NC0028916_NPDES Draft Permit_20000619

Comments: TowniitTroy_ P NPDES Renewal and Expansion to 1.2 MGD
-This office concurs that the expansion to 1.2 should be granted based on the revised USGS
stream data.
-It is requested that the third paragraph of the CHRONIC TOXICITYPASS/FAIL PERMIT
LIMIT (QRTRLY) page be in BOLD type to avoid compliance problems with the new
toxicity compliance protocols
-Concur with proposed limits for 0.84mgd and 1.2mgd.
- It is understood that limitations for 1.2mgd will begin the following month after the
Division has received the engineer's certification for the upgraded disinfection
system.
- Noted is the monitoring requirement for "Chlorides". It is suggested (if not already
included in P&E's SOP) that all POTW's that have a significant industrial
contribution of chlorides have such monitoring. -It is also suggested that ESB
provide the Permitting Unit the effluent concentration that chlorides
toxicity could be projected andthis information shared with[the DWQ Pretreatment
Unit to establish Industrial User Permit limitations to prevent NPDES limits
violations.
-Be 'advised that the influent equalization basin noted in the "Supplement'To Permit Cover
Sheet" as well as.the current chlorination basin were flooded during recent
hurricanes. It is the understanding of this office that the proposed modification of
disinfection equipment will be constructed well above the 100 yr flood level. Since the
noted hurricanes were above the 24hr25yr storm event this is not believed to be an issue
with the influent EQ basin. .

Division of Water Quality
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North Carolina Department of Environment and Natural Resources
PO Box 29535, Raleigh, North Carolina 27626-0535 / Phone: [phone]

DENR/DWQ
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
RENEWAL FOR 0.84 MGD AND EXPANSION TO 1.2 MGD
NPDES No. NC0028916, Troy WWTP
Facility Information
Applicant/Facility Name:
'Troy WWTP
Applicant Address:
444 North Main Street, Troy, NC 27371
Facility Address:
650 Glen Road, Troy, NC
Permitted Flow
0.84 MGD, Expansion to 1.2 MGD
Type of Waste:
- 75% Domestic/ - 25% Industrial (est. from application)
Facility/Permit Status:
Renewal & Expansion
County:
Montgomery
Miscellaneous
Receiving Stream:
Denson's Creek
Regional Office:
FRO
Stream Classification:
C
SI: 13-25-20(9)
USGS Topo Quad:
F19NW
Star
303(d) Listed?:
NO
Permit Writer:
S. Wilson
Subbasin:
03-07-15
Date:
June 19, 2000
Drainage Area (mi2):
32
Summer 7Q 10 (cfs)
0.35
, am Y�IP ,.
Winter 7Q10 (cfs) :
2.42
Average Flow (cfs):
32
IWC (%): -
79% (at 0.84
MGD)
84% (at 1.2 MGD)
Primary SIC Code:
NA
SUMMARY
The Town of Troy plant is currently permitted for 0.84 MGD flow. Limits for 1.2 MGD were
presented to the Town via speculative letter July 23, 1999. The situation with the Town of Troy
is unusual in that' essentially all components necessary_to rrieet. the_design flow of 1-:2-MGD- are
,already in:place. The upgraded -disinfection--::unit (UV disinfection was _proposed with the
chlorine disinfection to be retained as backup?) is the _ only treatment -unit that- needs_ to_be
upgraded- to accommodate the _1.2_ MGD- flow. After further consideration and review of the
updated SEPA rules [15A 01C .0504 (3)], the Division agreed that a SEPA report was not
necessary for this increase in flow (under the 0.5 MGD expansion criteria - the 1/3 IWC does
not apply to existing/expanding facilities). This WLA represents both the renewal at the
existing flow and the expansion to 1.2 MGD.
Upon-theTown's request,_ USGS provided_ updated-strearriflow information for Denson's- Creek.
The new _low flow (7Q10s) stfeamflow=iinformation. was estimated as 0.35_ cfs _(the previous being
T).l-cfs). The expansion phase to 1.2 MGD reflects limits based on 0.35 cfs. Additionally; -the
updated toxicant information for the existing permitted flow of 0.84 MGD is based on the new
7Q 1 Os flow.
The are no active ambient monitoring stations on Denson's Creek and there is no special
management strategy for this creek.
TOXICANT PARAMETERS
A reasonable potential analysis (RPA) was conducted for all toxicants currently monitored [Cd,
Cr, CN, Pb, Ni, Cu, Hg, Ag, Zn, Se, Mo, chlorides]. Troy has an active pretreatment program
and is required to monitor specific metals on a quarterly basis. The table below represents the
outcome of the RPA for Troy.
Troy WWTP
NPDES Permit Renewal/Modification
Page 1

