NC0047597_Permit Issuance_20110919

NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins Dee Freeman
Governor Director Secretary
September 19, 2011
Robert Dodson, Superintendent
City of Durham Department of Water Management
101 City Hall Plaza
Durham, North Carolina 27701
Subject: Issuance of Permit NC0047597
South Durham WRF
Class IV Facility
Durham County
Dear Mr. Dodson:
Division of Water Quality (Division) personnel have reviewed and approved your application for
renewal of the subject permit. Accordingly, we are forwarding the attached NPDES discharge permit.
It is issued pursuant to the requirements of North Carolina General Statute 143-215.1 and the
Memorandum of Agreement between North Carolina,.and the U.S. Environmental Protection Agency
dated October 15, 2007.
There were several changes to your permit from the draft permit issued June 8, 2011. They include
the following:
• Quarterly monitoring requirements for copper and selenium were removed. A review of additional
monitoring results shows that there is no reasonable potential for these pollutants to cause an
exceedance of water quality standards.
• Quarterly monitoring for bis(2-ethylhexyl)phthalate was also removed. The laboratory has
confirmed that the only sample result above detection limits for this pollutant should be discarded,
since there is zero confidence inits accuracy.
• As a result of the revised reasonable potential analysis, daily and monthly limits were implemented
for total mercury, with a monitoring frequency of once per month. These limits are conditioned with
a 12-month compliance period, such that they will not go into effect until November 1, 2012.
Additionally, the City may petition for a reduction to quarterly monitoring after 12 consecutive
months of sampling results under the water quality standard of 12 ng/L.
• The special condition concerning nitrogen optimization was deleted. The Division is reviewing its
policy on this subject.
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: [phone] FAX: [phone] \ Customer Seivice:1-877-623-6748
Internet: www.ncwaterquality.org
M Equal opportunity 1 Affirmative Action Employer
ose NCarolina
atura!ly

The following modifications from the draft permit remain in effect:
• In accordance with the Jordan Lake nutrient management strategy, a new annual mass discharge
limit for total nitrogen of 185,345 pounds per year, effective January 1, 2016, was added.
• Limits for fluoride were removed, due to the results of the reasonable potential analysis.
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 take 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 demand is
made, this permit remains final and binding.
This permit is not transferable except after notifying the Division of Water Quality. The Division may
modify and re -issue, or revoke 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 assistance, please contact Mr. Gil Vinzani at
[[e-mail]] or call [phone].
Sincerely,
141
leen H. Sullins
Enclosure: NPDES Permit FINAL NC0047597
Cc: US EPA Region IV, Pamala Myers*
Raleigh Regional Office, Surface Water Protection Section
Environmental Services Section, Aquatic Toxicology Unit, Susan Meadows*
NPDES Files
Central Files
*E-mail Copy
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: [phone] FAX: [phone] \ Customer Service: 1-877-623-6748
Internet: www.ncwaterquality.org
An Equal Opportunity\ Affirmative Action Employer
None
rthCaroli na
baturallg

Permit No. NC0047597
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
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 Durham
is hereby authorized to discharge wastewater from a facility located at the
South Durham Water Reclamation Facility
6605 Farrington Road
Chapel Hill, NC
Durham County
to receiving waters designated as an unnamed tributary to New Hope Creek in 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, 2011.
This permit and authorization to discharge shall expire at midnight on April 30, 2016.
Signed this day September 19, 2011:
Q�1
een H. Sullins, Director
eft7 Division of Water Quality
By Authority of the Environmental Management Commission

Permit No. NC00475971
•
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby
revoked. As of this permit issuance, any previously issued permit bearing this number is no longer
effective. Therefore, the exclusive authority to operate and discharge from this facility arises under the
permit conditions, requirements, terms, and provisions included herein.
The City of Durham
is hereby authorized to:
1. Continue to operate an existing 20.0 MGD wastewater treatment facility consisting of the following:
• Mechanically cleaned bar screens
• Long channel grit chambers
• Primary clarifiers
• Aeration basins
• Final clarifiers
• Flocculation basins
• Traveling bridge effluent sand filters
• UV disinfection
• Anaerobic digesters
• Aerobic digesters
• Gravity belt thickener
• Clarifier
• Sand drying beds
• Belt filter press
Facility is located at 6605 Farrington Road, Chapel Hill, NC, in Durham County, and
2. Discharge from said treatment works at the location specified on the attached map into an unnamed
tributary to New Hope Creek, classified WS-IV NSW waters in the Cape Fear River Basin.

South Durham WRF - NC0047597
USGS Quad Name: Southwest Durham
Receiving Stream: New Hope Creek
Stream Class: WS-IV NSW
Subbasin: Cape Fear - 030605
Lat.: 35°58'18"
Long.: 78°58'28"
HUC: 03020101
North
SCALE 1:24,000

Permit No. NC0047597
A (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
Beginning upon the effective date of this permit and lasting until expiration, the Permittee is authorized
to discharge treated wastewater from Outfall 001. Such discharges shall be limited and monitored by
the Permittee as specified below:
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Flow
20.0 MGD
Continuous
Recording
I or E
Total Monthly Flow (MG)
Monitor
& Report
Monthly
Recorded or Calculated
Calculated
or E
BOD, 5-day, (20°C) 2
(April 1 — October 31)
5.0 mg/L
7.5 mg/L
Daily
Composite
I & E
BOD, 5-day, (20°C) 2
(November 1 — March 31)
7.0 mg/L
10.5 mg/L
Daily
Composite
I & E
Total Suspended Solids2
30.0 mg/L
45.0 mg/L
Daily
Composite
I & E
NH3 as N (April 1-October 31)
1.0 mg/L
3.0 mg/L
Daily
Composite
E
NH3 as N (November 1-March
31)
2.0 mg/L
6.0 mg/L
Daily
Composite
E
Dissolved Oxygen3
Daily
Grab
E
pH 4
Daily
Grab
E
Total Residual Chlorines •
17.0 pg/L
Daily
Grab
E
Temperature (°C)
Daily.
Grab
E
Fecal Coliform
(geometric mean)
200/100 ml
400/100 ml
Daily
Grab
E
TKN
Monitor
& Report (mg/L)
Weekly
Composite
E
NO3-N + NO2-N
Monitor
& Report (mg/L)
Weekly
Composite
E
Total Nitrogen, TN 6
Monitor
& Report (mg/L)
Weekly
Composite
E
TN Load'�a
Monitor
334,705
185,345
& Report (Ib/mo)
lb/yr (until 12/31/2015)
lb/yr (effective 1/1/2016)
Monthly
Annually
Annually
Calculated
E
Total Phosphorus, TP
Monitor
& Report (mg/L)
Weekly
Composite
E
TP Load 7's
Monitor
& Report (Ib/mo)
14,053 lb/yr
Monthly
Annually
Calculated
E
Total Mercury 9
12 ng/L
36 ng/L
Monthly
Grab
E
Total Zinc
Quarterly
Composite
E
Chronic Toxicity 1°
Quarterly
Composite
E
Annual Pollutant Scan"
Annually
See A (5)
E
Footnotes are shown on the next page.

Permit No. NC0047597 ,
Footnotes to Table A (1) on the previous page:
1. I = Influent; E = Effluent. See Condition A (2) for instream monitoring requirements.
2. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15% of the
respective influent value (85% removal).
3. The daily average dissolved oxygen effluent concentration shall not be Tess than 6.0 mg/L.
4. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
5. Monitoring requirement and limit applies only if chlorine is added for disinfection. The Division shall consider
all effluent TRC values reported below 50 pg/L to be in compliance with the permit. However, the Permittee
shall continue to record and submit all values reported by a North Carolina certified laboratory (including field
certified), even if these values fall below 50 pg/L.
6. TN = TKN + NO3-N + NO2-N, where TN is total nitrogen, TKN is Total Kjeldahl Nitrogen, and NO3-N and NO2-
N are Nitrate and Nitrite Nitrogen, respectively.
7. TN or TP Load is the mass quantity of Total Nitrogen and Total Phosphorus discharged in a given period of
time. See Special Condition A (8) Calculations of Total Nitrogen or Total Phosphorus Loads.
8. Compliance with mass limits shall be determined in accordance with Special Condition A (7), Annual Limits
for Total Nitrogen or Total Phosphorus.
9. Total mercury shall be sampled using low-level Method 1631 E. Both limits will take effect November 1, 2012.
Monthly monitoring commences November 1, 2011. After 12 consecutive months of monitoring with no
sample results above water quality standards (12 ng/L), the Permittee may petition for a reduction to quarterly
monitoring.
10. Chronic Toxicity (Ceriodaphnia) P/F @ 90%; January, April, July, and October (See A (4) Special Conditions
of the Supplement to Effluent Limitations).
11. See Special Condition A (5) Effluent Pollutant Scan.
There shall be no discharge of floating solids or foam in other than trace amounts.
A (2) INSTREAM MONITORING REQUIREMENTS
Monitoring Locations: Upstream - New Hope Creek at 1-40
Downstream - At NCSR 1107
Parameter
Frequency
Sample Type
Dissolved Oxygen
3/week, June 1— September 30; 1/week, October 1 — May 31
Grab
Fecal Coliform
3/week, June 1— September 30; 1/week, October 1— May 31
Grab
Temperature
3/week, June 1 — September 30; 1/week, October 1— May 31
Grab
Conductivity
3/week, June 1— September 30; 1/week, October 1— May 31
Grab
pH
3/week, June 1— September 30; 1/week, October 1 — May 31
Grab
Total Phosphorus
1/week, June 1 — September 30
Grab
NO3-N + NO2-N
1/week, June 1— September 30
Grab
TKN
1/week, June 1 — September 30
Grab
PO4
1/week, June 1— September 30
Grab
A (3) PROVISIONAL WAIVER OF INSTREAM MONITORING REQUIREMENTS
Instream monitoring requirements in A (2) above shall be provisionally waived so long as the Permittee
remains a member of the Upper Cape Fear River Basin Association and the Association continues to
function as approved by the Division and Environmental Management Commission. If the Permittee
does not participate in the Association or if the Association ceases to function, the instream monitoring •
requirements in this permit become effective immediately; and the Division may reopen this permit by
administrative letter to establish additional instream monitoring requirements it deems necessary to
adequately characterize the effects of the discharges on water quality in the receiving stream.
1,

Permit No. NC0047597
. t:
A (4) CHRONIC TOXICITY PASS/FAIL PERMIT LIMIT
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant
mortality to Ceriodaphnia dubia at an effluent concentration of 90%.
The permit holder shall perform at a minimum, quarterly monitoring using test procedures outlined in
the "North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised February 1998, or
subsequent versions or "North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure"
(Revised -February 1998) or subsequent versions. The tests will be performed during the months of
January, April, July, and October. Effluent sampling for this testing shall be performed at the NPDES
permitted final effluent discharge below all treatment processes.
If the test procedure performed as the first test of any single quarter results in a failure or ChV below
the permit limit, then multiple -concentration testing shall be performed at a minimum, in each of the two
following months as described in "North Carolina Phase II Chronic Whole Effluent Toxicity Test
Procedure" (Revised -February 1998) or subsequent versions.
The chronic value for multiple concentration tests will be determined using the geometric mean of the
highest concentration having no detectable impairment of reproduction or survival and the lowest
concentration that does have a detectable impairment of reproduction or survival. The definition of
"detectable impairment," collection methods, exposure regimes, and further statistical methods are
specified in the "North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised -
February 1998) or subsequent versions.
All toxicity testing results required as part of this permit condition will be entered on the Effluent
Discharge Monitoring Form (MR-1) for the months in which tests were performed, using the parameter
code TGP3B for the pass/fail results and THP3B for the Chronic Value. Additionally, DWQ Form AT-3
(original) is to be sent to the following address:
NCDENR/ DWQ/ Environmental Sciences Section
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental Sciences Section no later
than 30 days after the end of the reporting period for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical measurements and all
concentration/response data, and be certified by laboratory supervisor and ORC or approved designate
signature. Total residual chlorine of the effluent toxicity sample must be measured and reported if
chlorine is employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is
required, the permittee will complete the information located at the top of the aquatic toxicity (AT) test
form indicating the facility name, permit number, pipe number, county, and the month/year of the report
with the notation of "No Flow" in the comment area of the form. The report shall be submitted to the
Environmental Sciences Section at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required, monitoring
will be required during the following month. Should any test data from this monitoring requirement 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, minimum control organism reproduction, and appropriate environmental controls, shall
constitute an invalid test and will require immediate follow-up testing to be completed no later than the last
day of the month following the month of the initial monitoring.

