NC0023973_Permit (Issuance)_20150825

NPDES DOCIMENT SCANNING COVER SHEET
NC0023973
Wilmington Southside WWTP
NPDES Permit:
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Technical Correction
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
August 25, 2015
This document is printed on reuse paper - ignore arty
content on the reszerse aide

NCDENR
North Carolina Department of Environment and Natural Resources
Pat McCrory
Governor
Mr. Jim Flechtner, PE
Executive Director
Cape Fear Public Utility Authority
235 Government Center Drive
Wilmington, NC 28403
Dear Mr. Flechtner:
Donald R. van der Vaart
Secretary
August 25, 2015
Subject: Issuance of NPDES Permit Modification
Permit No. NC0023973
M'Kean Maffitt (Southside) WWTP
New Hanover County
Facility Class IV (SIC 4952)
Division personnel have reviewed and approved your application to expand the permitted discharge from 12
MGD to 24 MGD. The Cape Fear Public Utility Authority expects to implement the expansion in phases
going from 12 MGD to 16 MGD to 20 MGD and finally to 24 MGD. Accordingly, we are forwarding the
attached NPDES discharge permit. This permit is issued pursuant to the requirements of North Carolina
General Statute 143-215.1 and the Memorandum of Agreement between North Carolina and the U.S.
Environmental Protection Agency dated October 15, 2007 (or as subsequently amended).
Please note that the receiving stream is listed as an impaired waterbody on the North Carolina 2014 303(d)
Impaired Waters List for copper and low dissolved oxygen. Addressing impaired waters is a high priority
with the Division, and instream data will continue to be evaluated. If there is noncompliance with permitted
effluent limits and stream impairment can be attributed to your facility, then mitigative measures may be
required
The final permit contains the following revisions made to the draft permit sent to you on May 20,
2015:
• Currently, the Southside WWTP is performing acute toxicity testing at 90% effluent. CFPUA would
like to receive credit for some dilution and perform chronic toxicity testing on its wastewaters
instead of' acute testing at 90%. The DWR Aquatic Toxicity Branch agreed that the chronic test is a
very effective test and approved the Authority's proposal to perform chronic toxicity tests using the
33:1 (IWC = 3% at 12 MGD) dilution based on the 2001 Environmental Fluid Dynamics Code
(EFDC) model. In discussions with EPA, this decision was found to be acceptable; however, it was
agreed that eventually a more comprehensive study/model should be performed by CFPUA to
validate the dilution factor for the M'Kean Maffitt (Southside) WWTP's specific outfall and
discharge volume. The Authority agreed to such a condition with its Northside WWTP permit and
suggested similar language for the M'Kean Maffitt WWTP. The following Special Condition was
added to the permit:
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Phone: [phone] Internet: www.ncdenr.gov
An Equal Opportunity 1 Affirmative Action Employer — Made in part by recycled paper

Mr. Jim Flechtner, PE
Executive Director
August 25, 2015
Page 2 of 4
A.(8.) MODELING REQUIREMENT
The Authority shall submit a CORMIX model (or equivalent) providing
additional information regarding end -of -pipe dilution no Iaer than 12
months after an engineer's certification for the completion of the 16.0
MGD plant expansion is issued. The model shall address dilution at the
approved 16.0 MGD increased flow rate into the Cape Fear River for
M'Kean Maffitt W WTP's specific discharge configuration. The dilution
factor determined by the CORMIX model (or equivalent) shall be used
by the permittee for the chronic effluent test concentration once the
model is reviewed and approved by the Division.
The 33:1 dilution factor was tentatively used to determine chronic effluent testing concentrations for
the other phased expansions until a CORMIX model (or equivalent) is submitted and approved.
• The Division agreed with EPA that the dilution factor of 33:1 would not be used in the
determination of allowable effluent concentrations for toxicants. Therefore, the Reasonable Potential
Analysis(RPA) was revised using no dilution. Copper was the only parameter showing reasonable
potential to violate Water Quality Standards in the revised RPA. Since the copper standard is an
action level limit and the facility is currently passing its Toxicity tests, no limitation was put in the
permit. Copper monitoring was put back in the permit at the same monitoring frequency as the
existing permit (quarterly).When the Authority submits an approvable CORMIX model (or
equivalent), the revised dilution factor can be used for toxicant limit development.
• Corrections to the components list were made as the Authority requested.
• The Authority requested that the TRC footnote require the permittee to report all data below 50 ug/L
as "< 50 ug/L". This request was formally presented by NCWQA to the Division of Water
Resources. The DWR laboratory staff is currently evaluating this request. When the evaluation is
completed, and if the outcome affects the wording in this permit, the Authority can request a permit
modification, if desired.
• The Authority recognized that chlorination will be replaced with UV disinfection when the facility is
expanded to16 MGD. As a result, wording was added to all the TRC footnotes in sections A.(2.),
(3.), and (4.) stating that reporting is only required if chlorine or chlorine derivatives are contained in
the wastewaters being discharged.
• The word CBOD in footnote #3 contained in sections A.(2.), (3.), and (4.) was changed to BOD.
• The Authority requested that special conditions on Historical Permit Limits and Anti -backsliding be
put into the permit. EPA, Region IV, reviewed the conditions and requested that the conditions
stipulated in the Anti -backsliding special condition be revised to be consistent with federal
regulations cited in 40 CFR 122.44(1). Both of the requested conditions were added to the permit
with some modification to the Anti -backsliding condition per EPA's comment. See sections A.(9.)
and A.(10.).
Detailed responses to all the Authority's comments contained in the letter dated June 24, 2015 can be found
in the Addendum to the Permit Fact Sheet included with the enclosed permit.

Mr. Jim Flechtner, PE
Executive Director
August 25, 2015
Page 3 of 4
As identified previously, the draft permit contains the following significant changes from your current
permit:
• The requirement to begin reporting discharge monitoring data electronically using the NC DWR's
Electronic Discharge Monitoring Report (eDMR) internet application has been added to your NPDES
permit. [See Special Condition A. (7.)]
For information on eDMR, registering for eDMR and obtaining an eDMR user account, please visit the
following web page: http://portal.ncdenr.org/web/wq/admin/bog/ipu/edmr.
For information on EPA's proposed NPDES Electronic Reporting Rule, please visit the following
website: http://www2.epa.gov/comp) iance/proposed-npdes-electronic-reporting-rule.
• Effluent Limitations and Monitoring Requirements have been added for each Phase of expansion:
Section A.(2.) for 16 MGD, Section A.(3.) for 20 MGD and Section A.(4.) for 24 MGD.
• A Reasonable Potential Analysis was performed on effluent metals monitoring data for arsenic,
cadmium, chromium, copper, cyanide, lead, molybdenum, nickel, selenium, silver, and zinc. None of the
metals except copper showed reasonable potential to violate Water Quality Standards at 12, 16, 20, or 24
MGD. Copper effluent monitoring was maintained in the permit. Sampling for all the metals shall
continue as part of CFPUA's Pretreatment Long Term Monitoring Program (LTMP).
• In accordance with the 2012 Mercury TMDL NPDES Guidance, effluent mercury data from 2010-2014
was evaluated. The data showed that the annual mean effluent concentrations were below the Water
Quality Based Effluent Limit of 204 ng/L (ie., the most stringent allowable concentration determined
using the maximum permitted flow of 24 MGD). It was difficult to verify that the Technology Based
Effluent Limit of 47 ng/L was being complied with since only two samples were reported using the
lower detection test method 1631 E. Both of these samples were reported below 47 ng/L. The Authority
will be required to continue monitoring mercury as part of its Pretreatment LTMP and its Effluent
Pollutant Scans. Pretreatment will be notifying Permittees that they must use EPA Test method 1631 E
and the Effluent Pollutant Scan special condition specifies the same. Effluent mercury data will be re-
evaluated upon permit renewal in 2016 to determine if a limit or a Mercury Minimization Plan (MMP)
will be required per the statewide TMDL.
• The Special Condition for Toxicity testing was changed to a chronic, 7-day pass/fail test using
Ceriodaphia dubia at an effluent concentration determined from the 2001 TetraTech dilution model. The
testing effluent concentrations are based on each phased permitted flow and are specified in special
condition A.(5.).
• Special Condition A.(6.) Effluent Pollutant Scan has been modified at the end to include 2nd species
Toxicity Testing Requirements for municipal permit renewals per Federal Regulations [40 CFR
122.21(j)(5)].
If any parts, measurement frequencies or sampling requirements contained in this permit are unacceptable to
you, you have the right to an adjudicatory hearing upon written request within thirty (30) days following
receipt of this letter. This request must be in the form of a written petition, conforming to Chapter 150B of

Mr. Jim Flechtner, PE
Executive Director
August 25, 2015
Page 4 of 4
the North Carolina General Statutes, and filed with the Office of Administrative Hearings (6714 Mail
Service Center, Raleigh, North Carolina 27699-6714). Unless such demand is made, this decision shall be
final and binding.
Please note that this permit is not transferable except after notice to the Division. The Division may require
modification or revocation and reissuance of the permit. This permit does not affect the legal requirements
to obtain other permits which may be required by the Division of Water Resources or any other Federal,
State, or Local governmental permits that may be required.
If you have any questions concerning this permit, please contact Julie Grzyb by email
([e-mail]) or phone at [phone].
Sincerely,
d
S. Jay Zimmerman, P.G.
go Director, Division of Water Resources
Enclosure: NPDES Permit N00023973
cc: NPDES Unit
Central Files
Wilmington Regional Office / Surface Water Quality
e-copy:
EPA Region IV (SIC 4952)
NC Division of Marine Fisheries, Habitat Protection Section
Susan Meadows, Aquatic Toxicity Branch
Steve Kroeger, WSS/ Ecosystems Branch
Carrie Ruhlman, WSS/ Ecosystems Branch
Frank Styers, Chief Operations Officer, CFPUA (Southside)

Permit NC0023973
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
(NPDES)
In compliance with the provision of North Carolina General Statute 143-215.1, other lawful
standards and regulations promulgated and adopted by the North Carolina Environmental
Management Commission, and the Federal Water Pollution Control Act, as amended, the
Cape Fear Public Utility Authority
is hereby authorized to discharge wastewater from outfall 001 located at the
M'Kean Maffitt (Southside) Wastewater Treatment Plant
3436 River Road
Wilmington
New Hanover County
to receiving waters designated as the Cape Fear River within the Cape Fear River Basin in
accordance with effluent limitations, monitoring requirements, and other conditions set forth in Parts
I, II, III, and IV hereof.
This permit modification shall become effective ...... October 1, 2015.
This permit and authorization to discharge shall expire at midnight on December 31, 2016.
Signed this day August 25, 2015.
011
`S. ay Zimmerman, P.G.
aef
/ Director, Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 14

Permit NC0023973
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked,
and as of this issuance, any previously issued permit bearing this number is no longer effective. Therefore,
the exclusive authority to operate and discharge from this facility arises under the permit conditions,
requirements, terms, and provisions described herein.
The Cape Fear Public Utility Authority is hereby authorized
to:
1. Continue discharging treated domestic and industrial wastewater from the existing 12.0 MGD wastewater
treatment facility that includes the following components:
• Influent metering
• Standby manual bar screen
• Dual mechanical bar screens, each with grit removal and storage unit
• Splitter box
• Dual primary clarifiers
• Dual trickling filters (180 feet diameter)
• Short-term aeration basin
• Splitter box
• Three screw lift pumps
• Dual secondary clarifiers
• Return activated sludge pumping station
• Chlorine gas disinfection facilities
• Liquid dechlorination facilities
• Flash mixer for chlorine gas
• Dual chlorine contact chambers
• Outfall structure with flow meter
• Main plant backup generator
• Lift -station generator, automatically activated (with backup generator)
• Primary and waste -activated sludge pump stations
• Two gravity -belt thickeners, two belt filter presses; four anaerobic digesters; alkaline stabilization,
covered storage area
• Solids land application
This facility is located at the M'Kean Moffitt (Southside) Wastewater Treatment Plant (3436 River
Road, Wilmington) in New Hanover County.
2. After receiving an Authorization to Construct from the Division, construct and operate facilities giving
the system a treatment capacity of 16.0 MGD; and
3. After receiving an Authorization to Construct from the Division, construct and operate facilities giving
the system a treatment capacity of 20.0 MGD; and
4. After receiving an Authorization to Construct from the Division, construct and operate facilities giving
the system an ultimate treatment capacity of 24.0 MGD; and
5. Discharge from said treatment facility through outfall 001 at the location specified on the attached map
into the Cape Fear River, classified as a Class SC stream in the Cape Fear River Basin.
Page 2 of 14

Permit NC0023973
PART I
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Beginning on the effective date of this permit and lasting until expansion above 12.0 MGD (and receipt of
the Engineer's Certification of completion) or permit expiration, the Permittee is authorized to discharge
treated wastewater from Outfall 001. Such discharges shall be limited and monitored' by the permittee as
specified below:
EFFLUENT
PARAME-TER
.� .. � . , :..,. � , ..
EFFLUENT
_: - : _ . :.:LIMITATIONS . :�:-
..:. � REQUIREMENTS_....._......
e
Measurement
Fre uen c
q ... Y
MONITORING
Sample
TYPe
.
� Sample
Location? ,
Monthly..
Average ::
..
Weekly
Average
.. ,....
Daily
.:fVtaximum.
Flow
12.0 MGD
Continuous
Recording
Influent or
Effluent
CBOD, 5-day, 20°C 3
25.0 mg/L
40.0 mg/L
2/Week
Composite
Influent and
Effluent
Total Suspended
'Solids 3
30.0 mg/L
45.0 mg/L
Meek
Composite
Influent and
Effluent
NH3 as N
3/Week
Composite
Effluent
Enterococci
(geometric mean)
35/100 mL
276/100 mL
2/Week
Grab
Effluent
.T•otal Residual Chlorine 4
13.0 pg/L
Daily
Grab
Effluent
Temperature
Daily
Grab
Effluent
pH
Between 6.8 and 8.5 standard units
Daily
Grab
Effluent
Dissolved Oxygen
Daily
Grab
Effluent
Total Phosphorus
Monthly
Composite
Effluent
Total Nitrogen
MonthlyComposite
Effluent
Total Copper
Quarterly
Composite
Effluent.
Whole Effluent Toxicity 5
Quarterly
Composite
Effluent
Dissolved Oxygens
Variable1
Grab
U, D
Temperatures
Variable' -
Grab
U, D
Effluent Pollutant Scan
Monitor and Report
Footnote 8
Footnote 8
Effluent
r ootnotes:
1. No later than 270 days from the effective date of this permit, begin submitting discharge monitoring reports
electronically using NC DWR's eDMR application system. See Special Condition A. (7).
2. U = upstream at a point equidistant between the radio tower north of the WWTP and the northern end of the
dredge spoil island immediately east of the outfall. D = downstream at a point equidistant between the mouth
of Barnards Creek and the southern end of the dredge spoil island immediately east of the outfall.
3. The monthly average effluent CBOD5 and Total Suspended Solids concentrations shall not exceed 15 % of
the respective influent value (i.e., 85% removal is required).
4. Total Residual Chlorine limit applies if chlorine or chlorine derivative is used for disinfection. The Division
shall consider all effluent TRC values reported below 50 µg/1 to be in compliance with this permit. The
permittee shall continue to record and submit all values reported by a North Carolina certified laboratory even
if these values fall below 50 mil.
5. Chronic Toxicity Testing using Ceriodaphnia dubia, 7-day pass/fail @ 3.0 % effluent. Perform tests during
March, June, September, and December [see A (5)]. Metals sampling shall coincide with toxicity
sampling.
l6 Stream Sampling — The permittee has deferred receiving -stream sampling to the Lower Cape Fear River
Program by memorandum of agreement (MOA). Should this MOA terminate for any reason, the permittee
shall immediately inform the Division in writing and immediately resume instream monitoring in accordance
with this permit.
V. Variable Frequency -- Stream samples shall be collected 3/week during the summer months of June, July,
August, and September; samples shall be collected weekly during the rest of the year.
8. The permittee shall perform three effluent pollutant scans during the term of this permit [see A (6)].
There shall be no discharges of floating solids or foam other than trace amounts.
Page 3 of 14

Permit NC0023973
A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Beginning upon receipt of the Engineer's Certification for completion of the 16 MGD expansion and lasting
until expansion above 16 MGD (and receipt of the Engineer's Certification of completion) or permit
expiration, the permittee is authorized to discharge treated wastewater from Outfall 001. Such discharges
shall be limited and monitored' by the permittee as specified below:
• EFFLUENT :'
PARAMETER .
EFFLUENT .
LIMITATIONS
MONITORING ..., . .
REQUIREMENTS:
Monthly
Average
Weekly
Average -
Daily
Maximum
Measurement:
Y Fre uenc
q �
Sample
T e
yP .
Sample
:Location 2
Flow
16.0 MGD
Continuous
Recording
Influent or
Effluent
BOD, 5-day, 20°C a
(April 1 — Oct. 31)
5.0 mg/L
7.5 mg/L
Daily
Composite
Influent and
Effluent
BOD, 5-day, 20°C a
(Nov. 1 — March 31)
10.0 mg/L
15.0 mg/L
Daily
• Composite
Influent and
Effluent
Total Suspended
Solids a
30.0 mg/L
45.0 mg1L
Daily
• Composite
Influent and
Effluent
NH3as N
(April 1 — Oct. 31)
1.0 mg/L
3.0 mg/L
3/Week
Composite
Effluent
NH3 as N
(Nov. 1 — March 31)
2.0 mg/L
6.0 mg/L
3/Week
Composite
Effluent
Enterococci
(geometric mean)
35/100 mL
276/100 mL
Daily
Grab
Effluent
Total Residual Chlorine4
13.0 pg/L
Daily
Grab
Effluent
Temperature
Daily
Grab
Effluent
pH
Between 6.8 and 8.5 standard units
Daily
Grab
Effluent
Dissolved Oxygen
Daily average > 6.0 mg/L
Daily
Grab
Effluent
Total Phosphorus
Monthly
Composite
Effluent
Total Nitrogen
(NOz-N+ NO3-N+ TKN)
Monthly
Composite
Effluent
Total Copper
Quarterly
Composite
Effluent
Whole Effluent Toxicity 5.6
Quarterly
Composite
Effluent
Dissolved Oxygen 7
Variable$
Grab
U, D
Temperature 7
Variable$
Grab
U, D
Effluent Pollutant Scan
Monitor and Report
Footnote 9
Footnote 9
Effluent
(Summer): April 1- October 31
(Winter): November 1 - March 31
(Daily): every day on which a wastewater discharge occurs except Saturdays, Sundays, and legal holidays
unless otherwise specified by the Director.
All footnotes are listed on the following page.
Page 4 of 14

Permit NC0023973
Section A.(2.) Footnotes:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (7).
2. U = upstream at a point equidistant between the radio tower north of the WWTP and the northern
end of the dredge spoil island immediately east of the outfall. D = downstream at a point
equidistant between the mouth of Barnards Creek and the southern end of the dredge spoil island
immediately east of the outfall.
3. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed
15 % of the respective influent value (i.e., 85% removal is required).
4. Limit and monitor only if the facility adds chlorine or chlorine derivatives to wastewater that is
eventually discharged. The Division shall consider all effluent TRC values reported below 50
µg/1 to be in compliance with this permit. The permittee shall continue to record and submit all
values reported by a North Carolina certified laboratory even if these values fall below 50 mil.
5. Chronic Toxicity Testing using Ceriodaphnia dubia, 7-day pass/fail @ 4.0 % effluent. Perform
tests during March, June, September, and December [see A (5)]. Metals sampling shall coincide
with toxicity sampling.
6. A dilution model shall be performed no later than 12 months after the engineer's certification for
completion is issued for the 16 MGD expansion. See Special Condition A.(8.).
7. Stream Sampling — The permittee has deferred receiving -stream sampling to the Lower Cape
Fear River Program by memorandum of agreement (MOA). Should this MOA terminate for any
reason, the permittee shall immediately inform the Division in writing and immediately resume
instream monitoring in accordance with this permit.
8. Variable Frequency — Stream samples shall be collected 3/week during the summer months of
June, July, August, and September; samples shall be collected weekly during the rest of the year.
9. The permittee shall perform three effluent pollutant scans during the term of this permit [see A
(6)].
There shall be no discharges of floating solids or foam other than trace amounts.
Page 5of14

Permit NC0023973
A. (3.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Beginning upon receipt of the Engineer's Certification for completion of the 20 MGD expansion and lasting
until expansion above 20 MGD (and receipt of the Engineer's Certification of completion) or permit
expiration, the permittee is authorized to discharge treated wastewater from Outfall 001. Such discharges
shall be limited and monitoredi by the permittee as specified below:
EFFLUENT
PARAMETER
EFFLUENT
LIMITATIONS
MONITORING
REQUIREMENTS
Monthly
Average
._Weekly
Average
Daily
Maximum
' Measurement
Frequency
Sample
' Type.
- Sample
Location2
Flow
.
20.0 MGD
• Continuous
Recordin g
Influent or
Effluent
BOD, 5-day, 20°C 3
(April-1—Oct.31)
5.0 mg/L
7.5 mg/L
Daily
Composite
Influent and
Effluent
BOD, 5-day, 20°C 3
(Nov. 1— March 31)
10.0 mg/L
15.0 mg/L
Daily
Composite
Influent and
Effluent
Total Suspended
Solids 3
30.0 mg/L
45.0 mg/L
Daily
Composite
Influent and
Effluent
NH3 as N
(April 1 — Oct. 31)
1.0 mg/L
3.0 mg/L
-
3/Week
Composite
Effluent
NH3 as N
(Nov. 1 — March 31)
2.0 mg/L
6.0 mg/L
3/Week
Composite
Effluent
Enterococci
(geometric mean)
35/100 mL
276/100 mL
Daily
Grab
Effluent
Total Residual Chlorine's
13.0 pg/L
Daily
Grab
Effluent
Temperature
Daily
Grab
Effluent
pH
Between 6.8 and 8.5 standard units
Daily
Grab
Effluent
Dissolved Oxygen
Daily average >_ 6.0 mg/L
Daily
Grab
Effluent
Total Phosphorus
Monthly
Composite
Effluent
Total Nitrogen
(NO2-N+ NO3-N+ TKN)
Monthly
Composite
Effluent
Total Copper
Quarterly
Composite
Effluent
Whole Effluent Toxicity 5
Quarterly
Composite
Effluent
Dissolved Oxygen 6
Variable?
Grab
U, D
Temperature 6
Variable'
Grab
U, D
Effluent Pollutant Scan
Monitor and Report
Footnote 8
Footnote 8
Effluent
(Summer): April 1- October 31
(Winter): November 1 - March 31
(Daily): every day on which a wastewater discharge occurs except Saturdays, Sundays, and legal holidays
unless otherwise specified by the Director.
All footnotes are listed on the following page.
Page 6 of 14

Permit NC0023973
Section A.(3.) Footnotes:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (7).
2. U = upstream at a point equidistant between the radio tower north of the WWTP and the northern
end of the dredge spoil island immediately east of the outfall. D = downstream at a point
equidistant between the mouth of Barnards Creek and the southern end of the dredge spoil island
immediately east of the outfall.
3. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed
15 % of the respective influent value (i.e., 85% removal is required).
4. Limit and monitor only if the facility adds chlorine or chlorine derivatives to wastewater that is
eventually discharged. The Division shall consider all effluent TRC values reported below 50
µg/1 to be in compliance with this permit. The permittee shall continue to record and submit all
values reported by a North Carolina certified laboratory even if these values fall below 50 µg/1.
5. Chronic Toxicity Testing using Ceriodaphnia dubia, 7-day pass/fail @ 5.0 % effluent. Perform
tests during March, June, September, and December [see A (5)]. Metals sampling shall coincide
with toxicity sampling.
6. Stream Sampling — The permittee has deferred receiving -stream sampling to the Lower Cape
Fear River Program by memorandum of agreement (MOA). Should this MOA terminate for any
reason, the permittee shall immediately inform the Division in writing and immediately resume
instream monitoring in accordance with this permit.
7. Variable Frequency — Stream samples shall be collected 3/week during the summer months of
June, July, August, and September; samples shall be collected weekly during the rest of the year.
8. The permittee shall perform three effluent pollutant scans during the term of this permit [see A
(6)].
There shall be no discharges of floating solids or foam other than trace amounts.
Page 7 of 14

Permit NC0023973
A. (4.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Beginning upon receipt of the Engineer's Certification for completion of the 24 MGD expansion and lasting
until expiration, the permittee is authorized to discharge treated wastewater from Outfall 001. Such
discharges shall be limited and monitored' by the permittee as specified below:
EFFLUENT
PARAMETER
EFFLUENT
LIMITATIONS
MONITORING
REQUIREMENTS.
Monthly
Average
Weekly
Average.
Daily
Maximum .
Measurement,
Frequency,
Sample
Sample
Flow
24.0 MGD
Continuous
RecordingInfluent
or
Effluent
BOD, 5-day, 20°C 3
(April 1 — Oct. 31)
5.0 mg/L
7.5 mg/L
Daily
Composite
Influent and
Effluent
BOD, 5-day, 20°C 3
(Nov. 1 — March 31)
10.0 mg/L
15.0 mg/L
Daily
Composite
Influent and
Effluent
Total Suspended
Solids 3
30.0 mg/L
45.0 mg/L
Daily
Composite
Influent and
Effluent
NH3 as N
(April 1 —Oct. 31)
1.0 mg/L
3.0 mg/L
3/Week
Composite
Effluent
NH3 as N
(Nov. 1 — March 31)
2.0 mg/L
6.0 mg/L
3/Week
Composite
Effluent
Enterococci
(geometric mean)
35/100 mL
276/100 mL
Daily
Grab
Effluent
Total Residual Chlorine4
13.0 pg/L
Daily
Grab
Effluent
Temperature
Daily
Grab
Effluent
pH
Between 6.8 and 8.5 standard units
Daily
Grab
Effluent
Dissolved Oxygen
Daily average >_ 6.0 mg/L
Daily
Grab
Effluent
Total Phosphorus
Monthly
Composite
Effluent
Total Nitrogen
(NO2-N+ NO3-N+ TKN)
Monthly
Composite
Effluent
Total Copper
Quarterly
Composite
Effluent
Whole Effluent Toxicity 5
Quarterly
Composite
Effluent
Dissolved Oxygen 6
Variable?
Grab
U, D
Temperature 6
Variable'
Grab
U, D
Effluent Pollutant Scan
Monitor and Report
Footnote 8
Footnote 8
Effluent
(Summer): April 1- October 31
(Winter): November 1 - March 31
(Daily): every day on which a wastewater discharge occurs except Saturdays, Sundays, and legal holidays
unless otherwise specified by the Director.
All footnotes are listed on the following page.
Page 8 of 14

Permit NC0023973
Section A.(4.) Footnotes:
1. No later than 270 days from the effective date of this permit, begin submitting discharge
monitoring reports electronically using NC DWR's eDMR application system. See Special
Condition A. (7).
2. U = upstream at a point equidistant between the radio tower north of the WWTP and the northern
end of the dredge spoil island immediately east of the outfall. D = downstream at a point
equidistant between the mouth of Barnards Creek and the southern end of the dredge spoil island
immediately east of the outfall.
3. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed
15 % of the respective influent value (i.e., 85% removal is required).
4. Limit and monitor only if the facility adds chlorine or chlorine derivatives to wastewater that is
eventually discharged. The Division shall consider all effluent TRC values reported below 50
µg/1 to be in compliance with this permit. The permittee shall continue to record and submit all
values reported by a North Carolina certified laboratory even if these values fall below 50 µg/1.
5. Chronic Toxicity Testing using Ceriodaphnia dubia, 7-day pass/fail @ 6.0 % effluent. Perform
tests during March, June, September, and December [see A (5)]. Metals sampling shall coincide
with toxicity sampling.
6. Stream Sampling — The permittee has deferred receiving -stream sampling to the Lower Cape
Fear River Program by memorandum of agreement (MOA). Should this MOA terminate for any
reason, the permittee shall immediately inform the Division in writing and immediately resume
instream monitoring in accordance with this permit.
7. Variable Frequency — Stream samples shall be collected 3/week during the summer months of
June, July, August, and September; samples shall be collected weekly during the rest of the year.
8. The permittee shall perform three effluent pollutant scans during the term of this permit [see A
(6)].
There shall be no discharges of floating solids or foam other than trace amounts.
Page 9 of 14

Permit NC0023973
SUPPLEMENT TO EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
SPECIAL CONDITIONS
A. (5.) CHRONIC TOXICITY PERMIT LIMIT (QUARTERLY)
[15A NCAC 02B .0200 et seq.]
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant mortality to
Ceriodaphnia dubia at an effluent concentration of 3.0% at 12 MGD; 4.0% at 16 MGD; 5.0 % at 20
MGD; and 6.0 % at 24 MGD.
The permit holder shall perform at a minimum, quarterly monitoring using test procedures outlined in the
"North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised December 2010, or
subsequent versions or "North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised -
December 2010) or subsequent versions. The tests will be performed during the months of March, June,
September, and December. These months signify the first month of each three-month toxicity testing
quarter assigned to the facility. Effluent sampling for this testing must be obtained during representative
effluent discharge and shall be performed at the NPDES permitted final effluent discharge below all treatment
processes.
If the test procedure performed as the first test of any single quarter results in a failure or ChV below
the permit limit, then multiple -concentration testing shall be performed at a minimum, in each of the
two following months as described in "North Carolina Phase H Chronic Whole Effluent Toxicity Test
Procedure" (Revised -December 2010) or subsequent versions.
All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge
Monitoring Form (MR-1) for the months in which tests were performed, using the parameter code TGP3B for
the pass/fail results and THP3B for the Chronic Value. Additionally, DWR Form AT-3 (original) is to be
sent to the following address:
Attention: North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1623 Mail Service Center
Raleigh, NC 27699-1623
Completed Aquatic Toxicity Test Forms shall be filed with the Water Sciences Section no later than 30 days
after the end of the reporting period for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical measurements and all
concentration/response data, and be certified by laboratory supervisor and ORC or approved designate
signature. Total residual chlorine of the effluent toxicity sample must be measured and reported if chlorine is
employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is
required, the permittee will complete the information located at the top of the aquatic toxicity (AT) test form
indicating the facility name, permit number, pipe number, county, and the month/year of the report with the
notation of "No Flow" in the comment area of the form. The report shall be submitted to the Water Sciences
Section at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required, monitoring will
be required during the following month. Assessment of toxicity compliance is based on the toxicity testing
quarter, which is the three month time interval that begins on the first day of the month in which toxicity
testing is required by this permit and continues until the final day of the third month.
Should any test data from this monitoring requirement or tests performed by the North Carolina Division of
Water Resources indicate potential impacts to the receiving stream, this permit may be re -opened and
modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control
organism survival, minimum control organism reproduction, and appropriate environmental controls, shall
constitute an invalid test and will require immediate follow-up testing to be completed no later than the last
day of the month following the month of the initial monitoring.
Page 10 of 14

Permit NC0023973
A. (6.) EFFLUENT POLLUTANT SCAN
.[G.S. 143-215.1(b)1
The Permittee shall perform a total of three (3) Effluent Pollutant Scans for all parameters listed below. One
scan must be performed in each of the following years: 2013, 2014, and 2015. Analytical methods shall be in
accordance with 40 CFR Part 136 and shall be sufficiently sensitive to determine whether parameters are present
in concentrations greater than applicable standards and criteria. Samples should be collected with one quarterly
toxicity test each year, and must represent seasonal variation [i.e., do not sample in the same quarter every year].
Unless otherwise indicated, metals shall be analyzed as "total recoverable."
Ammonia (as N) Trans-1,2-dichloroethylene Bis (2-chloroethyl) ether
Chlorine (total residual, TRC) 1,1-dichloroethylene Bis (2-chloroisopropyl) ether
Dissolved oxygen 1,2-dichloropropane Bis (2-ethylhexyl) phthalate
Nitrate/Nitrite 1,3-dichloropropylene 4-bromophenyl phenyl ether
Kjeldahl nitrogen Ethylbenzene Butyl benzyl phthalate
Oil and grease Methyl bromide 2-chloronaphthalene
Phosphorus
Total dissolved solids
Hardness
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury (EPA Method 1631E)
Nickel
Selenium
Silver
Thallium
Zinc
Cyanide
Total phenolic compounds
Volatile organic compounds:
Acrolein
Acrylonitrile
Benzene
Bromoform
Carbon tetrachloride
Chlorobenzene
Chlorodibromomethane
Chloroethane
2-chloroethylvinyl ether
Chloroform
Dichlorobromomethane
1,1-dichloroethane
1,2-dichloroethane
Methyl chloride
Methylene chloride
1,1,2,2-tetrachloroethane
Tetrachloroethylene
Toluene
1,1, 1-trichloroethane
1,1,2-trichloroethane
Trichloroethylene
Vinyl chloride
Acid -extractable compounds:
P-chloro-m-cresol
2-chlorophenol
2,4-dichlorophenol
2,4-dimethylphenol
4,6-dinitro-o-cresol
2,4-dinitrophenol
2-nitrophenol
4-nitrophenol
Pentachlorophenol
Phenol
2,4,6-trichlorophenol
Base -neutral compounds:
Acenaphthene
Acenaphthylene
Anthracene
Benzidine
Benzo(a)anthracene
Benzo(a)pyrene
3,4 benzofluoranthene
Benzo(ghi)perylene
Benzo(k)fluoranthene
Bis (2-chloroethoxy) methane
4-chlorophenyl phenyl ether
Chrysene
Di-n-butyl phthalate
Di-n-octyl phthalate
Dibenzo(a,h)anthracene
1,2-dichlorobenzene
1,3-dichlorobenzene
1,4-dichlorobenzene
3,3-dichlorobenzidine
Diethyl phthalate
Dimethyl phthalate
2,4-dinitrotoluene
2,6-dinitrotoluene
1,2-diphenylhydrazine
Fluoranthene
Fluorene
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclo-pentadiene
Hexachloroethane
Indeno(1,2,3-cd)pyrene
Isophorone
Naphthalene
Nitrobenzene
N-nitrosodi-n-propylamine
N-nitrosodimethylamine
N-nitrosodiphenylamine
Phenanthrene
Pyrene
1,2,4-trichlorobenzene
Reporting. Test results shall be reported on DWQ Form -A MR-PPA1 (or in a form approved by the
Director) by December 31' of each designated sampling year. The report shall be submitted to the following
address: NC DENR / DWR / Central Files, 1617 Mail Service Center, Raleigh, North Carolina 27699-
1617.
Page 11 of 14

Permit NC0023973
Additional Toxicity Testing Requirements for Municipal Permit Renewal. Please note that Municipal
facilities that are subject to the Effluent Pollutant Scan requirements listed above are also subject to additional
toxicity testing requirements specified in Federal Regulation 40 CFR 122.21(j)(5). The US EPA requires four
(4) toxicity tests for a test organism other than the test species currently required in this permit. The multiple
species tests should be conducted either quarterly for a 12-month period prior to submittal of the permit
renewal application, or four tests performed at least annually in the four and one half year period prior to the
application. These tests shall be performed for acute or chronic toxicity, whichever is specified in this permit.
The multiple species toxicity test results shall be filed with the Aquatic Toxicology Branch at the following
address:
North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1623 Mail Service Center
Raleigh, North Carolina 27699-1623
Contact the Division's Aquatic Toxicology Branch at 919-743-8401 for guidance on conducting the
additional toxicity tests and reporting requirements. Results should also be summarized in Part E (Toxicity
Testing Data) of EPA Municipal Application Form 2A, when submitting the permit renewal application to the
NPDES Permitting Unit.
A. (7.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
[G.S. 143-215.1(b)]
Proposed federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and
specify that, if a state does not establish a system to receive such submittals, then permittees must submit
DMRs electronically to the Environmental Protection Agency (EPA). The Division anticipates that these
regulations will be adopted and is beginning implementation in late 2013.
NOTE: This special condition supplements or supersedes the following sections within Part II of this permit
(Standard Conditions for NPDES Permits):
• Section B. (11.)
• Section D. (2.)
• Section D. (6.)
• Section E. (5.)
Signatory Requirements
Reporting
Records Retention
Monitoring Reports
1. Reporting [Supersedes Section D. (2.) and Section E. (5.) (a)1
Beginning no later than 270 days from the effective date of this permit, the permittee shall begin reporting
discharge monitoring data electronically using the NC DWR's Electronic Discharge Monitoring Report
(eDMR) internet application.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
submitted electronically using eDMR. The eDMR system allows permitted facilities to enter monitoring
data and submit DMRs electronically using the internet. Until such time that the state's eDMR
application is compliant with EPA's Cross -Media Electronic Reporting Regulation (CROMERR),
permittees will be required to submit all discharge monitoring data to the state electronically using eDMR
and will be required to complete the eDMR submission by printing, signing, and submitting one signed
original and a copy of the computer printed eDMR to the following address:
NC DENR / DWR / Information Processing Unit
ATTENTION: Central Files / eDMR
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Page 12 of 14

Permit NC0023973
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the facility
being physically located in an area where less than 10 percent of the households have broadband access,
then a temporary waiver from the NPDES electronic reporting requirements may be granted and
discharge monitoring data may be submitted on paper DMR forms (MR 1, 1.1, 2, 3) or alternative forms
approved by the Director. Duplicate signed copies shall be submitted to the mailing address above.
Requests for temporary waivers from the NPDES electronic reporting requirements must be submitted in
writing to the Division for written approval at least sixty (60) days prior to the date the facility would be
required under this permit to begin using eDMR. Temporary waivers shall be valid for twelve (12)
months and shall thereupon expire. At such time, DMRs shall be submitted electronically to the Division
unless the permittee re -applies for and is granted a new temporary waiver by the Division.
Information on eDMR and application for a temporary waiver from the NPDES electronic reporting
requirements is found on the following web page:
http://portal.ncdenr.org/web/wq/admin/bog/ipu/edmr
Regardless of the submission method, the first DMR is due on the last day of the month following the
issuance of the permit or in the case of a new facility, on the last day of the month following the
commencement of discharge.
2. Signatory Requirements [Supplements Section B. (11.) (b) and supersedes Section B.
(11.) (d))
All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part II,
Section B. (11.)(a) or by a duly authorized representative of that person as described in Part II, Section B.
(11.)(b). A person, and not a position, must be delegated signatory authority for eDMR reporting
purposes.
For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user account
and login credentials to access the eDMR system. For more information on North Carolina's eDMR
system, registering for eDMR and obtaining an eDMR user account, please visit the following web page:
http:l/portal.ncdenr.org/web/wq/admin/bog/ipu/edmr
Certification. Any person submitting an electronic DMR using the state's eDMR system shall make the
following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION WILL BE
ACCEPTED:
"1 cert, under penalty of law, that this document and all attachments were prepared under my direction
or supervision in accordance with a system designed to assure that qualified personnel properly gather
and evaluate the information submitted. Based on my inquiry of the person or persons who manage the
system, or those persons directly responsible for gathering the information, the information submitted is,
to the best of my knowledge and belief true, accurate, and complete. I am aware that there are significant
penalties for submitting false information, including the possibility of fines and imprisonment for knowing
violations."
3. Records Retention [Supplements Section D. (6.)1
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR submissions.
These records or copies shall be maintained for a period of at least 3 years from the date of the report.
This period may be extended by request of the Director at any time [40 CFR 122.41].
Page 13 of 14

Permit NC0023973
A.(8.) MODELING REQUIREMENT
[G.S. 143-215.1(b)]
The Authority shall submit a CORMIX model (or equivalent) providing additional information regarding end -
of -pipe dilution no later than 12 months after an engineer's certification for the completion of the 16.0 MGD
plant expansion is issued. The model shall address dilution at the approved 16.0 MGD increased flow rate
into the Cape Fear River for M'Kean Maffitt WWTP's specific discharge configuration. The dilution factor
determined by the CORMIX model (or equivalent) shall be used by the permittee for the chronic effluent test
concentration once the model is reviewed and approved by the Division.
A.(9.) HISTORICAL PERMIT LIMITS
The Division recognizes that prior to issuance of the permit, the M'Kean Maffitt (Southside) WWTP was
permitted to discharge with secondary limits of 25.0 mg/L CBOD5, 30.0 mg/L TSS, and no limit for NH3 as
N. At the permitted flow of 12.0 MGD, these limits translate approximately to mass loads of 457 tons per
year (tpy) BOD5, 548 tpy TSS, and 365 tpy NH3 as N (assuming 20 mg/L). The mass loads described in this
paragraph will be one factor the Division considers when developing future wasteload allocations resulting
from the TMDL process or when considering future expansion requests for the M'Kean Maffitt WWTP.
A.(10.) ANTI -BACKSLIDING
The BOD5 and ammonia nitrogen (NH3 as N) limits in this permit may be replaced with less stringent limits
without violating state and Federal anti -backsliding provisions if:
a. Material and substantial alterations or additions to the permitted facility occurred after permit
issuance that justifies less stringent limits;
b. Events occurred beyond the permittee's control for which there is no reasonably available remedy;
c. Permittee has properly installed and operated required treatment equipment that cannot achieve
permit limits; or
d. New information (other than revised regulations, guidance, or test methods) is available that justifies
less stringent limits;
and provided that the Division deems such modification appropriate and consistent with applicable laws and
regulations."
Page 14of14

Cape Fear Public Utility Authority
M'Kean Moffitt (Southside) WWTP
ceivinq Stream: Cape Fear River 8-Digit HUC: 03030005
:itude: 34° 09' 56" N Sub -Basin: 03-06-17
igitude: 77° 56' 56" W Permitted Flow: 12.0 MGD to 24 MGD
eam Class: SC Grid/Quad: K 27 NW / Wilmington
North
NPDES Permit No. NC0023973
New Hanover County

