NC0020605_wasteload allocation_19941121

NPDES DOCYNENT SCANNINS COVER SHEET
NPDES Permit:
NC0020605
Tarboro WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Speculative Limits
Correspondence
Re:
Instream Assessment (67B)
Environmental Assessment (EA)
Permit
History
Document Date:
November 21, 1994
This document is printed on reuse paper - ignore any
content on the reverse side

NPDES WASTE LOAD ALLOCATION
PERMIT NO.: NCO020605
PERMIZTEE NAME:
FACILITY NAME:
Town of Tarboro
Tarboro Wastewater Treatment Plant
Facility Status: Existing
Permit Status: Renewal
Major _q Minor
Pipe. No.: 001
Design Capacity: 5.0 MGD
Domestic (% of Flow): 91
Industrial (% of Flow):
9%
Comments:
Percent industrial flow based on 5.0 MGD and SILT flows from
application.
RECEIVING STREAM: the Tar River
Class: C-NSW
Sub -Basin: 03-03-03
Reference USGS Quad: D 28 NE (pleas a attach)
County: Edgecombe
Regional Office: Raleigh Regional Office
Previous Exp. Date: 8/31/93 Treatment Plant Class: IV
Classification changes within three miles:
No -class change(IMFP
Requested by: Charles Alvarez
Prepared by:
Reviewed by:
Modeler Date Rec. # ,
Drainage Area (mil )_�� gp Avg. Streamflow (cfs): Q
7Q10 (cfs) .90 Winter 7Q10 (cfs) -2,1 p 30Q2 (cfs)_2
Toxicity Limits: IWC _I % Acu Chromc
Instream Monitoring:
Parameters ;7=- T4 60,
Upstream e.S Location L
-• Downstream Location
Wasteflow (MGD):
BOD5 (mgft
NH3N (mg/1):
DO (mg/1):
TSS (mg/1):
Fecal Col. V100 ml):
pH (SU):
Residual Chlorine (µg/1):
Oil & Grease (mg/1):
TP (mg/1):
TN (mg(1):
Cyanide (ug/1):
Mercury (ug/1):
"Silver (ug/1):
Monthly Average
Summer
Winter
5.0
5.0
30
30
9.0
18.0
5.0
5.0
30
30
200
200
6.0-9.0
6.0-9.0
monitor.
monitor
monitor monitor
monitor monitov-
Weekly Avg.
Daily Max.
63
252
0.2
0.8
monitor
quarterly

Facility Name:
NPDES No.:
Type of Waste:
Facility Status:
Permit Status:
Receiving Stream:
Stream Classification:
Subbasin:
County:
Regional Office:
Requestor:
Date of Request:
Topo Quad:
FACT SHEET FOR WASTELOAD ALLOCATION
Town of Tarboro WWTP
NCO020605
91% Domestic, 9% Industrial
Existing
Renewal
Tar River
C NSW
03-03-03
Edgecombe
Raleigh
Charles Alverez
8/18/94
8/31/93
Wasteload Allocation Summary
(approach taken, correspondence with region, EPA, etc.)
Request # 7979
Stream Characteristic:
USGS #
0.208.3500.00
Date:
10/20/87
Drainage Area (mi2):
2180
Summer 7Q10 (cfs):
90
Winter 7Q10 (cfs):
210
Average Flow (cfs):
2230
30Q2 (cfs):
350
IWC (%):
8
Limits for mercury and cyanide will be in permit as per updated analysis of monitoring data.
Monitoring for cadmium, chromium, lead, nickel, copper and zinc can be removed from NPDES
permit requirements. These parameters will continue to be monitored quarterly through the LIMP.
Silver was detected in 1994 APAM at concentration above allowable level, so quaterly silver
monitoring will be in permit (parameter not covered by LTMP). Chloride monitoring can be
dropped. Tarboro is a member of the Tar/Pamlico Basin Association, and permit will have
appropriate nutrient reopener language for Phase II of NSW Strategy.
InstreAssessment
*Negion Supervisor:
Permits & Engineeri
RETURN TO TECHNICAL SUPPORT BY:
NOV 12 1994
N
C"

2
CONVENTIONAL PARAMETERS
Existing Limits:
Monthly Average
Summer
Winter
Wasteflow (MGD):
5.0
5.0
BOD5 (mg/1):
30
30
NH3N (mg/1):
9.0
18.0
DO (mg/1):
5.0
5.0
TSS (mg/1):
30
30
Fecal Col. (/100 ml):
200
200
pH (SU):
6.0-9.0
6.0-9.0
Residual Chlorine (µg/l):
monitor
monitor
Oil &Grease (mg/1):
TP (mg/1):
monitor
monitor
TN (mg/1):
monitor
monitor
Recommended Limits:
Wasteflow (MGD):
BOD5 (mg/1):
NH3N (mg/1):
DO (mg/1):
TSS (mg/1):
Fecal Col. (/100 ml):
pH (SU):
Residual Chlorine (µg/l):
Oil & Grease (mg/1):
TP (mg/1):
TN (mg/1):
Monthly Average
Summer
Winter
5.0
5.0
30
30
9.0
18.0
5.0
5.0
30
30
200
200
6.0-9.0
6.0-9.0
monitor
monitor
monitor monitor
monitor monitor
Limits Changes Due To: NONE
Change in 7Q10 data
Change in stream classification
Relocation of discharge
Change in wasteflow
Other (onsite toxicity study, interaction, etc.)
Instream data
New regulations/standards/procedures
New facility information
WQ or EL
WQ
WQ
EL
EL
EL
Parameters Affected
(explanation of any modifications to past modeling analysis including new flows, rates, field data,
interacting discharges)
(See page 4 for miscellaneous and special conditions, if applicable)