Permit No. NC0047597
,T
A (5) EFFLUENT POLLUTANT SCAN
The Permittee shall perform an annual Effluent Pollutant Scan for all parameters listed in the attached
table. The analytical methods shall be in accordance with 40 CFR Part 136 and shall be sufficiently
sensitive to determine whether parameters are present in concentrations greater than applicable
standards and criteria. Samples shall represent seasonal variations. Unless otherwise indicated,
metals shall be analyzed as "total recoverable."
Ammonia (as N)
Chlorine (total residual, TRC)-
Dissolved oxygen
Nitrate/Nitrite
Kjeldahl nitrogen
Oil and grease
Phosphorus
Total dissolved solids
Hardness
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury*
Nickel
Selenium
Silver
Thallium
Zinc
Cyanide
Total phenolic compounds
Volatile organic compounds:
Acrolein
Acrylonitrile
Benzene
Bromoform
Carbon tetrachloride
Chlorobenzene
Chlorodibromomethane
Chloroethane
2-chloroethylvinyl ether
Chloroform
Dichlorobromomethane
1,1-dichloroethane
1,2-dichloroethane
Trans-1 ,2-dichloroethylene
1,1-dichloroethylene
1,2-dichloropropane
1,3-dichloropropylene
Ethylbenzene
Methyl bromide
Methyl chloride
Methylene chloride
1,1,2,2-tetrachloroethane
Tetrachloroethylene
Toluene
1,1,1-trichloroethane
1,1,2-trichloroethane
Trichloroethylene
Vinyl chloride
Acid -extractable compounds:
P-chloro-m-cresol
2-chlorophenol
2,4-dichlorophenol
2,4-dimethylphenol
4,6-dinitro-o-cresol
2,4-dinitrophenol
2-nitrophenol
4-nitrophenol
Pentachlorophenol
Phenol
2,4,6-trichlorophenol
Base -neutral compounds:
Acenaphthene
Acenaphthylene
Anthracene
Benzidine
Benzo(a)anthracene
Benzo(a)pyrene
3,4 benzofluoranthene
Benzo(ghi)perylene
Benzo(k)fluoranthene
Bis (2-chloroethoxy) methane
Bis (2-chloroethyl) ether
Bis (2-chloroisopropyl) ether
Bis (2-ethylhexyl) phthalate
4-bromophenyl phenyl ether
Butyl benzyl phthalate
2-chloronaphthalene
4-chlorophenyl phenyl ether
Chrysene
Di-n-butyl phthalate
Di-n-octyl phthalate
Dibenzo(a,h)anthracene
1,2-dichlorobenzene
1 ,3-dichlorobenzene
1,4-dichlorobenzene
3,3-dichlorobenzidine
Diethyl phthalate
Dimethyl phthalate
2,4-dinitrotoluene
2,6-dinitrotoluene
1,2-diphenylhydrazine
Fluoranthene
Fluorene
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclo-pentadiene
Hexachloroethane
Indeno(1,2,3-cd)pyrene
Isophorone
Naphthalene
Nitrobenzene
N-nitrosodi-n-propylamine
N-nitrosodimethylamine
N-nitrosodiphenylamine .
Phenanthrene
Pyrene
1,2,4-trichlorobenzene
Test results shall be reported to the Division in DWQ Form- DMR-PPA1 or in a form approved by the
Director within 90 days of sampling. The report shall be submitted to the following address:
NCDENR/ DWQ/ Central Files
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
* Mercury samples shall be analyzed using EPA Method 1631.

Permit No. NC0047597
A (6) NUTRIENT ALLOCATIONS
(a) The following table lists the Total Nitrogen (TN) and Total Phosphorus (TP) allocations
assigned to, acquired by, or transferred to the Permittee in accordance with the Jordan Lake
nutrient management rule (T15A NCAC 02B .0270) and the status of each as of permit
issuance. For compliance purposes, this table does not supersede any TN or TP limit
established elsewhere in this permit or in the NPDES permit of a compliance association of
which the Permittee is a Co-Permittee Member.
Total Nitrogen Allocation
•'
' , : ION
c r z w,,r ,
SOURCEz f
--, , ,4
DATE
ALLOCA,VON
0. 4J., t,►..K1,, ,, -
AMOUNT (1
I,-11,c.�=, , s -
k _,
STATUS
:fir' w
:Delivered, (Ib/yr)
Disc ate (Itityr) i
Base .
• Assigned by Rule
(T15A NCAC 02B
.0270)
8/11/09
139,009
185,345
Active
TOTAL
139,009
185,345
Active
Footnote:
(1) Nitrogen Transport Factor = 75%
Total Phosphorus Allocation
r
e ;
A LOCATION
TY
y 4•
3Fx a r tr'. ...�
� ytL f -ve .•:,. TF` xir`=. 11-�ci
z K
SOS- CE"F
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..�-- J
� ♦
.r�Js3
DATE
: �<
?J" .7, tZ„ti3T,Y
2 LLO 'ION A••:• O N7',)
i•i� lfi s - �
L-�1S tt art p.'•�; •1. u"
. T-
$ � l
� �A
��;c _
-�
-+sue-- - i : r�.
Dts'cy h rcye (Ib/r)' .
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l�U� •
-
4it; s - ..
Yb ii •
2 -6 �«i1'r.L f. .J�Li Ff:
,L`
`�.L,.-.. g` ... :
Base
Assigned by Rule
(T15A NCAC 02B
.0270)
8/11/09
9,415
14,053
.
Active
TOTAL
9,415
14,053
Active
Footnote:
(1) Phosphorus Transport Factor = 67%
(b) Any addition, deletion, or modification of the listed allocation(s) (other than to correct
typographical errors) or any change in status of any of the listed allocations shall be
considered a major modification of this permit and shall be subject to the public review
process afforded such modifications under state and federal rules.

Permit No. NC0047597
A (7) ANNUAL LIMITS FOR TOTAL NITROGEN OR TOTAL PHOSPHORUS
(a) Total Nitrogen (TN) and Total Phosphorus (TP) allocations and load limits for NPDES
dischargers in the Jordan Lake watershed are annual limits and apply on a calendar year basis.
(b) For any given calendar year, the Permittee shall be in compliance with the annual TN (or TP)
Load limit in this Permit if:
(i) the Permittee's annual TN (or TP) Load is Tess than or equal to the effective limit, or
(ii) the Permittee is a Co-Permittee Member of a compliance association.
The TN (or TP) Load limit in this Permit may be modified as the result of allowable changes in
the Permittee's allocations.
Allowable changes include those resulting from purchase of TN (or TP) allocation from
an authorized mitigation banker, the Ecosystem Enhancement Program, or other source
allowed under applicable regulations; purchase, sale, trade, or lease of allocation
between the Permittee and other dischargers; regionalization; and other transactions
approved by the Division.
(ii) The Permittee may request a modification of the TN (or TP) Load limit in this Permit to
reflect allowable changes in its allocation(s).
(A) Upon receipt of timely and proper application, the Division will modify the permit as
appropriate and in accordance with state and federal program requirements.
(B) Changes in TN (or TP) limits become effective on January 1 of the year following
permit modification. The Division must receive application no later than August 31 for
changes proposed for the following calendar year.
(iii) Any requests for modification should be sent to:
NCDENR/ DWQ/ NPDES Programs
Attn: Jordan Lake Watershed Coordinator
1617 Mail Service Center
Raleigh, NC 27699-1617
(d) If the Permittee is a member and co-permittee of an approved compliance association on
January 1 of a given year, its TN and TP discharges during that year are governed by that
association's, group NPDES permit and the limits therein.
(i)
(i)
The Permittee shall be considered a Co-Permittee Member for any given calendar year
in which it is identified as such in Appendix A of the association's group NPDES permit.
(ii) Association roster(s) and members' TN and TP allocations will be updated annually and
in accordance with state and federal program requirements.
(iii) If the Permittee intends to join or leave a compliance association, the Division must be
notified of the proposed action in accordance with the procedures defined in the
association's NPDES permit.
(A) . Upon receipt of timely and proper notification, the Division will modify the permit as
appropriate and in accordance with state and federal program requirements.
(B) Membership changes in a compliance association become effective on January 1 of
the year following modification of the association's permit.
(e) The TN and TP monitoring and reporting requirements in this Permit remain in effect throughout
the term of the Permit and are not affected by the Permittee's membership in a compliance
association.

Permit No. NC0047597
A (8) CALCULATION OF TOTAL NITROGEN OR TOTAL PHOSPHORUS LOADS
(a) The Permittee shall calculate monthly and annual TN Loads as follows:
(i) Monthly TN (or TP) Load (Ib/mo) = TN (or TP) x TMF x 8.34
where:
TN or TP = the average Total Nitrogen or Total Phosphorus concentration
(mg/L) of the composite samples collected during the month
TMF = the Total Monthly Flow of wastewater discharged during the
month (MG/mo)
8.34 = conversion factor, from (mg/L x MG) to pounds
(ii) Annual TN (or TP) Load (Ib/yr) = Sum of the 12 Monthly TN (or TP) Loads for the
calendar year
(b) The Permittee shall report monthly Total Nitrogen and Total Phosphorus results (mglL and
Ib/mo) in the appropriate discharge monitoring report for each month and shall report each
calendar year's results (Ib/yr) with the December report for that year.
A (9) NUTRIENT MONITORING REOPENER
Pursuant to N.C. General Statute Section 143-215.1 and the implementing rules found in Title 15A of
the North Carolina Administrative Code, Subchapter 2H, specifically, 15A NCAC 2H.0112(b) (1) and
2H.0114(a), and Part II, Sections B-12 and B-13 of this permit, the Director of DWQ may reopen this
permit to require supplemental nutrient monitoring of the discharge. The additional monitoring will be to
support water quality modeling efforts within the Cape Fear River Basin, and shall be consistent with a
monitoring plan developed jointly by the Division and affected stakeholders.

DIVISION OF WATER QUALITY
FACT SHEET FOR NPDES PERMIT RENEWAL
NPDES No. NC0047597
Facility Information
Applicant/Facility Name:
City of Durham/ South Durham WRF
Applicant Address:
101 City Hall Plaza, Durham, North Carolina 27701
Facility Address:
6605 Farrington Road, Chapel Hill, North Carolina 27517
Permitted Flow
20.0 MGD
Type of Waste:
Municipal
Facility/Permit Status:
Class IV /Active; Renewal
County:
Durham
Miscellaneous
Receiving Stream:
UT New Hope
Creek
Regional Office:
Raleigh
Stream Classification:
WS-IV NSW
State Grid /
USGS Quad:
D23NW/
Southwest Durham
303(d) Listed?
Yes
Permit Writer:
Gil Vinzani
Subbasin:
03-06-05
HUC:
03020101
Drainage Area (mi2):
75
Facility Location
•
Lat. 35° 58' 18" N Long. 78° 58' 28" W
S7Q10 (cfs)
0.15
W7Q10 (cfs)
2.0
Average Flow (cfs):
77
IWC (%):
99.5%
Background
The South Durham WRF has a permitted flow of 20.0 MGD. South Durham has a full
pretreatment program with the Division's Pretreatment Unit. It has three significant industrial
users and one categorical industrial user. The two largest SIU's are both laundry facilities -
Angelica Textile Service at an average flow of 83,600 GPD and Alsco at 67,900 GPD. The City
has not requested any specific changes to the permit.
On July 9, 2010, this permit was one of 14 that were modified to include total phosphorus
discharge limits in accordance with the Jordan Lake nutrient management strategy wastewater
discharge requirements at 15A NCAC 02B .0270. The new annual mass discharge limits for
phosphorus were equal to the facility's TP discharge allocation. To further comply with the
strategy, this permit draft includes nitrogen limits proposed to go into effect on January 1, 2016.
DMR Data Review
This facility discharges to an unnamed tributary to New Hope Creek in subbasin 030605 of the
Cape Fear River Basin. The receiving stream is classified WS-IV NSW waters, and is listed as
impaired on the 2010-303(d) list due to impaired biological integrity and turbidity. DMR data
from January 2008 through April 2011 were reviewed. Data are summarized in Table 1.
Table 1. NC0047597 DMR Data Summary (January 2008-April 2011)
Flow
(MGD)
BOD
(mg/L)
TSS
(mg/L)
NH3-N
(mg/L)
TN
(mg/L)
TP
(mg/L)
Average
10.15
2.16
2.45
0.15
8.75
0.53
Maximum
33.65
14
77
3.86
19.6
2.55
Minimum
6.57
<2.0
<1.0
<0.05
3.3
0.04
NC0047597
Page 1

Compliance Review
In general, compliance at this facility has been excellent. The South Durham WRF has had no
permit limit exceedances and received no Notices of Violation (NOVs) or Enforcements Actions
over the course of the past two permit term. Additionally, the facility has also been in long-term
compliance with its toxicity limit going back to at least 2001, with no toxicity test failures. The
Raleigh Regional Office last conducted a Compliance Evaluation Inspection on March 30, 2010
and found the facility to be in compliance.
As a member of the Upper Cape Fear River Basin Association, the permittee does not collect
instream data. The waiver of instream monitoring may continue as long as this membership
continues.
Reasonable Potential Analysis (RPA)
The Division conducted EPA -recommended analyses to determine the reasonable potential for
toxicants to be discharged by this facility, based on DMRs and pretreatment data from January
2008-April 2011, and also using PPA results supplied with the permit application. All parameters
of concern were included.
The results of the RPA showed that reasonable potential to exceed water quality standards was
present for the following parameters: silver, zinc, and mercury. As an action level parameter,
quarterly monitoring was implemented for zinc. Silver will continue to be monitored in the
facility's pretreatment long term monitoring plan.
Total mercury had one sample result above the 12 ng/L standard. Monthly monitoring, with
limits, will be added to the permit. The City may petition for a reduction to quarterly monitoring
after 12 consecutive months of sampling results showing no reasonable potential to cause an
exceedance of water quality standards.
No reasonable potential was found for arsenic, beryllium, cadmium, total phenolic compounds,
chromium, cyanide, fluoride, lead, copper, selenium, and molybdenum. The monthly monitoring
for fluorides will be removed from this draft permit.
Toxicity Testing
Current Requirement: Chronic toxicity P/F @ 90%; January, April, July, October. This draft
permit recommends that chronic toxicity continue to be monitored P/F @ 90%; January, April,
July, and October.
Jordan Lake Nutrient Management Strategy
This permit was modified in July 2010 to implement the permitting strategy addressing the
Jordan Lake rules. This strategy establishes nitrogen and phosphorus allocations for all existing
wastewater dischargers that treat nutrient -bearing wastes. In accordance with these
requirements, this draft permit includes a new annual mass discharge limit for total nitrogen of
185,345 pounds per year, effective January 1, 2016.
Another requirement of this strategy is for a nitrogen optimization plan. The permittee submitted
a plan to the Division on February 17, 2010. An updated special condition A (9) addresses
further requirements regarding nitrogen optimization implementation.
Summary of Proposed Changes
The following are changes from the draft permit were incorporated into this final permit:
• Quarterly monitoring requirements for copper and selenium were removed. A review of
additional monitoring results shows that there is no reasonable potential for these
pollutants to cause an exceedance of water quality standards.
NC0047597
Page 2

