NC0021121_Wasteload Allocation_19910827

NPDES DOCUWENT SCANNINS COVER SHEET
NPDES Permit:
NC0021121
Mount Airy WWTP
Document Type:
Permit Issuance
(Wasteload
Allocation
'ttzmwkv- r
Authorization to Construct (AtC)
Permit Modification
Speculative Limits
Staff Report
Instream Assessment (67B)
Environmental Assessment (EA)
Permit
History
Document Date:
August 27, 1991
This document is printed on reuse paper - ignore nay
content on the resrerse side

r
NPDES WASTE LOAD ALLOCATION
PERMIT NO.: NCO021121
PERMITTEE NAME: City of Mount Airy
FACILITY NAME: Mount Airy WWTp
Facility Status: Existing
Permit Status: Renewal
Major Minor
Pipe No.: 001
Design Capacity: 7.0 MGD
Domestic (% of Flow): 57.6 % 7, p M G D
Industrial (% of Flow): 42.4 oIo
Comments:
The facility is currently at 4.0 MGD. The ex ansion will be completed,
by nPYt vPnr D or,o «. :_r--_-_ -. . . —_
--- u• i•+� 10.l.11ll 11T1S 11Ut
et done a pollutant analysis. '2e J, ae�,_ � j an y, o o"d
016 70 7 -f 7e �daea�i�
RECEIVING STREAM: the Ararat River
Class: C
Sub -Basin: 03-07-03
Reference USGS Quad: B 16 NE (please attach)
County: Su ry
Regional Office: Winston-Salem Regional Office
Previous Exp. Date: 12/31/91 Treatment Plant Class: Class 4
Classification changes within three miles:
none within 3 miles
Requested by: Rosanne Barona
Prepared by:
Reviewed by:
`3i aD,.` 11 "5-Cs /�D Ccu�
Date: 6/18/91
Date: Q 1,21D /C)
Date:
Modeler Date Rec. #
SAW at (0300
Drainage Area (mil)��- Avg. Streamflow (cfs):_
7Q10 (cfs) 141. C11�Winter 7Q10 (cfs) 31J) 30Q2 (cfs)
Toxicity Limits: IWC % Acute hronic
Instream Monitoring:
lem . fi �etr.l eol�- orm a
Parameters V�
Upstream_ Location (= Hwy 5a �}
Downstream Locatio ,n; / +►�+� C'.iaYECaI•iIb®►1LE�/�
1. bedcre ean�l�atr� u,/Giddlr�,-
Characteristics I _ISU At.)iyll
BOD5 (m )
NH3-N (mg/1)
�3 /tjOZ—
D.O. (mg/1)
TSS (mg/1)
F. Col. (/100 ml)
a00
pH (SU)
►t t V ( n
34
rol
'ititevuu-&5A) o.vaQ
t bAo -;v r 4� r= �h �or� x�, 7p Tit/, eoPpeYZ•jv, 51 veY
Comments: Clew ",6j4U(,t,m / 7i{. J ij

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:
nr.c�wn .
FACT SHEET FOR WASTELOAD ALLOCATION
J G L 16 1g91
Request # 6300
W;nston_Salem
City of Mount Airy
flegloal office
NC0021121
57.6% Domestic, 42.4% Industrial
Existing
Renewal
Ararat River
C
030703
Surry
Stream Characteristic:
WSRO
USGS #
2.1136.4410
Barona
Date:
1988
6/18/91
Drainage Area (mi2):
75.2
B16 NE
Summer 7Q10 (cfs):
14.9
Winter 7Q10 (cfs):
31.0
Average Flow (cfs):
90.0
30Q2 (cfs):
IWC (%):
42
Wasteload Allocation Summary
(approach taken, correspondence with region, EPA, etc.)
Renewal of existing limits for 7.0 MGD (except for toxics).
Facility currently under an S OC until 1993.
