NC0023965_Permit (Issuance)_20040922

NPDES DOCUMENT !SCANNING COVER SHEET
NC0023965
Wilmington Northside WWTP
NPDES Permit:
Document Type: (ermitIssuan)ce
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
September 22, 2004
This document is printed on reuse paper - ignore any
content on the re'rerse side

Michael F. Easley, Govemor
State of North Carolina
William G. Ross, Jr., Secretary
Department of Environment and Natural Resources
Alan W. Klimek, PE, Director
Division of Water Quality
September 22, 2004
Mr. Hugh T. Caldwell, P.E.
Director of Public Utilities
City of Wilmington
P.O. Box 1810
Wilmington, North Carolina 28402
Subject: Issuance of NPDES Permit NC0023965
Expansion from 8.0 MGD to 16.0 MGD for the
James A. Loughlin (Northside) WWTP
New Hanover County
Dear Mr. Caldwell:
In response to your request to expand flow at the subject site, the Division of Water Quality (the
Division) hereby issues the subject permit. This permit is issued for the James A. Loughlin (Northside)
WWTP 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 May 9,
1994, or as subsequently amended. The Division offers the following responses to permit draft
comments:
Concerning Total Residual Chlorine (TRC). The Division acknowledges the pending Authorization
to Construct (ATC) for UV disinfection, and also Wilmington's existing chlorination and manual de -
chlorination facilities. Considering that a compliance period for constructing new facilities is typically
18 months, the Division hereby waves the 28 µg/L TRC permit limit for 8.0 MGD-regulated flows in
anticipation of the construction of new facilities. In the interim, Wilmington shall continue to chlorinate
and de -chlorinate its effluent using existing facilities.
Seasonal Limits for BOD5 and Ammonia Nitrogen (NH3 as N). As noted in Wilmington's draft -
permit comments, seasonal limits were not included. This inadvertent error has been corrected for the
final permit. Summer and winter limits have been added to the final permit for flows regulated by
expansion to 16.0 MGD (see permit Section A. 2.)
Concerning Effluent Mixing. The Division has reviewed Permittee submittals and modeling efforts to
evaluate effluent -mixing conditions in the Lower Cape Fear River. To date, these appear insufficiently
detailed to define end -of -pipe dilution. Due to the lack of detail and the permitted discharge increase, the
EPA has voiced concerns about potential future impact. Based on these concerns, the Division has added
Special Condition A.(7.) to this permit.
ATA.
NCDENR
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 [phone] Customer Service
1 800 623-7748

City of Wilmington
James A. Loughlin (Northside) WWTP
Issuance of NPDES Permit NC0023965
Including Expansion from 8.0 to 16.0 MGD
Page 2
Outfall Location. Considering that the pending Authorization to Construct (ATC) addresses parallel
effluent force mains and dual outfalls, this discharge shall be regulated by Special Condition, A. 6, as
quoted here.
"By Authorization to Construct (ATC) for expansion to 16 MGD, the Division of Water
Quality shall approve a new effluent force main and outfall (with diffuser)
approximately parallel to the existing effluent force main. The Permittee shall sample
final treated effluent upstream of any flow split to effluent pump stations or discharge
force mains. The Division of Water Quality acknowledges separate outfalls, however
due to the single sampling regime conducted prior to splitting, and the relative proximity
of the discharge lines and outfalls, the Division shall designate and regulate this
discharge as a single outfall. Should conditions change or problems arise, the Division
may reopen this permit to designate separate outfalls, if needed."
Note: mapped Latitude and Longitude of the discharge outfall to the Cape Fear River reflects the pre -
expansion outfall location.
Concerning Effluent Dissolved Oxygen (DO). The Fact Sheet contains errors describing DO
conditions in the Lower Cape Fear River Estuary, and hereby stands amended for this final permit. Not
withstanding Fact Sheet corrections, the Division remains constant in its permitting approach to mandate
that the City of Wilmington provide Tertiary Treatment Technology for oxygen -consuming wastes.
Meeting a minimum level of 6.0 mg/L effluent DO (for 16 MGD expansion flows) is consistent with this
approach. Therefore, the permit stands as drafted concerning effluent DO.
Copper, Silver, and Zinc — Reasonable Potential Analyses (RPA) Revisited. Wilmington provided
revised databases for copper, silver, and zinc. The Division therefore, has revisited the RPA for these
metals at the permittee's request. Wilmington's RPA evaluates acute impacts appropriate for discharges
under tidal conditions (see Fact Sheet). Results indicate that reasonable potential remains for all three
metals (see Fact Sheet Addendum). Therefore, the permit stands as drafted concerning these metals.
Considering that Wilmington has consistently passed Whole Effluent Toxicity (WET) testing (last 18
calendar quarters), and under the condition that they continue to pass, the Division shall regulate these
"action level" parameters by monitoring only, 2/Monthly -- no permit limits.
Concerning Permit Limits Trading. Any consideration of limits trading must be developed as part of
the implementation of an EPA -approved Total Maximum Daily Load (TMDL).
If any parts, measurement frequencies, or sampling requirements contained in this permit are
unacceptable, you have the right to an adjudicatory hearing upon written request within thirty (30) days
after receiving this letter. Your request must be in the form of a written petition conforming to Chapter
150B of the North Carolina General Statutes, and must be filed with the office of Administrative
Hearings, 6714 Mail Service Center, Raleigh, North Carolina 27699-6714. Unless such a demand is made,
this permit shall be final and binding.

C;,gy of Wilmington
J:.mes A. Loughlin (Northside) WWTP
•
issuance of NPDES Permit NC0023965
Including Expansion from 8.0 to 16.0 MGD
Page 3
This permit is not transferable except after notifying the Division of Water Quality. The Division may
require modification, or revocation and re -issuance of this permit. Please notice that this permit does not
affect your legal obligation to obtain other permits required by the Division of Water Quality, the Division
of Land Resources, the Coastal Area Management Act, or other federal or local governments.
If you have questions, or if we can be of further service, please contact Joe Corporon at
[Joe.Corporon(a�ncmail.net] or call [phone], extension 597.
Respectfully,
gilg(jA
Alan W. Klimek, P.E.
cc: Central Files
Wilmington Regional Office / Water Quality Section
NPDES Unit t
EPA Region 4
Pretreatment Unit
Aquatic Toxicology Unit

Permit NC0023965
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
(NPDES)
In compliance with the provisions 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
City of Wilmington
is hereby authorized to discharge wastewater from a facility located at the
James A Loughlin (Northside) Wastewater Treatment Plant
2311 North 23`d Street, 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 shall become effective November 1, 2004.
This permit and authorization to discharge shall expire at midnight on December 31, 2006.
Signed this day September 22, 2004.
o.e)4
Alan W. Klimek, P.E., Director
Division of Water Quality
By Authority of the Environmental Management Commission

Permit NC0023y6ee '
SUPPLEMENT TO PERMIT COVER SHEET
The exclusive authority to operate and discharge from this facility arises under the permit conditions,
requirements, terms, and provisions described herein. All previous NPDES Permits issued to this
facility, whether for operating or discharging are hereby revoked, and as of this issuance, any previously
issued permit bearing this number is no longer effective.
The City of Wilmington is hereby authorized to:
1. continue to operate the existing 8.0 MGD WWTP consisting of
• mechanical bar screen
• grit removal device
• dual primary clarifiers
• dual trickling filters
• an aeration basin
• dual secondary clarifiers
• effluent pump station
• chlorine disinfection facilities
• manually -controlled de -chlorination facilities
• end -of -pipe effluent diffuser [three each, 11-inch diameter -ID iron pipes diffusing over a 90° radius]
• primary and waste -activated sludge pump stations
• sludge thickening facility
• anaerobic digesters with gas storage
• sludge de-wate ' g facilities
• 3 v�
located at the James A. Loughlin (Northside) Wastewater Treatment Plant, 2311 North 23'd Street,
Wilmington, New Hanover County, and
2. after receiving an Authorization to Construct (ATC) permit from the Division of Water Quality, and
submitting an acceptable Engineer's Certification Form to the Division at completion of
construction, begin operating new facilities sufficient to treat 16.0 MGD of wastewater, and
3. discharge from said treatment facilities through parallel effluent force mains (see Special Condition
A. 6.), at locations specified on the attached map, into the Cape Fear River, a waterbody classified
as SC waters within the Cape Fear River Basin.

11001061111§11110111161lio
-.-
IS .Doivnstreai ample
'17 D1 lotated_+'.2 miles
do%vnstream of the dis
f
!i %!1
IL.
City of Wilmington
James A. Loughlin (Northside) W WTP
Receivine Stream: Cape Fear River
34° 14' 27" N
77° 57' 10" W
SC
Latitude:
Longitude•
Stream Class:
Drainage Basin: Cape Fear River Basin
Sub -Basin: 03-06-17
Permitted Flow: 8.0 MGD
Grid/Quad: K 27 NW / Wilmington, NC
i�akiF� j '�
Sch
r
NPDES Permit No. NC0023965
New Hanover County

Permit NC0023965
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS [8.0 MGD]
During the period beginning on November 1, 2004 and lasting until expansion above 8.0 MGD or permit
expiration [whichever comes sooner], 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
PARAMETERS
EFFLUENT
LIMITATIONS
MONITORING
REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
Locations
Flow
8.0 MGD
Continuous
Recording
I or E
BOD, 5-day, 20° C
30.0 mg/L
45.0 mg/L
Daily
Composite
I and E
Total Suspended Solids
30.0 mg/L
45.0 mg/L
Daily
Composite
I and E
NH3 as N
3/Week
Composite
E
Fecal Coliform (geometric mean)'
200/100 ml
400/100 ml
Daily
Grab
E
Total Residual Chlorine3
Daily
Grab
E
Temperature
Daily
Grab
E
p114
Daily
Grab
E
Dissolved Oxygen
Daily
Grab
E
Total Phosphorus
Monthly
Composite
E
Total Nitrogen
(NO2 -N + NO3 -N + TKN)
Monthly
Composite
E
Total Copper 5
2/Month
Composite
E
Total Cyanide 5
2/Month
Composite
E
Total Silver 5
2/Month
Composite
E
Total Zinc 5
2/Month
Composite
E
Acute Toxicity 6
Quarterly
Composite
E
Total Mercury 7
Variable 8
Grab
U1, U2, D
Dissolved Oxygen 7
Variable 8
Grab
U1, U2, D
Temperature 7
Variable 8
Grab
U1, U2, D
Footnotes:
1. I = influent; E = effluent; U1 = upstream in the NE Cape Fear River at the U.S. Highway 421 crossing; U2 = Upstream at
Muddy Point; D = downstream at the Port Authority.
2. Calculate Fecal Coliform using the geometric mean (see procedure Part IL Section A ,Paragraph 9b)
3. Total Residual Chlorine (TRC) monitoring shall apply only if chlorine is used by the facility.
4. pH shall not fall below 6.8 nor exceed 8.5 standard units.
5. Toxicants: Should the permittee provide valid justification for additional dilution at this flow rate, the Division will
consider revising monitoring requirements based on additional data review.
6. Acute Toxicity — (Ceriodaphnia dubia 24-hour) no significant mortality at 90 %; February, May, August and
November; refer to Special Condition A. (3).
7. Stream Sampling — deferred to the Lower Cape Fear River Program by Memorandum of Agreement (MOA). Should
membership in this association terminate for any reason, the Permittee shall immediately inform the Division of Water
Quality in writing and immediately resume instream monitoring as presented in this permit.
8. Variable Frequency — Stream sample 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.
Units: mg/L = milligrams per liter
MGD = million gallons per day
ml
milliliters
Discharge shall contain no floating solids or foam visible in other than trace amounts.
Annual Priority Pollutant Analysis also applies to this permit [see Special Condition A.(8.)].

Permit NC00296 '
A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS [16.0 MGD]
Beginning with expansion above 8.0 MGD capacity, and lasting until permit expiration, the permittee is authorized to
discharge treated wastewater from parallel discharge lines designated as Outfall 001. Such discharge shall be limited and
monitored by the Permittee as specified below:
AL
S ;
L
•PARAMETERSS; ,d.,
• .t� 04 -
r �1-MontYLy-Ye
-^•r. =iJ iy
y^�
�.�
��- sl
t
"�Average'1
r" + :
1a*-'-r
a d :
Fl��
t
1..
7v
tEy tiVtl�i
- -
�x q
LF"ue y y
. . .
"pyppe
Flow
16.0 MGD
Continuous
Recording
I or E
BOD, 5-day, 20° C
(Apr 1 -- Oct 31)
5.0 mg/L
7.5 mg/L
Daily
Composite
I & E
BOD, 5-day, 20° C
(Nov i— Mar 31)
10.0 mg/L
15.0 mg/L
Daily
Composite
I & E
Total Suspended Solids
30.0 mg/L
45.0 mg/L
Daily
Composite
I & E
NH3 as N (Apr 1 — Oct 31)
1.0 mg/L
3.0 mg/L
Daily
Composite
E
NH3 as N (Nov 1 — Mar 31)
2.0 mg/L
6.0 mg/L
Daily
Composite
E
Fecal Coliform (geometric mean)2
200/100 ml
400/100 ml
Daily
Grab
E
Total Residual Chlorine3
28 µg/L
Daily
Grab
E
Temperature
Daily
Grab
E
pH
> 6.8 and < 8.5 standard units
Daily
Grab
E
Dissolved Oxygen
6.0 mg/L
Daily
Grab
E
Total Phosphorus
Monthly
Composite
E
Total Nitrogen
(NO2 -N + NO3 -N + TKN)
Monthly
Composite
E
Total Copper 4
2/Month
Composite
E
Total Cyanide 4
2/Month
Composite
E
Total Silver 4
2/Month
Composite
E
Total Zinc 4
2/Month
Composite
E
Acute Toxicity 5
Quarterly
Composite
E
Total Mercury 6
Variable 7
Grab
Ul, U2, D
Dissolved Oxygen 6
Variable 7
Grab
U1, U2, D
Temperature 6
Variable 7
Grab
U1, U2, D
Footnotes:
1. I = influent; E = effluent; U1 = upstream in the NE Cape Fear River at the U.S. Highway 421 crossing; U2 = Upstream at
Muddy Point; D = downstream at the Port Authority.
2. Calculate Fecal Coliform using the geometric mean (see procedure Part II. Section A ,Paragraph 9b)
3. Total Residual Chlorine (TRC) monitoring shall apply only if chlorine is used by the facility.
4. Toxicants: Should the permittee provide valid justification for additional dilution at this flow rate, the Division will
consider revising monitoring requirements based on additional data review.
5. Acute Toxicity — (Ceriodaphnia dubia 24-hour) no significant mortality at 90 %; February, May, August and
November; refer to Special Condition A. (3).
6. Stream Sampling — deferred to the Lower Cape Fear River Program by Memorandum of Agreement (MOA). Should
membership in this association terminate for any reason, the Permittee shall immediately inform the Division of Water
Quality in writing and immediately resume instream monitoring as presented in this permit.
7. Variable Frequency — Stream sample 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.
Units: mg/L = milligrams per liter µg/L = micrograms per liter
MGD = million gallons per day ml = milliliters
Discharge shall contain no floating solids or foam visible in other than trace amounts.
Annual Priority Pollutant Analysis also applies to this permit [see Special Condition A. (8.)].

Permit NC0023965
EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
SPECIAL CONDITION
A. (3.) ACUTE TOXICITY PASS/FAIL PERMIT LIMIT (Quarterly)
The permittee shall conduct acute toxicity tests on a quarterly basis using protocols defined in the North Carolina Procedure
Document entitled "Pass/Fail Methodology For Determining Acute Toxicity In A Single Effluent Concentration" (Revised
July, 1992 or subsequent versions). The monitoring shall be performed as a Ceriodaphnia dubia 24-hour static test. The
effluent concentration at which there may be at no time significant acute mortality is 90% (defined as treatment two in the
procedure document). Effluent samples for self -monitoring purposes must be obtained during representative effluent
discharge below all waste treatment. The tests will be performed during the months of February, May, August and
November.
All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge Monitoring Form
(MR-1) for the month in which it was performed, using the parameter code TGE3B. Additionally, DWQ Form AT-2
(original) is to be sent to the following address:
Attention:
North Carolina Division of Water Quality
Environmental Sciences Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Test data shall be complete and accurate and include all supporting chemical/physical measurements performed in association
with the toxicity tests, as well as all dose/response data. 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 Environmental Sciences Branch at the address cited above.
Should any single quarterly monitoring indicate a failure to meet specified limits, then monthly monitoring will begin
immediately until such time that a single test is passed. Upon passing, this monthly test requirement will revert to quarterly in
the months specified above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required, then monthly monitoring will
begin immediately until such time that a single test is passed. Upon passing, this monthly test requirement will revert to
quarterly in the months specified above.
Should any test data from either these monitoring requirements or tests performed by the North Carolina Division
of Water Quality 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 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.

Permit NC002396ia
EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
SPECIAL CONDITION
A. (4.) HISTORICAL PERMIT LIMITS
The Division recognizes that prior to issuance of this permit, the City of Wilmington James A. Loughlin
Wastewater Treatment Plant was permitted to discharge with secondary limits of 30 mg/L of BOD5, 30 mg/L of
TSS, and no limit for NH3 as N. At the previously permitted flow of 8.0 MGD, these limits translate
approximately to mass loads of 365 tons per year (tpy), BOD5, 365 tpy of TSS, and 244 tpy of 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 James A. Loughlin WWTP.
A. (5.) 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:
1) circumstances predicating the issuance of this permit have materially and substantially changed;
2) there are material and substantial changes to the facility;
3) new information comes available (such as the determination of a TMDL); or
4) new regulations become promulgated,
provided that the Division deems such modification appropriate and consistent with applicable laws and
regulations.
If the permittee assembles information relevant to the above criteria, including but not limited to, information
based on calibrated modeling or similar reliable studies of the Cape Fear River Basin, the Permittee may submit
this information in support of a request to modify this permit (pursuant to 40CFR 122.62 and 122.44). The
Division will review this modification request and provide written determinations, including appropriate
justification of its decisions (40CFR 124.5). Finally, the Division will make every reasonable effort to review and
respond to this request without undue delay.
A. (6.) STIPULATION OF PARALLEL FORCE MAINS
By Authorization to Construct (ATC) for expansion to 16 MGD, the Division of Water Quality shall approve a
new effluent force main and outfall (with diffuser) approximately parallel to the existing effluent force main. The
Permittee shall sample final treated effluent upstream of any flow split to effluent pump stations or discharge
force mains. The Division of Water Quality acknowledges separate outfalls, however due to the single sampling
regime conducted prior to splitting, and the relative proximity of the discharge lines and outfalls, the Division
shall designate and regulate this discharge as a single outfall. Should conditions change or problems arise, the
Division may reopen this permit to designate separate outfalls, if needed.
A. (7.) EFFLUENT MIXING MODEL
Prior to renewing this permit, the City of Wilmington shall submit a CORMIX Model (or equivalent) providing
additional information regarding end -of -pipe dilution. 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.

DENR / DWQ / NPDES Unit
FACT SHEET ADDENDUM
FOR NPDES PERMIT DEVELOPMENT AND EXPANSION TO 16 MGD
Wilmington Northside WWTP -- NPDES Permit NC0023965
Copper, Silver, and Zinc — Reasonable Potential Analyses (RPA) Revisited. At Wilmington's
request, after considering revised databases for copper, silver, and zinc, the Division has revisited the
RPA. Wilmington's RPA evaluates acute impacts appropriate for discharges under tidal conditions (see
Fact Sheet). New results indicate same conclusion -- reasonable potential remains for all three metals (see
Table 1). Therefore, there are no changes from the draft permit. Considering that Wilmington has passed
Whole Effluent Toxicity (WET) testing (last 18 calendar quarters), and under the condition that they
continue to pass, the Division shall continue to regulate these "action level" parameters by monitoring
only, 2/Monthly -- no permit limits.
Table 1.
Northside WWTP — Revisited RPA Review Summary and Renewal Actions
Para peter
Samples
(n)
Hits '
(n):
:Ma 'inuwri
% FAV -
' (Saltwater)
RP--
yin
()fitments /`
Predicted, 1
Renewal Action _ _
Copper
52
50
404.7 µg/L
5.8 µg/L
Yes
Action Level, therefore
no limit. Increased
monitoring to 2/Monthly
Silver
52
2
10.4 µg/L
1.9 µg/L
Yes
Action Level, therefore
no limit. Increased
monitoring to 2/Monthly
Zinc
25
22
268.9 µg/L
95.0 µg/L
Yes
Action Level, therefore
no limit. Added
monitoring 2/Monthly
1. RP = data indicate "reasonable potential" to exceed '/2 FAV (based on revised databases).
Concerning Effluent Dissolved Oxygen (DO). The Fact Sheet contains errors regarding DO
conditions in the Lower Cape Fear River (see Fact Sheet, Verifying Existing Stream Conditions,
Page 2, paragraph 3). This paragraph is hereby corrected to reads as follows:
The Cape Fear River Estuary (5,000 acres) was listed in 1996 as partially supporting
(PS) due to low DO. This same area was listed PS in the year 2000 and added to the
Division's 303(d) list of impaired waters. The Division suspects that impairment
within this subbasin results from the cumulative impacts of WWTP discharges and
non -point sources of pollution including marinas, canal systems, and septic systems.
Swamp water drainages feeding into the estuary may also contribute to low DO.
Not withstanding Fact Sheet corrections, the Division remains constant in its permitting approach to
mandate that the City of Wilmington provide tertiary treatment for oxygen -consuming wastes.
Meeting a minimum level of 6.0 mg/L effluent DO (for 16 MGD expansion flows) is consistent with
this approach. Therefore, the permit stands as drafted concerning effluent DO.

