Participants includes residential,
commercial, and industrial users. Water consumption minus 10 percent of loss is typically
considered as the wastewater flow potential. Data from the Participants for water consumption,
however,does not correlate well with the actual WWTP flows as the water consumption averages 40
percent higher than wastewater plant flow. The disparity of water use to actual WWTP flow is
greatest in the summer months,which indicates that irrigation contributes to the consumptive loss.
In most of the service area, irrigation consumption is not metered. Also, the water consumption data
includes master municipal water meters where no sewer service is available.
Inflow of the system was analyzed based on flow into the Northeast Brunswick WWTP after a
rainfall event on December 25, 2009, of 2.14 inches preceded by five days of little or no
precipitation. Average influent preceding the event was 1.344 MGD. On the day of the rainfall
event, influent was 1.511 MGD. Resulting inflow,therefore, was 0.167 MGD. Based on industrial
flows and population of the service area, inflow per capita was not excessive at 8 GPD per capita.
Infiltration of the system was evaluated by comparing the three wettest months wastewater
treatment plant flows to expected flows by water consumption. For the months July through
September 2009, average flow was 1.007 MGD. Water billing records for the same period was
2.386 MGD. Usually a standard 10 percent consumption rate is applied to the water consumption to
estimate expected wastewater flows. However, in this case the water consumption expected flow is
2.147 MGD which indicates that irrigation and other losses are influencing the water consumption.
The water consumption data indicates that irrigation and other losses are influencing the
water consumption. Approximately 900 residences(189,000 gpd) are water customers that are not
connected to the sewer system. From review of the water records in the service area, it is apparent
that irrigation significantly impacts the consumptive loss from April through October. The average
water consumption for the year is 1.8 MGD with 1.14 MGD sewer flow. The pattern of water
usage increases in April through October by 21 percent to 2.18 MGD while the sewer usage
decreases 10 percent to 1.03 MCD. The pattern for November through March represents increased
sewer (15 percent) as expected in the wet period and significant decrease in water consumption (-
22 percent). As the sewer flow increases as expected in wet weather season but is not influenced
by water consumption, the data supports irrigation as the cause of the high consumptive loss rather
than exfiltration. See attached summary of meter records and graph for March 2009 through
February 2010 in Appendix F.
Because the actual wastewater flow in this wet period (1.007 MGD) is below both the
average annual flow(1.111 MGD) and the expected wastewater flow, there is no significant
infiltration in the system.
12

Because the actual wastewater flow in this wet period (1.007 MGD) is below both the average
annual flow(1.111 MGD) and the expected wastewater flow,there was no significant infiltration in
the system.
The participants are actively tracking and pursuing inflow and infiltration reduction to reduce
operating costs. H2GO has completed a sanitary sewer evaluation study(SSES) in 2010. Brunswick
County monitors flows and cleans and TVs the collection system. Navassa's Public Works director is
actively working on collection system repair to reduce I/I. Leland has completed SSES and is
installing sewer guards.
Future Residential Flow:
The projection of future residential flow has been computed by applying 70 GPD per capita
to the increased population over the 20-year period. The resulting flow for an increase of 24,775
people is an additional 1.734 MGD.
Future Commercial Flow:
Per capita commercial flow is projected as 15 GPD per capita. By applying 15 GPD per
capita to the increased population, the resultant additional flow is 0.372 MGD.
Future Industrial Flow:
Future industrial flow in a region is often calculated as 10 percent of the
design wastewater flows excluding Infiltration/Inflow(I/I). In the project
service area,the current industrial water consumption is approximately 10
percent of the design wastewater flow. There is a planned County Industrial
Park on US 74 at the Brunswick County and Columbus County border. For
the future industrial flow projection,we include the planned industrial park
and industrial reserve for the resultant additional flow of 0.515 MGD.The
industrial park flow is included in the 10% industrial reserve volume as the
projected flow from the planned industrial park is not available.
Projected Flow 20-Year:
The resulting total of the current flow, planned industrial flow, estimated increase in
residential and commercial flow, and industrial reserve is tabulated as follows:
Table 6- Flow Projection
Residential Commercial Industrial Total Flow
Year Population (GPD) (GPD) (GPD) (GPD)
2010 25,102 1,207,000 207,000 165,000 1,579,000
2011 25,980 1,268,500 220,178 190,750 1,679,428
2012 26,890 1,332,152 233,818 216,500 1,782,470
2013 27,696 1,388,620 245,919 242,250 1,876,789
13

Table 6- Flow Projection
2014 28,527 1,446,783 258,382 268,000 1,973,165
2015 29,383 1,506,690 271,219 293,750 2,071,660
2016 29,971 1,547,827 280,034 319,500 2,147,361
2017 30,570 1,589,786 289,026 345,250 2,224,061
2018 31,182 1,632,584 298,197 371,000 2,301,781
2019 31,805 1,676,239 307,551 396,750 2,380,540
2020 32,441 1,720,766 317,093 422,500 2,460,359
2021 33,252 1,777,538 329,258 448,250 2,555,047
2022 34,250 1,847,369 344,222 474,000 2,665,590
2023 35,620 1,943,269 364,772 499,750 2,807,790
2024 37,045 2,043,005 386,144 525,500 2,954,649
2025 38,527 2,146,730 408,371 551,250 3,106,351
2026 40,453 2,281,573 437,266 577,000 3,295,839
2027 42,476 2,423,159 467,605 602,750 3,493,514
2028 44,812 2,586,690 502,648 628,500 3,717,837
2029 47,276 2,759,235 539,622 654,250 3,953,107
2030 49,877 2,941,269 578,630 680,000 4,199,899
C. ALTERNATIVES ANALYSIS
Alternatives considered for wastewater treatment and disposal for the projected flows in the
Northeast Brunswick service area include:
1. No Action
2. Connection to an existing wastewater treatment plant
3. Expansion of the Northeast Brunswick Regional WWTP with disposal by spray
irrigation
4. Expansion of the Northeast Brunswick Regional WWTP with disposal by surface
water discharge
C.1. Alternative 1 - No Action
As described in Section B. continued population growth and development in the service
area is anticipated. Without providing centralized wastewater treatment to new residents and
businesses, small "package plants" will be necessary, especially along the rapidly growing US 17
and US 74/76 corridors. These types of systems are not only much less effective at removing
pollutants from wastewater, especially nutrients, but they are much less reliable than regional,
professionally managed and maintained tertiary wastewater treatment plants. For these reasons,
this option is not viable, and is eliminated from further consideration.
C.2. Alternative 2 -Connection to an Existing Regional WWTP
Existing wastewater treatment facilities in the area include the subject Northeast Brunswick
Regional WWTP(located in Navassa), Brunswick County West Regional Reclamation Facility(WRF,
located in Supply), Cape Fear Public Utility Authority(CFPUA) Northside James A. Loughlin WWTP
14

(located in Wilmington), CFPUA Southside M'Kean Maffit WWTP(located in Wilmington), and
H2GO Belville WWTP(located in Belville).
Location of the existing facilities in the region presents a challenge for transmission with long
distances and water body crossings. Also, service at the existing facilities would require expansion of
these facilities. The WRF is about 27 miles from the Northeast Brunswick Regional facilities. The
WRF has recently been expanded from 3 to 6 MGD to serve Oak Island. The CFPUA Northside
WWTP is 5.5 miles from the Northeast Brunswick WWTP and would require crossing of the Cape
Fear River, the Northeast Cape Fear River,and Smith Creek. The CFPUA Northside WWTP has
recently been expanded to 16 MCD to serve the CFPUA existing flows and projected flows. The
CFPUA Southside WWTP is about 11 miles away but would require crossing the Cape Fear River
and construction of a force main along congested road corridors. The Southside WWTP is in design
for expansion to 16 MGD. The H2GO Bellville WWTP is approximately 7 miles from the Northeast
Brunswick WWTP. The H2GO Bellville WWTP has a design capacity of 0.4 MGD, and a 0.8 MGD
permitted discharge capacity.
The CFPUA facilities are planned to serve the CFPUA service area and have limited site area
for expansion. The Belville WWTP does not have adequate area for 2.15 additional treatment
capacity with the current 0.4 MGD WWTP and planned 0.4 MCD WWTP replacement. Therefore
the Brunswick County WRF is the most viable facility for accepting flow with land area available for
expansion to serve the Northeast Brunswick Regional Participants service area.
Expansion of the WRF would include transmission, expansion, and non- discharge disposal.
The associated costs and total present worth are presented in the following table.
Table 7. Estimated Cost for Expansion of the West Brunswick Regional Water Reclamation
Facility
WWTP Expansion $23,330,000
WWTP Disposal Expansion $6,450,000
Transmission from NEB WWTP to other $24,500,000
WWTP
Construction Cost(with 10% contingency) $59,708,000
Land Cost $5,885,000
Professional Services $9,056,000
Present Worth Replacement Cost $403,036
Present Worth Salvage Value $3,782,026
Present Worth Annual O&M $15,276,345
Total Present Worth $94,110,407
C.3. Alternative 3—Treatment at the Northeast Brunswick WWTP and Disposal by Spray
Irrigation
The existing 1.65 MGD Northeast Brunswick facility can readily be expanded. Expansion of
the Northeast Brunswick WWTP to 3.8 MGD can be implemented in two phases as the existing
WWTP configuration is readily expandable to 2.475 and there is area on the property to increase the
Phase 1 capacity with additional 1.325 MGD capacity. The expansion to 2.475 MGD would include
15

improvements to the existing headworks, an equalization basin, common wall oxidation ditch
systems, clarifier, disk filtration,disinfection channel with ultraviolet disinfection, sludge digester,
and additional sludge storage. A site layout plan is included in the project's Engineering Alternatives
Analysis(EAA) (Appendix F).
This alternative considers non-discharge spray application in accordance with 15A NCAC 2T
.0900 for the treated effluent. The planned 20 year facility expansion effluent capacity of 2.15 MGD
was evaluated for non- discharge. In this option, large tracts of land would be used for storage and
spray application of reclaimed water. Brunswick County owns and operates similar facilities that use
drip irrigation at silvaculture sites and golf course irrigation systems for the Water Reclamation
Facility.
W. K. Dickson and Co., Inc. has contacted the industrial facility, DAK Americas (formerly
DuPont), to inquire about the potential for use of reclaimed water. Ms. Elizabeth Wike of DAK
Americas reported that the facility uses withdrawal from the Cape Fear River and has no need for
reclaimed water. No other industrial facilities have expressed the ability and willingness to utilize
reclaimed water in this area.
According to the Soil Survey of Brunswick County, North Carolina(Soil Conservation
Service, USDA, November 1986), predominant soil types for the study area are Baymeade, Murville,
Torhunta, Leon, Norfolk, Blanton,and Mandarin. Each of these soil types has low hydraulic capacity
which affect application rate. By using an application rate to the potential sites of 0.5 inches per
week,the area needed can be calculated as follows:
Table 8- Land Area for Alternative 3 Application Sites
Spray Irrigation
Flow, MGD 2.15
Rate (in/wk.) 0.5
Gal/Acre-Feet 325,851
Area, Acre 1,110
Buffers and Storage 272
Total Land 1,382
Preliminary review indicates five sites that have potential for land application. No site
investigations have been performed, but from review of the Brunswick County Soil Survey and aerial
photography these sites west of the Northeast Brunswick WWTP are undeveloped and have the
potential for high draining characteristics of the Baymeade and Kureb soil types. The total area of
these sites is 1,026 acres, which is not sufficient to dispose of all of the Phase 2 Northeast Brunswick
WWTP effluent. However,for comparison, land application costs for the five sites are evaluated.
Table 9. Estimated Cost for Alternative 3
WWTP Expansion $23,330,000
Transmission to Disposal $5,431,000
Storage and Disposal $8,381,000
16

Construction Cost(with 10% contingency) $40,856,000
Land Cost $5,885,000
Professional Services $6,228,000
Present Worth Replacement Cost $424,137
Present Worth Salvage Value $3,782,026
Present Worth Annual O&M $14,570,659
Total Present Worth $71,745,822
C.4. Alternative 4 —Treatment at the Northeast Brunswick WWTP and Disposal by Surface
Water Discharge
The existing 1.65 MGD Northeast Brunswick facility can readily be expanded and the
discharge increased for disposal into the Cape Fear River. A speculative limits letter has been issued
for expansion to 4.975 MGD.
Expansion of the Northeast Brunswick WWTP to 3.8 MGD can be implemented in two
phases. The existing WWTP configuration is readily expandable to 2.475 with existing piping and
common wall construction adjacent to existing oxidation ditches on the existing Brunswick County
Parcel. The next phase of expansion will involve similar components on an adjacent Brunswick
County property for additional 1.325 MGD capacity. A site layout plan is included in Appendix F.
Associated costs of this alternative for the two phases are as follows:
Table 10. Estimated Cost for Alternative 4
WWTP Expansion $23,330,000
Disposal $829,250
Construction Cost(with 10%contingency) . $26,575,250
Land Cost $0
Professional Services . $4,086,000
Present Worth Replacement Cost $63,159
Present Worth Salvage Value , $3,782,026
Present Work Annual O&M $9,072,215
Total Present Worth $43,578,650
A summary of the three alternatives present worth costs is provided in the following table.
Table 11 -Alternative Cost Summary
Capital and Recurring Costs Alternative 2 Alternative 3 Alternative 4
WWTP Expansion $23,330,000 $23,330,000 $23,330,000
WWTP Disposal Expansion $6,450,000 $5,431,000 $829,250
Transmission from NEB WWTP to other $24,500,000 $8,381,000
WWTP $0
Construction Cost(with 10% contingency) $59,708,000 $40,856,000 $26,575,250
Land Cost $5,885,000 $5,885,000 $0
Professional Services $9,056,000 $6,228,000 $4,086,000
17