Plecse '?16je C16W1 fre&ky1 M0A; V y; 1 l oeAA6YIS kwa
Special Schedule Requirements and additional comments from Reviewers:
c-n
Recommended by:OaAzl' Date: 1
Reviewed by Instream Assessment: I-/ �. L _ Y'.Ll Date: -7! 11 4 1�-
a
Regional Supervisor: Date: g / 2
Permits & Engineering: aq��4-Date:
RETURN TO TECHNICAL SERVICES BY: AUG 10 1991

CONVENTIONAL PARAMETERS
Existine Limi
Monthly Average
Monthly Average
Summer
Winter
Summer
Winter
Wasteflow (MGD):
4.0
4.0
7.0
7.0
BOD5 (mg/1):
30
30
30
30
NH3N (mg/1):
--
13
---
DO (mg/1):
2
--
5
---
TSS (mg/1):
30
30
30
30
Fecal Col. (/100 ml):
1000
1000
1000
1000
pH (SU):
6-9
6-9
6-9
6-9
Residual Chlorine (µg/1):
monitor
monitor
monitor
monitor
Oil & Grease (mg/1):
TP (mg/l):
monitor
monitor
monitor
monitor
TN (mg/1):
monitor
monitor
monitor
monitor
Recommended Limits:
Monthly Average
Dal Max
Summer
Winter
WQ or EL
Wasteflow (MGD):
7.0
7.0
BOD5 (mg/l):
30
30
WQ
NH3N (mg/1):
13
--
WQ
DO (mg/1):
5
--
WQ
TSS (mg/1):
30
30
Fecal Col. (/100 ml):
200
200
pH (SU):
6-9
6-9
Residual Chlorine (µg/1):
monitor
monitor
Oil & Grease (mgp):
30
30
60
TP (mg/1):
monitor
monitor
TN (mg/1):
monitor
monitor
Limits Changes Due To: Parameter(s) Affected
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 Fecal Coliform
New facility information Oil & Grease
(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)

Type of Toxicity Test:
Existing Limit:
Recommended Limit:
Monitoring Schedule:
Existin Limits
imits
Wasteflow (MGD):
Cadmium (ug/1):
Chromium (ug/1):
Copper (ug/1):
Nickel (ug/1):
Lead (ug/1):
Zinc (ug/1):
Cyanide (ug/1):
Phenols (ug/1):
Mercury (ug/1):
Silver (ug/1):
TOXICS/METALS
32% Chronic @ 4.0 MGD / 42% Chronic @ 7.0 MGD
42% Chronic Toxicity Test Quarterly
Jul, Oct, Jan, Apr
4.0
128
Monitor
Recommended Limits @ 7.0 MGD only
Daily Max.
7.0
4.7
Monitor
Monitor
Monitor
Monitor
11.9
Monitor
WQ or EL
Cadmium (ug/1):
4.7
WQ
Chromium (ug/1):
119
WQ
Copper (ug/1):
Monitor
Nickel (ug/1):
209
WQ
Lead (ug/1):
59
WQ
Zinc (ug/1):
Monitor
Cyanide (ug/1):
12
WQ
Phenols (ug/1):
----
Mercury (ug/1):
0.028
WQ
Silver (ug/1):
Monitor
Limits Changes Due To:
Change in 7Q10 data
Change in stream classification
Relocation of discharge
Change in wasteflow
New pretreatment information
Failing toxicity test
Other (onsite toxicity study, interaction, etc.)
Parameter(s) Affected
Cr, Ni, Pb, Hg, Ag
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.

INSTREAM MONITORING REQUIREMENTS
Upstream Location: Above discharge at HWY 52
Downstream Location: 1) below disch. —1.0 mi before confluence with Stewarts Creek
2) below disch. —6.0 mi before confluence with Caddle Creek
Parameters: Temperature, D.O. fecal coliform, and conductivity
Special instream monitoring locations or monitoring frequencies:
Attached schematic showing possible access roads to downstream monitoring locations.
MISCELLANEOUS INFORMATION & SPECIAL CONDITIONS
Adequacy of Existing Treatment
Has the facility demonstrated the ability to meet the proposed new limits with existing treatment
facilities? Yes -,"No,,A-
�`�OAs�ic/17�i �q !�'.� c�l�t✓a/ AO �i-/qi� `�.f�ilPss tt i;� !'n�a�i �r i Slcv/Qiuiri /irifs
If no, which parameters cannot be met?
Would a "phasing in" of the new limits be appropriate? Yes No,_--r
If yes, please provide a schedule (and basis for that schedule) with the regional
office recommendations:
If no, why not?
it/ICJ /i:�.�S ��i'rC/�i v �. .•. , lo�hrr�r�-f
Special Instructions or Conditions
Wasteload sent to EPA? (Major) _Y_ (Y or N)
(If yes, then attach schematic, toxics spreadsheet, copy of model, or, if not modeled, then old
assumptions that were made, and description of how it fits into basinwide plan)
Additional Information attached? Y (Y or N) If yes, explain with attachments.
Wasteload allocation file notes, old model results, and schematic.

Facility Name_l of jy� Permit # Ila Pipe # UO
CHRONIC TOXICITY PERMIT LIMIT (QRTRLY)
(**Chronic Toxicity (Ceriodaphnia) ChV at �ja%,dVli (kJ,T_M. A9 y , See Part _, Condition .)
The effluent discharge shall at no time exhibit 48 hour acute toxicity as lethality in an
effluent concentration of 42% nor measure a quarterly arithmetic average chronic value
less than this same percentage of waste. The chronic value will be determined using the
geometric mean of the highest concentration having no statistically detectable impairment of
reproduction or survival and the lowest concentration that does have a statistically
detectable impairment of reproduction or survival. The presence of 48 hour acute toxicity
will be determined using Fisher's Exact Test at 48 hours from test initiation. Collection
methods, exposure regimes, and further statistical methods are defined in: The North
Carolina Phase lI Chronic Whole Effluent Toxicity Test Procedure (July, 1991) or
subsequent versions.
The permit holder shall perform at a minimum, quarterly monitoring using these procedures
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,'Sol. Or{, --lay) Apy
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 measures 48 hour acute
toxicity or a chronic value less than that specified above, then multiple concentration testing
shall be performed, at a minimum, in each of the two following months.