• Quarterly monitoring for bis(2-ethylhexyl)phthalate was also removed. The laboratory
has confirmed that the only sample result above detection limits for this pollutant should
be discarded, since there is zero confidence in its resulting concentration.
• As a result of the revised reasonable potential analysis, daily and monthly limits were
implemented for total mercury, with a monitoring frequency of once per month. In order
to provide time for the city to achieve compliance, these limits will become effective
October 1, 2012. The city may petition for a reduction to quarterly monitoring after 12
consecutive months of sampling results showing no reasonable potential to cause an
exceedance of water quality standards.
• The condition concerning nitrogen optimization (former condition A9) was deleted. The
Division is reviewing its policy on this subject.
The following modifications from the draft permit remain in effect:
• In accordance with the Jordan Lake nutrient management strategy, a new annual mass
discharge limit for total nitrogen of 185,345 pounds per year, effective January 1, 2016,
was added.
• Limits for fluoride were removed, due to the results of the reasonable potential
analysis.
• The monitoring frequency for zinc was reduced to quarterly, in accordance with Division
policy regarding action -level parameters.
Proposed Schedule for Permit Issuance
Draft Permit to Public Notice: June 8, 2011
Permit Scheduled to Issue: September 2011
NPDES Unit Contact
If you have questions regarding any of the above information or on the attached permit, please
contact Gil Vinzani at [phone] or at [e-mail].
SIGNATURE:
DATE: A ust- /2, 27//
NC0047597
Page 3

South Durham WRF REASONABLE POTENTIAL ANALYSIS
NC0047597
Qw (MGD) = 20.00
1 Q I OS (cfs) = 0.13
7Q I OS (cfs) = 0.15
7Q1OW (cfs) = 2.00
30Q2 (cfs) = 3.60
Avg. Stream Flow, QA (cfs) = 77.00
Receiving Stream: UT New Hope Crrek
WWTP/WTP Class: IV
IWC @ 1QIOS = 99.58%
IWC @ 7Q10S = 99.52%
IWC @ 7Q1OW = 93.94%
IWC @ 30Q2 = 89.60%
IWC @ QA = 28.70%
Stream Class: WS-IV NSW
Outfall 001
Qw=20MGD
PARAMETER
TYPE
(1)
STANDARDS & CRITERIA (2)
a
0
z
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
NC WQS / Applied 1/2 FAV /
Chronic Standard Acute
Max Pred
n # Det. Cw Allowable Cw
Arsenic
Arsenic
C
C
50 FW(7QIOs)
10 HH/WS(Qavg)
ug/L
ug/L
21 1
21 1
4.0
4.0
Acute: NO WQS
___ _ _______ ____
Chronic: 50.2
No valu_e> Allowable Cw___
Chronic: 34.8
No value > Allowable Cw
_____________________________
___ __________�______________
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Beryllium
NC
6.5 FW(7Q10s)
ug/L
4 0
Note: n < 9
Limited data set
1.7
Default C.V.
Acute: NO WQS
__ _ _______ ____
Chronic: 6.5
No value > Allowable Cw
_ _____ ____`__________ _____
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Cadmium
NC
2 FW(7Q10s) 15
ug/L
21 0
0.8
Acute: 15.1
_ _ _______ ___.
Chronic: 2.0
No value > Allowable Cw
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required ______________
No RP , Predicted Max a 50% of Allowable Cw -
defer to LTMP
Chlorides (AL)
NC
230 FW(7Q10s)
mg/L
0 0
N/A
Acute: NO WQS
___ _ _______ ____
Chronic: 231
___________________________
Chlorinated Phenolic Compounds
NC
1 A(30Q2)
ug/L
0 0
N/A
Acute: NO WQS
___ _ _______ ____
Chronic: 1.1
__________w_____________w____
Total Phenolic Compounds
NC
300 A(30Q2)
ug/L
4 0
Note: n <_ 9
Limited data set
47.4
Default C.V.
Acute: NO WQS
___ _ ________________________,____.______,__
Chronic: 334.8
No value > Allowable Cw
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Chromium
NC
50 FW(7Q10s) 1022
ug/L
21 1
11.3
Acute: 1,026.3
___ _ _______ ____
Chronic: 50.2
No value > Allowable Cw
________________________—
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Copper(AL)
NC
7 FW(7Q10s) 7
ug/L
21 17
7
Acute: 7.3
___ _ _______ ____
Chronic: 7.0
No value > Allowable Cw
_____________________________
No RP , Predicted Max a 50% of Allowable Cw -
defer to LTMP
Cyanide
NC
5 FW(7Q10s) 22
10
ug/L
21 0
5.0
Acute: 22.1
___ _ _______ ____
Chronic: 5.0
No value > Allowable Cw
______________!______________
No hits; no limits or monitoring required
Page 1 of 2
S. Durahm New RPA, rpa
7/20/2011

South Durham WRF
REASONABLE POTENTIAL ANALYSIS
O utfa l l 001
Qw = 20 MGD
Fluoride
NC
1800
FW(7Q10s)
ug/L
142
142
1.2
Acute: NO WQS
___ _ _____ _ _ __
Chronic: 1,808.7
No value > Allowable Cw
I ,
4
___________ _________________
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Lead
NC
25
FW(7Q10s)
33.8
ug/L
21
1
3.7
Acute: 33.9
_ _ _______ ____
Chronic: 25.1
No value > Allowable Cw
_____________________________
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Mercury
NC
12
FW(7Q10s)
0.5
ng/L
20
18
74.3
Acute: NO WQS
___ _ _______ ____
Chronic: 12.0
1 value(s) > Allowable Cw
RP for non -AL - apply Monthly Monitoring with Limit
_____________________________
Molybdenum
NC
160
WS(7Q10s)
ug/L
24
6
32.2
Acute: NO WQS
___ _ _______ ____
Chronic: 160.8
No value > Allowable Cw
____________________________
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Nickel
NC
88
FW(7Q10s)
261
ug/L
21
2
8.6
Acute: 262.1
___ _ _______ ____
Chronic: 88.4
No value > Allowable Cw
_____________________________
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Selenium
NC
5
FW(7Q10s)
56
ug/L
24
1
3.1
Acute: 56.2
___ _ _______ ____
Chronic: 5.0
No value > Allowable Cw
___ _________________________
No RP , Predicted Max a 50% of Allowable Cw -
defer to LTMP
Sliver (AL)
NC
0.06
FW(7Q10s)
1.23
ug/L
21
2
0.935
Acute: 1.235
___ _ _______ ____
Chronic: 0.060
17 value(s) > Allowable Cw
___ _____ ___________________
RP for action level with - defer to LTMP quarterly
monitoirng
Zinc (AL)
NC
50
FW(7Q10s)
67
ug/L
92
92
103.2
Acute: 67.3
___ _ _______ ____
Chronic: 50.2
30 value(s) > Allowable Cw
___________________ _________
RP for AL(Cu,Zn,Ag,Fe,CI) - apply Quarterly
Monitoring in conjunction with TOX Test
0
0
N/A
Acute:
— ----------------------------------------
Chronic:
0
0
N/A
Acute:
— ----------------------------------------
Chronic:
0
0
N/A
Acute:
— ----------------------------------------
Chronic:
0
0
N/A
Acute:
— ----------------------------------------
Chronic:
Page 2 of 2
S. Durahm New RPA, rpa
8/9/2011

REASONABLE POTENTIAL ANALYSIS
Arsenic - FW Standard
Date Data BDL=1/2DL Results
3/5/2008 < 2 1 Std Dev. 0.4681
4/22/2009 < 2.8 1.4 Mean 2.3457
4/14/2010 2.96 2.96 C.V. 0.1995
3/13/2011 < 2.8 1.4 n 21
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
1/15/2007 < 5 2.5 Mull Factor = 1.34
4/16/2007 < 5 2.5 Max. Value 3.0 ug/L
7/16/2007 < 5 2.5 Max. Pred Cw 4.0 ug/L
1/1/2008 < 5 2.5
4/1/2008 < 5 2.5
7/1/2008 < 5 2.5
10/1/2008 < 5 2.5
1/1/2009 < 5 2.5
4/1/2009 < 5 2.5
7/1/2009 < 5 2.5
10/1/2009 < 5 2.5
1/1/2010 < 5 2.5
4/1/2010 < 5 2.5
7/1/2010 < 5 2.5
10/1/2010 < 5 2.5
1/1/2011 < 5 2.5
4/1/2011 < 5 2.5
2
Arsenic - HH/WS Standards
Date Data BDL=1/2DL Results
1 3/5/2008 < 2 1 Std Dev.
2 4/22/2009 < 2.8 1.4 Mean
3 4/14/2010 0 2.96 2.96 C.V.
4 3/13/2011 < 2.8 1.4 n
5
6 1/15/2007 < 5 2.5 Mult Factor =
7 4/16/2007 < 5 2.5 Max. Value
8 7/16/2007 < 5 2.5 Max. Pred Cw
9
10 1/112008 < 5 2.5
11 4/1/2008 < 5 2.5
12 7/1/2008 < 5 2.5
13 10/1/2008 < 5 2.5
14 1/1/2009 < 5 2.5
15 4/1/2009 < 5 2.5
16 7/1/2009 < 5 2.5
17 10/1/2009 < 5 2.5
18 1/1/2010 < 5 2.5
19 4/1/2010 < 5 2.5
20 7/1/2010 < 5 2.5
21 10/1/2010 < 5 2.5
22 1/1/2011 < 5 2.5
23 4/1/2011 < 5 2.5
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
NO "COPY"
THIS SECTION
0.4681
2.3457
0.1995
21
1.34
3.0 ug/L
4.0 ug/L
S. Durahm New RPA, data
- 1 • 7/20/2011

REASONABLE POTENTIAL ANALYSIS
Beryllium
Date Data BDL=1/2DL Results -
1 3/5/2008 < 0.7 0.35 Std Dev. 0.1500
2 4/22/2009 < 0.1 0.05 Mean 0.1250
3 4/14/2010 < 0.1 0.05 C.V. (default) 0.6000
4 3/13/2011 < 0.1 0.05 n 4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Mult Factor =
Max. Value
Max. Pred Cw
USE ONLY
"PASTE
SPECIAL-
alues" WITH
"COPY"
Cadmium
4.74
0.4 ug/L
1.7 ug/L
Date Data BDL=1/2DL Results
1 3/5/2008 < 0.5 0.25 Std Dev. 0.1359
2 4/22/2009 < 0.14 0.07 Mean 0.4371
3 4/14/2010 < 0.36 0.18 C.V. 0.3108
4 3/13/2011 < 0.36 0.18 n 21
5
6 1/15/2007 < 1 0.5 Mult Factor -=
7 4/16/2007 <:= 1 0.5 Max. Value
8 7/16/2007 < 1 0.5 Max. Pred Cw
9
10 1/1/2008 1 0.5
11 4/1/2008 _ 1 0.5
12 7/1/2008 ., < 1 0.5
13 10/1/2008 < 1 0.5
14 1/1/2009 < 1 0.5
15 4/1/2009 < 1 0.5
16 7/1/2009 < 1 0.5
17 10/1/2009 < 1 0.5
18 1/1/2010 < 1 0.5
19 4/1/2010 < 1 0.5
20 7/1/2010 < 1 0.5
21 10/1/2010 < 1 0.5
22 1/1/2011 < 1 0.5
23 4/1/2011 < 1 0.5
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
1.57
0.5 ug/L
0.8 ug/L
S. Durahm New RPA, data
- 1 - 7/20/2011