Present Worth Replacement Cost $403,036 $424,137 $63,159
Present Worth Salvage Value $3,782,026 $3,782,026 $3,782,026
Present Worth Annual O&M $15,276,345 $14,570,659 $9,072,215
Total Present Worth $94,110,407 $71,745,822 $43,578,650
C.S. Conclusions and Recommendations
The Northeast Brunswick Regional System service area flow allocations and population and
flow projection present the need for wastewater treatment capacity of 4.2 MGD for the 20-year
period. Existing facilities in the region do not have excess capacity or sufficient land area for
expansion. Cost of transmission to other regional facilities becomes prohibitive with the long
distances and water body crossings. Non discharge effluent disposal is limited to the amount of
available well draining soils. The most cost effective and viable alternative for wastewater treatment
in the service area is to expand the existing Northeast Brunswick Regional WWTP to 3.8 MGD since
H2GO plans to maintain 0.4 MGD treatment.
An expansion with utilization of common facilities in the existing facility is the most
expeditious and cost effective initial phase. A Phase 1 expansion can increase the WWTP's treatment
capacity by 0.825 MGD, from 1.65 MGD(NPDES Permit NC0086819) to 2.475 MGD.
When the Phase 1 expansion's capacity approaches 70 percent,the Phase 2 design will
begin. A Phase 2 expansion will increase capacity from 2.475 to 3.8 MGD. The Phase 2 expansion
will occur in the 20 year period. The Phase 2 expansion will on Brunswick County property adjacent
to the existing WWTP.
The planned WWTP expansion will be designed based on the speculative limits provided
and the reclaimed water effluent standards of 15A NCAC 02T.0906. As the reclaimed standards
have reduced limits on total suspended solids and fecal coliform, the design will include processes of
filtration by disk filters and disinfection by ultraviolet radiation to meet the reclaimed water
standards. The design parameters will include nutrient removal and the net loading of oxygen-
demanding substances. The existing Class A biosolids program will be expanded for this project by
additional ATAD process equipment and a biosolids storage tank. The process equipment for
treatment, filtration, disinfection and biosolids treatment will be located on the existing county
parcel.
Considering that nutrient removal and dissolved oxygen content of the surface water
discharge will be regulated for the receiving stream, the preferred alternative is expansion of the
existing Northeast Brunswick Regional WWTP and disposal by surface discharge.
The collection and transmission system for delivery of raw wastewater to the WWTP will be
upgraded for the 20-year projected flows. The existing transmission system will gain capacity by
constructing parallel mains in existing transmission force main easements and pumping system
improvements. The near term known transmission system improvements for Phase 1 include 3,300
linear feet (LF)of 12-inch parallel upgrade of the existing 6-inch force main from behind the existing
strip mall to Navassa Road; 3,100 LF of 18-inch parallel force main along Navassa Road to the north
side of Sturgeon Creek; and 1,500 LF of 12-inch force main from NC Highway 133, along the west
side of State Road 1551, under US 17 to the Clairmont pump station. Other future transmission
18

system improvements will involve similar parallel force mains and pump station upgrades. A
connection to the WWTP for the future transmission upgrade is known to be a 200 LF section of 24-
inch force main on Royster Road at the WWTP; 2,716 LF of 18-inch force main along Royster Road;
and 1,200 LF of 12-inch force main between the Clairmont pump station and the Phase 1 3,300 12
inch force main (behind the existing strip mall). The routing and committed timeframes of the other
improvements are not currently known.
D. EXISTING ENVIRONMENTAL CHARACTARISTICS OF THE PROJECT
AREA
In addition to evaluating existing environmental characteristics of the project area through
on-site reconnaissance and existing publications, a public educational meeting was held on 9 June
2009 in the Town of Leland's Council Chambers. No one except project proponents attended
(Appendix G).
D.1. Topography and Geology
Northeastern Brunswick County is in the Cretaceous Pee Dee formation of the Coastal Plain
physiographic province. This formation consists of sand, clayey sand, and clay that is greenish
gray to olive black. Locally, it can be fossiliferous, glauconitic and calcareous (N.C. Division of
Land Resources, 1985).
Elevations in the project area range from sea level at the Cape Fear River to 20 feet above
mean sea level at the existing WWTP and the western property line. The bottom of the wet ditch
immediately north of the WWTP is 14 feet above mean sea level. Its banks have approximately ten
percent slopes. The Phase 1 and Phase 2 construction areas are relatively flat and sandy. The
service area's elevations range from sea level at the Cape Fear River, to 78 feet above mean sea
level along NC 87, north of Leland (Figure 4a).
FEMA 100 and 500 year flood plains are located along the effluent outfall, and the portions
of the transmission system that cross the unnamed tributary to the Brunswick River and Sturgeon
Creek. None are located within the proposed Phase 1 and Phase 2 expansion areas (Figures 5a-
5b).
D.2. Soils
Soil series in the project construction and service areas include both upland soils suitable for
development and hydric soils unsuitable for construction or for septic systems (Figure 6). Three
soils are mapped within the Phase I and Phase II construction areas(Baymeade, Blanton, and
Mandarin). The transmission system traverses Baymeade fine sand, Blanton fine sand, Baymeade
and Marvyn soils, Chowan silt loam, Foreston loamy fine sand, Muckalee loam, and Pactolus fine
sand.
Baymeade fine sand (Ba).
Baymeade fine sand occurs on low ridges and convex divides. Runoff is slow. It is well
drained, has moderately rapid permeability, and a low available water capacity. The soil is very
strongly acid or strongly acid throughout, unless the soil has been limed. The seasonal high water
table is 4 to 5 feet below the surface. This soil is listed on the National Hydric Soil List(NRCS) and
North Carolina Hydric Soil List as containing up to 10 percent hydric inclusions. Within Brunswick
County, most of the acreage is woodland with the remaining acreage divided between cultivated
crops and urban development. The sandy nature of the soil, seepage, and caving of cut banks are
19

the main limitation. The sandy nature of the soil makes it subject to droughty conditions and wind
erosion.
Wanton fine sand (Bn)
Blanton fine sand occurs on slightly convex interstream divides. Runoff is slow. It is well
drained, has rapid permeability, and a low available water capacity. It is well drained, has
moderately rapid permeability and a low available water capacity. The soil is very strongly acid or
strongly acid throughout, unless the soil has been limed. The seasonal high water table is 5 to 6
feet below the surface. This soil is listed on the National Hydric Soil List(NRCS) and North
Carolina Hydric Soil List as containing up to 5 percent hydric inclusions. Within Brunswick
County, most of the acreage is woodland with a small acreage divided between cultivated crops
and urban development. The sandy nature of the soil, seepage, and caving of cut banks are the
main limitation. The sandy nature of the soil makes it subject to droughty conditions and wind
erosion.
Mandarin fine sand (Ma)
Mandarin fine sand occurs on broad interstream areas and in depressions. Runoff is slow. It
is somewhat poorly drained, has moderate to rapid permeability, and a low available water
capacity. The soil is extremely acid or very strongly acid throughout, unless the soil has been
limed. The seasonal high water table is 1.5 to 3.5 feet below the surface. This soil is listed on the
National Hydric Soil List(NRCS) and North Carolina Hydric Soil List as containing up to 5 percent
hydric inclusions. Within Brunswick County, most of the acreage is woodland with a small acreage
divided between cultivated crops and urban development. This soil is wet in the winter and
droughty in the summer. The major limitations are wetness, seepage, caving of cut banks, and the
sandy nature of the soil.
Within the service area, upland soil map units include Baymeade and Marvyn soils,
Norfolk loamy fine sand, Baymeade fine sand, Bragg fine sandy loam, Pactolus fine sand,
Tomahawk loamy fine sand, Lynchburg fine sandy loam, Foreston loamy fine sand, Goldsboro fine
sandy loam, Blanton fine sand, Mandarin fine sand, Kureb fine sand, and Onslow fine sandy loam
(Figure 6). Brunswick County lists acceptable soils for Rural-Industrial development uses as
Baymeade, Baymeade-Marvin, Bragg, Foreston, Goldsboro, Kureb, Newhan, and Norfolk. The
hydric soils in the project construction and service areas (greater than 50 percent hydric) include
Chowan silt loam, Croatan muck, Dorovan muck, Griffon fine sandy loam, Lafitte muck, Leon fine
sand, Muckalee loam, Murville mucky fine sand, Pantego mucky loam, Rains fine sandy loam,
Torhunta loamy fine sand, Woodington fine sandy loam (NRCS). Additionally, pits, urban land, and
water comprise approximately 1.3 percent of the service area.
Suitability of soils for septic use was identified in the Brunswick County Land Use Plan as
the most important constraint to development. The water table is high throughout much of the
service area, and flood prone areas extensive, as identified on FEMA maps, by the Corps of
Engineers Special Program, and in the composite natural hazards map incorporated in the
Brunswick County Land Use Plan. Large unincorporated areas of the county are, however, not in
flood hazard zones.
20

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Table 12. Soil Series Characteristics
Depth to Seasonal Percentage
Percent Hydric Drainage Surface
Soil Series Symbol Landscape Position Permeability Taxonomic class High Water Table of Service
Slope Class* Class Runoff
(feet) Area
Kureb fine sand KrB 1-8 B Undulating areas Excessively Rapid Slow Spodic > 6.0- 0.5%
Quartzipsamments
Floodplains at
Nearly Moderately Very
Lafitte muck LA A elevations less than 5 Very poorly Typic Haplosaprists 0.0-0.5 0.1%
level Rapid slow
feet above sea level
Broad,smooth
Nearly Rapid to
Leon fine sand Lo A interstream areas and Poorly Slow Aeric Alaquods 0.0-1.0 7.3%
level Moderate
depressions
Lumbee fine Moderately Very
Lu 0-2 — Stream terraces Poorly Typic Ochraquults 0.0-1.5 0.0%
sandy loam high to high slow
Lynchburg fine Nearly Somewhat
sandy loam Ly level B Interstream areas poor) Moderate Slow Aeric Paleaquults 0.5-1.5 2.5%
Y
Mandarin fine Nearly Broad interstream Somewhat Moderate to
Ma B Slow Oxyaquic Alorthods 1.5-3.5 2.5%
sand level areas and depressions poorly rapid
Nearly Floodplains along Very
Muckalee loam Mk A Poorly Moderate Typic Fluvaquents 0.5-1.5 3.9%
level freshwater streams Slow
Murville mucky Very Umbric
Mu Nearly A Depressions in broad Very poorly Rapid 0.0-1.0 6.8%
fine sand level interstream areas Slow Endoaquods
Newham fine Typic
NhE 2-30 — Edges of mainland and Excessively Very Rapid Slow > 6.0- 0.1%
sand,dredged near Cape Fear river Quartzipsamments
Norfolk loamy Convex interstream
fine sand NoB 2-6 B Well Moderate Medium Typic Kandiudults 4.0-6.0 3.4%
divides
Onslow fine Nearly Moderately
On B Along drainage ways Moderate Slow Spodic Paleudults 1.5-3.0 1.0%
sandy loam level Well
22

•
Table 12. Soil Series Characteristics
Depth to Seasonal Percentage
Percent Hydric Drainage Surface
Soil Series Symbol Landscape Position Permeability Taxonomic class High Water Table of Service
Slope Class' Class Runoff
(feet) Area
Moderately
Pactolus fine Slight depressions and well and Aquic
PaA 0-2 B Rapid Slow 1.5-3.0 0.1%
sand on terraces Somewhat Quartzipsamments
poorly
Pantego mucky Nearly Broad interstream
Pn A Very poorly Moderate Slow Umbric Paleaquults 0.0-1.5 3.1%
loam level areas
Broad,smooth
Rains fine sandy Nearly
Ra A interstream areas and Poorly Moderate Slow Typic Paleaquults 0.0-1.0 2.2%
loam level
depression
Moderately
Tomahawk Nearly Low,slightly convex well and Moderately Aquic Arenic
Tm B Slow 1.5-3.0 0.5%
loamy fine sand level ridges Somewhat rapid Hapludults
poorly
Broad interstream
Torhunta loamy Nearly Moderately
To A areas and stream Very poorly Slow Typic Humaquepts 0.5-1.5 8.1%
fine sand level rapid
terraces
Broad,smooth
Woodington fine Nearly Moderately
Wo A interstream areas and Poorly Slow Typic Paleaquults 0.5-1.0 10.5%
sandy loam level rapid
depression
Somewhat
Very low to
Yaupon silty clay Near edges of the poorly to
YaB 0-3 — moderately Slow Aquic Udorthents 2.0-4.0 0.2%
loam mainland moderately
low
well
23

D. 3. Land Use
Aerial photographs indicate that the Phase 1 and Phase 2 WWTP expansion area parcels,
which border the existing WWTP's northern and western fence-lines, were clearcut between 1998
and 2002. Heavy industrial use (waste oil processing and storage) occupies the parcels
immediately east of the existing WWTP.
The WWTP's parcel is zoned Heavy Industrial, as are those to the southeast, east, north,
and west. The parcel immediately south of the WWTP site is zoned Light Industrial, and the ones
approximately 400 feet southwest of the WWTP parcel's southwest corner are zoned R-15 (Low
Density Single-Family Residential). The nearest residential structure is approximately 1,400 feet
west/southwest of the WWTP parcel's southwestern boundary (Figure 7a).
Most of the transmission system is located in rights of way that are not zoned. The Phase 1
12 inch force main traverses Leland Zoning Districts Residential Low Density, and Office and
Industrial. The Phase 2 12 inch force main traverses Leland Zoning District Commercial Business
District — Regional Business (Figure 7b). The balance of the Phase 1 and Phase 2 transmission
system alignments are located in un-zoned rights of way.
The service area's zoning includes:
Table 13. Service Area Zoning
Zonin: Districts Acres Service Area To
Belville
Business Highway District 141.3 0.13%
Central Business District 168.0 0.16%
Industrial District 117.0 0.11%
Multifamil District 18.6 0.02%
Manufactured Homes District 10.1 0.01%
Moderate Density Sin:le-Famil Residential 590.2 0.56%
Brunswick County
Commercial Intensive 2,233.8 2.13%
Commercial Low Densi 1,037.1 0.99%
Conservation and Protection 1,071.0 1.02%
Industrial General 5,936.2 5.67%
Low Densit Residential 2,481.0 2.37%
Medium Densi Residential 2,619.0 2.50%
Medium Density Site Built Residential 3,497.5 3.34%
Militar Installation 608.7 0.58%
Multifamil Residential 10.4 0.01%
Nei:horhood Commercial 105.0 0.10%
Rural Residential 58,916.5 56.30%
40,
Leland
Commercial Business District, General 355.3 0.34%
Commercial Business District, Regional 472.9 0.45%
24