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 THP313 for the Chronic Value and TGA3B for the 48
hour Acute Toxicity measure (Pass/Fail). Additionally, DEM Form AT-3 (original) is to be
sent to the following address:
Attention: Environmental Sciences Branch
North Carolina Division of
Environmental Management
4401 Reedy Creek Road
Raleigh, NC 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 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 testconditions 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.
Permitted Flow TO MGD Basin & Sub -basin 0-103
7Q10 I�I.cl cfs Receivin Stream mya l�iVFY
IWC e{2- % County �OyytL
Recommended by: t tW — Date: bb l q
PIIQLR Version 7191

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06/30/91 ver 3.1
Facility:
NPDES Permit No.:
status (E, P, or M):
Permitted Flow:
Actual Average Flow:
Subbasin:
Receiving Stream:
Stream Classification:
7Q10:
IWC:
Stn'd / Bkg
Pollutant AL Cone.
(ug/1) (ug/1)
Cadmium S
Chromium S
Copper AL
Nickel S
Lead S
Zinc AL
Cyanide S
Mercury S
Silver AL
Selenium S
Arsenic S
Phenols 5
NH3-N C
T.R.Chlor.AL
Pollutant
Cadmium S
Chromium s
Copper AL
Nickel S
Lead S
Zinc AL
Cyanide s
Mercury S
Silver AL
Selenium S
Arsenic S
Phenols S
NH3-N C
T.R.Chlor.AL
2.0
50.0
7.0
88.0
25.0
50.0
5.0
0.012
0.06
5.00
50.00
NA
17.0
0.0
Allowable
Load
(t/d)
2.79
23.27
0.95
14.46
14.70
6.98
1.36
0.01
0.11
0.56
5.59
T O X I C S R E V I E W
City of Mt Airy
NCO021121
E
7.0 mgd
3.8 mgd
'030703
Ararat River --------PRETREATMENT DATA -------------- I ---- EFLLUENT DATA---- I
C ACTUAL PERMITTED 1
14.9 cfs Ind. + Ind. + I FREQUENCY 1
42.14 i Domestic PERMITTED Domestic I OBSERVED of Chronicl
Removal Domestic Act.Ind. Total Industrial Total I Eflluent Criteria I
Elf. Load Load Load Load Load I Cone. Violations)
4 (t/d) (t/d) (t/d) (t/d) (t/d) (ug/1) (tvio/tsam)I
_______ ________________ _________________ I -------- ___-__-_-
92% 0.0 0.2 0.25 0.2 0.248 2.0
76% 0.1 1.8 1.89 3.2 3.308 82.0 I
18% 0.3 4.1 4,38 9.4 9.714 110.0 N
321 0.5 2.9 3.39 1.3 1.799 0.0 P
Bit 0.3 5.4 5.68 1.4 1.675 0.0 U
20% 2.3 7.2 9.44 16.2 18.480 0.0 T
59% 0.1 0.9 0.98 0.3 0.449 0.0
86% 0.0 3.5 3.48 0.0 0.010 0.0 S
94% 0.0 0.2 0.22 0.1 0.184 I E
0% 0.0 0.0 0.00 0.0 0.000 I C
04 0.0 0.0 0.00 0.0 0.000 I I T
77% 0.4 3.5 3.90 24.5 24.960 1 1 1
01 0
0% N
I I
I I
I I
ALLOWABLE PRDCT'D PRDCT'D PRDCT'D--------- MONITOR/LIMIT --------- 1--ADTN'L RECMMDTN'S--
Effluent Effluent Effluent Instream I Recomm'd
Cone. using using Cone. Based on Based on Based on FREQUENCY INSTREAM
CHRONIC ACTUAL PERMIT using ACTUAL PERMITTED OBSERVED I Eff. Mon. Monitor.
Criteria Influent Influent OBSERVED Influent Influent Effluent I based on Recomm'd ?
(ug/1) (ug/1) (ug/1) (ug/1) Loading Loading Data OBSERVED (YES/NO)
------------------------------------------------- ---------I --------- -__-__--
4.747 0.645 0.632 0.84 Limit Limit Limit I NCAC NO
118.664 14.450 25.292 34.55 Limit Limit Limit I NCAC YES
16.613 114.498 253.758 46.35 Monitor Monitor Monitor Weekly YES
208.848 73.525 38.974 0.00 Limit Limit I NCAC NO
59.332 34.350 10.137 0.00 Limit Limit I NCAC NO
118.664 240.461 470.982 0.00 Monitor Monitor i Monthly NO
11.866 12.813 5.861 0.00 Limit Limit I NCAC NO
0.028 15.524 0.043 0.00 Limit Limit I NCAC NO
0.142 0.415 0.352 0.00 Monitor Monitor
11.866 0.000 0.000 0.00 1
118.664 0.000 0.000 0.00 I
0.000 28.569 162.888 0.00 i
0.000 0.00 I
40.346 0.00
I
I
I
I
I
I
A
I N
I A
I L
I Y
S
I I
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I E
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15

>.em : +'D"d1 5
Damao« ,c&Y OF ,OU"l—t
ememlm yrpar : ARARAT RIVER
The au D.m w sas m6.