AFFIDAVIT OF PUBLICATION
STATE OF NORTH CAROLINA
COUNTY OF NEW HANOVER
Public Notice North Carolina Envi-
ronmental Management Commis-
sion/NPDES Unit 1617 Mail Service
Center Raleigh, NC 27699-1617
Notice of Intent to Issue a NPDES
Wastewater Permit
The North Carolina Environmental
Management Commission proposes
to issue a NPDES wastewater dis-
charge permit to the person(s)
listed below. Written comments re-
garding the proposed permit will be
accepted until 30 days after the
publish date of this notice. The Di-
rector of the NC Division of Water
Resources (DWR) may hold a public
hearing should there be a signifi-
cant degree of public interest.
Please mall comments and/or in-
formation requests to DWR at the
above address. Interested persons
may visit the DWR at 512 N. Salis-
bury Street, Raleigh, NC to review
information on file. Additional in-
formation on NPDES permits and
this notice may be found on our
website:
htax/iportal. nr.denr. orglweblwcdswafps/npdesical
endar, or by calling [phone].
Th Cape Fear Public Utility Author-
ity requested renewal of permit
NC0023973 for Its M'Kean Maffitt
(Southside) WWTP in New Hanover
County; this permitted discharge is
treated municipal wastewater to
the Cape Fear River, Cape Fear
River Basin.
Before the undersigned, a Notary Public of Said County and State,
Jarimy Springer
Who, being duly sworn or affirmed, according to the law, says that he/she is
Accounting Specialist
of THE STAR -NEWS, a corporation organized and doing business under the Laws of the State of
North Carolina, and publishing a newspaper known as STAR -NEWS in the City of Wilmington
Public Notice North Carolina Environmental Management Commission/NPDES Unit 1617
Mail Service Center Raleigh, NC 27699-1617 Notice of Intent to Issue a NPDES Wastewater
Permit The North Carolina Environmental Management Commission proposes to issue a
NPDE
was inserted in the aforesaid newspaper in space, and on dates as follows:
5/221x
And at the time of such publication Star -News was a newspaper meeting all the requirements and
qualifications prescribed by Sec. No. 1-597 G.S. of N.C.
•
Title: Accounting Specialist
Sworn or affirmed to, and subscribed before me this day of
/" a , A.D., o IS
In Testimony Whereof, I have hereunto set my hand and affixed my offici
year aforesaid.
l /+f\
My commission expires 'C day of l 0-16 . 20 16
Upon reading the aforegoing affidavit with the advertisement thereto annexed it is adjudged by the Court that the said
publication was duly and properly made and that the summons has been duly and legally served on the defendant(s).
This day of
MAIL TO:
Clerk of Superior Court

Z•is MikTh' Moc
DENR / DWR / NPDES Unit
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES Permit No. NC0023973 Expansion
Facility Information
Applicant/Facility Name:
Cape Fear Public Utility Authority / M'Kean Maffitt (Southside) WWTP
Applicant Address:
235 Government Center Drive, Wilmington, North Carolina 28403
Facility Address:
3436 River Road, Wilmington, North Carolina
Permitted Flow:
12 MGD, 16 MGD, 20 MGD, and 24 MGD
Type of Waste:
Municipal
Facility/Permit Status:
Modification for expansion to 24 MGD
County:
New Hanover
Miscellaneous
Receiving Stream:
Cape Fear River Regional Office:
Stream Classification: SC
Subbasin:
8-Di•it HUC:
Stream Index:
03-06-17
303(d) Listed?
03030005
18-(71)
Yes, Cu and DO
Summer 7Q10 (cfs)
Average Flow (cfs):
IWC (%):
Revised CORMIX model
required after 16 MGD
expansion.
Tidal
Tidal
N/A for RPA
For WET test:
3% at 12 MGD
4% at 16 MGD
5% at 20 MGD
6% at 24 MGD
Wilmington
State Grid / USGS Quad: K 27 NW/Wilmin
•
ton
Date:
Addendum added:
Permit Writer:
May 12, 2015
July 31, 2015 and
revised 8/17/15
Julie Grz b
Lat. 34° 14' 27" N Long. 77° 57' 10" W
Background:
• This permit was originally issued in 1982.
• This is a permit modification for Cape Fear Public Utility Authority (CFPUA, formerly
the City of Wilmington), which owns and operates the M'Kean Maffitt (Southside)
WVVTP. The facility proposes phased future expansions to 16 MGD (Phase I), 20
MGD (Phase 2), and 24 MGD (Phase 3).
• This facility is a Major POTW with a full pretreatment program. The WWTP has one
SIU, New Hanover Regional Medical Center, which contributes an average daily flow
of 103,000 gallons per day from laundry, kitchen, and laboratory wastes.
• The current permit expires on 12/31/2016. The facility submitted an application (EPA
Form 2A) for an expansion/modification which was received on 10/27/14. The facility
included three Effluent Pollutant Scans with the submission.
Facility Description:
• The CFPUA was created by the City of Wilmington, NC and New Hanover County,
NC on July 1, 2008 to consolidate provision of water and wastewater services within
their combined service areas. The CFPUA operates and maintains three wastewater
treatment plants and two water treatment plants.
Fact Sheet
Renewal -- NPDES Permit NC0023973
Page 1

• This Southside WWTP was originally placed into service in 1972 as a 6 MGD facility
serving the City of Wilmington. It was later expanded to a 12 MGD secondary
treatment level facility to serve New Hanover County and the Town of Wrightsville
Beach as well.
• Annual average wastewater flow was 8.4 MGD (or 70% of permitted flow) for the
period of July 2012 to June 2013. The annual average wastewater flow was 8.92
MGD in 2014.
• Current treatment consists of dual mechanical bar screens, dual grit collectors, a
manual bypass screen which provides redundancy, two treatment trains which
include a primary clarifier and a trickling filter, an aeration basin, dual secondary
clarifiers, chlorine contact tanks and dechlorination. Sludge is sent to the anaerobic
digesters, dewatered using a belt filter press, and land applied off -site.
• The three Phase expansion from 12 MGD to 16 to 20 to 24 MGD will include
capacity expansions to five pump stations, upsizing of approximately 4,200 linear
feet of force main, addition of a mechanical bar screen and a grit collector, two new
115 foot diameter primary clarifiers, six new aeration basins at 1.65 million gallons,
four 160-foot diameter secondary clarifiers, deep bed tertiary filters, UV disinfection,
and installation of a 60 inch diameter effluent disposal pipe to the Cape Fear River.
The existing secondary clarifiers will be used for influent flow equalization storage in
all expansion phases. Three new gravity belt thickeners will be added for WAS
thickening, three new anaerobic digesters will be added, and four belt filter presses.
Receiving Stream:
• The facility discharges treated domestic wastewater via Outfall 001 to the Cape Fear
River in the Cape Fear River Basin (subbasin 03-0617, HUC 03030005).
• At the outfall location, the receiving stream is classified SC waters (stream
assessment unit 18-(71)a3 which extends from Greenfield Creek (above Hwy 421)
down to Barnards Creek by Silver Lake.
• This segment of the lower Cape Fear River is listed as impaired on the 2014 303(d)
list for copper and low dissolved oxygen. Much of the low DO condition in the lower
Cape Fear River has been attributed to swamp water inputs.
• The Permittee is a member of the Lower Cape Fear River Program (LCFRP), which
conducts water quality monitoring within the basin to gain a broad water quality
perspective. Instream monitoring requirements as part of a NPDES permit are
waived as long as the facility maintains membership within the LCFRP. The MOA
between DWR and the LCFRP was renewed in 7/1/2011.
• There is a LCFRP station (B9795000) located within this stream segment. Data for
2011-2014 confirms the low DO condition during summer months.
Facility Performance/Compliance Review:
• DMR Data. In 2014, effluent monthly averages ranged as follows: flow (8.0-11.2
MGD), BOD (5.4-8.3 mg/L), NH3-N (14.5-28.6 mg/L), TSS (4.0-8.7 mg/L),
enterococci (2.7-10.9/100mI), TN (19-35 mg/L), and TP (2.5-4.8 mg/L). The two
months with minimum monthly average DO values, ranged from 6.1-6.2 mg/L.
• Permit Violations. No permit limit violations have occurred since the issuance of the
existing permit on June 1, 2012.
• Compliance Inspections. A routine Compliance Evaluation was performed on 9-10-
2014 and the facility received a rating of "Extremely Reliable". A Pretreatment
Compliance Inspection was performed on 9-7-2012 and the facility received a rating
of "Very Reliable".
Fact Sheet
Renewal -- NPDES NC0023973
Page 2

• Aquatic Toxicity Testing. Overall the facility has passed 21 of 25 toxicity tests
performed since 2010. Two failures occurred in 2012 and since the facility discharge
had a strong record of compliance the Permittee informally began Toxicity
Identification Evaluation procedures to identify the cause of toxicity. The Permittee
spilt samples with DWR on several occasions and the study results are in a letter
dated March 6, 2015. In conclusion, CFPUA has requested that their acute toxicity
monitoring requirement be changed to chronic with an IWC based on a dilution study
performed by Tetra Tech dated May 2001. The Aquatic Toxicity Branch sent an
email confirming that the toxicity testing requirements should be changed to a 7-day
pass/fail chronic test using Ceriodaphia dubia .at the effluent concentration
determined using the modeled dilution.
Permit Limit Development (Existing Conditions —12.0 MGD):
• Maintain limits for CBOD at 25 mg/L, TSS at 30 mg/L, and Enterococci at 35/100
mL year round based on secondary treatment standards.
• Maintain pH limits at 6.8 — 8.5 s.u. range. WQS for Class SC waters.
• Maintain effluent DO limit at 6 mg/L. This segment of the Cape Fear is impaired
for DO.
• Reasonable Potential Analysis (RPA): Effluent metals data for As, Cd, Cr, Cu,
CN, Pb, Mo, Ni, Se, Ag, and Zn was reviewed for the period of Dec. 2011
through Jan. 2015. Samples for As, Cd, Cr, Pb, Mo, Ni, and Se were all reported
below detection levels for that time period. A RPA was performed on Cu, CN, Ag,
and Zn
0
be removed from the permit. See the Addendum at the end of the Fact Sheet. A
revised RPA was performed using an IWC of 100%. All the metals listed above
will continue to be monitored by the CFPUA as part of their Pretreatment LTMP.
• The Aquatic Toxicity monitoring requirement was changed from acute to chronic.
Based on a dilution model performed by Tetra Tech in 2001 an IWC of 3% was
determined for a Permitted flow of 12 MGD from the M'Kean Maffitt WWTP.
Therefore, the toxicity testing will be revised to chronic toxicity testing using an
effluent concentration of 3% and Ceriodaphnia Dubia as the test organism.
Permit Limit Development (Proposed Phased Expansion to 16 MGD, 20 MGD, and
24 MGD):
• SEPA/FONSI Determination. The proposed expansion was subject to review by
governmental agencies under the State of North Carolina Environmental Policy
Act (SEPA EA), and DWR has concluded that the proposed project will not result
in significant impacts to the environment. A Finding of No Significant Impact
(FONSI) was issued on September 13, 2013 and is available for inspection at the
State Clearinghouse.
• Water Quality Loading Evaluation. In consideration of the 303(d)-listed impaired
waters designation for this river segment due to low dissolved oxygen conditions,
an evaluation of oxygen demand from historical loading versus future loading
was conducted (see Attached). The historical Ultimate Oxygen Demand (UOD)
was determined for the period 2009-2010. Over this period, the facility discharge
averaged 8.51 MGD, with satisfactory CBOD5 effluent levels (7.7 mg/I), but there
were no ammonia limits and relatively little nitrification, with resultant effluent
ammonia concentrations averaging 26 mg NH3-N/I. At full expansion to 24
MGD, the facility will need to comply with advanced BOD5 limits of 5 mg/I
Fact Sheet
Renewal -- NPDES NC0023973
Page 3

1
summer/10 mg/I winter, and with significant reductions in ammonia to comply
with future limits of 1 mg NH3-N/I summer and 2 mg NH3-N/I winter. From a
loading perspective (attached), there will be a slight increase in CBODu loading
(from 822 Ib/d to 1722 Ib/d), but a much more significant reduction in NBODu
loading (from 8289 Ib/d down to 1276 Ib/d). Overall, the UOD load will be
decreased from historical averages of 9111 Ib/d down to 3048 Ib/d, or a 66%
reduction in ultimate oxygen demand. The conclusion of this loading evaluation is
that the proposed expansion/upgrade will provide a net benefit to instream
dissolved oxygen conditions.
• Antideqradation Review. Per NC Anitdegradation Policy (15A NCAC 26.0201),
each applicant for an NPDES permit expansion must document an effort to
consider non -discharge alternatives pursuant to 15A NCAC 2H.0105(c)(2). This
alternatives evaluation was submitted as part of the SEPA EA document, and
resubmitted as an Engineering Alternatives Analysis (EAA) for the permit renewal
and modification. DWR staff reviewed both the flow justification as well as the
alternatives analysis. DWR staff concurred with the projected needs based on a
20-year planning horizon. CFPUA's 2007 Wastewater Master Plan determined
an annual growth rate of —4% per year for the entire 20 year planning cycle.
Most of the growth is expected to occur in the southern portion of Wilmington and
New Hanover County. Maximum wastewater flow is expected to increase from
9.4 MGD in 2013 to 24 MGD in 2033.
Likewise, DWR concurred with the alternatives analysis conclusion that
expansion at the current location with a direct discharge to surface water was the
most environmentally sound alternative from the reasonably cost-effective
options (per 15A NCAC 2H.0105). A cost evaluation for a non -discharge spray
irrigation option for the expanded wastewater volume (12 MGD) would require
16,800 acres and a total project cost of $791 Million; the total estimated project
cost for a non -discharge high -rate infiltration option would require 276 acres and
a total project cost of $340 Million; and in comparison, the total estimated project
cost for expanding the current WWTP with a direct discharge was estimated at
$201.5 Million, representing a 69% cost savings compared to high -rate
infiltration. In addition, this project is likely to provide an alternative for outdated
failing septic systems throughout the County. DWR concludes that the proposed
expansion will provide for public health benefits and social benefits to the
community by providing necessary regional wastewater treatment services to
accommodate future growth.
• Proposed Limits/Monitorinq for 16 MGD, 20 MGD and 24 MGD.
o BOD/NH3-N: Reduce to 5/1 mg/L (summer) and 10/2 mg/L (winter) based
on Best Available Technology for this stream segment as recommended
in Chapter 30 of the Cape Fear River Basinwide Plan.
o TSS. Maintain at 30/45 mg/L secondary treatment levels.
o Dissolved Oxygen (DO): a limit of 6 mg/L based on Cape fear River
Basinwide Plan
o Enterococci bacteria. Maintain monthly average limit of 35/100 mL and
Weekly average limit of 276/100 mL.
o Copper. The revised reasonable potential analysis showed reasonable
potential for copper in the effluent wastewaters to violate saltwater
standards. Copper monitoring was maintained throughout the permit.
o Nutrients: There are no nutrient limits proposed in this permit, since the
receiving waterbody is not listed as NSW and/or 303(d) impaired for
Fact Sheet
Renewal -- NPDES NC0023973
Page 4

chlorophyll -a. Monthly nutrient monitoring will continue per 15A NCAC 2B
.0500.
o In accordance with the 2012 Mercury TMDL NPDES Guidance, effluent
mercury data from 2010-2014 was evaluated. The pretreatment data
showed that the annual mean effluent concentrations were below the
Water Quality Based Effluent Limit of 204 ng/L. Only two of the three
effluent pollutant scans reviewed used the low-level mercury detection
test and that data showed that it was below the Technology Based
Effluent Limit of 47 ng/L. The City will be required to continue monitoring
mercury as part of its LTMP and its Effluent Pollutant Scans.
Pretreatment will be notifying Permittees that they must use method 1631
E and the Effluent Pollutant Scan condition in the permit specifies low
level mercury testing. Low level mercury test results will be re-evaluated
upon permit renewal in 2016 and assessed in accordance with 2012
Statewide Mercury TMDL.
Proposed Schedule of Issuance:
Draft Permit to Public Notice: May 19, 2015 (estimate)
Permit Scheduled to Issue: July 13, 2015 (estimate)
NPDES Unit Contact:
If you have questions regarding any of the above information or on the attached permit,
please contact Julie Grzyb at Julie.grzyb(a�ncdenr.gov or call [phone].
SIGNATURE: 61
DATE: (G — a (`�—
Comments:
Written comments received from EPA on June 4, 2015, June 26, 2015, and August 5, 2015.
Written comments received from the CFPUA on June 2, 2015.
N.C. Division of Coastal Management stated, "Provided that the project is within state water quality,
storm water and waste water treatment standards, I do not have any comments."
ADDENDUM TO FACT SHEET:
EPA review and discussions:
Model and calculated dilution factor:
Informal comments were received from EPA questioning the validity of the 33:1 dilution ratio
used in determining allowable effluent concentrations for toxicant pollutants of concern and the
effluent concentration to be used for chronic toxicity testing. The three-dimensional water
quality model of the Lower Cape Fear River for the City of Wilmington and New Hanover
County was developed by Tetra Tech in 2000 and 2001 using the Environmental Fluid
Dynamics Code (EFDC) model. As stated in Tetra Tech's 2008 Northside WWTP Effluent
Dilution Analysis Memo, "A general analysis of dilution of the Northside and Southside WWTP
discharges was conducted using EFDC's integrated "jet plume" code (JP-EFDC); although that
analysis was not conducted specifically for establishing dilution ratios for NPDES permit limits,
the modeling tool represents a significant investment already made by what is now the
Fact Sheet
Renewal -- NPDES NC0023973
Page 5

CFPUA." The 2008 study by Tetra Tech was to address dilution at the increased flow of 16
MGD at the Northside WWTP for both the existing and new discharge line diffusers. The dye
study conducted on the Northside VVWTP discharge was used in the 2008 study to validate
near field mixing and far field transport of the existing effluent at the Northside outfall. A 25:1
dilution ratio was determined for Northside in the 2001 report and the 2008 study resulted in a
20.7:1 ratio being used for permit limit development in Northside's 2012 permit renewal.
Currently, the Southside WVVTP is performing acute toxicity testing at 90% effluent. CFPUA
would like to receive credit for some dilution and perform chronic toxicity testing on its
wastewaters instead of acute testing at 90%. The DWR Aquatic Toxicity Branch agreed that the
chronic test is a very effective test and approved the Authority's proposal to perform chronic
toxicity tests using the 33:1 (IWC = 3% at 12 MGD) dilution based on the 2001 model. In
discussions with EPA, this decision was found to be acceptable; however, it was agreed that
eventually a more comprehensive study/model should be performed by CFPUA to validate the
dilution factor for the M'Kean Maffitt (Southside) WWTP's outfall and discharge volume. The
Authority agreed to such a condition with its Northside WWTP permit and suggested similar
language for the M'Kean Maffitt VWVTP. The following Special Condition was added to the
permit:
A.(8.) MODELING REQUIREMENT
The Authority shall submit a CORMIX model (or equivalent) providing additional
information regarding end -of -pipe dilution no later than 12 months after an
engineer's certification for the completion of the 16.0 MGD plant expansion is
issued. The model shall address dilution at the approved 16.0 MGD increased
flow rate into the Cape Fear River for M'Kean Maffitt WVVTP's specific discharge
configuration. The dilution factor determined by the CORMIX model (or
equivalent) shall be used by the permittee for the chronic effluent test
concentration once the model is reviewed and approved by the Division.
The 33:1 dilution factor was tentatively used to determine chronic effluent testing
concentrations for the other phased expansions until a CORMIX model (or equivalent) is
submitted and approved. The Division agreed with EPA that the dilution factor of 33:1 would not
be used in the determination of allowable effluent concentrations for toxicants (RPA). When the
Authority submits an approvable CORMIX model (or equivalent), the revised dilution factor can
be used for toxicant limit development.
RPA Revision:
The RPA was revised using no dilution. See attached RPA sheet with flows marked as Tidal, IWC
= 100%. Copper was the only parameter showing reasonable potential to violate Water Quality
Standards. Since the copper standard is an action level limit and the facility is currently passing its
Toxicity tests, no limitation was put in the permit. Copper monitoring was put in the permit at the
same monitoring frequency as the existing permit (quarterly).
Comments from CFPUA:
Comments were received from CFPUA on July 2, 2015. The comments are summarized below
along with Division responses and any changes made to the permit as a result of these comments.
1. Comments 1 and 2: CFPUA is not submitting eDMR's and substitute Authority for City.
The final cover letter will not contain the statement on receiving eDMR submittals
and City will be replaced with the word Authority.
Fact Sheet
Renewal -- NPDES NC0023973
Page 6

2. Comment 3 on modeling: The Authority recognized that the EFDC model does provide
some level of support for the dilution factor but is willing to commit to performing a CORMIX
model (or equivalent) providing additional information regarding end -or -pipe dilution at
SSVVWTP, if necessary.
The Division agrees that the 2001 EFDC is sufficient to allow the Authority some
temporary dilution credit in the toxicity test. Therefore, the 33:1 dilution ratio at 12
MGD was used in the permit to determine the effluent concentration to be used for
the chronic toxicity test. A more thorough dilution study shall be performed as
described in the special condition outlined above and in Section A. (8.) of the permit.
The 33:1 dilution factor was not used in assessing compliance with Water Quality
Standards.
3. Comments 4,5,6,7, and 8 on the Supplement to Cover sheet: The Authority requested
corrections to the components list.
Corrections to the components list were made as requested.
4. Comment 9 on TRC: The Authority requests that the TRC footnote require the permittee to
report all data below 50 ug/L as "< 50 ug/L".
This request was formally presented by NCWQA to the Division of Water
Resources. CFPUA is a member of this organization. The DWR laboratory staff is
currently evaluating this request. When the evaluation is completed, and if the
outcome affects the wording in this permit, the Authority can request a permit
modification, if desired.
5. Comments 10, 14, 18, 22 on the Coalition MOA verses instream requirements in the permit:
The Authority is concerned between the differences in the Coalition MOA sampling
requirements and the permit instream sampling requirements and does one affect the other.
The MOA between the LCFRP Coalition and the Division is a separate agreement
from the NPDES permit. The NPDES permit states that if the MOA agreement
should be terminated for any reason the permittee should notify the Division and
resume instream sampling as specified in the NPDES permit. This would also apply
if the permittee terminated its membership with the Lower Cape Fear River
Program. The monitoring frequencies and sampling requirements in the MOA and
the permit are not necessarily meant to be the same. If the renewed MOA in 2016 is
different than the existing one it will not affect the instream monitoring requirements
in the permit. The instream monitoring footnote in all sections A. (1.-4.) will remain
the same.
6. Comments 11, 15, and 19 on monitoring frequency reductions: The Authority wants the
monitoring frequency reductions to continue in the phased expansion Effluent Limitations
and Monitoring Requirements sheets A.(2.), (3.), and (4.).
The expansion from 12 to 16 MGD will be a change in treatment going from
secondary to advanced tertiary treatment. The Authority will have to demonstrate
consistent, long-term treatment performance at levels far below the new effluent
limitations (<50%) at 16 MGD to be considered for a reduction in monitoring from
those specified in 15A NCAC 2B .0500. Once consistent compliance is
demonstrated at the tertiary treatment level (16 MGD) the other phased expansions
sheets can be modified to only require daily sampling for 6 months in order to show
continued consistent compliance at that expanded flow.
7. Comments 12, 16, and 20 are a repeat of comment 9 above (see #4.) and recognition that
chlorination will be replaced with UV disinfection at 16 MGD.
Fact Sheet
Renewal -- NPDES NC0023973
Page 7

Same response as discussed in #4 above and wording was added to all the TRC
footnotes in sections A.(2.), (3.), and (4.) that reporting is only required if chlorine or
chlorine derivatives are contained in the wastewaters being discharged.
8. Comments 13, 17, and 21 are to change CBOD to BOD in footnote #3.
The word CBOD in footnote #3 contained in sections A.(2.), (3.), and (4.) was
changed to BOD.
9. Comment 23 on special conditions relating to TMDLs: The Authority requested that special
conditions on Historical Permit Limits and Anti -backsliding be put into the permit similar to
those contained in the Northside WVVTP permit. On August 5, 2015 EPA, Region IV,
requested that the condition on Anti -backsliding be revised in order to be consistent with
federal regulations cited in 40 CFR 122.44(1).
Both of the requested conditions were added to the permit with some modification to
the Anti -backsliding condition per EPA's comment. See sections A. (9.) and A. (10.).
10. Comment 24 on Standard Conditions: There are several references to treatment facilities
and collection system. CFPUA possess separate permits for its VVWTPs and its collection
system; they are independent of each other, and while one can reference the existence of
the others it should not incorporate one into the other.
The Standard Conditions get reviewed and revised periodically and are sent to EPA
for approval. Currently the state wastewater rules are under review. Since the
current standard conditions dated Nov. 9, 2011 have been approved by EPA, these
conditions will be added to the Authority's final permit. NPDES will carefully
consider your comment during the next periodic review of the Standard conditions.
Fact Sheet
Renewal -- NPDES NC0023973
Page 8

M'Kean Maffitt (Southside) WWTP
NC0023973
Qw (MGD) = 12.00
1QIOS (cfs)= Acute IWC = 1
7Q10S (cfs)= Tidal, IWC = 1
7QI0W (cfs)= Tidal, IWC = 1
30Q2 (cfs) = Tidal, 1WC = 1
Avg. Stream Flow, QA (cfs) = Tidal, IWC = 1
Receiving Stream: Tidal, IWC = 1
2014 Saltwater RPA 95% Probablity/95% Confidence
MAXIMUM DATA POINTS = 58
WWTP/WTP Class: Class IV
00% IWC @ 1QIOS = 100.00%
00% IWC @7Q10S= 100.00%
00% IWC @ 7QIOW = 100.00%
00% 1WC @ 30Q2 = 100.00%
00% IWC @ QA = 100.00%
00% Stream Class: SC
Outfall 001
Qw = 12 MGD
PARAMETER
TYPE
STANDARDS & CRITERIA (2)
a
y
z
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
NC WQS /
Chronic
Applied
Standard
'/ PA\' /
Acme
Max Prcd
# Det. C ` Allowable Cw
Cw
Arsenic
C
10
HH
ug/L
0
0
N :\
Acute: NO WQS
Chronic---10.0 -----—
All samples < 1. < 3, or < 5 ug/L
-------
Cadmium
NC
5
SW
ug/L
0
li
': \
Acute: 42.0
_ _ _ _
All samples < 0.1, < 1. or < 2 ug/L.
Chromium
NC
20
SW
ug/I.
0
U
' :\
Acute: NO WQS
All +nm les < I or < 5 ug/L.
p
Copper (ALI
NC
.\\
>.s
ne I
_u
_ii
_ ...
Acute: 5.8
--------
—--------
Chronic:3.0
20 value(s) > Allowable Cw
,Zn,A .Fe,
RPA for AL CuCI apply
( 8 ) - PP Y Quarterly
Monitoring in conjunction with TOX Test
•----- ---------- --
Cyanide
NC
SW
1
10.0
ug/L
Acute: 1.0
Chronic: 1.0
14 value(s) > Allowable Cw
All samples < 10 ug/L (PQL)
Maintain sampling as part of Pretreatment
LTMP
Lead
NC
7
SW
221
u)..1
0
0
\.,\
Acute: 221.0
25.0 —------------——
All samples < 1, < 3, or < 5
P ug/L.
Molybdenum
NC
i
H14
❑ - ;
0
0
N/A
Acute: NO WQS
__ _ _ -----------------------------------
hronic2.0
Chronic:_
All samples < 1, < 5, <10, or <100 ug/L.
--
Nickel
NC
s;
1
16
6
6.7
Acute: 75.0
_ _ _
--Chronic------- ---------
8.
No value > Allowable Cw
No RPA. Predicted Max >_ 50% of Allowable
Cw - defer to LTMP
—•-------------------
Selenium
NC
71
S1\
url
0
0
N/A
Acute: NO WQS
Chronic-----7LU ----------•-------------------
All samples 1, < 5, or <10 a L.
P
Silver (AL)
NC
n 10
SW1'7n
lc! 1
1 i,
5
1.6
Acute: 1.900
Chronic 0.100
14 value(s) > Allowable Cw
All samples < 2 ug/L
Maintain sampling as part of Pretreatment
LTNIP
Zinc (AL)
NC
,en
SC•,'
��;
ur
19
19
36.58
Acute: 95
Chronic-----' 86 ------------------------------
No value > Allowable Cw
No RPA, Predicted Max < 50% of Allowable
Cw- continue monitoring as part of the
Pretreatment LTMP
Page 1 of 1
NC0023973 9595 modelledSALTWATER RPA2015ver2.xlsm,rpa
5/17/2015

M'Kean Maffitt (Southside) WWTP
NC0023973
Qw (MGD) =
1QIOS (cfs) =
7Q10S (cfs)
7Q1OW (cfs) =
30Q2 (cfs) =
Avg. Stream Flow, QA (cfs) =
Receiving Stream:
12.00
Acute IWC = 100%
Modeled, IWC % defined
Modeled, IWC % defined
Modeled, IWC % defined
Modeled, IWC % defined
Tidal, IWC = 100%
2014 Saltwater RPA 95% Probablity/95% Confidence
MAXIMUM DATA POINTS = 58
WWTP/WTP Class: Class IV
IWC © IQ1OS = 100.00%
IWC ® 7QIOS = 3.00%
IWC @ 7QIOW = 3.00%
IWC [r 30Q2 = 3.00%
IWC ©QA= 3.00%
Stream Class: SC
Outfall 001
Qw = 12 MGD
PARAMETER
TYPE
(
STANDARDS & CRITERIA (2)
—Ico
a
2
REASONABLE POTENTIAL RESULTS
NC WQS / Applied 1/2 FAV /
Chronic Standard Acute
Max Pred
t1 # Dct. Cw Allowable Cw
RECOMMENDED ACTION
Arsenic
C
10 H1-1(Qavg)
ugil.
0 0
N/A
Acute: NO WQS
Chronic:-- 333.3—
All samples < 1, < 3, or < 5 ug/L
—------—------
Cadmium
NC
5 SW(7Q10s) 42
ug L
0 0
N/A
Acute: 42.0
All samples <0.1, < 1, or <2 ug/L.
Chromium
NC
20 S\V(30Q2)
ultlL
0 0
N/A
Acute: NO WQS
Chronic:-- 667 —
All samples < 1 or <5 ug/L.
—-------------
Copper(AL)
NC
3 SW(7Q10s) 5.8
ug/L
20 20
21.2
Acute: 5.8
_ — ______
Chronic: 100.0 —
No value> Allowable Cw
No RPA, Predicted Max < 50% of Allowable Cw
_NoMonitori0required — — — — — —
— — —
Cyanide
NC
1 SW(7Q10s) 1
10.0
ug/L
14 4
5.0
Acute: 1.0
_ _ _ _ _ _ —
Chronic: 33.3
No value> Allowable Cw
No RPA, Predicted Max < 50% of Allowable Cw
_NoMonitorilsrequired — — — — — —
Lead
NC
25 SW(7Q10s) 221
ug&
0 0
Acute: 221.0
Chronic--- 833.3—
All samples < I, < 3. or < 5 u L.
p
—--------—----
Molybdenum
NC
0 111-1(7Q10s)
mp L
U
\%',
Acute: NO WQS
Chronic:-- 66.7 —
All samples < I. < 5, <10, or <100
P ug/L.
—--------———--
Nickel
NC
8.3 SW(7Q10s) 75
tig11.
I i
6.7
Acute: 75.0
_ _ _ — — _ _
Chronic: 276.7 —
No value > Allowable Cw
No RPA, Predicted Max < 50% of Allowable Cw
_No Monitoriu required — — —
--•--- -----.
Selenium
NC
71 SW(7Q10s)
of/L
0 0
N/A
Acute: NO WQS
_ _ --- _ _
Chronic: 2,366.7------------------------------
All samples < 1, < 5, or <10 ug/L.
Silver(AL)
NC
0.10 SW(7Q10s) 1.90
ug/L
16 5
1.6
Acute: 1.900
-_ _ __ _ _
Chronic: 3.333
No value> Allowable Cw
No RPA, Predicted Max < 5a of Allowable Cw
_N_oM_ onilor_imrequired — — — — — —
Zinc (AL)
NC
86 SW(7Q10s) 95
ug/L
19 19
36.58
Acute: 95
_ _ _
Chronic:-- 2867—w
No value> Allowable Cw
No RPA, Predicted Max <50% of Allowable
Cw- continue monitorinuls Fart of the --- —
—----—
Page 1 of 1
NC0023973 9595 modelledSALTWATER RPA20141.xlsm,rpa
5/12/2015

M'Kean Maffitt (Southside) WWTP
NC0023973
Qw (MOD)_
1Q1OS (cfs)=
7Q1OS (cfs) =
7Q10W (cfs) =
30Q2 (cfs) =
Avg. Stream Flow, QA (cfs)=
Receiving Stream:
24.00
Acute IWC = 100%
Modeled, IWC % defined
Modeled, IWC % defined
Modeled, IWC % defined
Modeled, IWC % defined
Tidal, IWC = 100%
2014 Saltwater RPA 95% Probablity/95% Confidence
MAXIMUM DATA POINTS = 58
WWTP/WTP Class: Class IV
IWC ® 1QIOS — 100.00%
IWC © 7Q1OS = 6.00%
IWC7Q1OW= 6.00%
IWC [(D 30Q2 = 6.00%
IWC ra QA= 6.00%
Stream Class: SC
Outfall 001
Qw=24MGD
PARAMETER
TYPE
(1)
STANDARDS & CRITERIA (2)
J
N
E
REASONABLE POTENTIAL RESULTS
NC WQS / Applied 1/2 FAY /
Chronic Standard Acute
IT
Max Pred
Il R DeL Cw Allowable Cw
RECOMMENDED ACTION
Arsenic
C
10 HH(Qavg)
ug L
0 0
N/A
Acute: NO WQS
.- Chronic: — - — - 16G.7 -----------------------------
All samples < I . <3, or < 5 ug/L
Cadmium
NC
5 SW(7Q10s) 42
ug 1.
0 0
N/A
Acute: 42.0
Cluenic:-- 83.3-—---—------———'
All samples < 0.1, < 1, or < 2 ug/L.
Chromium
NC
20 SW(30Q2)
ug 1_
0 0
N/A
Acute: NO WQS
Chronic:-- 333 —
All samples < 1 or < 5 ug/L.
———-----------
Copper(AL)
NC
3 SW(7Q10s) 5.S
ug/L
20 20
21.2
Acute: 5.8
____
Chronic: 50.0
No value > Allowable Cw
No RPA, Predicted Max < 50% of Allowable Cw
-NM oonitorin r uired
Cyanide
NC
1 SW(7Q10s) I
In
❑,
1 i 4
5.0
Acute: 1.0
_ _ ______ _
Chronic: 16.7
No value> Allowable Cw
No RPA, Predicted Max < 50% of Allowable Cw
-No Monitorin re uired
Lead
NC
25 SW(7Q10s) 22 I
ug/L
0 0
\,
Acute: 221.0
All samples < 1, < 3, or < 5 ug/L.
--•-----------•—'
Molybdenum
NC
2.0 HH(7Q10s)
mg/L
0 0
N/A
Acute: NO WQS
_ _
- Chronic: ---- 33.3 •-----------------------------.
All samples < 1, < 5, <10, or <100 ug/L.
Nickel
NC
8.3 SW(7Q10s) 75
ug/L
16 6
6.7
Acute: 75.0
_ _ ni _ _TAT_
Chroc: TAT
No value > Allowable Cw
No RPA, Predicted Max < 50% of Allowable Cw
-NoMrinonitore uired
Selenium
NC
71 SW(7QIOs)
ug/L
0 0
N/A
Acute: NO WQS
All samples < ►, < 5, or <10 ug/L.
Silver (AL)
NC
0.10 SW(7QI0s) 1.90
ug/L
16 5
1.6
--
Acute: 1.900
_ _ _ _
Chronic:--•-- 1.667 -------•-------------•-------.
No value > Allowable Cw
No RPA, Predicted Max > 50% of Allowable
Cw - defer to LTMP
Zinc (AL)
NC
86 SW(7QIOs) 95
ug/L
19 19
36.58
Acute: 95
_ _
Chronic:----1433--
No value > Allowable Cw
No RPA, Predicted Max < 50% of Allowable
Cw - continuua e monitorinsoart of the— — —
—------
NC0023973 9595 modelledSALTWATER RPA20141.xlsm.rpa
Page 1 of 1 5/19/2015

M'Kean Maffitt (Southside) WWTP
NC0023973 2014 Saltwater RPA 95% Probablity/95% Confidence
MAXIMUM DATA POINTS = 58
Qw (MGD) = 24.00
IQ10S (cfs) = Acute IWC = 100%
7QIOS (cfs) = Modeled, IWC % defined
7Q10W (cfs) = Modeled, IWC % defined
30Q2 (cfs) = Modeled, IWC % defined
Avg. Stream Flow, QA (cfs) = Modeled, IWC % defined
Receiving Stream: Tidal, IWC = 100%
W WTP/WTP Class: Class IV
1WC ® 1Q1OS = 100.00%
IWC ® 7QIOS = 6.00%
IWC®7QIOW= 6.00%
IWC ®30Q2 = 6.00%
IWC®QA= 6.00%
Stream Class: SC
Outfall 001
Qw=24MGD
PARAMETER
TYPENC
STANDARDS & CRITERIA (2)
2
N
E
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
WQS /
Chronic
Applied
Standard
1/2FAV /
Acute
n
Max Pred
# Det. Cw Allowable Cw
Arsenic
C
10
HH(Qavg)
ug'I.
0
0
\':\
\cute: NO WQS
- __—•—__ _ __---_-----------------------.
hrunic 166.7
All samples < I, < 3, or < 5 ug/L
Cadmium
NC
5
SW(7Q10s)
42
ug/L
0
0
\ :\
Acute: 42.0
Chronic: ---• 83.3------------------------------
All samples < 0.1, < 1, or < 2 ug/L.
Chromium
NC
20
SW(30Q2)
u 4
0
a
\_
Acute: NO WQS
---- _ _ ------------------------------.
Chronic: 333
All samples < l or < 5 ug/L.
P
Copper (AL)
NC
3
SW(7Q10s)
5.8
ue!l
'!%
.'u
.'1 '
Acute: 5.8
__ _ ---_ _—_
Clvon_ic: 50.0
No value > Allowable Cw
No RPA, Predicted Max <50%of Allowable Cw
_N_oMon_itori_tt�required ------------
Cyanide
NC
I
SW(7Q10s)
1
10.0
ug/L
14
4
5.0
Acute: 1.0
_ _ — — —
Chronic� - 16.7
No value> Allowable Cw
No RPA, Predicted Max <50%of Allowable Cw
_NoMonitorirequired ---- — --- —
------
Lead
NC
25
SW(7Q10s)
221
c i�
0
0
Acute: 221.0
Chronic:----:IIG.7---------------•-------•-----
All sam samples
p �'
Molybdenum
NC
2.0
HH(7Q10s)
m._ I
0
0
N/A
Acute: NO WQS
.. Chronic: ---- 33.3----------------------------•—
All samples < 1, < 5, <10, or <I00 ug/L.
Nickel
NC
8.3
SW(7Q10s)
75
ugl'I.
16
6
6.7
Acute: 75.0
---__
Chronic:
No value > Allowable Cw
No RPA, Predicted Max < 50% of Allowable Cw
-NoMonitoringrequired _-----------
Selenium
NC
71
SW(7Q10s)
u, 1.
()
I)
\ \
:_
Acute: NO WQS
-- Clvonic-----1.183.3-----------------------------
All samples < 1, < 5. or <10 ug/L.
Silver (AL)
NC
0.I0
SW(7Q10s)
1.90
ug/L
16
5
1.6
Acute: 1.900
_ _ _ _
---- —•---------------------------.
Chronic 1.667
No value > Allowable Cw
No RPA, Predicted Max >_ 50% of Allowable
Cw - defer to LTMP
Zinc(AL)
NC
86
SW(7QI0s)
95
ug/L
19
19
36.58
Acute: 95
- _ _ _--__ __—
Chronic: 1433
No value > Allowable Cw
No RPA, Predicted Max < 50% of Allowable
_Cw_ -c_o_ntinu_e_mo_nit_oring_asQartoftlre_____
Page 1 of 1
NC0023973 9595 modelledSALTWATER RPA20141.xlsm,rpa
5/19/2015

5
Copper (AL)
Date Data
1 1/11/2012
2 2/8/2012
3 3/7/2012
4 4/12/2012
5 5/2/2012
6 6/6/2012
7 9/11/2012
8 12/18/2012
9 1 /23/2013
10 3/13/2013
11 4/10/2013
12 6/5/2013
13 7/16/2013
14 9/10/2013
15 12/3/2013
16 3/4/2014
17 6/3/2014
18 9/9/2014
19 12/2/2014
20 1/20/2015
21
10
18
11
9
10
10
10
7
9
10
11
8.5
6.9
4.5
7.8
6.8
8
9
8
BDL=1/2DL
18
11
9
10
10
10
7
9
10
11
8.5
6.9
4.5
7.8
6.8
8
9
8
6 6
8 8
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max_ Value
Max. Pred Cw
Use "PASTE SPECIAL -
Values" then "COPY" .
Maximum data points
= 58
Cyanide
Nickel
Date
1 12/7/2011
2 1/11/2012
3 2/8/2012
4 3/7/2012
5 4/12/2012
6 5/2/2012
7 6/6/2012
8 9/11/2012
9 12/18/2012
10 1/23/2013
11 3/13/2013
12 4/10/2013
13 6/5/2013
14 7/16/2013
15 9/10/2013
16 12/3/2013
17 3/4/2014
18 6/3/2014
19 9/9/2014
20 12/2/2014
21
Data
BDL=1/2DL
5 2.5
5 2.5
5 2.5
10 5
5 2.5
5 2.5
5
3
2
2.1
1.8
1.6
1.6
10
10
10
2.5
3
2
2.1
1.8
1.6
1.6
5
5
5
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max_ Pred Cw
2.7152
8.9250
0.3042
20.0
1.2
18.0 ug/L
21.2 ug/L
Use "PASTE
SPECIAL -Values"
then "COPY" .
Maximum data
points = 58
12311
2.9438
0.4352
16
1.3300
5.0 ug/L
6.7 ug/L
Date Data
1 1/11/2012 <
2 2/8/2012 <
3 3/7/2012 <
4 4/12/2012 <
5 5/2/2012
6 6/6/2012
7 9/11/2012 < 5
8 12/18/2012 5.5
9 1/23/2013
10 3/13/2013 c 5
11 4/10/2013
12 6/5/2013 7.2
13 7/16/2013
14 9/10/2013 < 5
15 12/3/2013 9.3
16 3/4/2014 < 5
17 6/3/2014 8.4
18 9/9/2014 < 5
19 12/2/2014 < 5
20 1/20/2015
21
12
BDL=1/2DL
10 5
10 5
10 5
10 5
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
5 Max. Value
5 Max. Pred Cw
5
5
5
5
5
5
5
5
Silver (AL)
Date Data BDL=1/2DL
1 12/7/2011 < 2 1
2 1/11/2012 < 2 1
3 2/8/2012 < 2 1
4 3/7/2012 < 2 1
5 4/12/2012 < 2 1
6 5/2/2012 < 2 1
7 6/6/2012
8 9/11/2012 < 0.1 0.05
9 12/18/2012 0.2 0.2
10 1/23/2013
11 3/13/2013 0.3 0.3
12 4/10/2013
13 6/5/2013 0.18 0.18
14 7/16/2013
15 9/10/2013 < 0.1 0.05
16 12/3/2013 0.14 0.14
17 3/4/2014 0.14 0.14
18 6/3/2014 < 2 1
19 9/9/2014 < 2 1
20 12/2/2014 < 2 1
21
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max_ Pred Cw
Use "PASTE
SPECIAL -Values"
then "COPY" ,
Maximum data
points = 58
0.0000
5.0000
0.0000
14
1.0000
5.0 ug/L
5.0 ug/L
Use "PASTE
SPECIAL -Values"
then "COPY"
Maximum data
points = 58
0.4383
0.G288
0.6971
16
1.5500
1.0 ug/L
1.6 ug/L