Concerning Total Residual Chlorine (TRC). The Division acknowledges the pending Authorization to
Construct (ATC) for UV disinfection, and also Wilmington's existing chlorination and manual de -
chlorination facilities. Considering that a compliance period for constructing new facilities is typically 18
months, the Division hereby waves the 28 gg/L TRC permit limit for 8.0 MGD-regulated flows in
anticipation of the construction of new facilities. In the interim, Wilmington shall continue to chlorinate
and de -chlorinate its effluent using existing facilities.
Outfall Location. Wilmington proposes to install a force main parallel to the existing effluent
discharge line as the most economically viable facility -upgrade option for this expansion. Approval of
the pending Authorization to Construct (ATC) will result in parallel effluent force mains and dual
outfalls. Therefore the Division shall regulate this discharge by Special Condition, A. 6, as quoted
here.
"By Authorization to Construct (ATC) for expansion to 16 MGD, the Division of
Water Quality shall approve a new effluent force main and outfall (with diffuser)
approximately parallel to the existing effluent force main. The Permittee shall
sample final treated effluent upstream of any flow split to effluent pump stations or
discharge force mains. The Division of Water Quality acknowledges separate
outfalls, however due to the single sampling regime conducted prior to splitting, and
the relative proximity of the discharge lines and outfalls, the Division shall designate
and regulate this discharge as a single outfall. Should conditions change or problems
arise, the Division may reopen this permit to designate separate outfalls, if needed."
Note: mapped Latitude and Longitude of the discharge outfall to the Cape Fear River reflects the pre -
expansion outfall location.
Concerning Effluent Mixing. The Division has reviewed Permittee submittals and modeling efforts
to evaluate effluent -mixing conditions in the Lower Cape Fear River. To date, these appear
insufficiently detailed to define end -of -pipe dilution. Due to the lack of detail and the permitted
discharge increase, the EPA has voiced concerns about potential future impact. Based on these
concerns, the Division has added Special Condition A.(7.) to this permit. This condition states:
"Prior to renewing this permit, the City of Wilmington shall submit a CORMIX Model
(or equivalent) providing additional information regarding end -of -pipe dilution. 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."
NPDES UNIT CONTACT
If you have questions larding an the above information or on the referenced permit, please
contact Joe Corpor jo .corpor. •► - cmail.net] or call [phone] ext. 597.
Ir L
NAME:
DATE: 5( �4_

,
REASONABLE POTENTIAL ANALYSIS
Wilmington Northside
NC0023965
Time Period 0
Qw (MGD) 16
7Q10S (cfs) 0
7Q10W (cfs) 0
30Q2 (cfs) 0
Avg. Stream Flow, QA (cfs) 0
Rechring Stream Cape Fear
WWTP Class IV
/WC (%) @ 7Q10S NIA
@ 7Q10W NIA
@ 30Q2 NIA
@ QA NIA
Stream Class SC
Outfall 001
Qw=16MGD
PARAMETER
TYPE
(1)
STANDARDS &
CRITERIA (2)
PQL
Units
REASONABLE POTENTIAL RESULTS
i RECOMMENDED ACTION
NC WQS/
Chronic
34 FAV/
Acute
n
, pe& Max Prod Cw Allowable Cw
Copper
NC
7
AL
5.8
ug/L
52
50
404.7
Acute: 6
_
_ __ #VALUE!
Chronic:
RP = YES
--------------------------------
Silver
NC
0.06
AL
1.9
ug/L
52
2
10.4
Acute: 2
_ _ _
Chronic: #VALUE!
RP = YES
—----------- ----------------
---
Zinc
NC
50
AL
95
ug/L
25
22
268.9
Acute: 95
Chronic: #VALUEi
RP = YES
--------------------------------
• Legend:
C = Carcinogenic
NC = Non -carcinogenic
A = Aesthetic
Freshwater Discharge
23965 — New Data for Cu Ag Zn — RPA test, rpa
9/10/2004

REASONABLE POTENTIAL ANALYSIS
Copper
Silver
Date
Data
BDL=1/2DL
Results
Date
Data
BDL=1/2DL
Results
1
Jan-2000
8
8.0
Std Dev.
21.5918
1
Jan-2000
<
2
1.0
Std Dev.
0.7044
2
Feb-2000
11
11.0
Mean
10.4038
2
Feb-2000
<
2
1.0
Mean
1.1154
3
Mar-2000
7
7.0
C.V.
2.0754
3
Mar-2000
<
2
1.0
C.V.
0.6316
4
Apr-2000
10
10.0
n
52
4
Apr-2000
<
2
1.0
n
52
5
May-2000
118
118.0
5
May-2000
<
2
1.0
6
Jun-2000
11
11.0
Mult Factor =
3.4300
6
Jun-2000
<
2
1.0
Mult Factor =
1.7400
ug/L
7
Jul-2000
9
9.0
Max. Value
118.0 ug/L
7
Jul-2000
<
2
1.0
Max. Value
6.0 ug/L
ug/L
8
Aug-2000
7
7.0
Max. Pred Cw
404.7 ug/L
8
Aug-2000
<
2
1.0
Max. Pred Cw
10.4 ug/L
9
Sep-2000
6
6.0
9
Sep-2000
<
2
1.0
10
Oct-2000
10
10.0
10
Oct-2000
<
2
1.0
11
Nov-2000
12
12.0
11
Nov-2000
2
2.0
12
Dec-2000
8
8.0
12
Dec-2000
<
2
1.0
13
Jan-2001
10
10.0
13
Jan-2001
<
2
1.0
14
Feb-2001
7
7.0
14
Feb-2001
<
2
1.0
15
Mar-2001
5
5.0
15
Mar-2001
6
6.0
16
Apr-2001
6
6.0
16
Apr-2001
<
2
1.0
17
May-2001
5
5.0
17
May-2001
<
2
1.0
18
Jun-2001
8
8.0
18
Jun-2001
<
2
1.0
19
Jul-2001
7
7.0
19
Jul-2001
<
2
1.0
20
Aug-2001
7
7.0
20
Aug-2001
<
2
1.0
21
Sep-2001
2
1.0
21
Sep-2001
<
2
1.0
22
Oct-2001
5
5.0
22
Oct-2001
<
2
1.0
23
Nov-2001
6
6.0
23
Nov-2001
<
2
1.0
24
Dec-2001
7
7.0
24
Dec-2001
<
2
1.0
25
Jan-2002
9
9.0
25
Jan-2002
<
2
1.0
26
Feb-2002
7
7.0
26
Feb-2002
<
2
1.0
27
Mar-2002
5
5.0
27
Mar-2002
<
2
1.0
28
Apr-2002
5
5.0
28
Apr-2002
<
2
1.0
29
May-2002
5
5.0
29
May-2002
<
2
1.0
30
Jun-2002
4
4.0
30
Jun-2002
<
2
1.0
31
Jul-2002
3
3.0
31
Jul-2002
<
2
1.0
32
Aug-2002
2
1.0
32
Aug-2002
<
2
1.0
33
Sep-2002
3
3.0
33
Sep-2002
<
2
1.0
34
Oct-2002
3
3.0
34
Oct-2002
<
2
1.0
35
Nov-2002
4
4.0
35
Nov-2002
<
2
1.0
36
Dec-2002
4
4.0
36
Dec-2002
<
2
1.0
37
Jan-2003
115
115.0
37
Jan-2003
<
2
1.0
38
Feb-2003
7
7.0
38
Feb-2003
<
2
1.0
39
Mar-2003
5
5.0
39
Mar-2003
<
2
1.0
40
Apr-2003
8
8.0
40
Apr-2003
<
2
1.0
41
May-2003
13
13.0
41
May-2003
<
2
1.0
42
Jun-2003
3
3.0
42
Jun-2003
<
2
1.0
43
Jul-2003
3
3.0
43
Jul-2003
<
2
1.0
44
Aug-2003
5
5.0
44
Aug-2003
<
2
1.0
45
Sep-2003
6
6.0
45
Sep-2003
<
2
1.0
46
Oct-2003
6
6.0
46
Oct-2003
<
2
1.0
47
Nov-2003
3
3.0
47
Nov-2003
<
2
1.0
48
Dec-2003
5
5.0
48
Dec-2003
<
2
1.0
49
Jan-2004
5
5.0
49
Jan-2004
<
2
1.0
50
Feb-2004
5
5.0
50
Feb-2004
<
2
1.0
51
Mar-2004
4
4.0
51
Mar-2004
<
2
1.0
52
Apr-2004
4
4.0
52
Apr-2004
<
2
1.0
53
53
54
54
!
55
55
56
56
57
57
58
58
59
59
60
60
199
199
200
200
23965 -- New Data for Cu Ag Zn -- RPA test, data
- 2 - 9/10/2004

REASONABLE POTENTIAL ANALYSIS
Zinc
Date Data BDL=1/2DL Results
1 Jan-2000 Std Dev. 17.9027
2 Feb-2000 Mean 20.1200
3 Mar-2000 29 29.0 C.V. 0.8898
4 Apr-2000 26 26.0 n 25
5 May-2000
6 Jun-2000 Mult Factor = 2.8300
7 Jul-2000 17 17.0 Max. Value 95.0 uglL
8 Aug-2000 Max. Pred Cw 268.9 ug/L
9 Sep-2000
10 Oct-2000 18 18.0
11 Nov-2000
12 Dec-2000
13 Jan-2001 30 30.0
14 Feb-2001 18 18.0
15 Mar-2001 37 37.0
16 Apr-2001 16 16.0
17 May-2001 13 13.0
18 Jun-2001 20 20.0
19 Jul-2001 17 17.0
20 Aug-2001 95 95.0
21 Sep-2001 5 2.5
22 Oct-2001 10 5.0
23 Nov-2001 33 33.0
24 Dec-2001 14 14.0
25 Jan-2002
26 Feb-2002
27 Mar-2002 15 15.0
28 Apr-2002
29 May-2002 14 14.0
30 Jun-2002
31 Jul-2002
32 Aug-2002
33 Sep-2002 6 6.0
34 Oct-2002 5 2.5
35 Nov-2002
36 Dec-2002
37 Jan-2003
38 Feb-2003 15 15.0
39 Mar-2003
40 Apr-2003
41 May-2003 13 13.0
42 Jun-2003
43 Jul-2003
44 Aug-2003 16 16.0
45 Sep-2003
46 Oct-2003
47 Nov-2003 11 11.0
48 Dec-2003
49 Jan-2004
50 Feb-2004 20 20.0
51 Mar-2004
52 Apr-2004
53
54
55
56
57
58
59
60
199
200
23965 - New Data for Cu Ag Zn - RPA test, data
-3 - 9/10/2004

?*3f-(
Frrrilin- Name =
NPDCS #
Qw(MGD)=
7Q!Os (ifs)=
JWC(%)
Wilmington (Southside) W WTP
NC0023973
12
0
100.00
FINAL. RESULTS
Silver
Max. Pred Cw
Allowable Cw
3.54
1.90
RESULTS
Sid Dee.
Mean
C.v.
Number
of data points
HITS
Molt Factor =
Max. Value
Max. Pred Cw
Allowable Cw
0.0000
2.0
0.0000
28
1.18
3.00 µg/l
3.54 PO
1.90 µg/I
�oWIC
<
Parameter =
Stamina! =
Actual Data
Silver
1.90
BDL=I/2DL
Mar-00 1
Apr-00 2
Aug-00 3 <
Oct-00 4 <
1a11.01
Feb-01
Mar-(11
5
G
7
<
r�
'v
�T 1
3'S ''
,a'k \,
e r' r
\v\pri-
(\i
k.vrr '` ' r)
()
V'S ' 'e•fl
4- dk
IMP ,co,
fp?
Apr-01
May-01
Jun-01
Jul-01
Aug-0I
Sep-0I
Oct-01
Nov-01
Dec-01
8
9
10 <
II <
12 <
13 <
14 <
15
16 <
r-eb-02 17 <
May-02
Aug.02
18 <
19
Dec-02 20 <
Mar-03 21 <
May.03 22 <
Sep-03 23 <
Nov-03 24 <
Mur-04 25 <
Apr.04 26 <
Mar-04 27
Apr-04 28 <
2.0
2-0
2.0
2.0
3.0
2.0
1.0
LO
1.0
1.0
2.0
µBA
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0

ti ,
Facility Name =
NPDES 4 =
Qw (MGD) _
7Q10s (Is).
1WC (%) _
Wilmington (Southside) W WTp
NC0023973
12
0
100.00
FINAL RESULTS
Zinc
Max. Fred Cw
Allowable Cw
Allowable #/day
543.1
86.0
0.0
RESULTS
Std Dev.
Mean
C.V.
Number
of data points
HITS
Mu1t Factor =
Max. Value
Max. Pred Cw
Allowable Cw
27.5953
19.0
1.4491
23
19
3.80
143.0 µg/1
543.1 µg/l
86.0 µg/I
Date
Jam-01
Feb-01
Mar-01
Apr-01
May-01
Jun-0I
Jul-01
Aug-01
Sep-01
Oct-01
Nov-01
Dec-01
Jan-02
Feb-02
Mar-02
Apr-02
May-02
Jun-02
Jul-02
Aug-02
Sep-02
Oct-02
Nov-02
L )
Parameter =
Standard =
Zinc
86.0
n < Actual Data BDL=I/2DL
3
4
5
6
7
8
9 <
10 <
11
12
13
14
15
16
17
18
19
20
21
22 <
23 <
18.0 18.0
15.0 15.0
27.0 27.0
13.0 13.0
10.0 10.0
12.0 12.0
14.0 14.0
143.0 143.0
10.0
10.0
13.0
16.0
18.0
17.0
14.0
20.0
10.0
12.0
14.0
22.0
10.0
10.0
10.0
5.0
5.0
13.0
16.0
18.0
17.0
14.0
20.0
10.0
12.0
14.0
22,0
10.0
5.0
5.0

REASONABLE POTENTIAL ANALYSIS
Wilmington Northside
NC0023965
Time Period 0
Qw (MGD) 8
7010S (cfs) 0
7010W (cfs) 0
3002 (cfs) 0
Avg. Stream Flow, QA (cfs) 0
Rec'ving Stream Cape Fear
WWTP Class IV
!WC (%) @ 7010S N/A
@ 7010W N/A
@ 3002 N/A
@ QA N/A
Stream Class SC
Outfall 001
Qw=8MGD
PARAMETER
TYPE
(t)
STANDARDS &
CRITERIA (2)
POL
Units
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
NCWD5/
Chronic
!4FAV/
Acute
n
#Det.
Max PredCw
AllowableCw
Copper
NC
7
AL
7.3
ug/L
52
50
404.7
Acute:
Chronic:
7
___
kAcute:
RP = YES
____------------ — --- —_ — —
Silver
NC
0.06
AL
1.23
ug/L
52
2
10.4
Chronic:
1
_
#VALUE!
RP = YES
--_---------------------------
-—
Zinc
NC
50
AL
67
ug/L
25
22
268.9
Acute:
_ _ _ _
Chronic:
67
_ _
#VALUE!
RP = YES
— _
'Legend:
C = Carcinogenic
NC = Non -carcinogenic
A = Aesthetic
' Freshwater Discharge
23965 -- New Data for Cu Ag Zn -- RPA, rpa
6/21/2004

REASONABLE POTENTIAL ANALYSIS
Copper
Silver
Date Data BDL=1/2DL Results
1 Jan-2000 8 B.0 Std Dev. 21.5918
2 Feb-2000 11 11.0 Mean 10.4038
3 Mar-2000 7 7.0 C.V. 2.0754
4 Apr-2000 10 10.0 n 52
5 May-2000 118 118.0
6 Jun-2000 11 11.0 Mult Factor = 3.4300
7 Jul-2000 9 9.0 Max. Value 118.0 ug/L
8 Aug-2000 7 7.0 Max. Pred Cw 404.7 ug/L
9 Sep-2000 6 6.0
10 Oct-2000 10 10.0
11 Nov-2000 12 12.0
12 Dec-2000 8 8.0
13 Jan-2001 10 10.0
14 Feb-2001 7 7.0
15 Mar-2001 5 5.0
16 Apr-2001 6 6.0
17 May-2001 5 5.0
18 Jun-2001 8 8.0
19 Jul-2001 7 7.0
20 Aug-2001 7 7.0
21 Sep-2001 < 2 1.0
22 Oct-2001 5 5.0
23 Nov-2001 6 6.0
24 Dec-2001 7 7.0
25 Jan-2002 9 9.0
26 Feb-2002 7 7.0
27 Mar-2002 5 5.0
28 Apr-2002 5 5.0
29 May-2002 5 5.0
30 Jun-2002 4 4.0
31 Jul-2002 3 3.0
32 Aug-2002 < 2 1.0
33 Sep-2002 3 3.0
34 Oct-2002 3 3.0
35 Nov-2002 4 4.0
36 Dec-2002 4 4.0
37 Jan-2003 115 115.0
38 Feb-2003 7 7.0
39 Mar-2003 5 5.0
40 Apr-2003 8 8.0
41 May-2003 13 13.0
42 Jun-2003 3 3.0
43 Jul-2003 3 3.0
44 Aug-2003 5 5.0
45 Sep-2003 6 6.0
46 Oct-2003 6 6.0
47 Nov-2003 3 3.0
48 Dec-2003 5 5.0
49 Jan-2004 5 5.0
50 Feb-2004 5 5.0
51 Mar-2004 4 4.0
52 Apr-2004 4 4.0
53
z
54 '4,-
55
56
57
58.
59
60
199
200 zi
Date Data BDL=1/2DL Results
1 Jan-2000 4 2 1.0 Std Dev. 0.7044
2 Feb-2000 4 2 1.0 Mean 1.1154
3 Mar-2000 <", 2 1.0 C.V. 0.6316
4 Apr-2000 < 2 1.0 n 52
5 May-2000 <' 2 1.0
6 Jun-2000 < 2 1.0 Mult Factor = 1.7400
7 Jul-2000 < 2 1.0 Max. Value 6.0
8 Aug-2000 <. 2 1.0 Max. Pred Cw 10.4
9 Sep-2000 <, 2 1.0
10 Oct-2000 < 2 1.0
11 Nov-2000 2 2.0
12 Dec-2000 < 2 1.0
13 Jan-2001 < 2 1.0
14 Feb-2001 < 2 1.0
15 Mar-2001 6 6.0
16 Apr-2001 < 2 1.0
17 May-2001 < 2 1.0
18 Jun-2001 < 2 1.0
19 Jui-2001 < 2 1.0
20 Aug-2001 <: 2 1.0
21 Sep-2001 <i 2 1.0
22 Oct-2001 <: 2 1.0
23 Nov-2001 < 2 1.0
24 Dec-2001 < 2 1.0
25 Jan-2002 <' 2 1.0
26 Feb-2002 < 2 1.0
27 Mar-2002 <. 2 1.0
28 Apr-2002 <• 2 1.0
29 May-2002 <,;. 2 1.0
30 Jun-2002 <. 2 1.0
31 Jul-2002 < 2 1.0
32 Aug-2002 <: 2 1.0
33 Sep-2002 < 2 1.0
34 Oct-2002 < 2 1.0
35 Nov-2002 <= 2 1.0
36 Dec-2002 <: 2 1.0
37 Jan-2003 < 2 1.0
38 Feb-2003 < 2 1.0
39 Mar-2003 <. 2 1.0
40 Apr-2003 < 2 1.0
41 May-2003 <; 2 1.0
42 Jun-2003 < 2 1.0
43 Jul-2003 < 2 1.0
44 Aug-2003 < 2 1.0
45 Sep-2003 < 2 1.0
46 Oct-2003 < 2 1.0
47 Nov-2003 < 2 1.0
48 Dec-2003 < 2 1.0
49 Jan-2004 < 2 1.0
50 Feb-2004 < 2 1.0
51 Mar-2004 < 2 1.0
52 Apr-2004 < 2 1.0
53
54
55
56
57
58
59
60
199
200
23965 -- New Data for Cu Ag Zn -- RPA, data
- 2 - 6/21/2004