Reasonable
Potential?
Limit?
Renewal
at 0.84
MGD
Limit?
Expansion to
1.2 MGD
Acute
Chronic
Acute
Chronic
Standard
Arsenic
MON.
(2/month)
MON.
(2/month)
Cadmium
MON.
(monthly)
Monitor
(monthly)
Chromium
No requirement
No reqmnt
Cyanide
Limit
22
6.3
Limit
22
5.9
Lead
No requirement
No reqmnt
Nickel
No requiremnt
No reqmnt
Copper
MON.
MON.
Mercury
No requirement
No reqmnt
Selenium
Noreqmnt
���No�reeqqu/ireeme�ntt
ort-ii,�/ ��f /l /
/ I/ �V ` i'1// ,'��/l/
�� r
�/` -
�/ �
g - '(/
j1
Zinc
MON.
MON.
Chlorides
MON (monthly)
MON
(monthly)
Monthly monitoring for cadmium will be required with this renewal/expansion. The facility has
had only 2 cadmium values of 106 samples reported above detection level within the past 2
years. Additionally, the 2 reportable values were recorded at the detection level (and under the
allowable level). Lead, chromium, mercury, and silver limits/monitoring will be eliminated with
this renewal. The reasonable potential analyses for these parameters were performed and not
predicted to exceed allowable levels (although dropped from the permit, these parameters will
have to be monitored quarterly through the LTMP). Cyanide will continue to be limited with
this permit. Arsenic was recently reported at a level above the detect; because all other values
have been reported below the MDL and the single value detected was below the allowable level,
monitoring (2/month) is recommended with this permit cycle. Copper and zinc monitoring will
be required 2/month (reported values were significantly higher than the action level standard
allowable). Chloride values have also been recorded well above the allowable level and
monitoring for chlorides will be required monthly (the facility is currently monitoring monthly
for this parameter).
TOXICITY TESTING:
Recommended Requirement: Chronic P/F @ 79% (at 0.84 MGD); 84% at 1.2 MGD.
The last toxicity failure was reported May 1998. However, the Town began testing at 79% prior
to modification of the permit (with the change in 7Q l Os flow) and the Town received a "bad
test" for January 2000.
COMPLIANCE SUMMARY:
The facility appears to be compliant with permitted limits at this time. The facility has had
sporadic toxicity problems in the past, but this appears to be corrected.
INSTREAM MONITORING:
The Town performs its own instream monitoring (appx. 1/8 mile upstream and IA mile
downstream) on Denson's Creek. Instream monitoring indicates slightly less dissolved oxygen
at the downstream sampling site, with no values recorded below the WQ standard of 5 mg/1.
PROPOSED CHANGES
Based on WQ modeling, the limits for oxygen consuming parameters will be more stringent
upon expansion of flow to 1.2 MGD.
(qr I3070 Ft-ovJS FA-I,t.S W i o C�Fl sS
Jll ri+cl4Ty)
Troy WWTP
NPDES Permit Renewal/Modification
Page 2

PROPOSED SCHEDULE FOR PERMIT ISSUANCE:
Draft Permit to Public Notice: July 12, 2000 (est.)
Permit Scheduled to Issue: August 28, 2000 (est.)
STATE CONTACT:
If you have any questions on any of the above information or on the attached permit, please
contact. Susan Wilson at [phone] ext. 510.
/1-/..
Sid AN A. WII.SON
REGIONAL OFFICE COMMENT:
e, e i CO-7-71A
NAME: '✓ \ -- 'DATE: ✓�O Cit�i
Troy WWTP
N.PDES Permit Renev:a)/Modification