REASONABLE POTENTIAL ANALYSIS
Total Phenolic Compounds
Date Data BDL=1/2DL Results
3/5/2008 < 20 10 Std Dev.
4/22/2009 < 20 10 Mean
4/14/2010 < 10 5 C V (default)
3/13/2011 < 20 10 n
Mult Factor =
Max. Value
Max. Pred Cw
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
2.5000
8.7500
0.6000
4
Chromium
4.74
10.0 ug/L
47.4 ug/L
Date Data BDL=1/2DL Results
1 3/5/2008 < 0.33 0.165 Std Dev. 1.1782
2 4/22/2009 < 0.33 0.165 Mean 2.1990
3 4/14/2010 < 0.45 0.225 C.V. 0.5358
4 3/13/2011 < 0.45 0.225 n 21
5
6 1/15/2007 < 5 2.5 Mult Factor =
7 4/16/2007 < 5 2.5 Max. Value
8 7/16/2007 < 5 2.5 Max. Pred Cw
9
10 1/1/2008 `< 5 2.5
11 4/1/2008 <. 5 2.5
12 7/1/2008 < 5 2.5
13 10/1/2008 < 5 2.5
14 1/1/2009 < 5 2.5
15 4/1/2009 < 5 2.5
16 7/1/2009 < 5 2.5
17 10/1/2009 5.4 5.4
18 1/1/2010 < 5 2.5
19 4/1/2010 < 5 2.5
20 7/1/2010 < 5 2.5
21 10/1/2010 < 5 2.5
22 1/1/2011 < 5 2.5
23 4/1/2011 < 5 2.5
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
USE ONLY
"PASTS
SPECIAL -
Values" WITH
"COPY"
2.10
5.4 ug/L
11.3 ug/L
S. Durahm New RPA, data
- 1 - 7/20/2011

REASONABLE POTENTIAL ANALYSIS
Copper (AL)
Date Data BDL=1/2DL Results
1 3/5/2008 1.5 1.5 Std Dev. 0.9071
2 4/22/2009 1.3 1.3 Mean 2.1371
3 4/14/2010 1.48 1.48 C.V. 0.4244
4 3/13/2011 2.1 2.1 n 21
5
6 1/15/2007 < 2 1 Mult Factor=
7 4/16/2007 3.3 3.3 Max. Value
8 7/16/2007 2.6 2.6 Max. Pred Cw
9
10 1/1/2008 2.7 2.7
11 4/1/2008 2 2
12 7/1/2008 2 2
13 10/1/2008 < 2 1
14 1/1/2009 2.1 2.1
15 4/1/2009 2.2 2.2
16 7/1/2009 4.1 4.1
17 10/1/2009 < 2 1
18 1/1/2010 3.7 3.7
19 4/1/2010 2 2
20 7/1/2010 2 2
21 10/1/2010 2.5 2.5
22 1/1/2011 3.3 3.3
23 4/1/2011 < 2 1
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
10
Cyanide
1.82
4.1 ug/L
7.5 ug/L
Date Data BDL=1/2DL Results
1 3/5/2008 < 4 5 Std Dev. 0.0000
2 4/22)2009 < 4 5 Mean 5.00
3 4/14/2010 < 5 5 C.V. 0.0000
4 3/13/2011 < 3.7 5 n 21
5
6 1/15/2007 < 5 5 MultFactor=
7 4/16/2007 < 5 5 Max. Value
8 7/16/2007 < 5 5 Max. Pred Cw
9
10 1/1/2008 < 5 5
11 4/1/2008 < 5 5
12 7/1/2008 < 5 5
13 10/1/2008 < 5 5
14 1/1/2009 < 5 5
15 4/1/2009 < 10 5
16 7/1/2009 < 5 5
17 10/1/2009 < 5 5
18 1/1/2010 < 5 5
19 4/1/2010 < 5 5
20 7/1/2010 < 5 5
21 10/1/2010 < 5 5
22 1/1/2011 < 5 5
23 4/1/2011 < 5 5
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
1.00
5.0 ug/L
5.0 ug/L
-1-
S. Durahm New RPA, data
7/20/2011

REASONABLE POTENTIAL ANALYSIS
11
Fluoride
Date Data BDL=1/2DL Results
1 0.9 0.9 Std Dev.
2 0.9 0.9 Mean
3 1 1 C.V.
4 1.1 1.1 n
5 1.1 1.1
6 1 1 Mult Factor =
7 1 1 Max. Value
8 0.9 0.9 Max. Pred Cw
9 0.8 0.8
10 0.8 0.8
11 0.5 0.5
12 0.6 0.6
13 0.4 0.4
14 0.5 0.5
15 0.4 0.4
16 0.4 0.4
17 0.5 0.5
18 0.5 0.5
19 0.6 0.6
20 0.6 0.6
21 0.5 0.5
22 0.4 0.4
23 0.5 0.5
24 0.5 0.5
25 0.5 0.5
26 0.6 0.6
27 0.7 0.7
28 0.8 0.8
29 0.8 0.8
30 0.7 0.7
31 0.6 0.6
32 0.8 0.8
33 0.7 0.7
34 0.8 0.8
35 0.7 0.7
36 0.8 0.8
37 0.8 0.8
38 0.7 0.7
39 0.7 0.7
40 0.7 0.7
41 0.8 0.8
42 0.9 0.9
43 0.6 0.6
44 0.9 0.9
45 0.7 0.7
46 0.9 0.9
47 0.9 0.9
48 1 1
49 0.8 0.8
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
0.1821
0.7232
0.2517
142
12
Lead
1.12
1.1 ug/L
1.2 ug/L
1
2
3
4
5
6 1 /15/2007 < 5
7 4/16/2007 < 5
8 7/16/2007 < 5
9
10 1/1/2008 < 5 2.5
11 4/1/2008 < 5 2.5
12 7/1/2008 < 5 2.5
13 10/1/2008 5 2.5
14 1/1/2009 5 2.5
15 4/1/2009 < 5 2.5
16 7/1/2009 < 5 2.5
17 10/1/2009 < 5 2.5
18 1/1/2010 < 5 2.5
19 4/1/2010 < 5 2.5
20 7/1/2010 < 5 2.5
10/1/2010 <. 5 2.5
1/1/2011 < 5 2.5
4/1/2011 < 5 2.5
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
Date Data BDL=1/2DL Results
3/5/2008 < 2 1 Std Dev. 0.5523
4/22/2009 2.6 2.6 Mean 2.2857
4/14/2010 < 1.9 0.95 C.V. 0.2416
3/13/2011 < 1.9 0.95 n 21
2.5 Mult Factor =
2.5 Max. Value
2 5 Max. Pred Cw
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
1.42
2.6 ug/L
3.7 ug/L
-1-
S. Durahm New RPA, data
7/20;2011

REASONABLE POTENTIAL ANALYSIS
13
Mercury
Date Data BDL=1/2DL Results
1 3/5/2008 0.801 0.801 Std Dev.
2 4/22/2009 0.679 0.679 Mean
3 4/14/2010 1.29 1.29 C.V.
4 n
5 1/15/2007 1.25 1.25
6 4/16/2007 1.72 1.72 Mult Factor =
7 7/16/2007 1 1 Max. Value
8 1/2/2008 18.3 18.3 Max. Pred Cw
9 4/1/2008 2.97 2.97
10 7/1/2008 < 1 0.5
11 10/1/2008 1.11 1.11
12 1/1/2009 4.38 4.38
13 4/1/2009 4.21 4.21
14 7/1/2009 8.15 8.15
15 10/1/2009 4.88 4.88
16 1/1/2010 6.19 6.19
17 4/1/2010 4.82 4.82
18 7/1/2010 2.39 2.39
19 10/1/2010 2.7 2.7
20 1/1/2011 1.7 1.7
21 4/1/2011 < 1 0.5
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
4.0816
3.4770
1.1739
20
4.06
18.3 ng/L
74.3 ng/L
14
Molybdenum
Date Data BDL=1/2DL Results
1 3/5/2008 6.7 6.7 Std Dev. 2.3262
2 4/22/2009 1.3 1.3 Mean 3.1929
3 4/14/2010 3.13 3.13 C.V. 0.7285
4 3/13/2011 2.5 2.5 n 24
5
6 1/15/2007 < 5 2.5 Mult Factor=
7 4/16/2007 <• 5 2.5 Max. Value
8 7/16/2007 < 5 2.5 Max. Pred Cw
9
10 1/15/2007 13 13
11 4/16/2007 5 5
12 7/16/2007 < 5 2.5
13
14 1/1/2008 <'_ 5 2.5
15 4/1/2008 <'. 5 2.5
16 7/1/2008 < 5 2.5
17 10/1/2008 < 5 2.5
18 1/1/2009 <r 5 2.5
19 4/1/2009 <= 5 2.5
20 7/1/2009 <. 5 2.5
21 10/1/2009 < 5 2.5
22 1/1/2010 < 5 2.5
23 4/1/2010 < 5 2.5
24 7/1/2010 < 5 2.5
25 10/1/2010 < 5 2.5
26 1/1/2011 < 5 2.5
27 4/1/2011 < 5 2.5
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
2.48
13.0 ug/L
32.2 ug/L
S. Durahm New RPA. data
- 1 - 7/20/2011

REASONABLE POTENTIAL ANALYSIS
15
Nickel
Date Data BDL=1/2DL Results
1 3/5/2008 < 2 1 Std Dev.
2 4/22/2009 2.3 2.3 Mean
3 4/14/2010 < 1.8 0.9 C.V.
4 3/13/2011 2.75 2.75 n
5
6 1/15/2007 < 10 5 Mult Factor =
7 4/16/2007 < 11 5.5 Max. Value
8 7/16/2007 < 10 5 Max. Pred Cw
9
10 1/1/2008 < 10 5
11 4/1/2008 < 10 5
12 7/1/2008 < 10 5
13 10/1/2008 < 10 5
14 1/1/2009 < 10 5
15 4/1/2009 < 10 5
16 7/1/2009 < 10 5
17 10/1/2009 < 10 5
18 1/1/2010 < 10 5
19 4/1/2010 < 10 5
20 7/1/2010 < 10 5
21 10/1/2010 < 10 5
22 1/1/2011 < 10 5
23 4/1/2011 < 10 5
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
USE ONLY
"PASTE
SPEC/AL-
Values° WITH
"COPY"
1.3768
4.4024
0.3127
21
16
Selenium
1.57
5.5 ug/L
8.6 ug/L
Date Data BDL=1/2DL Results
1 3/5/2008 2.3 2.3 Std Dev. 0.3533
2 4/22/2009 < 3.4 1.7 Mean 2.3625
3 4/14/2010 .<; 2.7 1.35 C.V. 0.1496
4 3/13/2011 2.7 1.35 n 24
5
6 1/15/2007 5 2.5 Mult Factor =
7 4/16/2007 r 5 2.5 Max. Value
8 7/16/2007 5 2.5 Max. Pred Cw
9
10 1/15/2007 < 5 2.5
11 4/16/2007 < 5 2.5
12 7/16/2007 < 5 2.5
13
14 1/1/2008 < 5 2.5
15 4/1/2008 < 5 2.5
16 7/1/2008 < 5 2.5
17 10/1/2008 < 5 2.5
18 1/1/2009 <= 5 2.5
19 4/1/2009 :_<•', 5 2.5
20 7/1/2009 04 5 2.5
21 10/1/2009 < 5 2.5
22 1/1/2010 : < 5 2.5
23 4/1/2010 < 5 2.5
24 7/1/2010 • < 5 2.5
25 10/1/2010 < 5 2.5
26 1/1/2011 < 5 2.5
27 4/1/2011 < 5 2.5
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
1.23
2.5 ug/L
3.1 ug/L
S. Durahm New RPA, data
• 1 - 7/20/2011

REASONABLE POTENTIAL ANALYSIS
17
Silver (AL)
Date Data BDL=1/2DL Results
1 3/5/2008 0.049 0.049 Std Dev.
2 4/22/2009 0.028 0.028 Mean
3 4/14/2010 < 0.1 0.05 C.V.
4 3/13/2011 < 0.1 0.05 n
5
6 1/15/2007 < 1 0.5 Mult Factor =
7 4/16/2007 < 1 0.5 Max. Value
8 7/16/2007 < 1 0.5 Max. Pred Cw
9
10 1/1/2008 < 1 0.5
11 4/1/2008 < 1 0.5
12 7/1/2008 < 1 0.5
13 10/1/2008 < 1 0.5
14 1/1/2009 < 1 0.5
15 4/1/2009 < 1 0.5
16 7/1/2009 < 1 0.5
17 10/1/2009 < 1 0.5
18 1/1/2010 < 1 0.5
19 4/1/2010 < 1 0.5
20 7/1/2010 < 1 0.5
21 10/1/2010 < 1 0.5
22 1/1/2011 < 1 0.5
23 4/1/2011 < 1 0.5
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
0
PASTE
'' SPECIAL -
Values" WITH
"COPY"
0.1834
0.4132
0.4439
21
18
Zinc (AL)
1.87
0.500 ug/L
0.935 ug/L
Date Data BDL=1/2DL Results
1 39. 39 Std Dev. 12.6754
2 53. 53 Mean 46.0455
3 C.V. 0.2753
4 64. 64 n 92
5 62. 62
6 86. 86 Mult Factor = 1.20
7 54. 54 Max. Value 86.0 ug/L
8 Max. Pred Cw 103.2 ug/L
USE ONLY
"PASTE
SPECIAL -
Values" WITH
"COPY"
9 53. 53
10 56. 56
11 51. 51
12 54. 54
13 56. 56
14 43. 43
15 45. 45
16 59. 59
17 43. 43
18
19 30. 30
20 20. 20
21 36. 36
22 48. 48
23
24 30. 30
25 33. 33
26 34. 34
27 30. 30
28 43. 43
29 50. 50
30 53. 53
31
32
33 32. 32
34 3/5/2008 81.1
35 4/22/2009 59
36 4/14/2010 47.7
37 37. 37
38 3/13/2011 60.9
39 44. 44
40
41 55. 55
42 67. 67
43 63. 63
44 66. 66
45 63. 63
S. Durahm New RPA, data
- 1 - 7/20/2011

