NC0026051_Wasteload Allocation_19900314

NPDES WASTE LOAD ALLOCATION
PERMIT NO.: NC0026051
PERMI'1"1'hE NAME:
Durham County / Triangle WWTP
Facility Status: Existing
Permit Status: Renewal
Major .\1 Minor
Pipe No.: 001
Design Capacity: 6.0 MGD
Domestic (% of Flow): 52.7 %
Industrial (% of Flow): 47.3 %
Comments:
pretreatment information attached
RECEIVING STREAM: Northeast Creek
Class: C-NSW
Sub -Basin: 03-06-05
Reference USGS Quad: D 23 NW
(please attach)
County: Durham
Regional Office: Raleigh Regional Office
Previous Exp. Date: 6/30/90 Treatment Plant Class: Class 2
Classification changes within three miles:
none
Requested by:
Prepared by:
Reviewed by:
Rosanne Barona
kiwi 7). seq. a
7-<)1t.t. S xi .L
Date:
2/1/90
Date: 316 (?()
Date: 3/ 7/90
4 end d0,4ns4wo.m sat hts 6cen u fc,1,,� -Fe g,ve.
a )3.t{4tc eccl&cn+.i iMpa'-t
.lkiat oil a
ant thn. Cre.4 s
Modeler
Date Rec.
#
M.b5
111\90
s1z-
Drainage Area (mi2 ) g.00 Avg. Streamflow (cfs): 20.00
7Q10 (cfs) 0,p Winter7Q10 (cfs) d,sp 30Q2 (cfs) 0.9
Toxicity Limits: IWC 99 % Acute/ hron'
cl.r n,c/Cer;o��hAM/Q�f�t
Instream Monitoring: i
Parameters Tennpeca. w-e DO, -c'tcal colr(okM ea/duck vil L/ — T `
Upstream 1 Y , Location Ai- 1 S2 1TOIL/ 7kL .:A
Downstream
Co
Y
Location 1� M}+ 5R Roo
R 1- sit 1132,
fin, IL.: d
NOi+1d03 N�31
Effluent
Characteristics
Summer
Winter
BOD5 (mg/1)
,S
1 0
NH3-N (mg/1)
!
!.9
D.O. (mg/1)
6
6
TSS (mg/1)
SO
3 0
F. Col. (/100 ml)
2.00
200
PH (SU)
6 _ et
6 - et
-3"P (r".)/)
O.5-
Z.O
CaJ( A(n )
Z
(Dw,,y Mo.x)
0,,,, �:um (M5f L)
N;Jct.( elk)
50
8 4
1
Ge. LAO)
c.)..:1. (i/t
ZS
5
i1,r,.ur7 1Ay/t
roe it C' �
0.012
Mon:+or
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1
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1�

DIVISION OF ENVIRONMENTAL MANAGEMENT
February 8, 1990
NEMORANDUM
TO: WLA File
FROM: Mike Scoville YID)
SUBJECT: Explanation of Recommended NPDES Permit Limits for Triangle WWTP
(NPDES No. NC0026051, Durham County)
The Triangle WWTP discharges to Northeast Creek at a point where the
summer 7Q10 is estimated to be 0 cfs. Northeast Creek is a tributary to
Jordan Lake and is swampy and slow -moving upstream of the lake zone. The
characteristics of the creek and the plant's location in the lake's headwat-
ers are important factors of the recommended limits.
The limitations of oxygen consuming waste (BOD and NH3) are being
reduced to protect instream DO concentrations. A rise in the DO limit to 6
mg/1 accompanies this change because the stream is dominated by the waste -
flow at 7Q10 flow conditions. Although there are currently no problems
downstream of the discharge due to the effluent, the facility is currently
operating at effluent levels below the recommended limits. The effluent
actually improves the stream quality from a DO standpoint because it often
has a higher DO and a lower BOD5 concentration than the upstream water. It
is expected that any increase of BOD loading to the stream will directly
impact the downstream water quality; the more stringent limits restrict the
potential impacts. Also, even though the facility is currently meeting the
proposed limits, it is operating at only about half of it's design capacity.
When the flow is increased, it is important that BOD loading be kept to a
minimum due to the sensitivity of the lake headwaters.
The recommended phosphorus limit is 0.5 mg/1 in the summer and 2.0 mg/1
in the winter. This recommendation is supported by instream and effluent
data and algal growth potential tests (AGPT) performed by the EPA on this
arm of Jordan Lake. The instream and effluent monitoring data clearly show
that the effluent TP concentration is approximately double that of the
upstream concentration most of the time, and probably constitutes a signifi-
cant amount of the downstream phosphorus. Lower TP concentrations in the
effluent will be critical in the summer months when the low flows of the
Creek coincide with optimal temperature conditions for algal growth.
Results of EPA AGPT tests indicate that the Northeast Creek arm of Jor-
dan Lake is very susceptible to eutrophic conditions. EPA suggests that a 5
to 10 range of mg dry weight of algae will not create nutrient problems,
while levels greater than 10 mg dry weight "are associated with highly pro-
ductive waters which may be subjected to nuisance bloom and fish kills" (see
attached). A range of 5 to 10 mg dry weight of algae roughly corresponds to
chlorophylla concentrations of 50 to 100 ug/1. The North Carolina stream