TOMCS/METALS
Type of Toxicity Test: Chronic (Ceriodaphnia)
Existing Limit: Quarterly, P/F @ 8 %
Recommended Limit: Renew with existing
Monitoring Schedule: Jan., Apr.', Jul., Oct.
Existing Limits
Daily Max.
Cadmium (ug/1):
monitor
Chromium (ugh):
monitor
Copper (ug/1):.
monitor
Nickel (ug/1):
monitor
Lead (ug/1):
monitor
Zinc (ug/1):
monitor
Cyanide (ug/1):
monitor
Chlorides (mg/1):
montior
Mercury (ug/1):
monitor
Silver (ug/1):
Recommended Limit
Daily Max. WQ or EL
Cadmium (ug/1):
LTMP*
Chromium (ug/1):
LTMP*
Copper (ug/1):
LTMP*
Nickel (ug/1):
LTMP*
Lead (ug/1):
LTMP*
Zinc (ug/1):
LIMP*
Cyanide (ug/1):
63 WQ
Chlorides (mg/1):
Mercury (ug/1):
0.2 WQ
Silver (ug/1):
monitor quarterly
LTMP* - Parameters are monitored quarterly in Long Term Monitoring Plan
Limits Changes Due To: Parameter(s) Affected
Change in 7Q10 data
Change in stream classification
Relocation of discharge
Change in wasteflow
New pretreatment & monitoring information X All toxicants
Failing toxicity test
Other (onsite toxicity study, interaction, etc.)
X Parameter(s) are water quality limited For some parameters, the available load capacity of
the immediate receiving water will be consumed. This may affect future water quality based
effluent limitations for additional dischargers within this portion of the watershed.
M
No parameters are water quality limited, but this discharge may affect future allocations.

4
J
INSTREAM MONITORING REQUIREMENTS
Upstream Location: NC Hwy 44
Downstream Location: NC Hwy 42
Parameters: Temperature, Dissolved Oxygen, Fecal Coliform, Conductivity
Special instream monitoring locations or monitoring frequencies:
MISCELLANEOUS INFORMATION & SPECIAL CONDITIONS
Ad.Quacy of Existing Treatment
Has the facility demonstrate ability to meet the proposed new limits with existing treatment
facilities? Yes No
If no, which parameters cannot be met? WAue-�, J tt(Cly
Would a "phasing in" of the new limits be appropriate? Yes No
If yes, please provide a schedule (and basis for that schedule) with the regional
office recommendations:
If no, why not?
Special Instructions or Conditions
Wasteload sent to EPA? (Major) Y (Y or N)
(If yes, then attach updated evaluation of facility, including toxics analysis, modeling analysis if
modeled at renewal, and description of how it fits into basinwide plan)
Additional Information attached? (Y or N) If yes, explain with attachments.

Facility Name T rkoro 1007� Permit #,L&5,2 l L Pipe* ov rr
CHRONIC TOXICITY PASS/FAIT. PERMIT LIMIT (QRTRLY)
The effluent discharge shall at no time exhibit chronic tonicity 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 I % (defined as treatment two in the North Carolina procedure document). The permit holder shall perform
Quarterly monitoring using this procedure to establish compliance with the permit condition. The fast test will be
performed after thirty days from the effective date of this permit during the months of
51ic. 4dr. \_T;�/. Oct. . Effluent sampling for this testing shall be performed at the NPDES
permiftedifinal 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-1 (original) is to be sent to the following address:
Attention: Environmental Sciences Branch
North Carolina Division of
Environmental Management
4401 Reedy Creek Road
Raleigh, N.C. 27607
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 CJD cfs
Permitted Flow o MGD
IWC %
Basin & Sub -basin 03- 03-0.3
Receiving Stream
County
Recommended by:
QCL P/F Version 9191

Page 1
- Note for Jason Doll
From: Jason Doll
Date: Mon, Nov 21, 199412:08 PM
Subject: Tarboro WWTP WLA
To: Charles Alvarez
Cc: Carla Sanderson
Judy Garrett (RRO) had comments on the fact sheet about the justification for the Hg limit I
recommended. I called and explained to her that they had detectable Hg (well above
allowable) in 1991 & 1992 APAM results, and there had not been enough data points since
then to dispell the possibility of future Hg. Only five samples (all non -detects) have been
taken since their NPDES quarterly monitoring requirement. took effect in 1993. I explained
that after a year's data with the limit, if no detectable Hg is reported, then we would be
perfectly comfortable with the pemuttee requesting a revision to drop the limit. Judy asked if
we could notify the permittee of that potential in the cover letter. I asked Dave G. and he said
that was fine, and said I should drop you a note about the whole issue, so it doesn't slip
through the cracks, which brings us finally to the point of this note. If you have any
questions, just let me know.