Vinzani, Gil
From: [e-mail]
Sent: Thursday, September 08, 2011 1:08 PM
To: Vinzani, Gil; Belnick, Tom
Cc: [e-mail]
Subject: Re: FW: NC0047597 South Durham WTF
Hello Gil,
Thank you for the gentle reminder. Yes, I looked at it again this morning to review my notes about the
mercury compliance schedule you are now allowing.
In summary, the EPA, in Region 4 has "no comments" for the revised draft NPDES permit #
NC0047597, South Durham WTF, in Chapel Hill, North Carolina at this time.
As always should there be additional public comments or major changes to the draft document prior to
issuance, please afford the EPA an additional period of time to review any of those changes.
Otherwise, please proceed to issue this permit at your earliest convenience.
Sincerely,
Pamala Myers
Environmental Engineer and Technical Advisor Pollution Control and Implementation Branch Water
Protection Division Municipal and Industrial NPDES Section U.S. EPA, Region 4 Atlanta, GA 30303
404.562.9421
404.562.8692 (fax)
From: "Vinzani, Gil" <[e-mail]>
To: Pamala Myers/R4/USEPA/US@EPA
Date: 09/08/2011 11:05 AM
Subject: FW: NC0047597 South Durham WTF
Hello, Pam:
Thank you for the review of Holly Springs.
You may recall this one from a couple of weeks ago. You had already signed off, but we changed a few
things. Please see the fact sheet under "Summary of Proposed Changes" for details. Please let me
know if you have any concerns; otherwise it is ready to issue.
Thanks,
Gil.
Original Message -----
From: Vinzani, Gil
Sent: Thursday, August 25, 2011 11:06 AM
1

Dodson, Robert
From: Link Thrower [[e-mail]]
Sent: Tuesday, July 26, 2011 1:50 PM
To: Dodson, Robert
Subject: RE: Data on Priority Pollutant Scan
Follow Up Flag:
Flag Status:
Follow up
Flagged
The MDL procedure is described in 40 CFR 136 Appendix B. It defines the method detection limit
(MDL) as "the minimum concentration of a substance that can be measured and reported with 99%
confidence that the analyte concentration is greater than zero". Basically MDL means a level of a
compound that you are fairly sure is above the background noise signal of your blank. MDL is
statistically determined from analyzing 7 or more replicates of spiked water. Calculate the standard
deviation and multiply that by Student T value to get the MDL. So the MDL is independent of
accuracy and somewhat independent of the actual value at which the study is performed (there is a
requirement that the MDL be within 10x of the true value or the study must be repeated). For
example, a method may have a low calibration point, or MRL, of 1.0 ppb. The MDL study may be
performed using a standard of 0.5 ppb. And yield a calculated MDL of 0.1 ppb. The accuracy of the
MDL runs is not controlled. The 0.5 standard may give a calculated result of 0.1 or even 0.8. It does
not matter, the MDL is calculated from the standard deviation, which is only a function of
reproducibility, not accuracy.
Results flagged with a "J" are estimates. There is zero confidence in the concentration. There is no
quality control or calibrations performed below the MRL(Method Reporting Limit). The only
confidence as defined by 40 CFR is that the value is greater than zero.
A. Link Thrower
Customer Service Manager
Environmental Conservation Laboratories, Inc.
102-A Woodwinds Industrial Court
Cary, NC 27511
[phone] ph
[phone] fax
Ithrower c(encolabs.com

1finzani, Gil
From: Vinzani, Gil
Sent: Wednesday, July 20, 2011 9:35 AM
To: 'Dodson, Robert'
Cc: Belnick, Tom
Subject: South Durham WRF Draft NPDES Permit
Bob:
This is in response to your comment letter and our subsequent phone conversations regarding the subject
draft permit. As you know, after issuing the draft I found additional sampling data results which are not in our
BIMS database.
1. The quarterly monitoring requirements for copper and selenium will be eliminated as you requested. With
the addition of the new sampling results, each of these now shows no reasonable potential to cause
exceedances of WQ standards.
2. Regarding bis (2 ethylhexyl) phthalate, one outlier data point caused the reasonable potential to be
exceeded. As we discussed, quarterly monitoring can be removed only upon notification from your
laboratory that the data point in question was not valid.
3. The additional data points for mercury sampling cause reasonable potential. One of the results is 18.3 ng/L,
which is above the freshwater standard of 12 ng/L. We propose to add daily maximum and monthly average
limits and monthly monitoring using EPA method 1631-E. As we discussed, you may also have some options,
including the possible implementation of a mercury minimization plan (MMP).
Thanks for working with us on these issues.
Gil Vinzani, P. E.
Complex NPDES Permits Unit
Phone: [phone]
E-mail correspondence to and from this address may be subject to the NC Public Records Act
1

DURHAM
* ***
1869
CITY OF MEDICINE
Administration
919-560.4381
:ustomer Billing Services
919-560-4412
Laboratory Services
919-560-4386
Plant Maintenance
919-560-4388
Regulatory Compliance
919-560-4381
Wastewater Treatment
North - 919- 560-4384
South - 919-560-4386
'ater Supply & Treatment
Williams - 919-560-4349
Brown - 919-560-4362
Water & Sewer Main.
919-560-4344
CITY OF DURHAM
DEPARTMENT OF WATER MANAGEMENT
101 CITY HALL PLAZA • DURHAM, NC 27701
919-560-4381 • FAX [phone]
www.durhamnc.gov
July 7, 2011
Mr. Gil Vinzani
North Carolina Division of Water Quality
NPDES Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
SUBJECT: Draft Permit, South Durham Water Reclamation Facility
Permit NC0047597
Dear Mr. Vinzani:
This letter is in response to the draft permit for the South Durham Water Reclamation
Facility, NC0047597, received on June 13, 2011. The following comments address
concerns by the City of Durham:
1. Quarterly monitoring requirements were added for copper and
selenium. Based on the data used in the Reasonable Potential
Analysis, RPA, provided by your office on June 16, 2011, there was
one data point for selenium measured during the priority pollutant scan
on March 5, 2008 that was above the detection limit. Upon review of
that data you will notice that there was a data qualifier attached to the
result indicating "the reported value is between the laboratory method
detection limit (MDL) and the laboratory method reporting limit
(MRL)". As discussed with Ms. Dana Satterwhite, Certification Unit
Supervisor with NCDWQ Laboratory Section, the reported value
indicates the analyte was present but there is no confidence in the
value under the MRL therefore it is not accurate to use a number below
the MRL for the RPA. In addition, I have attached DMR data for
selenium through 2001 demonstrating there has not been a recorded
value above detection limit in the 49 data points over ten years. Based
on this information, the City is requesting removing the selenium
monitoring requirement.
JUL 8 20i1
Good Things Are Happening In Durham
DENP.-Van; FEr, +C.UALi rY
POINT SOUP" �E BRANCH

Page 2
Mr. Gil Vinzani
July 7, 2011
2. Also attached are 49 data points for the same time period as selenium from
Priority Pollutant Scans and submitted DMR data for copper. The highest
reported data for the period is 4.1 ug/1, with an average of 1.16 ug/1, well
under the 7.0 ug/1 action level. Again, the City would request the removal of
the copper monitoring requirement based on 10 years of data that is well
below the action level.
3. The draft permit adds quarterly monitoring for bis(2-ethylhexyl)phthalate due
to a result that was above the federal water quality criteria. This was a result
submitted from the 2011 Priority Pollutant Scan that was qualified by the
laboratory. The qualifier indicated "the reported value is between the
laboratory method detection limit (MDL) and the laboratory method reporting
limit (MRL)". As discussed in Item 1 above, it is not accurate to use a number
below the MRL for the RPA. A review of the data used in the RPA illustrates
the reported value in 2011 is lower than two of the other data points that are
reported as a less than value. Given this information, the City requests
removal of the monitoring requirement of bis(2-ethylhexyl)phthalate.
We appreciate the opportunity to comment on the draft permit and would welcome
further discussion if necessary. If you need any additional information, please contact
me at 919-560-4386.
Sincerely,
Robert Dodson
Superintendent
attachment
cc: Don Greeley, Director, Department of Water Management
Vicki Westbrook, Assistant Director of Water Management
Don O'Toole, Senior Assistant City Attorney
Good Things Are Happening In Durham

Data for the South Durham Water Reclamation Facility
Reported Values Cu & Se 2001- 2011
SD Eff Cu
µg/L
MRL
Cu
SD Eff
Se
µg/L
MRL
Se
11/12/2001
0.0
<2.0
0.0
<5.0
7/16/2001
0.0
<2.0
0.0
<5.0
4/23/2001
0.0
<2.0
0.0
<5.0
1/24/2001
0.0
<2.0
0.0
<5.0
10/7/2002
0.0
<2.0
0.0
<5.0
7/8/2002
0.0
<2.0
0.0
<5.0
4/8/2002
0.0
<2.0
0.0
<5.0
1/7/2002
0.0
<2.0
0.0
<5.0
1/6/2003
0.0
<2.0
0.0
<5.0
4/22/2003
0.0
<2.0
0.0
<5.0
7/14/2003
0.0
<2.0
0.0 j
<5.0
10/6/2003
0.0
<2.0
0.0
<5.0
1/5/2004
0.0
<2.0
0.0
<5.0
4/12/2004
0.0
<2.0
0.0
<5.0
7/19/2004
0.0
<2.0
0.0
<5.0
10/11/2004
0.0
<2.0
0.0
<5.0
1/10/2005
0.0
<2.0
0.0
<5.0
4/4/2005
0.0
<2.0
0.0
<5.0
7/18/2005
2.4
<2.0
0.0
<5.0
10/17/2005
2.5
<2.0
0.0
<5.0
1/23/2006
2.5
<2.0
0.0
<5.0
4/24/2006
2.5
<2.0
0.0
<5.0
7/24/2006
3.0
<2.0
0.0
<5.0
10/9/2006
2.3
<2.0
0.0
<5.0
11/20/2006
0.0
<2.0
0.0
<10.0
1/15/2007
0.0 C J
<2.0
0.0
<5.0
3/14/2007
0.0
<2.0
0.0
<10.0
4/16/2007
2.0 3.3
<2.0
0.0
<5.0
7/17/2007
0.0 2,6
<2.0
0.0
<5.0
10/8/2007
2.8 :/
<2.0
0.0
<5.0
11/26/2007
2.0
<2.0
0.0
<5.0
1/14/2008
2.7
<2.0
0.0
<5.0
2/25/2008
1.5 (/'
<1.0
2.3
<10.0
4/21/2008
2.0 ,j
<2.0
0.0
<5.0
7/21/2008
2.0 ✓
<2.0
0.0
<5.0
10/20/2008
0.(
<2.0
0.0
<5.0
1/28/2009
2.1
<2.0
0.0
<5.0
4/21/2009
1.3
<1.0
0.0
<10.0
4/27/2009
2.2
<2.0
0.0
<5.0
7/27/2009
4.1
<2.0
0.0
<5.0
10/26/2009
0.0
<2.0
0.0
<5.0
SD Eff Cu
µg/L
MRL
Cu
SD Eff
Se
µg/L
MRL
Se
1/25/2010
3.7
<2.0
0.0
<5.0
4/5/2010
2.0
<2.0
0.0
<5.0
4/13/2010
1.48
<1.0
0.0
<10.0
7/26/2010
2.0
<2.0
0.0
<5.0
10/4/2010
2.5
<2.0
0.0
<5.0
1/24/2011
3.3
<2.0
0.0
<5.0
3/14/2011
2.1
<1.0
0.0
<10.0
4/18/2011
0.0
<2.0
0.0
<5.0
Average
Max
Min
Count
1.2
4.1
0.0
49.0
Bold - Priority Pollutant Scans
f0
ce
0.0
2.3
0.0
49.0
2/25/2008 - Se Data Qualified being between the Method Detection Limit and the
Lab. Method Reporting Limit (MRL).

