NC0021849_Speculative Limits_19980716

State of North Carolina -
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
July 16, 1998
Mr. John Christiansen
Town of Hertford
Post Office Box 32
Hertford, North Carolina 27944
.NCDENR
Subject: Speculative Limits for Town of Hertford
Permit No. NCO021849
Perquimanns County - s
Dear Mr. Christiansen:
This letter is in response to your speculative effluent limits request for an expansion at the wastewater
treatment plant that currently discharges to a channel to the Perquimanns River (C-Swamp). You
requested speculative limits for 0.7 MGD of treated domestic wastewater. We have reviewed the request
and provide the following response.
The speculative limits presented here are based on our understanding of the proposal and of present
environmental conditions. The Division of Water Quality (DWQ) cannot guarantee that it will issue the
Town an NPDES permit to discharge treated wastewater into waters of the State. Nor can we guarantee
that the effluent limitations and other requirements included in any permit will be exactly as presented
here. Final decisions on these matters will be made only after the Division receives and evaluates a
formal permit application for the Town's proposed discharge.
Speculative Effluent Limits
As stated earlier, the Town of Hertford currently discharges to a channel to the Perquimanns River that is
classified C-Swamp. The Perquimanns River is a black water, swampy system that does not maintain
advective flow. The Division recently completed a study that recommended summer limits of 15 mg/l
BOD5 and 4 mg/l NH3N to protect water quality in such systems.
Review of instreani monitoring data (1980 - present) collected at an ambient water quality monitoring
station located at NCSR 13 3 6 about one mile downstream of the confluence of the channel with the
Perquimanns River indicated dissolved oxygen values less than the 5.0 mg/l standard occurring regularly
during periods of warmer weather.
It is difficult to conclude whether the Town of Hertford WWTP is contributing to the low dissolved
oxygen values at the ambient monitoring station. Based on the uncertainty of the WWTP's contributions
and using the Division's results from the swamp study, the Town of Hertford will have the following
limits at 0.7 MGD:
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] FAX[phone]
An Equal Opportunity Affirmative Action Employer 50% recycled / 10% post -consumer paper

Mr. Christiansen
July 16, 1998
Page 2
Effluent Limits
BOD5 and NH3-N. The limits for these parameters are based on a swamp waters study that established
ffFes—e 1-im-it-s-Ta-�eT-on reasonably achievable technology and the waste assimilating capacity of swampy
systems that do not maintain advective flow.
TSS. The limits for total suspended solids are standard for secondary treatment of municipal wastewater.
Fecal Coliform, pH. The limits for fecal coliform bacteria and pH are derived to protect water quality in
ffFe-r—eceiving stream.
Nutrients: Total Phosphorus, Total Nitrogen. No limits for nutrients are recommended at this time.
B—owever, iffuture instream assessments inificate that the accumulation of nutrients are creating
eutrophication problems, nutrient limits may be added to the permit.
Should the Town of Hertford expand their WWTP from 0.4 to 0.7 MGD, they will be required to relocate
their existing outfall from the channel to the Perquimanns River. In addition, instream monitoring will be
required. Stream samples should be collected via boat mid -channel in the river if possible because
samples collected from the bank would not be as useful given the nature of the Perquimanns River.
Weekly monitoring will be required in the summer (June, July, August, and September) whereas monthly
monitoring should be adequate during the winter. These instrearn monitoring requirements are indicated
on the draft effluent sheet attached to this letter.
I trust this response offers sufficient guidance for the Town's treatment plant. If you have any additional
questions about these limits, feel free to contact Paul Clark at [phone], extension 580.
Sincer�ly,
David A. Goodrich
I
Supervisor, NPDES nit
cc: Central Files
Washington Regional Office, Water Quality Section
NPDES Unit Files

Town of Hertford March 1998 Request - SPECULATIVE LIMITS 06/15/98
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS — Permit No. NCO021849
During the period beginning on the effective date of the permit and lasting until expiration, the Permittee is authorized to discharge from tf6ll($) 6 , erial number
001. Such discharges shall be limited and monitored by the Permittee as specified below:
EFFLUENT CHARACTERISTIP 7 - 7 7
7 LIMITS
.Monthly
Average
Weekly
Average.
Daily Ximum
_NFa
Measurement
Frequency,
5 ample
Type
Sample, .
Location'.