0
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TARBORO WWTP
NCO020605
Residual Chlorine
Ammonia as NH3
(summer)
7010 (CFS)
90
7010 (CFS)
90
DESIGN FLOW (MGD)
5
DESIGN FLOW (MGD)
5
DESIGN FLOW (CFS)
7.75
DESIGN FLOW (CFS) -
7.75
STREAM STD (UG/L)
17.0
STREAM STD (MG/L)
1.0
UPS BACKGROUND LEVEL (UG/L)
0
UPS BACKGROUND LEVEL (MG/Q.
0.22
IWC (%)
7.93
IWC (%)
7.93
Allowable Concentration (ug/1)
214.42
Allowable Concentration (mg/1)
10.06
Ammonia as NH3
(winter)
7Q10 (CFS)
210
Fecal Limit 200/100ml DESIGN FLOW (MGD)
5
Ratio of 11.61 DESIGN FLOW (CFS)
7.75
STREAM STD (MG/L)
1.8
UPS BACKGROUND LEVEL (MG/L)
0.22
IWC (%)
3.56
Allowable Concentration (mg/1)
44.61

TOXICANT ANALYSIS
Facility Name
Tarboro WWTP
NPDES #
NCO020605
Ow MGD
5
7Q10s cls
IWC %
90.._.._.._.____
7.93
RecWng Stream
Tar River
Stream Class
C NSW
FINAL RESULTS
Cadmium
Max. Prod Cw
is b 0
Allowable Cw
252
Chromium
Max. Pred Cw
54.6
Allowable Cw
630.6
Lead
Max. Pred Cw
50
Allowable Cw
315.3
Nickel
Max. Pred Cw
75.4
Allowable Cw
1109.9
Cyanide
Max. Pred Cwj
160
Allowable Cw
63.1
Mercury
Jed
Max. Pred Cw
0; 5 a. 0
Allowable Cw
1 A 0.2
Copper
Max. Pred CwI
702
Allowable Cw
88.3
Silver
u
Max. Prod Cw
/.0 0
Allowable Cw
n,, 0.8
Zinc
Max. Pred Cw
208
Allowable Cw
630.6
Chlorides
Max. Pred Cw
717.6
Allowable Cw
2901.0
0
Max. Pred Cwj
0
Allowable CwI
0.0
0eOA To crmp
LrIYI
m&AjT To
j)Qvp � L-Tm.P
10/13/94 PAGE

TOXICANT ANALYSIS
Parameter=
Cadmium
Paramefer= ..Chromium
Standard =
2
/l
Standard = ••
50
/I
n
BDL=1/2DL
Actual Data
RESULTS
n
BDL=1/2DL
Actual Data
RESULTSk>
1
<2
Std Dev.
#DIV/01
1
1
<2
Std Dev.
3.488
2
<5
Mean
#DIV/01
2
21
21
Mean
3.656
3
<2
C.V.
#DIV/01
3
2.5
<5
C.V.
0.954
4
<2
4
2.5
<5
;`<>
5
<5
5
2.5
<5
6
<2
.............
Mult Factor =
6
1
<2
Mult Factor =
_.._.._..
2.6
7
<2
Max. Value
0
/I
7
1
<2
Max. Value
21
/1 r<''
8
<2
Max. Pred Cvy
0
ILgA,
8
1
<2
Max. Pred Cw
54.6
9
<2
Allowable Cw
25.2
/I
9
2.5
<5
Allowable Cw
630.6
/1
10
<2
10
2.5
<5
11
<2
11
2.5
<5
12
<2
12
2.5
<5
13
<2
13
2.5
<5
14
<2
14
2.5
<5
><`
15
<5
15
2.5
<5
16
<2
16
2.5
<5
17
<2
17
2.5
<5
18
<2
18
2.5
<5
19
<3
19
3
<6
20
<5
20
2.5
<5
21
<2
21
2.5
<5
22
<5
22
2.5
<5
23
<2
23
2
2
24
<5
24
6
6
25
<2
25
6
6
26
<5
26
5
<10
27
<5
27
5
<10
28
<5
28
5
<10
29
<5
29
5
<10
30
<5
30
5
<10
31
<5
31
5
<10
32
<5
32
5
<10
<€'
33
33
341
34
m
10/13/94 PAGE'