standard for chlorophylls is 40 ug/1 for lakes, reservoirs, and other slow -
moving waters not designated as trout waters. The maximum potential algal
growth in Northeast Creek downstream of the discharge is approximately 300
mg dry weight, about 30 times the recommended trouble level. Although this
is the maximum growth potential, a 0.5 mg/1 TP limit is necessary to reduce
the potential and will be especially important in the summer low flow
months. Again, when the plant is operating at full capacity, it's effluent
will be a significant source of TP to the system.
It is important to note that the proposed limits of oxygen -consuming
wastes and TP for the Triangle WWTP is consistent with the Division's hand-
ling of other wasteload allocations in similar situations. As more informa-
tion becomes available it is becoming quite clear that peidmont reservoirs,
such as Jordan Lake and Falls Lake, are very sensitive systems that need to
be carefully managed if their resources are to be protected. Recent alloca-
tions for large, dominating discharges to the headwaters of these lakes have
been given limits similar to or more stringent than those currently recom-
mended for the Triangle WWTP. Examples of these include Durham's Farrington
Road and Northside WWTPs and the John Umstead Hospital in Butner. OWASA is
also likely to receive similar limits upon the upcoming expansion of their
facility.

RECEIVED
►vi�R 05 1990
Request
bw APPROVAL
WASTELOAD ALLOC� FARM
Facility Name:
NPDES No.:
Type of Waste:
Status:
Receiving Stream:
Classification:
Subbasin:
County:
Regional Office:
Requestor:
Date of Request:
Quad:
Summer Winter
Wasteflow (mgd) : 6 6 Cadmium (ug/1) :
BOD5 (mg/1) : 5 (%' look.) Chromium (ug/1)
NH3N (mg/1) : 1 o) 2 Dui Nickel (ug/1) :
DO (mg/1) : 6 ts) 6 (-6) Lead (ug/1) :
TSS (mg/1) : 30 30 Cyanide (ug/1) :
Fecal coliform (#/100m1): 200 200 Mercury (ug/1):
pH (su): 6-9 6-9 Copper (ug/1):
TP (mg/1) : 0.501 2 (a) Silver (ug/1) :
Zinc (ug/1) :
Toxicity Testing Req.: Chronic/Ceriodaphnia/Qrtrly
MONITORING
Upstream (Y/N): Y Location: At SR 1102
Downstream (Y/N): Y Location: 1) At the SR 1100 Bridge
2) At the SR 1702 Bridge
COMMENTS
Limits have been slightly revised due to the proximity of the discharge
to Jordan Lake and the characteristics of Northeast Creek (see attached).
Metals limits are in accordance with a new pretreatment headworks
analysis. Past effluent concentrations of the individual metals have
been high, and the facility is not consistently passing it's whole
effluent toxicity test . Chorine_ rn hart ban retporbitie for ttX CLh.).
A second downstream monitoring site has been added to give a better
indication of the effluent's impact and the Creek's assimilative capacity.
DurhamlCounty/Triangle WWTP
NC0026051
52.7% Domestic, 47.3% Industrial
Existing/Renewal
Northeast Creek
C-NSW
030605
Durham
Raleigh
Rosanne
2/1/90
D23NW
No.:
5572G
c^
Drainage area:
Summer 7Q10:
Winter 7Q10:
Barona Average flow:
30Q2:
18.00 sq mi
0.00 cfs
0.50 cfs
20.00 cfs
cfs
RECOMMENDED EFFLUENT LIMITS
0:tn Daily
Max.
2,0
50
88
25
5.O
0.012
Monitor
Monitor
Monitor
Recommended by:
Reviewed by
Instream Assessment:
/ =L.( S roil\
Date:
S{,Date:
Regional Supervisor: Date:
Permits & Engineering:
RETURN TO TECHNICAL SERVICES BY:
MAR 13 1990
Date: 3/41(1'