The Endem:ls mae m «.
The- End wmo is ?.36 G«.
cement 1
RE, a. cn I
Reach Reach
Rm:e
Peach
Reach
•mach }
m m,
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--L.'fw-..te1 (75,i; 1.'+.':� I,I1 nt :'L'
DeS1.q? I@!i)nc�n7T_YI
ILENSTHI SLOPE] VELOCITY 1 DEFTHI Kd I K:d I Ka I Ka 1 KN 1 KN I KNR I KNR I
I mile I ftlmil fps I ft [design] a201 Idesigni 0201 Idesigni 9`201 Idesignl @201 1
-
I I I I I I I I I I I I I
Segment 1 1 0,261 8.201 0..`,40 1 1.78 1 0.35 1 0.26 i 4.44 1 3.981 0.44 1 0.30 1 0.44 1 0.00 1
--Reach 1 1 ! _--_-I---- I I I
I I I I I I I I I I I I l
Segment 1 1 0.721 8,201 0.589 1 1.9B 1 0.33 1 0.26 1 3.95 1 3.551 0.44 1 0.30 1 0.44 1 0.00 1
Reach 2 1 1 1 1 1 i I I I I I I i
I I I I I I I I I i I i I
Segment 1 1 1.201 8.201 0.720 1 2.33 1 0.33 1 i1.26 1 3.43 1 3.081 0.44 1 0.30 1 0.44 1 0.00 1
Reach 3 1 1 1 1 I I I I I
I I I I I I I I I i I I i
Segment 1 1 2.201 8.201 0,723 1 2.36 1 0.33 1 0.26 1 3.38 1 3.031 0.44 0.30 1 0.44 1 0.00 1
Reach 4 1 1I I 1 I I I I
I I i I I I i i I 1 I I I
Seement I 1 1.651 8.201 0.732 1 2.36 1 0.33 j 036 3.38 1 3.031 0.44 1 0.3o 1 0.44 1 0.00 1
Reach 5 1 1 1 1 i I
-----------------------------------------------------------------------------------------------------
I I I I
Segment 1 1 2.101 10.501 v�,''90 12,30 1 0.35 1 G.2B 13.67 1 3.291 0.44 1 0.3(1 1 0.44 1 0.00 1
Reach 6 I I I I I i
I I i I i i I I I I 1 I I
Segment 1 1 1.501 10.ill 1 C'.B(u 1 2.33 1 0.35 1 0.23 1 3.62 1 3.251 0.44 1 0.30 1 0.44 1 0.00 1
Reach 7 1 1 1 i I I I I I I I I I
----------------------------------------------------------------------------
I FIc'1.,
CB3QD
JE;i_ID I
,).0,
1 cfs
n1gy;. I
fm:.g%7 1
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1.i.7.8.`_711]
1 (_,t),i_)CiC) 1
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Runoff
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t 1 !•:;
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r 1. l'_;
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, 1.000 1
i.,.;. i.
1
4
Segment 1
Reach ,...
Tributary
1 0.000
1 2.000
1 1.000 0 1
7.440
Runoff
1 0.580 1
2.000
1 1.000 1
..440
Segment 1 Reach 6
Waste
1 0.000 1
0.000 1
0.000 1
0.00O -
Tributary
I 0.:38V 1
2.000 1
1.000 1.
7„440
Runoff
1 0.380 1
2.000 1
1.000 1
7.440
Segment 1
Reach 7
Waste
1 0.000 1
0.000 1
0.000 1
0. 000
Tributary
1 0.770 1
2.000 1
1.000 1
7.440 _
Runoff
1 1.700 1
2.000 1
1.000 1
7.4.40
Runoff flow is in cfs/mi.le

Seg �
| Reach #
| Seg Mi
T.O. I
CSDD
1
1
5.32
26.44
1
1
().02
5.29
26.42
1
1
3. 04
5.27
26.40
1
l
(::),(>b
5.24
26.3B
1
1
(),()8
5,22
E6.33
1
l
0,10
5^19
26^33
1
1
0.1t
5.17
26.31
|
A.
0.14
5.15
26.29
1
l
0.16
5.12
26.27
1
L
0.18
5,10
26.25
1
1
O.20
5.08
26.23
1
l
0^22
5.06
26.21
1
1
0^24
5i.03
26.19
1
1
0.26
26.16
1
2
0.26
5.64
19.96
1
2
9.30
5"60
19.93
1
2
0.34
5.57
19.90
1
2
0.38
5.53
19.88
1
2
0.42
5.50
19.85
1
2
0.46
5.47
19"92
1
2
0.50
5.44
19.79
1
2
0.54
5.41
19"76
1
2
0.58
5.37
19^73
1
2
0.62
5.35
19"70
1
2
0.66
5.32
17.68
1
2
().7()
5.29
19.65
1
2
�:).74
5.26
19.62
1
2
0"79
5.23
19.59
1
`
2
O^G2
5.20
19.56
1
2
0.B6
5.18
19^53
1
2
0.90
5.15
19.51
1
2
0.94
5
19"48
1
2
0.90
19.45
1
73
O.98
6,05
1E"29
1
3
1.18
5.97
12.31
1
3
1.39
5.90
12^22
1
3
1.58
I.G]
12.14
1
3
1.78
5.7?