?k 3
REASONABLE POTENTIAL ANALYSIS
Zinc
ug/L
ug/L
Date Data BDL=1/2DL Results
1 Jan-2000 Std Dev 17.9027
2 Feb-2000 Mean 20 1200
3 Mar-2000 29 29.0 C.V. 0.8898
4 Apr-2000 26 26.0 n 25
5 May-2000
6 Jun-2000 Mult Factor = 2.8300
7 Jul-2000 17 17.0 Max. Value 95.0 ug/L
8 Aug-2000 Max. Pred Cw 268.9 ug/L
9 Sep-2000
10 Oct-2000 18 18.0
11 Nov-2000
12 Dec-2000
13 Jan-2001 30 30.0
14 Feb-2001 18 18.0
15 Mar-2001 37 37.0
16 Apr-2001 16 16.0
17 May-2001 13 13.0
18 Jun-2001 20 20.0
19 Jul-2001 17 17.0
20 Aug-2001 95 95.0
21 Sep-2001 < 5 2.5
22 Oct-2001 < 10 5.0
23 Nov-2001 33 33.0
24 Dec-2001 14 14.0
25 Jan-2002
26 Feb-2002
27 Mar-2002 15 15.0
28 Apr-2002
29 May-2002 14 14.0
30 Jun-2002
31 Jul-2002
32 Aug-2002
33 Sep-2002 6 6.0
34 Oct-2002 < 5 2.5
35 Nov-2002
36 Dec-2002
37 Jan•2003
38 Feb-2003 15 15.0
39 Mar-2003
40 Apr-2003
41 May-2003 13 13.0
42 Jun-2003
43 Jul-2003
44 Aug-2003 16 16.0
45 Sep-2003
46 Oct-2003
47 Nov-2003 11 11.0
48 Dec-2003
49 Jan-2004
50 Feb-2004 20 20.0
51 Mar-2004
52 Apr-2004
53
54
55
56
57
58
59
60
199
200
23965 -- New Data for Cu Ag Zn -- RPA, data
- 3 - 6/21/2004

DENR / DWQ / NPDES Unit FACT SHEET
FOR NPDES PERMIT DEVELOPMENT AND EXPANSION TO 16 MGD
NPDES Permit NC0023965
INTRODUCTION
The City of Wilmington (herein called Wilmington or the permittee) requires a National Pollutant
Discharge Elimination System (NPDES) permit to dispose treated wastewater to surface waters of the
state. The permittee's 5-year NPDES permit expired December 31, 2001 and they have requested
permit renewal from the Division of Water Quality (the Division). This Fact Sheet summarizes
background information and rationale used by the Division's NPDES Unit to determine permit limits
and monitoring conditions.
FACILITY RECORDS REVIEW
Facility Description. The James A. Loughlin (Northside) Wastewater Treatment Plant (WWTP) is a
Class IV 8.0 MGD publicly owned treatment works (POTW) utilizing a trickling filter system with
advanced secondary treatment for domestic and industrial wastewater (Table 1). The treatment system
utilizes: a mechanical bar screen; grit removal device; dual primary clarifiers; dual trickling filters; an
aeration basin; effluent pump station; chlorine disinfection facilities; a final end -of -pipe effluent denser 01 :P46 R
(three each, 11-inch diameter -ID black pipes spread in a 90° arch); sludge pump stations; sludge
thickening facility; anaerobic digesters; de -watering facilities; and solids land application. The Permittee
proposes to apply for an Authorization to Construct permit to expand facilities to 16.0 MGD.
Table 1.
Wilmington's James A. Loughlin (Northside) WWTP
Facility Information ,
Applicant/Facility Name
City of Wilmington / James A. Loughlin (Northside) WWTP
Applicant Address
P.O Box 1810 Wilmington , NC 28402
Facility Address
2311 North 23`I Street, Wilmington, NC 28401
Permitted Flow (MGD)
8.0 and 16.0
Type of Waste
Domestic (99%) and Industrial (1%) process wastewater; Primary SIC
Code 4952; WW Code Prim. 01; Treatment Unit Code 40/08- 0 x 3
Related Permits
Sludge: land application WQ0001271 and WQ0011869
Facility Class / Permit Status
Class IV, Major / Renewal
Drainage Basin / County
Cape Fear River Basin / New Hanover County
Miscellaneous
Receiving Stream
Cape Fear River
Regional Office
Wilmington
Stream Classification
SC
State Grid /
USGS Topo Quad
K 27 NW/
Wilmington, NC
303(d) Listed?
No
Permit Writer
Joe R. Corporon
Subbasin
03-06-17
Date:
26Feb02
Drainage Area (sq. mi.)
NA
,. ref nab i
.
Lat. 34° 14' 27" Long. 77° 57' 10"
Summer 7Q10 (cfs)
Tidal'
Winter 7Q10 (cfs)
Tidal
30Q2 (cfs)
Tidal
Average Flow (cfs)
Tidal
IWC (%)
NA
I.%pa11'.,1011 and e n .i) • ` %? ... Y..:il'].` \{ .i)U.'..39(i

Waste Load Allocation (WLA). The Division prepared the last WLA for the receiving stream in
May 1996 and developed effluent limits and monitoring requirements considering discharge under
tidal conditions [in -stream waste concentration (IWC) not readily calculable]. The Division views
these limits and monitoring requirements appropriate for renewal except as discussed below (see
Permitting Approach).
Verifying Existing Stream Conditions. This facility discharges to the Cape Fear River [Stream
Segment 18-(71)], just downstream of its confluence with the NE Cape Fear River. Discharge occurs
in Class SC waters located within Subbasin 03-06-17, Cape Fear River Basin. Cape Fear Estuary
downstream is listed as "partially supporting" and is generally impaired due to seasonally high
concentrations of fecal conform bacteria and seasonally low dissolved oxygen (DO). There is also
an advisory concerning mercury detected in some fish species in the Cape Fear River.
Monitoring data supplied by the Lower Cape Fear River Association (LCFRA) was collected at
sampling stations upstream and downstream from the discharge. Although DO is seasonally low,
levels generally remain above the DO Standard of 5.0 mg/L, typically 11 or 12 mg/L except during
hurricane conditions when DO fell to approximately 1.6 mg/L in September of 1996 (Hurricane Fran)
and September of 1998 (Hurricane Bonnie). In October of 1999 (Hurricane Floyd), the DO low was
measured slightly higher at 2.3 mg/L.
CORRESPONDENCE
Staff Report. Wilmington Regional Office (WiRO) conducted an annual facility inspection and Ed
Beck prepared a Staff Report dated October 25, 2001. WiRO staff found the facility in "very good
condition" and in compliance with the permit. The WiRO recommended that the NPDES Unit renew
the permit.
Division Records and Permittee's Renewal Application. The current permit originally expired on
June 30, 2001 but the Division extended it to December 31, 2001 to stagger the permit renewal
workload by river basin. The Division noted inconsistencies in the 1996 discharge location (Latitude
and Longitude) incorrectly indicating a discharge on Smith Creek, and has corrected these errors for
renewal. A note will be added to the permit cover letter.
The Division received the permittee's renewal request (Standard Form A) on July 6, 2001. However,
due to the additional review required by the Division and EPA to resolve outstanding issues, the
permittee has revised and resubmitted its application (received January 29, 2004) to include a request
to expand this facility from 8.0 MGD to 16.0 MGD. These intended upgrades are relevant to this
renewal (see Permitting Approach).
Concerning Renewal Application Supplements. Wilmington has submitted all required
application supplements including additional Priority Pollutant Analyses (PPA) and second -species
Whole Effluent Toxicity Testing in support of the renewal application. The Division shall forward
these data to EPA for review.
1.;Apon,..w,n -- M I)t:5
1!

COMPLIANCE REVIEW
Discharge Monitoring Reports (DMRs). The Division reviewed up to 52 months of DMR data
(January 1998 through April 2002) depending on the parameter of concern (see Permitting
Approach). Northside's DMRs appear regular, thorough, and complete. Total flow for the time period
January 1999 through December 2001 averaged about 5.77 MGD or about 71 % of permitted
capacity."
Effluent Chlorine. Wilmington's Northside WWTP monitors Total Residual Chlorine (TRC) daily,
but is currently not restricted by a TRC limit. Furthermore, Northside does not de -chlorinate its
effluent. Reported effluent TRC concentrations average less than 700 µg/L over 20 months with
occasional monthly maximums to 2,100 µg/L TRC. In keeping with the Division's policy a TRC
limit will be imposed on this discharge. The Division understands that the permittee intends to install
UV disinfection.
Instream Monitoring Review. Under Memorandum of Agreement (MOA), the Lower Cape Fear
River Association assumed responsibility for instream monitoring, effective July 3, 1996.
Subsequently, the permittee discontinued receiving -stream sampling. A footnote to the permit
specifies that the permittee must resume stream monitoring immediately according to the permit if the
MOA is canceled.
Acute Whole Effluent Toxicity (WET) Test. Quarterly monitoring results for Acute Whole
Effluent Toxicity (WET) testing indicates "pass" for the last 18 quarters (January 1998 through May
2002).
Notices of Violation (NOVs) and Penalty Assessment. Division records for this permit cycle
indicate permit limit violations during January and September of 1999 only. NOVs were issued for
exceeding Weekly Average and Monthly Average fecal coliform limits. No other violations have
been issued.
Pretreatment Compliance. This NPDES permit requires Northside to maintain a Long Term
Monitoring Plan (LTMP) or Pretreatment Program under federal regulations 40CFR 403 and NC
State regulations 15A NCAC 2H.0900. Northside currently services four (4) Significant Industrial
Users (SIUs), Table 2.
Table 2.
Significant Industrial Users (SIUs)
SIU
INDUSTRY
FLOW
(MGD)
COMMENTS
Corning, Inc.
Fiber Optics
0.0605
Continuous; Corning considers
production data proprietary
Textilease, Inc.
Soiled Laundry
0.0569
Continuous; 30,000 pounds/month (?)
Southern Graphic
Systems, Inc
Printing Cylinders
0.00065
Intermittent; 18 cylinders/ month (?)
AAI International
New
No Information as of Application.

•
PERMITTING APPROACH
Dilution under Tidal Conditions. This permit considers discharge to the Cape Fear River estuary, a
receiving stream influenced by wind and ocean tides. Under tidal conditions, stream -flow parameters (7Q10
and 30Q2) are not readily available, therefore previous permits did not include water -quality limited
Weekly Averages. Similarly, past permits have included monitoring only for metals and toxicants, but have
not required limits. The Division assumes that considerable dilution is available to protect against the
chronic impacts of this discharge and notes a positive acute WET Testing history ("pass" for 18 quarters).
However for this renewal, the Division has further evaluated this effluent for the potential acute impacts of
metals and toxicants.
Toxicant Renewal Criteria — Pollutants of Concern (POCs). To establish POCs, the Division reviewed
the permit application, five -and -a -half years of discharge monitoring reports (January 1997 through June
2002), pretreatment data, and the Cape Fear River Basin PIan. The Division employed the standard
Reasonable Potential Analysis (RPA) to calculate acute impacts as a maximum predicted concentration for
each POC. Each maximum was compared to the POC's Final Acute Value (V2 FAV) for saltwater (Table 3).
If by this method, a POC showed reasonable potential to exceed its'/2 FAV, the Division included a permit
limit as a Daily Maximum to protect the receiving stream against potential acute toxic affects. However,
current data do not suggest a need for Daily Maximum limits. Monitoring frequencies were increased to
2/Monthly appropriate for a Class IV facility according to current Division permitting guidance (15A:
02B.0500 and supplements). Additional considerations are addressed below.
Table 3.
Northside WWTP -- RPA Review Summary and Renewal Actions
Parameter
Samples
(n)
Hits
(n)
Maximum
Predicted
Y2 FAY `
(Saltwater) '
- RP r
yin
Comments /
Renewal Action
Cadmium
39
0
1.9 µg/L
42.0 µg/L
No
No change to permit
Chromium
39
3
12.7 µg/L
None available
No
No change to permit
Copper
67
66
280.5 µg/L
5.8 µg/L
Yes
Action Level, therefore no limit.
Increased monitoring to
2/Monthly
Total
Cyanide
67
28
85.2 µg/L
None
available2
No
Additional data suggests
"faults positives"
(see text, Concerning Cyanide).
Lead
39
1
2.7 µg/L
221.0 µg/L
No
No change to permit
Mercury
67
3
0.762 µg/L
1.8 µg/L
No
Discontinued Monthly
monitoring.
Nickel
39
1
9.5 µg/L
75.0 µg/L
No
No change to permit
Silver
63
7
11.84 µg/L
1.9 µg/L
Yes
Action Level, therefore no limit.
Increased monitoring to
2/Monthly
Zinc
38
36
179.8 µg/L
95.0 µg/L
Yes
Action Level, therefore no limit.
Added monitoring 2/Monthly
1. RP = data indicate "reasonable potential" to exceed 1 FAV.
2. Cyanide -- Recommend 1 FAV (CMC) is 1.0 µg/L expressed as free cyanide. Effluent data are expressed as total cyanide.
Total Residual Chlorine (TRC). In keeping with the adoption of a new statewide water quality
Standard for Total Residual Chlorine (TRC), the Division has added TRC limits for this renewal.
±•.

Mercury. Mercury data suggest no reasonable potential to exceed the t/ FAV. Therefore, effluent
monitoring will be discontinued and relegated to the pretreatment program. Furthermore the acute criterion,
1.8 µg/L, is well above the current test -method detection limit of 0.2 µg/L. Therefore, the permittee will not
be required to employ clean -sampling techniques (EPA Method 1631) to document acute impact
compliance. It follows then, that text regarding the future need for Method 1631 has not been added to the
permit cover letter, nor to the effluent conditions page as a footnote, per agreement with the EPA.
Concerning Cyanide. Early data suggested that 20 of 53 samples contained Total Cyanide, however
recent laboratory studies suggest that faulty sample -preparation procedures may have caused "false
positives" (see Wilmington's e-mail to Division dated 10Dec03). Independent of this study, the Division
considers all cyanide detected below 10 µg/L to be zero for permit compliance purposes due to questions
about consistency in the test -method practical quantitation level (PQL). The Permittee has supplied new
data (January 2002 through March 2004) indicating that Total Cyanide was detected only once (19 µg/L)
above the Division's 10 µg/L recommended for permit compliance. Based on these new data, the Division
is less concerned that cyanide may pose an environmental hazard.
The Division therefore has softened its concerns about cyanide expressed in the previous draft permit.
During the previous draft review, the EPA's requested "free available cyanide" data, but the permittee
explained that there is no "free cyanide" wastewater test method currently certified by North Carolina.
Based on the new Total Cyanide data, the Division shall amend the draft Fact Sheet and the draft permit's
Effluent Limitations and Monitoring Requirements page to remove the Free Cyanide monitoring
requirement but continue Total Cyanide monitoring (2/Month per Class IV, no limit). In follows also that
draft Special Condition A. (3.), to conduct an internal study comparing "free available" to "total" cyanide,
is no longer appropriate and has been deleted from the permit.
Concerning BOD5, Dissolved Oxygen (DO), and Ammonia (NH3 as N). Monitoring frequency for
ammonia will increase from Weekly to 3/Week consistent with Class IV facility requirements. This
municipality does not require ammonia limits with the current flow of 8.0 MGD, however ammonia will
require limits of 1.0 mg/L (Monthly Average) and 3.0 mg/L (Weekly Average) at 16.0 MGD. Because DO
remains a parameter of concern in the estuary, (see Cape Fear River Basin Plan), the Permittee will increase
effluent DO monitoring from Weekly to Daily consistent with Class IV facility requirements. In addition
expansion to 16.0 MGD requires an effluent DO limit of 6.0 mg/L. The Division will also require stricter
limits for BOD5 at 16.0 MGD of 5.0 mg/L (Monthly Average) and 7.5 mg/L (Weekly Average).
Monitoring and limits are summarized in Table 4.
Table 4
Effluent Limits Summar
PARAMETER
FLOW C $ MGD
FLOW @ 16.0: MGD
Monthly:
Average.
" Weekly
Average
Monthly
Average
Weekly
Average
Flow
8.0 MGD
16.0 MGD
BOD, 5-day, 20° C
30.0 mg/L
45.0 mg/L
5.0 mg/L
7.5 mg/L
Total Suspended Solids
30.0 mg/L
45.0 mg/L
30.0 mg/L
45.0 mg/L
NH3asN
1.0mg/L
3.0mg/L
Fecal Col i form (geometric mean) 2
200/100 ml
400/100 ml
200/100 ml
400/100 ml
Total Residual Chlorine3
28 µg/L
Temperature
pH4
Dissolved Oxygen
6.0 mg/L
Fact Shcct
t.qvn,,infl and Renewal -- `t't )t-c; (.4)O' sf16i
Page

Concerning WET Testing Alternate Species. The Permittee's proposes to replace the existing
Daphnia Pulex with an alternate species Ceriodaphnia Dubia for acute WET testing. The Division
has no objections and has therefore revised the permit to reflect this substitution [see permit Special
Condition A.(3.)].
Renewal Summary
• Discharge to the Cape Fear River Estuary impaired for fecal coliform and dissolved oxygen.
• Application to Renew: contains required PPA and second -species TOX supplements.
• Expansion above 8.0 MGD requires the permittee to submit a request for an Authorization to
Construct (ATC) permit.
• Permittee must submit a satisfactory Engineer's Certification Form after completing construction and
prior to discharging expanded flow.
• Division Investigations in progress including possible estuary TMDL for DO.
Effluent Monitoring
• Created Phased Permit: 8.0 MGD plus added limits and monitoring page for expansion to 16.0 MGD
• RPA conducted to establish acute impacts only, under tidal conditions.
• TRC added with Daily Maximum limit at 8.0 MGD and 16.0 MGD, per statewide policy.
• Ammonia: Weekly Average limits not required at 8.0 MGD but added for 16.0 MGD flow.
• Mercury Method 1631: not required -- permit limit potentially above previous test method PQL.
Parameter Changes
Ammonia (NH3 as N)
Increased monitoring to 3/Week for Class IV facility
TRC
Added limit (Daily Maximum) per statewide policy
Total Cyanide
Increased monitoring to 2/Month (Class IV, no limit)
Total Mercury
Discontinued effluent monitoring (no RP)
Total Copper
Increased monitoring to 2/Month (Class IV, no limit)
Total Silver
Increased monitoring to 2/Month (Class IV, no limit)
Total Zinc
Added monitoring 2/Month (RP)
Instream Monitoring
Previous Requirements:
Changes:
Total Mercury
Dissolved Oxygen (DO)
Temperature
Monitoring Deferred to the Lower Cape Fear River
Basin Association (July 3,1996 under MOA).
No changes recommended.
PROPOSED SCHEDULE OF ISSUANCE
Draft Permit to Public Notice:
Permit Scheduled to Issue:
April 28, 2004.
June 17, 2004
Fact Slit:.;
rx{,,itr. un and Rcnewal -- \Pt.)LS('()(12 0)(,7,
Page 6

NPDES UNIT CONTACT
If you have questions regarding any of the above information or on the attached permit, please
contact Joe Corporon [[e-mail]] or call [phone] ext. 597.
NAME: JD& cO P9eQ-0f�(
DATE:
REGIONAL OF F I L E COMMENTS
N "fi(-lc.5rT roNS / -& Cl N DE 2. , -t'iT(- &)C-4sL r DrnW&
176 1-(0c1 AD s11Y _ r (R j� 2 ((Lk y 0-7,1 a Su Q 574- rlT( y 6H0-AI&ED,
1 y� t-Ee r-t [T L->s� (< 5 eg9O D ,4- N D N J. (--cc red. 1 �7 do r(
NAME:
IECEHE
MAY - 6 2004
DENR-WATER DUALITY
POINT SOURCE BRANCH
4)a,2,e9
DATE: 17/2 Sir
REGIONAL SUPERVISOR: ��„� ( tz,i _ 4 Ajt, AA Oil DATE: Qom' 0 Ct n
NPDES SUPERVISOR: DATE:
Fact Sheet
Expansion and Renewal -- NPDES NC0023965
Page 7