10/89
Facility Name D kAdtka^'t COCA Ail / Tti An1Ie WWT'P Permit # NGOO 2.6 051
CHRONIC TOXICITY TESTING REQUIREMENT (QRTRLY)
The effluent discharge shall at no time exhibit chronic toxicity in any two consecutive toxicity tests,
using test procedures outlined in:
1.) The North Carolina Ceriodaphnia chronic effluent bioassay procedure (North Carolina Chronic
Bioassay Procedure - Revised *September 1989) or subsequent versions.
The effluent concentration at which there may be no observable inhibition of reproduction or
significant mortality is q9 % (defined as treatment two in the North Carolina procedure
document). The permit holder shall perform guarterty monitoring using this procedure to establish
compliance with the permit condition. The first test will be performed after thirty days from
issuance of this permit during the months of FA Hay, hu , A(oV . Effluent
sampling for this testing shall be performed at the'NPDES p&tmitted final effluent discharge below
all treatment processes.
All toxicity testing results required as part of this permit condition will be entered on the Effluent
Discharge Monitoring Form (MR-1) for the month in which it was performed, using the parameter
code TGP3B. Additionally, DEM Form AT -I (original) is to be sent to the following address:
Attention: Environmental Sciences Branch
North Carolina Division of
Environmental Management
P.O. Box 27687
Raleigh, N.C. 27611
Test data shall be complete and accurate and include all supporting chemical/physical measurements
performed in association with the toxicity tests, as well as all dose/response data. Total residual
chlorine of the effluent toxicity sample must be measured and reported if chlorine is employed for
disinfection of the waste stream.
Should any single quarterly monitoring indicate a failure to meet specified limits, then monthly
monitoring will begin immediately until such time that a single test is passed. Upon passing, this
monthly test requirement will revert to quarterly in the months specified above.
Should any test data from this monitoring requirement or tests performed by the North Carolina
Division of Environmental Management indicate potential impacts to the receiving stream, this
permit may be re -opened and modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum
control organism survival and appropriate environmental controls, shall constitute an invalid test
and will require immediate retesting(within 30 days of initial monitoring event). Failure to submit
suitable test results will constitute noncompliance with monitoring requirements.
7Q10 0.0 cfs
Permited Flow 6,0 MGD Recommended by: 3
IWC% t0 0.
Basin & Sub -basin o3o6os
Receiving Stream Northeast Cra k ittektd 7. Sco
dit
County Dom( hA,vi Date / Vri 4v
**Chronic Toxicity (Ceriodaphnia) P/F at 41 %, fib/ MA Au5, Nov , See Part 3 , Condition I .

❑ 5t 1100 (Up)
Vonthly Average Monitoring Data — DO
Northeast Creek
12
4
1
Dec-89 Oct-89 Aug-89 Jun-89 Apr-89 Feb-89 Dec-88 Oct-88 Aug-88 Jun-88 Apr-88 Feb-88
+ SR 1101 (Down)
Month
O Triangle WWTP Effl.

BOD5, mg/I
❑ SR 1100 (Up)
Vonth
7
5
4
y Avercce Vonitorinc Data — 30C)5
Northeast Creek
Dec-89 Oct-89 Aug-89 Jun-89 Apr-89 Feb-89 Dec-88 Oct-88 Aug-88 Jun-88 Apr-88 Feb-88
+ SR 1101 (Down)
Month
o Triangle WWTP Effl.

o SR Ilob (Up)
Vonthly Avercce Vonitorinc Data — TP
Northeast Creek
0 I i 1 1 1 1 i I I 1 1 1 1
Dec-89 Oct-89 Aug-89 Jun-89 Apr-89 Feb-89 Dec-88 Oct-88 Aug-88 Jun-88 Apr-88 Feb-88
+ SR 1101 (Down)
Month
0 Triangle WWTP Effl.