Table 13. Service Area Zoning
Zoning Districts Acres Service Area %
Commercial Trucking District 36.9 0.04%
Conservation District 144.9 0.14%
Multifamily District 821.8 0.79%
Office and Institutional District 186.0 0.18%
Planned Unit Development District 6,682.8 6.39%
Residential District, Low Density 420.2 0.40%
Residential District, Medium Density 715.7 0.68%
Residential District, Medium Density with
Performance 1,509.0 1.44%
Residential Manufactured Home District 85.8 0.08%��
"�.�� `�, >*1-4,- ;;;;, '„�tip: .'�. >. z E s'i��,,,-,*"€$,a ,,y10.72`kr;,t .
Navassa
Conservation & Recreation 314.3 0.30%
General Business 10.2 0.01%
Heavy Industrial 2,447.8 2.34%
Light Industrial 243.9 0.23%
Low Density Single-Family Residential 278.0 0.75%
Moderate Density Single-Family Residential 786.7 0.75%
High Density Single-Family Residential 66.7 0.06%
Multiple-Family Residential 2.0 0.00%
Neighborhood Business 4.1 0.00%
Rural 4,510.5 4..3p1%
`3-� sti'tx
A g l rrt . . Total ''� �'�`U: ,8.26 IAF
Northwest
Agricultural/Forestry District 1,996.7 1.91
Commercial District 3 83.3 0.08%
Light Industrial District 263.1 0.25%
Multiple-Family Residential District 20.6 0.02%
Medium Density Residential 394.0 0.38%
Residential District (15,000 sq. ft.) 1,424.4 1.36%
Total 4.00% ',:
Sandy Creek
Residential 798.6 0.76%
Total 0.76%
Comparison of NCDOT Brunswick County aerial photography (1993, 1998, 2002, 2004,
and 2008) indicates significant increases in residential development over the last 16 years.
Conversion from forest and farmland has been significant along the US 17 and US 74/76 corridors,
especially immediately west of their intersection (e.g. Magnolia Greens and Waterford).
D.4. Wetlands
Wetlands within the project service area consist primary of Palustrine forested, Palustrine
Scrub-shrub and Estuarine sub-tidal wetlands. Over 34,000 acres are mapped as National
Wetlands Inventory (NWI) wetlands within the service area (Figure 10). No NWI wetlands are
• 25

mapped within the WWTP site.
WK Dickson scientists Ward Marotti and Brian Hockett delineated jurisdictional wetlands
within the WWTP and outfall areas during April 2009 and along all six of the proposed
transmission system alignments during August 2010 using the COE Wetlands Delineation Manual
(Environmental Laboratory, 1987) and subsequent regulatory guidance. The WWTP expansion and
outfall areas contain three wetlands. Wetland WA drains west to east through recently harvested,
early successional pine plantation. This wetland appears to be an old "ditch" created to drain
adjacent pine plantation areas. After a preliminary site visit on 28 April, Emily Hughes (Regulatory
Specialist, US Army Corps of Engineers, Wilmington Regulatory Field Office) determined that the
portion of Wetland WA that the proposed access road will traverse (impact) is not a jurisdictional
wetland or water. She agreed that Wetland WC is CAMA-jurisdictional. Because no other impacts
are anticipated in and around the WWTP site, the balance of wetlands shown in figures 3a, 7a, and
11a were not evaluated and are, for purposes of this document, assumed to be jurisdictional.
Wetland WB is located in the WWTP expansion area's northeast corner. It is also
dominated by early successional shrub-scrub vegetation and drains west to east. Wetland WC is
located in the outfall area along the Cape Fear River. It is tidally influenced and dominated by bald
cypress and black gum. Inside the existing, maintained outfall right of way, herbaceous vegetation
dominates. Wetland WD is a tidal marsh located within Sturgeon Creek's floodplain adjacent to
Navassa Road. Wetland WE is a Palustrine forested wetland located on the northwest side of US
Highway 17, approximately 500 feet from the Brunswick River's western bank. Wetland WE
drains northwest to southeast through a bald cypress and black gum forested floodplain. Wetland
WF is located approximately 400 feet south of Wetland WE, south of US Highway 17 and mostly
within its right-of-way. Vegetation within Wetland WF is primarily scrub-shrub (Figures 11a and b).
D.S. Prime and Unique Farmland
Prime farmland soils in the service area include: Foreston loamy fine sand, Goldsboro fine
sandy loam,Johns fine sandy loam, Lumbee fine sandy loam, Norfolk loamy fine sand, and
Onslow fine sandy barns. Leon and Murville series are unique farmland soils, in areas where they
are outside incorporated municipal limits and not already developed (Barnhill, 1986).
No prime or unique farmland soils are present within the WWTP expansion or effluent
outfall areas, or along the transmission system alignments.
D.6. Public Lands and Scenic, Recreational, and State Natural Areas
No public lands, state natural areas, or parks are present on the WWTP site. The Cape Fear
River, into which the outfall discharges, is a Public Trust Water, as is Sturgeon Creek,which the
Phase 1, 18 inch force main traverses.
In addition to the Cape Fear River, Public Trust Waters inside and immediately adjacent to
the service area include: the Brunswick River, Hood Creek, Indian Creek, Welch's Creek, Sturgeon
Creek, Mill Creek,Jacky's Creek, Mallory Creek, and Town Creek.
In the spring of 2008 the Town of Leland opened its first public water access site, the first of
four potentially planned sites. Areas adjacent to Sturgeon Creek(the Sturgeon Creek Tidal
Wetlands)are listed as a significant Natural Heritage Area. This is a rare example of a Tidal
26

Freshwater Marsh (Freshwater Variant) with a cypress-gum canopy. One of North Carolina's few
populations of cypress knee sedge occurs here. This site is privately owned. Davis Creek, north of
Navassa, has a boat ramp and a park with picnic tables, nature trails, and gazebo. Another, in
southwestern Navassa, has a baseball field and tennis courts.
Additionally, as shown in a map provided by the NC Natural Heritage program and
summarized in their review of the 7 March 2011 EA (Appendix H), "The Natural Heritage Program
has several records of rare species, significant natural communities, significant natural heritage
areas, and conservation/managed areas either at or close to the project area," including the
Sturgeon Creek Tidal Wetlands natural area of Regional significance and the Brunswick River/Cape
Fear River Marshes natural area of State significance.
D.7. Areas of Archaeological or Historical Value
No areas of archaeological or historic significance are known to exist on the existing
WWTP site, the proposed Phase 1 and Phase 2 expansion areas, or along the effluent discharge
alignment and outfall locations. By stating that they had "no comment" in response to the project's
scoping letter, the State Historic Preservation Office (SHPO) confirmed this (Appendix H). The
transmission system alignments were not included in the original scoping document, but because
they will be located within existing rights of way and low wet areas, archaeological sites are not
anticipated to be present. No historic sites are located along the alignment, based on State Historic
Preservation Office GIS data.
D.8. Air Quality
The N.C. Division of Air Quality(DAQ) operates no ambient air quality monitoring stations
in Brunswick County, but has four stations in neighboring New Hanover County. Air quality data
collected by DAQ from the New Hanover County stations during 2008 are presented in Table 14.
None of these pollutants exceeds EPA or DAQ standards. Neither Brunswick County nor New
Hanover County has been designated an EPA non-attainment area, and neither currently requires
annual emission testing of automobiles. Surrounding land use is primarily industrial manufacturing.
The nearest residential structure is approximately 1,400 feet west/southwest of the existing WWTP.
Adjacent industrial use includes a used-oil refining company.
Table 14. DAQ 2008 Air Quality Monitoring Data from New Hanover County.
Air Pollutant Number of N.C.Air Quality Standard Observed Maximum Value
Samples (and Period of Average) Value Observed
/Site (and Period of
Average)
Particulate Matter 63/d annual arith. mean 50 ug/m3 17 -
-2.5 microns
Sulfur Dioxide 8,280/c annual arith. mean 0.03 ppm 0.009 —
(SO2)
24-hr 2nd maximum 0.14 ppm 0.027 0.031 (24-hr)
3-hr 2nd maximum 0.5 ppm 0.072 0.125 (3-hr)
Ozone(03) 4,968/b 1-hr.expected
2nd maximum 0.12 ppm 0.081 0.081 (1-hr)
8-hr.expected
27

Table 14. DAQ 2008 Air Quality Monitoring Data from New Hanover County.
Air Pollutant Number of N.C.Air Quality Standard Observed Maximum Value
Samples (and Period of Average) Value Observed
/Site (and Period of
Average)
119/b 2nd maximum 0.08 ppm 0.072 0.073 (8-hr)
Site a = New Hanover County,site number 37-129-0002,6028 Holly Shelter Road.
Site b = New Hanover County,site number 37-129-0006,Highway 421 North.
While ambient odor can occasionally be detected near the WWTP, especially close to the
influent bar screen, no formal odor complaints have been received. The nearby oil refining facility
has received formal odor complaints.
D.9. Noise Levels
Noise is subject to the federal Noise Control Act of 1972 (PL-92-574) and Quiet
Communities Act of 1978 (PL-95-6009) which require standards of compliance and recommend
approaches to abatement for stationary sources such as airports, highways, and industrial facilities.
There are no facilities subject to federal noise regulation in the service area. Noise levels
generated from the existing WWTP are minimal during normal operation. No complaints have
been filed.
D.10. Water Resources
D.10.1. Surface Water Resources
The project area and service area are located in the Cape Fear Watershed in USGS
Cataloging Unit(CU) 03030005 (DWQ Cape Fear River Subbasin 03-06-17). Tablel5 and Figure
12 show the DWQ use classification for all surface waters within the service area. No public raw
water intakes or water supply watersheds are inside the service area.
Table 15. DWQ Surface Water Use Classifications(service Area)
Stream Name DWQ Classification
Alligator Branch C Sw
Banton Branch C Sw
Batarora Branch C Sw
Bay Branch C Sw
Bear Branch C Sw
Beaverdam Swamp C Sw
Big Branch C Sw
Bishop Branch C Sw
Brunswick River SC
Bryant Mill Creek C Sw -
Cape Fear River SC; C Sw
Cartwheel Branch SC Sw
Cherry Tree Prong C Sw
Clabber Branch C Sw
Coffin Branch C Sw
28

Table 15. DWQ Surface Water Use Classifications(service Area)
Cow Pen Branch C Sw
Double Run C Sw
Fox Grape Branch C Sw
From source to Mulberry Branch C Sw
Gapway Creek C Sw
Gapway Swamp C Sw
George Brown Branch C Sw
Goodland Branch C Sw
Grist Mill Branch C Sw
Hood Creek C Sw
Indian Creek C Sw
Jackeys Creek C Sw
Lindscomb Branch C Sw
Little Mallory Creek(Beaverdam Branch) C Sw
Livingston Creek (Broadwater Lake) C Sw
Mallory Creek C Sw
Maple Branch C Sw
McClennen Branch C Sw
Mill Branch C Sw
Mill Creek C Sw
Morgan Branch C Sw
Mulberry Branch C Sw
Neal Branch C Sw
Pasture Pond Branch C Sw
Piney Branch C Sw
Rattlesnake Branch C Sw
Rowell Branch _ C Sw
Skipper Hill Branch C Sw
Sturgeon Creek C Sw
Town Creek(Rattlesnake Branch) C Sw
Turkey Branch C Sw
Waters Branch C Sw
The existing effluent outfall discharges into the Cape Fear River approximately 1.75 miles
upstream of its confluence with Toomer's Creek, and approximately 2.4 miles downstream from
Indian Creek(NCDWQ Assessment Unit (AU) number 18-(63)b). This reach's use classification is
C;SW(freshwaters protected for secondary recreation, fishing, aquatic life including propagation
and survival, and wildlife; waters which have low velocities and other natural characteristics which
are different from adjacent streams) (Figurel2). The Cape Fear Basinwide Water Quality Plan
(2005) data indicate that Low Dissolved Oxygen (DO) was recorded at numerous stations (BA589
= 8.8 percent exceedance, BA639 = 13.8 percent exceedance, and BA640 = percent
exceedance). Nonetheless, no criteria were exceeded for Aquatic Life Assessment and Recreation
Assessments were supporting for all stations. No site-specific data were reported along the waters
that the proposed transmission system traverses.
Other water quality assessment results in the service area included:
•
29

The Brunswick River [18-77] from the source to the Cape Fear River was Impaired for
Aquatic Life because the DO standard was violated in 14.3 percent of samples at BA707. SC
classified waters have a dissolved oxygen standard of 5 mg/I. The pH standard was also violated at
19.6 percent of the samples. The low pH readings could be associated with swamp drainage from
Black and Northeast Cape Fear rivers.
The Cape Fear River [18-(63)a] from International Paper intake to Bryant Mill Creek which
is approximately 3.8 miles is rated as Impaired. This rating is on a monitored basis in the fish
consumption category.
The Cape Fear River [18-(71)a] from Toomers Creek to Snows Cut is rated as Impaired for
aquatic life. Like the Brunswick River, both the (DO) dissolved oxygen and the pH were in
violation. The dissolved oxygen standards were violated at six sample sites(10.4 percent of
samples collected). The pH was also below standards at the same six samples sites. Like in the
Brunswick River, low pH readings may be associated with swamp drainage from the Black and
Northeast Cape Fear rivers.
The Cape Fear River [18-A(71)b]from Snows Cut to Federal Marsh has a rating of
Supporting aquatic life. No criteria were exceeded at sample site BA722, although significant
violations were recorded within the last two years. Kure Beach WWTP(NC0025763) had
violations of total suspended solids (TSS) during the last two years of the assessment period.
Town Creek[18-81] from source to the Cape Fear River is rated as Supporting aquatic life.
D.10.2 Groundwater Resourses
The service area is underlain by salty portions of the Lower Cape Fear, Upper Cape Fear,
and Black Creek aquifers; as well as transitional areas of the Black Creek and Peedee aquifers. The
Castle Hayne Aquifer, which provides drinking water to many areas of southeastern North
Carolina, does not underlie the service area. Because the groundwater that underlies the service
area is salty and/or brackish, it is not used for irrigation or consumption. Groundwater depth in the
service area is variable, based on surficial topography. NC Division of Water Resources data
indicate that typical groundwater depth at the Maco well (CC 3302; USGS ID 341718078092601)
is between 11 and 18 feet below the surface. Similarly, the Town Creek well (DD 33Y1; USGS ID
341018078095501) indicates typical groundwater surface elevation between 10 and 14 feet below
the surface.
D.11. Forestry Resources
Natural communities are described according to the N.C. Natural Heritage Program (NHP)
community classification system (Schafale and Weakley, 1990). Forest types named by other
authors (Box, 1994; Okuda, 1994; Ohno, 1994; Monk et al., 1990; Burk, 1959; Wells, 1928,
1946)are given to more clearly differentiate the community types. Some of the service area is
urban or agricultural land, for which there is no formal classification.
Five upland communities and two floodplain communities occur in the service area.
Upland forested communities present in northeast Brunswick County are determined primarily by
their hydroperiod (Wells, 1928), which is the amount of water beneath the soil surface. The forest
types in the project area are Pine Savanna (Okuda, 1994; Schafale and Weakley, 1990), Southern
Mixed Hardwoods Community both with and without white oak(Monk et al., 1990), and the Xeric
Sandhill Scrub (Box, 1994; Monk et al., 1990; Burk, 1959; Wells, 1928, 1946). The floodplain
30