n BDL=1/2C
1 1
2 2
3 1
4 1
5 1
6 1
7 1
8 1
9 2
10 1
11 1
12 1
13
14
15
16
17
18
19
20
21
22
23
24
27
31
10/13/94
10
10
10
10
10
10
25
12.5
12.5
12.5
2.5
2.5
2.5
2.5
2.5
2.5
16
TOXICANT ANALYSIS
Data
RESULTS
<20
Std Dev.
6.426
<50
Mean
10.89
<20
C.V.
0.59
<20
<20
<20
Mult Factor = i
_.._.
2
<20
Max. Value
25
<20
Max. Pred Cw
50
<50
Allowable Cw
315.3
<20
<20
<20
24
<20
<20
<200
<20
<20
<20
<20
<20
<50
<25
<25
<25
<5
<5
<5
<5
<5
<5
16
arameter= ; Nickel
Standard = i 88
m©�
m®�
m©�
m©�
m-�
)ata
RESULTS
<5
Std Dev.
7.6805
<10
Mean
8.5469
5
C.V.
0.8986
<10
<10
...............
<5
Mult Factor =
2.6
<5
Max. Value
29
<5
Max. Pred Cw
75.4
<10
Allowable Cw
1109.9
<10
<10
<10
<10
<10
<10
<5
<10
<10
<10
<10
<10
<10
<10
<10
13
24
27
20
29
20
17
16
PAGE Ire

TOXICANT ANALYSIS
P @mete=!
Ca|de|
N)
Mec
as d r =|
S ;
l
/ &a d m=
0.012
/
n
BDL 1mDL
Actual Data
RESULTS
.
) n
BDL 1/2DL
Actual Data
RESULTS
25
<
SdDe.
9.194
) 1
01
<.2
SdDev
2
2.5
<
Mean
7.96667
2
01
< 2
I Men .
S
8
8
C.V.
1235
) a
01
<2
C.V.
4
2.5
<
. ) 4
01
< 2
'
5
12
12
; 5
01
<02
8
2.5
<
MulFactor =|
3 2
) 8
0.5
05
Mu■1 Factor
7
25
<
Max. Value
5
% \ 7
0.
02
Max. Value
8
25
<
Max. PedC
16
/1 8
Max.Pe Gv
@
25
<
Allowable C■
63.1
%/ §
Allowable Cw
10
2.5
- <
) 10
11.
7
7
11
12
2.5
<
) 12
13
2.5
<
.
\ 43'
14
8
B
) 14
15
11
11
) 16
18
5
5
/ 18
17
23
<
) 17
18
2.5
<
{ 18
`
19
-8
8
\ 19
2
2.5
<
( 2
2
8
e
/ 2
22
3
e
!
2
2.5
<
\ 2
2
2.5
<
) 2
2
@
9
. ) 2
2
13
13
) 2
2
22
2
) § 2
2
2.5
<
/ 2
2
2
2
.
/ 2
3
2.5
<
( 3
3
2.5
<
31
321
13
13
.
) 3
331
3
341
3
�
�
�
101/3/9 - . PAGE |

TOXICANT ANALYSIS
arameter =
Copper
€parameter =
Silver
Standard =
7
/l
<< Standard =
0.06
/I
n
BDL=1/2DL
Actual Data
RESULTS
">A' n
BDL=1/2DL
Actual Data
RESULTS
1
15
15
Std Dev.
7.15356
1
<10
Std Dev.
#####
2
17
17
IMean
14.1875
`< 2
<5
Mean
#####
3
12
12
C.V.
0.50422
3
<5
I C.V.
#####
4
6
6
`?" 4
<5
5
2.5
<5
"" 5
<10
____
-6
9
9
Mu/t Factor = ;
1.8
6
<5
Mult Factor =
i
7
7
7
Max. Value
39
/I.'.':. 7
<5
Max. Value
0
/I
8
7
7
Max. Pred Cw
70.2
/I . .8
<5
Max. Pred Cw
0
/I
9
12
12
Allowable Cw
88.3
/I . 9
<5
Allowable Cw
0.8
/I
10
10
10
10
<10
<`
11
9
9
t': 11
<10
12
10
10
12
<5
13
10
10
13
<5
14
15
15
'':<< 14
<5
15
12.5
<25
15
<5
16
6
6
{' 16
<10
17
23
23
17
<5
18
11
11
18
<5
19
8
8
19
<5
20
14
14
20
<5
21
15
15
21
<5
22
13
13
22
<10
23
19
19
23
<10
24
14
14
24
<10
25
22
22
25
<5
26
11
11
26
<5
27
22
.22
27
<5
28
19
19
28
<5
29
39
39
29
<5
30
31
23
19
23
19
>.f
.{{, 30
. 31
<5
<5
32
22
22
32
<5
33
33
34
34
10/13/94 PAGE z

TOXICANT ANALYSIS
7,arameter=
zinc
���1
-
��1
- -
fix• •
I
10/13/94 PAGE,'

--�
WN
LONG TERM MONITORING PLAN REQUEST h ��
FACILITY: 7 v by r� 1/►11.V %i� �(�nn 'Da Na; e
NPDES NO.: OjC00 2©6 6S g1a �qc�.
EXPIRATION DATE: AUG,
J
REGION: � � �
FACILITIES_ ASSESSMENT UNIT
P&E REQUESTOR: C
PRETREATMENT CONTACT: Ale y
DATE OF REQUEST: fl�l tom"! 9 Y
INDICATE THE STATUS OF PRETREATMENT PROGRAM:
1) THE FACILITY HAS NO SIU-S AND SHOULD NOT HAVE PRETREATMENT LANGUAGE.
2) HE FACILI HAS R IS DEVELOPING A PREATREATMENT PROGRAM.
3) ADDITIONAL CONDITIONS REGARDING JHE PRETREATMENT PROGRAM ATTACHED.
�-- VLo Yie, n eed ea
PERMITTED FLOW:
INDUSTRIAL
% DOMESTIC
Pretreatment Unit Staff (Region)
Jeff Poupart (WSRO) Dana Folley RRO WaRO)
Tom Poe (FRO, ARO, WRO) Joe Pearce (MRO)
a,�
P P©GCry CU-� P b, I'L� �� A�s , Se. I,1'vl o
vl- It
1t�ls! ✓ ✓ I - ✓ ✓- ✓✓ ✓ _ �r--
} -I -- -L --- - - - --