12.06
1
3
199
5.71
11.98
1
3
2.18
5.6s
11.90
1
4
2.18.
5.68
11.77
1
4
2"38
V.W
11.68
l
4
2.58
5.59
11.60
1
4
2"78
5,54
11.52
1
4
2"9G
5.51
11.43
1
4
3.18
5,47
11,35
1
4
11;138
5.44
11,27
1
4
3"58
5.41
11.17
1
4
3.78
5.39
11.11
1
4
3.98
5.36
11,03
1
4
4.18
5.34
10.95
1
4
4.38
5.32
10.88
1
5
4.39
5.32
10.89
1
5
4.43
5.32
10.27
1
5
4.48
5.31
10.85
1
5
4.53
5M
10.83
5.30
1()M
]
5
�-63
Q.30
10. 130
`
SUMMER
AT 7 MGD
8DD5=50,
NH3N,135DO7
SOD, UPSTR
DO=5.55,
O'COuNE
NBCD !
Flco i
25.23
25.7�
25.20
F5.17
25.75
25.75
�
25.15
25.7�
25.12
25.%,
25.10
25.76
25.07
25.76
25.04
25.76
23.02
25.76
24.99
25.76
�
24.96
25.77
24.94
25.77
24.91
25.77
24.88
25.77
`
18.75
34.67
18.72
34.67
19'68
34.08
18,65
34,68
18,61
34.69
18^57
34.69
�
18.54
34.69
-
18^50
34.69
18.47
34.70
�
18.43
34.70
�
1B.40
34.70
-` �
18.36
34.71
18.33
34,71
18.29
34.71
^
18.26
S4.72
^
18.22
34.?2
18,19
34.72
18.15
34.73
18.12
34.73
11.19
58.23
11.09
5B.40
11.00
58.40
1M90
58.56
10,81
58.63
10.72
58,7|
10.62
58.78
10.50
59.58
10.40
59.70
'
10.30
59"82
l0.�1
59.93
10.10
60.O5
W.02
60,16
9.93
60.29
9.84
b0. 40
lop
9,75
60.51
9.66
60.63
9.57
60.74
9.49
60.&-.,
9,52
60,S9
9.50
0.92
9.48
60.9-,
9.46
60^99
9.44
61.00
`
9.42
_/

�
3.2y
it .70
�
�
4 73
^
5 29
�O 74
'
^
9 3��
` � l2
' 1
5
4.83
5.29
10.72
PAR
W. 1�
15
4.98
5.20
10.70
9.31
61.1115
�
3
4.93
5.29
10.69
9.29
61.21
` 1
5
4,98
ME8
10.16
9127
V,
1
5
5.03
5.27
10.64
9.F5
al.27
1
5
5.0B
5.27
10�03
9.23
61.2�
1
5
5.13
5.27
MAl
9,H0
al22
1
5
5.18
5.27
10.59
9.19
6|.?5
l
5
5.23
5.26
10.57
V16
61BID
1
5
5.2E}
5.26
10.55
9.14
11.41.
1
5
5^33
5,26
10`53
9.12
61.04
1
5
5.39
5.26
10.51
9.10
61.47
1
5
5"43
5.25
10.49
9.09
61.50
1
5
5.48
5"25
10.48
9.06
61.53
1
5
5.53
5.25
10.46
9.04
61.56
1
5
5.58
5.25
10.44
9.02
61.58
1
5
5.63
5.25
10.42
9'00
61.61
1
5
5.68
5.25
10.40
8.98
61,64
1
5
5.73
�~5.2
10"3E|
8.96
61.67
�
5
5.78
.24
10.37
8.94
61.70
1
5
5.83
.p4
10.35
8.92
al.73
1
5
5.88
.24
10.33
8.90
61.76
1
5
5.93
.24
1.24
10"31
B"89
61.77
1
5
5.98
10.29
8.86
61.82
1
5
6.03 �~~�5.24J
10.28
8.84
61.85
1
b
6"03
5.25
10422
8^79
62.23
1
6
6.13
5.25
l0.19
8.76
62.26
1
6
6.23
5.25
10,16
8.72
62.30
1
6
6.33
5.26
10^13
8.69
6M34
1
6
6.43
5.26
10"09
8.65
62.3B
1
6
6.53
5.26
10.06
8.62
62.42
l
6
6.63
5"26
10.03
8.58
62.45
l
6
6.73
5.26
10.()0
9.55
6R,49
1
6
6,B3
5.27
9.96
B.52
M53
` 1
6
6,93
5.27
9.93
B.4B
w2.57
1
6
7'03
5.27
9.90
8.45
6E.61
l
6
7.13
5.28