NPDES PERMIT
DRAFT / FINAL
FILE CONTENTS:
Leaside:
New Tracking Slip.
O Old Tracking Slip.
Right side:
❑ Streamline Package Sheet
Er1,Draft Permit Cover Letter.
azir Draft Permit
Facility Map
a Fact Sheet.
r.,ermit Writer's Notes
/ Staff Report from Region
L: Old Permit
0::
ermit Application.
137/13,
Acknowledgement Letter
ermittee Responses
Waste Load Allocation
Note: Italics indicate special
O Submitted to
CHECK LIST
Facility v h4:-70
MC(1' TN S( (i3 "33.)T
Permit No. JC;.��T �'S
11.FAJc7-,)4A-L (;\tp
NPDES Permit Writer:
(to region, only if strean}li ed)
(add new policy text; sti marine mar changes to permit)
(order: cover, supple ' nt, map, of uent sheets, special conditions)
(E-Map: include fac' ty Outfalls; and D sample locations)
(document permit writer's issues and re -issue logic)
(if not in Facts Sheet -- chronology, strategy, DMR Review, RPA, etc.)
(as appropriate -- not needed if streamlined)
(Text, Effluent Sheets and Special Conditions)
(New Permit or Renewal; any additional permittee correspondence)
(NPDES Unit written response to Renewal Application)
(to acknowledgement letter, if any)
(reference date; notes if recalculated for current action)
conditions rot always required or applicable.
for Peer Review: Date
Meer Review completed by ti
O Public Notice System Update
Er
Permit Mailed �F�Mailed
Date
BIMS Update: Events Limits
(Regional Staff) by - Date __
14,
. Admin cutoff
2$
APR
/Regional Office Review completed by Date
❑ Submitted to for P, blic Notice on : Notice Date 9-6 44
7`14?-7- ('/k t (ev)S \
(!'Additional Review by nix -a --(A) c�*(00 ( 1 ?c 1 initiated by --c Date 4 `_
❑ Additional Review completed by on: Date
FINAL toeMk+S for signature on o�c
DI Additional Review
O Additional Review
ta' Final Files transferred to Server (Permits Folder)
srf
Letter Dated
225f
ap;ra01-
a_6
681
. BIMS Update: Events

i(TVLet
N FINAL to Dave Goodrich for signature on Letter ated
/Additional Review � 6c0 r"`1--`•ik-(y-A.Cr 2-' '
/Additional Review VK� 1( ( 6- t( 5CU S S tAsl PF"-m 1TTEL
NPDES PERMIT
DRAFT / FINAL
FILE CONTENTS:
Lef de:
New Tracking Slip.
16, 0 Old Tracking Slip.
Right side:
—❑/ Streamline Package Sheet
G'/Draft Permit Cover Letter.
Draft Permit
C "Facility Map
I�/Fact Sheet.
I3'/ Permit Writer's Notes
Staff Report from Region
1117.-_,,Old Permit
:. Permit Application.
C>" Acknowledgement Letter
❑ /Permittee Responses
I2' Waste Load Allocation
CHECK LIST
Facility
USt(44( AiG T-Od Iv 5 ( r tbAr P
Permit No. W2`3q 65
NPDES Permit Writer:
(to region, only if str . mlined)
(add new policy t: t; summarize ajor changes to permit)
(order: cover, • pplement, map, ffluent sheets, special conditions)
(E-Map: n de facility; Outfall ; U and D sample locations)
(docu - ' permit writer's issues and re -issue logic)
(if not n Facts Sheet -- chronology, strategy, DMR Review, RPA, etc.)
(as appropriate -- not needed if streamlined)
(Text, Effluent Sheets and Special Conditions)
(New Permit or Renewal; any additional permittee correspondence)
(for Renewal Application, from NPDES Unit)
(to acknowledgement letter, if any)
(reference date; recalculated for current action?)
`Note: Italics indicate
�special
�conditions
-7not always required or applicable.
K Submitted to 1l 4 S4 1 t'-1 ►`� for Peer Review: Date TOLER__. Admin cutoff
Ct3' Peer Review completed by Tr-S\C-$4-- Date
Permit Mailed -Maile to e o uck._ (Regional Staff) by � Date
❑ Regional Office Review completed by(✓t`er
Additional Review by t1J - _ " t 4-1
Date
initiated by
r CeEsOSs
Er/ Additional Review completed by fli t✓
❑Submitted to-w-k�r-"r 7A- ( for Public Notice on
Date
on: Date
: Notice Date
Public Notice System Update 6 ZSL'ar`�� QS Update 2 �� ` = 3t Wit"7
f�G. �I�L'1
a

AFFIDAVIT OF PUBLICATION
STATE OF NORTH CAROLINA
COUNTY OF NEW HANOVER
publi
This
NOTICE OF PUBLIC
MEETING TO BE HELD BY
THE NORTH CAROLINA
ENVIRONMENTAL MAN-
AGEMENT COMMISSION
ON INTENT TO ISSUE
STATE NPDES PERMIT
SUBJECT: A public meet-
ing has been scheduled
conceming the proposed
issuance of State NPDES
Permit for the following
facility:
Permit NC0023965
City of Wilmington's
James A. Loughlin (North -
side) WWTP
PURPOSE: The facility
listed above has applied
to renew their permit to
discharge treated waste-
water to the Cape Fear
River. On the basis of
preliminary staff review
and application of Article
21 of Chapter 143, Gen-
eral Statutes of North
Carolina, and other lawful
standards and regula-
tions, the North Carolina
Environmental Manage-
ment Commission pro-
poses to issue State
NPDES permit subject to
specific pollutant limita-
tions and special condi-
tions. The Director of the
Division of Water Quality
pursuant to NCGS 143-
215. 1(c) (3) and Regula-
tion 15 NCAC 2H, Section
.1000 has determined
that it is in the public in-
terest that a meeting be
held to receive all perti-
nent public comment on
whether to issue, modify,
or deny the permit.
AGENDA:
The meeting will be con-
ducted in the following
manner.
1. Explanation of the NC
Environmental Manage-
ment Commission's Per-
mit Procedure by the Di-
vision of Water Quality;
2. Explanation of the ac-
tion for which the permit
is required by the appli-
cants or their representa-
tive(s):
3. Public Comment -
The public meeting is a
forum for the Division to
obtain water quality in- My commission expires day of
formation that was either
overlooked or unavailable
during the draft permit
preparation period. In-
formationisforpresented in .oregoing affidavit with the advertisement thereto annexed it is adjudged bythe Co
this forum should address $ $
specifically those issues perly made, and that the summons has been dulyand legally served on the defendan
resulting from this facil-
ity's Y $ Y
wastewater dis-
charge and its potential
to impact water quality.
Before entering the
meetinghouse, persons
intending to speak should
indicate this intent to the
JUL 6 2004
Before the undersigned, a Notary Public of Said Count, and . tate,
DENR - WATER QUALITY
DIANE P. KEENAN POINT SOURCE BRANCH
Who, being duly sworn or affirmed, according to the law, says that he'she ja..
lJ
CLASSIFIED ADVERTISING MANAGER
of THE WILMINGTON STAR -NEWS, INC., a corporation organized and doing business under
the Laws of the State of North Carolina, and publishing a newspaper known as WILMINGTON
MORNING STAR & SUNDAY STAR -NEWS in the City of Wilmington
NOTICE OF PUBLIC MEETING TO BE HELD BY THE NORTH CAROLINA
ENVIRONMENTAL MAN- AGEMENT COMMISSION ON INTENT TO ISSUE STATE
NPDES PERMIT 7 SUBJECT: A public meeting has been scheduled concerning the proposed
issuance of State NPDES Permit for the follow
was inserted in the aforesaid newspaper in space, and on dates as follows:
6/261x
And at the time of such publication Wilmington Star -News was a newspaper meeting all the
requirements and qualifications prescribed by Sec. Igo. 1-597 G.S. of N.C.
)D41/447.4t,
r affirmed to, and su
In TestimoWhereof, I have hereunto set my hand and affixed my officia the day and
year aforesaid. �
Title: CLASSIFIED ADVER. MGR
before me this / day of
8
GIYt/ • i.
meeting clerk at the time
of registration. Com-
ments, statements, data
and other inforrnation
may be presented orally,
or may be submitted in
writing prior to, or _during
the meeting. However,
oral presentations ex-
ceeding three minutes
must be accompanied by
three (3) written copies
to be filed with the meet-
ing clerk at the time of
,en:rfrmf;nn Tr. mrrnm-
27.
.4
' 1�0
niHQ+ta
llic
Clerk of Superior Court

muuate au pe! wiu ucai-
ing to speak, oral state-
ments may be time -
limited at the discretion
of the hearing officer.
4. Cross-examination
of persons presenting
testimony will not be al-
lowed; however, the hear-
ing officer may ask ques-
tions for clarification.
5. The meeting record
will be closed at the
conclusion of the
meeting, or at the
discretion of the hearing
WHEN: July 29, 20414 at
7 p.m. (Registration be-
gins at 6:30 pm). Speak-
ers will be assigned in
their order of registration.
WHERE: New Hanover
County Arboretum
6206 Oleander Dr.
Wilmington,
North Carolina
FOR INFORMATION:
Permit renewal docu-
ments and other informa-
tion remain on file at the
Division of Water Quality,
512 North Salisbury
Street, Room 925, Arch-
dale Building, Raleigh,
North Carolina, and at the
Wilmington Regional Of-
fice (WiRO) located at
127 Cardinal Drive Exten-
sion, Wilmington, North
Carolina. Documents may
be inspected during nor-
mal office hours. Upon
request, the Division will
provide copies of all pub-
lic documents, but inter-
ested parties must pay
the cost of document re-
production.
Interested persons may
obtain copies of the draft
NPDES permit, • including
a map showing the loca-
tion of the discharge(s),
by writing or calling:
Mr. Charles Weaver,
NPDES Unit
NC Division of Water
Quality
1617 Mail Service Center
Raleigh, North Carolina
27699-1617
Telephone:
[phone], ext. 511
Alan W. Klimek, P.E.,
Director
Division of Water Quality

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 4
ATLANTA FEDERAL CENTER
61 FORSYTH STREET
ATLANTA, GEORGIA 30303-8960
7 7054
I
'Tan W. Klimek, Director
Division of Water Quality
North Carolina Department of Environment and
Natural Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
SUBJ: Review of Draft NPDES Permit
City of Wilmington Northside WWTP - No. NC0023965
Dear Mr. Klimek:
J UN 4 n 2004
DIV. OF WATER QUALITY
DIRECTOR'S OFFICE
This office is in receipt of the draft permit for the above referenced facility. The Form 2A
application transmitted to the Region for review with the draft permit, however, did not include a
sufficient number of priority pollutant scans. It is thus not consistent with the requirements of 40 Code
of Federal Regulations (C.F.R.) Sections 122.21(j)(4)(ii) and (vi). As such, it does not serve as a
complete permit application. Because the information provided is inadequate to determine whether the
draft permit meets the guidelines and requirements of the Clean Water Act, I request that a complete
permit application for this facility be submitted that is consistent with the requirements of 40 C.F.R.
Sections 122.21(j)(4)(ii) and (vi). Pursuant to federal regulatory requirements and language of Section
VII.A. of the North Carolina/EPA National Pollutant Discharge Elimination System Memorandum of
Agreement (MOA), this letter constitutes an interim objection to the issuance of this permit.
In accordance with the MOA and federal regulations, the full period of time for review of this
draft permit will recommence when the requested information is received by this Office. I look forward
to receipt of the information. If you have any questions, please call me or have your staff contact
Mr. Marshall Hyatt at 404/562-9304.
Sincerely,
ames D. Giattina, Director
Water Management Division
cc: Hugh T. Caldwell, P.E, City of Wilmington
Kevin B. Smith, OLS, OEA
JP
Internet Address (URL) . http://www,epa,gov
Recycled/Recyclable • Printed wtth Vegetable Oil Based Inks on Recycled Paper (Minimum 30% Postconsumer)

Re: SSWWTP Renewal
Subject: Re: SSWWTP Renewal
From: [e-mail]
Date: Wed, 16 Jun 2004 12:55:20 -0400
To: Joe Corporon <[e-mail]>
CC: [e-mail]
Joe - I've just been informed that another driver for a discussion next
week is Mr. Gavin being unvailable on/after 06/28, and hence a need to know
before his departure whether a tentative resolution has been reached. On
that basis, it looks like 06/22 AM, 06/23, or 06/24 are currently on the
table. If Dave cannot make the determination this week and pass it along
so I can inform Hugh, I would suggest he contact Hugh first thing next week
to schedule the call to your (Dave, Joe, Hugh) mutual convenience on any of
the previously noted dates. Ken.
Joe Corporon
<joe.corporon@ncm To: [e-mail]
ail.net> cc:
Subject: Re: SSWWTP Renewal
06/16/2004 11:54
1 of 2 6/21/2004 7:24 AM

Re: SSWWTP Renewal
Sorry, my last reply was not responsive -- Yes, I think the 28th or
29th would be ok for me, but I have no way of confirming with Dave until
monday.
[e-mail] wrote:
Joe - Dave had been trying to arrange a conference call between Dave,
Hugh,
you, and me to discuss resolution of the issues under consideration for
the
adjudicatory hearing. Hugh is on vacation this week and I'm on vacation
next week. Is it absolutely essential for us to discuss and resolve
pending issues next week, or do we have time within the hearing framework
to arrange the call for early the following week, either 06/28 or 06/29?
If
we must confer next week, please advise of a date/time convenient for Dave
and you, and providing it is not 06/25 as Hugh will be unavailable. Dave
had indicated Tues AM, Wed, Thurs, and Fri as possibilities. Ken.
of 2 6/21/2004 7 : 24 AM

06/10/2004
Hi Joe:
I have attached a modeling report on dilution process in the Lower Cape Fear River
Basin. The name of the model is " 3-Dimentional EFDC Water Quality Model of the
Lower Cape Fear River and its Estuary". The model is developed by Tetra Tech on May
2001 and is approved by DWQ. As I understand, the attached report includes all the
information that you are looking for your presentation. If you need further information,
please let me know. I would be happy to provide you information with my best. Thank
you.
With regards
Raj
(Narayan Rajbhandari)
DWQ, Modeling Unit
t OO €90
(er-
ice
wrc--(14kt

4 - DISCHARGE DILUTION ANALYSIS
The calibrated and verified hydrodynamic model was applied to evaluate near field and far
field mixing and transport of the Wilmington Northside and Southside Wastewater Treatment
Plant (WWTP) effluents. The concept of dilution was used to quantify the degree of mixing and
the transport of the effluent in the Cape Fear system. For each treatment plant, a conservative
tracer having concentration Ce was introduced into the plant effluent. The hydrodynamic and
transport model was then used to simulate the distribution of the tracer in the system for a two
month period encompassing June and July 1998. The July monthly mean flows in the Cape Fear,
Black and Northeast Cape Fear Rivers were 29.42 cms (1036 cfs), 1.93 cms (68 cfs), and 2.01
cms (71 cfs), respectively. Tracer concentrations were predicted to reach a quasi -steady state,
i.e., the concentration time variation in all cells of the model repeated with each subsequent tidal
cycle, by the last week of July. The dilution of the effluent during the last tidal cycle in each
model cell was then determined by
D=�
C
where D is the dilution and C is the concentration in the cell of interest. The following two
sections summarize the results of the near and far field dilution analyses.
4.1 Near Field Dilution
(4.1)
The near field dilution analysis was conducted to determine the mixing and dilution of the
effluents in the immediate vicinity of the plant discharges. For the Northside treatment plant, two
approaches were used. The first simple approach assumed that the effluent is instantaneously
mixing in the horizontal model cell in which the discharge is located. Since the Northside
discharge has a two -nozzle submerged diffuser, the second approach used a jet -plume sub -model.
The EFDC model includes an embedded version of the JETLAG (Lee and Cheung, 1990,
Hamrick, 1998) jet -plume model. The JETLAG model is based on the Lagrangian formulation
used in the UM component of the US EPA's PLUMES model (Baumgartner, Frick, and Roberts,
1994). The JETLAG model has been extensively tested against CORMIX1 (Jirka, Doneker, and
Hinton, 1996) by Davidson and Pun (1998) who conclude that the two models provide
quantitatively similar predictions of mixing and dilution from single port discharges over a wide
range of conditions. The JETLAG model embedded in EFDC allows the two-way interaction
between nearfield and far field processes, with the EFDC far field model providing dynamic
ambient conditions for JETLAG, with JETLAG appropriately transferring the equivalent far field
source to EFDC. For the jet -plume based analysis, the two port Northside diffuser head is
represented by a dynamically equivalent single port discharge. Since the Southside treatment
plant does not have a submerged discharge structure, only the first approach was used.
The results of the near field dilution analysis are summarized in Table 4.1. For the Northside
discharge, accounting for the mixing dynamics of the submerged discharge structure results in
approximately 30 percent greater dilutions in the model cell where the discharge is located. The
Northside discharge is located in a high energy region of the river system with tidal mixing
dominating the dilution process. The Southside discharge is located is a less energetic region and
has correspondingly lower near field dilutions. The model cell in which the Northside discharge
is located has a surface area of approximately 0.07 square kilometers and a mean depth of
STetra Tech, Inc. 4-1

May 2001 Chapter 4
DISCHARGE DILUTION ANALYSIS
approximately 10 meters. The model cell in which the Southside discharge is located has a
surface area of approximately 0.11 square kilometers and a mean depth of approximately 1 meter.
Thus the model grid constrained volume of the Northside discharge cell is approximately 6 times
that of the Southside discharge cell which is consistent with the results of the simple dilution
approach. Figures 4.1 and 4.2 illustrate the Northside and Southside near field dilutions over two
tidal cycles.
4.2 Far Field Dilution
Dilution of the Northside and Southside treatment plant discharges were determined in all
model cells. Table 4.2 summarizes dilutions at a number of selected locations of interest. At
Navassa, the dilutions from both treatment plants are lower at the bottom of the water column
than at the surface. During the relatively low flow in the Cape Fear River during the simulation
period, there is upstream intrusion of salinity well past Navassa. This upstream salinity intrusion
is accompanied by a tidally averaged, density driven transport upstream in the bottom portion of
the water column and downstream in surface portion (Hamrick, 1979). The upstream average
transport is responsible for an increased upstream transport of material from the treatment plants
near the bottom and a compensating decreased in the upstream transport near the surface. The
strength of this two -layered, upstream -downstream net transport is approximately proportional to
the salinity gradient. A different situation is observed 6 miles upstream in the Northeast Cape
Fear River at station NCF6. Although, salinity is present at this station, the much lower
freshwater discharge from the Northeast Cape Fear River results in a weaker salinity gradient and
net two layer circulation. As a result, dilutions at the bottom and surface of the water column are
approximately the same.
Dilution of the Northside effluent is greater in the bottom layer at the downstream main
estuary stations, M61, M54, and M42, due to a compensating effect of the smaller bottom layer
dilution upstream in the Cape Fear River. For the Southside effluent, the higher surface dilution
at the upstream M61 station is consistent with the salinity intrusion effect. At the two
downstream stations, M54 and M42, higher bottom dilutions of the Southside effluent occur,
consistent with that observed for the Northside effluent at downstream stations. Figures 4.3-4.5
show two tidal cycle plots of the Northside effluent dilution at Navassa, NCF6, and Marker 61.
Figures 4.6-4.9 show two tidal cycle plots of the Southside effluent dilution at Markers 61, 54,
and 42.
The far field dilution analysis can be used to make a very simplified estimation of the impacts
of the Wilmington treatment plant effluents on low dissolved oxygen near Navassa and NCF6. If
ultimate biochemical oxygen demand was simplistically represented as conservative tracer, the
contribution of the Northside effluents BODU to the oxygen deficit at Navassa could be crudely
estimated as
BODu BODu
DOde o = +
D northstde D southstde
(4.2)
Using minimum dilutions of 300 and 391 for the Northside and Southside effluents at
Navassa (from Table 4-2), and ultimate BOD's of 35 mg/liter for both effluents (from Figures 5-2
and 5-3), equation (4.2) gives a contribution to the dissolved oxygen deficit of approximately 0.2
mg/liter during summer low flow conditions. A similar calculation for six miles up the Northeast
Cape Fear River gives a value of 0.17 mg/liter. These simple estimates can be viewed as
conservative since the minimum bottom layer dilution rather than the tidally average dilution over
4-2 ® Tetra Tech, Inc.

Chapter 4 May 2001
DISCHARGE DILUTION ANALYSIS
both layers has been used, and the effects of oxidation between the discharge and the points of
interest have been neglected. It is also noted that the value of 0.2 mg/liter is near typical field
instrument sensitivity.
The general conclusion that can be drawn from the discharge dilution analysis is that both of
the Wilmington treatment plant discharges are well diluted by natural physical mixing processes
in the river system. Model predicted dilutions at various locations in the river system are very
consistent with classical estuarine circulation patterns which lend credence to the results. Using
the dilution predictions in conjunction with Equation 4.2 as the basis for a simple analysis, the
two Wilmington discharges in combination are estimated to be responsible for approximately 0.2
mg/liter or less of dissolved oxygen deficit in dissolved oxygen impaired regions of the river
system.
EDTetra Tech, Inc.
4-3

May 2001 Chapter 4
DISCHARGE DILUTION ANALYSIS
FIGURE 4-11 NEARFIELD NORTHSIDE EFFLUENT DILUTION, BASED ON JET -PLUME ANALYSIS APPROACH.
Dilution Facto
900
800
700
600
500
400
300
200
100
0
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.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21.222324
Hour
4-4
CDTetra Tech, Inc.

Chapter 4 May 2001
DISCHARGE DILUTION ANALYSIS
FIGURE 4-3. DILUTION OF NORTHSIDE EFFLUENT AT NAVASSA.
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour
(11 Tetra Tech, Inc. 4-5

May 2001 Chapter 4
DISCHARGE DILUTION ANALYSIS
FIGURE 4-4. DILUTION OF NORTHSIDE EFFLUENT 6 MILES UP THE NORTHEAST CAPE FEAR RIVER.
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour
4-6
® Tetra Tech, Inc.

Chapter 4 May 2001
DISCHARGE DILUTION ANALYSIS
FIGURE 4-5. DILUTION OF NORTHSIDE EFFLUENT AT CHANNEL MARKER 61.
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour
® Tetra Tech, Inc.
4-7

May 2001 Chapter 4
DISCHARGE DILUTION ANALYSIS
FIGURE 4-6. DILUTION OF SOUTHSIDE EFFLUENT AT CHANNEL MARKER 61.
1
4-8
0 Tetra Tech, Inc.