Permit No. NC0028916
STA1'r, OF NORTH CAROLINA
DEPARTMENT OF' ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provisions of North Carolina General Statute 143-215.1, other lawful standards
and regulations promulgated and adopted by the North Carolina Water Quality Commission, and the
Federal Water Pollution Control Act, as amended,
Town of Troy
is hereby authorized to discharge wastewater from a facility located at
Troy Wastewater Treatment Plant
Off NCSR 1324
Troy
Montgomery County
to receiving waters designated as Denson's Creek in the Yadkin - Pee Dee River Basin
in accordance with the discharge limitations, monitoring requirements, and other conditions set forth in
Parts I, II, III, and IV hereof.
This permit shall become effective
This permit and the authorization to discharge shall expire at midnight on
Signed this day
DRAFT
2L,04-
Kerr T. Stevens, Director
Division of Water Quality
By the Authority of the Environmental Management Commission

SUPPLEMENT TO PERMIT COVER SHEET
Town of Troy
Troy WWTP
is hereby authorized to:
1. Continue to operate a 0.84 MGD wastewater treatment facility consisting of flow
equalization (from previously permitted lagoon system), mechanical bar screen, grit
removal, oxidation ditch, secondary clarification, sludge digestion and holding,
disinfection via UV disinfection or chlorination/dechlorination (back-up) located at
the Troy Wastewater Treatment Plant, 650 Glen Road, Troy, Montgomery County, and
2. Discharge wastewater from said treatment works at the location specified on the
attached map into Denson's Creek which is classified C waters in the Yadkin - Pee Dee
River Basin.
3. After submittal of the Engineering Certification for the: disinfection system, operate a
1.2 MGD design flow wastewater treatment facility, with limits as specified in Part
I.A.(2). and continue to discharge effluent at the located sited in (2).
Town of Troy
NPDES No. NC0028916

A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - FINAL
During the period beginningon the effective date of the permit and lasting until expansion above
0.84 MGD, the Permittee is authorized to discharge from outfall 001. Such discharges shall be
limited and monitored by the Permittee as specified below:
Effluent Characterlsti
Limits
;:'.
Monitoring :Requirements -
Monthly
Average
Weekly
Average ;=
Daily
Maximum "
Measurement;
" Frequency
Sample Type
Sample
Locations:
Row
0.84 MGD "
Continuous
Recording
Influent or
Effluent
BOD, 5 day (20°C)2
[April 1 - October 31]
13 mg/I
19.5 mg/I
3/Week
Composite
Influent &
Effluent
BOD, 5 day (20°C)2
[November 1 - March 31]
26 mg/1
39 mg/1
3/Week
-
Composite
Influent &
Effluent
Total Suspended Residue2
30 mg/I
45 mg/1
3/Week
Composite .
Influent &
Effluent
NH3 as N [April 1- October 31]
2.0 mg/I
3/Week
Composite
Effluent
NH3 as N [November 1- March 31]
4.0 mg/I
3/Week
Composite
Effluent
Dissolved Oxygen3
3/Week
Grab '
', Effluent
Dissolved Oxygen
3/Week
Grab
Upstream &
Downstream
Fecal Coliform (geometric mean)
200/100 ml
400/100 ml
3/Week
Grab
Effluent
Fecal Coliform (geometric mean)
3/Week
Grab
Upstream &
Downstream
Total Residual Chlorine4
3/Week
Grab
Effluent
Total Nitrogen (NO2+NO3+TKN)
Quarterly
Composite,
Effluent
Total Phosphorus
Quarterly
Composite
Effluent
Temperature (°C)
Daily
- Grab
Effluent
Temperature (°C)
3/Week
Grab
Upstream &
Downstream
Conductivity
3/Week
Grab
Effluent
Conductivity
3iWeek
Grab
Upstream &
Downstream
Chronic Toxicity5
Quarterly
Composite
Effluent
Arsenic
2/Month
Composite
Effluent
Cadmium
Monthly
Composite
Effluent
Chlorides
Monthly
Composite
Effluent
Copper
2/Month
Composite
Effluent
Cyanide6
-
6.3 pg/I
22 pgll
Weekly
Grab
Effluent
Zinc
2/Month
Composite
Effluent
pH7
6-9
3/Week
Grab
Effluent
(Footnotes on next page)
Town of Troy
NPDES No. NC0028916