13
Zinc (AL)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Date Data BDL=1/2DL
31
16
22
17
21
12/7/2011 31
1/11/2012 16
2/8/2012 22
3/7/2012 17
4/12/2012 21
5/2/2012
6/6/2012 18
9/11/2012 16
12/18/2012 17
1/23/2013 19
3/13/2013 16.9
4/10/2013 15
6/5/2013 8.6
7/16/2013 20.1
9/10/2013 16
12/3/2013 15
3/4/2014 21
6/3/2014 24
9/9/2014 12
12/2/2014 28
18
16
17
19
16.9
15
8.6
20.1
16
15
21
24
12
28
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
Use"PASTE
SPECIAL -Values"
then "COPY"
Maximum data
points = 53
5.2435
18.6105
0.2817
19
1.1800
31.000 ug/L
36.580 ug/L

5/12/15 WQS = 12 ng/L MERCURY WQBEL/TBEL EVALUATION V:2013-6
Facility Name 5outhside/ NC0023973
/Permit No. :
Total Mercury 1631E PQL = 0.5 ng/L 7Q10s =
Date Modifier Data Entry Value Permitted Flow =
No MMP Required
595.200
24.000
cfs
WQBEL = 204.00 ng/L
���L = 47 ng/L

Mercury
DATE (ng/L)
1/11/2012 <200
2/8/2012 <200
3/7/2012 <200
4/12/2012 <200
5/2/2012 <200
6/6/2012
9/11/2012 <200
12/18/2012 <200
1/23/2013
3/13/2013 <200
4/10/2013
6/5/2013 <200
7/16/2013
9/10/2013 <200
12/3/2013 <200
3/4/2014
6/3/2014 <200
9/9/2014 <200
12/2/2014 <200
1/20/2015
Scans
Jun-13, 4.43
Jun-14 '\, 3.15

NC0023973- CFPUASouthside/Historical Loading CFPUA Southside Future Loading
Month Flow CBOD5 NH3-N CBOD5 CBODu NH3-N NBODu UOD Flow CBOD5 cBODS cBODu NH3-N NH3-N NBODu UOD
mgd mg/I mgN/I lb/d lb/d lb/d lb/d lb/d mgd mg/I lb/d lb/d mgN/I lb/d lb/d lb/d
2009 1 7.94 5.7 25.5 377 566 1689 7599 8165 24 8.33 1667 2501 2 400 1801 4302
2 7.7 6.75 27 433 650 1734 7802 8453 24 8.33 1667 2501 2 400 1801 4302
3 7.79 7 26.3 455 682 1709 7689 8371 24 8.33 1667 2501 .2 400 1801 4302
4 7,73 6.8 24.8 438 658 1599 7195 7852 24 4.17 835 1252 1 200 901 2153
5 7.93 5.3 25.7 351 526 1700 7649 8174 24 4.17 835 1252 1 200 901 2153
6 8.19 5.8 25.1 396 594 1714 7715 8309 24 4.17 835 1252 1 200 901 2153
7 8.62 5 22.3 359 539 1603 7214 7753 24 4.17 835 1252 1 200 901 2153
8 8.47 7.9 24.5 558 837 1731 7788 8625 24 4.17 835 1252 1 200 901 2153
9 8.85 6.4 20.9 472 709 1543 6942 7650 24 4.17 835 1252 1 200 901 2153
10 8.57 5.8 24.7 415 622 1765 7944 8566 24 4.17 835 1252 1 200 901 2153
11 8.84 5.9 25.6 435 652 1887 8493 9146 24 8.33 1667 2501 2 400 1801 4302
12 9.18 8.3 24.4 635 953 1868 8406 9360 24 8.33 1667 2501 2 400 1801 4302
2010 1 8.84 9.2 25.6 678 1017 1887 8493 9511
2 9.01 9.5 23.3 714 1071 1751 7879 8950 5.90 1182 1772 1.42 284 1276 3048
3 8.9 10.2 28.3 757 1136 2101 9453 10588
4 8.3 8.2 31.3 568 851 2167 9750 10601 Assumptions/Future Loadings:
5 7.92 6.3 31.7 416 624 2094 9422 10047 BOD5= 5 mg/I summer and 10 mg/I winter
6 8.19 7.4 25.4 505 758 1735 7807 8565 CBODS= 4.17 mg/I summer and 8.33 mg/I winter
7 8.18 9 28.2 614 921 1924 8657 9578 CBOD5 x 1.5 = CBODu
8 8.34 8.9 26 619 929 1808 8138 9067 NH3-N= 1 mg/I summer and 2 mg/I winter
9 9.29 9.8 27.8 759 1139 2154 9693 10832 NH3-N x 4.5 = NBODu
10 10.44 5.9 22.5 514 771 1959 8816 9586 UOD= CBODu + NBODu= Ultimate Oxygen Demand
11 8.54 9.4 28.1 670 1004 2001 9006 10010
12 8.47 14.3 29.5 1010 1515 2084 9377 10893 UOD (Historical Loading)= 9111 lb/d
UOD (Future Loading)= 3048 lb/d
avg 8.51 7.70 26.02 548 822 1842 8289 9111 UOD Reduction = 6063 lb/d or 66%

•
NPDES/Aquifer Protection Permitting Unit Pretreatment Information Request Form
PERMIT WRITER COMPLETES THIS PART:
PERMIT WRITERS - AFTER you get this form back
Check all that
f
from PERCS:
apply
Notify PERCS
Date of Request
4/10/2015
municipal renewal
if LTMP/STMP data we said should be
on DMRs is not really there, so we can get it for you
Requestor
Julie Grzyb
new industries
(or NOV POT\).
Facility Name
M'Kean Maffitt
WWTP expansion
v
- Notify PERCS if you want us to keep a specific POC
Permit Number
NC0023973
Speculative limits
in LTMP/STMP so you will have data for next permit
Region
WiRO
stream reclass.
renewal.
- Email PERCS draft fact sheet, RPA.
Basin
Cape Fear
outfall relocation
permit,
- Send PERCS paper copy of permit (w/o NPDES
7Q10 change
boilerplate), cover letter, final fact sheet. Email RPA if
other
changes.
other
check
applicable PERCS staff:
Other Comments to
PERCS:
V
BRD, CPF, CTB, FRB, TAR - Sarah Morrison (807-6310)
CHO, HIW, LUM, LTN, NES, NEW, ROA, YAD - Monti
Hassan (807-6314)
CFPUA has applied for an expansion from 12 MGD to 24 MGD.
A FONSI was issued on Sept. 13, 2013.
The NPDES Form 2A identifies one SIU and zero CIU's.
The SIU is listed as New Hanover Regional Medical Center.
PERCS
Status
PRETREATMENT STAFF COMPLETES THIS PART:
of Pretreatment Program (check all that apply)
1) facility has no SIU's, does have Division approved Pretreatment Program that is INACTIVE
2) facility has no SIU's, does not have Division approved Pretreatment Program
X
3) facility has SlUs and DWQ approved Pretreatment Program (list "DEV" if program still under development)
X
3a) Full Program with LTMP
3b) Modified Program with STMP
4) additional conditions regarding Pretreatment attached or listed below
Flow, MGD
Permitted
Actual
Time period for Actual
STMP time frame:
Industrial
0.35
0.15712
April 2009-April 2012
Most recent:
N/A
Uncontrollable
n/a
8.1567
April 2009-April 2012
Next Cycle:
N/A
POC in LTMPI
STMP
Parameter of
Concern (POC)
Check List
POC due to
NPDESI Non-
Disch Permit
Limit
Required by
EPA*
Required
by 503
Sludge"
POC due
to SIU"'
POTW POC
(Explain
below)""
STMP
Effluent
Freq
LTMP
Effluent
Freq
X
BOD
Q
i-
X
TSS
X
X
Q
-Q Quartet _
X
NH3
X
Q
M =Monthly
X
Arsenic
X
Q
'1
Cadmium
4
X
Q
4
Chromium
4
X
Q
4
Copper
4
X
X
Q
X
Cyanide
Q
Is all data on DMRs?
/
Lead
4
X
Q
YES
X
Mercury
X
X
Q
NO (attach data)
X
Molybdenum
X
Q
4
Nickel
4
X
Q
X
Silver
X
Q
X
Selenium
X
Q
4
Zinc
q
X
X
Q
Is data in spreadsheet?
Total Nitrogen
Q
YES (email to writer)
X
X
Phosphorus
Q
NO
X
CBOD
X
X
Q
X
Barium
X
Q
X
Aluminum
Q
X
Iron
Q
X
Chloride
Q
X
Oil & Grease
Q
X
TKN
Q
X
TS
Q
*Always in the LTMP/STMP **Only in LTMP/STMP if sludge land app or composte (dif POCs for incinerators)
***Only in LTMP/STMP while SIU still discharges to POTW --Only in LTMP/STMP when pollutant is still of concern to POTW
ICnmmantc fn Dnrmit Wrifnr Inv nvnlnnafinn of anv Drlfe- info vni, hwn nn 111 rnhtnri invnctinnfinnc infn idDIlFC nrnhInmcl•
NPDES Pretreatment request form for NC0023973.xlsx
Revised: July 24, 2007

4/27/2015 Icfrp.tmtw.edu/dverdatabase/stationQttery1.php?station%5B%5D=B979'S000&beginDat�2011-01-01&ertdDate=2015-01-278Jogged irt=1&submit=V ew...
The data contains the remarks code. �J��' . ' A}�
For Help with the remarks code, please check h tp://www.cormp.org/CFP/CFPremarks.php
. Station Info:
Station
HUC
Latitude
Longitude
Location
County
Comment
Stream
Class
Sub
Basin
Active
B979S000/LCFRP M54
3030005
34.13930
-77.94600
Cape Fear River at Channel
Marker 54
New
Hanover
Dns Wilmington Southside
WWTP
SC
CPF17
yes
Query Results:
Stations:B9795000 Time Period: 2011-01-01-2015-04-27
Click Here
to Download data
station
measurement time
control
depth(m)
Temperature(C)
pH(su)
DOixygen(mg/L) ssolved
Conductivity(umhos/cm)
Colf orm(eol/100m1)
Enterococcus(co1/100m1)
Turbo
B9795000
2011-01-19
13:05:00
Yes
0.1
6.3
7.9
11.1
25870
10
B9795000
2011-02-01
13:30:00
yes
0.1
7.3
7.8
11.3
17632
10
B9795000
2011-03-02
13:56:00
Yes
0.1
14.4
7.6
9.4
15837
55
B9795000
2011-04-19
13:10:00
Yes
0.1
20.7
7.5
7.4
11532
19
E
B9795000
2011-05-03
13:40:00
Yes
0.1
23.8
7.4
6.8
13397
10
B9795000
2011-05-18
11:35:00
Yes
0.1
23.7
7.6
6.9
26719
B9795000
201 I-06-07
13:20:00
Yes
0.1
28.6
8
8.1
31615
10
B9795000
2011-06-21
12:10:00
Yes
0.1
29.2
7.9
7.2
35788
B9795000
2011-07-12
12:05:00
Yes
0.1
29.6
7.7
6
34104
37
B9795000
2011-07-28
12:25:00
Yes
0.1
29.7
7.5
4.7
34415
B9795000
2011-08-10
12:20:00
Yes
0.1
31
7.5
5
35709
10(B2)
B9795000
2011-08-23
11:30:00
Yes
0.1
29.2
7.5
5
30485
B9795000
2011-09-08
12:20:00
yes-
0.1
27.7
7.1
3.5
7859
19
B9795000
2011-09-28
11:15:00
Yes
0.1
26.1
7.4
4.7
26913
B9795000
2011-10-12
12:50:00
Yes
0.1
22.3
7.7
6.8
34308
46
B9795000
2011-11-10
12:50:00
Yes
0.1
16.5
7.6
7.5
28662
10(2)
B9795000
2011-12-06
12:25:00
Yes
0.1
14
7.5
8.4
12932
46
B9795000
2012-01-25
12:50:00
Yes
0.1
12
7.8
9.4
25505
39
B9795000
2012-02-09
12:50:00
Yes
0.1
12.3
7.9
7.9(1.11)
25408
10
B9795000
2012-03-08
12:50:00
Yes
0.1
15.1
7.5
9.3
7712
46
B9795000
2012-04-03
12:48:00
Yes
0.1
20.2
7.2
7.3
5813
109
B9795000
2012-05-11
12:12:00
Yes
0.1
22.1
7.5
6.7
20867
10(112)
B9795000
2012-05-17
12:20:00
Yes
0.1
24.3
7.4
5.8
22355
B9795000
2012-06-05
12:25:00
Yes
0.1
25.1
7.4
5.1
16317
10(131)
B9795000
2012-06-19
12:20:00
Yes
0.1
26.1
7.5 5.4
25840
B9795000
2012-07-10
12:50:00
yes
0.1
30.6
7.7
5.3
29675
1047
B9795000
2012-07-24
12:20:00
Yes
0.1
30.3
7.8
6.3
23860
B9795000
2012-08-07
13:00:00
yes
0.1
29.7
7.7
5.1
18805
20
IB9795000
2012-08-23
If
I II II
I II
I-
http://lcfrp.tmcw.eduIriverdatabase/statIonQueryl.php?station%5B%5D=B9795000&beginDate=2011-01-01&erdDate=2015-04-278Jogged in=18submit=View+... 1/2

4/27/2015 Icfrp.uncw.edu/riverdatabaselstationQueryl.php?station%5B%5D=B9795000&beginDate=2011-01-01&endDate=2015-04-27&logged_in=1&submit=View...
' . 110:55:00
Yes
10.1 I28.5
17.2
3.6
I4628
B9795000
2012-09-05
13:20:00
Yes
0.1
27.9
7.3
4.4
8797
20
B9795000
2012-09-20
11:00:00
Yes
0.1
25.7
7.1
5.1
17324
B9795000
2012-10-04
13:10:00
Yes
0.1
25.7
7.6
5.5
24321
649
B9795000
2012-11-12
13:15:00
Yes
0.1
15.4
7.9
8
33185
20
B9795000
2012-12-04
12:50:00
Yes
0.1
12.9
7.9
8.5
30357
10
B9795000
2013-01-09
13:25:00
yes
0.1
9.4
7.4
9.3
13856
41
B9795000
2013-02-05
13:35:00
Yes
0.1
10.2
7.6
9.9
14295
31
139795000
2013-03-19
13:10:00
Yes
0.1
13.8
7.4
9
8574
20
B9795000
2013-04-10
12:55:00
Yes
0.1
17
7.4
8.6
7673
63
B9795000
2013-05-01
13:10:00
Yes
0.1
19.8
7.5
7.5
16985
41
B9795000
2013-05-29
11:13:00
Yes
0.1
24
7.4
6
10105
B9795000
2013-06-17
10:15:00
Yes
0.1
25.1
6.5
4.2
678
97
B9795000
2013-06-27
12:14:00
Yes
0.1
26.7
7.2
4.7
1760
B9795000
2013-07-08
12:45:00
Yes
0.1
26.2
6.3
3.3
92
275
B9795000
2013-07-22
12:24:00
Yes
0.1
27.3
6.6
3.4
213
B9795000
2013-08-05
12:45:00
Yes
0.1
28
7.1
4.7
11314
121
B9795000
2013-08-26
13:20:00
Yes
0.1
27.2
7
5.6
6193
B9795000
2013-09-03
12:40:00
Yes
0.1
27.4
7.1
5.2
12753
41
B9795000
2013-09-13
12:00:00
Yes
0.1
27.8
7.1
4.7
17755
B9795000
2013-10-01
11:50:00
Yes
0.1
23
7.6
6.2
30674
10(M)
B9795000
2013-11-14
12:35:00
Yes
0.1
14.3
7.9
8.3
28775
10(1)
B9795000
2013-12-05
12:15:00
yes
0.1
13
7.9
8
28558
10( )
B9795000
2014-01-15
00:00:00
No
0.1
9.3
7.3
10.6
3727
985
B9795000
2014-01-15
12:45:00
No
0.1
9.3
7.3
10.6
3727
985
B9795000
2014-01-15
12:45:00
No
0.1
9.3
7.3
10.6
3727
985
B9795000
2014-02-03
11:50:00
No
0.1
6.9
8
12.2
15252
10(U)
B9795000
2014-03-19
12:55:00
No
0.1
9.9
7.4
10
6578
10
http://Icfrp.uncw.edu/riverdatabase/stati onQuery 1.php?station%5B%5D= B9795000&beginDate=2011-01-01 &endD ate=2015-04-27&I ogged_i n=1 &submit=View+... 2/2

Grzyb, Julie
From: Grzyb, Julie
Sent: Wednesday, August 05, 2015 11:37 AM
To: 'Hesterlee, Craig'
Subject: RE: Revised - Permit Modification for CFPUA's M'Kean Maffitt WWTP (NC0023973) (SIC
4952)
Craig,
Thanks for the quick response. I'll suggest the following revision to special condition A.(10.). —Thanks, Julie
"The BOD5 and ammonia nitrogen (NH3 as N) limits in this permit may be replaced with less stringent limits without
violating state and Federal anti -backsliding provisions if:
a. Material and substantial alterations or additions to the permitted facility occurred after permit issuance that justifies
less stringent limits;
b. Events occurred beyond the permittee's control for which there is no reasonably available remedy;
c. Permittee has properly installed and operated required treatment equipment that cannot achieve permit limits; or
d. New information (other than revised regulations, guidance, or test methods) is available that justifies less stringent
limits;
and provided that the Division deems such modification appropriate and consistent with applicable laws and regulations."
From: Hesterlee, Craig [mailto:[e-mail]]
Sent: Wednesday, August 05, 2015 10:52 AM
To: Grzyb, Julie
Cc: Davis, Molly; Schwartz, Paul; Seiwert, Carla
Subject: FW: Revised - Permit Modification for CFPUA's M'Kean Maffitt WWTP (NC0023973) (SIC 4952)
Julie- based on our review, we request that DENR revise the conditions stipulated in A.(10.) of the permit to be
consistent with federal regulations (see below). Please give me a call if we should discuss. Thank you.
Craig Hesterlee
EPA Region 4 Water Protection Division
Acting Section Chief
Data and Information Analysis Section
404-562-9749
From: Schwartz, Paul
Sent: Tuesday, August 04, 2015 5:44 PM
To: Hesterlee, Craig
Cc: Seiwert, Carla; Davis, Molly
Subject: RE: Revised - Permit Modification for CFPUA's M'Kean Maffitt WWTP (NC0023973) (SIC 4952)
Are these WQBELs — basic rule for anti -backsliding with WQBELs is if the new effluent limit will not cause or contribute
to a violation of WQS you can do it but you have to go through anti -deg. See 402(o)(1). For tbels the exceptions are
stated in 402(o)(2) and 40 cfr 122.44(1). In either case, their statement is not tracking the exceptions language
accurately and should be fixed.
t

From: Hesterlee, Craig
Sent: Tuesday, August 04, 2015 3:58 PM
To: Schwartz, Paul
Cc: Seiwert, Carla; Davis, Molly
Subject: FW: Revised - Permit Modification for CFPUA's M'Kean Maffitt WWTP (NC0023973) (SIC 4952)
Paul- please take a look at the language proposed in A.(10.) —
Here are the codified exceptions to anti -backsliding:
• Substantial expansion or alteration to the facility after permit issuance that justifies less stringent limits;
• Events occurring beyond the permittee's control for which there is no reasonably available remedy;
• Permittee has properly installed and operated required treatment equipment that cannot achieve permit limits; or
• New information (other than revised regulations, guidance, or test methods) is available that justifies less stringent limits.
And here is what the permit provision states:
"The BOD5 and ammonia nitrogen (NI-I3 as N) limits in this permit may be replaced with less stringent limits without
violating state and Federal anti -backsliding provisions if:
a. Circumstances predicating the issuance of this permit have materially and substantially changed;
b. There are material and substantial changes to the facility;
c. New information comes available (such as the determination of a TMDL); or
d. New regulations become promulgated;
provided that the Division deems such modification appropriate and consistent with applicable laws and regulations."
In your opinion, is this language acceptable? Proposed permit is attached. Thanks for the feedback. Permit writer's
notes to me below..
Craig Hesterlee
EPA Region 4 Water Protection Division
Acting Section Chief
Data and Information Analysis Section
404-562-9749
From: Grzyb, Julie [mailto:[e-mail]]
Sent: Friday, July 31, 2015 4:16 PM
To: Hesterlee, Craig
Subject: Revised - Permit Modification for CFPUA's M'Kean Maffitt WWTP (NC0023973) (SIC 4952)
Craig,
In May 2015 I sent Region IV the draft permit modification for the Cape Fear Public Utility Authority expansion at the
M'Kean Maffitt WWTP,
Permit No. NC0023973. We had some discussions on the modeling and the resulting dilution factor that was used in the
development of permit limits and the effluent concentration for the toxicity test.
2

Since than I have rewritten the permit and have tried to address your concerns and some of the issues brought up by
CFPUA.
I was just going to issue this as a final permit since the revisions are more stringent — added a special condition A. (8.)
requiring a CORMIX model- which the Authority volunteered to do to resolve any concerns over the dilution factor;
however, the permittee requested that two special conditions be added to their permit. See sections A.(9.) and A.(10.).
Tom, thought EPA should review the permit again in case Region IV wanted to comment on these special
conditions. These same conditions were added to CFPUA's Northside WWTP permit in 2012. They are odd conditions
and I cannot think of a reason the Division would ever allow less stringent limits but the conditions were important to
the permittee and we do not really have a problem putting them in the permit.
The revised permit which I hope to issue as final is attached along with a revised Fact Sheet. The Addendum to the fact
sheet starts on page 5 —that is where I specifically address EPA's and CFPUA's concerns and list any changes made to the
draft permit I sent you at the end of May.
Since you have already reviewed this permit, application, and fact sheet, I thought it would be best to send the revision
directly to you. I left you a phone message — I was going to discuss with you how best to handle this. We do not intend
to re -Public Notice this permit.
Thanks for your help on this matter,
Julie
Julie A. Grzyb, Environmental Engineer
NC DENR / Division of Water Resources / Water Quality Permitting
NPDES Complex Permitting, Wastewater Branch
1617 Mail Service Center, Raleigh, NC 27699-1617
919/807-6389 (wk)
[e-mail]
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.
3

4,74
NCDENR
North Carolina Department of Environment and Natural Resources
Pat McCrory
Governor
MEMORANDUM:
TO: Julie Grzyb, NPDES Complex Permitting, Wastewater Branch
THROUGH: Doug Huggett, DCM Assistant Major Permit Coordinator 6
FROM: Gregg Bodnar, DCM Fisheries Resource Specialist ��' cl " �� /�`
SUBJECT: M'Kean Maffitt WWTP
DATE: 7/14/2015
Donald R. van der Vaart
Secretary
A North Carolina Division of Coastal Management (DCM) Fisheries Resource Specialist has reviewed the
subject permit application for proposed actions that impact fish and fish habitats.
Provided that the project is within state water quality, storm water and waste water treatment
standards, I do not have any comment.
Contact Gregg Bodnar at [phone] ext. 213 or gregg.bodnar(cancdenr.gov with further questions
or concerns.
1601 Mail Service Center, Raleigh, North Carolina 27699-1601
Phone: [phone] Internet: www.ncdenr.gov
M Equal Opportunity lAffirmalive Action Employer— Made in part by recycled paper

11111111 Cape Fear
Milt Utility Authority
Stewardship. Sustainability. Service.
June 24, 2015
Ms. Julie A. Grzyb, Environmental Engineer
NCDENR/Division of Water resources/Water Quality Permitting
NPDES Complex Permitting, Wastewater Branch
1617 Mail Service Center
Raleigh, NC 27699-1617
RECEIVEDIDENR/DWR
JUL, 0 2 2015
Water Quality
Permitting Section
Re: CFPUA Review Comments — M'Kean Maffitt (Southside) WWTP — NPDES NC0023973
Permit Modification
Dear Ms. Grzyb,
CFPUA's comments upon the SSWWTP draft NPDES permit modification accompany. These
comments address both the 05.20.2015 document itself and subsequent issues which arose after
initial document availability during the course of the public review period. They are sent as a
follow-up to the same positions/comments emailed to you on June 24, 2015.
1. Cover letter, page 1, bullet 1 indicates CFPUA is already submitting eDMRs. While
certain facilities may be doing so, and while the CFPUA's three WWTPs are in the
process of preparing to do so, none of CFPUA's WWTPs is actually submitting eDMRs
at this time.
2. Cover letter page 2, bullet 1 indicates that The City will continue monitoring mercury as
part of its LTMP and its Effluent Pollutant Scans. Please substitute The CFPUA or The
Authority for The City.
3. Cover letter page 2, bullet 2 references the change in the Whole Effluent Toxicity (WET)
testing requirement from the previous Acute Whole Effluent Toxicity (AWET) testing
requirement to a Chronic Whole Effluent Toxicity (CWET) testing requirement together
with associated terms and conditions as requested by the CFPUA. This issue has
subsequently become the subject of additional discussion as a result of USEPA
intervention subsequent to DWR's initial draft permit availability pending the outcome of
evaluating the 33:1 dilution value used to determine the 7Q10 as summarized in DWR's
05.27.2015 email as follows.
EPA is questioning the accuracy of the 33:1 dilution value used to establish the
235 Government Center Drive
Wilmington, North Carolina 28403
www.cfpua.org
Page 1 of 7
Ms. Julie A. Grzyb
June 29, 2015

Cape Fear
th; tic Utility Authority
Stewardship. Sustainability. Service.
effluent concentration at which to perform the chronic toxicity test. I pulled this
value from the May 2001 Tetra Tech report - Discharge Dilution Analysis, Table 4-
1. Summary of Near Field Dilution Analysis. This dilution value was used by Jim
McKay to determine the 7Q10 and then that 7Q10 value was used to determine the
IWC at a permitted flow of 12 MGD and 24 MGD.
In looking into the study more, Southside does not appear to discharge via a
diffuser. Therefore, we are finding it difficult to understand how a dilution value
was calculated. I believe it was really meant to just be an estimate which is why a
true hydrodynamic simulator EFDC/JP-EFDC model was performed on the
Northside facility's discharge in 2008, prior to expansion.
First can you support the 33:1 dilution value as adequate to be used in the
calculation of limits?
If 33:1 is not supportable, I will have to re-evaluate the limits without a mixing zone
and I do not see how we can support a chronic toxicity test at a set dilution until we
have a true dilution factor.
Is it correct Southside does not have a diffuser and one is not planned with the
expansion?
Do you have a CORMIX or EFDC model that was performed on Southside's
discharge?
DWR's 06.04.2015 email supplemented the 05.27.2015 email as follows.
Upon further review, if the dilution value is inadequately supported by the 2001
model and no additional work is submitted or performed to justify a dilution value —
it is my understanding that the Toxicity test should be changed back to an acute test
at 90% effluent for all flows. In addition, quarterly monitoring for copper would be
added to the permit (no limit) because without dilution it is showing a reasonable
potential to violate Water Quality Standards. However, note that quarterly copper
monitoring is already being performed by the facility as part of the Utility's
Pretreatment LTMP. No other changes to the permit appear necessary based on the
removal of the dilution values.
I will address both your questions and CFPUA's response to these latest developments in
more detail as follows.
The SS W WTP does not currently discharge through a diffuser system and current plans
do not call for one in the future.
235 Government Center Drive
Wilmington, North Carolina 28403
www.cfpua,org
Page 2 of 7
Ms. Julie A. Grzyb
June 29, 2015

itene fear
L= -i._ L1L ithiltiolLiltoritv
Stewardship. Sustainability. Service.
The existing modeling information is believed to provide a certain level of support for the
referenced dilution factor. In fact, much modeling has been performed in the general
vicinity of the CFPUA WWTPs, making it a modeling -rich environment, more so than
exists in many other regions. The three documents to which I'm referring are:
a. 3-Dimenssional EFDC Water Quality Model of the Lower Cape Fear River and its
Estuary, May 2001, Tetra Tech Inc.
b. Technical Memorandum: Cape Fear Public Utility Authority NSWWTP Effluent
Dilution Analysis, September 2008, Tetra Tech.
c. Development and Use of a Three -Dimensional Water Quality Model to Predict
Dissolved Oxygen Concentrations in the Lower Cape Fear River Estuary, North
Carolina, October 2009, James D. Bowen and others under NCDENR oversight using
the EFDC model to resolve the low DO TMDL for the Lower Cape Fear River
Estuary impaired waters.
They should all be available at NCDENR; let me know if you cannot locate them and we
will endeavor to supply them for you and/or USEPA.
No CORMIX or EFDC model on a level of detail comparable with the 2008 CFPUA
NSWWTP Effluent Dilution Analysis has been performed by the CFPUA for the
SSWWTP; the 2008 model established grid cell sizing enabling a higher resolution. It
was initially determined early in the WWTP master planning process (1998 — 2000) that,
in order to avoid any unnecessary effort and cost, such modeling would not be performed
unless additional detail was required. The 2001 study addressed both the NSWWTP and
the SSWWTP and was based upon a simpler algorithm not reflective of the more detailed
analysis performed in the 2008 study for the NSWWTP. It was performed as a 3-
dimensional EFDC model with a jet plume subroutine for near field evaluation
recognized as comparable to the CORMIX model. The 33:1 dilution factor utilized was
based upon the most conservative 1 hour result rather than an average of results over a
prescribed period of time. However, while performed for the NSWWTP, and due to their
proximity within the watershed, general findings from the 2008 study could be deemed
applicable to both facilities. While not performed for the same purposes as CFPUA's
modeling, NCDENR's TMDL modeling may likewise yield information applicable to the
SSWWTP dilution factor determination.
Upon due consideration, should the previously discussed explanation not provide ample
evidence to establish a dilution factor applicable to the SSWWTP CWET testing, perhaps
considering incorporating NCDENR USEPA study/data needs within this NPDES permit
modification might prove to be the most beneficial course of action for all parties.
Much CWET testing results exist for the SSWWTP. Might NCDENR/USEPA be
receptive to either maintaining the CWET testing requirement using the draft dilution
235 Government Center Drive
Wilmington, North Carolina 28403
www.cfpua.org
Page 3 of 7
Ms. Julie A. Grzyb
June 29, 2015

MN Cape Fear
Public Utility Authority
Stewardship. Sustainability. Service.
factors until a suitable study can be performed or a more conservative lower dilution
factor?
For your convenience, in the event it's needed, I've provided the text of the special
condition which had appeared within a previous NSWWTP NPDES permit. Perhaps
something similar could be adapted for use with the SSWWTP.
A.8 EFFLUENT MIXING MODEL
The City of Wilmington shall submit a CORMIX model (or equivalent) providing
additional information regarding end -or -pipe dilution no later than 12 months after an
engineer's certification for the completion of 16.0 MGD expansion is issued. The model
shall address dilution at the approved 16.0 MGD increased flow rate into the Cape Fear
River for both the existing and the new discharge line diffusers.
Please note that the specific conditions then -applicable to the NSWWTP may be different
from those which may currently apply to the SSWWTP, particularly the discharge
configuration and study timing. A study may be advised sooner due to additional AWET
failures being experienced at the existing SSWWTP or later due to construction of the
SSWWTP Expansion/Upgrade Project in order to justify a change in WET testing from
AWET to CWET. In either case, CFPUA notes that the need for any such supplemental
modeling is limited to its use in establishing dilution factors to be used within the WET
process.
4. Supplement to Permit Cover Sheet page 2/13, item 1, bullet 1 — there is not a single
influent meter; influent metering is provided through the totalization of several tributary
influent force main flow meters.
5. Supplement to Permit Cover Sheet page 2/13, item 1, bullet 3 — indicates SSWWTP has a
comminutor installed; it does not.
6. Supplement to Permit Cover Sheet page 2/13, item 1, bullet 13, 14 — dual secondary
clarifiers and return activated sludge pumping station are listed out of process flow
sequence; they should probably be inserted after current bullet 10 three screw lift pumps.
7. Supplement to Permit Cover Sheet page 2/13, item 1, bullet 18 — lists a lift station
generator automatically activated when the main plant backup generator is activated. In
addition, the main plant backup generator should probably be listed immediately before
this unit as its own bullet.
8. Supplement to Permit Cover Sheet page 2/13, item 1, bullet 20 — lists four digesters/three
in use all four digesters are in use. Supplement to Permit Cover Sheet page 2/13, item 1,
bullet 22 also lists four anaerobic digesters. I would suggest revising bullet 20 as follows
and deleting bullet 22 — Two gravity belt thickeners; two belt filter presses; four
anaerobic digesters; alkaline stabilization; covered storage area.
9. Part 1, Section A.1 — The daily maximum Total Residual Chlorine (TRC) limit is 13.0
235 Government Center Drive
Wilmington, North Carolina 28403
www.cfpua.org
Page 4 of 7
Ms. Julie A. Grzyb
June 29, 2015

1.1111Cape Fear
Public Utility Authority
Stewardship. Sustainabili:y. Service.
µg/L and Footnote 4 indicates that the Division considers all effluent TRC values
reported below 50 µg/L to be in compliance with this permit and to continue to record
and submit all values reported by a North Carolina certified laboratory even if these
values fall below 50 µg/L. Values below 50 µg/L are non -quantifiable and therefore we
cannot properly certify that data. Footnote 4 should require that the permittee report all
data below 50 µg/L as "<50 µg/L".
10. Part 1, Section A.1, Footnote 7 — Consistent with the current MOA, the variable
frequency for stream sampling indicates that stream samples shall be collected 3/week
during the summer months of June, July, August, and September; samples shall be
collected weekly during the rest of the year. The current MOA spans 07/01/2011 through
06/30/2016; these sample frequencies may be revisited and/or revised prior to the
SSWWTP NPDES permit's 12/31/2016 expiration date.
11. Part 1, Section A.2 — DWR has reverted to daily monitoring for BOD5, TSS, and
Enterococci. CFPUA requests that the current 2/week parameter measurement frequency
be reinstated, but in no event should it take in excess of 6 months to regain its former
value.
12. Part 1, Section A.2 — The daily maximum Total Residual Chlorine (TRC) limit is 13.0
µg/L and Footnote 4 indicates that the Division considers all effluent TRC values
reported below 50 µg/L to be in compliance with this permit and to continue to record
and submit all values reported by a North Carolina certified laboratory even if these
values fall below 50 µg/L. Values below 50 µg/L are non -quantifiable and therefore we
cannot properly certify that data. This requirement should be N/A under this flow
condition as the facility will replace chlorination with UV disinfection.
13. Part 1, Section A.2, Footnote 3 — CBOD5 should be changed to BOD5.
14. Part 1, Section A.2, Footnote 7 — Consistent with the current MOA, the variable
frequency for stream sampling indicates that stream samples shall be collected 3/week
during the summer months of June, July, August, and September; samples shall be
collected weekly during the rest of the year. The current MOA spans 07/01/2011 through
06/30/2016; these sample frequencies may be revisited and/or revised prior to the
SSWWTP NPDES permit's 12/31/2016 expiration date.
15. Part 1, Section A.3 — DWR has reverted to daily monitoring for BOD5, TSS, and
Enterococci. CFPUA requests that the current 2/week parameter measurement frequency
be reinstated, but in no event should it take in excess of 6 months to regain its former
value.
16. Part 1, Section A.3 — The daily maximum Total Residual Chlorine (TRC) limit is 13.0
µg/L and Footnote 4 indicates that the Division considers all effluent TRC values
reported below 50 µg/L to be in compliance with this permit and to continue to record
and submit all values reported by a North Carolina certified laboratory even if these
values fall below 50 µg/L. Values below 50 µg/L are non -quantifiable and therefore we
cannot properly certify that data. This requirement should be N/A under this flow
condition as the facility will replace chlorination with UV disinfection.
235 Government Center Drive
Wilmington, North Carolina 28403
www,cfpua.org
Page 5 of 7
Ms. Julie A. Grzyb
June 29, 2015

Cape Fear
Public Utility Authority
Stewardship. Sustainability. Service.
17. Part 1, Section A.3, Footnote 3 — CBOD5 should be changed to BOD5.
18. Part 1, Section A.3, Footnote 7 — Consistent with the current MOA, the variable
frequency for stream sampling indicates that stream samples shall be collected 3/week
during the summer months of June, July, August, and September; samples shall be
collected weekly during the rest of the year. The current MOA spans 07/01/2011 through
06/30/2016; these sample frequencies may be revisited and/or revised prior to the
SSWWTP NPDES permit's 12/31/2016 expiration date.
19. Part 1, Section A.4 — DWR has reverted to daily monitoring for BOD5, TSS, and
Enterococci. CFPUA requests that the current 2/week parameter measurement frequency
be reinstated, but in no event should it take in excess of 6 months to regain its former
value.
20. Part 1, Section A.4 — The daily maximum Total Residual Chlorine (TRC) limit is 13.0
µg/L and Footnote 4 indicates that the Division considers all effluent TRC values
reported below 50 µg/L to be in compliance with this permit and to continue to record
and submit all values reported by a North Carolina certified laboratory even if these
values fall below 50 µg/L. Values below 50 µg/L are non -quantifiable and therefore we
cannot properly certify that data. This requirement should be N/A under this flow
condition as the facility will replace chlorination with UV disinfection.
21. Part 1, Section A.4, Footnote 3 — CBOD5 should be changed to BOD5.
22. Part 1, Section A.4, Footnote 7 — Consistent with the current MOA, the variable
frequency for stream sampling indicates that stream samples shall be collected 3/week
during the summer months of June, July, August, and September; samples shall be
collected weekly during the rest of the year. The current MOA spans 07/01/2011 through
06/30/2016; these sample frequencies may be revisited and/or revised prior to the
SSWWTP NPDES permit's 12/31/2016 expiration date.
23. Special conditions relating to TMDLs — The James A. Loughlin (Northside) WWTP
(NC0023965) contains two special conditions addressing permittee TMDL concerns.
While progress within the TMDL process has been attained, several issues remain
unresolved. These issues had never been a concern with regard to previous SSWWTP
NPDES permit transactions inasmuch as they had been renewals and had not required
any changes to effluent quantity and quality. The pending permit modification does
affect effluent quantity and quality, and the CFPUA believes that the timing is now
appropriate to request that similar special conditions be inserted into the SSWWTP
NPDES permit. The suggested language follows.
HISTORICAL PERMIT LIMITS
The Division recognizes that prior to issuance of the permit, the M'Kean Maffitt
(Southside) WWTP was permitted to discharge with secondary limits of 25.0 mg/L
CBOD5, 30.0 mg/L TSS, and no limit for NH3 as N. At the permitted flow of 12.0 MGD,
these limits translate approximately to mass loads of 457 tons per year (tpy) BOD5, 548
tpy TSS, and 365 tpy NH3 as N (assuming 20 mg/L). The mass loads described in this
235 Government Center Drive
Wilmington, North Carolina 28403
www.cfpua.org
Page 6 of 7
Ms. Julie A. Grzyb
June 29, 2015

MI Cape Fear
PlifiAlt 'Utility Authority
Stewardship. Sustainability. Service.
paragraph will be one factor the Division considers when developing future wasteload
allocations resulting from the TMDL process or when considering future expansion
requests for the M'Kean Maffitt WWTP.
ANTI -BACKSLIDING
The BOD5 and ammonia nitrogen (NH3 as N) limits in this permit may be replaced with
less stringent limits without violating state and Federal anti -backsliding provisions if:
a. Circumstances predicating the issuance of this permit have materially and
substantially changed;
b. There are material and substantial changes to the facility;
c. New information comes available (such as the determination of a TMDL); or
d. New regulations become promulgated;
providing that the Division deems such modification appropriate and consistent with
applicable laws and regulations.
24. Standard Conditions — There are several references to treatment facilities and collection
system. CFPUA possesses separate permits for its WWTPs and its collection system;
they are independent of each other, and while one can reference the existence of the
others it should not incorporate one into the other.
Please let me know if you have any questions or need to discuss any of the CFPUA's positions or
comments further.
Sincerely,
/74--
Kenneth L. Vogt, Jr., PE, EF
CFPUA Wastewater Treatment Superintendent
kv/ls
Copies: J. Flechtner
F. Styers
B. Eckert
L. Miles
M. Vann
C. Wilson
B. Blake
235 Government Center Drive
Wilmington, North Carolina 28403
www.cfpua.org
Page 7 of 7
Ms. Julie A. Grzyb
June 29, 2015