communities include Tidal Cypress/Gum Swamp (Schafale and Weakley, 1990; Wells, 1928) and
Brackish Marsh (Schafale and Weakley, 1990). Urban and Agricultural is treated as a fifth upland
community type. Section D.3. (Land Use) details the forest resources indicated in USGS's 2004
Land Use/Land Cover dataset. Based on this dataset, approximately 80 percent of the service area
(over 68,000 acres) is occupied by mature forest resources.
The Phase 1 and Phase 2 WWTP sites were timbered between 1998 and 2002 (Google
Earth aerial photography) and are now dominated by early successional hardwoods. The proposed
12-inch Phase 2 force main that will extend northwest from the Clairmont Pump Station will
traverse mature cypress-gum swamp for its entire length (1,200 feet). The balance of the proposed
transmission system improvements do not traverse forested areas.
D.12. Shellfish or Fish and Their Habitats
The Cape Fear and Brunswick rivers and their tributaries in northeastern Brunswick County
have low gradients and sandy substrata. Dominant fishes include the longnose gar (Lepisosteus
osseus), American eel (Anguilla rostrata), shad (Alosa and Dorosoma spp.), carp (Cyprinus carpio),
golden shiner (Notemigonus crysoleucas), ironcolor shiner (Notropis chalybaeus), silver redhorse
(Moxostoma collapsum), creek chubsucker (Erimyzon oblongus), channel catfish (Ictalurus
punctatus), bullheads (Ameiurus spp.), pirate perch (Aphredoderus sayanus), Atlantic needlefish
(Strongylura marina), mosquitofish (Gambusia affinis), white perch (Morone americana), striped
bass (Morone saxatilis), sunfishes (Lepomis spp.), largemouth bass (Micropterus salmoides), black
crappie (Pomoxis nigromaculatus), tessellated darter (Etheostoma olmstedi), and yellow perch
(Perca flavescens).
The portion of the Cape Fear River into which the existing outfall discharges is a Joint
Anadramous Fish Spawning Area. Sturgeon Creek, which the proposed Phase 1-18 inch forcemain
will traverse, is an Inland Anadramous Fish Spawning Area (North Carolina Division of Marine
Fisheries and Wildlife Resources Commission, personal communication).
D.13. Wildlife, Natural Vegetation and Protected Species
D.13.1. Wildlife
Typical wildlife of communities in the Phase 1 and Phase 2 expansion areas, transmission
corridors, and service area(including swamp forests, bottomland forests, and marshes) include the
leopard frog(Rana utricularia), bullfrog(Rana catesbiana), cricket frog(Acris gryllus), rough green
snake (Opheodrys aestiva), redbelly water snake (Nerodia erythrogaster), mud turtle (Kinosternon
subrubrum), snapping turtle (Chelydra serpentina), muskrat (Ondatra zibethicus), marsh rabbit
(Sylvilagus palustris), cotton mouse (Peromyscus gossypinus), mink (Mustela vison), and beaver
(Castor canadensis). Birds observed during the site visits include red-winged blackbird (Agelaius
phoeniceus), great blue heron (Ardea herodias), green heron (Butorides virescens), pileated
woodpecker (Dyrocopus pileatus), red-bellied woodpecker (Melanerpes carolinus), mallard (Anas
platyrhynchos) and wood duck (Aix sponsa). Fiddler crabs (Lica spp.) were abundant in marshes
and often extended well upstream into freshwater swamps.
D.13.2. Natural Vegetation
The Phase 1 and Phase 2 WWTP expansion areas are dominated by early-successional
forest, including: wax myrtle (Myrica cerifera), loblolly pine (Pinus taeda), red maple, sweetgum
31

(Liquidambar styraciflua), water oak(Quercus nigra), persimmon and tulip tree (Liriodendron
tulipifera). The transmission system traverses maintained rights of way, as well as tidal
cypress/gum swamp and brackish marsh, as described below.
Natural vegetation in the service area includes:
Urban and Agricultural Land
Urban and agricultural lands are characterized by a prevalence of non-native vegetation
and wildlife, frequent habitat disturbance, and limited cover. Competition and predation from
domestic or feral animals also reduces habitat quality. Typical native wildlife in these areas
include the eastern bluebird (Sialia sailis), song sparrow (Melospiza melodia), cardinal (Cardinalis),
robin (Turdus migratorius), gray squirrel (Sciurus carolinensis), eastern cottontail (Sylvilagus
floridanus), opossum (Didelphis virginiana) and raccoon (Procyon lotor).
Pine Savanna Community
The Pine Savanna Community(Schafale and Weakley, 1990; Okuda, 1994) is normally
dominated by longleaf pine (Pinus palustris). Common understory shrubs include inkberry (Ilex
glabra), blueberry (Vaccinium spp.), and wax myrtle. Due to timber harvesting and fire
suppression, most savannas in the project area are dominated by loblolly pine, and have a greater
than normal proportion of red maple, sweetgum, water oak, and tulip tree (Liriodendron tulipifera).
Southern Mixed Hardwoods without Quercus
The Southern Mixed Hardwood Forest without Q. alba (Monk et al., 1990) is dominated by
live oak(Quercus virginiana), Darlington's oak (Q. hemispherica), sweetbay(Magnolia virginiana),
and loblolly pine (Pinus taeda). It primarily occurs in the Belville area along NC 133, next to the
Brunswick River. Little of this forest type is left because of intensive logging of live oak for
shipbuilding.
Southern Mixed Hardwoods with Quercus alba
The Southern Mixed Hardwood Forest with Q. alba (Monk et al., 1990) is dominated by
sweetgum,water oak, white oak, American beech (Fagus grandifolia), and loblolly pine.
Understory species include flowering dogwood (Cornus florida) and redbud (Cercis canadensis).
This forest type is ubiquitous on uplands of the service area.
Xeric Sandhill Scrub.
Xeric Sandhill Scrub (Schafale and Weakley, 1990; Monk et al., 1990; Box,1994) is
dominated by longleaf pine and turkey oak(Quercus laevis) and has been shown to occur
primarily on the Norfolk sandy loam soil type (Burk, 1959) and the Baymeade type(Schafale and
Weakley, 1990). This community type occurs in a small wooded lot along Forest Hills Drive in
Leland on Baymeade soil.
Tidal Cypress/Gum Swamp
Tidal Cypress/Gum Swamp (Ohno, 1994; Schafale and Weakley, 1990) is dominated by
bald cypress (Taxodium distichum), swamp gum (Nyssa biflora), and red maple (Acer rubrum), and
is distinctive from all other forest types(Schafale and Weakley, 1990). Understory species include
red bay (Persea palustris), sweetbay(Magnolia virginiana), and wax myrtle (Myrica cerifera). Few
shrubs or herbs occur in this community. This community type occurs along Sturgeon Creek,
Jackey's Creek, Mill Branch, and the Cape Fear River.
32

Brackish Marsh
Brackish Marsh (Schafale and Weakley, 1990) has a mixture of high and low salinity
tolerant vegetation. Where the salinity is low as in an upper estuary, rush (/uncus roemerianus)
predominates, and where the salinity is high, as in lower reaches of the estuary, salt-meadow
cordgrass (Spartina patens) predominates. This community is present along the Brunswick River,
Cape Fear River, and Sturgeon Creek. It grades into a freshwater marsh community upstream of
Navassa Road on Sturgeon Creek.
D.13.3. Protected Species
The U.S. Fish and Wildlife Service (FWS) and N.C. Natural Heritage Program (NHP)
provided information on protected plant and animal species known from Brunswick County.
Protected species include those federally listed as Endangered (E), Threatened (T), or Federal
Species of Concern (FSC), and those species state listed as E, T, or Special Concern (SC).
Eighty-six protected species have been reported in Brunswick county(NHP,July 2009),
including 43 vertebrate animals, 7 invertebrate animals and 36 vascular plant species. Fourteen
species are federally endangered or threatened, including 11 animals and three plants. An
additional 72 species are protected under state law as endangered, threatened, or special concern
(Tables 16 and 17).
Eight of the protected species known from Brunswick County are restricted to ocean
beaches or adjacent marine waters, habitats that do not occur in the construction or service areas.
These include the federally protected loggerhead turtle (Caretta caretta), green seaturtle(Chelonia
mydas), leatherback seaturtle (Dermochelys coriacea), Kemp's Ridley turtle(Lepidochelys kempii),
piping plover (Charadrius melodus), and the state protected gull-billed tern (Sterna nilotica),
American Oystercatcher (Haematopus palliates), and black skimmer (Rynchops niger). These
species will not be affected and are not discussed further.
Table 16. Protected Plant Species in Brunswick County
Common Name Scientific Name State Federal
Status Status
Seabeach Amaranth Amaranthus pumilus T T
Savanna Indigo Bush Amorpha georgiana confusa T FSC
Nutmeg Hickory Carya myristiciformis E —
Florida Scrub Frostweed Crocanthemum nashii E —
Blue Witch Grass Dichanthelium caerulescens E —
Harper's Fimbry Fimbrystylis perpusilla E FSC
Shortleaf Sneezeweed Helenium brevifolium E —
Spring Sneezeweed Helenium vernale E —
Florida Sunflower Helianthus floridanus E —
Thin-wall Quillwort Isoetes microvela E FSC
Carolina Grasswort Lilaeopsis carolinensis T —
Golden-crest Lophiola aurea E —
Rough-leaf Loosestrife Lysimachia asperulifolia E E
Carolina Bogmint Macbridea caroliniana T FSC
Pinebarren Smokegrass Muhlenbergia torreyana E —
Loose Watermilfoil Myriophyllum laxum T FSC
Carolina Grass-of- Parnassus Parnassia caroliniana E FSC
33

Table 16. Protected Plant Species in Brunswick County
Common Name Scientific Name State Federal
Status Status
Large-leaf Grass-of-Parnassus Parnassia grandifolia T FSC
Pineland Plantain Plantago sparsiflora E FSC
Yellow Fringeless Orchid Plantanthera integra T —
Snowy Orchid Plantanthera nivea T —
Sandhills Pyxie-moss Pyxidanthera brevifolia E FSC
Awned Meadow Beauty Rhexia aristosa T FSC
Fragrant Beaksedge Rhynchospora odorata E —
Coastal Beaksedge Rhynchospora pleiantha T FSC
Thorne's Beaksedge Rhyncospora thornei E FSC
Plymouth Rose-Gentain Sabatia kennedyana T-SC —
Hooded Pitcher Plant Sarracenia minor T —
Spring-flowering Goldenrod Solidago verna T FSC
Coastal Goldenrod Solidago villosicarpa E FSC
Giant Spiral Orchid Spiranthes longilabris T —
Wire-leaf Dropseed Sporobolus teretifolius T FSC
Pickering's Dawnflower Stylisma pickeringii var.pickeringii E FSC
Cooley's Meadowrue Thalictrum cooleyi E E
Piedmont Bladderwort Utricularia olivacea T —
Rain Lily Zephyranthes simpsonii E FSC
NC NHP database- updated on Friday,January 9th, 2009.
Table 17. Protected Animal Species in Brunswick County
Common Name Scientific Name State Federal
Status Status
Shortnose Sturgeon Acipenser brevirostrum E E
Bachman's Sparrow Aimophila aestivalis SC FSC
American Alligator Alligator mississippiensis T T
Eastern Henslow's Sparrow Ammodramus henslowii susurrans SC FSC
Loggerhead Seaturtle Caretta caretta T T
Piping Plover Charadrius melodus T T
Wilson's Plover Charadrius wilsonia SC —
Green Seaturtle Chelonia mydas T T
Star-nosed Mole Condylura cristata SC —
Rafinesque's Big-eared Bat Corynorhinus rafinesquii SC FSC
Eastern Diamondback Rattlesnake Crotalus adamanteus E —
Timber Rattlesnake Crotalus horridus SC —
Leatherback Seaturtle Dermochelys coriacea E E
Little Blue Heron Egretta caerulea SC —
Snowy Egret Egretta thula SC —
Tricolored Heron Egretta tricolor SC —
Carolina Pygmy Sunfish Elassoma boehlkei T FSC
Pod Lance Elliptio folliculata SC —
Waccamaw Spike Elliptio waccamawensis E FSC
34