Flow (MGD)
0.7
Continuous
rding',
I or L
BOD, 5-day, 20OC2 (April 1 — October 31)
/L
�V�,mg/L
ji, b
�/rpqnth.%
Composite
BOD, 5-day, 20OC2 (November 1 — March 31)_
30.0 mg/L
q5_-Fmg
�4imontn'
I I . .1
ComposTie
Total Suspended Residue2
30.0 mg /L
�5iQ Mg/L
.4
2/month,
ComposTie
E
NH3-N (April 1 — October 31)
__7E
__TU Mg
Tg/L
�11
%monthly
Composit e
I-
NH3-N (November 1 — March 31)
8.0 mg/L
PRTWL
.9.)
'�.',,,Monthly.
Composife
E
pH3
2/montn
Grab
Total Residual Chlorine4
28 pg/1
Daily
Grab
E
Temperature OC
Weekly
----Grab
E, U, D
Dissolved Oxygen
Weekly
Grab
U, D
Conductivity
Weekly
Grab
U, D
iTe—cal Goliform (geometric mean)
400/1
___27m`6nth
Grab
E, U, 0
Tota Nitrogen (NU2+NL) +TKN)
Quarterly
Composite
I otal Phosphorus
Quarterly
Composite
Notes:
Sample Locations: E about 0.75 miles of effluent channel/Perquimanns River confluence (nearterminus ofdirt road in this vicinity), D
— Downstream about 0.33.,mile�,df.'dfflUdnt,dhdhr�el/P6rquimanns River confluence (at railroad bridge). Instrearn monitoring shall be grab samples taken weekly
-MAY),.
(Jun -Sep) and monthly'�0.6t
2 The monthly,,avefagd.-i?fflU*ent,,B'6Ds and Total Suspended Residue concentrations shall not excee�0/6 of the respective influent value (85% removal required).
A
3
ThepH sWI-Q.,b6 14'ss"t6bri-6.0 standard units nor greater than 9.0 standard units.
4 hi
Mon toffig re uire, e applies only if chlorine is added for disinfection.
r/'5 ChronidTo 'ici Cenodaphnia) PIF @ 0.9%; January, April, July, October; See the Supplement to Effluent Limitations page.
There shal�166—n—oddi'sch�arge �of floating solids or visible foam in other than trace amounts-.
Page I of 3

STATION: 02043892
Perquimans River at SR 1336 at Hertford
DATE
Temp
DO
DO sat
Cond
pH
NH3N
TKN
NOx
TP
hloride
Salinity
TSS
Cu
Zn
As
Hg
(deg C)
(mg/1)
(%)
(umhos)
(SU)
(mg/1)
(mg/1)
(mg/1)
(mg/1)
(mg/1)
(ppt)
(mg/1)
(ug/1)
(ug/1)
(ug/1)
(ug/1)
02/05/80
2
7.5
54.2
03/24/80
13
8.5
80.7
04/21/80
19
11.4
122.9
<0.05
4.6
0.17
12
<40
50
10
<0.5
05/06/80
21
6.3
70.7
06/23/80
20
6.5
71.5
08/14/80
31
7
94.2
0.05
0.7
<0.05
0.21
12
<40
50
<0.5
08/22/80
26
7.5
92.5
09/18/80
29
8.3
107.9
10/29/80
15
8.5
84.3
<0.05
0.6
0.06
0.09
9
<40
70
10
<0.5
11/12/80
12
9.5
88.2
12/15/80
8
9.5
80.2
02/18/81
10
12.5
110.8
03/24/81
8
11.6
98.0
1300
04/13/81
18
9.7
102.5
<0.05
0.9
0.07
0.11
1000
<40
<50
10
<0.5
05/11/81
19
8.9
96.0
6720
1900
6
06/04/81
25
6.9
83.5
07/31/81
29
7
91.0
0.08
1.5