Grzyb, Julie
From: Microsoft Outlook
To: [e-mail]
Sent: Thursday, May 21, 2015 4:24 PM
Subject: Relayed: Draft modification for CFPUA's M'Kean Maffitt (Southside) WWTP (NC0023973)
- SIC 4952
Delivery to these recipients or groups is complete, but no delivery notification was sent by the
destination server:
r4npdespermitsepa.gov (r4npdespermits0epa.gov)
Subject: Draft modification for CFPUA's M'Kean Maffitt (Southside) WWTP (NC0023973) - SIC 4952
1

Grzyb, Julie
From: Ken Vogt <[e-mail]>
Sent: Friday, May 08, 2015 12:17 PM
To: Grzyb, Julie
Cc: Jim Flechtner; Frank Styers; Milton Vann; Beth Eckert; Tony Boahn
([e-mail]); Nailor, David A. ([e-mail])
Subject: FW: M'Kean Maffitt WWTP permit modification
Julie - Your inquiry to Jim Flechtner was directed to my attention for response. CFPUA is receptive to using BOD5 in
lieu of CBOD for phased effluent limits sheets for all post-expansion/upgrade project NPDES permit flows (16, 20, and
24 MGD). We have assumed that CBOD will be removed as a monitored parameter with enforceable limits with the
inclusion of BOD5. We have also assumed that the existing pre-expansion/upgrade project 12 MGD secondary facility
effluent limits sheet will continue using the same CBOD monitoring and enforceable limits. If your position should
differ, please advise. Thx. Ken.
From: Jim Flechtner
Sent: Tuesday, May 05, 2015 17:56
To: Ken Vogt; Frank Styers
Subject: Fwd: M'Kean Maffitt WWTP permit modification
Please respond as needed. Thanks.
Sent from my iPhone
Begin forwarded message:
From: "Grzyb, Julie" <[e-mail]>
Date: May 5, 2015 at 5:46:32 PM EDT
To: "[e-mail]" <[e-mail]>
Subject: M'Kean Maffitt WWTP permit modification
Jim,
I am not sure who to send this email to but perhaps you can address my question or forward it to
whoever can. I am working on the CFPUA (Southside) permit modification and renewal. The speculative
limitations were written for BOD5 not CBOD. I noticed the current permit has CBOD limits. I intend to
put BOD5 limits in the Phased Effluent sheets for 16, 20, and 24 MGD. Will that be okay. Thinking that
since the ammonia is being reduced it will not matter much.
Also, note that the only conversion numbers we have for CBOD to BOD are EPA's 25 to 30. So if you do
want CBOD do you have data to help with this conversion or would using those be fine.
Thanks for your help on this matter,
Julie
Julie A. Grzyb, Environmental Engineer
NC DENR / Division of Water Resources / Water Quality Permitting
NPDES Complex Permitting, Wastewater Branch
1617 Mail Service Center, Raleigh, NC 27699-1617
919/807-6389 (wk)
[e-mail]
1

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.
2

Zo1s weTlss-?
Cape Fear
Public Utility Authority
Stewardship. Sustainability. Service.
March 6, 2015
Mr. Jeff Poupart
Wastewater Branch Supervisor
N.C. Department of Environment and Natural Resources
Division of Water Resources
1617 Mail Service Center
Raleigh, N.C. 27699-1617
RECEIVED/DENR/DWR
MAR _ 6 201!'
Water Quality
Permitting Section
RE: Cape Fear Public Utility Authority
M'Kean Maffitt (Southside) Wastewater Treatment Plant
Pending 24 MGD NPDES Permit Modification Application — CFPUA SSWWTP NPDES
Permit NC0023973 — Additional Modification Request — Whole Effluent Toxicity (WET)
Testing
Dear Mr. Poupart:
The current CFPUA SSWWTP NPDES permit NC0023973 establishes an acute WET (AWET)
test requirement - pass/fail methodology for determining acute toxicity in a single effluent
concentration. It is performed quarterly as a Ceriodaphnia dubia 24 hour static test upon a
sample consisting of 90% plant effluent as a means of demonstrating no significant acute
mortality. The SSWWTP has experienced previous difficulty in consistently passing its AWET
test.
Beginning in September 2012 intermittent whole effluent toxicity to Ceriodaphnia dubia had
been observed. Because the SSWWTP had demonstrated a strong record of compliance with
NPDES permit WET requirements prior to that period, the CFPUA informally began Toxicity
Identification Evaluation (TIE) procedures by conducting preliminary testing in an effort to
identify the cause of toxicity. Prior to September 2012, SSWWTP WET testing performed by
ETS and Pace had not observed toxicity in the SSWWTP effluent in more than two years of
regular quarterly NPDES monitoring. Furthermore, the effluent was never reported to be toxic
over at least the previous seven years. Meritech began serving as the provider of WET testing
beginning in July 2012 with the September 2012 results being the first indicator of toxicity.
Meritech and ETS conducted preliminary TIE testing and split sample analysis. Tetra Tech
assisted CFPUA with a full Phase I TIE and Phase II testing in early 2013. As a result of these
investigations, several observations were identified: (a) ammonia levels seemed to influence
WET testing outcomes; minor process modifications were considered in an effort to reduce
effluent ammonia levels; (b) vessel headspace conditions seemed to influence WET testing
outcomes; test procedure manipulations were tried with open and closed test vessels; (c)
significant pH shifts were noted during the conduct of the tests which also seemed to influence
the WET testing outcomes.
235 Government Center Drive, Wilmington, N.C. 28403
Phone: [phone] Fax: [phone]
WASTEWATER TREATMENT: www.cfpua.org

NM Cape Fear
Public utility Authority
Stewardship. Sustainability. Service.
Late 2012 through the middle of 2013 seemed to be characterized by mixed passing and failing
AWET test results. At about this time, CFPUA began considering use of the Chronic WET test
(CWET) in lieu of the AWET. In preparation for conducting CWET testing, the NCDENR
Division of Water Quality Surface Water Protection Section was consulted in an effort to
establish the IWC applicable to our conditions; in their 07.03.2013 email, a copy of which
accompanies, they established the IWC at 3.03%. Also about this time, the NCDENR Aquatic
Toxicology Unit offered to perform supplemental tests, particularly CWET, and to assist our
analysis and interpretation of the data. From about the middle of 2013 until the end of 2014, we
consistently passed both the quarterly AWET and CWET tests. In December 2014, we
unfortunately experienced another AWET failure, but passed the CWET. Follow-up testing
during January yielded passes for both AWET and CWET tests.
During the course of these deliberations, NCDENR had maintained that the preferred toxicity
testing assignment when the IWC is known is chronic testing (reference 11.04.2013 ATU
summary report and CFPUA 01.14.2014 correspondence; copy accompanies). Given the
previously documented uncertainties in SSWWTP WET testing compliance, we believe that the
best and most prudent course of action is to transition to use of the CWET test within our
NPDES permit as soon as practical. NCDENR is currently reviewing CFPUA's 24 MGD major
NPDES permit modification application which was submitted in late 2014. If DWR is receptive
to acceptance of the 3.03% IWC, CFPUA would request DWR consider incorporating the
CWET requirement into the NPDES for the existing 12 MGD secondary facility as well as all
future flows (16 MGD; 20 MGD; 24 MGD) under the currently applicable advanced level of
treatment prescribed for the Cape Fear River estuary.
Please let us know at your earliest convenience if this request can be accommodated, and let us
know if there are any questions or concerns we can address.
Sincerely,
Kenneth L. Vogt, Jr., P.E. BCEE
Wastewater Treatment Superintendent
cc: Jim Flechtner
Frank Styers
Beth Eckert
Milton Vann
Craig Wilson
Bryan Blake (McKim & Creed)
Attachments
235 Government Center Drive, Wilmington, N.C. 28403
Phone: [phone] Fax: [phone]
WASTEWATER TREATMENT: www'` w.cfpua.org

Ken Vogt
From: Pam Ellis
Sent: Wednesday, July 03, 2013 11:45
To: Ken Vogt
Subject: FW: South Side Dilution Factor - from Jim McKay
Attachments: Dilutation factor for CFPUA Southside WWTP.xlsx
From: Mckay, James [mailto:james.mckay@ncdenr,gov]
Sent: Wednesday, July 03, 2013 10:55 AM
To: Pam Ellis
Cc: Gore, Deborah
Subject: South Side Dilution Factor
Please contact me if you have further questions.
Sincerely,
Jim McKay, Environmental Engineer
NC DENR / Division of Water Quality / Surface Water Protection Section
Point Source Branch
1617 Mail Service Center, Raleigh, NC 27699-1617
919/807-6404 (work); 919/807-6489 (fax)
**Please note, my email address has changed to [e-mail]
ncdenr.gov
E-mail correspondence to and from this address may be subject to the North Carolina Public Records la►v and may be
disclosed to third parties.
1

Calculation of Dilution Factor for CFPUA Southside WWTP.
Goal: To evaluate Tetra Tech's modeling work in 2001 report to determine dilution factors
to be used to perform headworks analysis for Wilimgton's Southside WWTP, and for
performing RPAs.
Basis:
From the internal document MIXING ZONES IN NORTH CAROLINA dated July 23,1999,
(1) Dilution is calculated as: D = (Qw + Qu)/ Q„
where Q,w is the maximum permitted wasteflow, and
Q, is the critical upstream streamflow, generally the summer 7Q10 flow.
From Tetra Tech's report dated May 2001, page 4-11, the minimum dilution for the
Southside WWTP is listed as 33 near the bottom.
The permitted flow for the Southside plant is 12.0 MGD x 1.55 CFS/ MGD = 18.6 CFS.
Entering these values into Equation (1) above gives: 33 = (18.6 + Qu)/ 18.6.
Multiply both sides by 18.6 to get: 613.8 = (18.6 + Qu)
= 613.8 -18.6 = 595.2 CFS. This is the calculated "S7Q10".
(2) IWC = [Qw/ (Qw + Qu)] X 100% = 18.6 / (18.6 + 595.2) X 100% = 3.03%. Round to 3% for WET testing.
(2.a) IWC = 1/ Dilution X 100% = 1/ 33 X 100% = 3.0% Check
Jim McKay
6 27 2012
A--F. /6,/t CPS'AI&.2 2 cfs
tAfe_ .ro,frt •e.. J `7 % l ° of c. / N1 CrI� 1 s
--_-. y, s /Ny. _s"
kik) k &? 9 r x „ „ 7, -_-_ C'Pa-
x /, f C �..� 37• k Cis
-= (37. a I- 9s-a) X �,��� S

NM Cape Fear
Public Utility Authority
Stewardship. Sustainability. Service.
January 14, 2014
Cindy Moore, Unit Supervisor
Aquatic Toxicology Unit/Environmental Sciences Section
North Carolina Division of Water Resources/DENR
1621 Mail Service Center
Raleigh, NC 27699-1621
Dear Ms. Moore:
Subject: Voluntary Toxicity Identification Evaluation for M'Kean Maffitt WWTP
Permit Number NCOO23973
Enclosed for your review is a Toxicity Identification Evaluation (TIE) report completed by Tetra Tech, Inc.
for the M'Kean Maffitt WWTP, NC0O23973. We began experiencing sporadic acute toxicity failures in
September 2012. Following exhaustive investigation by staff during the fall of 2012 and the winter of
2013 we decided that a more formal approach was needed arid contracted with Tetra Tech in March
2013 to conduct an analysis of existing toxicity and plant operational data. We also asked they conduct
a TIE to aid with identifying the root cause of the toxicity. The July 15, 2013 TIE report summarizes their
findings and includes seven attachments: A through G. This report should not be considered conclusive,
adopting its findings as accepted for implementation, or representing the final position of the Authority.
We sincerely appreciate the investigative support provided by you and your staff in the DWR Aquatic
Toxicology lab. Your assistance with evaluating results from certified laboratories to determine accuracy
of reported results provided insight to the complexity of our toxicity problem. Split sample laboratory
results have often been vastly different between labs; frequently one lab has reported a "Pass" and the
other lab a "Fail. Your findings along with those of Tetra Tech, Inc. indicate that the acute toxicity
observed in M'Kean Maffitt effluent is being caused by extreme rise in pH during the toxicity testing
period which results in a rise in concentration of un-ionized ammonia. The amount of un-ionized
ammonia is affected by small differences in pH and may explain disparity between lab results. While
there is some evidence leading to this conclusion, I don't believe the Authority fully accepts this finding
as being conclusive and exclusive as unanswered/unaddressed questions remain.
Toxicity testing results using closed vessels versus open cups confirms that pH rise is correlated with
mortality of test organisms for those samples reported as "Fail." Not only has the cause of extreme rise
of pH in samples not yet been fully explained, it does not simulate actual field conditions. Rising pH
during toxicity testing was not reported for most samples taken prior to September 2012. Although the
evidence points towards pH and related un-ionized ammonia concentration as a possible cause, we
believe that the variability of testing results leaves open the possibility for some constituent other than
ammonia being the source of toxicity.
We appreciate your offer to perform chronic testing to assist us with determining the effect of our
effluent on mortality and reproduction. Three chronic testing events have been performed and all
results indicate no toxicity expressed at dilutions well above in -stream waste concentrations (IWCs)
235 Government Center Drive, Wilmington, NC 28403
t: 910-799-6064 f: 910-799-6066 www.cfpua.org

MN Cape Fear
Public Utility Authority
Stewardship_ SustaInabhm. Service.
believed representative of the volumes, confluence location, and mixing characteristics of the M'Kean
Maffitt plant with the Cape Fear River. We are requesting your assistance with conducting one
additional chronic test in March 2014. This will provide us with four quarters of monitoring to cover all
seasons. We are hoping that chronic testing continues to have consistent results and does not
demonstrate extreme variability as we have observed with acute testing.
You indicated in the summary report sent to us November 4, 2013 that "...the preferred toxicity testing
assignment when the IWC is known" is chronic testing. While all CWET efforts to date are very
promising, and although we are considering a request to change our toxicity test assignment, in the
meantime we recognize the need to continue to investigate the root cause of acute toxicity. We remain
curious about anomalies in AWET results, including varying results obtainable in static renewal, non -
renewal, flow through, open system and closed system options. In addition, and even though this plant
was not designed for ammonia conversion or nitrogen removal, we continue to investigate and
implement plant adjustments and changes intended to reduce or eliminate effluent toxicity. We are
evaluating these changes and adjustments specifically as they relate to their impact on toxicity testing
results. Split sample toxicity testing results for monitoring performed in December 2013 were reported
as a "Pass" from both labs with 0% mortality.
We plan to continue to be proactive with our investigation of intermittent toxicity. Thank you for the
collaborative support provided to aid with resolving our toxicity problem. If you have any questions
about the TIE report, please feel free to call me at 910.332.6586 or email me at [e-mail].
Sincerely,
Kenneth L. Vogt Jr., P.E., B.0 E.
Wastewater Treatment Superintendent
Copies: J. Flechtner, M. Richardson, B. Eckert, P. Ellis, T. Clements
235 Government Center Drive, Wilmington, NC 28403
t: 910-799-6064 f: 910-799-6066 www.cfpua.orq

Division of Water Resources
November 4, 2013
MI MO.IUM
To:
Through: Cindy A. Moore
Supervisor, Aquatic Toxicology Branch
From:
Milton Vann
ORC, M'Kean Maffit Southside WWTP
Carol Hollenkamp
Environmental Sen r pecialist, Aquatic Toxicology Branch
Subject: Summary of the Whole Effluent Toxicity Tests Performed by the Aquatic
Toxicology Branch Laboratory for M'Kean Maffit Southside WWTP between
June and September 2013.
PURPOSE
This report summarizes the Whole Effluent Toxicity (WET) tests conducted by the Aquatic Toxicology
Branch (ATB) laboratory for the Cape Fear Public Utility Authority's (CFPUA) M'Kean Maffitt Southside
WWTP (SSWWTP) between June and September 2013. The intent is to provide supplemental data to assist
with the current study being performed by CFPUA and its consultant, Tetratech, to identify and solve the
toxicity issues that SSWWTP has been experiencing. This report does not provide a detailed analysis of all
the tests and analyses that CFPUA has conducted, as that will be in CFPUA's final report. ATB will be
conducting at least one additional test in December 2013 and this information should further assist in
resolving the unusual and intermittent toxicity issues that SSWWTP has been experiencing.
BACKGROUND
SSWWTP (NC0023973) began experiencing intermittent toxicity failures on acute pass/fail Ceriodaphnia
dubia tests in September 2012. The failure that occurred in September 2012 was SSWWTP's first failure
that involved using a North Carolina (NC) certified laboratory on an acute daphnid test since 1999.
After the September 2012 failure, SSWWTP began proactively investigating the cause of the failure and
initial investigations indicated that ammonia may be the cause of toxicity. In January 2013, the facility
began splitting effluent samples between two NC -certified laboratories. The intermittent nature of the
failures has occurred both: 1) when splitting effluent samples among laboratories and 2) from quarter to
quarter at the same laboratory. Split tests have been performed using the following five laboratories:
Environmental Testing Solutions, Inc. (ETS); Meritech Inc.; Pace Analytical Raleigh; Tetratech; and the DWR
ATB Laboratory. ETS, Meritech, and Pace Analytical Raleigh are all certified to conduct acute Ceriodaphnia
tests for NPDES compliance in North Carolina.

Most of the failures have had a large increase in pH from the beginning of the test to the end of the test;
however, not all tests with large increases in pH have failed. The EPA "Acute Manual" notes in Section 9.5.9
that "pH drift during acute, static -renewal, or non -renewal toxicity tests may contribute to artifactual
toxicity when ammonia or other pH -dependent toxicants (such as metals) are present. This problem can be
minimized by conducting a test in a static -renewal mode rather than a non -renewal mode, or the problem
can be avoided by conducting the test in a flow -through mode, rather than a static -renewal or non -renewal
mode" (USEPA 2002). SSWWTP does have high ammonia levels (typically 20-30 mg/L) and therefore would
be susceptible to ammonia toxicity due to pH drift. However, conducting flow -through testing is not an
economically -feasible option anymore, and because the test is only 24 hours, renewals are also not a good
approach. Although the EPA "Chronic Manual" offers acceptable techniques for pH adjustments, these are
not included in the EPA "Acute Manual".
It should be also noted that prior to March 2011, Pace Analytical in Asheville had performed all toxicity
testing for SSWWTP. A review of the tests conducted by Pace Asheville between 2006 and 2010 shows a
much smaller variation in pH, with the pH rarely rising above 8.0. The pH on the December 2010 sample
did show a large drift and passed only due to a large variation in the test treatments, which skews the
statistics to be less sensitive to detecting higher rates of mortality as statistically significant. The pH drifted
from 7.45 to 8.12 and the percent mortality was 22.5%; this was not statistically significant on this
particular test. Pace Asheville closed in 2011.
Although Pace Asheville did not have large shifts in pH exceeding 8.0 between 2006 and 2010, ATB
conducted an acute Ceriodaphnia pass/fail test on August 17, 2006 that failed due to 100% mortality in the
90% test treatment. However, the test conducted by ATB was not a permit compliance test or a split test,
but simply part of the routine bioassay compliance inspections performed by the Regional Offices.
Although ATB tests are not used to determine compliance with permit limits, it should be noted that the
ATB test that failed also exhibited a large upward pH shift similar to the large pH shift observed in recent
failures. The initial pH of the 90% treatment was 7.92 and the final pH was 8.45. ATB also conducted
another routine bioassay compliance inspection test on September 29, 2010. This test was a split with Pace
Asheville and both tests passed with pHs that only drifted up to 7.9 and 8.1.
Between January and September 2013, there have been 6 sampling events in which samples split among
labs have resulted in one lab passing and the other lab failing the test. Often, the difference is extreme.
For instance, one lab may have little or no mortality and the other lab may have extremely high mortality.
One lab is not consistently failing and one lab is not consistently passing. This indicates the variable results
are not due to standard lab technique, but due to characteristics of the sample chemistry during testing and
sometimes statistical insensitivity caused by high control or test treatment variability. CFPUA's
investigation has also indicated that when headspace of the samples is eliminated, pH drift is minimized
and the test will pass at 24 hours. This finding is also indicative that the toxicity is due to a pH -dependent
toxicant.
ATB policy for disagreeing split tests is that all WET monitoring results must be submitted. Then, ATB
conducts a review to evaluate if all required quality assurance (QA) practices and quality control (QC)
criteria have been met for each of the tests. If all QA/QC criteria on each test are met and no difference
between can be found among them, the passing result is accepted as the final result. DWR received a letter
Page 2 of 10

dated August 28, 2013 from CFPUA regarding the July 2013 disagreeing split samples indicating that a pass
and a fail received on a split sample is considered a pass. ATB would like to clarify that this is after ATB
reviews all tests performed on the split sample and determines that the all QA/QC criteria were met.
Although we do occasionally have disagreeing split test results, the frequency of the disagreement for the
SSWWTP split tests is unprecedented. Because an acute test failure triggers the immediate requirement for
a facility to continue testing until a passing result is received, ATB has advised CFPUA that when they
receive a pass and a fail, follow-up testing will not be required unless the review of the split tests indicates
that the passing test did not meet all QA/QC criteria. In other words, SSWWTP does not have to
immediately initiate follow-up testing if it performs a split test and receives a passing result and a failing
result. ATB will notify CFPUA if follow-up testing is required after the split tests are reviewed.
Due to the unprecedented rate of disagreeing split test results and the sudden appearance of intermittent
failures in SSWWTP's toxicity tests, ATB participated in split tests conducted on the sample collected in June
2013. The June sample was split between ETS, Meritech, Tetratech, and ATB. Meritech and ATB failed,
whereas ETS and Tetratech passed. After these results were reviewed, it was noted that ATB and Meritech
had the highest pH drift and that they both used soft surface water as opposed to the synthetic laboratory
water used by ETS and Tetratech. ATB then participated in another round of split tests in July to help
understand if the type of culture or dilution water was affecting the pH drift.
CULTURE/DILUTION WATER
Under EPA and DWR protocol, the water used as the culture and/or dilution water for freshwater toxicity
tests can be prepared either from high purity laboratory water or non -toxic surface water. The laboratory
prepared water is typically referred to as either soft synthetic water (hardness of 30-50 mg/L CaCO3) or
moderately hard synthetic water (hardness of 80-100 mg/L CaCO3). DWR requires that all water used for
dilution water on NPDES compliance tests have a hardness of 30-50 mg/L CaCO3 because this is most
reflective of receiving waters across North Carolina and hardness can play a critical role in the toxicity of
some substances, most notably metals.
Each of the Tabs that have performed testing for SSWWTP uses a different type of water. The types of
water used by each lab are summarized below in Table 1.
Table 1: Tvae of Water Used by Each Lab
Laboratory
Culture Water
Dilution Water
ETS
Moderately Hard Synthetic
Soft Synthetic
Meritech
Soft Surface
Soft Surface
Tetratech
Moderately Hard Synthetic'
Moderately Hard Synthetic'
Pace (Raleigh)
Soft Surface
Soft Surface
DWR ATB2
Soft Surface
Soft Surface
'Based on preliminary reports, ATB believes Tetratech conducted the tests in moderately hard synthetic water, but
soft synthetic water may have been used on some of the tests they performed.
2ATB's primary laboratory water is soft surface water, but ATB also maintains cultures and reference toxicant tests for
moderately hard and soft synthetic water cultures.
Page 3 of 10

In order to look into the varying test results, the DWR ATB laboratory participated in the July 2013 sampling
event using various types of culture and dilution water on acute tests as well as conducting a chronic full -
range test. The objectives of the ATB tests in July were: 1) to assess whether and how the type of dilution
water affected tests results while removing the effect of variability among laboratories and 2) to evaluate if
a chronic test might be a more appropriate toxicity test assignment for SSWWTP. ATB performed four
acute Ceriodaphnia tests and one chronic full -range Ceriodaphnia test on the July sample. In September,
ATB performed another chronic full -range Ceriodaphnia test. These six tests are described in Table 2.
Table 2: Tests performed by ATB in July and September 2013 for CFPUA SSWWTP
Da%• f
__ d
Test Type;'
_
j kCul ire" 11 lat r '
- r
iDllution Water. .
itreitWater)
7/17/13
Acute#1
Soft Surface
Soft Surface
7/17/13
Acute#2
Soft Synthetic
Soft Synthetic
7/17/13
Acute#3
Moderately Hard Synthetic
Soft Synthetic
7/17/13
Acute#4
Moderately Hard Synthetic
Moderately Hard Synthetic
7/17/13
Chronic#1
Soft Surface
Soft Surface
9/11/13
Chronic#2
Soft Synthetic
Soft Synthetic
Acute test #4 was to evaluate if performing the test in hard water has any effect on the results. ATB
protocol requires that tests be performed in soft water (water with a hardness of 30-50 mg/L CaCO3),
unless it is determined that an alternate hardness range would be more appropriate for the testing
objectives. Therefore, acute test #4 is not a valid test option unless it was demonstrated that the receiving
waters consistently have a hardness value between 80-100 mg/L CaCO3.
Chronic test #1 was to evaluate if chronic testing would be more appropriate for SSWWTP. When toxicity
testing was first assigned to the facility, the lnstream Waste Concentration (IWC) was unknown. Per DWR
policy, when the IWC is unable to be calculated, acute testing at 90% effluent at 24 hours is assigned.
Recently, the facility completed a study in which there may be sufficient information to evaluate the IWC.
Chronic testing at the facility's IWC is the required toxicity testing assignment when the IWC is known as
this is a more comprehensive evaluation of the effect on the receiving waters. It is estimated that the
facility's IWC may be as low as 3%; therefore, the chronic test was run at the following five concentrations
of effluent: 3, 6,12, 24, and 48%.
Chronic Test #2 was to evaluate if the chronic test results exhibited variability among months and water
type. ATB will conduct another chronic test in December 2013 to further explore the potential of variability
among seasonality and water type.
RESULTS & DISCUSSION
ACUTE TESTS
The results of the acute tests are presented in Table 3. In addition to the standard information regarding
toxicity tests, ATB also analyzed the total ammonia concentrations of the effluent and the initial and final
Page 4 of 10

ammonia concentrations in each of the test treatments. The total ammonia of the 100% effluent was 22
mg/L. The total ammonia concentrations of each of the treatments as well as the potential concentration
range of un-ionized ammonia (NH3) are shown in Table 3. Ammonia is relatively unique in its behavior as
pH and temperature changes. When ammonia dissolves in water, some of the molecules react to form the
ammonium ion NH4+, and the equilibrium between these species is affected by pH and temperature. The
toxicity of ammonia to some aquatic species appears to be primarily caused by the un-ionized form. The
equilibrium shifts to increase the un-ionized ammonia concentration with increasing pH and increasing
temperature (USEPA 1993).
Table 3: July 2013 ATB Acute Tests Results
.
Acute Test
;' Awe Test #2 ,_
Acute Test #3
, _Acute -Test 4
Culture Water
Soft Surface
Soft Synthetic
Moderately Hard
Moderately Hard
Test Water
Soft Surface
Soft Synthetic
Soft Synthetic
Moderately Hard
Effluent pH
7.51
7.51
7.51
7.51
Initial pH treatment
8.08
8.0
8.12
8.09
Final pH treatment
8.29
8.34
8.33
8.35
Initial total ammonia
(mg/L)
20
20
20
20
Initial un-ionized
ammonia range' (mg/L)
1.25-1.8564
1.006-1.495
1.25-1.8564
1.25-1.8564
Final total ammonia
(mg/L)
14
17
18
16
Final un-ionized
ammonia range' (mg/L)
1.3384-1.526
1.7208-1.962
1.6252-1.853
1.872-2.128
% Mortality
57.5%
30%
95%
_
82.5%
Pass/Fail
Pass (Insensitive,
Invalid)
Pass (Insensitive,
Invalid)
Fail (Valid)
Fail (Valid)
'Calculated from Table 10, Percent Un-ionized Ammonia in Aqueous Ammonia Solutions, from EPA's "Acute Manual",
2002. The range was calculated by multiplying the % un-ionized ammonia from the table by the total ammonia value
of the treatment, at 24°C for the low range and 26°C for the high range
The range of the toxic form of ammonia, un-ionized ammonia, which is predicted to be found in the
samples, is close to the predicted Median Lethal Concentrations (LC50s) calculated from an EPA study (see
Table 4). The LC50 is the concentration of a substance at which 50% of a population is killed during a
certain amount of time. In this case, the time period is 24 hours.
Page 5 of 10

Table 4: Calculated Un-ionized and Total Ammonia LC5Os (me/L1*
pH
Percent
Unionized at
25°C
Un-ionized Ammonia
Expected 24hr LCSO
Total Ammonia
24hr LC50
Un-ionized Ammonia
Expected 24 hr LCSO
Total Ammonia
48hr LC50
7.6
2.21
1.48
67
1.14
_
52
7.7
2.77
1.61
58
1.24
45
7.8
3.46
1.73
50
1.33
38
7.9
4.32
1.83
42
1.42
33
8.0
5.38
1.93
36
1.49
28
8.1
6.68
2.01
30
1.55
23
8.2
8.27
2.08
25
1.61
20
8.3
10.2
2.14
21
1.65
16
8.4
12.5
2.19
18
1.69
14
8.5
15.2
2.23
15
1.73
11
*Table Adapted from `Table 3-2, Calculated Un-Ionized Ammonia LC50s (mg/L) based on 24-hr and 48-hr results of a
Cerlodaphnla dubla Toxicity Test Conducted at pH 8.0 and 25°C," USEPA 1993.
The intermittent nature of the toxicity may be occurring because the expected ranges of the toxic un-
ionized ammonia concentrations are so close to the LC50 values. Critical fluctuations in the amount of un-
ionized ammonia occur with minute shifts in pH and temperature values. Additionally, the rate at which pH
drifts upwards and ammonia dissipates out of the sample will be slightly different for each test. Small
differences can result in critical differences in the amount of un-ionized ammonia for each toxicity test. For
example, in a sample with 24 mg/L total ammonia at 25.0°C, 5.38% of it would be in the toxic un-ionized
ammonia form at a pH of 8.0. With an increase of only 0.3 pH units, the percent of ammonia in the toxic
form almost doubles to 10.2%. These percentages correspond to 1.29 mg/L at pH 8.0, and 2.45 mg/L at 8.3.
The un-Ionized ammonia expected 24 hr LC50s are 1.93mg/L at 8.0 and 2.14 mg/L at 8.3. With a shift of
just 0.3 pH units, the percentage of un-ionized ammonia in the sample has gone from being 67% of the
LC50 to 114% of the LC50. Micro -variations in temperature, pH, and the rate of change in ammonia in the
sample coupled with the rate of pH shift, can each cause critical changes in toxicity among replicates and
among laboratories.
CHRONIC TESTS
The results of the chronic tests are shown in Table 5. Both tests indicate that no acute or chronic toxic
effects would be expected at IWCs of 48% or less. On the July test, there was a statistically significant effect
at 48%. However, per DWR policy, a significant effect must show statistical significance coupled with a 20%
or greater decrease in reproduction. Therefore, the effect at 48% is not considered a significant toxic effect
because the reduction in reproduction was 17%. On the September test, there was an inversion in the
amount of reproduction at 3%, with the 3% treatment showing a 31.8% reduction in reproduction
compared to the control. However, this effect was not statistically significant. The 6,12, 24, and 48%
treatments all had higher reproduction than the 3%, indicating the reduction at 3% was an anomaly. The
reason there was a large reduction in reproduction but not a statistically significant effect at 3% was that 3
of the 10 replicates did not reproduce at all, while the other 7 replicates had very high rates of reproduction
causing them to rank very high in the Steele's Rank test.
Page 6 of 10

Table 5. July & September 2013 ATB Chronic Full -Range Test Results
:Chronic Test #
.Chronic Test #2
Test Start Date
7/17/13
9/11/13
Water Type
Soft Surface Water
Soft Synthetic Water
Test Endpoints
ChV1= >48%
NOEC2= 48%
LOEC3 = >48%
ChV1= >48%
NOEC2= 48%
LOEC3 = >48%
Control Survival
100%
90%
Control Mean
Reproduction
32.5
31.7
Test Treatment Survival
100% at all concentrations
100% at all concentrations
Test Treatment Mean
Reproduction
29.4 at 3%
30.7 at 6%
32.1 at 12%
31.1 at 24%
27.0 at 48% (statistically significant,
but < 20% reduction so no effect)
21.6 at 3% (this is a non -statistically
significant inversion)
32.0 at 6%
34.4 at 12%
33.3 at 24%
29.8 at 48%
Initial Sample pH
7.55 for sample collected 7/16
7.46 for sample collected 9/10
7.51 for sample collected 9/12
Initial Treatment pH
7.84 at 3%
8.16 at 48%
7.80 at 3%
7.99 at 48%
Final Treatment pH
7.75 at 3%
8.16 at 48%
7.73 at 3%
8.19 at 48%
Initial Sample Total
Ammonia (mg/L)
Not measured
100% effluent: 25
Final Sample Total
Ammonia (mg/L)
Not measured
Friday 3%: 0.81
Friday 48%: 8.4
Monday 3%: 0.9
Monday 48%: 8.4
Wednesday 3%: 0.8
Wednesday 48%: 9.4
'ChV = Chronic Value. The Chronic Value is the geometric mean of the No Observed Effect Concentration and the
Lowest Observed Effect Concentration. For standard North Carolina multi -concentration chronic WET tests, a ChV
lower than the permit limit for the facility is considered a "Fail".
2NOEC = No Observed Effect Concentration. In this test, this is the highest effluent concentration tested at which
there is no significant reduction in reproduction from the control.
3LOEC =Lowest Observed Effect Concentration. In this test, this is the lowest effluent concentration tested that shows
a significant reduction in reproduction from the control.
ALGAL ANALYSIS
A phycologist with DWR Environmental Sciences Sectio's Ecosystems Branch evaluated aliquots of the July
samples received on 7/15/13 and 7/17/13. He reported that: "There were no known problematic forms of
algae. The algae present were sparse, mainly some greens, and epiphytic in nature. There were also some
stalked rotifers, ciliates, and sheathed bacteria" (Vander Borgh, 7/22/2013 email communication).
Page 7 of 10

STATISTICS
The acute tests demonstrate that sometimes the statistics for acute pass/fail tests with 4 replicates at an
alpha level of 0.01 may not be powerful enough to detect differences between the control and tests
concentrations when there is high variability in either the control or the test cups. EPA guidance in the
document "Understanding and Accounting for Method Variability in WET Applications under the NPDES
Program" advises that tests lack sensitivity when the percent minimum significant difference (PMSD)
exceeds the 90th percentile from their data set of reference toxicant tests. For an acute Ceriodaphnia test
this upper boundary is 21%. In the event that the PMSD exceeds the upper bound and there is no
significant difference between the means for the control and the 1WC treatment, then the test is
considered invalid. If the PMSD exceeds the upper bound and there is a significant difference, then the test
is considered valid (USEPA 2000). There was an unusually high variation in the test treatments on the ATB
tests. The high variation in the test cups on the surface water test and the soft synthetic water tests cause
the PMSD to be extremely high, resulting in the statistics being insensitive and unable to detect a statistical
difference even with extremely high mortality rates. For instance, the surface water test showed no
mortality in the control. However, the 4 treatment cups ranged from 0% mortality in one replicate; 70%
mortality in two replicates; and 100% mortality in the fourth replicate. Due to the high variability in
treatment response, the PMSD for the test would require 107% reduction in reproduction before a
statistical significant effect was noted. This percent reduction is not possible. Therefore, the statistics did
not find a 57.5% reduction in reproduction significant at a 0.01 alpha level. Per EPA guidance, this test
should be considered invalid. As with the unprecedented rate of disagreeing split test results, this extreme
variability in test replicates could potentially be linked to micro -variations in temperature, pH, and the rate
of pH change versus the rate of ammonia change in each of the test cups. ATB will use these results to
identify additional statistical considerations that may need to be incorporated into the ATB Acute Pass/Fail
Statistical Protocol. However, despite the weakness of statistics in some of the tests, the role this plays in
this particular situation is a minor one and does not change the unusually high number of fails and
disagreeing split test results with this particular effluent during the past year.
SUMMARY
ATB's acute tests did not clearly demonstrate whether or how the type of water used would affect the
result of the test. However, a few observations should be noted:
1. The initial amount of total ammonia was the same for all treatments, regardless of dilution water.
2. The final amount of total ammonia varied among the dilution water used in the treatments, with
the surface water showing the most reduction from the initial result to the final result. However,
this is a one-time, small dataset and replication would be needed to determine if this is repeatable
and statistically significant.
3. All water types showed a significant amount of mortality in the acute tests, but the statistical power
of the soft synthetic water and the soft surface water tests was insufficient to detect significant
differences due to the amount of variability in the treatment replicates.
Page 8 of 10

Technically, following ATB guidelines, the soft synthetic water test and the soft surface water test passed.
These tests showed a 30% and 57.5% mortality rate, respectively, which are rates that would rarely pass.
However, the statistics were too insensitive to detect these mortality rates as significant due to the
extreme variability in test treatment response. These passing results would be considered invalid by EPA
guidelines; therefore, for the purposes of this study, they should not be considered as useful or valid
passing results as they do not clearly demonstrate a lack of effect. The other acute tests failed statistically,
with 82.5% and 90% mortality. All controls had 100% survival, so the weakness in the statistics was due to
the high variability in the 90% treatments.
The two chronic tests conducted by ATB indicate that conducting chronic tests would be a good choice for
SSWWTP if it can demonstrate that its IWC is below 48%. Total ammonia values were relatively consistent
for the 3% effluent concentration and the 48% effluent concentration on the Friday, September 13 and
Monday, September 16 changeovers and the termination date on Wednesday, September 18. The
ammonia values and pH drift were more significant in the 48% than in the 3% effluent concentration.
However, ATB recommends conducting more chronic tests to ensure they don't exhibit the same type of
variability as the acute tests. ATB has arranged to conduct another multi -concentration chronic test at the
same effluent concentrations in December.
Chronic testing is always the preferred toxicity testing assignment when the IWC is known, as this is a more
comprehensive evaluation of the effect on the receiving waters. Acute testing is only assigned for major
dischargers when an IWC is unable to be estimated. Changing the toxicity test assignment to chronic
testing at the IWC is consistent with DWR's policy to protect surface waters for chronic toxicity. In fact, if
the SSWWTP does have an approved IWC, the required test assignment is the chronic test. This change in
testing would not be a strategy to avoid dealing with the disparity in acute toxicity results or in addressing
the high ammonia levels in the effluent, but rather to be consistent with rules for the protection from
chronic toxicity in all surface water streams. In the future, it is likely SSWWTP will need to address its
ammonia output in light of EPA's recently updated ammonia water quality standards, which can be found
at the following link:
http://water.epa.gov/scitech/swguidance/standards/criteria/aalife/ammonia/index.cfm.
EPA advocates for all states to adopt the new nutrient water quality criteria, and there is the potential in
the future that NC will be required to adopt the EPA ammonia water quality standards. Although it is not
clear if or how the application of these standards would affect dischargers, there is the potential that this
might affect the amount of ammonia that could be discharged by SSWWTP.
Page 9 of 10

REFERENCES
North Carolina Pass/Fail Methodology for Determining Acute Toxicity in a Single Effluent Concentration,
Version 3.0. Revised December 2010, or subsequent versions.
USEPA 1993. Methods for Aquatic Toxicity Identification Evaluations. Phase II Toxicity Identification
Procedures for Samples Exhibiting Acute and Chronic Toxicity. EPA/600/R-92/080.
USEPA 2000. Understanding and Accounting for Method Variability in WET Applications Under the National
Pollution Discharge Elimination System. EPA 833-R-00-003.
USEPA 2002. Short Term Methods for Estimating the Acute Toxicity of Effluents and Receiving Waters to
Freshwater Organisms. Fifth Edition. EPA821-R-02-012.
Vander Borgh, Mark. DWR/ESS/ EB. Personal email communication, 7/22/2013.
Page 10 of 10

j/Pf r, 5 �'
- Zol s,lADa MoI1
MP Cape Fear
Public Utility Authority
Stewardship. Sustainability. Service.
October 17, 2014
Mr. Jeff Poupart
Wastewater Branch Supervisor
N.C. Department of Environment and Natural Resources
Division of Water Resources
1617 Mail Service Center
Raleigh, NC, 27699-1617
RE: Cape Fear Public Utility Authority
M'Kean Maffitt (Southside) Wastewater Treatment Plant
NPDES Permit Modification, Permit No. NC0023973
Dear Mr. Poupart,
James R. Flechtner, PE
Executive Director
235 Government Center Drive
Wilmington, NC 28403
910-332-6542
[e-mail]
RECEIVEDIDENRJDWR
OCT 27/.:
Water uuauty
Permitting Section
Enclosed are three (3) copes of the National Pollutant Discharge Elimination System (NPDES) permit modification
package for the Cape Fear Public Utility Authority (CFPUA) M'Kean Maffitt (Southside) Wastewater Treatment
Plant (WWTP) Expansion Project. This application is for an expansion of the M'Kean Maffitt (Southside) WWTP
from the current capacity of 12 million gallons per day (mgd) to 24 mgd. This application package includes the
following information:
• Cover letter
• Application fee of $1,030.00 (Check No. 56308)
• Completed NPDES Permit Application — Form 2A
• Residuals Management Plan
• Speculative Limits for a WWTP expansion to 24 mgd — Letter provided by the Division of Water Resources
(DWR) on April 7, 2010.
• Department of Administration Cleared Letter and FONSI dated September 13, 2013.
• Engineering Alternatives Analysis excerpted from the Environmental Assessment prepared by McKim and
Creed, Inc., dated September 2013.
The Environmental Assessment (EA) concluded that the most feasible and cost effective alternative was the
expansion of the effluent discharge into the Cape Fear River. This conclusion was supported by the technical
analysis documented in the EA. The Finding of No Significant Impact (FONSI) was sent to the Department of
Administration (DOA) Environmental Clearinghouse in September 2013 by the Division of Water Resources (DWR).
The project cleared the DOA on October 17, 2013.