Table 17. Protected Animal Species in Brunswick County
Common Name Scientific Name State Federal
j Status Status
Peregrine Falcon Falco peregrinus E —
Gull-billed Tern Gelochelidon nilotica T —
American Oystercatcher Haematopus palliatus SC —
Bald Eagle Haliaeetus leucocephalus T —
Greenfield Rams-horn Helisoma eucosmium E FSC
Least Killifish Heterandri formosa SC —
Southern Hognose Snake Heterodon simus SC FSC
Least Bittern Ixobrychus exilis SC —
Loggerhead Shrike Lanius ludovicianus SC —
Nothern Yellow Bat Lasiurus intermedius SC —
Kemp's Ridley Seaturtle Lepidochelys kempii E E
Eastern Pondmussel Ligumia nastuta T —
Carolina Diamondback Terrapin Malaclemys terrapin centrata SC —
Eastern Coral Snake Micrurus fulvius E —
Wood Stork Mycteria americana E E
Eastern Woodrat Neotoma floridana T —
Broadtail Madtom Noturus sp. 2 SC FSC
Mimic Glass Lizard Ophiosaurus mimicus SC FSC
Eastern Painted Bunting Passerina ciris ciris SC FSC
Red-cockaded Woodpecker Picoides borealis E E
Northern Pine Snake Pituophis melanoleucas _ SC FSC
Magnificent Rams-Horn Planorbella magnifica E FSC
Glossy Ibis Plegadis falcinellus SC —
Waccamaw Crayfish Procambarus braswelli SC —
Eastern Cougar Puma concolor couguar E E
Carolina Gopher Frog Rana capito T FSC
Black Skimmer Rynchops niger SC —
Pigmy Rattlesnake Sistrurus miliarius SC —
Least Tern Sterrnula antillarum SC —
West Indian Manatee Trichechus manatus E E
Cape Fear Threetooth Triodopsis soelneri T FSC
NC NHP database- updated on Friday,January 9th, 2009.
WK Dickson scientist Ward Marotti surveyed the Phase 1 and Phase 2 construction areas
for protected species and their habitats during October, 2008 and March,June,July, and August,
2009. The transmission system corridors were surveyed during August 2010. Diagnostic features,
habitat requirements, locations of previous sightings, and seasonal limitations for conducting
surveys were compiled from Harper (1944), Dadswell et al. (1984), Chase and Hitchcock (1971),
Fernald (1950), Wilbur (1955), Bassett(1967), Radford et al. (1968), Cooper et al. (1977), Kral
(1977), Martof et al. (1980), Godfrey and Wooten (1981), Duncan and Kartesz (1981), Kral
(1983a,b), Sieren (1984), Webster et al. (1985), LeGrand and Hall (1997), Clark (1987), Adams et
al. (1990), Potter et al. (1990), Parks (1992), Boyer (1994), Brewster (1995), Sorrie (1995), Weakley
(1995), NHP records, and personal communication with agency biologists. Surveys were
conducted where suitable habitat occurs in the project area.
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While potential habitat for several protected species exists, none were observed within or
adjacent to the proposed Phase 1, Phase 2, or transmission system construction areas. A known
element occurrence of shortnose sturgeon exists in the reach of the Cape Fear River into which the
existing outfall discharges, as does an American alligator element occurrence (see NHP-provided
map in Appendix H).
E. Predicted Environmental Effects of Project
E.1. Topography
Because the Phase 1 and Phase 2 WWTP expansion areas are relatively flat, only minimal
grading will be necessary. In order to reduce the slope of the planned access road across the wet
ditch (between the plant site and the equalization basins) some fill will be necessary. Upon
completion, topography along the outfall and transmission system alignments will be returned to
pre-construction conditions. Direct impacts to topography will therefore be minimal.
With the exception of the proposed effluent outfall and the portions of the transmission
system that traverse Sturgeon Creek and the Unnamed Tributary to the Brunswick River, all of the
Phase 1 and Phase 2 construction areas are outside the FEMA floodplains and floodways (Figure 5a
and b). Because the outfall and transmission system will be installed below existing grade and
original slope and contour will be restored, no direct impacts to FEMA floodplains or floodways are
anticipated.
Based on the projections presented in Table 6, the service area's population is expected to
nearly double over the next 20 years,from 25,102 in 2010 to 49,877 in 2030. Brunswick County
Census data(2000) indicates an average of 2.67 residents per household. This equates to 9,279
new residential service connections. While some of these will be new connections to existing
dwellings that currently use septic systems, the majority of new connections will be to new
residences, many of which have already been platted and permitted to connect to the collection
system. Assuming two residences per acre, based on existing and anticipated density, including
associated infrastructure (e.g. roads, bridges, marinas, power transmission/transfer systems, etc.),
disturbance of approximately 7.25 square miles is anticipated. Depending on site-specific design,
and associated grading, cut, fill, and construction, this scale of future development in the service
area will result in secondary and cumulative impacts to topography, geology, floodplains, and
floodways.
E.2. Soils
Direct impact to soils in the Phase 1 construction area will be limited to the approximately
1.0 acre under the proposed equalization tank's access road (70 percent Blanton fine sand and 30
percent Baymeade fine sand) and approximately 10,00 square feet of Baymeade fine sand within
the equalization tank's fence line. Phase 2 will impact approximately 0.5 acre of Mandarin fine
sand and approximately 9.5 acres of Blanton fine sand. Because soils within the new transmission
system alignments (both Phase 1 and Phase 2)will be re-filled with the existing materials (which
will be temporarily"side-cast" during construction) and re-graded to original slope and contour
following installation, permanent impacts to soils within these alignments will not occur.
Based on the approximate disturbance associated with increased population within the
service area (described above in E.1.) secondary and cumulative impacts to soils are anticipated.
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Because not all disturbance will result in the elimination of existing soil conditions (new
impervious surface area will range from less than ten percent, to nearly 70 percent), secondary and
cumulative impacts to soils, resulting from increased impervious area and other fill within the
service area, are anticipated to be between four and six square miles by 2030.
E.3. Land Use
The Phase 1 and Phase 2 sites'zoning(Heavy Industrial) will not be changed as a result of
WWTP expansion. Similarly, existing zoning along the transmission corridors will not change as a
result of construction. Direct impacts to land use are, therefore, not anticipated to result from the
project.
Indirect and cumulative impacts to land use from development served by the project are
likely to exceed direct impacts. Portions of the agricultural, forested, and rural residential lands of
Brunswick County within the service area are likely to be converted to residential, commercial
and/or light industrial uses. The Brunswick County Land Use Plan anticipates that future industrial
development will be primarily concentrated in the northern one-third of the County along the US
17 corridor (Appendix I).
E.4. Wetlands
Because, as stated in Section D.4 above, the portion of wetland WA, where a road crossing
to the equalization storage tank must be installed was determined to be not jurisdictional. No
impacts(temporary or permanent) to wetland WA are, therefore, anticipated. Approximately 0.057
acre of Wetland WC will be impacted during the new outfall's instillation. Because this wetland's
surface is actively maintained and will be returned to original slope and contour following
construction, these impacts will be temporary.
Temporary wetland impacts along the transmission system corridors will result from
clearing a 40 foot wide construction corridor. Temporary wetland impacts total approximately
0.961 acre and include Palustrine forested wetlands, Palustrine scrub-shrub wetlands, and
Estuarine sub-tidal wetlands. Because these corridors are actively maintained, not forested, and will
be returned to original slope and contour, impacts associated with the outfall upgrade construction
and transmission system will be temporary (Table 18).
Table 18. Wetland Impacts Total Wetland Impacts
(acres)
Wetland -Type Impact Type Phase I Phase II
WC-Coastal Temporary 0.057
WD-Coastal Temporary 0.291
WE-Coastal Temporary 0.045 0.559
WF-Coastal Temporary 0.066
As additional areas are developed throughout the service area, secondary and cumulative
impacts to wetlands and waters are likely to occur, especially in the industrial and high density
residential zoning districts, and in locations that will require transportation and other public
infrastructure to cross wetlands and waters. While most of these impacts will be offset through the
US Army Corps of Engineers/NCDWQ 404/401 permitting process, additional impacts to wetland
function and value may result. Typically, this type of impact results from: small-scale projects that
do not have stormwater controls, storm events that exceed stormwater treatment design
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parameters, project sites with inadequately designed and/or maintained stormwater controls, and
violations of stormwater control plans.
E. 5. Prime and Unique Farmland
Because no prime or unique farmland soils are present in the Phase 1 or Phase 2 WWTP
sites, outfall corridor, or along the transmission lines, no direct impacts are anticipated.
Prime and unique farmland soils are typically the "highest" and "driest" Coastal Plain soils.
New residential, commercial, and industrial development is, therefore, likely to result in secondary
and cumulative impacts to these resources in the service area. Based on the disturbance area
assumptions outlined in Section E.1., and assuming that prime and unique farmland soils will
occupy half of new development within the service area, between three and four square miles of
prime and unique farmland soils will be removed from agricultural production within 20 years.
E.6. Public Lands and Scenic, Recreational, and State Natural Areas
Because no public lands, parks, Public Trust Waters, or state natural areas are present
within the Phase 1 or Phase 2 WWTP sites, no direct impacts to these resources are anticipated.
Upgrade of the existing outfall will cause temporary impacts to the Cape Fear River, but after
construction, public access, utilization, and aesthetics will not change. Impacts from the
transmission system are not anticipated. No permanent direct impacts to public lands, scenic,
recreational, and state natural areas are anticipated.
As populations in the service area's incorporated and unincorporated areas increase, so will
those jurisdictions'tax bases. This is likely to provide additional funding for public parks and
recreational facilities. While increased population may result in more frequent visits to protected
natural areas, public education is likely to improve public perception of natural areas' inherent
value. Secondary and cumulative impacts to public lands, scenic, and natural areas is, therefore,
likely to be positive.
E.7. Areas of Archaeological or Historical Value
Pursuant to the State Historical Preservation Office (SHPO) scoping letter (Appendix H), no
areas of archaeological or historical value will be impacted by Phase 1 or Phase 2 WWTP
expansion or the effluent discharge alignment. Because the transmission system is located along
existing, maintained rights of way and low wet areas, impacts to archaeological and historic
resources are not anticipated
E.B. Air Quality
An increase in airborne particulates and exhaust emissions from construction vehicles, as
well as limited open burning of cleared vegetation, is likely to occur during construction. This is
not expected to impact public health. Expansion of the plant will create a minor increase in odor.
Operational air quality impacts of the WWTP will be negligible and comparable to that of the
existing plant. Because additional staff will not be necessary to operate the expanded WWTP,
additional automobile emissions are not anticipated.
Induced urban growth may create long-term increases in air pollutants, primarily from
vehicle traffic. To date, air quality violations have not been problematic in the greater Wilmington
area.
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E.9. Noise Levels
Noise from construction activities will be temporary and will only occur between 8:00 AM
and 6:00 PM Monday through Friday. Once completed, the project will not produce objectionable
levels of noise. Because the nearest residence is approximately 1,400 feet west/southwest of the
WWTP site,and surrounded by mature forest, significant noise levels at this location are not
anticipated. Minor increases in noise levels will occur along transmission system construction
corridors but,once construction is completed, increased noise levels are not anticipated.
Induced urban growth is likely to create long-term increases in noise from construction
activities and increased vehicle traffic.
E.10. Water Resources
E.10.1 Surface Water Resources
Permanent direct impacts to water resources associated with construction are not
anticipated. In addition to the temporary impacts to the Cape Fear River described in Section E.4,
temporary impacts to water quality may result from stormwater runoff caused by significant
precipitation events during construction.
The expanded wastewater treatment plant will discharge tertiary-treated effluent into the
Cape Fear River. Speculative effluent limitations were provided by NC DWQ on 13 May 2009
(Appendix A) and a correction noted in a comment letter dated May 17, 2011. They will result in
an overall reduction of pollutant concentrations discharged into the Cape Fear River. Table 19
compares the existing NPDES Permit NC0086819 limitations with the speculative limits.
Table 19. Existing Effluent Limitations vs. Speculative Limitations
Effluent Limitations(Monthly Average)
Parameter Existing Speculative
BOD, 5-day, 20° 5 mg/L* 5 mg/L
(April 1-October 31)
BOD, 5-day, 20° 10 mg/L
(November 1-March 31)
Total Suspended Solids 30 mg/L 10 mg/L
NH3-N 2 mg/L* 1 mg/L
(April 1-October 31)
NH3-N 2 mg/L
(November 1-March 31)
Dissolved Oxygen > 5 mg/L >_6 mg/L
pH 6-9 6.8-8.5
Enterococci 35 MPN 35/100 mL
Total Residual Chlorine 13,ug/L 13 pg/L
*Seasonal variability not specified in existing permit
As noted in the Speculative Limits letter, Preliminary results shows(sic] that the lower
dissolved oxygen levels are not significantly affected by the discharge from Northeast Brunswick
County's present outfall. The speculative limits' higher dissolved oxygen requirements are
anticipated to improve the site's existing conditions.
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Additionally, Development and Use of a Three Dimensional Water Quality Model to
Predict Dissolved Oxygen Concentrations in the Lower Cape Fear River Estuary, North Carolina
(2009) determined that:
The three scenarios tested had time-averaged flow of 1.65, 4.65 and 15 MGD...Despite the
relatively large changes in the assumed wastewater flow, there were only very small
differences in the predicted dissolved Oxygen concentrations, for summertime conditions
in the impaired region. Across the entire range of dissolved oxygen concentrations, the
differences between the base case and each of the three scenarios were always less than
0.05 mg/L.
An analysis was performed to attribute the observed depletion within the estuary to
riverine loadings of degradable waste, wastewater discharges, and sediment oxygen
demand. It was found that for three sites in the impaired region during the summer, less
than 10% of the dissolved oxygen deficit was attributable to wastewater discharges.
Riverine loadings and sediment oxygen demand each contributed similar amounts to the
remaining 90% of the deficit.
Therefore, the regional WWTP expansion in accordance with the Speculative Limits, will
accommodate new development without further impairment of the dissolved oxygen level in the
Cape Fear River from the wastewater discharges. Additionally, the removal of failing septic
systems within the service area will increase removal of BOD, nutrients, and fecal coliform
loadings not accounted for in the Speculative Limits.
Future urban growth supported by the increased wastewater treatment capacity may
adversely affect surface water quality and quantity through several mechanisms: When forests and
fields are replaced with lawns and impervious surfaces, rainfall infiltration decreases and peak
storm flow rates typically increase, which often exacerbates channel erosion. Base flows during
dry weather can be subsequently reduced, concentrating pollutants and creating high temperature
and low-oxygen problems during the warm months of the year. Typical pollutants in urban
stormwater may include eroded soil, heavy metals, pesticides, fertilizers, solvents, detergents,
petroleum products, vehicle fluids,and trash. Where vegetated riparian buffers are sufficiently
wide and receive diffuse, rather than channelized, stormwater flow, some of this pollution is
trapped or detoxified before reaching surface waters. Stormwater that is channeled through
buffers,either intentionally(pipes or ditches) or unintentionally(erosion gullies) transports most of
its pollutant load directly into surface waters. Riparian forest removal, culverts, dams, drainage
improvements, and poor channel stabilization practices may also contribute to destabilization of
stream channels and water quality degradation. Destabilized streams may aggrade (fill with
sediment) or degrade (downcut).
E.10.2 Groundwater Resources
No direct adverse impacts to groundwater will result from this project.
Septic systems have a limited life span and require ongoing, sometimes costly,
maintenance. Because connection to regional collection systems is often significantly cheaper than
repairing and/or replacing existing septic systems, many existing septic systems are likely to be
retired during this project's 20-year planning period. The service area's significant amount of
sandy soils, as well at its relatively high water table results in significant connection between septic
fields and groundwater. By reducing the number of operating septic fields, the proposed project is
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likely to improve groundwater quality.
North Carolina General Statute 130A-336 prohibits the issuance of on-site septic permits
within areas served by sewer. In order to comply with this, Brunswick County has developed the
following policy:
1. Environmental Health (EH) and Central Permitting(CP)will cease to accept
applications for on-site permits within areas known to be served by sewer. Sewer providing
authorities shall provide EH and CP staff current maps of their designated sewer boundaries and a
list of street names contained in those boundaries. Once such notification has occurred,
designated boundaries shall remain stable until such time as the sewer entity notifies EH and CP of
a change of designated boundaries in writing, and includes a new map and new list of street
names. The Brunswick County Utilities Department shall provide the designation for all sites on all
county sewer collection systems as well as all unincorporated areas.
2. After establishment and notification of designated boundaries all applications for on-site
permits will be checked against the maps and list of street names.
3. Permit applications that fall within the designated boundaries shall not be accepted.
Applicants are to be referred to the particular sewer authority to apply for sewer as required by the
authority.
4. Occasionally, persons applying for a permit within authority designated boundaries may
assert that while their property is located within the authority's designated boundary, sewer service
is not available. In those cases, applicants are to be asked to go to their particular sewer authority
and request a letter stating that they are not currently served by sewer. Once the letter is received
confirming that they are not served by sewer their application for an on-site permit will be
processed by EH and CP in the usual manner.
E.11. Forestry Resources
The areas where Phase 1 (1.25 acres) and Phase 2 (ten acres) WWTP expansion will be
constructed do not contain mature forest resources. Direct impacts to these areas' early
successional forest will result from construction. Similarly, after construction, these areas will be
permanently removed as a forestry resource. Installation of the 12-inch force main from the
Clairmont pump station will result in impacts to no more than 0.559 acre of cypress-gum forest.
Because there is already a 20-30 foot wide corridor adjacent to the existing alignment without
mature trees, the impact of construction activity in this area is minor.
Additional impacts (secondary and cumulative) to forestry resources are likely to result as
forested areas (mature pine and hardwood stands and early-successional stands) within the service
area are cleared and permanently developed.
E.12. Shellfish or Fish and Their Habitats
The project will cause a net increase in wastewater volume discharged into the Cape Fear
and Brunswick rivers, but effluent quality will be higher and total mass loadings of BOD, TSS, and
fecal coliform will decrease, as discussed in section E.10.1. The effect on fish populations, if any,
should be positive, provided erosion and sedimentation control plans associated with plant
expansion and transmission system construction are followed. Should these plans be violated,
impacts to shellfish and/or fish habitats may result. The elimination of failing septic fields should
41