Chapter 4 May 2001
DISCHARGE DILUTION ANALYSIS
FIGURE 4-7. DILUTION OF SOUTHSIDE EFFLUENT AT CHANNEL MARKER 54.
9 i0 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour
LITetra Tech, Inc.
4-9

May 2001 Chapter 4
DISCHARGE DILUTION ANALYSIS
FIGURE 4-8. DILUTION OF SOUTHSIDE EFFLUENT AT CHANNEL MARKER 42.
450
400
350
300
0
, 250
u.
a
a 200
0
150
100
50
0
•
—,c--Bottom
—s—S uriace
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
4-10
El Tetra 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
33
63
Near Surface Dilution in Discharge
Ce11 Using Jet -Plume Approach
332
797
Near Bottom Dilution in Discharge
Ce11 Using Jet -Plume Approach
303
420
Dilution at Maximum Plume Rise
4.5 .
25.4
TABLE 4-2. FAR FIELD DILUTION AT SELECTED LOCATIONS
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
® Tetra Tech, Inc.
4-11

comment on NC0023965 - Wilmington Northside WWTP
4
Subject: comment on NC0023965 - Wilmington Northside WWTP
From: [e-mail]
Date: Thu, 03 Jun 2004 11:08:56 -0400
To: [e-mail]
CC: [e-mail]
1. The facility is expanding from
assessed based on acute conditions
are
acute. No assessment of potential
lack
of information regarding tidal mixi
the
draft permit include a provision that dye studies and/or modeling be
conducted during the next permit term to more accurately evaluate
the
extent of mixing of this expanded discharge. With this
information,
appropriate decisions about the need for effluent or WET provisions
to
protect against chronic impacts can be made.
8.0 MGD to 16.0 MGD. RPA was
and the permit's WET provisions
chronic impact was done due to a
ng. We strongly recommend that
1 of 1 6/3/2004 11:52 AM

Co lee" *a/o
17t101c. kieitvinct
1
i
MEMORANDUM
To:
From:
Date: June 2, 2004
Subject:
Dave Goodrich, Supervisor NP ►,
Joe Corporon, Permit Writer
,1
City of Wilmington's Northside WWTP,
Renewal of NPDES Permit NC0023965
New Hanover County
Michael F. Easley, Governor
State of North Carolina
William G. Ross, Jr., Secretary
Department of Environment and Natural Resources
Alan W. Klimek, P.E., Director
Division of Water Quality
nit
This is to inform you that, during the draft permit comment period, beginning with Public Notice on
April 28, 2004, the Division has received at least eight requests for a public hearing.
Written and e-mail requests for a public hearing focus on a perceived need to be better informed about
the total environmental impact of the proposed expansion project, and specifically request the Division
to add a stormwater permit or stormwater management plan to the NPDES permit.
cc. NPDES File
�FZ
NCDENR
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 [phone] Customer Service
1 800 623-7748

Michael F. Easley, Governor
State of North Carolina
William G. Ross, Jr., Secretary
Department of Environment and Natural Resources
Alan W. Klimek, P.E., Director
Division of Water Quality
MEMORANDUM
To: Dave Goodrich, Supervisor NP! nit
From: Joe Corporon, Permit Write
Date: June 2, 2004
Subject: City of Wil ; gton's Northside WWTP,
Renewal of NPDES Permit NC0023965
New Hanover County
This is to inform you that, during the draft permit comment period, beginning with Public Notice on
April 28, 2004, the Division has received at least eight requests for a public hearing.
Written and e-mail requests for a public hearing focus on a perceived need to be better informed about
the total environmental impact of the proposed expansion project, and specifically request the Division
to add a stormwater permit or stormwater management plan to the NPDES permit.
cc. NPDES File
NCDENR
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 [phone] Customer Service
1 800 623-7748

CITY OF WILMINGTON
PUBLIC UTILITIES DEPARTMENT
May 26, 2004
Mr. Joe R. Corporon
NPDES Unit
Division of Water Quality
DENR
1617 Mail Service Center
Raleigh, NC 27699-1617
P.O. Box 1810
WILMINGTON, NC 28402
TDD [phone]
Re: NPDES Permit NC0023965 Expansion from 8.0 MGD to 16 MGD for the James
A. Loughlin (Northside WWTP) New Hanover County - Permittee's Comments
on the Draft Permit
Dear Mr. Corporon:
We have completed our review of the draft permit for the above referenced
facility and we offer the following comments.
General Comments
1. Proposed "Phased Limits" Condition — We are disappointed that the request for
phased limits until establishment of a TMDL has been denied. DWQ states that it
continues to find impaired conditions downstream of the NSWWTP and the lower Cape
Fear River remains 303(d)-listed for DO. The Fact Sheet indicates that DO "levels
generally remain above the DO Standard of 5.0 mg/L, typically 11 or 12 mg/L except
during hurricane conditions". DWQ's inference in denying the request for phased limits
is that DO impairment is significantly attributable to the NSWWTP, and this is not borne
out by the best scientific information currently available or by the statement in the Fact
Sheet.
DWQ stated in the permit cover letter that in the absence of new data to support
additional nutrient loading, the proposed phased limit condition must be denied.
However, the City/County water quality model for the Lower Cape Fear River developed
by Tetra Tech and its findings are not mentioned, and do provide new data in support of
loading greater than that allowed by the current basin policy plan. Both the model and
the 01/16/2003 DO Trend Analysis report by Tetra Tech determined that loadings from
the expanded/upgraded NSWWTP represent an extremely minor impact upon Cape Fear
River DO. The DO Trend Analysis clearly indicates that over a recent extended period of
record, point sources loadings have progressively declined while DO levels remain
ADMINISTRATION ENVIRONMENTAL SERVICES UTILITY SERVICES
VOICE [phone] VOICE [phone] VOICE [phone]
Fax [phone] FAx [phone] FAx [phone]
WASTEWATER TREATMENT
LOUGHUN PLANT MAFFTR PLANT
VOICE [phone] VOICE [phone]
FAX [phone]
WATER TREATMENT
VOICE [phone]
FAX [phone]

Mr. Joe R. Corporon
May 26, 2004
Page-2
largely unchanged, signifying that other, more significant major driving forces are
influencing DO depletion within the Cape Fear River.
We understand DWQ's position that the 303(d) listing mandates reduction to the
system's nutrient load, and have requested phased limits that accomplish a reduction
while not imposing the policy -based 5/1 standard at this time. The expanded/ upgraded
NSWWTP has been designed to the 5/1 standard. However, given the fact that the
corrective TMDL is currently underway, the City believes imposition of the proposed
phased limit condition upon the expanded/upgraded NSWWTP is appropriate and
justified. Phased limits will have the additional benefit of setting the stage for a future
pollution offset/trading program. We request that the proposed phased limits be given
additional consideration.
2. Seasonal Limits — The draft permit does not provide seasonal limits for effluent
ammonia concentrations. Our understanding is that the basin policy has resulted in less
stringent effluent ammonia concentrations during winter periods for other pennittees,
including the New Hanover County NPDES permit. Please revise the draft permit to
reflect these seasonal limits.
3. Dissolved Oxygen — The draft permit indicates that expansion to 16 MGD requires an
effluent DO limit of 6.0 mg/1. As noted in item 1 above, the best available scientific data
indicates that the DO depletion within the Cape Fear River is not related to point source
discharges. The Fact Sheet indicates that DO "levels generally remain above the DO
Standard of 5.0 mg/L, typically 11 or 12 mg/L except during hurricane conditions".
Please provide the basis for imposition of this permit limit.
4. Total Residual Chlorine (TRC) — The draft permit establishes a TRC limit of 28 ug/1
as a daily maximum. While the existing NSWWTP provides chlorination and
dechlorination systems, the expanded/upgraded NSWWTP will be converted to
ultraviolet disinfection. Due to the temporary nature of the dechlorination facilities, and
to the fact that no TRC limit was in place when those facilities were constructed, the
facilities were only provided with coarse manual control. It is unlikely this type of
control will yield the mandated performance to comply with the stringent TRC limit and
modifications to the facility controls would be required. We request that this requirement
be waived for the 8 mgd permit since new replacement facilities for disinfection without
chlorination will soon be under construction.
5. Fact Sheet/Facility Record Review/Verifying Existing Stream Conditions — Subbasin
03-06-17 is cited as being impaired due to seasonally high concentrations of fecal
coliform bacteria. Has this issue been formally recognized and will a TMDL be
forthcoming?
6. Effluent Limitations and Monitoring Requirements Special Conditions, Paragraph A
(5) Anti -Backsliding — As written, the City must meet all 5 requirements listed in order
for less stringent limits to be allowed without violating anti -backsliding provisions. We

Mr. Joe R. Corporon
May 26, 2004
Page - 3
feel that any of these conditions individually warrant consideration for less stringent
permit limits and that the likelihood of all 5 requirements occurring simultaneously is
extremely remote. Subsequently, we request that the first sentence of this section be
amended to read "The BOD5 and ammonia nitrogen (NH3 as N) limits in the permit may
be replaced with less stringent limits without violating state and federal anti -backsliding
provisions if any of the following conditions occur:"
Bullet 5) makes reference to "established permitting policies and procedures". Since
policy based limits and decisions are a major source of our concern, we request revision
of bullet 5) to delete the reference to policies and practices.
Factual Corrections
1. Cover Letter/Outfall Location — Our permit application inadvertently omitted the
location map for Outfall 002, which was described in the permit application. A location
map for Outfall 002 and a corrected location map for Outfall 001 are enclosed.
2. Cover Letter/Reasonable Potential Analysis and Renewal Procedures — DWQ has
increased the monitoring frequencies for silver, zinc, and copper from monthly to
2/month, citing permitting guidance for a Class IV WWTF (15A:02B.0500 and
supplements). Upon review of the cited references, we were unable to verify guidance to
this monitoring frequency. Please provide confirmation of the guidance reference for the
increased monitoring frequencies.
Additional effluent data for silver, zinc and copper is enclosed. Please update the
Reasonable Potential Analysis utilizing this additional data. We believe that an updated
RPA will provide further basis for deletion or reduction in the monitoring requirements
for silver, zinc and copper.
3. Fact Sheet/ Facility Description — Please modify the description of the existing
facility, which incorrectly omits secondary clarifier facilities following "an aeration
basin" and omits manually controlled dechlorination facilities following "chlorine
disinfection facilities". The existing NSWWTP incorporates sodium bisulfite
dechlorination facilities, which began operation on or about February 17, 2003 as noted
in correspondence from the City of Wilmington dated February 11, 2003 to NCDENR
(copy enclosed).
4. Fact Sheet/ Table 1 — Please update the table to reflect Outfalls 1 and 2.
5. Fact Sheet/Compliance Review/Effluent Chlorine — Northside does currently
dechlorinate its effluent. Please see Item 3 above.
6. Fact Sheet/Permitting Approach/Toxicant Removal Criteria — Pollutants of Concern
(POCs) — Please see Item 2 above.

Mr. Joe R. Corporon
May 26, 2004
Page-4
7. Supplement to Permit Cover Sheet — The description of the existing facility
incorrectly omits secondary clarifier facilities following "an aeration basin" and omits
manually controlled dechlorination facilities following "chlorine disinfection facilities".
8. Permit/A(2) Effluent Limitations and Monitoring Requirements — There appears to be
a typographical error inasmuch as total copper is listed twice while total CN is not listed
at all on this page.
Other Considerations
Would DWQ consider "Trading" as a valid method to provide an alternate method in lieu
of the current basin policy plan to control the reduction of oxygen demanding constituents
in the Cape Fear River Basin? The City requests consideration for "Trading" between
15/10 limits and the 5/1 design limits to be included in the permit language if determined
by the TMDL or other credible evaluation/data that becomes available in the future.
We would appreciate a response concerning the issues mentioned at your earliest
convenience.
Yours very truly,
Hugh T. Caldwell, P. E.
Director of Public Utilities
Enclosures: Revised outfall map
Additional Ag, Zn and Cu effluent data
Dechlorination facility letter
cc: Ken Vogt, P. E., City Wastewater Treatment Superintendent
Greg Thompson, P. E., County Engineer
Tony Boahn, P. E., McKim and Creed Engineers
Ron Taylor, P. E., Hazen and Sawyer Engineers

Receiving Stream: Cape Fear River
Latitude: 34° 14' 27" N
Longitude: 77° 57' 10" W
Stream Class: SC
Downstream -Sample ' saint
D1 located -3.2 miles / _ - 'p
downstream of the dis 12atgaa--, ;\(jlu,dRedmona
/Q/
City of Wilmington
James A. Loughlin (Northside) VVWTP
Drainage Basin: Cape Fear River Basin
Sub -Basin: 03-06-17
Permitted Flow: 8.0 MGD
Grid/Quad: K 27 NW / Wilmington, NC
Facility
Location
not to scale
North
NPDES Permit No. NC0023965
New Hanover County

City of Wilmington Northside Wastewater Treatment Plant
Effluent Data (All values in mg/L)
SILVER
2004
2003
2002
2001
Jan <0.002
<0.002
<0.002
<0.002
<0.002
Feb <0.002
<0.002
<0.002
<0.002
<0.002
Mar <0.002
<0.002
<0.002
0.006
<0.002
Apr <0.002
<0.002
<0.002
<0.002
<0.002
May
<0.002
<0.002
<0.002
<0.002
June
<0.002
<0.002
<0.002
<0.002
July
<0.002
<0.002
<0.002
<0.002
Aug
<0.002
<0.002
<0.002
<0.002
Sept
<0.002
<0.002
<0.002
<0.002
Oct
<0.002
<0.002
<0.002
<0.002
Nov
<0.002
<0.002
<0.002
0.002
Dec
<0.002
<0.002
<0.002
<0.002
ZINC
2004
2003
2002
2001
2000
Jan
0.030
Feb 0.020
0.015
0.018
Mar
0.015
0.037
0.029
Apr
0.016
0.026
May
0.013
0.014
0.013
June
0.020
July
0.017
0.017
Aug
0.016
0.095
Sept
0.006
<0.005
Oct
<0.005
<0.010
0.018
Nov
0.011
0.033
Dec
0.014
COPPER
2004
2003
2002
2001
2000
Jan 0.005
0.115 /
0.007
0.009
0.010
0.008
Feb 0.005
0.007
0.007
0.007
0.011
Mar 0.004
0.005
0.005
0.005
0.007
Apr 0.004
0.008
0.005
0.006
0.010
May
0.013
0.005
0.005
0.118
June
0.003
0.004
0.008
0.011
July
0.003
0.003
0.007
0.009
Aug
0.005
<0.002
0.007
0.007
Sept
0.006
0.003
<0.002
0.006
Oct
0.006
0.003
0.005
0.010
Nov
0.003
0.004
0.016
0.012
Dec
0.005
0.004
0.007
0.008
1. Data recorded above was reported on DMRs for January 2000 through April 2004.
2. Silver data indicates no detection in the effluent since March 2001.
3. Zinc data indicates detection in most samples taken. Concentrations are usually less
than 0.030 mg/L.
4. Copper data indicates detection in most samples taken. Two data points are
questionable. Concentrations are usually less than 0.010 mg/L.

05/26/2004 15:45 9103414659
WASTEWATER TREATMENT PAGE 01
CITYOF WILMINGTON
PUBLIC UTILITIES DEPARTMENT
February 11, 2003
Mr. Steve West
Environmental Chemist II
NCDENR
Wilmington Regional Office
127 Cardinal Drive Ext.
Wilmington, NC '28405
RE: NSWWTP Dechlorination Facilities
Dear Mr. West,
P.O. Box 1810
WILMINGTON, NC 28402
TDD [phone]
Post-Ir Fax Note 7671
°ate / /t)y Ales 11' T—
T.
o /e cd-Li of
o fl1
f
/�/�
From c� V ear
Co./Dept
Co.
..,...
Phone#
Phone# 3T/".7k0may
�[
Fax * -4 W • AMR,
Fax #
During several NPDES compliance Inspections, NC DENR has recommended
Installation of dechlorination facilities at the NSWWTP to minimize effluent chlorine
toxicity while simultaneously maintaining adequate chlorine .residual levels. This is to
notify you that the City has installed dechiorination facilities at its NSWWTP and will
be placing them into service on or about February 17, 2003. Please advise if there Is
anything necessary for us or by you prior to starting up this system.
Sincerely,
;L,0,.+124
fE
I
Kenneth L. Vogt, Jr. PE
WW1 Superintendent
KLV/b
CC; Hugh Caldwell, Public Utilities Director
Pam Ellis, Superintendent, Environmental Services
Jeff Cermak, NSWWTP Supervisor
ADMINISTRATION ENVIRONMENTAL SERVIQEIf ()wry SERVICES WASTEWATER TREATMENT WATER TREATMENT
Voice (010) 341-T005 Vasce [phone] Vacs (#1o) 341-7QM Lomax PLANT /WRIT PIANT VOICU 010) 3434600
FAX [phone]ui FAX [phone] FAX [phone] Vow (9101341-r69e vacs (910179041100 FAX [phone]

I..VUI11x Vrnievv11H1VVvrat --.
Before the undersigned, a Notary Public of Said County and State,
DIANE P. KEENAN
Who, being duly sworn or affirmed, according to the law, says that he/she is
CLASSIFIED ADVERTISING MANAGER
pub/
This
PUBLIC NOTICE
STATE OF
NORTH CAROLINA
ENVIRONMENTAL
MANAGEMENT
COMMISSION/NPDES UNIT
1617 MAIL SERVICE
CENTER
RALEIGH, NC 27699-1617
NOTIFICATION OF INTENT
TO ISSUE A NPDES
WASTEWATER PERMIT
On the basis of thorough
staff review and applica-
tion of NC General Stat-
ute 143.21, Public law 92-
500 and other lawful
standards and regula-
tions, the North Carolina
Environmental Manage-
ment Commission pro-
poses to issue a National
Pollutant Discharge
Elimination System
(NPDES) wastewater dis-
charge permit to the per-
son(s) listed below effec-
tive.,45 days from the
publish date of this no-
tice.
Written comments re-
garding the proposed
unit will be acce
til 30 days afterpted the
publish date of this no-
tice. All comments re-
ceived prior to that date
are considered in the fi-
nal determinations re-
garding the proposed
permit. The Director of
the NC Division of. Water
Quality may decide to
hold a public meeting for
the proposed permit
should the Division re-
ceive a significant degree
of public interest.
Copies of the draft permit
and other supporting in-
formation on file used to
determine conditions
present in the draft per-
mit are available upon
request and payment of
the costs of reproduction.
Mail comments and/or
requests for information
to the NC Division of Wa-
ter Quality at the above
address or call Ms. Valery
Stephens at (919) 733-
5083, extension 520.
Please include the NPDES
permit number (attached)
in any communication.
Interested persons may
also visit the Division of
Water Quality at 512 N.
Salisbury Street, Raleigh,
NC 27604-1148 between
the' hours of 8:00 a.m.
and 5:00 p.m. to review
information on file.
Cogentrix Energy, Inc. has
applied for a renewal of
the NPDES permit
(NC0065099) for its
Southport cogener-Ition
facility in Brunswick
County. This facility oper-
ates two permitted out -
falls, 001 and 002, both
discharging to the Atlan-
tic Ocean. class SB wa-
ters in the Cape Fear
River Basin. No parame-
ters are water quality lim-
ited at this time, however
this discharge may im-
pact future allocation of
the resource.
Wilmington Northside
WWTP, NPDES Permit
NC0023965, has applied
for renewal and expan-
sion of its permitted dis-
charge to the Cape Fear
River within the Cape
Fear River Basin. The fol-
lowing parameters are
water quality limited:
BOOS, TSS, ammonia ni-
trogen (NH3 as N), fecal
coliform, Total Residual
Chlorine, and dissolved
oxygen. These parame-
ters may affect future al-
locations to the receive
stream.
of THE WILMINGTON STAR -NEWS, INC., a corporation organized and doing business under
the Laws of the State of North Carolina, and publishing a newspater known as WILMINGTON
MORNING STAR & SUNDAY STAR -NEWS in the City of Wilmington
PUBLIC NOTICE STATE OF NORTH CAROLINA ENVIRONMENTAL MANAGEMENT
COMMISSION/NPDES UNIT 1617 MAIL SERVICE CENTER RALEIGH, NC 27699-1617
NOTIFICATION OF INTENT TO ISSUE A NPDES WASTEWATER PERMIT On the basis
of thorough staff review and application of
was inserted in the aforesaid newspaper in space, and on dates as follows:
5/1 Ix
And at the time of such publication Wilmington Star -News was a newspaper meeting all the
requirements and qualifications prescribed by Sec. No. 1-597 G.S. of N.C.
Title: CLASSIFIED ADVER. MGR
d before me this ✓ day of
worn or affirmed to, and
, A.D
In Te imony Whereof, I have hereunto set my hand and affixed my I fb j e 1, the day and
year aforesaid. r� x����
�'f•
Public
My commission expires
day of dill_ 20' `-
foregoing affidavit with the advertisement thereto annexed it is adjudged by tiiQ u11mt
operly made, and that the summons has been duly and legally served on the defenc�aAt
id
1 "'ITT 1 `'4[1 Inv_ is
Clerk of Superior Court

[Fwd: Re: DRAFT Review -- Wilmington Northside -- Expansion / Renewal...
Subject: [Fwd: Re: DRAFT Review -- Wilmington Northside -- Expansion / Renewal, NC0023965]
From: John Giorgino <[e-mail]>
Date: Wed, 21 Apr 2004 13:02:11 -0400
To: Joe Corporon <[e-mail]>
Looks good. Thanks.
-John
Original Message
Subject:Re: DRAFT Review -- Wilmington Northside -- Expansion / Renewal, NC0023965
Date:Wed, 21 Apr 2004 11:45:01 -0400
From:Matt Matthews <[e-mail]>
To:Joe Corporon <[e-mail]>
CC:John Giorgino <[e-mail]>
References: <40867D2C. 8060702 @ ncmail.net>
Joe,
I wasn't sure how quick turnaround needed to be on this so I went ahead
and reviewed. Everything looks fine to me regarding WET. John Giorgino
is out today, but I've forwarded this to him for his review as well.
Matt
Joe Corporon wrote:
> Ladies and Gentlemen,
> Please review the attached documents for completeness and accuracy.
elX:r
1 of 2 4/21/2004 1:11 PM