Mr. Jeff Poupart
NCDENR
October 17, 2014
Page Two
The DWR speculative limits letter provided speculative limits for 16 mgd and 24 mgd. CFPUA respectfully requests
an additional phase of 20 mgd to manage CFPUA's available funds. The first phase is an expansion from 12 to
16 mgd. The second phase is an expansion from 16 to 20 mgd. Phase 3 consists of an expansion from 20 to 24 mgd.
We respectfully request effluent permit limits for the future expanded flows of 16, 20, and 24 mgd.
We appreciate the time and effort of the NPDES Unit to consider our requests for this permit modification. If you
have any questions or comments concerning this permit modification package, please do not hesitate to contact
us.
Sincerely,
*ix 4)1--
James R. Flechtner, PE
Executive Director
cc:
Frank Styers, Cape Fear Public Utilities Authority
Ken Vogt, Cape Fear Public Utilities Authority
Craig Wilson, Cape Fear Public Utilities Authority
Beth Eckert, Cape Fear Public Utilities Authority
Tony Boahn, PE, McKim and Creed, Inc.
Bryan Blake, PE, McKim and Creed, Inc.
David Nailor, PE, Hazen and Sawyer
Mary Sadler, PE, Hazen and Sawyer
RECEIVED/DENR/DWR
OCT 2 7 2014
Water Quality
Permitting Section

Table 1: Summary of M'Kean Maffit (Southside) WWTP Toxicity Testing 2011- 2014
9096 Dilution - acute
Date
Contract
Lab
Organism
pH
DO
Cond
Cl2
Mortality
Location
Compliance/
Nonmmp
Comment
Zinc
pg/L
Copper
pg/L
start
finish
start
finish
runty, March 0e, 2011
ETS
Minnow
7.81
8.08
8.4
7.8
693
<0.10
74.0%'
Eff
•
•LCSO; permit renewal
ETS
Flea
7.85
8.17
8.1
7.9
693
<0.10
0.0%
Eff
Comp
wednnd y. tune 1S, 2011
ETS
Flea
7.88
8.30
7.9
8.2
878
<0.10
0.0%
Eff
Comp
Wednesday, September 14, 2011
ETS
Flea
7.80
8.23
8.0
7.6
880
<0.10
0.0%
Eff
Comp
Wednesday, December 07, 2011
ETS
Flea
7.99
7.92
8.2
8.0
836
<0.10
0.0%
Eff
Comp
Wednesday, Much 02, 2012
ETS
Flea
7.90
7.80
7.8
7.6
763
<0.10
0.0%
Eff
Comp
Wednesday, Aneo6,2012
ETS
Flea
7.98
7.95
8.1
7.6
942
<0.10
0.0%
Eff
coma
Tuesday, scptenbe 11.2012
Meritech
Flea
7.79
8.54
7.8
7.1
870
<0.10
92.5%
Eff
Comp
18.1
7.4
Tuesday, September ts. 2012
Meritech
Flea
7.75
8.57
8.5
7.2
897
<0.10
75.096
Oper Eff
Noncomp
ETS
Flea
7.77
8.19
8.2
7.8
864
<0.10
27.5%
Oper Eff
Noncomp
Tuesday, October 09, 2011
ETS
Flea
7.63
8.40
8.0
8.0
755
<0.10
62.5%
Oper Eff
Noncomp
24 hours= open cups
8.33
8.1
100.096
Oper Eff
Noncomp
48 hours = open cups
7.63
7.68
8.0
8.0
0.0%
Oper Eff
Noncomp
24 hours= closed vessels
7.52
7.9
0.0%
Oper Eff
Noncomp
48 hours= closed vessels
tunny, October 09, 2012
ETS
Flea
7.67
8.38
7.6
8.0
756
<0.10
42.5%
Sec Clar
Noncomp
24 hours = open cups
8.24
8.0
97.5%
Sec Clar
Noncomp
48 hours = open cups
7.67
7.69
7.6
7.1
0.0%
Sec Clar
Noncomp
24 hours= closed vessels
7.49
7.9
0.0%
Sec Clar
Noncomp
48 hours= closed vessels
Tuesday, October 23, 2012
ETS
Flea
7.96
8.01
7.9
8.0
817
<0.10
2.5%
Oper Eff
Noncomp
Meritech
Flea
7.74
8.46
8.0
7.3
856
<0.10
10.096
Oper Eff
Noncomp
Wednesday, October 24, 2012
ETS
Flea
7.45
7.61
7.9
8.0
821
<0.10
0.096
Eff
comp
Ltd Method - Open cups
ET5
Flea
7.45
7.47
7.9
8.0
821
<0.10
0.0%
Eff
comp
Closed vessels
roneay, November 27, 2032
Meritech
Flea
7.80
8.48
8.1
7.4
824
<0.10
10096
Oper Eff
Noncoms
ETS
Flea
8.03
8.26
8.2
7.7
825
<0.10
32.5%
Oper Eff
Noncomp
Tuesday, December 04, 2012
ETS
Flea
8.03
7.92
8.2
7.9
821
<0.10
7.5%
Oper Eff
Noncomp
Sid Method - open cups
ETS
Flea
8.03
7.58
8.2
7.7
821
<0.10
0.0%
Oper Eff
Noncomp
Closed vessels
Tuesday, Decembea13,2012
Meritech
Flea
7.77
8.56
7.9
7.2
840
<0.10
85.0%
Eff
Comp
15.8
8.6
Wednesday, January 23. 2011
ETS
Flea
7.49
8.09
8.0
7.8
662
<0.10
27.5%
Eff
comp
16.9
9.8
Meritech
Flea
7.83
8.38
7.8
7.2
707
<0.10
12.5%
Eff
comp
Wednesday, March 13, 2013
ETS
Flea
7.79
8.06
7.9
8.0
734
<0.10
12.5%
Eff
Comp
Std Method - open cups
19.0
10.9
ETS
Flea
7.79
7.45
7.9
6.4
734
<0.10
0.096
Eff
comp
Closed vessels
Meritech
Flea
7.85
8.46
7.6
7.0
790
<0.10
10096
Eff
Comp
Wednesday, April 10, 2013
ETS
Flea
7.74
8.03
8.0
7.9
711
<0.10
2.5%
Eff
Comp
Sid Method - Open cups
16.9
8.5
ETS
Flea
7.74
7.50
8.0
6.9
711
<0.10
0.0%
Eff
Camp
Closed vessels
Meritech
Flea
7.78
8.42
7.6
7.2
750
<0.10
75%
Eff
Comp
Wednesday, June OS. 2013
ETS
flea
7.81
8.19
8.1
7.7
795
<0.10
65.096
Eff
comp
Ltd Method - Open cups
15.0
6.9
ETS
Flea
7.81
7.63
8.1
6.3
795
<0.10
0.096
Eff
comp
Closed vessels
Meritech
Flea
7.94
8.42
7.5
7.4
837
<0.10
77.5%
Eff
comp
Tuesday, July 16, 2013
Pace
Flea
7.23
8.42
8.0
7.9
743
<0.10
0.0%
Eff
comp
8.6
4.5
ETS
Flea
7.93
8.24
8.2
8.0
674
<0.10
20.0%
Eff
comp
Tuesday, September 10, 2013
Pace
Flea
7.69
7.52
7.6
7.3
797
<0.10
50.0%
Eff
Comp
34
1.8
ETS
Flea
7.91
8.07
8.1
8.1
765
<0.10
2.5%
Eff
Comp
Tuesday, December 03, 2033
Pace
Flea
7.74
8.17
7.5
7.1
800
<0.10
0.096
Eff
Comp
16
6.8
ETS
Flea
7.94
8.07
8.2
8.4
736
<0.10
0.0%
Eff
comp
Tuesday, March Or, 2014
Pace
Flea
7.88
8.26
8.4
7.2
757
<0.10
2.5%
Eff
comp
21
9.0
ETS
Flea
7.76
8.03
7.8
8.4
688
<0.10
5.0%
Eff
Comp
roesday, bane 03, 2014
Pace
Flea
7.89
8.25
8.1
6.9
757
<0.10
0.0%
Eff
Comp
15
8.0
ETS
Flea
7.80
8.00
8.1
7.9
697
<0.10
0.0%
Eff
Comp
Tuesday, September. as,2D14
Pace
Flea
8.01
8.33
7.5
8.0
772
<0.10
0.0%
Eff
comp
Pending
Pending
ETS
Flea
7.85
7.94
7.6
7.6
713
<0.10
0.096
Eff
Comp
December 2014
PASS March
PASS June
PASS September
PASS December
PASS March
PASS June
FAIL September
PASS October
FAIL December
PASS January
FAIL March
PASS April
FAIL June
PASS July
PASS September
PASS December
PASS March
PASS June
PASS September

FACILITY NAME AND PERMIT NUMBER:
M'Kean Maffitt WWTP, NC0023973
PERMIT ACTION REQUESTED:
Major Modification
RIVER BASIN:
Cape Fear
SUPPLEMENTAL APPLICATION INFORMATION
PART F.INDUSTRIAL USER DISCHARGES AND RCRA/CERCLA WASTES
All treatment works receiving discharges
complete part F.
GENERAL INFORMATION:
F.1. Pretreatment program. Does the treatment
❑ Yes ❑ No
F.2. Number of Significant Industrial Users
industrial users that discharge to the
a. Number of non -categorical SIUs.
b Number of ClUs.
SIGNIFICANT INDUSTRIAL USER
Supply the following information for each
provide the information requested for each
from significant industrial users or which receive RCRA,CERCLA, or other remedial wastes must
works have, or is subject ot. an approved pretreatment program?
(SIUs) and Categorical Industrial Users (ClUs). Provide the number
treatment works.
1
of each of the following types of
0
INFORMATION:
to the treatment works, copy questions F.3 through F.8 and
SIU. If more than one SIU discharges
SIU.
F.3. Significant Industrial User Information. Provide the name and address of each SIU discharging to the treatment works. Submit additional pages
as necessary.
Name: New Hanover Regional Medical Center
Mailing Address: PO Box 9000
Wilmington, NC 28402
F.4. Industrial Processes. Describe all the industrial processes that affect or contribute to the SIU's discharge.
Health care facility providing most currently available medical services; includes onsite laundry, kitchen, coffee shop and laboratory facility.
F.5. Principal Product(s) and Raw Material(s). Describe all of the principal processes and raw materials that affect or contribute to the SIU's
discharge.
Principal product(s): None; medical services provider
Raw material(s): None
F.6. Flow Rate.
a. Process wastewater flow rate. Indicate the average daily volume of process wastewater discharge into
day (GPD) and whether the discharge is continuous or intermittent.
103,000 GPD ( X continuous or intermittent)
the collection system in gallons per
into the collection system
b. Non -process wastewater flow rate. Indicate the average daily volume of non -process wastewater flow discharged
in gallons per day (GPD) and whether the discharge is continuous or intermittent.
N/A GPD ( continuous or intermittent)
F.7. Pretreatment Standards. Indicate whether the SIU is subject to the following:
a Local limits ® Yes 0 No
b Categorical pretreatment standards 0 Yes 0 No
If subject to categorical pretreatment standards, which category and subcategory?
NPDES FORM 2A Additional Information

FACILITY NAME AND PERMIT NUMBER:
M'Kean Maffitt WWTP, NC0023973
PERMIT ACTION REQUESTED:
Major Modification
RIVER BASIN:
Cape Fear
F.S. Problems at the Treatment Works Attributed to Waste Discharge by the SIU. Has the SIU caused or contributed to any problems (e.g.,
upsets, interference) at the treatment works in the past three years?
❑ Yes CO No If yes, describe each episode.
RCRA HAZARDOUS WASTE RECEIVED BY TRUCK, RAIL, OR DEDICATED PIPELINE:
F.9. RCRA Waste. Does the treatment works receive or has it in the past three years received RCRA hazardous waste by truck, rail or dedicated pipe?
❑ Yes ® No (go to F.12)
F.10. Waste transport. Method by which RCRA waste is received (check all that apply):
❑ Truck 0 Rail 0 Dedicated Pipe
F.11. Waste Description. Give EPA hazardous waste number and amount (volume or mass, specify units).
EPA Hazardous Waste Number Amount Units
CERCLA (SUPERFUND) WASTEWATER, RCRA REMEDIATION/CORRECTIVE ACTION
WASTEWATER, AND OTHER REMEDIAL ACTIVITY WASTEWATER:
F.12. Remediation Waste. Does the treatment works currently (or has it been notified that it will) receive waste from remedial activities?
❑ Yes (complete F.13 through F.15.) ® No
F.13. Waste Origin. Describe the site and type of facility at which the CERCLA/RCRA/or other remedial waste originates (or is excepted to origniate in
the next five years).
F.14. Pollutants. List the hazardous constituents that are received (or are expected to be received). Include data on volume and concentration, if
known. (Attach additional sheets if necessary.)
F.15. Waste Treatment.
a. Is this waste treated (or will be treated) prior to entering the treatment works?
❑ Yes ❑ No
If yes, describe the treatment (provide information about the removal efficiency):
b. Is the discharge (or will the discharge be) continuous or intermittent?
❑ Continuous 0 Intermittent If intermittent, describe discharge schedule.
END OF PART F.
REFER TO THE APPLICATION OVERVIEW (PAGE 1) TO DETERMINE WHICH OTHER PARTS
OF FORM 2A YOU MUST COMPLETE
NPDES FORM 2A Additional Information

Outfall 001
Latitude: 34° 09' 56" N
Longitude: 77° 56' 56" W
•
C>
dt>`1. d T' '.r. n I.
SCALE
0.25 0.5
MMINNIII Miles
1 in = 0.5 miles
1111110CapeFear
Public Utility Authority
j
Legend
,.0 0 M'Kean Maffitt (Southside) VVWTP Boundary
HAZENAND SAWYER
Environmental Engineers d Sr,
Figure 1
Topographic Map
M'Kean Maffitt (Southside) WWTP
NPDES Permit NC0023973

Secondary
Clarifier
1
Aeration
Basin
Scum/RAS Station
Trickling Filter
2
WAS PS
Trickling Filter
1
Blower Building
Primary
Clarifier
2
Primary
Clarifier
1
Influent
Sampling
Building
♦
tY I
L I
RI i 1 Intermediate
't= j PS
a
U ' Recirculation
PS
/ Chlorine
Contact t
1♦ Tanks —/❑
_
Outfall
i
Outfall
Structure
♦ Chlorine /
Effluent
I1 , Sampling
Building
•
♦
♦
♦
i
1
♦
•
Legend
- - - Property Line
♦
♦
♦ ♦ 30377-001-Figure 2 Existing Site Plan
•
•
♦
Primary Sludge PS
Splitter Boxes
Screening and Grit
Removal
Electrical Switchgear
Influent Junction Box
Operations Building
Maintenance Building
B'osolids ♦♦
Building
Anaerobic
Digester
Building
TWAS Storage
Cake Unloading
•
♦
♦
♦
♦
r— Lime Stabilization
Sludge Pad
♦
♦
♦
♦
•
•
♦
♦
•
♦
♦
•
♦
Figure 2:
Existing Site Plan
M'Kean Maffitt WWTP
NPDES Permit NC0023973

/♦
/
Outfall
/ Structure
♦ Maintenance
Building
•
1
/�
/
/AS PS
Stormwater
Pond
Stormwater
Pond
Generators —110 1110--
L1
Secondary
Clarifier
Secondary
Clarifier
Secondary
Clarifier
Legend
- - - Property Line
16 MGD
I-1 20 MGD
l 24 MGD
♦
Fuel Storage r— Step Feed Distribution Box I
♦ ♦30377-001-Figure 3 Expanded Capacity Site Plan
Odor Control
Administration/Operations Building
Existing Anaerobic Digesters
•
Anaerobic
Digester
Anaerobic
Digester
Cogen
Digester Gas Handling Facility
— Primary Sludge Pump Station
Sludge Pad
Lime Stabilization
Waste Gas
Flare
uewate
♦
110
♦
TWAS/DS Storage
•
Figure 3:
Expanded Capacity Site Plan
M'Kean Maffitt WWTP
NPDES Permit NC0023973

Cape Fear Public Utility Authority (CFPUA)
2014 NPDES Permit Modification Application
CFPUA Process Narrative
M'Kean Maffitt (Southside) WWTP Existing 12 mgd Rated Capacity Process Flow
The M'Kean Maffitt (Southside) WWTP is currently rated to treat up to 12 mgd. The Cape Fear Public
Utility Authority (CFPUA) is conducting planning and engineering efforts to expand the plant rated
capacity in phases to 16 mgd, 20 mgd, and an ultimate future expansion to 24 mgd. Figure 4 provides a
schematic of the existing plant unit processes for 12 mgd capacity, including a water balance through
the plant. The following narrative summarizes existing unit processes.
The CFPUA has multiple remote wastewater pump stations that collect flow from the service area to
route to the Southside WWTP. Wastewater flow from the influent force mains and the Northeast
Interceptor combine upstream of the screening/grit removal facility. Plant influent flows through two
mechanical bar screens and two grit collectors. A manual bypass screen provides redundancy.
Flow is then split to two treatment trains, with one primary clarifier and one trickling filter per train.
Primary sludge and primary scum are pumped to the anaerobic digesters. From the anaerobic digesters,
the effluent then undergoes dewatering with a belt filter press followed by land application off -site.
Recirculation pumps recycle trickling filter effluent back to the trickling filter influent box.
Trickling filter effluent flows by gravity to the aeration basin where it combines with return activated
sludge (RAS). The effluent from the aeration basin flows to the intermediate pump station and is split to
the two secondary clarifiers. RAS flows by gravity back to the aeration basin. Waste activated sludge is
pumped to the sludge thickening building, where it is thickened using a gravity belt thickener. The
thickened sludge then is moved to the anaerobic digesters. From the anaerobic digesters, the effluent
then undergoes dewatering with a belt filter press followed by land application off -site.
Secondary clarifier effluent (SCE) flows by gravity to the chlorine contact tanks. Effluent from the
chlorine contact tanks is dechlorinated with sodium bisulfite and flows by gravity through the effluent
weir box and into the river.
The phased plant expansion will require that more stringent NPDES permit limits be met. As such, the
existing 12 mgd site layout will require modification to accommodate the phased expansion with
advanced treatment. Components of the existing infrastructure will be removed and some existing
infrastructure will be modified as part of the upgrade.
Treatment Upgrade and Expanded Rated Capacity Process Flow (16, 20, and 24 mgd)
CFPUA is currently planning to upgrade the M'Kean Maffitt (Southside) WWTP to include advanced
treatment processes. This includes expansions of capacity in phases of 16 mgd, 20 mgd, and 24 mgd. A
schematic and water balance for each is provided in Figures 5, 6, and 7 for the design capacity of
16 mgd, 20 mgd, and 24 mgd, respectively. The following is a narrative description of the unit processes
in the expanded capacity scenarios:

Preliminary Treatment
For the 16 mgd expansion, an influent force main will convey wastewater to two mechanical screens
with a third screen as a standby unit. In the 20 and 24 mgd expansion phases, all three mechanical
screens will be required for peak flows. A manual bar rack will be used as the standby unit in the 20 and
24 mgd capacity scenarios. In the three expansion scenarios, a total of three grit collectors with
capacities of 20 mgd each and six grit pumps will be installed to remove grit prior entering to the
primary clarifiers. The grit collector tanks will be sized to accommodate future flows with no additional
structural improvements.
The existing secondary clarifiers will be used for influent flow equalization storage in all expansion
phases. The tanks will be capable of storing 1.8 million gallons and will be capable of providing
equalization of both raw influent and primary effluent. The tanks will also serve as filter backwash
waste storage. Pumps will be installed to return equalized flow to the next treatment process.
Primary Clarifiers and Primary Sludge Pumping
In the 16 mgd expansion, two new 115-foot diameter primary clarifiers with influent and effluent piping
will be constructed. These two clarifiers are sufficient for a plant capacity of 24 mgd. Two duty and one
standby primary sludge pumps will convey primary sludge to the anaerobic digesters. The primary
sludge pumps will be progressing cavity positive displacement pumps and will include variable frequency
drives.
Aeration Basins
Four new aeration basins with volumes of 1.65 million gallons will be constructed for the 16 mgd
capacity expansion. An additional aeration basin of the same dimension will be added during each
phase of expansion from 20 to 24 mgd.
Secondary Clarifiers and Activated Sludge Pumping
Two 160-foot diameter secondary clarifiers will be constructed for the 16 mgd capacity expansion. A
third secondary clarifier will be added during the 20 mgd capacity expansion phase. A fourth clarifier
will be added for the 24 mgd capacity expansion phase. Four activated sludge pumps with variable
frequency drives will pump activated sludge to the WAS and RAS channels.
Tertiary Filters
Tertiary treatment filters will be added to the treatment processes for all three capacity expansion
phases. The tertiary filters will be deep bed filters with coarse mono -media sand. For the 16 mgd
expansion, four 9.5-foot by 60-foot filters will be constructed. An additional tertiary filter will be added
during each phase of expansion for a total of 6 filters at 24 mgd.
Ultraviolet Disinfection
Ultraviolet disinfection will replace chlorination and dechlorination in the expansion from 16 mgd to
24 mgd. Seven UV channels will be constructed during the 16 mgd expansion phase, with five channels
equipped with low pressure, high intensity lamps. Lamps will be added to one of the unequipped
channels during the 20 mgd expansion. Equipment will be added in the seventh channel for the 24 mgd

expansion. The lamps will be designed to have the capability of providing a dose of 30 mJ/cm2 at the
peak hour flow, with one channel out of service at 24 mgd.
Waste Activated Sludge Thickening
A new thickening and dewatering facility will be part of the capacity expansion at the Southside WWTP.
Three new gravity belt thickeners will be used for WAS thickening. Thickened WAS will be stored to
equalize thickened sludge production to allow for 24-hour digester feeding with intermittent thickening
operations.
Anaerobic Digestion and Stabilization
Two new anaerobic digesters will be required for the expansion to 16 mgd. The two new digesters will
have a diameter of 85 feet and a volume of 1.061 million gallons each. An upgrade to the largest
existing anaerobic digester will be part of the 20 mgd expansion, so that three total anaerobic digesters
are available at 20 mgd expansion. One additional anaerobic digester will be required for the 24 mgd
expansion, bringing the total number of digesters to four at 24 mgd.
Digested Residuals Dewatering
Four belt filter presses designed to operate at a normal hydraulic loading rate of 75 gallons per minute
per meter and a solids loading rate of up to 750 dry pounds per hour per meter will be required to
dewater anaerobically digested residuals. The plant will be capable of storing dewatered cake for up to
45 days.

Q=120mgd --*
•
Bar Screens
Grit
Removal
Cape Fear
River
Primary Clarifier
(x2)
Primary Sludge
6666e6660 666
I,.66
666Q poo6616666 6 6 66
66a66666e
666n 666666666666666
Trickling Filter
(x2)
Q = 24 mgd
O
Dechlorination
TWAS
Storage
Primary Sludge Anaerobic
Pump Station Digester
(x3)
f
or
Recirculation
Pump Station
Chlorine Disinfection
Gravity Belt
Thickening
Filtrate
Belt Filter Press
30377-U01-50U Figure 4 Existing Process Flow Diagram 12 MGD Capacity
Filtrate
Pump Station
4
♦
Q = 12.0 mgd
Q=12.0mgd
RAS
Aeration Tank
—i►
In ermediate
Pump Station
Secondary Clarifier
(x2)
WAS
Q = 1.0 mgd
WAS Pump
Station
Lime
Stabilization
Off -Site Disposal
Figure 4:
Existing Process Flow Diagram
M'Kean Maffitt WWTP
NPDES Permit NC0023973

Q=160mgd
♦
Bar Screens
Q = 32.0 mgd
Grit Primary Clarifier
Removal (x2)
Cape Fear
b)
River .4_
Q = 16.0 mgd
UV Disinfection
Primary Sludge
Primary Sludge
Pump Station
Q = 16.0 mgd
4
Tertiary Filters
(x4)
RAS
Aeration Basin
(x4)
V
Secondary Clarifier
(x2)
TWAS
Storage
Anaerobic
Digester
(x2)
4
Filtrate
0
Gravity Belt
Thickening
Belt Filter Press
Filtrate
Pump Station
30377-001-500 Figure 5 Process Flow Diagram 16 MGD Capacity
4
WAS
Q = 1.3 mgd
4
jQ17.3md
RAS/WAS
Pump Station
•
Lime
Stabilization
Off -Site Disposal
Figure 5:
16.0 MGD Process Flow Diagram
M'Kean Maffitt WWTP
NPDES Permit NC0023973

Q = 20 0 mgd
♦
Bar Screens
Grit
Removal
Cape Fear
2.„..5 River
4—
V
Primary Clarifier
(x2)
Q = 40.0 mgd
Q = 20.0 mgd
UV Disinfection
Primary Sludge
4
Q=20.0mgd
Tertiary Filters
(x5)
RAS
Aeration Basin
(x5)
Secondary Clarifier
(x3)
TWAS
Storage
Primary Sludge Anaerobic
Pump Station Digester
(x3)
4
Filtrate
Gravity Belt
Thickening
Belt Filter Press
Filtrate
Pump Station
30377-001-500 Figure 6 Process Flow Diagram 20 MGD Capacity
4
WAS
Q = 1.7 mgd
Q=21.7mgd
RAS/WAS
Pump Station
•
Lime
Stabilization
Off -Site Disposal
Figure 6:
20.0 MGD Process Flow Diagram
M'Kean Maffitt WWTP
NPDES Permit NC0023973

Q = 24 0 mgd —*
♦
Bar Screens
Grit
Removal
Cape Fear
River
.s
4—
Primary Clarifier
(x2)
Q = 48.0 mgd
Q = 20.0 mgd
UV Disinfection
Primary Sludge
Q = 24.0 mgd
Tertiary Filters
(x6)
RAS
Aeration Basin
(x6)
Secondary Clarifier
(x4)
TWAS
Storage
1
Primary Sludge Anaerobic
Pump Station Digester
(x4)
4-
Filtrate
Gravity Belt
Thickening
Belt Filter Press
Filtrate
Pump Station
30377-001-500 Figure7 Process Flow Diagram 24 MGD Capacity
4
WAS
Q = 2.0 mgd
Q=26.0mgd
RAS/WAS
Pump Station
Lime
Stabilization
Off -Site Disposal
Figure 7:
24.0 MGD Process Flow Diagram
M'Kean Maffitt WWTP
NPDES Permit NC0023973

Cape Fear Public Utility Authority (CFPUA)
SSWWTP 2014 NPDES Permit Modification Application
CFPUA Residuals Management
Introduction
The Cape Fear Public Utility Authority (CFPUA) was created by the City of Wilmington, NC and New
Hanover County, NC on July 1, 2008 to consolidate provision of water and wastewater services within
their combined services areas. Its core principles are stewardship, sustainability, and service, and its
mission is to provide high quality service in an environmentally responsible manner while maintaining
the lowest practicable cost. The Authority strives to provide the safest and highest quality water and
wastewater services with heightened consideration of the unique environment within which it operates
and the efficiency and effectiveness of service as it impacts its customers whose user fees are its sole
funding source.
The Cape Fear Public Utility Authority (CFPUA) operates and maintains three wastewater treatment
plants (WWTP) and two water treatment plants (WTP) — the James A. Loughlin WWTP (Northside
Wastewater Treatment Plant — NSWWTP), the M'Kean Maffitt WWTP (Southside Wastewater Treatment
Plant — SSWWTP), the Walnut Hills Wastewater Treatment Plant (WHWWTP), the Sweeney Water
Treatment Plant (SWTP), and the Nanofiltration Water Treatment Plant (NFWTP).
Residuals sources within these facilities include NSWWTP digested residuals, SSWWTP digested
residuals, WHWWTP digested residuals, SWTP alum residuals, and NSWWTP digestion system, SSWWTP
digestion system, and SWTP water treatment tankage contents removal associated with periodic
maintenance campaigns. Residuals produced by these facilities are processed and managed in
accordance with NCDENR Permit WQ0001271 governing land application of Class B wastewater
residuals and Permit WQ0011869 governing distribution of Class A wastewater residuals. As applicable,
and in conformance with all regulatory programs/authorizations, the CFPUA also supports a process of
receiving non-CFPUA residuals for processing and disposal under its residuals permits, including any
modifications necessary to enable and support this practice.
The NSWWTP is a 16 million gallon per day (MGD) advanced treatment level facility located at 2311 N.
23rd Street in Wilmington, NC. It was originally placed into service in 1970 as an 8 MGD secondary
treatment facility, and many improvements have been incorporated in the intervening period.
Construction was completed in 2009 on an $80,000,000 plant expansion/upgrade project begun in 2005.
Liquid treatment processes installed at this facility include screening, grit removal, primary
sedimentation, activated sludge secondary biological treatment, filtration, and ultraviolet (UV)
disinfection. Solids treatment processes include gravity belt thickening, anaerobic digestion, and belt
filter press dewatering. The liquid leaving the plant (effluent) is of extremely high quality as set forth in
the facility's National Pollutant Discharge Elimination System (NPDES) permit limits and is currently
returned to the environment by discharge to the Cape Fear River. Solids/residuals produced within the
plant's processes are stabilized to North Carolina Class B land application standards and are returned to
the environment as a soil amendment applied to nearby agricultural lands. Additionally, they can be
processed to North Carolina Class A Product/Distribution standards using alkaline stabilization. Residuals

generated within the CFPUA's Sweeney Water Treatment Plant (SWTP) are pumped to the NSWWTP for
processing.
The SSWWTP is a 12 MGD secondary treatment level facility located at 3436 River Road in Wilmington,
NC. It was originally placed into service in 1972 as a 6 MGD facility serving the city of Wilmington. It was
later expanded to 12 MGD to serve New Hanover County and the Town of Wrightsville Beach, and other
improvements were also incorporated throughout the intervening period. Improvements in the capacity
and level of treatment processes currently installed at this facility include screening, grit removal,
primary sedimentation, trickling filtration and activated sludge secondary biological treatment,
secondary clarification, chlorine disinfection, and sodium bisulfite dechlorination. Solids treatment
processes include gravity belt thickening, anaerobic digestion, and belt filter press dewatering. The
liquid leaving the plant (effluent) is of high quality as set forth in the facility's National Pollutant
Discharge Elimination System (NPDES) permit limits and is currently returned to the environment by
discharge to the Cape Fear River. Solids/residuals produced within the plant's processes are stabilized to
North Carolina Class B land application standards and are returned to the environment as a soil
amendment applied to nearby agricultural lands. Additionally, they can be processed to North Carolina
Class A Product/Distribution standards using alkaline stabilization.
The WHWWTP is a 0.1 MGD advanced treatment level facility located at 17 Little Creek Road in
Wilmington, NC. It was originally placed into service in 1970. Liquid treatment processes currently
installed at this facility include activated sludge biological treatment, secondary clarification, filtration,
chlorine disinfection, and calcium thiosulfate dechlorination. Solids treatment processing consists of
aerobic digestion and liquid transport to the NSWWTP for co -processing with NSWWTP residuals. The
liquid leaving the plant (effluent) is of extremely high quality as set forth in the facility's National
Pollutant Discharge Elimination System (NPDES) permit limits and is currently returned to the
environment by discharge to the Northeast Cape Fear River. Solids/residuals produced within the plant's
processes are stabilized to North Carolina Class B land application standards and are returned to the
environment as a soil amendment applied to nearby agricultural lands. Additionally, they can be
processed to North Carolina Class A Product/Distribution standards using alkaline stabilization.
CFPUA Residual Permits
The CFPUA currently possesses two residuals permits — Class A Residuals Permit WQ0011869 and Class B
Residuals Permit WQ0001271.
The Class A Permit allows the conversion of a maximum of 3,500 DTPY of residuals from the NSWWTP,
SSWWTP, and SWTP into a maximum of 7,000 DTPY of Class A EQ residuals for distribution using an
alkaline stabilization process/system located at the SSWWTP. No residuals were processed through this
system during CY 2012. This permit expires on 02.28.2015.
The Class B Permit allows land application of a maximum of 7,300 DTPY of residuals cake from the
NSWWTP, SSWWTP, SWTP, and WHWWTP onto permitted sites. During 2012, approximately 20,873 CY
of cake from the NSWWTP, SSWWTP, WHWWTP, and SWTP were applied onto a total of 466.4 acres on
30 sites. A total inventory of 3,818.4 acres on 143 sites is currently identified within this permit. The
permit expires on 05.31.2015.

As currently practiced in accordance with WQ001271, NSWWTP and SSWWTP residuals receive 40 CFR
503.32(b)(3) Class B, Alternative 2 PSPR (Anaerobic Digestion) Pathogen Reduction (PR) and 40 CFR
503.33(b)(1) Vector Attraction Reduction (VAR) (Minimum 38% Volatile Solids Mass Reduction)
processing. WHWWTP residuals receive 40 CFR 503.32(b)(2) Class B, Alternative 1 PSRP (Seven sample
GM FC<2,000,000 colonies/g TS dry weight basis) Pathogen Reduction (PR) and 40 CFR 503.33(b)(4)
Vector Attraction Reduction (VAR) (Specific Oxygen Uptake Rate (SOUR) in an aerobic process <_ 1.5
milligrams of oxygen per hour per gram of total solids (dry weight basis) at a temperature of 20°C)
processing; they can also be reprocessed through the NSWWTP anaerobic digestion process. PR — and
VAR — processed WWTP residuals are dewatered and blended with dewatered WTP residuals, and SWTP
alum residuals ca be separately dewatered at NSWWTP and separately transported to SSWWTP where
they are blended with dewatered SSWWTP anaerobically digested residuals. They can also be co -
mingled co-dewatered, and co -transported. Occasionally, as conditions warrant, these residuals may
receive additional alkaline stabilization processing at SSWWTP in the form of 40 CFR 503.32(a)(4) Class
A, Alternative 2 (Biosolids Treated in a High pH -High Temperature Process) Pathogen Reduction (PR) and
40 CFR 503.33(b)(6) Vector Attraction Reduction (VAR) (Alkaline Addition under Specified Time and pH
Conditions) in accordance with WQ0011869 to yield an exceptional quality Class A product suitable for
unrestricted distribution.
Further details concerning the CFPUA's residuals management program practices and performance may
be found in its annual residuals management reports.
CFPUA Residuals Management Contracting
Including the experience of its predecessor (the City of Wilmington) in residuals management
contracting, the CFPUA has been involved in contracting selected residuals management services since
about 1988. Initially, liquid residuals disposal was practiced, but cake residuals disposal has been the
preferred disposal method for most of this period.
In continuing this approach, it is important to note the following goals:
• The contract must be able to accommodate changing needs and requirements. Factors such as
wastewater infrastructure, regulatory impacts, and market/economic climate must receive
continuous assessment and may result in changing technologies and quantity and quality of
residuals.
• Due to the many regulatory and economic influences exerted beyond its direct control, the
CFPUA embraces a policy of flexibility and diversity in its overall residual management strategy
through development of other residuals processes and products.
• The CFPUA encourages the sharing of contract risk and benefit between CFPUA and the
contractor, including use of innovative, creative residuals management approaches to
accomplish this.
Various services are offered under the current contractual arrangement, including operation and
maintenance of selected residuals processing equipment at the NSWWTP and the SSWWTP; inter -plant
residuals cake transport to, unloading, storage, reloading, and land application (discing; incorporation)
at permitted sites; where required, lime addition at certain sites; limited specified Class A product
production, marketing, and distribution; regulatory monitoring; administrative support services (CFPUA
permit administration/maintenance; site inventory additions and deletions; annual residuals report for

USEPA and NCDENR; agronomic and analytical services); product sale/revenue generation; inter -plant
liquid residuals transport; WWTP digester maintenance cleanout; WTP process tank maintenance
cleanout; and mobile dewatering.
Contract bids are accepted for various levels of technical services — WWTP mechanized equipment
O&M, land application, or both/all — with all pricing including related program support/administrative
services. The pricing structure includes a base monthly charge with a $/CY surcharge applied once the
throughput exceeds a 20,000 CY annual threshold. Other pricing includes $/gallon charges applicable to
inter -plant liquid residuals transport, WWTP digester maintenance cleanout, WTP process tank
maintenance cleanout, and mobile dewatering. Invoices are rendered monthly and pricing is adjusted
quarterly based upon quarterly changes in the USDOL BLS Consumer Price Index —All Southern Urban
Consumers.

Pat McCrory, Governor
North Carolina
Department of Administration
13i11 Daughtridge, Jr., Secretary
October 17, 2013
Ms. Jackie Roddy
NCDENR
Division of Water Resources
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Re: SCH File # 14-E-4300-0118; EA/FONSY; Proposed project is for the expansion of the
Southside WWTP from 12 to 24 mgd. Project will include expansions to five pump stations,
upsizing approx 4,200 If of force main and installation of a 60 inch diameter effluent
disposal pipe.
Dear Ms. Roddy:
The above referenced environmental impact information has been reviewed through the State
Clearinghouse under the provisions of the North Carolina Environmental Policy Act.
No comments were made by any state/local agencies in the course of this review. Therefore, no further
environmental review action on your part is required for compliance with the Act.
cc: Region 0
Nailing Address:
301 Mail Service CentCt
Raleigh, NC )?699_01)1
Sincerely,
Crystal Best
State Environmental Review Clearinghouse
Telephone: [phone]
I : e (')I9)7 1.9i71
Stale Courier 45 i-01.(lh
e -mrrii aYute clew irr('Irouse,:41rinu rrc
ifrt 1.:rlurr! Oppoetrutrtyv, ilir-mative intern iwitplover.
Location elr(rlres's:
I( Wet lone5 tilteCI
Raleigh, Norih Calolin,!