IWC Calculations
Facility: South Durham WRF
NC0047597
Prepared By: GTV
Enter Design Flow (MGD):
Enter s7Q10 (cfs):
Enter w7Q10 (cfs):
20
0.15
2
Total Residual Chlorine (TRC)
Daily Maximum Limit (ug/I)
s7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
Upstream Bkgd (ug/l)
IWC (%)
Allowable Conc. (ug/I)
Fecal Coliform
Monthly Average Limit:
(If DF >331; Monitor)
(If DF<331; Limit)
Dilution Factor (DF)
0.15
20
31
17.0
0
99.52
17
Ammonia (Summer)
Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
Upstream Bkgd (mg/I)
IWC (%)
Allowable Conc. (mg/I)
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/I)
w7Q10 (CFS)
200/100mI DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
1.00 Upstream Bkgd (mg/I)
IWC (%)
Allowable Conc. (mg/i)
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N)
1. If Allowable Conc > 35 mg/I, Monitor Only
2. Monthly Avg limit x 3 = Weekly Avg limit (Municipals); capped at 35 mg/I
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis); capped at 35 mg/1
4. BAT for Minor Domestics: 2 mg/I (summer) and 4 mg/I (winter)
5. BAT for Major Municipals: 1 mg/I (year-round)
0.15
20
31
1.0
0.22
99.52
1.0
2
20
31
1.8
0.22
93.94
1.9
Fecal Coliform
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non -Muni)
NPDES Server/Current Versions/WLA; TB 1/16/2009

NC 2010 Integrated Report Categories 4 and 5 Impaired Waters
All 13,123 Waters in NC are in Category 5-303(d) List for Mercury due to statewide fish consumption advice for several fish species
AU Number AU Name
AU_Description LengthArea AU_Units Classification
Category Parameter Reason for Rating
Use Category Collection Year 303(d)year
Cape Fear River Basin
B Everett Jordan Lake -New Hope River Watershed 0303000206
Q 16-41-2-(9.5)
4t Chlorophyll a
Morgan Creek
(including the
Morgan Creek Arm of
New Hope River Arm
of B. Everett Jordan
Lake)
From Chatham County SR 1726 (Durham 836.2 FW Acres WS-
County SR 1109) to New Hope Creek Arm of IV;NSW,CA
New Hope River Arm of B. Everett Jordan
Lake
Standard Violation Aquatic Life
2008 2008
5 High pH
Standard Violation Aquatic Life
2008 2008
5 Turbidity
Standard Violation Aquatic Life
2008 2008
Q 16-41-2-(1.5)
5 Chlorophyll a
Morgan Creek
(University Lake)
From a point 1.4 miles downstream of NC 163.2 FW Acres WS-
Hwy 54 to dam at University Lake
Standard Violation Aquatic Life
I I;HQW, NSW,
2008 2010
Q 16-41-1-(11.5)a New Hope Creek
4s Ecological/biological Integrity Benthos
From a point 0.3 mile upstream of Durham
County SR 2220 to SR 2220
Fair Bioclassification Aquatic Life
0.4 FW Miles WS-IV;NSW
1987 2006
5 Fecal Coliform (recreation)
Standard Violation Recreation
2008 2006
5 Low Dissolved Oxygen
Standard Violation Aquatic Life
2008 2006
5 Turbidity
Data Inconclusive Aquatic Life
2008 2006
Q 16-41-1-(11.5)b New Hope Creek From SR 2220 to 140 3.5 FW Miles WS-IV;NSW
4s Ecological/biological Integrity Benthos
Fair Bioclassification
Aquatic Life
1987 2000
5 Fecal Coliform (recreation)
Standard Violation Recreation
2008 1998
5 Low Dissolved Oxygen
Standard Violation Aquatic Life
2008 1998
5 Turbidity
Standard Violation Aquatic Life
2008 1998
Q 16-41-1-(11.5)c New Hope Creek From 1-40 to a point 0.8 mile downstream 4.0 FW Miles WS-IV;NSW
of Durham County SR 1107
4s Ecological/biological Integrity Benthos
Fair Bioclassification Aquatic Lifc
2008
5 Turbidity
Standard Violation Aquatic Lifc
2008 2006
Q 16-41-1-(14)
4t Chlorophyll a
New Hope Creek
(including New Hope
Creek Arm of New
Hope River Arm of B.
Everett Jordan Lake)
From a point 0.8 mile downstream of 1,415.7 FW Acres WS-
Durham County SR 1107 to confluence with IV;NSW,CA
Morgan Creek Arm of New Hope River Arm
of B. Everett Jordan Lake
Standard Violation Aquatic Life
2008 2006
5 Turbidity
Standard Violation Aquatic Life
2008 2008
NC 2010 Integrated Report Category 4 and 5 303(d) List EPA Approved Aug 31, 201 9/20/2010 Page 7 of 145

•
, .
ATA
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Environmental Health
Beverly Eaves Perdue Terry L. Pierce Dee Freeman
Governor Director Secretary
MEMORANDUM
TO: Gil Vinzani, P.E.
DWQ/NPDES Program
FROM: Michael L. Douglas, P.E., Regional Engineer i\A
Public Water Supply Section
Raleigh Regional Office
SUBJECT: Draft National Pollutant Discharge
Elimination System Permit NC0047597
South Durham Water Reclamation Facility
6605 Farrington Road
Chapel Hill, North Carolina
Durham County
DATE: June 15, 2011
Reference is made to the above -mentioned Draft National Pollutant Discharge Elimination System
Permit. Upon review of this permit application to continue to operate an existing 20 MGD South Durham
Water Reclamation wastewater treatment facility located at 6605 Farrington Road in Durham County, it appears
that no adverse effect on water quality will occur to the existing public water supply intakes.
We concur with the issuance of this permit provided this facility is operated and maintained properly;
the stated effluent limits are met prior to discharge at Outfall 001 to New Hope Creek in the Cape Fear River
Basin; and the discharge does not contravene the designated water quality standards.
If we can be of further assistance, please contact me at 919-791-4200.
cc: James McRight, PWSS-Technical Services Branch, 2728 Capital Boulevard
Public Water Supply Section — Jessica G. Miles, Chief
Raleigh Regional Office
3800 Barrett Drive,1628 Mail Service Center, Raleigh, North Carolina 27699-1628
Phone: [phone] FAX: [phone] Internet: ncdrinkingwater.state.nc.us
An Equal Opportunity \ Afftrmative Action Employer
IJUN 17 2011
DENR-WATER QUALITY
POINT SOURCE BRANCH
None Carolina
Naturally

ijc tcvnth3un
Trusted & Essential
Affidavit of Publication
State of North Carolina,
Durham County
To Whom It May Concern:
This is to certify the
Advertisement attached
Hereto has been published
in -
The Herald Sun
on the following dates:
;r-ID-lI
Swor to on this 1344.) day
of L , , 2011
�L (�0 /411.4
Her
d Sun Representative
Sworn to and Subscribed
Befor me this\ day
of , 2011
Notary Public
Public Nctice
North Carolina Environmental
Management
CcmmissioniNPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
Notice of Intent to Issue a
NPDES Wastewater Permit
The Ncrth Carolina Environ-
mental Management Commis-
sion proposes to issue a
NPDES wastewater discharge
permit to the person(s) listed
below.
Written comments regarding
the proposed permit will be ac-
cepted until 30 days after the
publish date of this notice. The
Director of the NC Division of
Water Quality (DWQ) may
hold a public hearing should
there be a significant degree of
public interest. Please mail
comments and/or information
requests to DWQ at the above
address. Interested persons
may visit the DWQ at 512 N.
Salisbury Street, Raleigh, NC
to review information on file.
Additional infcrmation on
NPDES permits and this notice
may be found on our website:
http://portal. ncdenr. orglweblwq
/swp/ps/npdes/calendar, or by
calling (919) 807- 6304.
The City of Durham requested
renewal of NPDES Permit
NCOO47597 fcr its South Dur-
ham Water Reclamation Facil-
ity in Durham County. This
permitted discharge is treated
municipal wastewater to an
unnamed tributary of New
Hope Creek in the Cape Fear
River Basin.
HS: June 10, 2011

SDWRF Removal Rate Calculations 2007
ARZ51r Ncc
Influent
mg/L
Used in
Calculation <
Effluent
mg/L
Used in
Calculation
Sample Date
7/8/2002
0.005
0.0025
< 0.005
0.0025
10/7/2002
0.005
0.0025
< 0.005
0.0025
1/6/2003
0.005
0.0025
< 0.005
0.0025
4/22/2003
0.005
0.0025
< 0.005
0.0025
7/15/2003
0.005
0.0025
< 0.005
0.0025
10/6/2003
0.005
0.0025
< 0.005
0.0025
1/5/2004
0.005
0.0025
< 0.005
0.0025
4/12/2004
0.005
0.0025
< 0.005
0.0025
7/19/2004
0.005
0.0025
< 0.005
0.0025
10/11/2004
0.005
0.0025
< 0.005
0.0025
1/10/2005
0.005
0.0025
< 0.005
0.0025
4/4/2005
0.005
0.0025
< 0.005
0.0025
7/18/2005
0.005
0.0025
< 0.005
0.0025
10/17/2005
0.005
0.0025
< 0.005
0.0025
1/23/2006
0.005
0.0025
< 0.005
0.0025
4/24/2006
0.005
0.0025
< 0.005
0.0025
7/24/2006
0.005
0.0025
< 0.005
0.0025
10/9/2006
0.005
0.0025
< 0.005
0.0025
1/15/2007
0.005
0.0025
< 0.005
0.0025
4/16/2007
0.005
0.0025
< 0.005
0.0025
7/16/2007
0.005
I
0.0025
< 0.005
0.0025
Column Averages =>
0.0025
0.0025
Unpaired Site Specific RR => 50 % BDL
Literature/Default RR =>
100 % of data is BDL
RR for this HWA =
45.00%
45.00 %
SD_rernoval07
Removal Rates
Page 1 of 5 pages
G�lpM1Utit
<
Influent
m
Used in
Calculation <
Effluent
mg/L
Used in
Calculation
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
0.003
0.003
0.001
0.001
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
0.036
0.036
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
0.0023
0.0005
Unpaired Site Specific RR => 50 %a BDL
Literature/Default RR =>
93 % of data is BDL
RR for this HWA =
67.00 %
67.00 %
ChoYetoM W M
<
Influent
mg/L
Used in
Calculation <
Effluent
mg/L
Used in
Calculation
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
0.0075
0.0075
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
0.043
0.043
< 0.005
0.0025
<
0.005
0.0025
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
0.0047
0.0025
Unpaired Site Specific RR => 50
Literature/Default RR =>
95 % of data is BDL
RR for this HWA =
82.00 %
82.00 %

SDWRF Removal Rate Calculations 2007
Sam.le Date
7/8/2002
lon/2o02
1/6/2003
4/22/2003
7/15/2003
i 0/6/2003
1/5/2004
4/12/2004
7/ 19/2004
10/11/2004
1/10/2005
4/4/2005
7/18/2005
10/17/2005
1/23/2006
4/24/2006
7/24/2006
10/9/2006
1/15/2007
4/16/2007
7/16/2007
Column Averages =>
SD_remova107
Removal Rates
Page 2 of 5 pages
co reEre.
<
Influent
mg/L
Used in Effluent
Calculation <I mg/L
Used in
Calculation
0.052
0.052
0.005
0.0025
0.032
0.032
<1 0.005
0.0025
0.0084
0.0084
< 0.005
0.0025
0.025
0.025
0.005
0.0025
0.081
0.081
..<
< 0.005
0.0025
<
0,005
0.0025
< 0.005
0.0025
0.044
0.044
< 0.005
0.0025
0.023
0.023
< 0.005
0.0025
0.009
0.009
0.0071
0.0071
0.047
0.047
< 0.005
0.0025
0.036
0.036
< 0.005
0.0025
0.052
0.052
< 0.005
0.0025
0.06
0.06
0.002
0.002
0.039
0.039
0.0025
0.0025
0.039
0.039
m
0.002
0.002
0.035
0.035
0.002
0.002
0.045
0.045
0.002
0.002
0.033
0.033
0.002
0.002
0.043
0.043
< 0.002
0.001
0.032
0.032
0.0033
0.0033
0.031
0.031
0.0026
0.0026
Unpaired
0.0366
RR =>
RR =>
0.0026
Site Specific
Literature/Default
92.98 %
86.00 %
31 %ofdata isBDL
RR for this HWA =
92.98 %
GYANtuE
<
Influent
mg/L
Used in
Calculation <
Effluent
m
Used in
Calculation
<
0.005
0.0025
< 0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.01
0.005
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
0.007
0.007
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
0.0029
0.0025
Unpaired Site Specific RR => . 50 % BDL.
Literature/Default RR =>
98 % of data is BDL
RR for this HWA =
69.00 %
69.00 %
<
Influent I
m
Used in
Calculation <
I Effluent
mg/L
I Used in
Calculation
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
0.0025
0.009
0.009
< 0.005
0.0025
0.063'
0.063
< 0.005
0.0025
0.005
0.005
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
0.005
0.005
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
0.012
0.012
< 0.005
0.0025
0.005
0.005
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
0.0065 1
0.0025
Unpaired Site Specific RR => 50 % BDI.
Literature/Default RR =>
86 % of data is BDL
RR for this HWA =>
61.00 %
61.00 c7