DIVISION OF ENVIRONMENTAL MANAGEMENT
March 2, 1995
MEMORANDUM
TO. Charles Alverez
FROM DoflVn� THROUGH: Carla San n W
Ruth Swanek 'X
SUBJECT: Comments on Draft NPDES Permit NCO020605
Town of Tarboro WWTP
Edgecombe County
The Instream Assessment Unit has reviewed the comments from John H. Chapman of
the Town of Tarboro regarding the draft NPDES permit for the town's wastewater
treatment plant. We have the following responses:
With regard to cyanide, mercury and silver, the specific limits and monitoring
requirements for the 5.0 MGD wasteflow are a result of the need to ensure protection of the
receiving stream from exceeding the state water quality standard for these parameters.
Allowable effluent concentrations are calculated on the basis of a mass balance analysis
which mathematically determines the maximum amount of cyanide, mercury or silver that
could be discharged at a wasteflow of 5.0 MGD without exceeding the state standard (or
action level, in the case of silver) for each toxicant. The allowable concentrations are
calculated for critical low flow conditions, using the dilution of the stream during a 7 day,
10 year low flow event (7Q10), and the 7Q10 for the Tarboro W WTP discharge location in
the Tar River is 90 cfs. The allowable concentrations are calculated with the following
formula:
Cw=[(Qd*Cd)-(Qu*Cu)]/Qw
where: Cw = Allowable Effluent Pollutant Concentration
Qw = Wasteflow (i.e. Permit Design Flow)
Cd = Allowable Downstream Pollutant Concentration (i.e. Standard)
Qd = Downstream Flow (i.e. Qw + Qu)
Cu = Upstream Pollutant Concentration (i.e. Background)
Qu = Upstream Flow (i.e. 7Q10)
Limits are applied to specific toxicants on the basis of a statistical analysis of the
available effluent data which predicts the maximum effluent concentration likely to occur,
given the number of data points available, and the deviation within the data set. If the
predicted maximum effluent concentration of a given parameter is greater than the
allowable load, calculated by the formula above, then a limit is applied to that parameter in
the NPDES permit (or a monitoring requirement is applied in the instance of parameters
having an action level). In instances where the actual maximum effluent concentration of
a parameter is greater than the allowable effluent concentration, a limit is automatically
applied.

0
In the Tarboro NPDES permit, the cyanide limit. was applied because the predicted
maximum effluent concentration was greater than the allowable concentration of 63.1 ug/l.
Mr. Chapman's letter makes the valid assertion that cyanide was only detected in 3 out of
12 effluent samples in 1994, and that the maximum detected concentration was only 12.0
ug/l. However, the letter does not mention that an effluent cyanide concentration of 50.0
ug/1 was reported for May 6, 1993, and six other detections were reported in that year. The
predicted maximum effluent concentration for cyanide is 160 ug/l, which makes the 63. D
ug/l limit necessary.
In the case of mercury, a limit was applied because actual effluent concentrations had
been reported that were higher than the allowable concentration. Mercury was reported in
the 1991 and 1992 APAM data at levels of 0.5 and 0.7 ug/l, respectively, and the allowable
effluent concentration for mercury is 0.2 ug/l. The five samples taken since the reported
detections do not constitute sufficient data to dispel the possibility of this discharge
violating the stream standard for mercury, so the limit is deemed necessary in this permit.
The monitoring requirement for silver was applied for the same reason. The 1993 APAM
data from Tarboro WWTP showed a detectable amount of silver in the effluent of 1.0 ug/l,
w and the allowable concentration for silver is 0.8 ug/l. In recognition of the fact that the
monitoring requirement was based on a single detection, the monitoring frequency was
relaxed to quarterly, rather than the 2/month frequency that would ordinarily be required for
a facility of this size.
If you have any further questions or require any additional information in this matter,
please let me know.
cc: Central Files
Dave Goodrich
Raleigh Regional Office

;yi
DIVISION OF ENVIRONMENTAL MANAGEMENT rpvt L C
Water Quality
Permits and Engineering Unit
February 7, 1995
To: Ruth Swanek, Supervisor, Instream Assessment Unit
From: Charles Alvarez, Environmental Engineer, NPDES Permits,
Water Quality
Subject: NC0020605, Town of Tarboro Draft Permit Comment Letter
Attached is the Town of Tarboro's comment on the WWTP draft
permit. The town requests that silver, mercury and cyanide
monitoring be removed from their permit. Please provide comments
as to the feasility of this request.
If you need any more information please call me at 733-5083
eat 553.