COUNTY HANOVER
PENDSR
NORTH CAROLINA STATE CLEARINGHOUSE
DEPARTMENT OF ADMINISTRATION
INTERGOVERNMENTAL REVIEW
H02: WASTEWATER TREATMENT
FACILITIES
MS LYN i:ARD.IISON
CLEARINGHOUSE COORDINATOR
DENR LEGISLATIVE AFFAIRS
GREEN SQUARE BUILDING - MSc': 11 1601
RALEIGH NC
REVIEW DISTRIBUTION
STATE NUMBER: .l4-•E--4300-0118
DATE RECEIVED: 09/16/2013
AGENCY RESPONSE: 10/11/2013
REVIEW CLOSED: 10/16/2013
CAPE FEAR COG
CC& E: S - DIV OF EMERGENCY MANAGEMENT
DEUR µ COASTAL MG'1'
DEN12 LEGISLATIVE AFFAIRS
DEPT OP CULTURAL RESOURCES
DEPT OF TRANSPORTATION
PROJECT INFORMATION
APPLICANT: NCf)EWR
TYPE: State Environmental Policy Act.
Environmental A: sessment../Vinding of No Signi1 ic,int Impact
DESC: Proposed project: is for the expan.liinn of: ,.he Sourhside WWTP trom 12 to 24 mgd.
Project wi1l include expans .ons to fives pump ,tat:i.c3;1::, upsiz.ing approx 4,200 1f
of force main artd installation of a 60 inch diamr-.l:er• ofCluenr disposal pipe.
The attached project: has been submi.ttcd to the N. C. State Clearinghouse for
intergovernmental review. Please review and submit your response by the above
indicated date to l301 Mail Service Center, Raleigh NC 21699--1.301..
If additional review time is needed, please contact this ofC.ic:0 at. (919)807--2425.
AS A RESULT OF THISREVIEWTHE FOLLOWING TS SUBMITTED: NO COMMENT Eil COMMENTS ATTACHED
SIGNED BY:
DATE: /o

COUNTY: NEW HANOVER
PENDER
NORTH CAROLINA STATE CLEARINGHOUSE
DEPARTMENT OF ADMINI S TRAT ION
INTERGOVERNMENTAL REVIEW
H02: WASTEWATER TREATMENT
FACILITIES
MS RENEE GLEDHILL-EARLEY
CLEARINGHOUSE COORDINATOR
DEPT OF CULTURAL RESOURCES .i•-. CA.'
STATE HISTORIC PRESERVATION OFICE
MSC 4 617 - ARCHIVES BUILDING
RALEIGH NC
REVIEW DISTRIBUTION
CAPE FEAR COG
CC&PS - DIV OF EMERGENCY MANAGEMENT \113
DENR - COASTAL MGT
DENR LEGISLATIVE AFFAIRS
DEPT OF CULTURAL RESOURCES
DEPT OF TRANSPORTATION
PROJECT INFORMATION
APPLICANT: NCDENR
TYPE: State Environmental Policy Act
Environmental Assessment/Finding of No Significant impact
DESC: Proposed project is for the expansion of the Southside WWT? from 12 to 24 mgd.
Project will include expansions to five pump stations, upsi.zing approx 4,200 if
of force main and installation. of a 60 inch diameter effluent disposal pipe.
The attached project has been submitted to the N. C. State Clearinghouse for
.nt_erycvecnmeritaJ. review. Please review and submit your response by the above
indicated date to 1301 Mail Service Center, Raleigh NC 27699-1301.
STATE NUMBER: 14-E-4300-0118
DATE RECEIVED: 09/16/2013
AGENCY RESPONSE: 10/11/2013
REVIEW CLOSED: 10/16/2013
%Jr z.+tt.
If additional review time is needed, please contact this office arc [phone].
AS n RESULT OF TNT. REVIEW THE FOLLOWING 1S SUBMITTED: 04 NO COMMENT I I COMMENTS ATTACHED
SIGNED BY:
e7D,Qt,A
r;-
44,
• f ▪ OCT 2013 m
1.1e-r3 Soir 900r
L''.4/4111r4-';:
DATE:
SEP 1 8 2013

COUNTY: NEW HANOVER
PENDER
NORTH CAROLINA STATE CLEARINGHOUSE
DEPARTMENT OF ADMINISTRATION
INTERGOVERNMENTAL REVIEW
H02:WASTEWATER TREATMENT
FACILITIES
MS CAROLYN PENNY
CLEARINGHOUSE COORDINATOR
CC&PS DTV OF EMERGENCY MANAGEMENT
FLOODPLAIN MANAGEMENT PROGRAM
MSC # 4719
RALEIGH NC
REVIEW DISTRIBUTION
CAPE FEAR COG
CC&PS -- DIV OF EMERGENCY MANAGEMENT
DENR - COASTAL MGT
DENR LEGISLATIVE AFFAIRS
DEPT OF CULTURAL RESOURCES
DEPT OF TRANSPORTATION
PROJECT INFORMATION
APPLICANT: NCDENR
TYPE State Environmental Policy Act
Environmental Assessment/Finding of No Significant Impact
DESC: Proposed project is for the expansion of the Southside WWTP from 12 to 24 mgd.
Project will. include expansions to five pump stations, upsizing approx 4,200 If
of foice main and installation of a 60 inch diameter effluent disposal pipe.
The attached project has been submitted to the N. C. State Clearinghouse for
intergovernmental review. Please review and submit your response by the above
indicated daLe to 1301 Mail Service Center, Raleigh NC 27699-1301.
If additional review time is needed, please contact this office at [phone].
STATE NUMBER: 14-E-4300-0118
DATE RECEIVED: 09/16/2013
AGENCY RESPONSE: 10/11/2013
REVIEW CLOSED: 10/16/20)3
,I.J 41. .
r4)
.? . , .
."4
vx-
.,7...::'
tIrtt-pb
kk:14 4ieg-
` •
tvi
riv
02';91
AS A RESULT OF THIS REVIEW THE FOLLOWING IS SUBMITTED:
SIGNED BY:
auv-611)%,
t '
s.„
-2 • • ‹iv:1•#,-4...Nififi-,7
ff
NC) COMMENT [-I COMMENTS ATTACHED
DATE:
.2 a .clezi,,J- c2 01

FINDING OF NO SIGNIFICANT IMPACT (FNSI) AND ENVIRONMENTAL ASSESSMENT (EA)
CAPE FEAR PUBLIC UTILITY AUTHORITY — M'KEAN MAFFIT (SOUTHSIDE) WASTEWATER
TREATMENT FACILITY UPGRADE AND EXPANSION TO 24 MGD
Pursuant to the requirements of the North Carolina Environmental Policy Act (N.C.G.S. § 113A-1, et seq.),
an EA has been prepared by Cape Fear Public Utility Authority (CFPUA) for a phased expansion of its
existing M'Kean Maffit (Southside) Wastewater Treatment Facility (WWTF) from 12 to 24 million gallons
per day (MGD). Phase 1 will consist of a treatment capacity expansion from 12 to 16 MGD; capacity
expansions to five pump stations; upsizing of approximately 4,200 linear feet (l.f.) of force main; and
installation of a 60-inch diameter effluent disposal pipe to the Cape Fear River. Phase 2 will involve WWTF
treatment capacity expansion from 16 to 20 MGD. Phase 3 will expand the WWTF from 20 to 24 MGD.
The treatment processes will be upgraded to comply with more stringent effluent limits. Also, CFPUA
intends to continue its existing contract for removal of biosolids as class B sludge.
Four alternatives were considered for wastewater treatment: 1) no action; 2) connect to CFPUA's Northside
facility; 3) construct a new facility; and (4) expand and upgrade the existing Southside WWTF. Option 4
was chosen for wastewater treatment. Under alternative 4, the entire hydraulic profile of the WWTF will be
raised so that influent wastewater can flow thru the facility by gravity. Due to the elevated headworks, five
offsite pump stations (COW 14, COW 17, COW21, COW 36, and COW 42) will need to be modified and
approximately 4,200 I.f. of force main upsized. Five effluent disposal alternatives were considered: I) land
application; 2) reuse; 3) high rate infiltration; (4) conjunctive use (reuse, high rate infiltration, and direct
discharge); and (5) direct discharge. Option 5 was chosen for effluent disposal.
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. Nuisance
noise levels are not expected from the operation of the expanded WWTF or related infrastructure
improvements. Minimal direct, permanent impacts to terrestrial habitat or wildlife are expected from
construction or operation of the proposed project. An approximately 7 acre site adjacent to the WWTF will
be utilized for the proposed project. Clearing associated with stream crossings should be minimal as they
will be crossed by directional drilling construction techniques. Topography and soils will be directly
impacted by grading and filling activities; however, most these impacts will be short term direct impacts and
will not result in permanent impacts to the topography or soil. The effluent pipe will be located within the
100-year floodplain and will impact 0.01 acres of wetland. Floodplains will be returned to pre-existing
conditions upon completion of construction so that there will be no permanent displacement of floodways or
elevation of flood elevations. Likewise, appropriate construction techniques and mitigation will ensure that
wetlands and creek hydrology are protected and pre-existing conditions are re-established. This project is
consistent with current land use classifications and zoning regulations for the area and is not anticipated to
require any conversions of these designations. Immediate local air quality at the construction sites will be
degraded by stirred dust and emissions from machinery, but the long-term operation of the upgraded WWTP
and wastewater transmission infrastructure are not anticipated to significantly impact air quality. If open
burning is required, it will be done in accordance with necessary permits. Construction associated with the
WW"1'F expansion and transmission infrastructure installation may cause surface water quality degradation
from runoff and sedimentation. Proper erosion and sedimentation practices will be followed during
construction to protect local water quality as well as aquatic habitat and wildlife. Substantial nutrient loading
to the Cape Fear River is not expected, and water quality in the river should improve over the long-term by
reducing the impacts of nutrients in the watershed from failing or inefficient wastewater treatment and
disposal systems. Temporary impacts to surficial groundwater are anticipated as a result of dewatering for
construction of below grade structures; however, these impacts should be negligible and of short duration.
Direct impacts to fish, shellfish, and their habitats will be temporary and minor and associated with water
quality impacts from construction/installation activities. The new NPDES permit will specify regular
effluent sampling to ensure that compliance limits are met so that aquatic species are not adversely impacted.

There will not be any significant direct negative impacts to prime or unique farmlands; public lands and
scenic, recreational and State natural areas; threatened or endangered species; or toxic substances.
The approximately 7 acres of land adjacent to the WWTF (site 3 1NH802) that will be cleared for this project
was subject to a Memorandum ofAgreement between CFPUA, the Division of Water Quality [now known as
the Division of Water Resources], and the State Historic Preservation Office (S1-UPO) because of its National
Register eligible status. The site underwent an Phase 3 Archaeological Data Recovery Plan to mitigate the
adverse impacts and has since been authorized for construction by SHPO. However, if human burials are
discovered during construction, CFPUA shall comply with provisions of the North Carolina General Statute
70(3) "The Unmarked Human Burial and Human Skeletal Remains Protection Act."
Secondary and cumulative environmental impacts (SCIs) may result from this project and are outlined in the
EA. Federal, state, and local programs and ordinances will help to offset potential SCIs resulting from the
proposed project. These programs include flood damage prevention ordinance; CAMA land use planning;
zoning regulations; open space preservation, erosion and sedimentation control, State coastal stormwater
management guidelines and permitting policies; and CFPUA Emergency Sewer Repair Standard Operating
Procedures Manual and the Sanitary Sewer Overflow/Spill Response Standard Operating Procedures
Manuals. 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 the review
by governmental agencies, the Division of Water Resources has concluded that the proposed project will not
result in significant impacts to the environment. This FNS1 and EA are prerequisites for the issuance of
Division of Water Resources permits necessary for the project's construction. An Environmental Impact
Statement will not be prepared for this project. This FNS1 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 Resources — Water Quality Programs
13 September 2013

ENVIRONMENTAL ASSESSMENT
CAPE FEAR PUBLIC UTILITY AUTHORITY
M'KEAN MAFFITT (SOUTHSIDE) WASTEWATER TREATMENT
FACILITY EXPANSION AND UPGRADE TO 24 MGD
IMP Cape Fear
Public Utility Authority
Stewardship. %stainability. Service.
Lead Review Agency:
NCDENR DWQ
1617 Mail Service Center
Raleigh, NC 27699-1617
[phone]
Owner Contacts:
CFPUA
Matt Jordan
Chief Executive Officer
235 Government Ctr Dr
Wilmington, NC 28403
Preparer Contacts:
Tony Boahn, PE
Kelly Ham, PE
McKim & Creed, INC.
243 North Front St.
Wilmington, NC 28401
[phone]
Prepared by
vMCKIIM&CREED
McKim & Creed, INC.
[phone]
243 North Front St.
Wilmington, NC 28401
M&C Project Number 05367-0001
NC Firm License No. F-1222
September, 2013

• Existing structures are not easily or economically expandable
C. ALTERNATIVES ANALYSIS
(Reference Exhibits 2, 4, 5, 6,16 and 17)
Several alternatives were evaluated in order to determine the best solution to meet the future
wastewater needs of the Southside WWTP service area.
I. Wastewater Treatment Plant Alternative Analysis
The following major wastewater treatment facility alternatives were evaluated:
• Alternative A - No Action Alternative
• Alternative B — Connect to Another WWTP
• Alternative C - Construct New WWTP in Southern New Hanover County
• Alternative D - Renovate / Upgrade and Expand Southside WWTP
1. Alternative A -No Action Alternative (Rejected)
The No Action Alternative was considered, but does not fulfill the needs of the proposed project
and therefore was rejected. If the No Action Alternative were selected, it would result in the
Southside WWTP functioning at its current capacity and condition and would leave the
Authority unprepared for the expected growth and service area demand over the 20-year
planning period (2012 - 2032).
The southern portion of Wilmington and New Hanover County is experiencing growth, which
requires a sustainable and reliable wastewater treatment capacity to maintain a high quality of
life. Population and commercial development in this area is growing, and is expected to follow
this trend for the foreseeable future. Ample wastewater system capacity is a critical component
in support of this projected growth. If the Southside WWTP were not expanded, existing septic
systems would continue to be used, potentially resulting in less efficient treatment processes
and possible water quality impacts. Although, it will not be required by the proposed project,
septic systems that fail will be encouraged to connect to the public sewer system, where
available. The Southside WWTP project will provide treatment capacity for current unsewered
areas (in the future), however, it is not part of this project to provide sewer collection
infrastructure to service such unsewered areas. This could potentially alleviate outdated, failing
septic systems throughout the County. In addition, the No Action Alternative would have a
negative impact on the Cape Fear River if new package plants and septic systems were
constructed to meet the growth needs in the southern portion of the County.
2. Alternative B - Connect to Another WWTP (Northside WWTP) (Rejected)
Southside WWTP EA Page 7 September 2013

The Authority owns and operates the Northside WWTP, which is located on 23rd St. in
Wilmington, and is currently permitted for 10 MGD and undergoing an expansion to 16 MGD.
The potential to convey wastewater from the Southside WWTP service area to the Northside
WWTP was evaluated. However, the Northside WWTP does not have sufficient capacity to
treat the additional 12 MGD projected wastewater flow from the Southside WWTP service area.
Even if the Northside WWTP were expanded to its 24 MGD footprint, it would not have the
capacity to accommodate its projected service area demands and the Southside WWTP
demands of an additional 12 MGD. Therefore this alternative was not deemed feasible as an
alternative to upgrade and expansion of the Southside WWTP.
3. Alternative C - Construct A New WWTP in Southern New Hanover County
(Rejected)
The potential to construct a new plant in the southern portion of the County with a discharge to
the Cape Fear River was investigated. This alternative would include renovation of the existing
Southside WWTP while a new plant is being constructed. One drawback to this alternative is
the high cost. An additional drawback is that two plants in southern New Hanover County
would need to be operated by the Authority. Due to land costs in this area, as well as costs
associated with operating another WWTP, this alternative is cost prohibitive. In addition,
significant public funds have been expended to develop sewer collection systems that deliver
flow to the existing Southside WWTP site. Due to prohibitive cost, lengthy project
implementation schedules, and lack of long-term benefits from operating an additional
treatment plant in the Southside WWTP service area, this scenario was not considered further.
4. Alternative D - Renovate / Upgrade and Expand Southside WWTP (Recommended)
This alternative would involve renovating the existing Southside facility technology and
expanding the capacity of the plant from 12 MGD to 24 MGD with an improved treatment
process and upgrading its currently permitted level of treatment. Treated effluent would be
discharged to the Cape Fear River through a new 60-inch plant effluent pipe. The existing
treatment processes are proposed to be upgraded from secondary to tertiary and discharge
limits are anticipated to be improved. Table 4 summarizes current and proposed parameters for
the Southside WWTP. Refer to Exhibit 6 for speculative limits letter.
Table 4 — Southside WWTP Current & Proposed Wastewater Effluent Parameters
Parameter
Current Facility.
Proposed. Facility
Capacity
12 MGD
24 MGD
CBODs (Monthly Average)
25 mg/L
5 mg/L (summer) 10 mg/L (winter)
NH3-N (Monthly Average)
N/A
1 mg/L (summer) 2 mg/L (winter)
Southside WWTP EA
Page 8
September 2013

Under this alternative, the entire hydraulic profile will be raised so that influent wastewater can
flow through the facility by gravity. Due to the elevated headworks, five of the offsite pump
stations that pump directly to the Southside WWTP will need to be modified and 4,200 LF of
force main will need to be replaced with a larger force main. These pump stations include;
COW 14, COW 17, COW 21, COW 36, and COW 42 and were found to be significantly impacted
by a higher influent structure at the Southside WWTP and will require modification to
accommodate this condition, as indicated in Table 5.
Table 5 — Offsite Pump Station Improvements
Pump
Station
Current
ADF
Firm
Capacity
(GPM)
Proposed
Firm
Capacity
(GPD)
Proposed Improvements
Cost of
Improvements
COW 14
1,336,009
1,842,510
Reprogramming/ logic modification
$15,000
COW 17
170,029
418,470
Upgrade pumps, electrical service &
generator. Replace 4,200 LF 6" force
main with 10" force main
$450,000
COW 21
108,812
148,550
Increase pump speed
$5,000
COW 36
44,801
424,130
Expand wet well. Reuse pumps, and
increase pump speed. Upgrade motors,
electrical service, and generator
$900,000
COW 42
151,344
229,520
Increase pump speed. Upgrade motor,
electrical service, and generator
$85,000
Due to the environmental, economic and strategic reasons previously discussed, Alternative D,
renovating and upgrading the Southside WWTP is the recommended alternative.
II. Treatment and Dispersal Alternatives Analysis
Alternatives for methods of treatment and dispersal were also evaluated in this section. As
required by SEPA guidelines, this document provides justification for 20-year wastewater needs
for the facility's service area. Alternatives for this section are as follows:
• Alternative A — Land Application via Low -Rate Spray/Drip Irrigation
• Alternative B — Beneficial Reuse
• Alternative C — High Rate Infiltration
• Alternative D — Direct Discharge
• Alternative E — Conjunctive Use
Southside WWTP EA Page 9 September 2013

1. Alternative A - Secondary Systems — Land Application via Low -Rate Spray/Drip
Irrigation (Rejected)
The alternative of secondary treatment and land application through either low -rate spray or
drip irrigation was investigated. Secondary land application systems allow for lower pre-
treatment levels than direct discharge or reclaimed water systems because the soil serves as the
final tertiary treatment step prior to discharge into the underlying groundwater. The rate of
dispersal is highly reliant on the soil's hydrologic capacity, water, and seasonal changes. Highly
variant and restrictive dispersal conditions combined with buffer restrictions necessitate large
quantities of land for irrigation systems. The spray or drip irrigation option would consist of a
biological treatment system capable of treating to secondary levels and a land application
system consisting of spray or drip irrigation fields. Based on the soil types and associated soil
loading rates proximal to the Southside WWTP, it was determined that 1400 acres of land
would be required to dispose of each 1 MGD of treated effluent. Considering that the 20-year
planning period wastewater flow projection for the service areas is 24 MGD (12 MGD of which
will be disposed of by direct discharge under the current Southside WWTP Permit NC0023973),
there is insufficient available land to make this alternative feasible. Further, if sufficient land
were available, this alternative would be cost -prohibitive.
2. Alternative B - Beneficial Reuse (Rejected)
The alternative of advanced treatment facilities to provide beneficial reuse of treated
wastewater effluent was considered. The City and County are home to a number of golf
courses, which could potentially use a portion of the treated effluent for irrigation purposes in
the future. However, this alternative would require construction of a reclaimed water
distribution system throughout the service area to provide reclaimed water to the potential
reuse customers.
Table 6 provides a summary of the existing irrigation demands for the golf courses within New
Hanover County. Many of these golf courses currently utilize individual wells or onsite ponds
for irrigation.
Table 6 — Estimated Average Day Irrigation Demands — Golf Courses
Owner
Estimated Average Day
Irrigation (GPD)
Acres
Beau Rivage Golf & Resort
24,000
130
Cape Fear Country Club
34,000
180
City of Wilmington Municipal Gold Course
26,000
140
Country Club Landfall
86,000
460
Eagle Point Golf Club
43,000
230
Echo Farms Golf & Country Club
26,000
140
Pine Valley Country Club
24,000
130
Southside WWTP EA
Page 10
September 2013

Owner
Estimated Average Day
Irrigation (GPD)
Acres
Porter's Neck Country Club
38,000
200
Total
301,000
1,610
* Information provided in Table 6 was obtained from the Cape Fear Public utility Authority Integrated Resources
Master Plan (CH2MH11.1., December 2010).
While the beneficial reuse alternative is attractive due to its potential to provide key
environmental benefits, such as conservation of groundwater supplies for use in golf course
irrigation, the projected reuse demand is only a small fraction of the additional 12 MGD that
must be dispersed. Further, at this time, there are no firm commitments to use the reclaimed
water in this manner. Additionally, construction of a reclaimed water distribution system is
cost -prohibitive at this time. Therefore, this alternative was not considered further in this
environmental assessment.
3. Alternative C - High -Rate Infiltration (Rejected)
The alternative of reclaimed standard level treatment and high -rate infiltration basins was
considered. Providing an advanced level of treatment allows for a variety of dispersal options,
including high -rate infiltration basins. High rate infiltration basins work well in certain sandy
soils found in the NC Coastal Plain to indirectly recharge aquifers and surface water with high
quality effluent. The infiltration basins are excavated so that the bottom is at below the typical
water table. Additional water added into the pond is forced down by gravity based on the
hydraulic and hydrogeologic capacity of the soil. This method requires less land than irrigation
options where soils are suitable due to the higher application rate. Additionally, the basins
preclude the need for wet weather flow equalization basins typical of irrigation systems. Since
the discharge comes into direct contact with groundwater without any further treatment, the
treatment process must treat to protect groundwater standards.
Assuming a typical infiltration rate of 1.0 gpd/sf, this alternative requires approximately 23
acres of land per 1 MGD of treated effluent for dispersal. Soils in the proposed infiltration basin
locations primarily include KuB, BaB, Wo and AuB, which are anticipated to be suitable for
disposal via high rate infiltration basins.
The proposed high rate infiltration alternative is not recommended for this project due to the
lack of sufficient land within the City or County to make this alternative feasible.
4. Alternative D - Direct Discharge (Recommended)
The Authority currently holds a NPDES Discharge Permit (NC0023973) to discharge up to 12
MGD of treated effluent into the Cape Fear River (reference Exhibit 2). The proposed project
will entail upgrade and expansion of the treatment facility to 24 MGD at an advanced level of
Southside WWTP EA Page 11 September 2013

treatment and construction of a new 60-inch diameter plant effluent pipe that will dispose of up
to 24 MGD treated effluent (reference Exhibit 4).
The existing NPDES permit limits for Southside WWTP are 25 mg/L BOD5 with no restriction
on NH3-N. The expansion of the Southside WWTP will be designed to meet the speculative
effluent limits (5 mg/L BOD5 and 1 mg/L NH3-N, monthly average, summer). Reference Exhibit
6 for the speculative limits letter.
5. Alternative E — Conjunctive Use (Rejected)
The alternative of conjunctive use via a combination of direct discharge, high -rate infiltration,
and beneficial reuse was considered; however, since there are no dedicated reuse customers at
this time and finding sufficient land proximal to the Southside WWTP suitable for high -rate
infiltration is not feasible, this alternative was not considered further.
6. Summary of Disposal Alternatives
A detailed economic comparison for each disposal alternative was completed for the proposed
project. Excerpts are included in Exhibits 16 and 17.
Estimated total project costs and annual O&M costs were evaluated on a net present worth basis
for each of the disposal alternatives, and a summary of present worth is provided below in
Table 7.
Table 7—Life Cycle Cost Estimate for Disposal Alternatives
Alternative Life Cycle Cost Estimate Summary
24 MGD
Alternative
Present Value 1, 2,
3
Alternative A: Spray/Drip Irrigation 4
$791,400,000
Alternative B: Beneficial Reuse 5
$300,500,000
Alternative C: High -Rate Infiltration
4
$339,700,000
Alternative D: Direct Discharge
$201,500,000
Alternative E: Conjunctive Use
Not Feasible
Total project costs are reported in Year 2012 dollars.
2 Note that present value analysis includes cost of upgrading the Southside WWTP to 24 MGD plus O&M costs,
unless otherwise noted.
3 Annual O&M costs were computed for each year between 2012 and 2032 and discounted (discount rate of 4.5%)
to obtain each years equivalent present worth. These discounted annual costs were then summed for the twenty year
period to obtain the total present worth of 20 years annual O&M costs for each alternative.
4 Sufficient land not available.
5 Sufficient customers not available
Southside WWTP EA Page 12 September 2013

Or
Summary of Recommended Alternatives:
The recommended project will involve expanding and upgrading the capacity of the existing
Southside WWTP from 12 MGD to 24 MGD, upgrading treatment for more stringent limits
(noted in the speculative limits letter) and constructing a new 60-inch plant effluent pipe for
dispersal of up to 24 MGD treated wastewater effluent to the Cape Fear River (reference Exhibit
4). This project will also require an elevated influent structure, the replacement of 4,200 LF of
force main and five collection system pump stations that pump directly to Southside WWTP
(COW 14, COW 17, COW 21, COW 36, and COW 42) will require modifications for this new
hydraulic condition.
D. EXISTING ENVIRONMENTAL CHARACTERISTICS OF THE PROJECT
AREA
1. Topography
(Reference Exhibits 1, 4, 8A, 8B and 9)
A. The Southside WWTP project site is adjacent to the Cape Fear River, near the
intersection of River Road and Melton Road in New Hanover County (reference Exhibit
1).
B. Surface waters from the project area flow to the Cape Fear River. Existing pump stations
COW 14, COW 32, and COW 42 and a portion of the existing Southside WWTP site,
adjacent to the Cape Fear River, are located within the 100 year floodplain according to
the Federal Emergency Management Agency's (FEMA) Flood Insurance Rate Map's
(FIRM) (Exhibit 8A and 8B).
C. Portions of the project service area are located proximal to the Cape Fear River, the
Intercoastal Waterway, and the Atlantic Ocean. FEMA FIRM maps for the service area
indicate that there are several low-lying areas that are associated with the various
tributaries located in the 100-year and 500-year flood zones (See Exhibit 8B).
D. A Letter of Map Revision (LOMR) was completed for this project and is included in
Exhibit 9.
E. The Authority's service area is in the lower part of the Coastal Plain physiographic
province. Elevations range from sea level to 60 feet. Most of the area is level to gently
sloping, but short breaks separate the uplands from the flood plains and marshes.
Ground elevations of the project sites range from approximately 5 — 30 mean sea level
(MSL).
2. Soils
(Reference Exhibits 10A, 10B and 10C)
A. The geology of much of the City of Wilmington and New Hanover County is
characterized by sand overlaying layers of clay and limestone.
Southside WWTP EA
Page 13 September 2013

North Carolina Department of Environment and Natural Resources
Division of Water Resources
Cash Receipts Batch Details
10/27/2014
Budget Code: 24300 Date: 10/24/14 Name: Wren Thedford Batch Number: PR2014102403
Batch Total: $1,090.00
Processed Date Name Payor Amount Check Number
10/27/14 NC0023973 - Cape Fear Public Utility Authority - Cape Fear Public Utility Authority $1,030.00 56308 10/27/2014
Wilmington Southside WWTP
10/24/14 NCG551643 - Deboroah J Brotherton - 2181 Sanders Bateman Civil Survey Company PC $60.00 7419
Road
Payment Method
Batch Totals # Batch Items
Check
$1,090.00 2
Division of Water Resources
Program Account # Company Center Account Description Account Total (For Deposit) # Account Items
NPDES WW
435100095 1602 2341
Permit & SOC Application and Annual Fees
Total (For Deposit)
Grand Total (For Deposit)
$1,090.00 2
$1,090.00 2
$1,090.00 2
Page #: 1

teltn Z 3973
Belnick, Tom
TW Tr
From: Hollenkamp, Carol
Sent: Wednesday, September 24, 2014 2:21 PM
To: Moore, Cindy; Belnick, Tom
Cc: Meadows, Susan
Subject: RE: NC0023973- Tox Code TGE3B
Tom,
Thanks for your time today.
q/Diy
TL3
Just wanted to let everyone know our question below was answered. The CFPUA will most likely not need to submit an
IWC with their expansion based on the characteristics of their effluent. The CFPUA (NC0023973) will remain testing at
the acute Ceriodaphnia dubia at 90% (TGE3B). If they decide they want to switch to chronic testing at a lower
concentration, then they can choose to submit a modeled IWC. From past information, it looks like their IWC would be
somewhere around 3%.
Carol Hollenkamp
Aquatic Toxicology Branch/Water Sciences Section
North Carolina Division of Water Resources/DENR
1621 Mail Service Center, Raleigh, NC 27699-1621
Please NOTE NEW PHONE #
Phone: [phone]
Fax: [phone]
Website: http://portal.ncdenr.org/web/wq/ess/atu
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.
From: Moore, Cindy
Sent: Friday, September 19, 2014 3:21 PM
To: Belnick, Tom
Cc: Hollenkamp, Carol; Meadows, Susan
Subject: RE: NC0023973- Tox Code TGE3B
We can leave the organism as Ceriodaphnia dubia per this paragraph from tox strategy. `Freshwater organisms may be
substituted in permit requirements for dischargers to estuarine and salt receiving waters where an evaluation has been
made by Aquatic Toxicology Unit staff that the freshwater organism provides the same level of protection as saltwater
organisms.
I have attached toxicity strategy. We have a question. Will this facility have to model in order to determine the IWC? If
they will , then that will determine the testing protocol. If IWC is <0.25 or has not been determined, then the facility will
do an acute.( Per tox strategy) If IWC has been determined and > .0.25% , then a chronic will be the correct test.
From: Belnick, Tom
Sent: Friday, September 19, 2014 2:24 PM

a.
To: Moore, Cindy
Subject: FW: NC0023973- Tox Code TGE3B
Cindy- looking through permit file, it appears that CFPUA ran Acute Daphnia pulex, then there was change to
Ceriodaphnia dubia in 2004 following contested permit. This is a discharge to salt SC waters in Cape Fear River. I'm
requesting Aquatic Tox to verify that this is appropriate test organism before the next permit renewal. Thanks.
Tom Belnick
Supervisor, NPDES Complex Permitting Unit
NCDWR/Water Quality Programs
919-807-6390
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
From: Belnick, Tom
Sent: Friday, September 19, 2014 2:15 PM
To: Beth Eckert; '[e-mail]'
Cc: Manuel, Vanessa; Moore, Cindy; Hunkele, Dean
Subject: NC0023973- Tox Code TGE3B
Pam/Ken- just a quick note on your NPDES Permit NC0023973 (CFPUA/Southside) issued 4/24/2012. The permit
incorrectly lists the Acute Toxicity parameter code as TGE3D, but it should be TGE3B for the Acute Pass/Fail, 90%,
Ceriodaphnia Dubia. I believe you are reporting with the correct code. We will correct the code in the next permit
renewal. Let me know if you have any questions.
Tom Belnick
Supervisor, NPDES Complex Permitting Unit
NCDWR/Water Quality Programs
919-807-6390
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

F°' 4' 4 � iw� r rah ew7/.la-1 ;;"7/1-- gedet)C 10x Jell- u�e�,,, 9/201 y
Belnick, Tom d �C� ifL' er2061-e Cie MP
q//q/
From: Belnick, Tom
Sent: Friday, September 19, 2014 2:24 PM
To: Moore, Cindy
Subject: FW: NC0023973- Tox Code TGE3B
Cindy- looking through permit file, it appears that CFPUA ran Acute Daphnia pulex, then there was change to
Ceriodaphnia dubia in 2004 following contested permit. This is a discharge to salt SC waters in Cape Fear River. I'm
requesting Aquatic Tox to verify that this is appropriate test organism before the next permit renewal. Thanks.
Tom Belnick
Supervisor, NPDES Complex Permitting Unit
NCDWR/Water Quality Programs
919-807-6390
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
From: Belnick, Tom
Sent: Friday, September 19, 2014 2:15 PM
To: Beth Eckert; '[e-mail]'
Cc: Manuel, Vanessa; Moore, Cindy; Hunkele, Dean
Subject: NC0023973- Tox Code TGE3B
Pam/Ken- just a quick note on your NPDES Permit NC0023973 (CFPUA/Southside) issued 4/24/2012. The permit
incorrectly lists the Acute Toxicity parameter code as TGE3D, but it should be TGE3B for the Acute Pass/Fail, 90%,
Ceriodaphnia Dubia. I believe you are reporting with the correct code. We will correct the code in the next permit
renewal. Let me know if you have any questions.
Tom Belnick
Supervisor, NPDES Complex Permitting Unit
NCDWR/Water Quality Programs
919-807-6390
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

Scardina, Maureen
From: Meadows, Susan
Sent: Monday, September 20, 2010 10:25 AM
To: Weaver, Charles; Glazier, Kipp
Cc: Scardina, Maureen; Belnick, Tom
Subject: RE: BIMS Permit Limit Change - NC0023973 Wilmington Southside WWTP
They should be running a Ceriodaphnia dubia 24 Hour Pass/Fall test, so the Code should be changed to TGE3B.
Susie
Susan Meadows, Environmental Biologist
Aquatic Toxicology Unit
DWQ/Environmental Sciences Section
4401 Reedy Creek Road Raleigh, NC 27607
[e-mail]
t: [phone]
f: [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.
From: Weaver, Charles
Sent: Monday, September 20, 2010 9:53 AM
To: Glazier, Kipp; Meadows, Susan
Cc: Scardina, Maureen; Belnick, Tom
Subject: RE: BIMS Permit Limit Change - NC0023973 Wilmington Southside WWTP
Kipp — there appears to be a typo in the permit.
Either the test code is correct (TGE3D), in which case the test organism should be Daphnia Pulex.
OR
The organism in the permit (Ceriodaphnia dubia) is correct, but the test code is wrong.
Susan — can you help us determine what should be corrected in the permit?
Thanks,
CHW
From: Glazier, Kipp
Sent: Monday, September 20, 2010 8:51 AM
To: Weaver, Charles
Subject: BIMS Permit Limit Change - NC0023973 Wilmington Southside WWTP
Charles, Would you change the tox test organism to Ceriodaphnia dubia for the subject permit.
Thanks
Kipp Glazier
NC DENR DWQ - WiRO
phone [phone]
i

CITY OF WILiVIINGTON
prr-
PUBLIC UTILITIES DEPARTMENT
PUBLIC UTILITIES DEPARTMENT
March 2, 2004
Mr. David A. Goodrich, NPDES Unit
NCDENR
DWQ
1617 Mail Service Center
Raleigh, NC 27699-1617
Re: Acute Toxicity Test Species
City of Wilmington NPDES Permits NC0023965 and NC0023973
P.O. Box 1810
WILMINGTON, NC 28402
TDD [phone]
Dear Mr. Goodrich,
The referenced permits require quarterly acute toxicity testing P/F at 90%,
using Daphnia pulex as the test organism. SimaLabs, the only North
Carolina -certified laboratory able to perform this test with this species, has
performed this testing for the City for several years. SimaLabs' recent
acquisition by Pace Analytical has resulted in our inability to identify another
laboratory providing equivalent services. This in turn requires our petitioning
DWQ to consider modifying these permits for a suitable substitute test
organism.
At this time, we are proposing Ceriodaphnia dubia as a substitute test
organism for the acute toxicity test. Limited previous data indicates it
provides comparable/similar response to Daphnia pulex. However, because
of our favorable history with Daphnia pulex and uncertain ability to achieve
similar compliance using Ceriodaphnia dubia, we are requesting DWQ waive
enforcement action against the City while we evaluate this substitution. A
one year (four tests) period to evaluate applicability of Ceriodaphnia dubia
for the City's acute toxicity testing is suggested.
We are proceeding accordingly while we await DWQ's response to our
proposal.
Sincerely,
/ /)
Kenneth L. Vogt, Jr., PE,
Wastewater Treatment Superintendent
Copies: H. Caldwell
P. Ellis
J. Cermak
M. Vann
TRATION
I) 341-7805
341-5881
ENVIRONMENTAL SERVICES
VOICE [phone]
FAX[phone]
UTILITY SERVICES
VOICE [phone]
FAX[phone]
WASTEWATER TREATMENT
LOUGHLIN PLANT MAFFITT PLANT
VOICE [phone] VOICE [phone]
FAX [phone]
WATER TREATMENT
VOICE [phone]
FAX [phone]

sk. 5EP4 oVZN1N619 fhk Mcoo?T$V5 q,
2013
•Belnick, Tom
From:
Sent:
To:
Cc:
Subject:
Belnick, Tom
Thursday, September 05, 2013 4:03 PM
'Kelly Ham'
Headrick, Hannah
RE: Southside WWTP EA - Concurrence
Kelly- I concur that the proposed changes address NPDES concerns. Thanks.
Tom Belnick
Supervisor, NPDES Complex Permitting Unit
NCDWR/Water Quality Programs
919-807-6390
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
- 2.(0e6
r�sol4�� or
Powjv- ���c� hi
From: Kelly Ham {mailto:khamOmckimcreed.com]
Sent: Thursday, September 05, 2013 2:56 PM
To: Belnick, Tom
Cc: Headrick, Hannah
Subject: Southside WWTP EA Concurrence
Tom,
Thanks again for speaking with me yesterday regarding the Southside WWTP EA.
Based on our conversation and subsequent discussion with Hannah Headrick, I understand that the Division of Water
Resources' comments on the EA were previously resolved by the letters issued to Hannah Headrick and Jim McKay on
July 25, 2013, with the exception of your comment about removing Aqua America flows from the EA.
In order to address the removal of the Aqua America flows comment, the following changes to the EA are proposed:
1. Page 5, B, Purpose and Need for the Proposed Project, Third Paragraph, Delete the third, fourth, and fifth
sentences, which read, "Wastewater flow projections also include 1.33 MGD of wastewater flow from areas
currently served by Aqua America, beginning in year 2028 and extending throughout the remainder of the project
planning period. Similar to the 2 MGD diversion previously noted, this was also recommended as part of the 2007
Wastewater Master Plan Update. (Note that Aqua America currently provides wastewater service to areas within
the Authority's service area and has existing infrastructure in place)." Next sentence, add "industrial" so that the
sentence reads, "Finally, a 10 percent industrial reserve capacity factor was applied to yield total average daily
wastewater flows for the Southside WWTP.
2. Page 6, Replace Table 2 with the following Table 2:
'' r ,.a -: .Y .�s �'.'t; S6 i. y �5�. t -is „i� f;M ,;4." iS
41�,s..?..ii-'r,4. .r..i*6.,.......... _....�_... ._.�„ ..,..._ r---.. ,. ..c..�,.....l...`".r :_.. .."+?`s-_.:—j..,-6:i!s�'.._.�a�Pi...,.F• ••-
sx y;f
:�^'!..1O.r31, :-
--- xY
018
�„
S i2023.�
? e si
2 28� 1
.- -
AJ
a203 .
Southside WWTP Service Area Base Demand (MGD)
7.9
9.6
11.7
14.2
17.3
2 MGD Diversion from NSVW TP (MGD)
0.0
0.0
0.0
2.0
2.0
Industrial Reserve (MGD)
0.2
0.38
0.56
0.75
0.94
Total Average Daily Flow, Including Industrial Reserve (MGD)
8.1
10.0
12.3
17.0
20.3
1

\' \
r
3. Page 6, Replace Table 3 with the following Table 3:
2013
2018
2023
2028
2033
Max Month Flow (MGD)
9.4
11.6
14.2
19.
23.5
2K m
We understand that the proposed changes to the EA noted above fully address DWR's comments on the EA. Please
respond to this email to confirm that your comments have been addressed.
Thanks so much for all your help!
-Kelly
Kelly Ham, PE I Project Engineer
Tel [phone] ext 233
243 North Front Street ( Wilmington, NC 28401
khamamckimcreed.com ( htto://www.mckimcreed.com
McKIM&CREED
ENGINEERS SURVEYORS PLANNERS
Follow us on: YouTube I twitter I facebook I Linkedln
To send me a file larger than 10MB please click here
This e-mail and any files transmitted with it are confidential
and intended solely for the use of the individual or entity to
whom they are addressed. If you have received this e-mail in
error please notify the system manager. Please note that any
views or opinions presented in this e-mail are solely those of
the author and do not necessarily represent those of the
company. Finally, the recipient should check this e-mail and
any attachments for the presence of viruses. The company
accepts no liability for any damage caused by any virus
transmitted by this e-mail.
2

Uk i//i /0041 CffVI4,"wt)
,Belnick, Tom
Subject:
Location:
Start:
End:
CFPUA/SEPA 24 MGD flow justification
jeff office
Wed 9/4/2013 10:00 AM
Wed 9/4/2013 10:30 AM
Recurrence: (none)
Meeting Status: Meeting organizer
Need to discuss CFPUA 24 MGD flow justification in SEPA EA.
WI4j(- vJ Q/0(644 4-0 49/4; r at) Mitt of A404-MOV ;
I,IAyihi"lUi1 t7wllc%wit
Tf'"' alia(pi)
91013 ' calla cOwl- '(.oNJ4/44-
Key) I-kvM 611D-343,oYrb
fia ahvi 4311401-
All)66 Iry ri met kta444

9f3iid»/ /IIj/ii q/q/,3
r°,114/1" 6YQUa Las _ 11M4 ,®lam
z) 141 04-nail f -, erv(
10)D Iv( OfeJ-ei V ( co,,Q/J4a -17-1
3) (4).( of /,!)80w --A, MA, in.g
LO i6 ivic14,43,4A44f4fii,(kb GL1✓ferkviP
hbkf //h4/T��lr'�+°J
ZYmi0
SEn4 - F1Gui{d447
tchl'A 4 0- 1101Y �v J.4 C 1I C u f
,&4

' . CfP4,/i)iidi PoI Zy�f6ii
8elnick, Tom
?I3
From: Mckay, James
Sent: Wednesday, July 31, 2013 8:27 AM
To: Belnick, Tom
Subject: FW: SSWWTP EA - Head's Up - Letters in Response to DWQ Comments
Attachments: Dean Hunkele.vcf; 072513 Hannah Ltr (2).pdf; 072513 Jim Ltr.pdf
rA}
Dean's latest comments.
This week I received copies of two letters McKim and Creed wrote in response to my comments regarding the EA for
Cape Fear Public Utilities expansion of Wilmington South Side WWTP.. They are sticking to their guns regarding the
growth rate and rationale for adding all the extra flow and safety factor. They seem to really want to lock up all the
allocation for the whole area. 1 don't know if this is a fight we want to get into now or not. Let's talk when you can.
Jim McKay, Environmental Engineer
NC DENR / Division of Water Quality / Surface Water Protection Section
Point Source Branch
1617 Mail Service Center, Raleigh, NC 27699-1617 4 C FPU't
919/807-6404 (work); 919/807-6489 (fax)
W Woltz-4i flan
**Please note, my email address has changed to [e-mail]
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.
From: Hunkele, Dean
Sent: Tuesday, July 30, 2013 4:09 PM j
To: Headrick, Hannah; Mckay, James ne{ K R I d iii6,2413
U
Cc: Gregson, Jim
Subject: RE: SSWWTP EA - Head's Up - Letters in Response to DWQ Comments
I think they should be able to dispose of some of the effluent from the facility at the Riverlights mixed -use development
as a Conjunctive -Use disposal system via infiltration at rates of 2-3 gpd/sqft. They could provide access for re -use
irrigation to residents and for common landscaping which doesn't have to be a golf course which will save potable
water. This on very sandy soil that will take a lot of water to grow and maintain landscaping — I know as I live on the
same sand within a mile and installed a private well not to use potable. I am certainly not looking at getting rid of a 12
MGD or even a major portion of that — but think 1-2 MGD is possible. McKim and Creed designed the Mercer Mill Tract
for receiving high rate infiltration for West Brunswick (wg0023693). Mercer mill tract is wando and kureb soils both
excessively drained/deep water table soils types and permitted for 2 gpd/sqft.
One item I forgot to mention in my comments before and not sure when it should be mentioned, but here it is:
They should have to move their discharge pipe closer to the main channel with a diffuser rather than dumping it on the
bank on the lower mixing side of the river.
I am done commenting on this, thus up to Raleigh to decide what is reasonable and best for the environment & citizens
of New Hanover County.
1

Dean Hunkele
Senior Env'ronrr _ntal specialist
NC DEPNR - Division of Water Quality
Dean.Hunkeb>Zm Pnr.cov
Wilmington Regional Office
Reception [phone]
Drect [phone]
Fax. [phone]
127 Cardinal Drive Extension
Vfdmington, NC 28405
WWW.r waterQualini.ora
From: Headrick, Hannah
Sent: Monday, July 29, 2013 9:10 AM
To: Mckay, James; Hunkele, Dean
Subject: FW: SSWWTP EA - Head's Up - Letters in Response to DWQ Comments
Good morning.
Please find responses from Kelly Ham on the subject project attached.
Can y'all let me know by Friday, August 9 if your concerns are resolved? If you need longer, let me know and when you
think you can get something to me.
Thanks!
Hannah
Hannah Headrick
SEPA Coordinator
NC Division of Water Quality - Planning Section
Physical location: 512 N. Salisbury Street, Raleigh, NC 27604 [Archdale Building - Office 62SJ]
Mailing address: 1617 Mail Service Center, Raleigh, NC 27699-1617
Phone: [phone] -- Fax: [phone]
http://porta I. ncdenr.org/web/wq/ps/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.
From: Kelly Ham [mailto:kham [e-mail]]
Sent: Friday, July 26, 2013 4:27 PM
To: Headrick, Hannah
Subject: SSWWTP EA - Head's Up - Letters in Response to DWQ Comments
Hannah,
I hope all is well.
Just wanted to give you a head's up that we placed the attached "....Hannah" letter in the mail to you and the attached
"....Jim" letter in the mail to Jim yesterday so that you all will hopefully receive your hard copies on Monday.
Please let us know if you have questions or need anything.
Thanks so much for all your help on this project!
-Kelly
Kelly Ham, PE I Project Engineer
2

Tel 9 i 0.251.6665 ext 233
243 North Front Street I Wilmington, NC 28401
`[e-mail] I http://www.mckimcreed.com
MCKftS4&cREED
ENGINEERS SURVEYORS PLANNERS
Follow us on: YouTube ( twitter I facebook I Linkedln
To send me a file larger than 10MB please click here
This e-mail and any files transmitted with it are confidential
and intended solely for the use of the individual or entity to
whom they are addressed. If you have received this e-mail in
error please notify the system manager. Please note that any
views or opinions presented in this e-mail are solely those of
the author and do not necessarily represent those of the
company. Finally, the recipient should check this e-mail and
any attachments for the presence of viruses. The company
accepts no liability for any damage caused by any virus
transmitted by this e-mail.