A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - FINAL
(Continued)
Footnotes:
1. Sample locations: U - Upstream at least 100 feet, D - Downstream approximately 0.4 miles
before the confluence with Spencer Branch. Stream samples shall be grab samples and shall
be collected 3/Week during June.- September and 1/Week during the remaining months of
the year.
2. The monthly average effluent BODS and Total Suspended Residue concentrations shall not
exceed 15% of the respective influent value (85% removal).
3. The daily average dissolved oxygen effluent concentration shall not be less than 5.0 mg/1.
4. Monitoring for total residual chlorine is required only if chlorine is used as a back-up
disinfection method or elsewhere in the process.
5. Chronic Toxicity (Ceriodaphnia dubia) P/F at 79%: January, April, July, and October [see Part
I, A(3.)]. Toxicity monitoring shall coincide with metals and cyanide monitoring.
6. The quantitation limit for cyanide shall be 10 ug/1 (10 ppb). Levels reported at less than 10
ug/1 shall be considered zero for compliance purposes.
7. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall
be monitored daily at the effluent by grab sample.
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Town of Troy
NPDES No. NC0028916

A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - FINAL
During the period beginning upon expansion above 0.84 MGD (not to exceed 1.2 MGD) and lasting until
expiration, the Permittee is authorized to discharge from outfall 001. Such discharges shall be limited and
monitored by the Permittee as specified below:
limited and monitored by the Permittee as specified below:
Effluer%t,Char'actertsti
$
Limits
Morntorinq°Requim reents
_
Monthly
Average -'
Weekly
Average ,
Daily
Maximum
Measurement;;
' Fre uenc
q Y
Sample Type
�
;Sample
, ...Location .
Row
1.2 MGD
Continuous
Recording
Influent or
Effluent
BOD, 5 day (20°C)2
[April 1 - October 31 ]
7 mg/I
10.5 mg/I
3/Week
Composite
Influent &
Effluent
BOD, 5 day (20°C)2
[November 1 - March 31]
14 mg/I
21 mg/I
- 3/Week
Composite
Influent &
Effluent
Total Suspended Residue2
30 mg/I
45 mg/I
3/Week -
Composite
Influent &
Effluent
NH3 as N [April 1 - October 31]
2.0 mg/1
3/Week
Composite
Effluent
NH3 as N [November 1- March 31]
4.0 mg/I
3/Week
Composite
Effluent
Dissolved Oxygen3
3/Week .
Grab
Effluent
Dissolved Oxygen
3/Week
Grab
Upstream &
Downstream
Fecal Coliform (geometric mean)
200/100 ml
400/100 ml
3/Week -'
Grab
Effluent
Fecal Coliform (geometric mean)
3/Week
Grab
Upstream &
Downstream
Total Residual Chlorine4
3/Week ,
Grab
Effluent
Total Nitrogen (NO2+NO3+TKN)
Monthly
Composite
Effluent
Total Phosphorus
-
Monthly
Composite-
Effluent
Temperature (°C)
Daily
Grab
Effluent
Temperature (°C)
3/Week
Grab .
Upstream &
Downstream
Conductivity
3/Week
Grab
Effluent
Conductivity
-
3/Week
Grab
Upstream &
Downstream
Chronic Toxicity5
Quarterly
Composite
Effluent
Arsenic
2/Month
Composite
Effluent
Cadmium
Monthly
Composite
Effluent
Chlorides
Monthly
Composite
Effluent
Copper
2/Month
Composite
Effluent
Cyanide6
6.3 pg/I
22 pg/I
Weekly
Grab
Effluen>
Zinc
2/Month
Composite
Effluent
pH7
6-9
3/Week
Grab
Effluent
(Footnotes on next page)
Town of Troy
NPDES No. NC0028916