9.87
B,42
62.64
1
6
7.23
5.28
9.84
8.38
6E`68
l
6
7.33
5.28
9.81
B.35
62.72
1
6
7.43
5^29
9^77
8.32
62.76
l
6
7.53
5.29
9.74
9,29
62,90
1
6
7.63
5.29
9.71
8.25
62.B3
1
6
7.73
5.30
9.68
8.22
62.97
l
6
7.83
5.30
9.65
6.19
6A.vi
1
6
7"93
5.30
9.62
B.16
62.95
1
6
2^03`
5.31
9.59
B.12
62.99
1
6
8,13
5.31
9.56
8.09
63.02
1
7
8.13
5.34
9.46
8.01
63"79
�
7
8.23
5.34
9.42
7.96
63.96
1
7
8.33
5.35
9.37
7.92
64.13
1
7
8,43
5.36
9.33
7,87
64.3f)
1
7
8.53
5.37
9.29
7.83
64.47
l
7
8.63
5.37
p.24
7.78
64.01
1
7
8.73
5'30
9.2()
7.74
64.81
1
7
8,83
5,39
9.15
7.69
64,98
1
7
9.93
5.40
7.11
7.65
65.15
1
7
9.03
5.40
9.07
7.61
65.32
1
7
9.13
5.41
9.02
7.57
65.49
1
7
9"23
5.42
B.98
7.52
65.66
1
7
9,33
5.43
8.94
7.48
65.83
1
7
9.43
5.44
9.90
7.44
66.09
1
7
9.53
5.44
8.26
7.40
66.17
�
7
9.&3
5,45
8M2
7,16
66.34

1
',
t/b yl5a Br,dc� e (c 6ov�> �namh, fJ� �r 5 R /?7,?
13:U. CrwK) 2re-4
%.q5_ (6.5) .'ILY,6 . _ _ 10 (� -.7-</7 (7 A). ly,?6_-7
.jVov'g0 .I6-5 g,I"? ("73)-. &43 10,-98 8.5 (7,/) 7,,21
7v ([� o) 185 I�-9._ ..7 CG.'7) a8a-I
5ep4 190.. P.q:rl . '13 (Co.�� - I(��a _ �v.5 .3-7 ((,..�)_ ..I C�a T
c9 7.67 (3 9) 5 -
1115
TT-,
761� 55

WHOLE EFbLUI.r 0XICI7Y'ITSTWG 0(SEI.F-MONI-FORWG SUMMARY] Sun, Jun 16, 1991
PDESN: NC 6728
Co-, IREDELI,
PP: 5.20
PDFSN NC0026573
Caunry: BURKE'
pr: 8.00
7QI0: 126.00
IORRISVILLE WWI'
PDF_511: NC0050041
County: WAKE;
Pr: 0.20
7QI0:00
I'1', AIRY WWII'
PDESn: NCT1021121
County: SURRY
I'F:4.0
]Q10: 11C
'E.IIOLI,Y W WI'P
PDFSB: N00021156
County: GASTON
PF: 4.W
PDPSN: N'C0001074
County: WAYNE
PF:0.40
NPDFSN; NM20575
Caunry; WAYNT.
PF: 1 0
7Q10:0.000
ME. PISGNI LODGER
NPOIi54: Nco(PZ129
County: I"MOOD
PF: P(132
7Q10:0.15
MURPIIY WWT?
NPDESC NC0020940
County: CT IIEROKEE
PF: 0.975
7Q10: 130.00
N.C. DEPARIWENT OT
NPDESX: NO)OU858
Ccunry: VAN'CE
PF: 0.015
_..
PERWFCHRONICLIMfr:94%
'8]- -
- - - (PASS)
-- -
(FAIL) - - (PAIL)
Bc&:4/ip39 Poo ooy: Q PIP A
'88 - --
(FAIL)
PAIL --
- PASS - -
Regim:MRO
M.Uu; FE B MAY AUG NOV
-89 FAIL -
PASS PASS NR
PASS NK
- - PASS -
SOC/IOC Req:
'90- PASS
- -- PASS ---
- PAIL
PASS -- PASS -
'C(%):94AS
'91 - PAIL
PASS --
PF:RMrF Cl IRONIC Limmq.(1%
'8l -'- '-'
'_ '- "' "'
'- -
- - - ( NR)
I,g ILIyB] fFT9acn0"Q PIP
'88 rA1L -
(-) --- PASS (-7
PASS --
- PASS
Rcgim: ARO
Momu: JAN APR In OCT
-89 PASS --
- PASS - -
PASS -
- PASS - -
SOC/JOC Rcq:
'90 PASS --
PASS. -
PASS --
- PASS - -
'C(%):8.96
'91 PASS
- -
bt
-REF.