SDWRF Removal Rate Calculations 2007
Sample Date
7/8/2002
10/7/2002
1/6/2003
4/22/2003
7/15/2003
10/6/2003
1/5/2004
4/12/2004
7/19/2004
10/11/2004
I/10/2005
4/4/2005
7/18/2005
10/17/2005
1/23/2006
4/24/2006
7/24/2006
10/9/2006
1/15/2007
4/16/2007
7/16/2007
Column Averages =>
SD_remova107
Removal Rates
Page 3 of 5 pages
fAci2cut2Y
<
Influent
mH/L
Used in
Calculation <
Effluent
ma./L
Used in
Calculation
<
0.0002
0.000I
< 0.0002
0.0001
<
0.0002
0.0001
< 0.0002
0.0001
<
0.0002
0.0001
'< 0.0002
0.0001
<
0.0002
0.0001
< 0.0002
0.000I
<
0.0002
0.0001
< 0.0002
0.0001
<
0.0002
0.0001
0.0000017
0.0000017
0.00010
0.00008
Unpaired Site Specific RR =>
Literature/Default RR =>
92 % of data is BDL
RR for this HWA =
50%BDL
60.00 %
60.00 %'n
MEt2cu21(
<
Influent
mg/L
Used in
Calculation1<
Effluent
mg/L
Used in
Calculation
l
0.000115
0.000115
0.0000014
0.0000014
<
5E-07
2.5E-07
0.0000017
0.0000017
0.000312
0.000312
0.000001
0.000001
6.05E-05
6.05E-05
0.0000025
0.0000025
0.000404
0.000404
0.0000021
0.0000021
3.17E-05
3.17E-05
0.000002
0.000002
7.35E-05
7.35E-05
0.000005
0.000005
1.43E-05
1.43E-05
0.0000024
0.0000024
0.000143
0.000143
0.0000026
0.0000026
0.0000448
4.48E-05
0.0000057
0.0000057
0.0000330
0.000033
0.0000015
0.0000015
0.0000364
3.64E-05
0.0000020
0.000002
0.0000382
3.82E-05
0.0000013
0.0000013
0.0000276
2.76E-05
0.0000017
0.0000017
0.0000950
0.000095
< 0.000001
0.0000005
Unpaired
0.0001
RR =>
RR =>
0.0000022
Site Specific
Literature/Default
97.67 %
60.00 %
7 % of data is BDL
RR for this HWA =>
I- IS-07
4-14. -6 7
7-(6-07
97.67 %
Nit cKEL
<
Influent
me/L
Used in
Calculation <
Effluent
mg/L
Used in
Calculation
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
0.016
0.016
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01_
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
0.011
0.011
<
0.01
0.005
<
0.01
0.005
<
0.01
0.00.5
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
<
0.01
0.005
0.011
0.011
<
0.01
0.005
<
0.01
0.005
0.0058
0.005
c 2S03/L
1 72_ n�/L
(.0 L
Unpaired Site Specific RR => 50 % BD]
Literature/Default RR =>
93 % of data is BDL
RR for this HWA =>
42.00
42.00 %

SDWRF Removal Rate Calculations 2007
} Sample Date
7/8/2002
10/7/2002
1/6/2003
4/22/2003
7/15/2003
10/6/2003
1/5/2004
4/12/2004
7/19/2004
10/11/2004
1/10/2005
4/4/2005
7/18/2005
10/17/2005
1/23/2006
4/24/2006
7/24/2006
10/9/2006
1/15/2007
4/16/2007
7/16/2007
Column Averages =>
SD_removal07
Removal Rates
Page 4 of 5 pages
5Et- NivM
<
Influent
mg/L
Used in
Calculation <
Effluent
mg/L
Used in
Calculation
<I
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.0054
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
..ate
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0,0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
0.0025
<
0.005
0.0025
< 0.005
0.0025
<
0.005
0.0025
0.0025
<
0.005
0.0025
- 5
0.0025
<
0.005
0.0025
< 0.005
0.0025
0.0025
(
0.0025
Unpaired Site Specific RR =>a 50 % BDL
Literature/Default RR =>
100 % of data is BDL
RR for this HWA =
50.00 %
50.00 %
St LVER
<
Influent
mg/L
Used in
Calculation <
Effluent
m
Used in
Calculation
0.017
0.017
< 0.001
0.0005
0.012
0.012
< 0.001
0.0005
0.0062
0.0062
< 0.001
0.0005
0.009
0.009
< 0.001
0.0005
0.009
0.009
< 0.001,
0.0005
0.022
0.022
< 0.001
0.0005
0.007
0.007
< 0.001
0.0005
0.0064
0.0064
< 0.001
0.0005
0.009
0.009
< 0.001
0.0005
0.011
0.011
< 0.001
0.0005
0.01
0.01
< 0.001
0.0005
0.0085
0.0085
< 0.001
0.0005
0.009
0.009
< 0.001
0.0005
0.008
0.008
< 0.001
0.0005
0.0059
0.0059
< 0.001
0.0005
0.0021
0.0021
< 0.001
0.0005
0.0029
0.0029
< 0.001
0.0005
0.0046
0.0046
< 0.001
0.0005
0.004
0.004
< 0.001
0.0005
0.0028
0.0028
< 0.001
0.0005
<
0.001
0.0005
< 0.001
0.0005
0.0079
0.0005
Unpaired Site Specific RR =>p 50 % BDL
Literature/Default RR =>
52 % of data is BDL
RR for this HWA =
75.00 %
75.00 %
<
Influent
mg/L
Used in
Calculation <
Effluent
mg/L
Used in
Calculation
0.228
0.228
0.033
0.033
0.182
0.182
0.015
0.015
0.099
0.099
0.036
0.036
0.117
0.117
0.031
0.031
0.53
0.53
0.027
0.027
0.364
0.364
0.027
0.027
0.257
0.257
0.03
0.03
0.15
0.15
0.022
0.022
0.237
0.237
0.019
0.019
0.3
0.3
0.019
0.019
0.261
0.261
0.02
0.02
0.307
0.307
0.024
0.024
0.304
0.304
0.032
0.032
0.212
0.212
0.03
0.03
0.25
0.25
0.048
0.048
0.263
0.263
0.032
0.032
0.194
0.194
0.021
0.021
0.411
0.411
0.021
0.021
0.741
0.741
0.044
0.044
0.397
0.397
0.04
0.04
0.334
0.334
_
0.045
Unpaired
0.292
RR =>
RR =>
0.029
Site Specific
Literature/Default
89.96 %
79.00 %
0 % of data is BDL
RR for this HWA =
89.96 %

SDWRF Removal Rate Calculations 2007
Sam. le Date
7/8/2002
10/7/2002
1/6/2003
4/22/2003
7/15/2003
10/6/2003
1/5/200
4/12/200
7/19/2004
10/11/2
1/10/2005
4/4/2005
7/18/2005
10/17/2005
1/23/2006
1.111.11.1g=
10/9/200.
1/15/2007
4/16/200
7116/2007
Column Averages =>
SD_removal07
Removal Rates
Page 5 of 5 pages
FL-oL.) (2cpE
<
Influent
mg/L
Used in
Calculation <
Effluent I
mg/L
Used in
Calculation
1.2
1.2
0.9
0.9
1.2
0.9
0.9
0.8,
0.8
0.7
0.7
0.8
0.8
0.7
0.7
1.
1.2
0.9
0.9
1.2
0.9
0.9
1
1
0.8
0.8
0.4
0.4
0.7
0.7
0.8
0.8
0.7
0.7
0.8
0.8
0.9
0.9
0.9
0.9
1
1
1
1
0.7
0.7
1
1
0.9
0.9
0.9
0.9
0.8
0.8
0.5
0.5
0.6
0.6
0.4
0.4
0.5
0.5
0.2
0.2
0.5
0.5
0.6
0.6
0.4
0.4
0.4
0.4
0.5
0.5
0.1
0.1
0.4
0.4
0.5
0.5
0.8
0.8
Unpaired
0.76
RR =>
RR =>r,
0.72
Site Specific
Literature/Default
4.40 %
0 % of data is BDL
RR for this HWA =
4.40 %
1f
<
Influent
mg/L
Used in
Calculation <
Effluent
mg/L
Used in
Calculation
6.73
6.73
0.58
0.58
4.87
4.87
0.63
0.63
3.35
3.35
0.15,
0.15
3.47
3.47
0.67
0.67
4.73
4.73
0.18
0.18
5.5
5.5
0.54
0.54
8.85
8.85
0.28
0.28
5.54
5.54
0.26
0.26
9.68
9.68
0.44
0.44
6.81
6.81
1.3
1.3
6.6
6.6
0.23
0.23
5.88,
5.88
0.25
0.25
6
6
0.26
0.26
6.52
6.52
1.8
1.8
6.45
6.45
0.92
0.92
7.08
7.08
0.46
0.46
6.02
6.02
0.41
0.41
6.95
6.95
0.15
_0.6
0.15
6.12
6.12
4.14
4.14
_
0.24
5.23
5.23
0.4
0.4
Unpaired
6.02
RR =>
RR =>I11
0.51
Site Specific
Literature/Default
91.50 %
0 % of data is BDL
RR for this HWA =
91.50 %
M0G'C13D6NvM
<
Influent
mg/L
Used in
Calculation ,..<
Effluent
mg/L
Used in
Calculation
0.012
0.019
0.019
0.0120
0.0095
0.0095
0.0075
0.0075
0.0054
0.0054
< 0.005
0.0025
0.007
0.007
< 0.006
0.003
0.012
0.012
0.0086
0.0086
0.023
0.023
< 0.005
0.0025
0.009
0.009
< 0.005
0.0025
<
0.005
0.0025
< 0.005
0.0025
0.019
0.019
0.007
0.007
0.027
0.027
0.021
0.021
0.021.
0.021
0.017
0.017
0.005
0.005
0.005
0.005
0.016
0.016
0.026,
0.026
0.03
0.03
0.021
0.021
0.0084
0.0084
< 0.005
0.0025
0.011
0.011
0.013
0.013
0.026
0.026
0.033
0.033
0.034
0.034
< 0.005
0.0025
0.031
0.031
< 0.005,
0.0025
0.026
0.026
< 0.005
0.0025
0.072
0.072
0.005
0.005
Unpaired
0.0197
RR =>
RR =
0.009481
Site Specific
Literature/Default
51.88 %
33.00 %
24 % of data is BDL
RR for this HWA =
33.00 %

.Vinzani, Gil
From: Templeton, Mike
Sent: Thursday, July 30, 2009 5:38 PM
To: [e-mail]
Cc: Vinzani, Gil
Subject: RE: TMDL allocation information request for City of Durham
Hi, Katya -
hope you're doing well!
Durham's plants are (or will soon be) subject to N & P limits under three nutrient management strategies.
1. The South plant is in the Jordan Lake watershed and subject to the TMDL and strategy for the Upper New Hope
arm of the lake. It will receive nutrient limits once the legislature takes final action on the nutrient rules. The
proposed discharge limits are 183,345 lb/yr TN and 14,053 lb/yr TP (3.04 and 0.23 mg/L, respectively, at the full
permitted flow of 20 MGD). The TP limit is to become effective in CY2010, the TN limit in CY2016.
2. The North plant is already subject to nutrient limits calculated to protect the Neuse estuary. It has a TN
discharge limit of 334,851 lb/yr (5.5 mg/L at 20 MGD permitted flow) and a TP limit of 2.0 mg/L, quarterly
average.
3. The North plant faces additional controls under the Falls Lake strategy. We are working through a stakeholder
process now to develop that strategy and an implementation schedule to meet the legislature's mandate that
the EMC adopt rules for the strategy by next July. We have not developed a TMDL for Falls Lake, and our aim is
to address the lake's WQ issues without going through the formal TMDL process.
Let me know if I missed anything or if you have any other questions about Durham's permit requirements.
- Mike T
Michael E. Templeton, P.E.
Point Source Branch/ NPDES
Surface Water Protection Section
NCDENR • DWQ Raleigh, NC
Tel: [phone]
Fax: [phone]
E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third parties.
From: Vinzani, Gil
Sent: Friday, July 24, 2009 1:10 PM
To: Templeton, Mike
Subject: FW: TMDL allocation information request for City of Durham
Mike:
Do you have this handy? Or should we refer them to the Modeling/TMDL unit?
Gil
Gil Vinzani, Engineer
Eastern NPDES Program
1

DURHAM
1
1869
CITY Of MEDICINE
Administration
919-560-4381
:ustomer Billing Services
919-560-4412
Laboratory Services
919-560-4386
Plant Maintenance
919-560-4388
Regulatory Compliance
919-560-4381
Wastewater Treatment
North - 919- 560-4384
South - 919-560-4336
'ater Supply & Treatment
Williams - 919-560-
4349
Brown - 919-560-4362
Water & Sewer
Maintenance
919-560-4344
CITY OF DURHAM
DEPARTMENT OF WATER MANAGEMENT
101 CITY HALL PLAZA • DURHAM, NC 27701
919-560-4381 • FAX [phone]
www.durhamnc.gov
October 21, 2010
Mrs. Dina Sprinkle
NC DENR/DWQ/NPDES
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Dear Mrs. Sprinkle:
Please find enclosed one original and two signed copies of the permit renewal for
the City of Durham's South Durham Water Reclamation Facility, NC0047597.
Information on sludge management is included in the description of the facility. The
only project completed since the last renewal was the addition of a cover over the
biosolids storage facility in 2006.
If you have any questions or need additional information, please call me at 919-560-
4386.
Sincerely,
LO-
Robert Dodson
Superintendent
enclosures
cc: Water Management
Good Things Are Happening In Durham

MyTopo Map Print
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0.5 Mi
2000 Ft
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I
a
*a
p1
• O
•
gist nos
*s
1
Influent lines to the South Durham Water Reclamation Facility
0.•
410M1,,C1
KECK

Locat
Gener.
Buildin
La..•
Imagery Date. May 31. 2007
Grit Chambers
Diesel and Natural Gas
Generators for Influent
lmping and Screening
N.
• Diese� w , . d,
3. Ge erator for • '" `.J.
. 1ainrPlant 3 Fi �,., — , : >
4Pro'cesses I-1\ ji ...• •it. 4
h i Drying Beds
Y g
Final Clarifiers
Sludge Storage
elev 0 it
hJV Disinfection