(17 601
Certified Mail
Town of Tarboro
P. O. Box 220 - 500 Main Street
Tarboro, NC -27886-0220
Telephone [phone]
Fax [phone]
January 12, 1995
hft
TARBORO
Al.l: AMERICA CITY
Mr. Charles Alvarez, Environmental Engineer
N. C. Department of Environment, Health
& Natural Resources
Division of Environmental Management -
Post Office Box 29535
.3
Raleigh, North Carolina 27626-0535
Re: Town of Tarboro'WWTP
NPDES Permit'No. NC0020605
Edgecombe County >�
Dear Mr. Alvarez:
We have reviewed the draft of the above referenced permit. We
ask that four (4) conditions in the permit be changed. These condi-
tions are: 1) the requirement that 85% influent suspended solids be
removed; 2) the requirement that cyanide be limited and monitored
twice per month; 3) the requirement that mercury be limited and
monitored twice per month; and 4) the requirement that silver be
monitored quarterly.
The Town has twice before requested, and twice before received,
a reduction in the percent removal requirement for total suspended
solids. Reference is made to a letter dated December 17, 1993 from
A. Preston. Howard, Jr. with the NC-DEM to Sam Noble with the Town,
and a letter dated June 11, 1993 from John H..Chapman, with the Town
to Coleen Sullins with the NC-DEM for the most recent correspondence
in this regard. This correspondence can be summarized as follows:
The Town has documented that the requirements of 40CFR133.103(d) are
satisfied, the State has reviewed this documentation and found it
adequate, and the 85% removal requirement has been reduced to 680.
This information was evidently overlooked when the most recent draft
permit was prepared. We ask that it be reviewed, and the draft per-
mit be altered accordingly.,
PRINTED ON RECYCLED PAPER

Mr. Charles Alvarez, Environmental Engineer
N. C. Department of Environment, Health
& Natural Resources
January 12, 1995
Page 2
In the December 17, 1993 letter referenced above, the Town was
told that a re=evaluation of the mercury, cyanide and other monitor-
ing requirements could be made after one (1) year. While the Town is
pleased to see that monitoring for many metals has been dropped, it
asks that the cyanide and mercury limits and monitoring requirements
also be dropped and that the silver monitoring requirement be
dropped. Attached is a summary of test data gathered by the Town un-
der the terms of our present permit, which was issued in December
1993. The four (4) quarterly analyses for mercury were all below
detection limits. The twelve (12) test results for silver were all
below detection limits. Accordingly, we ask that both the monitoring
requirement and effluent limit for mercury be dropped from the per-
mit, and that the monitoring requirement for silver be dropped.
Cyanide was not detected in nine (9) out -of the twelve (12) months.
In one (1) month, cyanide was reported at 0.005 mg/l, the test detec-
tion limit, and in another month at 0.006 mg/l, just above the detec-
tion limit. At concentration levels this low, false positive results
must be suspected. In the third month in which tests showed some
cyanide, the level noted was, only 0.012 mg/l. The draft permit ef-
fluent limits for cyanide are a weekly average of 0.063 mg/l and a
daily maximum of 0.252 mg/l. In view of the fact that actual monitor-
ing data shows cyanide to be no where near these levels, we ask that
the cyanide limit and the cyanide monitoring requirement be dropped,
or, failing that, that the monitoring frequency be reduced to semi-
annually. Please note that the Town has an active pretreatment
program, but no industrial sources of cyanide, mercury or silver.
Your assistance in making the requested permit modifications
would be appreciated. If we can provide any additional information,
please do not hesitate to contact me..
Sincerely,
John H. Chapman
Director of Public Works
jrc
Attachment
cc Samuel W. Noble, Jr., Town Manager
Moses'A. Ray, Mayor
Town Council Members

Tarboro Wastewater Treatment Plant
1994
Cv anide
Mercury
Silver
January
< 0.005 ing/I
< 0.2 ug/l
< 5 ug/1
Atmual
Pollutant A BIA,
13DL
< 1 ug/l
February
< 0.005 ing/l
< 5 ug/l
March
< 0.005 ntg/l
< 5 ug/l
April
0.012 tng/l
< 0.2 ug/l
< 10 ug/l
M ay
< 0.005 nig/l
< 5 ug/l
June
0.006 mg/l
< 5 ug/l
JUIV
<0.005 mg/l
< 0.2 ug/l
< 5 ug/l
August
< 0.005 mg/l
< 10 tig/I
September
0.00.5 mg/l
< 5 ug/l
October
< 0.00.5 mg/l
< 0.2 ug/l
< 5 ug/l
November
< 0.005 mg/l
< 5 ug/l
December
< 0.005 mg/l
< 5 ug/l
6