LETTER CHRONIC TARGFf:99%
'8]
0cgin 8117190 Frt ucnry: Q PIP A
.88 -
- -
PASS
NR
NR
NR
NR
NR NH NR
Rcgim: RRO
MmJu: TAN APR JUL OCT
'89 NH
NR NH
NH
NR
NR
NR
NR
NR NH NR
SOC/JOC Keq:
'90 NR
PASS NK
NR
PASS
-
NH
PASS
- NR NR
'C(%):IW
'91 bt
_ PASS
NR
WRMN CUR I.IMI1':32%,42% Cm XMGD B: COMPLIANT
Y'87 NH
77,11 N'ON1;,I:
I110
89.99
(PASS)
-
-
JPANS) - -
BegimS/I8199 Foyucnry: Q P/F A
88 -
- (FAIL)
PASS
-
f-0
PASS
--
-- FAIT, -
Rcgim:WSRO
Mmlhs: JUL OCT IAN APR
'89 FAII,
- --
FAIT.
I -All.
["All,
PASS
PASS
- PASS bt
SOC/JOC H q:
'90 PASS
--
P,P
-
-
PASS
-
- PASS -
IC(%):32.2
SOC-2/13/91-3/1/93, ACUTE LLMIT 34%; Cl IR MON Q AT
'91 PASS
- PASSf
FA11Pf
PA55f .
PVi ff Cl IRONIC L1Mrr;6.1%
-87
Ikein:4/1/88 Fmqueory: Q P/r
'88 -
-
_
( SIR
-
NONE
(-)
NONE
PASS -
PASS
-
Regim:MRO
Mmtlu: MAY AUG NOV FEB
'89-
PASS
-
-
PASS
-
-
PASS
- -
PASS
-
SOC/IOC Req:
'90-
PASS
-
-
PASS
-
-
PASS
- -
PASS
-
IC(%):6.10
91 —
PASS
—
--
PASS
PE1LMfT CITRON IC LLA rf:99%
Y'8719
10
27
NR
23
ur
18
14
15 13
6.0
NR
IkginWAS rmqucnry: Q P/F
'88 (16)
32
-
(18.5)
-
-
(-)
-
NR -
NR
-
Rcgim:WARD
Mmths: FEB MAY AUG NOV
'89-
NR
-
21.9
NR
-
37.6
NR
- -
49
_.
SOC/)OC Rcq:
'9058.7
-
-
47.2
-
-
64.3
-
- Z.O.
NR
-
/C(%):100.00
7/90-7/1193 QUARTER1. Y 4811R ACUTE MON fFOR NO.
9141.9'
NR
-
M.H.
PERM IT CI IRON IC 61 M F:99%
'87
Begin: 2/1/88 I:mqu=nry: Q PIP
'88 -
(PASS)
--
-
(IIASS)
-
-
-
NR -
-
PASS
Rcgim: WARD
Nlmths: MAR JUN SEP DEC
'89 -
-
PASS
---
--
PASS
-
-
PASS -
-
PASS
SOC/JOC Flcq:
'90-
--
bt
FAIL
LATE
FAIT,
-
PASS
PASS -
-
lA'GE
JC(%): 100.00
91 PASS
-
PASS
-
,TION AREA
LETIFR CHRONIC TARGFT:25%
'87
Ikgin: 6/IAI rnq my: SA A
as
Regim: ARO
N1mJu: JUN AUG
'89
SOC/JOC Rcq:
190
191
PERC1rr Cl IRONIC UMfT:I.I%
.87
Begin: 711/88 Iicquemy: Q PIP
'88 - -
Rcgim:ARO
Maidn: MAR JUN SEP DEC
'89- --
SOQIOC R q:
'90 - -
'C(%): 1.15
91 PASS
CT JOIN
ItiRMFf CHRONIC LN1rC99%(GRAB)
'87
lkein: 8/1190 ro uo cyc Q PIP A
'88
Rcgim: RRO
MmJu: FEB MAY AUG NOV
'89
SOCJIOC Rcq:
'90
rrr%t tm
' 91 FAIL NR
- --- - - PASS - - PASS
PASS - - PASS - - PASS - - PASS
PASS - - PASS -- PASS - - IAIE
IAIE PASS
FAL NR
FAR - - FAR -
0 2cmxcmivc Bduv=sigrJBununmrvmpliancc Y Pm1987dausvapabk
LEGEND:
PF=hlmmd Dow(MGD),7Q10=Rcmiving soeam low paw aiterim(crs), 1WC%=bmruam wastee =ooatim, Begin=Rust mmth mquved, Finapterwyz4N1mimnng Leq=my): IQ-Qma rly;M Moo)A,BM-BimmJJy,SA-Semiammsllr A-Armually;
OW D�OFdy when dischugiRE; DD'urmtinued tnorutvm8 requimrrcnr IS-Cmduetine independent study], P/FWasyPsl dumk bioassay, AcsAm¢, Chr-Ovoruc, A�varurly mmibring'vueass to nnntNy upm single f.iluee,
)Dau Noutim): If=FaPe.d Mimow, •d<riodvpM'v sp., mYc4lysid shrimp, ChV=Uronie value, P-MaW Try of surcd percevge at highest comm�wtim, at=PerfarrteJ by DEM Aq Tox Gmp, h=6ad vt),
URpming Noutlm):l-=Datato icq+ d,NR=NILmpmd,O=Oegimmng ofQuarter), (Facdiry Aaivhy Sums): p=4ucJw, N=Newly Iazoed(Towmwct), I I=Aciivc tut md'utlurgingl
32

06/30/91
ver 3.1
T O% I C
S R E V
I E W
Facility:
City of Mt
Airy
NPDES Permit No.:
NCO021121
_
Status (E, P, or M):
E
Permitted Flow:
7.0
mgd
Actual
Average Flow:
3.8
mgd
Subbasin:
'030703
Receiving Stream:
Ararat River
---------PRETREATMENT
DATA --------------
I----
EFLLUENT DATA ----
Stream Classification:
C
I
ACTUAL
PERMITTEDI
I
7Q10:
14.9
cfs
Ind. +
Ind. + I
FREQUENCY
I
IWC:
42.14
i
Domestic
PERMITTED
Domestic I
OBSERVED
of Chronicl
Stn'd / Big
I Removal
Domestic
Act.Ind.