also improve aquatic habitat in small streams throughout the service area.
New development that will be supported by expansion of the wastewater collection system
may result in additional impervious surfaces and stormwater runoff volume. Increasing stormwater
runoff has the potential to impact water quality and habitat both chemically and physically.
Increasing nutrient loadings, for example, can cause eutrophication, which results in hypoxic
conditions and can cause fish kills. Increased sediment loads can eliminate aquatic habitat.
E.13. Wildlife, Natural Vegetation and Protected Species
Because surveys for terrestrial protected species in the proposed Phase 1 and Phase 2
WWTP expansion areas were conducted during all appropriate seasons, as discussed in Section
D.13.3, and none were observed, no direct impacts to terrestrial protected species are anticipated
at these locations. The outfall construction cannot be conducted between February 1 and June 30.
Direct impacts to shortnose sturgeon are therefore not anticipated. Phase 1 and Phase 2
construction will permanently impact approximately 11 acres of early-successional forest.
Common wildlife species associated with this habitat type that will be permanently displaced into
surrounding areas of similar habitat include: Eastern box turtle (Terrapene carolina carolina), green
anole (Anolis carolinensis), black rat snake (Elaphe obsolete obsolete), green treefrog(Hyla
cinerea), common reccoon (Procyon loctor), Eastern gray squirrel (Sciurus niger), and opossum
(Didelphus virginiana). Because most of the new transmission system will be located within
existing rights of way, permanent displacement of common wildlife species and their habitats is not
anticipated. Temporary displacement of these,and other common species is likely to result from
noise, dust, and the presence of equipment during construction.
As the wastewater collection system is expanded, development will increase in the service
area. Secondary and cumulative and impacts to wildlife and natural vegetation are likely to occur
as residential, commercial, and industrial uses replace natural vegetation and wildlife habitat.
While protected species are unlikely to be impacted by individual projects, the cumulative removal
of their habitat may result in less reproductive success and thereby reduced populations.
E.14. Introduction of Toxic Substances
Potential sources of toxic substances during construction include exhaust emissions, oil,
fuel, and other vehicle fluids.
Urbanization may increase toxic substance loading to streams via stormwater. Vehicle
fluids, heavy metals, fertilizers, pesticides, detergents, paint, solvents, and construction materials
contribute to stormwater toxicity.
F. Mitigative Measures
The direct environmental impacts of a project are most often the easiest to quantify and
mitigate. Mitigation for direct impacts is described in each section below.
Additional secondary and cumulative environmental impacts must also be considered.
Secondary impacts generally occur to environmental resources as a result of the project itself, not
just its construction. Secondary impacts from individual projects can also create a cumulative effect
on the area environment. Generally, indirect and cumulative impacts relate to growth or
development pressures that occur as the population moves outward from urban areas to
neighboring rural areas. Local, state and federal laws, regulations and permits are the primary
42

mechanisms for controlling secondary and cumulative impacts. The relevant local regulations are
summarized in the sections below. The full regulatory text is provided on DVD in Appendix I.
F.1. Topography
Compliance with site-specific erosion and sedimentation control plans (including silt fences
and other structures) and grading plans will facilitate the avoidance and minimization of direct
impacts to topography, geology and floodplains.
The following summarizes ordinances that the Participants have in place to avoid and
minimize secondary and cumulative impacts to floodplains. In Sandy Creek and other
municipalities within the service area that do not have local regulations in place that mitigate
secondary and cumulative impacts to natural resources, Brunswick County regulations are
applicable:
Brunswick County:
Flood Damage Prevention Ordinance
This ordinance, which applies to all Special Flood Hazard Areas within the County's jurisdiction
including ETJs, is intended to minimize public and private losses due to flood conditions by
provisions designed to:
o Restrict or prohibit uses that are dangerous due to water or erosion hazards or that result in
damaging increases in erosion, flood heights or velocities;
o Require that uses vulnerable to floods be protected against flood damage at the time of
construction;
o Control the alteration of natural floodplains, stream channels, and natural protective barriers;
o Control filling, grading, dredging, and other development that may increase erosion or flood
damage; and
o Prevent or regulate the construction of flood barriers that will unnaturally divert floodwaters or
which may increase flood hazards to other lands.
This ordinance provides for the issuance of Floodplain Development Permits and provides the
County with the authority to issue violations for non-compliance to these regulations. Variances to
these regulations can be issued if they are deemed to be the minimum requirement necessary to
afford relief of exceptional hardship.
Provisions for hazard reduction in the Special Flood Hazard Areas include the following
requirements for new construction and substantial improvements to existing structures:
o Must be designed (or modified) to prevent flotation, collapse, and lateral movement of the
structure;
o Must be constructed with materials and utility equipment resistant to flood damage;
o Must be constructed using methods and practices that minimize flood damages;
o For residential structures (other than mobile homes) the reference level, including basement,
elevated two (2) feet above base flood elevation;
o For mobile homes the reference level shall be two (2) feet above base flood elevation and they
shall be securely anchored to an adequately anchored foundation to resist flotation, collapse,
and lateral movement as provided by an licensed engineer's certification.
o For non-residential structures the reference level, including basement, elevated no lower than
the regulatory flood protection elevation.
o Utilities including, but not limited to, electrical, HVAC, and appliances shall be designed
and/or located to prevent water from entering or accumulating during conditions of flooding;
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o New and replacement water supply systems shall be designed to minimize or eliminate
infiltration of floodwaters;
o New and replacement sanitary sewage systems shall be designed to minimize or eliminate
infiltration of floodwaters and discharges from the system into flood waters;
o On-site waste disposal systems shall be located and constructed to avoid impairment or
contamination;
o New solid waste disposal facilities and sites, hazardous waste management facilities, salvage
yards, and chemical storage facilities shall not be permitted;
o All subdivision proposals and other development proposals shall be consistent with the need to
minimize flood damage and shall have public utilities located and constructed to minimize
flood damage;
o All subdivision and other development proposals shall have adequate drainage provided to
reduce exposure to flood hazards; and
o All subdivision and other development proposals shall have received all necessary permits for
which approval is required by Federal or State law.
Fully enclosed areas of new construction or substantially improved structures which are below the
lowest floor of an elevated building shall:
o Not be used for human habitation;
o Shall be constructed entirely of flood resistant materials up to the regulatory flood protection
elevation;
o Shall include, in zones required, flood openings to automatically equalize hydrostatic flood
forces on walls as certified by a licensed professional engineer; and
o Shall provide for breakaway walls, open wood latticework, or insect screening in Coastal High
Hazard Areas provided they are not part of the structural support of the building.
In areas where no Base Flood Elevation (BFE) data is available, the following provisions shall apply:
o No encroachments, including fill, new construction, substantial improvements or new
developments within a distance of twenty (20) feet each side from top of bank or five (5) times
the width of the stream whichever is greater, unless certification with supporting technical data
is provided by a registered professional engineer;
o If BFE data is available from other sources,all new construction and substantial improvements
within such areas shall be in accordance with standards in Sections 9.1.4.0 (11 and 12);
o All subdivision, mobile home park, and other development proposals shall provide BFE data if
development is greater than five (5) acres or has more than fifty (50) lots/mobile home sites.
Such BFE data shall be adopted by reference per Section 9.1.3.B; and
o When BFE data is not available from a Federal, State, or other source,the reference level shall
be elevated to at or above the regulatory flood protection elevation.
Leland:
Flood Damage Prevention
This ordinance was established to minimize public and private losses within flood prone
areas within the town and the ETJ, as applicable, by restricting property uses within all special
flood hazard areas that would be subject to increases in erosion, flood heights, or velocities and
which control the alteration of natural floodplains, stream channels and natural protective barriers
which serve to attenuate floodwaters. This ordinance also places controls on filling, grading,
dredging, and other development that may increase erosion or flood damage and regulates the
construction of flood barriers that would divert floodwaters thereby increasing flood hazards to
other areas.
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This ordinance requires a floodplain development permit prior to the commencement of
any development activities within the special flood hazard areas and includes development that
occurs as a result of the extension, conversion, or alteration of existing structures.All new
construction and substantial improvements shall be constructed with materials that are resistant to
flood damage. This includes but is not limited to electrical, heating, ventilation, plumbing, and air
conditioning equipment.
All new and replacement water supply and sanitary sewer systems shall be designed to
minimize or eliminate infiltration of floodwaters into the system. On-site waste disposal systems
shall be located and constructed to avoid impairment to them or contamination from them and
new solid waste disposal facilities and sites, hazardous waste management facilities, salvage yards,
and chemical storage facilities are not permitted.
This ordinance requires elevation certification, relative to established flood hazard areas,
prior to the start of any new construction, and an engineer's certified report if a watercourse in the
special flood hazard area is to be altered or relocated. New construction or substantial
improvement of any residential or non-residential structure, including manufactured homes, shall
have the reference level, including basement, elevated no lower than the regulatory flood
prevention elevation and must be certified by a registered professional engineer or architect.
Manufactured homes must be anchored according to the most current edition of the State of North
Carolina Regulations for Manufactured Homes and requires an engineering certification when
chassis' elevations exceed 36 inches in height.
Within special flood hazard areas where no base flood elevation (BFE) data has been
provided by FEMA, substantial improvements and new development shall not be permitted within
a distance of 20 feet each side from top of bank or five times the width of the stream whichever is
greater unless certification with supporting technical data by a registered professional engineer is
provided. All development, including subdivision and manufactured home parks, shall provide BFE
data if development is greater than five acres or has more than 50 lots/manufactured home sites or
shall indicate the reference level to be above the regulatory flood protection elevation.
Navassa:
Flood Damage Prevention Ordinance
This ordinance outlines the administration of the floodplain development permit and certification
requirements as well as the administration agreement with Brunswick County.
F.2. Soils
Because the required erosion and sedimentation control plans will avoid and minimize
erosion within the Phase 1 and Phase 2 construction areas, sediment deposition outside the
construction areas will be avoided and minimized. Mitigation for impacts to soils will, therefore,
not be necessary.
Compliance with local sediment and erosion control plans and adherence to local zoning
standards will mitigate secondary and cumulative impacts to soils in the service area.
F.3. Land Use
While existing land use in the Phase 1 and Phase 2 construction areas will be permanently
45

changed, the entire site is currently zoned as heavy industrial. This use has been planned for the
area and no mitigation is therefore necessary.
Enforcement of existing zoning ordinances within the service area and compliance with
existing approved land use plans(Appendix I)will mitigate negative secondary and cumulative
land use impacts.
F.4. Wetlands
Because no permanent wetland impacts are anticipated, mitigation is unlikely to be
required, pursuant to USACE Nationwide Permit 12. Additionally, adherence to site-specific
erosion and sediment control plans will avoid accidental deposition of erosive material into
wetlands and waters adjacent to construction sites.
Secondary and cumulative impacts to wetlands will be mitigated through project-specific
USACE and DWQ permitting.
F.5. Prime and Unique Farmland
Because no prime or unique farmland is located within the Phase 1 or Phase 2 construction
areas, no direct impacts will occur and no mitigation will be necessary.
Like Land Use, conforming to the existing, locally approved land use plans and zoning
ordinances will facilitate the avoidance and minimization of impacts to prime and unique farmland
soils.
F.6. Public Lands and Scenic, Recreational, and State Natural Areas
Because no significant impacts to public lands, scenic, recreational, or state natural areas
are anticipated, no mitigation will be necessary.
F.7. Areas of Archaeological or Historical Value
Because no archaeological or historic resources will be impacted, mitigation will not be
necessary.
F.8. Air Quality
To mitigate potential air quality impacts during construction, disturbed soil will be kept
moist to reduce off-site particulate conveyance. Cleared vegetation will be transported to the
County's solid waste disposal facility in Bolivia or chipped on site and applied as mulch. On-site
burning during construction will not be permitted. Because odor control has not been a problem at
the existing WWTP site, additional odor control measures at the expanded plant are not anticipated
to be necessary. If, however, odor control measures become necessary in the future, retrofits will
be selected and installed, as appropriate.
Commercial and industrial growth supported by WWTP expansion will be required to
comply with site/project specific air quality parameters. Should increased automobile volume and
subsequent emissions create air quality issues, Brunswick County will comply with DAQ
requirements for vehicle emission testing.
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F.9. Noise Levels
To minimize noise levels during project construction, outdoor construction activities will
be limited to daylight hours between 8:00 AM and 6:00 PM, Monday through Friday.
Secondary and cumulative noise impacts will be similarly controlled on a site-and project-
specific basis.
F.10. Water Resources
F.10.1 Surface Water Resources
To minimize direct impacts to water resources during project construction, an approved
erosion and sedimentation control plan will be included in the project's final design plans.
Ongoing on-site construction inspections will ensure that construction contractors are following
these DENR-approved plans. Permanent stormwater control and treatment will comply with
General Permit NCG110000.
To mitigate secondary and cumulative impacts to water resources the Participants have the
following enforceable protections (complete language is contained in Appendix l's DVD):
Coastal Stormwater Rules
Required for:
• Nonresidential developments in the Coastal Counties that will
o add more than 10,000 square feet of built upon area
o Require sedimentation and erosion control plan
o CAMA Major Development Permit
• Residential development
o Sedimentation and erosion control plan
o CAMA major development permit
• Sediment and Erosion Control plan if:
o One or more acre of disturbance
Development within 0.5 mile and draining into SA waters:
• Low density, high density, and stormwater discharge requirements (above)
All other development activities:
• Low density
o Built upon area of 24 percent or less
o Stormwater transported primarily by vegetated conveyances, which shall not
include stormwater collection systems
■ Flow through wetlands shall be at non-erosive velocity
o Development contains 50 foot wide vegetative buffer for new development and 30
foot wide buffer for redevelopment. Buffer width is as described under High density
requirements (above)
• High density
o Built upon area of greater than 24 percent
o The development uses control systems that are any combination of infiltration
systems,wet detention ponds, bioretention systems, constructed stormwater
47

wetlands, sand filters, rain barrels, cisterns, rain gardens or alternative stormwater
management systems
o Control systems must be designed to store, control, and treat the stormwater runoff
from all surfaces generated by one and one-half inch of rainfall
o Stormwater runoff from built upon areas that is directed to flow through any
wetlands shall flow into and through these wetlands at a non-erosive velocity
o Development contains 50 foot wide vegetative buffer for new development and 30
foot wide buffer for redevelopment. Buffer width is as described under High density
requirements (above)
Requirements for Structural Stormwater Controls:
• Remove an average of 85% of Total Suspended Solids
• Detention ponds draw down treatment volume no faster than 48 hours(no slower than 120
hours)
• Discharge the storage volume at rate less than or equal to predevelopment discharge rate
for the one-year, 24-hour storm
• Meet the General Engineering Design Crieria set forth in 15A NCAC 02H .1008(c)
• Minimum separation of 2 feet from seasonal high-water table where practicable that require
separation. No minimum separation is required for secondary stormwater BMP used in
series with another stormwater BMP
Coastal Wetlands under 15A NCAC 07H .0205 are not included in calculations for impervious
surface density
Limited residential development within one-half mile of Class SA waters with built upon area
greater than 12%; add more than 10,000 sf of built upon area; do not require a stormwater
management permit under Residential and Non-Residential development(above) can obtain a one-
time, nonrenewable stormwater management permit that requires stormwater runoff to be treated
using some combination of the following:
• Rain cisterns or rain barrels to collect rooftop runoff for first one and one-half inches of rain
installed to facilitate reuse and directing overflow to a vegetated area with uncovered
driveways, parking areas, walkways, and patios to be constructed out of permeable
pavement or other pervious materials
• Rooftop runoff from the first one and one-half inches directed to a rain garden with
uncovered driveways, parking areas, walkways, and patios to be constructed out of
permeable pavement or other pervious materials
• Stormwater best management practice that meets requirements of 15A NCAC 02H .1008 to
control and treat stormwater runoff from built upon areas from the first one and one-half
inches of rain
Exclusions from the requirements for Residential and Non-Residential Development:
• NCDOT activities in accordance with provisions of their NPDES Stormwater Permit
• Development activities conducted under one of the following authorizations:
o State Stormwater Permit issued under the provisions of 15A NCAC 02H .1005
o Stormwater Certification issued under provisions of 15A NCAC 02H .1000 prior to
December 1, 1995
o Coastal Area Management Act Major Permit
o 401 Certification that contains an approved Stormwater Management Plan
48