A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - FINAL
(Continued)
Footnotes:
1. Sample locations: U - Upstream at least 100 feet, D - Downstream approximately 0.4 miles
before the confluence with Spencer Branch. Stream samples shall be grab samples and shall
be collected 3/Week during June - September and 1/Week during the remaining months of
the year.
2. The monthly average effluent BOD5 and Total Suspended Residue concentrations shall not
exceed 15% of the respective influent value (85% removal).
3. The daily average dissolved oxygen effluent concentration shall not be less than 5.0 mg/1.
4. Monitoring for total residual chlorine is required only if chlorine is used as a back-up
disinfection method or elsewhere in the process.
5. Chronic Toxicity (Ceriodaphnia dubia) P/F at 84%: January, April, July, and October [see Part
I, A(4.)]. Toxicity monitoring shall coincide with metals and cyanide monitoring.
6. The quantitation limit for cyanide shall be 10 ug/1 (10 ppb). Levels reported at less than 10
ug/1 shall be considered zero for compliance purposes.
7. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall
be monitored daily at the effluent by grab sample.
There shall be no discharge of floating solids or visible foam in other than trace
amounts.
Town of Troy
NPDES No. NC0028916

A (3). CHRONIC TOXICITY PASS/FAIL PERMIT LIMIT (QRTRLY)
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant
mortality to Ceriodaphnia dubia at an effluent concentration of 79 %.
The permit holder shall perform at a minimum, quarterly monitoring using test procedures
outlined in the "North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised
February 1998, or subsequent versions or "North Carolina Phase II Chronic Whole Effluent
Toxicity Test Procedure" (Revised -February 1998) or subsequent versions. The tests will be
performed during the months of January, April, July, and October. Effluent sampling for this
testing shall be performed at the NPDES permitted final effluent discharge below all treatment
processes.
If the test procedure performed as the first test of any single quarter results in a failure or ChV
below the permit limit, then multiple -concentration testing shall be performed at a minimum, in
each of the two following months as described in "North Carolina Phase II Chronic Whole Effluent
Toxicity Test Procedure" (Revised -February 1998) or subsequent versions.
The chronic value for multiple concentration tests will be determined using the geometric mean of
the highest concentration having no detectable impairment of reproduction or survival and the
lowest concentration that does have a detectable impairment of reproduction or survival. The
definition of "detectable impairment," collection methods, exposure regimes, and further statistical
methods are specified in the "North Carolina Phase II Chronic Whole Effluent Toxicity Test
Procedure" (Revised -February 1998) or subsequent versions.
All toxicity testing results required as part of this permit condition will be entered on the Effluent
Discharge Monitoring Form (MR-1) for ,the months in which tests were performed, using the
parameter code TGP3B for the pass/fail results and THP3B for the Chronic Value. Additionally,
DWQ Form AT-3 (original) is to be sent to the following address:
Attention: North Carolina Division of Water Quality
Environmental Sciences Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental Sciences Branch no
later than 30 days after the end of the reporting period for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical measurements
and all concentration/response data, and be certified by laboratory supervisor and ORC or
approved designate signature. Total residual chlorine of the effluent toxicity sample must be
measured and reported if chlorine is employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which -toxicity monitoring
is required,' the permittee will complete the information located at the top of the aquatic toxicity
(AT) test form indicating the facility name, permit number, pipe number, county, and the
month/year of the report with the notation of "No Flow" in the comment area of the form. The
report shall be submitted to the Environmental Sciences Branch at theaddresscited above.
Should the permittee fail to monitor during a month in which toxicity 'monitoring is required,
monitoring will be required during the following month.
Should any test data from this monitoring requirement or tests performed by the North Carolina
Division of Water Quality indicate potential impacts to the receiving stream, this permit may be re-
opened and modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum
control organism survival, minimum control organism reproduction, and appropriate
environmental controls, shall constitute an invalid test and will require immediate` follow-up
testing to be completed no later than the last day of the month following the month of the initial
monitoring.
Town of Troy
NPDES No. NC0028916