[Fwd: Re: DRAFT Review -- Wilmington Northside -- Expansion / Renewal...
•
Matt Matthews
NC DENR/Division of Water Quality
Aquatic Toxicology Unit
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
John Giorgino
v-[phone]
f-[phone]
MailTo:[e-mail]
http://www.esb.enr.state.nc.us
Environmental Biologist
North Carolina Division of Water Quality
Aquatic Toxicology Unit
Mailing Address:
1621 MSC
Raleigh, NC 27699-1621
Office: 919 733-2136
Fax: [phone]
Email: [e-mail]
Web Page: http://www.esb.enr.state.nc.us
2 of 2 4/21/2004 1:11 PM

Re: City of Wilmington Northide NPDES Permit
Subject: Re: City of Wilmington Northide NPDES Permit
From: Joe Corporon <[e-mail]>
Date: Fri, 02 Apr 2004 10:55:54 -0500
To: Tony Boahn <[e-mail]>
CC: Matt Matthews <[e-mail]>
Tony, there seem to be two issues here:
1) \alternate -species Jesting for renewal -- this is straight forward -- NC Labs
recommends fathead minnow acute tests, and
2) a "compliance schedule" for converting from D. pulex to Ceriodaphnia -- the
lab can't imagin why you might have trouble with this species change. You should
not. The Division does not recommend adding a compliance schedule to the permit.
For additional information or questions, contact me or Matt Matthews at NC Labs.
Tony Boahn wrote:
Joe,
Per our recent conversation, we have collected the necessary data for additonal
priority pollutant analysis tests. However, the City does not have 2nd species
acute toxicity tests available as needed for the permit, which was generally
addressed in a letter from Ken Vogt to David Goodrich on March 2, 2004. In this
letter, Ken noted that quarterly testing required the use of Daphnia pulex for the
test organism and that Simalabs was the only NC lab that could perform this test -
unfortunately, Simalabs was recently purchased by Pace Analytical and no longer
provides certified testing with this species. Ken requested the use of
Ceriodaphnia dubia as a substitute species since indications are that it provides
results similar to Daphnia pulex. However, as noted in his letter, the City has had
a favorable history with Daphnia pulex and is uncertain that they can achieve
similar compliance with Ceriodaphnia dubia - given this, Ken requested that the
State waive enforcement of this for the quarterly testing for a one year period (4
tests) to evaluate the applicability of Ceriodaphnia dubia.
The City has done a fairly extensive amount of toxicity testing, which can certainly
be provided - we are looking for guidance on how to solve this issue and not delay
the permitting process. Could you provide me with a recommendation of how to
proceed?
I will go ahead and forward the PPA's to your attention. Thanks in advance for
1 of 2 4/2/2004 10:56 AM

Re: City of Wilmington Northide NPDES Permit
1
your help.
Tony Boahn, P.E.
McKim & Creed, P.A.
243 N. Front Street
Wilmington, NC 28401
[phone]
[phone] (Fax)
[phone] (Cell)
www.mckimcreed.com
2 of 2
4/2/2004 10:56 AM

Re: [Fwd: City of Wilmington Northide NPDES Permit]
•
Subject: Re: [Fwd: City of Wilmington Northide NPDES Permit]
From: Matt Matthews <matt.matthews @ ncmail.net>
Date: Thu, 25 Mar 2004 22:31:42 -0500
To: Joe Corporon <[e-mail]>
CC: Kevin Bowden <[e-mail]>
Joe,
It seems to me there are two questions here:
1) Alternate species for permit renewal. They should be doing fathead minnow
acutes. this is very straightforward.
2) They want a schedule for converting from D. pulex to Ceriodaphnia. I can't
imagine they'd have any problem meeting their limit usingCeriodaphnia. I would
not advise a schedule.
Matt
Joe Corporon wrote:
Matt, can you advise me about Wilmington's this request regarding second
species tests.
Original Message
Subject:City of Wilmington Northide NPDES Permit
Date:Thu, 18 Mar 2004 07:55:26 -0500
From:Tony Boahn <[e-mail]>
To:Joe Corporon <[e-mail]>
Joe,
Per our recent conversation, we have collected the necessary data for additonal
priority pollutant analysis tests. However, the City does not have 2nd species
acute toxicity tests available as needed for the permit, which was generally
addressed in a letter from Ken Vogt to David Goodrich on March 2, 2004. In this
letter, Ken noted that quarterly testing required the use of Daphnia pulex for the
test organism and that Simalabs was the only NC lab that could perform this test -
1 of 2 4/2/2004 10:33 AM

Re: [Fwd: City of Wilmington Northide NPDES Permit]
unfortunately, Simalabs was recently purchased by Pace Analytical and no longer
provides certified testing with this species. Ken requested the use of
Ceriodaphnia dubia as a substitute species since indications are that it provides
results similar to Daphnia pulex. However, as noted in his letter, the City has had
a favorable history with Daphnia pulex and is uncertain that they can achieve
similar compliance with Ceriodaphnia dubia - given this, Ken requested that the
State waive enforcement of this for the quarterly testing for a one year period (4
tests) to evaluate the applicability of Ceriodaphnia dubia.
The City has done a fairly extensive amount of toxicity testing, which can certainly
be provided - we are looking for guidance on how to solve this issue and not delay
the permitting process. Could you provide me with a recommendation of how to
proceed?
I will go ahead and forward the PPA's to your attention. Thanks in advance for
your help.
Tony Boahn, P.E.
McKim & Creed, P.A.
243 N. Front Street
Wilmington, NC 28401
[phone]
[phone] (Fax)
[phone] (Cell)
www.mckimcreed.com
2 of 2
4/2/2004 10:33 AM

CITY OF WILMINGTON
PUBLIC UTILITIES DEPARTMENT
March 2, 2004
Mr. David A. Goodrich, NPDES Unit
NCDENR
DWQ
1617 Mail Service Center
Raleigh, NC 27699-1617
P.O. Box 1810 ,
WILMINGTON, NC 28402
TDD [phone]
,, _
(r: ,,,,m‘-,,,,,ei ,
i ;-.4 4 y
e�,` try
Re: Acute Toxicity Test Species
City of Wilmington NPDES Permits NC0023965 and NC0023973
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.
4rj
Kenneth L. Vogt, Jr., PE
Wastewater Treatment Superintendent
•
Copies: H. Caldwell
P. Ellis
J. Cermak
M. Vann
ADMINISTRATION ENVIRONMENTAL SERVICES UTILITY SERVICES WASTEWATER TREATMENT
VOICE [phone] VOICE [phone] VcxcE [phone] LOUGH IN PLANT MAFFR PLANT
FAX [phone] FAx [phone] FAX [phone] VOICE [phone] VOICE [phone]
FAx [phone]
WATER TREATMENT
VOICE [phone]
FAx [phone]

Willmington EA dated April 2003 -- NC0023965
$
• Subject: Willmington EA dated April 2003 -- NC0023965
Date: Wed, 09 Jul 2003 15:51:03 -0400
From: Joe Corporon <[e-mail]>
To: Alex Marks <[e-mail]>
Alex,
The NPDES Unit has reviewed the subject Environmental Assessment (EA)
for Wilmington Northside's proposed expansion to 16.0 MGD. Our review
focused on their justification of flow rate, and also particularly on
compliance with current Cape Fear River Basin policy -based discharge
limits.
Northside's projected needs appear reasonable. Considering that the City
of Wilmington has elected to design the Northside WWTP to meet
policy -based limits for the Cape Fear [BOD5 and NH3-N (5/1 mg/L)], the
Unit has no objections and no further comments.
Thanks for the opportunity to review.
Joe
1 of 1
7/9/03 3:51 PM

0,0-)Pc(671;
\ 10,(5.fc-N)
ENVIRONMENTAL ASSESSMENT
OF
NORTHSIDE WASTEWATER TREATMENT PLANT
UPGRADE AND EXPANSION
I. PURPOSE OF DOCUMENT
The purpose of this Environmental Assessment (EA) is to provide the North Carolina
Department of Environment and Natural Resources and associated agencies with a
decision -making tool to determine if the proposed Northside Wastewater Treatment Plant
upgrade and expansion project in New Hanover County is of sufficient impact to the
environment as to require the preparation of an Environmental Impact Statement (EIS). If
an EIS is not warranted, a Finding of No Significant Impact (FONSI) will be issued prior
to the action on the National Pollutant Discharge Elimination System (NPDES) permit.
The Division of Water Quality coordinates the state review of this EA. Other commenting
state agencies include the Divisions of Coastal Management, Land Resources, Water
Resources, Marine Fisheries, Environmental Health, Archives and History, Community
Assistance as well as the Wildlife Resources Commission, The North Carolina Natural
Heritage Program, the Department of Administration and the Department of
Transportation. Commenting Federal agencies may include the Environmental Protection
Agency, U.S. Army Corps of Engineers, National Marine Fisheries Service, and the U.S.
Fish and Wildlife Service.
II. PROPOSED PROJECT DESCRIPTION
The City of Wilmington currently owns and operates two secondary wastewater treatment
plants; Northside WWTP and Southside WWTP. These facilities treat wastewater
originating within the City of Wilmington (City), the New Hanover County Water and
Sewer District (County), and the Town of Wrightsville Beach. The two facilities currently
have a total permitted capacity of 20 MGD, with the Northside WWTP currently
permitted for 8 MGD and the Southside WWTP currently permitted for 12 MGD. Both
facilities possess NPDES permits requiring secondary treatment to 30 mg/L Biological
Oxygen Demand (BOD) and 30 mg/L Total Suspended Solids (TSS) with no currently
applicable ammonia (NH3-N) limit.
Environmental Assessment
Northside Wastewater Treatment Plant, New Hanover County 1

A comprehensive master plan (Appendix A) performed in accordance with City and
County development standards identified wastewater service area needs of 28 MGD by
the year 2020. Of this total, the Northside WWTP has been identified to handle 16 MGD
while the Southside WWTP will continue to remain at its 12 MGD capacity.
In the late 1960's, the Northside WWTP facility was constructed adjacent to 23rd Street,
across from Wilmington International Airport in New Hanover County (Figures 1 and 2).
A 30" force main was built in 1982 and extends from the plant to the outfall at the Cape
Fear River, just south of the Coastline Convention Center. Increasing wastewater
treatment flows to proposed levels will require -a major upgrade and expansion of the
Northside WWTP. Advanced secondary treatment to achieve complete nitrification will
be provided. An additional 30" force main will be installed from the Northside WWTP.
This pipe will be installed 42" underground (from top of pipe) and run approximately
parallel to the existing pipe; following the path of the old railroad bed, crossing under
Smith Creek, and eventually terminating at the Cape Fear River. The new outfall location
will terminate at a position north of the Hilton Wilmington Riverside Inn. In addition, a
new effluent diffuser "T" will run perpendicular to the shipping channel and be aligned
approximately 8' landward of the toe of its slope. This diffuser will be marked and noted
on navigational charts.
The current Cape Fear River Basin Wide Water Quality Plan has recommended 5 mg/1
BOD5 and 1 mg/1 NH3-N limits for new or expanding discharges to reverse a trend of
declining dissolved oxygen within the river basin and restore it to levels supporting
designated water body use(s). These limits were proposed by DWQ as speculative limits
for the Northside WWTP (Appendix B). Because these limits lack conclusive scientific
support and can be considered policy -based, the City/County elected to perform modeling
to provide further technical justification toward establishing necessary levels of treatment.
This water quality modeling (Appendix C) was developed primarily in conjunction with
NPDES permitting for its service area needs and revealed as imposition of stringent.
limits upon the City's WWTP discharges would result i____ j�n egliible Capsiearaixer--
water quality improvement; (b) a 16 MGD capacity secondary WWTP would not cause
appreciable water quality degradation; and (c) non -point source loading of organic
materials to the estuary sediment and oxygen loss in adjacent swampland comprise the
preponderance of dissolved oxygen deficit in the lower Cape Fear River. .
Collectively, the EFDC modeling study shows that the current wasteload allocation for
the two WWTPs is sufficient to protect dissolved oxygen levels in the estuary. In
addition, the City and the County are pursuing the expansion of the Northside facility to
continue providing the capacity to meet regional wastewater treatment needs. Table 1
summarizes the current (30/20), preferred (15/10), and policy -mandated (5/1) wasteload
limits for the Northside WWTP. While the preferred alternative represents scientifically
supported levels of treatment, these limits are in conflict with the current basin policy -
based limits. Therefore, in order to facilitate the regulatory review and approval process,
Environmental Assessment
Northside Wastewater Treatment Plant, New Hanover County 2

the City and the County have elected to design the Northside WWTP expansion for the
current policy -based limits (5/1).
In light of the previous observations, the City and the County have concluded that higher
loading of dissolved oxygen (DO) and ammonia could be permitted without significant
impacts to the Cape Fear River. The City and the County do not believe this approach
represents the best course of action, nor would it be consistent with reasonable
environmental responsibility. Therefore, although limiting its discharge to currently
permitted mass loading levels with higher levels of treatment at higher capacities is
considered an acceptable alternative based on the EFDC study results, the City and the
County have elected to design the Northside WWTP expansion to meet the current
policy -based limits (5/1).
III. PURPOSE & NEED
The need for the proposed wastewater system expansion is driven by the past and
continued growth in population and commercial development within the City and the
County. Since 1990, the City and the County have experienced a 30 percent growth in
population.. To accommodate this rapid growth, it is important that infrastructure
improvements be planned in advance. The City and the County prepared a joint
Wastewater Master Plan (Appendix A) that resulted in population projections and land
use forecasts for existing and proposed sewer service areas for a 20-year planning period
(2000 — 2020). Projections were based on residential growth trends, existing land use and
zoning patterns, and the availability of developable, vacant land using the 1999 CAMA
Land Use Plan Update and Comprehensive Plan (Land Use Plan).
The projected domestic and commercial/retail growth for the planning period (2000 —
2020) will require the City to increase the wastewater treatment capacity of its WWTPs to
accommodate an additional 72,385 service population. These population estimates are
higher than those conducted by the State of North Carolina, and the calculation of future
wastewater flows is based on these higher values to ensure adequate capacity. By the year
2020, approximately 37 percent of the population will be located in the City, 62 percent
in the County, and approximately 1 percent in the Town of Wrightsville Beach.
The current capacity of the Northside and Southside Wastewater Treatment plants is 8
and 12 MGD, respectively. The anticipated growth in the Northside WWTP service area
and the transfer of flow from the Southside WWTP's service area will require the City to
expand the Northside facility's treatment capacity to 16 MGD. With the transfer of flow
to the Northside WWTP's service area, the current treatment capacity of the Southside
WWTP is projected to be adequate for the 20-year planning period.
Environmental Assessment
Northside Wastewater Treatment Plant, New Hanover County 3

IV. ALTERNATIVES ANALYSIS
Due to the high cost of upgrade and expansion of the Northside wastewater treatment
facility, the engineering team of McKim & Creed and Hazen & Sawyer examined several
alternatives to the preferred project. The engineering team performed a wastewater
infrastructure assessment and alternatives analysis.
A. No -Action Alternative
This alternative would result in the Northside WWTP functioning at its current capacity
and would leave both the City of Wilmington and New Hanover County unprepared for
the expected growth and service area demand over the 20-year planning period (2000 —
2020).
The northern section of Wilmington is experiencing major changes in land use patterns,
which require a sustainable and reliable wastewater treatment capacity to maintain a high
quality of life. The downtown area has recently added a significant number of small
businesses, residential condominiums, and apartments to its tax base and the City is
considering construction of a convention center. Facilities like the Hilton Wilmington
Riverside and Cape Fear Community College have doubled in size and new industry and
commercial establishments are being built along Wrightsboro Road and U.S. 421 North.
This segment of the County will soon act as a regional hub for several interstate highways
that will join at the "Wilmington Bypass". Even though the limited access thoroughfare
will bypass most of downtown Wilmington, the northern section of New Hanover County
is projected to experience an influx of product distribution centers and large growth in the
retail sector. Regional commitments have been made and the infrastructure to
accommodate this growth is currently being established. Ample wastewater system
capacity is a critical component in support of this projected growth. If the Northside
WWTP were not expanded, aging septic tank and package systems would remain in their
present condition and be overworked, resulting in less efficient treatment processes and
perhaps even permit violations. In addition, the "No Action Alternative" would have a
negative impact on the Northeast Cape Fear River if new package plants and septic
systems are installed to meet the growth needs in the northern portion of the County.
Furthermore, a major part of the proposed project is the reallocation of existing sewer
infrastructure and service area boundaries from the Southside WWTP to the Northside
WWTP, where lift stations and volume of movement are more efficient. The reallocation
of flows is primarily from the northern portion of New Hanover County, which will
reduce the detention time in force mains, collectors and pump stations, resulting in less
system odor and corrosive production. A no -action alternative would result in the
Southside plant being overburdened. Furthermore, based on the Land Use Plan and the
"Urban Growth Boundary", New Hanover County has made previous fiscal commitments
to allow sections of the County that currently rely on dry sewers to tie into the sewer
Environmental Assessment
Northside Wastewater Treatment Plant, New Hanover County 4

•
M
system.
For these reasons, the no -action alternative is not considered a viable option for the City
of Wilmington or New Hanover County.
B. Construction of a New Wastewater Treatment Plant
The project team evaluated two scenarios concerning the construction of a new plant to
treat the projected County flow for the Northside WWTP. One scenario located the new
plant in the northern part of the County and the other scenario located the plant on
property contiguous with the existing Northside WWTP.
Scenario 1. The potential to construct a new plant in the northern part of the County with
a discharge into the Northeast Cape Fear River was investigated. However, the cost per
unit of capacity was determined to be much higher than the unit cost of obtaining that
capacity at the City's existing Northside facility. In addition, the conditions in the
Northeast Cape Fear River (lower dissolved oxygen and less flushing) do not favor
development of a wastewater discharge in this area.
Scenario 2. The second scenario would involve renovating the existing Northside facility
to correct current problems with aging equipment and constructing a new 8 MGD plant
on land contiguous to the Northside WWTP. Treated wastewater from the new plant
would be discharged to the Cape Fear River with a new effluent force main. The new
force main will be located downstream of the existing Northside WWTP discharge
location. The existing facility will continue to operate under its current NPDES permit
with the following effluent discharge limits.
❑ Flow — 8 MGD
❑ BOD5 — 30 mg/L (2,002 PPD)
❑ TSS — 30 mg/L (2002 PPD)
❑ No Ammonia Limit
The new 8 MGD WWTP would be designed for the following effluent discharge limits.
O Flow — 8 MGD
❑ BOD5 —15 mg/L (1,001 PPD)
O TSS — 30 mg/L (2,002 PPD)
O NH3-N — 10 mg/L (667 PPD)
The limits for the new plant would be in accordance with the water quality modeling
performed by Tetra Tech and presented to EPA and NCDENR.
A new plant that would meet the current basin wide policy requirements was also
evaluated. The new plant was evaluated at the following effluent discharge limits.
Environmental Assessment
Northside Wastewater Treatment Plant, New Hanover County 5

Table 1. Summary of waste load allocation scenarios for the Northside WWTP.
Northside WWTP WASTE LOAD ALLOCATION
Current (8MGD)
Proposed (16 MGD) (2)
Policy Based (16 MGD) (3)
BOD5
NH3-N
mg/L Pounds / day
30 2,002
20 (I) 1,335
mg/L Pounds / day
15 2,002
10 -1,335
mg/L Pounds / day
5 667
1 134
(1) Assumed value since the Northside WWTP currently does not have an ammonia limit.
(2) Scientifically supported by the Water Quality Modeling Report, Appendix C.
(3) Cape Fear River Basin Policy Mandate and WWTP Design Basis.
Environmental Assessment
Northside Wastewater Treatment Plant, New Hanover County
46