DMSION OF ENVIRONMENTAL MANAGEMENT
September 13, 1993
MEMORANDUM
TO: Randy Kepler
FROM: Susan A. Wilson
THROUGH: Ruth Swanek its
SUBJECT: Town of Tarboro (NPDES No. NC0020605)
Tar River, Tar River Basin (030303)
Edgecombe County
The Rapid Assessment Group (RAG) offers the following additional comments with regard
to the Town of Tarboro's inquiry to their proposed permit, as discussed in your Friday,
September 10 meeting. The items listed below refer to the facility's June 11, 1993 letter.
Item (2) - Quarterly mercury and chloride monitoring were recommended based on the
elevated levels found in the facility's annual priority analysis monitoring. Based on 15A
NCAC 2B .0505 (e)(2), the Division may require additional monitoring for any parameter
which has the potential to exceed instream water quality standards or action levels. As
stated in RAG's July 12 memo, the Town of Tarboro may request that the Division re-
evaluate the monitoring requirements after one year's worth of data has been collected.
The other chemical parameters (cadmium, chromium, cyanide, nickel, lead) were
recommended for monitoring based on pretreatment information, and/or observed effluent
concentrations. The monitoring for these parameters should be performed in accordance
with the classification of the facility.
Item (3) - In the previous memo RAG agreed to drop the furthest downstream monitoring
point at SR 1400 in Pitt County for this short term permitting period only. The upstream
monitoring point at Hwy 44 and the downstream monitoring point at Hwy 42 should
remain in the permit. One or more upstream and downstream sampling points may be
required in a permit pursuant to 15A NCAC 2B .0505 (c)(2)(B). The Town's instream
monitoring was required due to its predicted effect on dissolved oxygen in the Tar River, at
the time the previous model was performed, the predicted dissolved oxygen sag fell
between the two recommended sampling points.
The Town of Tarboro's permit is up for renewal in February 1995 in accordance with the
Tar River Basinwide plan. All instream monitoring along the Tar River mainstem will be
re-evaluated at that time, and the sampling points for Tarboro are subject to change based
on the new Tar River mainstem model.
cc: Tim Donnelly, RRO
Dana Polley, Pretreatment Unit

Page 1
Note for Susan Wilson
From: Randy Kepler
Date: Mon, Sep 13, 1993 9:45 AM
Subject: RE: Tarboro
To: Susan Wilson
Kind of, I need specifics on Mercury and Chlorides and why the monitoring locations are
where they are. They think they are located too far away from the discharge.
From: Susan Wilson on Mon, Sep 13, 1993 9:43 AM
Subject: RE: Tarboro
To; Randy Kepler .
i though i already did respond to those concerns
From: Randy -Kepler on Mon, Sep 13, 1993 8:17 AM
Subject: Tarboro
To: Susan Wilson
Sorry, One last time. I met with Tarboro fdday and tried to explain why we were doing what
we were doing and told them what we could do. They still had concerns why mercury and
chlorides were in the permit and why the upstream and downstream monitoring location are
so far away from the actual discharge ( they brought up Rocky Mount's locations and said
they were so close to the plant's discharge). If you could respond to these concerns so I may
issue this permit.
Thanks, Randy j

V Z-10 5
DIVISION OF ENVIRONMENTAL MANAGEMENT Ina R rem
July 12, 1993
TO: Randy Kepler
FROM: Susan A. Wilson
THROUGH: Ruth Swanek (X�
Carla Sanderson
SUBJECT: Town of Tarboro (NPDES No. NC0020605)
Tar River, Tar River Basin
Edgecombe County
The Rapid Assessment Group (RAG) has the following comments with regard to the Town
of Tarboro's inquiry to their proposed permit:
Item (1) - RAG defers to the NPDES Group to comment on the required removal efficiency
for TSS.
Item (2) - The chemical parameters referred to (cadmium, chromium, cyanide, nickel, lead,
mercury, and chlorides) were recommended for monitoring based on pretreatment
information, observed effluent concentrations, and annual priority analysis monitoring
(mercury and chlorides). RAG recommends that the monitoring requirements not be
dropped. After one year's worth of data has been collected, the Town of Tarboro may
request that the Division re-evaluate the monitoring requirements. In order to best evaluate
the first year of data, RAG recommends that the best available detection levels be used
Item (3) - RAG will agree to drop the Town's downstream monitoring point at SR 1400 in
Pitt County for this short term permitting period only. However, the upstream monitoring
point and the downstream monitoring point at Highway 4& should remain in the permit.
The Town of Tarboro's permit is up for renewal in February 1995 in accordance with the
Tar River Basinwide plan. All instream monitoring along the Tar River mainstem will be
re-evaluated at that time, so the sampling points for Tarboro may change.
cc: Tim Donnelly, RRO
Dana Folley, Pretreatment Unit

Memorandum
TO:
FROM:
DIVISION OF ENVIRONMENTAL MANAGEMENT %-,
Permits and Engineering/ NPDES Unit
Instream Assessment Unit
Susan Wilson
Randy Kepler G2tK
SUBJECT: Town of Tarboro WWTP
NCO020605
Edgecombe County
June 28, 1993
ECHh
PIN 2 i
Please review and provide comments where appropriate on the
attached draft comments from Tarboro. I have also requested that the Raleigh
Regional Office review and comment. If you have any questions please call.
Thank You.
cc. Permit File