A (4). CHRONIC TOXICITY PASS/FAIL PERMIT LIMIT (QRTRLY)
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant
mortality to Ceriodaphnia dubia at an effluent concentration of 84 %.
The permit holder shall perform at a minimum, quarterly monitoring using test procedures
outlined in the "North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised
February 1998, or subsequent versions or "North Carolina Phase II Chronic Whole Effluent
Toxicity Test Procedure" (Revised -February 1998) or subsequent versions. The tests will be
performed during the months of January, April, July, and October. Effluent sampling for this
testing shall be performed at the NPDES permitted final effluent discharge below all treatment
processes.
If the test procedure performed as the first test of any single quarter results in a failure or ChV
below the permit limit, then multiple -concentration testing shall be performed at a minimum, in
each of the two following months as described in "North Carolina Phase II Chronic Whole Effluent
Toxicity Test Procedure" (Revised -February 1998) or subsequent versions.
The chronic value for multiple concentration tests will be determined using the geometric mean of
the highest concentration having no detectable impairment of reproduction or survival and the
lowest concentration that does have a detectable impairment of reproduction or survival. The
definition of "detectable impairment," collection methods, exposure regimes, and further statistical
methods are specified in the "North Carolina Phase II Chronic Whole Effluent Toxicity Test
Procedure" (Revised -February 1998) or subsequent versions.
All toxicity testing results required as part of this'permit condition will be entered on the Effluent
Discharge Monitoring Form (MR-1) for the months in which tests were performed, using the
parameter code TGP3B for the pass/fail results and THP3B for the Chronic Value. Additionally,
DWQ Form AT-3 (original) is to be sent to the following address:
Attention: North Carolina Division of Water Quality
Environmental Sciences Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental Sciences Branch no
later than 30 days after the end of the reporting period for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical measurements
and all concentration/response data, and be certified by laboratory supervisor and ORC or
approved designate signature. Total residual chlorine of the effluent toxicity sample must be
measured and reported if chlorine is employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring
is required, the permittee will complete the information located at the top of the aquatic toxicity ,
(AT) test form indicating the facility name, permit number, pipe number, county, and the
month/year of the report with the notation of "No Flow" in the comment area of the form. The
report shall be submitted to the Environmental Sciences Branch at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required,
monitoring will be required during the following month.
Should any test data from this monitoring requirement or tests performed by the North Carolina
Division of Water Quality indicate potential impacts to the receiving stream, this permit may be re-
opened and modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum
control organism survival, minimum control organism . reproduction, and appropriate
environmental controls, shall constitute an invalid test and will require immediate follow-up
testing to be completed no later than the last day of the month following the month of the initial
monitoring.
Town of Troy
NPDES No. NC0028916

Permit No. NC0028916
STATE OF NORTH CAROLINA
ATMENT OF ENVIRONMENT, HEALTH, AND NATURAL RESOURCES
DIVISION OF ENVIRONMENTAL MANAGEMENT
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provision of North Carolina General Statute 143-215.1,
other lawftil standards and regulations promulgated and adopted by the North Carolina Environmental
Management Commission, and the Federal Water Pollution Control Act, as amended, -
The Town of Troy
is hereby authorized to discharge wastewater from a -facility located at
Troy Wastewater Treatment Plant
NCSR 1324
east of Troy
Montgomery County
to receiving waters designated as Densons Creek in the Yadkin -Pee Dee River Basin
in accordance with effluent limitations, monitoring requirements, and other conditions set forth in
Parts I, 11, and HI hereof.
This permit shall become effective May 1, 1994
This permit and the authorization to discharge shall expire at midnight on October 31, 1998
:71
; 7
-- Signed this day March 28, 1994 C3
--__
'. T - ......
1r . f-77
AC47:1_ A
„...
, .,..
,-_-_-
A. Preston Howard, Jr., P.E., Director
Division of Environmental Management
By Authority of the Environmental Management Commission