TETRA TECH, INC.
3200 Chapel Hill - Nelson Highway
Cape Fear Building - Suite 105
P.O. Box 14409
Research Triangle Park, NC 27709
Telephone: [phone] Telefax: [phone]
TECHNICAL MEMORANDUM
To:
From:
Subject:
Hugh Caldwell
Ken Vogt
Wyatt Blanchard
Jason Doll
Trevor Clements
Results of Dissolved Oxygen and Pollutant
Loading Trend Analyses
Date: January 16, 2003
Project: City of Wilmington
Pjn: 10572-01
Tetra Tech performed a detailed evaluation of the ambient dissolved oxygen data used by NCDWQ as the
basis for including a segment of the Cape Fear River estuary on the 303(d) List submitted to the USEPA.
Additionally, advanced statistical analyses were performed to determine if ambient dissolved oxygen
(DO) data or data for point source loads of oxygen demanding wastes exhibit significant trends over time
in the Cape Fear Estuary. The methods and results of these analyses are presented in this memo.
Evaluation of 303(d) Listing Source Data
To arrive at the decision to include a 5000-acre segment of the Cape Fear Estuary on the 303(d) List as
impaired by low DO levels, NCDWQ evaluated data from its ambient monitoring station network from
September 1, 1993 to August 31, 1998. Communications with Cam McNutt, NCDWQ basinwide
management coordinator for the Cape Fear River Basin, have indicated that the data were evaluated
against the daily average instream dissolved oxygen standard of 5.0 mg/1, as opposed to the instantaneous
minimum standard of 4.0 mg/1. However, DWQ currently uses the instantaneous minimum standard to
evaluate waterbodies for DO impairment (McNutt, 2003).
Within the time period reflected by the dataset evaluated by DWQ, two hurricanes made landfall in the
immediate Lower Cape Fear Region. Hurricane Bertha made landfall as a Category 2 hurricane
(Saffir/Simpson Hurricane Scale) near Wrightsville Beach on the evening of July 12, 1996, and Hurricane
Fran made landfall as a Category 3 hurricane near the mouth of the Cape Fear River on the evening of
September 5, 1996. Prolonged periods of depressed instream dissolved oxygen levels in the Cape Fear
Estuary followed each storm with conditions approaching anoxia at several monitoring locations after
Fran (Mallin et al., 1997).
The 303(d) listing status of a waterbody is based on the use support status determined per section 305(b)
of the Clean Water Act, which requires that states periodically evaluate each waterbody, and based on
available data, determine whether water quality within the waterbody is adequate to support its designated
uses. Per the 305(b) requirement, at the time the segment of the Cape Fear River estuary in question was
evaluated, NCDWQ assigned use support ratings to each indicating whether they are "Fully Supporting,"

Trend Analysis Memo January 16, 2003
"Supporting but Threatened," "Partially Supporting," or "Not Supporting" their designated uses. Section
303(d) of the Clean Water Act requires that states place waters that are rated "Not Supporting" or
"Partially Supporting" on a list of Impaired Waters, referred to as the 303(d) List. Section 303(d) also
requires that a Total Maximum Daily Load (TMDL) be determined for any waterbody that is impaired by
a specific identifiable pollutant or pollutants. The intent of the TMDL is to identify sources for the
specific pollutant(s) and reduce the pollutant loads from those sources to the extent necessary to improve
water quality to a level that will restore the uses deemed impaired. It should be noted, that in its current
application of use support evaluation, per 305(b), that NCDWQ has consolidated use support ratings into
three simpler categories; "Supporting," "Impaired," and "Not Rated." The latter category applies for
waterbodies for which data are insufficient to provide for a definitive rating.
NCDWQ staff have previously indicated, and Mr. McNutt confirmed, that dissolved oxygen data
collected during periods when the system was either sustaining or recovering from the effects of
hurricanes were not excluded when the frequencies of DO standard violations that instigated the listing
status were determined. Based on NCDWQ's analysis, incidents of violations of the 5.0 mg/1 standard
were determined to be greater than 10% at five ambient monitoring stations, leading to placement of a
5000-acre segment of the estuary and Livingston Creek on the state's 303(d) List. The five stations are
listed below in Table 1.
Table 1. Ambient Stations with >10% violations of 5 mg/l DO
Station
STORET
Livingston Creek near Reiglewood
B8450000
Hale Point Landing
B9020000
Navassa
B9050000
Channel Marker 60
B9800000
Channel Marker 54
B9820000
To evaluate the appropriateness of the 303(d) listing status of the estuary segment in question, STORET
data were assembled for the four stations located in the estuary mainstem. The Livingston Creek station
was excluded from this analysis because it is located on a tributary outside the area of concern in this
memo. The dissolved oxygen data from these stations covering the specific data window evaluated by
NCDWQ were isolated and the percentage of monitoring events were tabulated for three scenarios: 1) DO
reported below 5.0 mg/1; 2) DO reported below 4.0 mg/1, and 3) DO reported below 4.0 mg/1 with periods
reflecting hurricane impacts removed. Previous analysis of monitoring data by the Lower Cape Fear
River Program indicated that dissolved oxygen levels in the estuary following Hurricane Bertha returned
to normal around the end of August and that the low DO impacts of Hurricane Fran extended well into
October (Mallin et al., 1997). For purposes of this analysis, data reported during the month that the
hurricanes made landfall and during the following month were removed in scenario #3. The hurricane
data screening resulted in the removal of data from July — October of 1996. No other data were excluded
from the tabulation in scenario #3. The results of the DO data tabulations are reported in Table 2.
Table 2. Percentage Occurrence of Selected DO Monitoring Events
Station
DO reported <5.0
mg/1
DO reported < 4.0
mg/1
DO reported < 4.0 mg/1
(hurricane data removed)
Hale Point Landing
30%
7%
7%
Navassa
29%
13%
11%
Channel Marker 60
27%
14%
12%
Channel Marker 54
21%
7%
6%
S
TETRA TECH, INC.
2

Trend Analysis Memo January 16, 2003
The percentages reflected in Table 2 show that if NCDWQ were to evaluate DO violations using the
instantaneous standard of 4.0 mg/1, rather than 5.0 mg/1, the number of stations reporting violations
greater than 10% of the time in the estuary would be reduced from 4 to 2. Once the data are weighed
against a standard of 4.0 mg/1, the additional action of removing data reported during hurricane impact
periods from consideration has only minimal effect on the percentage of violations experienced at each
station. If NCDWQ had utilized the standards and approach outlined herein to evaluate DO data for the
Cape Fear Estuary, one possible outcome may have been that a portion of the estuary would still have
been placed on the 303(d) List, but the size of the listed area may have been significantly less than the
area currently listed. Additionally, the two remaining stations barely exceed the threshold for designation
as "partially supporting," which may have prompted NCDWQ to examine other factors before deciding to
list the segment (e.g., long-term trends, naturally occurring low DO in swamp waters draining to the
estuary, etc.).
Trend Analysis Methods
Dissolved Oxygen Data
Dissolved oxygen data were obtained from NCDWQ and from Legacy STORET data. Three stations
were selected for analysis based on location and period of record. The stations were Cape Fear River at
Navassa (B9050000), NE Cape Fear River at US 117 near Wilmington (B9740000), and Channel Marker
54(B9820000). These three stations were chosen for the analysis because they offered the longest
available monitoring records and because they are each located either directly within or immediately
adjacent to the 303(d) listed portion of the Cape Fear estuary. Only DO measurements within one foot the
water surface were evaluated, because historical depth stratified monitoring data has consistently
indicated strong mixing with little vertical stratification in the estuary. One outlier was removed from the
dataset — 0.4 mg/1 at the NE Cape Fear station in February 1998. Observations associated with hurricane
events were also removed as discussed in the previous data evaluation. We performed the trend analyses
on data from 1981 through 2002 at the Channel Marker 54 and NE Cape Fear stations, and from 1984 to
2002 for the Navassa station. Data recorded prior to 1984 were not available for Navassa. Truncated
versions of the available data sets, from 1991 through 2002, were also examined for trends.
Figures 1 through 3 show the dissolved oxygen observations for the three stations selected. The hurricane
event observations that were not used in the analysis are shown in red.
c:i TETRATECH, MC.
3

Trend Analysis Memo
January 16, 2003
Figure 1. DO data for the Cape Fear River at Navassa (no trend detected)
16
Navassa
—.— DO
• Hurricane Obs.
'84 '85 '88 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02
Figure 2. DO data for the Northeast Cape Fear River at US 117 near Wilmington (no trend detected).
16
14
12
Northeast Cape Fear
—.— DO
• Hurricane Obs.
'81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02
TETRA TECH, INC.
4

Trend Analysis Memo
January 16, 2003
Figure 3. DO data for the Cape Fear River at Channel Marker 54 (no trend detected).
16
14
12
10
E 8
0
0
6
4
2
0
Channel Marker 54
+DO
• Hurricane Obs.
'81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02
Discharger Data
_J
Data were obtained from NCDWQ and the City of Wilmington for major facilities discharging BOD5 and
ammonia from January of 1994 through October of 2002. Previous point source pollutant loading
assessments by NCDWQ have shown that, based on actual summer effluent data from 1998 and 1999,
90% of the total point source based oxygen demanding pollutant load to the estuary comes from three
facilities — International Paper, and the Wilmington Northside and Southside WWTPs (NCDWQ, 1999).
For that reason, we chose to focus our analysis on those three point sources.
For each of the facilities, monthly loads of BOD5 and ammonia were estimated using monitoring data. In
most cases, BOD5 and ammonia were reported as a daily concentration. Daily load was calculated on
days where both daily concentration and daily flow data existed. The one exception was BOD5 from
International Paper, which was already reported as a daily load. These daily loads were then averaged on
a monthly basis, and multiplied by the number of days in the month to obtain the monthly load. There
were a few cases where monthly loads had to be estimated differently:
Th
• Daily discharge data were not available from NCDWQ at the time of' this writing for Southside
during 1999. As a result, City of Wilmington monthly discharge data were used for this period.
• Ammonia data were not reported on a routine basis during 1994-1996 at International Paper.
Missing values were set equal to a value in the same season. Three seasons during that time frame
had no values, so an average of the previous and next season was used to estimate values for
those seasons. A total of 28 values were estimated using these methods.
TETRA TLCI-4, INC.
5

Trend Analysis Memo January 16, 2003
• Data were not available to estimate BOD5 during November 2001 at International Paper. There
was also an apparent reporting error for January 1997 at International Paper. Both values were
estimated by taking the average of the value for the previous month and the subsequent month.
Monthly BOD5 loads were converted to CBODu using multipliers provided in the previous loading
analysis from NCDWQ (NCDWQ, 1999). Monthly ammonia loads were converted to NBODu using a
multiplier of 4.5 (the stoichiometric ratio for the amount of DO required for the oxidation of ammonia).
Both constituents (CBODu and NBODu) were summed into a monthly BODu for each facility, which
were then summed into a total monthly BODu for all three facilities (Figure 4).
Figure 4. Total monthly BODu loads for 3 largest point sources (with trend line).
Total BODu (NBODu + CBODu)
Combined total from International Paper, Northside, and Southside
3,500,000
3,000,000
2,500,000
2.000,000
1,500,000
1,000,000
500,000
0
1994 1995 1996 1997 1998 1999 2000 2001 2002
Trend Analysis
There are several factors that may influence the value of an observation at a given point in time. For
instance, the time of year influences both DO and BODu observations. This seasonal influence can be
readily seen in the DO observations as increasing and decreasing cycles on an annual basis. The seasonal
influence is less apparent in the BODu data, but the peaks during winter months are easy to see.
Statistical analysis can be used to describe seasonal cycles and account for their influence on the data.
Another factor that may influence observations through time is trend. A trend exists if the data values are
generally increasing or decreasing through time. The purpose of this analysis is to discern if a trend is
present in the DO observations and in the BODu effluent loads.
(h�
Tt I RATtCH, INC.
6

Trend Analysis Memo January 16, 2003
The Seasonal Kendall Test and Seasonal Kendall Slope Estimator (Gilbert, 1987) were selected as the
most appropriate statistical tools for detecting a trend in both the dissolved oxygen observations and the
aggregated BODu data. Any statistical test that detects trend must either remove the seasonal influence on
the data first, or not be affected by it. The Seasonal Kendall Test offers several benefits for detecting
trends in data with a seasonal influence. It is not influenced by a few missing values (as is the case with
the DO data), each season is evaluated independently of the other, and the data do not have to be normally
distributed (which is often the case with water quality data).
One important step in using the Seasonal Kendall Test is determining the best way to define the seasons.
While we are accustomed to using calendar seasons, the test allows for defining seasons on a monthly
basis (or any other arbitrary time period). We evaluated the data divided into monthly seasons and
quarterly seasons. For any given season (monthly or quarterly), all the values in that month or quarter
were averaged into a single representative value, a requirement of the Seasonal Kendall Test.
Another consideration in using the Seasonal Kendall Test is to make sure that the combination of
seasonality and trend describe the time -dependent relationships in the data. If the seasonality and trend
are removed from the data, but the data still show a relationship through time, then it is possible that the
calculated trend is not accurate. In terms of statistics, this is evaluated by measuring the autocorrelation
(or correlation through time) of adjacent points in time. If one point in time is correlated to the next point
in time after seasonality and trend are removed, there is a relationship in addition to seasonality and trend
that is not being accounted for. This is often the case when narrowly defined (such as monthly) seasons
are used. When this occurs, it is considered appropriate to then apply the Seasonal Kendall Test to
aggregate the data to broader (e.g., quarterly) seasons. The autocorrelation of adjacent points in time is
still evaluated, of course, after the quarterly data have seasonal and trend components removed.
Results of Trend Analysis
Dissolved Oxygen
The Seasonal Kendall Test was applied to the datasets from the three stations, both on the entire datasets
and on datasets from 1991— 2002. When the data were evaluated using monthly seasons, there was
significant autocorrelation on adjacent points in time, well above a 95% confidence limit. However, the
autocorrelation was small for data evaluated on a quarterly basis, well below the 95% confidence limit.
This indicated that using the Seasonal Kendall Test on quarterly data was appropriate.
In all the analyses performed, there was no evidence of trend either on the full datasets or on the 1991-
2002 datasets. In each case, the probability of trend was well below the 85% confidence limit reported in
the WQStat software.
Discharger Data
The Seasonal Kendall Test was applied to the combined BODu monthly load for the three facilities from
1994 — 2002. When the data were evaluated using monthly seasons, there was significant autocorrelation
on adjacent points in time, well above a 95% confidence limit. However, the autocorrelation was small
for data evaluated on a quarterly basis, well below the 95% confidence limit. This indicated that using
the Seasonal Kendall Test on quarterly data was appropriate.
The Seasonal Kendall Test showed a highly significant trend (well above a 95% probability level) for
declining levels of BODu from 1994 through 2002. The slope of the trend line determined by the
Seasonal Kendall Slope Estimator was —62,290 lbs of BODu per year. The trend line is shown in Figure 4.
OTETRATECK, INC.
7

Trend Analysis Memo
Conclusions
January 16, 2003
A significant downward trend was detected in the total oxygen demanding pollutant loads from the three
facilities that comprise 90% of all point source loads to the Cape Fear Estuary. Extrapolated over the nine
years of data considered in this analysis, the downward trend represents an overall load reduction of
approximately 25%. Despite this substantive reduction in point source loading, no discernable trend was
discovered in ambient dissolved oxygen data for the stations selected, whether the data were examined
from 1984 through 2002 or 1991 through 2002 (the later period corresponding more closely to the record
of point source data examined). If point source discharges were a significant contributor to the dissolved
oxygen deficits observed in the Lower Cape Fear, one would expect to find an upward trend in ambient
dissolved oxygen levels in response to the evident load reduction. The absence of a detectable trend in
dissolved oxygen data provides further evidence that calls into question the assumption that discharges
are a major factor in dissolved oxygen levels within the estuary.
The conclusions of this trend analysis further support the findings of the previous EFDC modeling
analysis developed by Tetra Tech for the City and New Hanover County. The EFDC model showed that,
even when all discharges were completely eliminated from the study area, the resulting increase in
predicted dissolved oxygen levels averaged 0.3 mg/l or less over the summer season (May — October) at
all stations for which model output was generated. The conclusions of this analysis also provide further
support to the conclusions of the EFDC modeling analysis regarding the impacts of the Wilmington
WWTP discharges in specific. The EFDC analysis indicated that if the current actual pollutant loads
from Wilmington Northside and Southside WWTP discharges were completely eliminated, the resulting
increase in predicted summer season dissolved oxygen levels would average less than 0.03 mg/1, with a
maximum predicted increase of only 0.07 mg/l in the Channel Marker 61 vicinity. Taken together, the
results of this trend analysis and the conclusions of the EFDC model indicate that reducing discharge
limits at either or both of the Wilmington WWTPs to advanced tertiary treatment levels (BOD5 = 5.0 mg/1
and NH3N = 1.0 mg/1) is unlikely to produce a measurable increase in ambient dissolved oxygen levels.
REFERENCES
Gilbert, R.O. 1987. Statistical Methods for Environmental Pollution
Monitoring. Van Nostrand Reinhold. New York, NY. 320 pp.
Tetra Tech, Inc. 2001. 3-Dimensional EFDC Water Quality Model of the Lower Cape Fear and Its
Estuary. 150 pp.
North Carolina Division of Water Quality. 1999. Point Source Loading Analysis Table prepared by
Andy McDaniel for Presentation to Lower Cape Fear River Program Technical Committee. 2 pp.
Mallin, Michael A., Posey, Martin H., Moser, Mary L., Shank, G. Christopher, McIver, Matthew R.,
Alphin, Troy D., Ensign, Scott H., and Merritt, James F. 1997. Water Quality in the Lower Cape Fear
River System, 1996-1997. University of North Carolina — Wilmington, Center for Marine Science
Research. 255 pp.
McNutt, Cam. 2002. Personal communication, NCDWQ Basinwide Management Planning Coordinator,
Cape Fear River Basin.
TETRATECH.INC.
8

1N A Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E. Director
Division of Water Quality
December 17, 2002
Ms. Kim Williams
Land Management Group, Inc.
P.O. Box 2522
Wilmington, NC 28402
Subject: City of Wilmington/New Hanover County Northside WWTP Upgrade and Expansion
Dear Ms. Williams:
The Division of Water Quality has received your request on behalf of the City of Wilmington and New
Hanover County for a review of the draft environmental assessment (EA) for the Northside Wastewater
Treatment Plant Upgrade and Expansion. Due to unresolved issues concerning the facility's NPDES
permit limits, we cannot initiate the EA review process at this time.
The NPDES permit limits for BOD5 and ammonia presented in the draft EA dated October 2002 are not
consistent with speculative effluent limits issued for the facility on February 27, 2002. The EA review
process cannot proceed until the document is modified to reflect limits approved by the Division.
If I can provide any additional assistance regarding the matter, please give me a call at 919.733.5083 ext.
555.
cc: Coleen Sullins
Dave Goodrich✓
Steve Zoufaly
Michelle Woolfolk
Rick Shiver
Hugh Caldwell
Sincerely,
J. Todd Kennedy
DWQ Water Quality Section
2_
DEC 1 8 2002
NcDENR
N. C. Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 [phone] Customer Service
1 800 623-7748

J01
eo soli.s
A y�51 .21lila Lu
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 4
ATLANTA FEDERAL CENTER
61 FORSYTH STREET
ATLANTA, GEORGIA 30303-8960
SEP 2 3 2002
SEP 2 5 2002
Mr. Joe Corporon
North Carolina Department of Environment and
Natural Resources
Division of Water Quality
NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
SUBJ: Proposed Final NPDES Permit
City of Wilmington Northside WWTP
Permit No. NC0023965
r" :: t - r='ATE ; OUALITY
SOURCE BRANCH
Dear Mr. Corporon:
In accordance with the EPA/NCDENR MOA, we have completed review of the proposed
final permit referenced above. Conditioned upon changing footnote 6 in Section A(1) from
"minor modification" to "major modification", we have no comments. We request that we be
afforded an additional review opportunity only if significant changes are made to the proposed
final permit prior to issuance or if significant comments regarding this proposed final permit are
received. Otherwise, please send us one copy of the final permit when issued.
Sincerely,
Marshall Hyatt, Environmental Scientist
Permits, Grants and Technical Assistance Branch
Water Management Division
Internet Address (URL) • http://www.epa.gov
Recycled/Recyclable • Printed with Vegetable Oil Based Inks on Recycled Paper (Minimum 30% Postconsumer)

Cyanide
Subject: Cyanide
Date: Tue, 17 Sep 2002 14:44:27 -0400
From: "Larry Ausley" <[e-mail]>
To: <[e-mail]>
CC: "Steve Tedder" <[e-mail]>, "Cindy Green" <[e-mail]>,
"Clemenstene Nunn" <[e-mail]>, <[e-mail]>,
"Marshall Hyatt"<[e-mail]>,
"Dianne Reid" <[e-mail]>, "James Meyer" <[e-mail]>
Joe, regarding your question on free and total cyanide, I have talked this over with Dianne Reid, Marshall Hyatt, and
our Certification Branch.
First, Dianne says that there is documentation from a past triennial review that the NC standard for cyanide is
interpreted as total. This is consistent with the way we treat metals and residual chlorine. So, any measurement
made as total would be a conservative estimate of free (i.e. toxic) cyanide. It is also consistent with the 1985 EPA
ambient WQ criterion document for cyanide that states:
"...because dissociation of several metallocyanide complexes is very dependent on pH in the range
that commonly occurs in many water bodies, a measurement such as (a) free cyanide at the lowest pH
occurring in the receiving water or (b) cyanide amenable to chlorination or total cyanide (U.S. EPA,
1983a) is probably more appropriate if only a few measurements are made on a water body and
whenever measurements are made on an effluent"
Total cyanide is the only analytical procedure currently certified by our Certification program. In 19,99 EPA
promulgated (promulgation text herehttp://www.epa:qov/reg3wapd/iiretreatment/pdfs txt/cvan.txt)\a method,for
"available cyanide" that they call the equivalent of "cyanide.amenable to chlorination". This -method would include
weakly dissociable forms of cyanide in the environment and wouldtherefore be slightly more conservative than a
measure of total HCN and CN- (free cyanide) and therefore more indicative of those forms that might easily become
toxic. The EPA method itself can be found at: htto:l/www.epa.qov/oamcinc1/0112126/1677.pdf.
The 1985 criterion document lists the following criteria for cyanide:
Fresh water
Final Acute Value = 62.68 ug/L (calculated from Genus Mean Acute Values)
Final Acute Value = 44.73 ug/L (lowered to protect rainbow trout)
Criterion Maximum Concentration = (44.73 ug/L) / 2 = 22.36 ug/L
Final Acute -Chronic Ratio = 8.568
Final Chronic Value = (44.73 ug/L) / 8.568 = 5.221 ug/L
Salt water
Final Acute Value = 2.030 ug/L
Criterion Maximum Concentration = (2.030 ug/L / 2 = 1.015 ug/L
Final Chronic Value = 1.015 ug/L
eMe-fa.';, -•: ;.e permitting is in freshwater (and, as you stated, your concern is with an acute standard, then 1/2
the FAV='31 ug/L. • • Cyanide measurement could be protective of this level. I believe the Wilmington North
is -in fresh water
1 of 2 9/17/02 3:50 PM