TOXICS
REVIEW 02/04/90
ver 3.0
Facility:
NPDES Permit No.:
Status (E, P, or M) :
Permitted Flow:
Actual Average Flow:
Subbasin:
Receiving Stream:
Stream Classification:
7Q10:
IWC:
Triangle WWTP
NC0026051
E
6.00 mgd
2.73 mgd
30605.00
Northeast Creek
C NSW
0.00 cf8
100.0 •
PRETREATMENT DATA
ACTUAL ACTUAL PERMITTED
or Ind. + Ind.
Default ACTUAL Domestic PERMITTED Domestic
Standard Acute I Removal Allowable Domestic Industrial Total Industrial Total
Pollutant AL Criteria 1 Eff. Load Load Load Load Load Load
(ug/1) (ug/1) 1 i (#/d) (#/d) (#/d) (#/d) (//d) (#/d)
Cadmium S 2.0 1.79 1 92% 0.57 0.03 1.93 1.96 0.14 0.170
Chromium S 50.0 984 1 89% 10.36 0.46 1.20 1.66 3.66 4.120
Copper AL 7.0 9.2 1 90% 1.59 0.56 2.39 2.95 2.02 2.580
Nickel S 88.0 789 1 39% 3.29 0.19 2.68 2.87 2.50 2.690
Lead S 25.0 34 1 81% 3.00 0.46 0.76 1.22 0.47 0.930
Zinc AL 50.0 65 1 84% 7.12 1.61 6.95 8.56 8.22 9.830
Cyanide S 5.0 22.0 1 59% 0.28 0.40 0.01 0.41 0.00 0.400
Mercury S 0.012 2.4 1 86% 0.00 0.00 0.03 0.03 0.00 0.000
Silver AL 0.060 1.2 1 94% 0.02 0.05 0.04 0.09 0.25 0.300
Selenium S 5.0 20 1 80% 0.57
Arsenic S 50.0 360 1 80% 5.70
Phenols S NA
ANALYSIS RESULTS
I I
I Allowable Allowable' Predicted Predicted I
I Effluent Effluent 1 on ACTUAL on PERMIT.'
Bkg 1 Conc. Conc. 1 Influent Influent 1 ACTUAL PERMITTED
Pollutant Conc. I CHRONIC ACUTE 1 Data Data 1 Influent
(ug/1) 1 (ug/1) (ug/1) 1 (ug/1) (ug/1) I Loading Loading
Cadmium S 1 2.000 1.790 1 6.883 0.597 I Limit Limit
Chromium S 1 50.000 984.320 1 8.015 19.893 I Limit Limit
Copper AL 1 7.000 9.220 1 12.949 11.325 1 Monitor Monitor
Nickel S 1 88.000 789.000 1 76.846 72.027 I Limit Limit
Lead S I 25.000 33.780 1 10.175 7.756 1 Limit Limit
Zinc AL 1 50.000 65.040 1 60.118 69.037 I Monitor Monitor
Cyanide S 1 5.000 22.000 1 7.289 7.199 I Limit Limit
Mercury S 1 0.012 2.400 1 0.209 0.000 1 Limit
Silver AL 1 0.060 1.230 1 0.248 0.790 1 Monitor Monitor
Selenium S 1 5.000 20.000 1 0.000 0.000 1
Arsenic S 1 50.000 360.000 1 0.000 0.000 1
Phenols S 1 0.000 0.000 1 0.000 0.000 1
EFFLUENT DATA ---
ACTUAL ACTUAL
Maximum Weekly
Daily Average
Value Value
(ug/1) (ug/1)
90.00
82.00
Monitor / Limit / Special Condition•
Actual Actual
Daily Max. Wk. Avg,
Influent Effluent Effluent
Data Data
Special
Special
INSTREAM MONITORING
Based on Based on
Actual Actual
Daily Max. Wk. Avg.
Monitor
Monitor