o Buiding permit subject to G.S. 153A-357 or G.S. 160A-417
o Site-specific development plan as defined by G.S. 153A-344.1(b)(5) and G.S. 160A-
385.1(b)(5)
o Phased development plan approved subject to G.S. 153A-344.1 or G.S. 160A-
385.1 that shows for the initial phase of development the type and intensity of use
for a specific parcel(s) including at a minimum the boundaries of the project and
subdivision plan approved subject to G.S. 153A-330 through G.S. 153A-335 or
G.S. 160A-371 through G.S. 160A-376 and for subsequent phases sufficient detail
so that implementation of the requirements to that phase would require a material
change in the phase of the plan
• A vested right to the development subject to common law
Exemptions from vegetative buffer requirements:
• Development in urban waterfronts that meets requirements of 15A NCAC 07H .0209(g)
• Development in new urban waterfront area that meets requirements of Session Law 2004-
117
• Activities listed in 15A NCAC 07H .0209(d)(10)(A) through 15A NCAC 07H
.0209(d)(10)(H)
• Development of upland marinas that have a Coastal Area Management Act Major Permit
Compliance with other rules
• Activities regulated under the Residential and Non-Residential development must also
comply with requirements of any other applicable law or rule
Designations of local governments with the 20 Coastal Counties that occurred after August 16,
2006 are rescinded; they are not precluded from future designations as Phase 2 municipalities
Brunswick County
Wastewater
The amended section "Mandatory Connection" specifies that owners of developed property that
contain one or more residential dwelling units or commercial establishments that will be served by
existing or newly constructed water and/or wastewater lines are required to connect to the water
and/or wastewater line and to pay the County for that connection according to a fixed fee
schedule. In addition, the owners of the developed property are required to pay the County a
periodic availability charge for the connection to the water and/or wastewater system. Article II of
this ordinance regulates the use of septic tanks and is applicable to the unincorporated portions of
the county unless a municipality has an agreement with the county for the county to enforce its
provisions.
Stormwater Quality Management& Discharge Control Ordinance
This ordinance is intended to protect and enhance the water quality of water courses and water
bodies in a manner consistent with with Federal Clean Water Act by reducing pollutants in
stormwater discharges to maximum extent practicable and by prohibiting nonstormwater
discharges into the storm drain system. This ordinance encourages sustainable development and
site planning that gives special consideration to preserving natural drainage ways, maximizing
infiltration, slowing stormwater runoff through the use of runoff management, structural and
nonstructural best management practices (BMPs), drainage structures, and stormwater facilities.
49

Under this ordinance, the County has the authority to distribute notices of violation and to enforce
penalties, fines up to and including the finding of a misdemeanor with appropriate penalties.
Prior to the start of any development, a stormwater permit must be obtained and is conditional
upon the receipt of a sediment and erosion control permit if one is required. The permit is valid for
one year and assumes that the extent of the development remains consistent with that detailed in
the permit applications. Significant changes to the development plan void the permit and require
the issuance of a new permit. The County may adopt requirements identifying appropriate BMPs to
control the volume, rate, and potential pollutant load of stormwater runoff from new development
and redevelopment. Any such requirements are incorporated into land use entitlement,
construction, or building-related permits.
This ordinance identifies the parameters under which a stormwater management plan is required
prior to the commencement of development and includes all commercial and industrial and other
non-residential development as well as any major subdivision development as defined in the
Brunswick County Stormwater Management Ordinance. Stormwater Management plans are also
required for any activity that disturbs land within thirty(30) feet of the banks of a stream or other
natural waterway; any filling or excavation that results in a change of land surface of four (4) inches
or more; and any activity or development that will ultimately result in the disturbance of a total of
one (1) or more acres except farmlands used for farm purposes and forestland for the production
and harvesting of timber. Such plans must demonstrate the impacts of the proposed development
as well as the measures being taken to control the impacts of the development.
This ordinance gives the county the authority to require correction, repair, replacement and/or
maintenance of any stormwater facility that is not performing as intended and to enter the property
and perform the necessary work(assessing the owner for the costs) if the owner does not respond
in a reasonable time period. The County has the authority, where it suspects that a facility may be
contributing to stormwater pollution, illegal discharges, and/or non-stormwater discharges to
undertake at the owner's expense monitoring and analysis of the facility's discharge.
This ordinance specifies the extent and the exemptions for the need of riparian buffers related to
perennial and intermittent streams, lakes and other natural waterways and specifically identifies
those activities that are not allowed in buffer areas. Individuals owning property through which a
natural watercourse passes are required to maintain them free of trash, debris, excessive vegetation
or other obstacles that would impair the quality or flow of water.
This ordinance addresses the prohibition of illegal discharges which includes specific definitions
related to what constitutes and illegal discharge as well as exceptions. Related to illegal discharges,
this ordinance includes details related to illicit connections. This ordinance requires owners or
operators of commercial or industrial establishment to provide reasonable protection from
accidental discharge or prohibited materials and to notify the County immediately of any
hazardous or non-hazardous spills or discharges and take all necessary steps to ensure the
discovery, containment, and cleanup of such discharges.
Wastewater Discharge Requirements
This ordinance sets forth uniform requirements for direct and indirect contributors into the
County's wastewater collection and treatment system to enable the County to comply with all
applicable state and federal laws including the clean Water Act(33 USC 1251 et seq.) and the
General Pretreatment Regulations (40 CFR 403). The objectives of this ordinance are to ensure the
50

County complies with its NPDES permits and that no pollutants either interfere with the operation
of the wastewater system or are inadequately treated before being discharged into waters of the
state.
No user is allowed to increase the use of process water, or in any way attempt to dilute a discharge
as a partial or complete substitute for adequate treatment. Users shall provide wastewater
pretreatment as necessary to comply with national categorical pretreatment standards. This
ordinance gives the County the authority to require users to restrict their discharge and to install
and maintain suitable storage and flow-control facilities to ensure equalization of flow. All
wastewater samples submitted as part of a wastewater discharge permit or report must be
representative of the user's typical discharge.
This ordinance specifies the reporting requirements for users prior to the discharge of any
hazardous wastes into the wastewater collection system. This includes quantities and quality of
waste as well as timeframe for reporting the discharge to the public utilities director.
•
This ordinance provides for the regulation through the issuance of permits, authorized monitoring
and enforcement up to and including termination of water supply to an industrial user that is not in
compliance and criminal prosecution. Permitting fees and user charges are levied to provide for
recovery of the costs of operating the wastewater system with industrial users subject to surcharges
based on the pretreatment required.
Any industrial user is categorized as a Significant Industrial User and must obtain a special permit
if they meet any of the following criteria.
o Has an average daily process wastewater flow of 25,000 gallons or more;
o Contributes more than five percent of any design or treatment capacity;
o Is required to meet a National Categorical Pretreatment Standard; or
o Is found by either the County, the division of water quality or EPA to have the potential for
impact, either singly or in combination with other contributing industrial users
Septic tank waste is allowed to be introduced into the County's wastewater treatment facility
provided the waste haulers have the appropriate permits. The County has the authority to collect
samples of each hauled load to ensure compliance with applicable standards and to require
industrial waste haulers to provide a waste-tracking form for every load which details the volume
and characteristics of the waste.
This ordinance includes provisions for the connection to the County's wastewater treatment system
and requires owners of property in areas of the County that have access to the wastewater system
to be connected to the public sewer. The construction or use of any facility, such as septic tanks,
are prohibited except when the property cannot be connected to the public sewer system and in
that case the owner must obtain a permit and the septic tank system must be completed to the
satisfaction of the County's public health department. Fees associated with connection to the
public wastewater collection system are detailed as are methods of connection, exceptions, are
prohibited connections.
All subdivisions in the County approved after September 1, 2002 are required to install a sewage
collection system unless the subdivision is in an area that is neither in an existing sewered area nor
in an area that is planned to be sewered.
51

All new golf course developments requiring the use of water to maintain their property or existing
golf course developments constructing a wastewater collection system are required to install a re-
use system for disposal of treated wastewater effluent subject to specific criteria.
Leland
Water and Sewer Use Ordinance
This ordinance sets forth uniform requirements for direct and indirect contributors into the town's
wastewater collection and treatment system to enable the town to comply with all applicable state
and federal laws including the clean Water Act (33 USC 1251 et seq.) and the General
Pretreatment Regulations (40 CFR 403). The objectives of this ordinance are to ensure the County
complies with its NPDES permits and that no pollutants either interfere with the operation of the
wastewater system or are inadequately treated before being discharged into waters of the state. This
ordinance also requires users located outside the town limits to agree to comply with its terms and
conditions and must be approved by the Town Council.
This ordinance provides for the regulation through the issuance of permits, authorized monitoring
and enforcement up to and including termination of water supply to an industrial user that is not in
compliance and criminal prosecution. Permitting fees and user charges are levied to provide for
recovery of the costs of operating the wastewater system with industrial users subject to surcharges
based on the pretreatment required. Any industrial user is categorized as a Significant Industrial
User and must obtain a special permit if they meet any of the following criteria.
o Has an average daily process wastewater flow of 25,000 gallons or more;
o Contributes more than five percent of any design or treatment capacity;
o Is required to meet a National Categorical Pretreatment Standard; or
o Is found by either the town of EPA to have the potential for impact, either singly or in
combination with other contributing industrial users
Privately owned and operated wastewater treatment facilities are permitted in the town's sewer
service area but they are subject to permitting and zoning requirements and must dedicate all
easements and facilities to the town and shall meet all state and local construction standards. The
town will not accept hauled industrial waste or septage from septic tanks without authorization
from the Town manager.
Stormwater
This ordinance was established to control the adverse effects of increased post-development
stormwater runoff and non-point and point source pollution associated with new development and
redevelopment. Ordinance requires that new development or redevelopment maintain the pre-
development hydrologic response as nearly as practicable; reduce flooding, stream bank erosion,
non-point and point source pollution and increases in stream temperature; and maintain the
integrity of stream channels and aquatic habitats.
This ordinance establishes provisions for long-term responsibility and maintenance of structural
and nonstructural stormwater BMPs; establishes administrative procedures with regard to
permitting compliance and enforcement; and sets requirements for undisturbed vegetative buffers
for development activities (50-foot wide for new and 30-foot wide for redevelopment). Vegetative
buffers included in this ordinance may be met concurrently with state water quality or coastal
management rules and may include:
52

o Approved stormwater control best management practices (BMPs) with the exception of wet
detention ponds are allowed in the buffer and the area required to construct the practices may
be disturbed;
o Walking trails, picnic areas, benches, and water dependant structures are allowed in the buffer
and area required to construct the practices may be disturbed provided all applicable Federal,
State, and Local permits are obtained; and
o Development in urban waterfronts that meet the requirements of 15A NCAC 07H .0209(g),
development in new urban waterfront areas that meet the requirements of Session Law 2004-
117, those activities listed in 15A NCAC 07H .0209(d)(10)(A) though 15A NCAC 07H
.0209(d)(10)(H), and development of upland marinas that have received a CAMA Major Permit
are allowed in the buffer and the area required to construct the practices may be disturbed.
Specific requirements for low-density development or redevelopment are provided that include
stormwater runoff being conveyed from the development primarily by vegetated conveyances and
shall flow through wetlands at a non-erosive velocity. The ordinance provides for corrective action
should excessive erosion be found to occur after construction and final inspection are complete.
For structural stormwater controls that require separation from the seasonal highwater table, this
ordinance requires a minimum separation of two feet unless the Division of Water Quality grants
relief from this requirement.
Navassa
On 16 December 2010 the Town Council adopted the Town of Navassa Phase II Stormwater
Ordinance. The complete document is included on the DVD in Appendix I. The ordinance is
applicable to all development and redevelopment, including but not limited to site plan
applications, subdivision applications, and Planned Unit Development application that meet any of
the following criteria, unless exempt pursuant to the Ordinance's Exemptions Section:
(1) All development and redevelopment in which the total land disturbance
is one acre or more;
(2) All non-residential development or redevelopment that will add 10,000
square feet or more of built upon area irrespective of the condition of the
existing surface upon which the impervious surface area is created;
(3) All development or redevelopment in which the total land disturbance is
less than one acre and does not add 10,000 square feet or more of built
upon area if such activities are part of a larger common plan of development
or sale, even though multiple, separate or distinct activities take place at
different times or different schedules;
(4) All development or redevelopment that requires a CAMA major permit
or a Sedimentation/Erosion Control Plan.
Ordinance Exemptions:
(1) Development and redevelopment that cumulatively disturbs less than
one (1) acre, does not add 10,000 square feet or more of built upon area
and is not part of a larger common plan of development or sale;
(2) Activities that are exempt from permit requirements of Section 404 of the
federal Clean Water Act as specified in 40 CFR 232 (primarily, ongoing
farming and forestry activities) are exempt from the provisions of this
ordinance. 6
. 53