Cyanide
•
If the facility you are permitting is in salt water (I believe Wilmington South is in salt), then 1/2 the FAV w be
ug/L. The total cyanide method has an MDL around 5-10 ug/L if you push a lab really hard on it. We're currently
rgrforfrng a PQL of 20 ug/L, the lower limit cited by the EPA method. The available cyanide method lists an MDL of
0.5 ug/L but, if it's like the total method, is not particularly robust to matrix effects. The ability to see that
concentration reliably in an effluent is going to be questionable, in my opinion. If the purpose of this is to establish
reasonable potential to violate a WQ std., then the values you cited me (up as high has 100ppb) have already
established reasonable potential so measurement of free cyanide is really moot relative to the standard.
You may be aware that an option for development of site -specific standards that allow for assessment of
free -cyanide toxicity are being proposed in this triennial review. My recommendation would be to stick with our
existing approach of regulating the conservative total cyanide and make the facility demonstrate the alternative (i.e.
that the amount of available cyanide in their particular wastestream is not toxic in situ), pending this possible change
in the standard. They could (might, depending on matrix effects) demonstrate this by generating "available" cyanide
data with EPA OIA-1677.
Marshall Hyatt with EPA said his review was just going along with y'alls supposition that the standard was for free
cyanide. I think should we straighten him out on that, then our approach with total cyanide would be acceptable to
him.
Let me know if you need further info.
Larry W. Ausley, Supervisor
Microbiology and Inorganic Chemistry Branch
NC Division of Water Quality
4405 Reedy Creek Road
1623 Mail Service Center Raleigh, NC 27699-1623
(t) 919.733.3908 x 222
(f) 919.733.6241
htto:l/www.dwcilab.org
2 of 2 9/17/02 3:50 PM

0ED stiff.
A UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
�m yW REGION 4
Q ATLANTA FEDERAL CENTER
yF�o= 61 FORSYTH STREET
yrgi pRolr- ATLANTA, GEORGIA 30303-8960
SEP 1 1 2002
Mr. Joe Corporon
North Carolina Department of Environment and
Natural Resources
Division of Water Quality
NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
SUBJ: NPDES Permit for City of Wilmington Northside WWTP
Permit No. NC0023965
Dear Mr. Corporon:
In accordance with the EPA/NCDENR MOA, we have completed review of the permit
referenced above and have no comments. We request that we be afforded an additional review
opportunity only if significant changes are made to the permit prior to issuance or if significant
comments regarding the draft permit are received. Otherwise, please send us one copy of the final
permit when issued.
Sincerely,
/V-t),,A,ti * \i �t
Marshall Hyatt, Environmental Scientist
Permits, Grants and Technical Assistance Branch
Water Management Division
SEP 1 3 �nn�
2002
P~.NR - WATER OUALITY
POINT SOURCE EMAN Cti
Internet Address (URL) • http://www.epa.gov
Recycled/Recyclable • Printed with Vegetable Oil Based Inks on Recycled Paper (Minimum 30% Postconsumer)

CITY OF WILMINGTON
PUBLIC UTILITIES DEPARTMENT
Joe R. Corporon
NC Division of Water Quality
NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
Re :
August 20, 2002
NPDES Draft Permit Comments
Permit No. NC0023965
James A. Loughlin (Northside) WWTP
Dear Mr. Corporon:
P.O. Box 1810
WILMINGTON, NC 28402
TDD [phone]
0
AUG 2 3 2002
CE':R - WATER QUALITY
POINT SOURCE BRANCH
We have reviewed the draft renewal permit transmitted on July 22, 2002 and subsequent
revisions. We have also reviewed the cover letter, fact sheet and amendment certification
statement that accompanied the draft. Following are our comments:
NPDES Draft Permit Comments
• The EFDC mixing study commissioned by the City of Wilmington and New Hanover
County includes a substantial analysis of near and far -field mixing dynamics for the
Northside effluent which indicates much higher levels of dilution than assumed by DWQ.
The study was submitted to DWQ in June 2001.
• Use of the mixing study dilution values could potentially eliminate the monitoring
requirements for zinc, silver and copper. We will be glad to provide a copy of the study
if you are unable to obtain it from Michelle Woolfolk.
• None of the typical Part II and Part III boiler plate was included in the 7/22/02 draft. Has
this been eliminated? If not, we need a copy for review and comment.
• The footnotes on the 8/14/02 revision to the effluent page are incorrectly numbered
• Based on discussions with other dischargers, stream monitoring for mercury seems to be
inconsistently applied in the Lower Cape Fear Basin.
• In -stream DO monitoring at 3/week is inconsistent with the Lower Cape Fear River
Program sampling protocol as approved in the MOA.
• The draft permit does not specify % removal requirements for BOD and TSS. Has this
been eliminated?
• The monitoring data used by DWQ to justify our permit is inconsistent with that
submitted on our DMRs. It is unclear how DWQ derived the data.
• Cyanide monitoring data is suspect at best. There are many interferences associated with
cyanide testing as demonstrated in studies by UNC-Chapel Hill.
ADMINISTRATION ENVIRONMENTAL SERVICES UTILITY SERVICES WASTEWATER TREATMENT
VOICE [phone] VOICE [phone] VOICE [phone] LOUGHUN PLANT MAFFTTT PLANT
FAX [phone] FAx [phone] FAX [phone] VOICE [phone] VOICE [phone]
FAX [phone]
WATER TREATMENT
VOICE [phone]
FAx [phone]

Joe R. Corporon
August 20, 2002
Page Two
• There is no wastewater certification for testing free cyanide. This requirement should be
eliminated until a reliable, certified testing method is developed.
• Our historical monitoring data has not indicated a problem with mercury. The stream
monitoring requirement for mercury should be deleted.
• In Sect A (2) the parameter code for acute toxicity should be TGE3D (daphnia pulex).
• In Sect A (3) the cyanide evaluation should be eliminated since there are no reliable,
certified test methods.
Fact Sheet Comments
• The facility description should read: "..utilizing trickling filter/activated sludge secondary
treatment for domestic....The treatment system utilizes: a mechanical bar screen; grit
removal device; dual primary clarifiers; dual trickling filters; an aeration basin; dual
secondary clarifiers; chlorine disinfection facilities; effluent pump station; a final end of
pipe effluent diffuser..."
• We believe the stream classification to be SC -Swamp
• The Lat/Long for the discharge differs from our current permit
• We understand that segments of the Lower Cape Fear River are 303(d) listed
• DMRs should be reviewed in complete 12 month increments to eliminate cyclical
variation and bias
• The number of samples and hits in Table 3 are inconsistent with our DMRs
Certification of Permit Application Amendment Comments
• Many inconsistencies have been discovered in the DWQ data to be submitted with the
permit amendment; therefore, I cannot sign the certification at this time.
• City of Wilmington staff are working with the permit writer to resolve the data
discrepancies. We anticipate at least 30 days of additional review time will be needed.
We feel these comments should be addressed prior to sending the permit for public
notice. If you have any questions please feel free to contact me.
Yours very truly,
":16-6, adat,,a,
Hugh T. Caldwell, PE
Director of Public Utilities
cc: Ken Vogt, Superintendent of Wastewater Treatment

Re: Northside Draft Permits -- RPA Database Review NC0023965
Subject: Re: Northside Draft Permits -- RPA Database Review NC0023965
Date: Tue, 27 Aug 2002 11:45:06 -0400
From: [e-mail]
To: Joe Corporon <[e-mail]>
CC: "[e-mail]" <[e-mail]>
I am presently working on the Northside Plant's database. I'll try to
expedite completion for Hugh's review and subsequent submittal to you.
Thanks.
Joe Corporon
<joe.corporon@ncm
ail.net>
08/27/02 10:47 AM
Ms Ellis; Mr. Calwell:
To: "[e-mail].u,
"[e-mail]" <H
cc:
Subject: Northside Draft Permits -- R
I'm reviewing Wilmington's recent comments on the Draft permit (20Aug).
These contain a question about DWQ's database used for the "reasonable
potential analysis" (RPA). Aside from unresolved dilution questions, I
assume Wilmington feels a revised database may impact the RPA. Let's
start with the database.
Could you please review the XL file (provided to Pam on 15Aug02) and
return me a corrected version? You may insert rows for new data as you
see fit (please include dates in Column E). Perhaps it would be prudent
to place corrections to a different column (maybe M?) for each parameter
needing revision.
Similarly, you should review and correct the database for the Southside
plant as well, because the RPA strategy is the same. However, please
send me Northside first. Feel free to call me if you have questions
(919-733-5083-597).
Thanks for your prompt attention,
_Joe Corporon
1 of 1 9/6/02 7:52 AM

[Fwd: Northside Draft Renewal Permit Comments]
O
Subject: [Fwd: Northside Draft Renewal Permit Comments]
Date: Tue, 20 Aug 2002 16:48:51 -0400
From: Dave Goodrich <[e-mail]>
To: Joe Corporon <[e-mail]>
Joe -
You need to jump on the issue of the RPA data not reflecting what was
reported on their DMRs. That looks like the biggest hold up.
Thanks,
Dave
Subject: Northside Draft Renewal Permit Comments
Date: Tue, 20 Aug 2002 16:30:52 -0400
From: [e-mail]
To: Joe Corporon <[e-mail]>
CC: [e-mail], [e-mail], [e-mail],
[e-mail], [e-mail],
[e-mail], [e-mail], [e-mail]
Joe, attached are our comments. I will follow up with a hard copy via
surface mail.
(See attached file: Northside NPDES Draft Renewal Permit Comments.doc)
MNorthside NPDES Draft Renewal Permit Comments.doc
Name: Northside NPDES Draft
Renewal Permit
Comments.doc
Type: Microsoft Word
Document
(application/msword)
Encoding: base64
Download Status: Not downloaded with
message
1 of 1 9/6/02 8:00 AM

Re: [Fwd: [Fwd: comments on DRAFT 2 for Wilmington Northside WWTP--NC0023965]]
.
Subject: Re: [Fwd: [Fwd: comments on DRAFT 2 for Wilmington Northside WWTP
--NC0023965]]
Date: Fri, 16 Aug 2002 09:01:43 -0400
From: [e-mail]
To: Joe Corporon <[e-mail]>
thanks for responding promptly. I've been out of the office most of
this week. Did Wilmington resolve its supplemental database and send
you the certification yet? I don't have any objections, but I think I
need to have the certification in hand before sending a no comment
letter. Is that ok? thanks Marshall
1 of 1 9/6/02 7:59 AM

file:///Untitled
• ' Marshall, about your other two questions:
• You probable noticed, we added a comment to the cover letter warning of a new TRC limit pending
the adoption of a standard. In the interim, our renewal policy remains that we require a TRC limit for
"...new and expanding discharges only." [For details, see the NPDES website.]
• Concerning the Application Supplement, Wilmington has asked to review the supplemental database
before a final is provided to EPA and before they sign their authorization form.We are currently
awaiting their question/comments and corrections, if any. They have indicated a possible resolution
by close of business tomorrow. They're working on draft permit comments.
[e-mail] wrote:
thanks for checking w/ Matt re the WET species issue. I'm satisfied.
Would like to hear back from you by this thursday re my other 2 comments
so I can send you a no comment letter. thanks.
1 of 1 8/14/02 2:38 PM

comments on DRAFT 2 for Wilmington Northside WWTP -- NC0023965
Subject: comments on DRAFT 2 for Wilmington Northside WWTP -- NC0023965
Date: Thu, 25 Jul 2002 08:44:36 -0400
From: [e-mail]
To: Joe Corporon <[e-mail]>
CC: [e-mail]
pls respond so we can resolve these and send a no comment letter.
thanks Marshall
- we did not receive a copy of the facility's permit application
certification. would you pls send us a copy for our files?
- why isn't TRC assessed in RPA Table 3
in the fact sheet?
- re WET, why isn't Mysidopsis bahia the test species since this
facility discharges to saltwater?
1 of 1 8/5/02 2:48 PM

Nc0023965 -- Northside's Renewal Application Supplement Databa
• c r
Subject: Nc0023965 -- Northside's Renewal Application Supplement Database
Date: Thu, 15 Aug 2002 11:03:02 -0400
From: Joe Corporon <[e-mail]>
To: [e-mail]
Pam,
As discussed in our phone conversations yesterday, the attached file is
intended to provide a summary of Northside's DMR effluent charateristics
to meet federal permit application requirements. EPA Region 4 agreed to
accept such a summary from facilities applying prior to 01Aug01 in lieu
of these facilities having to resubmit a Form 2A application. DWQ
generated the attached summary from Northside's DMR data in our tracking
system.
Please review and complete these data, or provide other data you can
certify as complete and correct (form provided). If you agree to alter
this database, please highlight additions and corrections so that we
might revise our tracking records. Feel free to add comments and/or add
color to clarify and return as an electronic copy. The NPDES Unit will
provide your corrected data and your signed certification form to EPA as
a supplement to your permit renewal application.
Thanks,
Joe
Supplemental -- effluentdata-wilmington.xls
Name: Supplemental -- effluentdata-wilmington.xls
Type: Microsoft Excel Worksheet
(application/vnd.ms-excel)
Encoding: base64
1 of 1 8/15/02 11:06 AM

NC0023965 — Fact Sheet and RPA Databas.
Subject: NC0023965 -- Fact Sheet and RPA Database
Date: Thu, 15 Aug 2002 11:04:51 -0400
From: Joe Corporon <[e-mail]>
To: [e-mail]
Pam,
Per your request, please find attached 1) the renewal Fact Sheet that documents DWQ decisions made to
create your draft permit (corrections discussed with you on 14Aug) and 2), the Reasonable Potential
Analysis (RPA) database used for this renewal. Again, because Northside discharges under tidal
conditions, these data were compared to acute water quality criteria only. Any comments or corrections to
the database that might alter the "reasonable potential" would be appreciated.
Thanks,
Joe
MNorthside 23965 Acute RPA.xls
Name: Northside 23965 Acute RPA.xls
Type: Microsoft Excel Worksheet (application/vnd.ms-excel)
Encoding: base64
Northside 23965 - Fact Sheet DRAFT 3.doc
Name: Northside 23965 - Fact Sheet DRAFT 3.doc
Type: Microsoft Word Document
(application/msword)
Encoding: base64
1 of 1 8/15/02 11:06 AM

Northside DRAFT -- Correction to Ammonia Monitoring Frequent
;; r
•
Subject: Northside DRAFT -- Correction to Ammonia Monitoring Frequency
Date: Wed, 14 Aug 2002 15:07:36 -0400
From: Joe Corporon <[e-mail]>
To: "[e-mail]" <[e-mail]>
Hugh,
I've found an error in your draft permit. Ammona (NH3 as N) should be reported3/Week consistant with a
Class IV facility, not 2/Month (see attached file). Please consider this in your draft review.
Thanks,
Joe
EFF Draft Page Correction -- Ammonia.doc
Name: EFF Draft Page Correction -- Ammonia.doc
Type: Microsoft Word Document
(application/msword)
Encoding: base64
1 of 1 8/15/02 11:07 AM

Re: [Fwd: comments on DRAFT 2 for Wilmington Northside WWTP -- NC0023965]
c
e
Subject: Re: [Fwd: comments on DRAFT 2 for Wilmington Northside. WWTP -- NC0023965]
Date: Fri, 09 Aug 2002 08:54:42 -0400
From: Matt Matthews <[e-mail]>
Organization: NC DENR DWQ
To: Joe Corporon <[e-mail]>
Joe,
As I recall, this facility outfall discharges to an area of the river that is at the boundary of fresh and
saltwater classifications and was, in fact classified as freshwater when the WET requirement was initially
applied.
That said, our routine permitting strategy applies fathead minnow acute pass/fail tests when the 7Q10 is
determined to be tidal, or when our modelers say that 7Q10 values are meaningless. The reason we've
operated in this way is based in a special study conducted with EPA Region IV back in the late 80's. We
did acute tests comparing fathead minnows to menidia and sheepsheads, and Ceriodaphnia to mysid
shrimp. We found that the organisms were generally equivalent in sensitivity, except for the sheepsheads,
which were less sensitive than the other two fish tested. Given this result, and the fact we'd rather not
tamper with the effluents by salting them with either dry salt or hypersaline brine, we've felt comfortable
using fathead minnows to evaluate for significant mortality. We allow permittees who discharge to SC
waters the option to use saltwater organisms if they prefer.
Marshall will see the above strategy applied to 15 other facilities. Three of those have opted for mysid
shrimp tests.
Wilmington, at their own preference, decided to request the use of Daphnia pulex. We were OK with that
since our previous experience with that animal showed it to be at least as sensitive to their effluent as
fatheads. Whenever I have spoken with Wilmington officials I have encouraged them to switch to either
fatheads or Ceriodaphnia if for no other reason than to make it easier on their lab.
Let me know if you need anything further.
Joe Corporon wrote:
Matt, can you answer Marshall's question about WET saltwater species? I
have attached the TOX page for Willmington Northside, but his question
will also apply to Willmington Southside (draft in progress).
Thanks,
- -Joe
pls respond so we can resolve these and send a no comment letter.
thanks Marshall
- we did not receive a copy of the facility's permit application
certification. would you pls send us a copy for our files?
- why isn't TRC assessed in RPA Table 3 in the fact sheet?
1 of 2 8/22/02 7:35 AM

Re: [Fwd: comments on DRAFT 2 for Wilmington Northside WWTP -- NC0023965]
- re WET, why isn't Mysidopsis bahia the test species since this
facility discharges to saltwater?
Matt Matthews
NC DENR/Division of Water Quality
Aquatic Toxicology Unit
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
v-[phone]
f-[phone]
MailTo:Matt.MatthewsCncmail.net
A few observations and much reasoning lead to error;
many observations and a little reasoning to truth.
--Alexis Carrel
2 of 2
8/22/02 7:35 AM

c.
PRO��
SEP 2 1 2004
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REG.IO.kA
ATLANTA FEDER t ENTER <w '
61i FORSY ..S3REET
ATLANTA, 3103 96Q, O the lllj U I
Dave Goodrich, Chief
Point Source Branch
Division of Water Quality
NC Dept. of Environment
and Natural Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
SEP 2 3 2004
DENR - WATER QUALITY
POINT SOURCE BRANCH
• b
SUBJ: Proposed Final NPDES Permit
City of Wilmington James A. Loughlin (Northside) WWTP
Permit No. NC0023965
Dear Mr. Goodrich:
II t�
We are in receipt of the proposed final National Pollutant Discharge Elimination System
(NPDES) permit for the facility referenced above, pursuant to Section III.B.3 of the Environmental
Protection Agency (EPA)/NC NPDES Memorandum of Agreement. Thank you for the
opportunity to provide our input.
Reasonable potential analyses for both the draft and proposed final NPDES permits
assessed acute water quality criteria only. The fact sheet indicates that due to the facility's tidal
discharge, it was concluded that a reasonable potential analysis for chronic water quality criteria
was not needed. However, no site -specific dye study or modeling results were cited as the basis
for this conclusion.
Because the facility's discharge is increasing from 8.0 million gallons/day (MGD) to 16.0
MGD, the EPA is concerned that the extent of any acute impact in the area of the discharge has not
been adequately characterized. Due to the lack of a specified mixing zone, it does not appear that
the mixing zone provisions of 15A North Carolina Administrative Code 02B .0204 have been
addressed. These include allowing free passage of aquatic organisms and exposing sessile aquatic
communities in the area of the discharge to acutely toxic conditions.
Due to the increased discharge and the lack of a specified mixing zone, the EPA is also
concerned that excursions of North Carolina's chronic aquatic life criteria may also occur. Existing
modeling and dye study results may provide information to address this concern, but we are not
aware that such an evaluation has been conducted.
Internet Address (URL) • htlp://www.epa.gov
Recycled/Recyclable • Printed with Vegetable Oil Based Inks on Recycled Paper (Minimum 30% Postconsumer)

2
Based on these concerns, the EPA requests that provisions be added to the permit to
require the facility to conduct and submit the results from sufficient modeling, dye, and/or biological
studies within one year of the increase in discharge so that a specific mixing zone can be assigned
and an assessment of acute and chronic water quality criteria and conditions in the area of the
discharge can be made by your office. If this information is not collected during the term of this
permit, any reissued permit will be subject to disapproval by the EPA due to the lack of these
assessments.
If you have any questions, please call me or have your staff contact Mr. Marshall Hyatt at
[phone].
Sincerely,
CtAiry
Wayne Aronson, Acting Chief
Permits, Grants and Technical Assistance Branch
Water Management Division
cc: Hugh T. Caldwell, P.E, City of Wilmington