Total
Industrial
Total I
Effluent
Criteria
I
Pollutant
AL Conn.
Eff.
Load
Load
Load
Load
Load I
Conc.
Vlolatlonsi
(ug/1) (ug/1)
Y
--------
(#/d)
--------
(k/d)
--------
(t/d)
--------
(k/d)
---------
(f/d)
--------
(ug/1)
--------
(lvlo/tsam)l
---------
I
---------
Cadmium
--
S
----------------
2.0 0.0
92%
0.0
0.2
0.25
0.2
0.248
2.0
I
Chromium
S
50.0
I 76%
0.1
1.8
1.89
3.2
3.308
82.0
I 1
Copper
AL
7.0
I 18%
0.3
4.1
4.38
9.4
9.714
110.0
I N
Nickel
S
88.0
1 32%
0.5
2.9
3.39
1.3
1.799
0.0
1 P
Lead
S
25.0
81%
0.3
5.4
5.68
1.4
1.675 1
0.0
I U
Zinc
AL
50.0
20%
2.3
7.2
9.44
16.2
18.480 1
0.0
T
Cyanide
S
5.0
I 59%
0.1
0.9
0.98
0.3
0.499 I
0.0
I
Mercury
S-
0.012
86%
0.0
3.5
3.48
0.0
0.010
0.0
S
Silver
AL
0.06
94%
0.0
0.2
0.22
0.1
0.184
E
Selenium
S
5.00
08
0.0
0.0
0.00
0.0
0.000
C
Arsenic
S
50.00
Oi
0.0
0.0
0.00
0.0
0.000
T
Phenols
S
NA
77%
('
..
24.960
1
NH3-N
C
0%
I
1 0
T.R.Chlor.AL
17.0
Oi
I
I
I
N
I
I---------------
I
I
ALLOWABLE
PRDCT'D
PRDCT'D
PRDCT'D
I
I
--------- MONITOR/LIMIT---------
I
I
1--ADTN'L RECMMDTN'S--
1
Effluent
Effluent
Effluent
Instream
I Recomm'd
1
Cost.
using
using
Conc.
Based on
Based on
Based on
I FREQUENCY
TNSTREAM
1 Allowable
CHRONIC
ACTUAL
PERMIT
using
ACTUAL
PERMITTED
OBSERVED
I Elf. Mon.
Monitor. 1
Pollutant
Load
Criteria
Influent
Influent
OBSERVED
Influent
Influent
Effluent
I based on
Recomm'd ?
I (!/d)
(ug/1)
tug/1)
(ug/1)
(ug/1)
--------
Loading
--------
Loading
--------
Data
---------I
OBSERVED
---------
(YES/NO)
-------- 1
---------
Cadmium
--
S
I---------
I 2.79
--------
4.747
---------
0.645
--------
0.632
0.84
Limit
Limit
Limit
NCAC
NO A
Chromium
S
I 23.27
118.664
14.458
25.292
34.55
Limit
Limit
Limit
I NCAC
YES 1 N
Copper
AL
0.95
16.613
114.498
253.758
46.35
Monitor
Monitor
Monitor
I Weekly
YES A
Nickel
S
14.46
208.848
73.525
38.974
0.00
Limit
Limit
I NCAC
NO I L
Lead
S
14.70
59.332
34.350
10.137
0.00
Limit
- Limit
I NCAC
NO I Y
Zinc
AL
6.98
118.664
240.461
470.982
0.00
Monitor
Monitor
Monthly
NO S
Cyanide
S
I 1.36
11.866
12.813
5.861
0.00
Limit
Limit
NCAC
NO I
Mercury
S
I 0.01
0.028
15.524
0.043
0.00
Limit
Limit
NCAC
NO I S
Silver
AL
0.11
0.142
0.415
0.352
0.00
Monitor
Monitor
I
Selenium
S
0.56
11.866
0.000
0.000
0.00
I
I R
Arsenic
S
5.59
118.664
0.000
0.000
0.00
E
Phenols
S
I
0.000
28.569
182.888
0.00
S
NH3-N
C
0.000
0.00
I
I U
T.R.Chlor.AL
40.346
0.00
I
I L
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