INSTREAM SELF -MONITORING DATA
MONTHLY AVERAGES
Discharger: `IV
�VTIC Permit No.: NCO()2.6o51
Receiving Stream: Noriivta<I (ccck Sub -basin:
Upstream Location: sR Iloo Downstream Location
Upstream -T Downstream 7r
DATE TEMP D.O. BODS eons TEMP D.O. BODSD
DEC-89
NOV-89 `� 9 " 3 ,'_ 48,i 2 o,y
ll 7
OCT-89 i.� , / I� _12_ 8.3 I,z
0.7
SEP-89 Iq z�—`�7- �^ 7, 7 i,75 0. g
AUG-89 ��/4 i 3`_ 6,7 3,z7, tom_
2 Z - 3 22, 5 G. 5- 7 2- , z6
JUL-89 .Li_ 5,4yqr 35 ,z. 2
JUN-89( ) 2z.g S,F� ) f.75 .6S
zz `i•6l 3,5- .ZZS 21. g_ - 3 zs 0.7
MAY-89
APR-89 _a_63�; 3.6 ,27 6, � b,6 z.2s . Li
MAR-89 '-Li--6, z.7S , 15 1 . s 7,6 7.2S o,so
FEB-89 ___I__ 10,f , I.�f , ,2Z 4.6 _IL. ,'1Z
JAN-89 —1.— 8,9 2.S . z5 , R, 3 , Zit 2.2.
.62S
DEC-88 __v—g 1 7.7 S z7s (. 3 Q, I 2,0 375
NOV-88 ___S.__ c.y z.z, 175 7,z g.y i.5 .675
OCT-88 3,`I .z9 93 6 • z 2.$' 0,6y
IZ 6,3�T.s> 3.0 .SzS ,N1,3 13 2,23 0,6s SEP-88 19 5.3(z,2) Z.y 27, I1,S 4,c
AUG-88 _ z3 2,N ;) y, H ,NS 23, z C H _L.Z__ A,sB
JUL-88 Z2 l4 r «. ►.Z __
JUN-88L 1°I yo( 3,N _.y� _ zl 9 . 6.H I,G7 _Li._
MAY-88 70 G 2,0 ,8z
IIG 2(.,,. z.33 0.� 16.3 6.3 1,33 t,3
APR-88 �_ 7,1 1 15 0, R X
MAR-88 7,z 2,67 !, 3�S
FEE-88 q.1 -r.75 I,GZS t,6 q.0 2,o Z37S
6 I o,7 1,7C , 175 7,0
JAN-88 Z tl. z, 9.7 1.75' O.S
DEC-87 Z o r1 I Z,g 10,? z, 0 35
NOV-87
OCT-87
SEP-87
AUG-87
JUL-87
JUN-87 Q V rL K
MAY-87
APR-87
MAR-87
FEB-87
JAN-87
DEC-86
NOV-86
OCT-86
SEP-86
AUG-86
JUL-86
JUN-86
MAY-86
APR-86
MAR-86
FEB-86
JAN-86

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NPDFS PRETRFATi��VT q0 0 / 2 5 01
INFORMATION REQUEST FORM
FACILITY NAME: (%ure4,7,71 LO - /J"-)'4K9/e " 4)Es NO. NCOO o2 46 O Si
REQUESTER: /IDS4K 1e 64,,ohq DATE: / / 22/90 RFX;ICN: _
47Pi qLi
PERMIT CONDITIONS COVERING PRETREATMENT
'this facility has no rlUs and should not have pretreatment language.
This facility should and/or is developing a
Please include the followingconditions:P g Pretreatment program,
PrLam Development
Phase I due //
Phase II due /_/
Additional Conditions
This facility is currentlyimplementing (attached)
Please include the following pretreatment program.
Program Implementation
Additional Conditions
(attached)
SIGNIFICANT INDUSTRIAL USERS' (SIUs) OONTRIBUTIONS
SIU FLOW - AL:
- C'C 06ITICN :
HFADWORfCS REVIEW
PARAMETER
Cd
Cr
NiCU
Pb
Zn
CN
Phenol
Other 14J _2 `
FQ.
a.$
TEXTILE: 0
METAL FINISHING: _ O 134
OTliER: %Zs, _ 0.346
C4feflrPowder �,
e<oo}
h., f4t i// 4, ss • 6.11119
erirow,^.48.1 - 0.437
a rice r../ s«(s - . - -Q4 i so
Abey- a fits, - _ , _ _ _ ...o,oso
o er - - --..0..23G
A1JX» BLE
.S�
14.99
•9.0
4.3y
0.410
-DAILY
DOMESTIC PERCETTED
56
.19 .50
.46 0.4�
. 0
5 .5 0 .05
9
59.36
7
RECEIVED: J/,25/ Q 0 REVIEWED BY :
24
32.99
MGD
MGD
VCD
M2D
r13D
L(W IN LRS/DAYheltA
INtsriutT.
keiszkve wage:
11.
A.39 90
2.69 39
0.96 vs
6.95 8�
0.00 5 59
O. 031
e.oy�t gig
-- 1
l0. ba p
RETURNED: i/a 9 11Q