McKIM&CREED
July 25, 2013
Ms. Hannah Headrick
NCDENR
SEPA Coordinator, DWQ
1617 Mail Service Center
Raleigh, NC 27699
ENGINEERS
SURVEYORS
PLANNERS
M&C 5367-0001 (13)
RE: New Hanover and Pender Co • - s — CFPUA's Proposed M'Kean Maffitt
(Southside) WWTF Expansion fro 12 to 24 GD DWQ # 14475
Dear Hannah:
Thank you for your memorandum on the above referenced project, dated June
21, 2013. This letter addresses your comments on a "comment for comment"
basis. Your comments are in regular text and responses are in italics. We hope
that this information fully addresses your comments and will enable you to
provide us with a letter indicating your concurrence with the EA; however, if
you have questions or require additional information, please do not hesitate to
contact me at 910-343-1048.
1. It was brought to our attention that conflicting information regarding the
conclusions drawn by the EAA for the subject project was provided by
staff in the Surface Water Protection Section staff in the Central Office and
the Wilmington Regional Office. Since your receipt of these comments,
staff have resolved this divergence. Therefore, please disregard the final
paragraph of the May 10, 2013 comments from the Complex (NPDES)
Permitting Unit on the EAA.
• OK
243 North Front Street 2. The EAA should be revised to consider high rate infiltration, spray
irrigation, or other reuse options for effluent. In particular, the River
Wilmington, N C 2 8 4 0) Lights site needs to be examined as a non -discharge site as it contains
sandy soils and has not yet been developed with streets, utilities, sewer or
homes. Also, the loading rates for infiltration and spray irrigation used in
9103431048 the EAA are both at the very bottom of the range of expected loading rates
Fox 910.251 828?
w w w m c k i rn c r e e d, c o m S:\5367\0001\10-Comm\ 13-Comm w Regulatory Bodies\072513 Headrick Commenl Response - SSW W TP Agency Review.doc

Ms. Hannah Headrick
July 25, 2013
Page 2
and should be reevaluated based on the soil conditions at the proposed
RiverLights site.
• As a clarification, the EA alternatives analysis currently considers high rate
infiltration, spray irrigation and reuse options for effluent in section C,
Alternatives Analysis, II, Treatment and Dispersal Alternatives Analysis. The
EA Indicates that each of these alternatives is rejected and includes the following
primary points for each alternative:
o Alternative A — Land Application via Low -Rate Spray/Drip Irrigation:
Based on the soil types and associated soil loading rates proximal to the
Southside WWTP, it wa sdetermined that 1400 acres of land would be
required to dispose of each 1 MGD of treated effluent. Considering that
the 20-year planning period wastewater flow projection for the service
area is 24 MGD (12MGD of which will be disposed of by direct
discharge under the current Southside WWTP Permit K0023973),
there is insufficient available land to make this alternative feasible.
Further, if sufficient land were available, this alternative would be cost -
prohibitive. For comparison, the entire Riverlights development is
approximately 1,360 acres.
o Alternative B — Beneficial Reuse: While the beneficial reuse alternative is
attractive due to its potential to provide key environmental benefits, such
as conservation of groundwater supplies for use in golf course irrigation,
the projected reuse demand (301,000 GPD based on evaluation of
potential golf course average daily irrigation demands) is only a small
fraction of the additional 12 MGD that must be dispersed. Further, at
this time, there are no firm commitments to use the reclaimed water in
this manner. Additionally, construction of a reclaimed water distribution
system is cost -prohibitive at this time. Therefore, this alternative was
not considered further in this EA.
o .Alternative C- High Rate Infiltration: Assuming a typical infiltration
rate of 1.0 gpd/sf, this alternative requires approximately 23 acres of land
per 1 MGD of treated nt for dispersal. Soils in the proposed
infiltration basin locations primarily include KuB, BaB, Wo and AuB,
which are anticipated to be suitable for disposal via high rate infiltration
basins. The proposed high rate infiltration alternative is not
v MCKIM&CREED

Ms. Hannah Headrick
July 25, 2013
Page 3
recommended for this project due to lack of sufficient Iand within the
City or County to make this alternative feasible.
o Alternative E — Conjunctive Use: The alternative of conjunctive use via
a combination of direct discharge, high -rate infiltration, and beneficial
reuse was considered; however, since there are no dedicated reuse
customers at this time and finding sufficient land proximal to the
Southside WWTP suitable for high -rate infiltration is not feasible, this
alternative was not considered further.
• As a clarification, the loading rates used in the current EA analysis are practical
for preliminary evaluation of irrigation or infiltration basins in New Hanover
County, in our opinion. In fact, the high rate infiltration loading factors were
based on soil types such as KuB, BaB, Wo and AuB, which soil types may be
suitable for high rate infiltration basins. KuB corresponds with Kureb Fine
Sand, which is the most abundant soil type on the RiverLights property,
although there are also many areas of Pamlico marsh, Leon Sand, Dorovan Soils,
and Tidal Marsh that are poorly to very poorly drained on the River Lights site,
according to the NRCS web soil survey. Additionally, there are many areas of
wetlands and other areas on the site that would require setbacks. In the absence
of a detailed hydrogeologic evaluation of a specific site, it is our opinion that this
design loading factor should be used instead of "best case" estimates, as the best
case may not be encountered in construction or operation of the facilities and
designing for such would thus not be prudent engineering judgment.
• As a clarification, the RiverLights site is in process of development. Streets have
been planned and some work on streets has already been conducted.
Additionally, RiverLights has an agreement with the City for the realignment of
River Road through the property. The utilities, including water and sewer, for
the development have been planned and some have already been permitted and
constructed.
• We do not believe it to be prudent to single out a specific development such as
RiverLights for analysis as a non -discharge site in an EA, particularly when the
EA already addresses this for the County as a whole. It is also noted that
utilization of residential lots for dedicated reuse would likely be required to
achieve even the minimal reuse capacity that might be available based on soil
types. This would require significant additional expense to the CFPUA for
operations and maintenance as well as have a potential negative impact on
v McK M&CREED
v

Ms. Hannah Headrick
July 25, 2013
Page 4
property values in the development.The RiverLights site is a platted development
and targeting this development specifically as a non -discharge may create
hardships for the developer, who has invested significant resources in the
development of this property and is currently operating under a previously
approved agreement with the CFPLIA for water and sewer services, which do not
include provisions for reuse.
• RiverLights previously entered into a development agreement with the City of
Wilmington, which Iists approved uses and development details, including
approval of a master plan, for the property. Use of the site for non -discharge
effluent dispersal is not one of the approved uses. RiverLights has also entered
into a development agreement with the CFPUA for water and sewer. The
developer has made significant investments in the development of this property
and, particularly within the requirements of the development agreement with the
City, it is anticipated that it would not be feasible for CFPUA to pursue land
application as a means of wastewater effluent dispersal on this site.
• CFPUA policy does not require that developers connect to reuse systems and
thus has no mechanism for requiring RiverLights to accept or use reuse water.
Implementing a reuse policy would likely require approval of the City of
Wilmington and New Hanover County.
• Further, CFPUA has no existing reuse distribution systems now and
construction of a reuse system would be cost prohibitive.
• CFPUA evaluated potential reuse demand previously as part of its Integrated
Water Resources Master Plan and only 140,000 GPD of total reuse water
demand was estimated for the RiverLights area at full build out of the
community, if a reuse system were to be developed. However, the document did
not recommend reuse for several reasons, including the capital cost of a reuse
system and the need for CFPUA to prioritize capital expenditures for existing
system maintenance and treatment facility needs that it currently faces.
Assuming that the RiverLights site could be utilized for reuse, 140,000 GPD is
significantly less than the 12 MGD of additional dispersal that CFPUA needs for
expansion of the Southside WWTP to 24 MGD.
• Further, as per your previous direction, we understand that if there are not firm
commitments from reuse customers, reuse cannot be included as part of the
wastewater effluent dispersal solution in the EA.
MCK[M&CREED

Ms. Hannah Headrick
July 25, 2013
Page 5
3. Once the EAA has been amended, please also update the discussion of
alternatives and other sections of the EA, as appropriate.
• Based on the responses above, we do not propose modifications to the EA to
address these comments.
Sincerely,
McKIM & CREED, INC.
ihmAdTta-m
Kelly Ham, PE
/jmf
Enclosures:
Mailing Notation: USPS
cc: Craig Wilson, CFPUA, Tony Boahn, PE, McKim & Creed, Bryan Blake,
PE, McKim & Creed
MCKIM&CREED

243 Noith Front Street
Wilmington, NC 28401
For. 910 251 8282
wvr:•:.mckimcreed.con:
MCKIIM&CREED
July 25, 2013
Mr. Jim McKay
NCDENR
Complex NPDES Permitting Unit
1617 Mail Service Center
Raleigh, NC 27699
ENGINEERS
SURVEYORS
PLANNERS
M&C 5367-0001 (13)
RE: NPDES Permitting Review of Environmental Assessment for Cape Fear
Public Utility Authority's Southside WWTP Expansion and Upgrade to 24 MGD
Dear Mr. McKay:
Thank you for your comments on the above reference project, dated May 10,
2013. This letter addresses your comments on a "comment for comment" basis.
Your comments are in regular text and responses are in italics. We hope that this
information fully addresses your comments and will enable you to provide us
with a letter indicating your concurrence with the EA; however, if you have
questions or require additional information, please do not hesitate to contact me
at 910-343-1048.
1. Please justify the use of an annual growth rate of 4% per year for the entire
20 year planning cycle.
• DMR data shows that the average annual flowrate for the facility has
been declining over the past several years. It was 9.3 MGD in 2005, but
down to 7.96 MGD for 2012 and is projected to be 7.9 MGD for 2013,
which represents approximately 66% of the currently permitted flow of
12 MGD.
o CFPUA's 2007 Wastewater Master Plan indicated Southside WWTP
was operating near 80% of its 12 MGD capacity (2006 data); and
recommended improvements to the Northeast Interceptor (NEI) and
Pump Station 77 to direct wastewater flows from these areas away from
Southside WWTP to Northside WWTP. Currently Pump Station 77,
which has a permitted capacity of 1.2 MGD, but is conveying
approximately 529,000 MGD ADF (according to recent flow
monitoring data) has been directed to Northside WWTP. This has
resulted in reduced ADF at the Southside WWTP. The Wastewater
S:\5367\0001\10•Comm\13-Comm W Regulatory Bodies\072513 NPDES Comment Response - SSWWTP Agency
Review.DocS:\5367\0001\10•Comm\I3-Comm w Regulatory Bodies\072513 NPDES Comment Response - SSWWTP Agency Review.doc

Mr. Jim McKay
July 25, 2013
Page 2
Master Plan recommends utilizing the NEI infrastructure in the future
to direct flows of 2 MGD away from Northside WWTP back to
Southside WWTP in order to manage flows between the two plants.
Additionally, CFPUA has experienced lower water consumption system
wide, thought to be Iargely due to the recent economic downturn.
However, it is anticipated that growth and subsequent wastewater flows
will recover in the future. Therefore it is recommended that planning
for wastewater flows associated with re -recession owth are mo e
approprta e rather than ows that were tem oraril decreased by the
economic downturn.
• Data from the OSBM website predicts a growth rate for all New Hanover
County, over the years 2000 to 2033 time frame, to be about 1.5% per year.
o The OSBM website also shows New Hanover County as the 12th fastest
growing county in NC with a e of 3.6% from April 2010 to
2012 thus indicating a level of rebound growth from the economic
downturn of 2007- 2009. The OSBM website maps growth in New
Hanover County in the category of fastest in the state. During this
period (2010 — 2012), the majority of the nation has faced slowed
growth as a result of the economic downturn. However, growth in the
county has still remained strong in the face of this downturn. Growth
from 2000 to 2010 was 26.42%, according to US Census data. This
growth was also likely affected by the economic situation. According to
City and County planning department staff, growth in New Hanover
County has historically been 2 to 4%. New Hanover County continues
to be an attractive place to live and work and growth is expected to
continue into the future and wastewater facilities must be planned to
accommodate this growth. Projecting 20 year wastewater flows using
growth rates that are depressed by recent economic conditions would
result in undersized wastewater facilities and associated potential
environmental impacts, which is not a desirable outcome. See response
to next comment.
• Similar data from the Development Services Department Planning
Division of Wilmington in March 2007 projected the population growth
of City of Wilmington out to the year 2020, using annual growth rates of
0.5%, 1.0% and 1.5% representing slow, moderate or rapid growth.
MCKIM&CREED

Mr. Jim McKay
July 25, 2013
Page 3
o City of Wilmington and New Hanover County Staff provided annual
Irowth rates tase in the 2007 Wastewater Master PIan. (See enclosed
growth rate information). These growth rates were also used in the
1 ` Master Plan,dated 2010. The
CFPUA's Integrated Water Resources
.5i0v*
1 R growth rates were 2% to over 4%, with the majority of the County
having a 3-4% growl z rate, with some areas over 4% and some less than
3%. The areas of the County in the Southside WWTP service area
primarily�iad 3 to over 4% growth rates, with just a small pocket of 2-
3% growth rates. These growth rates were recommended by local
planning staff that have greater knowledge of local upcoming projects
and recent and foreseeable future growth than state or other agency
projections (which typically would not have the benefit of such local
knowledge). Using the 4% growth rate is prudent lanning for meeting
the future wastewater nee s o e area.
o Note that this population growth rate is for new population in the
County; however, there are some existing developed areas of the County
that are not currently on public sewer. It is anticipated that capacity
for wastewater flow from some of these areas will also be needed in the
future.
2. Please justify the use a 10% reserve factor air ss the board for
Isik) calculating flow projec ons.
• The Infrastructure Finance Section does allow for a 10% reserve factor,
but only based on industrial waste, which is only about 10% of the
current total flow. The E.A. flow projection also applied a 10% increase
in the 2013 expected flow basis.
o Please note that the funding for this project will be provided solely by the
CFPUA and is not funded bu the Infrastructure Finance Section. Even
prior to the formation of CFPUA, the City of Wilmington and New
Hanover County have planned for a 10% wastewater reserve flow as an
important part of their wastewater planning process for more than a
decade. This 10% reserve was factored as part of the Northside WWTP
upgrade and expansion, which was completed in 2010 and increased
capacity of that facility from 8 MGD to 16 MGD. This reserve factor
provides a factor of safety in the event that actual wastewater flows are
higher than those projected and is prudent planning. A wastewater
treatment facility expansion is a significant capital investment and has a
V
McIQM&CREED

J
(AN
Ceb4 b!,/
coN) ?MIA
!off
i° I° d
Mr. Jim McKay
July 25, 2013
Page 4 VA491/1
4
\44
�j
long planning and construction timeframe; therefore, it is prudent to
plan ahead for a reserve factor and to design most prudent and
economically viable solution.
o However, in order to address your comment, we have reviewed the
Infrastructure Finance Guidance for industrial reserve, which allows
industrial reserve flow of 10% of the flow growth over the planning
period. The average daily wastewater flow projections in the following
table include the 10% industrial reserve flow applied to the Southside
WWTP Service Area Base Demand, but exclude any other reserve flows.
It is also noted that the Southside WWTP is measured based on
"maximum month" flows and Notice of Violations are applicable if the
facilitu exceeds its rated ciw(citi] in ant t liven monthly ctjde.
2013
2018
2023
2028
2033
Southside WWTP Service Area Base Demand (MGD)
7.9
9.6
11.7
142
17.3
2 MGD-Di ersionfrom NSWWTP MGD)
0.0
0.0
0.0
2.0
.0
• , :.. ; a America Area (M i
0.0
0.0
0.0
1.3
Industrial Reserve (MGD)
0.2
0.38
0.56
0.75
0.94
Total Average Daily Flow, Including Industrial Reserve (MGD)
8.1
10.0
12.3
18.3
21.6
Month Flow Pro ections are as lows: I • S
7
o Corre ottdin Max I
sp R I �
2013
2018
2023
2028
2033
Max Month Flow (MGD)
9.4
11.6
14.2
21.2
25.0
3. Please justify the addition of 3.3 MGD to the projected flow in the year
2028. (1.33 MGD from treatment facilities owned by Aqua America, and 2.0
MGD diverted from the Northside WWTP).
• In order to receive credit for taking flow from an existing permitted
facility, there must be a signed agreement -or a Letter of Intent with dates
and • -_ • et • • re a d• , ^ the commitment.
o Aqua America currently holds permits for a total of 1.33 MGD of
tewater treatment (See enci, :_ , ► ' �«
o Pursuant to 15A NCAC 2H.0105(c) (1), the need for this is justified and
demonstrated by CFPUA's responsibility to serve residents of the district
and prudently plan for future potential demands. The regulations do not
L WO WA Mwk elavul
Ave, co ierivw-1 owl, "kJ v..McKIlVI&CREED

Mr. Jim McKay
July 25, 2013
Page 5
specificall refer to or require aformalized agreement to iusti _and
demonstrate the need for capacity. Similarly, the NCDENR accepted 20-
year planning process for wastewater treatment facilities includes a
number of assumptions based on growth, undeveloped areas, and future
planned development. These factors are used to justify and demonstrate
need in the service area for future capacity without formalized
agreements. Further, undeveloped areas may not materialize in the 20-
year period, may develop at a lesser density, or may utilize other
alternatives for wastewater treatment and disposal exclusive of the
CFPUA infrastructure. Similarly, planning for potential capacity needs
utilizes projections and assumptions and incorporation of future flows
from Aqua America facilities should be planned for as well. In the event
that Aqua America is unable to operate its system in the future (e.g.
bankruptcy, ownership change, out of business),the CFPUA will be in
position to accommodate these demands at the Southside facility and
provide environmentally sound wastewater treatment and public sewer
service to customers. Additionally, it should be noted that if Aqua
America demands were directed to the Southside facility, the NPDES
permit currently held by Aqua America would be nullified as it would be
incorporated at the Southside facility. Therefore, the total pollutant load
for the Cape Fear River would not change or increase as a result of such
an event. It is the intent of the CFPUA to acquire the necessary NPDES
permit to accommodate the projected 20-year demands, however,
construction of the facility would be phased based on actual demands.
o The 2 MGD diversion of wastewater flow from Northside WWTP to
Southside WWTP is part of the CFPUA's flow management strategy for
managing flows between the two facilities. The 2007 Wastewater Master
Plan recommended diverting 2 MGD from Northside WWTP to
Southside WWTP after Southside WWTP is expanded in order to delay
the need to upgrade the Northside WWTP, which was recently upgraded
in 2010.
• The Northside WWTP is currently expanding to 16 MGD from the
current 10 MGD permitted flow. Is that not sufficient to handle the
service area projected growth?
McKIM&CREED

•
Mr. Jim McKay
July 25, 2013
Page 6
o The 2007 Wastewater Plan and the 2010 Integrated Water Resources
Master Plan both indicated the need to expand both Northside WWTP
(beyond 16 MGD) and Southside WWTP in the future.
o The CFPUA plans to manage wastewater flows between the WWTPs
using NEI infrastructure that has the potential to convey 2 MGD from
one plant to the other.
o 24 MGD is anticipated to be buildout footprint of Northside WWTP on
current site, with current treatment technology. There are large
unsewered and undeveloped areas within the county, particularly in the
northern portion of the county, which would be served by Northside
WWTP in the future. If all of these areas were to be sewered under an
ultimate build out flow scenario, an additional wastewater treatment
facility would be required, as there would not be capacity (to expand
within existing footprints of the plants, considering current treatment
technologies) at the Northside WWTP and Southside WWTP.
4. Please provide information regarding failing septic tanks in the service
area, as discussed on page-7 of the Alternatives Analysis for case A — No
Action.
• Comments submitted from the 2008 review of the Scoping Document for
this project requested more information on failing septic tanks in the
service area, which has not been provided.
o The 2007 Wastewater Master Plan identified and prioritized 28 areas of
New Hanover County on septic tanks for public sewer. (See enclosed
septic area prioritization map). However, the EA does not currently
provide information regarding specific failing septic tanks in the area
because the CFPUA requested that the EA indicate that the Southside
WWTP will provide capacity for future elimination of septic tanks, but
that specific areas of septic tank elimination had not been finalized and
should thus not be specifically mentioned in the EA. However, since that
time, New Hanover County has pursued Clean Water State Revolving
Fund funding and partnered with CFPUA to begin design of public
sewer for two large areas of septic tank failures, Marquis Hills and
Heritage Park. The Marquis Hills area will be served by the Southside
WWTP. Marquis Hills has 234 failing septic systems, according to
documentation from the County Health Department. Approximately
690 parcels are in the Marquis Hills area, which would equate to an
MCKIMM&CREED

Mr. Jim McKay
July 25, 2013
Page 7
average daily wastewater flow of approximately 0.25 MGD, which is
anticipated to be conveyed to CFPIIA's existing Mott's Creek Pump
Station, which ultimately discharges to Southside WWTP. A separate
Environmental Information Document has been prepared for the
Marquis Hills project and has been approved by Infrastructure Finance
Section.
• The current EA uses failing septic tanks as one justification for the
expansion, but does not provide any information regarding how big a
problem this is. It also states that this project does not include providing
wastewater collection systems for areas currently using septic tanks.
o See response to comment above. Additionally, of the 28 areas noted in the
2007 Wastewater Master Plan, 12 are identified in the Southside WWTP
service area. There are approximately 2,750 lots in these 12 areas, which
would equate to an average daily wastewater demand of approximately
990,000 gallons per day, based on 360 gallons per day per lot. Note that
some of the lots are large tracts that could be subdivided into several
smaller lots in the future if public sewer were available, further
increasing the potential future wastewater demand from these areas.
Sincerely,
McKIM & CREED, INC.
4911A19ja 11‘'71‘. 61. 10 '° 3
Kelly Ham, PE
/jmf
Enclosures: Growth Rate Information, Septic Area Prioritization Map, Aqua
Information
Mailing Notation: USPS
cc: Craig Wilson, CFPUA, Tony Boahn, PE, McKim & Creed, Bryan Blake,
PE, McKim & Creed
v MCKEMM&CREED
V

New Hanover County Planning Department
March 6, 2007
Annual Growth Rate

Keay Ham
Mahn and Creed
243.N. Front S#eet
‘Wilmington, NC 28401
March 13,- 2007. .
—. Dear Ms. Ham:
•
•
Development Services
Planning
305 Chestnut Street
PO Box 1810
Wilmington, NC 28402-1810
910 254-0900
910 341-3264 fax
wimingtonnc.gov.
Oat 71111YNace
•
The City of'Wiln3mgton adopted a omprehhensi!ve Future sand Use Plan -in 2004:: The Alas
outlines preferred developinentpa•t#ergs for t•he emau •ng vacant lan•d in the•y a well as
targeted redeVelopmeii areas.: •- •
At this time, the city is nearly .0% built out Historically, the,•city's build -out rate has been
•betwreen 2% and 4% per year: As we: approach boil eou w anticipate that ths:xate will .
decrease slightlywhile fhe:redevelopment rate.ipereases: We;anticipate mcr'eased densities: along
both the: Cape Fear River and the Intracoastal Waterway, as well,as ih roughout the dt wnto�wti
cea.
Sincerely, .•
•
:Jr* Gra3rheal`, Acting Director.

New Hanover County
Planning Department .
Chris O'Keefe
Planning Director
March 6, 2007
Kelly Ham, EI
McKim & Creed
243 N. Front Street
Wilmington, NC 28401
Dear Kelly:
County Annex Building
230 Government Center Drive, Suite 150
Wilmington, NC 28403
P 910.798.7165
F 910.798.7053
Thank you for the opportunity to speak with you about growth in unincorporated New Hanover
County. This is an interesting time to talk about growth with so many questions about our ability to
provide infrastructure to meet our growth rate. Nevertheless, given our historic growth rate over the past
15 years and the perception that the desire for residential living in proximate to our coastal waters is
insatiable, our growth should remain strong and relatively constant for the foreseeable future.
Some areas of the county are more poised for growth then others. Developers in Northern New
Hanover County anxiously await the completion of the North side Waste Water Treatment Plan so that
they can have a predictable allotment of water and sewer service for proposed projects. Two large
planned development projects, River Road and Blue Clay Farms, promise to bring large mixed use
communities m their respective locations. Higher.density development seems to be clustering near
established commercial nodes like Monkey Junction, Porters Neck, Middle Sound and the Cape Fear
Community College/North Chase area.
The attached map highlights areas which may be considered growth hot -spots. The map assumes the
average growth rate in the County will remain between 2 and 4% annually. Areas where higher growth
rates are projected are indicated as described in the key. If you have more questions or require
additional information please do not hesitate to call. I look forward seeing the completed update of the
Master Plan.
O'Kee
Hanover :Co 1 't ty Planning Director
Encl.

V LCWyrgMAkingbnWY10/4MC_WanrOcgv Wsu0170TA 17 SWFlec_101TWsaE 10/1IA7
Cathay/ Wlndgate
Final Prioritization
Rank
Prioritization
p Lower Priority
= Low Priority
Q Medium Priority
17:3 High Priority
0 Septic System Area
Streets
16.Burton/ Seaviev tz^__
13. Bent Tree/ Fallen Tree
M1 ';/
f
hz
8. Royal Oak/ Hickory Knoll
Appendix A-17
Evaluation of Areas on
Septic Systems for Sewer Service
Final Prioritization
City of Wilmington and
New Hanover County
2007 Wastewater Master Plan Update
1re, .vaa SOCOIw:
McKMM&CREED

— AQUA NPDFS Permits South of Wilmington
Facility,,Name
r : :,
Permit :Number � ��
i
ep
� .U[tmat Permitted Capacity
Beau Rivage
NC0065480
0.5 mgd
The Cape
NC0057703
0.35 mgd
Dolphin Bay
NC0055107
0.08 mgd
Ocean Forest
NC0059978
0.4 mgd
-
Total Permitted Flow
1.33 mgd
In an effort to regionalize operations and minimize discharges to surface waters,
AQUA intends to consolidate its southern service operations at The Cape, taking
Dolphin Bay off-line and making construction of the Ocean Forest treatment
facility unnecessary. Consolidation of these three facilities at The Cape
necessitates an ultimate permitted flow of 0.83 mgd. This Engineering
Alternatives Analysis is intended to support consolidation of wastewater
discharges at The Cape with expansion from 0.26 mgd to 0.83 mgd. NPDES
permits for the subject facilities are provided in Attachments A — C.
4
Stearns & Wheler, PLLC
ot..m.rr 5b.... aye worm
rm
The Cape WWTP Regionalization
Engineering Alternatives Analysis

fit c00,23`11'i
Calculation of Dilution Factor for CFPUA Southside WWTP.
Goal: To evaluate Tetra Tech's modeling work in 2001 report to determine dilution factors
to be used to perform headworks analysis for Wilimgton's Southside WWTP, and for
performing RPAs.
Basis:
From the internal document MIXING ZONES IN NORTH CAROLINA dated July 23, 1999,
(1) Dilution is calculated as: D = (Qw + Q„)/ Q,,,,
where Qw is the maximum permitted wasteflow, and
Q„ is the critical upstream streamflow, generally the summer 7Q10 flow.
From Tetra Tech's report dated May 2001, page 4-11, the minimum dilution for the
Southside WWTP is listed as 33 near the bottom.
The permitted flow for the Southside plant is 12.0 MGD x 1.55 CFS/ MGD = 18.6 CFS.
Entering these values into Equation (1) above gives: 33 = (18.6 + Qu)/ 18.6.
Multiply both sides by 18.6 to get: 613.8 = (18.6 + Qu)
= 613.8 -18.6 = 595.2 CFS. This is the calculated "S7Q10".
(2) IWC = [Qw/ (Qw + Qu)] X 100% = 18.6 / (18.6 + 595.2) X 100% = 3.0%.
Jim McKay
6 27 2012

Gl+u �r digt.thQvi
v0i'i1J''
f K e t-s • F61 -- e. ,�t •MAY Z2092
f
-- INTRODUCTION " a rr � eat "
Ao wit re Poe
1
DENR-WATER QUALITY
POINT SOURCE BRANCH
1.1 Background
The City of Wilmington and New Hanover County are working jointly to evaluate future
wastewater collection system, treatment system, and discharge needs within the region. The
population in this popular coastal area is expected to continue increasing at a relatively rapid rate,
thereby increasing wastewater production from residential, commercial, and industrial sources.
The North Carolina Division of Water Quality (DWQ) through its National Pollution Discharge
Elimination System (NPDES) permitting process must approve new or expanded wastewater
discharges.
Typically, DWQ uses water quality models to evaluate the impacts of new or expanding
discharges, and then sets NPDES permit limits reflecting minimum federal and state guidelines or
more restrictive levels when needed to protect water quality standards in the receiving water.
This is not the case in the lower Cape Fear River basin at this time, however, because DWQ does
not have a water quality model that the Division believes can be used reliably to make wasteload
allocation decisions. instead, DWQ is making NPDES permit decisions based on policy that is
'"-PU A
TA,e..01
Plan (NCDENR,1996
f S0� � � � A.� contained in the Cape Fear River Basinwide Water Quality Management
and 2000 update), which applies limits of 5 mg/1 BODS and 1 mg/l NH3N (ammonia nitrogen) to
new or expanding discharges of oxygen demanding wastewater.
According to the Basin Plan, a segment of the Lower Cape Fear River has been assessed by
DWQ as not supporting its existing and designated uses because of dissolved oxygen standard
violations (Figure 1-1). DWQ has placed this segment on its Clean Water Act -based 303(d) list
that identifies impaired segments and prioritizes them for development of Total Maximum Daily
Loads (TMDLs) based on assessed violations of the North Carolina standard for instream
dissolved oxygen (DO). DWQ has stated publicly that ilintends to develop a water quality model
for the Lower Cape Fear River to establish an appropriate TMDL, which could then be used to
support future wasteload allocation decisions. However, DWQ expects that model development
might take several years because of the complexity of the estuarine system to be simulated and
the relative cost for data collection and model calibration/validation. In the interim, DWQ plans
to use the Basin Plan policy.
The B{OD5 and NH3N limits established for the Basin Plan policy reflect the most stringent
permit requirements applied by DWQ for these parameters. In contrast, the existing NPDES
permit limits for the Wilmington Northside and Southside facilities are 30 mg/1 BOD5 with no
restriction on NH3N. These existing limits were issued long ago and reflect federally mandated
minimum secondary treatment requirements for municipal wastewater. Application of the Basin
Plan policy to expansions at either of Wilmington's existing discharges would therefore involve a
change from the least restrictive limits allowed to the most restrictive limits issued by the State.
The consulting team of McKim & Creed, Hazen & Sawyer, and Tetra Tech Inc. was hired by
the City of Wilmington and New Hanover County to fully evaluate wastewater collection,
treatment, and discharge options. The latter includes consultation on the NPDES permitting
process. The consulting team's preliminary evaluation of the ramifications of the Basin Plan
policy for BODS and NH3N indicated that the cost to the City and County would be high, on the
order of millions of dollars in increased treatment facility cost. Programmatically, the City and
1 ® Tetra Tech, Inc.
1-1

May 2001 Chapter 1
INTRODUCTION
County stand to lose substantial amounts of the existing allocations for BODS and NH3N (for
example, 67 percent and 90 percent respectively for the Northside facility under current
expansion plans). Loss of assimilative capacity allocation is particularly important because any
BOD5 and NH3N loads given up now are potentially irretrievable in the future due to state and
federal anti -backsliding regulations.
Given the potential high cost to the City and County from application of the Basin Plan
policy, the consulting team was directed to examine the environmental benefit associated with the
policy's resulting reductions in BODS and NH3N loading. A three-dimensional, hydrodynamic
water quality model of the lower Cape Fear River estuary was developed by Tetra Tech to meet
this need. This report documents the model basis and it's set-up, calibration, and application to
the lower Cape Fear River.
1.2 Purpose of Modeling Project
The purpose of this project is to construct a numeric model of the hydrodynamic processes
and primary factors affecting dissolved oxygen concentrations in the lower Cape Fear River
estuary. The model is intended to address several objectives including:
• Simulation of the mixing and transport of the City/County existing and proposed future
Northside and Southside facility effluents.
• Simulation of the impact of existing and proposed future Northside and Southside
facility pollutant loads for oxygen -demanding substances.
• Evaluation of multiple sources and cumulative loads of oxygen -demanding substances
to the lower Cape Fear River estuary.
• Analysis of the various processes affecting dissolved oxygen and their relative
contribution to ambient dissolved oxygen deficit levels.
The resulting modeling analyses provide the City/County and DWQ with scientific
information heretofore unavailable for evaluating impacts on dissolved oxygen in the lower Cape
Fear River. Given the model results and corresponding reliability, local and state officials should
be able to use the modeling analyses to provide a scientific and technically -sound basis for
altering the current Basin Plan policy for allocating BOD5 and NH3N. Additionally, the
modeling results can be used to guide further water quality model development to support
DWQ's longer -term goal of establishing a TMDL for the lower basin.
1.3 Scope and Approach for the Modeling Project
The water quality model covers the portion of the Cape Fear River below Lock and Dam No.
1 to the outlet to the Atlantic Ocean, along with the tidally -influenced portion of the Black River
and the Northeast Cape Fear River (Figure 1-2). Tetra Tech selected the Environmental Fluid
Dynamics Code (EFDC) model (Hamrick 1992a; Park et al. 1995) for this application. EFDC is a
public domain surface water modeling system incorporating fully integrated hydrodynamic, water
quality, and sediment -contaminant simulation capabilities. EFDC is very versatile and can be
used for 1, 2, or 3-dimensional simulation of rivers, lakes, estuaries, coastal regions and wetlands.
The water quality component of EFDC is based on water quality kinetic from the Chesapeake
Bay Water Quality model or CE+QUAL-IC (Cerco and Cole, 1993). For this application, Tetra
Tech was tasked to develop a 3-dimensional application of EFDC to help the City/County and
DWQ gain insight as to the advantages and disadvantages of a 3D versus 2D water quality model
1-2 13 Tetra Tech, Inc.

Chapter 1 May 2001
INTRODUCTION
for the lower Cape Fear River. DWQ has proposed a 2-dimensional model for its long-term
approach to develop a TMDL. Some vertical stratification is evident from historical monitoring
data, but less is known about lateral gradients. The EFDC application was intended to provide a
scoping level analysis for evaluating model dimensions. The results of this study indicate that a
minimum two -layer vertical resolution combined with detailed horizontal resolution, including
representation of the navigational channel, reproduce hydrodynamic processes with a high level
of confidence.
Calibration of the EFDC model was achieved using available information, plus data obtained
during two Rhodomine dye release studies performed by the consulting team in late November
and early December 2000. In addition to providing data to support calibration of the
hydrodynamic portion of the model, the dye studies provided a basis for examining near field
mixing and far field transport of the existing effluents. As part of the modeling scope, Tetra Tech
agreed to evaluate potential alternatives to existing outfall structure designs for the Northside and
Southside facilities if modeling indicated that redesign or relocation could enhance mixing in the
receiving waters. Results of these analyses are included in this report.
The level of reliability and uncertainty in model predictions were established through
predefining model performance criteria and including sensitivity and uncertainty components in
the selected model application scenarios. The modeling team initiated its effort by pre -specifying
desired accuracy levels consistent with US EPA technical guidance for estuary waste load
allocation, and proceeded with model calibration and verification to achieve these targets.
Finally, model applications included sensitivity analyses to identify the model parameters and key
assumptions that most influence model predictions. Modeling analysis report conclusions include
recommendations for additional study that could help reduce uncertainty for areas found to be
most important to the future decision -making process.
El Tetra Tech, Inc. 1-3

Chapter 1 May 2001
INTRODUCTION
1 — Introduction 1-1
1.1 Background 1-1
1:2 Purpose of Modeling Project 1-2
1.3 Scope and Approach for the Modeling Project 1-2
Figure 1-1. Segment of the Lower Cape Fear Estuary Listed as Impaired on 303(d) List 1-4
Figure 1-2. Cape Fear Estuary Model Study Area 1-5
STetra Tech, Inc. 1-7

May 2001 Chapter 2
THE LOWER CAPE FEAR RIVER SYSTEM
(Figure 2.2). The human population of the basin is roughly 1.4 million, as of the 1990 Census.
Agriculture is also very prominent in the Cape Fear Basin with numerous confined animal -
feeding operations. Over 50% of North Carolina's swine operations, accounting for roughly 3.8
million swine, by 1998 estimates, are located in the Cape Fear Basin, with the majority of those
located in the three Coastal Plain counties of Bladen, Duplin and Sampson.
2.2 Hydrology and Hydrodynamics
Hydrology of the Cape Fear estuary system is typical of midsize to large estuaries along the
Atlantic Coast, with high flows in the late fall through late spring and low flows in the summer
and early fall. From a hydrodynamic perspective, the Cape Fear is one of the more energetic
estuaries along the east coast with two meter tide ranges and strong tidal current in the
navigational channel of the open estuary and the narrow tidal river channels of the three
tributaries. During the high river flow portion of the year, the combination of energetic tidal
mixing and fresh water flushing of the tributary rivers prevent the accumulation of organic
material in the system. The low summer flows result in salinity intrusion into the Cape Fear and
Northeast Cape Rivers and less flushing of organic material and nutrients from these tributaries
and the Black River tributary of the Cape Fear River. The movement of the fresh water -salt water
interface upstream to the Navassa region of the Cape Fear is likely a component of the low
dissolved oxygen problem in this region, with particulate organic material being trapped in the
area. The low flow summer and early fall conditions in the Cape Fear are frequently perturbed by
tropical storms with high flows due to storm precipitation over the drainage basins persisting for a
few days to a few weeks. These summer storm events are capable of flushing organic material
from black water swamps along the tributaries and moving the fresh water —salt water interface
into the estuary proper below Wilmington.
From a hydrodynamic modeling perspective, the Cape Fear exhibits sufficient three-
dimensional feature to warrant a three-dimensional modeling approach. In the estuary proper, the
combination of a narrow, deep navigation channel bordered by wider shallow areas requires both
horizontal resolution to properly represent the channel and vertical resolution to represent the
predominance of landward transport of saltier water along the channel and seaward transport over
the shallow areas. Although during portions of the year, stratification may not be significant and
a depth average model might be appropriate, depth average models are not capable of
representing circulation associated with wind. For this reason, a minimum two -layer vertical
resolution is desirable. Additionally, the narrow tidal reaches of the three tributary rivers are
bordered by significant black water swamp and tidal marsh areas. These areas can produce large
natural organic material loads into open water regions and two-dimensional horizontal resolution
is essential in representing exchange between the tidal river channel and swamps and marshes.
2.3 Factors Influencing Dissolved Oxygen
Dissolved oxygen dynamics in estuaries are influenced by a combination of natural physical
and biogeochemical processes and human activity. Sinks of dissolved oxygen include oxidation
of naturally produced organic material and organic material in municipal and industrial
discharges as well as nitrification of ammonia in these discharges. Naturally produced organic
material includes algae mortality and metabolic products and organic material from wetlands and
swamps. These materials typically have both dissolved and particulate components, with
dissolved material producing oxygen demand in the water column and the portion of particulate
material settling to the bed producing sediment oxygen demand due to decomposition in the bed.
Likewise, carbonaceous material from municipal and industrial discharges can have both
2-2 11 Tetra Tech, Inc.

Chapter 2 May 2001
THE LOWER CAPE FEAR RIVER SYSTEM
2 — The Lower Cape Fear River System 2-1
2.1 Physical Setting 2-1
2.2 Hydrology and Hydrodynamics 2-2
2.3 Factors Influencing Dissolved Oxygen - 2-2
2.4 Observational Data to Support Modeling 2-3
Figure 2-1. Orientation of Cape Fear River Basin within North Carolina 2-5
Figure 2-2. Primary Geographic Features of the Cape Fear River Basin 2-6
STetra Tech, inc. 2-7

May 2001 Chapter 3
HYDRODYNAMIC AND TRANSPORT MODEL
FIGURE 3-12. MODEL PREDICTED AND OBSERVED SALINITY AT USA COE STATION 1.3 DURING THE SUMMER OF
1993.
35
34
N 32
a
31
co
30
29
1111111111111
— Observed
- Predicted
28 N NN N N N N MM pp pp
- NNNNNNNNNNN N N N N N
Julian Day (1993)
FIGURE 3-13. MODEL PREDICTED AND OBSERVED SALINITY AT USA COE STATION 2.0 DURING
THE SUMMER OF 1993.
35
33
32
6 31
n. •
30
vw 29
28
27
26
Q1
0
1
- Observed
l_
- Predicted
25 NN�..,.��y�,,�,.,.....�..j,.,..,�.. .,.y.u����w,� uuisu�n�crrctifro. wu�usi,.... uuuiiNsII.,...n w�a�+criu
c
N N N N N N N • - N N CO N N N N N N N N N N N N N N N N
Julian Day (1993)
3-16
STetra Tech, Inc.