<0.05
0.11
1500
23
<40
<50
10
<0.5
08/11/81
28
6.6
84.3
7520
2200
4
09/14/81
26
5.1
62.9
1224
1400
1
10/15/81
16
9.5
96.3
5310
0.06
0.9
0.12
0.06
1800
4
<40
<50
10
<0.5
11/03/81
18
9.7
102.5
4
6
12/16/81
5
11
86.2
6720
4
3
01/19/82
2
10.2
73.8
3942
0.42
1.2
1.2
0.05
1400
2
7
<40
50
10
<0.2
02/02/82
0.16
0.8
0.43
0.09
02/12/82
6
7.4
59.5
966
1
13
03/10/82
10
8.9
78.9
1170
1
8
04/07/82
12
8,6
79.8
1260
6.3
0.26
1.3
0.82
0.16
1
30
<40
<50
10
<0.2
05/10/82
19
5.9
63.6
1120
6.5
0.32
1.7
0.23
0.13
1
7
06/03/82
28
6.1
78.0
6.7
0.07
1.1
0.17
0.12
6
07/08/82
30
5.4
71.5
1350
6.1
0.1
1
0.24
0.15
2
<40
<50
10
0.6
08/09/82
27
6
75.3
1056
6.2
<0.05
0.9
0.15
0.11
1
5
09/09/82
25
4.8
58.1
460
6
0.3
1.4
0.24
0.15
0
4
10/11/82
20
4.5
49.5
242
5.3
0.13
1
0.29
0.1
3
<20
50
10
1
11/08/82
16
0.7
7.1
177
6.6
0.08
1.1
0.03
0.12
0
7
12/02/82
14
4.9
47.6
98
6.5
0.38
1.2
0.18
0
4
01/10/83
8
8.5
71.8
576
6.2
0.16
0.9
0.66
0.1
0
5
<20
40
10
0.2
02/02/83
8
11
92.9
1206
6.7
0
3
03/08/83
13
7.5
71.2
110
6
0.15
0.7
0.64
0.1
0
10
04/14/83
15.5
5.1
51.1
109
5.9
0.18
1.1
0.41
0.1
5
<20
<20
10
<0.2
05/12/83
22
6.9
78.9
135
6.4
0.14
1.1
0.2
0.14
6
06/24/83
25.3
4.5
54.8
114
6.4
0.44
1.9
0.34
0.23
3
07/18/83
28.7
5.5
71.2
239
6.5
0.04
0.7
0.17
0.17
0
5
<20
<20
10
<0.2
08/24/83
27.7
5.2
66.1
280
6.7
0.04
0.6
0.04
0.19
4
09/13/83
23
4.6
53.6
320
7
0.03
0.5
0.02
0.16
5
10/17/83
19.9
5.9
64.8
660
6.4
0.03
0.5
0.02
0.12
2
<20
<20
10
<0.2
11/21/83
12.2
8.4
78.3
3460
7
0.03
0.4
0.02
0.05
2.1
3
12/12/83
10.4
7.3
65.3
2510
6.6
0.31
0.7
0.06
0.1
1.1
4
01/13/84
2
12.6
91.1
2560
7.5
0.24
0.6
0.14
0.07
2
4
<20
<20
10
<0.2

DATE
Temp
DO
DO sat
Cond
pH
NH3N
TKN
NOx
TIP
hloricle Salinity
TSS
Cu Zn As Hg
(deg C)
(mg/1)
(%)
(umhos)
(SU)
(mg/1)
(mg/1)
(mg/1)
(mg/1)
(mg/1)
(Ppt)
(mg/1)
(ug/1) (ug/1) (ug/1) (ug/i)
02/09/84
3.7
11.8
89.3
2770
7.1
0.12
0.8
0.45
0.08
1.4
5
03/07/84
8.4
8.8
75.1
704
6.6
0.24
0.9
0.46
12
5
04/25/84
15.8
4.4
44.4
187
6.4
0.17
1
0.18
0.1
0
4
<20 <20 10 <0.2
05/23/84
22.5
4.8
55.4
6.7
0.14
0.8
0.24
0.1
4
06/27/84
26
4.3
53.0
650
6.8
0.06
0.7
0.14
0.1
0
6
07/05/84
27.5
5.9
74.7
700
7
0.02
0.6
0.01
0.21
0.2
7
<20 <20 10 <0.2
08/13/84
29.5
5.5
72.2
437
6.8
0.02
0.6
0.03
0.19
0
3
09/27/84
18
6.5
68.7
0.11
0.8
0.04
0.16
3
10/17/84
19
8.1
87.3
280
0.04
0.4
0.02
0.09
4
<20 <20 10 <0.2
11/27/84
9
8
69.2
70
0.16
2
0.1
0.14
3
12/12/84
7
8.6
70.9
900
0.18
0.6
0.08
0.1
2
01/31/85
3
12
89.2
0.3
0.7
0.28
0.08
6
<20 <20 10 <0.2
04/30/85