I17iTll Town of Tarboro
a P. O. Box 220 - 500 Main Street
�;1 ol601 Tarboro, NC 27886-0220
c0�� Telephone [phone]
—&—p ,;, Fax [phone]
June 11, 1993
Ms. Coleen Sullins
NPDES Permits Group
N.C. Division of Environmental Management
P. O. Box 27687
Raleigh, North Carolina 27611-7687
Re: NPDES Permit NC 0020605
Tarboro, North Carolina
Dear Ms. Sullins:
TARBORO
AIL-AMMICA CM
7
The Town of Tarboro has carefully reviewed the draft of the above
referenced permit. Based on that review, we request some changes in
the permit. The changes we request are itemized below. Making
these changes should have no effect on receiving water quality, but
would reduce costs to the Town. Specific changes requested are as
follows:
1. The Town requests that the required total suspended
residue removal be 68% as in our existing permit.
g� l�-
The 30 mg/L TSR limit presents no problems, but the
85 % removal required by the draft permit would. ` . A
¢,0'
�ti��
large portion of plant influent is wastewater from
�o,��
textile dye operations that is extremely low in
\\\'�'�' (6y
suspended solids. A review of our last year's
monitoring data indicates several months when we
\�p y
would not have been able to meet the 85% removal re-
quirement, -despite compliance with the 30 mg/L stan-
dard. Even the removal percentages we have recently,,
achieved are deceiving. Recessionary production cut-
backs have resulted in a lower percentage of they
plant flow being textile waste than has been histori-
cally the case. Many of our textile industries are
t
now increasing production, and this .will lead to
lower influent suspended solids concentrations and
consequently lower removal percentages, although ef-
fluent suspended solids concentrations will not
PRIN710 ON RECYCLED PAPER

Ms. Coleen Sullins
NPDES Permits Group
June 11, 1993
Page 2
change. In addition, we have become increasingly ac-
tive in encouraging active pretreatment system main-
tenance for our industrial users. This has
resulted in some lessening of solids loading into our
plant, and we expect it to produce even greater
results when we renew the, majority of the pretreat-
ment permits next August. Finally, our water plant
sludge is discharged into our wastewater system.
While we have no immediate plans to discontinue this
practice, we would like the flexibility to pursue
other options. The water plant sludge increases our
influent suspended solids concentrations. If we dis-
continued the discharge of water plant sludge it
would effectively lower our influent suspended solids
concentrations. and suspended solids removal percent-
age, again without changing the amount of suspended
solids in our effluent: We do not quarrel with the
30 mg/L standard, but feel the required removal per-
centage should remain unchanged from our present per-
mit.
2. The draft permit adds monthly monitoring for cadmium,
chromium, cyanide, nickel, and lead, and quarterly
monitoring for mercury and chlorides. We are unaware
of any problems with these pollutants, and would
prefer, if the monitoring requirement cannot be
eliminated, that the frequency at least be reduced.
Our laboratory -is not equipped to run these tests,
and the costs for having them run by a private
laboratory are high. Staff time spent preparing
samples and transporting them to the laboratory, coor-
dinating delivery times, etc. is particularly costly.
We have found with the increased record keeping,
monitoring, reporting, etc. associated not only with
the NPDES permit, but also with our sludge permits
and the State pretreatment program, that our staff
has progressively less time available for wastewater
treatment. Accordingly, anything that could be done
to reduce demands on staff time and budget, that
would not impact water quality, such as reducing
monitoring frequency for these metals, would be ap-
preciated.,

Ms. Coleen Sullins
NPDES Permits Group
June 11, 1993
Page 3
3. Finally, we ask that adjustments be made in our up-
stream and/or downstream monitoring. Our upstream
monitoring point is only 12.2 river miles distant
from the Rocky Mount downstream monitoring point. The
furthest downstream monitoring point for Tarboro,
that at NCSR 1400 in Pitt County, is. only 10.6 river
miles distant from the Greenville Utilities Commis-
sion upstream monitoring point. This latter monitor-
ing point is particularly vexing. During June
through September, because of the distance to the
lowest downstream point and the 3 times Iper week
monitoring requirement, we now lose the services of
one of our staff and one of our vehicles for 1 1/2
days per week. One-half day is required to travel to
the sampling points and return to the treatment
plant. We ask that either the furthest most
downstream monitoring point be dropped, or the fre-
quency of downstream monitoring be reduced, par-
ticularly the 3 times per week requirement in'the sum-
mer months. We realize that the State needs stream
data for modeling purposes, but ask that, in view of
the cost to the Town, and the close proximity of the
Tarboro monitoring points to those of Rocky Mount and
Greenville, that the locations of the upstream and
downstream monitoring points and monitoring fre-
quencies for the Town be reconsidered.
Your consideration of the Town's requested modifications is greatly
appreciated. Tarboro is committed to maintaining a wastewater treat-
ment system that protects the Tar River. We do not ask -.for any
changes that would adversely impact water quality, or that would
make the effluent limits any less stringent than those proposed in
the draft permit.
Sincerely,
John H. Chapman
Director of Public Works
jrc
pc Samuel W. Noble, Jr., Town Manager
Moses A. Ray, Mayor
Town Councilmen