Permit No. NC0028916
SUPPLEMENT TO PERMIT COVER SHEET
The Town of Troy
s hereby authorized to:
1. Continue to operate an existing 0.84 MGD wastewaterareatmentifiers, acing onlrest ng of
effluent
bar
screen, comminutor, aeration basin, dual secondary Wastewater
flow meter, aerated sludge holding tank and sludge
orneg beds located at ry County (See Part IyII of this Permit),
Treatment Plant, NCSR 1324, east of Troy, g
and
Discharge from said treatment works at thnloceatispecified e Dee the River ased hed map into Densons
2 Creek which is classified Class C waters i

A. ( ). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS SUMMER (April 1 - October 31) Permit No. NC0028916
During the period beginning on June 1, 1995 of the permit and lasting until expiration, the Permittee is authorized to discharge from outfall(s)
serial number 001. Such discharges shall be limited and monitored by the permittee as specified below:
Effluent Characteristics . Discharge Limitations
Monthly Avg,
Flow 0.840 MG
BOD, 5 day, 20°C** _ 13.0 mg/I
Total Suspended Residue** 30.0 mg/I
NH3asN 2.0 mg/I
Dissolved Oxygen***
Fecal Coliform (geometric mean)
Total Residual Chlorine
Temperature
Total Nitrogen (NO2 + NO3 + TKN)
Total Phosphorus
Conductivity
* Sample locations: E - Effluent, I - Influent, U - Upstream 100 feet, D - Downstream
Stream samples shall be collected three times per week during June, July, August, and
months of the year. - - .
** The monthly average effluent BODS and Total Suspended Residue concentrations s
% removal). -
*** The daily average dissolved oxygen effluent concentration shall not be less than 5.
**** Chronic Toxicity (Ceriodaphnia) P/Fat O°lo, January, April, July, and October,
The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and
sample.
Weekly Avg, Daily Max
19.5 mg/I
45.0 mg/I
200.0 /100 ml - 400.0 /100 ml
Monitoring
Measurement
Frequency
Continuous
3/Week
3/Week.
3/Week
3/Week "
3/Week
3/Week
Daily
Quarterly
Quarterly
3/Week
Requirements
Sample
Tvoe
Recording
Composite
Composite
Composite
Grab
Grab
Grab
Grab
Composite
Composite
Grab
*Sample
Location
I or E
E, I
E, I
E
E, U, D
E,U,D
E
E
E
E
U, D
0.4 mi. before confluence with Spencer Branch
September and once per week during the remaining
hall not exceed 15 % of the respective influent value (85
o mg/l.
,ticE4 .R.6)(k)
See Part III, Condition G.
shall be monitored 3/week at the effluent by grab
There shall be no discharge of floating solids or visible foam in other than trace amounts.

A. ( ). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS SUMMER (April 1 - October 31) Permit No. NC0028916
During the period beginning on June 1, 1995 of the permit and lasting until expiration, the Permittee is authorized to discharge from outfall(s)
serial number 001. (Continued)
Effluent Characteristics
Cadmium
Chromium
Lead _-
Cyanide
Copper ..
Nickel
Zinc
Chronic Toxicity"" Uf'
Silver _
Temperature
2: =,.) k G
Discharge Limitations
Units (specifyl
Monthly Avg, Weekly Avg, Daily Max
(Ue,1.Y0j N-0/0 (t o ,2_ <;t v' i , � 2 : p g / I— __._ 5 ; 4 u g /
_ 54 O.ug/.1......
I----
�5�4 µg/I
Monitoring
Measurement
Frequency
________Weekly
Weekly
Weekly
Weekly
2/Month
2/Month
2/Month
Quarterly
2/Month
,3./Week
Requirements
Sample
Type
Composite
Composite
Composite
Grab
Composite
Composite
Composite
Composite
Composite
Grab
*Sample
Location
E
E
E
E
E
E
E
E
E
U,D