20
7.4
81.4
0.03
0.6
0.09
0.11
670
9
<20 <20 10 <0.2
07/24/85
26
5.5
67.8
860
7
07/24/85
0.04
0.4
<0.01
0.07
<20 <20 10 0.2
10/29/85
18
3.7
39.1
1938
6.8
0.18
0.8
0.08
0.14
530
1
4
<20 <20 10 <0.2
01/02/86
6
9.2
73.9
2070
6.6
0.37
1.1
0.31
0.07
760
1.4
4
<10 22 10 <0.2
04/11/86
16
7.6
77.0
1770
7.1
0.06
0.7
0.14
0.08
580
0.6
8
<10 <10 10 <0.2
07/02/86
28
5.7
72.8
2350
7
0.02
0.5
0.01
0.07
710
1.3
2
<10 <10 10 <0.2
10/20/86
17
7.9
81.8
3596
7.2
0.01
0.5
<0.01
0.05
1200
2.2
2
<10 <10 10 0.3
01/06/87
6
7.7
61.9
3864
6.7
0.28
0.8
0.33
0.16
1400
2.5
9
04/30/87
17
8
82.8
1276
6.9
0.05
1
0.49
0.05
37
0.8
3
07/30/87
29
4.8
62.4
1380
6.6
0.01
0.7
<0.01
0.08
400
0.5
38
10/27/87
16
8.5
86.1
1298
6.8
0.01
0.4
0.01
0.06
300
0.3
5
01/25/88
4
10.1
77.1
1420
6.6
0.32
1
2.4
0.07
380
0.8
11
04/19/88
14
9
87.4
1830
6.1
0.08
0.6
0.38
0.07
530
0.3
9
07/21/88
27.5
5.9
74.7
1377
6.7
0.07
0.6
0.05
0.11
24
0.05
4
10/03/88
24.5
6.9
82.8
192
6.2
0.01
0.5
<0.01
0.05
710
1
1
01/24/89
7
9.4
77.5
2244
7.1
0.23
0.7
0.28
0.09
700
1.5
4
04/10/89
14.5
4.6
45.1
230
6
0.2
0.8
O�87
011
16
0
6
07/26/89
30
8.9
117.8
203
7.1
0.04
0.8
0.18
0.19
34
0
7
10/19/89
20.5
6.6
73.3
267
7.2
0.12
0.9
0.11
0.16
49
0
4
01/16/90
0.29
1
0.81
0.12
01/16/90
7
8.2
67.6
163
6.4
18
0.3
13
04/03/90
14
6.7
65.0
195
6.6
0.26
1
0.45
0.13
27
0
3
07/12/90
30
5.7
75.4
347
6.4
0.02
0.6
0.04
0.12
83
0
2
10/03/90
22
6.8
77.8
254
6.6
0.05
0.6
0.03
0.11
79
0
3
01/14/91
8
6.8
57.4
235
6.7
0.31
1
0.55
0.13
32
0
3
04/11/91
19
7.5
80.9
246
6.9
0.05
0.8
0.24
0.08
36
0
5
07/30/91
27
20.7
259.9
230
6.7
0.17
0.9
0.15
0.2
37
0
4
10/21/91
16
4
40.5
189
6.2
0.17
0.8
0.16
0.19
24
0
6
01/16/92
8
8.7
73.5
255
6.4
0.11
0.7
0.84
0.06
800
2
8
04/13/92
17
8.2
84.9
2668
6.8
0.06
0.7
0.17
0.05
800
1.5
4
07/23/92
31
4.9
66.0
2904
6.5
0.02
0.5
<0.01
0.05
880
1.5
2
10/21/92
15
6.4
63.5
156
6.7
0.12
0.6
0.21
0.14
440
0.5
4
01/27/93
7
8.7
71.7
150
5.5
0.27
1.2
1.5
0.15
17
0
6
04/22/93
18
6.6
69.7
148
6.3
0.07
0.8
0.22
0.1
16
0
8
07/28/93
30
5
66.2
405
6.7
0.12
0.7
0.05
0.16
96
0
5
10/19/93
20
6.8
74.8
451
6.7
0.07
0.5
0.14
0.09
110
0
5
04/27/94
21
6.8
76.3
400
6.2
0.12
1.1
0.58
0.1
81
0
3
07/21/94
31
6.4
86.2
528
6
0.07
0.6
<0.01
0.11
150
0
3

DATE
Temp
DO
DO sat
Cond
pH
NH3N
TKN
NOx
TP
hloride Salinity
TSS
Cu
Zn
As
Hg
(deg C)
(mg/1)
(%)
(umhos)
(SU)
(mg/1)
(mg/1)
(mg/1)
(mg/1)
(mg/1)
(ppt)
(mg/1)
(ug/1)
(ug/1)
(ug/1)
(ug/1)
10/17/94
0.03
0.6
0.02
0.06
10/17/94
18
9
95.1
2736