(3) The installation, repair, replacement or maintenance of subsurface
utilities by public or private utility operators.
The design, implementation, and performance of all submitted plans, including technical
specifications and standards must comply with the NC Division of Water Quality Stormwater Best
Management Practices Design Manual or the Brunswick County, Low Impact Development
Guidance Manual. Should there be a conflict between these documents, the more stringent
standards shall apply.
Permit applications shall contain detailed descriptions of:
• The post-development stormwater runoff control and management;
• The design of all stormwater facilities and practices;
• Site identification information;
• Ownership information; and,
• A written narrative explaining how the proposed project shall meet the
requirements of the ordinance.
Concept plan and consultation meetings are encouraged and should address:
• Existing conditions/proposed site plans
• Natural resources inventory
• Stormwater management system concept plan
The Draft Ordinance's general standards include:
• Undisturbed vegetated buffers: 50 foot wide for new development and
30 feet wide for redevelopment;
o Measured horizontally form normal pool elevation of
impounded structures, from the top of bank for each side of
streams or rivers, and from the mean high waterline of tidal
waters, perpendicular to the shoreline
o May be cleared or graded, but must be planted with and
maintained in grass or any other vegetative or plant material
o Minor variances may be granted by Town
Low Density Standards
• Runoff shall be transported by vegetated conveyances
• Built upon areas shall be at least 30 feet landward of all perennial and
intermittent surface waters
• Any flow through wetlands shall be non-erosive
• Recorded deed or protective covenants or both must insure that
approved project plans are maintained
High Density Standards
• Shall control and treat runoff from all surfaces generated by one and
one-half inches of rain
• Waters draining within one-half mile and draining into SA waters must
control and treat the difference in stormwater runoff from the pre- and
post development conditions for the 1-year, 24-hour storm; runoff
volume draw down time shall be a minimum of 48 hours , but not more
54

than 120 hours
• All structural systems shall have a minimum of 85% Total Suspended
Solids removal
• General design criteria shall be in accordance with 15A NCAC 2H.1008
or as explained in the Design Manuals
• Built upon areas shall be at least 350 feet landward of all perennial and
intermittent surface waters
• Any flow through wetlands shall be non-erosive
• Recorded deed or protective covenants or both must insure that
approved project plans are maintained
Pet Waste
• Dogs at large are prohibited
• Pet waste disposal
o The Town discourages animals to be taken off the owner's
property without properly removing and disposing of the
animal's feces
o Owners and custodians must clean the animal's feces from
any public or private property outside the owner's property
including but not limited to: parks, rights-of-way, paths,
sidewalks, and public access areas
• Pet waste stations
o Required in all new developments that create public open
space
o One station per 1.5 acres of public open space
Belville
Subdivisions shall have a storm water drainage system constructed to the standards of the NCDOT
subject to review by the Town's Consulting Engineer. Such standards include:
• Curb and gutter is strongly encouraged;
• No surface water shall be channeled or directed into a sanitary sewer;
• Subdivider shall connect to an existing surface water drainage system,where feasible;
• Where existing surface water drainage system cannot feasibly be extended to the
subdivision surface drainage system shall be designed to protect the proposed development
from water damage;
• Surface drainage courses shall have side slopes of at least three (3) feet of horizontal
distance for each one (1) foot of vertical distance and shall be of sufficient size to
accommodate drainage area without flooding;
• Minimum grade along the bottom of the surface drainage course shall be a vertical fall of at
least one (1) foot in each two hundred (200) feet of horizontal distance;
• Stream banks and channels downstream from any land disturbing activity shall be protected
from increased degradation by accelerated erosion caused by increased velocity of runoff
from the land disturbing activity;
• Dams or impoundments within the subdivision must comply with the North Carolina Dam
Safety Law of 1967 and the North Carolina Administrative Code Title 15, Subchapter 2 K;
• In all special flood hazard areas, subdivision proposals shall have adequate drainage to
reduce exposure to flood damage; and
55

O
• • Stormwater runoff shall not increase more than five (5%) percent over preconstruction
runoff.
Stormwater drainage as it relates to runoff shall be controlled on site with the benefit of engineered
systems which require intensive maintenance.
Northwest and Sandy Creek both require compliance with Brunswick County stormwater
regulations.
F.10.2 Groundwater Resources
Because negative impacts to groundwater resources are not anticipated, mitigation will not
be necessary.
F.11. Forestry Resources
Direct impacts to forestry resources in the WWTP expansion area will be minimal and
mitigation will not be necessary. Impacts to forestry resources adjacent to the WWTP expansion
and the transmission system improvements will be avoided by following the required erosion and
sedimentation control plans, which will reduce and/or eliminate erosive storm flow velocities and
deposition.
Because conversion of commercially viable forestry resources to other land uses will be
made by individual landowners on a case by case basis, mitigation will not be necessary. For non-
commercially viable forestry resources, impacts will be minimized by following local ordinance
language that requires vegetated buffers (Appendix I).
F.12. Shellfish or Fish and Their Habitats
To ensure that negative direct impacts to joint Anadromous Fish Spawning Areas do not
occur, all outfall construction will be conducted between July 1 and January 31.
Secondary and cumulative impacts to fish and their habitats will be mitigated through
project specific CAMA, USACE, and DWQ permitting. Because shellfish and fish habitats are
directly related to water quality, local ordinance language summarized in Section F.10.1 and
provided in Appendix I will also avoid, minimize and mitigate secondary and cumulative impacts
to these resources.
F.13. Wildlife, Natural Vegetation and Protected Species
Direct impacts to the only protected species that may occur within the construction areas
(shortnose sturgeon) will be avoided by limiting outfall construction to between July 1 and January
31 (i.e. outfall construction will not take place from February 1 to June 30). Clearing and grading
in the Phase 1 and Phase 2 construction areas will be limited to areas necessary. Other native
vegetation and habitat in the project area will be left to grow naturally. The availability of
significant amounts of similar habitat immediately adjacent to the construction areas will mitigate
impacts to common wildlife species that may be displaced during and following construction, as
described in Sections D.13 and E.13.
F.14. Introduction of Toxic Substances
Escape of toxic substances will be minimized by vehicle maintenance practices and
56

collection and disposal of fluid containers. Uncured concrete will not be allowed to contact
surface waters. The wastewater treatment plant wiI I not release toxic and hazardous substances. All
regulated substances will be stored and handled in compliance with state regulations, including
spill barriers in storage areas. MSDS data for regulated substances will be stored on site and filed
with the local fire department.
57

SE/TA/NC&ws wi et/ c' 9 0,6141,44--
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Belnick, Tom --- -��
From: Belnick, Tom M04441 E1101/'
Sent: Monday,April 25, 2011 11:00 AM
To: Poupart,Jeff; Templeton, Mike; Grzyb,Julie (0.444
Cc: Stecker, Kathy
Subject: FW: re your question about the expansion of an eastern NC •isc - •- o an impaired water
Fyi. . . generic discussion with EPA Permitting regarding use of modeling results (in this case
the Bowen et al 2009 DO model for lower Cape Fear)to determine whether EPA would concur with
expansion for NE Brunswick at modeled BOD=5 and NH3 = 1. I had relayed to Marshall that this
model was used to evaluate specific expansion scenarios for NE Brunswick (up to 15 MGD), and
for gall scenarios the difference in DO between base case and expansions was <0.05 mg/1.
Tom Belnick
Supervisor, Complex NPDES Permitting Unit NC DENR/Division of Water Quality
1617 Mail Service Center, Raleigh, NC 27699-1617
(919) 807-6390; fax (919) 807-6495
E-mail correspondence to and from this address may be subject to the North Carolina Public
Records Law and ma be disclosed ..rties.
Original Message
From: Hyatt.MarshallOepamail.epa.gov [mailto:Hyatt.Marshall(aepamail.epa.gov]
Sent: Monday, April 25, 2011 10:01 AM
To: Belnick, Tom
Cc: Myers.Pamala0aepamail.epa.gov
Subject: re your question about the expansion of an eastern NC discharger to an impair-•
water
Bill Melville in our TMDL section confirmed that if there is a
calibrated model that shows any expansion to have an effect on DO that
is less than model sensitivity, that is a sufficient demonstration:
let me know if you need anything else.
•
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• cw+e (10 ') ora P/ 'v n OM uel 41
DEVELOPMENT AND USE OF A THREE-DIMENSIONAL WATER QUALITY MODEL
TO PREDICT DISSOLVED OXYGEN CONCENTRATIONS IN THE LOWER
CAPE FEAR RIVER ESTUARY,NORTH CAROLINA
James D. Bowen, Solomon Negusse,J. Matthew Goodman, Benoit Duclaud,
Mathieu Robin, and Jesslyn Williams
Department of Civil and Environmental Engineering
William States Lee College of Engineering
University of North Carolina at Charlotte
Charlotte,NC 28223
The research on which this report is based was supported by funds provided by the North
Carolina General Assembly through the North Carolina Department of Environment and Natural
Resources.
Frome D October 2009
TanDesk of

r r
6.9 Effect of Changing Brunswick County Wastewater Loadings
Three model scenarios considered the impact of changing the wastewater flow of a single
discharger(Brunswick County wastewater treatment plant). Based on the discharge monitoring
reports for the model period(2003-2005),the base condition had a time-averaged flow of 0.38
MGD. The three alternate scenarios tested had time-averaged flows of 1.65,4.65 and 15 MGD.
These scenarios therefore represented the effect of changing the wastewater treatment flow by
factors of 4.3, 12.1, and 39.1. In these alternate loading scenarios,each discharge flow was
increased by a constant factor. All concentrations were assumed to be constant. Thus the
wastewater loadings had identical patterns of time variation,but had time-averaged flows that
equaled the values given above. As for the other scenarios,twice daily dissolved oxygen
concentrations were collected and compared to the base case at eighteen sites within the impaired
region, from all eight layers of the model and from every day within the summertime period
(April 1 —October 31,2004).
Despite the relatively large changes in the assumed wastewater flow, there were only
very small differences in the predicted dissolved oxygen concentrations, for summertime
conditions in the impaired region. Across the entire range of dissolved oxygen concentrations,
the differences between the base case and each of the three scenarios was always less than 0.05
mg/L(Figure 86). ,Thus there was essentially no effect of changing he wastewater flow. One
limitation of this analysis is the assumption that loading would increase solely byinn erceaasing the
flow. Since the organic matter concentrations were only slightly higher than the receiving
waters, it is not surprising that changing the loading by holding effluent concentrations constant
while increasing the flows had a very small effect on dissolved oxygen concentrations.
N 143
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6-18

: hu14&4Jk1Kfila V UP/
Belnick, Tom
From: Vinzani, Gil
Sent: Wednesday,April 27, 2011 9:20 AM
To: Belnick,Tom
Cc: Grzyb, Julie; Poupart,Jeff
Subject: NPDES Comments NE Brunswick SEPA
Attachments: Brunswick_test.pdf; IP_vs_WWTP.pdf; narayan.rajbhandari.vcf
Tom:
Regarding the NE Brunswick SEPA, I have no comments on the draft SEPA review. Here is an old
E-mail from Raj which goes into some detail on the EFDC WQ model done by Dr. Bowen.
Gil Vinzani, P. E.
Complex NPDES Permits Unit
,1/6604.1..1 fr
Phone: [phone]
AO) Uf() $' W�
E-mail correspondence to an. rom this address may be subject to the NC Public Records Act
Original Messa:
From: narayan B. .jbhandari ailto:[e-mail]]
Sent: Tuesday, Ma ch 18, 200: 4:50 PM
To: Kathy Stecker; a an . k
Cc: narayan B. rajbhandari; Gil Vinzani; Paul Rawls; Matt Matthews; Cam Mcnutt; Nora Deamer;
James D. Bowen
Subject: Re: Updates of EFDC WQ model for LCFR
Dear Kathy and Alan,
Please find the attached two corrected cumulative frequency graphs, Brunswick_Test.pdf and
IP_vs_WWTP.pdf. According to Dr. Bowen, the previous scenario test graphs for the WWTPs,
including Brunswick Co, had some calculation problems and should be discarded. So, please
replace the old ones with these new ones for our meeting tomorrow at 2:30 pm.
Thanks.
Raj
narayan B. rajbhandari wrote:
> Dear Kathy and Alan,
> Please find attached three graphical files of the scenario test
> results, as send by Dr. Bowen. The results address averaged DO
> concentrations during the lower DO time period, April through
> November, in the impaired water body from Toomers Creek to Snows Cut
> in . -
according
according to the results, the effect of Brunswick County WWTP is
almost negligible. The attached cumulative graph suggests that
changing the requested flows from 1.7 mgd to 15 mgd don't change DO
► concentration significantly in the entire impaired estuary. (Please
see Brunswick_Test.pdf.) We have not, however, analyzed to see it
effect at the immediate re:ion aroul • •
> . - :ni icant impact on DO concentration due to point
> sources (a big change after adding missing WWTPs). The DO
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> concentration line moved towards high value when all WWTPs are cut
> off. (Please see All_WWTP_Test.pdf.). But, interestingly it appears
> that the DO concentration remained less than 5 mg/L at the 30th
> percentile without point sources, suggesting effect from background
> condition.
> Furthermore, it is interesting to observe that the International
> Paper, which is upstream of the impaired area, is by far the largest
> single point source to affect DO concentration as compare to other
> point sources in the estuary. The cumulative DO concentration did not
> considerably change by simulating the model with all WWTPs turned off
> and IP source alone turned off. (Please see IP_VS_WWTP.pdf.)
> The results seem quite impressive. Please let me know if you have any
> further questions. Thanks.
> With regards,
> Raj
> narayan B. rajbhandari wrote:
» Dear Kathy and Alan,
» I am working with Dr. Bowen to obtain significant scenario test
» results by next week. After adding the a few missing point sources
» into the EFDC input files, we found some differences between the
» model prediction and observed DO concentration at Navasa. Therefore,
» it took a few days more to re-calibrate the model for WQ. However,
» re-calibration of the model is successfully completed now. Attached
» is an example time history plot of the calibration run, showing
» predicted vs. observed DO at Navassa. A predicted vs. observed
» cumulative frequency plot is also attached herewith. The model fits
» the DO data amazingly well (R-Square = 0.80+). Setting up the
» scenarios as per my last email (below) is also almost done. Things
» are going well now. Thanks.
» With regards,
» Raj
» narayan B. rajbhandari wrote:
>» Hi Kathy and Alan,
»>
>» I met with Dr. Bowen last week (2/23) at his office and briefed him
»> our comments (collected during our meeting with Chuck Wakild last
»> week) on the cumulative graph. He has agreed to do further analysis
>>> to see the cumulative responses of DO with and without NPDES permits
»> at the critical area - from upstream mouth of Toomers Cr to Snows
»> cut, including Brunswick River. The analysis will focus DO load
»> during summer period vs whole years (2003 through 2005).
»>
»> Dr. Bowen and I reviewed the NPDES permits in the LCFRB and found
>» some permits missing in Northeast Cape Fear River as well as in Cape
»> Fear River. I have collected all the required data for the missing
>» permits and have sent the data to Dr. Bowen to be included in his
»> final model simulation. I have attached a google earthmap herewith,
»> showing the ambient stations, USGS stations, and NPDES permit
»> locations for your information.
»>
»> Dr. Bowen is currently setting up the model to test the following
»> scenarios.
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•
>>• 1. Brtunswick Co WWTP flow @ 1.65 mgd (exiting max permit) 2.
4» Brtunswick Co WWTP flow @ 4.65 mgd (first phase permit request) 3.
»> Brtunswick Co WWTP flow @ 15 mgd (final phase permit request) 4. All
»> WWTP's turned off 5. All WWTP's NH4 turned off 6. Just Wilmington
»> WWTP's turned off
»>
>» Please suggest me if you have further proposals for the scenario
»> test. I am expecting the scenario test results by next week.
»>
»> I have brought back the training computer (out of order) to set up
»> password and user-id. Daniel Price helped me to fix it and now it
>» can be turned on without any problem.
»>
»> I am sorry to be late to send this modeling progress report. I was
»> fixing and collecting the missing NPDES data for the model. I think
»> it is all set now. Thank you for your patience.
>>>
>» With regards,
»> Raj
>> ---
» ---
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