South Durham Water Reclamation Facility
The South Durham Water Reclamation Facility was originally built in 1984 as a 10 MGD
activated sludge facility. In 1990, the facility was upgraded to include processes for
chemical and biological phosphorous removal in addition to belt filter presses for sludge
dewatering. Traveling bridge effluent filters were also added to improve effluent quality.
In 1994, the facility was expanded to 20 MGD and upgraded to include biological
nutrient removal, gravity belt thickeners, ultraviolet light disinfection, odor scrubbing and
a computer control system. With the addition of two anaerobic digesters in 1998, all
sludges, primary and waste activated, are digested anaerobically then land applied as a
Class B product. The City contracts with Synagro Southeast to land apply biosolids to
privately owned farm land that is permitted in the City of Durham's name.
The South Durham facility is home to the Water and Wastewater Laboratory. This
laboratory runs all analyses for two (2) water plants, two (2) wastewater plants, the
Industrial Pretreatment Program and the Storm Water Program. .
Hazen and Sawyer Engineers are in the preliminary stages of designing a supplemental
carbon feed facility as well as designing other process modifications to improve nitrogen
removal in anticipation of the 2016 permit limit. The operations staff is continuing to
make process adjustments in an effort to continue to lower nitrogen discharges.
Flow moves through the following processes:
Preliminary Treatment: Barscreens and Grit Chambers
Primary Treatment: Primary Clarifiers
Secondary Treatment: 5 stage Bardenpho Activated Sludge and Final
Clarification
Tertiary Treatment: Chemical Addition, if needed, and Effluent
Filtration
Disinfection: Ultraviolet Light
Sludge Management Plan
Sludge is anaerobically digested and dewatered using belt filter presses or
sand drying beds. Dewatered biosolids are stored on a sludge storage pad and
land applied as a Class B product on permitted sites under Land Application Permit,
WQ0003504. The City contracts with Synagro for the land application of all biosolids
produced at the facility.
Attached is a list and specifications for all equipment and tankage at the facility.

SOUTH DURHAM WRF
DESIGN DATA
20 MGD DESIGN "CAPACITY .
Influent Pump Station
Influent Bar Screens
Number .
Clear opening between bars
Method of cleaning
Influent Pumps
Number
Capacity range of each pump
Total dynamic head at. maximum capacity
Motor horsepower
Grit Collectors
Number
Capacity of each unit
Type
Method of velocity control
Method of cleaning
Primary Settling Basing
Number
Dimensions of each basin
Length
Width
Average depth
Total surface area
Surface overflow rate at design flow
Volume of each basin
Total volume
Detention time at design flow
Primary Solids Pumps
Number
Capacity of each pump
Total dynamic head
Horsepower
Scum Handling Facilities
Scum Pumps
Number
Capacity of each pump
Total dynamic head
Horsepower
2
3/4 inch
Mechanical
(with Timer Control)
4
6.8 to 23 mgd
50 ft.
250
4
Approximately 15 mgd
Horizontal flow, .
velocity control
Parshall flume
Mechanical
4
98 ft..
'40 ft.
10.5 ft.
_ 15,680 ft.2
1,275 gpd/ft.2
0.31 mil. gal.
123 mil. gal.
1.5 hrs.
4
125 gpm
35 ft.
10
2
150 gpm
25 ft. •
3

Primary Settling Basins (continued)
Scum Concentrator
Number 1
Maximum flow rate 150 gpm
Influent solids concentration
(by weight) 1 - 2%
Anoxic Tanks (Anaerobic Zone).
Number
Dimensions of each tank
Length
Width
Depth
Volume of each tank
Total volume
• Detention time at design flow
Aeration Basins
2
240 f1
30 ft.
Approximately 15.25 ft.
0.82 mil. gal:
1.64 mil. gal.
2.0 hours
Number 8
Dimensions of each basin
Length 304 ft.
Width 4 @ 50 ft.
4 @ 75 ft.
Depth 15 ft.
Volume of each basin 4 @ 1.71 mil. gal.
4 @ 2.56 mil. gal. •
Total volume 17.1 mil. gal.
Total detention time at design flow 20.5 hours
First Anoxic Zone
Length 51 ft.
Total volume 2.86 mil. gal.
Total detention time at design flow 3.4 hours
Aerobic Zone
Length 190 ft.
Total volume 19.66 mil. gal.
Detention time at design flow ff.8 hours
Second Anoxic Zone
Length 51 ft.
Total volume 2.86 mil. gal.
Detention time at design flow 3.4 hours
Reaeration Zone
Length 12 ft.
Total volume 0.67 mil. gal.
Detention time at design flow 0.8 hours

Mixin IA ration S t m
a) Mixing System Jet nozzle
Type � 5
Number of header systems in each aeration basin 40
systems 4 @ 10
Total number z es per header 4@ 14
Number of Number of pumps per basin 76
Total number of pumps 52@ 2. •
•mgd
Capacity of each pump 28 @ 3.8 mgd
Fine bubble diffused air, disc type
b) . Aeration systems
Type
Number of diffusers
Aeration zone
Reaeration zone
Total
4@794
4 @ 1,100
4@44
4 @ 96
8,136
c) Recirculation System 4
Number of pumps per basin 32
Total number of pumps 4 @ mgd
Capacity of each pump 12 @ 3.0 mgd
4 @ 3.9 mgd
12 @ 5 mgd
.d) Blowers
Engine -Driven Blowers 2
Number 8,850 icfm
Maximum capacity of each blower
Motor -Driven Blowers 4
Number 2 @ 6,700 icfm
Capacity of each blower 2 @ 7,900 icfm
Final Clarifiers
6
Number 4 @ 80 ft.
Diameter 2 @ 120 ft.
42,730 ft.2
Total surface area � 470 gpolft?
Surface overflow rate at design flow 4 @ 16 ft.
Sidewali water depth 2 @ 15.3 ft.
S.Omil. gal.
tot\ Total volume ' 6.0 hours
Detention time at design flow Suction -type
Type of solids removal system
. I A 11 nst SECTION.1

Return Activated Sludge Pump Stations
Number of pump stations
Total number of pumps
Maximum capacity of each pump
Horsepower
Type of variable speed drive
Flocculation Basins
• Number
Dimensions
- Length
Width
Depth
Total volume
Detention time at design flow
Rapid Mixers
Number
Horsepower per mixer
Flocculators
Number per basin
Total number
Horsepower per flocculator
Effluent Filters
Number
Type of filters
Dimensions of each filter
Length
Width
Depth of anthracite
Depth of sand
Total surface area
Filtration rate at design flow
Disinfection Facilities
Type
Number of channels
Number of banks per channel
Number of modules oer bank
2
7
2 @ 2,250 gpm
2 © 2,900 gpm
3 © 5,000 gpm
4@15
3 @ 30
Variable frequency (VFD)
4
70 ft.
15.5 ft.
10.5 ft.
0.34 mil. gal.
24.5 min.
2
15
4
16
1.5
4
Dual -media, traveling
bridge, automatic
backwash type, with air
scour
111.7 ft.
15 ft.
8 in.
8 in.
6,700 ft.2
2.1 gpm/ft.2
Ultraviolet
6
1
20

Effluent Flow Measurement
Type Parshall flume
Throat .width 6 ft.
Post Aeration Facilities
Type of post aeration
Height of fall after effluent Parshall flume
Waste Activated Sludge Thickeners
Free fall
8-10ft.
Number 2
Type Gravity belt
Belt width per thickener 2 meters
Maximum feed, rate per thickener .500 gpm
Maximum solids loading rate per thickener 2,000 lbJhr.
Anaerobic Digesters (for Primary and Waste Activated Sludge2
Number 2 2
Dimensions of each digester
• Diameter 70 ft.
Sidewall water depth 22.42 ft.
Volume of each digester - 97,840 ft3 123,088 ft3 .
Total volume . 195,680 ft? . 246,176 ft3
Design total solids production
(annual average conditions) 40,670 lb/day
Detention time at design solids production
(4% solids) 12 days .
Volatile solids loading (75% V.S.) 0.16 lbJft.3-day
Digested biosolids production (50% VSS destroyed) 25,4201biday
Type of covers Floating
Digester mixing system
Type Expendable piston
pump
Number of mixers per digester 7
Barrel diameter 30 in.
Recirculation pumps
Number 2
Capacity of each pump 410 gpm
Total dynamic head 34 ft.
Horsepower 7-1/2

Anaerobic Digesters (for Primary and .Waste Activated Sludge) (Continued
Transfer pumps
Number
Capacity
Total dynamic head
Horsepower
Gas Holder
Number
Volume
2•
1 @ 300 gpm.
1 @ 200 gpm
1 @40ft.
1 @48.5ft.
1 @ 15
1 @ 10
1
50,000 ft?
Aerobic Digesters/Solids Storage Tanks
Number of tanks • 2
Dimensions of each tank
Length 70.5 ft. •
Width 55 ft.
Depth 16 ft.
Volume of each tank 62,040 ft?
Total volume 124,080 ft?
Detention time at design digested biosolids production
(4% solids) .12 days
Aeration system
Diffuser type and pattern . Coarse bubble, cross roll
Number of diffusers 280
Aerobic Digester Pump Station
Number of pumps 3
Capacity of each pump 210 gpm
Horsepower • 10
Blend Tanks
• Number 2
Diameter 30 ft.
Maximum depth 12 ft.
*Total volume 127,000 gal.
Belt Filter Presses
Number
Belt width per press
Feed rate per press
Solids loading rate per press
3
2 meters
60 -140 gpm
1,600 IbJhr.

Sand D in B d
Number
Dimensions
Length
Width
Total area
Digested biosolids loading •
Method of biosolids removal
Reactor Clarifiers
Number
Diameter of each unit
Total surface area
Maximum belt filter press filtrate (two presses)
Overflow rate
Assuming use for biosolids produced over 4 months of the year.
36
135 ft.
48ft.
233,280 ft!
13.3 lb./l 2-yr'
Front-end loader or
truck -mounted vacuum
2
30 ft.
1,410 ft?
576,000 gpd
410 gpd/ft.2
4.4

Two (2) additional anaerobic digesters were constructed in 1998 with a
diameter of 85 feet and a sidewall depth of 28 feet. Each has a volume
of approximately 1.3 MG. This provides enough capacity to digest both
primary and secondary sludges anaerobically.

4
FIGLlRE=1=
FAJRIISJ _^.-�
R
INFW IT Id�PLANT'S (YI
BAR INFUJENT
SCREENS PUMP
(2) STATION
CONCENTRATOR
EFFLUENT
ALUM
GRIT
REMOVAL
FACILITIES
SCUM
CONCENTRATOR
LEGEND
NORMAL OPERAIKIH
--- ALTERNATE OPERATION
DB
DC
F
FB
FOR
FE
uL
YIR
PE
Ps
RAS
Sc
sU
1su
UR
WAS
DIGESTED BIOSOLJDS
DIGESTER CAS
FILTRATE
FILTER BACXWASH
FILTER BAOOVASH RETURN
FILTER MUMMY
WED UGUGR
M D UCUOR RECIRCULAIIGN
PRIMARY EFFLUENT
PRIMARY SOURS
RETURN ACTIVATED SLUDGE
SCUM
DIGESTER SUPERNATANT
WOOLED SOURS
THICKENER SUPERNATANT
UN ERDRAIN RETURN
IMAS1E ACTIVATED SLUDGE
PUMPS
t
SCREENINGS
AND GRIT
TO LANDFILL
yo3
IJAZENAND SAWYER
irPRIMARY
SETIUNG
BASINS (4)
SU
PRIMARY SOUDS
PUMP STATIONS (2)
Su
o? 5
Ps
372
©ay
ANOXIC
TANKS
(2)
I
3 f
MLR •
ALUM
AERATION IIE
BANS
(8)
r
�°lo cf I
RAS r.04
WAS WAS I
i
P I
I I
as0(00 LI 14$1 1f0oc�cs
II
GRAVITY BELT 14 l
THICKENERS
(2) 1 I WAS
CAL- I
ALUM OR
POLYMER
• FINAL
CLARIFIERS
(6)
15ti�o
• t.-DG TO ENGINE -DRIVEN BLOWERS
Z.
o��r
c3S5103WDAy
prirr4
r3,Isep o'u 200 ?
RAS
PUMP
Fe_
STATIONS
(2)
� F
FLocaJLAnoN
BASNS
(4)
TSU
WAS
ir
J
tf
AEROBIC
DIGESTERS/
SOLIDS
STORAGE 0 T
TANKS (2)
DB
DS
EFFLUENT
ALTERS
(4)
DB
t
ro16a
ULTRAVIOLET
IEe 0.1 DISINFECTION
43a6 S ys
F/UR/TSU
EFFLUENT TO
NEW HOPE CREEK t0 5"3
I(hCr0
--- REACTOR
CLARIFIERS
- (2)
Lr--ALUM
SAND
DRYING
BEDS (36)
BELT
FILTER
PRESSES (3)
DISPOSAL
SOLIDS BY LAND
STOCKPILE APPUCATIC
AREA
SOUTH DURHAM
WATER RECLAMATION FACILITY
PROCESS FLOW SCHEMATIC
20 MGD DESIGN CAPACITY
Environmental Engineers & Scientists