7.4
800
1.5
5
11/28/94
13
8
76.0
5828
6.9
0.08
0.6
0.04
0.05
2000
3.5
5
12/15/94
11
8.5
77.1
595
7.1
0.25
0.6
0.06
0.09
2000
0
8
01/24/95
8
8.2
69.3
4757
7
0.22
0.8
0.11
0.06
1600
3
4
02/09/95
4
10
76.3
5893
7.1
0.23
0.7
0.18
0.03
2200
4
2
03/28/95
15
9.3
92.3
2280
6.9
0.09
0.9
0.89
0.08
610
1
5
04/25/95
20
6.7
73.7
2530
6.7
0.1
0.7
0.34
0.06
830
1.5
7
05/24/95
26
6.1
75.2
3038
6.4
0.07
0.4
<0.01
0.07
1000
1.5
6
<2
33
10
<0.2
06/22/95
0.07
0.6
<0.01
0.07
4
51
10
<0.2
06/22/95
26
6.5
80.1
3038
6.2
900
1.5
7
07/18/95
32
6.1
83.5
3010
6.2
0.04
0.4
<0.01
0.07
960
1.5
5
3
24
10
<0.2
08/08/95
28
8.2
104.8
3900
5.7
0.03
0.5
<0.01
0.05
2.2
8
3
68
40
<0.2
09/25/95
22
7.3
83.5
3233
6.5
0.01
0.4
<0.01
0.05
950
2
7
6
19
10
<0.2
10/30/95
20
7.7
84.7
2640
6.8
0.01
0.5
0.09
0.08
800
2
3
<2
16
10
<0.2
11/28/95
11
10.1
91.6
3520
6.7
0.07
0.6
0.1
0.06
1100
2
10
2
35
10
<0.2
12/18/95
8
11.5
97.1
2479
7
0.01
1
0.09
0.2
790
1.5
14
5
14
10
<0.2
01/23/96
6
7.3
58.7
676
6.4
0.19
0.7
2
0.1
190
0.2
15
2
13
10
<0.2
02/21/96
8
9.7
81.9
516
6.3
0.12
0.7
2.4
0.13
120
0
4
5
37
10
<0.2
03/12/96
7
9.8
80.8
258
5.9
0.04
0.8
0.87
0.09
41
0
6
4
18
10
<0.2
04/24/96
21
7.4
83.0
367
6.1
0.06
0.7
0.54
0.06
68
0
1
3
17
10
<0.2
05/28/96
23
6.3
73.5
728
6.1
0.08
1.1
0.14
0.09
170
0.2
3
2
30
10
<0.2
06/26/96
28
4.7
60.1
846
6.2
0.18
1
0.08
0.11
220
0.5
3
<2
10
10
<0.2
07/22/96
30
8.9
117.8
540
6.5
0.06
1
<0.01
0.16
130
0
7
4
84
10
<0.2
08/28/96
27
3.1
38.9
538
6.3
0.29
1.2
0.03
0.27
130
0.2
1
3
60
10
<0.2
09/26/96
22
2.7
30.9
456
6.7
0.4
1.4
0.02
0.24
110
0.1
2
<2
19
10
<0.2
10/17/96
18
3.2
33.8
143
6.5
0.18
0.7
0.21
0.13
23
0
2
<2
<10
10
<0.2
11/21196
10
7.4
65.6
507
6.7
0.19
0.8
0.17
0.15
120
0.5
4
<2
74
10
<0.2
12/17/96
9
8.9
77.0
337
6.8
0.18
0.9
0.29
0.09
62
0
1
16
55
10
<0.2
01/27/97
8
9.7
81.9
188
6.7
0.24
0.7
0.66
0.07
30
3
6
77
10
<0.2
02/27/97
13
8.8
83.5
184
6.7
0.1
0.7
0.93
0.07
24
6
<2
30
10
<0.2
03/25/97
14
8.4
81.5
153
6.6
0.18
0.7
0.63
0.11
22
3
3
92
10
<0.2
04/21/97
17
7.8
80.7
273
6.5
0.07
0.8
0.42
0.11
53
5
4
20
10
<0.2
05/27/97
22
6.9
78.9
276
6.2
0.14
0.7
0.47
0.14
52
9
4
13
10
<0.2
06/16/97
27
7.9
99.2
322
6.4
07/31/97
27.6
5.7
72,3
446
6.5
0.05
0.6
0.03
0.17
100
0.2
1
3
79
10
<0.2
08/27/97
27.4
6.2
78.4
1108
6.3
0.01
0.4
0.01
0.08
320
0.5
6
2
89
10
<0.2
09/29/97
22.2
7.1
81.5
1462
7.3
0.05
0.3
<0.01
0.05
480
0.8
3
34
10
<0.2
10/20/97
19
7.7
83.0
1770
6.6
0.9
11/20/97
0.06
0.4
0.04
0.06
900
1
3
79
10
<0.2