A. (). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS WINTER (November 1 - March 31) Permit No. NC0028916
During the period beginning on June 1, 1995 and lasting until expiration, the Permittee is authorized to discharge from outfall(s) serial number
001. Such discharges shall be limited and monitored by the perrriittee as specified,below:
Effluent Characteristics Discharge Limitations — Monitoring Requirements
Measurement Sample *Sample
Monthly Avg, Weekly Avg, Daily Max Frequency - Type Lo'catIon
Flow 0.840. WO ' Continuous Recording I or E
BOD, 5 day, 20°C" 26.0 mg/I 39.0 mg/I 3/Week Composite E,
Total Suspended Residue* 30.0 mg/I 45.0 mg/I 3/Week Composite . E,
NH3 as N 4.0 mg/I 3/Week Composite E
Dissolved Oxygen*** 3/Week Grab E, U, D
Fecal Coliform (geometric mean) 200.0 /100 ml 400.0 /100 ml 3/Week Grab E,U,D
Total Residual Chlorine 3/Week Grab E —
Temperature Daily 'Grab E
Total Nitrogen (NO2 + NO3 + TKN) Quarterly - " Composite E
Total Phosphorus - Quarterly Composite E
Conductivity 3/Week Grab U, D
* Sample locations: E - Effluent, I - Influent; U - Upstream, D - Downstream 0.4 mi. before confluence with Spencer Branch
Stream samples shall be collected three times per week during June, July, August, and September and once per week during the remaining
months of the year.
*,* The monthly average effluent BOD5 and Total Suspended Residue concentrations shall not exceed 15 % of the respective influent value' (85
% removal). .
*** The daily average dissolved oxygen effluent concentration shall not be less than 5.0 mg/I.
**** Chronic Toxicity (Ceriodaphnia) P/F at 90%, January, April, July, and October, See Part III, Condition G.
The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall -be monitored 3/week at the effluent by grab
sample.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

A. ( ). EI+LUENT LIMITATIONS AND MONITORING REQUIREMENTS WINTER (November 1 - March 31) Permit No. NC0028916
During the period beginning on June 1, 1995 and lasting until expiration, the Permittee is authorized to discharge from outfall(s) serial number
001. (Continued)
Effluent Characteristics
Cadmium
Chromium
Lead
Cyanide
Copper
Nickel _.._._....__.
Zinc
Chronic Toxicity'!'
...Silver__....
Temperature
Saf-
Discharge Limitations
Units [specify)
Monthly Avg, Weekly Avg,
µg%I._
Monitoring
Measurement
Daily Max Frequency
5.4 ug/I Weekly
..._.Weekly
27:0—µg71 37.0 ug/1 Weekly
Weekly
(0. Lz 2/Month
2/Month
2/Month
Quarterly
2/Month
3/Week
Requirements
Sample
Type
Composite
Composite
Composite
Grab
Composite
Composite
Composite
Composite
Composite
Grab
*Sample
Location
E
E
-E
E
E
E
E
E
E
U,D

Part III
Permit No. NC0028916
G. Chronic Toxicity Testing Condition - Densons Creek
The effluent discharge shall at no time exhibit chronic toxicity 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 90% (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 first test will be performed after thirty days from issuance of this
permit during the months of January, April; July, and October. Effluent sampling for this testing
shall be performed at the NPDES permitted final effluent discharge below all treatment processes.
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
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 reopened 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 initialmonitoring event). Failure to submit
suitable test results will constitute noncompliance with monitoring requirements.
H. Nutrient Condition for Permits Without Phosphorus Limits .
Thispermit may be modified, or revoked and reissued to include an effluent limitation on nutrients
for this discharge depending upon the following:
1. The findings of a study by the Division of Environmental Management determine nutrient
control is necessary. .
2. Local actions do not successfully reduce the nutrient loading on the receiving waters.
3. The onset of problem conditions in the receiving waters.