Chapter 3 May 2001
HYDRODYNAMIC AND TRANSPORT MODEL
3 — Hydrodynamic and Transport Model 3-1
3.1 Model Theory 3-1
3.2 Model Configuration for the Cape Fear System 3-2
3.3 Model Forcing Functions 3-3
3.4 Model Calibration 3-4
3.5 Model Verification 3-6
Figure 3-1. EFDC Horizontal Grid for the Cape Fear River System 3-8
Figure 3-2. Grid in the Vicinity of Wilmington 3-9
Figure 3-3. Swamp Areas Identified on the Basis of Elevation from the NOAA Coastal Relief Data Base
3-10
Figure 3-4. Swamp Areas Identified on the Basis of Hydrographic GIS data from the National
Hydrographic Data Base. 3-11
Figure 3-5. Cape Fear River Flow during 1993. 3-12
Figure 3-6. Black River and Northeast Cape Fear River Flows During 1993 3-12
Figure 3-7. Cape Fear River Flow during 1997 and 1998. 3-13
Figure 3-8. Black River and Northeast Cape Fear River Flows During 1997 and 1998 3-13
Figure 3-9. Daily Average Wind Speed During 1997 and 1998. 3-14 •
Figure 3-11. Model Predicted and Observed Water Surface Elevation at the NOAA Tide Gauge in
Wilmington during a portion of the Summer 1993 calibration period. 3-14
Figure 3-10. Fixed Water Level Recording Stations for 1993 USACOE Study. 3-15
Figure 3-12. Model Predicted and Observed Salinity at USA COE Station 1.3 during the Summer of
1993. 3-16
Figure 3-13. Model Predicted and Observed Salinity at USA COE Station 2.0 during the Summer of
1993. 3-16
Figure 3-14. Model Predicted and Observed Salinity at USA COE Station 3.0 during the Summer of
1993 3-17
Tetra Tech, Inc. 3-35

Chapter 3
May 2001 HYDRODYNAMIC AND TRANSPORT MODEL
Figure 3-15. Model Predicted and Observed Salinity at USA COE Station 3.5 during the Summer of
1993. 3-17
Figure 3-16. Model Predicted and Observed Salinity at USA COE Station 4.0 during the Summer of
1993. 3-18
Figure 3-17. Model Predicted and Observed Salinity at USA COE Station 6.0 during the Summer of
1993. 3-18
Figure 3-18. Model Predicted and Observed Salinity at USA COE Station 7.0 during the Summer of
1993. 3-19
Figure 3-19. Model Predicted and Observed Salinity at USA COE Station 8.0 during the Summer of
1993. 3-20
Figure 3-20. Model Predicted and Observed Water Surface Elevation at the TT/ATM Diurnal Monitoring
Station during the December 1999 verification 3-20
Figure 3-21. Model Predicted and Observed Salinity at the TT/ATM Diurnal Monitoring Station during
the December 1999 verification. 3-21
Figure 3-22. Model Predicted versus Observed Salinity at the Water Sampling Stations during December
1999 Dye Release from Wilmington Southside STP. 3-21
Figure 3-23. Model Predicted versus Observed Salinity at the Water Sampling Stations during December
1999 Dye Release from Wilmington Northside STP. 3-22
Figure 3-24. Model Predicted and Observed Salinity at the Marker 42 Water Quality Monitoring Station
during 1997. 3-22
Figure 3-25. Model Predicted and Observed Salinity at the Marker 61 Water Quality Monitoring Station
during 1997. 3-23
Figure 3-26. Model Predicted and Observed Salinity at the Navassa Water Quality Monitoring Station
during 1997. 3-23
Figure 3-27. Model Predicted and Observed Salinity at the Marker 42 Water Quality Monitoring Station
during 1998. 3-24
Figure 3-28. Model Predicted and Observed Salinity at the Marker 61 Water Quality Monitoring Station
during 1998. 3-25
Figure 3-29. Model Predicted and Observed Salinity at the Navassa Water Quality Monitoring Station
during 1998. 3-25
3-36 (*Tetra Tech, Inc.

Chapter 3 May 2001
HYDRODYNAMIC AND TRANSPORT MODEL
Table 3-1. Error Measure for Tidal Calibration to the NOAA Station at Wilmington. (note B.#s in the first
column refer to equation numbers in Appendix B) 3-26
Table 3-2. Comparison of Observed and Model Predicted Tidal Harmonic Constituents. 3-26
Table 3-2. (Continued) Comparison of Observed and Model Predicted Tidal Harmonic Constituents. 3-27
Table 3-3. Relative Errors Between Observed and Model Predicted Tidal Harmonic Constituents. (see
Appendix B, equations B.15 and B.16 for discussion of the error measures in the last two columns)3-
28
Table 3-3. (Continued) Relative Errors Between Observed and Model Predicted Tidal Harmonic
Constituents. (see Appendix B, equations B.15 and B.16 for discussion of the error measures in the
last two columns) 3-29
Table 3-4. Salinity Calibration using 1993 US Army COE Data. (note B.#'s in the first column 3-30
Table 3-5. Comparison of Water Surface Elevation Time Series Error Measures for December 1999 with
those for the 1993 Calibration. (note B.#'s in the first column refer to equation numbers in Appendix
B) 3-30
Table 3-6. Error Measures for Salinity Verification at the TT/ATM DMS during December 1999. (note
B.#'s in the first column refer to equation numbers in Appendix B) 3-31
Table 3-7. Error Measures for Salinity Sampling during December 1999 Dye Releases. (note B.#'s in the
first column refer to equation numbers in Appendix B) 3-31
Table 3-8. Error Measures for Salinity Samples Collected during 1997 Water Quality Monitoring. (note
B.# in the column headings refer to equation numbers in Appendix B) 3-32
Table 3-9. Error Measures for Salinity Samples Collected during 1998 Water Quality Monitoring. (note
B.# in the column headings refer to equation numbers in Appendix B) 3-33
OTetra Tech, Inc. 3-37

May 2001 Chapter 4
DISCHARGE DILUTION ANALYSIS
FIGURE 4-1. NEARFIELD NORTHSIDE EFFLUENT DILUTION, BASED ON JET -PLUME ANALYSIS APPROACH.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour
FIGURE 4-2. NEARFIELD SOUTHSIDE EFFLUENT DILUTION, BASED SIMPLE ANALYSIS APPROACH.
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour
4-4
STetra Tech, Inc.

Chapter 4 May 2001
DISCHARGE DILUTION ANALYSIS
TABLE 4-1. SUMMARY OF NEAR FIELD DILUTION ANALYSIS
Dilution Criteria
Minimum
Northside Plant
Dilution
Maximum
Northside Plant
Dilution
Minimum
Southside Plant
Dilution
Maximum
Southside Plant
Dilution
Near Surface Dilution in Discharge
Cell using Simple Approach
248
613
36
109
Near Bottom Dilution in Discharge
Cell using Simple Approach
241
331•
63
Near Surface Dilution in Discharge
Cell Using Jet -Plume Approach
332
797
Near Bottom Dilution in Discharge
Cell Using Jet -Plume Approach
303
420
-)
Dilution at Maximum Plume Rise
4.5
25.4
____
TABLE 4
IA), n s-4 zO,7 :141r'! J vt
for/M1hZ.412.renetAlo f
1M)010A U dA Zo
- . D..DIL-UFIO
ELECTED LOCATIONS
�,,.�ouJ�l1ld doltartioi
Dilution Criteria and Location.
Minimum
Northside Plant
Dilution
Maximum
Northside Plant
Dilution
Minimum
Southside Plant
Dilution
Maximum
Southside Plant
Dilution
Near Surface Dilution at Navassa
(jet -plume approach)
791
(799)
3103
(3372)
1160
4054
Near Bottom Dilution at Navassa
(jet -plume approach)
300
(325)
448
(500)
391
609
Near Surface Dilution at NCF6
(jet -plume approach)
359
(356)
803
(813)
464
1105
Near Bottom Dilution at NCF6
(jet -plume approach)
357
(356)
799
(809)
464
.
1099
Near Surface Dilution at M61
(jet -plume approach)
301
(307)
375
(374)
327
474
Near Bottom Dilution at M61
(jet -plume approach)
443
(455)
489
(495)
269
291
Near Surface Dilution at M54
364
439
184
355
Near Bottom Dilution at M54
400
493
203
255
Near Surface Dilution at M42
418
650
222
338
Near Bottom Dilution at M42
543
787
274
400
STetra Tech, Inc.
4-11

Chapter 4 May 2001
DISCHARGE DILUTION ANALYSIS
4 — Discharge Dilution Analysis 4-1
4.1 Near Field Dilution 4-1
4.2 Far Field Dilution 4-2
Figure 4-1. Nearfield Northside Effluent Dilution, based on jet -plume analysis approach. 4-4
Figure 4-2. Nearfield Southside Effluent Dilution, based simple analysis approach. 4-4
Figure 4-3. Dilution of Northside Effluent at Navassa 4-5
Figure 4-4. Dilution of Northside Effluent 6 miles up the Northeast Cape Fear River 4-6
Figure 4-5. Dilution of Northside Effluent at Channel Marker 61. 4-7
Figure 4-6. Dilution of Southside Effluent at Channel Marker 61 4-8
Figure 4-7. Dilution of Southside Effluent at Channel Marker 54 4-9
Figure 4-8. Dilution of Southside Effluent at Channel Marker 42 4-10
Table 4-1. Summary of Near Field Dilution Analysis 4-11
Table 4-2. Far Field Dilution at Selected Locations 4-11
STetra Tech, Inc. 4-13

Chapter 5 May 2001
WATER QUALITY MODEL
5 • — Water Quality Model 5-1
5.1 Model Theory 5-1
5.1.1 Model State Variables 5-1
5.1.2 Conservation of Mass Equation 5-3
5.1.3 Algae 5-4
5.1.4 Organic Carbon 5-8
5.1.5 Phosphorus 5-13
5.1.6 Nitrogen 5-18
5.1.7 Silica 5-22
5.1.8 Chemical Oxygen Demand 5-24
5.1.9 Dissolved Oxygen 5-25
5.1.10 Total Active Metal 5-27
5.1.11 Fecal Coliform Bacteria 5-28
5.1.12 Method of Solution 5-28
5.2 Model Configuration 5-29
5.2.1 Selection of State Variables 5-29
5.2.2 Selection of State Kinetic Coefficients 5-32
5.3 Model Loads 5-33
5.4 Water Quality Model Calibration 5-35
5.5 Water Quality Model Verification 5-37
Figure 5-1. Schematic Diagram of EFDC Water Quality Model Structure 5-38
Figure 5-2. Long -Term BOD Test for Wilmington Northside Treatment Plant 5-39
Figure 5-3. Long -Term BOD Test for Wilmington Southside Treatment Plant 5-39
Figure 5-4. Long -Term BOD Test for international Paper 5-40
STetra Tech, Inc. 5-67

May 2001 Chapter 5
WATER QUALITY MODEL
Figure 5-5. 1998 Annual Average of Monthly Actual Pollutant Loads Reported for Significant NPDES
Permitted Discharges within Study Area 5-41
Figure 5-6. Maximum Permitted Pollutant Loads Reported for Significant NPDES Permitted Discharges
within Study Area 5-42
Figure 5-7. Monthly Average BOD5 from Major Point Sources in the Study Area
Figure 5-8. Monthly Average Ammonia from Major Point Sources in the Study Area
Figure 5-9.
Figure 5-10.
Figure 5-11.
Figure 5-12.
Figure 5-13.
Figure 5-14.
Figure 5-15.
Figure 5-16.
Figure 5-17.
Figure 5-18.
Figure 5-19.
Figure 5-20.
Figure 5-21.
Figure 5-22.
Figure 5-23.
Figure 5-24.
Figure 5-25.
Figure 5-26.
Figure 5-27.
Figure 5-28.
Figure 5-29.
5-42
5-43
Monthly Average Total Nitrogen from Major Point Sources in the Study Area. 5-43
Cape Fear River BOD and TOC Loads 5-44
Black River BOD and TOC Loads 5-44
Northeast Cape Fear River BOD and TOC Loads 5-45
Cape Fear River Ammonia and Total Nitrogen Loads 5-45
Black River Ammonia and Total Nitrogen Loads 5-46
Northeast Cape Fear River Ammonia and Total Nitrogen Loads 5-46
NC DWQ and LCFRP Water Quality Monitoring Stations 5-47
Dissolved Oxygen, at Navassa, 1998 Calibration Run 5-48
Dissolved Oxygen at NCF6, 1998 Calibration Run 5-48
Dissolved Oxygen at Marker 61, 1998 Calibration Run 5-49
Dissolved Oxygen at Marker 54, 1998 Calibration Run 5-49
Dissolved Oxygen at Marker 42, 1998 Calibration Run 5-50
Nitrogen at Navassa, 1998 Calibration Run 5-50
Nitrogen at NCF6, 1998 Calibration Run 5-51
Nitrogen at Marker 61, 1998 Calibration Run 5-51
Nitrogen at Marker 54, 1998 Calibration Run 5-52
Nitrogen at Marker 42, 1998 Calibration 5-52
Dissolved Oxygen at Navassa, 1997 Verification Run 5-53
Dissolved Oxygen at NCF6, 1997 Verification Run 5-53
Dissolved Oxygen at Marker 61, 1997 Verification Run 5-54
•
5-68 ®Tetra Tech, Inc.

Chapter 5 May 2401
WATER QUALITY MODEL
Figure 5-30. Dissolved Oxygen at Marker 54, 1997 Verification Run 5-54
Figure 5-31. Dissolved Oxygen at Marker 42, 1997 Verification Run 5-55
Figure 5-32. Nitrogen at Navassa, 1997 Verification Run 5-55
Figure 5-33. Nitrogen at NCF6, 1997 Verification Run 5-56
Figure 5-34. Nitrogen at Marker 61, 1997 Verification Run 5-56
Figure 5-35. Nitrogen at Marker 54, 1997 Verification Run 5-57
Figure 5-36. Nitrogen at Marker 42, 1997 Verification Run 5-57
Legend 5-38
Table 5-1. EFDC model water quality state variables 5-58
Table 5-2. Primary Reaction Rates and Distribution Coefficients 5-58
Table 5-3. Permitted Loads of Oxygen Demanding Pollutants for Major Discharges 5-59
Table 5-4. 1998 Actual Loads of Oxygen Demanding Pollutants for Major Discharges 5-59
Table 5-5. Load Distribution Factors 5-59
Table 5-5. Load Distribution Factors 5-60
Table 5-6. NC DWQ Sediment Oxygen Demand Test Data within EFDC Study Area 5-60
Table 5-7. Error Measures for Dissolved Oxygen, 1998 Calibration 5-61
Table 5-8. Error Measures for Ammonia, 1998 Calibration 5-61
Table 5-9. Error Measures for Nitrate, 1998 Calibration 5-62
Table 5-10. Error Measures for Total Organic Nitrogen, 1998 Calibration 5-62
Table 5-11. Error Measures for Total Nitrogen, 1998 Calibration 5-63 •
Table 5-12. Error Measures for Dissolved Oxygen, 1997 Verification 5-63
Table 5-13. Error Measures for Ammonia, 1997 Verification 5-64
Table 5-14. Error Measures for Nitrate, 1997 Verification 5-64
Table 5-15. Error Measures for Total Organic Nitrogen, 1997 Verification 5-65
Table 5-16. Error Measures for Total Nitrogen, 1997 Verification 5-65
[1] Tetra Tech, Inc. 5-69

6 - WATER QUALITY SCENARIOS AND SENSITIVITY ANALYSIS
6.1 Evaluation of Discharge Scenarios
A series of model applications were run with altered wastewater discharge scenarios to
evaluate the impacts of major point sources on dissolved oxygen levels in the Cape Fear River
Estuary. Time series model output of predicted surface dissolved oxygen (DO) levels at key
water quality monitoring locations within the estuary are presented in Figures 6-1 through 6-5. In
each figure the output from the 1998 final model calibration run is plotted as a baseline condition
(black line) to provide a frame of reference for comparison of the discharge scenarios. Refer to
Table 5-4 for the 1998 pollutant loads associated with the major discharges in the estuary, which
are simulated in the baseline conditions run. The observed surface dissolved oxygen levels at
each station during 1998 as measured by the Lower Cape Fear River Program are also plotted on
each figure (black dots). The figures are arranged in upstream to downstream order (refer to map
in Figure 5-16).
6.1.1 Maximum Permitted Point Source Allocation Scenario
In the first scenario pollutant loads for BOD5 and NH3-N from all major wastewater
discharges within the study area were increased to maximum permitted levels and run in the 1998
simulation year (pink line). The purpose of this model run was to evaluate the impact of the
collective NPDES permitted loads on instream DO in the estuary relative to actual point source
pollutant loads in 1998. The permitted summer discharge limits reflected in this model run are
the same as those presented in Table 5-3. When comparing these two model runs it should be
noted that, during 1998, International Paper (formerly Federal Paperboard) was operating under
Special Order by Consent, which allowed discharge of up to 7000 lbs/day of BOD5. As a
consequence of the order, during periods of 1998, the paper mill discharged in excess of the 5000
lbs/day of BOD5 allowed in their NPDES permit, and the resulting increased TOC loads are
reflected in the 1998 baseline conditions model run. The allocation run reflects the 5000 lbs/day
BOD5 load allowed in the paper mill's permit, so the permitted allocation scenario actually
reflects a decrease in loading from the mill relative to the baseline scenario.
At the Navassa monitoring station (Figure 6-1), the full permitted allocation run resulted in an
average decrease in predicted surface DO of 0.09 mg/1 below baseline conditions and a maximum
decrease of 0.26 mg/1 below baseline conditions during the warm/summer season, defined here as
May — October. The full permitted allocation resulted in a predicted minimum instream surface
DO of 4.38 mg/1 compared to a predicted minimum of 4.60 mg/1 for baseline conditions. Both
minimum values are exclusive of the September 1998 period in which DO conditions in the
estuary were dominated by the effects of Hurricane Bonnie.
At the NCF6 monitoring station, located in the Northeast Cape Fear near General Electric, the
permitted allocation scenario resulted in an average decrease in predicted surface DO of 0.09
mg/1 below baseline levels with a maximum decrease of 0.24 mg/1 (Figure 6-2). The minimum
surface DO levels at this location were 4.82 mg/1 for the permitted allocation scenario and 5.04
mg/1 for baseline conditions, excluding the hurricane period.
At Channel Marker 61 (Figure 6-3), located near downtown Wilmington, the maximum
differences in predicted surface DO levels between baseline and permitted allocation scenarios
Tetra Tech, Inc. 6-1

May 2001 Chapter 6
Water Quality Scenarios and Sensitivity Analysis
occur. At this location the permitted allocation scenario resulted in an average decrease in
predicted surface DO of 0.14 mg/1 below baseline levels with a maximum decrease of 0.28 mg/1.
The predicted minimum surface DO levels at Marker 61 were 4.89 mg/1 for the permitted
allocation scenario and 5.09 mg/1 for baseline conditions, excluding the hurricane period.
Moving downstream to Marker 54 (Figure 6-4) and Marker 42 (Figure 6-5), the impact on
dissolved oxygen levels from collective permitted wasteloads relative to baseline conditions
remains constant while the overall predicted DO profile increases. At Channel Marker 42, located
well downstream of Wilmington, the permitted allocation scenario results in an average decrease
in predicted surface DO of 0.14 mg/1 below baseline levels with a maximum decrease'of 0.24
mg/1. The minimum predicted surface DO levels at Marker 42 were 5.14 mg/1 for the permitted
allocation scenario and 5.37 mg/1 for baseline conditions, again excluding the hurricane period.
6.1.2 Wilmington Discharges Removed
To evaluate the impact of the 1998 actual pollutant loads of oxygen demanding wastes
discharged by Wilmington's wastewater treatment plants, the 1998 baseline conditions scenario
was run with the Wilmington discharges removed. Eliminating the two discharges resulted in
average increases in predicted surface DO levels of 0.03 mg/1 or less above baseline conditions at
all monitoring stations during the warm/summer season (May — October). The maximum
increase in predicted surface DO levels at any given station was 0.07 mg/I, which occurred at
Channel Marker 61 in October. Time series output of predicted surface DO levels from this
scenario are plotted Figures 6-1 through 6-5 as a red line.
6.1.3 No Discharge Scenario
To evaluate the degree to which existing wastewater discharge levels collectively affect the
DO profile within the Cape Fear estuary the 1998 baseline condition model was run with all
wastewater discharges eliminated (green line). Refer to Table 5-4 for a detailed list of the
pollutant loads from major wastewater discharges that are reflected in the 1998 baseline
conditions. At Navassa (Figure 6-1) the elimination of all discharges resulted in an average
increase in predicted surface DO levels of 0.29 mg/1 during the warm/summer season (May —
October) and a maximum increase of 0.54 mg/1 relative to 1998 baseline conditions. At the
NCF6 station (Figure 6-2) in the Northeast Cape Fear the elimination resulted in an average
increase of 0.13 mg/1 and a maximum increase of 0.34 mg/1 relative to baseline conditions.
Moving downstream in the Cape Fear mainstem the elimination of discharges resulted in average
increases in predicted surface DO of 0.18, 0.13, and 0.09 mg/1 at Marker 61 (Figure 6-3), Marker
54 (Figure6-4), and Marker 42 (Figure 6-5), respectively. The maximum increases predicted at
the three stations were 0.37, 0.29, and 0.17 mg/1. The predicted minimum surface DO level for
these five stations occurred at Navassa under both scenarios, where the predicted minimum was
4.60 mg/1 for baseline conditions and 5.03 mg/1 with all discharges eliminated.
6.2 Evaluation of Maximum Permitted Discharge Allocations
A series of model applications were run to evaluate the combined impact of maximum
permitted discharge loads from all major point sources on dissolved oxygen (DO) profiles within
the estuary and specifically to evaluate Wilmington's contribution to the impact of that collective
allocation. Time series model output of predicted surface DO levels at key water quality
monitoring locations within the estuary are presented in Figures 6-6 through 6-10. In each figure
the DO profile from the model run simulating all discharges at maximum permitted pollutant
6-2 S Tetra Tech, Inc.

Chapter 6 May 2001
Water Quality Scenarios and Sensitivity Analysis
loads (described in Section 6.1.1) is plotted as the pink line to provide a frame of reference for
comparison of the allocation scenarios. Refer to Table 5-3 for the maximum permitted pollutant
loads associated with the major discharges in the estuary. The observed surface dissolved oxygen
levels at each station during 1998 as measured by the Lower Cape Fear River Program are also
plotted on each figure (black dots). The figures are arranged in upstream to downstream order
(refer to map in Figure 5-16).
An estimate of the contribution of the maximum permitted pollutant loads from all point
sources to instream dissolved oxygen deficits can be obtained by comparing the dissolved oxygen
profiles generated by simulating all discharges at maximum permitted loads (pink line) to the
profiles generate by simulating the estuary with all wastewater discharges removed (green line).
The daily difference between these two profiles, which is an estimate of the collective point
source contribution to DO deficits in the estuary, is plotted at the bottom of each figure as the
purple line. The average warm/summer season difference in predicted surface DO for these two
scenarios was 0.38 mg/1 at Navassa, 0.22 mg/1 at NCF6, 0.33 mg/1 at Marker 61, 0.27 mg/1 at
Marker 54, and 0.23 mg/1 at Marker 42. At the same stations the maximum differences in
predicted surface DO were 0.66 mg/1, 0.54 mg/1, 0.57 mg/1, 0.50 mg/land 0.38 mg/1. As in
previous scenarios, the collective impact of point sources diminishes as you move downstream
into the open estuary.
To generate a quantified estimate of the impact that could be attributed to the current
permitted pollutant loads from the City of Wilmington's Northside and Southside wastewater
treatment facilities, the model scenario reflecting all discharges at maximum permitted pollutant
loads was run with the Wilmington discharges removed. The permitted allocation minus
Wilmington is plotted in Figures 6-6 through 6-10 as a blue line. The daily increase in predicted
surface DO levels resulting from the removal of the two discharges is plotted as the red line at the
bottom of each figure. The average warm/summer season increase in predicted surface DO was
0.05 mg/1 at Navassa, 0.07 mg/1 at NCF6, 0.10 mg/1 at Marker 61, 0.10 mg/1 at Marker 54, and
0.08 mg/1 at Marker 42. At the same stations the maximum increases in predicted surface DO
resulting from removal of the two discharges were 0.15 mg/1, 0.16 mg/1, 0.19 mg/1, 0.18 mg/1 and
0.14 mg/1. The maximum impact of Wilmington's pollutant loads is predicted to occur at
Channel Marker 61, and diminish at stations proceeding upstream or downstream from that
location.
Examining the red line relative to the purple line at the bottom of each figure provides an
indication of Wilmington's portion of the point source allocation within the Lower Cape Fear
Estuary. Wilmington's portion of the allocation can also be expressed as the predicted surface
DO increase generated by removing the City's two discharges as a percentage of the predicted
DO increase resulting from the elimination of all discharges, relative to the maximum permitted
pollutant loading scenario. In upstream to downstream order, the average percentage of predicted
daily increase in surface DO that could be attributed to Wilmington's discharges was 9% at
Navassa, 26% at NCF6, 25% at Marker 61, 33% at Marker 54, and 33% at Marker 42. Note that
the average daily percentage calculation was based only on days in which elimination of all
discharges was predicted to result in a difference greater than 0.0 mg/I in predicted surface DO
levels.
6.3 Model Sensitivity to Changes in Sediment Oxygen Demand
To evaluate the sensitivity of the Cape Fear EFDC model to fluctuations in sediment oxygen
demand (SOD), the model was run with the SOD rate from baseline conditions, 1.0 gr/m/day,
STetra Tech, Inc. 6-3

•
Chapter 6 May 2001
Water Quality Scenarios and Sensitivity Analysis
6 — Water Quality Scenarios and Sensitivity Analysis 6-1
6.1 Evaluation of Discharge Scenarios 6-1
6.1.1 Maximum Permitted Point Source Allocation Scenario 6-1
6.1.2 Wilmington Discharges Removed 6-2
6.1.3 No Discharge Scenario 6-2
6.2 Evaluation of Maximum Permitted Discharge Allocations 6-2
6.3 Model Sensitivity to Changes in Sediment Oxygen Demand 6-3
6.4 Model Sensitivity to Changes in Tributary Pollutant Loads 6-4
6.5 Model Sensitivity to Changes in Floodplain Wetland Configuration 6-5
6.6 Conclusions from Water Quality Scenarios and Sensitivity Analyses 6-6
Figure 6-1. Surface DO Time Series for Discharge Scenarios at Navassa 6-7
Figure 6-2. Surface DO Time Series for Discharge Scenarios at NCF6 6-7
Figure 6-3. Surface DO Time Series for Discharge Scenarios at Marker 61 6-8
Figure 6-4. Surface DO Time Series for Discharge Scenarios at Marker 54 6-8
Figure 6-5. Surface DO Time Series for Discharge Scenarios at Marker 42 6-9
Figure 6-6. Surface DO Time Series for Allocation Scenarios at Navassa 6-9
Figure 6-7. Surface DO Time Series for Allocation Scenarios at NCF6 6-10
Figure 6-8. Surface DO Time Series for Allocation Scenarios at Marker 61 6-10
Figure 6-9. Surface DO Time Series for Allocation Scenarios at Marker 54 6-11
Figure 6-10. Surface DO Time Series for Allocation Scenarios at Marker 42 6-11
Figure 6-11. Surface DO Time Series for SOD Sensitivity Analysis at Navassa 6-12
Figure 6-12. Surface DO Time Series for SOD Sensitivity Analysis at NCF6 6-12
Figure 6-13. Surface DO Time Series for SOD Sensitivity Analysis at Marker 61 6-13
Figure 6-14. Surface DO Time Series for SOD Sensitivity Analysis at Marker 54 .6-13
(11 Tetra Tech, Inc. 6-21

May 2001 Chapter 6
Water Quality Scenarios and Sensitivity Analysis
A
Figure 6-15. Surface DO Time Series for SOD Sensitivity Analysis at Marker 42
Figure 6-16.
Figure 6-17.
Figure 6-18.
Figure 6-19.
Figure 6-20.
Figure 6-21.
Figure 6-22.
Figure 6-23.
Figure 6-24.
Figure 6-25.
Figure 6-26.
19
6-14
Surface DO Time Series for Tributary Load Sensitivity Analysis at Navassa 6-14
Surface DO Time Series for Tributary Load Sensitivity Analysis at NCF6 6-15
Surface DO Time Series for Tributary Load Sensitivity Analysis at Marker 61 6-15
Surface DO Time Series for Tributary Load Sensitivity Analysis at Marker 54 6-16
Surface DO Time Series for Tributary Load Sensitivity Analysis at Marker 42 6-16
Surface DO Time Series for Swamp Sensitivity Analysis at Navassa 6-17
Surface DO Time Series for Swamp Sensitivity Analysis at NCF6 6-17
Surface DO Time Series for Swamp Sensitivity Analysis at Marker 61 6-18
Surface DO Time Series for Swamp Sensitivity Analysis at Marker 54 6-18
Surface DO Time Series for Swamp Sensitivity Analysis at Marker 42 6-19
Predicted Relative Impact of Sources of Oxygen Demand in the Estuary (July 19, 1998) . 6-
Figure 6-27. Predicted Impacts of Point Source and Tributary Loads Relative to DO Saturation (July 19,
1998) 6-20
Figure 6-28. Predicted Impacts of SOD and Floodplain Swamps Relative to DO Saturation (July 19,
1998) 6-20
6-22 STetra Tech, Inc.

Environmental Assessment of the Lower
Cape Fear River System, 2015
By
Michael A. Mallin, Matthew R. McIver and James F. Merritt
November 2016
CMS Report No. 16-02
Center for Marine Science
University of North Carolina Wilmington
Wilmington, N.C. 28409
Working the shallows
of the Infra Coastal
Waterway, Wilmington
gal b.,(1
FOi -��
.stream in F
sin.,,X
k'
Plume break of the
Cape Fear River in
the Atlantic Ocean

Table 2.1 Water temperature (°C) 2015 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NC11 AC DP BBT IC NCF6
JAN 7.3 11.1 10.9 11.2 11.1 12.4 12.2 12.7 JAN 6.6 6.7 6.7 7.4 7.2 8.1
FEB 4.0 4.0 4.2 * 4.7 5.1 5.6 6.1 6.4 FEB 6.4 6.3 6.4 6.5 7.1 7.4
MAR 13.6 14.4 14.2 14.4 14.3 13.9 13.4 13.0 MAR 5.5 5.5 5.7 7.0 6.4 7.5
APR 21.1 20.5 20.8 21.2 21.0 20.9 20.2 19.6 APR 13.2 13.5 14.0 14.4 14.2 15.2
MAY 19.3 20.0 20.1 20.1 20.1 21.3 21.0 20.9 MAY 22.1 21.7 21.9 22.2 22.1 21.9
JUN 25.3 25.6 26.8 25.5 26.6 26.7 26.2 26.0 JUN 26.4 26.3 26.1 24.3 25.1 24.7
JUL 28.1 28.9 28.8 29.2 29.0 28.5 28.2 28.2 JUL 28.5 28.3 28.5 28.1 28.5 29.3
AUG 29.1 29.2 30.2 29.3 29.5 29.1 28.6 28.6 AUG 30.5 30.1 28.9 28.4 28.9 28.8
SEP 28.7 29.2 28.7 29.0 28.0 28.1 27.7 27.9 SEP 27.6 27.8 27.3 27.2 27.6 27.5
OCT 19.6 19.9 19.7 20.0 20.2 20.8 21.1 23.3 OCT 18.9 19.1 19.1 19.1 19.4 19.8
NOV 18.5 18.5 18.7 19.3 19.6 20.1 20.7 20.9 NOV 17.7 17.9 18.0 18.1 18.0 19.2
DEC 11.8 12.3 12.1 13.2 13.3 14.0 15.1 15.5 DEC 13.2 13.2 13.4 13.5 13.6 13.3
mean 18.9 19.5 19.6 19.8 19.8 20.1 20.0 20.3 mean 18.1 18.0 18.11 18.0 18.2 18.6
std dev 8.3 8.0 8.2 7.8 7.7 7.4 7.2 7.1 std der 9.1 9.0 8.8 8.3 8.5 8.2
median 19.5 20.0 19,9 20.1 20.2 20.9 20.9 20.9 median 18.3 18.5 18.6 18.6 18.7 19.5
max 29.1 29.2 30.2 29.3 29.5 29.1 28.6 28.6 max 30.5 30.1 28.9 28.4 28.9 29.3
min 4.0 4.0 42 4.7 5.1 5.6 6.1 6.4 min 5.5 5.5 5.7 6.5 6.4 7.4
ANC SAR GS NC403 P13 LRC ROC 6RC LCO GCO SR BRN HAM NCF117 B210 COL SR -WC LVC2 SC -CH
JAN 13.9 13.1 12.1 12.1 12.0 13.0 14.0 JAN 12.6 12.7 12.4 11.8 12.5 12.1 JAN 6.1 5.5 5.7 5.2 7.0 6.9
FEB 8.4 5.4 7.3 6.8 6.0 7.6 6.6 FEB 9.8 9.4 9.8 8.6 9.1 8.5 FEB 5.5 3.4 2.6 2.5 3.2 5.9
MAR 7.7 7.1 6.6 7.1 6.7 8.3 8.7 MAR 7.2 6.4 6.5 6.6 9.3 9.5 MAR 13.1 13.6 15.8 13.9 13.9 15.1
APR 15.3 15.9 15.7 17.0 16.6 17.6 17.8 APR 12.8 13.2 14.1 14.4 15.1 14.8 APR 17.8 18.4 17.8 17.4 17.4 19.1
MAY 20.2 23.3 24.3 25.6 26.4 24.6 25.4 MAY 18.0 18.5 18.9 19.9 18.2 16.4 MAY 22.6 21.4 19.7 21.5 20.5 23.0
JUN 23.1 25.6 24.8 25.7 25.7 25.5 23.2 JUN 23.1 23.6 25.0 24.2 22.1 21.5 JUN 29.9 29.8 26.8 28.2 28.2 30.4
JUL 23.9 24.6 25.9 23.7 25.0 26.1 24.4 JUL 25.0 25.0 25.9 27.2 24.9 25.1 JUL 29.1 28.1 24.8 26.1 29.5
AUG 23.2 23.6 24.6 25.2 25.8 26.1 23.6 AUG 24.3 24.0 24.4 24.5 24.2 23.8 AUG 27.6 25.2 23.8 24.6 28.0
SEP 22.8 22.9 22.5 22.9 23.5 23.2 22.8 SEP 21.9 21.6 22.2 22.1 20.7 20.7 SEP 24.7 23.8 21.7 22.2 25.5
OCT 19.6 19.4 20.5 19.3 20.1 19.3 18.3 OCT 13.7 13.5 13.8 13.0 15.7 14.7 OCT 17.7 13.2 14.7 14.3 19.3
NOV 13.4 11.1 11.8 11.5 10.9 12.3 11.1 NOV 18.2 18.3 18.6 18.2 19.2 18.9 NOV 13.7 18.5 18.6 18.0 15.4
DEC 15.6 15.2 15.8 15.2 14.7 16.5 14.9 DEC 14.6 14.0 14.1 13.5 14.3 14.3 DEC 14.5 13.8 14.6 13.6 15.7
mean 173 173 17.7 17.7 17.8 18.3 17.6 mean 16.8 16.7 17.1 17.0 17.1 16.7 mean 183 17.9 17.2 17.3 15.0 19.5
std dev 5.7 7.0 7.0 7.1 7.7 6.9 6.5 std dev 5.9 6.1 6.3 6.7 5.3 5.4 std dev 8.4 8.4 7.3 7.9 9.1 8.2
median 17.6 17.7 18.2 18.2 18.4 18.5 18.1 median 16.3 16.2 16.4 16.3 17.0 15.6 median 17.8 18.5 18.2 17.7 15.7 19.2
max 23.9 25.6 25.9 25.7 26.4 26.1 25.4 max 25.0 25.0 25.9 27.2 24.9 25.1 max 29.9 29.8 26.8 28.2 28.2 30.4
min 7.7 5.4 6.6 6.8 6.0 7.6 6.6 min 7.2 6.4 6.5 6.6 9.1 8.5 min 5.5 3.4 2.6 2.5 3.2 5.9

Table 2.5 Dissolved Oxygen (mg/l) 2015 at the Lower Cape Fear River Program stations.
NAV HB BRR M61 M54 M35 M23 M18 NCII AC DP BBT IC NCF6
JAN 10.5 8.7 8.9 8.8 8.9 8.9 8.7 8.9 JAN 11.5 11.4 11.3 10.5 10.5 9.8
FEB 12.7 116 12.4 11.9 11.8 11.4 10.8 10.4 FEB 11.9 11.8 11.7 11.2 11.1 10.0
MAR 9.5 8.9 9.0 8.6 9.0 9.3 9.6 9.4 MAR 11.8 11.8 11.7 10.4 11.2 10.4
APR 6.6 6.7 6.9 6.8 7.2 7.5 7.6 7.6 APR 9.6 9.4 9.1 8.1 8.5 7.3
MAY 7.0 6.7 7.0 6.6 6.7 7.4 7.6 7.9 MAY 7.1 6.4 6.0 4.2 5.4 5.0
JUN 4.6 4.6 5.1 4.4 5.8 6.2 6.1 6.5 JUN 6.5 5.9 5.2 4.3 4.6 4.4
JUL 4.3 4.8 5.6 6.5 7.5 7.0 6.2 6.2 JUL 5.8 5.4 4.9 3.9 4.3 4.5
AUG 3.8 3.8 4.5 4.4 5.1 5.5 5.9 6.4 AUG 4.4 4.0 3.7 3.7 3.5 4.0
SEP 4.1 4.5 4.6 5.1 4.8 5.3 5.9 6.0 SEP 5.2 5.0 3.9 3.8 3.9 4.3
OCT 5.5 5.2 5.3 4.7 4.8 5.5 6.3 6.3 OCT 7.4 7.1 6.7 4.2 5.0 3.8
NOV 6.5 6.9 6.2 6.0 6.2 6.6 7.1 7.1 NOV 7.2 6.8 6.6 4.3 5.4 5.0
DEC 8.7 8.5 8.6 7.9 8.1 8.0 8.1 8.0 DEC 9.3 9.1 8.6 6.7 7.6 6.5
mean 7.0 6.8 7.0 6.8 7.2 7.4 7.5 7.6 mean 8.1 7.8 7.5 6.3 6.8 6.3
sld dev 2.8 2.5 2.3 2.2 2.1 1.8 1.6 1.4 std dev 2.6 2.8 3.0 3.0 2.9 2.5
median 6.6 6.7 6.6 6.6 7.0 7.2 7.4 7.4 median 7.3 7.0 6.7 4.3 5.4 5.0
N max 12.7 12.6 12.4 11.9 11.8 11.4 10.8 10.4 max 11.9 11.8 11.7 11.2 11.2 10.4
min 3.8 3.8 4.5 4.4 4.8 5.3 5.9 6.0 min 4.4 4.0 3.7 3.7 3.5 3.8
ANC SAR GS NC403 PB LRC ROC 6RC LCO GCO SR BRN HAM i CF117 B210 COL SRWC LVC2 SC -CH
JAN 6.1 7.5 8.2 7.6 7.5 10.9 8.1 •JAN 9.3 8.3 7.7 7.3 9.7 9.3 JAN 10.1 10.8 9.4 10.9 9.6 9.5
FEB 9.5 11.7 12.4 11.0 10.7 12.2 11.2 FEB 10.1 10.3 8.9 8.3 10.6 10.6 FEB 10.7 12.3 11.5 12.7 12.0 11.0
MAR 8.9 11.0 11.9 10.8 11.5 12.0 10.5 MAR 10.5 10.9 11.0 10.9 10.8 11.0 MAR 8.6 9.1 6.0 8.7 8.6 8.6
APR 7.3 7.3 7.3 1.4 7.5 10.6 8.2 APR 9.0 8.4 8.2 8.0 9.0 9.3 APR 6.6 7.0 5.9 7.7 6.6 7.2
MAY 6.3 5.3 5.8 3.5 7.2 7.2 5.5 MAY 8.0 7.8 6.7 3.6 8.7 7.6 MAY 3.9 4.9 9.2 6.5 5.8 4.5
JUN 4.4 5.7 2.7 1.4 7.8 8.1 6.1 JUN 6.8 6.9 6.1 3.6 7.9 6.6 JUN 3.0 4.1 4.2 5.6 3.6 4.0
JUL 2.6 5.7 0.8 3.3 5.8 6.4 5.5 JUL 6.5 6.1 6.2 3.5 7.6 6.9 JUL 3.7 4.9 5.3 4.8 3.4 4.0
AUG 4.9 5.7 4.9 4.8 5.3 7.5 6.0 AUG 6.5 6.8 6.1 0.5 7.4 6.5 AUG 4.3 4.7 4.2 5.8 4.2
SEP 4.4 6.5 1.8 4.7 6.6 8.7 6.2 SEP 7.1 6.7 6.6 0.5 7.8 6.2 SEP 4.4 5.2 5.4 5.9 4.7
OCT 4.5 6.1 3.0 5.9 5.0 7.5 6.9 OCT 9.0 9.3 8.1 3.4 9.2 8.4 OCT 4.5 8.8 7.2 6.9 5.7
NOV 6.5 8.4 8.5 8.3 8.2 10.2 9.1 NOV 6.2 5.7 5.3 3.9 7.6 7.4 NOV 5.2 5.2 4.9 7.1 5.8
DEC 6.8 7.0 6.9 7.5 6.7 9.6 8.4 DEC 8.5 7.6 6.7 5.7 8.9 8.6 DEC 6.0 7.3 5.8 7.6 6.9
mean 6.0 7.3 6.2 5.9 7.5 9.2 7.6 mean 8.1 7.9 73 4.9 8.8 8.2 mean 5.9 7.0 6.6 7.5 7.1 63
std dev 2.0 2.1 3.8 3.3 2.0 2.0 1.9 std dev 1.5 1.6 1.6 3.2 1.2 1.6 sll dev 2.6 2.7 2.3 2.3 3.2 2.3
median 6.2 6.8 6.4 5.4 7.4 9.2 7.5 median 8.3 7.7 6.7 3.8 8.8 8.0 median 4.9 6.1 5.9 7.0 6.6 5.8
max 9.5 11.7 12.4 11.0 11.5 12.2 11.2 max 10.5 10.9 11.0 10.9 10.8 11.0 max 10.7 12.3 11.5 12.7 12.0 11.0
min 2.6 5.3 0.8 1.4 5.0 6.4 5.5 min 6.2 5.7 5.3 0.5 7.4 6.2 min 3.0 4.1 4.2 4.8 3.4 4.0